Bracket for steering device and manufacturing method of the same and steering device

Abstract

To provide a bracket for a steering device which enables sufficient reduction of influence on side plates exerted by heat generated during welding.SOLUTION: An upper bracket 4 includes a top plate 33 having a bridge part 36, and a pair of side plates 34. The side plates 34 are fixedly welded to the bridge part 36 in a state that widthwise outer side surfaces of upper ends of the side plates 34 are overlapped with a widthwise inner side surface of the bridge part 36. Between the bridge part 36 and the side plate 34, a laser welding part 50 made of weld metal which is fused from the side plate 34 into the bridge part 36 is formed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a bracket for a steering device, a manufacturing method thereof, and a steering device. [Background technology]

[0002] Steering devices are installed in vehicles such as automobiles, and transmit the movement of the steering wheel operated by the driver to a steering gear unit via a steering shaft, thereby applying a steering angle to the left and right steered wheels. Steering devices are equipped with a position adjustment device that allows the position of the steering wheel to be adjusted according to the driver's physique and driving posture.

[0003] 12 and 13 show a conventional structure of a steering device equipped with a steering wheel position adjustment device, which is described in Japanese Patent Application Laid-Open No. 2023-131680.

[0004] The steering device 100 includes a steering shaft 101 to the rear end of which a steering wheel (not shown) is fixed, and a steering column 102 that supports the steering shaft 101 rotatably on the inside.

[0005] The front portion of the steering column 102 is supported by a lower bracket 103, and the middle portion of the steering column 102 in the front-to-rear direction is supported by an upper bracket 104. The lower bracket 103 and the upper bracket 104 are supported on the vehicle body. The steering device 100 is equipped with an electric assist device 105 on the front portion of the steering column 102 to reduce the force required to operate the steering wheel.

[0006] The steering column 102 is configured so that its overall length can be extended or contracted by fitting the rear side of an inner column 106 located at the front with the front side of an outer column 107 located at the rear to allow relative displacement in the axial direction, in order to enable adjustment of the fore-and-aft position of the steering wheel. The outer column 107 has a column-side through-hole 108 that extends in the fore-and-aft direction, is configured so that its diameter can be contracted, and is supported by the upper bracket 104 so as to be movable in the fore-and-aft direction. The steering shaft 101 is configured by combining an inner shaft and an outer shaft 109 (not shown) in such a way that they can transmit torque and be extended or contracted.

[0007] The steering column 102 is supported by a lower bracket 103 so as to be capable of swinging about a tilt axis 110, allowing adjustment of the vertical position of the steering wheel. The outer column 107 is supported by an upper bracket 104 so as to be movable in the vertical direction.

[0008] The upper bracket 104 comprises a top plate 111 that is supported by the vehicle body, and a pair of side plates 112 that are arranged on both sides of the outer column 107 in the width direction. The side plates 112 have bracket-side through holes 113 that extend in the vertical direction.

[0009] The steering device 100 operates an adjustment lever 115 fixed to the end of an adjustment rod 114 that is inserted through the column-side through-hole 108 and the bracket-side through-hole 113, and expands and contracts a cam device (not shown), thereby expanding and contracting the distance between the widthwise inner surfaces of the pair of side plates 112. This makes it possible to adjust the tightening force applied to the outer column 107 by the widthwise inner surfaces of the pair of side plates 112.

[0010] When clamping, reducing the distance between the widthwise inner surfaces of the pair of side plates 112, the diameter of the outer column 107 reduces, and the force with which the outer column 107 holds the outer peripheral surface of the inner column 106 increases. This makes it impossible to adjust the position of the steering wheel.

[0011] In contrast, during unclamping when the distance between the widthwise inner surfaces of the pair of side plates 112 is widened, the outer column 107 elastically restores its original shape, and the force with which the outer column 107 holds the outer peripheral surface of the inner column 106 decreases. For this reason, it is possible to adjust the fore-and-aft position and up-and-down position of the steering wheel within the range in which the adjustment rod 114 can move inside the column-side through-hole 108 and the bracket-side through-hole 113. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2023-131680 Summary of the Invention [Problem to be solved by the invention]

[0013] In the steering device 100 of the conventional structure, the top plate 111 and the pair of side plates 112 that constitute the upper bracket 104 are welded and fixed by arc welding.

[0014] In particular, in a steering device 100 with a conventional structure, a weld pocket 116 is formed between the top plate 111 and the upper end of the side plate 112, and a weld bead 117 formed by arc welding is housed within this weld pocket 116. This increases the distance from the weld bead 117 to the portion of the side plate 112 that clamps the outer column 107, and suppresses a decrease in the surface precision of the portion of the side plate 112 that clamps the outer column 107 due to the effects of heat from the weld bead 117.

[0015] However, the steering device 100 of the conventional structure still has room for improvement in terms of further reducing the effect of heat caused by welding on the side plate 112 .

[0016] An object of the present disclosure is to provide a bracket for a steering device that can sufficiently reduce the effect of heat caused by welding on a side plate. [Means for solving the problem]

[0017] A bracket for a steering device according to one aspect of the present disclosure includes a top plate and a pair of side plates.

[0018] The top plate has an inverted U-shaped cross section, includes a bridge portion disposed above the steering column, and is supported by the vehicle body.

[0019] The pair of side plates are disposed on both outer sides of the steering column in the width direction.

[0020] The side plates are welded to the bridge portion with the outer side surfaces of the upper ends thereof in the width direction overlapping the inner side surfaces of the bridge portion in the width direction.

[0021] In the steering device bracket according to one aspect of the present disclosure, a laser weld is formed between the bridge portion and the side plate, and is made of weld metal that melts from the side plate toward the bridge portion.

[0022] In the steering device bracket according to one aspect of the present disclosure, the laser welded portion may extend in the axial direction of the steering column.

