Abstract:
A mounting device for a rim disk of a full face wheel for a vehicle has a disk disposed on a rotating table rotated by a rotating device about the center axis (X) of a full face wheel and radially positioned by a hub hole fitting piece and a rim disposed on the disk and radially positioned by arresting a rim drop part by a rim position arresting means, with the disk and rim being pressingly held between a disk support piece and a rim support piece by upwardly pulling an aligning rod connected to the rotating table through a rod connection means along the center axis (X) of the full face wheel while downwardly pressing a rim flange part by the rim support piece to bring the disk and the rim into a pressed state. By the rim disk mounting device, the disk and the rim radially positioned with high accuracy can be brought into pressed state with a strong holding pressure, and both the disk and the rim can be stably rotated. Thus, a thermal deformation can be suppressed and welding can be uniformly and accurately performed.

Description:
CROSS-REFERENCE TO PRIOR APPLICATION  
       [0001]     This is a U.S. National Phase Application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2003/016927, filed Dec. 26, 2003, which is incorporated by reference herein. The International Application was published in Japanese on Jul. 21, 2005as International Publication No. WO 2005/065969 under PCT Article 21(2).  
       TECHNICAL FIELD  
       [0002]     The present invention relates to a device for assembling an article and in particular, to a rim disk assembling device for use in the manufacture of full face wheels for vehicles to put together a disk and a rim at the time of welding.  
       BACKGROUND  
       [0003]     The full face wheel for vehicles is made up of a disk and a rim. The disk has a circumferential disk flange for holding the tire bead from its side. The rim has, at its one end opening, a joint opening circumferential end to be joined by welding to the back face of the disk and, at its other end opening, a rim flange portion. Here, it is a common practice to join the disk and the rim, in the state of the joint opening circumferential end of the rim made into contact with a specified position on the back face of the disk, by fillet welding from outside along the circumferential direction.  
         [0004]     When the disk and the rim are joined by welding, they must be radially positioned so that their radial centers are in agreement with each other, and high accuracy is required in the radial positioning. If the radial positioning accuracy were low, anti-wobble accuracy of the welded full face wheel would be low, which could result in that the vehicle provided with such wheels cannot exhibit desired driving performance. The disk and the rim are also required to be joined by welding in the state of both components being put together and pressed against each other with relatively great forces. This is to restrict thermal deformation due to weld heat produced during welding and to prevent the anti-wobble accuracy from lowering due to the thermal deformation by pressing together the disk and the rim.  
         [0005]     A rim disk assembling device, that makes it possible to radially position the disk and the rim with high accuracy and restrict the thermal deformation, as described above, is described in the Patent Document JP-B-2793001. This rim disk assembling device has a structure in which the hub hole of a disk is fit over a hub hole guide provided on a rotary table, and a rim clamp, capable of contacting the rim as guided with a centering pole provided in the center of the hub hole guide, is pressed against the rim placed on the disk.  
         [0006]     The hub hole is fit over the hub hole guide to radially position the disk. Further, by pressing the rim clamp against the rim, to bring the disk and the rim placed on the rotary table into pressed contact state and, at the same time, the outside round taper surface of the rim clamp with its wedge effect radially positions the rim. In this way, it is possible to radially position the rim and the disk with high accuracy and bring the both components into pressed contact state.  
         [0007]     With respect to the above described rim disk assembling device, the pressing force for bringing the disk and the rim into pressed contact state becomes a direct load onto the rotary table rotated at the time of welding. In order that the load may not work on the driving motor, transmission members, such as gears, are interposed between the rotary table and the driving motor for rotating the rotary table, and the rotary shaft of the driving motor and the rotary shaft of the rotary table are not disposed on the same axis. As for the transmission member, such as gears, it is a common practice to provide small clearance, the so-called backlash, between meshing gears to transmit rotation smoothly. However, due to this backlash, the rotation of the driving motor is not transmitted accurately to the rotary table at the times of start and stop of rotation. As a result, it is hard to rotate the disk and the rim in a stabilized manner at the time of welding, which causes a limit to stabilizing the weld quality.  
         [0008]     Moreover, the pressing force for bringing the disk and the rim into pressed contact state is also applied directly to the bearings and the like supporting the rotary table. As a result, local stress concentration occurs on the bearings due to errors occurring inherently in the manufacture of the disk and the rim. The stress concentration could lower strength and durability of the rotary table and the bearings. Moreover, to alleviate such a problem, the magnitude of the pressing force for bringing the disk and the rim into pressed contact state must be limited. As a result, welding cannot be made under a satisfactorily pressed contact state. Therefore, there is a limit to restricting thermal deformation occurring during welding.  
       SUMMARY  
       [0009]     An object of the present invention is to provide a rim disk assembling device for a vehicle full face wheel that makes it possible to solve the above problems, to radially position the disk and the rim with high accuracy, and to restrict sufficiently the thermal deformation occurring during welding.  
         [0010]     According to one embodiment of the present invention, a rim disk assembling device for a vehicle full face wheel includes a centering rod moving up and down along a center axis of a full face wheel and a rotary table rotated about the center axis by a rotating means. The device has a hub hole fitting member disposed on the rotary table to radially position a disk by fitting to the hub hole of the disk and also includes a disk supporting member disposed on the rotary table to support the disk from the designed surface side of the area joined to a rim. A rim supporting member moves down along the center axis together with the centering rod to support the rim disposed on the disk supported with the hub hole supporting member and the disk supporting member by pressing from above its rim flange portion. The system includes a rim position restraining means that radially positions the rim by radially restraining the inside circumferential surface of a rim drop portion as centered on the centering rod.  
