Steering system

Abstract

To provide a steering device that can reduce manufacturing costs by reducing the number of parts. [Solution] The steering device 1 comprises an outer jacket 7 supported by the vehicle body, an inner tube 8 slidably fitted into the outer jacket 7, and a steering shaft 9 housed inside the outer jacket 7 and the inner tube 8. A steering shaft support portion 52 made of resin material is formed at the front end FR of the outer jacket 7, and the steering shaft support portion 52 has a through hole 60 that directly supports the steering shaft 9.

Description

[Technical Field]

[0001] The present invention relates to a steering apparatus. [Background Art]

[0002] A steering apparatus comprises an outer jacket supported on a vehicle body, an inner tube slidably fitted to the outer jacket, and a steering shaft housed inside the outer jacket and the inner tube (see Patent Document 1). In Patent Document 1, between the outer jacket (outer pipe) and the steering shaft, a bearing is provided on the front side of the vehicle body, a bearing is provided on the rear side of the vehicle body, and a bearing made of a bearing or a resin elastic member is provided at an intermediate portion between the two bearings, so that the steering shaft is supported at three points. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2011-105267 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the steering apparatus of Patent Document 1, since three members including bearings and other supporting components are used, the number of parts increases, which may lead to an increase in manufacturing cost.

[0005] The present invention has been made in view of the problems of such conventional technologies. An object of the present invention is to provide a steering apparatus that can reduce the number of parts and achieve a reduction in manufacturing cost. [Means for Solving the Problem]

[0006] A steering device according to one aspect of the present invention comprises an outer jacket supported by the vehicle body, an inner tube slidably fitted to the outer jacket, and a steering shaft housed inside the outer jacket and inner tube. A steering shaft support portion made of a resin material is formed at the front end of the outer jacket on the vehicle body side, and the steering shaft support portion has a through hole for directly supporting the steering shaft. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a steering device that can reduce the number of parts and thereby lower manufacturing costs. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing an example of a steering device according to this embodiment. [Figure 2] This is a schematic front view of the steering system as seen from the rear of the vehicle. [Figure 3] This is a perspective view of the outer jacket and inner tube. [Figure 4] This is a close-up perspective view of the steering system, showing key components as seen from the front of the vehicle. [Figure 5] This is a close-up perspective view of the outer jacket, showing key parts as seen from the front of the vehicle. [Figure 6] This is a schematic rear view of the outer jacket as seen from the front of the vehicle. [Figure 7] This is an enlarged view of section A in Figure 6. [Figure 8] This is a cross-sectional view of the steering device corresponding to the BB line section in Figure 6. [Figure 9] This is an enlarged view of section C in Figure 8. [Modes for carrying out the invention]

[0009] The steering device according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios.

[0010] In Figure 1, arrow FR indicates the front of the vehicle in the longitudinal direction, and arrow RR indicates the rear of the vehicle in the longitudinal direction.

[0011] The steering device 1 according to this embodiment, shown in Figure 1, is manually operated. As shown in Figure 1, the steering device 1 comprises a fixed bracket 2 fixed to the vehicle body and a steering column 3 supported by the fixed bracket 2 so as to be able to swing vertically (tilt position adjustable).

[0012] As shown in Figures 1 and 2, the fixing bracket 2 is equipped with a fixing portion 4 that is fixed to the ceiling surface (not shown) of the vehicle body. A pair of side wall portions 5 hang down from the fixing portion 4. Each side wall portion 5 has a tilt slot (not shown) that defines the tilt position adjustment range along the vertical direction (tilt direction). This tilt slot is composed of an arc-shaped slot centered on the pivot support portion 6.

[0013] The steering column 3 mainly consists of an outer jacket 7 disposed between a pair of side wall portions 5, and an inner tube 8 supported so as to be movable (telescopic position adjustable) in the longitudinal direction of the vehicle body relative to the outer jacket 7. The steering column 3 is provided with a locking mechanism 10 that integrally fastens the fixing bracket 2, the outer jacket 7, and the inner tube 8. This locking mechanism 10 includes, for example, an operating lever 11, a locking bolt 12, a fixing cam 13, a rotating cam 14, and a nut 15.

[0014] Furthermore, the steering shaft 9 is housed inside the outer jacket 7 and the inner tube 8. This steering shaft 9 is made extendable and retractable by connecting the upper shaft 9a and the lower shaft 9b with serrations.

[0015] As shown in Fig. 3, the outer jacket 7 includes a cylindrical portion 22 provided with a slit 21 extending in the vehicle longitudinal direction, and a pair of clamp portions 23 hanging down from the cylindrical portion 22. The outer jacket 7 is located on the vehicle front side FR relative to the fixing bracket 2, and an inner tube 8 is slidably fitted into the cylindrical portion 22 of the outer jacket 7. Each clamp portion 23 is provided with a hole 24 through which the lock bolt 12 is inserted.

