Support bracket for steering system and steering system

Abstract

To accomplish a structure of a steering device supporting bracket capable of securing the surface accuracy of a width-direction inside surface of a step portion provided at a supporting plate.SOLUTION: An upper bracket 7 includes an attaching plate 25, a pair of supporting plates 26 and a welding bead 27. The attaching plate 25 includes a bridge portion 29, a pair of side plate portions 30 and a pair of connecting portions 31. Each of the pair of supporting plates 26 includes a supporting plate body 35 with a step portion 42, and a welding edge portion 36. Each of the pair of connecting portions 31 is formed in a planar shape, and is inclined in a direction toward the outside in a width direction as going downward. Consequently, a welding pocket 45 that stores the welding bead 27 is formed between a width-direction inside surface of each of the pair of connecting portions 31 and an upper end of a width-direction outside surface of each of the pair of supporting plate bodies 35.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a support bracket for a steering device and a steering device.

Background Art

[0002] A steering device incorporated in a vehicle such as an automobile transmits the movement of a steering wheel operated by a driver to a steering gear unit via a steering shaft, and imparts a steering angle to left and right steering wheels. The steering device is provided with a position adjusting device that enables adjustment of the position of the steering wheel according to the physique and driving posture of the driver.

[0003] FIG. 10 shows an example of a steering device provided with a position adjusting device for a steering wheel. The steering device 100 includes a steering shaft 101 to which a steering wheel (not shown) is fixed at a rear end portion, and a steering column 102 that rotatably supports the steering shaft 101 inside.

[0004] The front side portion of the steering column 102 is supported by a lower bracket 103, and the middle portion in the front-rear direction of the steering column 102 is supported by an upper bracket 104 corresponding to a support bracket. The lower bracket 103 and the upper bracket 104 are supported by a vehicle body 105. An electric assist device 106 for reducing the force required for operating the steering wheel is provided at the front side portion of the steering column 102.

[0005] To allow adjustment of the fore-aft position of the steering wheel, the steering column 102 is configured to be extendable and retractable in length by fitting the rear part of the inner column 107, which is positioned forward, and the front part of the outer column 108, which is positioned rearward, so as to allow relative displacement in the axial direction. The outer column 108 has a column-side through hole (not shown) that extends in the front-rear direction and is configured to be retractable in diameter, and is supported so as to be movable in the front-rear direction relative to the upper bracket 104. The steering shaft 101 is configured by combining the inner shaft 109 and the outer shaft 110 so as to be able to transmit torque and be extendable and retractable by spline engagement or the like.

[0006] To allow adjustment of the vertical position of the steering wheel, the steering column 102 is supported relative to the lower bracket 103 so as to be able to swing around the tilt axis 111. The outer column 108 is supported relative to the upper bracket 104 so as to be able to move vertically.

[0007] In the illustrated structure, the upper bracket 104 comprises a mounting plate portion 112 supported by the vehicle body 105 and a pair of support plate portions 113 arranged on both sides in the width direction of the outer column 108. Each of the pair of support plate portions 113 has a bracket-side through hole 114 that extends in the vertical direction.

[0008] An adjustment rod 115 is inserted in the width direction through a bracket-side through hole 114 and a column-side through hole provided in the outer column 108. In the illustrated steering device 100, by operating an adjustment lever 116 located at the end of the adjustment rod 115, the axial dimension of the cam device 128 is expanded or contracted, thereby expanding or contracting the distance between the widthwise inner surfaces of a pair of support plate portions 113. This adjusts the clamping force on the outer column 108 by the widthwise inner surfaces of the pair of support plate portions 113. When clamped with the distance between the widthwise inner surfaces of the pair of support plate portions 113 reduced, the outer column 108 is reduced in diameter, increasing the force with which the outer column 108 holds the outer circumferential surface of the inner column 107. As a result, the position of the steering wheel becomes unadjustable. In contrast, when the spacing between the inner surfaces of the pair of support plate sections 113 in the width direction is widened during unclamping, the outer column 108 elastically recovers, reducing the force with which the outer column 108 holds the outer surface of the inner column 107. As a result, the fore-aft and up-down positions of the steering wheel can be adjusted within the range in which the adjustment rod 115 can move inside the column-side through-hole and the bracket-side through-hole 114.

[0009] Figures 11 and 12 show the specific structures of the upper bracket 104a and outer column 108a as described in Japanese Patent Publication No. 2017-197178 (Patent Document 1).

[0010] The upper bracket 104a comprises a mounting plate portion 112a and a pair of support plate portions 113a.

[0011] The mounting plate portion 112a comprises a bridge portion 117 located in the center in the width direction, a pair of side plate portions 118 located on both outer sides in the width direction, and a pair of connecting portions 119 that connect the outer ends of the bridge portion 117 in the width direction to the pair of side plate portions 118.

[0012] The bridge section 117 has an inverted U-shaped cross-section and is positioned above the outer column 108a. The bridge section 117 has a central plate section 120 positioned in the center in the width direction and a pair of lateral inclined plate sections 121 positioned on both outer sides in the width direction. Each of the pair of lateral inclined plate sections 121 is inclined in a direction that is further outward in the width direction as it extends downward.

[0013] Each of the pair of side plate sections 118 has a flat shape and is provided with a locking notch 122 opening at its rear edge. A detachable capsule (not shown) is locked into the locking notch 122.

[0014] Each of the pair of connecting parts 119 has a roughly arc-shaped cross-section, as shown in an enlarged view in Figure 13, and connects the lateral inclined plate part 121 and the side plate part 118 that constitute the bridge part 117. Specifically, the inner surface of the connecting part 119 in the width direction is a convex curved surface, and connects the outer (lower) end of the lateral inclined plate part 121 in the width direction to the inner end of the side plate part 118 in the width direction.

