Steering device

Abstract

To provide a steering device that can change the amount of forward displacement of an upper column to a lower column without using an impact absorption member.SOLUTION: A steering device includes: a steering column 2 provided with a lower column 10 and an upper column 11; a switching lever 3 capable of switching between a locked state and a lock released state; a restriction engagement portion 4 insertable and retractable with respect to a restriction elongated hole 20 disposed in the upper column 11; a restriction release preload spring 5 configured to apply elastic force to the restriction engagement portion 4 so as to separate the restriction engagement portion from the restriction elongated hole 20; and a restriction cam member 6 rotatable with the switching lever 3. The restriction cam member 6 includes a restriction cam surface 42 adapted to press the restriction engagement portion 4 in a direction toward the restriction elongated hole 20.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a steering device capable of adjusting the front-rear position of a steering wheel.

Background Art

[0002] FIG. 16 shows an example of an automotive steering device. In the steering device 100, a steering wheel 101 operated by a driver is attached to the rear end portion of a steering shaft 102. The steering shaft 102 is rotatably supported inside a steering column 103 supported by a vehicle body. The rotational movement of the steering wheel 101 is transmitted to a pinion shaft 107 constituting a steering gear unit 106 via the steering shaft 102, a universal joint 104a, an intermediate shaft 105, and another universal joint 104b. The rotational movement of the pinion shaft 107 is converted into a linear movement of a rack shaft (not shown) constituting the steering gear unit 106. Thereby, a pair of tie rods 108 are pushed and pulled, and a steering angle corresponding to the operation amount of the steering wheel 101 is imparted to the left and right steering wheels.

[0003] The steering device usually has a telescopic adjustment function for adjusting the front-rear position of the steering wheel according to the build of the driver and the driving posture, and a shock absorption function for mitigating the impact load applied to the driver's body during a secondary collision.

[0004] Specifically, to ensure telescopic adjustment, the steering shaft comprises an upper shaft located at the rear and a lower shaft located at the front, which are combined to allow relative axial displacement and torque transmission. The overall length can be extended or retracted by displacing the upper and lower shafts relative to each other in the axial direction. The steering column comprises an upper column located at the rear and a lower column located at the front, which are combined to allow relative axial displacement. The overall length can be extended or retracted by displacing the upper and lower columns relative to each other in the axial direction. The lower shaft is supported inside the lower column, allowing only rotation. The upper shaft is supported inside the upper column, allowing only rotation. The steering wheel is attached to the rear end of the upper shaft. When adjusting the fore-aft position of the steering wheel, the steering wheel, upper shaft, and upper column are displaced axially, i.e., in the fore-aft direction, relative to the lower shaft and lower column.

[0005] To ensure impact absorption, the steering system includes, for example, an impact-absorbing structure between the lower column and the upper column. In the event of a collision, following the primary collision in which the vehicle collides with another vehicle, a secondary collision occurs in which the driver's body collides with the steering wheel. When a strong forward impact load is applied to the steering wheel, upper shaft, and upper column, the impact load is absorbed by the impact-absorbing structure as the upper column is displaced forward relative to the lower column. This reduces the impact on the driver's body when it collides with the steering wheel.

[0006] During a secondary collision, the upper column needs to be able to displace forward relative to the lower column by a greater amount than under normal conditions, i.e., when adjusting the fore-aft position of the steering wheel.

[0007] A structure for switching the amount by which the upper column can be displaced forward relative to the lower column is described, for example, in Japanese Patent Publication No. 6661447.

[0008] The structure described in Japanese Patent Publication No. 6661447 comprises a switching lever, a restricting slot, a shock-absorbing leaf spring, and a restricting engager. The switching lever is supported on the lower column so as to be able to rotate about a pivot axis in the width direction, and by changing the rotational position about the pivot axis, it is possible to switch between a locked state in which the front-to-back position of the steering wheel cannot be adjusted and an unlocked state in which such adjustment is possible. The restricting slot is provided on the upper column and extends in the axial direction of the upper column. The shock-absorbing leaf spring swings in conjunction with the rotation of the switching lever. The restricting engager is fixed to the tip of the shock-absorbing leaf spring and moves toward and away from the restricting slot in conjunction with the swing of the shock-absorbing leaf spring due to the rotation of the switching lever.

[0009] The restricting element enters the restricting slot as the switching lever rotates from the locked position to the unlocked position. In this unlocked state, which allows adjustment of the fore-aft position of the steering wheel, the upper column can be displaced axially relative to the lower column, but only to the extent that the restricting element can move axially within the restricting slot.

[0010] The restricting engager disengages from the restricting slot as the switching lever rotates from the unlocked position to the locked position. Therefore, in this state, i.e., the locked state in which the fore-aft position of the steering wheel cannot be adjusted, a greater amount of forward displacement of the upper column relative to the lower column can be secured in the event of a secondary collision. Furthermore, in this structure, when a secondary collision occurs, a friction load is generated between the base end of the shock-absorbing leaf spring and a part of the upper column, and the shock load is absorbed by this friction load. The contents of Japanese Patent No. 6661447 are incorporated herein by reference. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Patent No. 6661447 [Overview of the project] [Problems that the invention aims to solve]

[0012] In the structure described in Japanese Patent Publication No. 6661447, the regulating engager is fixed to the tip of the shock-absorbing leaf spring. Therefore, when adjusting the fore-aft position of the steering wheel in the unlocked state, if the front or rear end of the regulating slot strikes the regulating engager with force, the shock-absorbing leaf spring may deform. If the shock-absorbing leaf spring is deformed, the shock absorption performance may become unstable during a secondary collision.

[0013] The present invention aims to provide a steering device that can switch the amount by which the upper column can be displaced forward relative to the lower column without using an impact-absorbing member. [Means for solving the problem]

[0014] A steering device according to one aspect of the present invention comprises a steering column, a switching lever, a restricting engaging element, a restricting release preload spring, and a restricting cam member.

[0015] The steering column comprises a lower column, an upper column combined with the lower column to allow axial displacement, and a restrictive elongated hole provided directly or via another member on the upper column and extending in the axial direction of the upper column.

