Abstract:
To provide a steering wheel position adjustment device in a steering device comprising a tilt telescopic adjustment mechanism, in which there is almost no change in operation feeling, particularly prior or posterior to telescopic adjustments, and that can maintain good operation feeling. A column housing, through which a column pipe passes and is fixed thereto, is fitted to a fixed bracket so that the column housing can either freely move or be fixed in the axial direction. The column pipe is inserted slidably in an insertion hole of a pivot housing that is fitted to be able to swing freely and be fixed freely to the front of the column housing in the axial direction. An upper shaft is provided, within the column pipe, that moves together with the column pipe in the axial direction. A lower shaft is provided in the pivot housing. The upper shaft transmits rotation to the lower shaft, and the upper shaft and the lower shaft are connected to be able to slide freely relative to each other.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a steering wheel position adjustment device in which there is almost no change in operation feeling particularly prior or posterior to telescopic adjustments, and that is capable of maintaining good operation feeling in a steering device provided with a tilt and telescopic adjustment mechanism.  
         [0003]     2. Description of the Related Art  
         [0004]     Conventionally there are many types of steering device provided with a tilt and telescopic adjustment mechanism. In particular, Japanese Patent Application Laid-open No. 2000-16305 is a device developed previously by an applicant in which tilt and telescopic position adjustments of the steering wheel can be made.  
       SUMMARY OF THE INVENTION  
       [0005]     However, in most of the steering devices provided with tilt and telescopic adjustment mechanisms, such as Japanese Patent Application Laid-open No. 2000-16305, when carrying out tilt adjustments the steering shaft is moved in the forward or backward axial direction, so the positions of the intermediate shaft and joint are changed. A universal joint is used in this joint, so if the position is changed to a certain extent the operation feeling is not affected to a great degree, but depending upon the driver a small change in feeling can be perceived. This phenomenon is seen in most steering devices provided with tilt and telescopic adjustment mechanisms. It is an object of the present invention to provide a steering device in which there is no change of operation feeling of the wheel due to this type of telescopic adjustment of position, and for which good operation feeling can be maintained.  
         [0006]     Therefore, as a result of dedicated research to solve the above problems, the inventors solved the problem with the invention according to claim  1 . A column housing through which a column pipe passes and is fixed thereto is fitted to a fixed bracket so that the column housing can either move freely or be fixed in the axial direction. The column pipe is inserted slidably in an insertion hole of a pivot housing that is fitted to be able to swing freely and be fixed freely to the front of the column housing in the axial direction. An upper shaft is provided, within the column pipe, that moves together with the column pipe in the axial direction. A lower shaft is provided in the pivot housing. The upper shaft transmits rotation to the lower shaft, and the upper shaft and the lower shaft are connected to be able to slide freely relative to each other.  
         [0007]     Next, the invention according to claim  2  solves the problem with a steering wheel position adjustment device including a fixed bracket having fixed support side parts on both sides in the width direction; a column housing fitted to the fixed bracket so that the column housing can move freely in the axial direction or be fixed as appropriate; a column pipe that passes through and is fixed to the column housing; an upper shaft having a transmission shaft part at an end in the axial direction and that is fitted within the column pipe to be able to rotate freely; a pivot housing, through which the column pipe is slidably inserted, and which has an insertion hole provided with a fastening part that fastens and fixes the column pipe at the appropriate position, and which is supported to pivot so as to swing freely and to be fixed freely in the fixed bracket; and a lower shaft, connected to a transmission shaft part of the upper shaft, having a transmission shaft part to which rotation is transmitted, wherein the lower shaft is fitted to be able to freely rotate within the pivot housing, and the transmission shaft part of the lower shaft and the transmitted shaft part of the upper shaft are connected to be able to freely slide.  
         [0008]     Next, the invention according to claim  3  solves the problem in a steering wheel position adjustment device with the above configuration, further including a first fastening adjustment fitting that passes through a set of tilt adjustment elongated holes formed in the fixed support side parts of the fixed bracket and a telescopic elongated hole formed in the column housing for carrying out fastening; and a second fastening adjustment fitting that passes through another set of tilt adjustment elongated holes and the fastening bolt holes formed in the fastening part of the pivot housing for carrying out fastening. The invention according to claim  4  solves the problem in a steering wheel position adjustment device with the above configuration, wherein a link is provided between the first fastening adjustment fitting and the second fastening adjustment fitting, and further comprises a locking lever provided on either the first fastening adjustment fitting or the second fastening adjustment fitting, for fastening.  