[0015] A pair of support plate sections 113a are arranged substantially parallel to each other on both outer sides in the width direction of the outer column 108a. The upper ends of each of the pair of support plate sections 113a are welded and fixed to the lower surface of the mounting plate section 112a. Each of the pair of support plate sections 113a consists of a plate-shaped member and comprises a support plate body 123 and welding tabs 124.

[0016] The support plate body 123 has a bracket-side through hole 114a that penetrates in the width direction, and a stepped portion 125 formed in the area including the bracket-side through hole 114a. The stepped portion 125 is formed by surface pressing and has a concave shape on the outer side in the width direction and a convex shape on the inner side in the width direction. The stepped portion 125 is formed so that when clamped, the inner surface of the stepped portion 125 in the width direction makes contact with the outer surface of the outer column 108a in the width direction over a wide area, without uneven contact. For this reason, the inner surface of the stepped portion 125 in the width direction is configured to be flat. In particular, in the illustrated structure, the upper edge 125a of the stepped portion 125 is positioned near the lower side of the boundary portion 126 between the support plate body 123 and the welding ear portion 124 so that the inner surface of the stepped portion 125 in the width direction can make contact with the outer surface of the outer column 108a in the width direction even when the vertical position of the steering wheel is adjusted to the uppermost position.

[0017] The welding ears 124 are positioned at the upper ends of each of the pair of support plate portions 113a, and are inclined inward in the width direction as they extend upward. The lower ends of the welding ears 124 are connected to the upper ends of the support plate body 123.

[0018] In the illustrated structure, the outer surface in the width direction of the welding ear portion 124 and the inner surface in the width direction of the lateral inclined plate portion 121 are in surface contact with each other and then welded and fixed (arc welding). death Furthermore, a weld bead 127, which is a raised weld mark, is formed at the welded joint between the widthwise outer surface of the welding ear portion 124 and the widthwise inner surface of the lateral inclined plate portion 121. Specifically, the weld bead 127 is formed in the area between the upper end of the widthwise outer surface of the support plate body 123 and the area extending from the widthwise inner surface of the connecting portion 119 to the widthwise inner end of the lower surface of the side plate portion 118. [Prior art documents] [Patent Documents]

[0019] [Patent Document 1] Japanese Patent Publication No. 2017-197178 [Patent Document 2] International Publication No. 2020 / 116350

Summary of the Invention

Problems to be Solved by the Invention

[0020] When the mounting plate portion 112a and the support plate portion 113a are joined by welding, due to the influence of heat, the surface accuracy of the stepped portion 125 formed on the support plate body 123 is likely to deteriorate.

[0021] Particularly, in the case of a structure where the upper edge 125a of the stepped portion 125 is located near the lower side of the boundary portion 126 between the support plate body 123 and the welding ear portion 124, as in the structure described in Japanese Patent Application Laid-Open No. 2017-197178, since the welding bead 127 and the upper edge 125a of the stepped portion 125 are arranged close to each other, the stepped portion 125 is likely to be affected by the heat of the welding bead 127. As a result, the surface accuracy of the inner side surface in the width direction of the stepped portion 125, which serves as the contact surface with respect to the outer side surface in the width direction of the outer column 108a, deteriorates, and the inner side surface in the width direction of the stepped portion 125 is likely to contact only one side with respect to the outer side surface in the width direction of the outer column 108a.

[0022] In addition, in order to ensure a large vertical distance between the welding bead 127 and the stepped portion 125, it is also conceivable to increase the radius of curvature of the connecting portion 119 to increase the volume between the inner side surface in the width direction of the connecting portion 119, which can accommodate the welding bead 127, and the upper end portion of the outer side surface in the width direction of the support plate body 123. However, in this case, increasing the radius of curvature of the connecting portion 119 may shorten the dimension in the width direction of the side plate portion 118, and it may be difficult to secure the necessary dimension in the width direction of the side plate portion 118, so it is difficult to adopt.

[0023] An object of the present invention is to provide a support bracket for a steering device that can ensure the surface accuracy of the inner side surface in the width direction of a stepped portion provided in a support plate portion.

Means for Solving the Problems

[0024] A support bracket for a steering device according to one aspect of the present invention comprises a mounting plate portion, a pair of support plate portions, and a weld bead. The mounting plate portion is located in the center in the width direction and has a bridge portion with an inverted U-shaped cross-section, a pair of side plate portions located on both outer sides in the width direction and each having a flat plate shape, and a pair of connecting portions that connect the outer ends of the bridge portion in the width direction to the pair of side plate portions, and is supported by the vehicle body. The pair of support plates are arranged facing each other with space between them in the width direction, and their respective upper ends are welded and fixed to the lower surface of the mounting plate. The welding bead is formed at the welded portion between the mounting plate portion and the pair of support plate portions.

[0025] In a support bracket for a steering device according to one aspect of the present invention, each of the pair of support plate portions includes a support plate body including a bracket-side through hole that penetrates in the width direction, and a stepped portion formed in the area including the bracket-side through hole, having a concave shape on the outward side in the width direction and a convex shape on the inward side in the width direction, and a welding lug portion provided above the support plate body. Each of the pair of connecting parts has a flat plate shape and is inclined outward in the width direction as it extends downward. As a result, the inner surface in the width direction of each of the pair of connecting parts and A pair of the aforementioned support plate bodies A welding pocket is formed between the upper end of each of the outer surfaces in the width direction of the weld bead.

[0026] In one aspect of the present invention, the support bracket for a steering device may have a pair of lateral inclined plate portions on both outer sides in the width direction, which are inclined in a direction that is further outward in the width direction as they are directed downward. Furthermore, the inclination angle of the connection portion with respect to a virtual plane parallel to the side plate portion can be made smaller than the inclination angle of the lateral inclined plate portion with respect to the virtual plane.

[0027] A steering device according to one aspect of the present invention comprises a steering column that rotatably supports a steering shaft internally, and a support bracket that supports the steering column relative to the vehicle body, wherein the support bracket can be the support bracket for the steering device of the present invention. [Effects of the Invention]

[0028] According to the present invention, a support bracket for a steering device can be realized that can ensure the surface accuracy of the inner surface in the width direction of the stepped portion provided on the support plate. [Brief explanation of the drawing]

[0029] [Figure 1] Figure 1 is a side view showing a steering device according to a first example of the embodiment. [Figure 2] Figure 2 is a cross-sectional view taken along line AA in Figure 1. [Figure 3] Figure 3 is a perspective view showing a steering device according to a first example of the embodiment. [Figure 4] Figure 4 is a magnified view of a portion of Figure 1. [Figure 5] Figure 5 is an enlarged view of Figure 2, with some parts omitted. [Figure 6] Figure 6 is a cross-sectional view showing the upper bracket removed from the steering device according to the first embodiment. [Figure 7] Figure 7 is a side view showing the upper bracket removed from the steering device according to the first embodiment. [Figure 8] Figure 8 is a perspective view showing the upper bracket removed from the steering device according to the first embodiment. [Figure 9] Figure 9 is an enlarged view of the portion corresponding to part B in Figure 6. [Figure 10] Figure 10 is a side view showing an example of a conventional steering device. [Figure 11]Figure 11 is a diagram corresponding to Figure 5, showing a conventional steering device described in Japanese Patent Publication No. 2017-197178. [Figure 12] Figure 12 is a perspective view showing the upper bracket removed from a conventional steering device described in Japanese Patent Publication No. 2017-197178. [Figure 13] Figure 13 is a diagram corresponding to Figure 9, relating to a conventional steering device described in Japanese Patent Publication No. 2017-197178. [Modes for carrying out the invention]

[0030] [First example of an embodiment] A first example of the embodiment will be described using Figures 1 to 9. In the following description, unless otherwise specified, the front-rear direction refers to the front-rear direction of the vehicle, the up-down direction refers to the up-down direction of the vehicle, and the width direction (left-right direction) refers to the width direction of the vehicle.

[0031] [Overall structure of the steering system] The steering device 1 in this example comprises a steering shaft 2 and a steering column 3. A steering wheel (not shown) is fixed to the rear end of the steering shaft 2. The steering column 3 has a substantially cylindrical shape and rotatably supports the steering shaft 2 via a plurality of rolling bearings (not shown) inside it.

[0032] The front portion of the steering column 3 is supported by the lower bracket 4. Specifically, a gear housing 6, which constitutes the electric assist device 5, is fixed to the front end of the steering column 3, and the gear housing 6 is supported by the lower bracket 4. An electric motor (not shown) is supported in the gear housing 6. The output torque of the electric motor is applied to the steering shaft 2 via a reduction mechanism housed inside the gear housing 6. This reduces the force required to operate the steering wheel.

[0033] The middle section of the steering column 3 in the longitudinal direction is supported by an upper bracket 7, which corresponds to a support bracket.

[0034] The steering system 1 in this example is equipped with a tilt mechanism for adjusting the vertical position of the steering wheel and a telescopic mechanism for adjusting the fore-aft position, respectively, according to the driver's physique and driving posture.

[0035] To form a telescopic mechanism, the steering column 3 consists of a roughly cylindrical inner column 8 positioned at the front (lower side) and a roughly cylindrical outer column 9 positioned at the rear (upper side). The inner column 8 and outer column 9 are fitted together to allow relative displacement in the axial direction. As a result, the steering column 3 is configured to be extendable and retractable in length. Furthermore, the outer column 9 is supported so as to be movable in the front-rear direction relative to the upper bracket 7.

[0036] Furthermore, the steering shaft 2 is composed of an inner shaft 10 and an outer shaft 11. The inner shaft 10 and the outer shaft 11 are connected in a way that allows for torque transmission, such as by spline engagement. As a result, the steering shaft 2 is configured to be extendable and retractable in length.

[0037] To form the tilt mechanism, the steering column 3 is supported so as to be able to oscillate around a tilt axis 13, which is positioned in the width direction relative to the vehicle body 12 (see Figure 2). Specifically, a gear housing 6 fixed to the front end of the steering column 3 is supported so as to be able to oscillate around the tilt axis 13 relative to a lower bracket 4 fixed to the vehicle body 12. In addition, the outer column 9 is supported so as to be able to move vertically relative to an upper bracket 7.

[0038] [Outer Column] The outer column 9 has a column body 14 that is substantially cylindrical in shape and fits over the inner column 8, and a reinforcing bridge portion 15.

[0039] The column body 14 has a front-to-back slit 16 extending in the front-to-back direction in the center of the width direction of its lower surface. The column body 14 has a front circumferential slit 17a extending in the circumferential direction in the front portion of the lower half, and a rear circumferential slit 17b extending in the circumferential direction in the rear portion of the lower half. The front circumferential slit 17a is formed to cross the front portion of the front-to-back slit 16 in the circumferential direction, and the rear circumferential slit 17b is formed to cross the rear portion of the front-to-back slit 16 in the circumferential direction.

[0040] The column body 14 has a pair of clamping portions 18. The clamping portions 18 are located on both sides in the width direction of the column body 14, surrounded on three sides by a front-to-back slit 16, a front circumferential slit 17a, and a rear circumferential slit 17b.

[0041] The column body 14 has a protruding ridge 19 that extends in the front-rear direction and protrudes outward in the width direction on both outer surfaces in the width direction, at the portion where its vertical position coincides with the central axis of the outer column 9. The protruding ridge 19 is positioned above the clamp portion 18. The tip surface (outer surface in the width direction) of the protruding ridge 19 has a flat upper clamping surface 20 that receives a clamping force from the inner surface in the width direction of the support plate portion 26, which constitutes the upper bracket 7, when clamped.

