Abstract:
In the transfer attachment construction of a 4WD vehicle, to facilitate assembly by making the retainer attachment bolts easier to tighten, to improve the coupling reliability of the retainer and mount bracket, to make easier the manufacture of the retainer by simplifying its design, to improve yield, and to make it less expensive, the retainer attachment bolts are prevented from interfering with the bracket attachment bosses. The bracket attachment bosses are disposed close enough to the transfer pinion axle center to avoid overlapping between the bracket attachment bosses and the retainer attachment bolts.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the transfer attachment construction of a 4WD vehicle and more particularly to the transfer attachment construction of 4WD vehicles that are based on FF vehicles (Front engine-Front drive). 
     BACKGROUND OF THE INVENTION 
     In 4WD vehicles in order to apply the engine&#39;s driving power to meet the running requirements, there exists, as power transmitters, a transmission, a differential, and, a transfer to distribute the driving power from the transmission. 
     However, in the case of 4WD vehicles that are based on FF vehicles (Front engine-Front drive), the transmission and differential are of one piece, and to the differential is connected a drive wheel axle. On top of the drive wheel axle is attached an independently formed transfer. 
     In the case of a transfer  102 , as shown in FIGS. 20 and 21, a retainer  108  is included and is attached to the rear of the transfer case  106  by retainer attachment bolts in the direction of transfer pinion axle center C at the rear of the vehicle and supported by the transfer pinion axle (not shown) which runs lengthwise of the vehicle, namely, at top right, retainer attachment bolt NO.  1  ( 104 - 1 ), at bottom right, retainer attachment bolt NO.  2  ( 104 - 2 ) at top left, retainer attachment bolt NO.  3  ( 104 - 3 ), and at bottom left, retainer attachment bolt NO.  4  ( 104 - 4 )(not shown). Also, protruding at the right of retainer  108  is the top right NO.  1  bracket attachment boss  110 - 1  and the bottom right NO.  2  bracket attachment boss  110 - 2 , to which is attached the mount bracket  114  by mount attachment bolt NO.  1  ( 112 - 1 ) and by mount attachment bolt NO.  2  (  112 - 2 ) in an almost perpendicular orientation to transfer pinion axle center C. The mount bracket forms an S shaped space which supports a mount (not shown), and comprises NO.  1  and NO.  2  bolt supporting bosses  118 - 1  and  118 - 2  which contain NO.  1  and NO.  2  bracket attachment bolt holes  116 - 1  and  116 - 2  (not shown) through which must pass NO.  1  and NO.  2  bracket attachment bolts  112 - 1  and  112 - 2 . It also comprises a first attachment section  120 , which is located at the right side of retainer  108 , and an opposite attachment section  122 , which is located in opposition to the first attachment section  120  and set apart from the right side of retainer  108 . At the tips of both attachment sections are mount supporting bosses  124  and  126 . Also, the first attachment section  120  is attached to another bracket attachment boss, the NO.  3  bracket attachment boss  128 , which is formed at the rear of retainer  108 . The first attachment section  120  is attached to the No.  3  bracket attachment boss  128  by the NO.  3  bracket attachment bolt  130 . In this case, as shown in FIG. 21, the center lines M 1  and M 2  of NO.  1  and NO.  2  bracket attachment bosses  110 - 1  and  110 - 2  are at distances E 1  and E 2  from the transfer pinion axle center C, and also, at transfer pinion axle center C, overlap the head sections of NO.  1  and NO.  2  retainer attachment bolts  104 - 1  and  104 - 2 . 
     Further, as shown in FIGS. 22 and 23, in the case of a transfer  202 , a retainer  208  is included, and is attached to the rear of the transfer case  206  by retainer attachment bolts, in a rearward direction from transfer pinion axle center C and supported by the transfer pinion axle (not shown) which runs lengthwise of the vehicle, namely, at top right, retainer attachment bolt NO.  1  ( 204 - 1 ), at bottom right, retainer attachment bolt NO.  2  ( 204 - 2 ), at top left, retainer attachment bolt NO.  3  ( 204 - 3 ), and at bottom left, retainer attachment bolt NO.  4  ( 204 - 4 )(not shown). Also, a one piece mount bracket  216  is formed to the right side of retainer  208  and comprises supporting boss  210 , first attachment section  212  and opposite attachment section  214 . 
