Patent Publication Number: US-2023148013-A1

Title: Off-Road Vehicle

Description:
RELATED APPLICATION INFORMATION 
     The present application is a continuation of PCT/CN2021/121822 filed Sep. 29, 2021. The entire contents of the above-referenced application are incorporated herein by reference. 
    
    
     FIELD OF THE DISCLOSURE 
     The disclosure relates to the technical field of off-road vehicles. 
     BACKGROUND OF THE DISCLOSURE 
     Off-road vehicles are designed for use on various types of rough terrain, rather than just on pavement. Off-road vehicles can also be used for sporting (on or off pavement), as well as for freight transportation. Off-road vehicles have a broad market due to their comprehensive functions. A four wheeled off-road vehicle basically includes a frame, a front suspension assembly, a rear suspension assembly, two front wheels and two rear wheels. The front suspension assembly is mounted at the front end of the frame, and the rear suspension assembly is mounted at the rear end of the frame. The front suspension assembly and the rear suspension assembly jointly provide shock absorption to the front and rear ends of the frame to improve the comfort of the driver and any passengers in the off-road vehicle. The front wheels are mounted on the front suspension assembly, and the rear wheels are mounted on the rear suspension assembly. The front suspension assembly may generally include a front torsion bar, which generates a reaction force on an opposing side of the front suspension assembly after a force is applied to one of the front wheels. The reaction force helps maintain the front wheels at substantially the same height, to prevent the vehicle from leaning and to assist the steering of the vehicle at the same time. However, existing installation positions and layouts of front torsion bars cause the reaction force generated by the front torsion bar to be delivered more indirectly and slowly than ideal. The indirect and delayed application of the reaction force damages the stability of the off-road vehicle. 
     SUMMARY OF THE DISCLOSURE 
     An off-road vehicle with good stability and smooth running is provided to solve the above problems. 
     An off-road vehicle includes a frame, front and rear wheels, a front suspension assembly and a rear suspension assembly. The frame can be viewed as having a front frame portion located at the front end of the off-road vehicle and a rear frame portion located at the rear end of the off-road vehicle. The front wheels include a left-front wheel and a right-front wheel. The rear wheels include a left-rear wheel and a right-rear wheel. The front suspension assembly is mounted on the front frame portion, with each side including a lower rocker arm, an upper rocker arm, a front shock absorber, and a front wheel shaft support assembly disposed between the lower rocker arm and the upper rocker arm. The rear suspension assembly is mounted on the rear frame portion, with each side including a lower rocker arm, an upper rocker arm, a control arm, a rear shock absorber, and a rear wheel shaft support assembly disposed between the rear lower rocker arm and the rear upper rocker arm. Both the front suspension assembly and the rear suspension assembly further include a torsion bar assembly. The front torsion bar assembly is rotatably mounted on the front frame portion and at least partially located above the front upper rocker arms and movably connected by links to the front upper rocker arms. The rear control arms are at an elevation between the lower and upper rear rocker arms, with one end of the control arm rotatably connected to the rear wheel shaft support assembly, and the other end rotatably connected to the rear frame portion. The rear torsion bar assembly is located between the lower and upper rear rocker arms, movably connected to the rear upper rocker arms. Each torsion bar assembly includes a torsion bar and two mounting seats fixed on the frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front perspective view of an off-road vehicle according to a preferred embodiment of the disclosure. 
         FIG.  2    is a front perspective view of the body and roll cage structure of the vehicle of  FIG.  1   . 
         FIG.  3    is a rear perspective view of the body structure of the vehicle of  FIG.  1   . 
         FIG.  4    is a mostly side, slightly in perspective view of the frame structure of the vehicle of  FIG.  1   . 
         FIG.  5    is an opposing side, more from above, perspective view of the frame of  FIG.  4   . 
         FIG.  6    is a perspective view from below of the frame of  FIGS.  4  and  5   . 
         FIG.  7    is an enlarged view of part A in  FIG.  6   . 
         FIG.  8    is a side schematic view of the preferred middle frame portion. 
         FIG.  9    is a perspective view of a selected portion of the frame of  FIGS.  4 - 6    from another point of view. 
         FIG.  10    is an enlarged view of part B in  FIG.  9   . 
         FIG.  11    is a rear perspective view of the front suspension assembly of the vehicle of  FIG.  1   . 
         FIG.  12    is a front perspective view of the front suspension assembly of  FIG.  11   . 
         FIG.  13    is a perspective view of the preferred front supporting plate . 
         FIG.  14    is a front perspective view of the rear suspension assembly of the vehicle of  FIG.  1   . 
         FIG.  15    is a side view of the rear suspension assembly of  FIG.  14   . 
         FIG.  16    is a side view of structure of the preferred left-rear wheel shaft support. 
         FIG.  17    is a rear perspective view of the rear suspension assembly of  FIGS.  14  and  15   . 
         FIG.  18    is an enlarged view of part C in  FIG.  17   . 
         FIG.  19    is a rear perspective view of a left portion of the rear suspension assembly in another embodiment. 
         FIG.  20    is a cross-sectional view of the rear suspension assembly of  FIG.  19   . 
         FIG.  21    is a perspective view of the state of the rear wheels when the control arm is at the lowest position of rear suspension travel. 
         FIG.  22    is a perspective view of the state of the rear wheels when the control arm is at the highest position of rear suspension travel. 
         FIG.  23    is a schematic view showing the distribution of electrical components on the off-road vehicle of  FIG.  1   . 
         FIG.  24    is a perspective view of the improved mode switch. 
         FIG.  25    is a cross-sectional view of the mode switch of  FIG.  24   . 
         FIG.  26    is a schematic side view of the plunger ball slots of the mode switch of  FIGS.  24  and  25   . 
         FIG.  27    is a schematic side view calling out the angular relationships of  FIG.  26   . 
         FIG.  28    is a cross-sectional view of the connection between the mode switch and the butt connection socket. 
         FIG.  29    is an enlarged view of part D in  FIG.  28   . 
         FIG.  30    is a partially side, partially schematic view of the preferred electrical terminal assembly as connected into the electrical system of  FIG.  23   . 
