Steering column assembly

A steering column assembly includes a jacket assembly, a mounting bracket, and a first telescope guide. The jacket assembly defines a first guide slot. The mounting bracket is disposed on the jacket assembly and has a first portion disposed opposite a second portion and a third portion extending between the first portion and the second portion. The first portion has a first rail received within the first guide slot. The first telescope guide is disposed between the first guide slot and the first rail.

BACKGROUND OF THE INVENTION

The present invention relates to a steering column assembly.

Telescoping steering column assemblies permit linear movement between movable components and stationary components of the steering column assembly. Complex geometries and additional components of the steering column assembly aid in meeting difficult vehicle packaging requirements and providing a substantially clearance free fit between the movable components and the stationary components of the steering column assembly. The additional components may include a de-lashing mechanism, a series of springs and wedges, or the like.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a steering column assembly is provided. The steering column assembly includes a jacket assembly, a mounting bracket, and a first telescope guide. The jacket assembly defines a first guide slot. The mounting bracket is disposed on the jacket assembly and has a first portion disposed opposite a second portion and a third portion extending between the first portion and the second portion. The first portion has a first rail received within the first guide slot. The first telescope guide is disposed between the first guide slot and the first rail.

According to another embodiment of the present invention, a steering column assembly is provided. The steering column assembly includes a jacket assembly, a mounting bracket, a first telescope guide, and a second telescope guide. The jacket assembly has a body and a support portion disposed on a central element extending from the body. The body, the central element, and the support portion defines a first guide slot and a second guide slot disposed opposite the first guide slot. The mounting bracket has a first portion disposed opposite a second portion. The first portion has a first rail received within the first guide slot. The second portion has a second rail received within the second guide slot. The first telescope guide is disposed between the first guide slot and the first rail. The second telescope guide is disposed between the second guide slot and the second rail.

According to yet another embodiment of the present invention, a method of manufacturing a steering column assembly is provided. The method of manufacturing includes providing a mounting bracket having a first portion, a second portion, a third portion. The first portion has a first rail. The second portion is disposed opposite the first portion and has a second rail. The third portion extends between the first portion and the second portion. The method of manufacturing further includes providing a second jacket assembly that receives a first jacket assembly. The second jacket assembly includes a body and a support portion disposed on a central element that extends from the body. The body, the support portion, and the central element define a first guide slot and a second guide slot disposed opposite the first guide slot. The method of manufacturing further includes inserting the second jacket assembly within the mounting bracket such that the first rail is received within the first guide slot and the second rail is received within the second guide slot. The method of manufacturing further includes inserting a first telescope guide between the first guide slot and the first rail and inserting a second telescope guide between the second guide slot and the second rail. The first guide slot and the second guide slot each include a first wall, a second wall disposed opposite the first wall, and a third wall extending between a first wall proximal end and a second wall proximal end. The third wall has a raised section extending towards a first wall distal end and a second wall distal end.

DETAILED DESCRIPTION

Referring toFIG. 1, a steering column assembly10is shown. The steering column assembly10is provided with a vehicle, such as a motor vehicle like a truck, bus, farm equipment, military transport or weaponry vehicle, or cargo loading equipment for land, air, or marine vessels. The steering column assembly10is operatively connected to a steering wheel that may articulate at least one vehicle wheel in response to rotation of the steering wheel.

The steering column assembly10is configured as a power tilt and/or telescoping steering column assembly. In at least one embodiment, the steering column assembly10is a manual steering column assembly or a rake column assembly provided with a telescoping feature. The steering column assembly10includes a steering shaft12extends longitudinally along a steering column axis14. At least a portion of the steering column assembly10is movable along the steering column axis14or is pivotable/tiltable relative to the steering column axis14. The steering column assembly10includes a first jacket assembly20, a second jacket assembly22, a mounting bracket24, a telescope actuator assembly26, a telescope guide assembly28, and a plastic component30.

The steering column assembly10is operatively connected to a vehicle structure by the mounting bracket24. Throughout this specification, the term “attach,” “attachment,” “connected”, “coupled,” “coupling,” “mount,” or “mounting” shall be interpreted to mean that one structural component or element is in some manner connected to or contacts another element—either directly or indirectly through at least one intervening structural element—or is integrally formed with the other structural element. Accordingly, it should be appreciated that the first jacket assembly20and/or the second jacket assembly22may be connected to the mounting bracket24in several different ways using at least one different structural element interconnecting the first jacket assembly20and/or the second jacket assembly22and mounting bracket24to each other.

