JP5935495B2 - Steering column shock absorbing mechanism and steering column device having the same - Google Patents

Description

  The present invention relates to an impact absorbing mechanism for a steering column mounted on a vehicle such as an automobile, and a steering column device including the same.

  For example, a vehicle such as an automobile is equipped with a steering column device having a function of absorbing a part of the impact load when an impact load greater than a predetermined load is applied to the steering wheel.

  Conventionally, this type of steering column device includes a steering column that is supported by a vehicle body side bracket and moves forward of the vehicle with an impact load greater than a predetermined load, and a ripping plate that is interposed between the steering column and the vehicle body side bracket. (For example, Patent Document 1).

  Further, the steering column device is provided with an impact absorbing mechanism having an impact absorbing plate that undergoes plastic deformation by receiving an impact load greater than a predetermined load from a support pin for tilt adjustment.

  After an automobile equipped with such a steering column device collides with an obstacle (for example, another automobile) (primary collision), the driver may collide with the steering wheel (secondary collision). In this case, if a collision load of a predetermined load or more acts on the steering column via the steering wheel during the secondary collision, the steering column moves forward of the vehicle, plastically deforms the shock absorbing plate, and tears off the ripping plate. Remove from position.

JP 2004-299489 A

  By the way, in the above-described steering column device, not only the impact absorbing plate but also the ripping plate is required for absorbing the impact at the time of the secondary collision. As a result, there are problems that the number of parts is increased, the entire structure is complicated, and the cost is increased.

  Accordingly, an object of the present invention is to provide a shock absorbing mechanism for a steering column and a steering column device provided with the same, which can reduce the number of parts, thereby simplifying the whole structure and reducing the cost. There is.

In order to achieve the above object, the present invention provides an impact absorbing mechanism for a steering column (1) to ( 3 ) and a steering column device including the same.

(1) A steering column that rotates around a tilt adjusting support pin that moves forward of the vehicle by an impact load greater than a predetermined load, and a bracket that rotatably supports the steering column and is attached to a vehicle body side member And the first impact absorbing piece attached to the bracket and plastically deformed by receiving the impact load from the support pin, and the support pin detached from the first impact absorbing piece are brought into contact with each other to be plastically deformed. and a shock absorbing plate having a second shock absorbing piece, said shock-absorbing plate, the first curved surface conforming to the outer peripheral surface of the support pin in its initial position has said first shock absorbing piece, As the plastic deformation of the first shock absorbing piece ends, the second shock absorbing piece has a second curved surface that contacts the outer peripheral surface of the support pin, and the first shock absorbing piece has a tip. The first shock absorbing mechanism of the steering column having a through a curved notch open to the support pin side inwardly site adjacent to section.

(2) In the shock absorbing mechanism of the steering column according to the above (1), wherein the impact absorption plate, the first shock absorbing piece opening on the opposite side of the support pin side outside portion away from the distal end Has a notch.

( 3 ) A steering column device comprising the steering column impact absorbing mechanism according to (1) or (2) .

  According to the present invention, it is possible to reduce the number of parts, simplify the entire structure, and reduce the cost.

Sectional drawing shown in order to demonstrate the whole steering column apparatus provided with the impact absorption mechanism of the steering column which concerns on embodiment of this invention. Sectional drawing shown in order to demonstrate the principal part (M part of FIG. 1) of the steering column apparatus provided with the impact absorption mechanism of the steering column which concerns on embodiment of this invention. The side view shown in order to demonstrate the impact-absorbing board in the impact-absorbing mechanism of the steering column which concerns on embodiment of this invention. The graph which shows the result of having considered about the case where an impact load acts on the steering column apparatus provided with the impact absorption mechanism of the steering column which concerns on embodiment of this invention. The side view shown as a modification in order to demonstrate the impact-absorbing plate in the impact-absorbing mechanism of the steering column which concerns on embodiment of this invention.

[Embodiment]
Hereinafter, a steering column apparatus including an impact absorber for a steering column according to an embodiment of the present invention will be described in detail with reference to the drawings.