[0016] The switching lever is supported on the lower column so as to be able to rotate about a pivot axis in the width direction, and can switch between a locked state in which the front-to-back position of the steering wheel cannot be adjusted and an unlocked state in which such adjustment is possible, based on a change in the rotational position about the pivot axis.

[0017] The restricting engager is supported on the lower column so as to be able to move toward and toward the restricting slot, and can enter the restricting slot when approaching the restricting slot and exit the restricting slot when moving away from the restricting slot.

[0018] The aforementioned preload spring for releasing the restriction imparts elasticity to the restricting engager in a direction away from the restricting elongated hole.

[0019] The restricting cam member rotates together with the switching lever about the pivot axis. The restricting cam member has a restricting cam surface that pushes the restricting engageor toward the restricting slot. The restricting cam surface is an inclined surface along the circumferential direction of the pivot axis, such that the position of the restricting slot and the restricting engageor changes in the near and far directions. Specifically, on the restricting cam surface, the portion that pushes the restricting engageor when the switching lever is in the unlocked rotation position is located closer to the restricting slot than the portion that pushes the restricting engageor when the switching lever is in the locked rotation position.

[0020] As the switching lever rotates from the locked position to the unlocked position, the restricting engager moves to a position where it is pushed by the restricting cam surface and enters the restricting slot, and as the switching lever rotates from the unlocked position to the locked position, it moves to a position where it is pushed by the elasticity of the restricting release preload spring and exits the restricting slot.

[0021] A steering device according to one aspect of the present invention includes a fixed gear extending in the axial direction, provided directly on the upper column or via another member, and a locking engager having a movable gear supported on the lower column so as to be able to move toward or toward the fixed gear, and which meshes with the fixed gear when approaching the fixed gear and disengages from the fixed gear when moving toward the fixed gear. The locking engager moves away from the fixed gear to a position where the meshing between the fixed gear and the movable gear is disengaged as the switching lever rotates from the locked position to the unlocked position, and moves closer to a position where the fixed gear and the movable gear mesh as the switching lever rotates from the unlocked position to the locked position.

[0022] A steering device according to one aspect of the present invention includes a preload spring for unlocking that imparts elasticity to the locking engageor in a direction away from the fixed gear, and a locking cam member that rotates together with the switching lever about the pivot axis. The locking cam member has a locking cam surface that pushes the locking engageor toward the fixed gear. The locking cam surface is an inclined surface along the circumferential direction of the pivot axis, such that the position of the fixed gear and the locking engageor changes in the near and far directions. Specifically, on the locking cam surface, the portion that pushes the locking engageor when the switching lever is in the locked rotation position is located closer to the fixed gear than the portion that pushes the locking engageor when the switching lever is in the unlocked rotation position. As the switching lever rotates from the locked position to the unlocked position, the locking engageor is pushed by the elastic force of the unlocking preload spring and moves to a position where the engagement between the fixed gear and the movable gear is released. At the same time, as the switching lever rotates from the unlocked position to the locked position, the locking engageor is pushed by the locking cam surface and moves to a position where the fixed gear and the movable gear engage.

Advantages of the Invention

[0023] According to the steering apparatus of one embodiment of the present invention, the amount by which the upper column can be displaced forward with respect to the lower column can be switched without using a shock-absorbing member.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a side view showing a steering apparatus according to an example of an embodiment of the present invention in a locked state where adjustment of the front-rear position of the steering wheel is disabled. [Figure 2] FIG. 2 is a view seen from above FIG. 1. [Figure 3] FIG. 3 is a view seen from below FIG. 1. [Figure 4] FIG. 4 is a view seen from the right side of FIG. 1. [Figure 5] FIG. 5 is an enlarged view of the middle portion in the left-right direction of FIG. 1. [Figure 6] FIG. 6 is an enlarged view of the middle portion in the left-right direction of FIG. 3 (a view seen from below FIG. 5). [Figure 7] FIG. 7 is a cross-sectional view taken along the line A-A of FIG. 5. [Figure 8] FIG. 8 is a view seen from the opposite side of FIG. 5. [Figure 9] FIG. 9 is a view corresponding to FIG. 5 showing the steering apparatus in an unlocked state where adjustment of the front-rear position of the steering wheel is enabled. [Figure 10] FIG. 10 is a view seen from below FIG. 9. [Figure 11] FIG. 11 is a cross-sectional view taken along the line B-B of FIG. 9. [Figure 12] FIG. 12 is a view seen from the opposite side of FIG. 9. [Figure 13] FIG. 13 is an exploded perspective view of a part of the steering apparatus seen from the rear and the upper left. [Figure 14] FIG. 14 is an exploded perspective view of a part of the steering apparatus seen from the rear and the upper right. [Figure 15]Figure 15(a) is a perspective view of the lower column, which constitutes the steering device, as seen from the rear and upper left, and Figure 15(b) is a perspective view of the lower column, as seen from the rear and upper right. [Figure 16] Figure 16 is a perspective view showing an example of a conventional steering system structure. [Modes for carrying out the invention]

[0025] An example of an embodiment of the present invention will be described with reference to Figures 1 to 15.

[0026] The steering device 1 in this example comprises a steering column 2, a switching lever 3, a restricting engaging element 4, a restricting release preload spring 5, and a restricting cam member 6.

[0027] With respect to the steering device 1, the longitudinal direction, width direction, and vertical direction refer to the longitudinal direction, width direction, and vertical direction of the vehicle body to which the steering device 1 is assembled. The front side is the left side in Figures 1-3, 5, 6, 9, and 10, and the right side in Figures 8 and 12. The rear side is the right side in Figures 1-3, 5, 6, 9, and 10, and the left side in Figures 8 and 12.

[0028] The steering device 1 in this example includes a switching mechanism 7 for switching between a locked state, which prevents adjustment of the fore-aft position and height of the steering wheel (not shown) operated by the driver, and an unlocked state, which enables such adjustment. The switching lever 3 constitutes part of the switching mechanism 7. Figures 1 to 8 show the steering device 1 in the locked state. Figures 9 to 12 show the steering device 1 in the unlocked state.

[0029] In the steering device 1 of this example, a steering shaft 8 is rotatably supported inside the steering column 2. The axial middle portion of the steering column 2 is supported by the vehicle body using a support bracket 9. The steering wheel is attached to the rear end of the steering shaft 8, which protrudes further rearward than the rear end of the steering column 2.

[0030] The steering column 2 is formed by combining a lower column 10 located at the front and an upper column 11 located at the rear, allowing for relative axial displacement. In this example, the lower column 10 is an outer column located radially outward, and the upper column 11 is an inner column located radially inward. However, when implementing the present invention, the lower column can also be an inner column and the upper column an ​​outer column.

[0031] In this example, the lower column 10 is constructed in a substantially cylindrical shape from a metal such as steel or an aluminum alloy. As shown in Figures 13 to 15(b), the lower column 10 has a slit 12 at its upper end, which is a portion in the circumferential direction, and extending from the middle to the rear end in the axial direction. The inner diameter of the lower column 10 is expandable and contractible based on the elastic expansion and contraction of the width of the slit 12. At the rear end of the lower column 10, there are two flange portions 13 that project radially outward (upward) from both sides of the slit 12 in the width direction. Each of the flange portions 13 has a through hole 14 that penetrates in the width direction at a location that is aligned with each other in the width direction.

[0032] The lower column 10 has a recess 15 that is recessed radially outward and extends axially at one end in the width direction (left side in Figures 4, 7, and 11), which is a circumferential portion of the inner surface of the portion extending from the axial middle to the rear end. The lower column 10 has a through hole 16 at one end in the width direction of the axial rear portion, which penetrates in the width direction and whose inner end in the width direction opens into the recess 15. The through hole 16 is a non-circular hole, with a portion of its inner surface in the circumferential direction being a flat surface and the remaining portion of its inner surface in the circumferential direction being a cylindrical surface. The lower column 10 has a through hole 17 at the other end in the width direction of the axial rear portion (right side in Figures 4, 7, and 11), which penetrates in the width direction. The through hole 17 is a circular hole. In the illustrated example, the through-hole 16 on one side and the through-hole 17 on the other side are positioned in front of the through-hole 14 in the axial direction of the lower column 10, and are aligned with each other in the width direction.

[0033] The lower column 10 has a widthwise insertion hole 18 at the upper part of its front end. A widthwise tilt shaft 19 (see Figure 1), supported by the vehicle body, is inserted through the insertion hole 18. This ensures that the lower column 10 does not displace forward relative to the vehicle body, not only under normal conditions but also during a secondary collision, while allowing for oscillating displacement around the tilt shaft 19 relative to the vehicle body.

[0034] In this example, the upper column 11 is cylindrical and made of a metal such as steel or an aluminum alloy. The front part of the upper column 11 is fitted into the rear part of the lower column 10, allowing for relative axial displacement.

[0035] As shown in Figure 14, the upper column 11 has a restrictive slot 20 that extends in the axial direction. In this example, the restrictive slot 20 is made up of a through hole that extends in the axial direction, provided at the other end in the width direction, which is a circumferential portion of the axial front side of the upper column 11. When the front side of the upper column 11 is fitted into the rear side of the lower column 10, a portion of the restrictive slot 20 in the extension direction faces the other through hole 17 of the lower column 10 in the width direction. When implementing the present invention, the restrictive slot can also be made up of a bottomed hole that opens only radially outward and extends in the axial direction. Furthermore, although the restrictive slot 20 is provided directly in the upper column 11 in this example, when implementing the present invention, the restrictive slot can also be provided in the upper column via another member, that is, in another member fixed to the upper column.

[0036] The steering shaft 8 comprises a lower shaft 21 located at the front and an upper shaft 22 located at the rear. The lower shaft 21 and the upper shaft 22 are spline-fitted to enable torque transmission and relative axial displacement.

[0037] The lower shaft 21 is supported by the lower column 10 by a rolling bearing (not shown) fitted into the front end of the lower column 10, allowing it to rotate only. The front end of the lower shaft 21, which protrudes forward from the front end of the lower column 10, is connected to the rear end of an intermediate shaft (not shown) via a universal joint (not shown).

[0038] The upper shaft 22 is supported by a rolling bearing 23 (see Figure 4) fitted and held inside the rear end of the upper column 11, allowing it to rotate only. The steering wheel is attached to the rear end of the upper shaft 22, which protrudes further rearward than the rear end of the upper column 11.

[0039] The support bracket 9 is made of metal such as steel and comprises a mounting plate portion 24 and two support plate portions 25a and 25b. The mounting plate portion 24 constitutes the upper part of the support bracket 9 and is arranged in the width direction. The mounting plate portion 24 is supported by the vehicle body. The two support plate portions 25a and 25b are arranged substantially parallel to each other, sandwiching the rear part of the lower column 10 from both sides in the width direction. The upper end of each of the support plate portions 25a and 25b is joined and fixed to the middle part of the mounting plate portion 24 in the width direction. Each of the support plate portions 25a and 25b is aligned with each other in the width direction and has a tilt slot 26 that extends in the vertical direction at a location that aligns with the through hole 14 of the flange portion 13. Each of the tilt slots 26 has an arc shape centered on the tilt axis 19.

[0040] The switching lever 3 constitutes part of the switching mechanism 7 (see Figures 5 and 7). In addition to the switching lever 3, the switching mechanism 7 includes a switching rod 27, a nut 28, a cam device 29, and a thrust bearing 30.

[0041] The switching rod 27 is inserted through the tilt slot 26 and the through hole 14 in the width direction. The switching rod 27 has a head 31 at its base end (left end in Figures 4 and 7) and a male threaded portion 32 at its tip end (right end in Figures 4 and 7).

[0042] The nut 28 is screwed onto the male threaded portion 32.

[0043] The cam mechanism 29 is positioned between the head 31 and one of the support plate portions 25a (the left side in Figures 4 and 7). The cam mechanism 29 has a drive cam 33 located on the outside in the width direction and a driven cam 34 located on the inside in the width direction. The driven cam 34 is engaged with the tilt slot 26 of the support plate portion 25a in a manner that prevents relative rotation. The driven cam 34 is fitted onto the switching rod 27 so that it can rotate and move in the axial direction. The drive cam 33 is fitted onto the switching rod 27 so that it cannot rotate or move in the axial direction.

[0044] The switching lever 3 is supported on the lower column 10 so as to be able to rotate about a pivot axis in the width direction. In this example, the base end of the switching lever 3 is fixed to the drive cam 33. That is, the switching lever 3 is supported on the base end of the switching rod 27 via the drive cam 33 so as to be able to rotate about the central axis of the switching rod 27. In this example, the central axis of the switching rod 27 corresponds to the pivot axis in the width direction.

[0045] The switching lever 3 is a component for switching between a locked state, which disables adjustment of the front-to-back position and height of the steering wheel, and an unlocked state, which enables such adjustment, based on changing the rotational position of the switching rod 27 around its central axis.

[0046] In this example, by synchronously rotating the switching lever 3, drive cam 33, and switching rod 27 around the central axis of the switching rod 27, the drive cam 33 and the driven cam 34 are rotated relative to each other. Based on the pressing of the opposing sides (cam surfaces) of the drive cam 33 and the driven cam 34 against each other, the axial dimension of the cam device 29 expands or contracts. In this example, when the switching lever 3 is rotated downwards from the locked rotation position shown in Figure 5 to the unlocked rotation position shown in Figure 9, the axial dimension of the cam device 29 decreases. Conversely, when the switching lever 3 is rotated upwards from the unlocked rotation position shown in Figure 9 to the locked rotation position shown in Figure 5, the axial dimension of the cam device 29 increases.

[0047] The thrust bearing 30 is positioned between the nut 28 and the other support plate portion 25b (to the right in Figures 4 and 7).

[0048] The restricting engager 4 is supported by the lower column 10 so as to be able to move toward and toward the restricting slot 20, and can enter the restricting slot 20 when approaching the restricting slot 20 and exit the restricting slot 20 when moving away from the restricting slot 20.

[0049] When implementing the present invention, a restricting engager can be structured to include a restricting supported portion that is supported on a lower column directly or via another member, allowing for movement toward and away from a restricting through-hole; a restricting engaging portion that can enter and exit a restricting elongated hole; a restricting release elastic receiving portion that is given elasticity in the direction away from the restricting elongated hole by a restricting release preload spring; and a restricting cam force receiving portion that is pushed toward the restricting elongated hole directly or via another member by a restricting cam surface. When implementing the present invention, any shape can be adopted for each of these parts. In this example, the restricting engager 4 is configured as a stepped cylindrical shape overall. In other words, the restricting engager 4 has a ring-shaped flange portion 35 that protrudes radially outward at the base end, and a cylindrical base shaft portion 36 located adjacent to the base end side (outward in the width direction) of the flange portion 35, a cylindrical intermediate shaft portion 37 located adjacent to the tip side (inward in the width direction) of the flange portion 35, and a cylindrical tip shaft portion 38 located adjacent to the tip side of the intermediate shaft portion 37, having a smaller outer diameter than the intermediate shaft portion 37. In this example, the other-side through hole 17 corresponds to the restricting support portion, the intermediate shaft portion 37 corresponds to the restricting supported portion, the tip shaft portion 38 corresponds to the restricting engage portion, the flange portion 35 corresponds to the restricting release elastic receiving portion, and the base shaft portion 36 corresponds to the restricting cam force receiving portion.

[0050] The restricting engager 4 is supported relative to the lower column 10 so as to be able to move toward and toward the restricting slot 20 in the width direction by fitting its intermediate shaft portion 37 into the other side through hole 17 of the lower column 10 so as to be able to move in the axial direction. In this example, the tip shaft portion 38 can be moved into the restricting slot 20 by moving the restricting engager 4 closer to the restricting slot 20 in the width direction, and the tip shaft portion 38 can be withdrawn from the restricting slot 20 by moving the restricting engager 4 further away from the restricting slot 20 in the width direction.

[0051] The preload spring 5 for releasing the restriction imparts elasticity to the restricting engageor 4 in a direction away from the restricting slot 20. When implementing the present invention, a spring can be used as the preload spring for releasing the restriction, which is positioned between the lower column or a member fixed to the lower column and the restricting engageor. In this example, the preload spring for releasing the restriction 5 is made of an annular coiled wave spring and is elastically sandwiched between the outer peripheral surface of the lower column 10, specifically the portion around the other through-hole 17, and the side surface of the flange 35 of the restricting engageor 4 on the tip side. As a result, the preload spring for releasing the restriction 5 imparts elasticity to the restricting engageor 4 in a direction away from the restricting slot 20 in the width direction. When implementing the present invention, the preload spring for releasing the restriction is not limited to a coiled wave spring; various other springs such as coil springs and leaf springs can be used.

[0052] The restricting cam member 6 rotates together with the switching lever 3 about the central axis of the switching rod 27. In this example, the restricting cam member 6 is fitted non-circularly to the tip portion of the switching rod 27 in such a way that relative rotation with respect to the switching rod 27 is impossible.

[0053] The regulating cam member 6 in this example is integrally constructed from a metal plate and is fitted non-circularly to the tip portion of the switching rod 27. It comprises a base plate portion 39 sandwiched between the thrust bearing 30 and the nut 28, a connecting plate portion 40 bent at approximately a right angle outward in the width direction from a circumferential portion of the outer circumference of the base plate portion 39, and a cam plate portion 41 bent at approximately a right angle in the opposite direction to the base plate portion 39 from the outer end of the connecting plate portion 40 in the width direction. Most of the cam plate portion 41, excluding the base end, has a roughly fan shape in which the circumferential width increases as it moves radially outward from the switching rod 27 (see Figure 8). At least a portion of the cam plate portion 41 is positioned on the widthward side of the regulating engager 4, regardless of the rotational position of the switching lever 3.

[0054] In this example, the restricting cam member 6 has a restricting cam surface 42 on the widthwise inner surface of the cam plate portion 41 that pushes the restricting engaging element 4 toward the restricting elongated hole 20, i.e., inward in the widthwise direction. In this example, the restricting cam surface 42 pushes the restricting engaging element 4 inward in the widthwise direction via a restricting reserve spring 43.

