Steering apparatus for an automobile

Construction is achieved wherein the front-end section of an outer column 18a can be assembled in the rear-end section of a housing 11a that houses an electric power steering apparatus 10a from below. At least the front-end section of the outer column 18a is formed into a U shape that is open on the top end. A connection and fastening section 36 that can be inserted inside the front-end section of the outer column 18a through an opening on the top end of the front-end section is provided on the rear-end section of the housing 11a. After the connection and fastening section 36 has been inserted inside the front-end section of the outer column 18a through the opening at the top end of the front-end section, fastening nuts 40 are screwed onto the tip end sections of fastening bolts 39 that are inserted in the left-right direction through portions near the top ends of the connection and fasting section 36 and the front-end section of the outer column 18a, and by tightening the nuts 40, the connection and fastening section 36 and front-end section of the outer column 18a are connected and fastened together.

TECHNICAL FIELD

The present invention relates to a steering apparatus for an automobile that is used for applying a steering angle to the steered wheels, and particularly, relates to construction of a connecting section between the front end section of the steering column and the housing of an electric power steering apparatus in a steering apparatus for an automobile provided with an electric power steering apparatus.

BACKGROUND ART

As illustrated inFIG. 8andFIG. 9, a steering apparatus for an automobile is constructed, for example, so that rotation of a steering wheel1is transmitted to an input shaft3of a steering-gear unit2, and as the input shaft3rotates, a pair of left and right tie rods4are pushed and pulled so as to apply a steering angle to the front wheels (steered wheels). The steering wheel1is supported by and fastened to the rear-end section of a steering shaft5, and with this steering shaft5inserted into a cylindrical shaped steering column6, the steering shaft5is supported by the steering column6so as to be able to rotate freely. Moreover, the front-end section of the steering shaft5is connected to the rear-end section of an intermediate shaft8by way of a universal joint7, and the front-end section of this intermediate shaft8is connected to the input shaft3by way of a separate universal joint9.

The steering apparatus for an automobile that is illustrated in the figures, together with comprising an electric power steering apparatus10that assists the operator steer by way of rotation of a motor, also comprises a tilt mechanism for adjusting the up-down position of the steering wheel, and a telescopic mechanism for adjusting the forward-backward position of the steering wheel1. Therefore, the front-end section of the steering column6fits with and fastens to the rear-end section of a housing11that houses the component parts of the electric power steering apparatus10, and this housing11is supported by the vehicle body12so as to be able to pivot around a horizontal shaft13that is arranged in the left-right direction. The steering shaft5comprises a combination of an inner shaft15and an outer shaft16that are capable of transmitting rotation force and are capable of relative displacement in the axial direction. On the other hand, the steering column6comprises a combination of an inner column17and an outer column18that are capable of relative displacement in the axial direction. Furthermore, the portion near the rear end of the outer column18is supported by a vehicle-side bracket19that is supported by the vehicle body19so that the fastened state to the vehicle side bracket19can be switched between a fastened state and unfastened state.

In order to achieve this kind of support construction, a pair of holding plate sections20of the vehicle-side bracket19are arranged at a position on both sides in the left-right direction of the portion near the rear end of the outer column18and a column-side bracket21that is attached and fastened to the bottom surface of this portion near the rear end. Arc-shaped long holes22in the up-down direction that center around the horizontal shaft13are formed at positions in these holding plate sections20so as to be aligned with each other. Moreover, long holes23that are long in the forward-backward direction in the axial direction of the outer column18are formed at positions in the side plate sections of the column-side bracket21so as to be aligned with each other. An adjustment rod24, which is a rod shaped member, is inserted in the forward-backward long holes23and the up-down long holes22. A head section25, which is a pressing section, is formed on the base-end section of this adjustment rod24. An adjustment nut26, which is a pressing section, is screwed onto the portion of the tip end section of this adjustment rod24that protrudes from the up-down hole22, and the base-end section of an adjustment lever27is connected and fastened to this adjustment nut26. In the construction illustrated in the figure, the adjustment rod24, the adjustment nut26and the adjustment lever27form an expanding-contracting mechanism for switching between the fastened state and unfastened state between the vehicle-side bracket19and the steering column6.

