Abstract:
A rotating axis supporting device of the present invention includes: a housing; a rotating axis rotatably pivoted to the housing; a case for fixing the housing; and an adjustment mechanism adjusting a position of the rotating axis by causing an attachment surface of the housing attached to the case to be perpendicular to an axial direction of the rotating axis, attaching the housing to move relative to the case in parallel to the attachment surface, and moving the housing and the case relative to each other in parallel to the attachment surface.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a rotating axis supporting device provided with a cradle type rotary table which is placed on a machine tool. 
         [0003]    2. Description of the Related Art 
         [0004]    As a rotary table, there is a case in which a rotary driving device is used singly, and there is a “cradle type” rotary table in which a jig plate is rotated by a rotary driving device and a rotating axis supporting device.  FIG. 9  is an example of a configuration of a cradle type rotary table. A cradle type rotary table  1  includes a jig plate  40  on which a workpiece  50  to be machined is installed, a rotary driving device  10  which rotates the jig plate  40 , a rotating axis supporting device  20  which is provided at a position opposing the rotary driving device  10  and supports the jig plate  40 , and a base plate  41  on which both the rotary driving device  10  and the rotating axis supporting device  20  are placed. The jig plate  40  has one end supported by a bracket  11  provided in the rotary driving device  10  and has the other end supported by a bracket  23  provided in the rotating axis supporting device  20 . In addition, in the rotating axis supporting device  20 , a housing  22  provided with a bearing for a rotating axis  24  is attached to a case  21 . 
         [0005]    In the cradle type rotary table  1  having the configuration illustrated in  FIG. 9 , when the rotary driving device  10  rotates the bracket  11  about a rotation center  13  of a rotating axis  12 , due to the rotation, the jig plate  40  having one end supported by the bracket  11  is rotated, and the bracket  23  that supports the other end of the jig plate  40  is rotated about a rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20 . Therefore, in order to cause smoothly rotate the workpiece  50  to be machined, which is placed on the jig plate  40  having the end portions supported by the brackets  11  and  23 , as illustrated in  FIG. 10A , the positions in a height direction of the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20  need to be adjusted to be coincident with each other. In addition, as illustrated in  FIG. 10B , the positions in a depth direction of the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20  need to be adjusted to be coincident with each other. Furthermore, for the smooth rotation, the axial direction of the rotation center  13  and the axial direction of the rotation center  25  need to be coincident with each other. Therefore, as illustrated in  FIGS. 11A and 11B , the inclinations in the height direction and the inclinations in the depth direction of the rotation centers need to be adjusted. 
         [0006]    In a case where the positions and axial directions of the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20  are not adjusted to be coincident with each other, when the jig plate  40  is rotated, a strain occurs in the jig plate  40  due to the discordance between the rotation centers  13  and  25 , resulting in deterioration in components such as a bearing. 
         [0007]    As a related art in which the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20  are adjusted in the height direction, for example, Japanese Registered Utility Model No. 3183365 discloses, as illustrated in  FIG. 12 , a technique in which spacers  42  and  43  for height direction adjustment are produced to cope with the height difference between the rotation centers  13  and  25 , and by installing the spacers  42  and  43  under the rotary driving device  10  or the rotating axis supporting device  20 , the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20  are adjusted in the height direction. In addition, as illustrated in  FIG. 13 , an additional machining may also be performed on the base plate  41 , on which the rotary driving device  10  and the rotating axis supporting device  20  are provided, according to the height difference between the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20  for adjustment. 
         [0008]    On the other hand, for adjustment in the depth direction of the rotation center  13  of the rotary driving device  10  and the rotation center  25  of the rotating axis supporting device  20 , the entirety of the rotary driving device  10  or the rotating axis supporting device  20  is caused to slide in the depth direction to cope with the adjustment. 
