JP3629147B2 - Resin-coated bush and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin-coated bush and a method for manufacturing the same, and more particularly, to a resin-coated bush and a method for manufacturing the resin-coated bush that prevent peeling of a coating film in a corrosive environment such as a wiper arm.
[0002]
[Prior art]
FIG. 3 is an explanatory view of a conventionally known wiper device 1 in which a wiper arm bush 10 is used. The wiper device 1 includes a wiper arm 2, and the wiper arm 2 includes a wiper arm head 3 and an arm 4 rotatably attached to the wiper arm head 3. The wiper arm head 3 is fixed to a wiper shaft 6 connected to a drive motor (not shown), and the wiper arm bush 10 is press-fitted into a bush mounting hole 3A for mounting the wiper arm bush 10. A wiper arm shaft 5 having a flange 5A is inserted into the mounting hole 4A of the arm 4 as shown by a dotted line, passes through the bearing portion 11 of the wiper arm bush 10 that is press-fitted into the wiper arm head 3, and enters the mounting hole 4B of the arm 4. Inserted and caulked outside the mounting hole 4B. The wiper arm shaft 5 is rotatably attached to the wiper arm bush 10, the spring 7 is hooked on a hook 7 </ b> A attached to the wiper arm head 3, and the other end is attached to a locking portion (not shown) of the arm 4. Since it is hung, the arm 4 is pivotably attached to the wiper arm head 3 while being pressed in the arrow Q direction.
[0003]
When the wiper device 1 is operated, the wiper blade (not shown) attached to the tip of the arm 4 wipes the glass surface by reciprocating rotation of the wiper shaft 6 in the direction of arrow P. Since it is pivotable and a pressing force is always applied to the arm 4 in the direction of arrow Q by the spring 7, the wiper blade can be wiped off reliably along the curved glass surface of the vehicle.
[0004]
FIG. 4 is a cross-sectional view of the wiper arm bush 10 used in the wiper device 1 taken along the line XX shown in FIG. The wiper arm bushing 10 is widely used in the wiper device 1, and stainless steel is used as a back metal for preventing corrosion. The wiper arm bushing 10 is formed by winding a stainless steel back metal material coated with polyamideimide resin. A bearing resin layer 11 </ b> A is formed on the bearing portion 11 and is press-fitted into the aluminum wiper arm head 3. A wiper arm shaft 5 is attached to the wiper arm bush 10, and the wiper arm shaft 5 is attached to the arm 4 through the attachment hole 4 </ b> A and the attachment hole 4 </ b> B of the arm 4. The wiper arm bushing 10 is formed with a bearing resin layer 11A, and can pivotally support the arm 4 while ensuring durability.
[0005]
[Problems to be solved by the invention]
However, as described above, the conventional wiper arm bushing 10 is widely used in the wiper device 1 in order to make the mounting arm 4 pivotable to the wiper arm head 3, but has the following problems.
[0006]
As described above, the wiper arm bushing 10 is made of stainless steel as a backing metal and is press-fitted into the aluminum wiper arm head 3. However, since aluminum and stainless steel are in contact with each other, the corrosive environment is exposed to raindrops. A corrosion battery is formed between electrically base aluminum and precious stainless steel, and the aluminum of the wiper arm head 3 may be corroded. The corrosion of the aluminum proceeds as shown by an arrow Y, for example, along the adhesion interface between the wiper arm head 3 and the coating layer 8 covering the surface thereof as shown in a partially enlarged manner in FIG. There is a risk that the quality of the wiper device 1 as well as the wiper arm head 3 may be impaired.
[0007]
The present invention has been made in view of the above, and provides a resin-coated bush that has a simple structure and prevents the occurrence of electrolytic corrosion in a corrosive environment such as a wiper arm, and prevents peeling of a coating film, and a method for manufacturing the same. The purpose is to do.
[0008]
[Means for Solving the Problems]
Resin coated bushing of the present invention, the filler filled in the back metal of stainless steel coated with polyamide-imide resin to form a resin layer on the bearing portions, in the bushing attached to the aluminum wiper arm heads, other than the bearing portion The back metal exposed portion is entirely covered with the polyamideimide resin containing the filler to form a resin layer.
[0009]
The filler is a solid lubricant made of molybdenum disulfide, tetrafluoroethylene resin, graphite and / or boron nitride, and has a weight ratio of 10 to 50% with respect to the polyamideimide resin.
[0010]
The thickness of the resin layer of the polyamide-imide resin is 5 to 25 μm at the bearing portion and 2 to 5 μm at other portions than the bearing portion.
[0011]
Furthermore, the manufacturing method of the resin-coated bush is as follows: a) coating a polyamideimide resin with filler on a stainless steel back metal, drying and firing, and forming a bearing layer; and b) coating the polyamideimide resin. A process of winding the processed material into a bush, and c) spray coating on the exposed portion other than the bearing layer of the bush , followed by drying and firing, and forming a polyamideimide resin film on the back and end surfaces of the bush to cover the entire surface And is attached to an aluminum wiper arm head .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention are described below.