[0042] The clamp portion 18 has a partially cylindrical inner surface in the width direction. The clamp portion 18 has a flat, protruding plate portion 21 at the lower end of its outer surface in the width direction, projecting outward in the width direction. The tip surface (outer surface in the width direction) of the protruding plate portion 21 has a flat intermediate clamping surface 22 that receives a clamping force from the inner surface in the width direction of the support plate portion 26, which constitutes the upper bracket 7, when clamped.

[0043] The reinforcing bridge section 15 has the function of improving the torsional rigidity of the outer column 9. The reinforcing bridge section 15 has a substantially U-shape when viewed in the width direction and is integrally constructed with the column body 14. The outer column 9 has a column-side through hole 23 that extends in the front-rear direction between the reinforcing bridge section 15 and the lower end (overhanging plate section 21) of the clamp section 18. If a telescopic mechanism is not provided, the column-side through hole is simply a circular hole.

[0044] Of the reinforcing bridge portion 15, the outer surface in the width direction of the portion located below the column-side through hole 23 has a flat lower clamping surface 24 that, when clamped, receives a clamping force from the inner surface in the width direction of the support plate portion 26, which constitutes the upper bracket 7 (described later).

[0045] As described above, the outer column 9 in this example has three clamping surfaces on both outer surfaces in the width direction: an upper clamping surface 20, an intermediate clamping surface 22, and a lower clamping surface 24.

[0046] [Upper Bracket] The upper bracket 7 has the function of supporting the outer column 9 against the vehicle body 12. The upper bracket 7 is made of a metal plate with sufficient rigidity, such as steel or an aluminum alloy, and has a mounting plate portion 25, a pair of support plate portions 26, and a weld bead 27.

[0047] Mounting plate section The mounting plate portion 25 is normally supported by the vehicle body 12, but in the event of a collision, it detaches forward based on the impact of a secondary collision, allowing the outer column 9 to be displaced forward. For this reason, the mounting plate portion 25 is locked to the locking capsule 28, which is supported and fixed to the vehicle body 12, so that it can detach forward.

[0048] The mounting plate portion 25 comprises a bridge portion 29 positioned in the center in the width direction, a pair of side plate portions 30 positioned on both outer sides in the width direction, and a pair of connecting portions 31 that connect the outer ends of the bridge portion 29 in the width direction to the pair of side plate portions 30.

[0049] The bridge section 29 has an inverted U-shaped cross-section and is positioned above the outer column 9. The bridge section 29 has a central plate section 32 positioned in the center in the width direction and a pair of lateral inclined plate sections 33 positioned on both outer sides in the width direction.

[0050] The central plate section 32 is constructed in a flat shape and is arranged approximately parallel to the pair of side plate sections 30.

[0051] A pair of lateral inclined plate sections 33 are positioned on both outer sides in the width direction of the central plate section 32. The pair of lateral inclined plate sections 33 are inclined in a direction that is further outward in the width direction as they extend downward. The inner ends of each of the pair of lateral inclined plate sections 33 in the width direction are connected to the outer ends of the central plate section 32 in the width direction.

[0052] Each of the pair of side plate sections 30 has a flat shape and is provided with a locking notch 34 opening at its rear edge. A locking capsule 28 is locked into the locking notch 34.

[0053] Each of the pair of connecting parts 31 connects the lateral inclined plate part 33 and the side plate part 30 that constitute the bridge part 29. Specifically, the connecting part 31 connects the outer (lower) end in the width direction of the lateral inclined plate part 33 and the inner end in the width direction of the side plate part 30. As shown in Figure 9, the connecting part 31 in this example has a flat plate shape and is inclined in the direction of being outward in the width direction as it goes downward. Therefore, the connecting part 31 has a flat inner surface in the width direction. The inclination angle α of the connecting part 31 (inner surface in the width direction) with respect to a virtual plane P parallel to the side plate part 30. 31 This can be, for example, about 20° to 50°, and the inclination angle α of the lateral inclined plate portion 33 (inner surface in the width direction) with respect to the virtual plane P. 33 Smaller than (α 31 <α 33 ). Furthermore, the ends on both sides in the width direction of the connecting portion 31, the outer end in the width direction of the lateral inclined plate portion 33, and the inner end in the width direction of the side plate portion 30 are each connected by connecting pieces with a substantially arc-shaped cross-section.

[0054] In this example, the mounting plate portion 25 has a first rib 46 in the middle of the mounting plate portion 25 in the front-rear direction in order to increase the rigidity of the bridge portion 29 compared to the rigidity of the pair of side plate portions 30. The first rib 46 extends in the width direction and has a shape that is convex on the upper side and concave on the lower side. The outer ends of the first rib 46 in the width direction are located at the inner ends in the width direction of the pair of side plate portions 30. For this reason, the first rib 46 is formed spanning the central plate portion 32 and the pair of lateral inclined plate portions 33, the pair of connecting portions 31, and the pair of side plate portions 30 that constitute the bridge portion 29.

[0055] The mounting plate portion 25 further has a pair of second ribs 47. The second ribs 47 are located on the rear portion of the mounting plate portion 25, opposite the widthwise outer end of the first rib 46, with the weld bead 27 in between, in the front-rear direction. The widthwise inner end of the second rib 47 is located at the widthwise outer end of the lateral inclined plate portion 33, and the widthwise outer end of the second rib 47 is located at the widthwise inner end of the side plate portion 30. For this reason, the second rib 47 is formed spanning the lateral inclined plate portion 33, the connecting portion 31, and the side plate portion 30.

