WO2008133389A1

WO2008133389A1 - Steering wheel in automobile and method for fabricating the same

Info

Publication number: WO2008133389A1
Application number: PCT/KR2007/005987
Authority: WO
Inventors: Ho-Il Kang
Original assignee: DONGHAE METAL Co Ltd
Current assignee: DONGHAE METAL Co Ltd
Priority date: 2007-04-27
Filing date: 2007-11-26
Publication date: 2008-11-06
Anticipated expiration: 2009-10-27
Also published as: KR100887532B1; KR20080096364A

Abstract

The present invention relates to a steering wheel for an automobile and a method for fabricating the same, and more particularly, to a steering wheel formed by being injection-molded twice for decreasing the deterioration and improving the productivity. The steering wheel for an automible includes: a metal frame including first and second portions; a rim including a first coating part covering the first portion, a second coating part covering the first coating part, and a third coating part covering the second portion; a plurality of spokes connected to the rim and installed at an inner side of the rim; a hub core connected to the plurality of spokes; and a steering axis connected to the hub core.

Description

STEERING WHEEL IN AUTOMOBILE AND METHOD FOR

FABRICATING THE SAME

Technical Field

[1] The present invention relates to a steering wheel for an automobile and a method for fabricating the same, and more particularly, to a steering wheel formed by being injection-molded twice for decreasing the deterioration and improving the productivity.

[2]

Background Art

[3] Generally, a steering system used in automobile controls a driving direction of an automobile and is broadly constituted of 3 parts such as an operating means, a gear part, and a linking means, etc.

[4] The operating means transfers an operating power of the driver to the gear part and the linking means, and includes a steering wheel, a steering axis and a column.

[5]

[6] In the steering system, when the driver operates the steering wheel along the circumference of the steering wheel for controlling the driving direction, the circumference motion of the steering wheel is transferred to a steering gear, and the steering gear moves tires of the automobile by changing the circumference motion to a liner motion, thereby controlling the driving direction.

[7]

[8] The driver always takes and operates the steering wheel for controlling the driving direction while preparing or taking a drive. The steering wheel hands should not slip from the driver's hands and is manufactured elegantly with a good feeling. The steering wheel is preferred to have a cushion by which the impact is not strongly transferred to a person when a car comes in collision.

[9]

[10] In accordance with such requirements, a ring of a metal frame wrapped by a hard foaming polyurethane resin is used for the steering wheel. In addition, recently, for grading up the elegance and classic mood, the steering wheel onto which a wood grain film having a veining pattern of tree is transcribed is used.

[H]

[12] In the above prior art, upper and lower portions of the steering wheel are made up of different materials and colors from other portions of the steering wheel in considering the beauties. The steering wheel is formed by injecting a resin as a transparent or translucent material into a mold. The steering wheel is not beautiful and elegant due to bubbles generated in a coating resin because an injected volume of the mold is large. Although the steering wheel is formed of a resin as an opaque material, the coating resin has brittleness due to the bubbles. Accordingly, the deterioration is increased and the productivity is decreased.

[13]

Disclosure of Invention Technical Problem

[14] It is an object of the present invention to provide a steering wheel for an automobile which is formed by being injection-molded twice for reducing a deterioration and improving a productivity and a method for fabricating the same.

[15]

[16] It is another object of the present invention to provide a steering wheel for an automobile, a part of which is formed of a transparent material or a translucent material for easily detecting a deterioration before a product is completed and a method for fabricating the same.

[17]

Technical Solution

[18] To achieve these objects in accordance with the present invention, a steering wheel for a automobile includes: a metal frame including first and second portions; a rim including a first coating part covering the first portion, a second coating part covering the first coating part, and a third coating part covering the second portion; a plurality of spokes connected to the rim and installed at an inner side of the rim; a hub core connected to the plurality of spokes; and a steering axis connected to the hub core.

[19] In the above steering wheel for the automobile, the thickness of the first and second coating parts is equal to the thickness of the third coating part.

[20] In the above steering wheel for the automobile, the first coating part is 0.5 to 1.5 times as thick as the second coating part.

[21] In the above steering wheel for the automobile, the first portion includes upper and lower portions of the rim and the second portion includes both side portions of the rim.