         [0009]     The invention according to claim  5  solves the problem in a steering wheel position adjustment device with the above configuration, wherein a slit-shaped cut-out is formed in the axial direction of the insertion hole of the fastening part of the pivot housing, and on both sides of the cut-out in the width direction fastening bolt holes are formed through which the second fastening adjustment fitting passes.  
         [0010]     According to the inventions of claims  1  and  2 , during telescopic adjustments only the column housing, column pipe, and the upper shaft to which the steering wheel is fitted move. The pivot housing and lower shaft do not move during telescopic adjustments, but remain static. Therefore, the universal joint of the lower shaft and the steering shaft also does not move, so good operation feeling can be maintained.  
         [0011]     The invention according to the claim  3  is provided with the first fastening adjustment fitting to fasten the column housing to the fixed bracket. Furthermore the second fastening adjustment fitting that fastens the column pipe at the fastening part of the pivot housing is provided on the fixed bracket. Therefore fixing the column housing and fixing the column pipe that is inserted in the pivot housing can be carried out separately. Also, the fixing condition of the column housing as well as the column pipe can be very strong and stable. In the invention according to claim  4 , a link is provided between the first fastening adjustment fitting and the second fastening adjustment fitting. Therefore the first fastening adjustment fitting and the second fastening adjustment fitting can be fastened at the same time with the locking lever, and telescopic adjustments can be carried out efficiently.  
         [0012]     According to the invention of claim  5 , the pivot housing is the center of pivoting for tilt movements, so it is not necessary to provide a new joint for the steering device, and the structure is simple. According to the invention of claim  5 , a slit-shaped cut-out is formed in the fastening part in the axial direction of the insertion hole. Fastening bolt holes are formed at the cut-out on both sides in the width direction through which the second fastening adjustment fitting passes, which is a very simple structure, and the column pipe can be securely fixed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1A  is a side view of the present invention,  1 B is a vertical sectioned view of  1 A with the fixed bracket removed;  
         [0014]      FIG. 2A  is an enlarged side view of part of the present invention,  2 B is a sectioned view at X 1 -X 1  in  2 A in the direction of the arrows,  2 C is a sectioned view at X 2 -X 2  in  2 A in the direction of the arrows,  2 D is a sectioned view at X 3 -X 3  in  2 A in the direction of the arrows;  
         [0015]      FIG. 3  is an isometric view of the main part of the present invention;  
         [0016]      FIG. 4  is an enlarged vertical sectioned view of part of the present invention;  
         [0017]      FIG. 5A  is a vertical sectioned view of the column pipe and upper shaft fitted to the column housing,  5 B is vertical sectioned view of the lower shaft fitted to the pivot housing;  
         [0018]      FIG. 6A  is an isometric view of the column pipe fitted to the column housing,  6 B is an exploded isometric view of the pivot housing;  
         [0019]      FIG. 7A  is a view with the wheel in the standard position,  7 B is a view in the shortest position due to telescopic adjustment, and  7 C is a view in the longest position due to telescopic adjustment; and  
         [0020]      FIG. 8  is an operation diagram showing that telescopic adjustments in the present invention do not affect the operation feel. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     The following is the description of the preferred embodiments based upon the drawings. The present invention includes mainly a fixed bracket A, a column housing B, a column pipe  9 , an upper shaft  15 , a pivot housing C, a lower shaft  16 , a first fastening adjustment fitting  20 , a second fastening adjustment fitting  21 , and a locking lever  25 . First, the fixed bracket A includes a pair of plate-shaped fixed support side parts  2 ,  2  formed in confrontation to each other at the two sides in the width direction of a head part  1 , as shown in  FIGS. 1A, 2A ,  2 C, and  2 D, and elsewhere. A fitting is formed at a prescribed position on the head part  1  to which a capsule member for shock absorption is fitted. The head part  1  is mounted to the vehicle body at the prescribed position via the capsule member. The structure is such that only when an impact occurs such as a crash, impact energy is absorbed through sliding relative to the mounting position, which softens the impact and protects the driver from the accident.  
