Patent Publication Number: US-2023137268-A1

Title: Independent Corner Module

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 10-2021-0145083, filed on Oct. 28, 2021, which application is hereby incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to an independent corner module. 
     BACKGROUND 
     A conventional suspension device of a vehicle prevents damage to a vehicle body or cargo and improves riding comfort by connecting an axle and the vehicle body to prevent vibration or a shock received from a road surface from being directly transmitted to the vehicle body when driving. The suspension device includes a suspension spring for absorbing an impact from the road surface, a shock absorber for improving riding comfort by attenuating free vibration of the suspension spring, and a stabilizer for suppressing a rolling of the vehicle. 
     As a suspension device applied to a commonly used vehicle, a solid axle suspension device in which left and right wheels are connected to each other by one axle is mainly used. Further, as a suspension spring, a leaf spring or an air spring is mainly used. 
     A steering device applied to the commonly used vehicle using the solid axle suspension device includes a pitman arm mounted on an output axis of a steering gear and configured to rotate, a drag link configured to transfer a movement of the pitman arm to a knuckle arm, the knuckle arm configured to operate a knuckle spindle by receiving the movement of the drag link, a tie-rod connecting left and right knuckle arms to each other, and so on. 
     As disclosed in  FIG.  1   , a suspension system in which a first end of the shock absorber is fixed to a vehicle body frame is illustrated. 
     In the vehicle using the air spring, the solid axle suspension device, and the steering device as described above, the air spring only performs a replacement of the leaf spring and does not significantly contribute to improving the riding comfort and steering characteristics. Further, due to structural characteristics, it is difficult to secure a design freedom to realize precise geometry. 
     In addition, an independent steering type suspension device in which a steering angle of a wheel is input to each of the suspension devices through a motor assembly has been recently developed. However, in the independent steering type suspension device as described above, there is a problem that a rotating force applied from a steering motor is difficult to be stably transferred to a knuckle and the wheel. In addition, when only a steering unit performing large steering is used, there is a problem that an interference with the vehicle body occurs. 
     Korean Patent Application Publication No. 10-2007-0103191 (published on Oct. 23, 2007) describes information related to the subject matter of the present disclosure. 
     SUMMARY 
     The present disclosure relates to an independent corner module. Particular embodiments relate to an independent corner module capable of applying wide ranges of a steering angle to a wheel by optionally or simultaneously driving a steering unit and a rack steering unit that are configured to input the steering angle to the wheel. 
     Accordingly, embodiments of the present disclosure have been made keeping in mind problems occurring in the related art, and an embodiment of the present disclosure provides an independent corner module that enables a steering driving unit and an axle gear portion to be independently rotated. 
     In addition, another embodiment of the present disclosure provides an independent corner module including a wheel to which a steering angle is applied by performing independent movements of a knuckle and a double wishbone knuckle. 
     Features of the present disclosure are not limited to the above features. Other and further features of the present disclosure should become apparent upon understanding of the various embodiments described below. Further, the features of embodiments of the present disclosure may be realized by means and combinations thereof indicated in the appended claims. 
     The independent corner module includes the following configurations. 
     Embodiments of the present disclosure may achieve the following effects from the embodiments and configurations described below, as well as combinations and relationships of use thereof. 
     In embodiments of the present disclosure, an effect that wider ranges of steering angle applied to a wheel are provided by independently rotating a steering unit and a rack steering unit. 
     In addition, since two kingpin axes are formed by providing different steering driving portions fastened to a knuckle unit, embodiments of the present disclosure have an effect that a stable behavior of the wheel is realized. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objectives, features, and other advantages of embodiments of the present disclosure will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a view of a conventional art illustrating a coupling relationship of a knuckle; 
         FIG.  2    is a perspective view illustrating an independent corner module according to an embodiment of the present disclosure; 
         FIG.  3    is a front view illustrating the independent corner module according to an embodiment of the present disclosure; 
         FIG.  4    is a view illustrating a coupling relationship of a lower arm, a steering frame, and a knuckle unit according to an embodiment of the present disclosure; 
         FIG.  5    is a bottom view illustrating the independent corner module according to an embodiment of the present disclosure; 
         FIG.  6    is a view illustrating two kingpin axes that are different from each other and that are configuring the independent corner module according to an embodiment of the present disclosure; 
         FIG.  7 A  shows an input of a steering angle through a rack steering unit of the independent corner module according to an embodiment of the present disclosure; 
         FIG.  7 B  shows an input of a steering angle through a steering unit of the independent corner module according to an embodiment of the present disclosure; and 
         FIG.  7 C  shows an input of a steering angle through both the rack steering unit and the steering unit of the independent corner module according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The present disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. In addition, the embodiments of the present disclosure are intended to fully describe the present disclosure to a person having ordinary knowledge in the art to which the present disclosure pertains. 