         [0009]    However, in the method disclosed in Japanese Registered Utility Model No. 3183365 in which the spacers  42  and  43  corresponding to the height difference between the rotation centers  13  and  25  are used for the adjustment in the height direction, the height of the rotation center  13  of the rotary driving device  10  and the height of the rotation center  25  of the rotating axis supporting device  20  need to be measured and the spacers  42  and  43  need to be produced according to the height difference therebetween. In addition, in the method of performing an additional machining on the base plate  41 , similarly, the height of the rotation center  13  of the rotary driving device  10  and the height of the rotation center  25  of the rotating axis supporting device  20  need to be measured and the additional machining of the base plate  41  according to the height difference therebetween is necessary. Therefore, even in either method, there is a problem that a corresponding number of processes to the adjustment are necessary. 
         [0010]    In addition, in the adjustment method described above, it is difficult to accurately move the rotary driving device  10  and the rotating axis supporting device  20  in parallel. Therefore, the adjusted inclinations in the axial directions of the rotation centers  13  and  25 , which have already been adjusted, may be deviated in a case of performing adjustment of the rotation centers  13  and  25  in the height direction and the depth direction, and the inclinations of the axial directions thereof need to be re-adjusted. Accordingly, there is a problem that the number of processes for the adjustment also increases. 
       SUMMARY OF THE INVENTION 
       [0011]    The invention provides a rotating axis supporting device capable of adjusting the position of a rotation center of a rotating axis without the production of a spacer, an additional machining of a base plate, and an effect on the inclination of the rotation center. 
         [0012]    According to the invention, a rotating axis supporting device includes: a housing; a rotating axis rotatably pivoted to the housing; a case for fixing the housing; and an adjustment mechanism adjusting a position of the rotating axis by causing an attachment surface of the housing attached to the case to be perpendicular to an axial direction of the rotating axis, attaching the housing to move relative to the case in parallel to the attachment surface, and moving the housing and the case relative to each other in parallel to the attachment surface. In the rotating axis supporting device, a bolt may be disposed as the adjustment mechanism in the case, and the position of the rotating axis may be adjusted by moving the housing and the case relative to each other in parallel to the attachment surface by fastening or loosening the bolt. 
         [0013]    The rotating axis supporting device may further include an elastic body provided on a side opposing the bolt in the case. 
         [0014]    In addition, according to the invention, a rotary table includes: a jig plate having a workpiece installed thereon; a rotary driving device rotating the jig plate; the rotating axis supporting device provided at a position opposing the rotary driving device to support the jig plate; and a base plate having the rotary driving device and the rotating axis supporting device placed thereon. 
         [0015]    According to the invention, regarding adjustment in the height direction of the rotation center of the rotating axis supporting device in the cradle type rotary table, there is no need to add a spacer for height direction adjustment or there is no need to perform an additional machining of a base plate. Therefore, there is no need to increase the number of processes for adjustment. In addition, adjustment of the rotation center in the height and depth directions is possible without affecting the inclination of the rotation center. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The above and other objects and features of the invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0017]      FIG. 1  is a side view of a cradle type rotary table according to a first embodiment of the invention; 
           [0018]      FIG. 2  is an enlarged view of the periphery of a rotating axis supporting device in  FIG. 1 ; 
           [0019]      FIG. 3  is a top view of the cradle type rotary table according to the first embodiment of the invention; 
           [0020]      FIG. 4  is an enlarged view of the periphery of the rotating axis supporting device in  FIG. 3 ; 
           [0021]      FIG. 5  is a side view of a cradle type rotary table according to a second embodiment of the invention; 
           [0022]      FIG. 6  is an enlarged view of the periphery of a rotating axis supporting device in  FIG. 5 ; 
