US20140186638A1

US20140186638A1 - Coating method and coating layer of brake hose fitting

Info

Publication number: US20140186638A1
Application number: US13/948,498
Authority: US
Inventors: Gyu Man Sim; Min Su Choi
Original assignee: Hyundai Motor Co; Kia Motors Corp
Current assignee: Hyundai Motor Co; Kia Corp
Priority date: 2012-12-27
Filing date: 2013-07-23
Publication date: 2014-07-03
Also published as: KR20140084714A; KR101449203B1

Abstract

Disclosed herein is a method of coating a brake hose fitting. The method includes plating a brake hose fitting with a zinc-nickel (Zn—Ni) alloy including about 6˜12 wt % of nickel (Ni). The method further includes post-treating the plated brake hose fitting with a silicon (Si) solution.

Description

BACKGROUND OF THE INVENTION

1. Technical Field
The present invention relates to a coating method and coating layer of a brake hose fitting, which can increase the durability of a brake hose fitting.
2. Description of the Related Art
As shown in FIG. 1, a brake hose fitting is an intermediate for connecting a caliper with a hose, and is configured to supply high-pressure brake oil to a caliper. Since such a brake hose fitting relates to safety by preventing the leakage of brake oil, it is important that the brake hose fitting exhibits corrosion resistance and durability.
The conventional surface treatment of a brake hose fitting has generally been performed by zinc plating or zinc-nickel alloy (e.g., having substantially high nickel content, Ni: about 12˜18%) plating. Here, zinc plating is advantageous because a zinc plated layer may not be easily damaged when connecting a brake hose to a brake hose fitting, however, the durability of a brake hose fitting is decreased due to the low corrosion resistance of the zinc plated layer.
Further, zinc-nickel alloy (e.g., having a substantially high nickel content) plating is advantageous because a zinc-nickel alloy plated layer exhibits substantially high corrosion resistance, however, the zinc-nickel alloy plated layer may be damaged when connecting a brake hose to a brake hose fitting, thus decreasing the durability of a brake hose fitting, similar to the zinc plating.
A conventional apparatus discloses a vehicle brake fitting structure, in which a sleeve of a brake fitting disposed on the circumference thereof with a plurality of screw threads is connected with a plated metal pipe by screw connection. This configuration improves corrosion of a plated layer and improves the adhesion and sealing properties between the sleeve and the plated metal pipe to prevent external corrosion causing materials from infiltrating therebetween, thereby preventing the brake fitting from corroding. For this purpose, the vehicle brake fitting structure includes: a sleeve manufacturing by swaging; a nipple formed in the sleeve and through which oil flows; and a rubber hose disposed between the sleeve and the nipple, wherein a plated metal pipe is connected with screw threads formed on the circumference of the sleeve. However, the conventional apparatus does not provide both increased corrosion resistance and durability.
It is to be understood that the foregoing description is provided to merely aid the understanding of the present invention, and does not mean that the present invention falls under the purview of the related art which was already known to those skilled in the art.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a coating method and coating layer of a brake hose fitting, which may increase the durability of the brake hose fitting.
An aspect of the present invention provides a method of coating a brake hose fitting, including: plating a brake hose fitting with a zinc-nickel (Zn—Ni) alloy including about 6˜12 wt % of nickel (Ni); and post-treating the plated brake hose fitting with a silicon (Si) solution.
The method may further include chromating the plated brake hose fitting.
Additionally, In the post-treating of the plated brake hose fitting, the plated brake hose fitting may be dipped into the silicon (Si) solution. The silicon (Si) solution may be a solution including about 10˜15 wt % of Si.
Another aspect of the present invention provides a coating layer of a braking hose fitting, including: a plated layer including zinc (Zn), about 6˜12 wt % of nickel (Ni); a corrosion-resistant layer formed on the plated layer by chromating the plated layer; and a finish layer formed on the corrosion-resistant layer by coating the corrosion-resistant layer with silicon (Si).

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exemplary view showing a brake hose fitting, according to a related art;

FIG. 2 is an exemplary flowchart showing a method of coating a brake hose fitting according to an exemplary embodiment of the present invention;

FIG. 3 is an exemplary view showing a coating layer of a brake hose fitting according to an exemplary embodiment of the present invention; and

FIGS. 4 and 5 are exemplary graphs showing the effects of the method of coating a brake hose fitting according to an exemplary embodiment of the present invention.