[22] In the above steering wheel for the automobile, the upper and lower portions are formed of ABS (acryloninitrile butadiene styrene) or PC (poly carbonate) and the both side portions are formed of polyurethane.

[23] In another aspect, a method for manufacturing a steering wheel of an automobile includes the steps of: inserting a metal frame including first and second portions into a first mold; forming a first coating part covering the first portion by injecting a first resin into the first mold; inserting the metal frame including the first coating part in a second mold; forming a second coating part covering the first coating part by injecting a second resin into the second mold; inserting the metal frame including the first and second coating parts in a third mold; and forming a third coating part covering the second portion by injecting a third resin into the third mold.

[24]

[25] In the above method for manufacturing a steering wheel of an automobile, the first mold includes a first central cavity in which a plurality of spokes and a hub core are disposed and a first coating cavity in which the first portion is disposed and the first resin is provided, the first coating cavity having a first diameter, and the second mold includes a second central cavity in which the plurality of spokes and the hub core are disposed and a second coating cavity in which the first coating part is disposed and the second resin is provided, the first coating cavity having a second diameter larger than the first diameter.

[26] In the above method for manufacturing a steering wheel of an automobile, the second diameter is 1.5 to 2.5 times as large as the first diameter.

[27] In the above method for manufacturing a steering wheel of an automobile, the first mold includes a first upper mold, a first lower mold and a first ejector and the second mold includes a second upper mold, a second lower mold and a second ejector.

[28] In the above method for manufacturing a steering wheel of an automobile, the first and second ejectors include a supporting plate for applying a separating pressure and a plurality of separating pins connected to the supporting plate and contacting the plurality of spokes.

[29] In the above method for manufacturing a steering wheel of an automobile, the first portion corresponds to upper and lower portions of the metal frame and the second portion corresponds to both side portions of the metal frame.

[30]

Advantageous Effects

[31] A steering wheel for an automobile and method for manufacturing the same according to an embodiment of the present invention have advantages as follows: [32] A deterioration is reduced and a productivity is improved because a part of a steering wheel is formed by being injection-molded in twice times. [33] Also, the deterioration such as bubbles may be easily detected because the part of the steering wheel is formed of a transparent material or a translucent material before the product is completed. [34]

Brief Description of the Drawings

[35] FIG. 1 is a perspective view of a steering wheel according to the present invention.

[36] FIG. 2 is a perspective view of a mold for manufacturing a steering wheel according to the present invention

[37] FIG. 3 is a plane view of a first upper mold according to the present invention

[38] FIG. 4 is a plane view of a first lower mold according to the present invention

[39] FIG. 5 is a plane view of a second upper mold according to the present invention

[40] FIG. 6 is a plane view of a second lower mold according to the present invention

[41] FIG. 7 is a cross-sectional view of a mold according to the present invention

[42] FIG. 8 is a flow chart of a method for manufacturing a steering wheel according to the present invention [43]

Best Mode for Carrying Out the Invention [44] The exemplary embodiment according to the present invention is explained with reference in accompanying drawings in detail hereinafter. [45] FIG. 1 is a perspective view of a steering wheel according to the present invention.

FIG. 2 is a perspective view of a mold for manufacturing a steering wheel according to the present invention. FIG. 3 is a plane view of a first upper mold according to the present invention. FIG. 4 is a plane view of a first lower mold according to the present invention. FIG. 5 is a plane view of a second upper mold according to the present invention. FIG. 6 is a plane view of a second lower mold according to the present invention. FIG. 7 is a cross-sectional view of a mold according to the present invention. FIG. 8 is a flow chart of a method for manufacturing a steering wheel according to the present invention. [46]

[47] A steering wheel 100 includes a rim 101 formed of a resin, upper and lower portions

102 and 103 corresponding to the top and bottom of the rim 101, respectively, a hub core 118 positioned in a central portion of the rim 101, and connected to a directional control axis (not shown in drawings). The upper and lower portions 102 and 103 are formed by injection-molding. An air bag module (not shown in drawings) is assembled on the hub core 118. [48]