[0056] In this example, the mounting plate portion 25 has mounting side slits 48 extending in the front-rear direction on the inner side in the width direction of each of the pair of side plate portions 30. The mounting side slits 48 are positioned approximately parallel to the weld bead 27 and are located at approximately the same front-rear position as the weld bead 27. In other words, the mounting side slits 48 are positioned between the outer end in the width direction of the first rib 46 and the outer end in the width direction of the second rib 47 with respect to the front-rear direction. The mounting side slits 48 reduce the rigidity of the side plate portion 30 relative to the bridge portion 29, preventing the accuracy of the upper surface of the side plate portion 30 and the mounting surface of the vehicle body 12 from affecting the bridge portion 29.

[0057] 《Support plate part》 The pair of support plate sections 26 are spaced apart in the width direction and facing each other. Furthermore, the pair of support plate sections 26 are positioned substantially parallel to the outer sides of the outer column 9 in the width direction, so as to sandwich the outer column 9 from both sides in the width direction. The upper ends of each of the pair of support plate sections 26 are welded to the lower surface of the mounting plate section 25. Each of the pair of support plate sections 26 consists of a plate-shaped member and comprises a support plate body 35 and welding tabs 36.

[0058] The support plate body 35 has an intermediate plate portion 37 located in the middle of the front-rear direction, a front reinforcing portion 38 located at the front end, and a rear reinforcing portion 39 located at the rear end.

[0059] The intermediate plate portion 37 has a stepped plate shape. The intermediate plate portion 37 is formed by applying press processing such as surface pressing or punching to a part of a flat plate-shaped material with a constant plate thickness. The intermediate plate portion 37 has a base plate portion 40, a bracket-side through hole 41, and a stepped portion 42 formed in the area including the bracket-side through hole 41.

[0060] The stepped portion 42 is formed by surface pressing on the substrate portion 40, and has a concave shape on the outer side in the width direction and a convex shape on the inner side in the width direction. In the illustrated example, the stepped portion 42 is formed over most of the substrate portion 40, excluding the upper side and the ends on both sides in the front-rear direction.

[0061] The inner surface of the stepped portion 42 in the width direction is a flat surface, protruding inward in the width direction from the inner surface of the base portion 40 in the width direction, and is positioned substantially parallel to the inner surface of the base portion 40 in the width direction. The inner surface of the stepped portion 42 in the width direction faces in the width direction the three clamping surfaces provided on the outer column 9: the upper clamping surface 20, the intermediate clamping surface 22, and the lower clamping surface 24. The outer surface of the stepped portion 42 in the width direction is recessed inward in the width direction from the outer surface of the base portion 40 in the width direction, and is positioned substantially parallel to the outer surface of the base portion 40 in the width direction. The outer surface of the stepped portion 42 in the width direction functions as a seating surface for the driven cam 58 and the pressing plate 56 that constitute the cam device 53 described later. The height (depth) of the stepped portion 42 relative to the base portion 40 is, for example, about 0.2 mm to 0.8 mm.

[0062] In this example, even when the vertical position of the steering wheel (not shown) is adjusted to its uppermost position, the upper edge 42a of the stepped portion 42 is positioned near the lower side of the boundary between the support plate body 35 and the welding ear portion 36 so that the inner surface of the stepped portion 42 in the width direction can be brought into contact with the upper clamping surface 20 provided on the outer column 9. The upper edge 42a of the stepped portion 42 has an inverted U shape when viewed in the width direction, and the middle portion in the front-rear direction is positioned higher than the sides in the front-rear direction. The middle portion of the upper edge 42a of the stepped portion 42 in the front-rear direction is inclined upward as it approaches the rear.

[0063] The bracket-side through-hole 41 is a through-hole that penetrates the intermediate plate portion 37 in the width direction. The bracket-side through-hole 41 has a partial arc shape centered on the tilt axis 13 and extends in the vertical direction. The bracket-side through-hole 41 is located in the middle of the stepped portion 42 in both the vertical and front-to-back directions. If a tilt mechanism is not provided, the bracket-side through-hole is simply a circular hole.

[0064] Each of the front reinforcing portion 38 and the rear reinforcing portion 39 has the function of preventing plastic deformation from occurring in the pair of support plate portions 26 even when torque (torsional torque) is applied to the pair of support plate portions 26 from the outer column 9, for example, when the steering wheel is operated with a large force while the steering lock device described later is activated. In other words, the front reinforcing portion 38 and the rear reinforcing portion 39 increase the section modulus of the support plate portion 26 and improve the bending rigidity of the support plate portion 26 in the width direction.

[0065] The front reinforcing portion 38 is positioned at the front end of the support plate body 35 and extends linearly in the vertical direction. The rear end of the front reinforcing portion 38 is connected to the front end of the intermediate plate portion 37. However, the upper end of the front reinforcing portion 38 is not connected to the bridge portion 29. The front reinforcing portion 38 is curved so that the outer side in the width direction is convex, and has a semi-circular cross-sectional shape. Therefore, the front end of the front reinforcing portion 38 faces inward in the width direction. However, the front end of the front reinforcing portion 38 is located further outward in the width direction than the inner surface of the stepped portion 42 in the width direction. Therefore, the front end of the front reinforcing portion 38 does not come into contact with the upper clamping surface 20, the intermediate clamping surface 22, and the lower clamping surface 24 of the outer column 9.

[0066] The rear reinforcing portion 39 is located at the rear end of the support plate body 35 and extends vertically. The rear reinforcing portion 39 is formed by bending the rear end of the support plate body 35 outward in the width direction at approximately a right angle. The front end of the rear reinforcing portion 39 is connected to the rear end of the intermediate plate portion 37. However, the upper end of the rear reinforcing portion 39 is not connected to the bridge portion 29. The upper half of the rear reinforcing portion 39 is located approximately parallel to the front reinforcing portion 38 and extends linearly vertically, while the lower half of the rear reinforcing portion 39 is inclined forward as it goes downward.