           [0023]      FIG. 7  is a top view of the cradle type rotary table according to the second embodiment of the invention; 
           [0024]      FIG. 8  is an enlarged view of the periphery of the rotating axis supporting device in  FIG. 7 ; 
           [0025]      FIG. 9  is a side view of a cradle type rotary table according to the related art; 
           [0026]      FIG. 10A  is a side view of the cradle type rotary table, illustrating adjustment of the positions of rotating axes in a height direction in the cradle type rotary table; 
           [0027]      FIG. 10B  is a top view of the cradle type rotary table, illustrating adjustment of the positions of the rotating axes in the depth direction in the cradle type rotary table; 
           [0028]      FIG. 11A  is a side view of the cradle type rotary table, illustrating adjustment of the inclinations of the rotating axes in the height direction in the cradle type rotary table; 
           [0029]      FIG. 11B  is a top view of the cradle type rotary table, illustrating adjustment of the inclinations of the rotating axes in the depth direction in the cradle type rotary table; 
           [0030]      FIG. 12  is a view illustrating adjustment of the positions of rotating axes in a height direction in a cradle type rotary table which uses spacers in the related art; and 
           [0031]      FIG. 13  is a view illustrating adjustment of the positions of rotating axes in a height direction in a cradle type rotary table through an additional machining of a base plate in the related art. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    Hereinafter, embodiments of the invention will be described with reference to the drawings. Like elements which are the same or similar to those of the related art are denoted by like reference numerals in the description. 
         [0033]      FIG. 1  is a side view of a cradle type rotary table provided with a rotating axis supporting device according to a first embodiment of the invention. In  FIG. 1 , a sectional view of portions of the periphery of a case is illustrated to cause the inside of the rotating axis supporting device to be recognized. A cradle type rotary table  1  illustrated in  FIG. 1  is configured such that a rotary driving device  10  and a rotating axis supporting device  20  of the embodiment of the invention are disposed on a base plate  41 . The rotating axis supporting device  20  of this embodiment is constituted by a case  21  and a housing  22  which rotatably supports a rotating axis  24  via a bearing. The case  21  is fixed onto the upper surface of the base plate  41 , and the housing  22  is attached to the case  21 . In addition, a bracket  11  and a bracket  23  are respectively fixed to the rotary driving device  10  and the rotating axis supporting device  20 . A jig plate  40  is installed on the brackets  11  and  23 . A workpiece to be machined is installed on the jig plate  40 , and the workpiece is subjected to indexing at a desired angle by the rotary driving device  10 . 
         [0034]      FIG. 2  is an enlarged view of the periphery of the rotating axis supporting device  20  of the cradle type rotary table  1  illustrated in  FIG. 1 . In  FIG. 2 , a sectional view of portions of the periphery of the case  21  is illustrated to cause the inside of the rotating axis supporting device  20  to be recognized. In the rotating axis supporting device  20  of this embodiment, an attachment surface  26  of the housing  22  attached to the case  21  is perpendicular to the axial direction of the rotating axis  24 . 
         [0035]    As illustrated in the figures, a plurality of insertion holes  28  having hole diameters slightly greater than the bolt diameters of fixing bolts  27  are provided in the housing  22 . In addition, in the case  21 , threaded holes  29  are provided at positions which correspond to the insertion holes  28  when the housing  22  is attached thereto. By respectively inserting the fixing bolts  27  into the insertion holes  28  and firmly screwing the fixing bolts  27  into the threaded holes  29  of the case  21 , the housing  22  is pressed against and fixed to the case  21  by the head portions of the fixing bolts  27 . In addition, by causing the fixing bolts  27  to be in a slightly loosened and temporarily fixed state, the housing  22  can be moved relative to the case  21  by the gap between the fixing bolt  27  and the insertion hole  28  in directions parallel to the attachment surface  26  (for example, a height direction and a depth direction) while the housing  22  is attached to the case  21 . In addition, although only two fixing bolts  27  are illustrated in  FIG. 2 , a sufficient number of fixing bolts  27  to obtain a pressing force to fix the housing  22  to the case  21  may be used. 