[49] The rim 101 is made up by coating a circular metal frame 106 with a resin. The metal frame 106 is divided into a first portion corresponding to the upper and lower portions 102 and 103 and a second portion corresponding to both side portions 107. The upper and lower portions 102 and 103 of the rim 101 are formed of a resin including different materials and colors from the both side portions 107. The upper portion 102 is larger than the lower portion 103 in considering the beauties. [50] [51] The upper portion 102 of the rim 101 includes a first upper coating part 104 which is applied to the metal frame 106 by a first injection molding operation and a second upper coating part 105 which is applied to the first upper coating part 104 by a second injection molding operation. The lower portion 103 of the rim 101 includes a first lower coating part 108 which is applied to the metal frame 106 by the first injection molding operation and a second lower coating part 109 which is applied to the first lower coating part 108 by the second injection molding operation such as the above mentioned method.

[52]

[53] A third coating part is coated on the second portion of metal frame 106 corresponding to the both side portions 107. The first upper coating part 104 is 0.5 to 1.5 times as thick as the second upper coating part 105. The first lower coating part 108 is 0.5 to 1.5 times as thick as the second lower coating part 109. The total thickness of the first and second upper coating parts 104 and 105 is equal to the thickness of the third coating part.

[54]

[55] A plurality of spokes 111 , a hub core 118 connected to the plurality of spokes 111 and assembled with an air bag module (not shown in drawing), and a core ring 112 to be connected to a steering axis (not shown in drawing) are installed at an inner side of the rim 101. The upper and lower portions 102 and 103 of the rim 101 are injection- molded of the same material for example an ABS (acryloninitrile butadiene styrene) or a PC (poly carbonate). A translucent PC is utilized, if possible, because the PC has better heat-resisting property than the ABS. The both side portions 107 excluding the upper and lower portions 102 and 103 of the rim 101 are formed by foaming a material including a polyol, an isocyanate, and a coloring agent.

[56]

[57] A deterioration such as bubbles may be easily found out in manufacturing process because the upper and lower portions 102 and 103 are formed of a translucent ABS or PC. The bubble generated in the upper and lower portions 102 and 103 is not beautiful and elegant. The upper and lower portions 102 and 103 have brittleness due to the bubble and the strength of the upper and lower portions 102 and 103 is reduced by the brittleness. Such a problem may result in unsafety driving conditions.

[58]

[59] A mold utilized in manufacturing process of a steering wheel in accordance with the present invention is explained hereinafter.

[60] FIG. 2 shows a perspective view of an assembled mold to be injection-molded for forming upper, lower and both side portions 102, 103 and 107 of a steering wheel 100. The mold includes an upper mold 113, a lower mold 114, and an ejector 115 for separating the steering wheel 100 from the mold. A gate 116 for providing a resin is installed at the upper mold 113.

[61] FIG. 7 shows a cross-sectional view of the mold. As shown in FIG. 7, the ejector 115 is installed under the lower mold 114 assembled with the upper mold 113. The ejector 115 includes a supporting plate 162 for applying a pressure thereto and separating pins 160 connected to the supporting plate 162 and corresponding to the plurality of spokes 111 of the steering wheel 100. The separating pins 160 contact the back surface of the plurality of spokes 111 inserted in the upper and lower molds 113 and 114 assembled with each other. The ejector 115 separates the steering wheel 100 from the lower mold 114. A block 161 may be disposed between the supporting plate 162 and the lower mold 114 for adjusting a height of the separating pins and the steering wheel 100.

[62]

[63] FIGs 3 to 6 show molds for forming upper and lower portions 102 and 103 of the steering wheel 100. As shown in FIGs. 3 and 4, a first mold for forming a first upper coating part 104 and a first lower coating part 108 includes a first upper mold 120, a first lower mold 130 and a first ejector (not shown in drawings). FIG. 3 shows the surface of the first upper mold 120 faced with the first lower mold 130. FIG. 4 shows the surface of the first lower mold 130 faced with the first upper mold 120.

[64]

[65] A first central cavity 121, a first upper coating cavity 122 and a first lower coating cavity 123 are formed in the first mold 130 by joining the first upper mold 120 to the first lower mold 130. The first central cavity 121 accommodates a hub core 103, a plurality of spokes 111, and a metal frame 106 corresponding to both side portions 107. A resin is not injected into the first central cavity 121.

