Patent Publication Number: US-2023132450-A1

Title: Steering device

Description:
FIELD 
     The present invention relates to a steering device. 
     BACKGROUND 
     A steering device disclosed in Patent Literature 1 includes a telescopic steering shaft supported by a cylindrical outer steering column. Accordingly, a position of a steering wheel can be changed in an axial direction of the steering shaft. The steering column also includes a lower column that is fixed to a vehicle body side and an upper column that supports the steering shaft. The upper column is slidably coupled to a lower shaft to be able to correspond to telescopic movement of the steering shaft. 
     The upper column by the steering device disclosed Patent Literature 1 is also restricted not to slide; thereby, a position of the steering wheel is secured in the axial direction. Specifically, the upper column disclosed in Patent Literature 1 includes a clamp that is externally slidably fitted to the lower column, a cylindrical part to which a bearing supporting the steering shaft is internally fitted, and a pair of protrusions that protrudes radially outward from an outer peripheral surface of the clamp. In addition, the steering device includes a bracket that includes a first side plate and a second side plate so that the clamp is interposed therebetween, and a fastening mechanism that fastens the first side plate and the second side plate. The fastening mechanism has a fastening shaft that penetrates the first side plate and the second side plate, and an operation lever that operates the fastening mechanism. A slit that has a groove width in a direction where the fastening shaft extends is provided in the clamp. The pair of protrusions is spaced apart from each other in the direction where the fastening shaft extends and is penetrated by the fastening shaft. In a case in which a fastening force of the fastening mechanism acts by the operation of the operation lever, the first side plate and the second side plate are brought close to each other along the fastening shaft. Thus, the pair of protrusions is fastened by the first side plate and the second side plate, and the groove width of the slit in the clamp is narrower. In other words, the clamp is deformed such that a diameter thereof is reduced to clamp the lower column disposed therein. As a result, the upper column is restricted not to slide, so that a position of the steering wheel is secured. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: Japanese Patent Application Laid-Open No. 2013-256193 
     SUMMARY 
     Technical Problem 
     In the upper column, the clamp is deformed during the operation of the operation lever, but the cylindrical part continuous with the clamp is not deformed. In other words, much stress is concentrated at a boundary between the clamp and the cylindrical part. For this reason, an upper column is provided with a rib near the boundary to improve a rigidity near the boundary. 
     However, in the case in which the rigidity near the boundary is improved, one end of the clamp continuous with the cylindrical part is difficult to be deformed. In addition, in a case of deforming the one end of the clamp continuous with the cylindrical part, a load on the operation lever increases, and the feel of operation of the operation lever is heavy. By contrast, in a case of deforming the other end of the clamp spaced apart from the cylindrical part, a load on the operation lever decreases, and the feel of operation of the operation lever is light. In other words, in a case in which the upper column slides to change a position fastened by the fastening mechanism, the feel of operation of the operation lever is changed, which gives an operator a sense of discomfort. 
     The present disclosure has been made in view of the above problem, and an objective of the present disclosure is to provide a steering device that enables an operation lever to be operated with the same feel of operation even though an upper column slides to change a fastening position of the fastening mechanism. 
     Solution to Problem 
     According to one aspect of the present disclosure, there is provided a steering device comprising: a telescopic steering shaft that extends in a first direction; a steering column that includes a lower column and an upper column that are configured to be relatively slidably coupled to each other in the first direction; a bracket including a first side plate and a second side plate configured to sandwich the steering column from a second direction orthogonal to the first direction; and a fastening mechanism that has an operation lever and a fastening shaft penetrating the first side plate and the second side plate and configured to fasten the first side plate and the second side plate, wherein the upper column includes: a clamp that has a slit extending in the first direction and that is configured to be externally slidably fitted to the lower column; a cylindrical part that extends from the clamp and that is configured to support the steering shaft; a pair of protrusions between which the slit is interposed, each of the protrusions protruding radially outward from the clamp and being provided with long groove into which the fastening shaft is inserted; and contact ribs that protrude from an outer peripheral surface of the clamp or side surfaces of the pair of protrusions and that are brought into contact with the first side plate and the second side plate fastened by the fastening mechanism, the clamp includes: a continuous clamp that is positioned near the cylindrical part and that is continuous with the cylindrical part; and a spaced clamp that is spaced apart from the cylindrical part, each of the protrusions includes: a continuous protrusion that protrudes from the continuous clamp; and a spaced protrusion that protrudes from the spaced clamp, the contact ribs include: a pair of first contact ribs each of which is disposed on the outer peripheral surface of the clamp and extends across the continuous clamp and the spaced clamp; a pair of second contact ribs each of which is disposed on a side surface of the protrusion and disposed opposite to the first contact rib with respect to the long groove, and extends across the continuous protrusion and the spaced protrusion; and at least one third contact rib that is disposed on a side surface of the spaced protrusion and disposed between the first contact rib and the long groove, and the at least one third contact rib has a protrusion amount greater than those of the first contact rib and the second contact rib. 
     The first side plate and the second side plate are brought close to the pair of protrusions by fastening of the fastening mechanism. Here, in a case in which the pair of protrusions interposed between the first side plate and the second side plate is a pair of the continuous protrusions, the first side plate and the second side plate come into contact with first contact ribs and second contact ribs. In addition, fastening of the fastening mechanism further causes the first side plate and the second side plate to press against the first contact ribs and the second contact ribs. Moreover, in the first side plate and the second side plate, the part between the portion brought in contact with the first contact rib and the portion brought in contact with the second contact rib is bent toward the upper column. Therefore, the operation force of the operation lever is used to deform the first side plate and the second side plate, which makes the feel of operation of the operation lever, normally heavy, becomes light. Meanwhile, in a case in which the pair of the protrusions interposed between the first side plate and the second side plate is a pair of the spaced protrusions, the first side plate and the second side plate are first brought into contact with a third contact rib, and then brought into contact with the first contact rib and the second contact rib. Accordingly, a load is started to be applied to the operation lever at a stage where the operation amount of the operation lever is small, and the feel of operation of the operation lever is heavy. In addition, more fastening of the fastening mechanism causes the first side plate and the second side plate to press against the first contact ribs, the second contact ribs, and the third contact rib, thereby, a pair of the spaced protrusions is fastened. Here, the first side plate or the second side plate is brought into contact with the third contact rib between the portion in contact with the first contact rib and the portion in contact with the second contact rib, so that the first side plate or the second side plate is not bent. Thus, the factor that makes the feel of operation of the operation lever lighter is eliminated. As described above, according to the steering device of the present disclosure, the feel of operation is lighter in a case in which the continuous clamp is fastened, and the feel of operation is heavier in a case in which the spaced clamp is fastened. Therefore, the difference in the feel of operation of the operation lever is small, which less causes discomfort to the operator. 
