JP2019171920A - Energy absorbing steering column - Google Patents

Abstract

To provide an energy absorbing steering column capable of properly setting a load while moving by a simple and inexpensive structure and facilitating a loading on a vehicle.SOLUTION: An energy absorbing member 30 is placed between a first cylindrical member (inner tube 10) and a second cylindrical member (outer tube 20). This energy absorbing member includes: a small-diameter cylindrical portion 31 which is held in the second cylindrical member and which has an open end abutting a tip of the second cylindrical member; a large-diameter cylindrical portion 32 which is held in the second cylindrical member and which is locked by the second cylindrical member at a predetermined position; and an annular coupling member 33 that integrally couples the large-diameter portion and the small-diameter portion. The second cylindrical member has, for example, multiple pawls (23) that protrude inwardly, and the open end of the large-diameter cylindrical portion is locked by those pawls, and thus a movement of the large-diameter cylindrical portion in an axial direction is prevented.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an energy absorbing steering column, and more particularly to an energy absorbing steering column that absorbs energy applied to a steering shaft of a vehicle.

  2. Description of the Related Art An energy absorbing steering column mounted on a vehicle is widely known as a means for imparting energy absorbing characteristics to a steering column, and various structures are employed. For example, in Patent Document 1 below, “the movement starting load and the moving load between the first cylindrical member and the second cylindrical member are set easily and appropriately while ensuring the necessary rigidity with an inexpensive configuration. The problem is to provide an energy absorbing steering column that can be used as a problem ”(described in paragraph [0006] of Patent Document 1). A diameter-reduced portion whose diameter is continuously reduced, and a plane portion in which a part of the outer peripheral surface of the diameter-reduced portion is cut off ”, and“ is fixed to the plane portion and extends toward the rear opening end of the vehicle. And an energy absorbing block having a friction engagement portion that is attached to the plate member and guides the friction member while applying a friction force during relative movement ”(paragraph [0007] of Patent Document 1). Has been proposed).

  Further, as an energy absorbing means that can be applied to a vehicle, the following Patent Document 2 states that “a large-diameter portion is formed on one end side of the tubular body relative to a metallic tubular body, and the tubular body is formed from the large-diameter portion. The portion where the tube diameter gradually decreases toward the other end of the tube is bent to the inside of the large-diameter portion to form a superposed portion where the bent portion expands outward, and is continuously connected to the superposed portion. In the large diameter portion, the tube diameter gradually decreases toward one end side of the tube body at a rate that is a gentler gradient than the gradually decreasing rate of the tube diameter of the overlapping portion, and the position at which the tube body is approximately the same diameter as the tube body. An energy absorbing tube has been proposed (described in paragraph [0006] of Patent Document 2) where a connecting portion that is bent is formed on the other end of the tube.

Japanese Patent No. 5228984 Japanese Patent No. 3993979

  As described in paragraph [0009] of Patent Document 1 above, “the plate-like member is securely held by the energy absorption block, guided while applying a frictional force, and energy is absorbed by plastic deformation of the plate-like member. However, it is necessary to form a “reduced diameter portion” and a “planar portion” on the first tubular member (inner tube). In addition, since the energy absorption block is mounted outside the conventional steering column, a predetermined space is required when mounted on the vehicle. On the other hand, the energy absorption tube described in Patent Document 2 cannot be mounted on a conventional steering column as it is, and has a unique structure, which is difficult when mounted on a vehicle.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an energy absorbing steering column that can appropriately set a moving load with a simple and inexpensive configuration and can be easily mounted on a vehicle.

  In order to achieve the above object, the present invention provides a first cylindrical member in which a steering shaft is accommodated and supported rotatably around an axis, and the first cylindrical member is accommodated in the first cylindrical member. A second cylindrical member that allows the relative movement of the first cylindrical member when the axial load of a predetermined value or more is applied to the steering shaft; An energy absorbing member interposed between a first cylindrical member and the second cylindrical member, wherein the energy absorbing member is accommodated in the second cylindrical member and the first cylinder A small-diameter cylindrical portion having an open end that comes into contact with the tip of the cylindrical member, a large-diameter cylindrical portion that is accommodated in the second cylindrical member and is locked to the second cylindrical member at a predetermined position, A diameter tube portion and an annular connecting portion to which the small diameter tube portion is integrally connected are provided. Than is.

