JPH08243459A - Packing device for needle valve of spray gun - Google Patents

Abstract

PURPOSE: To easily adjust degree of tightening of a packing set and to completely seal each part by separately providing a fixed seal, at the time of mounting of the body of a cartridge, and a packing pusher, and to reduce a pushing force imparted to the packing set by loosening a packing push screw. CONSTITUTION: In a packing set 7 accommodated in a packing chamber 10a, if a packing pusher 11 is screwed in, a lip portion of a lip packing 1 pushes a sliding surface of a needle valve 3, by means of an elasticity imparting ring 2 made of an independent foam material, to seal the sliding surface. The outer periphery of the packing 1 is sealed by a pressing force against the bottom surface and side surface of the chamber 10a which are finely finished. The pressing force against the packing set 7 is determined by the degree of tightening of screw of the packing pusher 11. In this case, while the needle valve 3 is caused to slide, control is performed so that the valve acts smoothly and a coating material, etc., is sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cartridge type needle valve packing device for a spray gun for spray painting a liquid such as paint.

[0002]

2. Description of the Related Art In a spray gun, a needle seal for preventing liquid such as paint from leaking from a sliding portion of a needle valve is roughly classified into a lip seal type and a flat packing type. ing. The flat packing type is sprayed with a ring-like punched leather that has been impregnated with a solvent-resistant resin, or a stack of several annular plates formed with a tetrafluorinated resin or the like in a ring shape. It is inserted into the packing hole formed in the gun body, the needle is inserted into the center hole, the packing pressure is narrowed down, and the sliding surface is sealed using the side pressure of the packing. This flat packing method has been used for many years in spray guns, but it is difficult to insert flat packings of annular plates one by one and when adapting to diversified coating materials, especially water-based paints. In addition, there is a problem of durability due to wear of the sliding surface, and a problem that a small amount of paint that has entered between the packings of one piece solidifies to hinder the sliding of the needle valve.

The lip seal type has been developed in order to improve the problems of the flat packing, and the basic structure thereof has been filed by the applicant of the present application, such as Japanese Patent Laid-Open No. 22661/1990
68 is known.

FIG. 1 shows a conventional needle packing device adapted to a spray gun by making the lip type packing set into a cartridge. In FIG. 1, reference numeral 1 designates a synthetic resin lip packing having high solvent resistance and abrasion resistance. Reference numeral 2 denotes an elastic material having closed cells, which is an elasticity imparting ring made of solvent-resistant polyethylene foam or the like.
The elasticity imparting ring 2 is the lip portion 1a of the lip packing 1.
Is elastically pressed against the sliding surface of the needle valve 3 to provide contact force and followability, and is fitted to the lip portion 1a. Then, the packing set 7 of the elasticity imparting ring 2 fitted to the lip packing 1 is inserted into the packing chamber 5 a formed in the needle valve packing pusher 5. The needle valve packing receiver 4 for pressing the packing set 7 inserted in the packing chamber 5a is pressed against the bottom surface of the hole into which the needle valve packing push 5 formed in the spray gun body 6 is screwed. There is. The needle valve packing receiver 4 is a packing chamber 5a for the needle valve packing pusher 5.
Further, the packing set 7 is pressed in such a manner that it is press-fitted.
And needle valve packing push 5 and packing set 7
The needle valve packing receiver 4 is shipped as an integrated cartridge packing.

In the above conventional structure, the needle valve 3 is inserted into the needle valve packing pushing hole of the cartridge and the needle valve packing pushing 5 is screwed in, so that the needle valve packing receiver 4 is pressed against the bottom surface of the hole of the main body 6. Sealing is performed to prevent leakage from the side surface of the cartridge, that is, leakage from the thread portion of the needle valve packing pusher 5. Then, the needle valve packing receiver 4 presses the elasticity imparting ring 2 in the packing chamber 5a of the needle valve packing pusher 5 and presses the lip portion of the lip packing 1 while elastically imparting the sliding surface of the needle valve 3. Tighten to seal liquid material such as paint. In this cartridge, the tighter the tightening of the needle valve packing pusher 5, the stronger the tightening strength of the lip packing pressed against the sliding surface of the needle valve. Therefore, the screwing position of the needle valve packing push 5 is adjusted to a screwing position of an appropriate strength at which the needle valve 3 slides smoothly and liquid such as paint can be sealed. However, in this adjustment, if the needle valve packing push 5 is too tight and the sliding becomes hard, or if the packing becomes thermally expanded and hard due to temperature change, etc., loosen the needle valve packing push 5 to make an adjustment. However, since the needle valve packing receiver 4 is pressed into the packing chamber 5a in a press-fitting manner, when the needle valve packing pusher 5 is loosened, the spray gun body 6 and the needle valve packing receiver 4 are released.
Adjusting the strength of tightening the lip packing 1 due to the problem that the sealing surface between and becomes incomplete and leakage occurs, and the needle valve packing receiver 4 is press-fitted to fit. I have a problem that I can not do.