     Preferably, in one aspect of the steering device described above, the at least one third contact rib is a single contact rib, the second side plate has a lower rigidity than that of the first side plate, the pair of protrusions includes a first protrusion facing the first side plate and a second protrusion facing the second side plate, the third contact rib is disposed on the second protrusion, the contact ribs further include a single fourth contact rib that protrudes from a side surface of the first protrusion, and the fourth contact rib is disposed on a side surface of the spaced protrusion and between the first contact rib and the long groove, and has a protrusion amount equal to those of the first contact rib and the second contact rib. 
     In a case in which the first side plate presses against the first contact rib and the second contact rib, the first side plate is brought into contact with a fourth contact rib between the portion brought into contact with the first contact rib and the portion brought into contact with the second contact rib, so that the first side plate is not bent. Thus, the factor that makes the feel of operation of the operation lever lighter is eliminated, and the feel of operation in the case in which the spaced clamp is fastened can be made further heavier. The second side plate having a lower rigidity is brought into contact with the third contact rib. In a case in which the first side plate having a higher rigidity is brought into contact with the third contact rib after brought into contact with the third contact rib, the first side plate may not be deformed and may not press against the first contact rib and the second contact rib. Thus, according to the present disclosure, after brought into contact with the third contact rib, the second side plate is deformed, and reliably presses against the first contact ribs and the second contact ribs. 
     Advantageous Effects of Invention 
     The steering device of the present disclosure enables the operation lever to be operated with the same feel of operation even though the upper column slides to change the fastening position of the fastening mechanism. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a side view of a steering device of the present embodiment. 
         FIG.  2    is a perspective view of the steering device of the present embodiment. 
         FIG.  3    is a side view of the steering device of the present embodiment. 
         FIG.  4    is a cross-sectional view of the steering device cut along an axis illustrated in  FIG.  3   . 
         FIG.  5    is a side view of an upper column of the present embodiment. 
         FIG.  6    is a side view of the upper column of the present embodiment. 
         FIG.  7    is a cross-sectional view cut along VII-VII arrow line illustrated in  FIG.  5   . 
         FIG.  8    is a bottom view of the upper column of the present embodiment. 
         FIG.  9    is a cross-sectional view cut along IX-IX arrow line illustrated in  FIG.  1   . 
         FIG.  10    is an enlarged side view of a part of  FIG.  5    enlarged. 
         FIG.  11    is an enlarged side view of a part of  FIG.  6    enlarged. 
         FIG.  12    is a cross-sectional view cut along XII-XII arrow line illustrated in  FIG.  10   . 
         FIG.  13    is a cross-sectional view cut along XIII-XIII arrow line illustrated in  FIG.  10   . 
         FIG.  14    is a cross-sectional view illustrating a clamp having a high rigidity before the clamp is fastened. 
         FIG.  15    is a diagram illustrating the clamp having a high rigidity immediately after fastening is started. 
         FIG.  16    is a diagram illustrating a case in which the clamp having a high rigidity has been fastened, and illustrating a state in which a first side plate and a second side plate press against first contact ribs and second contact ribs. 
         FIG.  17    is a cross-sectional view illustrating a clamp with a low rigidity before the clamp is fastened. 
         FIG.  18    is a diagram illustrating the clamp having a low rigidity immediately after fastening is started. 
         FIG.  19    is a diagram illustrating a case in which the clamp having a low rigidity has been fastened, and illustrating a state in which the first side plate and the second side plate press against the first contact ribs and the second contact ribs. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, the present invention is described in detail with reference to the drawings. The present invention is not limited to the following embodiment (hereinafter referred to as an “embodiment”). In addition, components in the following embodiment include components capable of being readily assumed by those skilled in the art, components substantially identical, and components within the so-called equal range. Furthermore, the components disclosed in the following embodiment can be combined as appropriate. 
       FIG.  1    is a side view of a steering device of the present embodiment.  FIG.  2    is a perspective view of the steering device of the present embodiment.  FIG.  3    is a side view of the steering device of the present embodiment.  FIG.  4    is a cross-sectional view of the steering device cut along an axis illustrated in  FIG.  3   .  FIG.  5    is a side view of an upper column of the present embodiment.  FIG.  6    is a side view of the upper column of the present embodiment.  FIG.  7    is a cross-sectional view cut along VII-VII arrow line illustrated in  FIG.  5   .  FIG.  8    is a bottom view of the upper column of the present embodiment.  FIG.  9    is a cross-sectional view cut along IX-IX arrow line illustrated in  FIG.  1   .  FIG.  10    is an enlarged side view of a part of  FIG.  5    enlarged.  FIG.  11    is an enlarged side view of a part of  FIG.  6    enlarged.  FIG.  12    is a cross-sectional view cut along XII-XII arrow line illustrated in  FIG.  10   .  FIG.  13    is a cross-sectional view cut along XIII-XIII arrow line illustrated in  FIG.  10   .  FIG.  14    is a cross-sectional view illustrating a clamp having a high rigidity before the clamp is fastened.  FIG.  15    is a diagram illustrating the clamp having a high rigidity immediately after fastening is started.  FIG.  16    is a diagram illustrating a case in which the clamp having a high rigidity has been fastened, and illustrating a state in which a first side plate and a second side plate press against a first contact ribs and a second contact ribs.  FIG.  17    is a cross-sectional view illustrating a clamp with a low rigidity before the clamp is fastened.  FIG.  18    is a diagram illustrating the clamp having a low rigidity immediately after fastening is started.  FIG.  19    is a diagram illustrating a case in which the clamp having a low rigidity has been fastened, and illustrating a state in which the first side plate and the second side plate press against the first contact ribs and the second contact ribs. 
     First, a basic configuration of a steering device  100  is described. As illustrated in  FIG.  1   , the steering device  100  includes a steering wheel  101 , a steering shaft  102 , a first universal joint  103 , an intermediate shaft  104 , a second universal joint  105 , and a pinion shaft  106 . 
     The steering wheel  101  is attached to one end  102   a  of the steering shaft  102 . In a case in which a driver operates the steering wheel  101 , the steering shaft  102  rotates around an axis O, and an operation torque is applied to the steering shaft  102 . 