[0023] A steering device according to one aspect of the present disclosure includes a steering shaft, a steering column that rotatably supports the steering shaft, and a bracket that supports the steering column relative to a vehicle body, the bracket being a bracket for a steering device according to one aspect of the present disclosure.

[0024] A method for manufacturing a steering device bracket according to an aspect of the present disclosure is a method for manufacturing a steering device bracket according to an aspect of the present disclosure, The method includes a process of welding and fixing the side panel to the bridge section by irradiating the widthwise inner surface of the side panel with laser light while the widthwise outer surface of the side panel is overlapped with the widthwise inner surface of the bridge section, and forming a laser weld between the bridge section and the side panel, which is made of weld metal that melts from the side panel toward the bridge section.

[0025] In a manufacturing method for a bracket for a steering device according to one embodiment of the present disclosure, the two side plates are clamped simultaneously using a center jig and two side jigs, and the widthwise outer surfaces of the two side plates can be overlapped with the widthwise inner surfaces of the bridge portion.

[0026] In the method for manufacturing a bracket for a steering device according to one aspect of the present disclosure, the center jig may have a structure that allows the laser light to pass through. [Effects of the Invention]

[0027] According to the steering device bracket according to one aspect of the present disclosure, the influence of heat generated by welding on the side plate can be sufficiently reduced. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a side view showing a steering device according to a first example of an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is a perspective view showing a steering device according to a first example. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Figure 5] FIG. 5 is a side view showing an upper bracket according to the first example. [Figure 6] FIG. 6 is a cross-sectional view taken along line BB in FIG. [Figure 7] FIG. 7 is a perspective view showing an upper bracket according to the first example. [Figure 8]8(A) and 8(B) are enlarged views of part C in FIG. 6, where FIG. 8(A) shows a case where the laser weld does not penetrate the bridge portion, and FIG. 8(B) shows a case where the laser weld penetrates the bridge portion. [Figure 9] 9(A) to 9(D) are views corresponding to FIG. 5, showing other examples of laser welds formed between the bridge portion and the side plate. [Figure 10] FIG. 10 is a cross-sectional view showing an example of a manufacturing process for the upper bracket according to the first example. [Figure 11] FIG. 11 is a perspective view showing an example of a center jig used in the manufacturing process of the upper bracket of the first example. [Figure 12] FIG. 12 is a side view showing an example of a steering device with a conventional structure. [Figure 13] FIG. 13 is a cross-sectional view showing an upper bracket provided in a steering device of a conventional structure. DETAILED DESCRIPTION OF THE INVENTION

[0029] [Example 1] A first example of an embodiment of the present disclosure will be described with reference to FIGS. 1 to 11. FIG.

[0030] In this example, a bracket for a steering device according to one aspect of the present disclosure is applied to an upper bracket for supporting an intermediate portion of a steering column on a vehicle body.

[0031] Below, the overall structure of the steering device 1 and the structure of the outer column 9 supported by the upper bracket 4 will be explained, and then the structure of the upper bracket 4 and a method for manufacturing the upper bracket 4 will be explained.

[0032] In the following description, unless otherwise specified, the front-rear direction means the front-rear direction of the vehicle, the up-down direction means the up-down direction of the vehicle, and the width direction (left-right direction) means the width direction of the vehicle. Note that the front-rear direction of the vehicle roughly coincides with the axial direction of the steering column 3.

[0033] [Overall structure of steering device] The steering device 1 includes a steering shaft 2, a steering column 3, and an upper bracket 4.

[0034] A steering wheel (not shown) is fixed to the rear end of the steering shaft 2. The steering column 3 has a generally cylindrical shape and rotatably supports the steering shaft 2 via a plurality of rolling bearings (not shown) inside the steering column 3. An upper bracket 4 supports the middle part of the steering column 3 in the fore-and-aft direction on the vehicle body 12.

[0035] The steering device 1 of this example further includes a lower bracket 5 and an electric assist device 6.

[0036] The lower bracket 5 supports the front portion of the steering column 3 on the vehicle body 12. Specifically, the lower bracket 5 supports the front portion of the steering column 3 on the vehicle body 12 via a gear housing 7 (described later) that constitutes the electric assist device 6.

[0037] The electric assist device 6 is provided on the front side of the steering column 3. The electric assist device 6 has a gear housing 7 fixed to the front end of the steering column 3, and an electric motor (not shown) supported by the gear housing 7. The output torque of the electric motor is applied to the steering shaft 2 via a reduction mechanism housed in the gear housing 7. This reduces the force required to operate the steering wheel.

[0038] The steering device 1 of this example is provided with a tilt mechanism for adjusting the vertical position of the steering wheel and a telescopic mechanism for adjusting the front-rear position in accordance with the driver's physique and driving posture.

[0039] The steering column 3 is made up of a substantially cylindrical inner column 8 located at the front (lower side) and a substantially cylindrical outer column 9 located at the rear (upper side) to enable adjustment of the fore-aft position of the steering wheel. 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 so that its entire length can be extended or retracted.

[0040] The steering shaft 2 is made up of an inner shaft 10 and an outer shaft 11. The inner shaft 10 and the outer shaft 11 are connected by spline engagement or the like to enable torque transmission. As a result, the steering shaft 2 is configured to be extendable and contractible over its entire length.

[0041] To enable adjustment of the vertical position of the steering wheel, the steering column 3 is supported to be able to pivot about a tilt shaft 13 disposed in the width direction relative to the vehicle body 12. Specifically, a gear housing 7 fixed to the front end of the steering column 3 is supported to be able to pivot about the tilt shaft 13 relative to the lower bracket 5.