[0055] The restricting cam surface 42 is an inclined surface whose position in the width direction, which is the distance between the restricting slot 20 and the restricting engager 4, changes along the circumferential direction of the central axis of the switching rod 27. On the restricting cam surface 42, the portion that presses the restricting engager 4 when the switching lever 3 is in the unlocked rotation position (part α2 in Figures 10 and 11) is located closer to the restricting slot 20 in the width direction (upper side in Figures 6 and 10, left side in Figures 7 and 11) than the portion that presses the restricting engager 4 when the switching lever 3 is in the locked rotation position (part α1 in Figures 6 and 7). When implementing the present invention, the overall shape of the restricting cam member can be any shape as long as it has a restricting cam surface (inclined surface).

[0056] In this example, the regulating reserve spring 43 is made of a U-shaped leaf spring. The regulating reserve spring 43 has a fitting hole 44 located on one end that is inward in the width direction, which is press-fitted onto the base end shaft portion 36 of the regulating engager 4, and a protrusion 45 that is located on the other end that is outward in the width direction and protrudes outward in the width direction is in contact with the regulating cam surface 42. In this state, the regulating reserve spring 43 is elastically held between the base end side of the flange portion 35 of the regulating engager 4 and the regulating cam surface 42. The spring constant of the regulating reserve spring 43 is greater than the spring constant of the release preload spring 5. For this reason, in the assembled state of the steering device 1 in this example, the amount of compression of the release preload spring 5 in the width direction is greater than the amount of compression of the regulating reserve spring 43 in the width direction. When implementing the present invention, various types of springs, such as disc springs, not just leaf springs, can be used as the regulating reserve spring.

[0057] The steering device 1 in this example includes a fixed gear 46, a locking engagement element 47, a preload spring 48 for unlocking, and a locking cam member 49 as additional elements of the switching mechanism 7.

[0058] In this example, the fixed gear 46 is formed on a gear plate 50 fixed to the upper column 11. The gear plate 50 is made of a metal plate such as a steel plate and is constructed in the shape of a rectangular flat plate with a large aspect ratio, and has a fixed gear 46 formed on one side along its extension direction. The fixed gear 46 has multiple teeth arranged at equal intervals in the extension direction of the gear plate 50. The gear plate 50 is fixed to one end in the width direction, which is a circumferential portion of the axial front part of the upper column 11, with its extension direction aligned with the axial direction of the upper column 11 and the fixed gear 46 facing outward in the width direction. With the front part of the upper column 11 fitted into the rear part of the lower column 10, the gear plate 50 is positioned in the recess 15 of the lower column 10, and a portion of the extension direction of the fixed gear 46 faces the one-sided through hole 16 of the lower column 10 in the width direction. In this example, the fixed gear 46 is provided to the upper column 11 via a gear plate 50, which is another component. However, when implementing the present invention, the fixed gear can also be directly provided to the upper column, i.e., directly formed.

[0059] The locking engager 47 is supported on the lower column 10 so as to be able to move toward and toward the fixed gear 46. The locking engager 47 also has a movable gear 51 which engages with the fixed gear 46 when it approaches the fixed gear 46 and disengages from the fixed gear 46 when it moves toward the fixed gear 46.

[0060] When implementing the present invention, the locking engager can be structured to include a locking support portion supported on the lower column directly or via another member, which is supported to allow for near-far movement relative to the fixed gear, a movable gear, a release elastic receiving portion which is given elasticity in the direction away from the fixed gear by a release preload spring, and a locking cam force receiving portion which is pushed in the direction toward the fixed gear directly or via another member by a locking cam surface. When implementing the present invention, any shape can be adopted for each of these parts. In this example, the locking engager 47 is configured as a stepped columnar shape overall. That is, the locking engager 47 has a flange portion 52 that protrudes radially outward at the base end portion, a base end shaft portion 53 at a position adjacent to the base end side (outward in the width direction) of the flange portion 52, a tip shaft portion 54 at a position adjacent to the tip side (inward in the width direction) of the flange portion 52, and a movable gear 51 on the tip surface of the tip shaft portion 54. The movable gear 51 has multiple teeth arranged at equal intervals in the extension direction of the fixed gear 46. The intermediate and base portions of the tip shaft portion 54 have a cross-sectional shape that fits non-circularly to the one-side through hole 16 of the lower column 10 so as not to rotate, but allowing the one-side through hole 16 to move axially; that is, a cross-sectional shape that is slightly smaller but similar to the cross-sectional shape of the one-side through hole 16. In this example, the one-side through hole 16 corresponds to the locking support portion, the intermediate and base portions of the tip shaft portion 54 correspond to the locked supported portion, the flange portion 52 corresponds to the unlocking elastic receiving portion, and the base shaft portion 53 corresponds to the locking cam force receiving portion.

[0061] The locking engager 47 is supported relative to the lower column 10, allowing for movement in the width direction relative to the fixed gear 46, by non-circular fitting of the intermediate and base portions of the tip shaft portion 54 into the through hole 16 on one side of the lower column 10, while allowing axial movement of the through hole 16. In this example, the movable gear 51 can be engaged with the fixed gear 46 by moving the locking engager 47 closer to the fixed gear 46 in the width direction, and the engagement between the movable gear 51 and the fixed gear 46 can be disengaged by moving the locking engager 47 further away from the fixed gear 46 in the width direction.

[0062] The preload spring 48 for unlocking imparts elasticity to the locking engageor 47 in a direction away from the fixed gear 46. When implementing the present invention, a spring can be used as the preload spring for unlocking, which is positioned between the lower column or a member fixed to the lower column and the locking engageor. In this example, the preload spring 48 for unlocking is made of an annular coiled wave spring and is elastically sandwiched between the outer peripheral surface of the lower column 10, around the through hole 16 on one side, and the side surface on the tip side of the flange 52 of the locking engageor 47. As a result, the preload spring 48 for unlocking imparts elasticity to the locking engageor 47 in a direction away from the fixed gear 46 in the width direction. When implementing the present invention, the preload spring for unlocking is not limited to a coiled wave spring; various springs such as coil springs and leaf springs can be used.