         FIG.  31    is a side view of the electrical terminal assembly of  FIG.  30    with the cover on. 
         FIG.  32    is an exploded perspective view of the electrical terminal assembly of  FIGS.  30  and  31   . 
         FIG.  33    is a schematic side view of an electrical terminal assembly according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     For better understanding of the above objects, features and advantages of the present disclosure, the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the following description, numerous details are set forth in order to for better understanding of the present disclosure. However, the present disclosure may be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the teachings of the present disclosure. Therefore, the present invention is not limited by specifics of the embodiments disclosed below. 
       FIG.  1    shows an off-road vehicle  100 , which may be used for travel on a wide variety of unpaved surfaces including beaches, hillsides and deserts. The general orientations of front, rear, up (upper), down (lower), left and right for the off-road vehicle  100  are defined in  FIG.  1   . The off-road vehicle  100  includes a frame assembly  11 , a front suspension assembly  15 , a rear suspension assembly  16 , two front wheels  17 , and two rear wheels  18 . The frame assembly  11  is used for carrying and connecting various components on the off-road vehicle  100  and bearing various loads from inside and outside the vehicle. The front suspension assembly  15  is disposed toward the front of the off-road vehicle  100  and is mounted on the frame assembly  11 . The front suspension assembly  15  is connected to the front wheels  17  so as to deliver forces from the front wheels  17  to the frame assembly  11 . The rear suspension assembly  16  is disposed toward the rear of the off-road vehicle  100 , and is mounted on the frame assembly  11 . The rear suspension assembly  16  is connected to the rear wheels  18  so as to deliver forces from the rear wheels  18  to the frame assembly  11 . The front suspension assembly  15  and the rear suspension assembly  16  collectively are capable of buffering impact forces from uneven surfaces over which the vehicle  100  travels to the frame assembly  11  and other components, so as to reduce vibration, thereby ensuring that the off-road vehicle  100  is able to run smoothly and stably. 
     The frame assembly  11  preferably includes a frame  111  and a vehicle body  112 , with the front suspension assembly  15  and the rear suspension assembly  16  respectively mounted on the front and rear ends of the frame  111 . The vehicle body  112  is mounted on the frame  111  and covers at least part of the frame  111 , so as to protect various parts and components on the vehicle  100  and improve the aesthetics of the vehicle  100 . The preferred layout of the vehicle  100  defines a driving place for the driver and a place for accommodating a passenger in a side-by-side arrangement, as well as a place to carry cargo. 
     Referring to  FIG.  4   , the frame  111  can be conceptually divided into a front frame portion  1111 , a middle frame portion  1112 , and a rear frame portion  1113 . The front frame portion  1111  carries components such as the front suspension assembly  15 , headlights, water tanks, and the like. The rear frame portion  1113  carries components such as the rear suspension assembly  16 , taillights and other components. The middle frame portion  1112  extends between the front frame portion  111  and the rear frame portion  113  and defines an accommodating space  111   a  for a cabin  1121 . The cabin  1121  serves as a cockpit for drivers and/or passenger compartment for passengers. 
     As further shown in  FIGS.  6  to  8   , the middle frame portion  1112  includes horizontal beams  1112   a  and sloping beams  1112   b . The horizontal beams  1112   a  and the sloping beams  1112   b  are interconnected to substantially form a load bearing structure. In one embodiment, the number of horizontal beams  1112   a  may be greater than one, and a plurality of the horizontal beams  1112   a  may be spaced apart and substantially located on the same plane. The number of sloping beams  1112   b  may also be greater than one, and a plurality of the sloping beams  1112   b  may be arranged between the plurality of the horizontal beams  1112   a  at intervals. It should be noted that the number of the horizontal beams  1112   a  may be two, three, four, or the like. Similarly, the number of the sloping beams  1112   b  may be two, three, four, or the like, i.e., the numbers of horizontal beams  1112   a  and sloping beams  1112   b  may be selected to correspond to the particular design objectives. 
     In this embodiment, the horizontal beams  1112   a  include a front cross beam  1112   c   and a rear cross beam  1112   d , and the front cross beam  1112   c  and the rear cross beam  1112   d  are substantially located at the same elevation in the same plane S. The sloping beams  1112   b  include a right longitudinal beam  1112   e  and a left longitudinal beam  1112   h . The right longitudinal beam  1112   e  may be provided to the right and the left longitudinal beam  1112   h  may be provided to the left of the longitudinal center line of the off-road vehicle  100 . The right longitudinal beam  1112   e  preferably includes a leading rod  1112   f  and a trailing rod  1112   g . The left longitudinal beam  1112   h  preferably includes a leading rod  1112   i  and a trailing rod  1112   j . One end of each leading rod  1112   f ,  1112   i  is connected to the front cross beam  1112   c , and the other end of each leading rod  1112   f ,  1112   i  extends toward the rear cross beam  1112   d . An angle between each leading rod  1112   f ,  1112   i  and the plane S is defined in  FIG.  8    as A1, and A1 is preferably in the range from 5° to 15°. One end of each trailing rod  1112   g ,  1112   j  is connected to the rear cross beam  1112   d , and the other end of each trailing rod  1112   g ,  1112   j  extends toward the front cross beam  1112   c  and is connected to the corresponding leading rod  1112   f ,  1112   i . An angle between the trailing rod  1112   g  and the plane S is defined in  FIG.  8    as A2, and A2 is preferably in the range from 5° to 15°, so that the bottom of the middle frame portion  112  is raised upwardly away from the horizontal plane and defines a peak. The distance of the off-road vehicle  100  from the underlying ground is increased under a central portion of the frame  111 , so that the ability of the off-road vehicle  100  to traverse over obstacles is effectively improved. 