When adjusting the up-down position and the forward-backward direction of the steering wheel1, the adjustment lever27is operated, and by loosening the adjustment nut26the distance between the inside surfaces of the holding plate sections20is expanded. As a result, the friction force that acts between the holding plate sections20and the side plate sections of the column-side bracket21is sufficiently decreased, and the fastened state of the outer column18to the vehicle-side bracket19is released. In this state, when the up-down position of the steering wheel1is adjusted, the steering column6and steering wheel1are pivoted around the horizontal shaft13within a range that the adjustment rod24can displace inside long hole22in the up-down direction. On the other hand, when the forward-backward position of the steering wheel1is adjusted, the entire length of the steering column6and steering shaft5is extended or contracted within the range the adjustment rod24can displace inside the long hole23in the forward-backward direction. After adjustment, the adjustment lever27is operated, and the adjustment nut26is tightened. By doing so, the friction force is sufficiently increased, and the outer column18is fastened to the vehicle-side bracket19. As a result, the steering wheel1is held in the adjusted position.

Incidentally, as construction for connecting the front-end section of the steering column6and the rear-end section of the housing11of this kind of steering apparatus, construction in which the front-end section and the rear-end section fit together in the axial direction is widely used. As an example of this kind of connecting construction, JP2011-46309(A) discloses construction in which the cylindrical shaped front-end section of the steering column is pressed onto and fits around a cylindrical shaped section that is formed on the rear end section of the housing with an interference fit. Moreover, JP2000-85596(A) discloses a method in which the front end section of a steering column having a notched cylindrical shape fits around a cylindrical section that is formed on the rear-end section of the housing, then a fastener fits around this front end section and by elastically constricting the diameter of the front-end section with this fastener, the inner surface of the front-end section forms a strong friction fit with the outer circumferential surface of the cylindrical section. Furthermore, JP2008-87583(A) discloses construction in which the cylindrical shaped front-end section of the steering column fits inside a circular hold that is formed on the rear-end section of the housing, and a flange section that is formed around the outer circumferential surface of the portion near the front end of the steering column is connected and fastened to the rear-end surface of the housing with a plurality of bolts.

When using any of the conventional construction as construction for connecting the front-end section of the steering column6and the rear-end section of the housing11, the assembled direction of the steering column6with respect to the housing11when assembling this connection is in the axial direction of the steering column6. On the other hand, when assembling the portion near the rear end of the steering column6in the vehicle-side bracket19, this portion near the rear end of the steering column6is inserted between the holding plate sections20of the vehicle-side bracket19from the bottom edge side of these holding plate sections20. In other words, the assembly direction of the steering column6in the vehicle-side bracket19is in the radial direction of the steering column6. In this way, in the case of the conventional construction, the assembly direction of the steering column6in the housing11and the assembly direction of the steering column6in the vehicle-side bracket19are different.

RELATED LITERATURE

Patent Literature

SUMMARY OF INVENTION

Problem to be Solved by the Invention

Taking the situation above into consideration, it is the object of the present invention to provide construction of a steering apparatus for an automobile wherein the assembly direction of the steering column in the housing of the electric steering apparatus and the assembly direction of the steering column in the vehicle-side support bracket coincide with each other.

Means for Solving the Problems

The steering apparatus for an automobile of the present invention has a steering column, a housing that is supported by the vehicle body and that houses an electric power steering apparatus, a vehicle-side bracket that is supported by the vehicle body, and an expansion and contraction mechanism.

The steering column has a front-end section that is formed in a U-shape that is open at the top and comprises a pair of left and right side plate sections that face each other and a bottom plate section that connects to the edges on the bottom ends of these side plate sections.

The housing for an electric power steering apparatus has a connection and fastening section on the rear that is capable of being inserted inside the front-end section of the steering column through an opening in the top end of the front-end section, and when inserted inside the front-end section is capable of a non-circular fit in the front-end section.