[66]

[67] The first upper coating cavity 122 and the first lower coating cavity 123 provide spaces into which the resin is injected for coating a first upper coating part 104 and a first lower coating part 108. The metal frame 106 corresponding to upper and lower portions 102 and 103 is disposed in the first upper coating cavity 122 and the first lower coating cavity 123. Each of the first upper and lower coating cavities 122 and 123 has a first diameter. If necessarily, the first upper coating cavity 122 may differ from the first lower coating cavity 123 in a diameter.

[68]

[69] A first gate (not shown in drawings) is installed at the first mold for providing the resin into the first upper coating cavity 122 and the first lower coating cavity 123. The first gate is vertically connected to each of the first upper and lower coating cavities 122 and 123 where an inlet of the first gate is positioned on the first upper mold 120. The first gate is horizontally connected to each of the first upper and lower coating cavities 122 and 123 where the inlet of the first gate is positioned on a side surface of the first upper mold 120 or the second lower mold 130.

[70]

[71] A second mold for forming second upper and lower coating parts 105 and 109 of the steering wheel 100 includes a second upper mold 140, a second lower mold 150 and a second ejector (not shown in drawings). FIG. 5 shows the surface of the second lower mold 150 faced with the second upper mold 140. FIG. 6 shows the surface of the second upper mold 140 faced with the lower mold 150. A second central cavity 141, a second upper coating cavity 142 and a second lower coating cavity 143 are formed in the second mold by joining the second upper mold 140 to the second mold 150.

[72]

[73] The second central cavity 141 accommodates a hub core 103, a plurality of spokes

111, and a metal frame 106 corresponding to both side portions 107 of the rim 101. A resin is not injected into the second central cavity 141. The second upper coating cavity 142 and the second lower coating cavity 143 provide spaces into which the resin is injected for coating a second upper coating part 105 and a second lower coating part 109. The first upper and lower coating parts 104 and 108 are disposed in the second upper coating cavity 142 and the second lower coating cavity 143. Each of the second upper and lower coating cavities 142 and 143 has a second diameter. If necessarily, the second upper coating cavity 142 may differ from the second lower coating cavity 143 in a diameter.

[74]

[75] The second diameter is 1.5 to 2.5 times, desirably 2 times as large as the first diameter. The first and second diameters may be controlled as occasion demands. Although it is not illustrated in drawings, the both side portions 107 are formed on the metal frame 106 between the upper and lower portions 102 and 103. The steering wheel 100 is disposed in a third mold (not shown in drawing) and then, the resin is injected into the third mold after forming the upper and lower portions 102 and 103 of the steering wheel 100. The space to be injection- molded is minimized because two molds are utilized for forming the upper and lower portions 102 and 103, thereby a deterioration such as bubbles being prevented.

[76]

[77] A method for manufacturing a steering wheel is explained referring to FIG. 8, first and second molds illustrated in FIGs. 3 to 6 and a third mold(not shown in drawings), hereinafter. As shown in SOOl step, first upper and lower molds 120 and 130 and a hub core 103 and a plurality of spokes 111 of a steering wheel 100 are heated at 60 to 8O⁰C for improving a liquidity of a resin to be injected. As shown in S002 step, the steering wheel 100 is disposed in the first lower mold 130. The hub core 103, the plurality of spokes 111, and the metal frame 106 corresponding to both side portions 107 are disposed in a first central cavity 121 and the metal frame 106 corresponding to upper and lower portions 102 and 103 is disposed in first upper and lower coating cavities 122 and 123 having a first diameter. As shown in S003 step, the first upper and lower molds 120 and 130 and a first ejector are joined with each other.

[78]

[79] As shown in S004 step, a material such as ABS (acryloninitrile butadiene styrene) or

PC (poly carbonate) is injected through a gate of the first mold by using a pump. As shown in S005 step, the first upper and lower molds 120 and 130 are cooled and then, the steering wheel 100 having the first upper and lower coating parts 104 and 108 is separated from the first upper and lower molds 120 and 130 by applying a pressure to the first ejector. As shown in S006 step, the second upper and lower molds 140 and 150 and the hub core 103 and the plurality of spokes 111 of the steering wheel 100 are heated at 60 to 8O⁰C for improving a liquidity of a resin to be injected.