[0067] The upper end of the front reinforcing portion 38 and the upper end of the rear reinforcing portion 39 are in approximately the same vertical position. In this example, most of the upper edge 42a of the stepped portion 42 is located above the upper ends of the front reinforcing portion 38 and the rear reinforcing portion 39, respectively.

[0068] The welding ears 36 are positioned at the upper ends of each of the pair of support plate portions 26. Specifically, the welding ears 36 are positioned above the intermediate plate portion 37 that constitutes the support plate body 35. Therefore, the lower end of the welding ears 36 is connected to the upper end of the intermediate plate portion 37. However, the lower end of the welding ears 36 is not connected to the upper ends of the front reinforcing portion 38 and the rear reinforcing portion 39. The welding ears 36 are inclined inward in the width direction as they extend upward. The inclination angle of the welding ears 36 with respect to the vertical plane is the same as the inclination angle of the lateral inclined plate portion 33 with respect to the vertical plane.

[0069] In this example, the upper bracket 7 is welded (arc welded) to the outer surface in the width direction of the welding ear portion 36 and the inner surface in the width direction of the lateral inclined plate portion 33 that constitutes the bridge portion 29, with the surfaces in contact with each other. In this example, as shown in Figure 9, with the mounting plate portion 25 and the support plate portion 26 welded together, the boundary between the support plate body 35 and the welding ear portion 36 is positioned near the boundary between the lateral inclined plate portion 33 and the connecting portion 31.

[0070] Welding bead The weld bead 27 is a raised weld mark formed at the weld between the widthwise outer surface of the welding ear portion 36 and the widthwise inner surface of the lateral inclined plate portion 33 that constitutes the bridge portion 29. In this example, the weld bead 27 joins the upper end of the widthwise outer surface of the intermediate plate portion 37 to the widthwise inner surface of the connecting portion 31. The weld bead 27 extends in the front-rear direction. In the front-rear direction, the weld bead 27 is located between the widthwise outer end of the first rib 46 and the second rib 47. The weld bead 27 has a roughly triangular cross-sectional shape and a lower surface that slopes downward as it approaches the inside in the width direction. Note that although the lower surface of the weld bead 27 is depicted as a flat surface in Figure 9, in reality, it may have minute irregularities in the front-rear direction.

[0071] In this example, the lateral inclined plate portion 33 and the side plate portion 30 of the bridge portion 29 are connected by a connection portion 31 with a flat surface on its inner width direction, rather than a connection portion with a convex curved surface on its inner width direction, as in conventional structures. This forms a welding pocket 45 for accommodating the welding bead 27, which has a roughly triangular cross-sectional shape, between the inner width direction surface of the connection portion 31 and the upper end of the outer width direction surface of the intermediate plate portion 37. The welding pocket 45 is located between the outer width direction end of the first rib 46 and the second rib 47 in the front-rear direction. In this example, as shown in Figure 9, by making the inner width direction surface of the connection portion 31 flat, the volume of the welding pocket 45 is increased compared to the case where the inner width direction surface of the connection portion is a convex curved surface, as in conventional structures (see dashed line in Figure 9). As a result, the lower end portion 27a of the weld bead 27 is positioned higher than the lower end portion 27x of the weld bead when the inner surface in the width direction of the connection portion is a convex curved surface (see the dashed line in Figure 9).

[0072] With the pair of support plate portions 26 constituting the upper bracket 7 arranged on both sides of the outer column 9 in the width direction, an adjustment rod 49 is inserted in the width direction through the column-side through hole 23 and the bracket-side through hole 41, respectively. The adjustment rod 49 has a head 50 at one end on the axial side (the left end in Figures 2 and 5) and a male threaded portion 51 at the other end on the axial side (the right end in Figures 2 and 5).

[0073] On one axial side of the adjustment rod 49, around the portion between the head 50 and the outer surface in the width direction of one of the pair of support plate portions 26 (the left one in Figures 2 and 5), the adjustment lever 52 and the cam device 53 are arranged in order from the outside in the width direction. On the other axial side of the adjustment rod 49, around the portion protruding from the outer surface in the width direction of the other of the pair of support plate portions 26 (the right one in Figures 2 and 5), the nut 54, the thrust bearing 55, and the pressure plate 56 are arranged in order from the outside in the width direction. The nut 54 is screwed onto the male threaded portion 51 of the adjustment rod 49.

[0074] In the steering device 1 of this example, the spacing between the inner surfaces in the width direction of the pair of support plate portions 26 can be expanded or contracted by swinging the adjustment lever 52 to expand or contract the axial dimension of the cam device 53. This allows the magnitude of the clamping force applied to the outer column 9 by the pair of support plate portions 26 to be adjusted.

[0075] The cam mechanism 53 consists of a drive-side cam 57 and a driven-side cam 58. The drive-side cam 57 is fixed to the base end of the adjustment lever 52 so as not to rotate relative to it.

[0076] Both the drive-side cam 57 and the driven-side cam 58 are made of sintered metal and have a ring-shaped plate. The drive-side cam 57 has a drive-side cam surface on its inner surface in the width direction (right side in Figures 2 and 5), which is a surface with irregularities in the circumferential direction. The driven-side cam 58 has a driven-side cam surface on its outer surface in the width direction (left side in Figures 2 and 5), which is a surface with irregularities in the circumferential direction. The driven-side cam 58 has an engaging projection on its inner surface in the width direction that is shaped like a roughly rectangular plate. The engaging projection of the driven-side cam 58 engages with the bracket-side through-hole 41 of one of the support plate portions 26, allowing displacement only along the bracket-side through-hole 41.