     In one embodiment, the angle A1 is larger than the angle A2, locating the peak forward of the midpoint between the front cross beam  1112   c  and the rear cross beam  1112   d . The horizontal beams  1112   a  and the sloping beams  1112   b  are preferably made of steel pipes, which are readily commercially available and are easily processed. The leading rods  1112   f ,  1112   i  may be welded or otherwise attached to the front cross beam  1112   c , and the trailing rods  1112   g ,  1112   j  may be welded or otherwise attached to the rear cross beam  1112   d . The leading rods  1112   f ,  1112   i  may be welded or otherwise attached to the trailing rods  1112   g ,  1112   j . Alternatively, other connection methods may be used. The leading rods  1112   f ,  1112   i  of the sloping beams  1112   b  are preferably parallel to each other, and the trailing rods  1112   g ,  1112   j  of the sloping beams  1112   b  are preferably arranged parallel to each other. 
     As also called out in  FIGS.  6  and  7   , the middle frame portion  1112  preferably includes at least two longitudinal reinforcement pipes  1112   k  and a plurality of cross reinforcement pipes  11121 . In the most preferred embodiment shown, the middle frame portion  1112  includes two longitudinal reinforcement pipes  1112   k  spaced apart with the sloping beams  1112   b  between the two longitudinal reinforcement pipes  1112   k . One end of each longitudinal reinforcement pipe  1112   k  is fixed on the front cross beam  1112   c , and the other end is fixed on the rear cross beam  1112   d . Each cross reinforcement pipe  11121  is connected between one of the sloping beams  1112   b  and the corresponding longitudinal reinforcement pipe  1112   k . Thus, the longitudinal reinforcement pipes  1112   k , the cross reinforcement pipes  11121 , the horizontal beams  1112   a  and the sloping beams  1112   b  together form a mesh-like structure, which effectively improves the structural strength and bearing capacity of the entire middle frame portion  1112 . 
     Referring back to  FIGS.  4  and  5   , the front frame portion  1111  preferably further includes two first pillars  1111   h  commonly called A-pillars, and the rear frame portion  1113  preferably further includes two second pillars  1113   a  commonly called B-pillars. The A-pillars  1111   h  and the B-pillars  1113   a  are used for bearing, supporting the vehicle, and protecting drivers and passengers. A bottom end of each A-pillar  1111   h  preferably connects to the front cross beam  1112   c , with the A-pillar  1111   h  extending upwardly therefrom. A bottom end of each B-pillar  1113   a  preferably connects to the rear cross beam  1112   d , with the B-pillar  1113   a  extending upwardly therefrom. 
     As called out in  FIGS.  4 ,  5 ,  9  and  10   , the preferred embodiment includes two reinforcement structures  1114  arranged between the rear frame portion  1113  and the middle frame portion  1112  to improve the connection strength between the rear frame portion  1113  and the middle frame portion  1112 . Each reinforcement structure  1114  preferably includes a first reinforcement rod  1114   a , a second reinforcement rod  1114   b  and a reinforcement plate  1114   c . Each first reinforcement rod  1114   a  is connected between one of the longitudinal reinforcement pipes  1112   k  and one of the B-pillars  1113   a . Each second reinforcement rod  1114   b  is connected between one of the B-pillars  1113   a  and a support bracket  1113   y . Each reinforcement plate  1114   c  is connected to both the first reinforcement rod  1114   a  and the second reinforcement rod  1114   b , extending outside its B-pillar  1113   a . Forces applied to the B-pillars  1113   a  by the first reinforcement rod  1114   a  and the second reinforcement rod  1114   b  are distributed by the reinforcement plate  1114   c , avoiding processes such as drilling holes in the two B-pillars  1113   a , thereby reducing the possibility of local deformation of the B-pillars  1113   a . Other structures may alternatively or additionally be used to connect the A- and B- pillars, cross beams and/or longitudinal beams. 
     Connections for the reinforcement structure may be by welding. The reinforcement plate  1114   c  may be integrally formed by stamping. Ends of the reinforcement plate  1114   c  preferably include reinforcement pieces  1114   d  abutting against and increasing the contact area between the reinforcement plate  1114   c  and the first reinforcement rod  1114   a  and the second reinforcement rod  1114   b , thereby improving the connection strength between the reinforcement plate  1114   c  and the first reinforcement rod  1114   a  and the second reinforcement rod  1114   b . 
     Referring back to  FIGS.  2  and  3   , the vehicle body  112  preferably includes interior trim  1122  and exterior trim  1123 . The interior trim  1122  is arranged on the frame  111 , and a cabin  1121  is defined by the frame  111  and the interior trim  1122 . That is to say, the interior trim  1122  is disposed around the cabin  1121 . Drivers and passengers may enter and exit the cabin  1121  through an opening  1121   a  on the sides of the off-road vehicle  100 . Exterior trim  1123  located at the front end, the rear end, and the side edges of the frame  111  shields and protects the front suspension assembly  15 , the rear suspension assembly  16 , various electrical devices, and the like. 
     The interior trim  1122  preferably includes a front baffle  1122   a , an instrument panel  1122   b , footrest  1122   c , a rear baffle  1122   d , and one or a plurality of seats  1122   f . The front baffle  1122   a  is disposed close to the front end of the off-road vehicle  100  to separate the various components at the front end of the off-road vehicle  100  from the cabin  1121 , and to block stones, sediment, and water. The instrument panel  1122   b  carries various instrument devices, such as a display screen, a dashboard, and the like on the vehicle. The footrest  1122   c  is mounted at the bottom of the accommodating space  111   a , and may be used as a plate to carry various components such as seats  1122   f , and as a position where the feet of the drivers or passengers are placed. The rear baffle  1122   d  is disposed close to the rear end of the off-road vehicle  100  and separates the various components at the rear end of the off-road vehicle  100  from the cabin  1121 . The rear baffle  1122   d  and the front baffle  1122   a  are spaced apart, with the footrest  1122   c  extending between the front baffle  1122   a  and the rear baffle  1122   d . Therefore, the cabin  1121  is defined by the front baffle  1122   a , the footrest  1122   c  and the rear baffle  1122   d . 
