JP2000225369A - Methods and apparatus for coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform coating work efficiently in a short time by sealing a surface to be coated with a space part left, enclosing coating into the sealed space part, and making the coating adhere to the surface at a time. SOLUTION: The inside surface 1a of a through hole 1x in a gear 1 and the peripheries 1b, 1c of both opening parts are made surfaces to be coated, the surfaces are heated, and the gear 1 is moved to a position where a coating apparatus main body part is installed and installed between a coating housing container 2 and a lid member 3 in this part with the through hole 1x of the gear 1 coincided. They are held/fixed integrally by a fixing means 4, the opening part 2a of the container 2 is made to communicate with the recessed part 3a of the lid member 3 through the through hole 1x. The surfaces to be coated are sealed with a space left. Coating from the container 2 is enclosed in the sealed space part, and the coating is made to adhere to the surfaces at a time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method and apparatus, and more particularly, to a coating part having a through hole such as a shaft hole of a gear, the inner peripheral surface of the through hole or the inner peripheral surface and the peripheral edge of the opening. The present invention relates to a coating method and an apparatus which are easily used, for example, when a carburizing / nitriding paint or the like is applied as a painted surface and the painted surface is to be left as a non-carburized / nitrided tough portion.

[0002]

2. Description of the Related Art In mechanical parts made of metal having through holes such as shaft holes for various gears and cutting tools used in automobiles and ships, etc., high toughness is required for the shaft hole portion and its periphery, while frictional force is high. A high level of abrasion resistance is required for the tooth tip and the like to be subjected to this. As a method of obtaining such a mechanical part having both toughness and wear resistance, there is a method of using a tough steel material and carburizing / nitriding only the part requiring the wear resistance to harden. In this case, a method is employed in which portions other than the portion to be hardened are masked to prevent carburization and nitriding and maintain toughness.

That is, for example, in a gear member, carburizing and nitriding treatment is performed in a state in which only the shaft hole portion to which toughness is required and its peripheral portion are masked, and the remaining entire surface including the cutting edge portion is hardened. Thus, a gear having both excellent toughness and wear resistance can be obtained.

As a masking material of this kind, copper plating, tin plating, etc. have been conventionally used. However, since plating for masking is complicated and time-consuming,
Recently, a paint-type masking material that forms a gas barrier film has been developed and rapidly spread. That is, a paint-type masking material is a mixture of a small amount of a resin and a solvent having a carburizing / nitriding-preventive chemical powder, such as borax, borosilicate or tin powder, prior to the heat treatment for carburizing / nitriding. For example, this paint is applied to the shaft hole of the gear and its periphery. When this is heated in a furnace in which a carburizing / nitriding agent is charged or kept in a carburizing / nitriding gas atmosphere at 300 to 1000 ° C., the resin in the paint is thermally decomposed and disappears, and at the same time, the carburizing is performed. The anti-nitriding component is baked on the shaft hole and its surroundings to form a carburizing / nitriding preventive film, thereby preventing contact with the carburizing / nitriding component, thereby preventing the carburizing / nitriding of the painted portion.

In this case, if the carburizing / nitriding prevention coating has uneven coating or a pinhole defect, the purpose of carburizing / nitriding prevention cannot be fulfilled, and therefore, it is necessary to form a defect-free uniform carburizing / nitriding prevention coating. The biggest point,
This paint has a low compounding amount of the resin component acting as a vehicle component (a large amount will cause the release of decomposed gas when thermally decomposed and inhibits the seizure of the carburizing / nitriding prevention film). In order to form a poor and uniform film, it is necessary to dilute with a solvent and apply repeatedly, which requires careful work using a brush or a brush, and requires a lot of time and labor.

Further, for example, when it is intended to automatically apply the above-described carburizing / nitriding paint to the shaft hole of the gear and the periphery of the opening thereof, the coating operation is restricted to the inner periphery of the shaft hole due to the structural limitation of the coating device. The surface, one side edge, and the other side edge must be applied in order, and it takes several hours for each part to be coated and dried, so the total required for coating all the surfaces to be coated is required. It may take 15 to 18 hours, which is not suitable for actual operation.

As a relatively new method of forming a carburizing / nitriding prevention coating, a heat-fusible powder coating containing a carburizing / nitriding component is used, and this is heated and fused to a non-carburizing / nitriding portion to mask. A method for forming a film has also been proposed. However, in the case of a powder coating, up to the technology of selectively and reliably forming a masking film only in a simple manner only in the shaft hole portion of a mechanical structural material having a shaft hole penetrated as intended in the present invention and its peripheral portion. Not established.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide an inner surface of a through-hole of a structural component having a through-hole such as a shaft hole of a gear, and the like. A method and an apparatus capable of forming a coating on these surfaces with a simple method reliably using the inner peripheral surface of the through hole or its peripheral surface as the surface to be coated, as in the case of masking the periphery of the opening as the surface to be coated. Is to provide.