     Examples of this kind of transfer construction are disclosed in published Japanese Patent Application Laid-Open No. 10-291426 and Japanese Patent Application Laid-Open No. 10-203190. In Japanese Patent Application Laid-Open No. 10-291426, an extension housing is connected to the transfer case, and also, in the cylindrically shaped rotating body, a lubricating oil passage is formed that connects with the extreme section on the transfer side In Japanese Patent Application Laid-Open No 10-203190, a lubricating oil groove is formed on the inner side of the transfer case and a mound is formed on one of the ball bearings in the spacer. 
     However, it has conventionally been the case that in a transfer as shown in FIGS. 20 and 21 the NO.  1  and NO.  2  bracket attachment bosses in the direction of the transfer pinion center overlap with the NO.  1  and NO.  2  bracket retainer attachment bolt heads. In such a case, when attaching the retainer to the transfer case the NO.  1  and NO.  2  retainer attachment bolts interfere with the NO.  1  and NO.  2  bracket attachment bosses, making it difficult to tighten the NO.  1  and NO.  2  retainer attachment bolts and thereby decreasing assembly efficiency as well as the coupling reliability of the retainer and mount bracket. 
     Also, in a transfer as shown in FIGS. 22 and 23, as the retainer and mount bracket are formed of a single piece, the construction of the complete retainer is complicated and the manufacture is made difficult. Furthermore, yield is decreased and manufacture is expensive. 
     SUMMARY OF THE INVENTION 
     Therefore, in order to eliminate the above-described disadvantages in the transfer attachment construction of a 4WD vehicle, the present invention is characterized by the retainer being attached to a transfer case by retainer attachment bolts in line with the center of a transfer pinion axle where the transfer pinion axle is disposed in a front-to-rear direction of the vehicle, by the retainer including a bracket attachment boss to which a mount bracket is attached by bracket attachment bolts and at an almost perpendicular orientation to the transfer pinion axis, and by the retainer attachment bolts being prevented from interfering with the bracket attachment boss by disposing the bracket attachment boss close enough to the transfer pinion axle to avoid overlapping between the bracket attachment boss and the retainer attachment bolts as the bolts are screwed into the transfer case in a direction in line with the transfer pinion axle. 
     According to the present invention, in order to prevent the retainer attachment bolts from interfering with multiple bracket attachment bosses, the bracket attachment bosses are disposed close enough to the transfer pinion axle to thereby avoid overlapping between the bracket attachment bosses and the retainer attachment bolts. By this means, when attaching the retainer to the transfer case, the retainer attachment bolts will not interfere with the bracket attachment bosses, the retainer attachment bolts are easier to tighten, thus increasing ease of assembly, and the coupling of the retainer and mount bracket is improved. To this same end, retainer construction design is simplified, making for ease of manufacture; also, yield is increased, and construction costs are lessened. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a right side view of a retainer as indicated by arrow number one in FIG.  3 . 
     FIG. 2 is a left side view of a retainer as indicated by arrow number  2  in FIG.  3 . 
     FIG. 3 is a plan view of a retainer. 
     FIG. 4 is a rear view of a retainer as indicated by arrow number  4  in FIG.  3 . 
     FIG. 5 is a right side view of a retainer to which a mount bracket is attached as indicated by arrow number  5  in FIG.  7 . 
     FIG. 6 is a left side view of a retainer to which a mount bracket is attached as indicated by arrow number  6  in FIG.  7 . 
     FIG. 7 is a plan view of a retainer to which a mount bracket is attached. 
     FIG. 8 is a rear view of a retainer to which a mount bracket is attached as indicated by arrow number  8  in FIG.  7 . 
     FIG. 9 is a right side view of a mount bracket as indicated by arrow number  9  in FIG.  10 . 
     FIG. 10 is a plan view of a mount bracket. 
