Patent Publication Number: US-2009224523-A1

Title: Heated steering wheel using induction current

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Application Number 10-2008-0019880, filed on Mar. 4, 2008, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a steering wheel, and more particularly, to a heated steering wheel that includes a ferromagnetic material for generating heat using induction current induced with a magnetic field caused by alternating current supplied to a conducting member that is provided in the steering wheel in order to quickly increase the temperature thereof. 
     2. Description of Related Art 
     As shown in  FIG. 1 , a heating coil  102  of a conventional heated steering wheel is provided between a main body  101   a  and an exterior member  101   b  surrounding the main body  101   a  of a rim portion of a steering wheel. The heating coil generates heat to increase the temperature of rim  101  of the steering wheel. When the outdoor air temperature is low, like in winter, the heating coil steering wheel increases the temperature of the rim portion  101  up to 20° C. in order to improve a driver&#39;s operation sensibility of rim  101  of the steering wheel. 
     However, since the heating rate of heating coil  102  of the conventional heating coil steering wheel is low, approximately 390 seconds are required to raise the temperature to 20° C. from below 0° C. and 270 seconds are required to raise the temperature to 20° C. from 0° C. as shown in  FIG. 2 . That is, about 4 minutes on average is required until the temperature of rim  101  of the steering wheel reaches 20° C. at which temperature a driver is comfortable. Therefore, until about 4 minutes passes from starting, the driver may not be comfortable due to the low temperature of the steering wheel. In particular, if exterior member  101   b  surrounding the main body  101   a  of rim  101  is made of wood instead of leather, much more time is required until the temperature of rim  101  reaches 20° C. 
     Meanwhile, if the diameter of heating coil  102  provided in the rim  101  of the steering wheel is decreased, the resistivity of heating coil  102  may be increased so that the temperature of rim  101  of the steering wheel can quickly rise. However, in this case, there is a problem in that the life of heating coil  102  is decreased. In addition, it is difficult to uniformly provide a thin heating coil  102  on the surface of cylindrical rim  101  of the steering wheel for uniform, distributed heating. 
     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY OF THE INVENTION 
     Various aspects of the present invention are directed to provide a heated steering wheel using induction current that includes a conductor for generating induction current using the change of a magnetic field caused by alternating current supplied to a conducting member that is provided at a rim region of a steering wheel to quickly increase the temperature thereof. 
     According to an aspect of the present invention, a heated steering wheel using induction current includes a main body; an exterior member that surrounds the main body; and a conductor provided between the main body and the exterior member, the conductor configured to generate induction current using the change of a magnetic field caused by alternating current. 
     The conductor may be composed of a ferromagnetic material. The ferromagnetic material may be metal powder. The conductor may be uniformly provided between the main body and the exterior member. The conductor may be formed in a circular shape along a circumference of the main body. The conductor may be provided along a circumference of the main body other than a region configured to receive a spoke of the steering wheel. The conductor may be formed in a polygonal shape. 
     In various embodiments, the heated steering wheel further includes a conducting member provided between the main body and the exterior member, the wire being supplied with alternating current. The conducting member may be a wire, such as an electrical wire. The conducting member may be wound around the main body. The wire may be provided between the main body and the exterior member in a similar shape as the main body. The conducting member may be provided adjacent the conductor with a predetermined gap therebetween. The heated steering wheel may include an insulation member that insulates the conducting member from the conductor. 
     Various aspects of the inventions are directed to a passenger vehicle including a heated steering wheel as defined above. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view showing a conventional heating coil steering wheel. 
         FIG. 2  is a temperature graph of the heating coil steering wheel of  FIG. 1 . 
         FIG. 3  is a schematic view showing an exemplary heated steering wheel using induction current according to the present invention. 
         FIG. 4  is a view illustrating the operation of the steering wheel of  FIG. 3 . 
         FIGS. 5A to 5C  are schematic views showing an exemplary heated steering wheel using induction current according to the present invention. 
         FIG. 6  is a schematic view showing an exemplary heated steering wheel using induction current according to the present invention. 
         FIG. 7  is a schematic view showing an exemplary heated steering wheel using induction current according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
     Various embodiments of the present invention will be described hereinafter with reference generally to  FIGS. 3 to 7 . 
     Referring to  FIG. 3 , a heated steering wheel using induction current according to the present invention may include a main body  1   a  of a rim portion  1  of steering wheel, an exterior member  1   b  that surrounds main body  1   a  of rim portion  1 , a conducting member  2  supplied with alternating current, and a conductor  10  that is provided substantially close to the conducting member  2  and generates heat with induction current caused by the alternating current supplied to the conducting member  2 . 
