Patent Publication Number: US-2023136419-A1

Title: Vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to Japanese Patent Application No. 2021-180501 filed on Nov. 4, 2021. The entire contents of this application are hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to vehicles, and more specifically to four-wheel off-road vehicles and the like. 
     2. Description of the Related Art 
     As an example of conventional techniques of this kind, U.S. Patent Application Publication No. 2004/0134707 discloses a four-wheel off-road vehicle. The four-wheel off-road vehicle, which has a frame and four wheels supported by the frame, has a long wheelbase ranging from 52 to 72 inches. 
     U.S. Patent Application Publication No. 2004/0134707 does not disclose anything about wheel travel (rebound stroke) nor ramp brake-over angle. 
     SUMMARY OF THE INVENTION 
     According to a preferred embodiment of the present invention, a vehicle includes a body; a front wheel and a rear wheel; a first suspension between the body and the front wheel; 
     and a second suspension between the body and the rear wheel, wherein, when an angle θ 1  represents a ramp brake-over angle, an angle θ 2  represents an angle in an up-down direction defined by a tangential line extending through a bottom portion of the body at a center of a wheelbase to the front wheel and a tangential line extending through the bottom portion of the body at the center of the wheelbase to the rear wheel when the first suspension and the second suspension are fully stretched, and the wheelbase is not smaller than about 1340 mm: the angle θ 1  is not smaller than about 55 degrees, and a ratio of the angle θ 2  to the angle θ 1  (θ 2 /θ 1 ) is not smaller than about 1.25. 
     According to another preferred embodiment of the present invention, a vehicle includes a body; a front wheel and a rear wheel; a first suspension between the body and the front wheel; and a second suspension between the body and the rear wheel; wherein, when an angle θ 1  represents a ramp brake-over angle, an angle θ 3  represents an angle in an up-down direction defined by a tangential line extending through a bottom portion of the body at a center of a wheelbase to the front wheel and a tangential line extending through the bottom portion of the body at the center of the wheelbase to the rear wheel when the first suspension is fully compressed and the second suspension is fully stretched, and the wheelbase is not smaller than about 1340 mm: the angle θ 1  is not smaller than about 55 degrees, and a ratio of the angle θ 3  to the angle θ 1  (θ 3 /θ 1 ) is not smaller than about 0.9. 
     According to another preferred embodiment of the present invention, a vehicle includes a body; a front wheel and a rear wheel; a first suspension between the body and the front wheel; and a second suspension between the body and the rear wheel; wherein, when an angle θ 1  represents a ramp brake-over angle, an angle θ 4  represents an angle in an up-down direction defined by a tangential line extending through a bottom portion of the body at a center of a wheelbase to the front wheel and a tangential line extending through the bottom portion of the body at the center of the wheelbase to the rear wheel when the first suspension is fully stretched and the second suspension is fully compressed, and the wheelbase is not smaller than about 1340 mm: the angle θ 1  is not smaller than about 55 degrees, and a ratio of the angle θ 4  to the angle θ 1  (θ 4 /θ 1 ) is not smaller than about 0.8. 
     According to another preferred embodiment of the present invention, a vehicle includes a body; a front wheel and a rear wheel; a first suspension between the body and the front wheel; and a second suspension between the body and the rear wheel; wherein, when the vehicle has a wheelbase not smaller than about 1340 mm and not greater than about 2000 mm: a wheel travel on a rear wheel side is not smaller than about 360 mm. 
     According to another preferred embodiment of the present invention, a vehicle includes a body; a front wheel and a rear wheel; a first suspension between the body and the front wheel; and a second suspension between the body and the rear wheel; wherein, when the vehicle has a wheelbase not smaller than about 1340 mm and not greater than about 2000 mm: a wheel travel ratio of a stretch-side to a compression-side (stretch-side/compression-side) on a rear wheel side is not smaller than about 0.5. 
     Preferably, the vehicle has a wheel travel ratio of a stretch-side to a compression-side (stretch-side/compression-side) on the front wheel side not smaller than about 0.5. 