[0013]
FIG. 1 shows a cross-sectional view of a wiper arm bush 30 according to the present invention. The wiper arm bush 30 is made of stainless steel used as a back metal for preventing corrosion, and a bearing resin layer 31A of a polyamide-imide resin containing a filler is formed on the bearing portion 31, and an end face 33 other than the bearing portion 31 and The rear surface 34 is entirely covered with the polyamideimide resin containing the filler, thereby forming an end surface resin layer 33A and a rear resin layer 34A. The bearing resin layer 31 </ b> A of the bearing portion 31 is formed on the surface of the bearing portion 31 by coating a polyamideimide resin with a filler on a stainless steel back metal and winding the material coated with the polyamideimide resin. The end surface resin layer 33A and the back surface resin layer 34A are formed by spray coating to be described later.
[0014]
The wiper arm bush 30 is press-fitted into an aluminum wiper arm head 3, and the arm 4 is attached to the wiper arm bush 30 via a wiper arm shaft 5. The wiper arm shaft 5 having the flange 5A is inserted into the mounting hole 4A of the arm 4, passes through the bearing portion 31 of the wiper arm bush 30, and the flange 5A comes into contact with the arm 4 around the mounting hole 4A. To the outside of the mounting hole 4B. The wiper arm bush 30 has an inner diameter and a thickness of the bearing resin layer 31 </ b> A so that the wiper arm shaft 5 can rotate, and the wiper arm head 3 is baked.
[0015]
The formation of the bearing resin layer 31A, the end surface resin layer 33A, and the back surface resin layer 34A uses a polyamideimide resin containing a filler, so that it has excellent insulation and wear resistance, heat resistance, and wiper arm bushing 30. It can endure the high temperature at the time of baking in the manufacturing process.
[0016]
As described above, the wiper arm bush 30 covers the entire surface of the wiper arm bush 30 with the polyamideimide resin filled with the bearing resin layer 31A, the end surface resin layer 33A, and the back surface resin layer 34A. The contact between the aluminum and the stainless steel of the wiper arm bush 30 can be avoided, and the electric corrosion of the wiper arm head 3 can be reliably prevented in a corrosive environment such as raindrops with a simple structure, and the coating film can be prevented from peeling off.
[0017]
In addition, the filler uses a solid lubricant composed of molybdenum disulfide, tetrafluoroethylene resin, graphite and / or boron nitride, and has a weight ratio of 10 to 50% with respect to the polyamideimide resin. To improve the wear resistance and wear resistance.
[0018]
Further, it is particularly effective that the thickness of the resin layer is 5 to 25 μm for the bearing resin layer 31A and 2 to 5 μm for the end surface resin layer 33A and the back surface resin layer 34A other than the bearing portion. That is, by setting the bearing resin layer 31A to a thickness of 5 to 25 μm, the wear resistance excellent in bearing performance can be made accurate, and the end resin layer 33A and the back resin layer 34A other than the bearing portion are 2 in thickness. By setting the thickness to ˜5 μm, the fitting property when press-fitting into the wiper arm head 3 is excellent, and the electrolytic corrosion of the wiper arm head 3 can be prevented.
[0019]
In the above embodiment, the wiper arm bush 30 is entirely covered with the resin layer. However, depending on the shape and size of the wiper arm bush 30, the resin layer may be omitted from the end surface 33, for example. It can also be.
[0020]
Next, the manufacturing method of the wiper arm bush 30 will be described.
[0021]
First, a polyamide-imide resin with a filler is coated on a stainless steel backing, and after coating, drying and firing are performed. Next, the material coated with the polyamide-imide resin is cut, and the surface coated with the polyamide-imide resin is wound inside to form a bush shape. Further, the polyamideimide resin containing the filler is spray coated on the bush processed, and after spray coating, drying and firing are performed, and the end surface resin layer 33A and the back resin layer 34A are also formed on the back surface 34 and the end surface 33 of the bush. To do. The wiper arm bush 30 can be manufactured through the above steps.
[0022]
In FIG. 2, the spray apparatus 50 which performs the said spray coating to the wiper arm bush 30 is shown.
[0023]
The spray device 50 includes a rotation driving device 52 provided on the base 58, a cylindrical basket 51 attached to the rotation driving device 52 and rotating in the arrow K direction, and a spray unit 53. The bush for spray coating opens the openable / closable lid 51A and puts it in the cylindrical cage 51 by a predetermined number, and the lid 51A is closed and locked.
[0024]
When spray coating is performed, the motor switch 52A provided in the rotation drive device 52 is operated, and the cylindrical cage 51 is rotated in the direction of arrow K by a motor (not shown). Next, the spray unit 53 is operated by the operation of the spray switch 52 </ b> B, and the coating liquid (polyamideimide resin with a filler) is sprayed by the nozzle 55 from the hole opened in the center of the side surface of the cylindrical basket 51. After spraying for a predetermined time, the rotation of the basket 51 is stopped, the opening / closing lid 51A is opened, the bush is taken out, and drying and baking are performed.