[0077] The steering device 1 in this example has a pair of tension springs 59 on both outer sides in the width direction of a pair of support plate portions 26 that constitute the upper bracket 7. Of the pair of tension springs 59, one tension spring 59 is stretched between one side plate portion 30 and the base end of the adjustment lever 52. In contrast, the other tension spring 59 of the pair of tension springs 59 is stretched between the other side plate portion 30 and the pressure plate 56. The pair of tension springs 59 prevent the steering column 3 from tilting so that the steering wheel falls forcefully when the clamping force is released.

[0078] The steering system 1 in this example incorporates a steering lock device (not shown), which is a type of vehicle anti-theft device. The steering lock device effectively prevents the steering shaft 2 from rotating when the ignition key is turned OFF.

[0079] In the steering device 1 of this example, when holding the steering wheel in a desired position, the steering wheel is moved to the desired position, and then the adjustment lever 52 is rotated in a predetermined direction (for example, upward) around the adjustment rod 49. As a result, the convex portion of the drive-side cam surface and the convex portion of the driven-side cam surface come into contact with each other, the axial dimension of the cam device 53 expands, and the distance between the inner surfaces of the pair of support plate portions 26 in the width direction decreases. At this time, the inner surfaces of the pair of support plate portions 26 (stepped portion 42) in the width direction press against the upper clamping surface 20, the intermediate clamping surface 22, and the lower clamping surface 24. As a result, the pair of clamp portions 18 elastically deform inward in the width direction, clamping the outer circumferential surface of the inner column 8 from both sides in the width direction. As a result, the steering wheel is held in the adjusted position.

[0080] When adjusting the position of the steering wheel, the adjustment lever 52 is swung in the opposite direction to the predetermined direction (for example, downward). This causes the convex portions of the drive-side cam surface and the convex portions of the driven-side cam surface to be alternately arranged in the circumferential direction, reducing the axial dimension of the cam device 53 and widening the distance between the inner surfaces of the pair of support plate portions 26 in the width direction. As a result, the pressing force of the pair of support plate portions 26 decreases, causing the pair of clamp portions 18 to elastically return to their original position, and reducing the force with which the pair of clamp portions 18 hold the outer circumferential surface of the inner column 8. In this state, the front-rear and up-down positions of the steering wheel can be adjusted within the range in which the adjustment rod 49 can move inside the column-side through hole 23 and the bracket-side through hole 41.

[0081] According to the steering device 1 of this example, as described above, the surface accuracy of the inner surface in the width direction of the stepped portion 42 provided on the pair of support plate portions 26 constituting the upper bracket 7 can be ensured. In other words, in this example, with respect to the mounting plate portion 25 of the upper bracket 7, the lateral inclined plate portion 33 and the side plate portion 30 of the bridge portion 29 are connected by a connecting portion with a convex curved surface on the inner surface in the width direction, as in the conventional structure shown in Figure 13, but by a connecting portion 31 with a flat surface on the inner surface in the width direction. As a result, a welding pocket 45 is formed between the inner surface of the connecting portion 31 in the width direction and the upper end of the outer surface of the intermediate plate portion 37 in the width direction, with a volume increased compared to the case where the inner surface of the connecting portion in the width direction is a convex curved surface (see dashed line in Figure 9). As a result, the lower end portion 27a of the welding bead 27 can be positioned higher, so the distance (vertical distance) between the welding bead 27 and the upper edge 42a of the stepped portion 42 can be increased compared to the conventional structure. Therefore, the stepped portion 42 is less affected by the heat of the welding bead 27, and the surface accuracy of the inner surface of the stepped portion 42 in the width direction can be ensured. As a result, the steering device 1 in this example prevents the inner surface of the stepped portion 42 in the width direction from making contact with the upper clamping surface 20, the intermediate clamping surface 22, or the lower clamping surface 24, thereby improving the support rigidity of the outer column 9 in the width direction by the upper bracket 7.

[0082] Furthermore, in this example, the widthwise dimension of the side plate portion 30 is not shortened, unlike methods that increase the volume capable of accommodating the weld bead by increasing the radius of curvature of the connection portion. In other words, in this example, the capacity of the welding pocket 45 for accommodating the weld bead 27 can be increased without shortening the widthwise dimension of the side plate portion 30.

[0083] Furthermore, in this example, the inclination angle α of the connection portion 31 (inner surface in the width direction) with respect to a virtual plane P parallel to the side plate portion 30. 31 The inclination angle α of the lateral inclined plate portion 33 (inner surface in the width direction) with respect to the virtual plane P. 33 It is smaller than this. Therefore, when the side plate portion 30 and the lateral inclined plate portion 33 are connected directly without a connecting portion (the inclination angle α of the connecting portion 31) 31 and the inclination angle α of the lateral inclined plate portion 33 33Compared to the case where the two are the same, the volume of the welding pocket 45 can be increased. As a result, the stepped portion 42 is less affected by the heat of the welding bead 27, and the surface accuracy of the inner surface of the stepped portion 42 in the width direction can be ensured.

[0084] Furthermore, in this example, the upper ends of the front reinforcing portion 38 and the rear reinforcing portion 39 provided on the support plate portion 26 of the upper bracket 7 are not connected to the bridge portion 29. Therefore, it is possible to prevent the pair of support plate portions 26 from becoming less susceptible to inward bending deformation in the width direction due to the provision of the front reinforcing portion 38 and the rear reinforcing portion 39. In addition, the welding ears 36 provided on the upper ends of the support plate portions 26 are welded and fixed to the lower surface of the lateral inclined plate portion 33, rather than to the side plate portion 30. Moreover, the rigidity of the bridge portion 29 is made higher than the rigidity of the side plate portion 30. Therefore, even if the accuracy of the mounting surface of the side plate portion 30 or the vehicle body 12 is not sufficiently high, it is possible to prevent this accuracy from affecting the pair of support plate portions 26.