         [0011]     A rod connecting means is configured for connecting the centering rod that has moved down along the center axis to the rotary table. The present device is adapted to bring into a pressed contact state the disk radially positioned with the hub hole fitting member and the rim radially positioned with the rim position restraining means by sandwiching them between the disk supporting member and the rim supporting member and by pulling up the centering rod connected through the rod connecting means to the rotary table while pressing down the rim flange portion with the rim supporting member.  
         [0012]     The above arrangement is to bring the radially positioned disk and rim into pressed contact state by the downward press with the rim supporting member and by the upward pull with the disk supporting member. In this way, the downward pressing force (hereinafter called the pressing force) and the upward pulling force (hereinafter called the pulling force) work as forces for sandwiching the disk and the rim (hereinafter called the sandwiching forces) so as to prevent a heavy load from working on the rotating means for rotating the rotary table. Here, making the pulling force greater than the pressing force results in that the load does not work directly on the rotating means. Further, making the pressing force and the pulling force about the same amount results in that almost all of the resultant force of those forces is used for sandwiching, so that the load is prevented from working on areas other than the working areas where the disk and the rim are sandwiched.  
         [0013]     Therefore, this rotating means is capable of rotating the rotary table stably and suitably even when the disk and the rim are in a pressed contact state. Besides, since no heavy load works on the rotating means while the disk and the rim are sandwiched, the pressing force and the pulling force may be made to work heavily so as to bring the rim and the disk into a pressed contact state to sufficiently restrict thermal deformation occurring during welding. This makes it possible to improve and stabilize weld quality of the disk and the rim. As a result, it is possible to manufacture the full face wheels for vehicles with higher anti-wobble accuracy, that exhibit lower vibration and lower noise characteristics in comparison with the rim disk assembling device of the conventional arrangement described above.  
         [0014]     Further, since no load works on the supporting member supporting the rotary table from under, stresses are prevented from locally concentrating on the supporting member, so that rotation may be maintained stably and suitably even if a large number of assembly processes are carried out.  
         [0015]     According to the present invention, the radial position of the rim is determined by restraining the rim drop portion using the rim position restraining means. Here, the rim drop portion is the portion formed generally with the highest accuracy. Therefore, this rim disk assembling device is capable of radially positioning the rim with high accuracy.  
         [0016]     On the other hand, according to the invention, the disk supporting member and the rim supporting member are disposed generally vertically directly above and below the joint area of the disk and the rim. In this way, the sandwiching forces for sandwiching the disk and the rim work directly on the joint area, so that pressed contact state between both the components is produced efficiently. Moreover, since the rim position restraining means radially restrains the rim drop portion, the rim drop portion is restricted from bend-deforming radially by the sandwiching forces of the disk and the rim. As a result, the sandwiching forces work suitably to press together the disk and the rim even if the pressing force and the pulling force are increased, thereby making it possible to create a firmly pressed contact state.  
         [0017]     Also with the rim disk assembling device for a vehicle full face wheel as described above, an arrangement is proposed in which the rod connecting means includes: a clamp portion formed at the tip of the centering rod; a rod insertion hole formed in the center of the rotary table for the centering rod to be inserted into; and a rod gripping device disposed on the underside of the rotary table to grip and fix the clamp portion of the centering rod inserted into the rod insertion hole and projecting from the underside and to bring the rotary table and the centering rod into connected state in which they can move as a single body.  
         [0018]     In the above arrangement, as the rod gripping device brings the centering rod and the rotary table into connected state, the rotary table may be pulled along the center axis to move up parallel along with the pulling action of the centering rod. Therefore, it is possible to pull up the disk supporting member evenly over the circumference and to sandwich the disk and the rim equally over the circumference. The rod gripping device is capable of producing the pressed contact state of the disk and the rim relatively easily and suitably. Here, the rod gripping device is preferably constituted to grip the clamp portion of the centering rod in plural directions, at two radially opposite positions, or three positions equally spaced over the circumference, etc.  
         [0019]     Also with the rim disk assembling device for a vehicle full face wheel as described above, an arrangement according to one embodiment includes a vertical motion rotary unit on which a rod pulling device for pulling the centering rod into action, a rim supporting member, and a rim position restraining means are mounted; and a vertical motion frame to which the vertical motion rotary unit is connected to be rotatable and making vertical action like a single body, and connected to a vertical driving device for drive-causing the vertical action, in which the vertical motion rotary unit rotates like a single body with the rotary table when the disk and the rim are brought into sandwich-pressed contact state by setting the rotary table connected to the centering rod into pulling action by means of the rod pulling device.  
         [0020]     The above arrangement is to make it possible to cause the vertical motion rotary unit to make vertical action like a single body by the drive of the vertical driving device and when brought into the pressed contact state to rotate the vertical motion rotary unit like a single body together with the rotary table relative to the vertical motion frame by the rotating means. Further it is possible to set the centering rod into pulling action by the rod pulling device independently of the vertical action caused with the vertical driving device. In other words, it is possible with relatively easy and simple arrangement, as described above, to bring the disk and the rim into pressed contact state by strong sandwiching forces with high accuracy and to suitably exhibit the function and effect of the invention for stably rotating the disk and the rim. Thus, it is possible to improve and stabilize the weld quality of the vehicle full face wheel.  