     FIG. 11 is a rear view of a mount bracket as indicated by arrow number  11  in FIG.  10 . 
     FIG. 12 is a right side view of a transfer as indicated by arrow number  12  in FIG.  14 . 
     FIG. 13 is a left side view of a transfer as indicated by arrow number  13  in FIG.  14 . 
     FIG. 14 is a plan view of a transfer. 
     FIG. 15 is a rear view of a transfer as indicated by arrow number  15  in FIG.  14 . 
     FIG. 16 is a cross-sectional view of a transfer. 
     FIG. 17 is a plan view of a section of a vehicle. 
     FIG. 18 is a right side view of a retainer according to a second embodiment 
     FIG. 19 is a right side view of a retainer according to a third embodiment of the present invention. 
     FIG. 20 is a plan view of a mount bracket as conventionally attached using parts of separate construction. 
     FIG. 21 is a right side view of a retainer as indicated by arrow number  21  in FIG.  20 . 
     FIG. 22 is a plan view of a mount bracket as conventionally attached using integrally constructed parts. 
     FIG. 23 is a side view of a retainer as indicated by arrow  23  in FIG.  22 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the present invention will now be described in detail and concretely according to the drawings. FIGS. 1 through 17 show a first embodiment of the invention. In FIG. 17, reference numeral  2  designates a 4WD vehicle (Four Wheel Drive vehicle) based on an FF vehicle (Front Engine, Front Drive vehicle) [referred to hereafter as vehicle], reference numeral  4  designates the engine room, reference numeral  6  designates the engine, reference numeral  8  designates the transmission, reference numeral  10  designates the transfer, reference numeral  12  designates the propeller shaft, reference numerals  14  designate the front axles, and reference numerals  16  designate the front wheels. 
     Engine  6 , transmission  8 , and transfer  10  are integrally connected and are given resilient support within the vehicle (not shown) by the engine side mount supporting section  18 , transmission side mount supporting section  20 , and the transfer side mount supporting section  22 . Also, the transfer  10  is separately attached to the transmission  8 . 
     In transfer  10 , as shown in FIGS. 12,  13 ,  14 ,  15 ,  16 , the retainer  26  is attached to the transfer case  24 . Also, the drive wheel axle  28  that is connected to the differential gear section (not shown) of the transmission  8  is supported by the transfer case  24 . Furthermore, the ring-shaped transfer power input axle  30  is loosely fastened around the drive wheel axle  28 . One end of this transfer power input axle  30  is connected with the differential case (not shown). At the approximate center of said transfer power input axle  30 , a transfer power input gear  32  is integrally formed. Also, in support of the transfer case  24 , there is a transfer counter axle  34  running approximately parallel to the transfer power input axle  30 . In the construction of this transfer counter axle  34  there is included transfer counter gear  36 , which meshes with the transfer power input gear  32 . Also, in the transfer counter axle  34 , there is a transfer bevel gear  38 , which is positioned in a row with the transfer power gear  36 . The transfer bevel gear  38  is connected to the transfer counter axle  34  in spline fashion and is also attached to the transfer counter axle  34  by an affixing nut  40  screwed onto the transfer counter axle  34 . 
     As for the retainer  26 , it is supported by the transfer pinion axle  42 , which is disposed in a front to rear direction of the vehicle  2 . The transfer pinion axle  42  includes a transfer pinion gear (bevel pinion)  44 , which meshes with transfer bevel gear  38 . The transfer pinion axle  42  serves as the transfer exit. 