     In various aspects of the present invention, the conducting member  2  may be provided between the main body  1   a  and the exterior member  1   b  of the steering wheel. The conducting member is supplied with an alternating current. The location of the conducting member  2 , however, may not be limited to the location between the main body  1   a  and the exterior member  1   b  of the steering wheel if the conducting member  2  can induce an induction current to the conductor  10  by a magnetic field. The conducting member  2  may also be a wire or wire-shaped conductor. 
     The conductor  10  may be a ferromagnetic material. In various aspects of the present invention, the ferromagnetic material may be metal powder that generates induction current using the change of a magnetic field for heating. Accordingly, when alternating current is supplied to the conducting member  2 , a magnetic field is generated around conducting member  2  and an induction current occurs in the ferromagnetic material  10  due to the induced magnetic field as shown  FIG. 4 . In this case, ferromagnetic material  10  generates induction current using the change of the magnetic field for heating the steering wheel&#39;s rim  1 . 
     Ferromagnetic material  10  is optionally a metal powder that generates induction current using the change of a magnetic field, and ferromagnetic material  10  emits heat caused by the induction current through the surface thereof. Accordingly, the heated steering wheel using induction current according to the present invention has a larger heating area as compared to conventional heated steering wheels which include only a heating coil (see, e.g.,  102  of  FIG. 1 ). Therefore, the heated steering wheel using induction current according to the present invention can more quickly increase the temperature of the steering wheel. As a result, the heated steering wheel of the present invention can improve operation sensibility of the steering wheel when outdoor air temperature is low like in winter. 
     Further, since the temperature of rim  1  of steering wheel is increased using heat generated from ferromagnetic material  10 , heat generation of conducting member  2  incurred by resistivity does not need to be considered in the heated steering wheel using induction current. That is, a conducting member  2  having low resistivity may be used in the heated steering wheel according to the present invention. 
     Meanwhile, ferromagnetic material  10  may be a metal powder, that is, a conductor. Accordingly, when ferromagnetic material  10  comes in contact with conducting member  2 , alternating current may also flow in ferromagnetic material  10 . Therefore, the heated steering wheel may further require an insulation member that insulates with conducting member  2  from ferromagnetic material  10  in order to prevent the alternating current, which is supplied to with conducting member  2 , from flowing to ferromagnetic material  10 . 
     In order to increase the amount of heat generated from ferromagnetic material  10  in the heated steering wheel of the present invention, ferromagnetic material  10 , that is, metal powder, may be formed in a circular shape and provided between main body  1   a  of rim  1  of steering wheel and exterior member  1   b , as shown in  FIG. 5A . In this case, the pattern of ferromagnetic material  10  is not limited to a circular shape and may be a polygonal shape such as a triangular shape similar to that shown in  FIG. 5B , a quadrangular shape similar to that shown in  FIG. 5C , or a pentagonal shape similar to that shown in  FIG. 5D . 
     One will appreciate from the foregoing that the conductor is not limited to ferromagnetic material. One will further appreciate that the conductor, and the ferromagnetic material, may include other materials and configurations than metallic powder that can generate an induction current from a change in the magnetic field caused by an alternating electrical current. One will appreciate from the foregoing that the positioning and configuration of the conductor may be further modified in accordance with the present invention. 
     Further, to improve heat generation efficiency of the heated steering wheel of  FIG. 6 , ferromagnetic material  10  may be provided between main body  1   a  and exterior member  1   b  at a rim region  1  of the steering wheel where a driver frequently comes in contact. The ferromagnetic material  10 , however, may be omitted from a region in the steering wheel where a spoke  3  and the rim region  1  are joined. 
     Even in this case, in order to increase the amount of heat generated from ferromagnetic material  10  in the heated steering wheel using induction current according to the present invention, ferromagnetic material  10  may be formed in a circular or polygonal shape between main body  1   a  of rim  1  and exterior member  1   b  at a region of rim  1  of steering wheel where a driver frequently comes in contact. 
     In the heated steering wheel of  FIG. 7 , conducting member  2  may be provided between main body  1   a  and exterior member  1   b  in the same shape as main body  1   a  along the circumference thereof similar to that shown in  FIGS. 3 to 6  described above. Alternatively, conducting member  2  may be wound around the circumference of main body  1   a . If conducting member  2  is wound around the main body  1   a , a strong magnetic field is generated by the conducting member  2  around rim  1  of steering wheel. Therefore, ferromagnetic material  10  generates a large induction current so that the temperature of rim  1  of steering wheel will quickly rise. 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper” or “lower”, “front” or “rear”, “inside” or “outside”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.