[0063] The locking cam member 49 rotates together with the switching lever 3 about the central axis of the switching rod 27. For this reason, in this example, the locking cam member 49 is integrally connected to the base end of the switching lever 3.

[0064] In this example, the locking cam member 49 is integrally manufactured with the switching lever 3 by the metal plate that constitutes the switching lever 3. The locking cam member 49 extends radially outward from a portion of the outer circumference of the base end of the switching lever 3 to the switching rod 27, and has a substantially fan shape in which the circumferential width increases towards the radially outward direction (see Figure 9). At least a portion of the locking cam member 49 is positioned on the widthwise outward side of the locking engager 47, regardless of the rotational position of the switching lever 3.

[0065] In this example, the locking cam member 49 has a locking cam surface 55 on its inner surface in the width direction that pushes the locking engaging element 47 toward the fixed gear 46, i.e., inward in the width direction. In this example, the locking cam surface 55 pushes the locking engaging element 47 inward in the width direction via a locking reserve spring 56.

[0066] The locking cam surface 55 is an inclined surface that changes position in the width direction, which is the distance direction between the fixed gear 46 and the locking engager 47, along the circumferential direction of the central axis of the switching rod 27. On the locking cam surface 55, the portion that presses the locking engager 47 when the switching lever 3 is in the locked rotation position (part β1 in Figures 6 and 7) is located in a width direction position closer to the fixed gear 46 (lower side in Figures 6 and 10, and right side in Figures 7 and 11) than the portion that presses the locking engager 47 when the switching lever 3 is in the unlocked rotation position (part β2 in Figures 10 and 11). When implementing the present invention, the overall shape of the locking cam member can be any shape as long as it has a locking cam surface (inclined surface). Furthermore, the locking cam member can be manufactured as a separate component from the switching lever and fixed to the switching lever or switching rod.

[0067] In this example, the locking reserve spring 56 is made of a U-shaped leaf spring. The locking reserve spring 56 has a fitting hole 57 at one end located on the inside in the width direction which is press-fitted onto the base end shaft portion 53 of the locking engager 47, and a protrusion 58 at the other end located on the outside in the width direction which protrudes outward in the width direction is in contact with the locking cam surface 55. In this state, the locking reserve spring 56 is elastically held between the base end side surface of the flange portion 52 of the locking engager 47 and the locking cam surface 55. The spring constant of the locking reserve spring 56 is greater than the spring constant of the unlocking preload spring 48. For this reason, in the assembled state of the steering device 1 in this example, the amount of compression of the unlocking preload spring 48 in the width direction is greater than the amount of compression of the locking reserve spring 56 in the width direction. When implementing the present invention, various types of springs, such as disc springs, not just leaf springs, can be used as the spare spring for locking.

[0068] In the structure of this example, when adjusting the fore-aft position and height of the steering wheel, the switching lever 3 is rotated downwards from the locked position shown in Figure 5 to the unlocked position shown in Figure 9.

[0069] This reduces the axial dimension of the cam device 29, thereby increasing the distance between the driven cam 34 and the thrust bearing 30. As a result, the frictional force acting between the widthwise inner surfaces of the two support plate portions 25a and 25b and the widthwise outer surfaces of the two flange portions 13 is reduced or lost, and the inner diameter of the lower column 10 expands to a free state, reducing or losing the frictional force acting between the inner circumferential surface of the lower column 10 and the outer circumferential surface of the upper column 11.

[0070] Furthermore, as described above, when the switching lever 3 rotates from the locked position to the unlocked position, the portion of the locking cam surface 55 that presses the locking engager 47 changes from portion β1 shown in Figures 6 and 7 to portion β2 shown in Figures 10 and 11. That is, the widthwise position of the portion of the locking cam surface 55 that presses the locking engager 47 changes in a direction away from the fixed gear 46. As a result, as shown in Figure 11, the locking engager 47 moves to a position where it is pushed outward in the widthwise direction by the elasticity of the unlocking preload spring 48, and the engagement between the fixed gear 46 and the movable gear 51 is released.

[0071] Furthermore, as described above, when the switching lever 3 rotates from the locked position to the unlocked position, the portion of the restricting cam surface 42 that presses the restricting engager 4 changes from portion α1 shown in Figures 6 and 7 to portion α2 shown in Figures 10 and 11. That is, the widthwise position of the portion of the restricting cam surface 42 that presses the restricting engager 4 changes in a direction that approaches the restricting slot 20. As a result, as shown in Figure 11, the restricting engager 4 is pushed inward in the widthwise direction by the restricting cam surface 42, and moves to a position where the tip shaft portion 38 of the restricting engager 4 enters the restricting slot 20.

[0072] In this state, the height position of the steering wheel can be adjusted by pivoting the steering column 2 around the tilt axis 19, within the range in which the switching rod 27 can move inside the tilt slot 26. In addition, the fore-aft position of the steering wheel can be adjusted by displacing the upper column 11 axially relative to the lower column 10, within the range in which the tip shaft portion 38 of the restricting engager 4 can move inside the restricting slot 20.

[0073] After adjusting the fore-aft and height positions of the steering wheel, rotate the selector lever 3 upwards from the unlocked position shown in Figure 9 to the locked position shown in Figure 5.

[0074] This increases the axial dimension of the cam device 29, thereby reducing the distance between the driven cam 34 and the thrust bearing 30. As a result, the frictional force acting between the widthwise inner surfaces of the two support plate portions 25a and 25b and the widthwise outer surfaces of the two flange portions 13 increases, and the frictional force acting between the inner circumferential surface of the lower column 10 and the outer circumferential surface of the upper column 11 increases as the inner diameter of the lower column 10 elastically shrinks.

[0075] Furthermore, as described above, when the switching lever 3 rotates from the unlocked position to the locked position, the portion of the locking cam surface 55 that presses the locking engager 47 changes from portion β2 in Figures 10 and 11 to portion β1 as shown in Figures 6 and 7. That is, the widthwise position of the portion of the locking cam surface 55 that presses the locking engager 47 changes in a direction that moves closer to the fixed gear 46. As a result, as shown in Figure 7, the locking engager 47 is pushed inward in the widthwise direction by the locking cam surface 55 and moves to a position where the fixed gear 46 and the movable gear 51 mesh.