     The retainer  26  is connected to the rear of transfer case  24  using the retainer attachment bolt holes located on the rim of the front retainer attachment flange  46 , namely the upper right NO.  1  retainer attachment bolt hole  48 - 1 , the lower right NO.  2  retainer attachment bolt hole  48 - 2 , the upper left NO.  3  retainer attachment bolt hole  48 - 3 , and the lower left NO.  4  retainer attachment bolt hole  48 - 4 . Through the retainer attachment bolt holes are passed retainer attachment bolts from the rear of the vehicle  2  and oriented to the transfer pinion axle  42  having center C. Namely, the upper right NO.  1  retainer attachment bolt  50 - 1 , the lower right NO.  2  retainer attachment bolt  50 - 2 , the upper left NO.  3  retainer attachment bolt hole  50 - 3 , and the lower left NO.  4  retainer attachment bolt hole  50 - 4  are passed through the bolt holes. The retainer attachment bolts NOs.  1 - 4  ( 50 - 1  through  50 - 4 ) are then screwed into case attachment holes (not shown) in the NOs.  1 - 4  case attachment bosses ( 52 - 1  through  52 - 4 ) at the rear of transfer case  24 . At the rear of the retainer  26 , there is provided a propeller shaft attachment flange  54 . 
     In the retainer  26 , as shown in FIGS. 1 through 4, there are bracket attachment bosses which are at an almost perpendicular orientation to axle center C of transfer pinion axle  42  and which, on their right side, have only length Al protruding, namely, the NO.  1  bracket attachment boss  56 - 1  and the NO.  2  bracket attachment boss  56 - 2 , which are of an integrated construction. From the extreme right face of NO.  1  bracket attachment boss  56 - 1  and the NO.  2  bracket attachment boss  56 - 2 , there are bolt screw holes, namely, NOs.  1  and  2  bracket attachment bolt screw holes  58 - 1  and  58 - 2 , respectively. Also, the center lines M 1  and M 2 , of NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2  are moved closer to the axle center C of transfer pinion axle  42 , to a distance of L 1  and L 2 , so that when the NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2  are passed through the NOs.  1  and  2  retainer attachment bolt holes  48 - 1  and  48 - 2 , the heads of the NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2  avoid interference with the outer surfaces of NO.  1  bracket attachment boss  56 - 1  and the NO.  2  bracket attachment boss  56 - 2 ; and at the same time, the heads of the Nos.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2  are positioned to a distance of B 1  and B 2  from the center lines M 3  and M 4  of NOs.  1  and  2  retainer attachment bolt holes  48 - 1  and  48 - 2 . By this means, in the direction of the axle center c of transfer pinion axle  42 , there will be formed an interval or space D 1  between the outer surface of NO.  1  bracket attachment boss  56 - 1  and the outer surface of the head of NO.  1  retainer attachment bolt  50 - 1 , and there will be no overlapping between NO.  1  bracket attachment boss  56 - 2  and NO.  1  retainer attachment bolt  50 - 1 . Also, there will be formed an interval or space D 2  between the outer surface of NO.  2  bracket attachment boss  56 - 2  and the outer surface of the head of NO.  2  retainer attachment bolt  50 - 2 , and there will be no overlapping between NO.  1  bracket attachment boss  56 - 2  and NO.  1  retainer attachment bolt  50 - 2 . 
     Also, in retainer  26 , in the same direction as NO.  1  bracket attachment boss  56 - 1  and NO.  2  bracket attachment boss  56 - 2 , and to a length A 2  to the right and left of axle center C of transfer pinion  42 , there are formed other bracket attachment bosses, including on the upper side NO.  3  bracket attachment boss  56 - 3  and on the lower side NO.  4  bracket attachment boss  56 - 4 . NO.  3  bracket attachment boss  56 - 3  is positioned closer to axis center C of transfer pinion axis  42  to a distance of L 3  from the axis center C of transfer pinion axis  42 . By this means, when passing NO.  1  and NO.  3  retainer attachment bolts  50 - 1  and  50 - 3  through NOs.  1  and  3  retainer attachment bolt holes  48 - 1  and  48 - 3  there will be no interference with the heads of the NOs.  1  and  3  retainer attachment bolts  50 - 1  and  50 - 3 . Also, NO.  4  bracket attachment boss  56 - 4  is positioned closer to axis center C of transfer pinion axis  42  to a distance of L 4  from the axis center C of transfer pinion axis  42 . By this means, when passing NO.  2  and NO.  4  retainer attachment bolts  50 - 2  and  50 - 4  through NOs.  2  and  4  retainer attachment bolt holes  48 - 2  and  48 - 4 , there will be no interference with the heads of the NOs.  2  and  4  retainer attachment bolts  50 - 2  and  50 - 4 . Therefore, as shown in FIGS. 3 and 4, both ends of NO.  3  bracket attachment boss  56 - 3  are positioned, in the direction of axis center C of transfer pinion axis  42 , so as not to overlap the heads of NOs.  1  and  3  retainer attachment bolts  50 - 1  and  50 - 3 . Also, both ends of NO.  4  bracket attachment boss  56 - 4  are positioned, so as not to overlap the heads of NOs.  2  and  4  retainer attachment bolts  50 - 2  and  50 - 4 . NO.  3  bracket attachment bolt hole  60 - 3  is formed in NO.  3  bracket attachment boss  56 - 3 . NO.  4  bracket attachment bolt hole  60 - 4  is formed in NO.  4  bracket attachment boss  56 - 4 . 
