This application is based on and claims priority under 35 U.S.C. ยง119 to Japanese Patent Application 2011-208391, filed on Sep. 26, 2011 and Japanese Patent Application 2011-208394 filed on Sep. 26, 2011, the entire contents of which are incorporated herein by reference.
This disclosure generally relates to a steering apparatus for a vehicle.
According to a known steering apparatus for a vehicle, various measures have been taken so as to inhibit looseness or shakiness between column members connected to each other. Specifically, according to a known steering apparatus for a vehicle configured to adjust an operation position of a steering wheel in a frontward and rearward direction, i.e., in a longitudinal direction, of a vehicle, it is important to inhibit looseness or shakiness between a main housing supported to a vehicle body and a movable column member movably connected to the main housing to thereby ensure a smooth sliding performance. For example, JP2000-280917A (which will be hereinafter referred to as Reference 1) discloses a steering position adjustment control apparatus including a fixed column, a moving column, a rotating column, a lower shaft, a center shaft, an upper shaft, a tilt mechanism, a telescopic mechanism, and a control unit. The fixed column substantially having a tubular form is fixed to a vehicle body so as to extend in a longitudinal direction of a vehicle. The moving column is fitted within the fixed column so as to axially and retractably move relative to the fixed column. The rotating column is pivotally supported to the moving column. The lower shaft is axially supported within the fixed column. The center shaft is arranged within the moving column while being retractably fitted to the lower shaft and integrally rotating with the lower shaft. The upper shaft is axially supported to the rotating column in a state where a steering wheel is fitted to the upper shaft so as to transmit a rotational operation of the steering wheel to the center shaft. The tilt mechanism causes the rotating column to rotate. The telescopic mechanism causes the moving column to be elongated or contracted relative to the fixed column. The control unit controls motors of the tilt mechanism and the telescopic mechanism. A cross-section of an end portion of the fixed column at a rear of the vehicle perpendicular to an axial direction of the fixed column is formed into a ring shape, i.e., having a continuous circumference. A bush having a cylindrical shape is disposed between fitting surfaces of the fixed column and the moving column therebetween. In order to ensure a sliding performance between the fixed column and the moving column, the bush having the cylindrical shape is disposed between the fixed column and the moving column accordingly.
JP2001-310741A (which will be hereinafter referred to as Reference 2) discloses a telescopic steering apparatus that achieves a smooth telescopic movement with simple configuration while not generating a rotational movement of a movable bracket relative to a fixed bracket during a telescopic movement. The telescopic steering apparatus disclosed in Reference 2 includes the fixed bracket fixed to a vehicle body, a fixed shaft rotatably supported to the fixed bracket, the movable bracket fitted to the fixed bracket such that the movable bracket is slidable in an axial direction thereof, a movable shaft connected to the fixed shaft such that the movable shaft is movable relative to the fixed shaft and rotates integrally with the fixed shaft, the movable shaft rotatably supported to the movable bracket, and a movement mechanism that moves the movable bracket and the movable shaft in the axial direction relative to the fixed bracket and the fixed shaft. In the telescopic steering apparatus disclosed in Reference 2, an external peripheral portion of the movable bracket fitted to the fixed bracket is provided with at least one flat surface portion, and a contact member provided with a flat surface end portion that comes in contact with the flat surface portion is retained to the fixed bracket.
The fixed column and the moving column described in Reference 1 correspond to the aforementioned main housing and the movable column member while the fixed bracket, which includes a steering column and a lower tube, and the movable bracket, which includes a telescopic tube and an upper tube, in Reference 2 correspond to the aforementioned main housing and the movable column member. Each of the members corresponding to the aforementioned main housing and the movable column member in each of Reference 1 and Reference 2 is a tubular member forming an outer tube or an inner tube. In order to inhibit looseness or shakiness between the outer tube and the inner tube to ensure a sliding performance therebetween, a bush having a cylindrical shape (a cylindrical bush) is provided as a bearing member.