The first jacket assembly20extends along the steering column axis14and is operatively engaged with the steering wheel. The first jacket assembly20is at least partially received within the second jacket assembly22. The first jacket assembly20or the tilt head is connected to the second jacket assembly22by at pivot pin or a tilt pin34. The first jacket assembly20is tiltable or pivotable about an axis defined by the tilt pin34relative to the second jacket assembly22. The first jacket assembly20and the second jacket assembly22are movable between a retracted position and an extended position along the steering column axis14with respect to each other.

Referring toFIGS. 1 and 2, the second jacket assembly22extends along the steering column axis14. The second jacket assembly22has a body40that defines a first side52, a second side54, a central element56, and a support portion58.

The first side52is disposed opposite the second side54. The first side52includes a first jacket stiffness rail60. The first jacket stiffness rail60is disposed between a top portion of the body40and a bottom portion of the body40. The first jacket stiffness rail60extends away from the steering column axis14in a first direction. The first stiffness rail60defines an opening that receives the pivot pin34.

The second side54includes a second jacket stiffness rail62. The second jacket stiffness rail62is disposed between the top portion of the body40and the bottom portion of the body40. The second jacket stiffness rail62extends away from the steering column axis14in a second direction disposed opposite the first direction. The second stiffness rail62defines an opening that receives the pivot pin34.

The central element56is disposed above the first side52and the second side54. The central element56is disposed substantially parallel to but not coplanar with the first side52and the second side54. The central element56is disposed closer to the steering column axis14than the first side52and the second side54. A first stepped surface64extends between a top portion of the first side52and a bottom portion of the central element56. A second stepped surface66, disposed opposite the first stepped surface64, extends between a top portion of the second side54and a bottom portion of the central element56. The central element56extends towards the support portion58.

The support portion58is disposed above the first side52, the second side54, and the central element56. The support portion58engages the central element56. The support portion58includes a first support surface70, a second support surface72, a third support surface74, and a fourth support surface76.

The first support surface70faces towards a top inner surface of the mounting bracket24. The second support surface72is disposed opposite the first support surface70. The third support surface74extends between the first support surface70and the second support surface72. The fourth support surface76is disposed opposite the third support surface74. The fourth support surface76extends between the first support surface70and the second support surface72.

The third support surface74is disposed farther from the steering column axis14than the central element56. The combination of the third support surface74and a portion of the first support surface70and a portion of the second support surface72that extends beyond the central element56in the first direction defines a first jacket lip80. The combination of the first jacket lip80, the central element56, and at least one of the first stepped surface64and a top of the first side52defines a first guide slot82. The first guide slot82is disposed between the first jacket lip80and the first jacket stiffness rail60.

The fourth support surface76is disposed farther from the steering column axis14than the central element56. The combination of the fourth support surface76and a portion of the first support surface70and a portion of the second support surface72that extends beyond the central element56and the second direction, defines a second jacket lip84. The combination of the second jacket lip84, the central element56, and at least one of the second stepped surface66and a top of the second side54defines a second guide slot86. The second guide slot86is disposed between the second jacket lip84and the second jacket stiffness rail62.

The mounting bracket24is disposed on the second jacket assembly22. The mounting bracket24has a first portion90, a second portion92, and a third portion94. The first portion90is disposed opposite the second portion92. The third portion94extends between upper portions of the first portion90and the second portion92.

The first portion90defines a first rail100. The first rail100extends towards the second jacket assembly22. The first rail100is received within the first guide slot82. The first rail100includes a first surface102, a second surface104, and an engagement surface106.

The first surface102is disposed substantially parallel to the first support surface70and the second support surface72. The second surface104is spaced apart from and is disposed opposite the first surface102. The second surface104is disposed substantially parallel to the first support surface70and the second support surface72.

The engagement surface106extends between the first surface102and the second surface104. The engagement surface106includes a first segment110and a second segment112. The first segment110extends from an end of the first surface102towards an intersection point114. The second segment112extends from an end of the second surface104towards the intersection point114. In at least one embodiment the engagement surface106has a generally V-shaped cross section.

