Steering device

Abstract

The present application provides a kind of steering device, even if the inside of the cylindrical part of lower column enters the inside of the cylindrical part of upper column, can prevent the discharge of lubricating grease.The steering device has: steering shaft, which extends along the first direction and is flexible;And the steering column of outer tube, which supports the steering shaft to be rotatable, the steering column has: lower column;And upper column, one end of which is slidably mounted to lower column, bearing is provided at the other end of the upper column to support the steering shaft, the upper column has: clamping part, which is slidably sleeved on lower column, the clamping part is provided with slit extending along the first direction;And cylindrical part, which is in the shape of a tube, one end of the cylindrical part is continuous with the clamping part, the other end of the cylindrical part is closed by embedding the bearing therein, and the cylindrical part has air hole, which is separated from one end of the cylindrical part and penetrates the outer peripheral surface and the inner peripheral surface of the cylindrical part.

Description

Technical Field

[0001] This invention relates to a steering device. Background Technology

[0002] In a vehicle, a steering system is provided to transmit the driver's operation of the steering wheel to the wheels. Such a steering system includes: a steering shaft on which the steering wheel is mounted; and a steering column with an outer cylinder that supports the steering shaft for rotation. Furthermore, the steering system sometimes includes a mechanism that allows the position of the steering wheel to be changed axially along the steering shaft. For example, the steering shaft in Patent Document 1 includes: a lower shaft; and an upper shaft slidably connected to the lower shaft. The steering column also includes: a lower column containing the lower shaft; and an upper column slidably connected to the lower column. When a load is applied to the steering wheel axially, the upper shaft slides, and the steering wheel is displaced axially. The upper column follows the sliding of the upper shaft.

[0003] Furthermore, the upper pillar of Patent Document 1 includes: a clamping portion that slides freely over the lower pillar; a cylindrical portion extending from the clamping portion toward the steering wheel; and a pair of protrusions that protrude radially outward from the outer periphery of the clamping portion. A slit extending axially is provided in the clamping portion. A bearing supporting the upper shaft is embedded within the cylindrical portion. The pair of protrusions are arranged to clamp the slit of the clamping portion. Furthermore, when a compressive load is applied to the pair of protrusions, the width of the slit in the clamping portion narrows. That is, the clamping portion clamps the lower pillar disposed inside. Thus, the upper pillar is prevented from sliding relative to the lower pillar. Furthermore, the upper shaft supported by the cylindrical portion is also prevented from sliding, and the position of the steering wheel is fixed.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2013-256193 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] Furthermore, regarding the two ends of the cylindrical section, one end is open and continuous with the clamping part, while the interior of the other end near the steering wheel is sealed by the bearing and the upper shaft. Therefore, the interior of the cylindrical section is connected to the external space via the slit of the clamping part. However, when the lower column enters one end of the cylindrical section, that end closes. Furthermore, the air inside the cylindrical section is compressed due to the entry of the lower column. As a result, the air inside the cylindrical section leaks into the external space through the space between the outer circumferential surface of the lower column and the inner circumferential surface of the cylindrical section. The outer circumferential surface of the lower column and the inner circumferential surface of the cylindrical section are sliding surfaces coated with grease. Therefore, the grease may be discharged into the external space along with the air passing between the lower column and the cylindrical section. Moreover, in Patent Document 1, the upper column has a cylindrical section and a clamping part, but in conventional steering devices, there are also cases where the lower column has a cylindrical section and a clamping part. Furthermore, if the upper column enters the cylindrical section of the lower column, the same problem arises.

[0009] The present invention was made in view of the above-mentioned problems, and its object is to provide a steering device that prevents grease leakage even when the lower column enters the interior of the cylindrical portion of the upper column. Alternatively, its object is to provide a steering device that prevents grease leakage even when the upper column enters the interior of the cylindrical portion of the lower column.

[0010] Solution for solving the problem

[0011] To achieve the above objectives, one technical solution of the present invention provides a steering device, wherein the steering device comprises: a steering shaft extending along a first direction and retractable; and a steering column with an outer cylinder supporting the steering shaft for rotational freedom, the steering column comprising: a lower column; and an upper column, one end of which is slidably mounted to the lower column, and the other end of which is provided with a bearing supporting the steering shaft, the upper column comprising: a clamping portion slidably fitted over the lower column, the clamping portion having a slit extending along the first direction; and a cylindrical portion, which is cylindrical, one end of which is continuous with the clamping portion, the other end of which is enclosed by the bearing, the cylindrical portion having an air hole separated from one end of the cylindrical portion and penetrating the outer and inner circumferential surfaces of the cylindrical portion.

[0012] The interior of the cylindrical section is always open through air holes. Therefore, when the lower column enters the interior of the cylindrical section, the air inside the cylindrical section is discharged to the outside space through the air holes. Thus, the grease applied to the outer circumferential surface of the lower column and the inner circumferential surface of the cylindrical section will not be discharged to the outside space along with the air.

[0013] Alternatively, in the aforementioned steering device, when the steering shaft is shortened, the lower column and the air hole may overlap in a direction orthogonal to the first direction.

[0014] As a desired technical solution for the aforementioned steering device, the inner circumferential surface of the cylindrical portion has: a first inner diameter portion that can slide in contact with the outer circumferential surface of the lower column; and a second inner diameter portion whose inner diameter is larger than that of the first inner diameter portion, and the air hole penetrates the second inner diameter portion.

[0015] When the lower column enters the interior of the cylindrical section, it is supported by the first inner diameter section. Therefore, it is possible to suppress the upper column from swaying relative to the lower column. Furthermore, when the lower column enters the interior of the cylindrical section, a gap is created between the lower column and the second inner diameter section. Therefore, the air vent remains open, reliably expelling air from the interior of the cylindrical section.

[0016] As a desired technical solution for the aforementioned steering device, the steering device comprises: a bracket having a first side plate and a second side plate clamping the clamping portion from a second direction orthogonal to the first direction; and a fastening mechanism having a fastening shaft passing through the first side plate and the second side plate, the fastening mechanism fastening the first side plate and the second side plate, the upper column having a pair of protrusions that protrude radially outward from the clamping portion clamping the slit, the pair of protrusions being pressed by the first side plate and the second side plate when the fastening mechanism is fastened, and the pair of protrusions having an elongated groove for the fastening shaft to be inserted into the pair of protrusions, the direction of the air hole being parallel to the direction of the elongated groove being parallel.

[0017] When air holes and elongated slots are formed using casting holes, the demolding directions of the molds for forming air holes and elongated slots are unified. In other words, air holes and elongated slots for expansion can be formed using a single mold, making the manufacture of the upper column easier.

[0018] In addition, to achieve the above objectives, another technical solution of the present invention provides a steering device, wherein the steering device comprises: a steering shaft extending along a first direction and retractable; and a steering column with an outer cylinder supporting the steering shaft for rotational freedom, the steering column comprising: a lower column; and an upper column, one end of which is slidably mounted to the lower column, and a bearing supporting the steering shaft is provided at the other end of the upper column, the lower column comprising: a cylindrical portion being cylindrical; and a clamping portion protruding from one end of the cylindrical portion and slidably fitted onto the upper column, the clamping portion having a slit extending along the first direction, the cylindrical portion having an air hole separated from one end of the cylindrical portion and penetrating the outer and inner circumferential surfaces of the cylindrical portion.

[0019] The interior of the cylindrical section is always open through air holes. Therefore, when the upper column enters the interior of the cylindrical section, the air inside the cylindrical section is discharged to the outside space through the air holes. Thus, the grease applied to the outer circumferential surface of the upper column and the inner circumferential surface of the cylindrical section will not be discharged to the outside space along with the air.

[0020] Alternatively, in the aforementioned steering device, when the steering shaft is shortened, the upper column and the air hole may overlap in a direction orthogonal to the first direction.

[0021] As a desired technical solution for the aforementioned steering device, the inner circumferential surface of the cylindrical portion has: a first inner diameter portion that can slide in contact with the outer circumferential surface of the upper column; and a second inner diameter portion whose inner diameter is larger than that of the first inner diameter portion, and the air hole penetrates the second inner diameter portion.

[0022] When the upper column enters the interior of the cylindrical section, it is supported by the first inner diameter portion. Therefore, swaying of the upper column relative to the lower column is suppressed. Furthermore, when the upper column enters the interior of the cylindrical section, a gap is created between the upper column and the second inner diameter portion. Therefore, the air vent remains open, reliably expelling air from the interior of the cylindrical section.

[0023] The effects of the invention

[0024] In the steering device of the present invention, even if the lower column enters the interior of the cylindrical portion of the upper column, grease leakage can be prevented. Alternatively, even if the upper column enters the interior of the cylindrical portion of the lower column, grease leakage can be prevented. Attached Figure Description

[0025] Figure 1 This is a side view of the steering device in this embodiment.

[0026] Figure 2 This is a perspective view of the steering device in this embodiment.

[0027] Figure 3 This is a side view of the steering device in this embodiment.

[0028] Figure 4 It is a section along the axis Figure 3 A cross-sectional view of the steering device.

[0029] Figure 5 This is a side view of the upper column in this embodiment.

[0030] Figure 6 yes Figure 5 Sectional view along line VI-VI.

[0031] Figure 7 This is a bottom view of the upper column in this embodiment.

[0032] Figure 8 yes Figure 1 Sectional view along line VIII-VIII.

[0033] Figure 9 This is a cross-sectional view of the upper column of this embodiment, cut along the axis. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings. Furthermore, the present invention is not intended to be limited to the manner in which it is carried out (hereinafter referred to as the embodiments). Additionally, the constituent elements in the following embodiments include elements readily conceived by those skilled in the art, substantially the same elements, and elements of so-called equivalent scope. Moreover, the constituent elements disclosed in the following embodiments can be appropriately combined.

[0035] Figure 1 This is a side view of the steering device in this embodiment. Figure 2 This is a perspective view of the steering device in this embodiment. Figure 3 This is a side view of the steering device in this embodiment. Figure 4 It is a section along the axis Figure 3 A cross-sectional view of the steering mechanism. Figure 5 This is a side view of the upper column in this embodiment. Figure 6 yes Figure 5 Sectional view along line VI-VI. Figure 7 This is a bottom view of the upper column in this embodiment. Figure 8 yes Figure 1 Sectional view along line VIII-VIII. Figure 9 This is a cross-sectional view of the upper column of this embodiment when it is cut along the axis.

[0036] First, the basic structure of the steering device 100 will be explained. For example... Figure 1 As shown, the steering device 100 includes a steering wheel 101, a steering shaft 102, a first universal joint 103, an intermediate shaft 104, a second universal joint 105, and a pinion shaft 106.

[0037] The steering wheel 101 is mounted on one end 102a of the steering shaft 102. Thus, when the driver operates the steering wheel 101, the steering shaft 102 rotates about the axis O, imparting operating torque to the steering shaft 102.

[0038] A gearbox 110 is sandwiched between the other end 102b of the steering shaft 102 and the first universal joint 103. An electric motor 120 is assembled in the gearbox 110 to provide auxiliary torque to the steering shaft 102. That is, the steering device 100 of this embodiment is an electric power steering device that uses the electric motor 120 to assist the driver's operation. In addition, the present invention can also be applied to steering devices that do not have a gearbox 110.

[0039] One end of the intermediate shaft 104 is connected to the first universal joint 103. The pinion shaft 106 is connected to the other end of the intermediate shaft 104 via the second universal joint 105. Thus, the operating torque of the steering shaft 102 is transmitted to the pinion shaft 106 via the first universal joint 103, the intermediate shaft 104, and the second universal joint 105.

[0040] like Figure 2 As shown, in addition to the above-described structure, the steering device 100 also includes a steering column 1, a first bracket 70, a second bracket 80, and a fastening mechanism 90. Next, each structure of the steering device 100 will be described in detail. Furthermore, in the following description, an XYZ orthogonal coordinate system will be used. The X-axis is parallel to the axis O of the steering shaft 102. The Y-axis is parallel to the width direction of the vehicle on which the steering device 100 is mounted. The Z-axis is perpendicular to both the X-axis and the Y-axis. The direction parallel to the X-axis is referred to as the X direction, the direction parallel to the Y-axis as the Y direction, and the direction parallel to the Z-axis as the Z direction. The direction in the X direction that faces forward towards the vehicle is referred to as the +X direction. The rightward direction when the operator faces the +X direction is referred to as the +Y direction. The upward direction in the Z direction is referred to as the +Z direction. Additionally, the X direction is sometimes referred to as the first direction, and the Y direction as the second direction.

[0041] like Figure 3 As shown, the steering shaft 102 is assembled with its end protruding from the steering column 1 in the -X direction. Figure 4 As shown, the steering shaft 102 includes an upper shaft 108 as a cylindrical shaft and a lower shaft 109 as a solid shaft. A steering wheel is mounted at the end of the upper shaft 108 in the -X direction (see reference). Figure 1 The upper shaft 108's +X direction end is fitted onto the lower shaft 109. Furthermore, the upper shaft 108's +X direction end and the lower shaft 109's -X direction end are splined together. Therefore, the upper shaft 108 can slide relative to the lower shaft 109 in the X direction.

[0042] The end of the lower shaft 109 in the +X direction enters the interior of the housing 111 of the gearbox 110. Inside the housing 111 of the gearbox 110, there is a torsion bar 112, an output shaft 114 serving as the outer cylinder of the torsion bar 112, and a worm gear 115 sleeved on the output shaft 114. The worm gear 115 meshes with a worm (not shown) connected to the output shaft 114 of the electric motor 120. Therefore, when the electric motor 120 is driven, torque is applied to the output shaft 114.

[0043] The outer peripheral surface of the lower shaft 109 in the +X direction slides in contact with the sealing member 118 fitted into the inner peripheral surface of the housing 111. Additionally, the lower shaft 109 in the +X direction is connected to the end of the torsion bar 112 in the -X direction. The end of the torsion bar 112 in the +X direction is connected to the output shaft 114 via a retaining pin 113. A first universal joint 103 is connected to the end of the output shaft 114 in the +X direction. Therefore, the steering torque of the lower shaft 109 is transmitted to the intermediate shaft 104 (see reference 104) via the torsion bar 112, the output shaft 114, and the first universal joint 103. Figure 1 Transmission. In addition, the torsion bar 112 is twisted accordingly based on the steering torque of the lower shaft 109, thereby generating a rotation angle difference between the lower shaft 109 and the output shaft 114.

[0044] To eliminate the rotational angle difference between the lower shaft 109 and the output shaft 114, a torque detection groove 114a is formed at the end of the output shaft 114 in the -X direction. Furthermore, a cylindrical member 116 is disposed on the outer periphery of the torque detection groove 114a. The cylindrical member 116 is fixed to the end of the lower shaft 109 in the +X direction and rotates integrally with the lower shaft 109. The cylindrical member 116 has a plurality of windows extending radially through it, which are not shown. A torque sensor 117 is disposed on the outer periphery of the cylindrical member 116.

[0045] The torque sensor 117 sends its detection result to a torque detection circuit board (not shown) located inside the housing 111. The torque detection circuit board detects the rotation angle difference between the lower shaft 109 and the output shaft 114. Based on the detection result, the torque detection circuit board drives the electric motor 120 to apply steering assist torque to the output shaft 114. As a result, the rotation angles of the lower shaft 109 and the output shaft 114 become the same.

[0046] like Figure 2 As shown, the first bracket 70 includes a pair of support plates 71 spaced apart from each other in the Y direction. Each support plate 71 includes a mounting plate 72 extending in both the X and Y directions, and a support plate 73 extending in both the X and Z directions. The mounting plate 72 is fixed to the vehicle body by bolts (not shown). At the -Z end of the support plate 73, a pivot 74 extending in the Y direction is rotatably provided. The gearbox 110 is fixed to the pivot 74. Therefore, the gearbox 110, steering shaft 102, steering column 1, and steering wheel 101 are supported on the first bracket 70 (see reference 1) in a manner that allows rotation about the pivot 74. Figure 1 Arrows A1 and A2).

[0047] like Figure 4As shown, the steering column 1 is an outer cylinder extending along the X direction and surrounding the steering shaft 102. The steering column 1 includes an upper column 2 and a lower column 3, which is disposed relative to the upper column 2 in the +X direction. The lower column 3 is cylindrical. The +X end of the lower column 3 is fitted over the housing 111 of the gearbox 110. Here, the opening at the -X end of the housing 111 is sealed by the lower shaft 109 and the sealing member 118. In addition, the internal sealing of the housing 111 of the gearbox 110 is high. Therefore, even if the internal air pressure of the lower column 3 increases, air is unlikely to enter the interior of the housing 111 from the opening at the +X end of the lower column 3.

[0048] Column 2 is formed by casting. For example... Figure 3 , Figure 4 , Figure 5 As shown, the upper column 2 includes a clamping portion 10 that is fitted over the lower column 3, a cylindrical portion 20 extending from the clamping portion 10 in the -X direction, a mounting portion 30 located at the end of the clamping portion 10 in the +X direction, and a pair of protrusions 40 protruding from the outer periphery of the clamping portion 10 in the -Z direction. Figure 3 , Figure 5 (Only one is shown in the figure), and the abutment rib 50 extending along the X direction (see reference). Figure 3 , Figure 5 ).

[0049] The inner circumferential surface of the cylindrical portion 20 is circular. The inner diameter of the cylindrical portion 20 is such that the lower column 3 can enter it. A bearing 21 is embedded in the end of the cylindrical portion 20 in the -X direction. Furthermore, the cylindrical portion 20 supports the upper shaft 108 for free rotation by means of the bearing 21. That is, the opening at the end of the cylindrical portion 20 in the -X direction is closed by the bearing 21 and the upper shaft 108, resulting in a high degree of sealing. In addition, if the bearing 21 has a seal (not shown) to prevent grease leakage from the inside of the bearing 21, the sealing performance of the opening at the end of the cylindrical portion 20 in the -X direction is further improved. Therefore, even if the air pressure inside the cylindrical portion 20 increases, it is difficult for air to escape from the opening at the end of the cylindrical portion 20 in the -X direction. Other structures of the cylindrical portion 20 will be described later.

[0050] like Figure 6 As shown, the clamping part 10 is provided with a slit 11. For example... Figure 7 As shown, the slit 11 of the clamping part 10 extends along the X direction. Therefore, the clamping part 10 extends along the X direction with an arc-shaped cross-section. Furthermore, when no external force is applied to the clamping part 10, the inner diameter of the clamping part 10 is approximately the same as the outer diameter of the lower column 3. In other words, the clamping part 10 can slide freely relative to the lower column 3.

[0051] like Figure 6As shown, when viewed from axis O, the slit 11 of the clamping part 10 is located in the -Z direction. Therefore, the width of the slit 11 is in the Y direction. Consequently, when a compressive load is applied to the clamping part 10 from the Y direction, the clamping part 10 deforms by narrowing the width of the slit 11. That is, the clamping part 10 reduces its diameter and clamps the lower column 3 disposed inside. As a result, a large frictional force exists between the inner circumferential surface of the clamping part 10 and the outer circumferential surface of the lower column 3, and the sliding of the upper column 2 is restricted.

[0052] like Figure 7 , Figure 9 As shown, a notch 31 is provided in a portion of the mounting portion 30 in the +Z direction. (As indicated...) Figure 7 As shown, the mounting portion 30 is spiraled in an arc shape relative to the lower column 3 in the -Z direction. A mounting rib 32 is provided on the outer peripheral surface of the mounting portion 30 facing the -Z direction. An internally threaded hole 33 is provided in the mounting rib 32. A bracket (not shown) for supporting electrical wiring, etc., is mounted in the internally threaded hole 33.

[0053] Furthermore, at both ends of the slit 11 in the X direction of the clamping portion 10, a first expanding slit 12 and a second expanding slit 13 are provided, with a groove width that expands circumferentially compared to the groove width of the slit 11. Through these first expanding slits 12 and second expanding slits 13, the portion of the clamping portion 10 that is not continuous with the adjacent cylindrical portion 20 and mounting portion 30 in the X-axis direction increases. As a result, the clamping portion 10 is less affected by the rigidity of the cylindrical portion 20 and mounting portion 30, and the clamping portion 10 is more prone to deformation.

[0054] like Figure 7 As shown, a pair of protrusions 40, 40 are arranged such that they clamp the slit 11 when viewed from the -Z direction. Hereinafter, of the pair of protrusions 40, 40, the protrusion positioned further in the -Y direction than the slit 11 will be referred to as the first protrusion 41, and the protrusion positioned further in the +Y direction than the slit 11 will be referred to as the second protrusion 42. The first protrusion 41 and the second protrusion 42 extend in the X direction with approximately the same length as the clamping portion 10. Figure 5 As shown, elongated slots 43 and 44 extending along the X direction are provided. For example... Figure 6 As shown, long grooves 43 and 44 are connected along the Y direction.

[0055] like Figure 6 As shown, the abutment rib 50 has a pair of first abutment ribs 51, 51 and a pair of second abutment ribs 52, 52. The first abutment rib 51 protrudes from the outer peripheral surface of the clamping portion 10. The second abutment rib 52 protrudes from the outer side surfaces of the first protrusion 41 and the second protrusion 42.

[0056] like Figure 5As shown, the first abutment rib 51 and the second abutment rib 52 extend in a straight line along the X direction. When viewed from the Y direction, the first abutment rib 51 overlaps with the axis O. The end of the first abutment rib 51 in the X direction is continuous with the second annular rib 23. The second abutment rib 52 is located at the end of the first protrusion 41 in the Z direction and the end of the second protrusion 42 in the Z direction, and extends along the edges of the elongated grooves 43 and 44. Thus, the first abutment rib 51 and the second abutment rib 52 are arranged sandwiching the elongated grooves 43 and 44.

[0057] like Figure 8 As shown, the second bracket 80 includes a pair of mounting plates 81, 82, a top plate 82, a first side plate 83, and a second side plate 84. Furthermore, the second bracket 80 is sometimes simply referred to as a bracket.

[0058] A pair of mounting plates 81 are plate-shaped members that sandwich the steering column 1 and are separated in the Y direction. The mounting plates 81 are connected to the vehicle body by means of a release capsule 85. The release capsule 85 is located at the end of the mounting plate 81 in the -X direction. The release capsule 85 is integrated with the mounting plate 81 by a resin member 86. The release capsule 85 is fixed to the side member of the vehicle body by bolts or the like. Furthermore, in the event of a secondary collision of the vehicle and a load in the +X direction acting on the steering column 1 (see reference...) Figure 1 Arrow D1), resin component 86 breaks, only mounting plate 81 moves in the +X direction, thus the second bracket 80 detaches from the vehicle body.

[0059] The upper plate 82 is a plate-like member that connects a pair of mounting plates 81, 81 to each other. The first side plate 83 and the second side plate 84 are plate-like members extending in the X and Z directions, respectively. The first side plate 83 is positioned closer to the -Y direction than the clamping portion 10. The second side plate 84 is positioned closer to the +Y direction than the clamping portion 10. That is, the first side plate 83 and the second side plate 84 are separated in the Y direction, clamping the clamping portion 10 of the steering column 1. The first side plate 83 and the second side plate 84 are integrated with the pair of mounting plates 81, 81 and the upper plate 82 by welding. An arcuate groove 83a extending in the Z direction is formed on the first side plate 83, and an arcuate groove 84a extending in the Z direction is formed on the second side plate 84. The arcuate grooves 83a and 84a are pivoted at 74 (see reference). Figure 1 , Figure 2 , Figure 3 The first side plate 83 is formed into an arc shape centered on the first side plate 84. Furthermore, a protruding plate 87 protruding in the -Y direction is provided at the end of the first side plate 83 in the +X direction. Therefore, the stiffness of the first side plate 83 in the Y direction is higher than the stiffness of the second side plate 84 in the Y direction.

[0060] The fastening mechanism 90 is a device for applying a compressive load to the clamping part 10 to fasten it. The fastening mechanism 90 includes a fastening shaft 91, an operating lever 92, a fixed cam 93, a rotating cam 94, a nut 95, a spacer 96, and a thrust bearing 97.

[0061] The fastening shaft 91 is a rod-shaped component. The fastening shaft 91 is inserted sequentially from the -Y direction toward the +Y direction into the arcuate groove 83a of the first side plate 83, the elongated grooves 43 and 44 of the clamping part 10, and the arcuate groove 84a of the second side plate 84, and extends along the Y direction. A head 91a is provided at the -Y direction end of the fastening shaft 91. An operating lever 92 is connected to the -Y direction end of the fastening shaft 91. The operating lever 92 extends from the fastening shaft 91 toward the -X direction and can be operated by the driver inside the vehicle (see reference). Figure 1 , Figure 2 Therefore, when the driver operates the control lever 92 by rotating it around the fastening shaft 91, the fastening shaft 91 rotates in conjunction with it.

[0062] A fixed cam 93 and a rotary cam 94 are disposed between the first side plate 83 and the operating lever 92, with a fastening shaft 91 passing through them. The fixed cam 93 is adjacent to the first side plate 83. A portion of the fixed cam 93 is fitted into the arcuate groove 83a of the first side plate 83. Therefore, the fixed cam 93 does not rotate in conjunction with the fastening shaft 91. The rotary cam 94 is adjacent to the operating lever 92. The rotary cam 94 is connected to the operating lever 92 and rotates integrally with the operating lever 92. On the opposing surfaces of the fixed cam 93 and the rotary cam 94, there are inclined surfaces along the circumferential direction. When the rotary cam 94 is rotated by operating the operating lever 92, the inclined surface of the fixed cam 93 rises or falls relative to the inclined surface of the rotary cam 94. As a result, the distance in the Y direction between the fixed cam 93 and the rotary cam 94 changes.

[0063] An external threaded portion 91b is provided at the end of the fastening shaft 91 in the +Y direction. The nut 95 is threaded into this external threaded portion 91b. Therefore, the fastening shaft 91 will not detach from the arcuate grooves 83a, 84a, and the elongated grooves 43, 44. The spacer 96 and the thrust bearing 97 are disposed between the second side plate 84 and the nut 95, with the fastening shaft 91 passing through them. The spacer 96 abuts against the portion of the second side plate 84 located around the arcuate groove 84a. The thrust bearing 97 is disposed between the nut 95 and the spacer 96.

[0064] Therefore, when the fixed cam 93 and the rotating cam 94 are separated in the Y direction by operating the lever 92, the head 91a of the fastening shaft 91 is pressed in the -Y direction, and the nut 95 moves in the -Y direction. As a result, the distance in the Y direction between the fixed cam 93 and the spacer 96 is shortened, and the friction between the fixed cam 93 and the first side plate 83 and the friction between the spacer 96 and the second side plate 84 increases. Consequently, the movement of the fastening shaft 91 in the Z direction along the arcuate grooves 83a and 84a is restricted. Therefore, the movement of the upper column 2, which is penetrated by the fastening shaft 91, in the Z direction is also restricted, and the position of the steering wheel 101 in the Z direction is fixed.

[0065] Furthermore, the self-fixing cam 93 and the spacer 96 fasten the first side plate 83 and the second side plate 84 along the Y direction. Therefore, the inner surfaces of the first side plate 83 and the second side plate 84 abut against a pair of second abutment ribs 52 of the upper pillar 2. Additionally, the first side plate 83 and the second side plate 84 are pressed together by the pair of second abutment ribs 52. As a result, the first protrusion 41 and the second protrusion 42 are subjected to a compressive load in the Y direction. The slot width of the slit 11 of the clamping part 10 narrows, thereby clamping the lower pillar. Thus, the upper pillar 2 is fixed to the lower pillar 3, and the movement of the steering wheel 101 in the X direction is restricted.

[0066] In addition, the first side plate 83 and the second side plate 84 press not only the pair of second abutting ribs 52, 52, but also the pair of first abutting ribs 51, 51. Thus, a compressive load can be applied to the pair of first abutting ribs 51, 51, causing the clamping portion 10 to narrow in diameter. Furthermore, the first abutting rib 51 is separated from the fastening shaft 91 that applies the fastening force. Therefore, the compressive load acting on the first abutting rib 51 is less than the compressive load acting on the second abutting rib 52. On the other hand, even if a compressive load is applied to the second abutting rib 52, there is a possibility that the first protrusion 41 and the second protrusion 42 tilt in such a way that only the ends of the first protrusion 41 in the -Z direction and the ends of the second protrusion 42 in the -Z direction approach each other, and the slit of the clamping portion 10 does not narrow. In other words, by using the first abutting rib 51, a compressive load can be applied to the clamping portion 10 without passing through the first protrusion 41 and the second protrusion 42. Therefore, when the operating lever 92 is operated, the clamping part 10 will reliably clamp the lower column 3.

[0067] On the other hand, when the fixed cam 93 and the rotating cam 94 are brought closer together in the Y direction by operating the lever 92, the distance between the fixed cam 93 and the spacer 96 in the Y direction increases. This reduces the friction between the fixed cam 93 and the first side plate 83. Furthermore, the friction between the spacer 96 and the second side plate 84 also decreases. Therefore, the fastening shaft 91 is allowed to move in the Z direction along the arcuate grooves 83a and 84a. And when a load in the Z direction is applied to the steering wheel 101, the steering column 1, steering shaft 102, and gearbox 110 will pivot around the pivot 74 (see reference 1). Figure 1 Rotate the steering wheel 101 along the direction of arrow A1 or arrow A2, with the steering wheel as the center. As a result, the position of the steering wheel 101 in the Z direction changes.

[0068] Furthermore, the fastening of the first abutment rib 51 and the second abutment rib 52 is released from the fastening of the first side plate 83 and the second side plate 84. Therefore, the slot width of the slit 11 of the clamping part 10 widens, releasing the clamping of the lower pillar 3. And, when a load in the X direction is applied to the steering wheel 101, the upper pillar 2 and the upper shaft 108 slide in the X direction. As a result, the position of the steering wheel 101 in the X direction changes (see reference). Figure 1 Arrows B1 and B2).

[0069] Next, the details of the cylindrical portion 20 of the upper column 2 will be explained. For example... Figure 5 As shown, on the outer peripheral surface 20a of the cylindrical portion 20, a first annular rib 22 and a second annular rib 23 are provided, arranged apart from each other in the X direction. On the outer peripheral surface 20a of the cylindrical portion 20, and at a position between the first annular rib 22 and the second annular rib 23, four straight ribs 24a, 24b, 24c, and 24d extending in the X direction are provided at 90-degree intervals (for straight rib 24d, refer to...). Figure 7 Therefore, the rigidity of the cylindrical part 20 is very high.

[0070] Here, as Figure 1 As shown, during a secondary collision, the load directed towards the front of the vehicle is applied to the steering wheel 101 (refer to...). Figure 1 Arrow D1). Thus, as Figure 5 As shown, when viewed from axis O, the wall portion of the cylindrical section 20 in the +Z direction experiences a compressive load (see reference). Figure 5 Arrow D2). Additionally, the wall portion of the cylindrical section 20, viewed from axis O, experiences a tensile load in the -Z direction (see reference). Figure 5 (Arrow D3). Assuming that when the cylindrical portion 20 deforms, the lower pillar 3 cannot enter the interior of the cylindrical portion 20. In other words, during a secondary collision, it is impossible to shorten the steering shaft 102 to absorb the collision energy. Therefore, the straight ribs 24a and 24c are ribs that improve the stiffness against the compressive and tensile loads acting on the cylindrical portion 20 during a secondary collision.

[0071] like Figure 5 , Figure 9 As shown, an air hole 25 is provided in the cylindrical portion 20, penetrating both the outer peripheral surface 20a and the inner peripheral surface 20b of the cylindrical portion 20. The air hole 25 is located in the wall portion of the cylindrical portion 20 in the +Y direction when viewed from the axis O, and is adjacent to the straight rib 24b. Therefore, even though the air hole 25 is provided in the cylindrical portion 20, the stiffness of the wall portions of the cylindrical portion 20 located in the +Z and -Z directions when viewed from the axis O will not be reduced.

[0072] Air hole 25 extends along the Y direction. That is, air hole 25 is parallel to the direction of elongated slots 43 and 44 that penetrate the protrusion 40. Here, elongated slots 43 and 44 are formed by casting holes. In detail, elongated slot 43 is formed by a mold that demolds from the upper column 2 in the -Y direction (see reference). Figure 6 Arrow C1). The long groove 44 is formed by a mold that demolds from the upper pillar 2 in the +Y direction (see reference). Figure 6 (Arrow C2). Therefore, the demolding directions of the mold forming the air hole 25 and the mold forming the long groove 44 are unified, and the air hole 25 and the long groove 44 can be formed using a single mold.

[0073] like Figure 9 As shown, the inner circumferential surface 20b of the cylindrical portion 20 includes: a flange portion 26 that restricts the bearing 21 from moving in the +X direction; a first inner diameter portion 27 that slides in contact with the outer circumferential surface of the lower column 3; and a second inner diameter portion 28 whose inner diameter is larger than that of the first inner diameter portion 27.

[0074] A flange portion 26 is located at the end of the cylindrical portion 20 in the -X direction. A first inner diameter portion 27 is located at the end of the cylindrical portion 20 in the +X direction. Furthermore, the first inner diameter portion 27 extends in the +X direction and is disposed across the inner circumferential surface of the clamping portion 10. This first inner diameter portion 27 is the surface through which the outer circumferential surface of the lower column 3 slides when the clamping portion 10 is not reduced in diameter. Additionally, a third inner diameter portion 14 is provided on the inner circumferential surface of the clamping portion 10. This third inner diameter portion 14 is separated from the first inner diameter portion 27 in the +X direction, and the inner diameter of the third inner diameter portion 14 is the same as the inner diameter of the first inner diameter portion 27. In other words, between the first inner diameter portion 27 and the third inner diameter portion 14, a fourth inner diameter portion 15 is provided, whose inner diameter is larger than both the inner diameters of the first and third inner diameter portions 14. Therefore, when the clamping part 10 has a reduced diameter, the clamping force of the clamping part 10 is concentrated on the first inner diameter part 27 and the third inner diameter part 14. The second inner diameter part 28 is located at the center of the cylindrical part 20 in the X direction. In addition, the air hole 25 is located at the center of the cylindrical part 20 in the X direction and is separated from the end of the cylindrical part 20 in the +X direction. Furthermore, the air hole 25 penetrates the second inner diameter part 28.