     In addition, the terms “ . . . knuckle”, “ . . . unit”, “ . . . portion”, “ . . . frame” and the like described herein may refer to a unit for processing at least one function or operation, and they may be implemented in hardware or a combination of hardware. 
     Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, like reference numerals indicate like or corresponding elements and redundant descriptions are omitted herein. 
     Embodiments of the present disclosure relate to an independent corner module. In a multi-wheel vehicle, the independent corner modules respectively fastened to wheels of a vehicle body may be included. Further, the independent corner module may be configured such that up to 90 degrees in left and right directions of a steering angle may be realized. More preferably, the independent corner module in which a steering unit  200  performing a large steering and a rack steering unit  300  performing a small steering are capable of independently inputting a steering angle thereof to a wheel  10  is provided. 
     Since the independent corner module can be fixed to the vehicle body, the independent corner module may be fastened to the vehicle body via welding, bolting coupling, or the like. Further, the independent corner module may be electrically connected to a battery positioned in the vehicle body so that electric power is capable of being applied to the steering unit  200  or the rack steering unit  300  from the vehicle body. As described above, the independent corner module may be configured such that the independent corner module is fastened to the vehicle body via a usual method and is also electrically connected to a vehicle. 
     Hereinafter, according to an embodiment of the present disclosure, the independent corner module including the wheel  10  positioned at a left side of the vehicle will be described. 
     In  FIGS.  2  and  3   , a perspective view and a front view of the independent corner module are illustrated as an embodiment of the present disclosure. 
     As illustrated in the drawings, the wheel  10  positioned at the outermost of the vehicle and a tire configured to cover the wheel  10  are included, and a knuckle unit  100  fastened to an inward area of the wheel  10  is provided. The knuckle unit  100  is configured such that the knuckle unit  100  is fixed to the vehicle body via an upper arm  510  positioned at an upper end of the knuckle unit  100  and a lower arm  520  positioned at a lower end of the knuckle unit  100 . More preferably, the knuckle unit  100  includes a knuckle no positioned at a first side adjacent to the wheel  10 , and a double wishbone knuckle  120  fastened such that the Knuckle no is capable of being rotated. Accordingly, the upper arm  510  and the lower arm  520  are fastened to the double wishbone knuckle  120 . 
     In an embodiment of the present disclosure, the wheel  10  may include an in-wheel motor (not illustrated), and a driving force of the vehicle may be applied to the wheel  10  through the in-wheel motor. 
     By a ball joint portion  130 , the knuckle no is fastened to the double wishbone knuckle  120  that is configured to surround an upper end of the knuckle no, and a lower end of the knuckle no is fixed by a lower link  600  such that a movement of the knuckle no in a width direction of the vehicle is restricted. Further, the double wishbone knuckle  120  is positioned between the upper arm  510  and the lower arm  520 , and is fastened to the vehicle body. The knuckle  110  is capable of being rotated with respect to the ball joint portion  130  that is fastened to the double wishbone knuckle  120 . 
     The steering unit  200  is positioned adjacent to a lower surface of the lower arm  520 , and is configured such that a second end of the steering unit  200  is rotated with respect to a first end of the lower arm  520  fastened to the knuckle unit wo, in response to a driving of a motor  210  that is positioned at the lower arm  520 . A steering frame  220  of the steering unit  200  that is rotated by the driving force of the motor  210  is configured such that a first end of the steering frame  220  is fastened to the double wishbone knuckle  120  together with the lower arm  520  and a second end of the steering frame  220  is formed in an arc shape. Therefore, the arc shape of the steering frame  220  facing the motor  210  is configured to be rotated according to the driving force of the motor  210 . In addition, the motor  210  includes a motor gear portion  230  provided at a rotary shaft of the motor  210 . Further, at a position where the steering frame  220  and the motor gear portion  230  are facing each other, a steering gear portion  240  positioned at a first end of the arc shape of the steering frame  220  is further included. 
     More preferably, at the first end where the lower arm  520  and the knuckle unit wo are fastened thereto, the lower arm  520 , the steering unit  200 , and the double wishbone knuckle  120  are fastened together through a joint unit  400 . The lower arm  520  and the steering unit  200  that are fastened by the joint unit  400  are configured to be independently rotated around the joint unit  400 . Therefore, when the steering frame  220  is rotated together with the double wishbone knuckle  120  by the motor  210  that is fastened to the one end of the lower arm  520 , the lower arm  520  maintains a fixed state. 