The vehicle-side bracket has a pair of holding plate sections that are located at positions on both the left and right sides of the middle section of the steering column, with the portion between the edges on bottom edges being open.

The expansion and contraction mechanism comprises a rod shaped member that is inserted in the left-right direction through through holes that are formed in positions of the holding plate sections that are aligned with each other, and a pair of pressing sections that are provided on both end sections of the rod shaped member. The expansion and contraction mechanism is constructed such that by moving these pressing sections away from each other or close to each other in the axial direction of the rod shape member, the distance between the holding plate sections is changed, and when this space is contracted, the expansion and contraction mechanism fastens the steering column to these holding plate sections.

With the connection and fastening section being fitted with a non-circular fit inside the front-end section, the connection and fastening section and the front-end section of the steering column are connected and fastened together by a bolt.

Preferably, when embodying the present invention, through holes in the left-right direction are formed at positions in side plate sections of the front-end section of the steering column and in the connection and fastening section of the housing that are aligned with each other; and together with inserting a bolt through these through holes that are formed in the side plate sections and the connection and fastening section, a nut is screwed on the tip end section of the bolt.

Furthermore, preferably, more than one set of the through holes is formed in the side plate sections and the connection and fastening section, and together with inserting a bolt through each of the through holes, a nut is screwed on the tip end section of the bolt.

The present invention can be applied to a steering apparatus that comprises a tilt mechanism for making it possible to adjust the up-down position of the steering wheel that is fastened to the rear-end section of the steering shaft. In this case, the housing is supported by the vehicle body so as to be able to pivotally displace around a horizontal shaft that is arranged in the left-right direction. The through holes in the holding plate sections are long holes in the up-down direction that are arc shaped around the center of the horizontal shaft, a through hole is formed in the middle section of the steering column at a position that is aligned with the long holes in the up-down direction, and the rod member is inserted through the long holes in the up-down direction of the housing and the through hole of the steering column. With this construction, when the fastened state of the steering column being fastened to the holding plate sections is released by enlarging the distance between the holding plate sections by the expansion and contraction mechanism, the up-down position of the steering column can be adjusted within the range that the rod shaped member can displace in the long holes in the up-down direction.

Furthermore, the present invention can be applied to construction that comprises a telescopic mechanism for making it possible to adjust the forward-backward position of the steering wheel. In this case, the steering column comprises a front column that is located on the front side, and a rear column that is located on the rear side and assembled so as to be able to displace relative to the front column. A front-end section is formed on the front column. A through hole is formed in the rear section of the front column at a position that is aligned with through holes in the holding plate sections. On the other hand, a long hole in the forward-backward direction that is long in the axial direction of the rear column is formed in the rear column at a position that is aligned with through holes in the holding plate sections and the through holes in the front column. The rod shaped member is inserted through the through holes in the holding plate sections, the through holes in the front column and the long holes in the forward-backward direction of the rear column. In this construction, when the fastened state of the rear column being fastened to the holding plate sections and front column is released by enlarging the distance between the holding plate sections by the expansion and contraction mechanism, it is possible to adjust the forward-backward position of the rear column within a range that the rod shaped member can displace inside the long hole in the forward-backward direction.

Preferably, the front column is an outer column, and this entire outer column is formed in a U-shape that is open at the top with the side plate sections and the bottom plate section. Moreover, the rear column is an inner column and is such that the front section of this inner column fits inside the rear section of the outer column. The expansion and contraction mechanism expands or contracts the inner dimension of the rear section of the outer column by changing the distance between the holding plate sections, such that when the inner dimension is contracted, displacement in the axial direction of the inner column with respect to the outer column is suppressed, and when the inner dimension is expanded, displacement in the axial direction of the inner column with respect to the outer column is possible.