[0085] Furthermore, in this example, an intermediate clamping surface 22 for elastically deforming a pair of clamping portions 18, and upper and lower clamping surfaces 20 and 24 for transmitting torque acting on the outer column 9, for example when the steering wheel is operated with great force while the steering lock device is activated, to the widthwise inner surface of the support plate portion 26 of the upper bracket 7, are provided separately and independently. In other words, the intermediate clamping surface 22 does not need to have the function of transmitting torque to the widthwise inner surface of the support plate portion 26. Therefore, the pair of clamping portions 18 only need to perform the function of clamping the inner column 8, and it is not necessary to ensure strength beyond what is necessary. Consequently, it becomes possible to flex the clamping portions 18 significantly in the widthwise direction. In contrast, the upper and lower clamping surfaces 20 and 24 do not need to flex significantly in the widthwise direction, and it is sufficient that they can perform the function of transmitting torque. As a result, the steering device 1 in this example can achieve both the assurance of strength for the outer column 9 and the assurance of holding force for the inner column 8.

[0086] Although embodiments of the present invention have 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.

[0087] When implementing the present invention, the shape of the support plate body is not limited to that shown in the embodiments. For example, as described in International Publication No. 2020 / 116350 (Patent Document 2), a second stepped portion (second stepped portion) having a concave shape on the axially outward side and a convex shape on the axially inward side can be provided within the area where the stepped portion is formed. By forming such a second stepped portion, even if bending deformation occurs in the support plate portion, the widthwise inner surface of the second stepped portion can be brought into contact with the widthwise outer surface of the outer column (for example, the upper clamping surface). Furthermore, when implementing the present invention, the shapes of the front reinforcement portion and the rear reinforcement portion are not limited to those shown in the embodiments. The front reinforcement portion and / or the rear reinforcement portion can be omitted. Also, regarding the structure of the steering column that is clamped from both sides in the widthwise direction by the upper bracket of the present invention, it is not limited to the structure described in the embodiments, and various conventionally known structures can be adopted. [Explanation of Symbols]

[0088] 1. Steering system 2 Steering shaft 3. Steering column 4 Lower Bracket 5. Electric assist device 6 Gear Housing 7 Upper Bracket 8 Inner Column 9 Outer Column 10 Inner Shaft 11 Outer Shaft 12 car bodies 13 Tilt axes 14 Column body 15 Reinforcement bridge section 16 Front and rear slits 17a Front circumferential slit 17b Rear circumferential slit 18 Clamp section 19 Projection part 20 Upper clamping surface 21 Overhang plate section 22 Intermediate clamping surface 23 Column side through hole 24 Lower clamping surface 25 Mounting plate section 26 Support plate part 27 Weld bead 27a, 27x bottom end 28 Locking Capsules 29 Bridge section 30 Side panel section 31 Connection part 32 Center plate part 33 Lateral inclined plate part 34 Locking notch 35 Support plate body 36 Welding lugs 37 Intermediate plate section 38 Front reinforcement part 39 Rear reinforcement section 40 Circuit board section 41 Through hole on the bracket side 42 Stepped section 42a Upper edge 45 Welding Pockets 46. ​​First Rib 47. Second Rib 48 Mounting side slit 49 Adjustment Rod 50 heads 51 Male threaded section 52 Adjustment lever 53 Cam mechanism 54 nuts 55 Thrust Underwater 56 Pressure Plate 57 Drive side cam 58 Driven cam 59 Tension spring 100 Steering System 101 Steering shaft 102 Steering column 103 Lower Bracket 104, 104a Upper Bracket 105 car body 106 Electric assist device 107 Inner Column 108, 108a Outer Column 109 Inner Shaft 110 Outer Shaft 111 Tilt axis 112, 112a Mounting plate section 113, 113a Support plate part 114, 114a Bracket side through hole 115 Adjustable Rod 116 Adjustment lever 117 Bridge section 118 Side panel section 119 Connection part 120 Center plate part 121 Lateral inclined plate section 122 Locking notch 123 Support plate body 124 Welding ear 125 Step section 125a Upper edge 126 Boundary 127 Weld Bead 128 Cam mechanism

Claims

1. A mounting plate portion supported by the vehicle body has a bridge portion located in the center in the width direction and having an inverted U-shaped cross-section, a pair of side plate portions located on both outer sides in the width direction and each having a flat plate shape, and a pair of connecting portions that connect the outer ends of the bridge portion in the width direction to the pair of side plate portions, A pair of support plate sections are positioned opposite each other, spaced apart in the width direction, with their respective upper ends welded and fixed to the lower surface of the mounting plate section. A weld bead is formed at the weld between the mounting plate portion and each of the pair of support plate portions, Equipped with, Each of the pair of support plate portions includes a support plate body including a bracket-side through hole that penetrates in the width direction, and a stepped portion formed in the area including the bracket-side through hole, having a concave shape on the outward side in the width direction and a convex shape on the inward side in the width direction, and a welding ear portion provided above the support plate body, Each of the pair of connecting parts has a flat plate shape and is inclined outward in the width direction as it extends downward. A welding pocket for accommodating the welding bead is formed between the inner surface in the width direction of each of the pair of connecting portions and the upper end of the outer surface in the width direction of each of the pair of support plate bodies. Support bracket for steering system.

2. The bridge section has a pair of lateral inclined plate sections on both outer sides in the width direction, which are inclined in a direction that is further outward in the width direction as they are directed downwards. The inclination angle of the connecting portion with respect to a virtual plane parallel to the side plate portion is smaller than the inclination angle of the lateral inclined plate portion with respect to the virtual plane. A support bracket for a steering device as described in claim 1.

3. A steering column that rotatably supports the steering shaft on the inside, The steering column is supported by a support bracket that supports it relative to the vehicle body, A steering device wherein the support bracket is a support bracket for a steering device as described in any one of claims 1 to 2.

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