The second portion92defines a second rail120. The second rail120extends towards the second jacket assembly22. The second rail120is received within the second guide slot86. The second rail120has a substantially similar configuration as the first rail100. As such, the second rail120includes a first surface102, a second surface104, and an engagement surface106.

The first surface102is disposed substantially parallel to the first support surface70and the second support surface72. The second surface104is spaced apart from and is disposed opposite the first surface102. The second surface104is disposed substantially parallel to the first support surface70and the second support surface72.

The engagement surface106extends between the first surface102and the second surface104. The engagement surface106includes a first segment110and a second segment112. The first segment110extends from an end of the first surface102towards an intersection point114. The second segment112extends from an end of the second surface104towards the intersection point114. In at least one embodiment the engagement surface106has a generally V-shaped cross section.

The first portion90defines an actuator mounting bracket130that receives the telescope actuator assembly26. The actuator mounting bracket130is spaced apart from the first rail100and the second rail120. The actuator mounting bracket130is disposed below the first rail100and the second rail120.

The telescope actuator assembly26is configured to translate the first jacket assembly20and the second jacket assembly22along the steering column axis14relative to each other. The telescope actuator assembly26includes a telescope drive bracket132, a telescope actuator134, and a lead screw136. The telescope drive bracket132is coupled to the second jacket assembly22. The telescope actuator134is spaced apart from the telescope drive bracket132. The telescope actuator134is received within the actuator mounting bracket130.

The telescope actuator134is operatively connected to the telescope drive bracket132by the lead screw136. The lead screw136extends from the telescope actuator134through an aperture of the telescope drive bracket132and engages a jackscrew nut of the telescope drive bracket132. The telescope actuator134imparts rotary motion to the lead screw136and the telescope drive bracket132converts the rotary motion of the lead screw136into linear motion to translate the first jacket assembly20and the second jacket assembly22along the steering column axis14relative to each other and the mounting bracket24. The telescope actuator134may be in electronic actuator, hydraulic actuator, pneumatic actuator, or the like.

The linear movement of the first jacket assembly20and the second jacket assembly22relative to the mounting bracket24may be impacted by clearances between the moving components and the stationary components of the steering column assembly10. In an attempt to minimize the clearance and present a structural lash free interface between the moving components and the stationary components of the steering column assembly10the telescope guide assembly28and the plastic component30are provided.

The telescope guide assembly28includes a first telescope guide140and a second telescope guide142. The first telescope guide140and the second telescope guide142may be light weight extrusions, an injection molded plastic component, or the like having a low coefficient of friction. The first telescope guide140and the second telescope guide142may be a teflon coated bronze mesh, an injection molded thin wall slider bearing, a combination thereof, or the like. The first telescope guide140and the second telescope guide142are light weight extrusions may be made of a material different than the material of the first jacket assembly20, the second jacket assembly22, or the mounting bracket24. The first telescope guide140is inserted into the second jacket assembly22such that the first telescope guide140is disposed between the first guide slot82and the first rail100. The first telescope guide140includes a first wall150, a second wall152, and a third wall154.

The first wall150is disposed substantially parallel to the first surface102of the first rail100. A top surface of the first wall150defines a first bearing surface160. The first bearing surface160is a sliding surface that engages the second support surface72of the support portion58of the body40of the second jacket assembly22.

The second wall152is spaced apart from the first wall150. The second wall152is disposed substantially parallel to the first wall150. The second wall152is disposed substantially parallel to the second surface104of the first rail100. A bottom surface of the second wall152defines a second bearing surface162. The second bearing surface162is a sliding surface that engages the first stepped surface64of the body40of the second jacket assembly22.

The third wall154extends between a proximal end of the first wall150and a proximal end of the second wall152. The third wall154is disposed opposite a distal end of the first wall150and a distal end of the second wall152.

At least a portion of the third wall154is disposed substantially parallel to the central element56of the body40. The third wall154includes a raised section164. The raised section164is a generally arcuate section that extends towards the distal end of the first wall150and the distal end of the second wall152. The raised section164extends towards and is spaced apart from engagement surface106of the first rail100.

The raised section164is expandable towards or away from at least one of the central element56of the body40of the second jacket assembly22and the engagement surface106. The raised section164expands to accommodate shape variances between the guide slots and the rails. The underside of the raised section164that faces towards the central element56of the body40of the second jacket assembly22may be used as a grease reservoir to maintain grease for the life of the steering column assembly10.