     According to another preferred embodiment of the present invention, a vehicle includes a body; a front wheel and a rear wheel; a first suspension between the body and the front wheel; and a second suspension between the body and the rear wheel; wherein, when an angle θ 1  represents a ramp brake-over angle, an angle θ 2  represents an angle in an up-down direction defined by a tangential line extending through a bottom portion of the body at a center of a wheelbase to the front wheel and a tangential line extending through the bottom portion of the body at the center of the wheelbase to the rear wheel when the first suspension and the second suspension are fully stretched, and the wheelbase is not smaller than about 1340 mm and not greater than about 2000 mm: a ratio of the angle θ 2  to the angle θ 1  (θ 2 /θ 1 ) is not smaller than about 1.25. 
     Preferably, the vehicle further includes a bar handle provided on the body. 
     Further preferably, the vehicle further includes a saddle-type seat provided on the body. 
     Further, preferably, the vehicle includes at least one of the front wheel and the rear wheel including a plurality thereof. 
     Preferably, the vehicle has a minimum ground clearance not smaller than about 275 mm. 
     For example, when the vehicle is traveling on a steep slope or over a large bump, there is a load shift toward the rear wheel side during uphill travel so that the rear wheel side second suspension sinks and the front wheel side first suspension stretches. During downhill travel, on the other hand, there is a load shift toward the front wheel side so that the front wheel side first suspension sinks and the rear wheel side second suspension stretches. In a preferred embodiment of the present invention, even if the vehicle has a long wheelbase, the ramp brake-over angle is made greater such that the minimum ground clearance is increased accordingly and there is less likelihood for the bottom of the vehicle to contact the ground. Also, increasing the wheel travel offers the same advantage. Preferred embodiments of the present invention provide vehicles each having a reduced likelihood of the bottom of the vehicle contacting the ground even if the vehicle has a long wheelbase. 
     It should be noted here that the term “ramp brake-over angle θ 1 ” refers to a ramp brake-over angle when the vehicle in an unmanned state is oriented horizontally. 
     Each of the angles θ 2 , θ 3 , and θ 4  is an angle corresponding to the ramp brake-over angle θ 1 . In other words, all of the angles θ 2 , θ 3 , and θ 4  are defined in the same way as the ramp brake-over angle θ 1 , i.e., an angle in an up-down direction defined by a tangential line extending through a bottom portion of the body at the center of a wheelbase to the front wheel and a tangential line extending through the bottom portion of the body at the center of the wheelbase to the rear wheel when the vehicle in an unmanned state is oriented horizontally. 
     All of the ramp brake-over angle θ 1  and the angles θ 2  through θ 4  are measured in a side view. 
     While it is possible to draw a tangential line through the bottom portion of the body at the center of the wheelbase to the front wheel, to whichever of an upper side and a lower side of the front wheel, the tangential line in preferred embodiments of the present invention is the tangential line extending to the lower side of the front wheel. The same applies to the tangential line extending to the rear wheel. 
     The term “wheelbase” is a distance between a front wheel axle and a rear wheel axle. 
     The term “bottom portion of the body at the center of the wheelbase” refers to a point where a bottom portion of the body is crossed by a plane which passes through the center of a fore-aft distance of the wheelbase vertically to the fore-aft direction. 
     The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side view which shows a vehicle according to a preferred embodiment of the present invention. 
         FIG.  2    is a perspective view which shows the vehicle in  FIG.  1   . 
         FIG.  3    is a side view which shows a first suspension, a second suspension and so on included in the vehicle in  FIG.  1   . 
         FIG.  4    is a perspective view which shows the first suspension, the second suspension and so on included in the vehicle in  FIG.  1   . 
         FIG.  5 A  is a front view which shows the first suspension in normal state.  FIG.  5 B  is a front view which shows the first suspension when fully stretched and when fully compressed. 
         FIG.  6 A  is a rear view which shows the second suspension in normal state.  FIG.  6 B  is a rear view which shows the second suspension when fully stretched and when fully compressed. 
         FIG.  7    is an illustrative drawing which shows a ramp brake-over angle, a wheelbase, a wheel travel, etc. 
         FIG.  8 A  is an illustrative drawing which shows a ramp brake-over angle θ 1 . Likewise,  FIG.  8 B  shows an angle θ 2 ,  FIG.  8 C  shows an angle θ 3 , and  FIG.  8 D  shows an angle θ 4 . 