In this construction as well, preferably through holes are formed in the left-right direction at positions in the side plate sections of the outer column and in the connection and fastening section of the housing that are aligned with each other, and together with inserting a bolt through these through holes that are formed in the side plate sections and the connection and fastening section, a nut is screwed on the tip end section of the bolt. In this case the through holes that are formed in the side plate section through which the bolt is inserted, and the through holes that are formed in the rear section of the side plate sections through which the rod shaped member is inserted are respectively formed in portions near the openings on the top end of the side plate sections.

Effect of the Invention

With the steering apparatus for an automobile of the present invention, it is possible to make the assembly direction of the steering column in the vehicle-side bracket and the assembly direction of the steering column in the housing for the electric power steering apparatus coincide with each other. Therefore, the work for this assembly can be performed in one process, and thus it is possible to improve the ease of assembly of the steering apparatus.

In other words, when assembling the steering column in the vehicle-side bracket, the middle section of the steering column is inserted between the pair of holding plate sections from the bottom edge side of the holding plate sections. That is, the assembly direction of the steering column in the vehicle-side bracket is in the radial direction of the steering column (direction from the bottom surface toward the top surface). On the other hand, when assembling the steering column in the housing, the connection and fastening section that is provided on the rear section of the housing is inserted into the front-end section of the steering column through an opening in the top end of the front-end section. That is, the assembly direction of the steering column in the housing is also in the radial direction of the steering column (direction from the bottom surface toward the top surface).

MODES FOR CARRYING OUT THE INVENTION

A first example of an embodiment of the present invention will be explained usingFIG. 1toFIG. 7. The steering apparatus for an automobile of this example comprises a steering column6a, a steering shaft5a, a housing11afor an electric power steering apparatus10a, a vehicle-side bracket19a, an energy-absorbing member28as an attached member and an expansion and contraction mechanism29.

In this example, in order to achieve the telescopic mechanism, the steering column6acomprises an outer column18athat is front column, and an inner column17athat is a rear column, that are combined so as to be capable of relative displacement in the axial direction. The outer column18ais formed by using a press to perform punching or bending of a metal plate material such as carbon steel plate having sufficient strength and rigidity, and is formed into a U shape that is open at the top comprising a pair of left and right side plate sections30, the inside surface of which face each other, and a bottom plate section31that is connected to the edges on the bottom ends of these side plate sections30. Moreover, both end sections in the width direction of the bottom plate section31are inclined at45degrees with respect to both the center section in the width direction of the bottom plate section and the side plate sections30. The dimension in the up-down direction of the side plate sections30(height dimension from the edge sections on both ends of the bottom plate section31) is comparatively large on the rear-end section and comparatively small on the front-end section, and in the portion between the rear-end section and the front-end section, the dimension changes so as to become smaller going toward the front-end side. The bending rigidity of the side plate sections30is maintained by forming a plurality of stiffening beads in both the rear-end section and the middle section of the side plate sections30, and by forming flange sections by bending the top ends of the middle sections 90 degrees toward the outside in the horizontal direction. Furthermore, restraining blocks32are fastened to the portion near the top end of the rear-end section of the inside surfaces of the side plate sections30by bolts, welding or the like. The bottom surfaces of these restraining blocks32are also inclined 45 degrees with respect to the side plate sections30and the center section in the width direction of the bottom plate section31. The portion that is surrounded by the inside surfaces of the side plate sections30, the top surface of the bottom plate section31and the bottom surface of the restraining blocks32is such that the center section in the width direction is open toward the top, and forms nearly an octagonal shaped holding space.

The inner column17ais formed by performing desired plastic working or milling on the end section of an intermediate material that is integrally formed by extrusion or drawing of a metal material containing a light alloy such as an aluminum alloy, magnesium alloy or the like. The outer perimeter surface of the inner column is an octagonal shape. The front section of this inner column17afits inside the rear section of the outer column18asuch that the forward-backward position is adjustable according to displacement in the axial direction. In other words, of the eight flat surfaces of the outer perimeter surface of the inner column17a, a pair of left and right surfaces that are parallel with each other come in contact with or closely face the inside surfaces of the side plate sections30, the three flat surfaces in the center and on both the left and right of the bottom side come in contact with or closely face the top surface of the bottom plate section31, and the two flat surfaces on the left and right of the top side come in contact with or closely face the bottom surfaces of the retaining blocks32. In construction that does not comprise a telescopic mechanism, the entire steering column can be formed into an arbitrary column shape, and only the front end section is formed into a U shape that is open at the top end by a pair of left and right side plate sections that face each other and a bottom plate section that connects the edges on the bottom ends of the side plate sections.