[0016] The inner tube 8 is formed in a cylindrical shape from metal or synthetic resin. A bearing 17 is mounted on the rear end portion of the inner tube 8 (see Fig. 1), and a bearing 18 is mounted on the front end portion of the inner tube 8 (see Fig. 4 and Fig. 5). The cylindrically formed inner tube 8 is inserted into the inner space of the cylindrical portion 22 of the outer jacket 7 in the cylinder axial direction. Accordingly, the inner tube 8 is supported by the outer jacket 7 so as to be movable in the cylinder axial direction (vehicle longitudinal direction) relative to the outer jacket 7.

[0017] In the present embodiment, the slit 21 is formed in the lower part of the cylindrical portion 22 of the outer jacket 7, and the pair of clamp portions 23, the operating lever 11 and the like are arranged below the cylindrical portion 22. However, the present invention is not limited thereto: the slit 21 may be formed in the upper part of the cylindrical portion 22 of the outer jacket 7, and the pair of clamp portions 23, the operating lever 11 and the like may be arranged above the cylindrical portion 22.

[0018] In the present embodiment, a spline fitting portion 16 for spline-fitting the outer jacket 7 and the inner tube 8 is formed on the inner diameter portion (inner circumferential surface) of the outer jacket 7 and the outer diameter portion (outer circumferential surface) of the inner tube 8.

[0019] As shown in FIGS. 1 to 3, the outer jacket 7 according to the present embodiment includes a metal plate portion 30 formed of a metal plate 31, and a resin portion 50 formed of a resin material and covering at least a part of the metal plate portion 30. That is, the outer jacket 7 is configured by molding (insert molding) the metal plate portion 30 formed of the metal plate 31 with resin.

[0020] The metal plate 31 is, for example, a steel plate (sheet metal), and the resin material is, for example, a thermoplastic resin.

[0021] The metal plate portion 30 is formed by pressing and bending a single metal plate (the metal plate 31). The metal plate portion 30 includes a semi-cylindrical portion 32 with an open lower portion, side plate portions 33 respectively extending downward from both left and right sides of the semi-cylindrical portion 32, and folded portions 34 formed by folding back from the tips of the side plate portions 33 toward the inner sides in the left-right direction. The side plate portion 33 is formed with a convex portion 35 that protrudes toward the inner sides in the left-right direction. The convex portion 35 is formed by bending a portion of the metal plate 31 corresponding to the side plate portion 33 to have a substantially trapezoidal cross-section, and a hook portion 36 facing the side surface of the convex portion 35 is formed at the tip of the folded portion 34 (see FIG. 2). In the present embodiment, there is a clearance between the side surface of the convex portion 35 and the hook portion 36, but the hook portion 36 may be in contact with the side surface of the convex portion 35. Further, the folded portion 34 is formed with a bent portion 34a that is bent so as to protrude toward the inner sides in the left-right direction.

[0022] The resin portion 50 is configured to include an inner tube support portion 51 as a first resin portion covering a rear end side portion of the metal plate portion 30, and a steering shaft support portion 52 as a second resin portion covering a front end side portion of the metal plate portion 30. The first resin portion (the inner tube support portion 51) covers at least the side plate portion 33 and the folded portion 34 of the metal plate portion 30. The first resin portion (the inner tube support portion 51) covers even the inner circumference of the semi-cylindrical portion 32. Further, the aforementioned hole portion 24 is provided in a lower portion of the first resin portion (the inner tube support portion 51) (see FIG. 3). Furthermore, a plurality of resin protrusions 53 are disposed on an upper portion of the first resin portion (the inner tube support portion 51).

[0023] Furthermore, in the portion of the first resin part (inner tube support part 51) between the side plate part 33 and the folded part 34, multiple material-reducing sections 54 extending in the longitudinal direction of the vehicle body are formed (see Figure 2). In other words, at the rear end of the first resin part (inner tube support part 51), multiple material-reducing sections 54 recessed toward the front side FR of the vehicle body are formed.

[0024] Furthermore, multiple material-removing portions 55 extending in the left-right direction are formed on both the left and right sides of the first resin portion (inner tube support portion 51). In other words, multiple material-removing portions 55 recessed inward on both the left and right sides are formed on both the left and right sides of the first resin portion (inner tube support portion 51).

[0025] Although not shown in the diagram, the metal plate portion 30 is placed in a predetermined position in the mold, and then molded (insert molded) with resin. This allows for the molding of an outer jacket 7, which is composed of a metal plate portion 30 and a resin portion 50.

