Steering device

Abstract

To provide a steering device configured so that a component can be effectively prevented from breaking.SOLUTION: A steering device 10 is provided with: a lower jacket 30; an upper jacket 20; a ladder-like lock plate 22 firmly fixed to the upper jacket 20; a tooth 50 that can oscillate with a resin shaft 48 as a center, between an engagement position where the tooth engages with the lock plate 22 and a disengagement position where the engagement is released; and a cam 44 that presses the tooth 50 in a direction in which the tooth approaches the disengagement position, when rotating together with a transmission shaft 42 up to a tilt releasing angle. The tooth 50 has a contact surface 56 that faces, in an axis direction, a partition bar 24, when the tooth 50 is at the engagement position, which is a circular arc surface which is nearly parallel to a circular arc with the resin shaft 48 as the center, and a protrusion 54 that protrudes toward the upper jacket 20, when the tooth 50 is at the engagement position.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present specification discloses a steering device mounted on a vehicle. [Background technology]

[0002] A steering device typically includes a steering member (for example, a steering wheel), a steering shaft that transmits the movement of the steering member to a steering mechanism, and a steering column that surrounds the steering shaft. Patent Document 1 discloses such a steering device.

[0003] In Patent Document 1, the steering column has a lower jacket and an upper jacket that is located axially further toward the tip end of the lower jacket (closer to the steering member) and that can move axially back and forth relative to the lower jacket. A ladder-shaped lock plate is fixed to the upper jacket, and a swingable lock member is provided on the lower jacket. The lock member has teeth that engage or disengage with the lock plate as the lock member swings. By disengaging the teeth from the lock plate, the axial movement of the upper jacket, and therefore the axial position of the steering member, can be adjusted. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-144810 Summary of the Invention [Problem to be solved by the invention]

[0005] In a steering device such as that described in Patent Document 1, not only the axial position of the steering member but also the tilt angle can be changed. To change the tilt angle and axial position, a specific release lever is operated. However, when the upper jacket is pushed toward the rear end in the axial direction and the lock plate is pressed against the teeth, the release lever may not be able to move properly. In such a case, if the user continues to forcibly rotate the release lever, an excessive load may be applied to the transmission shaft fixed to the release lever, potentially causing damage to the transmission shaft.

[0006] Therefore, this specification discloses a steering device that can effectively prevent damage to components. [Means for solving the problem]

[0007] The steering device disclosed in this specification includes a steering column having a lower jacket and an upper jacket that can advance and retreat in the axial direction relative to the lower jacket, a ladder-shaped lock plate that is fixed to the upper jacket and has a plurality of partition bars and partition holes that are arranged alternately in the axial direction, teeth that are attached to the lower jacket so as to be swingable, and that can swing about a resin shaft between an engagement position where the teeth enter the partition holes and engage with the lock plate, and a disengagement position where the teeth disengage from the partition holes, and a transmission shaft that rotates the transmission shaft to a specified tilt release angle. and a cam fixed to the transmission shaft, which presses the tooth in a direction approaching the disengagement position when it rotates together with the transmission shaft to the tilt release angle, wherein the tooth has an abutment surface that faces the partition bar in the axial direction when the tooth is in the engagement position, and is an arc surface that is approximately parallel to an arc centered on the resin shaft, and a protrusion that protrudes toward the upper jacket when the tooth is in the engagement position. [Effects of the Invention]

[0008] According to the steering device disclosed in this specification, damage to components can be effectively prevented. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of a steering device. [Figure 2] FIG. 2 is a schematic diagram of a steering device. [Figure 3] FIG. [Figure 4] FIG. 4 is an enlarged view of part A in FIG. 3 in a state where the tilt angle is unlocked. [Figure 5] FIG. 1 is a diagram showing an example of a conventional tooth. DETAILED DESCRIPTION OF THE INVENTION

[0010] The configuration of the steering device 10 will be described below with reference to the drawings. Fig. 1 is a perspective view of the steering device 10. Fig. 2 is a schematic diagram showing the configuration of the steering device 10.

