Steering apparatus

The invention provides a steering apparatus which includes: an inner column 3; an outer column 4 fitted with the inner column 3 in such a manner that it is movable in a telescopic manner; a steering shaft 102 which is rotatably supported on the inner column 3 and outer column 4, and on the vehicle body rearward side of which a steering wheel 103 can be mounted; a lock apparatus 7 including a lock pin 73A which can be operated by an actuator to thereby prevent the rotation of the steering shaft 102; and, a lock housing 71 which is formed integrally with the outer column 4 and stores the lock apparatus 7 therein.

TECHNICAL FIELD

The present invention relates to a steering apparatus which includes an antitheft lock apparatus. Specifically, the invention relates to an improvement in a lock housing for mounting the lock apparatus.

BACKGROUND ART

In recent years, there have been increasing vehicle thefts and thus various antitheft apparatus have been used in vehicles. As one of such antitheft apparatus, there is known a lock apparatus which disables the operation of a steering wheel unless a regular key is used. The lock apparatus, as shown in, for example, the patent reference 1 to 4, includes a lock unit provided on a steering column and a key lock groove formed in a steering shaft. And, in operation (in key locked operation), a lock pin provided on the lock unit is inserted into the key lock groove to thereby prevent the rotation of the steering shaft.

In order to secure a sufficient antitheft effect which is provided by such lock apparatus, in a state where the function of the steering apparatus remains secured, it is necessary that the lock unit cannot be removed. In the patent reference 1, there is disclosed a lock apparatus which is structured to be able to meet such need.

In the steering apparatus including the lock apparatus disclosed in the patent reference 1, a lock housing for storing the lock apparatus therein is constituted of a part formed separately from an outer column, and the lock housing is mounted on the outer column for rotatably supporting a steering shaft using a bolt. When such separate lock housing is mounted onto the outer column using a bolt in this manner, it is difficult to enhance the rigidity of the lock housing which receives a reaction force given when the steering shaft is locked. Thus, there is raised a problem that the number of parts and the weight of the lock housing must be increased in order to compensate the shortage of the rigidity of the lock housing.

Also, as disclosed in the patent reference 5, there is proposed a steering apparatus including a clamp device for adjusting the telescopic position of a steering shaft and a lock apparatus for locking the steering shaft. However, in this steering apparatus, there is also raised the following problem.

That is, in the clamp device, the telescopic position of the steering shaft can be adjusted using a slit which is formed in an outer column. In other words, the clamp device applies a fastening force to the outer column to reduce the width of the slit to thereby prevent the steering shaft and outer column from moving relative to each other, while, when the fastening force of the clamp device is relieved, the width of the slit is increased to thereby allow the telescopic movement of the steering shaft relative to the outer column, whereby the clamp device is allowed to adjust the telescopic position of the steering shaft.

On the other hand, the lock apparatus includes a key lock groove formed in the steering shaft, a through hole formed in the outer periphery of the outer column, and a lock unit having a lock pin and disposed on the outer periphery of the outer column. When locking the steering shaft, the lock pin is inserted through the through hole of the outer column into the key lock groove of the steering shaft to thereby prevent the rotation of the steering shaft.

In the steering apparatus including the clamp device and lock apparatus structured in this manner, the slit of the clamp device and the through hole of the lock apparatus are formed in the same outer column. This reduces the strength of the portion of the outer column that exists near the slit and through hole. Thus, when the clamp device applies the fastening force to the outer column, there is a fear that there can be produced a crack between the slit and through hole.

This makes it impossible to dispose the slit and through hole adjacently to each other and, therefore, the mounting position of the lock apparatus is limited and the fastening force of the clamp device cannot be increased.Patent Reference 1: Japanese Patent Publication 2006-36106Patent Reference 2: Japanese Patent Publication 2004-237973Patent Reference 3: Japanese Patent Publication 2004-98788Patent Reference 4: Japanese Patent Publication 2006-36107Patent Reference 5: Japanese Patent Publication 2000-168501

DISCLOSURE OF THE INVENTION

Problems that the Invention is to Solve

In view of the above-mentioned conventional circumstances, it is an object of the invention to provide a steering apparatus including a lock apparatus which can enhance the rigidity of a lock housing and a column, which receive a reaction force given when locking a steering shaft, and also can reduce the weights of the lock housing and column, thereby being able to increase a telescopic clamp force.

According to the invention, there is provided following steering apparatuses.

(1) A steering apparatus including:

an inner column;

an outer column fitted with the inner column in such a manner that it can be moved in a telescopic manner;

a steering shaft rotatably supported by the inner and outer columns, with a steering wheel mountable on the vehicle body rearward side thereof;

a lock apparatus including a lock pin actuatable by an actuator for preventing the rotation of the steering shaft; and

a lock housing formed integrally with the outer column for storing the lock apparatus therein.

(2) The steering apparatus disclosed in (1), wherein

the lock housing projects from the outer column in the direction of the width of a vehicle or toward the lower side of a vehicle body.

(3) The steering apparatus disclosed in (2), wherein

the outside diameter of a connecting portion between the outer column and lock housing is set larger than the outside diameter of the outer column.

(4) The steering apparatus disclosed in (1), wherein:

a rib extending parallel to the axis of the outer column is formed between the lock housing and the outer periphery of the outer column; and

the rib is formed integrally with the lock housing and outer column.

(5) The steering apparatus disclosed in (1), wherein:

the lock housing is opened in the diameter direction of the outer column;

a first through hole is formed at a position of the outer column as corresponds to the lock housing;

a key lock recessed portion is formed at a position of the steering shaft as corresponds to the first through hole;

the lock apparatus includes a lock unit having a lock pin;

the lock apparatus is fixed to the inside of the lock housing using a fixing screw;

the lock pin can penetrate through the first through hole of the outer column, move in the diameter direction of the outer column and project into the key lock recessed portion of the steering shaft; and

in a state where the steering shaft is arranged on the inside diameter side of the outer column, the head portion of the fixing screw is disposed at a position where it cannot be operated by a tool.

(6) The steering apparatus disclosed in (5), wherein:

a second through hole, having a diameter larger than the diameter of the shaft portion of the fixing screw and smaller than the diameter of the head portion of the fixing screw, is formed in a portion of the outer column surrounded by the lock housing as exists out of the first through hole;

a third through hole, having a diameter larger than the diameter of the head portion of the fixing screw, is formed in a portion of the outer column as exists on the opposite side to the second through hole in the peripheral direction thereof;

the shaft portion of the fixing screw is inserted into the second through hole and the fixing screw is threadedly engaged with a screw hole formed in the lock unit to thereby fix the lock unit to the inside of the lock housing; and

the steering shaft is situated between the second and third through holes.

(7) The steering apparatus disclosed in (5), wherein:

a recessed portion, which is recessed downwardly of the upper surface of the lock housing, is formed in a portion of the upper surface of the lock housing;

a second through hole, having a diameter larger than the diameter of the shaft portion of the fixing screw and smaller than the diameter of the head portion of the fixing screw, is formed in the recessed portion; and

the shaft portion of the fixing screw is inserted through the second through hole and the fixing screw fixes the lock unit to the inside of the lock housing.

(8) The steering apparatus disclosed in (5), wherein:

a second through hole, having a diameter larger than the diameter of the shaft portion of the fixing screw and smaller than the diameter of the head portion of the fixing screw, is formed in the front surface of the lock housing; and

the fixing screw with its shaft portion inserted into the second through hole is threadedly engaged with a screw hole opened up in the front surface of the lock unit to thereby fix the lock unit to the inside of the lock housing.

(9) The steering apparatus disclosed in (1), wherein:

the outer column is made of steel;

the lock housing is made of a light alloy; and

a portion of the outer column is embedded in a portion of the lock housing, whereby these two parts are formed as an integral body.

(10) The steering apparatus disclosed in (1), wherein:

a slit extending in the axial direction of the outer column and opened in the front end of the outer column is formed on the front end side of the outer column;

a clamp device is provided for changing the width of the slit to reduce or increase the diameter of the front end portion of the outer column, thereby switching the steering shaft between a state where the steering shaft is prevented from moving in the axial direction thereof and a state where it is allowed to move in the axial direction thereof;

a through hole is formed in the lower surface of such portion of the front end side of the outer column as exists out of the slit;

a key lock recessed portion is formed in the steering shaft, at a position corresponding to the through hole in the axial direction of the steering shaft;

the lock housing is formed integrally with such portion of the outer peripheral surface of the outer column as exists out of the slit and near to the through hole in such a manner that it projects downwardly of the outer column;

the lock apparatus includes the lock pin and a lock unit connected through a connecting member to the outer column; and

the lock pin can penetrate through the through hole of the outer column, move in the diameter direction of the outer column and project into the key lock recessed portion of the steering shaft.

(11) The steering apparatus disclosed in (10), wherein:

the slit is formed in the lower surface of the outer column;

the through hole and lock housing are respectively formed in such portion, of the lower surface of the outer column as exists nearer to the rear end side of the outer column than the slit;

the lock housing includes a front plate portion formed in the lower surface of the outer column; and

the front plate portion partitions a portion between the slit and through hole in the longitudinal direction of the outer column.

(12) The steering apparatus disclosed in (10), wherein:

the lock housing has a box shape which surrounds the periphery of the through hole and opens in the lower surface thereof; and

the lock unit includes a held portion which is to be held within the lock housing.

(13) The steering apparatus disclosed in (12), wherein:

the lock housing includes a pair of side plate portions for sandwiching the held portion of the lock unit from both sides in the width direction of a vehicle body;

the pair of side plate portions respectively have lock housing side insertion holes;

the held portion of the lock unit includes lock unit side insertion holes respectively formed at positions corresponding to a pair of insertion holes formed in the pair of side plate portions;

the connecting member is constituted of a bolt and a nut;

the bolt is inserted through the lock housing side insertion holes and lock unit side insertion holes; and

the nut is threadedly engaged with such portion of the bolt as projects from the respective insertion holes.