  The small-diameter cylindrical portion may have a cylindrical shape, and a small-diameter opening end that comes into contact with the distal end portion of the first cylindrical member, and a large-diameter opening end that gradually increases in outer diameter from the small-diameter opening end and reaches the annular coupling portion. It may be a truncated cone shape.

  In the above energy absorption steering column, the second cylindrical member is formed by arranging a plurality of inwardly protruding cuts in an annular shape, and the plurality of cuts are provided at open ends of the large-diameter cylindrical portion. It is good to comprise so that axial movement of the said large diameter cylinder part may be prevented by latching.

  Further, when the axial load exceeding the second predetermined value exceeding the predetermined value is applied to the steering shaft, the projecting amount to the inside of the plurality of cut and raised portions is the open end of the large diameter cylindrical portion. It is good to set it as the structure which is set to the protrusion amount which the said energy absorption member detaches | leaves from a plurality of said cutting up by plastic deformation.

  In the energy absorbing member, for example, an outer annular corner portion where the annular connecting portion and the large diameter cylindrical portion are integrally connected, and the annular connecting portion and the small diameter cylindrical portion are integrally connected. An inner annular corner portion, and an amount of plastic deformation of the inner annular corner portion due to an axial load applied from the steering shaft to the opening end of the small-diameter tubular portion via the first tubular member. The amount of plastic deformation of the outer annular corner is preferably set larger. The outer annular corner and the inner annular corner may be formed into curved surfaces.

  Since this invention is comprised as mentioned above, there exist the following effects. That is, in the energy absorbing steering column of the present invention, the energy absorbing member is interposed between the first cylindrical member and the second cylindrical member, and the energy absorbing member is the second cylindrical member. A small-diameter cylindrical portion having an open end that is accommodated in the member and abuts against the tip of the first cylindrical member, and a large-diameter that is accommodated in the second cylindrical member and is locked to the second cylindrical member at a predetermined position. Since the cylindrical portion and the annular connecting portion to which the large diameter cylindrical portion and the small diameter cylindrical portion are integrally connected are provided, the load during movement can be appropriately set with a simple and inexpensive configuration, and the steering column Can be easily assembled to an existing steering column without increasing the size. In particular, since the energy absorbing member provided in the present invention has a small number of parts and is easy to assemble, the cost can be reduced.

  The small diameter cylindrical portion constituting the energy absorbing member may have a cylindrical shape, or may have a small diameter opening end that abuts on the distal end portion of the first cylindrical member, and the outer diameter gradually increases from the small diameter opening end to the annular coupling portion. The shape may be a truncated cone having a large-diameter opening end, and can be appropriately selected according to the mounting target. However, the frustoconical energy absorbing member has a structure in which stress is concentrated on the annular connecting portion, and therefore a shape corresponding to the required load / stroke characteristics can be selected.

  In the above energy absorption steering column, the second cylindrical member is formed by arranging a plurality of protrusions protruding inward in a ring shape, and the opening end of the large-diameter cylindrical portion is locked to the plurality of protrusions. If the large diameter cylindrical portion is configured to be prevented from moving in the axial direction, the energy absorbing member can be easily locked at a predetermined position with respect to the second cylindrical member.

  Further, when an axial load of a second predetermined value or more exceeding a predetermined value is applied to the steering shaft, the opening end of the large-diameter cylindrical portion is plastically deformed. If it is set as the protrusion amount which the energy absorption member detaches | leaves from several cutting | raising and raising, it can be set as the state after applying a load during movement easily and reliably.

  The energy absorbing member includes an outer annular corner portion in which the annular coupling portion and the large diameter cylindrical portion are integrally coupled, and an inner annular corner portion in which the annular coupling portion and the small diameter cylindrical portion are integrally coupled. The amount of plastic deformation of the inner annular corner due to the axial load applied from the steering shaft to the opening end of the small-diameter tubular portion via the first tubular member is greater than the amount of plastic deformation of the outer annular corner. If it is set to a large value, the required load / stroke characteristics can be set easily and appropriately. For example, if a plurality of cuts and protrusions set to the protruding amount are arranged in parallel, energy absorption due to an axial load applied from the steering shaft to the opening end of the small-diameter cylindrical portion via the first cylindrical member. As a result of plastic deformation of the member, the outer annular corner is reduced in diameter, and the outer diameter of the outer annular corner is smaller than the inner diameter of the cylindrical space formed by the plurality of cuts, and energy is absorbed from the plurality of cuts. The member can be easily and reliably detached, and a desired state can be obtained after applying a load during movement.