[0009]

The coating method according to the present invention, which can solve the above-mentioned problems, relates to a part to be coated having a through hole such as a shaft hole, or an inner peripheral surface of the through hole, and A method of applying powdery, liquid or suspension-like paint to the peripheral edges of both openings of the through-holes as surfaces to be coated, wherein the surface to be coated is sealed while leaving a space, and sealed. The gist is that the paint is sealed in the stopped space, thereby simultaneously depositing the paint on the surface to be coated.

In carrying out this method, if a method in which a heat-fusible powder coating is used as the coating and the coating is applied while the surface to be coated is heated is adopted, the coating operation can be further shortened. It is preferable that the coating be performed efficiently in a short time and that the coating be sealed in the space and that sufficient vibration be applied to further improve the uniformity of the coating.

[0011] The coating apparatus according to the present invention may be configured such that the inner peripheral surface of the through-hole, or the inner peripheral surface of the through-hole and the peripheral edge of the opening in the component to be coated having a through-hole such as a shaft hole, are the surfaces to be coated. An apparatus for applying a powdery, liquid or suspension-like paint to these, and a paint storage container having an opening of a size and shape corresponding to one opening of the through hole or the periphery thereof, A cover member having a recess having a size and a shape corresponding to the opening on the other side of the through hole or the periphery thereof, and fixing means for holding and fixing these with the parts to be coated sandwiched therebetween, also in this device, It is extremely effective to add, as a component, a vibration mechanism for integrally vibrating the part to be coated and the coating apparatus in the above-mentioned clamped and fixed state, thereby enabling a further uniform coating.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Under the above-mentioned problems, the present inventors have developed an inner peripheral surface or an inner peripheral surface of a through hole in a machine structural part having a through hole such as a shaft hole of a gear. The present invention has been conceived as a result of conducting various studies with the aim of establishing a technique capable of easily forming a film for masking or the like only in the peripheral portion thereof in a short time.

Hereinafter, a coating method and a coating apparatus according to the present invention will be described in detail with reference to the drawings showing one embodiment, with reference to the drawings. Instead, the present invention can be appropriately modified and implemented within a range that can be adapted to the gist of the preceding and following descriptions, and these are naturally included in the technical scope of the present invention.

In the following embodiment, a gear and the like are mainly used as a typical mechanical structural component having a through hole, and a method and an apparatus for forming a film on the inner peripheral surface and the peripheral portion of the penetrated shaft hole will be described as an example. However, the application of the present invention is not limited to gears of the illustrated shape, gears of any other shapes and structures, or various mechanical structural parts having shaft holes other than gears, such as cutting tools, The present invention can be similarly applied to a ratchet wheel, a flywheel, a Geneva wheel, a chain wheel, and the like.

FIG. 1 is a schematic process explanatory view showing an embodiment of the present invention, in which an inner peripheral surface 1a of a shaft hole (through hole) 1x of a gear 1 and peripheral edges 1b and 1c of openings on both sides thereof are thermally fused. Carburizing / nitriding through the following steps: (A) heating, (B) transfer, (C) encapsulation, (D) inversion / vibration, (E) release, and (F) removal using powder coating powder 1 shows a method and apparatus for forming a protective coating.

In practicing the present invention, FIG.
As shown in (A), the inner peripheral surface 1a of the through hole and the peripheral edges 1b and 1c of the through hole in the gear (part to be coated) 1 having the through hole (shaft hole) 1x are the surfaces to be coated. The surface to be coated is heated using a heater H or the like in order to enable heat fusion of the heat-fusible powder coating material. The heating temperature may be appropriately adjusted according to the heat fusing temperature of the powder coating to be used, and the arrangement position of the heater H is not limited to the illustrated example. Any heating means may be employed as long as heating can be performed.

The heated gear 1 on the surface to be coated is then moved to the installation position of the coating apparatus main body as shown in FIG. 1 (B), where the size and shape correspond to the opening peripheral edge 1c. The through hole 1x of the gear 1 is arranged between the paint container 2 having the opening 2a and the lid member 3 having the concave portion 3a having a size and shape corresponding to the opening peripheral edge 1b. At any time before and after this step, the paint T is loaded in the container 2.