       FIGS.  11  and  12    show the front suspension assembly  15 , each right and left side of which preferably includes a lower rocker arm  151 , an upper rocker arm  152 , a front wheel shaft support assembly  153 , and a front shock absorber assembly  154 . Inner ends of the lower rocker arm  151  and the upper rocker arm  152  are respectively mounted on the vehicle frame  111 , with the upper rocker arm  152  above the lower rocker arm  151 . Each front wheel shaft support assembly  153  is used to connect one of the front wheels  17  and extends between the lower rocker arm  151  and the upper rocker arm  152 . The lower rocker arm  151  and the upper rocker arm  152  are respectively rotatably connected to the front wheel shaft support assembly  153 . One end of the front shock absorber  154  is preferably mounted on the first upper rocker arm  152 , and the other end may be connected to the frame  111  or other components to buffer and filter the shock caused by vibration of the front wheel  17 . A front torsion bar assembly  155 , preferably located above the upper rocker arms  152 , is rotatably connected between the upper rocker arms  152 . The front torsion bar assembly  155  includes a front torsion bar  1551  which rotates within mounting seats  1552  connected to the frame  111 . Ends of the front torsion bar  1551  are connected to the upper rocker arms  152  by connecting rods  1553 . The connections between the connecting rods  1553  and both the torsion bar  1551  and the upper rocker arms  152  may use ball pins, or alternatively may use bearings or other connection structure. When the front wheels  17  are forced upwardly, the upper rocker arm  152  lifts up and compresses the front shock absorber  154 , so that vibration may be absorbed and filtered by the front shock absorber  154 . At the same time, when the first upper rocker arm  152  is forced upward, the front torsion bar  1551  is driven by the upper rocker arm  152  through the connecting rod  1553  to rotate within its mounting seat  1552 . When the right front wheel  17  is forced upward more than the left front wheel  17  (or vice versa), the front torsion bar  1551  twists applying a vertical reaction force to the opposing upper rocker arm  152 . The front torsion bar assembly  155  thereby helps to resist swaying of the off-road vehicle  100  during turning and helps keep the front wheels  17  in better contact with the ground. Thus, the overall handling performance is effectively improved, the stability of the vehicle body  112  is ensured and the inclination angle of the vehicle body  112  is reduced when the vehicle is cornering at high speed. Secondly, the direct connection of the front torsion bar assembly  155  with the upper rocker arm  152  delivers forces more directly for faster response. 
     The lower rocker arm  151  preferably includes a first rocker  1512  and a second rocker  1513  both joined to a connecting base  1514 . The connecting base  1514  is mounted to the wheel shaft support  153  by one or more fasteners such as bolts and screws. The first rocker  1512  is preferably arc-shaped and arched upward, as is the second rocker  1513 . The arc-shape may be capable of not only bearing a greater force, but also exerting a greater downward pressure on the wheel shaft support  153  when the wheel shaft support  153  moves upward, thereby ensuring the driving stability of the wheel  17 . An angle may be defined between the second rocker  1513  and the first rocker  1512 . 
     In the preferred embodiment, the structure, shape and the connection method of the first rocker  1512  may be the same in principle as the second rocker  1513 , thereby facilitating processing and cost control. Alternatively, the structure and/or shape of the first rocker  1512  may differ from the second rocker  1513 . 
     The lower rocker arm  151  preferably further includes a connecting rod  1515  connected between midsections of the first rocker  1512  and the second rocker  1513 . The connecting rod  1515  helps the first rocker  1512  and the second rocker  1513  to function together, so as to effectively improve the structural strength and working stability of the lower rocker arm  151 . The upper rocker arm  152  may similarly include two rockers  1522  and  1523 , a connecting base  1524 , and a connecting rod  1525 , all connected and shaped similarly to corresponding parts of the lower rocker arm  151 . 
     The number of front shock absorbers  154  could alternatively be increased/decreased according to the requirements of front shock absorption. Moreover, structure and operating principles of shock absorbers  154  are well-known, and will not be described in detail. 
     The mounting seats  1552  may be mounted on the front frame portion  1111  using two mounting seat supports  1554  called out in  FIGS.  5  and  9   , a preferred one of which is shown in  FIG.  13   . The supports  1554  are fixed to the front frame portion  1111  such as by welding. Each mounting seat support  1554  preferably includes a supporting plate  1555 , and a first extending wall  1556  and a second extending wall  1557  located at ends of the supporting plate  1555 . Each mounting seat  1552  is fixed on its mounting seat supporting plate  1555  by bolts or the like extending through holes in the mounting seats  1552  and through corresponding holes in the supporting plate  1555 . One end of the first extending wall  1556  away from the supporting plate  1555  is abutted against the upper rocker arm  152 , and the other end is connected such as by welding to the front frame portion  1111 , and the end of the second extending wall  1557  is connected to the front frame portion  1111  such as by welding. The delivery path of the load of the front torsion bar  1551  uses the first extending wall  1556  and the second extending wall  1557 , which walls  1556 ,  1557  increase the surface area of load transfer and reduce the likelihood of breakage of the connection. The angle between the second extending wall  1557  and the front supporting plate  1555  is defined as γ, and γ is preferably in the range from 30° to 50°. Within this range, the stress value between the second extending wall  1557  and the front support  1554  is smaller, which is favorable for the connection between the second extending wall  1557  and the frame  111 . 
       FIGS.  14 ,  15  and  17    show the rear suspension assembly  16 , which is mounted on the rear frame portion  1113  and connected to the rear wheels  18  to buffer and filter vibrations caused by the rear wheels  18 . The rear suspension assembly  16  preferably includes right and left lower rocker arms  161 , right and left upper rocker arms  162 , right and left rear wheel shaft support assemblies  163 , right and left rear shock absorber assemblies  164  and a rear torsion bar assembly  166 , each of which are arranged and operate similarly to their counterparts in the front suspension assembly  15 . However, the rear shock absorber assemblies  164  are preferably mounted on the lower rocker arms  161 , and the rear suspension assembly  16  preferably also includes right and left control arm assemblies  167 . 