It is sectional drawing which shows a part of energy absorption steering column which concerns on one Embodiment of this invention. It is a perspective view which shows the energy absorption member provided to one Embodiment of this invention. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is a graph which shows the load and stroke characteristic in one embodiment of the present invention. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is sectional drawing which shows plastic deformation when an axial load is applied with respect to the energy absorption member with which one Embodiment of this invention is provided. It is a perspective view which shows the other aspect of the energy absorption member provided to one Embodiment of this invention. It is sectional drawing which shows a plastic deformation when an axial load is applied with respect to the other aspect of the energy absorption member with which one Embodiment of this invention is provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an energy absorbing steering column according to an embodiment of the present invention. A steering shaft 1 is connected to a rear end portion of a steering wheel (not shown), and has a cylindrical upper shape also called an outer shaft. The shaft 1a is composed of a lower shaft 1b which is spline-coupled to the inner cylindrical surface of the upper shaft 1a and is also called an inner shaft. That is, the upper shaft 1a and the lower shaft 1b are connected so as to be relatively movable in the axial direction but not to be relatively rotatable, and the front end portion of the lower shaft 1b is connected to a steering mechanism (not shown). The steering shaft 1 is supported on a vehicle body (not shown) by a bracket (not shown) via a column housing 2 so as to form a predetermined angle with respect to a floor surface (not shown) of the vehicle.

  In the column housing 2, a metal inner tube 10 is provided as a first cylindrical member that accommodates the steering shaft 1 and is supported rotatably about an axis. That is, the upper shaft 1 a accommodated in the inner tube 10 is rotatably supported by the rear end portion of the inner tube 10 via the bearing 3. However, the relative movement in the axial direction between the upper shaft 1a and the inner tube 10 is restricted, and the upper shaft 1a and the inner tube 10 are configured to be able to move in the axial direction as a unit. Further, a metal outer tube 20 is provided as a second cylindrical member that accommodates the first cylindrical member and is normally held at a predetermined position, via the bearings 3a and 3b. Are supported by the column housing 2. And when the load more than predetermined value is applied with respect to the steering shaft 1, it is comprised so that the axial direction relative movement of the inner tube 10 with respect to the outer tube 20 (as a result, the axial direction movement of the upper shaft 1a) is permitted.

  The outer tube 20 of the present embodiment has a first holding portion 21 formed on the inner surface at a predetermined distance in the axial direction from the vehicle rear opening end (hereinafter referred to as the rear opening end), and the rear opening end. A second holding portion 22 is formed on the inner surface in the vicinity. The first holding portion 21 is configured by an annular recess formed on the inner peripheral surface of the outer tube 20, and the second holding portion 22 extends integrally from the inner peripheral surface of the outer tube 20 in the axial direction. It is comprised by the formed annular convex part.

  Further, the inner tube 10 of the present embodiment has an outer diameter step portion 11 at a position spaced a predetermined distance from the rear opening end, and is formed with a relatively small diameter from the outer diameter step portion 11 toward the front of the vehicle. A small-diameter portion 12 and a large-diameter portion 13 that is adjacent to the small-diameter portion 12 via the outer-diameter step portion 11 and that has a relatively large diameter toward the rear of the vehicle. In addition, the inner tube 10 has a first enlarged-diameter portion 14 whose diameter is increased in the vicinity of the opening end (hereinafter referred to as the front opening end) in front of the vehicle, and a portion spaced apart from the front opening end by a predetermined distance in the axial direction is expanded. A second enlarged diameter portion 15 having a diameter is provided.