         [0022]     A sloping surface is formed in the head part  1  at approximately the middle in the long direction. A step is formed in the head part  1  by the sloping surface. Specifically, the front side of the head part  1  in the long direction (the front wheel side) is formed higher than the rear side (steering wheel  27  side). The pair of fixed support side parts  2 ,  2  support while sandwiching the column housing B and part of a pivot housing C which are described later, so that tilt and telescopic adjustments can be carried out (see  FIGS. 2B, 2C , and  3 ). The column housing B can move freely in the axial direction relative to the fixed bracket A and is fixed as appropriate to the fixed bracket A. Also, the pivot housing C is pivotally supported so that the pivot housing C can pivot freely and be fixed freely relative to the fixed bracket A. The means of fixing the column housing B and the pivot housing C to the fixed bracket A is the first fastening adjustment fitting  20  and the second fastening adjustment fitting  21 , which are described later.  
         [0023]     A pair of tilt adjustment elongated holes  3 ,  3  is formed in each of the pair of fixed support side parts  2 ,  2 . Specifically, as shown in  FIGS. 1A, 2A ,  2 B, and elsewhere, two tilt adjustment elongated holes  3 ,  3  are formed in each fixed support side part  2  in the long direction of the fixed bracket A. The tilt adjustment elongated holes  3  are elongated in the vertical direction. Furthermore, as shown in  FIGS. 1A and 2A , two opposing pivot supports  4 ,  4  are formed in the head part  1  in the front of the long direction and at both sides in the width direction. The two pivot supports  4 ,  4  are plate shaped, in which pivot support holes  4   a,    4   a  are formed (see  FIG. 2B ).  
         [0024]     The pair of pivot supports  4 ,  4  enclose a pivot part  13  of the pivot housing C, which is described later, and support the pivot housing C so that it can pivot freely (see  FIGS. 2B, 2D , and  3 ). The pivot supports  4 ,  4  are made continuous with the fixed support side parts  2 ,  2  with a pair of continuity plates  5 ,  5 . Specifically, along the long direction of the head part  1  from the rear side to the front side the fixed support side parts  2 , the continuity plates  5 , and the pivot supports  4  are formed continuously. Also, the continuity plates  5 ,  5  perform the role of reinforcing the fixed support side parts  2  and the pivot supports  4 .  
         [0025]     Next, as shown in  FIGS. 2B, 2C ,  3 ,  5 A, and  6 A, the column housing B includes a main housing  6 , a telescopic elongated hole  7 , and a column through hole  8 . The main housing  6  is formed as an approximately cubic shaped block, as shown in  FIG. 6A . The telescopic elongated hole  7  penetrates the main housing  6  in the width direction, as shown in  FIGS. 2B, 2C ,  6 A, and elsewhere. The telescopic elongated hole  7  is also elongated in the long direction of the main housing  6 . Also, the column through hole  8  is formed in the long direction of the main housing  6  from the rear side to the front side.  
         [0026]     The telescopic elongated hole  7  and column through hole  8  are formed at a suitable spacing in the vertical direction of the main housing  6 , as shown in  FIG. 6A . The column through hole  8  is positioned higher than the telescopic elongated hole  7 . A column pipe  9  passes through the column through hole  8  and is fixed and anchored. The column pipe  9  is fixed to that it projects from the column housing B at both ends in the axial direction. A specific example of the fixing means is press fitting.  
         [0027]     Next, as shown in  FIGS. 2B, 2D ,  3 ,  5 B,  6 B, and elsewhere, the pivot housing C includes a main housing  10 , and the pivot part  13 . The main housing  10  includes an insertion hole  11  and a fastening part  12 . The main housing  10  is formed as an approximately cubic shaped block. The insertion hole  11  is formed as a through hole in the long direction of the main housing  10 . The insertion hole  11  overlaps with the external surface of the column pipe  9  fixed to the column housing B, as shown in  FIGS. 1B and 4 , so that the column pipe  9  can slide within the insertion hole  11 , as shown in  FIGS. 7A through 7C .  
