JPH0415376A - Gas cock - Google Patents

Abstract

PURPOSE:To maintain the superior lubricity and airtightness for a long period by forming the first film which is formed by dispersion-mixing the fine particles of fluorinated resin in one of the sliding surfaces of a cock body and a plug body and forming the second film on the outside of the first film. CONSTITUTION:The first and second films 6 and 7 are formed on the outer peripheral surface 22 of a cock body 2. The first film 6 is made of polyamide imide resin or polyimide resin, and operates as binder for firmly fixing the second film 7 on the cock body 2, and protects the second film 7 by the toughness of itself. In the first film 6, fine particles 8 made of fluorinated resin are mixed nearly uniformly, and a portion of the fine particles 8 is embedded inside the first film 6, and other portions of the fine particles 8 are projected from the first film 6. The second film 7 is made of epoxy phenol resin, and the frictional resistance between a cock body and the plug body 2 is reduced by the lubricity, porosity and the proper softness of itself, and airtightness is secured.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention aims to maintain good lubricity and airtightness between the sliding surfaces of the cock body and the stopper over a long period of time. Regarding the gas cock that can be used.

[Prior Art] Generally, in a gas cock, silicone oil or grease is interposed between the sliding surfaces of the hook body and the stopper in order to ensure lubricity and airtightness between the sliding surfaces.

However, simply interposing silicone oil or grease between sliding surfaces makes it difficult to maintain lubricity and airtightness over a long period of time, and the performance of both or either of them may deteriorate over a short period of time. It ends up.

Recently, various types of gas hooks have been developed in which a coating is formed on at least one of the sliding surfaces (usually the outer circumferential surface of the stopper), and the effect of this coating is to maintain lubricity and airtightness over a long period of time. It has been proposed (Japanese Unexamined Patent Publication No. 57-401
Publication No. 70, Special Publication No. 59-752, Publication No. 61-
(See Japanese Utility Model Publication No. 44036, Japanese Utility Model Publication No. 63-7739, and Japanese Utility Model Application Publication No. 63-74569).

[Problems to be Solved by the Invention] However, although gas cocks treated with a film can maintain good lubricity and airtightness over a long period of time compared to gas hooks that do not form a film, However, it was still difficult to say that the results were fully satisfactory. Considering the original purpose of the gas cock, this is a quality characteristic that naturally requires improvement.

This invention was made in consideration of the above-mentioned circumstances, and aims to provide a gas cock that can maintain good lubricity and airtightness over a long period of time.

[Means for Solving the Problems] In order to achieve the above object, the present invention uses a polyamide-imide resin in which fine particles of fluorocarbon resin are almost uniformly dispersed and mixed in at least one of the sliding surfaces of the cock body and the stopper body. Alternatively, a first film made of polyimide resin is formed, and this first film is made of polyimide resin.
It is characterized in that a second coating made of epoxy phenol is formed on the outside of the coating.

[Function] The second coating made of Evokinyuphenol is highly flexible, slightly porous, and can contain oil and grease, so it maintains airtightness between the sliding surfaces of the cock body and the stopper body. In addition, its lubricity reduces the frictional resistance between the cock body and the stopper, thereby reducing the turning torque of the stopper. On the other hand, the first coating made of polyamide-imide resin or polyimide resin firmly bonds the sliding surface and the second coating to prevent the second coating from peeling off from the sliding surface, and also uses its toughness to prevent the second coating from peeling off from the sliding surface. The stress concentrated at the boundary between the coating and the second coating is alleviated to protect the second coating. Therefore, the lubricity and airtightness provided by the second coating are maintained in good condition for a long period of time.

Furthermore, even if the second coating were to peel off or otherwise be removed due to multiple rotations of the stopper, even if part of the second coating was removed, the part that was exposed from the first coating from the beginning would be removed. Fine particles of fluorine resin or fine particles of fluorine resin exposed from the first coating due to abrasion of the surface of the first coating are crushed as the plug rotates, thereby forming fluorine resin on the surface of the first coating. Forms a thin film. This thin film
This prevents deterioration in lubricity and airtightness due to removal of the second coating. Therefore, the lubricity and airtightness between the sliding surfaces are maintained well for a longer period of time.

[Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

First, the overall structure of the gas hook in this embodiment will be explained based on FIG. 3.

This is the main body 1. The cock body 1 is made of cast iron or the like, and has an inlet 11 and an outlet 12 formed therein to which gas pipes are connected. A stopper storage hole 13 in the form of a thank-you note is formed between them. Plug storage hole 13
A plug body 2 having a through hole 21 is rotatably housed in the housing.

The plug body 2 is made of metal such as iron or brass,
Due to the biasing force of the spring 3, its outer circumferential surface (sliding surface) 22 is pressed into contact with the inner circumferential surface (sliding surface) 13a of the stopper storage hole 13. Further, the plug body 22 is connected to the handle 5 via the joint 4. Then, when the stopper 2 is rotated approximately 900 times from the closed state shown in the figure using the handle 5, each end of the through hole 21 faces the inlet 11 and the outlet 12, respectively, so that the open state is established. It is configured.

As shown in FIG. 1 and FIG. Second coatings 6 and 7 are formed.