  As shown in FIG. 1, an elastic bush 3c is interposed between the first enlarged diameter portion 14 and the first holding portion 21, and the elastic bush 3c, the inner tube 10 and Since a frictional force is ensured between the outer tube 20 and the outer tube 20, the steering shaft 1 is held in a state where the relative movement in the axial direction between the inner tube 10 and the outer tube 20 is blocked. In contrast, the second enlarged diameter portion 15 is press-fitted and held in the second holding portion 22, and the second enlarged diameter portion 15 side of the inner tube 10 is press-fitted between the inner tube 10 and the outer tube 20. The axial load is set so that it reacts relatively sensitively to the margin and is relatively difficult to displace relative to the external force.

  Further, an energy absorbing member 30 is interposed between the inner tube 10 and the outer tube 20. As shown in FIGS. 1 and 2, the energy absorbing member 30 of the present embodiment includes a small-diameter cylindrical portion 31, a large-diameter cylindrical portion 32, an annular coupling portion 33 in which these are integrally coupled, The outer annular corner portion 34 is integrally connected to the large diameter cylindrical portion 32 with a curved surface, and the inner annular corner portion 35 is integrally connected to the annular connecting portion 34 and the small diameter cylindrical portion 31 with a curved surface. And is accommodated in the outer tube 20. That is, the outer annular corner portion 34 and the inner annular corner portion 35 are formed as curved surfaces as shown in FIGS. The small-diameter cylindrical portion 31 is disposed so that the opening end thereof is in contact with the distal end portion of the inner tube 10, and the large-diameter cylindrical portion 32 is locked to the outer tube 20 at a predetermined position. It will be described later.

  In the present embodiment, the amount of plastic deformation of the inner annular corner 35 due to the axial load applied to the opening end of the small diameter cylindrical portion 31 via the steering shaft 1 (inner tube 10) is the plasticity of the outer annular corner 34. By setting appropriately the diameters D1 and D2, the axial dimensions L1 and L2, and the thickness and material of the small diameter cylindrical portion 31 and the large diameter cylindrical portion 32 shown in FIG. The moving load by the absorbing member 30 can be adjusted as appropriate. For example, the moving load region (M) in the load / stroke characteristics shown in FIG. 4 can be set easily and appropriately, which will be described later with reference to FIGS.

  The outer tube 20 of the present embodiment is formed with a plurality of cuts and protrusions (typically indicated by 23) that protrude inward from the cylindrical body part. The opening ends of 32 are in contact with each other and are locked to the outer tube 20. Therefore, the energy absorbing member 30 can be easily locked at a predetermined position with respect to the outer tube 20. In the present embodiment, an axial load greater than or equal to the second predetermined value is applied to the steering shaft 1 (inner tube 10) so that the amount of protrusion to the inside of the plurality of cut-and-raised portions 23 exceeds the aforementioned predetermined value. In some cases, the opening end of the large-diameter cylindrical portion 32 is plastically deformed and cut and raised, and the amount of protrusion from which the energy absorbing member 30 is detached from the 23 is set. Thereby, it can be set as the state after applying the load during movement easily and reliably.

  For example, as a result of plastic deformation of the energy absorbing member 30 due to an axial load greater than or equal to a second predetermined value applied to the opening end of the small diameter cylindrical portion 31, the outer annular corner portion 34 is reduced in diameter and a plurality of cuts 23 The outer diameter of the outer annular corner portion 34 is smaller than the inner diameter of the cylindrical space formed by the above, and the energy absorbing member 31 is easily and surely detached from the cut and raised 23 to be in a state after applying a desired load during movement. be able to. In addition, although it is good also as fixing the energy absorption member 30 to the outer tube 20 by caulking or laser welding, in that case, the state after the above-mentioned moving load application cannot be set.

  The operation of the energy absorbing steering column having the above-described configuration will be described. Normally, the second expanded portion 15 of the inner tube 10 is press-fitted into the second holding portion 22 of the outer tube 20 in the state shown in FIG. At the same time, the first expanded portion 14 of the inner tube 10 and the first holding portion 21 of the outer tube 20 are held in a pressed state by the elastic force of the elastic bush 3c. The tube 10 and the outer tube 20 are held in a state in which relative movement in the axial direction is prevented.