         [0021]     With the above rim disk assembling device for a vehicle full face wheel, an arrangement is provided in which the vertical motion rotary unit has: a rim supporting member and a rim position restraining means mounted both on its underside; a rod pulling device disposed in its upper part; and a vertical motion table with a rod passage hole formed in its center for a centering rod to be inserted into to be vertically movable. The above arrangement is the one in which the vertical motion table or the above-described vertical motion rotary unit is disposed as a core; and the rim supporting member, the rim position restraining means, the centering rod, and the rod pulling device are suitably disposed on the vertical motion table. This makes it possible with the vertical motion rotary unit as a whole to perform accurately and easily the above described vertical action by the drive with the vertical driving device and the rotary action like a single body together with the rotary table. Therefore, it is possible, as described above, to exhibit more suitably the function and effect of the invention, bringing the disk and the rim into pressed contact state with high accuracy and rotating them stably.  
         [0022]     Here, an arrangement is proposed in which the rim position restraining means includes: a plural number of radial restraining members disposed in the vertical motion table at about constant angular intervals around the centering rod, each made up of a holding case, suspended from a vertical motion table, urged downward, and vertically movable; and a pressing member installed in the holding case, radially movable, urged radially inward, with its inside end having a pressed portion, and with its outside end having a contacting portion for contacting the inside circumferential surface of the rim drop portion; and a conversion guide member suspended from the vertical motion table to contact the pressed portions of the pressing members along with the downward motion of the vertical motion table, to cause the pressing members to extend radially outward, and to cause the contacting portions of the pressing members to press against the inside circumferential surface of the rim drop portion in the state in which the rim supporting member contacts the rim flange portion from above.  
         [0023]     This arrangement is to change the downward motion of the vertical motion table into radially expanding action of the pressing member disposed on the radial restraining members by means of the conversion guide member. Disposing the plural number of radial restraining members at about constant angular intervals on the circumference makes it possible to restrain the rim drop portion evenly along the circumference so as to radially position the rim with high accuracy. Since the rim drop portion is restrained in the state in which the rim supporting member contacts the rim flange portion from above, the rim and the disk radially positioned with high accuracy are suitably sandwiched together. On the other hand, as the vertical motion table moves up and the conversion guide member moves up relative to the radial restraining member, the pressing members having radially expanded are retracted by radially inward urging forces. This comes to the release of restraint on the rim drop portion. Thus the arrangement radially positions the rim with high accuracy and maintains the state until the welding of the rim and the disk is over, so that improvement and stability in weld quality are further enhanced. The rim position restraining device is made with a relatively simple mechanism, so that its action is stable. Maintenance and replacement are also easy, with excellent advantage that their costs can be reduced.  
         [0024]     On the other hand, an arrangement is proposed in which the rotating means is a rotating device with a rotary shaft disposed under the rotary table along the center axis to rotate the rotary table. In this arrangement, the rotation center of the rotary table and the rotary shaft of the rotating device may be placed on the center axis, so that the rotating device directly rotates the rotary table, without a speed reduction mechanism or gears interposed between the rotating device and the rotary table. This arrangement is easily made possible by the invention as described above in which no strong load works on the lower part of the rotary table when the disk and the rim are sandwiched together. This arrangement permits stabilized rotation of the rotary table about the center axis. Further, no backlash inherent in the speed reduction mechanism or gears is present, so that the rotation of the rotary table is optimized even at start point or stop point of rotation. Therefore, it is possible to weld the disk and the rim in the pressed contact state further evenly along the circumferential direction, so that weld quality is further improved.  
         [0025]     According to another aspect, an arrangement is provided in which the rotating device is a direct drive motor. The direct drive motor can produce continuously large torque and its rotation can be controlled with high accuracy because the current to torque characteristic is linear. As the direct drive motor directly rotates the rotary table, it is possible to further stabilize the rotation of the disk and the rim brought into pressed contact state with strong squeezing forces. As the rotation is controlled with high accuracy even at start point and stop point of rotation, it is possible to stabilize and make smooth the rotation of the rotary table from start to stop of rotation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0026]     The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings of illustrative embodiments of the invention in which:  
         [0027]      FIG. 1  is a schematic view of a rim disk assembling device for a vehicle full face wheel according to one embodiment of the present invention;  
         [0028]      FIG. 2  is a front view of the rim disk assembling device of  FIG. 1  ;  
         [0029]      FIG. 3  is an enlarged sectional view of a part, for squeezing together a disk and a rim, of the rim disk assembling device of  FIG. 1 ;  
         [0030]      FIG. 4  is an enlarged sectional view of a conversion guide member and a radial restraining member;  
         [0031]      FIG. 5  is a partially exploded sectional view in which the disk and the rim are placed in the rim disk assembling device of  FIG. 1 ;  
         [0032]      FIG. 6  is a sectional view in which a vertical motion rotary unit is being lowered with a vertical driving device;  
         [0033]      FIG. 7  is a sectional view of a state, following the stat of  FIG. 6 , in which the vertical motion rotary unit is in a lowered position; and  
         [0034]      FIG. 8  is a vertical sectional view of a vehicle full face wheel. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0035]     A schematic of a rim disk assembling device  1  for the vehicle full face wheel according to one embodiment of present invention is shown in  FIG. 1 . The rim disk assembling device  1  for use in assembling a vehicle full face wheel is shown as an embodiment in FIGS.  2  to  4 .  
         [0036]     The rim disk assembling device  1  for the vehicle full face wheel makes it possible to manufacture, for example, the vehicle full face wheel  70  shown in  FIG. 8  by putting together and welding the disk  72  and the rim  71 . The rim  71  has a rim flange portion  73  formed on its one circumferential opening end and a joint opening circumferential end  74  on the other circumferential opening end. The disk  72  has a disk flange portion  75  formed on its outside circumference. The full face wheel  70  is made as a single body by fillet welding the joint opening circumferential end  74  of the rim  71  to the back side of the disk  72 . Here in this embodiment, arc welding is used for the fillet welding. It is also possible for the fillet welding to use other known welding techniques, such as laser welding.  