(14) The steering apparatus disclosed in (13), wherein

the head portion of the bolt is disposed inside the insertion hole formed in one of the paired side plate portions and, in a state where the held portion and the other side plate portion are held by and between the head portion of the bolt and nut, the nut is fastened to thereby bring the side surface of the held portion into contact with the inner surface of the other side plate portion.

(15) The steering apparatus disclosed in (13), wherein

at least one lock housing side slit, which opens in the lower surface of the lock housing, is formed in the lock housing.

Effects of the Invention

According to the steering apparatus of the invention, the lock housing for storing the lock apparatus is formed integrally with the outer column. Therefore, the rigidity of the lock housing and outer column, which receive a reactive force occurring when the steering shaft is locked, can be increased, the weights of these parts can be reduced, and the telescopic clamp force thereof can be increased.

Also, according to the steering apparatus disclosed in (5), the lock housing and steering column (outer column) cannot be separated from each other and thus, in a state where the steering shaft and steering column are left supported at given positions, the head portion of the lock housing fixing screw cannot be operated with a tool. Owing to this, while securing the freedom of the design of the steering apparatus, the antitheft function thereof can be enhanced.

Also, since the steering column and lock housing are formed as an integral body or are combined together in an integral manner, the assembling operation of the steering apparatus can be facilitated and thus the manufacturing cost of the lock apparatus can be reduced. Further, the size and weight of the whole steering apparatus with the lock apparatus incorporated therein can be reduced.

Further, according to the steering apparatus disclosed in (10), the lock housing for mounting the lock unit onto the outer column is formed such that it does not project rightward or leftward of the outer column but projects downward thereof. Owing to this, the lock housing of the steering apparatus according to the invention can be mounted onto both of a right-hand drive vehicle and a left-hand drive vehicle. That is, since only one lock housing is necessary, in a state where the steering apparatus is mounted on the vehicle, there is no possibility that there can occur a lock housing which is not in use.

Further, even when, as a fastening force by the clamp device is applied, there is generated internal stress in the outer column, the front plate portion can prevent a crack from occurring between the slit and through hole.

Also, the lock housing of the steering apparatus of the invention is formed to have any one of the following structures: that is, a box-like structure; a structure including a front plate portion, a rear plate portion and a side plate portion; and, a structure including a front plate portion and a rear plate portion. Therefore, when compared with a structure employing a plane lock housing (mounting portion), the mounting position of the lock unit is hard to shift and the mounting strength of the lock unit can be secured easily.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

BEST MODE FOR IMPLEMENTING THE INVENTION

First to Fourth Embodiments

First to fourth embodiments according to the invention respectively relate to a steering apparatus which includes a lock housing and a column high in rigidity and light in weight and can apply a large telescopic clamp force. In the following embodiments, description will be given below of an example in which the invention is applied to a tilt/telescopic type of steering apparatus for adjusting the positions of both of the vertical-direction position and longitudinal-direction position of a steering wheel.

First Embodiment

FIG. 1is a perspective view of the whole of a steering apparatus101according to a first embodiment of the invention, showing a state where it is mounted on a vehicle. The steering apparatus101supports a steering shaft102rotatably. On the upper end (vehicle body rear side) of the steering shaft102, there is mounted a steering wheel103and, on the lower end side (vehicle body front side) of the steering shaft102, there is connected an intermediate shaft105through a universal joint104.

To the lower end of the intermediate shaft105, there is connected a universal joint106and, to the universal joint106, there is connected a steering gear107constituted of a rack and pinion mechanism and the like.

When a driver operates and rotates the steering wheel103, the rotation force of the steering wheel103is transmitted to the steering gear107through the steering shaft102, universal joint104, intermediate shaft105and universal joint106to move a tie rod108through the rack and pinion mechanism, thereby being able to change the steering angle of the front wheel of the vehicle.

FIG. 2is a perspective view of the main portions of the steering apparatus according to the first embodiment of the invention. As shown inFIGS. 2 to 5, the steering apparatus101of the invention includes a vehicle body mounting upper bracket2, an inner column (lower column)3, an outer column (upper column)4and the like.

Referring here to a vehicle body mounting upper bracket2which is disposed on the vehicle rear side (inFIGS. 2 to 4, the left side), its upper plate21is fixed to a vehicle body11(seeFIGS. 3 and 5) through capsules24and24.

In the vehicle body front side end portion of the inner column3, there is formed a bracket31integrally therewith. The bracket31is connected through a tilt center collar32to a lower bracket12by a bolt33. The vehicle body mounting lower bracket12is fixed to the vehicle body11. With the bolt33as a fulcrum, the vehicle body front side end portion of the hollow cylindrical inner column3is rotatably supported on the vehicle body11in such a manner that its tilt position can be adjusted (it can oscillate in a plane parallel to the sheet ofFIG. 3).

With the outer surface of the outer periphery of the cylindrical inner column3on the vehicle body rear side (inFIGS. 2 to 4, on the left side), there is fitted the inner periphery of the hollow cylindrical outer column4in such a manner that its telescopic position can be adjusted (it can slide parallel to the center axis of the inner column3).

The outer column4is formed of a magnesium alloy by casting such as by die casting. The material of the outer column4is not limited to the magnesium alloy but there may also be used an aluminum alloy, a zinc alloy, a titanium alloy, and case iron.

On the outer column4, there is rotatably supported an upper steering shaft102A and, to the end portion of the upper steering shaft102A on the vehicle rear side, there is fixed the steering wheel3(seeFIG. 1).

On the inner column3, there is rotatably supported a lower steering shaft102B, while the lower steering shaft102B is spline fitted with the upper steering shaft102A. Therefore, regardless of the telescopic position of the outer column4, the rotation of the upper steering shaft102A can be transmitted to the lower steering shaft102B.

The vehicle body front side (inFIGS. 2 to 4, the right side) of the lower steering shaft102B is connected through the universal joint104(seeFIG. 1) to the steering gear107(seeFIG. 1). When a driver turns the steering wheel103by hands, the lower steering shaft102B is rotated through the upper steering shaft102A to thereby be able to change the steering angle of the vehicle front wheel.

As shown inFIGS. 2 to 5, the upper plate21of the vehicle body mounting upper bracket2includes a left side plate22and a right side plate23respectively extending downwardly parallel to each other. By and between the respective inner surfaces of the left and right side plates22and23, there are held the right and left side surfaces46(column fastening surfaces) of the outer column4in such a manner that they can slide tiltingly and telescopically.

In the left and right side plates22and23of the vehicle body mounting upper bracket2, there are respectively formed tilt adjusting elongated grooves25. Also, in the right and left side surfaces46of the outer column4, there are formed telescopic adjusting elongated grooves41respectively. Into the tilt adjusting elongated grooves25and telescopic adjusting elongated grooves41, there is inserted a round-bar-like fastening rod5from a direction perpendicular to the sheet surface ofFIG. 3.

When an operation lever6mounted on the left end (inFIG. 5, the left side end) of the fastening rod5is operated and oscillated, a cam lock mechanism constituted of a fixed cam and a movable cam is operated to thereby fasten the left and right side plates22and23of the vehicle body mounting upper bracket2. As a result of this, the left and right side surfaces46of the outer column4are fastened strongly against the left and right side plates22and23of the vehicle body mounting upper bracket2.

Here, the outer column4has a slit (not shown) formed in the lower surface thereof. That is, in this case, the slit of the outer column4is compressed and thus the diameter of the outer column4is reduced, thereby fastening the outer periphery of the inner column3strongly. Owing to this, the outer column4is clamped by the vehicle body mounting upper bracket2at desired tilt position and telescopic position.

As shown inFIGS. 2 to 5, on the vehicle body rear side of the outer column4, there is formed the lock housing71of a lock apparatus7integrally with the outer column4by die casting. In the lock housing71of the lock apparatus7, there is incorporated an electronic unit73which includes an operation mechanism for operating a lock pin73A (seeFIG. 2) using an actuator (not shown). The lock pin73A is engaged with the key lock groove of the upper steering shaft102A to thereby lock the steering shaft102against rotation.

The lock housing71is formed to have a hollow box shape which projects from the outer column4rightward in the vehicle width direction. When it is viewed inFIG. 5, the lock housing71is symmetric in the vertical direction, while its height H1is set substantially equal to the outside diameter dimension of the cylindrical outer periphery42of the outer column4. Also, the height H2of the connecting portion72between the outer periphery42of the outer column4and lock housing71is set larger than the outside diameter dimension of the outer periphery42of the outer column4.

Therefore, since a connecting surface between the outer periphery42of the outer column4and connecting portion72is formed substantially ¾ of the periphery of the outer periphery42of the outer column4, the connecting strength between the lock housing71and outer column4can be increased. Owing to this, the lock pin elongated hole can be designed small. Also, since the height H2of the connecting portion72is large, the rigidity of the connecting portion72itself is also enhanced.

Also, as shown inFIGS. 2 to 5, on the vehicle body front side and rear side side surfaces74and75of the lock housing71, there are provided three thin-plate-shaped ribs76and77apiece which are used to connect the outer periphery42of the outer column4to the vehicle body front side side surface74and connect the outer periphery42of the outer column4to the vehicle body rear side side surface75.

Each rib76extends from the vehicle body forward side surface74toward the vehicle body front side parallel to the axis of the outer column4. Also, each rib77extends from the vehicle body rearward side surface75toward the vehicle body rear side parallel to the axis of the outer column4. As shown inFIG. 4, the ribs76and77are respectively formed to have a substantially triangular shape. When the ribs76are respectively extended up to the right and left side surfaces46(column fastening surfaces) of the outer column4, the strength thereof in the twisting direction can be enhanced.

Therefore, since the ribs76,77increase the connecting strength between the outer column4and lock housing71, the rigidity of the lock housing71is enhanced to thereby increase the strength thereof when the steering shaft is locked. Also, since the lock housing71itself may be light in weight, the weight of the whole steering apparatus can be reduced.

Also, since the strength of such portion of the outer column4as existing around the lock housing71is also enhanced, it is possible to prevent a crack from occurring in a slit formed in the lower surface of the outer column4. This can reduce restrictions on the mounting position of the lock apparatus and also can increase the telescopic clamp force.

Second Embodiment

Next, description will be given below of a second embodiment according to the invention.FIG. 6is a structure view of the main portions of a steering apparatus according to the second embodiment of the invention, corresponding toFIG. 4. In the following description, description will be given only of the structural portions of the second embodiment different from the above-mentioned first embodiment and thus the duplicate description of the same portions is omitted here. Also, the same parts are given the same reference numerals.

The second embodiment provides the modified versions of the shape of the connecting portion between the outer periphery42of the outer column4and lock housing71and the shape of the vehicle body front side side surface74of the lock housing71.

As shown inFIG. 6, in the second embodiment as well, similarly to the first embodiment, on the vehicle body rear side of the outer column4, there is formed the lock housing71of the lock apparatus7integrally with the outer column4by die casting.

The lock housing71is formed to have a hollow box shape which projects from the outer column4to the right in the vehicle width direction. Also, the outer periphery42of the outer column4and lock housing71are connected together by two ribs78which respectively project in the radial direction of the outer periphery42of the outer column4further outwardly than the outside diameter dimension of the outer periphery42. This structure can increase the connecting strength between the outer periphery42of the outer column4and lock housing71.

Also, as shown inFIG. 6, on the vehicle body forward side surface74and rearward side surface75of the lock housing71, there are provided multiple thin-plate-shaped ribs79and77which are respectively used to connect the outer periphery42of the outer column4to the vehicle body forward side surface74and to connect the outer periphery42of the outer column4to the vehicle body backward side surface75.

Each rib79extends from the vehicle body forward side surface74forwardly of the vehicle body parallel to the axis of the outer column4up to the side surface46(column fastening surface) of the outer column4, thereby enhancing the strength in the twist direction of the outer column4. Each rib77for connecting together the outer periphery42of the outer column4and the vehicle body backward side surface75has the same shape as the rib used in the first embodiment.

Thus, in the present embodiment, due to provision of such ribs79and77, the connecting strength between the outer column4and lock housing71is greater than that in the first embodiment. This can enhance the rigidity of the lock housing71to thereby increase the strength of the lock housing71when the steering shaft is locked, and also can reduce the weight of the lock housing71itself to thereby reduce the weight of the whole steering apparatus.

Also, since the strength of such portion of the outer column4as exists around the lock housing71is increased, it is possible to prevent the slit formed in the lower surface of the outer column4from cracking, whereby restrictions on the mounting position of the lock apparatus can be reduced and the telescopic clamp force of the outer column4can be increased easily.

Third Embodiment

Next, description will be given below of a third embodiment according to the invention.FIG. 7is a structure view of the main portions of a steering apparatus according to the third embodiment of the invention, corresponding toFIG. 5. In the following description, description will be given only of such structural portions of the second embodiment as are different from the above-mentioned first embodiment and thus the duplicate description of the same portions is omitted here. Also, the same parts are given the same reference numerals.

The third embodiment provides the modified version of the shape of the lock housing71. As shown inFIG. 7, in the third embodiment as well, on the vehicle body rear side of the outer column4, there is formed the lock housing71of the lock apparatus7integrally with the outer column4by die casting.

The lock housing71is formed to have a hollow box shape which projects from the outer column4to the right in the vehicle width direction. That is, the housing71, when it is viewed inFIG. 7, is symmetric in shape in the vertical direction and the height H1of the right projecting end711of the housing71is substantially equal to the outside diameter dimension of the cylindrical outer periphery42of the outer column4. Also, the height H2of a connecting portion72between the outer periphery42of the outer column4and lock housing71is set larger than the outside diameter dimension of the cylindrical outer periphery42of the outer column4, while the lock housing71is formed tapered from the connecting portion72toward the projecting end711.

Since the connecting surface between the outer periphery42of the outer column4and connecting portion72is formed to extend substantially ¾ of the outer periphery42of the outer column4, the connecting strength between the lock housing71and outer column4is increased. Also, since the height H of the connecting portion72is large, the rigidity of the connecting portion72itself can also be enhanced.

Also, in the third embodiment, similarly to the first embodiment, there are provided three thin-plate-shaped ribs (not shown) which are respectively used to connect the outer periphery42of the outer column4to the vehicle body forward side surface and three thin-plate-shaped ribs77which are respectively used to connect the outer periphery42of the outer column4to the vehicle body rearward side surface. In the third embodiment, since the shape of the lock housing71is simplified, the shape of a die for die casting the lock housing71can be simplified, thereby being able to enhance the formability of the lock housing71.

Fourth Embodiment

Next, description will be given below of a fourth embodiment according to the invention.FIG. 8is a perspective view of the main portions of a steering apparatus according to the fourth embodiment of the invention. In the following description, description will be given only of such structural portions of the second embodiment as are different from the above-mentioned first embodiment and thus the duplicate description of the same portions is omitted here. Also, the same parts are given the same reference numerals.

The fourth embodiment provides an example in which the projecting direction of the lock housing71from the outer column4is set for a direction going downwardly of the vehicle body. As shown inFIG. 8, in the fourth embodiment as well, similarly to the first to third embodiments, on the vehicle body rear side of the outer column4, there is formed the lock housing71of the lock apparatus7integrally with the outer column4by die casting.

Into the lock housing71of the lock apparatus7, there is incorporated an electronic unit73having an operation mechanism which operates the lock pin73A (seeFIG. 2) using an actuator (not shown). In operation, the lock pin73A is engaged into the key lock groove of the upper steering shaft102A to thereby prevent the steering shaft102(seeFIG. 1) against rotation.

The lock housing71is formed as a hollow box which projects from the outer column4downwardly of the vehicle body and the vehicle body downward side of which is opened. The lock housing71is symmetric in shape in the vehicle body right and left direction, and the width of the lock housing71in the vehicle body right and left direction is set substantially equal to the outside diameter dimension of the cylindrical outer periphery42of the outer column4. Also, the width of a connecting portion between the outer periphery42of the outer column4and lock housing71in the vehicle body right and left direction is set larger than the outside diameter dimension of the outer periphery42of the outer column4.

Since the connecting surface between the outer periphery42of the outer column4and connecting portion72is formed to extend substantially ¾ of the outer periphery42of the outer column4, the connecting strength between the lock housing71and outer column4is increased, thereby being able to reduce the size of the lock pin elongated hole. Also, since the width of the connecting portion72in the vehicle body right and left direction is large, the rigidity of the connecting portion72itself is enhanced. The extension range of the connecting surface between the outer periphery42of the outer column4and connecting portion72is not limited to ¾ of the outer periphery42of the outer column4, but it may also be selected differently depending on cases; for example, ½ to ⅘ of the outer periphery42of the outer column4can also be selected.

Also, although not shown, on the vehicle body forward side (inFIG. 8, the left) surface and backward side (in FIG.8, the right) surface of the lock housing71, there may be provided multiple thin-plate-shaped ribs which are respectively used to connect the outer periphery42of the outer column4to the vehicle body forward side surface and to connect the outer periphery42of the outer column4to the vehicle body rearward side surface.

Therefore, since the strength of such portion of the outer column4as exists around the lock housing71is increased, it is possible to prevent the slit formed in the lower surface of the outer column4from cracking, whereby restrictions on the mounting position of the lock apparatus can be reduced and the telescopic clamp force of the outer column4can be increased easily.

In the previously described first to third embodiments, the lock housing71is formed to project from the outer column4in the vehicle width direction. When the lock housing71is formed to project from the outer column4in the vehicle width direction, preferably, there can be avoided a possibility that the knees of a driver can hit against the lock housing71, and also the visibility of a meter panel can be enhanced.

In the fourth embodiment, since the lock housing71is formed to project from the outer column4in the vehicle downward direction, the visibility of a meter panel can be enhanced. Also, before the steering apparatus is mounted onto the vehicle body, when assembling peripheral parts to the steering apparatus, the steering apparatus may be turned upside down. In this case, when the lock housing71projects from the outer column4in the vehicle downward direction, it is easy to incorporate the electronic unit73of the lock apparatus7and arrange wiring.

Also, when die-cast forming the right and left side surfaces46(column fastening surfaces) of the outer column4, the mold removing direction provides the vehicle width direction (a direction perpendicular to the right and left side surfaces46of the outer column4). Therefore, when the lock housing71is formed to project from the outer column4in the vehicle width direction, preferably, it is easy to form the lock housing71. Also, as in the fourth embodiment, when the lock housing71is formed to project from the outer column4in the vehicle downward direction, the mold removability is good when the mold removing direction provides the vehicle body vertical direction.

Although, in the first to fourth embodiments, the inner column3is constituted of a lower column and the outer column4is constituted of an upper column, the inner column3may also be constituted of an upper column and the outer column4may also be constituted of a lower column. In the above embodiments, there is formed a slit in the lower surface of the outer column4and the space of this slit is compressed to fasten the outer periphery of the inner column3. Also, the slit structure may also be applied to a column structured such that only the lower portions of the column fastening surfaces46are connected together to connect together the column fastening surfaces46.

Also, in the first to fourth embodiments, description has been given of an example in which the invention is applied to a tilt/telescopic type of steering apparatus capable of adjusting both its tilt position and telescopic position. However, the invention may also be applied to a steering apparatus capable of adjusting one of its tilt position and telescopic position; or, to a steering apparatus structured such that it adjusts neither its tilt position nor its telescopic position. Further, on the portion near to the mounting position of the vehicle body mounting lower bracket12, there may be mounted the reduction mechanism of an electric power steering apparatus.

Fifth to Tenth Embodiments

Next, description will be given below of fifth to tenth embodiments according to the invention.

The fifth to tenth embodiments respectively relate to a steering apparatus which can enhance the rigidity of a housing and also, while securing the freedom of the design of the steering apparatus, can enhance its antitheft function.

Prior to description of the fifth to tenth embodiments according to the invention, description will be given of the structure and problems of a conventional steering apparatus to thereby make clear the improvements that can be made by the fifth to tenth embodiments.

FIGS. 22 and 23respectively show a conventional steering apparatus disclosed in the patent reference 1. In this steering apparatus, on the inside diameter side of a cylindrical steering column1002supported on a vehicle body1001, there is rotatably supported a steering shaft1003. To the rear end portion of the steering shaft1003that projects backwardly beyond the rear end opening of the steering column2, there is fixed a steering wheel1004.

When rotating the steering wheel1004, the rotation of the steering wheel1004is transmitted through the steering shaft1003, universal joint1005a, intermediate shaft1006and universal joint1005bto the input shaft1034of a steering gear unit1007. When the input shaft1034is rotated, a pair of tie rods1008and1008respectively disposed on both sides of the steering gear unit1007are pushed and pulled to apply a steering angle, which corresponds to the operation amount of the steering wheel1004, to a pair of right and left front wheels.

Here, in the structure shown inFIG. 21, in order to be able to adjust the back and forth position of the steering wheel1004, as the steering column1002and the steering shaft1003, there are used a steering column and a steering shaft which are respectively of a telescopic type. The back and forth positions of an outer column and an inner column constituting such telescopic type of steering column, and the back and forth positions of an outer tube and an inner shaft constituting such telescopic type of steering shaft may also be reversed to those of the structure shown inFIG. 21.

A lock housing1009is fixed to a portion of a steering column1002ausing a clamp metal member1010and a pair of bolts1011and1011.

The lock housing1009includes a tubular-shaped storage portion1012, a bottom plate portion1013provided in a state where it closes the base end opening of the storage portion1012, and a pair of mounting flange portions1014and1014disposed in such a manner that they project from the base end portion outer peripheral surface of the storage portion1012. In a portion of the bottom plate portion1013, there is formed a through hole (not shown) and, in a portion of the steering column1002athat is matched to the through hole of the bottom plate portion1013, there is formed another through hole (not shown), whereby the interior of the storage portion1012and the interior of the steering column1002aare allowed to communicate with each other. Also, such portion of a steering shaft1003athe axial position of as coincides with the above two through holes is formed as a male spline shape having a rough pitch, whereby there are formed multiple key lock grooves1015,1015in the multiple portions of the steering shaft1003ain the circumferential direction thereof.

Also, a lock unit1016is stored into the lock housing1009and further the lock unit1016is fixed to the interior of the lock housing1009using a fixing screw1017. The fixing screw1017, in a state where it is inserted into a recessed hole1018formed in the lock housing1009, is threadedly engaged into a screw hole1019formed in the lock unit1016and is then fastened further. The lock unit1016includes a lock pin1021which can be advanced and retreated by an electric actuator1020.

The above-structured lock apparatus operates in the following manner. That is, when an ignition key is rotated up to a lock position, the actuator1020advances the lock pin1021toward the inside diameter portion of the steering column1002a. To the lock pin1021, there is applied by an elastic portion (not shown) an energizing force in a direction where the lock pin1021is made to advance. Owing to this, the lock pin1021penetrates through the two through holes and the leading end of the lock pin1021moves into the grooves of the key lock grooves1015, whereby the lock pin1021prevents the steering shaft against rotation.

In the steering apparatus including the above-mentioned conventional lock apparatus, the opening of the recessed hole1018, in which the head portion1022of the fixing screw1017for fixing the lock unit1016is stored, is covered with the steering column1002a. Thus, as the lock housing1009is left fixed to the steering column1002a, the fixing screw1017cannot be operated. Therefore, it is possible to prevent the fixing screw1017from being loosened and thus to prevent the lock unit1016from being removed from the lock housing1009. However, since the pair of bolts1011and1011, which connect and fix the lock housing1009and clamp metal member1010to each other, are exposed, there is a possibility that a sufficient antitheft effect cannot be always obtained.

That is, since the two bolts1011and1011are exposed to the outside, it is possible to loosen the two bolts1011and1011using some tool. And, when two bolts1011and1011are loosened to thereby separate the lock housing1009and clamp metal member1010from each other, the leading end portion of the lock pin1021can be removed from the key lock groove1015and thus the steering shaft1003acan be rotated.

Although one of the two bolts1011and1011can be made inoperable, for example, by disposing it such that it adjoins and opposes a portion fixed to the vehicle body, it is difficult to design such that neither of the two bolts1011and1011can be operated. In other words, undesirably, the freedom of the design of the steering apparatus is impaired.

And, if any one of the two bolts1011and1011is loosened, there is a possibility that, by inserting a tool such as a crowbar into between the lock housing1009and steering column1002a, the lock housing1009can be separated from the steering column1002a.

Now, description will be given below of the fifth to tenth embodiments of the invention in which, in view of the above conventional steering apparatus and the problems thereof, an antitheft function is improved.

Fifth Embodiment

FIGS. 9 to 14respectively show the fifth embodiment according to the invention. The description of such structures and operations of the fifth embodiment as are similar to the above conventional steering apparatus is omitted or simplified, and thus description will be given below mainly of the characteristic portions of the present embodiment.

According to the present embodiment, the lock housing1009ais formed integrally with the steering column (for example, outer column)1002b. That is, by die casting a light alloy such as an aluminum alloy and a magnesium alloy, the lock housing1009aand steering column1002bare formed as an integral body. Therefore, the lock housing1009aand steering column1002bare connected to each other in such a manner that they cannot be separated from each other.

Here, in the illustrated example, the steering column1002bis formed as an outer column for constituting a telescopic type of steering apparatus which is used to adjust the back and forth positions of a steering wheel. Thus, in the steering column1002b, there are formed a slit1023(seeFIG. 12) for elastically increasing or decreasing the diameter of the steering column1002b, and two bracket portions25(seeFIGS. 9 and 10) which are disposed such that they sandwich the slit1023from both sides and also which respectively include an elongated hole1024formed long in the axial direction thereof. However, the structure and operation of a telescopic type of steering apparatus including such elongated hole1024and bracket portion25are conventionally widely known and are not associated with the subject matter of the present invention. Thus, the illustration and description thereof are omitted here.

The lock housing1009ais disposed on the outer peripheral surface of the steering column1002bin such a manner that it is opened outwardly in the diameter direction of the steering column1002b. Also, in such portion of the steering column1002bas is matched to the lock housing1009a(the portion that is surrounded by the lock housing1009a), there is formed a through hole1026(seeFIG. 12). The through hole1026penetrates through the steering column1002bin the diameter direction thereof.

In a state where the lock unit1016ais stored in the lock housing1009, the leading end portion of a lock pin1021aprovided in a lock unit1016a, as shown inFIG. 12, is situated within the through hole1026. As an ignition key is turned up to the lock position, the lock pin1021ais projected through the through hole1026from the inner peripheral surface of the steering column1002binwardly in the diameter direction thereof.

A lock collar1027, as shown inFIGS. 13 and 14, is fitted with and fixed to the outer surface of such portion of the steering shaft1003brotatably supported on the inside diameter side of the steering column1002bas faces the through hole1026. The lock collar1027is fixed to the steering shaft1003bby welding or the like in such a manner that it can be prevented against rotation even when a large rotational force is applied to the lock collar1027.

Also, in the multiple portions of the lock collar1027in the circumferential direction thereof, there are formed elongated holes (not shown) respectively long in the axial direction of the lock collar1027, while they are used as key lock grooves into which the leading end portion of the lock pin1021acan be engaged. The shape and the like of such lock collar1027are also conventionally widely known and thus the detailed description thereof is omitted here.

Here, the fixed state of the lock collar1027to the steering shaft1003bmay not be such that it is completely prevented against rotation with respect to the steering shaft1003b. That is, the lock collar1027may only be fitted with the outer surface of the steering shaft1003bin such a manner that it can generate resistance of such degree as can substantially prevent execution of a steering operation by the steering wheel. Therefore, the lock collar1027may also be fitted with the outer surface of the steering shaft1003bby close fit, or may be fitted with such outer surface through a sleeve-like member which is made of a plate spring or the like and also which can generate large frictional resistance.

In the deep end face of the lock unit1016a, that is, in the surface of the lock unit1016afacing such portion of the outer peripheral surface of the steering column1002bas is surrounded by the lock housing1009a, there is formed a screw hole1019a. With the screw hole1019a, there can be threadedly engaged a fixing screw1017awhich is used to fix the lock unit1016ato the inside of the lock housing1009a.

Also, in such portion of the portion of the steering column1002bsurrounded by the lock housing1009aas is shifted from the through hole1026and is matched to the screw portion1019a, there is formed a second through hole1028. The second through hole1028is formed to have a size which allows the shaft portion1029of the fixing screw1017ato pass therethrough but prevents the head portion1022aof the fixing screw1017aagainst passage. However, in such portion of the second through hole1028as exists in the opening peripheral edge portion of the inner peripheral surface side of the steering column1002b, there is formed a recessed portion1030which is capable of storing the head portion1022atherein.

Also, in such portion of the steering column1002bas exists on the opposite side to the second through hole1028in the peripheral direction of the steering column1002b, there is formed a third through hole1031having a size which allows the head portion1022aof the fixing screw1017ato pass therethrough.

To fix the lock unit1016ato the inside of the lock housing1009a, the lock unit1016amay be inserted into the lock housing1009afrom the lock pin1021aand screw hole1019a.

And, the shaft portion1029of the fixing screw1017ahaving passed through the third through hole1031is inserted into the second through hole1028and a male screw formed in the outer peripheral surface of the shaft portion1029is threadedly engaged with the screw hole1019a. And, a tool such as a driver is inserted from the third through hole1031to fasten the fixing screw1017a, whereby the lock unit1016ais fixed to the inside of the lock housing1009a.

After the lock unit1016ais fixed to the inside of the lock housing1009ain this manner, as shown inFIGS. 13 and 14, the steering shaft1003bis assembled to the inside diameter side of the steering column1002b.

In this state, the steering shaft1003bis situated between the second and third through holes1028and1031. Therefore, even when a tool is inserted from the third through hole1031, the tool is prevented from being engaged with the head portion1022aof the fixing screw1017a. That is, according to the present embodiment, while the steering shaft1003bis left situated within the steering column1002, the fixing screw1017acannot be loosened. In other words, while the function of the steering apparatus remains secured, the lock unit1016ais prevented from being removed from the lock housing1009a.

Also, since the lock housing1009ais formed integrally with the steering column1002b, even a tool such as a file or a hack-saw is used, it takes a long time to separate the lock housing1009atogether with the lock unit1016afrom the steering column1002b. This can enhance the antitheft function.

Since the tool and the head portion1022aof the fixing screw1017acannot be engaged with each other unless the steering shaft1003bis taken out from the steering column1002b, there is eliminated the need to arrange the respective structure members specially for preventing them from being engaged with each other, and thus there is eliminated a possibility that the freedom of the design of the steering apparatus can be lowered.

Also, since the steering column1002band lock housing1009aare formed an integral body, it is possible to facilitate the assembling operation and thus to reduce the manufacturing cost of the steering apparatus.

Further, since the steering column1002band lock housing1009aare formed an integral body, the size and weight of the whole steering apparatus with a lock apparatus incorporated therein can be reduced.

Sixth Embodiment

FIG. 15shows a sixth embodiment according to the invention. In the present embodiment, on such portion of the outer peripheral surface of the steering shaft1003bas faces the through hole1026(seeFIG. 12), there are formed rough male-spline-groove-shaped uneven portions respectively serving as lock collars1027awhich can be fitted with and fixed to the outer surface of such portion. The structures and operations of the other remaining portions of the present embodiment are similar to those of the above-mentioned fifth embodiment, and thus the illustration and description of the equivalent portions thereof are omitted here.

Seventh Embodiment

FIG. 16shows a seventh embodiment according to the invention. In the present embodiment, to such portion of the inner peripheral surface of the steering column1002bas exists on the opposite side to the lock housing1009ain the peripheral direction of the steering column1002b, there is fixed by adhesion or the like a backup piece1032which is formed to have a partial arc shape to match the shape of, for example, the inner peripheral surface of the steering column1002b.

The backup piece1032prevents the steering shaft1003bfrom shifting in a direction where it parts away from the lock housing1009a. That is, in a state where the lock pin1021a(seeFIGS. 9 and 12) and key lock groove are engaged with each other, when trying to rotate the steering shaft1003bthrough the steering wheel with a large force, there is a possibility that the steering shaft1003bcan shift in a direction to part away from the lock housing1009ato thereby remove the engagement between the lock pin1021a(seeFIGS. 9 and 12) and key lock groove. However, according to the present embodiment, the backup piece1032can prevent the steering shaft1003bfrom shifting in a direction to part away from the lock housing1009aand thus can prevent the removal of the engagement between the lock pin1021aand key lock groove, thereby being able to secure the antitheft function of the lock apparatus.

Here, the backup piece32, in a vehicle crash, is slipped down from the inner peripheral surface of the steering column1002to thereby prevent the steering shaft1003bfrom shifting forwardly. The structures and operations of the other remaining portions of the present embodiment are similar to those of the above-mentioned fifth and sixth embodiments, and thus the illustration and description of the equivalent portions thereof are omitted here.

Eighth Embodiment

FIGS. 17 and 18respectively show an eighth embodiment according to the invention. In the present embodiment, a steering column (outer column)1002cis made of steel and a lock housing1009bis made of a light alloy. They are both formed by die casting into an integral body. Specifically, a portion of the outer column1002cis embedded into a portion of the lock housing1009bto thereby form them as an integral body. In this manner, the outer column1002cand lock housing1009bare connected together in such a manner that they cannot be separated from each other. The structures and operations of the other remaining portions of the present embodiment are similar to the above-mentioned fifth embodiment. Thus, the illustration and description of the equivalent portions are omitted here.

Ninth Embodiment

FIG. 19shows a ninth embodiment according to the invention. In the ninth embodiment, similarly to the eighth embodiment, a steering column1002cmade of steel and a lock housing1009bmade of a light alloy are formed into an integral body. Further, in the front end portion of the upper surface of the lock housing1009b, there is formed a recessed portion1033which is recessed downwardly of the longitudinal direction central and rear end portions of the above upper surface. Also, in such portion of the recessed portion1033as exists on the steering column1002cside, there is formed a second through hole1028ahaving a size which allows the shaft portion1029of the fixing screw1017ato pass therethrough but prevents the head portion1022aof the fixing screw1017afrom passing therethrough.

In order that the lock unit1016acan be inserted into the lock housing1009bwithout shaking, the outer peripheral surface of the lock unit1016ais formed to have a shape substantially equal to or slightly smaller than the shape of the inner peripheral surface of the lock housing1009b. In such portion of the upper surface of the lock unit1016aas is matched to the second through hole1028a, there is formed a screw hole1019b. A male screw formed in the shaft portion1029of the fixing screw1017acan be threadedly engaged with the screw hole1019b. And, when, after the shaft portion1029of the fixing screw1017ais inserted into the second through hole1028a, it is threadedly engaged with the screw hole1019band is tightened further, the lock unit1016acan be supported by and fixed to the inside of the lock housing1009b.

Here, in a state where the steering column1002cis supported on the vehicle body, between the upper surface of the lock housing1009band a portion to be fixed to the vehicle body such as a dash board, there must not be generated a clearance having a size which allows the engagement between the head portion22aof the fixing screw1017aand a tool. For example, the clearance between the upper surface of the lock housing1009band the portion to be fixed to the vehicle body should be set substantially equal to the axial dimension of the head portion1022aof the fixing screw1017a, or a level difference the recessed portion1033and lock housing1009bshould be set substantially equal to the axial dimension of the head portion1022aof the fixing screw1017a. The structures of the other remaining portions of the present embodiment are similar to the above-mentioned fifth embodiment. Thus, the duplicate illustration and description of the equivalent portions are omitted here.

In the structure according to the present embodiment as well, since, while securing the function of the steering apparatus, the lock unit1016ais prevented from being removed from the lock housing1009a, the antitheft function of the lock apparatus can be enhanced.

Tenth Embodiment

FIG. 20shows a tenth embodiment according to the invention. In the present embodiment, in such end portion of the front surface of the lock housing1009bas, exists on the steering column1002cside, there is formed a second through hole1028ahaving a size which allows the shaft portion1029of the fixing screw1017ato pass therethrough but prevents the head portion1022aof the fixing screw1017afrom passing therethrough. In such portion of the front surface of the lock unit1016aas is matched to the second through hole1028a, there is formed a screw hole1019cwith which there can be threadedly engaged a male screw formed in the shaft portion1029of the fixing screw1017a. And, when, after the shaft portion1029of the fixing screw1017ais inserted into the second through hole1028a, it is threadedly engaged with the screw hole1019band is tightened further, the lock unit1016acan be supported by and fixed to the inside of the lock housing1009b.

According to this structure, in a state where the steering column1002cis supported on the vehicle body, between the front surface of the lock housing1009band a portion to be fixed to the vehicle body such as a dash board, there must not be generated a clearance having a size which allows the engagement between the head portion1022aof the fixing screw1017aand a tool. The structures of the other remaining portions of the present embodiment are similar to the above-mentioned eighth embodiment. Thus, the duplicate description of such portions is omitted here.

Here, in enforcing the above-mentioned fifth to tenth embodiments, the structure of the lock unit is not limited to any specific one. That is, besides the above-mentioned structure in which, by rotating an ignition key up to the lock position, the lock pin is projected from the inner peripheral surface of the steering column, there may also be employed a structure in which the lock pin is left projected from the inner peripheral surface of the steering column unless a regular key is used.

Eleventh to Twenty-Second Embodiments

Now, description will be given below of eleventh to twenty-second embodiments according to the invention.

The eleventh to twenty-second embodiments respectively relate to a steering apparatus which is enhanced in the rigidity of a housing, includes a housing structured such that, whether the steering apparatus is mounted on a right-hand drive vehicle or a left-hand drive vehicle, a portion not in use is left therein, and, even when the slit of a clamp device and the through hole of a lock apparatus are disposed adjacent to each other, a crack is hard to occur between the slit and through hole.

Before describing eleventh to twenty-second embodiments according to the invention, in order to make clear the improvements that can be made by the eleventh to twenty-second embodiments according to the invention, description will be given below firstly of the structure of a conventional steering apparatus and problems found in the conventional steering apparatus. In a steering apparatus for applying a steering angle to the front wheels of a vehicle, as shown inFIG. 43, a steering shaft2002with a steering wheel2001fixed to the rear end portion thereof is rotatably supported on the inside diameter side of a steering column2003which is supported on the vehicle body. To the front end portion of the steering shaft2002, there is connected the rear end portion of an intermediate shaft2005through a universal joint2004. Also, to the front end portion of the intermediate shaft2005, there is connected through a universal joint2006a steering gear unit2007which is constituted of a rack and pinion and the like.

In this state, when a driver operates and rotates the steering wheel2001, the rotation force of the steering wheel2001is transmitted through the above respective members2002,2004,2005and2006to the steering gear unit2007. As a result of this, a tie rod2008, which is connected to the two end portions of the steering gear unit2007, is pushed and pulled to thereby apply a steering angle to the right and left front wheels2009.

Here, since the position relationship between the steering wheel2001and a driver's seat varies depending on the build and driving posture of the driver, in order to realize a proper driving posture, it is necessary to use, in addition to a device for adjusting the back and forth position of the driver's seat, a device for adjusting the back and forth position and vertical position of the steering wheel2001.

FIGS. 44 and 45respectively show an example of a conventional structure of a steering apparatus having such steering wheel position adjusting function. Here, of theseFIGS. 44 and 45,FIG. 44is a side view of the rear end side portion of the conventional structure, andFIG. 45is a partially omitted view of the conventional structure when it is viewed from belowFIG. 44.

A steering column2003aconstituting the conventional structure is produced in the following manner. That is, a cylindrical outer column2010situated on the rear side of the vehicle body (on the right side inFIGS. 44 and 45, and inFIGS. 24,25,35,36,38,40,42,46,48and49which will be respectively discussed later) and a cylindrical inner column2011situated on the front side of the vehicle body (on the right side inFIGS. 44 and 45, and inFIGS. 24,25,35,36,38,40,42,46,48and49which will be respectively discussed later) are combined together in such a manner that the whole length thereof can be increased or decreased, that is, a telescopic manner. These outer column2010and inner column2011are respectively formed of a light alloy such as an aluminum alloy and a magnesium alloy by die casting.

Referring to the structure of the inner column2011, its front end portion is supported in such a manner that it can be only oscillated about a transverse shaft2012with respect to the vehicle body. Also, referring to the structure of the outer column2010, its front end portion to its front half section is fitted with the outer surface of the rear end portion to its rear half section in such a manner that it can be shifted only in the axial direction. Also, in the front half section of the lower surface of the outer column2010, there is formed a slit2013which is opened on the front end edge of the outer column2010and extends in the axial direction of the outer column2010. And, owing to formation of such slit2013, the diameter dimension of the front half section of the outer column2010can be elastically changed easily.

Also, such portion of the intermediate portion of the steering column2003aas corresponds to the engagement portion between the outer column2010and inner column2011is supported by a clamp device2014which is fixed to the vehicle body.

The clamp device2014can be switched by the rotational operation of a lever2015between a state where it applies fastening forces to such portion of the outer column2010as ranges from the front end portion thereof to the outer peripheral surface of the front end side thereof from both sides in the right and left direction (in the front and back direction inFIG. 44, andFIGS. 24,33,35,38,40,42and46to be discussed later; in the vertical direction inFIG. 45, andFIGS. 25,36,48and49to be discussed later; in the right and left direction inFIGS. 26,27,29to32,34,37,39,41,47A and47B to be discussed later) which is the width direction of the vehicle body, and a state where it does not apply such fastening forces.

Also, on the inside diameter side of the steering column2003a, there is rotatably supported a steering shaft2002a. The steering shaft2002ais structured such that it can bring the front end portion of a circular-pipe-shaped outer shaft2016disposed on the rear side of the vehicle body and the rear end portion of a rod-shaped inner shaft2017disposed on the front side of the vehicle body into engagement with each other to thereby be able to transmit its rotation force and also to increase or decrease the whole length thereof.

In the thus structured steering shaft2002a, the rear end side of the outer shaft2016is supported on the rear end portion of the outer column2010and the front end side of the inner shaft2017is supported on the front end portion of the inner column2011respectively by their respective antifriction bearings (not shown) such as radial ball bearings in such a manner that only the rotational movements thereof are allowed. And, on such portion of the rear end portion of the outer shaft2016as projects backwardly from the rear end of the outer column2010, there is supported and fixed the steering wheel2001(not shown inFIG. 44or45; seeFIG. 43). Also, to such portion of the front end portion of the inner shaft2017as projects forwardly from the front end of the inner column2011, there is connected the rear end portion of the intermediate shaft2005(seeFIG. 43) through the universal joint2004.

According to the above conventional steering apparatus, the state where the fastening force given by the clamp device2014is applied and the state where such fastening force is not applied are switched over to each other to thereby adjust the position of the steering wheel2001in the following manner.

That is, in the fastening force applied state, since the oscillatory displacement of the steering column2003aabout the transverse shaft2012is prohibited, the vertical position of the steering wheel2001is fixed. Also, since the width of the slit2013of the outer column2010narrows and the front half section of the outer column2010reduces in diameter, a frictional force in the engagement portion between the outer column2010and inner column2011increases sufficiently. As a result of this, the axial displacement of the outer column2010with respect to the inner column2011is prohibited, whereby the back and forth position of the steering wheel2001is fixed.

On the other hand, in the fastening force not-applied state, since the oscillatory displacement of the steering column2003aabout the transverse shaft2012is possible, the vertical position of the steering wheel2001can be changed. Also, since, due to the elasticity of the outer column2010, the width of the slit2013spreads and the front half section of the outer column2010increases in diameter, the frictional force in the engagement portion between the outer column2010and inner column2011decreases sufficiently. As a result of this, the axial displacement of the outer column2010with respect to the inner column2011is possible, whereby the back and forth position of the steering wheel2001can be changed.

Next,FIGS. 46,47A and47B respectively show, as an example of a conventionally used lock apparatus for preventing the theft of a vehicle, a lock apparatus disclosed in the patent reference 5. According to this lock device, when an ignition switch is turned off and also, in order to remove an ignition key from a key hole (not shown), the ignition key is turned up to its lock position, as shown inFIG. 47A, a lock pin2018is elastically projected from a key cylinder (not shown) fixed to the steering column2003binwardly in the diameter direction of the steering column2003bthrough a through hole2020formed in the steering column2003b.

And, the leading end portion of the lock pin2018is inserted into and engaged with the key lock hole2021of a key lock collar2019fixed to the steering shaft2002b. And, such engagement prevents the rotation of the steering shaft2002b. On the other hand, in a state where the ignition switch is turned on, as shown inFIG. 47B, the lock pin2018does not project inwardly of the steering column2003bbut the steering shaft2002bwith the key lock collar2019fixed thereto is allowed to rotate.

Here, to assemble the above-mentioned lock apparatus to the rear end portion (the portion that does not interfere with the clamp device2014) of the outer column2010constituting the conventional steering apparatus shown inFIGS. 44 and 45, the lock housing of a lock unit including a key cylinder must be provided on the outer peripheral surface of the rear end side of the outer column2010.

FIG. 48shows an example in which the structure of the lock housing disclosed in the patent reference 2 is applied to the rear end side of the outer column2010. In the structure shown inFIG. 48, on the rear end side of the outer column2010, a pair of plate-shaped lock housings2022aand2022b, which respectively project on both sides in the width direction of a vehicle, are formed by die casting integrally with the outer column2010.

And, owing to formation of the paired lock housings2022aand2022b, according to the structure of a vehicle to which the steering apparatus is to be assembled, such as the structure of a so called right-hand drive vehicle and the structure of a so called left-hand drive vehicle, one of the paired lock housings2022aand2022bcan be chosen as a lock housing on which the lock unit is to be mounted.

However, in the structure shown inFIG. 48, there is raised a state where the other of the paired lock housings2022aand2022bis not in use. Due to this, the manufacturing cost of the other lock housing is wasted and also, by an amount equivalent to the other lock housing, the installation space of the steering apparatus increases.

Also, when assembling the above-mentioned lock apparatus to the rear end side of the outer column2010of the conventional steering apparatus shown inFIGS. 44 and 45, the through hole2020(seeFIGS. 46,47A and47B), into which the lock pin2018can be inserted, must be formed in the rear end portion of the outer column2010.

FIG. 49shows an example in which the through hole2020is formed in the rear end portion of the outer column2010. In this structure, the periphery of the through hole2020of the outer column2010provides a portion which is reduced in strength when compared with the other remaining portion. Thus, as shown inFIG. 49, in the structure where the through hole2020is formed in a portion near to the rear end edge of the slit2013, due to the stress that is generated when the fastening force by the clamp device (seeFIG. 44) is applied, there is raised a possibility that there can be caused a crack K between the slit2013and through hole2020.

In view of the above-mentioned conventional steering apparatus and problems raised by such steering apparatus, description will be given below of the eleventh to twenty-second embodiments according to the invention.

Eleventh Embodiment

FIGS. 24 to 26respectively show the eleventh embodiment according to the invention. Here, the present embodiment is characterized by the structure of a lock apparatus which is provided on the rear end side of an outer column2010aconstituting a steering column2003c. The structures and operations of the present embodiment similar to those of the above-mentioned conventional steering apparatus are omitted or simplified here. That is, description will be given below mainly of the characteristic portions of the present embodiment.

According to the present embodiment, in order to structure the above lock apparatus, in the lower half section of the rear end side of the outer column2010a, there is formed a through hole2020awhich allows the inside and outside of the outer column2010ato communicate with each other. Also, in such portion of the lower half section of the rear end side of the outer column2010aas surrounds the periphery of the through hole2020a, there is formed by die casting a box-like lock housing2023with its lower surface opened in such a manner that it projects downwardly from the above portion and is formed integrally with the outer column2010a.

The lock housing2023includes: a front plate portion2024and a rear plate portion2025respectively formed in such a manner that they extend parallel to each other downwardly from the two front and rear end edge portions of the through hole2020a; and, a pair of parallel side plate portions2027aand2027brespectively formed in such a manner that they extend downwardly from the two right and left end edge portions of the through hole2020athrough a pair of connecting plate portions2026aand2026bextending right and left.

The two right and left end portions of the front plate portion2024and rear plate portion2025and the two front and rear end portions of the connecting plate portions2026a,2026band side plate portions2027aand2027bare respectively formed to continue with each other. Also, in the two mutually matched front and rear end portions of the lower sides of the side plate portions2027aand2027b, there are formed insertion holes2028and2028respectively.

Also, a cylindrical key lock collar2019ais fitted with and fixed to the outer surface of such portion of the rear end side of the outer shaft2016rotatably supported on the inside diameter side of the outer column2010aas is matched to the through hole2020ain the axial direction. In the outer peripheral surface of the key lock collar2019a, there are formed multiple key lock grooves2047,2047, which are respectively key lock recessed portions, at regular intervals in the circumferential direction thereof.

Also, inside the lock housing2023, there is held a held portion2031which constitutes a lock unit2029. The lock unit2029includes a columnar portion2030and the above-mentioned held portion2031which is fixed to the upper portion of the colúmnar portion2030and has a substantially rectangular block (cuboid) shape. The columnar portion2030includes a key hole (not shown) which formed in one (inFIG. 24, the deep side) axial-direction end face thereof and into which an ignition key can be inserted. Also, the held portion2031, as shown inFIG. 25, can be inserted through the lower surface opening of the lock housing2023into the lock housing2023without shaking greatly. The held portion2031includes a recessed surface portion2032which is formed in the right-and-left direction intermediate portion of the upper surface of the held portion2031and also which has a radius of curvature slightly larger than the radius of curvature of the inner peripheral surface of the outer column2010a.

Also, in the central portion of the held portion2031, there is formed a cylinder hole2033the upper end portion of which is opened in the central portion of the recessed surface portion2032; and, into the inside of the cylinder hole2033, there is inserted a lock pin (not shown). And, in a state where the held portion2031is inserted into the inside of the cylinder hole2033, in such portion of the held portion2031as is matched to the respective insertion holes2028and2028respectively formed in the paired side plate portions2027aand2027brespectively constituting the lock housing2023, there are formed a pair of insertion holes2034and2034which are arranged concentric with the insertion holes2028and2028respectively.

And, into inside the insertion holes2028and2034that are matched to each other, there are inserted the shaft portions2036and2036(which are not shown inFIG. 24) of bolts2035and2035respectively; and, nuts2038and2038are respectively threadedly engaged with such portions of these shaft portions2036and2036as project from the respective insertion holes2028and2028, and the nuts2038and2038are fastened further (the pair of side plate portions2027aand2027bconstituting the lock housing2023are firmly held from both right and left sides by the head portions2037,2037of the bolts2035,2035and the nuts2038,2038). Owing to this, the lock unit2029is connected to the outer column2010a(the lock housing2023).

Here, according to the present embodiment, in the thus connected state, in order to prevent the held portion2031from shaking within the lock housing2023, the dimensions of the respective members are regulated in such a manner that the dimensions a1, a2, b1, b2, c1, c2, d1, d2, e1, e2of clearances respectively existing between the lock housing2023, held portion2031and the respective bolts2035,2035can be reduced sufficiently, or can be set for 0 or negative values (a state of light pressure insertion). The above is the structure of the lock apparatus according to the present embodiment.

The above lock apparatus operates in the following manner. That is, when the ignition switch is turned off and, in order to pull out the ignition key from the above key hole, the ignition key is turned up to the lock position, a lock pin (not shown) is elastically projected inwardly in the diameter direction of the outer column2010afrom the cylinder hole2033formed in the held portion2031through the through hole2020aformed in the lower surface of the outer column2010a. And, the leading end portion of the lock pin is inserted into and engaged with the key lock groove2047of the key lock collar2019afixed to the steering shaft2002a. This engagement prevents the rotation of the steering shaft2002a.

On the other hand, in a state where the ignition switch is turned on, the lock pin does not project into inside the outer column2010a(it is pulled into inside the lock unit2029) and thus the steering shaft2002awith the key lock collar2019afixed thereto is free to rotate.

As described above, in the steering apparatus according to the present embodiment, the lock housing2023, which is used to mount the lock unit2029onto the outer column2010a, is formed such that it does not project rightward or leftward of the outer column2010agreatly but projects mainly downwardly. In both of a right-hand drive vehicle and a left-hand drive vehicle, the lock housing2023can be used in common. Also, since only one lock housing2023may be provided, in a state where the lock apparatus is assembled to the vehicle, there is no possibility that a lock housing not in use can occur.

Also, according to the present embodiment, the lock housing2023is formed in such a manner that it is connected to such portion of the outer column2010aas exists around the through hole2020a. Owing to this, the peripheral portion of the through hole2020acan have sufficient strength.

Especially, the front plate portion2024constituting the lock housing2023is formed in such a manner that it partitions a portion, which exists between the slit2013formed in the front half section of the lower surface of the outer column2010aand the through hole2020aformed in the rear end portion of the lower surface of the outer column2010a, in the back and forth direction of the outer column2010a. Therefore, even when the fastening force is applied by the clamp device2014to generate internal stress in the outer column2010a, the front plate portion2024can prevent a crack from occurring between the rear end edge of the slit2013and the above through hole2020a.

Twelfth Embodiment

FIGS. 27 and 28respectively show a twelfth embodiment according to the invention. According to the present embodiment, the head portion2037aof a bolt2035ahas a cylindrical outer peripheral surface and a hexagonal hole2039formed in the base end face thereof. Also, between the head portion2037aand one (inFIG. 27, the left) side plate portion2027aconstituting a lock housing2023, there is interposed a washer2040.

Further, a nut2038is fitted with the inner surface of a tubular portion2041which is provided on and projected from the outer surface of the other side plate portion2027bconstituting the lock housing2023. And, the outer peripheral surface of the hexagonal-shaped nut2038is engaged with the inner peripheral surface of the hexagonal-shaped tubular portion2041to thereby prevent the nut2038from being rotated from outside. Also, when the leading end portion of the shaft portion2036of the bolts2035ais threadedly engaged with the nut2038and is fastened further by a hexagonal wrench (not shown) engaged with the hexagonal hole2039of the head portion2037aof the bolt2035a, the nut2038can be prevented from rotating together with the bolt2035a.

Here, when the nut2038has been previously pressure inserted (including light pressure insertion) into the inside of the tubular portion2041or has been cast thereinto, it is possible to prevent the nut2038from slipping off the tubular portion2041. In this case, the above-mentioned engaging and fastening operation can be facilitated.

Also, according to the present embodiment, between the outer peripheral surface of the outer shaft2016and the inner peripheral surface of a key lock collar2019a, there is interposed a friction sleeve2042. The friction sleeve2042allows the key lock collar2019ato rotate relative to the outer shaft2016with a large torque. Therefore, according to the present embodiment, in a state where a lock pin and a key lock groove2047are engaged with each other, unless there is applied such a large torque to a steering wheel as the steering wheel cannot be operated, it is impossible to operate the steering wheel. Therefore, the present embodiment can secure its antitheft function and also can prevent the damage of the lock pin and the like. The remaining structures and operations of the present embodiment are similar to those of the previously described eleventh embodiment.

Thirteenth Embodiment

FIG. 29shows a thirteenth embodiment according to the invention. According to the present embodiment, into the inside of an insertion hole2028aformed in one (inFIG. 29, left) side plate portion2027aconstituting a lock housing2023, there is inserted the head portion2037aof a bolt2035a. The head portion2037aof the bolt2035aand a nut2038threadedly engaged with the leading end portion of the shaft portion2036of the bolt2035acooperate together in sandwiching a held portion2031and the other (inFIG. 29, right) side plate portion2027bconstituting the lock housing2023between them. Also, in this state, by fastening the nut2038, the mutually opposed side surfaces of the held portion2031and the other side plate portion2027bare contacted with each other.

Owing to this structure, the held portion2031can be prevented from shaking in the right and left direction with respect to the lock housing2023. Also, since a clearance between the outer peripheral surface of the head portion2037aof the bolt2035aand the inner peripheral surface of the insertion hole2028ais set for a value in the range of approximately 0.1 mm to the light pressure insertion level, these two peripheral surfaces can be prevented from shaking in the diameter direction relative to each other. The remaining structures and operations of the present embodiment are similar to those of the previously described eleventh and twelfth embodiments.

Fourteenth to Sixteenth Embodiment

FIGS. 30 to 32respectively show fourteenth to sixteenth embodiments according to the invention. In these embodiments, the structures of the shaft portions2036b,2036cand2036dof bolts2035b,2035cand2035dare different from the above-mentioned thirteenth embodiment.

Firstly, in the fourteenth embodiment shown inFIG. 30, on the whole area of the outer peripheral surface on the base end side of the shaft portion2036bof the bolt2035b, there is integrally formed an engaging portion2042bwhich expands outwardly in the diameter direction from the outer peripheral surface and also which has an outer peripheral surface having a semicircular arc shaped section.

Also, in the fifteenth embodiment shown inFIG. 31, on the whole area of the base end side outer peripheral surface of the shaft portion2036cof the bolt2035c, there is integrally formed an engaging portion2042cwhich expands in the diameter direction from the outer peripheral surface and also which has a cylindrical outer peripheral surface.

Also, in the sixteenth embodiment shown inFIG. 32, on the whole area of the base end side outer peripheral surface of the shaft portion2036dof the bolt2035d, there is integrally formed an engaging portion2042dwhich expands in the diameter direction from the outer peripheral surface and also which has a tapered outer peripheral surface, while the tapered outer peripheral surface is inclined in a direction where the outside diameter thereof increases as it goes toward the base end side of the shaft portion2036d.

And, in all of these embodiments, the engaging portions2042b,2042cand2042dare respectively inserted, or light pressure inserted or pressure inserted into the inside of an insertion hole2034formed in a held portion2031with a fit clearance of approximately 0.1 mm. Owing to such structure, it is possible to effectively prevent the shaft portions2036b,2036cand2036dand insertion hole2034from shaking relative to each other. The remaining structures and operations of these embodiments are similar to those of the previously described thirteenth embodiment.

Here, in the fourteenth to sixteenth embodiments, the engaging portion to be formed in the shaft portion of the bolt is formed integrally with the shaft portion. However, the engaging portion may also be formed of resin, rubber, soft metal or the like as a separate member. In this case, the separate member may have a ring shape the whole periphery of which is continuously connected, or may have a partially chipped ring shape a portion of which, in the circumferential direction thereof, has a discontinuous portion.

Seventeenth Embodiment

FIG. 33shows a seventeenth embodiment according to the invention. The present embodiment is different from the eleventh embodiment shown inFIGS. 24 to 26in that, in the longitudinal direction two end edges of one side plate portion2027aconstituting the lock housing2023, there are formed a pair of second slits which are opened in the lower end edge of the side plate portion2027a.

That is, according to the present embodiment, owing to formation of the paired second slits2043and2043, one side plate portion2027acan be easily deformed elastically in a direction where it moves toward and away from the other side plate portion2027b(seeFIG. 26). Thus, by fastening the respective nuts2038and2038(not shown inFIG. 33; seeFIGS. 25 and 26) which are threadedly engaged with the leading end portions of the respective bolts2035and2035, one side plate portion2027ais elastically deformed toward the other side plate portion2027b, whereby the inner surfaces of the two side plate portions2027aand2027bare respectively contacted with the two side surfaces of the held portion2031(with no clearance between them).

This structure can prevent the held portion2031from shaking in the right and left direction with respect to the lock housing2023. The remaining structures and operations of the present embodiment are similar to those of the previously described eleventh embodiment shown inFIGS. 24 to 26.

Here, when enforcing the present invention, in order that, using the above-mentioned structure of the seventeenth embodiment, the other side plate portion2027bcan be easily deformed elastically, in the longitudinal direction two end portions of the other side plate portion2027bas well, there may also be formed second slits which are respectively opened in the lower end edge of the side plate portion2027b.

Eighteenth Embodiment

FIG. 34shows an eighteenth embodiment according to the invention. According to the present embodiment, in order to obtain similar effects to the above-mentioned seventeenth embodiment, there is employed a structure which can easily deform elastically a pair of side plate portions2027aand2027bconstituting a lock housing2023in a direction where they move toward and away from each other.

Specifically, in the width direction one-end portions (inFIG. 34, left end portions) and the near-to-other-end portions (inFIG. 34, the near-to-right-end portions) of a front plate portion2024and a rear plate portion2025(not shown inFIG. 34) respectively constituting the lock housing2023, there are formed second slits2043a,2043bwhich are respectively opened in the lower end edges of their associated plate portions. The remaining structures and operations of the present embodiment are similar to those of the previously described seventeenth embodiment.

Here, when enforcing the present invention, in order that the side plate portions constituting the lock housing can be easily deformed elastically, the number and positions of the second slits to be formed in the side plate portions constituting the lock housing can be changed according to cases.

Nineteenth Embodiment

FIGS. 35 to 37respectively show a nineteenth embodiment according to the invention. The present embodiment is different from the eleventh embodiment shown inFIGS. 24 to 26in that a lock housing2023aexcludes one side plate portion2027aand a pair of connecting plate portions2026aand2026b(seeFIGS. 24 to 26). Also, due to such exclusion, in the present embodiment, the dimension of a held portion2031ain the right and left direction is reduced accordingly. And, the head portions2037,2037of the bolts2035,2035(not shown inFIG. 35) and nuts2038,2038threadedly engaged with the leading end portions of the shaft portions2036,2036of the bolts2035,2035cooperate together in sandwiching the held portion2031aand a side plate portion2027b(in the eleventh embodiment, the other side plate portion) constituting the lock housing2023abetween them.

Also, in this state, by fastening the nuts2038,2038, the mutually opposed side surfaces of the held portion2031aand side plate portion2027bare contacted with each other (with no clearance between them). And, employment of this structure can prevent the held portion2031afrom shaking in the right and left direction with respect to the lock housing2023a. Also, according to the present embodiment, since the lock housing2023aexcludes one side plate portion2027a(seeFIGS. 24 to 26), the operation to arrange the held portion2031awithin the lock housing2023acan be facilitated (due to the enhanced freedom of the insertion direction of the held portion2031a) accordingly.

Also, in this case, when the shaft portions2036,2036of the paired bolts2035,2035have been previously inserted into a pair of insertion holes2034,2034respectively formed in the held portion2031a, the operation to connect the held portion2031ato the lock housing2023acan be facilitated further. The structures and operations of the remaining portions of the present embodiment are similar to the above-mentioned eleventh embodiment shown inFIGS. 24 to 26.

Twentieth Embodiment

FIGS. 38 and 39respectively show a twentieth embodiment according to the invention. The present embodiment is different from the above-mentioned nineteenth embodiment in that a connecting band2044made of metal is used as a connecting member for connecting the held portion2031ato a lock housing2023a.

That is, according to the present embodiment, the intermediate portion of the connecting band2044is provided over the upper half section of the outer column2010ain such a manner that their peripheral surfaces are contacted with each other with no clearance between them, while the side plate portion2027bconstituting the lock housing2023aand the held portion2031aare sandwiched by and between the two end portions of the connecting band2044from both right and left sides. Also, in a state where the shaft portions2036,2036of the bolts2035,2035(which are not shown inFIG. 38) are inserted into insertion holes2045,2045respectively formed in the two end portions of the connecting band2044, there are fastened the nuts2038,2038which are threadedly engaged with the leading end portions of the shaft portions2036,2036.

Owing to this, the inner surface of one end portion (inFIG. 41, left end portion) of the connecting band2044and the inner surface of the side plate portion2027bconstituting the lock housing2023aare respectively contacted with the two side surfaces of the held portion2031a(with no clearance between them). According to the present embodiment, by an amount equivalent to provision of the connecting band2044, the connecting strength of the held portion2031ain the vertical direction with respect to the lock housing2023acan be enhanced. The structures and operations of the remaining portions of the present embodiment are similar to the above-mentioned nineteenth embodiment.

FIGS. 40 and 41respectively show a twenty-first embodiment according to the invention. The present embodiment is different from the twentieth embodiment shown inFIGS. 38 and 39in that a lock housing2023bexcludes the side plate portion2027b(seeFIG. 39).

Specifically, according to the present embodiment, the two end portions of a connecting band2044aare contacted with the two side surfaces of a held portion2031arespectively. Also, according to the present embodiment, in the intermediate portion of the connecting band2044a, there is formed a rectangular-shaped thickness reduced portion2046. This can reduce the weight of the connecting band2044aand also can enhance the bending property of the intermediate portion of the connecting band2044a, whereby the intermediate portion of the connecting band2044acan be easily contacted closely with the outer peripheral surface of the upper half section of the outer column2010a. The structures and operations of the remaining portions of the present embodiment are similar to the above-mentioned twentieth embodiment.

FIG. 42shows a twenty-second embodiment according to the invention. According to the present embodiment, a front plate portion2024aand a rear plate portion2025arespectively constituting a lock housing2023care formed to extend over the whole area of the outer peripheral surface of the outer column2010a. This enhances the strength of the outer column2010a, front plate portion2024aand rear plate portion2025a.

Also, the size (the dimension in the axial direction of the outer column2010aand the dimension in the peripheral direction thereof) of a through hole2020bformed between the front plate portion2024aand rear plate portion2025aon the rear end side of the lower surface of the outer column2010ais reduced when compared with the above-mentioned respective embodiments. The structures and operations of the remaining portions of the present embodiment are similar to the above-mentioned twenty-first embodiment.

Here, in enforcing the present invention, when the size of the through hole to be formed in the lower surface of the outer column is set to have a size of a necessary minimum value that allows the smooth insertion of the lock pin, the inner peripheral edge of the through hole can prevent the lock pin from falling down in the peripheral direction when the steering shaft is locked.

Although the invention has been described heretofore in detail and with reference to the specific embodiments thereof, it is obvious to those skilled in the art that various changes and modifications are possible without departing from the spirit and scope of the invention.

The present patent application is based on the Japanese Patent Application (Patent Application No. 2007-293891) filed on Nov. 13, 2007, Japanese Patent Application (Patent Application No. 2007-308807) filed on Nov. 29, 2007, Japanese Patent Application (Patent Application No. 2007-316568) filed on Dec. 7, 2007, and Japanese Patent Application (Patent Application No. 2007-329979) filed on Dec. 21, 2007, and thus the contents thereof are incorporated herein for reference.

INDUSTRIAL APPLICABILITY

According to a steering apparatus of the invention, a lock housing and an outer column can be increased in rigidity and can be reduced in weight. Therefore, the invention can provide a steering apparatus which can provide a large telescopic clamp force.

Also, according to the invention, there can be provided a steering apparatus which is excellent in the freedom of design and has an excellent antitheft function.

Further, according to the invention, it is possible to provide a steering apparatus which can be mounted onto both of a right-hand drive vehicle and a left-hand drive vehicle and also can prevent the occurrence of a lock housing which is not in use. Also, it is possible to provide a steering apparatus in which, even when a fastening force by a clamp device is applied, a crack is hard to occur between the slit of the clamp device and the through hole of a lock apparatus.