[0026] As shown in Figures 1, 4 to 9, the second resin part (steering shaft support part 52), which is made of the above-mentioned resin material, is formed at the front end of the outer jacket 7 (the front end of the vehicle body FR). This steering shaft support part 52 is configured to have a through hole 60 that directly supports the lower shaft 9b of the steering shaft 9. "Directly supporting" means that there are no bearings or the like placed between the outer circumferential surface of the lower shaft 9b and the inner circumferential surface of the through hole 60, and the outer circumferential surface of the lower shaft 9b and the inner circumferential surface of the through hole 60 are in contact (contact).

[0027] A projection 61 is formed on the inner circumferential surface of the through-hole 60, which fixes the steering shaft 9 in the longitudinal direction of the vehicle body. An inclined surface 61a is formed on the rear side RR of the projection 61 to facilitate engagement of the steering shaft 9 with the projection 61 when inserting it into the through-hole 60. For this reason, the projection 61 has an inclined surface 61a on the rear side RR of the vehicle body and is formed in a substantially trapezoidal cross-section (see Figure 9). By appropriately setting the protrusion height of the projection 61 from the inner circumferential surface of the through-hole 60, the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted.

[0028] On the other hand, a circumferential groove 63 is formed on the outer circumference of the steering shaft 9 (lower shaft 9b) that engages with a projection 61 formed on the inner circumference of the through hole 60 (see Figures 8 and 9).

[0029] Furthermore, a grooved portion 62 is formed on the inner circumferential surface of the through-hole portion 60, with multiple grooves 62a extending in the axial direction of the through-hole portion 60 arranged in the circumferential direction of the through-hole portion 60. Multiple projections 61 are arranged alternately with the grooves 62 in the circumferential direction of the through-hole portion 60. Therefore, multiple grooves 62 are arranged alternately with the projections 61 in the circumferential direction of the through-hole portion 60. By dividing the projections 61 into multiple parts (four parts in this embodiment) and arranging them in the circumferential direction of the through-hole portion 60, the insertion load of the steering shaft 9 into the through-hole portion 60 can be adjusted.

[0030] Furthermore, by forming a groove 62 on the inner circumferential surface of the through-hole 60, grease accumulates in the groove 62 (groove 62a), making it easier for the grease to be retained by the steering shaft support 52. As a result, the grease is more easily retained by the steering shaft support 52, preventing grease depletion and allowing the steering shaft 9 to rotate smoothly.

[0031] Furthermore, on the back side (outer circumference side) of the through-hole 60, multiple (four of each) ribs 64 and 65 for stiffening are arranged in the circumferential direction of the through-hole 60. In this embodiment, the height from the base to the top of the four ribs 64 arranged on the back side (outer circumference side of the through-hole 60) is lower than the height from the base to the top of the other four ribs 65. Therefore, ribs 64 and 65 are not formed on the outer circumferential surface of the through-hole 60 where the projection 61 is formed. In addition, ribs 64 with low rib heights and ribs 65 with high rib heights are arranged alternately in the circumferential direction on the back side (outer circumference side) of the through-hole 60. By lowering the rib heights of the four ribs 64 arranged on the back side (outer circumference side of the through-hole 60), the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted.

[0032] Next, the tilt position adjustment operation and telescopic position adjustment operation of the steering device 1 of this embodiment will be described.

[0033] To fix the inner tube 8 in the desired position, first move the inner tube 8 to the desired position in the tilt direction (up and down direction) and the telescopic direction (front and rear direction of the vehicle body), and then swing the operating lever 11 upward. Swinging the operating lever 11 upward causes the lock bolt 12 to rotate around its axis in the fastening direction.

[0034] As the lock bolt 12 rotates in the fastening direction, the peaks of the fixed cam 13 and the rotating cam 14 overlap, increasing the axial dimension. This tightens the lock bolt 12, clamping the outer jacket 7's clamp portion 23 between the pair of side wall portions 5, and holding the inner tube 8 in any desired position.

[0035] Furthermore, to adjust the position of the inner tube 8, the fastening of the outer jacket 7 and the inner tube 8 to the fixing bracket 2 is released. To do this, first, the operating lever 11 is swung downward. Swinging the operating lever 11 downward causes the lock bolt 12 to rotate around its axis in the direction of release.

[0036] As the lock bolt 12 rotates in the unlocking direction, the peak of the fixed cam 13 and the valley of the rotating cam 14 overlap, narrowing the axial dimension. This loosens the lock bolt 12, widening the gap between the pair of side wall portions 5, relieving the pressure contact between the side wall portions 5 and the clamp portion 23 of the outer jacket 7, allowing the inner tube 8 to move in the tilt and telescopic directions relative to the fixed bracket 2.

[0037] The effects and advantages of this embodiment will be explained below.