REFERENCE NUMERALS

S100: plating
S200: corrosion-preventing
S300: post-treating

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is understood that the tem “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, combustion, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum).
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from the context, all numerical values provided herein are modified by the term “about.”
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an exemplary view showing a brake hose fitting. Brake hoses may generally be configured to transfer oil pressure, and a brake hose fitting may generally be configured to connect the brake hoses. For this purpose, the brake hose fitting may be made of a metal material. Therefore, the performance of a brake may be maintained when the brake hose fitting is coated with a material other than metal.
FIG. 2 is an exemplary flowchart showing a method of coating a brake hose fitting according to an exemplary embodiment of the present invention. The method of coating a brake hose fitting may include: plating a brake hose fitting with a zinc-nickel (Zn—Ni) alloy including about 6˜12 wt % of nickel (Ni) (S100); and post-treating the plated brake hose fitting with a silicon (Si) solution (S300).
The conventional surface treatment of a brake hose fitting has been generally performed by zinc plating or zinc-nickel alloy (e.g., high nickel content, Ni: 12˜18%) plating. In the conventional embodiment, zinc plating is advantageous in that a zinc plated layer may not be easily damaged when a brake hose is connected to a brake hose fitting, however, the durability of a brake hose fitting decreases due to the low corrosion resistance of the zinc plated layer.
Further, zinc-nickel alloy (e.g., having a substantially high nickel content) plating is advantageous because a zinc-nickel alloy plated layer exhibits increased corrosion resistance, however, the zinc-nickel alloy plated layer may be damaged when a brake hose is connected to a brake hose fitting, thus decreasing the durability of a brake hose fitting, similar to the zinc plating.
Accordingly, in the present invention, a zinc-nickel alloy having a substantially low nickel content may be used to increase durability and corrosion resistance to a brake hose fitting when a brake hose is connected to a brake hose fitting. Specifically, a plating layer may be formed of a Zn—Ni alloy including zinc (Zn) as a main component, about 6˜12 wt % of nickel (Ni) having potential impurities.
Meanwhile, the step (S300) of post-treating the plated brake hose fitting with a silicon (Si) solution may be performed by dipping the plated brake hose fitting into the silicon (Si) solution, wherein the silicon (Si) solution may be a solution including about 10˜15 wt % of Si. Specifically, the silicon (Si) solution may be prepared by dissolving about 10˜15 wt % of Si in a solvent.
FIG. 4 shows the result of evaluating the aperture clogging and corrosion resistance of a brake hose fitting based on the content of silicon (Si). Generally, a 80 wt % dilute silicon solution may be used in evaluation of small hardware such as bolts, nuts and the like. However, when the 80 wt % dilute silicon solution is used in a brake hose fitting, the dilute silicon solution may collect in the brake hose fitting due to the screw threads and inner holes through which fluid flows disposed within the brake hose fitting. For example, when the 80% dilute silicon solution is applied to the brake hose fitting, a threaded gauge may not be inserted into the brake hose fitting due to the clogged dilute silicon solution. Therefore, the concentration of a post-treating solution may be adjusted to about 30 wt %, about 50 wt % and about 80 wt % to prevent the collection of the dilute silicon solution within the brake hose fitting and to increase the corrosion resistance of the brake hose fitting.
Consequently, when 30 wt % and 50 wt % of dilute silicon solutions were used, the dilute silicon solution did not clog the brake hose fitting, however, when 80 wt % of the dilute silicon solution was used, the clogging increased. Further, when 50 wt % and 80 wt % of dilute silicon solutions were used, the corrosion resistance of the brake hose fitting remained substantially consistent, however, when 30 wt % of the dilute silicon solution was used, the corrosion resistance decreased. Therefore, when the concentration of the diluted silicon solution is about 10˜15 wt %, the clogging of the dilute silicon solution may decrease and the corrosion resistance of the brake hose fitting may remain substantially consistent.
Meanwhile, the method of coating a brake hose fitting may further include chromating the plated brake hose fitting (S200). In this step (S200), a corrosion-resistant layer may be formed between a plated layer and a post-treated layer by chromating the plated layer. In particular, the corrosion resistant layer may be formed by dipping the plated layer into a solution including chromate or dichromate as a main component. The chromating of the zinc-plated layer may improve the corrosion resistance of the brake hose fitting, prevent the occurrence of white rust and prevent contaminants such as fingerprints and the like from adhering to the brake hose fitting. Further, the chromating of the zinc-plated layer may improve the external appearance of the brake hose fitting and increase the adhesivity between the brake hose fitting and a dye.
FIG. 3 is an exemplary view showing a coating layer of a brake hose fitting according to an exemplary embodiment of the present invention. As shown in FIG. 3, the coating layer of the brake hose fitting of the present invention may include: a plated layer 100 including zinc (Zn) as a main component, about 6˜12 wt % of nickel (Ni) having impurities; a corrosion-resistant layer 200 formed on the plated layer by chromating the plated layer; and a finish layer 300 formed on the corrosion-resistant layer 200 by coating the corrosion-resistant layer 200 with silicon (Si).
FIG. 5 is an exemplary graph showing the estimated endurance term of the brake hose fitting provided with the coating layer of the present invention, wherein the time taken for the thickness of a rust layer to reach about 1 mm (e g , stable limit value) is evaluated. As shown in FIG. 5, the estimated endurance term of the brake hose fitting fabricated by general zinc plating is about 12 years, the estimated endurance term of the brake hose fitting fabricated by zinc-nickel alloy (e.g., having substantially high nickel content) plating is about 14 years, and the estimated endurance term of the brake hose fitting of the present invention fabricated by zinc-nickel alloy (e.g., having substantially low nickel content) plating is about 21 years. Therefore, the estimated endurance term of the brake hose fitting of the present invention fabricated by zinc-nickel alloy plating is increased.
As described above, according to the coating method and coating layer of a brake hose fitting of the present invention, both corrosion resistance and durability may be improved, and the brake hose fitting may be connected to a brake hose to thereby increase corrosion resistance of the brake hose fitting of the present invention by about 2˜4 times compared to that of the conventional brake hose fitting, and the estimated endurance term of the brake hose fitting of the present is predicted to be about 21 years or more.
Although the exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

What is claimed is:

1. A method of coating a brake hose fitting, comprising:

plating a brake hose fitting with a zinc-nickel (Zn—Ni) alloy including about 6˜12 wt % of nickel (Ni); and

post-treating the plated brake hose fitting with a silicon (Si) solution.

2. The method of claim 1, further comprising:

chromating the plated brake hose fitting.

3. The method of claim 1, wherein, in the post-treating the plated brake hose fitting, the plated brake hose fitting is dipped into the silicon (Si) solution.

4. The method of claim 1, wherein the silicon (Si) solution is a solution including about 10˜15 wt % of Si.

5. A coating layer of a braking hose fitting, comprising:

a plated layer including zinc (Zn) and about 6˜12 wt % of nickel (Ni);

a corrosion-resistant layer formed on the plated layer by chromating the plated layer; and

a finish layer formed on the corrosion resistance layer by coating the corrosion resistance layer with silicon (Si).