Each of the fixed column in Reference 1 and the steering column and the lower tube constituting the fixed bracket in Reference 2 serves as the aforementioned main housing. That is the main housing is the tubular member (the outer tube) so that the bush is disposed between the main housing (the outer tube) and the movable column member (the inner tube). As a result, a highly-accurately processing may be required at inner and outer surfaces of both the tubular members (the outer tube and the inner tube). In addition, according to Reference 1, for example, a cross-section of an end portion of the cylindrical bush at a rear of the vehicle perpendicular to an axial direction of the bush is required to be circumferentially continuously formed, i.e., formed into a ring shape. According to each of Reference 1 and Reference 2, the bush having the cylindrical shape is configured to be press-fitted between the both tubular members (the outer tube and the inner tube). Therefore, a strict dimensional control is necessary when the tubular members are manufactured and an assembly of the tubular members is difficult.
Further, for a steering apparatus configured to adjust an operation position of a steering wheel in a longitudinal direction of a vehicle, a means for restricting an axial movement of a movable column member supported to be axially movable relative to a main housing supported to a vehicle body is required so that the movable column member is inhibited from disengaging from the main housing. Such means, i.e., a movement restriction means is disclosed in JP11-70880A (which will be hereinafter referred to as Reference 3). According to a steering position adjustment control apparatus disclosed in Reference 3, a fixed column is fixed to a vehicle body by means of an attachment bracket and a movable column is slidable relative to the fixed column in a longitudinal direction of a vehicle. The movable column is axially guided by a pin provided at the fixed column so that a rotation of the movable column relative to the fixed column is restricted.
According to a steering column disclosed in JP2010-188901A (which will be hereinafter referred to as Reference 4), an outer tube is supported to a column housing by means of bearings. The outer tube is press-fitted to an inner wall of the column housing by a friction mechanism including a disc spring. Thus, a sliding performance in a thrust direction of a steering wheel is ensured without looseness or shakiness. The bearings are disposed between the column housing and the outer tube. Further, according to the steering column disclosed in Reference 4, the outer tube is assembled on an inner tube in a state where an engagement pin fixed to the outer tube engages with an engagement bore formed at the inner tube. The engagement pin projects at an inner side of the outer tube so as to make contact and engage with an inner wall surface of the engagement bore at a front end of the vehicle. The projection height of the engagement pin is specified so that the engagement pin is inhibited from making contact with an outer surface of a flat surface portion formed at the inner tube. Accordingly, the inner tube is securely inhibited from disengaging from the outer tube at a rear side of the vehicle.
However, as for the axial movement of the movable column member relative to the main housing as mentioned above, the bearings disclosed in Reference 4 may not restrict the axial movement of the outer tube relative to the column housing. In addition, the engagement pin in Reference 4 inhibits the inner tube from disengaging from the outer tube but does not restrict the axial movement of the outer tube relative to the column housing. On the other hand, the pin disclosed in Reference 3 contributes to not only the restriction of the rotation of the movable column but also the restriction of the axial movement of the movable column. At this time, the fixed column and the movable column in Reference 3 correspond to the aforementioned main housing and the movable column member respectively. In addition, the column housing and the outer tube in Reference 4 correspond to the aforementioned main housing and the movable column member respectively.
In order to achieve a means for restricting the axial movement of the movable column member relative to the main housing, not only the pin but also a hole into which the pin is inserted is required to be processed according to Reference 3, which leads to an increase of the number of components and assembly hours. According to Reference 4, the axial movement of the outer tube may not be restricted by the bearings only.
A need thus exists for a steering apparatus for a vehicle which is not susceptible to the drawback mentioned above.
According to an aspect of this disclosure, a steering apparatus for a vehicle configured to adjust an operation position of a steering wheel at least in a frontward and rearward direction of a vehicle, the steering apparatus includes a main housing retained to a vehicle body and including first and second side walls extending in an axial direction of the main housing with an opening formed between the first and second side walls, the main housing including opening portions at opposing ends in the axial direction, a movable column member formed by a tubular member and supported to the main housing to be movable in the axial direction relative to the main housing, the movable column member accommodated into the main housing through one of the opening portions at the opposing ends of the main housing in the axial direction, the movable column member being connected to the steering wheel, a bearing member mounted at an inner wall of the main housing through the opening formed between the first and second side walls, the bearing member supporting the movable column member to be slidable relative to the main housing, and a biasing member fixed to respective end surfaces of the first and second side walls of the main housing to bias the movable column member. The movable column member is supported to the main housing in a state where the biasing member biases the movable column member to the main housing via the bearing member.