     A gearbox  110  is interposed between the other end  102   b  of the steering shaft  102  and the first universal joint  103 . An electric motor  120  is assembled with the gearbox  110  to apply an assist torque to the steering shaft  102 . In other words, the steering device  100  of the present embodiment is an electric power steering device that assists steering of the driver by using the electric motor  120 . The present invention may be applied to a steering device without the gearbox  110 . 
     One end of the intermediate shaft  104  is coupled to the first universal joint  103 . The pinion shaft  106  is coupled to the other end of the intermediate shaft  104  through the second universal joint  105 . As described above, the operation torque of the steering shaft  102  is transmitted to the pinion shaft  106  through the first universal joint  103 , the intermediate shaft  104 , and the second universal joint  105 . 
     As illustrated in  FIG.  2   , the steering device  100  further includes a steering column  1 , a first bracket  70 , a second bracket  80 , and a fastening mechanism  90 , in addition to the above-mentioned components. Next, the details of each component of the steering device  100  will be described. The XYZ Cartesian coordinate system is used in the following description. An X axis is parallel to the axis O of the steering shaft  102 . A Y axis is parallel to a vehicle width direction of a vehicle on which the steering device  100  is mounted. A Z axis is perpendicular to both the X and Y axes. A direction parallel to the X axis is described as the X direction, a direction parallel to the Y axis is described as the Y direction, and a direction parallel to the Z axis is described as the Z direction. A direction toward the front of the vehicle in the X direction is a +X direction. In a case in which an operator faces the +X direction, the right direction is a +Y direction. The upward direction in the Z direction is a +Z direction. The X direction may be referred to as a first direction, and the Y direction may be referred to as a second direction. 
     As illustrated in  FIG.  3   , the steering shaft  102  is assembled in a state of protruding from an end of the steering column  1  in a -X direction. As illustrated in  FIG.  4   , the steering shaft  102  has an upper shaft  108  that is a cylindrical shaft, and a lower shaft  109  that is a solid shaft. The steering wheel (see  FIG.  1   ) is attached to an end of the upper shaft  108  in the -X direction. An end of the upper shaft  108  in the +X direction is externally fitted to the lower shaft  109 . The end of the upper shaft  108  in the +X direction and an end of the lower shaft  109  in the -X direction are spline-fitted to each other. Therefore, the upper shaft  108  can slide on the lower shaft  109  in the X direction. 
     An end of the lower shaft  109  in the +X direction enters an inside of a housing  111  of the gearbox  110 . A torsion bar  112 , an output shaft  114  that is an outer cylinder of the torsion bar  112 , and a worm wheel  115  that is externally fitted to the output shaft  114  are provided inside the housing  111  of the gearbox  110 . The worm wheel  115  is engaged with a worm (not illustrated) that is coupled to the output shaft  114  of the electric motor  120 . Therefore, in a case in which the electric motor  120  is driven, a torque is applied to the output shaft  114 . 
     The end of the lower shaft  109  in the +X direction is coupled to an end of the torsion bar  112  in the -X direction. An end of the torsion bar  112  in the +X direction is coupled to the output shaft  114  by a fixing pin  113 . The first universal joint  103  is coupled to an end of the output shaft  114  in the +X direction. Therefore, a steering torque of the lower shaft  109  is transmitted to the intermediate shaft  104  (see  FIG.  1   ) through the torsion bar  112 , the output shaft  114 , and the first universal joint  103 . The torsion bar  112  twists in response to the steering torque of the lower shaft  109 , so that an angular difference in rotation between the lower shaft and the output shaft  5  is made. 
     In order to eliminate the angular difference in rotation between the lower shaft  109  and the output shaft  114 , a torque detection groove  114   a  is formed at an end of the output shaft  114  in the -X direction. A cylindrical member  116  is disposed on an outer peripheral side of the torque detection groove  114   a . The cylindrical member  116  is fixed to the end of the lower shaft  109  in the + direction and is integrally rotated with the lower shaft  109 . The cylindrical member  116  has multiple windows (not illustrated) penetrating in a radial direction. A torque sensor  117  is disposed on an outer peripheral side of the cylindrical member  116 . 
     The torque sensor  117  transmits a detection result to a torque detection circuit board (not illustrated) that is provided inside the housing  111 , and the torque detection circuit board detects the angular difference in rotation between the lower shaft  109  and the output shaft  114 . The torque detection circuit board causes the electric motor  120  to be driven based on the detection result to provide a steering assist torque to the output shaft  114 . As a result, the same angle in rotation between the lower shaft  109  and the output shaft  114  is achieved. 
     As illustrated in  FIG.  2   , the first bracket  70  includes a pair of support pieces  71  and  71 . The support pieces  71  are spaced apart from each other in the Y direction. Each of the support pieces  71  includes an attachment plate  72  extending in the X direction and the Y direction and a support plate  73  extending in the X direction and the Z direction. The attachment plate  72  is fixed to a vehicle body by a bolt (not illustrated). A pivot shaft  74  extending in the Y direction is rotatably provided at an end of the support plate  73  in the -Z direction. The gearbox  110  is fixed to the pivot shaft  74 . Thus, the gearbox  110 , the steering shaft  102 , the steering column  1 , and the steering wheel  101  are supported by the first bracket  70  to be able to rotate around the pivot shaft  74  (see arrows A 1  and A 2  in  FIG.  1   ). 
     As illustrated in  FIG.  4   , the steering column  1  is an outer cylinder that extends in the X direction and surrounds the steering shaft  102 . The steering column  1  includes an upper column  2  that is a column disposed near the steering wheel  101 , and a lower column  3  that is a column disposed in the -X direction with respect to the upper column  2 , and that is spaced apart from the steering wheel  101 . The lower column  3  has a cylindrical shape. An end of the lower column  3  in the X direction is externally fitted to the housing  111  of the gearbox  110 . 
     The upper column  2  is produced by casting. As illustrated in  FIGS.  3 ,  4 ,  5 , and  6   , the upper column  2  includes a clamp  10  that is externally fitted to the lower column  3 , a cylindrical part  20  that extends from the clamp  10  in the -X direction, an attachment part  30  that is provided at an end of the clamp  10  in the +X direction, a pair of protrusions  40  and  40  (only one protrusion is illustrated in  FIG.  5   , see  FIG.  6   ) that protrudes in the -Z direction from the outer peripheral surface of the clamp  10 , and contact ribs  50  (see  FIGS.  3 ,  5 , and  6   ) that extend in the X direction. 
     The cylindrical part  20  has a circular inner peripheral surface. An inner diameter of the cylindrical part  20  has a size enough to allow the lower column  3  to enter the inside. A bearing  21  is internally fitted to an end of the cylindrical part  20  in the -X direction. The cylindrical part  20  rotatably supports the upper shaft  108  by using the bearing  21 . In addition, an opening at the end of the cylindrical part  20  in the -X direction is blocked by the bearing  21  and the upper shaft  108 . 