[0042] The steering device 1 is equipped with an expansion / contraction device 14 in order to be able to switch between a clamped state in which the outer column 9 is held by the upper bracket 4, and an unclamped state in which the outer column 9 is not held by the upper bracket 4. The expansion / contraction device 14 has an adjustment rod 15, an adjustment lever 16, and a cam device 17.

[0043] The adjustment rod 15 is inserted in the width direction through a pair of side plates 34 (described later) that constitute the upper bracket 4 and the outer column 9. A nut 18 is threadedly engaged with the tip end of the adjustment rod 15.

[0044] The adjustment lever 16 and the cam device 17 are disposed around the portion of the adjustment rod 15 between the head of the adjustment rod 15 and one of the side plates 34 that constitute the upper bracket 4 .

[0045] A thrust bearing 19 and a pressure plate 20 are disposed around the portion of the adjustment rod 15 between the nut 18 and the other side plate 34 that constitutes the upper bracket 4 .

[0046] The magnitude of the force with which the upper bracket 4 holds the outer column 9 can be adjusted by swinging the adjustment lever 16 up and down to expand and contract the cam device 17.

[0047] The steering device 1 is provided with tension springs 21 between the adjustment lever 16 and the upper bracket 4 and between the pressure plate 20 and the upper bracket 4 to prevent the steering column 3 from tilting forcefully when the force holding the outer column 9 is released.

[0048] [Outer column] The outer column 9 has a column body 22, a reinforcing bridge portion 23, and a column-side through-hole 24.

[0049] The column body 22 has a substantially cylindrical shape and fits onto the outer surface of the inner column 8. The column body 22 has a front-rear slit 25 that extends in the front-rear direction. The front-rear slit 25 is provided in the center of the lower end of the column body 22 in the width direction.

[0050] The column body 22 has a front circumferential slit 26a extending in the circumferential direction in the front portion of the lower half, and a rear circumferential slit 26b extending in the circumferential direction in the rear portion of the lower half. The front circumferential slit 26a circumferentially crosses the front portion of the front-rear slit 25. The rear circumferential slit 26b circumferentially crosses the rear portion of the front-rear slit 25.

[0051] The column body 22 has a pair of clamp portions 27. The pair of clamp portions 27 are arranged on both widthwise sides of the column body 22, surrounded on three sides by the front-rear slits 25, the front circumferential slits 26a, and the rear circumferential slits 26b.

[0052] The column body 22 has a protruding portion 28 that protrudes outward in the width direction at a portion of its outer peripheral surface that overlaps in the up-down direction with the central axis of the outer column 9. The protruding portion 28 extends in the front-to-rear direction and is positioned above the clamping portion 27. A flat upper fastening surface 29 is provided on the tip surface (outer surface in the width direction) of the protruding portion 28, which receives a fastening force from the inner surface in the width direction of the side plate 34 that constitutes the upper bracket 4 when clamped.

[0053] The clamp portion 27 has a widthwise inner surface shaped like a partial cylinder that matches the outer peripheral surface of the inner column 8. The clamp portion 27 has, at its lower end, a flat protruding plate portion 30 that protrudes outward in the widthwise direction. The protruding plate portion 30 extends in the front-to-rear direction. A flat intermediate fastening surface 31 is provided on the tip surface (outer surface in the widthwise direction) of the protruding plate portion 30, which receives a fastening force from the widthwise inner surfaces of the side plates 34 that constitute the upper bracket 4 when clamping.

[0054] The reinforcing bridge portion 23 is located below the column main body 22 and improves the torsional rigidity of the outer column 9. The reinforcing bridge portion 23 has a substantially U-shape when viewed in the width direction, and is configured integrally with the column main body 22.

[0055] The reinforcing bridge portion 23 has a flat lower fastening surface 32 on its outer widthwise surface that receives a fastening force from the inner widthwise surfaces of the side plates 34 that constitute the upper bracket 4 when clamped.

[0056] As described above, the outer column 9 of this example has three fastening surfaces, namely, the upper fastening surface 29, the intermediate fastening surface 31, and the lower fastening surface 32, on both outer surfaces in the width direction thereof.

[0057] The adjustment rod 15 that constitutes the expansion / contraction device 14 is inserted in the width direction through the column-side through-hole 24. The column-side through-hole 24 is provided between the column main body 22 and the reinforcing bridge portion 23. The column-side through-hole 24 is configured as an elongated hole that is long in the front-rear direction. When implementing a steering device according to one aspect of the present disclosure, if the steering device does not have a telescopic mechanism, the column-side through-hole can be configured as a circular hole.

[0058] [Upper bracket] The upper bracket 4 supports a middle portion of the steering column 3 in the front-rear direction on the vehicle body 12. Specifically, the upper bracket 4 supports the outer column 9 on the vehicle body 12.

[0059] The upper bracket 4 is made of a metal plate having sufficient rigidity, such as steel or an aluminum alloy.

[0060] The upper bracket 4 has a top plate 33 and a pair of side plates 34.

[0061] In this example, the top plate 33 and the side plates 34 are made of the same type of metal. However, when implementing a bracket for a steering device according to one aspect of the present disclosure, the top plate and the side plates may be made of different types of metal.

[0062] <Tabletop The top plate 33 is supported by the vehicle body 12. In this example, the top plate 33 is normally supported by the vehicle body 12, but in the event of a collision accident, it detaches forward due to the impact of the secondary collision, allowing the outer column 9 to be displaced forward. For this reason, the top plate 33 is engaged with a detachment capsule 35 that is fixed to the vehicle body 12 by bolts or the like (not shown) so as to be able to detach forward.

[0063] The top plate 33 has a bridge portion 36. In this example, the bridge portion 36 has an inverted U-shaped cross section when viewed in the axial direction of the steering column 3, and is disposed above the outer column 9 that constitutes the steering column 3. The bridge portion 36 is provided in the center of the top plate 33 in the width direction.

[0064] The bridge portion 36 has a central plate portion 37 having a generally flat plate shape, and a pair of inclined plate portions 38 arranged on both outer sides of the central plate portion 37 in the width direction.

[0065] The pair of inclined plate portions 38 are configured in a generally flat plate shape, and their widthwise inner ends are connected to widthwise outer ends of the central plate portion 37. The inclined plate portions 38 are inclined with respect to the central plate portion 37. Specifically, the inclined plate portions 38 are inclined downward as they move away from the central plate portion 37 in the width direction.

[0066] The top plate 33 of this example further has a pair of side plate portions 39. The pair of side plate portions 39 are configured in a substantially flat plate shape and are arranged on both outer sides of the bridge portion 36 in the width direction. The inner ends of the side plate portions 39 in the width direction are connected to the outer ends (lower ends) of the inclined plate portions 38 in the width direction. The pair of side plate portions 39 are arranged at the same height position relative to each other in the up-down direction and substantially parallel to the central plate portion 37.

[0067] The side plate portion 39 has a notch 40. The notch 40 is formed in the rear side of the side plate portion 39 and opens to the rear end edge of the side plate portion 39. The release capsule 35 is engaged in the notch 40.

[0068] The top plate 33 of this example has a linear rib 41 extending in the width direction in its front-to-rear middle portion. This makes the bridge portion 36 more rigid than the side plate portions 39. The linear rib 41 is configured so that the upper surface of the central plate portion 37 and the widthwise outer surface sides of the inclined plate portions 38 are convex, and the lower surface of the central plate portion 37 and the widthwise inner surface sides of the inclined plate portions 38 are concave. The linear rib 41 is provided across the entire width of the bridge portion 36. The widthwise outer end of the linear rib 41 is located at the widthwise inner end of the side plate portions 39. Therefore, the linear rib 41 is formed across the bridge portion 36 and the side plate portions 39.

[0069] In addition to the linear ribs 41, the top plate 33 further has a plurality of (two in the illustrated example) dotted ribs 42. The dotted ribs 42 are arranged rearward of the linear ribs 41 and are formed at the connection between the inclined plate portion 38 and the side plate portion 39.

[0070] In this example, the side plate 39 has a slit 43 extending in the front-rear direction on its inner widthwise portion. The slit 43 is located between the outer widthwise end of the linear rib 41 and the outer widthwise end of the point-like rib 42 in the front-rear direction. The slit 43 reduces the rigidity of the side plate 39 relative to the bridge portion 36, thereby preventing the influence of the surface accuracy of the upper surface of the side plate 39 and the accuracy of the mounting surface of the vehicle body 12 on the bridge portion 36.

[0071] Side Panel The pair of side plates 34 are arranged on both outer sides of the steering column 3 in the width direction. In this example, the pair of side plates 34 are arranged on both outer sides of the outer column 9 in the width direction. The pair of side plates 34 are arranged facing each other and spaced apart in the width direction.

[0072] The side plates 34 are welded and fixed to the bridge portions 36 with the outer surfaces of their upper ends in the width direction overlapping the inner surfaces of the bridge portions 36 in the width direction.

[0073] The side plate 34 is a plate-shaped member and has a side plate main body 44 that presses the outer column 9 inward in the width direction, and a welding piece 45 provided on the upper side of the side plate main body 44.

[0074] The side plate main body 44 has a bracket-side through-hole 46 through which the adjustment rod 15 is inserted in the width direction. In this example, the bracket-side through-hole 46 is configured as an elongated hole that is curved in an arc shape around the tilt axis 13 and extends in the up-down direction. When implementing a steering device according to one aspect of the present disclosure, if the steering device does not include a tilt mechanism, the bracket-side through-hole can be configured as a circular hole.

[0075] In this example, the side plate main body 44 has a step portion 47 in a range that includes the portion where the bracket-side through-hole 46 is formed. The step portion 47 is formed by surface pressing and is configured so that the outer side in the width direction is concave and the inner side in the width direction is convex. The inner surface of the step portion 47 in the width direction is configured as a flat surface and protrudes inward in the width direction by, for example, approximately 0.2 mm to 0.8 mm from the portion outside the step portion 47. The inner surface of the step portion 47 in the width direction faces in the width direction the upper fastening surface 29, the middle fastening surface 31, and the lower fastening surface 32, which are three fastening surfaces provided on the outer column 9. In other words, in this example, the step portion 47 of the side plate 34 is the portion that clamps the outer column 9. When implementing a bracket for a steering device according to one aspect of the present disclosure, it is optional for the side plate (side plate main body) to have a step portion.

[0076] In this example, the side plate main body 44 further includes a front reinforcing portion 48 and a rear reinforcing portion 49. The front reinforcing portion 48 and the rear reinforcing portion 49 increase the section modulus of the side plate main body 44 and improve the bending rigidity of the side plate main body 44 in the width direction.

[0077] The front reinforcement portion 48 is provided at the front end portion of the side plate main body 44. The front reinforcement portion 48 is configured so that the outer side in the width direction is convex and the inner side in the width direction is concave, and has a cross-sectional shape that is curved in a semicircular arc. The upper end portion of the front reinforcement portion 48 is not connected to the lower end portion of the weld piece 45.

[0078] The rear reinforcement portion 49 is provided at the rear end portion of the side plate main body 44. The rear reinforcement portion 49 is formed by bending the rear end portion of the side plate main body 44 outward in the width direction at a substantially right angle. The upper end portion of the rear reinforcement portion 49 is not connected to the lower end portion of the weld piece 45.

[0079] When implementing the steering device bracket according to one aspect of the present disclosure, it is optional for the side plate (side plate main body) to have a front reinforcing portion and a rear reinforcing portion. Furthermore, the shapes of the front reinforcing portion and the rear reinforcing portion can be changed as appropriate.

[0080] The welding piece 45 has a generally flat plate shape and constitutes the upper end of the side plate 34. The lower end of the welding piece 45 is connected to the upper end of the side plate main body 44. In this example, the lower end of the welding piece 45 is connected only to the upper end of the middle part of the side plate main body 44 in the front-rear direction.

[0081] The weld pieces 45 are inclined relative to the side panel main body 44. Specifically, the weld pieces 45 are inclined inward in the width direction as they extend upward. The inclination angle of the weld pieces 45 relative to the vertical plane is the same as the inclination angle of the inclined plate portions 38 relative to the vertical plane. The vertical dimension of the weld pieces 45 is slightly smaller than the vertical dimension of the inclined plate portions 38, and the front-to-rear dimension of the weld pieces 45 is slightly smaller than the front-to-rear dimension of the inclined plate portions 38.

[0082] In this example, the weld piece 45 has a substantially U-shape when viewed in the width direction, so that the vertical dimension of the weld piece 45 is larger at both ends in the front-rear direction than at the middle part in the front-rear direction.

[0083] The welding piece 45 is welded and fixed to the inclined plate portion 38 with its widthwise outer surface overlapping the widthwise inner surface of the inclined plate portion 38 that constitutes the bridge portion 36, i.e., in surface contact (close contact).

[0084] In this example, when the welding piece 45 and the inclined plate portion 38 are welded and fixed, the boundary (bending portion) between the welding piece 45 and the side plate main body 44 is located near the boundary (bending portion) between the inclined plate portion 38 and the side plate portion 39.

[0085] In the upper bracket 4, a laser weld 50 is formed between the bridge portion 36 and the side plate 34, and is made of weld metal that melts from the side plate 34 toward the bridge portion 36. In the upper bracket 4 of this example, a laser weld 50 is formed between the inclined plate portion 38 that constitutes the bridge portion 36 and the weld piece 45 that constitutes the side plate 34, and is made of weld metal that melts from the weld piece 45 toward the inclined plate portion 38.

[0086] The laser weld 50 is a lap weld (full weld, stake weld) formed by overlapping the widthwise inner surface of the inclined plate portion 38 and the widthwise outer surface of the weld piece 45 together.

[0087] As shown in FIGS. 8(A) and 8(B), a bead (weld mark) is formed on the widthwise inner surface of the weld piece 45 of the inclined plate portion 38 welded to the weld piece 45 by the laser weld 50. However, as shown in FIG. 8(A), a bead does not have to be formed on the widthwise outer surface of the inclined plate portion 38. In other words, the laser weld 50 does not have to penetrate all the way to the widthwise outer surface (rear surface) of the inclined plate portion 38. Alternatively, as shown in FIG. 8(B), a bead may also be formed on the widthwise outer surface of the inclined plate portion 38. In other words, the laser weld 50 may penetrate all the way to the widthwise outer surface (rear surface) of the inclined plate portion 38.

[0088] The height of the bead of the laser weld 50 formed on the widthwise inner surface of the weld piece 45 is not limited to this value, but is, for example, 0.1 mm or less, preferably 0.05 mm or less, and the width dimension (diameter) of the bead is not limited to this value, but is, for example, 2 mm or less, preferably 1 mm or less.

[0089] In this example, the laser welds 50 are formed at two positions in the front-rear direction on the overlapping portion 51 between the inclined plate portion 38 and the weld piece 45, sandwiching the linear rib 41. In other words, one weld piece 45 is welded and fixed to one inclined plate portion 38 by two laser welds 50.

[0090] However, when implementing a steering device bracket according to one embodiment of the present disclosure, the laser weld 50 may be formed only in a portion of the overlapping portion 51 that is rearward of the linear rib 41, as shown in Fig. 9(A), or only in a portion of the overlapping portion 51 that is forward of the linear rib 41, as shown in Fig. 9(B). Alternatively, if no linear rib is present in the overlapping portion 51, the laser weld 50 may be formed over the entire overlapping portion 51 in the front-to-rear direction, as shown in Fig. 9(C).

[0091] In this example, the laser weld 50 extends in the axial direction of the steering column 3. Therefore, the laser weld 50 is configured in a linear shape that extends in the front-to-rear direction. The width and length of the linear laser weld 50 can be determined appropriately.

[0092] When implementing a steering device bracket according to one embodiment of the present disclosure, the laser welds 50 are not limited to being linear, but may be configured in a dotted pattern as shown in Fig. 9(D) . In this case, the number, diameter, and pitch of the dotted laser welds 50 can be determined appropriately.

[0093] Plate Guide The upper bracket 4 of this example further includes a pair of plate guides 53 that constitute the impact absorbing mechanism 52. However, when implementing a bracket for a steering device according to one aspect of the present disclosure, it is optional for the upper bracket to include the plate guides.

[0094] The impact absorbing mechanism 52 is a member that absorbs impact energy during a secondary collision, and includes a pair of plate guides 53 and a pair of impact absorbing plates 54.

[0095] The plate guide 53 is a pressed metal plate and has a substantially U-shaped cross section. The plate guide 53 is welded and fixed to the side plate 39, with its upper end surface abutting against the lower surface of the side plate 39 that constitutes the top plate 33.

[0096] The impact absorbing plate 54 is a strip-shaped metal plate that is bent in a horizontal J-shape when viewed in the width direction. The rear end of the impact absorbing plate 54 is fixed to the vehicle body 12 together with the breakaway capsule 35, and the front end is housed in the plate guide 53. During a secondary collision, the impact absorbing plate 54 is pressed forward by the rear end of the plate guide 53 and plastically deforms, thereby absorbing the impact of the secondary collision.

[0097] In the steering device 1 of this example, when the steering wheel is held at a desired position, the steering wheel is moved to the desired position, and then the adjustment lever 16 is rotated in a predetermined direction (for example, upward) around the adjustment rod 15. This increases the width dimension of the cam device 17, and reduces the distance between the widthwise inner surfaces of the pair of side plates 34. At this time, the widthwise inner surfaces of the stepped portions 47 of the pair of side plates 34 press against the upper fastening surface 29, the middle fastening surface 31, and the lower fastening surface 32. This causes the pair of clamp portions 27 to elastically deform inward in the width direction, and clamp the outer peripheral 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.

[0098] When adjusting the position of the steering wheel, the adjustment lever 16 is swung in the direction opposite to the predetermined direction (for example, downward). This reduces the widthwise dimension of the cam device 17, and the distance between the widthwise inner surfaces of the pair of side plates 34 increases. As a result, the pressing force of the pair of side plates 34 decreases, causing the pair of clamp portions 27 to elastically restore their original shape, and the force with which the pair of clamp portions 27 hold the outer peripheral surface of the inner column 8 decreases. In this state, the fore-and-aft position and up-and-down position of the steering wheel can be adjusted within the range in which the adjustment rod 15 can move inside the column-side through-hole 24 and the bracket-side through-hole 46.

[0099] [Manufacturing method of upper bracket] Next, an example of a method for manufacturing the upper bracket 4 will be described with reference to FIGS.

[0100] In the manufacturing method of the upper bracket 4 of the present disclosure, first, a metal plate material is subjected to press working or the like to manufacture one top plate 33, two side plates 34, and two plate guides 53. Then, a process of welding and fixing the two side plates 34 to the bridge portion 36 that constitutes the top plate 33, and a process of welding and fixing the two plate guides 53 to a pair of side plate portions 39 that constitute the top plate 33 are performed.

[0101] In this example, we will explain a case where two plate guides 53 are welded to a pair of side plate portions 39 that make up the top plate 33, and then two side plates 34 are welded to a bridge portion 36 that makes up the top plate 33.

[0102] However, when carrying out the manufacturing method for a bracket for a steering device according to one embodiment of the present disclosure, a process of welding and fixing the side plates to the bridge portion that constitutes the top plate can also be carried out before carrying out the process of welding and fixing the plate guide to the pair of side plate portions that constitute the top plate.

[0103] The process of welding and fixing the two plate guides 53 to a pair of side plate portions 39 that make up the top plate 33 can be carried out using various conventionally known welding methods, such as arc welding and laser welding, so a detailed explanation will be omitted. Below, we will explain the process of welding and fixing the two side plates 34 to the bridge portion 36 that makes up the top plate 33.

[0104] In one example of the manufacturing method of this example, the welding process is performed using one center jig 55, two side jigs 56, one base jig 57, and a total of two laser heads 58 connected to the laser processing machine body (not shown).

[0105] The widthwise outer surface of the center jig 55 is formed by a flat surface that can come into surface contact with the widthwise inner surface of the side plate 34. The width dimension of the center jig 55 is the same as the distance between the widthwise inner surfaces of the pair of side plates 34 that make up the upper bracket 4 in the completed state. In this example, the vertical dimension of the center jig 55 is the same as the vertical dimension of the side plate main body 44 that makes up the side plate 34, or is smaller than the vertical dimension of the side plate main body 44, but it may be larger than the vertical dimension of the side plate main body 44.

[0106] In this example, the center jig 55 has a structure that allows the laser light to pass through. Specifically, as shown in Fig. 11 , the center jig 55 has a hollow skeletal structure rather than a solid structure. When carrying out a manufacturing method for a steering device bracket according to one aspect of the present disclosure, the center jig is not limited to the structure shown in Fig. 11 , and other structures, such as a structure provided with a through hole for passing the laser light, can also be employed.

[0107] The center jig 55 has a pair of vertical plates 59 , a top plate 60 , and a pair of beams 61 .

[0108] The pair of vertical plates 59 are spaced apart in the width direction and arranged approximately parallel to each other. The outer surfaces of the vertical plates 59 form the widthwise outer surfaces of the center jig 55. The upper ends of the pair of vertical plates 59 are connected to both outer widthwise ends of a top plate 60. The top plate 60 is configured in the shape of a substantially rectangular plate. The pair of beams 61 are spaced apart in the front-to-rear direction (the front-to-back direction in FIG. 10 ) and arranged approximately parallel to each other. Note that in FIG. 10 , the front side of FIG. 10 corresponds to the rear side, and the back side of FIG. 10 corresponds to the front side. Both longitudinal ends of the pair of beams 61 are connected to the lower ends of the pair of vertical plates 59. Note that the center jig may be configured from only a pair of vertical plates and a top plate without the pair of beams, or may be configured from only a pair of vertical plates and a pair of beams without the top plate, as long as rigidity during clamping can be ensured.

[0109] The center jig 55 has a lower opening 62 in a portion surrounded on all four sides by a pair of vertical plates 59 and a pair of beams 61. The lower opening 62 is open across almost the entire underside of the center jig 55, and its front-to-rear dimension is approximately the same as the front-to-rear dimension of the overlapping portion 51 (weld piece 45). The center jig 55 also has a front opening 63 in a portion surrounded on all four sides by the pair of vertical plates 59, the top plate 60, and one of the beams 61 located on the front side. The center jig 55 also has a rear opening 64 in a portion surrounded on all four sides by the pair of vertical plates 59, the top plate 60, and the other beam 61 located on the rear side.

[0110] The two side jigs 56 are arranged on both outer sides of the center jig 55 in the width direction, and are capable of moving relative to the center jig 55 in the width direction.

[0111] The base jig 57 has, on its upper end surface, a pair of mounting surfaces 65 and an accommodating recess 66 arranged in the width direction between the pair of mounting surfaces 65. The accommodating recess 66 has a depth and width dimension that can accommodate the bridge portion 36 that constitutes the top plate 33.

[0112] In this example, the top plate 33 is set on the pedestal jig 57 in an orientation upside down from the state in which it is attached to the vehicle body 12 (see FIG. 2). Specifically, the top plate 33 is set on the pedestal jig 57 with the bridge portion 36 positioned below the pair of side plate portions 39. Then, the pair of side plate portions 39 are placed on the pair of mounting surfaces 65, and the bridge portion 36 is accommodated inside the accommodation recess 66.

[0113] Before or after the top plate 33 is set on the base jig 57, the two side plates 34 are simultaneously clamped using the center jig 55 and the two side jigs 56. Specifically, the two side plates 34 are clamped with the weld pieces 45 facing downward and protruding downward beyond the center jig 55 and the side jigs 56. In this way, a clamp assembly 67 consisting of the center jig 55, the two side jigs 56, and the two side plates 34 is formed.

[0114] Next, the clamp assembly 67 is moved above the top plate 33 and lowered so that the widthwise outer surfaces of the two side plates 34 overlap the widthwise inner surfaces of the bridge portions 36 that make up the top plate 33. In this example, the widthwise outer surfaces of the weld pieces 45 of each of the two side plates 34 are brought into surface contact with the widthwise inner surfaces of the pair of inclined plate portions 38 that make up the bridge portion 36 without any gaps.

[0115] After the top plate 33 and the two side plates 34 are set as described above, the laser head 58 emits laser light.

[0116] Specifically, the tip of the laser head 58 is opposed to the widthwise inner surface of the side plate 34, and the laser head 58 irradiates the widthwise inner surface of the side plate 34 with laser light. In this example, the entire weld piece 45 that constitutes the side plate 34 becomes the overlapping portion 51 that is overlapped with the inclined plate portion 38 that constitutes the bridge portion 36. For this reason, the tip of the laser head 58 is opposed to the widthwise inner surface of the weld piece 45, and the laser head 58 irradiates the widthwise inner surface of the weld piece 45 with laser light. When irradiating the widthwise inner surface of the weld piece 45 with laser light, the tip of the laser head 58 can also be opposed to the widthwise inner surface of the weld piece 45 from above, and the laser light can be irradiated in the vertical direction (only with the vertical component).

[0117] On the inner side surface in the width direction of the welding piece 45, a protrusion or a recess may be formed to serve as a mark for the irradiation position of the laser beam.

[0118] In this example, the two laser heads 58 are each positioned in front of or behind the center jig 55, or alternatively, the two laser heads 58 are positioned one in front of and one behind the center jig 55, and laser light is emitted from the two laser heads 58 simultaneously.

[0119] When the two laser heads 58 are disposed in front of the center jig 55, the light from the two laser heads 58 passes through the front opening 63 and the lower opening 62 in this order to irradiate the widthwise inner surface of the piece 45 to be welded. On the other hand, when the two laser heads 58 are disposed behind the center jig 55, the light from the two laser heads 58 passes through the rear opening 64 and the lower opening 62 in this order to irradiate the widthwise inner surface of the piece 45 to be welded. When two laser heads 58 are disposed, one in front of the center jig 55 and one behind it, the light from one laser head 58 passes through the front opening 63 and the lower opening 62 in this order to irradiate the widthwise inner surface of one piece 45 to be welded, and the light from the remaining laser head 58 passes through the rear opening 64 and the lower opening 62 in this order to irradiate the widthwise inner surface of the other piece 45 to be welded.

[0120] In this example, the laser head 58 is moved back and forth or swung back and forth while emitting the laser light.

[0121] This forms a laser weld 50 between the bridge portion 36 and the side plate 34, consisting of weld metal that melts from the side plate 34 toward the bridge portion 36. In this example, a laser weld 50 is formed between the inclined plate portion 38 and the weld piece 45, consisting of weld metal that melts from the weld piece 45 toward the inclined plate portion 38. After the laser weld 50 is formed, the clamping by the two side jigs 56 is released, and the center jig 55 is pulled out from between the pair of side plates 34.

[0122] When carrying out the manufacturing method for a bracket for a steering device according to one embodiment of the present disclosure, the process of welding and fixing the side plates to the bridge portion can involve welding and fixing two side plates simultaneously, or welding and fixing two side plates separately.

[0123] When carrying out the manufacturing method for a bracket for a steering device according to one embodiment of the present disclosure, the welding process can also be carried out with the top plate and the two side plates arranged upside down compared to the case shown in FIG.

[0124] According to the steering device 1 of this embodiment, the influence of heat generated by welding on the side plate 34 of the upper bracket 4 can be sufficiently reduced.

[0125] In other words, in the present example, the upper bracket 4 is formed by welding the side plate 34 to the bridge portion 36 with the widthwise outer surface of the upper end of the side plate 34 overlapping the widthwise inner surface of the bridge portion 36, and a laser weld 50 is formed between the bridge portion 36 and the side plate 34, consisting of weld metal that melts from the side plate 34 toward the bridge portion 36.

[0126] For this reason, the distance from the laser welded portion 50 to the portion of the side plate 34 that clamps the outer column 9 can be made greater than the distance from the weld bead to the portion of the side plate that clamps the outer column in the conventional structure described in JP 2023-131680 A. In this example, the distance from the laser welded portion 50 to the step portion 47 of the side plate 34 can be made greater. Therefore, the effect of heat from welding on the step portion 47 can be sufficiently reduced.

[0127] This makes it possible to prevent a decrease in the surface precision of the stepped portion 47, thereby stabilizing the fastening force applied by the side plate 34. In this example, it is possible to prevent the inner surface of the stepped portion 47 in the width direction from coming into uneven contact with the upper fastening surface 29, the intermediate fastening surface 31, and the lower fastening surface 32, improving the supporting rigidity of the outer column 9 by the upper bracket 4.