The second telescope guide142is inserted into the second jacket assembly22such that the second telescope guide142is disposed between the second guide slot86and the second rail120. The second telescope guide142has a substantially similar configuration as the first telescope guide140. Includes a first wall150, a second wall152, and a third wall154that includes a raised section164that extends towards and is spaced apart from the engagement surface106of the second rail120.

Referring toFIGS. 3 and 4, the plastic component30is inserted between the first rail100of the mounting bracket24and the first telescope guide140. The plastic component30is injected within a cavity formed by the first telescope guide140and the first rail100. The plastic component30is configured to adhere the first telescope guide140to the first rail100of the mounting bracket24. The shape of the plastic component30may vary depending on vehicle requirements such as space constraints, stiffness required, stroke load required, etc.

The plastic component30is an expandable material. The plastic component30fills gaps or spaces between the first telescope guide140and the first rail100and the second telescope guide142and the second rail120to inhibit relative movement between the first and second telescope guides140,142and the second jacket assembly22.

The plastic component30is inserted between the second rail120of the mounting bracket24and the second telescope guide142. The plastic component30is injected within a cavity formed by the second telescope guide142and the second rail120. The plastic component30adheres the second telescope guide142to the second rail120. The shape of the plastic component30may vary depending on vehicle requirements such as space constraints, stiffness required, stroke load required, etc.

The plastic component30is inserted between the rails and the telescope guides by a variety of methods including injection such that the plastic component30is an injected plastic that fixes the first telescope guide140and the second telescope guide142to the first rail100and the second rail120of the mounting bracket24, respectively. The first telescope guide140, the second telescope guide142, and the plastic component30remain stationary with the mounting bracket24during translation or telescope motion of at least one of the first jacket assembly20and the second jacket assembly22. The first telescope guide140, the second telescope guide142, and the plastic component30provide a tight, lash free interface that permits or allows translation or telescope motion of at least one of the first jacket assembly20and the second jacket assembly22.

The injection of the plastic component30between the first telescope guide140and the first rail100and the second telescope guide142and the second rail120enables a match fit or the mating between the second jacket assembly22and the mounting bracket24to create a low stroke load, highly stiff or rigid steering column assembly10without performing expensive machining processes.

The plastic component30conforms to the shape of the first telescope guide140and the first rail100. The conformance permits the self-adjustment of the first telescope guide140to the mating component size, i.e. the first rail100, during the injection process. The first telescope guide140seals off a leak path of the liquid plastic injected during the plastic injection process.

The plastic component30conforms to the shape of the second telescope guide142and the second rail120. The conformance permits the self-adjustment of the second telescope guide142to the mating component size, i.e. the second rail120, during the injection process. The second telescope guide142seals off a leak path of liquid plastic injected during the plastic injection process.

Referring toFIG. 5, a method of manufacturing a steering column assembly is shown. A mounting bracket24is provided at block200. The mounting bracket24may be fixedly positioned during the manufacturing process. A second jacket assembly22is provided at block202. A first jacket assembly20may also be provided that is inserted into the second jacket assembly22such that the combination of the first jacket assembly20and the second jacket assembly22are provided at block202. The second jacket assembly22is inserted within the mounting bracket24at block204. A first telescope guide140and a second telescope guide142are provided at block206. The first telescope guide140is inserted between a first guide slot82of the second jacket assembly22and a first rail100of the mounting bracket24and the second telescope guide142is inserted between a second guide slot86of the second jacket assembly22and a second rail120of the mounting bracket24at block208. In at least one embodiment, the first telescope guide140and the second telescope guide142is substantially simultaneously inserted between the second jacket assembly22and the mounting bracket24.

A plastic component30is injected between the telescope guides to fixedly position the telescope guides relative to the rails at block210. The plastic component30is injected between the first telescope guide140and the first rail100of the mounting bracket24to join the first telescope guide140to the first rail100of the mounting bracket24. The plastic component30is injected between the second telescope guide142and the second rail120of the mounting bracket24to join the second telescope guide142to the second rail120of the mounting bracket24. In at least one embodiment, the plastic component30is injected substantially simultaneously between the telescope guides and the rails.