Abstract:
Disclosed is a switch module located within a steering wheel of a vehicle that includes an input switch module, a feedback module, and a controller. The input switch module allows a driver to conduct a variety of switching operations by, for example, pressing the left, right, front, or back of the steering wheel, or by making a leftward or rightward torsional motion or a leftward or rightward diagonal motion with respect to the steering wheel. The switch module controller receives inputs from the input switch module that correlate to these switching operations, and outputs a signal to a vehicle device such as, for example, a head up display, and also to a feedback module, which provides a feedback response to the driver confirming the switching operation. The present invention allows the driver to control vehicle devices and systems while maintaining contact with the steering wheel, thereby improving vehicle safety.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims under 35 U.S.C. §119(a) the benefit of Korean Patent Application No. 10-2011-0131713 filed on Dec. 9, 2011, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    (a) Technical Field 
         [0003]    The present invention relates to a switch module built into a steering wheel. More particularly, the invention relates to a switch module in which an input switch module and a feedback module are combined and installed within the steering wheel, so that a switching operation can be performed while a driver is holding the steering wheel. 
         [0004]    (b) Background Art 
         [0005]    A steering wheel is designed to control the direction of a vehicle, and typically includes a grip portion in the form of a circular ring, an airbag module installed in the inner diameter of the grip portion, and a horn. A variety of switches are generally mounted around the grip portion of the steering wheel, or the airbag module, in order to operate a variety of vehicle functions such as Audio, Video, and Navigation (AVN), a Head Up Display (HUD), or the like. 
         [0006]    Conventional art switches are generally small and arranged around the grip portion of the steering wheel in complicated patterns; consequently they have the major drawback of requiring that a driver release the grip portion of the steering wheel in order to operate the switches, thereby creating a hazardous and unsafe driving condition. Additionally, such conventional art switches are disadvantageous because their small size and complicated layout increase the likelihood that a driver will inadvertently touch the wrong switch. 
         [0007]    In view of the foregoing, it is clear that there is a need for switches that will allow a driver to control vehicle functions, such as AVN, HUD, or the like, while allowing the driver&#39;s hands to maintain constant contact with the grip portion of the steering wheel. 
       SUMMARY OF THE DISCLOSURE 
       [0008]    The present invention provides a switch module that may be built into a steering wheel. The switch module includes an input switch module and a feedback module. The input switch module includes a force-torque sensor that functions by receiving a torque operating force such as for example, a holding force or a torsional force, from a driver. The feedback module functions by providing a feedback sensation (e.g. auditory signal or vibration) to the driver, thereby allowing the driver to confirm that the switching function was actuated. When the switch module is installed within the steering wheel, switching operation of the input switch module can be performed by a variety of actions by the driver, such as, for example, pressing the steering wheel forward or backward, or twisting the steering wheel leftward or rightward, while maintaining contact between the driver&#39;s hands and the steering wheel. 
         [0009]    In one aspect, the present invention provides a switch module built into the grip portion of a steering wheel that includes an input switch module having a force-torque sensor operated by total of seven (7) motions including: a push or pull motion, a brief pressing motion, a leftward or rightward torsional motion, and a wrapping motion in a left or right diagonal direction. Additionally, the switch module includes a feedback module for providing a feedback sensation (e.g. auditory signal or vibration) to the driver. 
         [0010]    In an exemplary embodiment, the switch module built into the grip portion of the steering wheel in accordance with the present invention may further include a controller that operates the feedback module by sensing an output signal that correlates to the operation of the input switch module. 
         [0011]    In another exemplary embodiment, the input switch module includes a first securing block fixed to a first transverse section of the grip portion of the steering wheel; a displaceable block torsionally displaceably mounted to the first securing block; a second securing block fixed to a second transverse section of the grip portion of the steering wheel; a six axis force-torque sensor located in between, and connected to, the displaceable block and the second securing block; and a plurality of input links connected to the displaceable block and the outer surface of the second securing block for applying a force or torque to the six axis force-torque sensor. The first and second transverse sections span the inner diameter and the outer diameter of the steering wheel, and are separated by a circumferential distance that corresponds approximately to the distance between the first and second securing blocks. 
         [0012]    In still another exemplary embodiment, a bonding substance of a flexible material is sandwiched between the first securing block and the displaceable block. 