     Mount bracket  62 , which makes up the transfer side support section  22 , is attached to retainer  26 . Mount bracket  62 , as shown in FIGS. 5-11, forms an S shaped space in support of the mount (not shown), and comprises NO.  1  and NO.  2  bolt supporting bosses  66 - 1  and  66 - 2 , which contain NO.  1  and NO.  2  bracket attachment bolt holes  60 - 1  and  60 - 2 , through which must pass NO.  1  and NO.  2  bracket attachment bolts  64 - 1  and  64 - 2 . Mount bracket  62  also includes a first attachment section  70  located on the right side of the retainer  26 , which comprises the NO.  3  and NO.  4  mount attachment bosses  68 - 3  and  68 - 4 , which include the NO.  3  and NO.  4  bracket attachment bolt screw holes  58 - 3  and  58 - 4 , into which are screwed the NO.  3  and NO.  4  bracket attachment bolts  64 - 3  and  64 - 4 . Mount bracket  62  also includes an opposite attachment section  72 , which is located in opposition to the first attachment section  70  and set apart from the right side of retainer  26 . At the tip of both attachment sections  70  and  72  are the first and opposite mount supporting bosses  74  and  76 . 
     NOs.  1  and  2  bracket attachment bolts  64 - 1  and  64 - 2  are those bolts which pass through NOs.  1  and  2  bracket attachment bolt holes  60 - 1  and  60 - 2  and are then screwed into NOs.  1  and  2  bracket attachment bolt screw holes  58 - 1  and  58 - 2 . NOs.  3  and  4  bracket attachment bolts  64 - 3  and  64 - 4  are those bolts which pass through NOs.  3  and  4  bracket attachment bolt holes  60 - 3  and  60 - 4  and are then,screwed into NOs.  3  and  4  bracket attachment bolts screw holes  58 - 3  and  58 - 4 . 
     Next, the operation of the first embodiment will be described. 
     When attaching retainer  26  to transfer case  24 , after passing each retainer attachment bolt  50  through each retainer attachment bolt hole  48  they will be screwed into the case attachment boss  52 . Since NOs.  1  and  2  bracket bosses  56 - 1  and  56 - 2  are positioned so as not to interfere with NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2 , tightening of NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2  is made easier, assembly efficiently improved, and the coupling between mount bracket  62  and retainer  26  also improved. 
     Also, mount bracket  62  is attached to retainer  26  by screwing NOs.  1  and  2  bracket attachment bolts  64 - 1  and  64 - 2  into NOs.  1  and  2  bracket attachment screw bolt holes  58 - 1  and  58 - 2  after passing them through NOs.  1  and  2  bracket attachment bolt holes  60 - 1  and  60 - 2 . Mount bracket  62  is also attached to retainer  26  by screwing NOs.  3  and  4  bracket attachment bolts  64 - 3  and  64 - 4  into NOs.  3  and  4  bracket attachment screw bolt holes  58 - 3  and  58 - 4  after passing them through NOs.  3  and  4  bracket attachment bolt holes  60 - 3  and  60 - 4 , in an opposite direction to NOs.  1  and  2  bracket attachment bolts  64 - 1  and  64 - 2 . Since NOs.  3  and  4  bracket bosses  56 - 3  and  56 - 4  are positioned at axle center C of transfer pinion axle  42 , assembly efficiency between the mount bracket  62  and retainer  26  is improved. 