Moreover, in construction comprising a telescopic mechanism, the steering shaft5ais such that by combining the rear section of the inner shaft15aon the front side and the front section of the outer shaft16on the rear side by a spline fit, the inner shaft15aand the outer shaft16aare capable of transmitting rotation force, and are capable of relative displacement in the axial direction. With this construction, the entire length of the steering shaft5ais able to expand and contract. The steering shaft5apasses through the inside of the steering column6a, and the portion near the rear end of the outer shaft16ais supported by the rear-end section of the inner column17aby a bearing such as a single-row deep-groove ball bearing that is capable of supporting both radial loads and thrust loads so that steering shaft5acan rotate freely.

An electric motor14a, which is an auxiliary driving source, is supported on one side of the upper portion of the housing11afor the electric power steering apparatus10a. Moreover, the housing11ahouses a plurality of component parts including a reduction gear34for transmitting the rotation driving force of the electric motor14ato the steering shaft5a. Furthermore, a support tube35is provided in the left-right direction at the top end section at the front of the housing11a. The housing11ais supported by the vehicle body such that it can pivotally displace around a horizontal shaft such as a bolt that is inserted through the support tube35. With this construction, the steering shaft5ato which the steering wheel is fastened to the rear-end section, and the steering column6athat supports the steering shaft5aare able to displace in the up-down direction. Therefore, in construction that does not comprise a tilting mechanism the housing11acan be supported by and fastened to the vehicle body by rigid construction.

Moreover, the rear-end section of the housing11ais connected and fastened to the front-end section of the outer column18a. In this example, a connection and fasting section36is provided in the center section of the rear-end surface of the housing11a, and protrudes toward the outer column18aside. The outer perimeter surface of this connection and fastening section36has a rectangular shaped cross section, and together with being able to be inserted into the front-end section of the outer column18athrough an opening on the top end of the front-end section, as illustrated inFIG. 5, when inserted inside the front-end section, makes a non-circular fit with the front-end section. The shape of the connection and fastening section36can be any arbitrary shape other than a rectangular shape as long as it can be inserted into the front-end section of the outer column18aand can make a non-circular fit with the front-end section.

In this example, the connection and fastening section36is such that when inserted inside the front-end section of the outer column18a, the surfaces on the left and right sides of the connection and fastening section36come in contact with the inside surfaces of the pair of side plate sections30of the outer column18a, and the center section in the width direction on the bottom surface of the connection and fastening section36comes in contact with the center section in the width direction of the bottom plate section31of the outer column18a. Moreover, through holes37,38in the left-right direction are formed in two locations in the forward-backward direction of portions near the top ends of the connection and fastening section36and the side plate sections30that are aligned with each other. Fastening bolts39are inserted through each of the through holes37,38that are formed at these two locations in the forward-backward direction, and fastening nuts40are screwed onto the tip end sections of these fastening bolts39and tightened. Then, by firmly holding the connection and fastening section36and the side plate sections30by the head sections41on the base end sections of the fastening bolts39and the fastening nuts40, the connection and fastening section36and front-end section of the outer column18aare connected and fastened together. Furthermore, in this state, the front-end section of the inner shaft15ais inserted inside the housing11athrough a center hole in the connection and fastening section36and connected to component parts of the electric power steering apparatus10athat are housed inside the housing11a.