         [0037]     The rim  71  has the rim flange portion  73  at the circumferential opening edge that is open on the back side in the wheel axis direction for holding one tire bead from its side, continuing, in the wheel axis direction toward the designed surface, to a bead seat portion  76  for seating the tire bead. Further, as continued from the bead seat portion  76 , a ledge portion  77  is formed on which is continuously formed a rim drop portion  78  for the tire bead to drop in when attaching the tire. On the other hand, the above-mentioned joint opening circumferential edge  74  is formed on the opening circumferential edge on the designed surface side in the wheel axis direction. Another bead seat portion  79  for seating the other bead of the tire is formed on the back side in the wheel axis direction. The bead seat portion  79  is formed continuous to the rim drop portion  78 . Incidentally, the back side of the vehicle full face wheel  70  in the wheel axis direction denotes the side opposite the designed surface side of the disk  72 .  
         [0038]     On the other hand, the disk  72  has in its center a hub hole  80 , with a hub attachment portion  81  formed on the radially outer side of the hub hole  80 , and with the hub attachment portion  81  jointed to a vehicle hub on its back side. The hub attachment portion  81  is provided with bolt holes (not shown). A swell portion  82  is formed to swell outward from the radially outer side of the hub attachment portion  81 . Plural number of decorative holes (not shown) are provided at constant circumferential intervals on the sloped surface sloping radially outward from the swell portion  82 . Further, a disk flange portion  75  is formed on the periphery of the disk  72 .  
         [0039]     Next, the rim disk assembling device  1  for the vehicle full face wheel is described. The following explanation refers to  FIG. 1 , which is illustrative of the rim disk assembling device  1 , of the invention.  
         [0040]     The rim disk assembling device  1  for the vehicle full face wheel is wholly supported on a base frame  2  as shown in  FIG. 2 . A vertical driving device  3  of an air cylinder type is disposed over the base frame  2 . The vertical driving device  3  is connected to a vertical motion frame  5  through a vertical motion shaft  4  for vertical drive. The vertical motion frame  5  is guided with guide rails  6 ,  6  provided vertically in the base frame  2  to move up and down along the center axis X of the full face wheel. The vertical motion frame  5  is connected through cross roller bearings  9  to a vertical motion rotary frame  8 . The vertical motion rotary frame  8  is adapted to be rotatable relative to the vertical motion frame  5  and also movable up and down together with the vertical motion frame  5  like a single body.  
         [0041]     Here, a rod pulling device  12  of a hydraulic cylinder type is installed in the vertical motion rotary frame  8 . The rod pulling device  12  pulls into action a centering rod  11  extending downward along the center axis X of the full face wheel. In other words, the centering rod  11  is pulled singly into action separately from other components such as a vertical motion rotary unit  7  and the vertical motion frame  5 . The centering rod  11  is driven with the vertical driving device  3  to move up and down together with the vertical motion rotary frame  8  like a single body along the center axis X. The tip of the centering rod  11  is formed to be a clamp portion  25  to be gripped with a rod connecting device  24  (See  FIG. 3 ) to be described later.  
         [0042]     Further, a vertical motion table  13  is attached to the underside of the vertical motion rotary frame  8 . The vertical motion table  13  as shown in  FIG. 3  is provided with a rod passage hole  45  in its center for passing the centering rod  11  in vertical direction, so that the centering rod  11  may be movable up and down within the rod passage hole  45 . On the underside of the vertical motion table  13 , four radial restraining members  14  and a conversion guide member  35  are provided. Further, a rim supporting member  15  is provided to support from above the rim flange portion  73  of the rim  71 . The rim supporting member  15  is of an annular shape about the center axis X to support the rim flange portion  73  evenly over its circumference. The vertical motion rotary unit  7  is made up of: the vertical motion rotary frame  8 , the rod pulling device  12  provided in the vertical motion rotary frame  8 , the vertical motion table  13 , the radial restraining members  14  attached to the vertical motion table  13 , the conversion guide member  35 , and the rim supporting member  15 .  
         [0043]     In the lower part of the base frame  2 , as shown in  FIGS. 2 and 3 , a direct drive motor  17  is disposed so that its rotary shaft  18  is coaxial with the center axis X. The rotary shaft  18  is connected through a rotary frame  19  to a rotary table  20 , so that the direct drive motor  17  directly drives the rotary table  20 . In this way, since the rotary table  20  is directly connected to the direct drive motor  17 , it has an advantage of being free from backlash between gears. Further, since the direct drive motor  17  can produce great torque continuously and its rotation can be controlled with high accuracy, the rotary table  20  may be rotated stably from start to stop of the rotation.  
         [0044]     The rotary table  20  is provided with a rod insertion hole  21  in its center as shown in  FIG. 3  for the centering rod  11  to be inserted and moved up and down on the center axis X. The top surface of the rotary table  20  is provided with a hub hole fitting member  28  formed about the center axis X of the full face wheel to make it possible to radially position the disk  72  with high accuracy by fitting into the hub hole  80  of the disk  72 . The hub hole fitting member  28  is disposed on a disk center supporting member  22  and formed also about the center axis X to support the hub attachment portion  81  of the disk  72  from the designed surface side as seen in the wheel axis direction. Here, the hub hole fitting member  28  and the disk center supporting member  22  are each provided with a hole (not shown) for the centering rod  11  to pass through. Thus, the centering rod  11  may pass from above the rotary table  20  downward through the hub hole fitting member  28 , the disk center supporting member  22 , and the rod insertion hole  21  of the rotary table  20 .  