         [0036]    On the other hand, in the case  21 , a height direction adjustment insertion hole  31  into which a height direction adjustment bolt  30  can be inserted is provided. In addition, in the housing  22 , a height direction adjustment threaded hole  32  is provided at a position which corresponds to the height direction adjustment insertion hole  31  when attached to the case  21 . By inserting the height direction adjustment bolt  30  into the height direction adjustment insertion hole  31 , screwing the height direction adjustment bolt  30  into the height direction adjustment threaded hole  32 , and changing the screwing amount, the positional relationship between the case  21  and the housing  22  in the height direction can be adjusted. These configurations function as an adjustment mechanism which adjusts the position of a rotation center  25  in the height direction in this embodiment. 
         [0037]      FIG. 3  is a top view of the cradle type rotary table provided with the rotating axis supporting device  20  according to this embodiment illustrated in  FIG. 1 , and  FIG. 4  is an enlarged view of the periphery of the rotating axis supporting device  20  of the cradle type rotary table  1  illustrated in  FIG. 3 . In  FIGS. 3 and 4 , sectional views of portions of the periphery of the case are illustrated to cause the inside of the rotating axis supporting device to be recognized. 
         [0038]    As illustrated in  FIG. 4 , in the case  21 , a depth direction adjustment insertion hole  34  into which a depth direction adjustment bolt  33  can be inserted is provided. In addition, in the housing  22 , a depth direction adjustment threaded hole  35  is provided at a position which corresponds to the depth direction adjustment insertion hole  34  when attached to the case  21 . By inserting the depth direction adjustment bolt  33  into the depth direction adjustment insertion hole  34 , screwing the depth direction adjustment bolt  33  into the depth direction adjustment threaded hole  35 , and changing the screwing amount, the positional relationship between the case  21  and the housing  22  in the depth direction can be adjusted. Although two depth direction adjustment bolts  33  are illustrated in  FIG. 4 , the configuration of the periphery of the depth direction adjustment bolt  33  on the lower side is the same as that of the depth direction adjustment bolt  33  on the upper side. These configurations function as an adjustment mechanism which adjusts the position of the rotation center  25  in the depth direction in this embodiment. 
         [0039]    In the rotating axis supporting device  20  of this embodiment having the above-described configurations, adjustment of the rotation center  25  in the height direction is performed in the following order. 
         [0040]    [Procedure 1] The inclination of the axial direction of a rotation center  13  of a rotating axis  12  of the rotary driving device  10  and the inclination of the axial direction of rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  in both the height direction and the depth direction are adjusted in advance. 
         [0041]    [Procedure 2] In order to cause the position in the height direction of the rotation center  13  of the rotating axis  12  of the rotary driving device  10  and the position in the height direction of the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  to be coincident with each other, the fixing bolts  27  for fixing the housing  22  of the rotating axis supporting device  20  to the case  21  are caused to be in a loosened and temporarily fixed state. 
         [0042]    [Procedure 3] Ina case of increasing the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  in height, the height direction adjustment bolt  30  is fastened. Contrary to this, in a case of a decrease in height, the height direction adjustment bolt  30  is loosened. 
         [0043]    [Procedure 4] After the adjustment, the fixing bolts  27  are finally fastened to fix the housing  22  to the case  21 . 
         [0044]    In addition, adjustment in the depth direction of the rotation center  25  in the rotating axis supporting device  20  of this embodiment is performed in the following order. 
         [0045]    [Procedure 5] In order to cause the position in the depth direction of the rotation center  13  of the rotating axis  12  of the rotary driving device  10  and the position in the depth direction of the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  to be coincident with each other, the fixing bolts  27  for fixing the housing  22  of the rotating axis supporting device  20  to the case  21  are caused to be in a loosened and temporarily fixed state 
         [0046]    [Procedure 6] When the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  is moved in the + direction of the depth direction, the depth direction adjustment bolt  33  on the − direction side is loosened, and the depth direction adjustment bolt  33  on the + direction side is fastened. Contrary, for movement in the − direction, the depth direction adjustment bolt  33  on the + direction side is loosened, and the depth direction adjustment bolt  33  on the − direction side is fastened. 