         FIG.  9    is a table which shows various dimensions and so on, according to preferred embodiments of the present invention and conventional examples. 
         FIG.  10    is a graph which shows the wheelbase, the ramp brake-over angle θ 1 , and θ 2 /θ 1  according to preferred embodiments of the present invention and comparative examples. 
         FIG.  11    is a graph which shows the wheelbase, the ramp brake-over angle θ 1 , and θ 3 /θ 1  according to preferred embodiments of the present invention and comparative examples. 
         FIG.  12    is a graph which shows the wheelbase, the ramp brake-over angle θ 1 , and θ 4 /θ 1  according to preferred embodiments of the present invention and comparative examples. 
         FIG.  13    is a graph which shows the wheelbase and the wheel travel on a rear wheel side according to preferred embodiments of the present invention and comparative examples. 
         FIG.  14    is a graph which shows the wheelbase and a ratio of the wheel travel on a stretch-side to that of a compression-side according to preferred embodiments of the present invention and comparative examples. 
         FIG.  15    is a graph which shows the wheelbase and θ 2 /θ 1  according to preferred embodiments of the present invention and comparative examples. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 
     Referring to  FIG.  1    and  FIG.  2   , a vehicle  10  according to a preferred embodiment of the present invention is a four-wheel off-road vehicle, which includes a body  12 , a pair of front wheels  14 , a pair of rear wheels  16 , a bar handle  18  provided on the body  12 , and a saddle-style seat  20  provided on the body  12 . Note that  FIG.  2    shows only one of the pair of rear wheels  16 . The bar handle  18  is provided between the pair of front wheels  14  in a plan view, at an intermediate portion in the vehicle&#39;s width direction, and in a side view, above the front wheels  14 . The saddle-style seat  20  is provided at an intermediate portion in the vehicle&#39;s width direction, and in a side view, at a higher position than the front wheels  14  and the rear wheels  16 , between the front wheels  14  and the rear wheels  16 . 
     Each front wheel  14  includes a wheel  14   a  and a front tire  14   b  attached to the wheel  14   a.  Likewise, each rear wheel  16  includes a wheel  16   a  and a rear tire  16   b  attached to the wheel  16   a.    
     Referring also to  FIG.  3    and  FIG.  4   , the vehicle  10  further includes a pair of first suspensions  22  and a pair of second suspensions  24 . The body  12  includes a body frame  26 . The pair of first suspensions  22  are provided between the pair of front wheels  14  and the body frame  26  in order to suspend the pair of front wheels  14 . The pair of second suspensions  24  are provided between the pair of rear wheels  16  and the body frame  26  in order to suspend the pair of rear wheels  16 . In other words, each first suspension  22  is provided between the body  12  and a corresponding one of the front wheels  14  while each second suspension  24  is provided between the body  12  and a corresponding one of the rear wheels  16 . It should be noted here that hereinafter, the expression “normal state” refers to a state in which there is no rider in the vehicle  10 . 
     In the normal state, the first suspension  22  is in a state as shown in  FIG.  5 A , and when fully stretched and when fully compressed, is in respective states as shown in alternate long and two short dashes lines in  FIG.  5 B . In the normal state, the second suspension  24  is in a state as shown in  FIG.  6 A , and when fully stretched and when fully compressed, is in respective states as shown in alternate long and two short dashes lines in  FIG.  6 B . 