     The effect of mounting the rear shock absorber  164  on the lower rocker arm  161  is further explained with reference to  FIG.  16   , which details various connection points in side view relative to the rear wheel shaft support  163 . The connection between the outer end of the lower rocker arm  161  and the rear wheel shaft support  163  is defined as a first connection point F. The connection between the outer end of the upper rocker arm  162  and the rear wheel shaft support  163  is defined as a second connection point N. A straight line Y is defined by connecting the point N and the center point of the rear wheel shaft support  163 . The connection between the rear shock absorber  164  and the lower rocker arm  161  (the point where force of the shock absorber  164  is applied) is defined as a third connection point M. The first connection point F and the second connection point N preferably do not coincide along the vertical direction, with the first connection point F instead being behind (and much lower) than the second connection point N. The third connection point M is behind (and at nearly the same elevation as) the first connection point F. In other words, in the front-rear direction of the off-road vehicle  100 , the first connection point F is closer to the third connection point M than the front-rear distance between the second connection point N and the third connection point M. The distance L4 from the first connection point F to the straight line Y may be in the range from 20 mm to 40 mm. The point of force of the rear shock absorber  164  is closer in elevation to the rear wheel shaft support  163 , and the moment arm of force between the point of force M and the first connection point F is reduced. The force when the rear wheel  18  hits a bump or obstacle is delivered to the rear wheel shaft support  163 , and the opposing force applied by the shock absorber  164  to the lower rocker arm  161  is more easily delivered and shared by the rear wheel shaft support  163 . Therefore, the lower rocker arm  161  can more easily meet the use requirements and the cost can be reduced. 
     Further referring to  FIG.  14    and similar to the front lower rocker arms  151 , the rear lower rocker arms  161  include two rockers  1612 ,  1613 , a connecting base  1614  and at least one connecting rod  1615 . 
     As called out in  FIGS.  14  and  17   , each lower rocker arm  161  preferably further includes a shock absorber attachment plate  1616 . The shock absorber attachment plate  1616  is preferably attached to and extends between the rear rocker  1612  and the connecting rod  1615 . This preferred location for the shock absorber attachment plate  1616  allows both the connecting rod  1615  and the rear rocker  1612  to share the force together when the suspension is forced, so as to avoid the deformation of the connecting rod  1615  or rocker  1612  due to force of the shock absorber  164 . A lower end of the rear shock absorber  164  is hinged on the shock absorber attachment plate  1616 , and the other end extends upward for connection to the rear frame portion  1113 . The shock absorber attachment plate  1616  may alternatively or additionally be connected to the front rocker  1613 , or to only the rear rocker  1612  or only the third connecting rod  1615 . The example above is only illustrative of several installation methods of the shock absorber attachment plate  1616 , and several modifications and improvements can be made without departing from the concept of the present application, which all belong to the scope of the present invention. 
     As called out in  FIG.  14    and  FIG.  17    and similar to the front upper rocker arm  152 , the rear upper rocker arm  162  includes two rockers  1622 ,  1623 , a connecting base  1624 , and a connecting rod  1627 . The rear rocker  1622  is preferably bent towards the front rocker  1623  of the rear upper rocker arm  162  so as to form an avoidance space  162   f . The rear shock absorber  164  extends through the avoidance space  162   f . 
     As best shown in  FIG.  18   , the preferred connecting base  1624  of each of the rear upper rocker arms  162  includes two support arm parts  1625  each having a connecting part  1626  with a curved surface  162   a . The two connecting parts  1626  may be connected to each other or may remain unconnected. One end of each support arm part  1625  is rotatably connected to the rear wheel shaft support  163 . The ends of the rockers  1622 ,  1623  are respectively welded or otherwise attached to the curved surface  162   a . Each rocker welding position may be welded within the range of the curved surface  162   a  at any angle according to requirements. That is to say, the connecting base  1624  can be adapted to the different rockers within requirements by providing a curved surface  162   a  of the connecting portions  1626 , thereby improving the versatility of the product and effectively reducing the cost. In the most preferred embodiment shown, the curved surface  162   a  is spherical. 
       FIGS.  19 - 22    show another embodiment of a rear suspension assembly  16 . This embodiment further includes an adjustment assembly  165  provided between the rear wheel shaft support assembly  163  and the rear upper rocker arm  162  and/or the rear lower rocker arm  161 . The adjustment assembly  165  allows adjustment of the camber angle of the rear wheel shaft support assembly  163 , which enables the off-road vehicle  100  meet the current use requirements. Similar adjustment assemblies may also be applied to the front suspension assembly  15  to adjust the camber angles of the front wheels  17 . 
     As best shown in  FIG.  20   , each adjustment assembly  165  includes a first seat body  1651 , a second seat body  1652 , an adjustment piece  1653 , and a fastener  1654 . The first seat body  1651  is rotatably connected to the wheel shaft support  163 . The second seat body  1652  is preferably connected to the upper rocker arm  162 . The adjustment piece  1653  is positioned between the first seat body  1651  and the second seat body  1652 , and is used to adjust the gap between the first seat body  1651  and the second seat body  1652 , thereby adjusting the overall length of the upper rocker arm  162  and changing the corresponding camber angle. The fastener  1654  is used to lock the adjusted first seat body  1651  and the adjusted second seat body  1652 ; or to unlock the first seat body  1651  and the second seat body  1652 . 
     In one embodiment, the first seat body  1651  and the second seat body  1652  are both hollow. One end of the fastener  1654  passes from the interior of the second seat body  1652  to the interior of the first seat body  1651 . The adjustment piece  1653  may be C-shaped or U-shaped, so that the C-shaped or U-shaped adjustment piece  1653  may be able to be directly clamped on the fastener  1654 . Therefore, the gap between the first seat body  1651  and the second seat body  1652  can be adjusted without removing the fastener  1654 , which is more convenient. The adjustable range of the gap between the first seat body  1651  and the second seat body  1652  may be less than or equal to 5 cm. The fastener  1654  may be a bolt. The bolt may pass through the first seat body  1651  to the second seat body  1652  and may be connected to a nut, and the adjustment piece may be sleeved on the bolt. 
     An arc-shaped slot  1655  is preferably provided on the second seat body  1652 . The connecting rod  1627  is preferably embedded in the arc-shaped slot  1655  and welded to the second seat body  1652 , thereby increasing contact area and improving the connection strength between the rocker arm  162  and the second seat body  1652 . 