[0006]

As described above,
The elastic packing ring (2) made of an independent foaming material is fitted to the lip packing having the seal lip, and the lip packing is fitted to the packing chamber (5a) inside the needle valve packing pusher.
In a cartridge type needle packing device that is inserted into the needle and pressed by the needle valve packing receiver (4), when tightening the needle valve packing push to adjust the sliding condition of the needle valve, tighten the needle valve packing push too tightly. However, if the sliding becomes stiff due to a change in heat, it is difficult to adjust the needle valve packing by loosening it. The present invention aims to obtain a new mechanism for solving this problem, and uses a lip packing (1) and an elasticized ring (2) made of an independent foam material to tighten the packing set. It is an object of the present invention to provide a needle valve packing device for a spray gun which is easy to adjust and has a perfect seal for each part.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a lip packing having a seal lip that abuts on a sliding surface of a needle valve, and a side of the lip packing that receives a liquid pressure of paint or the like are made of an independent foam material. A needle packing set having an elasticity imparting ring fitted to a seal lip, which has a packing guide into which the packing set is fitted and which is mounted on a spray gun body, and which presses the packing set to the packing guide in an adjustable manner. With a needle valve packing device that is a one-piece cartridge by screwing the packing pusher, a resin-made fixed sealing material for sealing the spray gun body and the cartridge on the side where the cartridge is mounted on the spray gun body. The packing guide of the cartridge fits the packing set when it fits in the cartridge. In Kkingaido holes, the elasticity imparting ring made independent foam material, a needle valve packing device of the spray gun with a packing guides with holes bottom to the hole wall surface sealing lip packing elastically presses.

[0008]

According to the present invention, when the cartridge type packing device is set in the spray gun body, the needle valve packing receiver conventionally presses the packing set of the lip packing and the elasticity imparting ring, and the cartridge is spray gun. Although it also served as a seal when it was attached to the main body, this was provided separately from the fixed seal when the main body of the cartridge was attached and the packing push for pressing the packing set to adjust the sliding condition. By loosening the push screw, the pressing force applied to the packing set can be weakened by using the elastic force of the elastic foaming ring made of an independent foam material so that the pressing force on the sliding surface can be weakened. Is. This allows the packing to be adjusted carefully so as not to overtighten the packing set, but even if the packing is tightened a little, you can easily adjust the sliding condition by loosening the packing push screw. Even when the sliding becomes stiff due to thermal expansion or the like, the sliding condition can be adjusted by loosening the packing push. In addition, since the needle packing receiver of the conventional cartridge was set by being pressed in, it was difficult for the user to take out the packing set.However, by removing the packing pusher separately, the packing set can be taken out. This has the effect of making it relatively easy.

[0009]

EXAMPLE An example of the present invention will be specifically described with reference to FIG. The same components as those described in the conventional example of FIG. 1 are designated by the same reference numerals and will be described, and redundant description will be omitted in principle.

In FIG. 2, 10 is a packing guide,
The packing guide 10 has a packing chamber 10a for accommodating the packing set 7. The packing chamber 10
“A” is a hole-shaped chamber having a bottom surface and a side surface whose surface is finished smoothly. A screw for screwing a packing pusher 11 for pressing and adjusting the packing set 7 is cut at the opening of the hole-shaped chamber. Also, packing guide 1
1 is formed with a screw 13 screwed to the spray gun body. A groove 14 into which the packing receiver 12 is fitted is bored at the tip of the packing guide 10, and the packing receiver 12 is arranged. The packing receiver 12 has a function of preventing the paint from leaking from the main body side and leaking to the outside, and preventing the paint from entering the screw portion and fixing the paint so that it cannot be removed. The above packing guide 10,
Packing push 11, packing set 7, packing receiver 1
A cartridge 15 is formed by integrating two parts.

In the packing set 7 housed in the packing chamber 10a having the above structure, the packing pusher 11 is screwed into the packing set 7 so that the lip portion of the lip packing 1 is slid on the needle valve 3 by the elasticity imparting ring made of an independent foam material. The sliding surface is sealed by pressing the moving surface. The seal around the packing is a smooth finished packing chamber 1.
The bottom surface and the side surface of 0a are sealed by a pressing force. The pressing force applied to the packing set 7 is determined by the screwing of the packing pusher 11. At that time, the needle valve 3 operates smoothly while sliding the needle valve 3, and
It is adjusted within the range where the liquid such as paint is sealed. If this tightening strength is too strong, the sliding of the needle valve 3 will become worse, or the sliding surface will wear faster. Therefore, it is desirable that the tightening strength be weak within the range where the liquid is sealed. If the packing set 7 is over-tightened, the packing pusher 11 is loosened to weaken the pressing force to the lip portion of the lip packing 1 due to the action of the elasticity imparting ring made of the independent foam material, and the lip packing 1 is packed. By pushing back to the push 11 side, the pushing force of the packing set 7 is weakened, and one of the conventional problems is solved. Further, since the packing receiver 12 is a fixed packing, it is completely squeezed and fixed when set in the spray gun body 6, so that the packing is sealed regardless of the operation of the packing pusher 11. One is resolved.