[0011] The steering device 10 is disposed in front of the driver's seat of the vehicle. The steering device 10 is disposed in a posture with the rear raised as a whole. Hereinafter, the longitudinal direction of the steering device 10 will be referred to as the "axial direction," the upper rear end of the steering device 10 will be referred to as the "tip end," and the lower front end will be referred to as the "base end."

[0012] The steering device 10 has a steering member 12 (e.g., a steering wheel), and the movement of this steering member 12 is transmitted to a steering mechanism 16 via a steering shaft 14. The steering shaft 14 is an axial member that is positioned in a rearward-raised position and is extendable and contractible in the axial direction.

[0013] The steering column 18 surrounds the steering shaft 14 and has a lower jacket 30 and an upper jacket 20 that is disposed distal to the lower jacket 30. The upper jacket 20 is a cylindrical member that surrounds the steering shaft 14. A ladder-shaped lock plate 22 (not visible in FIG. 1) is fixed to the periphery of the upper jacket 20, which will be described later.

[0014] The lower jacket 30 is also a cylindrical member. However, as shown in FIG. 1, a portion of the tip end of the lower jacket 30 is not cylindrical, but rather U-shaped with a downward opening. Hereinafter, the cylindrical portion of the lower jacket 30 will be referred to as the "cylindrical portion 32," and the U-shaped portion will be referred to as the "U-shaped portion 34." As shown in FIG. 2, a portion of the base end of the upper jacket 20 extends into the interior of the lower jacket 30.

[0015] A tilt shaft hole 38 is formed at the rear end of the lower jacket 30. A tilt shaft (not shown) is inserted into the tilt shaft hole 38, and this tilt shaft is fixed to a fixing member 100 (see FIG. 2). This allows the steering device 10 including the lower jacket 30 to swing around the tilt shaft hole 38, thereby changing the tilt angle of the steering member 12.

[0016] As described above, the U-shaped portion 34 has a U-shape that opens downward, and a portion of the upper jacket 20 fits inside the U-shaped portion 34. In other words, the U-shaped portion 34 has a pair of clamping plates 36 that sandwich the upper jacket 20 from the left and right. The U-shaped portion 34 is sandwiched between a pair of fixing plates 102. The fixing plates 102 are plate-like members fixed to the vehicle body.

[0017] The steering device 10 further has a release lever 40 that accepts operation by the user. A transmission shaft 42 is fixed to the base end of the release lever 40, and the release lever 40 swings around this transmission shaft 42. The transmission shaft 42 is an axial member that extends in the left-right direction of the vehicle and is rotatable relative to the clamping plate 36 and the fixed plate 102. A tilt hole 104 (see FIG. 1 ) through which the transmission shaft 42 passes is formed in the fixed plate 102. The tilt hole 104 is an arc-shaped hole that allows movement of the transmission shaft 42 as the tilt angle is changed.

[0018] The steering device 10 is also provided with a tilt adjustment mechanism (not shown) that allows the tilt angle and axial position of the steering device 10 to be changed by rotating the transmission shaft 42 to a specified tilt release angle. The tilt adjustment mechanism includes, for example, a first bushing and a second bushing disposed between the release lever 40 and the fixed plate 102. The first bushing is fixed to the transmission shaft, and the second bushing is fixed to the fixed plate 102. The first bushing and the second bushing are partially formed with convex and concave portions. The first bushing rotates as the transmission shaft 42 rotates, changing the relative rotational phase of the first and second bushings and the contact relationship between the convex and concave portions. This changes the force with which the first bushing presses the fixed plate 102 via the second bushing, and ultimately the force with which the fixed plate 102 clamps the U-shaped portion 34.