(Overall structure of the steering column)
FIG. 1 shows the entire steering column device. As shown in FIG. 1, the steering column device 1 includes a steering shaft 2 that is rotated by a rotation operation of the steering wheel 100, a steering column 3 that rotatably supports the steering shaft 2, and an electric motor on the axis of the steering column 3. a housing 4 for accommodating the assist mechanism (not shown), and is configured roughly from the impact absorbing mechanism 5 for absorbing a portion of the predetermined load or more impact load P ₁ by the steering mechanism side of the housing 4.

(Configuration of steering shaft 2)
The steering shaft 2 has an upper shaft 20 and a lower shaft 21, and is supported in the steering column 3 so as to be rotatable about its axis, and is connected to a steering mechanism (not shown) via a universal joint 6, an intermediate shaft 7, and the like. Are connected. The steering shaft 2 transmits the rotational force of the steering wheel 100 as a steering force to the steering mechanism to steer the steered wheels.

  The upper shaft 20 is disposed on the upper side (steering wheel 100 side) of the steering shaft 2 so as to be partially exposed to the outside of the steering column 3, and is entirely formed of a cylindrical member that opens in both axial directions.

  The lower shaft 21 is disposed on the lower side (steering mechanism side) of the steering shaft 2 and is coupled to the upper shaft 20 so as to be relatively movable along the axis thereof. The lower shaft 21 is connected to the upper shaft 20 by, for example, spline fitting.

(Configuration of steering column 3)
The steering column 3 has an outer tube 30 and an inner tube 31 that can move relative to each other, and is disposed in front of a vehicle driver's seat (not shown). And the steering column 3 supports the steering shaft 2 rotatably.

  The outer tube 30 is attached to the movable bracket 33 of the upper column brackets 32 and 33 (fixed bracket 32 and movable bracket 33), and is connected to the inner tube 31 by a connecting wire (not shown). ing. The outer tube 30 is moved (telescopically adjusted) together with the upper shaft 20 in the axial direction by operating the operation lever 35 of the lock / unlock mechanism 34 interposed between the fixed bracket 32 and the movable bracket 33. It is possible to rotate (tilt adjustment) around the rivet 101 for tilt adjustment as the rotation center of the steering shaft 2 (steering column 3). The fixed bracket 32 is attached to a vehicle body (not shown) via a vehicle body side member 36, and the movable bracket 33 is supported by the fixed bracket 32 via a lock / unlock mechanism 34.

  The lock / unlock mechanism 34 is disposed between the fixed bracket 32 and the movable bracket 33. The lock / unlock mechanism 34 switches between a locked state and an unlocked state of the expansion / contraction operation and the rotation operation of the steering column 3 (the steering shaft 2) by operating the operation lever 35.

The inner tube 31 is disposed on the outer tube 30 so as to be relatively movable along the axial direction thereof, and rotates around the rivet 101 via the housing side bracket 102 to the lower side column bracket 37 (tilt). Adjustable) is connected. Column bracket 37 of the lower side receives an impact load P ₁ has a guide groove (the long hole) 37a for guiding the rivet 101 to move forward vehicle, it is attached via the vehicle body-side member 38 to the vehicle body. The bracket 102 on the housing side has a rivet insertion hole 102a through which the rivet 101 is inserted, is interposed between the vehicle body side member 38 and the steering column 3, is attached to the housing 4, and is attached to the lower column bracket 37. It is rotatably connected via 101.

(Configuration of housing 4)
The housing 4 includes a sensor housing 40 and a speed reduction mechanism housing 41, and is arranged on the axis of the inner tube 31. The housing 4 accommodates an assist mechanism (not shown) that applies an operation assisting force for steering operation to the steering shaft 2. An electric motor (not shown) constituting an assist mechanism is attached to the housing 4 together with a torque sensor (not shown) and a speed reduction mechanism (not shown). The sensor housing 40 is disposed on the upper side, and the speed reduction mechanism housing 41 is disposed on the lower side. A housing tube 42 as a steering column side member that houses the universal joint 6 and the rivet 101 is provided on the lower side of the housing 41 for the speed reduction mechanism.

  Note that the assist mechanism is activated by an operation of the steering wheel 100 by an operator (driver). When the steering wheel 100 is operated, the electric motor is driven with a predetermined voltage based on the detected values of the torque sensor and the vehicle speed. Then, the driving force (rotational force) of the electric motor is transmitted to the steering shaft 2 via the speed reduction mechanism, and the steering assist for the driver's steering operation is performed.