     As shown in  FIGS.  14 ,  15  and  17   , the preferred rear torsion bar assembly  166  includes a rear torsion bar  1661 , two rear mounting seats  1662 , and two rear connecting rods  1663 . The rear torsion bar assembly  166  is mounted and operates similarly to the front torsion bar assembly  155 , except that the rear torsion bar  1661  is preferably below the rear upper rocker arms  162 , such that connecting rods  1663  extend from the ends of the rear torsion bar  1661  upwardly. The rear mounting seats  1662  may be fixed to the rear frame portion  1113  or to components, such as the vehicle body  112 . In one embodiment, the connecting rods  1663  are connected to the upper rocker arms  162  by ball pins, though other connections such as bearings may alternatively be used. The rear torsion bar assembly  166  may be located toward the front of the rear frame portion  1113 , so as to make the entire rear suspension assembly  16  more compact, to reduce the protrusion of the rear torsion bar  1661 , and to improve the integrity and aesthetics when viewed from the rear end of the off-road vehicle  100 . Additionally, this location of the rear torsion bar  1661  reduces interference of the rear torsion bar  1661  and its movement with the installation of other components. In addition, this location of the rear torsion bar  1661  also protects the rear torsion bar  1661  by the rear frame portion  1113 . 
     The control arm assemblies  167  are preferably located toward the rear of the rear frame portion  1113 , opposite to the position of the rear torsion bar assembly  166 . The control arm assemblies  167  are preferably located at an elevation between the second lower rocker arm  161  and the second upper rocker arm  162 . Each control arm assembly  167  includes a control arm  1671 , one end of which is rotatably connected to the rear wheel shaft support assembly  163 , and the other end of which is rotatably connected to the frame  111 . During rear suspension travel, the rear wheel shaft support assembly  163  is driven to swing along the movement track of the rigid control arm  1671 , so as to change the camber and toe-in angle of the attached rear wheel  18 , thereby improving stability of the vehicle. 
     Each preferred control arm assembly  167  includes the control arm  1671  and two rotating bases  1672  which are fixed to the rear frame portion  1113  and the rear wheel shaft support assembly  163 , respectively. The control arm  1671  is rotatably connected to the rotating bases  1672 . The control arm  1671  and the rotating bases  1672  are preferably rotatably connected by ball pins to realize relative rotation and swing between the control arm  1671  and the rear frame portion  1113 . Other connection methods, such as joint bearing connection, may alternatively be used. 
       FIG.  21    shows the state of the rear wheels  18  when the control arm  1671  is at its lowest position during suspension travel.  FIG.  22    shows the state of the rear wheels  18  when the control arm  1671  is at its highest position. The control arm assemblies  167  maintain the toe-in value of the rear wheels  18  within a range conducive to the driving of the off-road vehicle  100 , thereby assisting the steering and handling the off-road vehicle  100 . 
     The technical features of the above embodiments can be combined selectively. In order to simplify the description, all possible combinations of the technical features in the above embodiments have not been expressly mentioned. However, as long as there is no contradiction between the combinations of these technical features, they should be considered to be within the scope of the description. 
       FIG.  23    shows a preferred electrical schematic layout of the off-road vehicle  100 , including a plurality of electrical components  19  and an electronic controller  21 . The various electrical components  19  and the electronic controller  21  may be directly or indirectly mounted on the frame assembly  11 , and the electrical components  19  are at least partially connected (electrically/signally) to the electronic controller  21  to enable control over the basic electrical functions of the off-road vehicle  100 . The electronic controller (referred to as ECU hereinafter)  21  is also referred to as “travelling computer”, and is used to monitor various input data (such as braking data, gear shifting data, etc.) and various states of vehicle operation (such as acceleration, skidding, fuel consumption, etc.); calculate the information transmitted by various sensors according to a pre-designed program; send various parameters (after processing) to various relevant actuators, such as electrical components  19 ; and perform various predetermined control functions. 
     In one embodiment, the electrical components  19  include instrumentation  200  and a plurality of switches  203 . The instrumentation  200  may include various electrical instruments, such as an ammeter, a charging indicator or a voltmeter, an oil pressure gauge, a thermometer, a fuel gauge, a vehicle speed and odometer, an engine tachometer, and the like. The instrumentation  200  is mainly used to display the status of relevant devices during the driving of the off-road vehicle  100 . A warning indicator may be mainly used to generate sound to prompt or provide warning. The plurality of switches  203  may include a mode switch  2031 , an air conditioning switch (not called out), a temperature adjustment switch (not called out), and the like. The mode switch  2031 , the air conditioning switch, and the temperature adjustment switch may be generally mounted on an instrument panel  1122   b  (shown in  FIG.  3   ) for the convenience of the driver and front passenger. The mode switch  2031 , the air conditioner switch, the temperature adjustment switch, and the like are electrically/signally connected to the electronic controller  21  by wiring harnesses  2042 , so as to control a series of functions of the off-road vehicle  100 , such as the switching of the two-wheeled drive and the four-wheeled drive, the turning on of the air conditioner, and the adjustment of the air conditioner temperature, and the like. 
     As better shown in  FIGS.  24  and  25   , the preferred mode switch  2031  includes images and positions for a four-wheeled drive gear  2031   a , a two-wheeled drive gear  2031   b , and a front-wheeled drive lock gear  2031   c . The image and position for the four-wheeled drive gear  2031   a  is preferably located between the images and positions for the two-wheeled drive gear  2031   b  and the front-wheeled drive lock gear  2031   c . The setting for the two-wheeled drive gear  2031   b  enables two-wheeled drive operation of the off-road vehicle  100 . The setting for the four-wheeled drive gear  2031   b  enables four-wheeled drive operation of the off-road vehicle  100 . The setting for the front-wheeled drive lock gear  2031   c  enables front differential locking of the off-road vehicle  100 . The mode switch  2031  includes a housing  2031   d , a pushing plate  2031   s , a switch shaft  2031   v , and a gear lever assembly  2031   u . The housing  2031   d  includes a cavity  2031   za , a first gear slot  2031   e , a second gear slot  2031   f , and a third gear slot  2031   j . The first gear slot  2031   e , the second gear slot  2031   f , and the third gear slot  2031   j  are all located in the cavity  2031   za . The second gear slot  2031   f  is located between the first gear slot  2031   e  and the third gear slot  2031   j . The pushing plate  2031   s  is rotatably connected to the housing  2031   d  by a switch pivot  2031   t . One end of the gear lever shaft  2031   v  is connected to the pressing plate  2031   s , and the other end of the gear lever shaft  2031   v  swings the gear lever assembly  2031   u  based on angular movement of the pressing plate  2031   s , switching a plunger ball  2031   y  between the first gear slot  2031   e , the second gear slot  2031   f , and the third gear slot  2031   j . 