     Referring to  FIG.  7    and  FIGS.  8 A to  8 D , an angle θ 1  ( FIG.  8 A ) is a ramp brake-over angle, i.e., an angle in the up-down direction defined by a tangential line extending through the body&#39;s bottom portion X at the center of a wheelbase to the front wheel  14  and a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the rear wheel  16  when the vehicle  10  in an unmanned state is oriented horizontally; an angle θ 2  ( FIG.  8 B ) is an angle in the up-down direction defined by a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the front wheel  14  and a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the rear wheel  16  when the first suspension  22  and the second suspension  24  are fully stretched; an angle θ 3  ( FIG.  8 C ) is an angle in the up-down direction defined by a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the front wheel  14  and a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the rear wheel  16  when the first suspension  22  is fully compressed and the second suspension  24  is fully stretched; and θ 4  ( FIG.  8 D ) is an angle in the up-down direction defined by a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the front wheel  14  and a tangential line extending through the body&#39;s bottom portion X at the center of the wheelbase to the rear wheel  16  when the first suspension  22  is fully stretched and the second suspension  24  is fully compressed. Referring also to  FIG.  7   , a wheel travel of the front wheel  14  on a stretch-side will be called FE; a wheel travel of the front wheel  14  on a compression-side will be called FC; a wheel travel of the rear wheel  16  on a stretch-side will be called RE; a wheel travel of the rear wheel  16  on a compression-side will be called RC; and a minimum ground clearance will be called H. It should be noted here that the ramp brake-over angle θ 1  and the angles θ 2  through θ 4  are calculated by ignoring tire deflections and using nominal tire sizes. 
     Referring to  FIG.  9    and  FIG.  10   , preferably, the wheelbase of the vehicle  10  is not smaller than about 1340 mm, the angle θ 1  is not smaller than about 55 degrees, and a ratio of the angle θ 2  to the angle θ 1  (θ 2 /θ 1 ) is not smaller than about 1.25. 
     Referring to  FIG.  9    and  FIG.  11   , preferably, the wheelbase of the vehicle  10  is not smaller than about 1340 mm, the angle θ 1  is not smaller than about 55 degrees, and a ratio of the angle θ 3  to the angle θ 1  (θ 3 /θ 1 ) is not smaller than about 0.9. 
     Referring to  FIG.  9    and  FIG.  12   , preferably, the wheelbase of the vehicle  10  is not smaller than about 1340 mm, the angle θ 1  is not smaller than about 55 degrees, and a ratio of the angle θ 4  to the angle θ 1  (θ 4 /θ 1 ) is not smaller than about 0.8. 
     Referring to  FIG.  9    and  FIG.  13   , preferably, the wheelbase of the vehicle  10  is not smaller than about 1340 mm and not greater than about 2000 mm, and the wheel travel on the rear wheel  16  side (RE+RC) is not smaller than about 360 mm. Further, preferably, the wheel travel on the front wheel  16  side (FE+FC) is not smaller than about 270 mm. 
     Referring to  FIG.  9    and  FIG.  14   , preferably, the wheelbase of the vehicle  10  is not smaller than about 1340 mm and not greater than about 2000 mm; the rear wheel  16  side wheel travel ratio of a stretch-side to a compression-side (stretch-side/compression-side: RE/RC) is not smaller than about 0.5; and further, preferably, the front wheel  14  side wheel travel ratio of the stretch-side to the compression-side (stretch-side/compression-side: FE/FC) is not smaller than about 0.5. 
     Referring to  FIG.  9    and  FIG.  15   , preferably, the wheelbase of the vehicle  10  is not smaller than about 1340 mm and not greater than about 2000 mm, and a ratio of the angle θ 2  to the angle θ 1  (θ 2 /θ 1 ) is not smaller than about 1.25. 
     Further preferably, the minimum ground clearance H of the vehicle  10  is not smaller than about 275 mm, and the front tires  14   b  and the rear tires  16   b  (front wheels  14  and rear wheels  16 ) have an outer diameter not smaller than about 30 inches. 
     According to the vehicle  10  as described above, when traveling uphill on a steep slope or traveling over a large bump for example, there is a load shift toward the rear wheel  16  side, so the rear wheel  16  side second suspensions  24  sink and the front wheel  14  side first suspensions  22  stretch. During downhill travel, on the other hand, there is a load shift toward the front wheel  14  side, so the front wheel  14  side first suspensions  22  sink and the rear wheel  16  side second suspensions  24  stretch. In the vehicle  10 , even if the wheelbase is long, the ramp brake-over angle θ 1  is made greater such that the minimum ground clearance H is increased accordingly and there is less likelihood for rubbing the ground with the bottom of the vehicle. Also, increasing the wheel travel offers the same advantage. 