     As illustrated in  FIGS.  5  and  6   , a first annular rib  22  and a second annular rib  23  that are disposed to be spaced apart from each other in the X direction are provided on an outer peripheral surface  20   a  of the cylindrical part  20 . Four straight linear ribs  24   a ,  24   b ,  24   c , and  24   d  that extend in the X direction are provided at a 90-degree interval on the outer peripheral surface  20   a  of the cylindrical part  20  and between the first annular rib  22  and the second annular rib  23 . Thus, the rigidity of the cylindrical part  20  is very high. The second annular rib  23  is provided at the boundary between the cylindrical part  20  clamp  10  and the cylindrical part  20 . 
     As illustrated in  FIG.  7   , the clamp  10  is provided with a slit  11 . As illustrated in  FIG.  8   , the slit  11  of the clamp  10  extends in the X direction. Therefore, the clamp  10  has a circular arc-shaped cross-section and extends in the X direction. While no external force acts on the clamp  10 , the inner diameter of the clamp  10  is approximately the same in size as the outer diameter of the lower column  3 . In other words, the clamp  10  is slidable on the lower column  3 . 
     As illustrated in  FIG.  7   , the slit  11  of the clamp  10  is positioned in the -Z direction as viewed from the axis O. Therefore, a groove width of the slit  11  is along the Y direction. According to this, in a case in which a compressive load for fastening the clamp  10  from the Y direction acts on the clamp  10 , the clamp  10  deforms so that the groove width of the slit  11  is narrower. In other words, the clamp  10  clamps the lower column  3  disposed therein by reducing its diameter. As a result, a high frictional force acts between an inner peripheral surface of the clamp  10  and an outer peripheral surface of the lower column  3  to restrict the sliding of the upper column  2 . 
     As illustrated in  FIGS.  8  and  10   , a part of the attachment part  30  in the +Z direction includes a cut-out portion  31 . As illustrated in  FIG.  8   , the attachment part  30  wraps around the lower column  3  in an arc shape in the -Z direction. An attachment rib  32  is provided on an outer peripheral surface of the attachment part  30 , which faces the -Z direction. The attachment rib  32  has a female thread hole  33 . A bracket (not illustrated) that supports a harness or the like is attached to the female thread hole  33 . 
     A first expansion slit  12  and a second expansion slit  13  whose groove widths are circumferentially wider than that of the slit  11  are provided at both ends of the slit  11  of the clamp  10  in the X direction. Parts of the clamp  10 , which are not continuous with the adjacent cylindrical part  20  and the adjacent attachment part  30  in the X axis direction, increase by the first expansion slit  12  and the second expansion slit  13 . As a result, the clamp  10  is less affected by the rigidity of the cylindrical part  20  and the attachment part  30  and is further easily deformable. Another configuration of the clamp  10  will be described later. 
     As illustrated in  FIG.  8   , the pair of protrusions  40  and  40  is disposed so that the slit is interposed therebetween as viewed from the -Z direction. Hereinafter, one protrusion  40  of the pair of protrusions  40  and  40 , which is disposed in the -Y direction relative to the slit  11 , is referred to as a first protrusion  41 , and the other protrusion  40  of the pair of protrusions  40  and  40 , which is disposed in the +Y direction relative to the slit  11 , is referred to as a second protrusion  42 . The first protrusion  41  and the second protrusion  42  extend in the X direction with approximately the same length as that of the clamp  10 . As illustrated in  FIG.  5   , long grooves  43  and  44  extending in the X direction are provided. As illustrated in  FIG.  7   , the long grooves  43  and  44  penetrate in the Y direction. 
     As illustrated in  FIG.  7   , the contact ribs  50  each have a pair of first contact ribs  51  and  51 , a pair of second contact ribs  52  and  52 , a single third contact rib  53 , and a single fourth contact rib  54 . The first contact ribs  51  protrude from the outer peripheral surface of the clamp  10 . The second contact ribs  52  are provided to protrude from outer surfaces of the first protrusion  41  and the second protrusion  42 , respectively. 
     As illustrated in  FIG.  5   , the first contact ribs  51  and the second contact ribs  52  extend in a straight line in the X direction. The first contact ribs  51  overlap the axis O as viewed from the Y direction. Each end of each first contact rib  51  in the -X direction is continuous with a second annular rib  23 . The second contact ribs  52  are positioned at ends of the first protrusion  41  and the second protrusion  42  in the -Z direction, respectively. The second contact ribs  52  extend along edges of the long grooves  43  and  44 . As described above, the first contact ribs  51  and the second contact ribs  52  are disposed so that the long grooves  43  and  44  are interposed therebetween. The details of the contact ribs  50  including the single third contact rib  53  and the single fourth contact rib  54  will be described below. 
     As illustrated in  FIG.  9   , the second bracket  80  includes a pair of attachment plates  81  and  81 , an upper plate  82 , a first side plate  83 , and a second side plate  84 . The second bracket  80  may be referred to simply as a bracket. 
     The pair of attachment plates  81  and  81  is plate-like members that are disposed to be spaced apart from each other in the Y direction so that the steering column  1  is interposed therebetween. The attachment plates  81  are coupled to the vehicle body by using release capsules  85 . Each of the release capsules  85  is disposed at an end of each of the attachment plates  81  in the -X direction. Each of the release capsules  85  is integrated with each of the attachment plates  81  by using each of resin members  86 . The release capsules  85  are fixed to a member on the vehicle body side by bolts or the like. In a case in which a load in the +X direction acts on the steering column  1  due to a secondary collision of the vehicle (see arrow B 1  in  FIG.  1   ), the resin members  86  are sheared and only the attachment plates  81  move in the +X direction; thereby, the second bracket  80  is released from the vehicle body. 
     The upper plate  82  is a plate-like member that couples the pair of attachment plates  81  and  81  to each other. The first side plate  83  and the second side plate  84  are plate-like members that extend in the X direction and the Z direction. The first side plate  83  is disposed in the -Y direction relative to the clamp  10 . The second side plate  84  is disposed in the +Y direction relative to the clamp  10 . In other words, the first side plate  83  and the second side plate  84  are spaced apart from each other in the Y direction so that the clamp  10  of the steering column  1  is interposed therebetween. The first side plate  83  and the second side plate  84  are integrated with the pair of attachment plates  81  and  81 , and the upper plate  82  by welding. The first side plate  83  and the second side plate  84  are formed with arc grooves  83   a  and  84   a  that extend in the Z direction, respectively. The arc grooves  83   a  and  84   a  have an arc shape centered on the pivot shaft  74  (see  FIGS.  1 ,  2 , and  3   ). A protruding plate  87  that protrudes in the -Y direction is provided at an end of the first side plate  83  in the X direction. Therefore, the first side plate  83  has a higher rigidity in the Y direction than the second side plate  84  does. 