Then, as shown in FIG. 1C, these are integrally clamped and fixed by a fixing means 4 such as a clamp. As a result, the opening 2a of the container 2 and the recess 3a of the lid member 3 communicate with each other through the through hole 1x of the gear 1, and the surface to be coated (that is, the inner peripheral surface 1a of the shaft hole and the peripheral edges of both openings). 1b, 1
c) will be sealed leaving a space.

The holding and fixing means for the sealing is not limited to the clamp as shown in the drawing, but any means can be used as long as the container 2 and the cover member 3 can be integrally held and fixed with the gear 1 therebetween. Any means may be adopted.

Next, as shown in FIG. 1 (D), the container 2, the gear 1, and the lid member 3 are turned over as a unit, and vibration is preferably applied in this state. Then, the powder coating material T loaded in the container 2 spreads from the opening 2a to the recess 3a of the lid member 3 through the through-hole 1x, and the inner peripheral surface 1a of the shaft hole serving as the surface to be coated and both the openings. The powder coating material T comes into contact with the peripheral edges 1b and 1c, but since the surface to be coated is heated,
The powder coating T in contact with the surface to be coated is immediately fused to form a coating T.
Form S.

Accordingly, if the surface to be coated is heated to an appropriate temperature, a powder coating in an amount corresponding to the balance between the heating temperature and the heat absorption due to melting is fused to form a film TS,
When the coating material reaches a certain thickness, the powder coating no longer fuses due to the temperature drop on the surface to be coated, so that the coating temperature of any thickness can be coated by adjusting the heating temperature according to the required film thickness. It can be formed simultaneously on the surface. After that, as shown in FIG. 1 (E), the holding means is released again and then removed and removed [FIG. 1 (F)].

According to this method, a film can be formed simultaneously on the inner peripheral surface 1a of the through hole and the peripheral surfaces 1b and 1c of the opening portions as shown in the figure, and the film forming operation can be performed simply and quickly. Can be performed. Moreover, according to this coating method, only the powder paint T consumed is used for forming the film, and all the remaining powder paint is returned to the container 2, so that no wasteful consumption occurs.

Further, by automating the individual steps from (A) supply and heating to (F) unloading of the gear, and by setting up a control line that can make each step continuous, a series of operations can be made continuous. It is possible to do.

FIG. 2 shows a specific part to be coated 1 (gear), a paint container 2 and a lid member 3 when the method of the present invention is put to practical use.
FIG. 2 is a cross-sectional view showing the pinching and fixing member 4, showing a state in which they are pinched and fixed.
May be performed in the same manner as described above. Also, the shape and structure of these individual members can be arbitrarily changed according to the shape and structure of the parts to be coated having through holes as described above so that they can be tightly clamped. In addition to the through-holes 1x, other through-holes or recesses may be provided in addition to the through-holes 1x. Further, the shape of the through-holes 1x is not only circular, but also polygonal such as square or hexagon, or elliptical depending on the case. And so on.

In the example of FIG. 1 described above, in the (D) inversion / vibration step, an example is shown in which the members held together are inverted by 180 ° C. and then excited, but the inversion angle is not necessarily 180 ° C. It is not necessary that the recess 3 of the lid member 3
The angle is 9 as long as the powder coating T can be spread in a.
It can be changed to any angle from 0 to 180 degrees. In addition,
It is extremely effective in uniformly and uniformly fusing the powder coating material T to the surface to be coated. As a vibrating means, a vibrating means in any direction such as a horizontal method using a known vibrator, a vertical direction, an oblique direction, etc. Alternatively, it is also possible to employ turning / swinging means or the like instead of the vibration means.

FIG. 3 is a schematic sectional explanatory view showing another embodiment of the present invention, and shows an example in which a film is formed only on the inner peripheral surface 1a of the through hole 1x in the component 1 to be coated.
That is, in this example, a paint container 2 having an opening 2a having a size and a shape corresponding to the lower opening of the through hole 1 is used as the paint container 2, and the lid member 3 is an upper opening of the through hole 1. One provided with a concave portion 3a having a size and shape corresponding to the portion is used.

The powder coating material A is stored in the coating material container 2.
And the lower opening of the through hole 1x of the part 1 to be coated is aligned with the opening 2a of the container 2,
The concave portion 3a of the lid member 3 is aligned with the opening on the upper side of x, and these are fixed by the sandwiching fixing member 4 so as not to be displaced.