The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with the reference to the accompanying drawings, wherein:
A steering apparatus for a vehicle according to embodiments will be described as follows referring to drawings. In the following embodiments, directions and orientations such as left, right, front, rear, top, and bottom correspond to those of a vehicle.
A main housing 10 is coaxially arranged with the steering shaft 1. The main housing 10 is retained by a fixing bracket 30. At the same time, the main housing 10 is retained at a pivoting center C such that the main housing 10 is pivotable thereat relative to a vehicle body 200. The fixing bracket 30 includes a pair of retaining portions 31 opposing each other extending in a downward direction of the vehicle. In
Within the main housing 10, a movable column member 20 is retained such that the movable column member 20 may move in the axial direction, which is the direction in a frontward and rearward direction of the vehicle. The movable column member 20 includes an inner tube 21 made of metal and an outer tube 22 made of metal. That is, the movable column member 20 is formed by a tubular member. The inner tube 21 accommodates the steering shaft 1 and retains the steering shaft 1 such that the steering shaft 1 may rotate at the axis. The outer tube 22 accommodates the inner tube 21. In an ordinary situation, the outer tube 22 retains the inner tube 21 at a predetermined position. The inner tube 21 is also referred to as an upper tube. The outer tube 22 is also referred to as a telescopic tube. The upper shaft 1a is rotatably supported to a rear end portion of the inner tube 21 via a bearing. A relative movement in the axial direction between the upper shaft 1a and the inner tube 21 is restricted. Accordingly, the upper shaft 1a and the inner tube 21 are configured to move integrally in the axial direction.
A telescopic mechanism 2 is configured such that the outer tube 22, the inner tube 21, the steering shaft 1, and the steering wheel 100 may move integrally in the axial direction relative to the main housing 10, so that the steering wheel 100 is adjusted to an intended position in the frontward and rearward direction of the vehicle. The telescopic mechanism 2 is configured to allow a relative movement of the inner tube 21, accordingly a relative movement of the upper shaft 1a, in the axial direction relative to the outer tube 22 in a case where the steering shaft 1 is applied with a load equal to or more than a predetermined value. In other words, the inner tube 21 and the outer tube 22 function as an energy absorbing means together with an annular frictional member, for example, a resilient bush made of metal, or similar placed between the inner tube 21 and the outer tube 22.
As
The outer tube 22, which is made of metal, is formed in a tubular form. The outer tube 22 is formed with a flat surface portion 22a, extending in the axial direction on the exterior surface of the outer tube 22. As illustrated in
As illustrated in
Accordingly, the outer tube 22 is smoothly slidable relative to the main housing 10 in the axial direction via the bushes 60a, 60b. In this case, a sliding surface of the bearing member 60 relative to the outer tube 22 may be positioned opposite to the biasing member 40, specifically, the contact members 43a, 43b. The sliding surface is not necessarily provided at an entire circumference of the outer tube 22. Therefore, each of the bushes 60a, 60b may be formed in a shape corresponding to an outer periphery of a fan shape, instead of a semicircle or a U-shape, so as to receive a necessary load by a further limited range. Accordingly, positions of the contact members 43a, 43b are more flexibly specified so that the outer tube 22 may be biased by the contact member 43a, 43b provided at appropriate positions. That is, according to a known annular bush, the outer tube 22 cannot be biased from directly above the annular bush. On the other hand, according to the aforementioned bushes 60a, 60b, a design flexibility may increase at a time of a positioning of the contact members 43a, 43b. Each of the engagement projections 60d, 60e formed at the bushes 60a, 60b may not only inhibit a misalignment of the bearing member 60 in a rotation direction thereof but also desirably include a cross-sectional area so as to overcome a frictional force generated when the outer tube 22 slides within the main housing 10.
According to the first embodiment, the biasing member 40 includes the base plate 41 made of steel and fixed to respective end surfaces 11a, 12a of the side walls 11, 12, and the spring members 42a, 42b biasing the outer tube 22 towards the bushes 60a, 60b at a position axially away from the flat surface portion 22a of the outer tube 22 by a predetermined distance. Each of the spring members 42a, 42b is formed by a lamination of plural disc springs and is positioned so as to press the flat surface portion 22a of the outer tube 22 via the contact members 43a, 43b made of synthetic resin and supported to the base plate 41. In a case where the biasing member 40 is fixed to the main housing 10, an intended pressing force is applied to the outer tube 22. The base plate 41 is fixed to the main housing 10 via a bolt, riveting, press-fitting of a pin, or any other methods to thereby securely fit the base plate 41 to the main housing 10. In addition, instead of the plural disc springs, a leaf spring or a coil spring may be applied to each of the spring members 42a, 42b.