     Moreover, since NOs.  3  and  4  bracket bosses  56 - 3  and  56 - 4  are positioned so as not to interfere with NOs.  1  through  4  retainer attachment bolts  50 - 1  through  50 - 4 , tightening of NOs.  1  through  4  retainer attachment bolts  50 - 1  through  50 - 4  is made easier and thus efficiency of assemble is improved. 
     Furthermore, mount bracket  62  is attached to retainer  26  as a separate construction, so that when compared to a one-piece integrated construction, the construction of retainer  26  is simplified, thus making its manufacture easier, increasing its yield, and reducing its cost. 
     FIG. 18 shows a specific constitution of the present invention as a second embodiment of the invention. 
     In this second embodiment, the same functional parts are designated by the same reference numerals with respect to the first embodiment. 
     The characteristics of the second embodiment reside in the following points. Taking retainer  26  as representative in shape of conventional retainers, the NO.  1  retainer attachment bolt hole  48 - 1  and NO.  2  retainer attachment bolt hole  48 - 2 , located in retainer side attachment flange  46 , are made to open outwards in a front to rear direction as well as to maintain an angle EΘ 1  in relation to the end face of retainer side attachment flange  46 . 
     In this specific second embodiment, however, by changing the angle Θ 1  alone of NO.  1  retainer attachment bolt hole  48 - 1  and NO.  2  retainer attachment bolt hole  48 - 2 , located in retainer side attachment flange  46 , other changes become unnecessary and interference between NOs.  1  and  2 , retainer attachment bolts  50 - 1  and  50 - 2  and NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2  is easily avoided. 
     FIG. 19 shows a specific constitution of the present invention as a third embodiment of the invention. 
     The characteristics of the third embodiment reside in the following points. Taking retainer  26  as representative in shape of conventional retainers, NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2 , in order to avoid interference with NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2 , have inclined their boss center line P to an angle Θ 2  in relation to the axle center C of transfer pinion axle  42 , and NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2  have positioned their center lines M 1  and M 2  at a distance of B 3  and B 4  from the center lines M 3  and M 4  of NO.  1  retainer attachment bolt hole  48 - 1  and NO.  2  retainer attachment bolt hole  48 - 2 . 
     In this specific third embodiment, however, by inclining to an angle Θ 2  (in relation to the axle center C of transfer pinion axle  42 ) the boss center line P that runs through NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2  alone, other changes become unnecessary, construction is simplified, and interference between NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2  and NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2  is easily avoided. 
     Further, in regard to this invention, as shown in FIG. 1, by slightly extending the rim of retainer attachment flange  46  and by constructing retainer attachment bolt hole  48  apart from axle center C of transfer pinion axle  42  it is also possible to place NOs.  1  and  2  retainer attachment bolts  50 - 1  and  50 - 2  so as to avoid interference with NOs.  1  and  2  bracket attachment bosses  56 - 1  and  56 - 2 . 
     As is clear from the detailed description of the invention, in order to prevent the retainer attachment bolts from interfering with the bracket attachment bosses, the bracket attachment bosses are disposed in line with and closer to the transfer pinion axle center thereby avoiding overlapping between the bracket attachment bosses and the retainer attachment bolts. By this means, when attaching the retainer to the transfer case, the retainer attachment bolts will not interfere with the bracket attachment bosses, the retainer attachment bolts are easier to tighten, thus increasing ease of assembly, and the coupling of the retainer and mount bracket is improved. To this same end, retainer construction design is simplified, making for ease of manufacture; also, yield is improved, and construction costs are lessened. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
       2 : Vehicle 
       6 : Engine 
       10 : Transfer 
       24 : Transfer case 
       26 : Retainer 
       42 : Transfer pinion axle 
       50 : Retainer attachment bolt 
       56 : Bracket attachment boss 
       62 : Mount bracket