         [0047]    [Procedure 7] After the adjustment, the fixing bolts  27  are finally fastened to fix the housing  22  to the case  21 . 
         [0048]    As described above, according to the structure of the invention, the housing can be simply moved by the height direction adjustment bolt. Therefore, there is no need to provide a spacer for height adjustment, and there is no need to perform an additional machining on the base plate. In addition, since the housing can be moved in parallel to the height direction, adjustment of the rotation center in the height direction is possible while maintaining the inclination of the rotation center. 
         [0049]    In addition, according to the structure of the invention, adjustment of the rotation center in the depth direction is also possible while maintaining the inclination of the rotation center. 
         [0050]      FIG. 5  is a side view of a cradle type rotary table provided with a rotating axis supporting device  20  according to a second embodiment of the invention, and  FIG. 6  is an enlarged view of the periphery of the rotating axis supporting device  20  of a cradle type rotary table  1  illustrated in  FIG. 5 . In  FIGS. 5  and  6 , sectional views of portions of the periphery of a case are illustrated to cause the inside of the rotating axis supporting device to be recognized. The rotating axis supporting device  20  of this embodiment is different from that of the first embodiment in that an elastic body is introduced into an adjustment mechanism which adjusts the position of a rotation center  25  in a depth direction and the position thereof in a depth direction. 
         [0051]    As in the first embodiment, a housing  22  of this embodiment is fixed to a case  21  by fixing bolts  27 . In addition, by causing the fixing bolts  27  to be in a slightly loosened and temporarily fixed state, the housing  22  can be moved relative to the case  21  in directions parallel to an attachment surface  26  while the housing  22  is attached to the case  21 . 
         [0052]    In addition, in the case  21  of this embodiment, a height direction adjustment threaded hole  36  which is threaded on the inner wall is provided. By screwing a height direction adjustment bolt  30  into the height direction adjustment threaded hole  36 , an end portion of the height direction adjustment bolt  30  protrudes from the inner portion of the case  21 , and by changing the screwing amount, the housing  22  can be pressed downward in the − direction of the height direction. 
         [0053]    On the other hand, a height direction adjustment elastic body  37  formed as a spring or the like is disposed at a position that opposes the height direction adjustment bolt  30  with the housing  22  interposed therebetween, and the housing  22  can be pressed upward in the + direction of the height direction by the elastic force. 
         [0054]      FIG. 7  is a top view of the cradle type rotary table provided with the rotating axis supporting device  20  according to this embodiment illustrated in  FIG. 5 , and  FIG. 8  is an enlarged view of the periphery of the rotating axis supporting device  20  of the cradle type rotary table  1  illustrated in  FIG. 7 . In  FIGS. 7 and 8 , sectional views of portions of the periphery of the case  21  are illustrated to cause the inside of the rotating axis supporting device to be recognized. 
         [0055]    As illustrated in  FIG. 8 , in the case  21  of this embodiment, a depth direction adjustment threaded hole  38  which is threaded on the inner wall is provided. By screwing a depth direction adjustment bolt  33  into the depth direction adjustment threaded hole  38 , an end portion of the depth direction adjustment bolt  33  protrudes from the inner portion of the case  21 , and by changing the screwing amount, the housing  22  can be pressed downward in the − direction of the depth direction. 
         [0056]    On the other hand, a depth direction adjustment elastic body  39  formed as a spring or the like is disposed at a position that opposes the depth direction adjustment bolt  33  with the housing  22  interposed therebetween, and the housing  22  can always be pressed in the + direction of the depth direction by the elastic force. 
         [0057]    In the rotating axis supporting device  20  of this embodiment having the above-described configurations, adjustment of the rotation center  25  in the height direction is performed in the following order. 