[80]

[81] As shown in S007 step, the steering wheel 100 is disposed in the second mold. That is, the hub core 103, the plurality of spokes 111 and the metal frame 106 corresponding to the both side portions 107 are disposed in a second central cavity 141 and first upper and lower coating parts 104 and 108 are disposed in the second upper and lower coating cavities 142 and 143, respectively. The second upper and lower coating cavities 142 and 143 have a second diameter lager than the first diameter of the first upper and lower coating cavities 122 and 123. As shown in S008 step, the second upper and lower molds 140 and 150 and a second ejector are joined with each other.

[82]

[83] As shown in S009 step, a material such as ABS (acryloninitrile butadiene styrene) or

PC (poly carbonate) is injected through a gate of the second mold by using a pump. As shown in SOlO step, the second upper and lower molds 140 and 150 are cooled and then, the steering wheel 100 having second upper and lower coating parts 105 and 109 is separated from the second upper and lower molds 140 and 150 by applying a pressure to the second ejector. Continuously, as shown in SOl 1 step, another resin different from the resin of the upper and lower parts 102 and 103 is coated on the both side portions 107 using the third mold.

[84]

[85] A deterioration is reduced by minimizing a space to be injection-molded because the upper and lower parts are formed by being injection-molded twice. If necessary, the upper and lower parts may be injection-molded over 2 times. Also, the deterioration such as a bubble generated in manufacturing process is easily detected before the product is completed because the upper and lower parts of the steering wheel are formed of transparent and translucent materials. Accordingly, the productivity is improved.

Claims

Claims[1] A steering wheel for an automible, comprising: a metal frame including first and second portions; a rim including a first coating part covering the first portion, a second coating part covering the first coating part, and a third coating part covering the second portion; a plurality of spokes connected to the rim and installed at an inner side of the rim; a hub core connected to the plurality of spokes; and a steering axis connected to the hub core. [2] The steering wheel according to claim 1 , wherein the thickness of the first and second coating parts is equal to the thickness of the third coating part. [3] The steering wheel according to claim 1, wherein the first coating part is 0.5 to

1.5 times as thick as the second coating part. [4] The steering wheel according to claim 1 , wherein the first portion includes upper and lower portions of the rim and the second portion includes both side portions of the rim. [5] The steering wheel according to claim 4, wherein the upper and lower portions are formed of ABS (acryloninitrile butadiene styrene) or PC (poly carbonate) and wherein the both side portions are formed by polyurethane. [6] A method for manufacturing a steering wheel of an automobile, comprising: inserting a metal frame including first and second portions into a first mold; forming a first coating part covering the first portion by injecting a first resin into the first mold; inserting the metal frame including the first coating part in a second mold; forming a second coating part covering the first coating part by injecting a second resin into the second mold; inserting the metal frame including the first and second coating parts in a third mold; and forming a third coating part covering the second portion by injecting a third resin into the third mold. [7] The method according to claim 6, wherein the first mold includes a first central cavity in which a plurality of spokes and a hub core are disposed and a first coating cavity in which the first portion is disposed and the first resin is provided, the first coating cavity having a first diameter, and wherein the second mold includes a second central cavity in which the plurality of spokes and the hub core are disposed and a second coating cavity in which the first coating part is disposed and the second resin is provided, the first coating cavity having a second diameter larger than the first diameter. [8] The method according to claim 7, wherein the second diameter is 1.5 to 2.5 times as large as the first diameter. [9] The method according to claim 7, wherein the first mold includes a first upper mold, a first lower mold and a first ejector and wherein the second mold includes a second upper mold, a second lower mold and a second ejector. [10] The method according to claim 9, wherein the first and second ejectors include a supporting plate for applying a separating pressure and a plurality of separating pins connected to the supporting plate and contacting the plurality of spokes. [11] The method according to claim 6, wherein the first portion corresponds to upper and lower portions of the metal frame and wherein the second portion corresponds to both side portions of the metal frame. [12] The method according to claim 6, wherein the first and second coating parts are formed of ABS (acryloninitrile butadiene styrene) or PC (poly carbonate). [13] The method according to claim 6, wherein the third coating part is a polyurethane resin which is foamed by using a polyol, an isocyanate, and a coloring agent.