         [0028]     In other words, the insertion hole  11  of the pivot housing C is a part that supports the sliding movement in the telescopic adjustments of the column pipe  9 , as shown in  FIGS. 4, 7 , and elsewhere. The fastening part  12  performs the role of fixing the column pipe  9  that slides freely within the insertion hole  11  at a suitable position. Specifically, as shown in  FIGS. 2B, 3 ,  6 B, and elsewhere, an approximately U-shaped cut-out  12   a  is formed along the long direction of the insertion hole  11  up to approximately the middle of the main housing  10  in the long direction. A pair of fastening projections  12   b,    12   b  are formed near the cut-out  12   a  and to the rear end of the main housing  10  in the long direction.  
         [0029]     The fastening projections  12   b  are provided on both sides of the cut-out  12   a  and in confrontation to each other in the width direction. A pair of fastening bolt holes  12   c,    12   c  are formed in the fastening projections  12   b,    12   b,  as shown in  FIGS. 2D and 6B , through which the second tightening adjustment fitting  21 , which is described later, passes. Then by bringing the fastening projections  12   b,    12   b  closer to each other, the cut-out  12   a  is narrowed in the width direction, and the column pipe  9  inserted in the insertion hole  11  is fastened and fixed at the desired position.  
         [0030]     Also, the pivot part  13  is fitted to the pivot supports  4 ,  4  of the fixed bracket A by a pair of pivot pins  14 ,  14  so that the pivot housing C is supported so that it can pivot freely, and function as a support point when adjusting the tilt of the steering wheel  27 . The pivot part  13  is formed at the front end in the long direction of the main housing  10  (see  FIG. 1A ). The specific form of the pivot part  13 , as shown in  FIG. 6B , is a component separate from the main housing  10 , fixed to the main housing  10  with fasteners such as screws or bolts. The pivot part  13  includes a connection part  13   a  and a pair of pivot side plates  13   b,    13   b.  The two pivot side plates  13   b,    13   b  are formed in confrontation with each other at the two ends in the width direction of the connection part  13   a.  Pivot holes  13   c,    13   c  are formed in each pivot side plate  13   b,    13   b.    
         [0031]     Then the pivot housing C can pivot about the pivot holes  13   c,    13   c  in the vertical direction, to form the tilt adjustment mechanism for the steering wheel  27 . Also, a shaft through hole  13   d  is formed in the connection part  13   a,  and part of the lower shaft  16 , which is described later, passes through the shaft through hole  13   d  in the axial direction (see  FIG. 2B ). Then the pivot part  13  is arranged between the two pivot support parts  4 ,  4  of the fixed bracket A, as shown in  FIG. 2B , and the pivot support holes  4   a  of each pivot support part  4  and the pivot holes  13   c  of the pivot side plates  13   b  are connected so as to allow pivoting with the pivot pin  14 , such as bolt and nut or pin members, etc.  
         [0032]     In this way, the pivot housing C can pivot in the vertical direction relative to the fixed bracket A. In this description the main housing  10  and the pivot part  13  are separate components, but the main housing  10  and the pivot part  13  may be formed integrally.  
         [0033]     Next, as shown in  FIGS. 1B, 4 ,  5 A, and elsewhere, the upper shaft  15  is fitted within the column pipe  9  so that it can freely rotate in the axial peripheral direction. A pair of bearings  17 ,  17  is provided on the column pipe  9  at the front and rear ends in the axial direction. The upper shaft  15  is supported through the bearings  17 ,  17 . Also, a transmission shaft part  15   a  is formed in the upper shaft  15  in the front end in the axial direction, and the steering wheel  27  is fitted to the rear end in the axial direction.  
         [0034]     Next, as shown in  FIGS. 4 and 5 B, a transmission shaft part  16   a  is formed in the lower shaft  16  at one end in the axial direction, and there is a universal joint  16   b  at a suitable position about the middle in the axial direction. The lower shaft  16  is fitted to the insertion hole  11  of the pivot housing C so that it can freely rotate in the axial peripheral direction, as shown in  FIGS. 1B and 4 . Specifically, the transmission shaft part  16   a  of the lower shaft  16  is inserted in the insertion hole  11  of the pivot housing C, and is supported so that it can freely rotate by a bearing  18  at the front end position  11   a  of the insertion hole  11  in the long direction.  