     The fastening mechanism  90  is a device that fastens the clamp  10  to apply a compressive load to the clamp  10 . The fastening mechanism  90  has a fastening shaft  91 , an operation lever  92 , a fixed cam  93 , a rotating cam  94 , a nut  95 , a spacer  96 , and a thrust bearing  97 . 
     The fastening shaft  91  is a rod-shaped member. The fastening shaft  91  is inserted, from the -Y direction toward the +Y direction, into the arc groove  83   a  of the first side plate  83 , the long grooves  43  and  44  of the clamp  10 , and the arc groove  84   a  of the second side plate  84  in this order, and extends in the Y direction. An end of the fastening shaft  91  in the -Y direction is provided with a head  91   a . The operation lever  92  is coupled near the end of the fastening shaft  91  in the -Y direction. The operation lever  92  extends from the fastening shaft  91  in the -X direction and can be operated by the driver in the vehicle (see  FIGS.  1  and  2   ). In a case in which the driver rotates the operation lever  92  around the fastening shaft  91 , the fastening shaft  91  is rotated in conjunction with the rotation of the operation lever  92 . 
     The fixed cam  93  and the rotating cam  94  are disposed between the first side plate  83  and the operation lever  92  in a state of being penetrated by the fastening shaft  91 . The fixed cam  93  is adjacent to the first side plate  83 . A part of the fixed cam  93  is fitted to the arc groove  83   a  of the first side plate  83 . Accordingly, the fixed cam  93  is not rotated in conjunction with the fastening shaft  91 . The rotating cam  94  is adjacent to the operation lever  92 . The rotating cam  94  is coupled to the operation lever  92  and is integrally rotated with the operation lever  92 . Tilted planes are provided on surfaces of the fixed cam  93  and the rotating cam  94 , which face each other, along the peripheral direction. In a case in which the rotating cam  94  is rotated by operation of the operation lever  92 , the tilted plane of the fixed cam  93  rides up or rides down on the tilted plane of the rotating cam  94 . As a result, a distance in the Y direction between the fixed cam  93  and the rotating cam  94  changes. 
     An end of the fastening shaft  91  in the +Y direction is provided with a male thread  91   b . This male thread  91   b  is screwed with the nut  95 . As a result, the fastening shaft  91  is prevented from falling out of the arc grooves  83   a  and  84   a  and the long grooves  43  and  44 . The spacer  96  and the thrust bearing  97  are disposed between the second side plate  84  and the nut  95  in a state of being penetrated by the fastening shaft  91 . The spacer  96  is brought into contact with the periphery of the arc groove  84   a , which is a part of the second side plate  84 . The thrust bearing  97  is disposed between the nut  95  and the spacer  96 . 
     As described above, in a case in which the fixed cam  93  and the rotating cam  94  are spaced apart from each other in the Y direction by the operation of the operation lever  92 , the head  91   a  of the fastening shaft  91  is pressed in the -Y direction, and the nut  95  moves toward the -Y direction. Accordingly, a distance in the Y direction between the fixed cam  93  and the spacer  96  is reduced, and a frictional force between the fixed cam  93  and the first side plate  83 , and a frictional force between the spacer  96  and the second side plate  84  increase. As a result, the movement of the fastening shaft  91  in the Z direction along the arc grooves  83   a  and  84   a  is restricted. Therefore, the movement of the upper column  2  in the Z direction, which is penetrated by the fastening shaft  91 , is also restricted, and a position of the steering wheel  101  in the Z direction is secured. 
     The first side plate  83  and the second side plate  84  are fastened in the Y direction by the fixed cam  93  and the spacer  96 . Thus, inner surfaces of the first side plate  83  and the second side plate  84  are brought into contact with the pair of second contact ribs  52  and  52  of the upper column  2 . The first side plate  83  and the second side plate  84  press the pair of second contact ribs  52  to be compressed against each other. As a result, a compressive load is applied to the first protrusion  41  and the second protrusion  42  in the Y direction. The groove width of the slit  11  of the clamp  10  is narrower to clamp the lower column. As a result, the upper column  2  is secured to the lower column  3 , and the movement of the steering wheel  101  in the X direction is restricted. 
     The first side plate  83  and the second side plate  84  press the pair of first contact ribs  51  and  51  in addition to the pair of second contact ribs  52  and  52 . As a result, a compressive load acts on the pair of second contact ribs  52  and  52  to be able to reduce the diameter of the clamp  10 . The first contact ribs  51  are spaced apart from the fastening shaft  91  on which a fastening force acts. Therefore, the compressive load acting on the first contact ribs  51  is smaller than the compressive load acting on the second contact ribs  52 . On the other hand, even though the compressive load is applied to the second contact ribs  52 , the first protrusion  41  and the second protrusion  42  are tilted so that only the ends of the first protrusion  41  and the second protrusion  42  in the -Z direction are close to each other; thereby, the slit of the clamp  10  may not be narrowed. In other words, the compressive load can be applied to the clamp  10  by using the first contact ribs  51  without using the first protrusion  41  and the second protrusion  42 . Therefore, during the operation of the operation lever  92 , the clamp  10  reliably clamps the lower column  3 . 
     By contrast, in a case in which the operation lever  92  is operated to bring the fixed cam  93  and the rotating cam  94  close to each other in the Y direction, the distance in the Y direction between the fixed cam  93  and the spacer  96  is increased. Thus, a frictional force between the fixed cam  93  and the first side plate  83  is reduced. Accordingly, a frictional force between the spacer  96  and the second side plate  84  is reduced. As a result, the fastening shaft  91  is allowed to move in the Z direction along the arc grooves  83   a  and  84   a . In a case in which a load in the Z direction is applied to the steering wheel  101 , the steering column  1 , the steering shaft  102 , and the gearbox  110  are rotated around the pivot shaft  74  in directions of arrow A 1  or arrow A 2  (see  FIG.  1   ). As a result, a position of the steering wheel  101  in the Z direction is changed. 