         [0013]    In yet another exemplary embodiment, an input link may include a pair of hinge links and an elastic link, whereby a first end of the pair of hinge links is pivotally engaged in a slot formed at the outer surface of the displaceable block; and the second end of the pair of hinge links is pivotally engaged to a first end of the elastic link, while the second end of the elastic link is fixed to the outer surface of the second securing block. 
         [0014]    In still yet another exemplary embodiment, the displaceable block and the second securing block of the input switch module are integrally connected to each other by a connecting block, and a feedback module is installed within the connecting block. 
         [0015]    In a further exemplary embodiment, the feedback module is separately encased at a location in the grip portion of the steering wheel adjacent to the input switch module. 
         [0016]    In another exemplary embodiment, the feedback module is employed as a vibration motor to be vibrated upon receiving an operating signal from a controller. 
         [0017]    According to the present invention, an input switch module having a force-torque sensor and a feedback module may be installed within the steering wheel, such that operation of the installed input switch module may be performed by a variety of driver actions, such as, for example, pressing the steering wheel forward or backward, or twisting the steering wheel leftward or rightward. Accordingly, the invention allows driver to easily operate the input switch module while maintaining contact with the grip portion of the steering wheel, thereby allowing the driver to maintain safe control of the vehicle. Additionally, since a variety of switches may (e.g. AVN, HUD, or the like) be integrated within one input switch module, the invention makes it possible to easily and safely operate all of the switches, while simultaneously providing a neat appearance by removing the myriad of small, obtusely arranged switches typical of the conventional art. 
         [0018]    Furthermore, it should be appreciated that the driver can detect the completion of the switching operation because a vibration outputted from the feedback module is made after the switching operation has been input into the input switch module. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated in the accompanying drawings which are given herein below by way of illustration only, and thus are not limitative of the present invention, and wherein: 
           [0020]      FIG. 1  is a perspective view illustrating an input switch module in accordance with the present invention; 
           [0021]      FIG. 2  is a schematic view illustrating an exemplary installation location of an input switch module within a steering wheel in accordance with the present invention; 
           [0022]      FIG. 3  is a cross-sectional view illustrating an exemplary embodiment of the input switch module within a steering wheel in accordance with the present invention; and 
           [0023]      FIGS. 4 and 5  are cross-sectional views illustrating operational examples of the switch module built in the steering wheel in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Hereinafter, reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. While the invention will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is 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. 
         [0025]    It is understood that the term “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, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
         [0026]    As shown in  FIG. 1 , the input switch module  20  includes a first securing block  21 , a displaceable block  23 , a six axis force torque sensor  24 , a connecting block  28 , and a second securing block  22 . The first securing block  21  and the second securing block  22  secure the respective ends of the input switch module  20  within the steering wheel. The displaceable block  23  is torsionally displaceably mounted to the first securing block  21 . A bonding substance  26  may be sandwiched in between the first securing block  21  and the displaceable block  23 . The displaceable block  23  is connected to a connecting block  28  via a six axis force-torque sensor  24 , which is located in between the displaceable block  23  and the connecting block  28 . The connecting block  28  is connected to the second securing block  22 . A plurality of input links  25  are connected to the displaceable block  23  and the outer surface of the second securing block  22 , and function to apply a force or torque to the six axis force-torque sensor  24 . Each of the input links  25  includes a pair of hinge links  25 - 1  and an elastic link  25 - 2 . A first end  25 - 1 - 1  of the pair of hinge links  25 - 1  is pivotally engaged in a slot  27  formed at the outer surface of the displaceable block  23 , and the second end  25 - 1 - 2  of the pair of hinge links  25 - 1  is pivotally engaged to a first end  25 - 2 - 1  of the elastic link  25 - 2 , while the second end  25 - 2 - 2  of the elastic link  25 - 2  is fixed to the outer surface of the second securing block  22 . In the exemplary embodiment shown, there are four input links  25 : a front input link  25   a,  a rear input link  25   b,  a left input link  25   c,  and a right input link  25   d  (directions are relative to the position of the steering wheel with respect to the driver, e.g., the surface of the steering wheel facing the driver is considered the front). 