  Next, when a load is applied to the steering shaft 1 and the steering shaft 1 moves forward together with the inner tube 10, the first enlarged diameter portion 14 of the inner tube 10 is removed from the first holding portion 21 and the elastic bush 3 c of the outer tube 20. At the same time, the second enlarged diameter portion 15 of the inner tube 10 is detached from the second holding portion 22 of the outer tube 20. The load at this time is the movement start load of the steering shaft 1, and therefore the movement is started by the first and second enlarged diameter portions 14 and 15, the first and second holding portions 21 and 22, and the elastic bush 3c. A load adding portion is configured.

  After a larger load is applied to the steering shaft 1, the inner tube 10 moves forward in the outer tube 20, and the opening end of the inner tube 10 comes into contact with the opening end of the small diameter cylindrical portion 31 of the energy absorbing member 30. As shown in FIGS. 3A to 3B, the inner tube 10 (and the steering shaft 1) shown in FIG. 1 moves forward while the energy absorbing member 30 is plastically deformed. As a result, a frictional load is applied to the inner tube 10, and the inner tube 10 moves while absorbing energy by plastic deformation of the energy absorbing member 30, and changes as shown in a moving load region (M) in FIG. The moving load application start stroke is set by a distance (indicated by Ls in FIG. 1) between the opening end of the inner tube 10 and the opening end of the small-diameter cylindrical portion 31.

  Thus, a desired energy absorption characteristic can be ensured by the energy absorption steering column configured as described above. First, when a load is applied to the steering shaft 1 and exceeds the above-described movement start load, the inner tube 10 starts to move relative to the outer tube 20. That is, the frictional force between the second enlarged diameter portion 15 of the inner tube 10 and the second holding portion 22 of the outer tube 20, the elastic bush 3 c, the first enlarged diameter portion 14, and the first holding portion 21. The inner tube 10 and the outer tube 20 move relative to each other in the axial direction against the frictional force between them, and a free state occurs when a predetermined stroke is exceeded. Furthermore, after the stroke of the steering shaft 1 moves the distance (Ls) between the outer diameter step portion 11 of the inner tube 10 and the rear end surface of the outer tube 20, the load due to plastic deformation of the energy absorbing member 30 is steered. The inner tube 10 moves relative to the outer tube 20 together with the steering shaft 1 in a state of being applied to the shaft 1. As a result, energy is appropriately absorbed even when the steering shaft 1 is making a stroke.

  5 to 14, an axial load (a load applied to the opening end of the small-diameter cylindrical portion 31 from the right direction in each figure) is applied to the opening end of the small-diameter cylindrical portion 31 of the energy absorbing member 30 shown in FIG. The plastic deformation of the energy absorbing member 30 at this time is verified by simulation, and shows the state of plastic deformation that changes in the order of FIGS. Each drawing is provided with a thin line to represent a curved surface portion. In FIG. 6, the open end of the large-diameter cylindrical portion 32 is bent inward, cut and raised at the outer peripheral edge, and locked to the 23. 10 to 12, the opening end of the small diameter cylindrical portion 31 bends outward and begins to deform into a bead shape, and further, in FIG. 13, the opening end of the large diameter cylindrical portion 32 bends inward and cuts. FIG. 14 shows a state in which the opening end of the small-diameter cylindrical portion 31 is deformed into a bead shape, and the large-diameter cylindrical portion 32 is cut up and separated from the 23. That is, FIG. 14 shows a state after applying a moving load (a state on the right side of the region M shown in FIG. 4).

  In the present embodiment, the plastic deformation amount of the inner annular corner portion 35 due to the axial load applied to the opening end of the small diameter cylindrical portion 31 is set larger than the plastic deformation amount of the outer annular corner portion 34. As shown in FIGS. 5 to 12, the axial dimension of the small-diameter cylindrical part 31 is sequentially reduced in the state where the outer diameter of the outer annular corner part 34 is maintained, and then the axial dimension of the large-diameter cylindrical part 32 is sequentially reduced. As shown in FIG. 14, the outer diameter of the outer annular corner portion 34 is maintained substantially until the large-diameter cylindrical portion 32 is finally cut and raised as shown in FIG.