     Fastening on the first contact ribs  51  and second contact ribs  52  by the first side plate  83  and the second side plate  84  is released. Therefore, the groove width of the slit  11  of the clamp  10  is widened, and clamping onto the lower column  3  is released. In a case in which a load in the X direction is applied to the steering wheel  101 , the upper column  2  and the upper shaft  108  slide in the X direction. As a result, a position of the steering wheel  101  in the X direction is changed (see arrow B 1  and arrow B 2  in  FIG.  1   ). 
     Next, the details of the clamp  10  and the contact ribs  50  will be described. A cross-sectional shape of the clamp  10  cut in a plane extending in the Y direction and the Z direction has substantially the same shape even through a cut position is moved in the X direction. In other words, the rigidity of each portion of the clamp  10  in the X direction is uniform. However, as illustrated in  FIGS.  10  and  11   , an end of the clamp  10  in the -X direction is continuous with the cylindrical part  20  in which the second annular rib  23  is provided. As a result, a portion of the clamp  10  near the cylindrical part  20  has a high apparent rigidity by the second annular rib  23 , and is less deformable. By contrast, an end of a spaced clamp  17  in the +X direction is continuous with the attachment part  30  in which the cut-out portion  31  is provided, and has a low apparent rigidity. As described above, the clamp  10  is composed of a continuous clamp  16  that is positioned near the cylindrical part  20  and that is less deformable, and the spaced clamp  17  that is spaced apart from the cylindrical part  20  in the X direction and that is easily deformable. Each of the protrusions  40  includes a continuous protrusion  46  protruding from the continuous clamp  16  and a spaced protrusion  47  protruding from the spaced clamp  17 . 
     In the present embodiment, in the clamp  10 , about two-thirds of the clamp  10  is composed of the continuous clamp  16 , and the remaining one-third is composed of the spaced clamp  17 . Here, the ratio of the continuous clamp  16  to the spaced clamp  17  described above is an example, and the clamp of the present invention is not limited thereto. Furthermore, the continuous clamp  16  that is less deformable since the continuous clamp  16  is continuous with the cylindrical part  20  is exemplified in the present embodiment, but the continuous clamp  16  of the present invention can also be applied to a case in which the continuous clamp  16  is less deformable since a wall thickness of a part of the clamp  10  is thicker than that of the other part of the clamp  10 . 
     In  FIG.  10   , an end surface  53   c  of the third contact rib  53  is illustrated as the hatched area to make the third contact rib  53  be clarified. As illustrated in  FIG.  10   , the third contact rib  53  is a rib that extends in the X direction. The third contact rib  53  is provided only on the second protrusion  42  of the pair of protrusions  40  and  40 . A width of the third contact rib  53  in the Z direction is narrower than those of the first contact ribs  51  and the second contact ribs  52 . An end  53   a  of the third contact rib  53  in the +X direction is positioned at an end of the second protrusion  42  in the +X direction. A length of the third contact rib  53  in the X direction is shorter than those of the first contact ribs  51  and the second contact ribs  52 , and is about one-third of the length of the second protrusion  42  in the X direction. In other words, an end  53   b  of the third contact rib  53  in the -X direction is positioned closer to the +X direction than the center of the second protrusion  42  in the X direction. As described above, the third contact rib  53  extends only to the extent of the spaced protrusion  47  of the protrusions  40 , which protrudes from the spaced clamp  17 . In addition, the third contact rib  53  extends along the long groove  44  of the second protrusion  42 . Accordingly, the long groove  44  is interposed between the second contact rib  52  and the third contact rib  53 . 
     In  FIG.  11   , an end surface  54   c  of the fourth contact rib  54  is illustrated as the hatched area to make the fourth contact rib  54  be clarified. As illustrated in  FIG.  11   , the fourth contact rib  54  is a rib that extends in the X direction. The fourth contact rib  54  is provided only on the first protrusion  41  of the pair of protrusions  40  and  40 . A width of the fourth contact rib  54  in the Z direction is narrower than those of the first contact ribs  51  and the second contact ribs  52 . An end  54   a  of the fourth contact rib  54  in the +X direction is positioned at an end of the first protrusion  41  in the +X direction. A length of the fourth contact rib  54  in the X direction is equal to the length of the third contact rib  53 . The length of the fourth contact rib  54  is shorter than those of the first contact ribs  51  and the second contact ribs  52 , and is about one-third of the length of the first protrusion  41  in the X direction. In other words, an end  54   b  of the fourth contact rib  54  in the -X direction is positioned closer to the +X direction than the center of the first protrusion  41  in the X direction. As described above, the fourth contact rib  54  extends only to the extent of the spaced protrusion  47  of the protrusions  40 , which protrudes from the spaced clamp  17 . In addition, the fourth contact rib  54  extends along the long groove  44  of the second protrusion  42 . Accordingly, the long groove  44  is interposed between the second contact rib  52  and the fourth contact rib  54 . 
     Next, protrusion amounts of the first contact ribs  51 , the second contact ribs  52 , the third contact rib  53 , and the fourth contact rib  54  are described with reference to  FIGS.  7 ,  12 , and  13   . As illustrated by auxiliary line W in  FIG.  7   , end surfaces  51   a  of the first contact ribs  51  and end surfaces  52   a  of the second contact ribs  52  are positioned at the same position in the Y direction. The cross-sectional view illustrated in  FIG.  7    is a cross-sectional view viewed from a cross-section of the continuous clamp  16  in the clamp  10 , and the third contact rib  53  and the fourth contact rib  54  are not illustrated in  FIG.  7   . 
     The protrusion amount of the first contact ribs  51  is constant at any position in the X direction where the first contact ribs  51  extend. The protrusion amount of the second contact ribs  52  is also constant at any position in the X direction where the second contact ribs  52  extend. In other words, as illustrated in  FIGS.  12  and  13   , positions of the end surfaces  51   a  of the first contact ribs  51  and positions of the end surfaces  52   a  of the second contact ribs  52  are not changed even though the positions are moved in the X direction. 
     As illustrated in  FIGS.  12  and  13   , the end surface  53   c  of the third contact rib  53  is positioned closer to the +Y direction than an end surface  51   a  of the first contact rib  51  and an end surface  52   a  of the second contact rib  52 , which are provided on the second protrusion  42  (see auxiliary line W in  FIGS.  12  and  13   ). Therefore, the protrusion amount of the third contact rib  53  is larger than those of the first contact rib  51  and the second contact rib  52 . In addition, the protrusion amount of the third contact rib  53  is constant at any position in the X direction where the third contact rib  53  extends. 