         [0027]    As shown in  FIG. 2 , the present invention has principal features in that an input switch module  20  having a six axis force-torque sensor  24  is installed within a grip portion  12  of a steering wheel  10  and at the same time, a feedback module  30  for providing a driver with a feeling of the switching operation is also disposed therein (see, e.g.,  FIG. 4 ). Hence, depending upon the driver&#39;s input to the input switch module  20  (such as, e.g., forward pressing, backward pressing, leftward pressing, rightward pressing, a twisting action of the grip portion, or the like), the switching output of the input switch module  20  within the grip portion  12  is generated, thereby activating the feedback module  30  and providing a feedback sensation (e.g. auditory signal or vibration) to the driver, confirming that the input switch module  20  was activated. 
         [0028]    In other words, the switching output of the input switch module  20  within the grip portion  12  is activated by, for example, seven motions, and the driver can confirm the switching operation by, for example, feeling a vibration as a feedback of the switching output. For example, the seven motions may include: a force by a pushing motion while holding the grip portion (a pressing motion, while pushing the front surface of the grip portion); a force by a pulling motion while holding the grip portion (a pressing motion, while pulling the rear surface of the grip portion); a force by a brief pressing motion through firmly grasping the entire grip portion; a force by a torsional motion through twisting the grip portion leftward; a force by a torsional motion through twisting the grip portion rightward; a force by a torsional motion through twisting the grip portion in a left diagonal direction (counterclockwise) while wrapping the grip portion; and a force by a torsional motion through twisting the grip portion in a right diagonal direction (clockwise) while wrapping the grip portion. 
         [0029]    Configurations of the input switch module  20  installed within the grip portion  12  of the steering wheel will be described hereinafter with reference to  FIGS. 2 and 3 . 
         [0030]    As shown in  FIG. 3 , a first securing block  21  of the input switch module  20  is fixed to a first transverse section “line a” of the grip portion  12 , while a second securing block  22  is fixed to a second transverse section “line b” of the grip portion  12 . In one exemplary embodiment, a displaceable block  23  may be torsionally displaceably mounted on the inner side surface of the first securing block  21  by a bonding substance  26  of a flexible material. 
         [0031]    In other words, since the bonding substance  26  of a flexible material is bonded at the boundary portion of the first securing block  21  and the displaceable block  23 , a torsional action of the displaceable block  23  can be obtained in a clockwise or counterclockwise direction with respect to the first securing block  21 . The inner side surface of the displaceable block  23  is integrally secured to the one side surface of the six axis force-torque sensor  24 , a hollow type connecting block  28  is integrally mounted at the inner side surface of the second securing block  22 , and the inner side surface of the connecting block  28  is integrally secured to the other side surface of the six axis force-torque sensor  24 . 
         [0032]    The six axis force-torque sensor  24  is employed as a conventional six axis force-torque sensor having a plurality of elastic beams (not shown), which are connected to the inner side surface of the displaceable block  23  and simultaneously connected to the inner side surface of the connecting block  28 . Each elastic beam of the six axis force-torque sensor  24  has a mechanically deformed characteristic such as, e.g., a torsion beam that is twisted with an elastic restoring force when any force or torque is applied thereto. 
         [0033]    A feedback module  30  may be installed within the connecting block  28 , in which the feedback module  30  may be employed, for example, as a vibration motor (not shown) that is subject to vibrate along with the switching output of the input switch module  20 . 
         [0034]    In another embodiment, the feedback module  30  may be installed inside of the grip portion  12  separate from the input switch module  20 . For example, the feedback module  30  may be separately installed within the grip portion  12  adjacent to either the first securing block  21  or the second securing block  22 , so as to promptly transfer a feedback sensation of the switch operation to the driver&#39;s hands. 
         [0035]    As shown in an exemplary embodiment of the invention in  FIG. 4 , a primary configuration for operating the input switch module  20  of the present invention includes a plurality of (e.g. four) input links  25  that are connected in the same spacing between the displaceable block  23  and the outer surface of the second securing block  22 . The input links  25  serve to deliver a force or torque according to the driver&#39;s operating forces to the six axis force-torque sensor  24 . The input links  25  include a pair of hinge links  25 - 1  that have a first end  25 - 1 - 1  pivotally engaged to a coupling end  29  integrally formed at the outer diameter surface of the displaceable block  23  by a hinge pin in a slot  27  of the coupling end  29 , and a second end  25 - 1 - 2  pivotally engaged to a first end  25 - 2 - 1  of an elastic link  25 - 2 , whose second end  25 - 2 - 2  is fixed to the outer diameter surface of the second securing block  22 . 