  As described above, in the energy absorbing steering column described above, the movement start load adding portion is formed by the first and second enlarged diameter portions 14 and 15, the first and second holding portions 21 and 22, and the elastic bush 3c. In addition, since the energy absorbing member 30 constitutes the moving load adding portion, the movement start load and the moving load in the axial relative movement between the inner tube 10 and the outer tube 20 are individually appropriate values. Can be set to Further, when an axial load equal to or greater than the second predetermined value is applied to the steering shaft 1 (inner tube 10), the open end of the large-diameter cylindrical portion 32 is plastically deformed and the plurality of cuts 23 are raised. Since the energy absorbing member 30 is detached, it can be in a state after applying a desired moving load.

  15 and 16 show another aspect of the energy absorbing member 30. The small-diameter cylindrical portion 31x has a truncated cone shape, and has a small-diameter opening end that comes into contact with the distal end portion of the inner tube 10, and an outside from the small-diameter opening end. It has a large-diameter opening end that gradually increases in diameter and reaches the annular connecting portion 33, and the other components are substantially the same as those in FIG. In the present embodiment, in order to suppress the plastic deformation amount of the outer annular corner portion 34 with respect to the plastic deformation amount of the inner annular corner portion 35 due to the axial load applied to the opening end of the small diameter cylindrical portion 31x, the outer annular corner portion 34 is It is formed so as to be deformed into a bead shape (shown in FIGS. 16 (A) and 16 (B)), and the annular connecting portion 33 and the inner annular corner portion 35 are connected by a small-diameter cylindrical portion 31x having a truncated cone shape. Stress is concentrated on the portion, and plastic deformation is performed as shown in FIGS. Thus, the shape shown in FIG. 2 or 15 can be selected as the energy absorbing member 30 according to the required load / stroke characteristics.

DESCRIPTION OF SYMBOLS 1 Steering shaft 1b Lower shaft 1a Upper shaft 10 Inner tube (1st cylindrical member)
20 Outer tube (second cylindrical member)
30 Energy absorbing member 31, 31x Small diameter cylindrical portion 32 Large diameter cylindrical portion 33 Annular connecting portion 34 Outer annular corner 35 Inner annular corner

Claims (5)

A first tubular member that houses a steering shaft and is supported rotatably about the shaft;
The first cylindrical member is accommodated and is normally held at a predetermined position, and when an axial load of a predetermined value or more is applied to the steering shaft, the first cylindrical member is A second tubular member that allows relative movement of
An energy absorbing member interposed between the first tubular member and the second tubular member,
The energy absorbing member is
A small-diameter cylindrical portion having an open end that is accommodated in the second cylindrical member and abuts against a tip end portion of the first cylindrical member;
A large-diameter cylindrical portion housed in the second cylindrical member and locked to the second cylindrical member at a predetermined position;
An energy-absorbing steering column comprising the large-diameter cylindrical portion and an annular coupling portion to which the small-diameter cylindrical portion is integrally coupled. The small diameter cylindrical portion is
2. The truncated cone shape according to claim 1, wherein the first cylindrical member has a truncated conical shape having a small-diameter opening end that comes into contact with a distal end portion, and a large-diameter opening end that gradually increases in outer diameter from the small-diameter opening end to reach the annular coupling portion. Energy absorbing steering column. The second cylindrical member is formed by arranging a plurality of protrusions protruding inward in an annular shape,
The energy absorbing steering column according to claim 1 or 2, wherein an opening end of the large-diameter cylindrical portion is engaged with the plurality of cuts and raised so that axial movement of the large-diameter cylindrical portion is prevented. . The amount of protrusion to the inside of the plurality of cut-ups is as follows:
When an axial load equal to or greater than a second predetermined value exceeding the predetermined value is applied to the steering shaft, the opening end of the large-diameter cylindrical portion is plastically deformed so that the energy absorbing member The energy absorption steering column according to claim 3, wherein the protrusion is set to a protruding amount from which the energy is released. The energy absorbing member is
An outer annular corner to which the annular coupling portion and the large-diameter cylindrical portion are integrally coupled;
An inner annular corner portion where the annular coupling portion and the small-diameter cylindrical portion are integrally coupled;
The amount of plastic deformation of the inner annular corner due to the axial load applied from the steering shaft to the opening end of the small-diameter tubular portion via the first tubular member is greater than the amount of plastic deformation of the outer annular corner. The energy absorption steering column according to any one of claims 1 to 4, wherein the energy absorption steering column is set to be large.

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