[0075] Next, refer to Figure 9The relationship between the cylindrical portion 20 and the lower column 3 is explained. Furthermore, the dashed lines indicated by reference numerals 3A, 3B, and 3C in the attached drawings represent the end face of the lower column 3 in the -X direction. When the length of the steering shaft 102 in the X direction is at its longest, the upper column 2 slides in the -X direction. At this time, as... Figure 9 As shown by reference numeral 3A in the attached drawing, the lower column 3 does not enter the interior of the cylindrical portion 20. Therefore, the end of the cylindrical portion 20 is open in the +X direction. The air inside the cylindrical portion 20 communicates with the external space through the air hole 25 or the slit 11 of the clamping portion 10.

[0076] Next, when the length of the steering shaft 102 in the X direction shortens and the upper column 2 slides in the +X direction, as follows: Figure 9 As shown by reference numeral 3B in the attached drawing, the lower column 3 enters the interior of the cylindrical portion 20. Thus, the interior of the cylindrical portion 20 is continuous with the interior of the lower column 3 via an opening at its end in the -X direction (see reference 3B). Figure 4 Furthermore, the +X end of the space formed by the interior of the cylindrical portion 20 and the interior of the lower column 3 is sealed by the lower shaft 109, the sealing member 118, and the gearbox 110. Additionally, the -X end of the space formed by the interior of the cylindrical portion 20 and the interior of the lower column 3 is sealed by the bearing 21 and the upper shaft 108. On the other hand, the interior of the cylindrical portion 20 communicates with the external space via the air hole 25. Therefore, when the air pressure in the space formed by the interior of the cylindrical portion 20 and the interior of the lower column 3 increases, the air inside the cylindrical portion 20 is discharged to the external space through the air hole 25.

[0077] Next, in the case where the length of the steering shaft 102 in the X direction is the shortest, such as Figure 9 As shown by reference numeral 3C in the attached drawing, the amount of the lower column 3 entering the interior of the cylindrical portion 20 increases. Then, when the amount of the lower column 3 entering exceeds a predetermined amount, the outer peripheral surface of the lower column 3 faces the air hole 25. In other words, the lower column 3 and the air hole 25 overlap in a direction orthogonal to the axis O. Here, the inner diameter of the second inner diameter portion 28 is larger than the inner diameter of the first inner diameter portion 27, creating a gap between the second inner diameter portion 28 and the outer peripheral surface of the lower column 3. Therefore, the air inside the cylindrical portion 20 communicates with the external space through the gap created between the second inner diameter portion 28 and the outer peripheral surface of the lower column 3 and the air hole 25. Therefore, according to this embodiment, the air inside the cylindrical portion 20 is not discharged to the external space through the gap between the lower column 3 and the first inner diameter portion 27.

[0078] As described above, the steering device 100 of the embodiment includes: a steering shaft 102 that extends and is retractable in a first direction; and a steering column 1 with an outer cylinder that supports the steering shaft 102 for rotational freedom. The steering column 1 includes: a lower column 3; and an upper column 2, one end of which is slidably mounted to the lower column 3, and the other end of which is provided with a bearing 21 supporting the steering shaft 102. The upper column 2 includes: a clamping portion 10 that is slidably fitted over the lower column 3, the clamping portion 10 having a slit 11 extending in the first direction; and a cylindrical portion 20 that is cylindrical, one end of which is continuous with the clamping portion 10, and the other end of which is enclosed by the bearing 21. The cylindrical portion 20 has an air hole 25 that is separated from one end of the cylindrical portion 20 and extends through the outer peripheral surface 20a and the inner peripheral surface 20b.

[0079] Air inside the cylindrical portion 20 is discharged to the outside through the air hole 25. In other words, air inside the cylindrical portion 20 will not be discharged between the outer peripheral surface of the lower column 3 and the inner peripheral surface of the cylindrical portion 20. Therefore, it is possible to prevent the grease applied to the outer peripheral surface of the lower column 3 and the inner peripheral surface of the cylindrical portion 20 from being discharged to the outside.

[0080] In the steering device 100 of this embodiment, when the steering shaft 102 is shortened, the lower column 3 and the air hole 25 overlap in a direction orthogonal to the first direction. Furthermore, the inner circumferential surface 20b of the cylindrical portion 20 of the steering device 100 of this embodiment has a first inner diameter portion 27 capable of sliding contact with the outer circumferential surface of the lower column 3, and a second inner diameter portion 28 with an inner diameter larger than that of the first inner diameter portion 27. The air hole 25 passes through the second inner diameter portion 28.

[0081] The lower column, which enters the interior of the cylindrical portion 20, is supported by the first inner diameter portion 27. Therefore, it is possible to suppress the upper column 2 from swaying relative to the lower column 3. Furthermore, since a gap exists between the lower column 3 and the second inner diameter portion 28, the air hole 25 remains open at all times.

[0082] The steering device 100 of this embodiment includes: a bracket having a first side plate 83 and a second side plate 84 clamping a clamping portion 10 from a second direction orthogonal to a first direction; and a fastening mechanism 90 having a fastening shaft 91 passing through the first side plate 83 and the second side plate 84, the fastening mechanism 90 fastening the first side plate 83 and the second side plate 84. The upper column 2 has a pair of protrusions 40, 40 that protrude radially outward from the clamping portion 10, clamping a slit 11, and when the fastening mechanism 90 is tightened, the pair of protrusions 40, 40 are pressed by the first side plate 83 and the second side plate 84. The pair of protrusions 40, 40 are provided with elongated slots 43, 44 for the fastening shaft 91 to be inserted. The direction in which the air hole 25 passes is parallel to the direction in which the elongated slots 43, 44 pass.

[0083] When air holes 25 and long grooves 44 are formed using casting holes, the demolding directions of the molds forming air holes 25 and long grooves 44 are unified, allowing air holes 25 and long grooves 44 to be formed by a single mold. Therefore, the manufacturing of the lower column 3 becomes easier.

[0084] The above describes the embodiments, but the steering device of the present invention can also be applied to a structure in which the lower column has a cylindrical portion and a clamping portion, and the upper column enters the cylindrical portion of the lower column. That is, the steering device includes: a steering shaft that extends and is retractable along a first direction; and a steering column with an outer cylinder that supports the steering shaft for rotational freedom. The steering column includes: a lower column; and an upper column, one end of which is slidably mounted to the lower column, and a bearing supporting the steering shaft is provided at the other end of the upper column. Furthermore, the lower column includes: a cylindrical portion that is cylindrical; and a clamping portion that protrudes from one end of the cylindrical portion and is slidably fitted onto the upper column, the clamping portion having a slit extending along the first direction. The cylindrical portion has an air hole that is separated from one end of the cylindrical portion and extends through the outer and inner circumferential surfaces. With such a steering device, when the upper column enters the cylindrical portion of the lower column, the air inside the cylindrical portion is discharged to the outside space through the air hole. Therefore, it can prevent the grease applied to the outer circumferential surface of the upper column and the inner circumferential surface of the cylindrical part from being discharged into the external space.

[0085] Furthermore, when the upper column enters the cylindrical portion of the lower column and the steering shaft shortens, the upper column and the air hole overlap in a direction orthogonal to the first direction. In this case, the inner circumferential surface of the cylindrical portion has a first inner diameter portion that can slide in contact with the outer circumferential surface of the upper column and a second inner diameter portion whose inner diameter is larger than that of the first inner diameter portion. The air hole can also penetrate the second inner diameter portion. Thus, the upper column, which enters the interior of the cylindrical portion, is supported by the first inner diameter portion. Therefore, swaying of the upper column relative to the lower column can be suppressed. Additionally, since a gap is created between the upper column and the second inner diameter portion, the air hole remains open.

[0086] Explanation of reference numerals in the attached figures

[0087] 100. Steering device; 101. Steering wheel; 102. Steering shaft; 108. Upper shaft; 109. Lower shaft; 110. Gearbox; 1. Steering column; 2. Upper column; 3. Lower column; 10. Clamping part; 11. Slit; 12. First expansion slit; 13. Second expansion slit; 20. Cylindrical part; 21. Bearing; 25. Air hole; 27. First inner diameter part; 28. Second inner diameter part; 30. Mounting part; 40 ( 41, 42) Protrusions (first protrusion, second protrusion); 43, 44, long grooves; 50, abutment ribs; 51, first abutment ribs; 52, second abutment ribs; 70, first bracket; 74, pivot; 80, second bracket; 83, first side plate; 84, second side plate; 90, fastening mechanism; 91, fastening shaft; 92, operating lever; 93, fixed cam; 94, rotating cam; 95, nut.

Claims

1. A steering device, wherein, The steering mechanism includes: A steering shaft that extends and retracts freely along a first direction; and The outer cylinder's steering column supports the steering shaft for free rotation. The steering column has: Lower pillar; and The upper column has one end slidably mounted to the lower column, and the other end of the upper column is provided with a bearing to support the steering shaft. The upper column has: A clamping part, which slides freely around the lower post, is provided with a slit extending along the first direction; and The cylindrical portion is cylindrical in shape, with one end continuous to the clamping portion and the other end of the cylindrical portion enclosed by the bearing. The cylindrical portion has an air hole, which is separated from one end of the cylindrical portion and extends through the outer and inner circumferential surfaces of the cylindrical portion. When the steering shaft is shortened, the lower column and the air hole overlap in a direction orthogonal to the first direction. The inner circumferential surface of the cylindrical portion has: The first inner diameter portion is capable of sliding contact with the outer peripheral surface of the lower column; and The second inner diameter portion has a larger inner diameter than the first inner diameter portion. The air hole extends through the second inner diameter portion.

2. A steering device, wherein, The steering mechanism includes: Steering shaft, which extends and retracts freely along the first direction; The outer cylinder has a steering column that supports the steering shaft for free rotation; A bracket having a first side plate and a second side plate that clamp the steering column from a second direction orthogonal to the first direction; and A fastening mechanism having a fastening shaft passing through the first side plate and the second side plate, the fastening mechanism fastening the first side plate and the second side plate. The steering column has: Lower pillar; and The upper column has one end slidably mounted to the lower column, and the other end of the upper column is provided with a bearing to support the steering shaft. The upper column has: The clamping part, which slidably fits onto the lower post, is provided with a slit extending along the first direction; and The cylindrical portion is cylindrical in shape, with one end continuous to the clamping portion and the other end of the cylindrical portion enclosed by the bearing. The cylindrical portion has an air hole, which is separated from one end of the cylindrical portion and extends through the outer and inner circumferential surfaces of the cylindrical portion. The upper column has a pair of protrusions that protrude radially outward from the clamping portion, clamping the slit. When the fastening mechanism is tightened, the pair of protrusions are pressed down by the first side plate and the second side plate. The pair of protrusions are provided with elongated slots for inserting the fastening shaft. The direction in which the air hole penetrates is parallel to the direction in which the long groove penetrates.

3. A steering device, wherein, The steering mechanism includes: A steering shaft that extends and retracts freely along a first direction; and The outer cylinder's steering column supports the steering shaft for free rotation. The steering column has: Lower pillar; and The upper column has one end slidably mounted to the lower column, and the other end of the upper column is provided with a bearing to support the steering shaft. The lower column has: The tubular part, which is tubular in shape; and A clamping part, which protrudes from one end of the cylindrical part and slides freely over the upper column, is provided with a slit extending along the first direction. The cylindrical portion has an air hole, which is separated from one end of the cylindrical portion and extends through the outer and inner circumferential surfaces of the cylindrical portion. When the steering shaft is shortened, the upper column and the air vent overlap in a direction orthogonal to the first direction. The inner circumferential surface of the cylindrical portion has: The first inner diameter portion is capable of sliding contact with the outer peripheral surface of the upper column; and The second inner diameter portion has a larger inner diameter than the first inner diameter portion. The air hole extends through the second inner diameter portion.

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