[0076] Furthermore, as described above, when the switching lever 3 rotates from the unlocked position to the locked position, the portion of the restricting cam surface 42 that presses the restricting engager 4 changes from portion α2 shown in Figures 10 and 11 to portion α1 shown in Figures 6 and 7. That is, the widthwise position of the portion of the restricting cam surface 42 that presses the restricting engager 4 changes in a direction away from the restricting slot 20. As a result, as shown in Figure 7, the restricting engager 4 is pushed outward in the widthwise direction by the elasticity of the restricting release preload spring 5, and moves to a position where the tip shaft portion 38 of the restricting engager 4 comes out of the restricting slot 20.

[0077] In this state, the steering column 2 cannot be oscillated around the tilt axis 19, i.e., the height position of the steering wheel cannot be adjusted, based on the frictional force acting between the widthwise inner surfaces of the two support plate portions 25a and 25b and the widthwise outer surfaces of the two flange portions 13. Also, the upper column 11 cannot be displaced axially relative to the lower column 10, i.e., the fore-aft position of the steering wheel cannot be adjusted, based on the frictional force acting between the inner surface of the lower column 10 and the outer surface of the upper column 11, and the meshing force between the fixed gear 46 and the movable gear 51. As a result, the steering wheel is held in the adjusted fore-aft position and height position.

[0078] In this example, the spring constant of the restricting reserve spring 43 is set to be greater than that of the release preload spring 5, and the spring constant of the locking reserve spring 56 is set to be greater than that of the release preload spring 48. Therefore, when switching between the locked and unlocked states, the change in the compression amount of the restricting reserve spring 43 and the locking reserve spring 56 is kept small, but the compression amount of the release preload spring 5 and the release preload spring 48 changes significantly. In other words, the change in the spring compression amount at this time is almost entirely due to the change in the compression amount of the release preload spring 5 and the release preload spring 48.

[0079] In the structure of this example, the role of the regulating reserve spring 43 is to allow the rotation of the switching lever 3 to continue even after the compression amount of the regulating release preload spring 5 has reached its maximum during the rotation of the switching lever 3 when switching from the locked state to the unlocked state, by increasing the compression amount of the regulating reserve spring 43. For this reason, if a setting is adopted in which the compression amount of the regulating release preload spring 5 does not reach its maximum during the rotation of the switching lever 3, the installation of the regulating reserve spring 43 can be omitted. Alternatively, even if a setting is adopted in which the compression amount of the regulating release preload spring 5 reaches its maximum during the rotation of the switching lever 3, if the rotation of the switching lever 3 can be continued by deflecting the regulating cam member 6 after the compression amount reaches its maximum, the installation of the regulating reserve spring 43 can be omitted.

[0080] In the structure of this example, the role of the locking reserve spring 56 is to increase the compression amount of the locking reserve spring 56 so that the rotation of the switching lever 3 can continue even after the tooth surface of the fixed gear 46 and the tooth surface of the movable gear 51 come into contact during the rotation of the switching lever 3, and the locking engager 47 can no longer move inward in the width direction. For this reason, if the rotation of the switching lever 3 can be continued by bending the locking cam member 49 after the locking engager 47 has stopped moving inward in the width direction during the rotation of the switching lever 3, the installation of the locking reserve spring 56 can be omitted.

[0081] When the steering wheel is held in its adjusted fore-aft position and height, if the vehicle is involved in a collision and a secondary collision occurs in which the driver's body strikes the steering wheel, a forward impact load is applied from the steering wheel to the upper column 11 via the upper shaft 22. This impact load disengages the fixed gear 46 and the movable gear 51, causing the upper column 11 to be displaced forward relative to the lower column 10.

[0082] In this process, the impact load during a secondary collision is absorbed based on the axial sliding of the outer circumferential surface of the upper column 11 and the inner circumferential surface of the lower column 10. Furthermore, when implementing the present invention, an impact-absorbing member that undergoes plastic deformation can be installed, and the impact load during a secondary collision can be further absorbed based on this plastic deformation.

[0083] In particular, in this example, as described above, when the upper column 11 is displaced forward relative to the lower column 10, the tip shaft portion 38 of the regulating engager 4 disengages from the regulating elongated hole 20. Therefore, the amount by which the upper column 11 can be displaced forward relative to the lower column 10 can be increased compared to when adjusting the position of the steering wheel, thereby enhancing driver protection.

[0084] Furthermore, in this example, the restricting engager 4 is not fixed to the shock-absorbing member. Therefore, when adjusting the fore-aft position of the steering wheel in the unlocked state, even if the front or rear end of the restricting elongated hole 20 forcefully strikes the tip shaft portion 38 of the restricting engager 4, the shock-absorbing member does not deform, preventing any inconvenience such as unstable shock absorption performance.

[0085] Although one example of an embodiment of the present invention has been described above, the present invention is not limited thereto and can be modified as appropriate without departing from the technical spirit of the invention.

[0086] In carrying out the present invention, the installation locations in the width direction of the telescopic range restricting element, which comprises a restricting slot, a restricting engaging element, a release preload spring, and a restricting cam member, and the locking element, which comprises a fixed-side gear, a locking engaging element, a release preload spring, and a locking cam member, can be reversed from those in the above-described embodiment. That is, the telescopic range restricting element can be installed on the same side as the switching lever in the width direction, and the locking element can be installed on the opposite side of the switching lever in the width direction. In this case, for example, the restricting cam member can be integrally connected to the base end of the switching lever, or the locking cam member can be non-rotatably fitted to a switching rod that rotates together with the switching lever.

[0087] When implementing the present invention, if a locking element including a locking engager having a fixed gear and a movable gear is installed, the engagement and disengagement of the fixed gear and the movable gear in conjunction with the rotation of the switching lever can also be achieved using an appropriate mechanism other than a preload spring for unlocking and a locking cam member.