Prior to this operation, the through-hole 1x is heated, and then the sandwiched and fixed paint storage container 2, the component to be coated 1, and the lid member 3 are processed in the same manner as described with reference to FIG. The powder paint is spread over the inner peripheral surface of the through-hole 1x in the part to be coated 1 as a whole. Then, the powder coating comes into contact with the inner peripheral surface of the through hole 1x, which has been heated in advance, and melts and adheres, thereby forming a film on the inner peripheral surface. After that, if these are reversed again and returned to the original state, the remaining powder coating material is returned to the storage container 2.

In the example shown in FIG.
a was used, but the lid member 3 in this case was used.
May function as a sealing member for preventing the paint from leaking from the upper opening of the through hole 1x. Therefore, a flat lid member 3 having no concave portion 3a may be used. .

FIGS. 4 and 5 show still another embodiment of the present invention. In the part 1 to be coated having a through hole 1x, the inner peripheral surface of the through hole 1x, the peripheral edges on both ends thereof, and the outer peripheral surface and the outer peripheral surface thereof are shown. An example in which a coating TS is formed on the periphery is shown. That is, in this example, a container having a double structure of the inner container 2x and the outer container 2y is used as the paint container 2 and the lid member 3
Also use a double structure of the inner lid 3x and the outer lid 3y,
The part 1 to be coated is sandwiched from above and below by the inner container 2x and the inner lid 3x, and the opening of the outer container 2y and the outer lid 3y can be closed and fixed by abutting each other. Note that, also in this example, the holding and fixing member is omitted in the drawings.

Also in this example, the procedure of the coating operation is substantially the same as that described with reference to FIG. 1, in which the powder coating material T is charged into the inner container 2x and the outer container 2y, and the surface to be coated is heated. As shown in FIG. 1, after fixing the part to be coated 1 integrally as shown in the drawing, the whole is turned upside down and vibrated to fuse the powder coating on the surface to be coated, and then turn over again to return to the original position. If this is the case, the coating TS can be formed on the surface to be coated as shown in black in each drawing. As is clear from the drawings, FIG. 4 shows an example in which a coating is formed on the inner peripheral surface of the through hole 1x of the part to be coated 1 and its peripheral edge, and the outer peripheral surface and its peripheral edge at once.
FIG. 5 shows an example in which a coating is formed only on the outer peripheral surface of the workpiece 1 and the inner peripheral surface of the through hole 1x.

FIG. 6 shows still another embodiment of the present invention, in which a coating is formed on the inner peripheral surface of each through-hole in a component 1 having a plurality of through-holes 1x, 1y, 1z formed in the same direction. Is performed. That is, in this example, jigs 5 having through holes 5x, 5y, 5z having dimensions and shapes corresponding to the openings of the through holes 1x, 1y, 1z formed in the workpiece 1 are used. The parts are combined and fixed together with the paint container 2 and the plate-shaped lid member 3 (the holding means is omitted in the drawing), and a film is formed on the inner surfaces of the three through holes in the same manner as in FIG. . FIG. 7 is a modification example of FIG. 6, and shows an example in which a coating is formed on the inner peripheral surface of each through hole 1x, 1y, 1z and the opening side peripheral edge of each through hole.

FIG. 8 shows still another embodiment of the present invention, in which a through-hole 1x, 1y is formed on the inner peripheral surface of each of the through-holes 1x, 1y in the workpiece 1 having two through-holes 1x, 1y intersecting in the orthogonal direction. In an example in which a film is formed, an opening 2 corresponding to the opening of the through holes 1x and 1y is provided above the paint container 1.
a, 2b are formed, and the other end opening side of each through hole 1x, 1y is closed by a lid member 3.
In this case as well, if the same operation and procedure as in the example of FIG. 1 are adopted after integrally fixed by a sandwiching fixing member (not shown), the coating can be easily applied to the inner peripheral surfaces of the through holes 1x and 1y. Can be formed.

As described above, according to the present invention, the inner peripheral surface of the through-hole or the inner peripheral surface and the inner peripheral surface of the through-hole can be targeted for various parts to be coated having one or more through holes regardless of the forming direction. The film can be reliably formed on the peripheral edge of the opening by an extremely simple operation and procedure.

This coating method is extremely suitable for forming a film by powder coating utilizing heat fusion as described above.
The present invention is not limited to this, and can be effectively used for forming a film using a liquid or suspension-like paint. In this case, it is desirable to take measures for preventing liquid leakage, such as disposing a sealing material at the interface of the members in close contact and sealing during the clamping and fixing.