[0128] Furthermore, since the distance from the laser welded portion 50 to the portion of the side plate 34 that clamps the outer column 9 is increased, the side plate 34 becomes more likely to bend, and the force required to operate the adjustment lever 16 when clamping is reduced.

[0129] Furthermore, because the side plates 34 and the bridge portion 36 are welded and fixed by the laser welds 50, thermal distortion of the side plates 34 and the bridge portion 36 is suppressed. Furthermore, because laser welding has a faster welding speed than other types of welding, the work time required for the process of welding and fixing the side plates 34 to the bridge portion 36 can be shortened. Because laser welding allows for precise welding, there is a high degree of freedom in the position and size of the laser welds 50. Therefore, even if the bridge portion 36 is provided with linear ribs 41 and dotted ribs 42, the laser welds 50 can be formed while avoiding the linear ribs 41 and dotted ribs 42.

[0130] Additionally, the overlapping portion 51 is formed by overlapping a portion of the inclined plate portion 38 with the entire welding piece 45. In other words, the entire welding piece 45 forms the overlapping portion 51. Therefore, in this example, unlike when the laser beam is irradiated onto the outer surface of the inclined plate portion 38, the position of the overlapping portion 51 can be confirmed by a position sensor or visually while irradiating the laser beam. This improves the accuracy of the welding position.

[0131] In particular, in this example, in the welding process, the center jig 55 placed between the two side plates 34 has a structure that allows laser light to pass through, so that the laser light can be irradiated onto the widthwise inner surfaces of the side plates 34 with the widthwise outer surfaces of the side plates 34 overlapping the widthwise inner surfaces of the bridge portion 36. Furthermore, the center jig 55 has a lower opening 62 whose front-to-rear dimension is approximately the same as the front-to-rear dimension of the overlapping portion 51 (weld piece 45). Therefore, by changing the position of the laser light passing through the lower opening 62, the laser weld 50 can be formed into a line that extends in the front-to-rear direction.

[0132] Furthermore, in this example, the two side plates 34 can be welded to the bridge portion 36 of the top plate 33 at the same time, which improves the manufacturing efficiency of the upper bracket 4. [Explanation of symbols]

[0133] 1 Steering device 2 steering shaft 3. Steering column 4 Upper bracket 5 Lower bracket 6 Electric assist device 7 Gear housing 8 Innacolumn 9 Outer Column 10 Inner shaft 11 outer shaft 12 Body 13 Tilt axis 14 Expanding device 15 Adjustment rod 16 Adjustment lever 17 Cam device 18 Nut 19 Thrust bearing 20 Pressing plate 21 Tension spring 22 Column body 23 Reinforced bridge section 24 Column side through hole 25 Front and rear slits 26a Front circumferential slit 26b Rear circumferential slit 27 Clamp section 28 Projection part 29 Upper fastening surface 30 Overhang plate part 31 Middle fastening surface 32 Lower fastening surface 33 Top plate 34 Side panel 35 Withdrawal Capsule 36 Bridge section 37 Center plate part 38 Inclined plate section 39 Side plate 40 Notch 41 Linear rib 42 Pointed Rib 43 Slit 44 Side panel body 45 Welding Pieces 46 Bracket side through hole 47 Step 48 Front reinforcement part 49 Rear reinforcement 50 Laser welded section 51 Overlapping section 52 Shock absorption mechanism 53 Plate guide 54 Shock absorbing plate 55 Center jig 56 Side jig 57 Base jig 58 Laser Head 59 Vertical board 60 Top Plate 61 Beam 62 Lower opening 63 Front opening 64 Rear opening 65 Placement surface 66 Storage recess 67 Clamp assembly 100 Steering device 101 Steering shaft 102 Steering column 103 Lower bracket 104 Upper bracket 105 Electric assist device 106 Innacolumn 107 Outer Column 108 Column side through hole 109 Outer shaft 110 Tilt axis 111 Top plate 112 Side panel 113 Bracket side through hole 114 Adjustment rod 115 Adjustment lever 116 Welded Pocket 117 Weld Bead

Claims

1. a top plate having an inverted U-shaped cross section, including a bridge portion disposed above the steering column, and supported by a vehicle body; a pair of side plates disposed on both outer sides of the steering column in the width direction; The side plates are welded to the bridge portion in a state where the outer side surfaces of the upper ends of the side plates in the width direction are overlapped with the inner side surfaces of the bridge portion in the width direction, A laser weld is formed between the bridge portion and the side plate, the laser weld being made of a weld metal that melts from the side plate toward the bridge portion. Bracket for steering device.

2. 2. The steering device bracket according to claim 1, wherein the laser welded portion extends in the axial direction of the steering column.

3. A steering shaft; a steering column that rotatably supports the steering shaft; a bracket that supports the steering column relative to a vehicle body, A steering device, wherein the bracket is the steering device bracket according to any one of claims 1 and 2.

4. A method for manufacturing a bracket for a steering device according to any one of claims 1 to 2, a step of welding and fixing the side plate to the bridge portion by irradiating the widthwise inner surface of the side plate with a laser beam while overlapping the widthwise outer surface of the side plate with the widthwise inner surface of the bridge portion, and forming a laser weld between the bridge portion and the side plate, the laser weld being made of a weld metal that melts from the side plate toward the bridge portion. A method for manufacturing a bracket for a steering device.

5. 5. The method for manufacturing a bracket for a steering device according to claim 4, wherein the two side plates are simultaneously clamped using a center jig and two side jigs, and the widthwise outer surfaces of the two side plates are overlapped with the widthwise inner surfaces of the bridge portion.

6. 6. The method for manufacturing a bracket for a steering device according to claim 5, wherein the center jig has a structure that allows the laser light to pass through.

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