         [0045]     Further on the top surface of the rotary table  20 , a disk supporting member  23  is formed about the center axis X on the radially outer side of the disk center supporting member  22  along the circumferential direction of the wheel. The disk supporting member  23  is placed in a position for supporting, from the designed surface side as seen in the wheel axis direction, the area of the disk  72  to which the joint opening circumferential end  74  of the rim  71  is joined. The disk supporting member  23  and the rim supporting members  15  are provided in circumferential, over and under positions approximately opposite to each other. Thus, squeezing forces work directly on the joint area between the disk  72  and the joint circumferential opening  74  of the rim  71 .  
         [0046]     The rod connecting device  24  for gripping the clamp portion  25  of the centering rod  11  projecting down through the rod insertion hole  21  is provided on the underside of the rotary table  20  on the radially outer side of the rod insertion hole  21 . The rod connecting device  24  is to grip on both sides of the clamp portion  25  of the centering rod  11  by extending gripping arms  26 ,  26  opposed to each other and capable of extending radially inward from outer retracted position. Thus, the rotary table  20  and the centering rod  11  are connected so that they move like a single body. Here, the rod connecting device  24  operates the gripping arms  26 ,  26  to extend/retract by means of air cylinders  27 ,  27 .  
         [0047]     On the other hand, as a rim position restraining means for radially positioning the rim  71 , as shown in  FIG. 3 , four radial restraining members  14  are provided on the underside of the vertical motion table  13  as suspended at about constant circumferential angular intervals around the rod insertion hole  45 . The radial restraining member  14  is made up of: a stripper bolt  42 , a holding case  38  suspended from the vertical motion table  13  by means of a holding spring  37  wound around the stripper bolt  42  to urge the radial restraining member  14  downward, and a pressing member  34  fit to be radially movable in the holding case  38  (See  FIG. 4 ). Here, the holding case  38  is vertically movable according to the movable length of the stripper bolt  42 . That is to say, when the holding spring  37  is elastically compressed as pressed from under, the vertical distance between the holding case  38  and the vertical motion table  13  decreases. When the pressure from under is removed, the elastic compression is released and the vertical distance, which has decreased, increases.  
         [0048]     Also here, as shown in  FIG. 4 , the pressing member  34  is installed in the holding case  38 , so that it moves vertically together with the holding case  38 . The pressing member  34  has a pressed portion  44  on its inside end and a contacting member  30  for contacting the inside circumferential surface of the rim drop portion  78  on its outside end. The pressed portion  44  has a sloped surface sloping up radially outward. Further, a spring groove  40  is formed between the pressed portion  44  and the contacting member  30 , and a pressing spring  33  is placed in the spring groove  40  so that the spring  33  expands and contracts in the radial direction. The pressing spring  33  is supported on its radially inside end with the groove inside surface (not shown) and on its radially outside end with a spring engaging portion  39  formed to project from the holding case  38  into the spring groove  40 . The pressing member  34  is urged with the pressing spring  33  radially inward in the holding case  38 . When the pressing spring  33  is compressed with a radially outward pressure, the pressing member  34  moves radially outward. When the radially outward pressure is removed, the elastic compression is released and the pressing member  34  retracts radially inward.  
         [0049]     Also as shown in  FIGS. 3 and 4 , a conversion guide member  35  is suspended from the underside of the vertical motion table  13  by means of a stripper bolt  41  and a guide spring  36  wound around the stripper bolt  41  to urge the conversion guide member  35  downward. The conversion guide member  35  is shaped with its outside having a guiding face  43  sloping up radially outward to be in contact with the pressed portion  44  of the pressing member  34 . The conversion guide member  35  is disposed within the radial restraining member  14  and around the rod insertion hole  45  so that the guiding face  43  may contact the pressed portion  44 . On the other hand, the conversion guide member  35  is suspended in a position that is higher than the radial restraining member  14 . The conversion guide member  35 , also like the holding case  38  described above, is adapted to be vertically movable according to the movable length of the stripper bolt  41 . That is to say, the vertical distance to the vertical motion table  13  decreases with pressing force from under, and when the pressing force is removed, the vertical distance, which has decreased, increases.  
         [0050]     Here, the guide spring  36  of the conversion guide member  35  is made to be harder to be elastically compressed by setting its spring constant higher than that of the holding spring  37  of the radial restraining member  14 , so that the conversion guide member  35  is harder to move upward than the radial restraining member  14 . In other words, when the vertical distance between the radial restraining member  14  and the vertical motion table  13  is shortened by a pressing force from under, the pressed portion  44  of the pressing member  34  contacts the guiding face  43 . At this time, since the conversion guide member  35  is hard to move upward, the pressing member  34  moves radially outward along the slope angle of the pressed portion  44  and the guiding face  43 , so that the distance between the radial restraining member  14  and the vertical motion table  13  decreases. On the other hand, when the pressing force from under is removed, the holding spring  37  elastically expands, the vertical distance between the radial restraining member  14  and the vertical motion table  13  increases, the guide spring  36  also expands elastically, and the pressing member  34  retracts radially inward. Incidentally in this embodiment, since the spring constant of the guide spring  36  is set considerably greater than that of the holding spring  37 , the elastic compression amount of the guide spring  36  is very small.  
         [0051]     As the radial restraining members  14  and the conversion guide member  35  are disposed using respectively the holding springs  37  and the guide springs  36 , the pressing forces of the pressing members  34  restraining the inside circumferential surface of the rim drop portion  78  are moderated by the respective elastic compression and do not become great forces to deform the rim drop portion  78  radially outward.  