The first coating 6 is made of polyamide-imide resin or polyimide resin, and functions as a binder to firmly adhere the second coating 7 to the stopper 2, and also protects the second coating 7 by its own toughness. It is for the purpose of Therefore, the thickness T1 of the first coating 6 is usually
The thickness is 3 μm to 20 μm, preferably 6 μm to 12 μm.
It is done to m.

Fine particles 8 made of fluorocarbon resin are almost uniformly mixed in the first coating 6, and some of the particles 8 are buried inside the first coating 6, while other particles 8 are part of the particles. is made to protrude from the first coating 6. This fine particle 8 is
The average particle size is 1 μm to 5 μm. Further, the volume of the total fine particles 8 is 0.5% with respect to the total volume of the first coating 6.
It is set to ~10%.

The second coating 7 is made of epoxy diphenol resin, and due to its own lubricity, porosity, and appropriate flexibility, it reduces the frictional resistance between the cock body 1 and the plug body 2, and Airtightness is ensured. For that purpose, the second
The thickness T of the coating 7 is set to 1 μm to 15 μm, more preferably 3 μm to 8 μm.

When forming the first film 6, fine particles 8 of fluorocarbon resin are uniformly mixed and dispersed in polyamide-imide resin or polyimide resin dissolved in a solvent, and the mixture is sprayed or applied onto the outer circumferential surface 22 to obtain a desired thickness. A first coating 6 is formed. After the polyamide-imide resin or polyimide resin has solidified, by spraying or applying molten epoxy phenol resin to the first coating 6,
A second coating 7 having a desired thickness is formed.

In the gas cock configured as described above, the second coating 7 maintains the lubricity and airtightness between the inner peripheral surface 13a of the plug storage hole 13 of the cock body 1 and the outer peripheral surface 22 of the plug body 2 in a good state. to be maintained. In this case, the first coating 6 prevents the second coating 7 from peeling off, and due to its toughness, the second coating 7
protect Therefore, good lubricity and airtightness can be maintained for a long period of time. Moreover,
Even if part of the second coating 7 is removed due to wear or other causes, the fine particles 8 made of fluorocarbon resin are crushed into a thin film that covers the first coating 6. This allows good lubricity and airtightness to be maintained for a longer period of time.

Note that lubricity and airtightness can be maintained by increasing the volume ratio of the fine particles 8 to the first coating 6;
If the amount is excessively large, the function of the first coating 6 as a binder for the second coating 7 will deteriorate. Therefore, the above ratio was adopted.

Next, a comparative example conducted to confirm such an effect will be described.

Comparative tests were conducted with a 3/4 inch diameter gas hook.

The gas cock body was made of cast iron, and the stopper was made of iron. Further, in the plug body according to the present invention, a first film having a thickness of 10 μm and a second VL film having a thickness of 3 μm were formed on the outer peripheral surface. A phosphoric acid coating having a thickness of 13 μm was formed on the plug body of the comparative example. Of course, other configurations are the same for both.

FIG. 4 shows the change in torque with respect to the number of rotations of the stopper. As is clear from this figure, in the case hook according to the present invention, the torque becomes almost constant when the rotation 1 exceeds 1000 times, whereas in the conventional product, the torque gradually increases.

Moreover, FIG. 5 is a diagram showing the relationship between the number of rotations and the amount of leakage. Invention ■ has no leakage at all. Invented product (■) had a slight leak, but no longer leaked again. This is the second
It is presumed that this is because a thin film was formed by fine particles of funoso resin after a part of the coating was removed. In contrast to these invented products ■ and ■, conventional products
If the number of rotations exceeds 1000 times, a large amount of leakage will occur.
Moreover, even if the number of rotations increases, the leakage does not disappear.

However, changes may be made as appropriate without departing from the gist thereof.

For example, in the above embodiment, the first and second coatings 6 and 7 are formed on the plug body 2, but they are not attached to the plug housing hole.
It may be formed on the inner circumferential surface 13a of No. 3. Moreover, it goes without saying that the present invention can be applied to gas cocks other than those described above.

[Effects of the Invention] As explained above, according to the gas cock of the present invention,
A first coating made of polyamideimide resin or polyimide resin in which fine particles of fluorocarbon resin are evenly mixed, and a second coating made of epoxy phenol resin are formed on the sliding surface between the main body and the plug body. Therefore, it is possible to maintain good lubricity and airtightness between sliding surfaces over a long period of time.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention, in which Figure 1 is a cross-sectional view of the plug body, Figure 2 is a cross-sectional view of the body, and Figure 4 is the number of rotations of the plug body. FIG. 5 is a diagram showing the test results of rotation frequency and torque, and FIG. 5 is a diagram showing the test results of rotation frequency and leakage position. 1... Cock body, 13... Storage hole, 13a...
Inner circumferential surface (sliding surface), 2... Plug body, 22... Outer circumferential surface (
sliding surface), 6... first coating, 7... second coating, 8.
...Fine particles.

Claims (1)

[Claims] A first coating made of polyamide-imide resin or polyimide resin in which fine particles of fluorocarbon resin are almost uniformly dispersed is formed on at least one of the sliding surfaces of the cock body and the stopper, and epoxy phenol is coated on the outside of this first coating. A gas cock characterized by forming a second coating consisting of: