JP2005162053A - Steering lock mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering lock mechanism capable of effectively regulating rotation of a steering shaft. <P>SOLUTION: This steering lock mechanism 10 comprises the steering shaft 2 structuring a rotary shaft of a steering wheel, a lock bar 12 capable of reciprocating in the radial direction in relation to the steering shaft 2 and having an end possible to be fitted in a lock hole 14 provided in the steering shaft 2, and a steering column tube 3, which has engaging recessed and projecting parts 16 to be engaged with engaging recessed and projecting parts 18 formed in the outer peripheral surface of the steering shaft, in the inner peripheral surface thereof. The engaging recessed and projecting parts 16 are structured to be set at a position opposite to the lock bar 12 in relation to the steering shaft 2 and while at a position offset in the rotating direction of the steering wheel from a reciprocating shaft X of the lock bar 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a steering lock mechanism that locks rotation of a steering shaft.

2. Description of the Related Art Conventionally, a steering lock mechanism that prevents rotation of a steering shaft by fitting a lock bar into a recess formed in an outer peripheral surface (lock collar) of the steering shaft is widely known. In this type of steering lock mechanism, a convex portion is further formed on the outer peripheral surface (deformation preventing member) of the steering shaft at a position diagonally opposite the concave portion across the steering shaft, and a through hole corresponding to the convex portion is formed. A technique of forming on the inner peripheral surface of a steering column is known (see, for example, Patent Document 1). In this document, when the steering wheel is forcibly rotated, the steering shaft bends in the direction of retreating from the lock bar. At the time of this bending, the convex portion of the steering shaft is engaged with the through hole of the steering column, It is stated that this engagement still prevents rotation of the steering shaft.
JP 10-86792 A

  However, in reality, when an excessive rotational torque is applied to the steering wheel in the steering lock state, the steering shaft bends / displaces not only in the direction of retracting from the lock bar but also in the direction perpendicular to the retracting direction. To do. Therefore, in the above-described prior art, there is a problem that the convex portion of the steering shaft may not actually be engaged with the through hole of the steering column.

  Accordingly, an object of the present invention is to provide a steering lock mechanism that can effectively regulate the rotation of the steering shaft.

In order to solve the above problems, according to one aspect of the present invention, a steering shaft that constitutes a rotating shaft of a steering wheel;
A lock member that is capable of reciprocating in a radial direction with respect to the steering shaft and having an end that can be fitted in a recess provided in the steering shaft;
A pipe member provided around the steering shaft and having an engaged portion on the inner peripheral surface, which is engageable with an engaging portion set on the outer peripheral surface of the steering shaft,
The engaged portion of the tube member is located at a position opposite to the lock member across the steering shaft and at a circumferential position offset in the rotational direction of the steering wheel with respect to the reciprocating shaft of the lock member. A steering lock mechanism is provided, characterized in that it is set.

  In this aspect, the recess provided in the steering shaft may be formed directly on the steering shaft, or may be formed on a member provided around the steering shaft. In addition, the engagement between the engaged portion of the tube member and the engagement portion of the steering shaft is realized by uneven portions (for example, grooves and splines that fit together) formed on the tube member and the steering shaft, respectively. Alternatively, it may be realized by using any other friction material / structure. The reciprocating shaft of the lock member is the linear shaft when the reciprocating motion of the lock member is linear, and the reciprocating motion of the lock member is not linear with the steering shaft when the reciprocating motion of the lock member is not linear. This is based on a linear movement direction (for example, a tangential direction in the case of a circular locus) when fitting. Further, the position of the engaged portion on the inner peripheral surface of the pipe member is a position opposite to the lock member across the steering shaft, and is offset from the reciprocating shaft of the lock member in the rotation direction of the steering wheel. Other circumferential positions may be included as long as they are included.

  According to this aspect, the engaged portion of the pipe member is set at an appropriate position, so that the steering shaft is in the steering lock state (that is, the end portion of the lock member is fitted in the recess of the steering shaft). When the rotational torque is applied, the deforming and moving steering shaft can be engaged with the engaged portion of the pipe member.

  Further, in this aspect, effectively, the engaged portion of the tube member is formed on a protruding surface formed to protrude radially inward on the inner peripheral surface of the tube member. Accordingly, it is possible to effectively regulate the deflection as well as the rotation of the steering shaft when the rotational torque is applied.

  According to the present invention, even when an excessive rotational torque is applied to the steering shaft in the steering lock state, the rotation of the steering shaft can be effectively regulated.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing an embodiment of a steering lock mechanism according to the present invention, and is a cross-sectional view taken along a plane perpendicular to a steering shaft axis. The steering lock mechanism 10 is set to the steering column. The steering shaft (main shaft) 2 constitutes a rotating shaft of the steering wheel and is accommodated in a steering column tube 3 which is a hollow tubular member (for example, a steel pipe). An end portion of the housing 11 of the steering lock mechanism 10 is provided on the outer peripheral side of the steering column tube 3. A bracket 13 is fastened to the end of the housing 11 with bolts 6. The bracket 13 has an inner peripheral surface that faces the inner peripheral surface of the end portion of the housing 11, and the outer peripheral surface of the steering column tube 3 is in contact with both inner peripheral surfaces over the entire periphery.

  The steering lock mechanism 10 includes a lock bar 12 that can reciprocate in the radial direction toward the axial center of the steering shaft 2. The lock bar 12 is provided in the housing 11, and is configured to be able to advance and retreat (reciprocate) with respect to the center of the steering shaft 2 through an opening 3 a formed in the steering column tube 3. On the outer peripheral surface of the steering shaft 2, a recess 14 (hereinafter referred to as “lock hole 14”) into which an end of the lock bar 12 can be fitted is formed. At least one lock hole 14 may be formed on the outer periphery of the steering shaft 2, or a plurality of lock holes 14 may be formed at predetermined intervals along the outer periphery of the steering shaft 2 (two in the diagonal position in this example).

  The reciprocating motion of the lock bar 12 may be realized using, for example, an electric motor (including a speed reducer). Further, the reciprocating motion of the lock bar 12 may be realized via an appropriate cam mechanism mechanically linked to the turning operation of the ignition key.

  The lock bar 12 protrudes toward the axial center of the steering shaft 2 when the ignition key of the vehicle changes from being inserted into a key hole of a key cylinder (not shown) to being removed from the key hole. It becomes possible. On the other hand, when the ignition key is inserted into the key hole and then operated from the IG off state to the ACC state, the steering shaft 2 cannot project to the axial center. Alternatively, the lock bar 12 may be allowed to protrude or not protrude according to a switch operation by the user in the IG off state.

  When the lock hole 14 of the steering shaft 2 comes to the rotational position facing the lock bar 12, the end of the lock bar 12 is fitted into the lock hole 14 of the steering shaft 2. Thereby, the rotation of the steering shaft 2 is restricted, and the steering lock state is realized. On the other hand, when the end portion of the lock bar 12 is detached from the lock hole 14 of the steering shaft 2, the rotation restriction of the steering shaft 2 is released, and the steering lock release state (normal state) is realized. In this released state, the lock bar 12 is securely held in its retracted position (unlock position) so that the steering lock state is not realized by mistake during engine operation.

  Next, an embodiment of a characteristic configuration of the steering lock mechanism 10 according to the present invention will be described. On the outer peripheral surface of the steering shaft 2 of the present embodiment, there are formed uneven portions 16 (hereinafter referred to as “engaged uneven portions 16”) such as grooves and serrations (a plurality of grooves extending in the axial direction). The engaging uneven portion 16 is formed in a portion excluding the lock hole 14 on the outer periphery of the steering shaft 2, and preferably formed continuously over substantially the entire periphery excluding the lock hole 14 on the outer periphery of the steering shaft 2. .

  On the other hand, an uneven portion 18 such as a groove or a serration (hereinafter referred to as “engaged uneven portion 18”) is formed on the inner peripheral surface of the steering column tube 3 corresponding to the engaging uneven portion 16. The engaged uneven portion 18 is formed on a surface that is separated from the outer peripheral surface of the steering shaft 2 at the nominal position by a predetermined distance Δ in the radial direction. In the embodiment shown in FIG. 1, the engaged uneven portion 18 is formed on a protruding surface that protrudes radially inward from the inner peripheral surface (basic surface) of the steering column tube 3.

  Further, the engaged uneven portion 18 is on the side opposite to the advancing / retreating side of the lock bar 12 (the opening 3a for the lock bar 12) of the steering column tube 3, and the reciprocating axis X of the lock bar 12 is It is formed at a position offset in the circumferential direction as a reference. At this time, the engaged irregularities 18 may be set at two positions symmetrically on both sides with respect to the reciprocating axis X of the lock bar 12. For example, in the embodiment shown in FIG. 1, the engaged irregularities 18 are formed at two locations that are offset on both sides in the circumferential direction with respect to the lock holes 14 that are not fitted to the lock bars 12 in the steering lock state. Yes. Specifically, the engagement uneven portion 18 has a lock bar 12 when assuming a two-dimensional polar coordinate composed of a reciprocation axis X and an axis orthogonal thereto with the origin O as the axial center of the steering shaft 2 at the nominal position. The point α on the reciprocation axis X on the forward and backward side is defined as zero degrees, and the positions B and C offset by ± θ from the position A of 180 degrees counterclockwise are formed. The set range of the engaged uneven portion 18 may include a range of about −45 degrees to about +45 degrees with the positions B and C as the center. The formation range / position in the axial direction of the engaged uneven portion 18 at least partially corresponds to the formation range / position in the axial direction of the engagement uneven portion 16.

  Next, with reference to FIG. 2, an operation (anti-theft property) of the steering lock mechanism 10 of the present embodiment will be described. Here, as shown in FIG. 2A, it is assumed that a large rotational torque as indicated by an arrow D is applied to the steering shaft 2 in the steering lock state. In this case, since the steering shaft 2 receives a rotational reaction force by fitting with the lock bar 12, the steering shaft 2 bends and moves in the direction of the arrow E as shown in FIG. By this movement, the engaging uneven portion 16 of the steering shaft 2 is fitted to the engaged uneven portion 18 of the steering column tube 3 (see the Z portion in the figure).

  Thus, according to the present embodiment, the rotation of the steering shaft 2 is locked not only by the lock bar 12 but also by the engaged uneven portion 18, so that the steering shaft 2 is deformed by receiving an excessive rotational torque. -Even if displaced, the rotation restriction of the steering shaft 2 is still realized. Further, since excessive rotational torque applied to the steering shaft 2 can be received not only by the lock bar 12 but also by the engaged uneven portion 18, the lock bar 12 can be reduced in size and simplified. Further, since the stress generated in the steering shaft 2 is also dispersed, it may not be necessary to impart strength to the periphery of the lock hole 14 of the steering shaft 2 or the end of the lock bar 12 by quenching or the like.

  That is, according to the present embodiment, the behavior of the steering shaft 2 when receiving excessive rotational torque (that is, the behavior of bending not only in the reciprocating axis X direction but also in the axial direction perpendicular thereto) is accurately grasped. And by setting the to-be-engaged uneven | corrugated | grooved part 18 in the position corresponding to the behavior, the miniaturization and simplification of each structural member can be achieved with improvement in anti-theft property. In addition, it should be understood that the above-mentioned argument holds similarly when the same rotational torque is applied in the direction opposite to the arrow D. However, in this case, the engaging uneven portion 16 of the steering shaft 2 is fitted to the other engaged uneven portion 18 of the steering column tube 3.

  Further, according to the present embodiment, when an excessive torque is applied, the engaging uneven portion 16 of the steering shaft 2 contacts and engages the engaged uneven portion 18 of the steering column tube 3 as described above. Therefore, the maximum displacement amount (maximum deflection amount) in the radial direction of the steering shaft 2 can be kept within a predetermined range (that is, ≦ Δ). Accordingly, the maximum displacement in the radial direction of the steering shaft 2 is regulated by appropriately setting the gap Δ between the engaged uneven portion 18 of the steering column tube 3 and the engaging uneven portion 16 of the steering shaft 2. be able to. As a result, the maximum bending stress that can be generated in the steering shaft 2 can be regulated, and the lock bar 12 can be reliably prevented from coming out of the lock hole 14 of the steering shaft 2. It should be noted that the engaged uneven portion 18 of the steering column tube 3 and the engaging uneven portion 16 of the steering shaft 2 are given sufficient strength so that the above-described rotation / deflection regulating function can be surely exhibited.

  Note that the behavior (particularly the bending direction) of the steering shaft 2 when subjected to excessive rotational torque can vary depending on the structure and strength (rigidity) of the steering shaft 2 and the lock bar 12. Therefore, the set position of the engaged uneven portion 18 is determined in consideration of the structure and strength (rigidity) of the steering shaft 2 and the lock bar 12. In the embodiment shown in FIG. 1, the center positions B and C of the engaged uneven portion 18 are set at an offset angle θ of about 45 degrees, and the setting ranges are about 30 degrees (−15 degrees to about −15 degrees). +15 degrees range).

  Next, an alternative embodiment of the steering lock mechanism 10 according to the present invention will be described with reference to FIGS. In the embodiment shown in FIG. 3, a lock holder 4 is press-fitted around the steering shaft 2. On the outer peripheral surface of the lock holder 4, an engagement uneven portion 16 similar to that in the above-described embodiment is provided. The configuration of the engaging uneven portion 16 may be the same as in the above-described embodiment. As described above, the engagement uneven portion 16 is not formed directly on the outer peripheral surface of the steering shaft 2 (for example, formed by cutting or the like), but is formed in a separate member, and the separate member is around the steering shaft 2. May be provided.

  Similarly, even if the engaged uneven portion 18 of the steering column tube 3 is formed directly on the steering column tube 3, it is formed on another member fixed to the steering column tube 3. It may be.

  In another alternative embodiment shown in FIG. 4, a second concave portion 17 is formed on the outer peripheral surface of the steering shaft 2 in place of the engaging concave and convex portion 16 such as serration. In this case, the opening width of the second recess 17 is smaller than that of the lock hole 14 into which the end of the lock bar 12 can be fitted. That is, the second concave portion 17 is set to a size such that the end of the lock bar 12 cannot be fitted. The second concave portion 17 is set at a position that is circumferentially separated from both sides of the lock hole 14 (that is, when there are two lock holes 14 as in this example).

  On the other hand, a convex portion 19 is also formed on the inner peripheral surface of the steering column tube 3 corresponding to the second concave portion 17. The upper surface of the convex portion 19 is formed at a position spaced apart from the bottom surface of the second concave portion 17 facing it by a predetermined distance Δ in the radial direction. As a result, as in the above-described embodiment, the maximum displacement in the radial direction of the steering shaft 2 when an excessive rotational torque is applied can be kept within a predetermined range (that is, ≦ Δ).

  Further, like the engaged concave-convex portion 18, the convex portion 19 is on the opposite side to the advance / retreat side of the lock bar 12 (the opening 3 a for the lock bar 12) of the steering column tube 3, and Are formed at positions offset in the circumferential direction with reference to the reciprocating axis X (for example, positions B and C offset by ± θ from position A in FIG. 2). Also in the case of the present embodiment, as in the above-described embodiment, when a large rotational torque is applied to the steering shaft 2 in the steering lock state, the steering shaft 2 is deformed and moved as described above, and the second of the steering shaft 2 is moved. The concave portion 17 is engaged with the convex portion 19 of the steering column tube 3. As a result, as in the above-described embodiment, even when an excessive rotational torque is applied, the rotation of the steering shaft 2 can be reliably prevented, and the burden of the rotational torque is reduced to the steering column tube 3 and the lock bar. Thus, the lock bar 12 and the like can be reduced in size and simplified.

  In this embodiment, the second recess 17 may have the same configuration as that of the lock hole 14, and the second recess 17 and the lock hole 14 may be set at substantially equal intervals on the outer peripheral surface of the steering shaft 2. (Typically, a total of 8 recesses). In this case, the end portion of the lock bar 12 and the convex portion 19 of the steering column tube 3 can be fitted into both the second concave portion 17 and the lock hole 14. That is, both the second concave portion 17 and the lock hole 14 cooperate with the lock bar 12 to restrict the rotation of the steering shaft 2 and cooperate with the convex portion 19 of the steering column tube 3 to be bent. It can also serve to prevent the steering shaft 2 from rotating.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and variations can be made to the above-described embodiments without departing from the scope of the present invention. Substitutions can be added.