(Configuration of shock absorbing mechanism 5)
FIG. 2 shows a main part of the steering column device. FIG. 3 shows an impact absorbing plate of the impact absorbing mechanism. As shown in FIG. 2, the shock absorbing mechanism 5 includes a steering column 3 (shown in FIG. 1) and a lower side column bracket 37, has a shock absorbing plate 50, and is arranged around the rivet 101. . The shock absorbing mechanism 5 to absorb a portion of the predetermined load or more impact load P ₁ as described above.

  As shown in FIG. 3, the shock absorbing plate 50 includes a base piece 500 and shock absorbing pieces 501 and 502 (first shock absorbing pieces 501 and second shock absorbing pieces 502). For example, it is attached by welding. As the shock absorbing plate 50, for example, a steel material such as hot rolled mild steel (SPHC) is used. The thickness t of the shock absorbing plate 50 is set to a dimension of t = 1.6 mm, for example.

  The base piece 500 is disposed on the steering wheel side (right side in FIG. 3) of the shock absorbing plate 50. The central portion of the end surface of the base piece 500 on the steering mechanism side (left side in FIG. 3) is interposed between the first shock absorbing piece 501 and the second shock absorbing piece 502 at the initial position on the outer peripheral surface of the rivet 101. It is formed with a suitable inner peripheral surface 500a. The base piece 500 functions as a mounted portion for the mounting portion of the lower column bracket 37.

The first shock absorbing piece 501 is an edge on the steering mechanism side of the base piece 500 and protrudes toward the steering mechanism side at a portion adjacent to the inner peripheral surface 500a of the base piece 500 on one side (upper side in FIG. 3). It is provided integrally. The first shock absorbing piece 501 has a substantially semi-disc-shaped tip, and is formed by a tongue that wraps a part of the outer peripheral surface of the rivet 101 from above. Then, the first impact absorbing piece 501 receives the impact load P ₁ from the rivet 101 and plastically deforms.

The inner side portion of the first shock absorbing piece 501 has curved surfaces 501a and 501b adapted to a part of the outer peripheral surface of the rivet 101 at its initial position, and a notch opened to the rivet 101 side adjacent to both curved surfaces 501a and 501b. 501c is provided. One curved surface (first curved surface) 501a is on the distal end side of the first shock absorbing piece 501, and the other curved surface 501a is on the proximal end side (base piece 500 side) of the first shock absorbing piece 501. Has been placed. The notch 501c is interposed between the curved surfaces 501a and 501b and is disposed at a position where it does not contact the rivet 101. Thus, the first shock absorbing piece 501a becomes susceptible to impact load _{P 1} of the rivet 101 is concentrated on the curved surface 501a.

A cutout 501 d that opens to the opposite side of the rivet 101 in the vicinity of the base piece 500 is provided in the outer portion of the first shock absorbing piece 501. Thus, a first impact absorption member 501 is smaller than the surface direction thickness of the other portions plane direction thickness of the notch 501d near the site, notches in the event of an impact load P ₁ from the rivet 101 501d It becomes easy to be plastically deformed due to stress concentration in the vicinity.

The second shock absorbing piece 502 is an edge on the steering mechanism side of the base piece 500 and protrudes toward the steering mechanism side at a portion adjacent to the inner peripheral surface 500a of the base piece 500 on the other side (lower side in FIG. 3). Are provided integrally. The second shock absorbing piece 502 has a substantially semi-disc-shaped tip, and is formed by a tongue piece that wraps the rivet 101 and the first shock absorbing piece 501 from below. Then, the second shock absorbing piece 502 is detached from the first shock absorbing piece 501 with the end of the plastic deformation to bring the rivet 101 into contact therewith, and the impact load P ₃ (P ₃ <P ₁ ) from the rivet 101. In response to plastic deformation. Thereby, the transition of the rivet 101 from the curved surface 501a of the first shock absorbing piece 501 to the curved surface 502b of the second shock absorbing piece 502 is smoothly performed. The total length of the second shock absorbing piece 502 is set to be larger than the total length of the first shock absorbing piece 501.