     The gear lever assembly  2031   u  defines a plunger cavity  2031   w  which houses a spring  2031   x  and at least part of the plunger ball  2031   y . The spring  2031   x  biases the plunger ball  2031   y  downwardly, pushing the ball  2031   y  into the first gear slot  2031   e , the second gear slot  2031   f , or the third gear slot  2031   j . 
     As better shown in  FIGS.  26  and  27   , the first gear slot  2031   e , the second gear slot  2031   f , and the third gear slot  2031   j  are each at least partially arc-shaped, and sequentially connected. More particularly for the most preferred embodiment, the second gear slot  2031   f  includes an arc-shaped bottom section  2031   g  between a first sloping straight section  2031   h , and a second sloping straight section  2031   i . The first gear slot  2031   e  includes a flat straight section  2031   k , and the third gear slot  2031   j  includes a flat straight section  2031   z . The flat straight section  2031   k  of the first gear slot  2031   e  intersects with the first sloping straight section  2031   h , creating a first intersection point P and a first angle β1. The flat straight section  2031   z  of the third gear slot  2031   j  intersects with the second sloping straight section  2031   i , creating a second intersection point Q and a second angle β2. Angles β1 and β2 are preferably different. For instance, the first angle β1 is preferably in the range from 120° to 140°, and the second angle β2 is preferably in the range from 100° to 125°, with the difference between β1 and β2 preferably in the range from 5° to 30°. That is to say, the slope of the second gear slot  2031   f  near the third gear slot  2031   j  is preferably larger than the slope of the second gear slot  2031   f  near the first gear slot  2031   e . The transition between the first gear slot  2031   e  and the second gear slot  2031   f  is smoother than the transition between the second gear slot  2031   f  and the third gear slot  2031   j . In this way, when switching, the damping of switching lever  2031   v  from the second gear slot  2031   f  to the third gear slot  2031   j  is larger than the damping of switching lever  2031   v  from the first gear slot  2031   e  to the second gear slot  2031   f . That is to say, the force values required for switching between switch positions are different. The force value required becomes larger when switching from four-wheeled drive to front-wheeled drive lock, helping to avoid unintended direct switching from two-wheeled drive gear to front-wheeled drive lock, improving safety. 
     In the most preferred embodiment, the position of the second intersection point Q is relatively higher than the position of the first intersection point P along the axis Z direction of the cavity  2031   za . In this way, the spring plunger stroke from the second gear slot  2031   f  to the third gear slot  2031   j  is increased, so damping is increased from four-wheeled drive to the front-wheeled drive lock, thereby helping to avoid over-shifting during the switching process. 
     Further, the first sloping straight section  2031   h  is at a third angle β3 measured relative to a base plane A1, and the second sloping straight section  2031   i  is at a fourth angle β4 measured relative to the base plane A1. The difference between the fourth angle β4 and the third angle β3 is preferably in the range from 5° to 30°. The third angle β3 is preferably in the range from 45° to 60°. The fourth angle β4 is preferably in the range from 55° to 75°. Therefore, the slope of the second sloping straight section  2031   i  with respect to the plane A1 is larger than the slope of the first sloping straight section  2031   h  with respect to the plane A1. Therefore, the force value required for the plunger ball  2031   y  to switch from the second gear slot  2031   f  to the third gear slot  2031   j  is increased. 
     In the most preferred embodiment, the flat straight section  2031   k  is at a fifth angle β5 with respect to the base plane A1, and the flat straight section  2031   z  is at a sixth angle β6 with respect to the base plane. The value of the fifth angle β5 is preferably the same as the value of the sixth angle β6. In this way, the operating force value of switching from two-wheeled drive to four-wheeled drive may be basically equal to the operating force value of switching from front-drive lock to four-wheeled drive, thereby improving the consistency of operation. 
     As best shown in  FIG.  25   , the switch  2031  preferably has a plurality of output contacts  20311  accessible on a bottom side of the housing  2031   d . The bottom side of the housing  2031   d  mates with a butt connection socket  2031   n  shown in  FIG.  28    to electrically connect the output contacts  20311  through the harness  2042  to the ECU  21 . The butt connection socket  2031   n  preferably includes a connection cover  2031   m  which surrounds a portion of the housing  2031   d  and additionally protects the output contacts  20311 . The butt connection socket  2031   n  is preferably provided with a sealing member  2031   q  formed of a soft, deformable material such as rubber or silicone, which can alternatively be provided on the housing  2031   d . After the housing  2031   d  is plugged into the butt connection socket  2031   n , the sealing member  2031   q  (shown in its uncompressed state in dashed lines) seals the gap between the butt connection socket  2031   n  and the housing  2031   d , so that the output contacts  20311   are in a sealed state, avoiding the possibility of short-circuiting due to water and the like. At the same time, during the plugging act, the connection cover  2031   m  plays a guiding role, which is beneficial to the connection of the butt connection socket  2031   n  and the switch  2031 , and assembly is more convenient. 
     In the preferred embodiment shown in  FIGS.  28  and  29   , the sealing member  2031   q  is disposed within a slot  2031   p  at a bottom of the connection cover  2031   m . The sealing is not only realized by the seal  2031   q , but also by covering the butt connection socket  2031   n  by the connecting cover  2031   m , thereby increasing the sealing path and improving the sealing effect. The sealing member  2031   q  may include one or a plurality of annular sealing protrusions  2031   r  extending outwardly. The plurality of sealing protrusions  2031   r  are preferably provided at intervals along the axial direction of the slot  2031   p . In other embodiments, the sealing member  2031   q  may alternatively be directly inwardly from the connection cover  2031   m , or may alternatively be directed inwardly or outwardly on the switch housing  2031   d . 