The vehicle-side bracket19acomprises a top plate section42and a pair of holding plate sections20a,20b. The top plate section42and holding plate sections20a,20bare formed by using a press to perform punching and bending of metal plate such as steel plate having sufficient strength and rigidity, and connected and fastened together to form a single piece by welding or the like. Installation holes, through which bolts or studs are passed in order to support the top plate section42and fasten the top plate section42to the vehicle body, are formed in the top plate section42. Moreover, holding plate sections20a,20bare placed at positions on both sides in the left-right direction of the rear-end section of the outer column18a. Long holes22a,22bthat are long in the up-down direction are formed at positions in the top portions of the holding plate sections20a,20bthat are aligned with each other. The long holes22a,22bin the up-down direction are arc shaped around the center axis of the support tube35.

In this example, an energy-absorbing member28, which is a component of the inner column17a, is attached and fastened to the top surface of the front-end section of the inner column17a. This energy-absorbing member is formed by bending metal plate, such as mild steel plate that is capable of plastic deformation, into a long rectangular frame shape that is long in the forward-backward direction, and an installation plate section43protrudes forward from the bottom-end section of the front-end surface thereof. An installation member44such as a rivet or screw that is inserted a through hole that is formed in this installation plate section43attaches and fastens the energy-absorbing member28to the inner column17a. This energy-absorbing member28expands due to plastic deformation that occurs during a secondary collision that accompanies a collision accident, and allows the inner column17ato displace in the forward direction together with the steering wheel. By this means, it is possible to protect the operator by absorbing energy that is transmitted from the body of the operator to the inner column17aby way of the steering wheel during a secondary collision.

Moreover, the expansion and contraction mechanism29is to expand and contract the distance between the inside surfaces of the holding plate sections20a,20b, and comprises an adjustment rod24a, which is a rod shaped member, an adjustment lever27a, and a cam device45. The adjustment rod24ais inserted in the left-right direction through the long holes22a,22bin the up-down direction, through holes46that are formed in the side plate sections30and restraining blocs32of the outer column18a, and long hole23ain the forward-backward direction that is long in the axial direction of the inner column17aand formed in the inside of the energy-absorbing member that is attached to the inner column17a. Moreover, the adjustment rod24ais such that a head section25ais formed on the base end section (right end section inFIG. 4andFIG. 7), and a convex section that is formed on the inside surface of this head section25afits inside one of the long holes22ain the up-down direction that is formed on one holding plate section20aof the two holding plate sections20a,20b(right holding plate section inFIG. 4andFIG. 7) so as to be able to displace (move up or down) only along this long hole22ain the up-down direction. Furthermore, the adjustment lever27ais such that the base end section is supported by the tip end section (left end section ofFIG. 4andFIG. 7) of the adjustment rod24aby way of a thrust sliding bearing47and nut48so that that adjustment lever27acan rotate with respect to the adjustment rod24a, and is prevented from displacement in the removal direction from the tip end section of the adjustment rod24a. The long hole23ain the forward-backward direction, instead of the energy-absorbing member, can also be formed in the inner column17aitself, or can be formed in a separate member that is attached to the inner column17a.

The cam device45is provided between the inside surface on the base end section of the adjustment lever27aand the outside surface of the other holding plate section20bof the two holding plate sections20a,20b(left holding plate section inFIG. 4andFIG. 7). The cam device45comprises a driving cam49that is supported by the inside surface of the base end section of the adjustment lever27aand that rotates together with the adjustment lever27a, and a driven cam50that fits in the other long hole22bin the up-down direction that is formed in the other holding plate section20bso as to be able to move only up or down. Cam surfaces are formed on the surfaces of the driven cam50and the driving cam49that face each other, and due to relative rotation between the driven cam50and driving cam49, the dimension in the axial direction of the cam device45expands or contracts. In this example, the head section25aand the driven cam50form a pair of pressing sections. Spacers51a,51b, which are formed using a material such as synthetic resin that slides easily, are placed over positions in the middle section of the adjustment rod24athat are located on the inside of the long holes22a,22bin the up-down direction, making it possible for the adjustment rod24ato smoothly displace along the long holes22a,22bin the up-down direction. Moreover, the spacer51bthat fits in the other long hole22bin the up-down direction, by engaging with the driven cam50, prevents rotation of the driven cam50. Furthermore, a cylindrical radial sliding bearing52that is made using a material that slides easily is located between the inner circumferential surface of the driving cam49and the outer circumferential surface of the adjustment rod24a.