     More specifically, the following functions and advantages are obtained: 
     By making the wheelbase not smaller than about 1340 mm, the angle θ 1  not smaller than about 55 degrees, and the θ 2  to θ 1  ratio (θ 2 /θ 1 ) not smaller than about 1.25, even if the vehicle  10  has a long wheelbase, it becomes possible to increase the ramp brake-over angle θ 1 . Further, it becomes possible to increase the front wheel  14  stretch-side wheel travel FE and the rear wheel  16  stretch-side wheel travel RE. Thus, the minimum ground clearance H is increased, making it less likely to rub the ground with the bottom of the vehicle regardless of road conditions (flat, uphill or downhill). 
     By making the wheelbase not smaller than about 1340 mm, the angle θ 1  not smaller than about 55 degrees, and the θ 3  to θ 1  ratio (θ 3 /θ 1 ) not smaller than about 0.9, even if the vehicle  10  has a long wheelbase, it becomes possible to increase the ramp brake-over angle θ 1 . Further, it becomes possible to increase the angle θ 3  to a value not significantly different from the ramp brake-over angle θ 1 . Therefore, it becomes less likely to rub the ground with the bottom of the vehicle especially in downhill situations. 
     By making the wheelbase not smaller than about 1340 mm, the angle θ 1  not smaller than about 55 degrees, and the θ 4  to θ 1  ratio (θ 4 /θ 1 ) not smaller than about 0.8, even if the vehicle  10  has a long wheelbase, it becomes possible to increase the ramp brake-over angle θ 1 . Further, it becomes possible to increase the angle θ 4  to a value not significantly different from the ramp brake-over angle θ 1 . Therefore, it becomes less likely to rub the ground with the bottom of the vehicle especially in uphill situations. 
     By making the wheelbase not smaller than about 1340 mm and not greater than about 2000, and rear wheel  16  side wheel travel (RE+RC) to a value not smaller than about 360 mm, it becomes possible to increase the rear wheel  16  side wheel travel (RE+RC) in the vehicle  10  whose wheelbase is longer than typical ATV but shorter than those of the ROVs (Recreational Off-Highway Vehicles). This arrangement makes it less likely to rub the ground with the bottom of the vehicle especially in uphill travel situations. 
     By making the wheelbase not smaller than about 1340 mm and not greater than about 2000, and rear wheel  16  side wheel travel ratio of the stretch-side to the compression-side (stretch-side/compression-side: RE/RC) to a value not smaller than about 0.5, it becomes possible to relatively increase the rear wheel  16  stretch-side wheel travel RE in the vehicle  10  whose wheelbase is longer than typical ATVs but shorter than those of the ROVs. This arrangement makes it less likely to rub the ground with the bottom of the vehicle especially in downhill travel situations. Further, by making the front wheel  14  side wheel travel ratio of the stretch-side to the compression-side (stretch-side/compression-side: FE/FC) not smaller than about 0.5, it becomes possible to relatively increase also the front wheel  14  stretch-side wheel travel FE. This arrangement makes it less likely to rub the ground with the bottom of the vehicle especially in uphill situations. 
     By making the wheelbase not smaller than about 1340 mm and not greater than about 2000 mm; and the θ 2  to θ 1  ratio (θ 2 /θ 1 ) not smaller than about 1.25, it becomes possible to increase the front wheel  14  stretch-side wheel travel FE and the rear wheel  16  stretch-side wheel travel RE in the vehicle  10  whose wheelbase is longer than typical ATV but shorter than those of the ROVs. Therefore, it becomes less likely to rub the ground with the bottom of the vehicle regardless of road conditions (flat, uphill or downhill). 
     By making the minimum ground clearance H not smaller than about 275 mm, even the vehicle  10  which has a long wheelbase becomes less likely to rub the ground with the bottom of the vehicle regardless of road conditions (flat, uphill or downhill). 
     Preferred embodiments of the present invention are suitably applied to the vehicle  10  which is a four-wheel off-road vehicle including the bar handle  18  and/or the saddle-style seat  20 . 
     In the preferred embodiment of the present invention described above, description was made for a case where the vehicle  10  includes the pair of front wheels  14  and the pair of rear wheels  16 . However, preferred embodiment of the present invention are not limited to this. The present invention is applicable to vehicles which include a front and a rear wheel, including a plurality of at least one of the front and rear wheels, and also applicable to tricycles too. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.