The inner surface of the second shock absorbing piece 502 is in contact with the curved surface 502a that fits in part with the outer peripheral surface of the rivet 101 at the initial position and the outer peripheral surface of the rivet 101 separated from the first shock absorbing piece 501 ( (Second curved surface) 502b and a flat surface 502c for moving the rivet 101 are provided. Further, an inflection portion 502d as a discontinuous portion interposed between the curved surface 502b and the flat surface 502c is provided in an inner portion of the second shock absorbing piece 502. Thus, the second shock absorbing piece 502 is easily plastically deformed by stress concentration on the curved portion 502d near the site in the event of an impact load P ₃ from the rivet 101.

After the vehicle equipped with the steering column device 1 configured as described above collides with an obstacle (for example, another vehicle) (primary collision), the driver collides with the steering wheel 100 (secondary collision). Assume that the collision load P ₁ is applied to the rivet 101 from the steering wheel 100 through the steering column 3. In this case, when the impact load P ₁ acts on the rivet 101, the rivet 101 leaves the rivet insertion hole 102 a of the bracket 102 on the housing side and moves along the guide groove 37 a of the column bracket 37 on the lower side along the second impact absorbing piece. An attempt is made to move forward on the plane 502c of the vehicle 502.

For this reason, the curved surface 501a of the first impact absorbing piece 501 receives the impact load P ₁ ′ (P ₁ ′ <P ₁ ) from the rivet 101, and the outer side (upper side in FIG. 3) as the rivet 101 moves forward. ) Plastically deformed. In this case, the first shock absorbing piece 501 starts plastic deformation at a position indicated by a solid line in FIG. 3, and ends plastic deformation at a position indicated by a two-dot chain line in FIG.

On the other hand, the rivet 101 moves from the initial position along the guide groove 37a on the plane 502c of the second shock absorbing piece 502 along the guide groove 37a in accordance with the plastic deformation of the first shock absorbing piece 501, and the first shock absorbing piece 501 With the end of the plastic deformation of the absorbing piece 501, it is separated from the first shock absorbing piece 501, and comes into contact with the curved surface 502b of the second shock absorbing piece 502. In this case, the impact load P ₃ from the rivet 101 acts on the curved surface 502 b of the second impact absorbing piece 502.

Therefore, the second shock absorbing piece 502 curved 502b receives an impact load _{P 3} from the rivet 101, plastically deformed outward with the movement of the vehicle in front of the rivet 101 (lower side in FIG. 3). In this case, the second shock absorbing piece 502 starts plastic deformation at a position indicated by a solid line in FIG. 3, and ends plastic deformation at a position indicated by a two-dot chain line in FIG.

Accordingly, in this embodiment, a portion of the impact load P ₁ in the first shock absorbing piece 501 and the second shock absorbing piece 502 is absorbed in two stages, the impact load P ₁ which occurs at the time of a secondary collision A part can be absorbed effectively.

  Next, the relationship between the impact load (P) generated at the time of the secondary collision and the elapsed time (t) will be considered using an automobile equipped with the steering column device 1 shown in the present embodiment.

This discussion, in an automobile equipped with the steering column device 1, the impact load P ₁ is applied to the steering wheel 100, (a reaction force from the steering wheel 100) shock load (P) elapsed time (t) measuring the Tried by.

As a result, be significantly changed substantially in proportion to the impact load P is the elapsed time t is between from t = 0 to t = t ₁ was confirmed. Further, the impact load P hardly changes between t = t ₁ and t = t ₂ , and P = P ₁ to P = P ₂ (first peak point: P ₂ <P ₁ ). confirmed. This is part of the impact load P ₁ is considered to be due to absorbed by the first shock absorbing piece 501.

On the other hand, in the time from t = t ₂ to t = t ₃ , the impact load P decreases with the passage of time, and from t = t ₃ to t = t _4, the steep slope is approximately proportional to the elapsed time t. It was confirmed that it became larger. Further, the impact load P slightly changes from t = t ₄ to t = t ₅ , and P = P ₃ (second peak point: P ₃ <P ₂ ) to P = P ₄ (P ₄ <P ₃ ). It was confirmed that This is considered to be because a part of the impact load P ₂ was absorbed by the second impact absorbing piece 502.