[0088] When implementing the present invention, if a mechanism other than a locking element, including a locking engager having a fixed gear and a movable gear, is used as a switching mechanism for switching between a locked state in which the front-rear position of the steering wheel cannot be adjusted and an unlocked state in which such adjustment is possible (for example, a mechanism that increases or decreases the frictional force acting between the inner surface of the outer column and the outer surface of the inner column, as in the embodiment described above), the locking element can be omitted.

[0089] When implementing the present invention, if the switching mechanism for switching between a locked state in which the front-to-back position of the steering wheel cannot be adjusted and an unlocked state in which such adjustment is possible is provided with a mechanism other than one that increases or decreases the frictional force acting between the inner surface of the outer column and the outer surface of the inner column (for example, the locking element), then the mechanism that increases or decreases the frictional force can be omitted. In this case, the switching rod having a width dimension equal to or greater than that of the steering column can be omitted, and a shorter shaft can be used as the axis that serves as the pivot point of the switching lever.

[0090] When implementing the present invention, the regulating slot and / or the fixed gear can also be installed in a portion that is circumferentially away from the widthwise end of the upper column. [Explanation of symbols]

[0091] 1. Steering system 2. Steering column 3. Switching lever 4 Regulatory engager 5. Preload spring for deregulation 6. Regulating cam member 7. Switching mechanism 8. Steering shaft 9 Support bracket 10 Roa Column 11 Upper Column 12 slits 13 Flange section 14 Through hole 15 recesses 16 One-sided through-hole 17 Other side through hole 18 Through hole 19 Tilt axis 20 Regulating elongated holes 21 Lower Shaft 22 Upper Shaft 23 Rolling bearings 24 Mounting plate section 25a, 25b Support plate part 26 Tilt elongated holes 27 Switching rod 28 nuts 29 Cam mechanism 30 Thrust bearings 31 Head 32 Male threaded section 33 Drive Cam 34 Driven cam 35 Guard section 36 Proximal shaft part 37 Intermediate shaft section 38 Tip shaft 39 Circuit board section 40 Connecting plate section 41 Cam plate section 42 Regulating cam surface 43. Spare spring for regulation 44 Fitting holes 45 Convex part 46 Fixed-side gear 47 Locking Engagement 48. Preload spring for unlocking 49. Locking cam component 50 Gear Plate 51 Movable gear 52 Guard section 53 Proximal shaft part 54 Tip shaft 55 Locking cam surface 56. Spare spring for locking 57 Fitting hole 58 Convex part 100 Steering System 101 Steering Wheel 102 Steering shaft 103 Steering column 104a, 104b Universal joint 105 Intermediate shaft 106 Steering Gear Unit 107 Pinion shaft 108 Tie Rod

Claims

1. a steering column including a lower column, an upper column combined with the lower column to be able to displace in an axial direction, and a restriction elongated hole that is provided in the upper column directly or via another member and extends in the axial direction of the upper column; a switching lever that is supported by the lower column so as to be rotatable about a rotation central axis in the width direction, and that is switchable between a locked state that disables adjustment of the fore-and-aft position of the steering wheel and an unlocked state that enables such adjustment, based on changing the rotation position about the rotation central axis; a restriction engaging element that is supported by the lower column so as to be movable toward and away from the restriction elongated hole, and that is capable of entering the restriction elongated hole when it approaches the restriction elongated hole and of coming out of the restriction elongated hole when it moves away from the restriction elongated hole; a restriction release preload spring that applies a resilient force to the restriction engaging element in a direction away from the restriction elongated hole; a regulating cam member that rotates together with the switching lever about the rotation central axis, The restricting cam member has a restricting cam surface that pushes the restricting engagement piece in a direction toward the restricting elongated hole, the restricting cam surface is an inclined surface whose position in the direction away from the restricting elongated hole and the restricting engaging element changes along the circumferential direction of the pivot central axis, and a portion that presses the restricting engaging element when the switching lever is in the rotation position for the unlocked state is located closer to the restricting elongated hole than a portion that presses the restricting engaging element when the switching lever is in the rotation position for the locked state, As the switching lever rotates from the rotation position in the locked state to the rotation position in the unlocked state, the restricting engagement piece is pushed by the restricting cam surface to move to a position where it enters the restricting elongated hole, and as the switching lever rotates from the rotation position in the unlocked state to the rotation position in the locked state, the restricting engagement piece is pushed by the elastic force of the restricting release preload spring to move to a position where it comes out of the restricting elongated hole. Steering device.

2. a fixed gear that is provided on the upper column directly or via another member and extends in the axial direction; a locking engager having a movable gear supported by the lower column so as to be movable toward and away from the fixed-side gear, which engages with the fixed-side gear when it approaches the fixed-side gear and is released from engagement with the fixed-side gear when it moves away from the fixed-side gear, As the switching lever rotates from the rotation position in the locked state to the rotation position in the unlocked state, the locking engagement piece moves away to a position where the fixed side gear and the movable side gear are disengaged from each other, and as the switching lever rotates from the rotation position in the unlocked state to the rotation position in the locked state, the locking engagement piece moves closer to a position where the fixed side gear and the movable side gear are engaged with each other. The steering device according to claim 1 .

3. an unlocking preload spring that applies elastic force to the locking engagement element in a direction away from the fixed-side gear; a locking cam member that rotates together with the switching lever about the rotation central axis, the locking cam member has a locking cam surface that pushes the locking engagement element in a direction toward the fixed-side gear, the locking cam surface is an inclined surface whose position changes in relation to the direction in which the fixed-side gear and the locking engaging element are spaced apart along the circumferential direction of the rotation central axis, and a portion that presses the locking engaging element when the switching lever is in a rotation position for the locked state is located closer to the fixed-side gear than a portion that presses the locking engaging element when the switching lever is in a rotation position for the unlocked state, As the switching lever rotates from the rotation position in the locked state to the rotation position in the unlocked state, the locking engagement piece is pushed by the elastic force of the unlocking preload spring and moves to a position where the meshing between the fixed side gear and the movable side gear is released, and as the switching lever rotates from the rotation position in the unlocked state to the rotation position in the locked state, the locking engagement piece is pushed by the locking cam surface and moves to a position where the fixed side gear and the movable side gear mesh. The steering device according to claim 2 .

Images