         [0036]    When the first end  25 - 2 - 1  end of the elastic link  25 - 2  pivotally engaged with the second end  25 - 1 - 2  of the hinge link  25 - 1  is pressed, the first end  25 - 2 - 1  of the elastic link  25 - 2  is twisted along the pressing direction about a fixed point, e.g., the second end  25 - 2 - 2  fixed to the second securing block  22 , accumulating the elastic restoration force therein. Meanwhile, the six axis force-torque sensor  24  is connected to the input side of a controller  40  for outputting a signal thereto, and a vibration motor employed as the feedback module  30  is connected to the output side of the controller  40 . 
         [0037]    Operations of the switch module built in the steering wheel of the present invention as constructed above will be described hereinafter. 
         [0038]    Referring to  FIG. 4 , if a driver makes a pressing motion by pushing the front surface of the grip portion  12  while holding the grip portion  12  of the steering wheel  10 , the front surface (the surface facing the driver) of the grip portion  12  is pressed, which applies a pressing force to a front input link  25   a  out of the four exemplary input links  25 . 
         [0039]    Hence, the elastic link  25 - 2  of the front input link  25 - 1  is pressed by accumulating the elastic force therein and simultaneously pushes the hinge link  25 - 1  toward the first securing block  21 . At the same time, the hinge link  25 - 1  is in a state to be translated toward the first securing block  21  along the slot  27  formed at the coupling end  29  of the displaceable block  23 . At this moment, the six axis force-torque sensor  24  connected with the displaceable block  23  detects the force generated when the hinge link  25 - 1  is being translated and outputs a signal to the controller  40 . 
         [0040]    In turn, the controller  40  sends operating signals to activate specific functions of the device such as, e.g., an AVN a HUD, or the like, and at the same time transfers an operating signal to the vibration motor employed as the feedback module  30 . The vibration motor then generates a vibration and the driver can feel a sensation of the switching operation by means of such a feedback vibration. 
         [0041]    As shown in  FIG. 4 , when the driver makes a pressing motion by pulling the rear surface of the grip portion  12  while holding the grip portion  12  of the steering wheel  10 , the rear surface of the grip portion  12  is pressed, which applies a pressing force to a rear input link  25   b  out of the four exemplary input links  25 . Hence, the same operations as those made when the front input link  25   a  is pressed are performed to activate another specific function of the device such as, e.g., an AVN, a HUD, or the like. 
         [0042]    Meanwhile, if the driver twists the grip portion  12  leftward or rightward while holding the grip portion  12  of the steering wheel  10 , i.e., makes a torsional motion by twisting the grip portion  12  leftward or rightward, the pressing force is applied to a left input link  25   c  or a right input link  25   d  out of the four exemplary input links  25 , respectively. Hence, the same operations as those made when the front input link  25   a  is pressed are performed to activate still another specific function of the device such as, e.g., an AVN, HUD, or the like. 
         [0043]    Referring to  FIG. 5 , when the driver makes a torsional motion by twisting the grip portion  12  in a left diagonal direction (clockwise) or in a right diagonal direction (counterclockwise) while wrapping the grip portion  12  of the steering wheel  10 , a torsional torque is applied to the hinge link  25 - 1  of each input link  25  and a torsional torque is simultaneously delivered to the displaceable block  23  connected to the hinge link  25 - 1 , such that a torsional action of the displaceable block  23  is achieved in a left or right direction about the bonding substance  26  of a flexible material. The six axis force-torque sensor  24  connected with the displaceable block  23  detects the torsional action of the displaceable block  23  and outputs a signal to the controller  40 , which activates yet another specific function of the device such as an AVN (Audio, Video, Navigation), a Head Up Display (HUD) or the like. 
         [0044]    Further, if the driver makes a brief pressing motion by firmly grasping the entire grip portion  12  while holding the grip portion  12  of the steering wheel  10 , the pressing force is simultaneously applied to four input links  25   a,    25   b,    25   c  and  25   d,  which activates still yet another specific function of the device which needs switch operations thereof. 
         [0045]    The invention has been described in detail with reference to exemplary embodiments thereof. However, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.