     When a steering input is applied to the wheel  10  via the steering unit  200 , the knuckle unit wo is configured to be rotated together with the steering unit  200  around a position where the knuckle unit wo is fastened to the lower arm  520  and the upper arm  510 . More preferably, when the first end of the arc shape of the steering frame  220  is rotated with respect to the joint unit  400 , the knuckle unit wo is configured to be rotated in an opposite direction to the steering frame  220  with respect to the joint unit  400 . That is, the upper arm  510  and an upper end of the double wishbone knuckle  120  may be fastened to each other to limit a vertical movement while the double wishbone knuckle  120  is in a rotatable state. Further, the steering frame  220  and the double wishbone knuckle  120  are fastened to each other, and are configured to be rotatable with respect to the joint unit  400  independently of the lower arm  520 . 
     The rack steering unit  300  is positioned at a lower end of the steering frame  220  of the steering unit  200 , and a second end of the rack steering unit  300  is fastened to the knuckle unit  100 . More preferably, the rack steering unit  300  includes a rack rod  320 . The rack rod  320  is fastened to the knuckle unit  100 , and is configured to apply force to the knuckle unit  100  toward the width direction of the vehicle in response to a driving of a rack motor  310 . The rack rod  320  is fastened to a lower end of the knuckle no at a position eccentric to a first side with respect to a center of a longitudinal direction of the knuckle no. Since the rack rod  320  is eccentrically fastened to the knuckle no and the rack rod  320  is configured such that a length of the rack rod  320  is varied according to the driving of the rack motor  310 , the knuckle no is configured to be rotated with respect to the double wishbone knuckle  120  in response to a change in the length of the rack rod  320 . 
     In addition, two lower links  600  are fastened to the lower end of the knuckle no to which the rack rod  320  is fastened. Further, second ends of the lower links  600  are fastened to a lower surface of the steering frame  220 . The lower links  600  prevent the lower end of the knuckle  110  from being moved in the width direction of the vehicle in response to the change in the length of the rack rod  320 , and are configured to enable the knuckle no to be rotated according to the change in the length of the rack rod  320 . More preferably, in response to the change in the length of the rack rod  320 , the knuckle no is configured to be rotated along a virtual contact point of extended tangential lines of two lower links  600  in a longitudinal direction. 
     In addition, a push rod  700  having a first end thereof positioned in a top surface of the lower arm  520  and having a second end thereof fastened to a shock absorber  900  through a crank  800  is included. The push rod  700  is configured to absorb shocks in a vertical direction and a width direction and to transfer the shocks to the crank  800 , and is configured to transfer the shocks to the shock absorber  900  that is fastened to the crank  800 . 
     Accordingly, in embodiments of the present disclosure, the steering angle can be input to the wheel  10  without a rotation of the knuckle. Further, a dual steering structure capable of independently inputting the steering angle via a rotation of the knuckle no by using the rack steering unit  300  is provided. 
     In  FIG.  4   , a structure in which the double wishbone knuckle  120 , the lower arm  520 , and the steering frame  220  are fastened to each other by the joint unit  400  is illustrated. 
     Since the joint unit  400  may be configured of a universal joint, an upper end portion  410  of the universal joint is positioned at and fastened to the double wishbone knuckle  120 , and a rotary shaft portion  420  of the universal joint including a rotary shaft penetrates through the lower arm  520  and is fastened to the steering frame  220 . The upper end portion  410  of the universal joint penetrates through the lower arm  520 , and is fastened to the rotary shaft portion  420  of the universal joint. Further, since the steering frame  220  may be configured to be rotated around the rotary shaft portion  420  independently of the lower arm  520 , the lower arm  520  may be in a state of being fixed to the vehicle body when the steering gear portion  240  of the steering frame  220  is rotated by the motor gear portion  230  of the motor  210 . 
     That is, when the motor gear portion  230  is rotated in response to the driving of the motor  210  and the steering gear portion  240  is rotated integrally with the steering frame  220 , the double wishbone knuckle  120  where the upper end portion  410  of the universal joint is fixed to and positioned on is rotated integrally with the steering frame  220 , and the rotary shaft portion  420  of the universal joint is configured to be rotated along a penetrating hole of the lower arm  520 . That is, when the steering frame  220  is rotated around the joint unit  400  as a central axis, the double wishbone knuckle  120  including the upper end portion  410  of the universal joint is configured to be rotated with respect to the penetrating hole of the lower arm  520 . 
     Therefore, in response to the driving of the steering unit  200 , a position of the lower arm  520  is fixed, and the steering frame  220  is configured to be rotated integrally with the double wishbone knuckle  120  according to the motor  210  that is positioned at the lower arm  520 . 