         [0035]     The transmission shaft part  16   a  of the lower shaft  16  and the transmission shaft part  15   a  of the upper shaft  15  are connected so that axial rotations are transmitted. Specifically, splines are formed on the transmission shaft part  15   a  and the transmission shaft part  16   a,  those on the transmission shaft part  15   a  being internal splines, and those on the transmission shaft part  16   a  being external splines. Then the transmission shaft part  16   a  is inserted in the transmission shaft part  15   a.  Therefore the upper shaft  15  and the lower shaft  16  can freely expand and contract at the position of the connection of the transmission shaft part  15   a  and the transmission shaft part  16   a.  Also, the rotation of the upper shaft  15  due to the action of the steering wheel  27  can be transmitted to the lower shaft  16  (see  FIG. 7 ).  
         [0036]     In other words, when the column pipe  9  slides relative to the pivot housing C, the transmission shaft part  15   a  of the upper shaft  15  slides relative to the transmission shaft part  16   a  of the lower shaft  16 . In this way, when making telescopic adjustments, even if the upper shaft  15  moves in the axial direction the lower shaft  16  does not move. Therefore the position of a universal joint  28  on a steering shaft  26  connected to a steering device on the front wheels does not change. Therefore the operation feeling can be maintained constant (see  FIG. 8 ).  
         [0037]     The column housing B in which the column pipe  9  is fitted is arranged between the two fixed support side parts  2 ,  2  of the fixed bracket A towards the rear in the long direction. The first fastening adjustment fitting  20  is fitted to the tilt adjustment holes  3 ,  3  formed in the two fixed support side parts  2 ,  2  and the telescopic adjustment elongated hole  7  of the column housing B (see  FIGS. 2A, 2B , and  2 C). Also, the pivot housing C is arranged between the fixed support side parts  2 ,  2  towards the front in the long direction. The second fastening adjustment fitting  21  is fitted to the fastening bolt holes  12   c,    12   c  of the two fastening projections  12   b,    12   b  of the pivot housing C and another set of tilt adjustment elongated holes  3 ,  3  (see  FIGS. 2A, 2B , and  2 D).  
         [0038]     The first fastening adjustment fitting  20  includes a first bolt  20   a  and a first fastening nut  20   b.  The second fastening adjustment fitting  21  includes a second bolt  21   a  and a second fastening nut  21   b.  The first bolt  20   a  is passed through the tilt adjustment elongated holes  3 ,  3  in the rear side (towards the steering wheel  27 ) of the fixed support side parts  2 ,  2  of the fixed bracket A and the telescopic adjustment hole  7  of the column housing B. The first fastening nut  20   b  is threaded onto the threaded part of the first bolt  20   a  projecting from the fixed support side part  2 , so that the fixed support side parts  2 ,  2  can be tightened.  
         [0039]     Also, the second bolt  21   a  is passed through the tilt adjustment elongated holes  3 ,  3  on the front side (towards the front wheels) of the fixed support side parts  2 ,  2  of the fixed bracket A and the fastening bolt hole  12   c  of the fastening part  12  of the pivot housing C. The second fastening nut  21   b  is threaded onto the threaded part of the second bolt  21   a  projecting from the fixed support side part  2 , so that the fixed support side parts  2 ,  2  can be tightened. At the same time the column pipe  9  inserted in the insertion hole  11  is fixed by the fastening part  12  of the pivot housing C.  
         [0040]     A first arm  22  is fixed to the first fastening nut  20   b  on the outside of the fixed support side part  2  on one side of the fixed bracket A so that the first arm  22  rotates together with the first fastening nut  20   b.  Also, a second arm  23  is fixed to the second fastening nut  21   b  so that the second arm  23  rotates together with the second fastening nut  21   b.  A link  24  pivotally connects the first arm  22  and the second arm  23 . Furthermore, a locking lever  25  is fitted to the first fastening nut  20   b  of the first fastening adjustment fitting  20  (see  FIGS. 2A and 2B ).  