3A and 3B show the packing guide 1
FIG. 3 (a) shows another embodiment of the fixed packing attached to the tip of No. 1 and FIG. It is an example of sealing the joint portion when performing. FIG.
(B) shows an example in which a resin ring packing 17 having solvent resistance and flexibility is fitted. In both cases, when screwed onto the spray gun body, it is completely squeezed and fixed. Further, in FIG. 3C, the packing set 7 and the packing receiver 12 are integrated and are all made of metal. It is possible to seal by strongly tightening only with the metal.

FIG. 4 is an example showing the overall structure of the spray gun embodying the present invention. Only the relevant parts of the needle valve packing device will be described in the drawings. The cartridge 15 of the needle valve packing device mounted on the spray gun body 6 is an important element that influences the performance of the spray gun.
If the seal in this part is incomplete, paint nozzle 1
Liquid such as paint on side 8 leaks from the cartridge part. Further, in the case of the suction type spray gun, air is mixed into the paint nozzle 18 from the cartridge 15 to cause a shortness of breath. If the needle valve 3 is excessively tightened, sliding of the needle valve 3 deteriorates, and when the trigger 20 is released to seal the paint at the tip of the paint nozzle, the force pressed by the needle valve spring 21 is weakened by the sliding resistance. Therefore, the pressing force at the tip of the needle decreases, the seal becomes incomplete, and leakage of the tip or paint accumulation at the tip causes a coarse coating particle called a "spit" at the beginning of blowing from the air cap 19 to cause a coating defect. The phenomenon occurs. Therefore, the needle valve packing should be adjusted to a proper tightening force after setting the cartridge 15 and operating the trigger 20 while watching the sliding condition of the needle valve 3, that is, the operating speed of the needle valve 3. I have to. The present invention solves the above problem by loosening the packing pusher 11 when the needle valve packing set 7 is overtightened or when sliding becomes stiff.

[0014]

According to the present invention, a lip packing having a seal lip and a packing set in which an elastic imparting ring made of an independent foaming material is fitted in a seal lip portion are fitted into a packing guide, and the packing set is pressed so as to be adjustable. By screwing the packing pusher to make it into an integral cartridge, the sliding adjustment of the needle valve is facilitated, obstacles due to over-tightening of the packing set are eliminated, and an appropriate tightening force is obtained. There is an effect that wear of the packing and the sliding surface of the needle valve is reduced, and the durability of the needle valve and the needle valve packing device is further improved.

Further, since the packing is separately pushed, the replacement of the packing set of the cartridge is facilitated, and the cost burden on the user is reduced.

Further, by disposing a seal separately from the spray gun main body by a fixed packing such as an O-ring in the cartridge, the paint leakage which has occurred at the time of adjustment is eliminated, and the seal is perfect, and the handling is easy. A cartridge type needle valve packing device that is easy to obtain is obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a needle valve packing device as a conventional example.

FIG. 2 is a sectional view of the needle valve packing device of the present invention.

3 (a), (b), (c) are sectional views of a needle valve packing device showing another embodiment of the present invention.

FIG. 4 is an example of a cross-sectional view showing the overall configuration of a spray gun embodying the present invention.

[Explanation of symbols]

 1 Lip packing 2 Elasticity imparting ring 3 Needle valve 7 Packing set 10 Packing guide 11 Packing push 12 Packing receiver 15 Cartridge 18 Paint nozzle 20 Trigger 21 Needle valve spring

Claims (3)

[Claims] 1. A lip packing having a seal lip that abuts a sliding surface of a needle valve, and the lip packing,
In a needle packing set that is equipped with an elasticity imparting ring made of an independent foam material by fitting it to a seal lip on the side that receives liquid pressure such as paint, a packing guide that fits the packing set and mounts it on the spray gun body is provided. A needle valve packing device for a spray gun, which is formed as an integrated cartridge by screwing a packing pusher that adjustably presses the packing set to the packing guide. 2. A resin-made fixed sealing material for sealing the spray gun body and the cartridge on the side where the cartridge having a packing set, a packing guide, and a packing pusher is mounted on the spray gun body. The needle valve packing device for a spray gun according to claim 1, which is fitted. 3. A packing set, a packing guide, and a packing guide of a cartridge integrally formed with a packing pusher are packing guide holes into which the packing set is fitted, and a hole wall surface seal and a lip packing of an elastic imparting ring made of an independent foam material. The needle valve packing device for a spray gun according to claim 1, which has a hole bottom surface for elastically pressing.