         [0058]    [Procedure 1] The inclination of the axial direction of a rotation center  13  of a rotating axis  12  of a rotary driving device  10  and the inclination of the axial direction of rotation center  25  of a rotating axis  24  of the rotating axis supporting device  20  in both the height direction and the depth direction are adjusted in advance. 
         [0059]    [Procedure 2] In order to cause the position in the height direction of the rotation center  13  of the rotating axis  12  of the rotary driving device  10  and the position in the height direction of the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  to be coincident with each other, the fixing bolts  27  for fixing the housing  22  of the rotating axis supporting device  20  to the case  21  are caused to be in a loosened and temporarily fixed state. 
         [0060]    [Procedure 3] Ina case of increasing the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  in height, the height direction adjustment bolt  30  is loosened. When the height direction adjustment bolt  30  is loosened, the housing  22  is raised by the elastic force of the height direction adjustment elastic body  37 . Contrary to this, in a case of a decrease in height, the height direction adjustment bolt  30  is fastened. By fastening the height direction adjustment bolt  30 , the housing  22  can be lowered against the elastic force of the height direction adjustment elastic body  37 . 
         [0061]    [Procedure 4] After the adjustment, the fixing bolts  27  are finally fastened to fix the housing  22  to the case  21 . 
         [0062]    In addition, adjustment in the depth direction of the rotation center  25  in the rotating axis supporting device  20  of this embodiment is performed in the following order. 
         [0063]    [Procedure 5] In order to cause the position in the depth direction of the rotation center  13  of the rotating axis  12  of the rotary driving device  10  and the position in the depth direction of the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  to be coincident with each other, the fixing bolts  27  for fixing the housing  22  of the rotating axis supporting device  20  to the case  21  are caused to be in a loosened and temporarily fixed state. 
         [0064]    [Procedure 6] When the rotation center  25  of the rotating axis  24  of the rotating axis supporting device  20  is moved in the + direction of the depth direction, the depth direction adjustment bolt  33  is loosened. By loosening the depth direction adjustment bolt  33 , the housing  22  is moved in the + direction of the depth direction by the elastic force of the depth direction adjustment elastic body  39 . Contrary, for movement in the − direction, the depth direction adjustment bolt  33  is fastened. 
         [0065]    By fastening the depth direction adjustment bolt  33 , the housing  22  can be moved in the direction of the depth direction against the elastic force of the depth direction adjustment elastic body  39 . 
         [0066]    [Procedure 7] After the adjustment, the fixing bolts  27  are finally fastened to fix the housing  22  to the case  21 . 
         [0067]    As described above, according to the structure of the invention, the housing can be simply moved by the height direction adjustment bolt. Therefore, there is no need to provide a spacer for height adjustment, and there is no need to perform an additional machining on the base plate. In addition, since the housing can be moved in parallel to the height direction, adjustment of the rotation center in the height direction is possible while maintaining the inclination of the rotation center. 
         [0068]    In addition, according to the structure of the invention, adjustment of the rotation center in the depth direction is also possible while maintaining the inclination of the rotation center. 
         [0069]    While the embodiments of the invention have been described above, the invention is not limited only to the above-described embodiments, and can be embodied in various forms by appropriately applying modifications. 
         [0070]    For example, in the above-described embodiments, the fixing bolts  27  are used to fix the housing  22  to the case  21 . However, for example, the housing  22  may be fixed to the case  21  by using an electromagnetic chuck or vacuum chuck, and in order to adjust the position of the rotation center, the housing  22  can be moved relative to the case  21  while being attached thereto in parallel to the attachment surface  26  by reducing a magnetic force applied to the electromagnetic chuck or reducing a suction force applied to the vacuum chuck. 
         [0071]    While the embodiments of the invention have been described above, the invention is not limited to the above-described embodiments, and can be embodied in other forms by appropriately applying modifications.