In the case of the steering apparatus of this example, when adjusting the up-down position or the forward-backward position of the steering wheel (not illustrated in the figure) that is fastened to the rear-end section of the steering shaft5a, the dimension in the axial direction of the cam device45is shortened by rotating the adjustment lever27ain the downward direction. As a result, the distance between the inside surfaces of the holding plate sections20a,20bis expanded and the surface pressure at the area of contact between the inside surfaces of these holding plate sections20a,20band the outside surfaces of the side plate sections30of the outer column18ais sufficiently reduced. At the same time, the distance between the side plate sections30and the restraining blocks32is expanded, and the surface pressure at the area of contact between the outer circumferential surface of the inner column17and inner circumferential surface of the outer column18ais sufficiently reduced. As a result, the state of the outer column18aand inner column17abeing fastened to the vehicle-side bracket19ais released. When the up-down position of the steering wheel is adjusted in this state, the steering column6aand the steering shaft5aare pivoted around the support tube35within the range that the adjustment rod24acan displace inside the long holes22a,22bin the up-down direction. On the other hand, when adjusting the forward-backward direction of the steering wheel, the entire length of the steering column6aand the steering shaft5ais extended or contracted within the range that the adjustment rod24acan displace in the long hole23ain the forward-backward direction. After adjustment, by rotating the adjustment lever27ain the upward direction, the dimension in the axial direction of the cam device45is expanded. As a result, due to an operation that is opposite that when releasing the fastened state above, the surface pressure at the areas of contact is sufficiently increased. Consequently, the steering wheel is maintained at the adjusted position.

Moreover, in this example, construction is provided for increasing the support strength for supporting the steering wheel in the adjusted up-down position. In other words, the base section of a pivot arm53is fitted over the portion of the adjustment rod24anear the tip end of the middle section so as to be able to pivot and displace. Moreover, a male gear54is provided on the tip end section of the pivot arm53and a female gear55is provided on part of the outside surface of the holding plate section20b, and as the pivot arm53pivots, the male gear54and female gear55can be placed in either the engaged state or released state. As the adjustment lever27ais rotated in a direction for adjusting the position of the steering wheel, the pivot arm53is pivoted in a direction that releases the engagement between the male gear54and the female gear55. When the male gear54and the female gear55are in the engaged state, the adjustment rod24ais connected with the holding plate section20bby way of the pivot arm53, so regardless of whether there is a large impact load during a secondary collision, the up-down position of the steering wheel does not move a large amount.

The driven cam50is assembled to the base section of the pivot arm53so as to be able to rotate relative to the pivot arm53as well as to be able to displace a little in the up-down direction with respect to the pivot arm53. The driven cam50, as described above, is such that relative rotation with respect to the holding plate section20bis prevented. Moreover, a restoring spring56is provided between the driven cam50and the pivot arm53such that the driven cam50is supported on the pivot arm53so as to be able move up or down a little about a neutral position. The reason for allowing this small amount of up or down movement is that, even though the up-down position of the steering wheel can be adjusted in a smooth non-step manner, the engagement position between the male gear54and female gear55is in steps, so this small amount of up or down movement absorbs that difference.

With the steering apparatus of this example, it is possible to make the assembly direction of the steering column6ain the vehicle-side bracket19acoincide with the assembly direction of the steering column6ain the housing11a. In other words, when assembling the steering column6ainto the vehicle-side bracket19a, the middle portion of the steering column6a(rear-end section of the outer column18a) is inserted between the pair of holding plate sections20a,20bof the vehicle-side bracket19afrom the bottom end edge side of these holding plate sections20a,20b. That is, the assembly direction of the steering column6awith respect to the vehicle-side bracket19ais in the radial direction of the steering column6a(direction from the bottom surface toward the top surface). On the other hand, when assembling the steering column6ain the housing11a, the connection and fastening section36that is provided on the rear-end section of the housing11ais inserted into the front-end section of the steering column6a(front-end section of the outer column18a) from an opening on the top end of this front-end section. That is, the assembly direction of the steering column6awith respect to the housing11acan also be in the radial direction of the steering column6a(direction from the bottom surface toward the top surface).