     As illustrated in  FIGS.  12  and  13   , the position of the end surface  54   c  of the fourth contact rib  54  in the Y direction overlaps the auxiliary line W and is positioned at the same position as those of the end surface  51   a  of the first contact rib  51  and the end surface  52   a  of the second contact rib  52 , which are provided on the first protrusion  41 . Therefore, the protrusion amount of the fourth contact rib  54  is equal to those of the first contact rib  51  and the second contact rib  52 . In addition, the protrusion amount of the fourth contact rib  54  is constant at any position in the X direction where the fourth contact rib  54  extends. 
     Next, a relationship between the first side plate  83  and the second side plate  84 , and the contact ribs  50  will be described. The description will be described as two cases of a case in which the fastening shaft  91  overlaps the continuous clamp  16  in the Z direction (see G 91  in  FIG.  10   ), and a case in which the fastening shaft  91  overlaps the spaced clamp  17  in the Z direction (see H 91  in  FIG.  10   ). In  FIGS.  14  to  19    used in this explanation, each component is abstractedly depicted. 
     First, the case in which the fastening shaft  91  overlaps the continuous clamp  16  (see G 91  in  FIG.  10   ) in the Z direction will be described. As illustrated in  FIG.  14   , the first contact ribs  51  and the second contact ribs  52  of the contact ribs  50  are present on a plane extending in the Y direction and the Z direction including the fastening shaft  91 . The first side plate  83  and the second side plate  84  are not fastened before the fastening mechanism  90  is operated, and are not in contact with the first contact ribs  51  and the second contact ribs  52 . 
     Next, as illustrated in  FIG.  15   , in a case in which the operation lever  92  is operated to cause the fastening mechanism  90  to fasten the first side plate  83  and the second side plate  84 , the first side plate  83  and the second side plate  84  are brought close to each other and then into contact with the first contact ribs  51  and the second contact ribs  52 . In a case in which the operation lever  92  is further operated, the first side plate  83  and the second side plate  84  press against the first contact ribs  51  and the second contact ribs  52 . 
     Here, the fastening force of the fastening mechanism  90  acts between each of the first contact ribs  51  and each of the second contact ribs  52  in the Z direction (see arrows F in  FIG.  15   ). The rigidity of the first side plate  83  and the second side plate  84  is less than that of the continuous clamp  16 . Therefore, in a case in which the first side plate  83  and the second side plate  84  press against the first contact ribs  51  and the second contact ribs  52 , middle portions of the first side plate  83  and the second side plate  84  in the Z direction are bent toward the clamp  10 , as illustrated in  FIG.  16   . In other words, in a case in which the continuous clamp  16  is fastened, part of the operation force of the operation lever  92  is used to deform the first side plate  83  and the second side plate  84 . As described above, the feel of operation of the operation lever  92  is lighter than a case in which the first side plate  83  and the second side plate  84  are not bent. 
     As illustrated in  FIG.  16   , the bending amount of the first side plate  83  is smaller than the bending amount of the second side plate  84 . This is because the first side plate  83  is difficult to deform due to the protruding plate  87  (see  FIG.  9   ). 
     Next, the case in which the fastening shaft  91  overlaps the spaced clamp  17  (see H 91  in  FIG.  10   ) in the Z direction will be described. As illustrated in  FIG.  17   , the first contact ribs  51 , the second contact ribs  52 , the third contact rib  53 , and the fourth contact rib  54  are present on a plane extending in the Y direction and the Z direction including the fastening shaft  91 . The first side plate  83  and the second side plate  84  are not in contact with any of the first contact ribs  51 , the second contact ribs  52 , the third contact rib  53 , and the fourth contact rib  54 , before the fastening mechanism  90  is operated. 
     Next, as illustrated in  FIG.  18   , in the case in which the operation lever  92  is operated to cause the fastening mechanism  90  to fasten the first side plate  83  and the second side plate  84 , the first side plate  83  and the second side plate  84  are first brought into contact with the third contact rib  53 . 
     Here, the second side plate  84  is further easily deformable than the first side plate  83 . Accordingly, as illustrated in  FIG.  19   , in a case in which the fastening mechanism  90  further fastens the first side plate  83  and the second side plate  84 , a portion of the second side plate  84  brought into contact with the third contact rib  53  is bent toward the + Y direction, and the second side plate  84  is then brought into contact with the first side plate  83  and the second side plate  84 . Meanwhile, the first side plate  83  is brought into contact with the other first contact rib  51 , the other second contact rib  52 , and the fourth contact rib  54  without deformation. 
     In addition, in the case in which the operation lever  92  is operated to cause the fastening mechanism  90  to further fasten the first side plate  83  and the second side plate  84 , the first side plate  83  and the second side plate  84  press the first contact ribs  51  and the second contact ribs  52 . Here, the middle portion of the first side plate  83  in the Z direction is brought into contact with the fourth contact rib  54 . In addition, the middle portion of the second side plate  84  in the Z direction is brought into contact with the third contact rib  53 . Therefore, the middle portions of the first side plate  83  and the second side plate  84  in the Z direction are not bent toward the clamp  10 . 
     As described above, in the case in which the spaced clamp  17  is fastened, the second side plate is first brought into contact with the third contact rib before the first contact rib  51  and the second contact rib  52 . Accordingly, a load is started to be applied to the operation lever  92  at a stage where the operation amount of the operation lever  92  is small, and the feel of operation of the operation lever is heavy. In addition, the middle portions of the first side plate  83  and the second side plate  84  in the Z direction are not bent toward the clamp  10 . In other words, a factor that makes the feel of operation of the operation lever  92  lighter is eliminated. Therefore, the feel of operation of the operation lever  92  in the case in which the spaced clamp  17  is fastened is heavy. In other words, the difference between the feel of operation in the case in which the continuous clamp  16  is fastened and the feel of operation in the case in which the spaced clamp  17  is fastened is small, so that the operation lever  92  can be operated with the same feel of operation. 