The powder coating preferably employed in the present invention contains, for example, borax, boron oxide, borosilicate, phenylboronic acid, etc. as a carburizing / nitriding preventive component, and further contains polyethylene or polypropylene as a heat-fusible resin. Thermoplastic resins such as polyolefin resins, polyester resins, acrylic resins, etc., or thermosetting resins that melt immediately before thermal decomposition and exhibit heat-fusibility, such as thermosetting polyester resins, A powder coating blended with an acrylic resin is exemplified.

Preferred suspension type carburizing / nitriding paints include powders of, for example, borax, boron oxide, borosilicate, phenylboronic acid, titanium oxide, silica, etc. as an anti-carburizing / nitriding component. And a suspension paint which is dispersed in an organic solvent or an aqueous solvent together with a binder component such as water, polyester resin, and water glass.

Further, in the above description, the description has been made mainly on the formation of a masking film for preventing carburization and nitriding. However, the present invention satisfactorily coats the film on the inner peripheral surface of the through hole or on the inner peripheral surface and the peripheral edges of both openings. Since it has a feature in the place where it can be formed, if this coating method and coating equipment are used,
For example, it can be effectively used as a means for forming a lubricating film, a rust-preventive film, an adhesive layer, and the like on the surface to be coated.

[0039]

The present invention is constituted as described above, and is used to coat the shaft holes of a mechanical structural member having a shaft hole, such as a gear, a ratchet wheel flywheel, a Geneva wheel, and a chain wheel, and both peripheral edges thereof. As a surface, a film can be formed quickly and reliably only on the surface to be coated with a very simple method and apparatus, and it can be very effectively utilized particularly for forming a masking film for carburizing / nitriding and a lubricating film.

[Brief description of the drawings]

FIG. 1 is a schematic sectional process explanatory view showing a specific example of a coating method and an apparatus according to the present invention.

FIG. 2 is a sectional view showing a specific example of a coating apparatus used in the present invention.

FIG. 3 is an explanatory sectional view showing another specific example of the present invention.

FIG. 4 is an explanatory sectional view showing still another specific example of the present invention.

FIG. 5 is an explanatory sectional view showing still another specific example of the present invention.

FIG. 6 is an explanatory cross-sectional view when the present invention is applied to a part to be coated having a plurality of through holes formed therein.

FIG. 7 is an explanatory sectional view of a case where the present invention is applied to another component to be coated having a plurality of through holes.

FIG. 8 is a cross-sectional explanatory view in a case where the present invention is applied to still another component to be coated having a plurality of through holes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Component to be coated (gear) 1a Inner peripheral surface of through hole 1b, 1c Opening edge 1x, 1y, 1z Through hole 2 Paint storage container 2a Opening 3 Cover member 3a Depressed portion 4 Nipping and fixing member 5 Jig H Heater T Powder paint TS Film

Claims (7)

[Claims] 1. A method for coating a powdery, liquid or suspension-like paint on a surface to be coated, wherein at least an inner peripheral surface of the through-hole in a part to be coated having the through-hole is a surface to be coated, A coating method, wherein the coating surface is sealed while leaving a space portion, and the coating material is sealed in the sealed space portion to thereby simultaneously apply the coating material to the coating surface. . 2. The coating method according to claim 1, wherein the surface to be coated is an inner peripheral surface of the through hole and a peripheral edge of both openings of the through hole. 3. The coating method according to claim 1, wherein the heat-fusible paint is used, and the paint is applied while the surface to be coated is heated. 4. The coating method according to claim 1, wherein a sufficient vibration is applied after the paint is sealed in the space to improve the uniformity of the coating. 5. An apparatus for coating a powdery, liquid or suspension-like paint on a surface to be coated, wherein at least an inner peripheral surface of the through-hole in the part to be coated having the through-hole is a surface to be coated. A paint container having an opening having a size and shape corresponding to one opening of the through hole, a lid member having a size and shape corresponding to the other opening of the through hole, and a component to be coated. A coating device comprising fixing means for sandwiching and fixing these. 6. A powdery, liquid, or suspension-like paint on the surface to be coated, wherein the inner peripheral surface of the through hole and the peripheral edges of both openings of the through hole in the part to be coated having the through hole are surfaces to be coated. A paint container having an opening having a size and shape corresponding to the periphery of the opening of the through hole, and a recess having a size and shape corresponding to the periphery of the opening of the through hole. A coating apparatus, comprising: a cover member having the cover member; and fixing means for sandwiching and fixing the parts to be coated. 7. The coating apparatus according to claim 5, further comprising a vibration mechanism for integrally vibrating the part to be coated and the coating apparatus in the pinched and fixed state.