Next, assembly procedures of the steering apparatus according to the first embodiment will be explained with reference to
After the bearing member 60 is retained within the main housing 10, the outer tube 22 is accommodated within the main housing 10. Then, the biasing member 40 is assembled on the main housing 10 from the upper side of the vehicle body 200 so as to be fixed to the main housing 10. That is, an intended pressing load is applied to the outer tube 22 in a case where the biasing member 40 is fixed to the main housing 10 where the outer tube 22 and the bearing member 60 are accommodated. In addition, because the outer tube 22 is pressed towards an axis thereof by a biasing force of the spring members 42a, 42b in a state where lower flat surface portions of the contact members 43a, 43b are in contact with the flat surface portion 22a of the outer tube 22, a rotation of the outer tube 22 at the axis thereof is securely inhibited. Further, the bearing member 60 appropriately supports the outer tube 22 in a state where the bearing member 60 is arranged at a lower side of the vehicle body 200 within the main housing 10 and a lower outer peripheral surface of the outer tube 22 is in contact with an inner wall of the bearing member 60. Thus, the axial sliding of the outer tube 22 is smoothly performed.
A drive portion of the telescopic mechanism 2 is described next. As
As illustrated in
In order to drive the telescopic mechanism 2 having the aforementioned configuration, the electric motor 70 is activated so that the output shaft of the electric motor 70 is driven to rotate. The rotation is reduced, or decelerated, through the reduction mechanism and transmitted to the threaded shaft 72, which in turn moves the nut 73 screwed to the threaded shaft 72 in the axial direction so that the outer tube 22 moves in the axial direction together with the attachment 2a that accommodates the nut 73. Along with the movement of the outer tube 22, the inner tube 21, the upper shaft 1a, and the steering wheel 100 move in the axial direction. Accordingly, by turning off the electric motor 70 in a state where the steering wheel 100 is at an intended position in the frontward and rearward direction of the vehicle, the steering wheel 100 is adjusted to the intended operational position.
The steering apparatus according to the first embodiment functions as the energy absorbing means. The energy, or a shock, is absorbed in a following manner.
According to the first embodiment, the bearing member 60 is formed as illustrated in
Next, a steering apparatus for a vehicle according to a second embodiment will be explained with reference to
As
The outer tube 22, which is made of metal, is formed in a tubular form. The outer tube 22 is formed with the flat surface portion 22a, extending in the axial direction on the exterior surface of the outer tube 22. As illustrated in
As illustrated in
As illustrate in
Accordingly, the outer tube 22 is smoothly slidable relative to the main housing 10 in the axial direction via the bushes 60a, 60b. In this case, the sliding surface of the bearing member 60 relative to the outer tube 22 may be positioned opposite to the biasing member 40. The sliding surface is not necessarily provided at an entire circumference of the outer tube 22. Therefore, each of the bushes 60a, 60b may be formed in a shape corresponding to an outer periphery of a fan shape as illustrated by a bearing member 60x in
On the other hand, as illustrated in
As illustrated in
Next, assembly procedures of the steering apparatus according to the second embodiment will be explained with reference to
After the bearing member 60 is retained within the main housing 10, the outer tube 22 is accommodated within the main housing 10. Then, the biasing member 40 is assembled on the main housing 10 from the upper side of the vehicle body 200 so as to be fixed to the main housing 10. That is, an intended pressing load is applied to the outer tube 22 in a case where the biasing member 40 is fixed to the main housing 10 where the outer tube 22 and the bearing member 60 are accommodated. Looseness or shakiness in a radial direction of the outer tube 22 is appropriately inhibited. Specifically, because the outer tube 22 is pressed towards the axis thereof by a biasing force of the spring members 42a, 42b in a state where the lower flat surface portions of the contact members 43a, 43b are in contact with the flat surface portion 22a of the outer tube 22, looseness or shakiness in the radial direction of the outer tube 22 is inhibited. In addition, a rotation of the outer tube 22 at the axis thereof is securely inhibited. Further, the bearing member 60 appropriately supports the outer tube 22 in a state where the bearing member 60 is arranged at the lower side of the vehicle body 200 within the main housing 10 and the lower outer peripheral surface of the outer tube 22 is in contact with the inner wall of the bearing member 60. Thus, the axial sliding of the outer tube 22 is smoothly performed.