[0019] In this example, when the transmission shaft 42 is at a predetermined initial angle, the U-shaped portion 34 is tightly sandwiched between the pair of fixed plates 102. Therefore, at the initial angle, the lower jacket 30 cannot move relative to the fixed plates 102, and the tilt angle of the steering device 10 cannot be changed. However, when the release lever 40 is swung in the predetermined release direction A and the transmission shaft 42 rotates to a predetermined tilt release angle, the clamping force of the fixed plates 102 is reduced, and the lower jacket 30 can swing about the tilt shaft hole 38. This allows the tilt angle of the steering member 12 to be changed.

[0020] A lock plate 22, a cam 44, and a lock member 46 are provided between the pair of clamping plates 36. Figure 3 is an enlarged view of the periphery of the lock member 46. The lock plate 22 is a ladder-shaped member in which partition bars 24, which extend in a direction substantially parallel to the transmission shaft 42, and partition holes 26 are arranged alternately in the axial direction. This lock plate 22 is fixed to the circumferential surface of the upper jacket 20. The cam 44 is provided in a position where it does not interfere with the lock plate 22. The cam 44 is fixed to the transmission shaft 42 and rotates together with the transmission shaft 42.

[0021] The locking member 46 is disposed closer to the base end than the cam 44. The locking member 46 rotates around a resin shaft 48, which is attached to the pair of clamping plates 36. The locking member 46 has teeth 50 that engage with the lock plate 22 and a pressure-receiving portion 60 that abuts against the cam 44. The teeth 50 and the pressure-receiving portion 60 are disposed such that the distance between them increases with increasing distance from the resin shaft 48. Therefore, the locking member 46 as a whole has a generally V-shape that opens toward the tip end of the steering device 10.

[0022] The locking member 46 can swing between an engaged position and a disengaged position. In the engaged position, the teeth 50 of the locking member 46 enter the partition hole 26 and engage with the lock plate 22. FIG. 2 shows the locking member 46 in the engaged position. In this state, axial movement of the lock plate 22, and therefore of the upper jacket 20 relative to the lower jacket 30, is prohibited. In the disengaged position, the teeth 50 of the locking member 46 are completely disengaged from the partition hole 26. In this state, axial movement of the lock plate 22, and therefore of the upper jacket 20 relative to the lower jacket 30, is permitted.

[0023] The locking member 46 is biased by a biasing member in a direction approaching the engaged position. When the user wishes to rotate the locking member 46 to the disengaged position against this biasing force, i.e., when the user wishes to change the axial position of the steering member 12, the user swings the release lever 40 in the release direction A. This causes the cam 44 to rotate together with the transmission shaft 42 in the release direction A, and the locking member 46, which is in contact with the cam 44, to rotate in the disengagement direction B.

[0024] Here, in the engaged position, the tooth 50 of this example has a protrusion 54 that protrudes from the top surface 52 toward the upper jacket 20, and an abutment surface 56 that axially faces the partition bar 24. The abutment surface 56 is an arcuate surface that is approximately parallel to the arc centered on the resin shaft 48. The reason for this configuration will be explained.

[0025] Fig. 5 is a diagram showing an example of a conventional tooth 50*. As shown in Fig. 5, the conventional tooth 50* does not have an arcuate surface that faces the partition bar 24 in the axial direction. The tip end surface of the tooth 50* is approximately parallel to the base end surface of the partition bar 24. In this case, there is a risk of damage to the transmission shaft 42 depending on the situation.

[0026] That is, as described above, when the user wants to change the tilt angle of the steering member 12, he or she rotates the release lever 40 and therefore the transmission shaft 42 in the release direction A. Because the cam 44 is fixed to the transmission shaft 42, as the transmission shaft 42 rotates, the cam 44 also rotates, and the locking member 46 that abuts against the cam 44 also rotates.

[0027] Now, suppose that the user applies their weight to the steering member 12, for example, and pushes the upper jacket 20 toward the base end in the axial direction. In this case, the lock plate 22 moves axially to a position where the tip end surfaces of the teeth 50* abut against the rear end surface of the partition bar 24, as shown in FIG. 5. In this state, the abutting relationship between the teeth 50* and the partition bar 24 prevents the lock member 46 from swinging in the removal direction B, even if an attempt is made to do so. Furthermore, since the teeth 50* cannot swing, the cam 44 and the transmission shaft 42 cannot rotate either.