     As described above, the steering device  100  of the embodiment includes the steering shaft  102 , the steering column  1 , the bracket (second bracket  80 ), and the fastening mechanism  90 . The steering shaft  102  is a telescopic steering shaft that extends in the first direction. The steering column  1  includes the lower column  3  and the upper column  2  that are relatively slidably coupled to each other in the first direction. The bracket (second bracket  80 ) includes the first side plate  83  and the second side plate  84  that sandwich the steering column  1  from the second direction orthogonal to the first direction. The fastening mechanism  90  has the operation lever  92  and the fastening shaft  91  penetrating the first side plate  83  and the second side plate  84  and fastens the first side plate  83  and the second side plate  84 . The upper column  2  includes the clamp  10 , the cylindrical part  20 , the pair of protrusions  40  and  40 , and the contact ribs  50 . The clamp  10  has the slit  11  extending in the first direction and is externally slidably fitted to the lower column  3 . The cylindrical part  20  extends from the clamp  10  and supports the steering shaft  102 . The pair of protrusions  40  and  40 , between which the slit  11  is interposed, protrudes radially outward from the clamp  10  and is provided with the long grooves  43  and  44  into which the fastening shaft  91  is inserted. The contact ribs  50  protrude from the outer peripheral surface of the clamp  10  or side surfaces of the pair of protrusions  40  and  40 , and are brought into contact with the first side plate  83  and the second side plate  84  fastened by the fastening mechanism  90 . The clamp  10  is composed of the continuous clamp  16  that is positioned near the cylindrical part  20  and that is continuous with the cylindrical part  20 , and the spaced clamp  17  that is spaced apart from the cylindrical part  20 . The protrusions  40  include the continuous protrusions  46  protruding from the continuous clamp  16  and the spaced protrusions  47  protruding from the spaced clamp  17 . The contact ribs  50  each have the pair of first contact ribs  51  and  51 , the pair of second contact ribs  52  and  52 , and at least one third contact ribs  53 . The pair of first contact ribs  51  and  51  is disposed on the outer peripheral surface of the clamp  10  and extends across the continuous clamp  16  and the spaced clamp  17 . The pair of second contact ribs  52  and  52  is respectively disposed on side surfaces of the protrusions  40  and disposed opposite to the first contact ribs  51  with respect to the long grooves  43  and  44 , and extends across the continuous protrusions  46  and the spaced protrusions  47 . The single third contact rib  53  is disposed on a side surface of the spaced protrusion  47  and disposed between the first contact rib  51  and the long groove  44 . The third contact rib  53  has the protrusion amount greater than those of the first contact rib  51  and second contact rib  52 . 
     According to the embodiment, in the case in which the continuous clamp  16  is fastened, the first side plate  83  and the second side plate  84  are bent toward the clamp  10 , which makes the feel of operation of the operation lever lighter. By contrast, in the case in which the spaced clamp  17  is fastened, the first side plate  83  and the second side plate  84  are not bent toward the clamp  10 . Thus, the factor that makes the feel of operation of the operation lever  92  lighter is eliminated. Moreover, since a load is applied to the operation lever  92  at a stage where the operation amount of the operation lever  92  is small, the feel of operation of the operation lever  92  is heavy. As described above, in the case in which the continuous clamp  16  and the spaced clamp  17  are fastened, the difference in the feel of operation of the operation lever  92  is small, which less causes discomfort to the operator. 
     In the steering device  100  of the embodiment, the third contact rib  53  is a single rib, and the second side plate  84  has a lower rigidity than the first side plate  83  does. The pair of protrusions  40  and  40  includes the first protrusion  41  facing the first side plate  83  and the second protrusion  42  facing the second side plate  84 . The third contact rib  53  is disposed on the second protrusion  42 . The contact ribs  50  include the single fourth contact rib  54  that protrudes from a side surface of the first protrusion  41 . The fourth contact rib  54  is disposed on a side surface of the spaced protrusion  47  and disposed between the first contact rib  51  and the long groove  43 , and has the protrusion amount equal to those of the first contact rib  51  and the second contact rib  52 . 
     According to the embodiment, in the case in which the first side plate  83  presses against the first contact rib  51  and the second contact rib  52 , the first side plate  83  is not bent toward the clamp  10 . Thus, the factor that makes the feel of operation of the operation lever  92  lighter is eliminated, and the feel of operation in the case in which the spaced clamp  17  is fastened can be further heavier. The second side plate  84  having a lower rigidity is brought into contact with the third contact rib  53 . In other words, the second side plate  84  is brought close to the third contact rib  53 , is then deformed, approaches toward the second protrusion  42 , and is brought into contact with the first contact rib  51  and the second contact rib  52 . Thus, the second side plate  84  can reliably press against the first contact rib  51  and the second contact rib  52 . 
     As described above, the embodiment has been described, but the present invention is not limited thereto. For example, in a case in which one-half of the clamp  10  corresponds to each of the continuous clamp  16  and the spaced clamp  17 , the third contact rib  53  and the fourth contact rib  54  may extend to the center of the first protrusion  41  and the second protrusion  42  in the X direction. In the embodiment, the fourth contact rib  54  is provided on the spaced protrusion  47  of the first protrusion  41 , and the third contact rib  53  is provided on the spaced protrusion  47  of the second protrusion  42 , but the present invention is not limited thereto. For example, the third contact rib  53  may be provided on the spaced protrusion  47  of the first protrusion  41 , and the fourth contact rib  54  may be provided on the spaced protrusion  47  of the second protrusion  42 . Alternatively, a third contact rib  53  may be provided on the spaced protrusion  47  of the first protrusion  41 , and the third contact rib  53  may be further provided on the spaced protrusion  47  of the second protrusion  42 . In other words, the present embodiment may have two or more third contact ribs  53 . Alternatively, the third contact rib  53  may be provided on either one of the spaced protrusion  47  of the first protrusion  41  or the spaced protrusion  47  of the second protrusion  42 , and any of the third contact rib  53  and the fourth contact rib  54  may not be provided on the other side. In other words, one or more third contact ribs  53  can be provided to prevent the first side plate  83  or the second side plate  84  from bending and to eliminate the factor that makes the feel of operation of the operation lever lighter. 
     REFERENCE SIGNS LIST 
     
         
           100  Steering device 
           101  Steering wheel 
           102  Steering shaft 
           108  Upper shaft 
           109  Lower shaft 
           110  Gearbox 
           1  Steering column 
           2  Upper column 
           3  Lower column 
           10  Clamp 
           11  Slit 
           12  First expansion slit 
           13  Second expansion slit (expansion slit) 
           16  Continuous clamp 
           17  Spaced clamp 
           20  Cylindrical part 
           21  Bearing 
           23  Second annular rib 
           30  Attachment part (extending part) 
           40  ( 41 ,  42 ) Protrusion (first protrusion, second protrusion) 
           43 ,  44  Long groove 
           46  Continuous protrusion 
           47  Spaced protrusion 
           50  Contact rib 
           51  First contact rib 
           52  Second contact rib 
           53  Third contact rib 
           54  Fourth contact rib 
           70  First bracket 
           74  Pivot shaft 
           80  Second bracket (bracket) 
           83  First side plate 
           84  Second side plate 
           90  Fastening mechanism 
           91  Fastening shaft 
           92  Operation lever 
           93  Fixed Cam 
           94  Rotating Cam 
           95  Nut