     Referring back to  FIG.  23   , the electrical components  19  includes a battery  1922  and an electrical terminal assembly  204 . The battery  1922  may be mounted on the middle frame portion  1112  for storing electricity for the vehicle  100 . Alternatively, the battery  1922  could be mounted on the front frame portion  1111  or the rear frame portion  1113 . The electrical terminal assembly  204  is electrically connected to the battery  1922  such as through the wiring harness  2042  at a location spaced away from the battery  1922  such as on a different frame portion. For instance, with the battery  1922  mounted on the middle frame portion  1112 , the electrical terminal assembly  204  may be mounted on the front frame portion  1111 . The purpose of the electrical terminal assembly  204  is to provide a convenient location for electrical connections to supply electricity to aftermarket accessories added to the off-road vehicle  100 . By providing such a convenient connection location, electrical aftermarket accessories can be added and wired without any splicing or other damage to the original wiring of the off-road vehicle  100 . 
     The preferred electrical terminal assembly  204  is better shown in  FIGS.  30 - 32   . The electrical terminal assembly  204  preferably includes a terminal block  2021  with a cover  2047 , and a harness  2042   a . The electrical terminal assembly  204  is connected to the battery  1922  through the wiring harness  2042 , which includes a power relay  2044 . The opening/closing of the power relay  2044  corresponds to the starting/key position of the off-road vehicle  100 . That is to say, the power relay  2044  is turned on when the off-road vehicle  100  is started or powered on, and the power relay  2044  is turned off when the off-road vehicle  100  is turned off. The terminal block  2041  includes a battery positive (B+) terminal  2043   c , a battery negative (B-) terminal  2043   d , and an accessory (ACC) terminal  2043   e . The B+ terminal  2043   c  and B-terminal  2043   d  have direct electrical connections to corresponding terminals of the battery  1922  through the wiring harnesses  2042   a  and  2042 . The connection of the ACC terminal  2043   e  to the positive terminal of the battery  1922  runs through the power relay  2044 . The ACC terminal  2043   e  conducts with the positive electrode of the battery  1922  when the power relay  2044  is turned on, and the ACC terminal  2043   e  is disconnected from the positive electrode of the battery  1922  when the power relay  2044  is turned off. In this way, if one or more aftermarket accessories need continuous electricity power supply, the accessories can be connected to the B+ and B- terminals  2043   c ,  2043   d  that are not controlled by the power relay  2044 . If the electricity supply of one or more aftermarket accessories needs to be controlled by the starting/key position of the off-road vehicle  100 , such accessories can be connected to the ACC and B- terminals  2043   d ,  2043   e  so their power is controlled by the power relay  2044 . If desired, in addition to aftermarket electrical accessories, the terminal assembly  204  can also be used to supply electricity to original equipment components, such as headlights, taillights, etc. 
       FIG.  34    shows an alternative embodiment which further includes a second ACC terminal  2043   f . Of course, the numbers of each of the B+, B- and ACC terminals may be one, two, three, four or other, respectively. The connection between the terminal block  2041 , the power relay  2044  and the battery  1922  may be a combination of the above two embodiments, or one of the above two embodiments or others according to actual needs, and this is not limited. 
     As shown in  FIG.  30   , the wiring harness  2042  preferably includes one or more fuse boxes  2045  for protecting the battery  1992 , so as to avoid the problem of feeding the battery  1922 . In the most preferred embodiment, the fuse boxes  2045  include a main fuse  2045   a  and a plurality of sub-fuses  2045   b . The main fuse  2045   a  is close to the positive electrode of the battery  1922 . One of the sub-fuses  2045   b  is on the connection between the terminal block  2041  and the positive electrode of battery  1922 . The other sub-fuse  2045   b  is on the connection between the terminal block  2041  and the power relay  2044 . In the embodiment shown in  FIG.  30   , the main fuse  2045   a  and the sub-fuses  2045   b  are both on the harness  2042 , with the main fuse  2045   a  and one of the sub-fuses  2045   b  provided in series, so as to achieve dual protection and further to avoid the feeding problem of the battery  1922 . Alternatively, the sub-fuses  2045   b  may be provided in the harness  2042   a  of the electrical terminal assembly  204 . As another alternative, only one sub-fuse may be provided, either in harness  2042  or harness  2042   a . 
     The cover  2047  is used to protect the wiring terminals  2043 , thereby avoiding the short circuit phenomenon of the wiring terminals  2043  caused by falling metal objects. The terminal block  2021  also preferably includes barrier plates  2046  between adjacent terminals  2043 . Two adjacent wiring terminals  2043  are thus isolated by one barrier plate  2046  to avoid interference and/or shorting between the two adjacent wiring terminals  2043 . Here, the barrier plates  2046  and the housing of the terminal block  2021  may be integrated. 
     As shown in  FIG.  30   , the end of the wiring harness  2042   a  of the electrical terminal assembly  204  is preferably provided with a wiring male plug  2042   b . The end of the wiring harness  2042  is preferably provided with a wiring female plug  2042   d . The wiring male plug  2042   b  may be plugged or unplugged with the wiring female plug  2042   d , so that the electrical connection between the terminal block  2021  and the battery  1922  can be easily realized or separated. During connection of the aftermarket accessory to the terminals  2043   c ,  2043   d ,  2043   e  of the electrical terminal assembly  204 , the user can unplug the plugs  2042   b ,  2042   d , so neither of the terminals  2043   c ,  2043   e  are hot and any shorting or sparking possibility is eliminated. In this way, the terminal block  2021  and the wiring harness  2042  on the battery  1922  may be integrated, and the wiring can be very simple and convenient. 
     The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention. Workers of ordinary skill in the art may make numerous modifications and improvements without departing from the concepts of the present invention. Therefore, the protection scope of the patent of the present invention is defined to include the full breadth of the appended claims.