On the other hand, in the steering column device that does not have the impact absorbing plate 50, the impact load P that is the first peak point at the time of the secondary collision is P = P ₅ (P ₅ > P ₂ ), and the second It was confirmed that the impact load P that is the peak point of P is P = P ₆ (P ₆ > P ₃ ).

  This is as shown in FIG. FIG. 4 shows the result of considering the relationship between the impact load (vertical axis) and the elapsed time (horizontal axis). In FIG. 4, the case of the steering column device 1 having the shock absorbing plate 50 is indicated by a solid line, and the case of the steering column device having no shock absorbing piece 50 is indicated by an alternate long and short dash line.

[Effect of the embodiment]
According to the embodiment described above, the following effects can be obtained.

A part of the impact load P ₁ can be absorbed stepwise by the first impact absorbing piece 501 and the second impact absorbing piece 502. Thereby, the number of parts can be reduced, and the whole structure can be simplified and the cost can be reduced.

  As mentioned above, although the impact absorption mechanism of the steering column and the steering column apparatus provided with the same according to the present invention have been described based on the above embodiment, the present invention is not limited to the above embodiment and departs from the gist thereof. The present invention can be carried out in various modes as long as it is not, for example, the following modifications are possible.

In the above embodiment, a case has been described in which absorb some of the impact load P ₁ in two steps, the present invention is not limited to this, a portion of the predetermined load or more impact load n (n> 3 ) May be absorbed over stages. For example, as illustrated in FIG. 5, the shock absorbing plate 200 with n = 4 includes shock absorbing pieces 200 a to 200 d that are arranged in parallel with the moving direction of the rivet 101. This makes it possible to absorb some of the impact load P ₁ over a period of four steps.

  DESCRIPTION OF SYMBOLS 1 ... Steering column apparatus, 2 ... Steering shaft, 20 ... Upper shaft, 21 ... Lower shaft, 3 ... Steering column, 30 ... Outer tube, 31 ... Inner tube, 32, 33 ... Upper side column bracket ( Fixed bracket 32, movable bracket 33, 34 ... lock / unlock mechanism, 35 ... operation lever, 36 ... vehicle body side member, 37 ... lower side column bracket, 37a ... guide groove, 38 ... vehicle body side member, 4 ... housing, DESCRIPTION OF SYMBOLS 40 ... Sensor housing, 41 ... Deceleration mechanism housing, 42 ... Housing tube, 5 ... Shock absorbing mechanism, 50 ... Shock absorbing plate, 500 ... Base piece, 500a ... Inner peripheral surface, 501, 502 ... Shock absorbing piece (First shock absorbing piece 501, second shock absorbing piece 502), 501 a, 501 b... Curved surface, 501 c, 501 d. Notches, 502a, 502b ... curved surface, 502c ... flat surface, 502d ... bent portion, 6 ... universal joint, 7 ... intermediate shaft, 100 ... steering wheel, 101 ... rivet, 102 ... housing bracket, 102a ... rivet insertion hole , 200 ... shock absorbing plate, 200a to 200d ... shock absorbing piece

Claims (3)

A steering column that rotates around a support pin for tilt adjustment that moves forward of the vehicle by an impact load equal to or greater than a predetermined load; and
A bracket that rotatably supports the steering column, and is attached to a vehicle body side member;
A first shock absorbing piece attached to the bracket and plastically deformed by receiving the impact load from the support pin, and a second support pin that is plastically deformed by contacting the support pin detached from the first shock absorbing piece. and a shock absorbing plate having a shock absorbing piece,
The shock absorbing plate has a first curved surface that has a first curved surface that matches the outer peripheral surface of the support pin at an initial position thereof, and the plastic deformation of the first shock absorbing piece ends with the end of the plastic deformation. The second shock-absorbing piece has a second curved surface that makes contact with the outer peripheral surface of the support pin, and the first shock-absorbing piece is located at an inner portion adjacent to the tip of the second shock-absorbing piece via the first curved surface. A shock absorbing mechanism for a steering column having a notch opened to the support pin side . 2. The shock absorbing mechanism for a steering column according to claim 1, wherein the shock absorbing plate has a notch that opens to an opposite side to the support pin side in an outer portion where the first shock absorbing piece is separated from a tip portion thereof. 3. The steering column apparatus provided with a shock absorbing mechanism of the steering column according to claim 1 or 2.

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