         [0052]     As the pressing members  34  move outward as described above, the contacting members  30  are pressed against the inside circumferential surface of the rim drop portion  78  to restrain it. According to the present invention, as all the four radial restraining members  14  equally move the respective pressing members  34  outward to press the respective contacting members  30  against the inside circumferential surface of the rim drop portion  78 , it is possible to radially restrain the rim drop portion  78  in a position in which the center of the rim  71  coincides with the center axis X. As described above, the rim  71  is radially positioned with high accuracy by the rim position restraining means of the invention constituted with the radial restraining members  14  and the conversion guide member  35 .  
         [0053]     In the rim disk assembling device  1  for the vehicle full face wheel of the invention described above, the respective components are provided along the center axis X of the full face wheel to carry out vertical motion along the center axis X and rotary and radial motions about the center axis X. Therefore, it is possible to radially position the disk  72  and the rim  71  with high accuracy with their axes coinciding with the center axis X and to bring them into pressed contact state with strong squeezing forces easily and stably.  
         [0054]     On the other hand, the rim disk assembling device  1  for the vehicle full face wheel of the invention, as shown in the lower part of the base frame  2  of  FIG. 2 , is provided with a welding device  50  for fillet welding the disk  72  and the rim  71  brought into pressed contact state with the rim disk assembling device  1 . The welding device  50  is disposed radially outside of the rotary table  20  to move a welding torch  51  radially back and forth by the back and forth drive of an air cylinder  52 . It is controlled so that, when the rim  71  and the disk  72  come to a pressed contact state, the welding torch  51  is moved to an extended position to carry out arc welding synchronously with the rotation of the direct drive motor  17 .  
         [0055]     Next will be described the process of assembling and welding the vehicle full face wheel  70  by means of the above-described rim disk assembling device  1 .  
         [0056]     As shown in  FIG. 5 , the disk  72  is placed so that its hub hole  80  fits over the hub hole fitting member  28 . At this time, as for the disk  72 , the designed surface of its hub attachment portion  81  is supported with the top surface of the disk center supporting member  22 , while an area of the rim  71  to be joined to the joint opening circumferential end  74  is supported from the designed surface, from under, with the disk supporting member  23 . The disk  72  is radially positioned as the hub hole fitting member  28  fits into the hub hole  80  so that the center of the disk  72  coincides with the center axis X. Next, the rim  71  is placed on the disk  72  to bring it to a radial position for roughly joining.  
         [0057]     Then, the vertical driving device  3  is operated to lower the vertical motion frame  5  and the vertical motion rotary unit  7  as a whole. Along with the lowering motion of the vertical motion rotary unit  7 , the centering rod  11  goes into the holes bored in the center of the hub hole fitting member  28  and the disk center supporting member  22 . Further, as for the radial restraining members  14  as shown in  FIG. 6 , its downward motion stops when the bottom surface of its holding case  38  comes into contact with the back surface of the hub attachment portion  81  of the disk  72 . In this stop position, the contacting members  30  of the pressing members  34  of the radial restraining members  14  are in about the same height position as the inside circumferential surface of the rim drop portion  78 .  
         [0058]     Also after that, the vertical driving device  3  continues operation and components excluding the radial restraining members  14  of the vertical motion rotary unit  7  lower. As a result, as described above, the holding springs  37  of the radial restraining members  14  are elastically compressed, and the vertical distance between the radial restraining members  14  and the lowering vertical motion table  13  continues to decrease (See  FIGS. 6 and 7 ). Along with the lowering of the vertical motion table  13 , the conversion guide member  35  also lowers, the guiding faces  43  of the conversion guide member  35  comes into contact with the pressed portions  44  of the pressing members  34  of the radial restraining members  14 . Here, as described above, the spring constant of the holding spring  37  of the radial restraining member  14  is set to be lower than that of the guide spring  36  of the conversion guide member  35 , so that the guide spring  36  is harder to be elastically compressed. Therefore, along with the lowering of the vertical motion table  13 , the pressed portions  44  of the pressing members  34  move radially outward along the guiding face  43  of the conversion guide member  35 . This results in that the holding springs  37  of the radial restraining members  14  are further compressed. In other words, the conversion guide member  35  lowers relative to the radial restraining members  14 . Then, the pressing members  34  moving radially outward relative to the holding case  38  causes their contacting members  30  to contact the inside circumferential surface of the rim drop portion  78  (See  FIG. 7 ). Such radial restraining members  14  as described before are provided in four positions at about constant circumferential angular intervals, so that the contacting members  30  of the pressing members  34  nearly evenly contact the rim drop portion  78  to restrain the rim drop portion  78 . Thus, the rim  71  is radially positioned with its center coinciding with the center axis X. As the pressing members  34  are further urged radially outward, the pressing members  30  are pressed against the inside circumferential surface of the rim drop portion  78 , so that the radial position is maintained. Incidentally, the pressing springs  33  installed in the spring grooves  40  of the pressing members  34  are elastically compressed according to the radial outward motion of the pressing members  34 .  
         [0059]     On the other hand, according to the lowering of the vertical motion rotary unit  7 , the rim supporting member  15  provided on the underside of the vertical motion table  13  contacts from above the rim flange portion  73 . The centering rod  11  passes through the rod insertion hole  21  of the rotary table  20 , and the clamp portion  25  of the centering rod  11  projects below from the rotary table  20 . As the rim supporting member  15  presses the rim flange portion  73  with a specified pressing force, the vertical driving device  3  stops operation (See  FIG. 7 ). Here, it is adapted that the contacting members  30  of the pressing members  34  are made to contact the rim drop portion  78  in the state in which the rim supporting member  15  comes in contact with the rim flange portion  73 . This results in that, as the vertical motion rotary unit  7  further lowers, the rim supporting member  15  presses the radially positioned rim  71 , while the pressing members  34  maintain the radial positioning.  