The drive portion of the telescopic mechanism 2 is described next. As
The electric motor 70 is retained to the main housing 10. The output shaft of the electric motor 70 is connected to the threaded shaft 72, and the nut 73 screwed to the threaded shaft 72 is arranged within the attachment 2a. The nut 73 arranged within the attachment 2a moves in the axial direction on the threaded shaft 72 in response to the rotation of the threaded shaft 72 driven by the electric motor 70. As a result, the nut 73 and the attachment 2a move in the frontward and rearward direction of the vehicle together with the outer tube 22, the inner tube 21, the upper shaft 13 and the steering wheel 100. The reduction mechanism is provided between the output shaft of the electric motor 70 and the threaded shaft 72 so that an appropriately reduced output power of the electric motor 70 is transmitted to the threaded shaft 72. As
In order to drive the telescopic mechanism 2 having the aforementioned configuration, the electric motor 70 is activated so that the output shaft of the electric motor 70 is driven to rotate. The rotation is reduced, or decelerated, through the reduction mechanism and transmitted to the threaded shaft 72, which in turn moves the nut 73 screwed to the threaded shaft 72 in the axial direction so that the outer tube 22 moves in the axial direction together with the attachment 2a that accommodates the nut 73. Along with the movement of the outer tube 22, the inner tube 21, the upper shaft 1a, and the steering wheel 100 move in the axial direction. Accordingly, by turning off the electric motor 70 in a state where the steering wheel 100 is at an intended position in the frontward and rearward direction of the vehicle, the steering wheel 100 is adjusted to the intended operational position. At this time, as illustrated in
According to the modified embodiment, the main housing 10 is provided with a larger size between the side walls 11, 12 relative to the maximum outer diameter of the outer tube 22 that constitutes the movable column member 20. The inner wall of the main housing 10 is provided with a curved surface fitting the exterior surface of the outer tube 22. The main housing 10 is provided with the cross-sectional shape obtained in the direction perpendicular to the axial direction, the cross-sectional shape including the pair of side walls 11, 12, in a U-shape. The projection portion 10p is integrally formed at the main housing 10 in each of the frontward direction and the rearward direction of the vehicle. Specifically, the projection portion 10p projects from the inner wall of the main housing 10 to an axial center thereof. The projection portion 10p is formed so as to fit the inner wall of the main housing 10 and the outer diameter of the outer tube 22, i.e., formed in a U-shape, for example. According to the modified embodiment, at a time when the main housing 10 is manufactured with aluminum die-cast, for example, the projection portion 10p may be formed at the same time. Thus, a boring process which is necessary for manufacturing a tubular housing may not be required, which leads to a simple manufacture of the main housing 10.
In a case where the rear end of the outer tube 22 in the rearward direction of the vehicle body 200 is accommodated via the opening portion 10b into the main housing 10, the outer tube 22 is retained by receiving the intended pressing load by the biasing member 40. Then, the outer tube 22 is smoothly slidable by means of the projection portion 10p. In a case where the enlarged diameter portion 22d makes contact with a side surface of the projection portion 10p, the axial movement of the outer tube 22 is securely blocked, i.e., the movable column member 20 is configured to be inhibited from moving in the axial direction.
The steering apparatus according to the second embodiment and the modified embodiment thereof also function as the energy absorbing means. The energy, or the shock, is absorbed in a following manner.