  For example, in the above-described embodiment, the engaging uneven portion 16 of the steering shaft 2 is not necessarily formed continuously over the entire circumference except for the lock hole 14 on the outer circumference of the steering shaft 2. The steering shaft 2 may be discretely formed at an appropriate location according to the behavior of the steering shaft 2.

  Further, in the above-described embodiment, instead of the combination of the engaging uneven portion 16 and the engaged uneven portion 18 such as serration, a material having a high coefficient of friction on the outer peripheral surface of the steering shaft 2 and the inner peripheral surface of the steering column tube 3 is used. A member (for example, a friction plate) may be set or mounted. Even in this case, rotation of the steering shaft 2 is prevented by the frictional force between the outer peripheral surface of the steering shaft 2 and the inner peripheral surface of the steering column tube 3, and is applied to the steering shaft 2 by the friction surface. Can share the rotational force.

  Moreover, in the Example mentioned above, although the lock hole 14 with which the lock bar 12 is fitted was set in two places, you may set three or more places. In any case, the plurality of lock holes 14 are not necessarily formed at diagonal positions. For example, a configuration in which two or more lock holes 14 are set and no other lock hole 14 exists at a diagonal position in one lock hole 14 may be employed. In this case, the engagement irregularities 16 may be formed on both sides in the circumferential direction from each lock hole 14 (or at a position offset by ± θ from each lock hole 14 as described above).

  Moreover, the lock hole 14 may be one place. In this case, and when two or more lock holes 14 are set and there is no other lock hole 14 at a diagonal position in one lock hole 14, the cover of the steering column tube 3 is covered. The engaging uneven portion 18 is not only located at a position offset in the circumferential direction with respect to the reciprocating axis X of the lock bar 12 as described above, but also on an extension line of the reciprocating axis X of the lock bar 12 (ie, position A in FIG. May be formed in the vicinity).

  In the above-described embodiment, the steering lock state and the unlock state are realized by linear movement (that is, reciprocation) of the lock bar 12, but the steering lock state and the unlock state are realized by the rotation of the lock bar 12. A state may be realized.

  Moreover, in each figure which concerns on the Example mentioned above, although the solid steering shaft 2 is shown in figure, it is applicable similarly to the hollow steering shaft 2. FIG. In this case, the end of the lock bar 12 is inserted into the lock hole 14 (through hole) of the steering shaft 2 to realize the steering lock state.

  In the above-described embodiment, the reciprocation of the lock bar 12 may be realized by using the electromagnetic force of the solenoid. In this case, a spring member that biases the lock bar 12 toward the steering shaft 2 is provided. The lock bar 12 is pulled away from the steering shaft 2 by the suction force of the solenoid against the biasing force of the spring member.

It is the schematic which shows one Example of the steering lock mechanism by this invention. It is explanatory drawing of an effect | action of the steering lock mechanism 10 of a present Example. It is sectional drawing similar to FIG. 1 which shows an alternative Example. It is sectional drawing similar to FIG. 1 which shows an alternative Example.

Explanation of symbols

2 Steering shaft 3 Steering column tube 10 Steering lock mechanism 11 Housing 12 Lock bar 14 Lock hole 16 Engagement uneven part 18 Engaged uneven part

Claims (2)

A steering shaft constituting the rotating shaft of the steering wheel;
A lock member that is capable of reciprocating in a radial direction with respect to the steering shaft and having an end that can be fitted in a recess provided in the steering shaft;
A pipe member provided around the steering shaft and having an engaged portion on the inner peripheral surface, which is engageable with an engaging portion set on the outer peripheral surface of the steering shaft,
The engaged portion of the tube member is at a position opposite to the lock member across the steering shaft and at a circumferential position offset in the rotational direction of the steering wheel with respect to the reciprocating shaft of the lock member. A steering lock mechanism characterized by being set.   2. The steering lock mechanism according to claim 1, wherein the engaged portion of the pipe member is formed on a protruding surface formed to protrude radially inward on an inner peripheral surface of the pipe member.

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