     In  FIG.  5   , a bottom surface of the independent corner module including two lower links  600  is illustrated. 
     As illustrated in the drawing, it is illustrated in that each of a first end of the lower links  600  is positioned at the steering frame  220  and two lower links  600  are fastened to the lower end of the knuckle no while being spaced apart from each other by a predetermined distance. 
     The lower links  600  are positioned between the steering frame  220  and the knuckle no, and are configured to fix the lower end of the knuckle no in response to the driving of the rack steering unit  300  and to guide the change in the steering angle of the knuckle no at the same time. In addition, as an embodiment of the present disclosure, two lower links  600  may be configured to be spaced apart from each other by the predetermined distance, and the two lower links  600  are configured to guide the amount of rotation and a rotating direction of the knuckle no. 
     That is, when the rack rod  320  extends in the longitudinal direction thereof, a first end where the lower link  600  positioned adjacent to the rack rod  320  and the knuckle no are facing each other is rotated in a direction toward a lower end of the drawing, and a first end where the lower link  600  positioned away from the rack rod  320  and the knuckle no are facing each other is also rotated in the direction toward the lower end of the drawing. Therefore, a steering angle having a left direction in the drawing is input to the knuckle no. 
     In contrast, when the rack rod  320  is retracted in the longitudinal direction thereof, the first end where the lower link  600  positioned adjacent to the rack rod  320  and the knuckle no are facing each other is rotated in a direction toward an upper end of the drawing, and the first end where the lower link  600  positioned away from the rack rod  320  and the knuckle no are facing each other is also rotated in the direction toward the upper end of the drawing. Therefore, a steering angle having a right direction in the drawing is input to the knuckle no. 
     Accordingly, in response to the longitudinal displacement of the rack rod  320 , the lower links  600  rotatably fastened to the steering frame  220  are rotated to a predetermined position, and the wheel  10  is also rotated in response to a turning radius of each of the lower links  600 , thereby applying the steering angle to the knuckle no. 
     In addition, since the lower links  600  are rotatably fastened to both the steering frame  220  and the knuckle no, the steering angle applied through the rack steering unit  300  may be set according to the amount of permissible rotation of the lower links  600  when the knuckle  110  is rotated. 
     That is, a tension in the width direction of the vehicle is applied to the first end of the knuckle  110  according to the longitudinal displacement of the rack rod  320 , and the knuckle no is rotated along a contact point of virtual extension lines of two lower links  600 , so that the steering angle is set. 
     In addition, as illustrated in  FIG.  6   , the contact point of the virtual extension lines of two lower links  600  set a lower end center point of a first kingpin axis A. 
     In  FIG.  6   , the first kingpin axis A that corresponds to a steering input driven through the rack steering unit  300  and a second kingpin axis B that corresponds to a steering input driven through the steering unit  200  are illustrated. 
     As illustrated in the drawing, the kingpin axis is an axis connecting center points of the upper end and the lower end of the knuckle unit  100  that is rotated in response to the steering input, and is determined to reduce both a torque of a steering wheel and a road surface reaction force and to provide a steering wheel restoration torque. 
     In embodiments of the present disclosure, the knuckle no driven through the rack steering unit  300  includes the first kingpin axis A that is formed by connecting a ball joint portion  130  at the upper end to the contact point of virtual extension lines of two lower links  600 , and includes the second kingpin axis B formed at the upper and lower ends of the double wishbone knuckle  120  that is positioned between the lower arm  520  and the upper arm  510 . More preferably, the second kingpin axis B formed between one end where the upper arm and the double wishbone knuckle are fastened to each other and a second end where the lower arm and the double wishbone knuckle are fastened to each other. 
     Compared to the second kingpin axis B, the first kingpin axis A is configured such that an offset C thereof is relatively small, so that the first kingpin axis A desensitizes the vehicle from disturbances such as a rotational moment generated on the first kingpin axis A by a braking force, a kickback situation caused by an external force transferred from a road surface, and the like, thereby improving driving stability. 
     In comparison, the second kingpin axis B has a relatively large offset C of the wheel  10  compared to the offset C of the first kingpin axis A, and the steering of the knuckle unit  100  is performed on the basis of the second kingpin axis B through the steering unit  200 . 
     Accordingly, in embodiments of the present disclosure, the first kingpin axis A is formed so that the steering angle is applied to the wheel  10  through the rack steering unit  300 , and the second kingpin axis B is formed so that the steering angle is applied to the wheel  10  through the steering unit  200 , thereby performing the rotation of the knuckle unit  100 . 