According to the aforementioned second embodiment, the steering apparatus includes the main housing 10 retained to the vehicle body 200 and including the opening portions 10a, 10b at opposing ends in the axial direction, and the movable column member 20 formed by a tubular member and supported to the main housing 10 to be movable in the axial direction relative to the main housing 10, the movable column member 20 including the enlarged diameter portion 22d obtained by an enlargement of a diameter of at least a portion of the movable column member 20 at the front side of the vehicle body 200. The steering apparatus further includes the bearing member 60 mounted at the inner wall of the main housing 10 and supporting the movable column member 20 to be slidable relative to the main housing 10, and the biasing member 40 fixed to the main housing 10 to bias the movable column member 20. The movable column member 20 is supported to be movable in the axial direction relative to the main housing 10 via the bearing member 60 in a state where the rear end of the movable column member 20 in the rearward direction of the vehicle body 200 is accommodated into the main housing 10 through one of the opening portions 10b in the frontward direction of the vehicle body 200 and the movable column member 20 is biased by the biasing member 40, the movable column member 20 being configured to be inhibited from moving in the axial direction in a case where the enlarged diameter portion 22d makes contact with the bearing member 60.
In addition, according to the aforementioned second embodiment, the steering apparatus configured to adjust the operation position of the steering wheel 100 at least in the frontward and rearward direction of the vehicle, the steering apparatus includes the main housing 10 retained to the vehicle body 200 and including the side walls 11, 12 extending in the axial direction of the main housing 10 with the opening formed between the side walls 11, 12, the main housing 10 including the opening portions 10a, 10b at opposing ends in the axial direction and integrally including the projection portion 10p projecting from the inner wall of the main housing 10 to the axial center thereof. The steering apparatus further includes the movable column member 20 supported to the main housing 10 to be movable in the axial direction relative to the main housing 10 and formed by a tubular member accommodated into the main housing 10 and supported to the projection portion lop to be slidable thereto, the movable column member 20 including the enlarged diameter portion 22d obtained by an enlargement of a diameter of at least a portion of the movable column member 20 at the front side of the vehicle body 200. The movable column member 20 is supported to be movable in the axial direction relative to the main housing 10 in a state where the rear end of the movable column member 20 in the rearward direction of the vehicle body 200 is accommodated into the main housing 10 through one of the opening portions 10b in the frontward direction of the vehicle body 200 and the movable column member 20 is biased by the biasing member 40, the movable column member 20 being configured to be inhibited from moving in the axial direction in a case where the enlarged diameter portion 22d makes contact with the projection portion 10p of the main housing 10.
According to the aforementioned first and second embodiments, the bearing member 60 is easily assembled on the main housing 10. In addition, looseness or shakiness between the main housing 10 and the movable column member 20 is securely inhibited by a reduced number of components and a reduced cost while an assembly performance is ensured.
The side walls 11, 12 of the main housing 10 forms a distance therebetween, a length of the distance being greater than the diameter of the tubular member forming the movable column member 20, and the inner wall of the main housing 10 includes a curved surface fitting the exterior surface of the movable column member 20.
Accordingly, because the main housing 10 may be manufactured with metal die-cast, the steering apparatus with the reduced number of components, easy processing and assembly, and the reduced cost is achieved.
The main housing 0 includes a cross-sectional shape obtained in a direction perpendicular to the axial direction, the cross-sectional shape being formed in a U-shape while including the side walls 11, 12, and the bearing member 60 is formed in a U-shape fitting the inner wall of the main housing 10.
Accordingly, the bearing member 60 is easily assembled on the main housing 10 through the opening formed at the main housing 10.
The main housing 10 includes the engagement bores 10g, 10h at the inner wall, and the bearing member 60 includes the engagement projections 60d, 60e engaging with the engagement bores 10g, 10h.
Accordingly, the bearing member 60 is stably retained within the main housing 10. In addition, after the outer tube 22 (the movable column member 20) is accommodated within the main housing 10, the engagement projections 60d, 60e within the engagement bores 10g, 10h are visually observed from the outside of the main housing 10 so that it is confirmed that the bearing member 60 is stably retained within the main housing 10.
The inner wall of the main housing 10 is formed by the recesses 10d, 10e, 10f retaining the bearing member 60.
Accordingly, the bearing member 60 is further easily assembled on the main housing 10 so that the bearing member 60 is securely retained within the main housing 10. Because the recesses 10d, 10e, 10f may be formed at the inner wall of the main housing 10 at the same time the main housing 10 is manufactured with die-cast, a later cutting process may not be necessary, which leads to a reduced manufacturing cost.
The bearing member 60 includes the pair of bushes 60a, 60b supporting the movable column member 20 at positions separated from each other by a predetermined distance in the axial direction.