[0028] If the user tries to forcibly rotate the release lever 40 in the release direction A in order to change the tilt angle of the steering member 12 without realizing that the state shown in Figure 5 is in place, an excessive load will be placed on the transmission shaft 42, which may cause damage to the transmission shaft 42.

[0029] To prevent such damage to the transmission shaft 42, in this example, the tip of the tooth 50 is provided with an abutment surface 56, which is an arcuate surface that faces the partition bar 24 in the axial direction. When the upper jacket 20 is pressed toward the axial base end, this abutment surface 56 abuts against the partition bar 24. Because this abutment surface 56 is parallel to the arc centered on the resin shaft 48, the tooth 50 can easily swing in the removal direction B even if the upper jacket 20 is pressed toward the axial base end. As a result, even when the upper jacket 20 is pressed toward the axial base end, the transmission shaft 42 and cam 44 can be rotated to the tilt release angle, and the tilt angle and axial position can be unlocked while preventing damage to the transmission shaft 42.

[0030] However, various problems arise if the locking member 46 rotates unrestrictedly. For example, in this example, if a strong axial compressive force is applied to the steering device 10 in a vehicle collision or the like, the force of the collision is transmitted from the lower jacket 30 via the lock plate 22 and the teeth 50 to the plastic shaft 48, causing the plastic shaft 48 to be destroyed first. In such a case, if the locking member 46 rotates unrestrictedly and the teeth 50 completely disengage from the partition holes 26 during a collision, the collision load cannot be transmitted to the plastic shaft 48.

[0031] Therefore, in this example, the tooth 50 is further provided with a protrusion 54 that protrudes from the top surface 52 toward the upper jacket 20. By providing such a protrusion 54, as shown in FIG. 4, the protrusion 54 abuts and catches on the base end surface of the partition bar 24 before the tooth 50 completely disengages from the partition hole 26. This prevents the locking member 46 from rotating unrestrictedly. As a result, the collision load can be reliably transmitted to the resin shaft 48 during a collision. [Explanation of symbols]

[0032] 10 steering device, 12 steering member, 14 steering shaft, 16 steering mechanism, 18 steering column, 20 upper jacket, 22 lock plate, 24 partition bar, 26 partition hole, 30 lower jacket, 32 cylindrical portion, 34 U-shaped portion, 36 clamping plate, 38 tilt shaft hole, 40 release lever, 42 transmission shaft, 44 cam, 46 lock member, 48 resin shaft, 50, 50* teeth, 52 upper surface, 54 protrusion, 56 contact surface, 60 pressure receiving portion, 100 fixing member, 102 fixing plate, 104 tilt hole.

Claims

[Claim 1] a steering column having a lower jacket and an upper jacket that is axially movable relative to the lower jacket; a ladder-shaped lock plate fixed to the upper jacket and having a plurality of partition bars and partition holes arranged alternately in the axial direction; a tooth attached to the lower jacket so as to be swingable relative to the lower jacket, the tooth being swingable about a resin shaft between an engagement position where the tooth enters the partition hole and engages with the lock plate, and a disengagement position where the tooth disengages from the partition hole; a tilt adjustment member having a transmission shaft, which allows the tilt angle and / or axial position of the steering column to be changed by rotating the transmission shaft to a specified tilt release angle; a cam fixed to the transmission shaft and configured to press the tooth in a direction approaching the disengagement position when the cam rotates together with the transmission shaft to the tilt release angle; The tooth comprises: a contact surface that faces the partition bar in the axial direction when the tooth is in the engagement position and is an arc surface that is approximately parallel to an arc centered on the resin shaft; a protrusion that protrudes toward the upper jacket when the tooth is in the engagement position; A steering device comprising:

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