         [0041]     When the locking lever  25  is rotated, the first fastening nut  20   b  as well as the first arm  22  rotate, and this rotation is transmitted to the second arm  23  by the link  24 . Therefore it is possible to carry out the fastening or releasing operations for the first fastening adjustment fitting  20  and the second fastening adjustment fitting  21  at the same time by the rotation of the locking lever  25 . Also, the locking lever  25  may be fitted to the second fastening nut  21   b  side of the second fastening adjustment fitting  21  (see the imaginary line in  FIG. 4 ).  
         [0042]     In this case the column housing B and the pivot housing C can be separately locked or released. Also, a retaining member is fitted on the outside of the fixed support side plate  2  on the other side of the fixed bracket A so that the first bolt  20   a  of the first fastening adjustment fitting  20  and the second bolt  21   a  of the second fastening adjustment fitting  21  will not idle. Besides the first fastening adjustment fitting  20  and the second fastening adjustment fitting  21  as described above, a cam mechanism or similar may be used as the means of fixing the column housing B and the pivot housing C to the fixed bracket A. Also, another fastening mechanism may be used.  
         [0043]     Also, as shown in  FIG. 2C , the first fastening adjustment fitting  20  performs the role of holding, fastening, and fixing the column housing B between the two fixed support side parts  2 ,  2 . Also, as shown in  FIG. 2D , the second fastening adjustment fitting  21  performs the role of holding, fastening, fixing the pivot housing C via the two fixed support side parts  2 ,  2 . In addition, by bringing the two fastening projections  12   b,    12   b  of the fastening part  12  of the pivot housing C and the cut-out  12   a  closer, the second fastening adjustment fitting  21  performs the role of fixing the column pipe  9  to the desired position.  
         [0044]     Tilt and telescopic adjustments with the present invention are carried out by first rotating the locking lever  25 , which loosens the first fastening adjustment fitting  20  and the second fastening adjustment fitting  21 . Then the telescopic adjustment is carried out within the range of the telescopic elongated hole  7  of the column housing B.  FIG. 7A  shows the standard position of the steering wheel  27 , which is at a distance S from the position of the pivot pin  14  of the pivot housing C.  FIG. 7B  shows the steering wheel  27  moved forward (towards the front wheels of the vehicle), so that the steering wheel  27  is at a distance (S−ΔS) from the position of the pivot pin  14  of the pivot housing C.  FIG. 7C  shows the wheel  27 , so that the steering wheel  27  is at a distance (S+ΔS) from the position of the pivot pin  14  of the pivot housing C.  
         [0045]     Also, tilt adjustments can be carried out at the same time using the tile adjustment elongated holes  3 ,  3  for the two fixed support side parts  2 ,  2 . During telescopic adjustment the column housing B moves due to the telescopic adjustment, and the column pipe  9  slides within the insertion hole  11  of the pivot housing C. Furthermore, the transmission shaft part  15   a  of the upper shaft  15  fitted within the column pipe  9  slides relative to the transmission shaft part  16   a  of the lower shaft  16  which is arranged within the insertion hole  11  of the pivot housing C.  
         [0046]     At this time the pivot housing C and the lower shaft  16  cannot move in the axial direction. Therefore the universal joint  28  that connects the lower shaft  16  with the steering shaft  26 , as shown in  FIG. 8 , does not move, and the operation feeling is maintained constant. In other words, in the present invention, when telescopic adjustments of the steering wheel  27  are made, the extension and contraction occur through movement of the column housing B, column pipe  9 , and upper shaft  15 . The pivot housing C and lower shaft  16  do not move in the direction of the telescopic adjustment. Therefore, the distance T from the pivot pin  14  of the pivot housing C to the universal joint  28  that connects with the steering shaft  26  is always constant. Therefore the angle of inflection α of the universal joint  28  connecting the steering shaft  26  and the lower shaft  16  is also constant. Therefore the rotation force at the wheel  27  is also constant; and the operation feeling at the wheel  27  can be maintained constant.  
         [0047]     Therefore, in telescopic adjustment, the joint with the steering shaft  26  does not move, so telescopic adjustment does not affect the steering shaft  26 , so the operation feeling is good. Also, the first fastening adjustment fitting  20  and the second fastening adjustment fitting  21  can be fastened at the same time by operating the locking lever  25 , through the first arm  22 , the link  24 , and the second arm  23 . Therefore, very accurate fastening can be achieved and high stiffness obtained.