         [0060]     Incidentally, in the present arrangement, the pressing force working from the rim supporting member  15  onto the rim  71  also works through the rotary table  20  onto the direct drive motor  17 . However, this pressing force is of such an amount the radial restraining members  14  exert for radially positioning the rim  71 , and is smaller enough than the squeezing force for squeezing the rim  71  and the disk  72  after the positioning. Therefore, the pressing force working on the direct drive motor  17  is very small, of the extent that does not affect the operation of the direct drive motor  17 , and so raises no problem.  
         [0061]     After the operation of the vertical driving device  3  is stopped as described above (See  FIG. 7 ), the gripping arms  26 ,  26  are radially extended by operating the air cylinders  27 ,  27  of the rod connecting device  24 . Next, as shown in  FIG. 3 , the gripping arms  26 ,  26  grip the radially opposite sides of the clamp portion  25  of the centering rod  11  projecting down below the rotary table  20  to interconnect the centering rod  11  and the rotary table  20 . Thus, the centering rod  11  and the rotary table  20  can move as a single body.  
         [0062]     After that, the rod pulling device  12  is operated to pull up the centering rod  11  while operating again the vertical driving device  3  so that the rim supporting member  15  depresses the rim flange portion  73 . Here, since the centering rod  11  is connected to the rotary table  20  as described above, the rotary table  20  is also pulled up. As a result, the disk supporting member  23  located on the rotary table  20  pushes up the joint area of the disk  72 . The hub attachment portion  81  of the disk  72  is also pushed up with the disk center supporting member  22 .  
         [0063]     Here, as the pulling force by the operation of the rod pulling device  12  and the pressing force by the operation of the vertical driving device  3  are made about the same each other, both the forces are almost entirely used to sandwich the disk  72  and the rim  71 . This means that no load due to the squeezing works on the rotary frame  19  and the direct drive motor  17 .  
         [0064]     As described above, the rim supporting member  15  depresses the rim flange portion  73  while the disk supporting member  23  pushes up the joint area of the disk  72 , so that the rim  71  and the disk  72  radially positioned respectively with high accuracy are sandwiched from above and under along the center axis X. Here, the squeezing forces on the rim  71  and the disk  72  work directly on the area where the rim  71  and the disk  72  are joined together. Besides, as the rim  71  is radially restrained along the rim drop portion  78  with the radial restraining members  14 , its radial deformation is restricted, which helps the squeezing forces work suitably on the joint area.  
         [0065]     As described above, the downward and upward forces required to sandwich the rim  71  and the disk  72  do not work on the direct drive motor  17  for rotating the rotary table  20 . Therefore, it is possible to further increase the depressing force produced with the vertical driving device  3  and the upward force produced with the rod pulling device  12  to further increase the squeezing forces for pressing together the rim  71  and the disk  72 . As a result, the rim  71  and the disk  72  are brought into pressed contact state with greater squeezing forces. Here, the depressing force and the upward force are set so that the squeezing forces are great enough to completely restrict thermal deformation caused by the weld heat during welding which will be described later.  
         [0066]     Then, after radially positioning the rim  71  and the disk  72  respectively with high accuracy and bringing them into pressed contact state with great forces as described above, they are joined together by arc welding. That is to say, by operating the air cylinder  52  of the welding device  50 , the welding torch  51  is extended and stopped at a position where welding of the rim  71  and the disk  72  is possible (See  FIG. 2 ). When the direct drive motor  17  is operated at a specified revolution to rotate the rotary table  20 , the torch  51  synchronously starts arc welding. As a result, the rim  71  and the disk  72  in pressed contact state are welded together over the circumferential direction. Incidentally here, along with the rotation of the rotary table  20 , the entire vertical motion rotary unit  7  rotates relative to the vertical motion frame  5 . When the rotary table  20  makes about one turn relative to the welding torch  51 , operation of the direct drive motor  17  is stopped and also welding operation with the welding torch  51  is stopped. Since the rim  71  and the disk  72  are maintained during the welding in pressed contact state with great squeezing forces as described above, thermal deformation due to weld heat can be almost perfectly restricted. Besides, since the rotary table  20  is rotated directly with the direct drive motor  17 , no backlash is present, great torque is produced stably under control, so that the rotary table  20  is rotated smoothly and evenly. Therefore, weld quality of the rim  71  and the disk  72  is improved and stabilized.  
         [0067]     After the welding with the welding device  50  as described above, the welding torch  51  is retracted. Then the pulling action with the rod pulling device  12  is stopped, and the load is removed. As a result, the squeezing forces acting on the disk  72  and the rim  71  are released. Further, the gripping arms  26 ,  26  of the rod connecting device  24  are retracted to release the connected state between the centering rod  11  and the rotary table  20 . After that, the vertical driving device  3  is operated to raise the vertical motion frame  5  and to raise the vertical motion rotary unit  7 . Here, along with the rise of the vertical motion table  13 , the holding springs  37  of the radial restraining members  14  elastically expand, so that the distance to the vertical motion table  13  increases. Since the conversion guide member  35  also rises, elastic compression of the pressing springs  33  is gradually released, so that the pressing members  34  move radially inward. As a result, the contacting members  30  of the pressing members  34  move off the inside circumferential surface of the rim drop portion  78  to release restraint on the rim drop portion  78  with the radial restraining members  14 .  