[0025]
The manufacturing method of the wiper arm bush 30 is an extremely simple process as described above, and can be easily and efficiently sprayed by the spray device 50 having the simple structure.
[0026]
Next, the effect confirmation result by the corrosion test generally performed is described.
[0027]
The conditions of the corrosion test conducted this time are:
1.1 cycle 24 hours 2.1 cycle test items (1) 35 ° C 5%-salt water spray test (2) 70 ° C-drying (3) 50 ° C 5%-salt water immersion (4) room temperature drying Free sample A wiper arm bush 30 is press-fitted into the wiper arm head 3.
4). N = 3
5. Performed in 30 cycles.
[0028]
As a result of the corrosion test, no white rust (white powder is generated) is observed in all the samples tested above, and all the samples are blistered (exfoliation of the coating film, etc.) Was also not seen.
[0029]
In the above embodiment, the wiper arm bush 30 attached to the wiper arm head 3 has been described. Of course, the present invention is not limited to this, and resin-coated bushes formed with the same resin layer as the wiper arm bush 30 can be used in various bush housings. It can be installed to achieve the same effect.
[0030]
【The invention's effect】
Resin coated bushing of the present invention, the filler filled in the back metal of stainless steel coated with polyamide-imide resin to form a resin layer on the bearing portions, in the bushing attached to the aluminum wiper arm heads, other than the bearing portion Since the back metal exposed part is covered entirely with the polyamideimide resin containing the filler to form a resin layer, it avoids contact between the aluminum of the bushing housing such as the wiper arm head and the stainless steel of the bushing, and corrosion such as raindrops with a simple structure It is possible to reliably prevent the occurrence of electric corrosion such as a wiper arm head under the environment and to prevent peeling of the coating film.
[0031]
Moreover, since the thickness of the resin layer of the polyamideimide resin is 5 to 25 μm at the bearing portion, it is possible to make the wear resistance excellent in bearing performance accurate, and 2 to 5 μm at other than the bearing portion. Therefore, it is excellent in fitting property with a bush housing such as a wiper arm head, and it is possible to reliably prevent electrolytic corrosion.
[0032]
Furthermore, the manufacturing method of the resin-coated bush is as follows: a) coating a polyamideimide resin with filler on a stainless steel back metal, drying and firing, and forming a bearing layer; and b) coating the polyamideimide resin. A process of winding the processed material into a bush, and c) spray coating on the exposed portion other than the bearing layer of the bush , followed by drying and firing, and forming a polyamideimide resin film on the back and end surfaces of the bush to cover the entire surface In order to manufacture bushes that can be attached to aluminum wiper arm heads, avoid contact between the bushing housing aluminum such as wiper arm heads and bushing stainless steel, and wiper arms in corrosive environments such as raindrops the occurrence of electrolytic corrosion, such as the head to prevent the release of reliably preventing coating, be prepared in a simplified process With it, it can be carried out easily and efficiently sprayed by a spray device of simple structure.
[Brief description of the drawings]
FIG. 1 is a sectional view of a wiper arm bush according to the present invention.
FIG. 2 shows a spray apparatus for performing spray coating on a wiper arm bush according to the present invention.
FIG. 3 is an explanatory view of a generally known wiper device in which a conventional wiper arm bush is used.
4 is a cross-sectional view taken along line XX of FIG. 3 of a conventional wiper arm bush used in a generally known wiper device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wiper apparatus 2 Wiper arm 3 Wiper arm head 4 Arm 5 Wiper arm shaft 6 Wiper shaft 10, 30 Wiper arm bush 31 Bearing part 31A Bearing resin layer 33 End surface 33A End surface resin layer 34 Back surface 34A Back surface resin layer 50 Spray device 51 Cylindrical cage 52 Drive unit 53 Spray unit 55 Nozzle

Claims (4)

By coating a polyamide-imide resin of the filled on the back metal of the stainless steel to form a resin layer on the bearing portions, in the bushing attached to the aluminum wiper arm head, the filler containing the back metal exposed portion other than the bearing portion A resin-coated bush characterized in that a resin layer is formed by covering the entire surface with a polyamide-imide resin. The filler is a solid lubricant composed of molybdenum disulfide, ethylene tetrafluoride resin, graphite and / or boron nitride, and has a weight ratio of 10 to 50% with respect to the polyamideimide resin. The resin-coated bush according to 1. 3. The resin-coated bush according to claim 1, wherein a thickness of the resin layer of the polyamide-imide resin is 5 to 25 μm at a bearing portion and 2 to 5 μm at portions other than the bearing portion. B) A process of forming a bearing layer by coating a polyamideimide resin with a filler on a stainless steel back metal, followed by drying and firing, and b) a process of winding the material coated with the polyamideimide resin into a bushing. And (c) an aluminum wiper manufactured by spray coating on the exposed portion of the bush other than the bearing layer, followed by drying and firing, and forming a polyamideimide resin film on the back and end surfaces of the bush to cover the entire surface. A method for producing a resin-coated bush, wherein the bush is attached to an arm head .

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