Therefore, when assembling the steering apparatus of this example, the housing11aand the vehicle-side bracket19aare set in a holding tool with the positional relationship illustrated inFIG. 6, and in this state, the front-end section and the middle section of the steering column6acan be assembled into the connection and fastening section36of the housing11aand the pair of holding plate sections20a,20bof the vehicle-side bracket19ain the radial direction of the steering column6afrom the bottom inFIG. 6. Therefore, assembling the steering column6ain the vehicle-side support bracket19aand assembling the steering column6ain the housing11acan be performed in one process, and thus it is possible to improve the ease of assembly of the steering apparatus by that amount. The actual work is performed in the positional relationship of up-and-down is opposite from the positional relationship illustrated inFIG. 6.

The work of inserting the connection and fastening section36inside the front-end section of the steering column6a, and the work of inserting the middle section of the steering column6ainto the portion between the holding plate sections20a,20bcan be performed in order as described below. First, the housing11aand the vehicle-side support bracket19aare set in a holding tool with the positional relationship illustrated inFIG. 6, and then only the housing11ais pivoted and displaced around the support tube35toward the bottom inFIG. 6. Then, in this state, the connection and fastening section36is inserted inside the front-end section of the steering column6athrough opening in the top ends of the front-end section. After that, the housing11aand the steering column6aare pivoted and displaced around the support tube35toward the top inFIG. 6, and the middle section of the steering column6ais inserted into the portion between the holding plate sections20a,20b. When insertion work is performed in this kind of order, with the insertion work of one completed, the phase in the rotational direction of the steering column6ais in the proper phase, and this proper phase is maintained, so it becomes easy to perform the following insertion work. In this case as well, the two insertions described above can be performed in one process on an assembly line for the steering apparatus.

In either case, in this example, the work of inserting the connection and fastening section36inside the front-end section of the steering column6athrough an opening on the top ends of the front-end section is performed in a state wherein the steering shaft5ais not placed inside the steering column6a, or is performed in a state wherein the front-end section of the steering shaft that has been placed inside the steering column6ais moved sufficiently out of the way toward the rear. In this way, the front-end section of the steering shaft5ais prevented from hindering the insertion work.

In the case of the steering apparatus of this example, the connection and fastening section36and the side plate sections30are fastened together at the portion near an opening on the top end of the side plate sections30(opposite side from the bottom plate section31) by fastening bolts39, so the side plate sections30bend or bow and are firmly tightened to the connection and fastening section36. Similarly, the expansion and contraction mechanism29is also constructed so as to be inserted into through holes46that are formed in portions near the top end of the side plate sections30, so in the fastened state, the side plate sections30bend or bow, so the tightening force by this expansion and contraction mechanism29is tight with respect to the steering column6a. Furthermore, the insertion direction of the adjustment rod24athrough the through holes46, and the insertion direction of the fastening bolts39through the through holes37,38are in the left-right direction, and coincide with each other, so it is possible to further improve the ease of assembly of the steering apparatus. In addition, in this example, a combination of through holes37,38, fastening bolts39and fastening nuts40that is used for connecting and fastening the connection and fastening section36and the front-end section of the steering column6ais provided at two locations that are separated in the forward-backward direction. Therefore, it is possible to sufficiently maintain the bending rigidity of the connecting section between the connection and fastening section36and the front-end section of the steering column6a.

INDUSTRIAL APPLICABILITY

In the embodiment of the present invention described above, the present invention is applied to construction that comprises both a tilt mechanism for making it possible to adjust the up-down position of the steering wheel, and a telescopic mechanism for making it possible to adjust the forward-backward position of the steering wheel. However, the present invention can also be applied to construction that comprises only one of these mechanisms.

EXPLANATION OF REFERENCE NUMBERS