     In addition, under a condition for providing the driving stability, it may be configured such that the steering angle is applied to the wheel  10  by using the first kingpin axis A. Further, under a condition for performing large steering, the steering angle is applied to the wheel  10  by using the steering unit  200  including the second kingpin axis B. 
     In  FIG.  7 A , as an embodiment of the present disclosure, top views of the independent corner module in which a steering angle is applied through the rack steering unit  300  are illustrated. 
     As illustrated in the drawing, the rack rod  320  of the rack steering unit  300  is configured such that the length thereof extends or retracts in response to the driving force of the rack motor  310 . More preferably, the rack rod  320  is configured such that the length of the rack rod  320  that is positioned between the rack motor  310  and the knuckle no is varied in response to the driving of the rack motor  310 . 
     In addition, the rack rod  320  is positioned at the lower end of the first side eccentric from the knuckle no of the knuckle unit  100 . Therefore, when the rack motor  310  retracts the length of the rack rod  320 , the first side end of the knuckle no fastened to the rack rod  320  is moved toward a position adjacent to a center of the vehicle, and a second side end of the knuckle no is moved toward a position away from the center of the vehicle. Through this, the knuckle no is rotated in response to the longitudinal displacement applied from the rack rod  320 . 
     In addition, when the knuckle no is moved in response to the longitudinal displacement of the rack rod  320 , the lower links  600  prevent the lower end of the knuckle no from moving away toward the width direction of the vehicle, and the lower links  600  guide the change in the steering angle of the knuckle  110 . 
     As a result, the knuckle no is rotated in response to the longitudinal displacement of the rack rod  320 , and also two lower links  600  fastened to the knuckle no are configured to guide the rotating direction of the knuckle  110 , so that the steering angle is applied to the knuckle unit  100 . 
     In comparison,  FIG.  7 B  shows the driving of the steering input in which the knuckle unit  100  is integrally rotated through the steering unit  200 . 
     As illustrated in the drawing, the motor  210  positioned at the lower arm  520  and fastened to the steering frame  220  is included, and the first end of the arc shape of the steering frame  220  where the steering gear portion  240  is positioned is moved along the motor gear portion  230  in response to the driving of the motor  210 . When the steering frame  220  is rotated, the knuckle unit  100  fastened to the steering frame  220  is integrally rotated through the joint unit  400 . In addition, the lower arm  520  is positioned between the knuckle unit  100  and the steering frame  220 , and is fastened to the joint unit  400  such that the lower arm  520  is independently positioned in response to the rotation of the steering frame  220 . 
     Therefore, when the steering frame  220  is rotated according to the driving of the motor  210 , the steering frame  220  is rotated with respect to the double wishbone knuckle  120  integrally with the double wishbone knuckle  120 , so that the steering angle is applied to the wheel  10 . 
     In addition,  FIG.  7 C  shows the driving of the independent corner module in which the steering unit  200  and the rack steering unit  300  are simultaneously providing the steering angle to the wheel  10 . 
     As illustrated in  FIG.  7 B , the steering frame  220  is rotated by the motor  210 , and is rotated around the joint unit  400  simultaneously with the double wishbone knuckle  120 . At the same time, the steering angle is input through the rack steering unit  300  along the contact point of the ball joint portion  130  and the lower links  600 . 
     In addition, since the motor  210  of the steering unit  200  and the rack motor  310  of the rack steering unit  300  are capable of being sequentially or simultaneously driven, up to 90 degrees to −90 degrees may be input to the wheel  10 . 
     As illustrated in  FIGS.  7 A to  7 C , the input of the steering angle to the wheel  10  may be performed by independently or simultaneously driving the rack steering unit  300  and the steering unit  200 . In addition, when the steering is performed under a driving condition of the vehicle, the steering through the rack steering unit  300  capable of inputting the steering angle through the first kingpin axis A may be performed early. Further, in response to a steering request exceeding the range of the steering angle of the rack steering unit  300 , an additional input of the steering angle of the steering unit  200  may be performed. 
     The foregoing detailed description is for illustrative purposes only. Further, the description provides embodiments of the present disclosure and the present disclosure may be used in other various combinations, changes, and environments. That is, the present disclosure may be changed or modified within the scope of the present disclosure described herein, a range equivalent to the description, and/or within the knowledge or technology in the related art. The embodiment shows an optimum state for achieving the spirit of the present disclosure and may be changed in various ways for the detailed application fields and use of the present disclosure. Therefore, the detailed description of the present disclosure is not intended to limit the present disclosure in the embodiments. Further, the claims should be construed as including other embodiments.