Accordingly, the movable column member 20 may be supported at appropriate positions.
The pair of bushes 60a, 60b is connected to be integrally formed.
Accordingly, the bearing member 60 is further easily assembled on the main housing 10, and a storage of the bearing member 60 before being assembled on the main housing 10 may be easily conducted, which leads to an increased productivity.
Each of the pair of bushes 60a, 60b is divided into the first portion making contact with the movable column member 20 (the outer tube 22) and the second portion inhibited from making contact with the movable column member 20 (the outer tube 22), and the thickness of the second portion is smaller than the thickness of the first portion.
Accordingly, a material and a weight of the bearing member 60 may be reduced.
Each of the pair of bushes 60a, 60b includes the portion making contact with the movable column member 20 (the outer tube 22) and including the inner surface, the inner surface being formed by the grooves 60g where a slide grease is retained.
Accordingly, a smooth sliding performance of the movable column member 20 (the outer tube 22) is ensured.
The biasing member 40 includes the base plate 41 fixed to the respective end surfaces 11a, 12a of the side walls 11, 12, and the pair of spring members 42a, 42b supported to the base plate 41 to bias the movable column member 30 towards the bearing member 60.
Accordingly, looseness or shakiness between the main housing 10 and the movable column member 20 is securely inhibited with the reduced number of components.
The movable column member 20 includes the enlarged diameter portion 22d obtained by an enlargement of a diameter of at least a portion of the movable column member 20 at the front side of the vehicle body 200, and the movable column member 20 is configured to be inhibited from moving in the axial direction in a case where the enlarged diameter portion 22d of the movable column member 20 makes contact with the bearing member 60 in a state where the rear end of the movable column member 20 in the rearward direction of the vehicle body 200 is accommodated into the main housing 10 through one of the opening portions 10b in the frontward direction of the vehicle body 200 and the movable column member 20 is biased by the biasing member 40.
Accordingly, a means for restricting the movement of the movable column member in the axial direction relative to the main housing 10 is easily and securely obtained by the movable column member 20 where the enlarged diameter portion 22d is formed and the bearing member, and the assembly performance is ensured.
The enlarged diameter portion 22d of the movable column member 20 includes the outer diameter greater than the inner diameter of the bearing member 60, and the movable column member 20 is arranged so that the enlarged diameter portion 22d is contactable with the side surface of the bearing member 60.
Accordingly, the axial movement of the movable column member 20 may be securely restricted by a simple structure.
The main housing 10 integrally includes the projection portion 10p projecting from the inner wall of the main housing 10 to the axial center thereof. The movable column member 20 is formed by the tubular member accommodated into the main housing 10 and supported to the projection portion 10p to be slidable thereto, the movable column member 20 including the enlarged diameter portion 22d obtained by an enlargement of a diameter of at least a portion of the movable column member 20 at the front side of the vehicle body 200. The movable column member 20 is supported to be movable in the axial direction relative to the main housing 10 in a state where the rear end of the movable column member 20 in the rearward direction of the vehicle body 200 is accommodated into the main housing 10 through one of the opening portions 10b in the frontward direction of the vehicle body 200 and the movable column member 20 is biased by the biasing member 40, the movable column member 20 being configured to be inhibited from moving in the axial direction in a case where the enlarged diameter portion 22d of the movable column member 20 makes contact with the projection portion 10p.
Accordingly, the means for restricting the movement of the movable column member in the axial direction relative to the main housing 10 may be easily and securely achieved by the movable column member 20 where the enlarged diameter portion 22d is formed and the projection portion 10p formed at the main housing 10. In addition, the assembly performance is ensured. Further, because the main housing 10 may be manufactured with die-cast, the steering apparatus with the reduced number of components and cost and easy processing and assembly may be obtained.
The side walls 11, 12 of the main housing 10 forms a distance therebetween, a length of the distance being greater than an outer diameter of the enlarged diameter portion 22d of the movable column member 20, and the inner wall of the main housing 10 includes a curved surface fitting the exterior surface of the movable column member 20.
Accordingly, the processing and the assembly of the main housing 10 and the movable column member 20 may be easily performed.
The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.
Number | Date | Country | Kind |
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2011-208391 | Sep 2011 | JP | national |
2011-208394 | Sep 2011 | JP | national |