         [0068]     Along with further rise of the vertical motion rotary unit  7 , when the maximum motion length of the stripper bolt  42  is reached, the radial restraining members  14  rise together with the vertical motion table  13 . Thus, the entire vertical motion rotary unit  7  rises and stops (See  FIG. 4 ). After that, the vehicle full face wheel  70  made by welding together the disk  72  and the rim  71  present on the rotary table  20  is taken out to finish the assembling and welding process.  
         [0069]     With the rim disk assembling device  1  for the vehicle full face wheel according to this embodiment described above, the vehicle full face wheel  70  is manufactured, with the wheel  70  formed of the disk  72  and the rim  71  fillet-welded together while their centers being coaxial with each other with high accuracy and thermal deformation due to weld heat being restricted. Further, it is possible to enhance and stabilize the weld quality. Such a vehicle full face wheel  70  is a product exhibiting high anti-wobble accuracy, excellent vibration characteristic, and low noise characteristic.  
         [0070]     The rim disk assembling device according to any one of the embodiments of the present invention can find particular utility in any number of different applications.  
         [0071]     For example, the rim disk assembling device for a vehicle full face wheel according to the invention is a device in which a disk, placed on a rotary table rotated with a rotary device and radially positioned with a hub hole fitting member, and a rim, placed on the disk and radially positioned with its rim drop portion restrained with a rim position restraining means, are brought into pressed contact state by squeezing them with a disk supporting member and a rim supporting member by pulling up a centering rod connected through a rod connecting means to the rotary table while depressing the rim flange portion with the rim supporting member. Therefore, the device provides the following effects.  
         [0072]     a. Since no load works on the rotating means for rotating the rotary table or on the supporting member for supporting the rotary table, when the disk and the rim are brought into pressed contact state by squeezing them, it is possible to rotate the rotary table stably and carry out uniform, accurate welding.  
         [0073]     b. Since no load works on the rotating means, it is possible to bring the disk and the rim into pressed contact state with great squeezing forces that can sufficiently restrict thermal deformation occurring during the welding process.  
         [0074]     c. Since the rim drop portion, generally formed with highest accuracy, is restrained, the rim is radially positioned with high accuracy.  
         [0075]     d. Since the disk and the rim are sandwiched from just above and under the joint area of the disk and the rim, the squeezing forces work directly on the joint area, and strongly pressed contact state is produced efficiently and suitably.  
         [0076]     e. In comparison with the rim disk assembling device of conventional constitution described above, it is possible to manufacture vehicle full face wheels having high anti-wobble accuracy and exhibiting excellent, low vibration and low noise characteristics.  
         [0077]     In addition, with the rim disk assembling device in which the rod connecting means brings the rotary table and the centering rod into connected state permitting concerted motion by gripping the clamp portion of the centering rod passed through the rod insertion hole of the rotary table with the rod gripping device disposed on the underside of the rotary table, since the rotary table may be pulled up parallel along its center axis by the centering rod pulled into action, it is possible to pull up the disk supporting members evenly along the circumference and sandwich the rim and the disk evenly along the circumference.  
         [0078]     Moreover, with the rim disk assembling device including the vertical motion rotary unit on which the rod pulling device for pulling the centering rod into action, the rim supporting member, and the rim position restraining means are mounted; and the vertical motion frame connected to the vertical motion rotary unit for rotation and concerted vertical motion and to the vertical driving device for drive-causing the vertical motion, in which the vertical motion rotary unit is rotated together with the rotary table when the disk and the rim are brought into pressed contact state, it is possible as described above to bring the disk and the rim into pressed contact state with high accuracy by great squeezing forces to exhibit suitably and easily the function and effect of the invention for stably rotating these components, and improve and stabilize the weld quality.  
         [0079]     In addition, with the rim disk assembling device in which the vertical motion rotary unit has the rim supporting member and the rim position restraining means mounted on its underside, the rod pulling device disposed in its upper part, and the vertical motion table with the rod passage hole formed in its center for the centering rod to be inserted into to be vertically movable, the vertical motion rotary unit as a whole is capable of performing accurately and easily vertical motion as driven by the vertical driving device and rotary motion together with the rotary table. This makes it possible to further suitably exhibit function and effect of the above-described invention.  
         [0080]     Also, with the rim disk assembling device in which the rim position restraining means is adapted to press the contact portions of the pressing members of the radial restraining members disposed at about constant circumferential angular intervals against the inside circumferential surface of the rim drop portion in the state in which the rim supporting member contacts from above the rim flange portion as the pressed portions of the pressing members contact the conversion guide member along with the downward motion of the vertical motion table and thereby the pressing members move radially outward, it is possible to radially position the rim with high accuracy and maintain the positioning until welding of together the rim and the disk is over and to further enhance and stabilize the weld quality. Further, since it is constituted with a relatively simple mechanism, the rim restraining action is carried out stably. Besides, maintenance and replacement may also be made easily.  
         [0081]     Further, with the rim disk assembling device in which the rotating means is the rotating device with the rotary shaft disposed below the rotary table along the center shaft to rotate the rotary table, since the rotating device may be connected directly to the rotary table without a speed reduction mechanism or gears interposed in between, it is possible to rotate the rotary table about the center axis stably, to weld the disk and the rim in pressed contact state all the more evenly along the circumferential direction, and to further improve the weld quality.  
         [0082]     In addition, with the rim disk assembling device in which the rotating device is the direct drive motor, it is possible to rotate the rotary table for rotating the disk and the rim brought into pressed contact state with strong squeezing forces stably, accurately, and smoothly from start to stop of the rotation.