[0038] (1) The steering device 1 comprises an outer jacket 7 supported by the vehicle body, an inner tube 8 slidably fitted into the outer jacket 7, and a steering shaft 9 housed inside the outer jacket 7 and the inner tube 8. A steering shaft support portion 52 made of resin material is formed at the front end FR of the outer jacket 7, and the steering shaft support portion 52 has a through hole 60 that directly supports the steering shaft 9.

[0039] By forming a through-hole 60 in the steering shaft support portion 52, which is made of resin material, that directly supports the steering shaft 9, bearings and other components for supporting the steering shaft 9 (lower shaft 9b) can be eliminated. In other words, since the through-hole 60 directly supports the steering shaft 9 (lower shaft 9b), one bearing or component for supporting the steering shaft 9 can be eliminated.

[0040] As described above, this embodiment provides a steering device 1 that can reduce the number of parts and thereby lower manufacturing costs.

[0041] (2) In the steering device 1, the outer jacket 7 is composed of a metal plate portion 30 made of a metal plate 31 and a resin portion 50 made of a resin material that covers at least a part of the metal plate portion 30.

[0042] Since the resin portion 50, which is part of the outer jacket 7, is made of resin material, the outer jacket 7 can be made lighter, and the degree of freedom in shape can be improved compared to when the entire outer jacket 7 is formed from a metal plate. In addition, since the outer jacket 7 is made by molding the metal plate portion 30 with resin, it is possible to suppress the increase in manufacturing costs that would otherwise be incurred by the welding process, and it is also possible to avoid thermal distortion and other factors affecting the dimensional accuracy of the outer jacket 7.

[0043] (3) In the steering device 1, a projection 61 is formed on the inner circumferential surface of the through hole 60 in the direction of the through hole 60, which fixes the steering shaft 9 in the longitudinal direction of the vehicle body.

[0044] By forming the projection 61 on the inner circumferential surface of the through-hole 60, the need for a C-ring or the like to fix the steering shaft 9 (lower shaft 9b) can be eliminated. Furthermore, by appropriately setting the protrusion height of the projection 61 from the inner circumferential surface of the through-hole 60, the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted.

[0045] (4) In the steering device 1, an inclined surface 61a is formed on the rear RR portion of the projection 61.

[0046] Since an inclined surface 61a is formed on the rear side (RR) portion of the projection 61, it is possible to easily engage the steering shaft 9 with the projection 61 when inserting the steering shaft 9 into the through-hole 60 from the rear side (RR) to the front side (FR) of the vehicle body. Furthermore, by appropriately setting the height of the projection 61 protruding from the inner circumferential surface of the through-hole 60, the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted.

[0047] (5) In the steering device 1, a groove portion 62 is formed on the inner circumferential surface of the through hole portion 60 by arranging a plurality of grooves 62a extending in the axial direction of the through hole portion 60 in the circumferential direction of the through hole portion 60, and a plurality of projections 61 are arranged alternately with the groove portion 62 in the circumferential direction of the through hole portion 60.

[0048] By forming a groove 62 on the inner circumferential surface of the through-hole 60, grease accumulates in the groove 62 (groove 62a), making it easier for the grease to be retained by the steering shaft support 52. As a result, the grease is more easily retained by the steering shaft support 52, preventing grease depletion and allowing the steering shaft 9 to rotate smoothly. Furthermore, by dividing the projection 61 into multiple sections (four sections in this embodiment) in the circumferential direction of the through-hole 60, the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted.

[0049] (6) In the steering device 1, a groove portion 62 is formed on the inner circumferential surface of the through hole portion 60, with a plurality of grooves 62a extending in the axial direction of the through hole portion 60 arranged in the circumferential direction of the through hole portion 60.

[0050] By forming a groove 62 on the inner circumferential surface of the through-hole 60, grease accumulates in the groove 62 (groove 62a), making it easier for the grease to be retained by the steering shaft support 52. As a result, the grease is more easily retained by the steering shaft support 52, preventing grease depletion and allowing the steering shaft 9 to rotate smoothly.

[0051] (7) In the steering device 1, a projection 61 extending in the circumferential direction of the through hole 60 is formed on the inner circumferential surface of the through hole 60, and a plurality of grooves 62 are arranged alternately with the projection 61 in the circumferential direction of the through hole 60.

[0052] Since an inclined surface 61a is formed on the rear side (RR) portion of the projection 61, it is possible to easily engage the steering shaft 9 with the projection 61 when inserting the steering shaft 9 into the through-hole 60 from the rear side (RR) to the front side (FR) of the vehicle body. Furthermore, by appropriately setting the protrusion height of the projection 61 from the inner circumferential surface of the through-hole 60, the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted. In addition, by dividing the projection 61 into multiple parts (four parts in this embodiment) in the circumferential direction of the through-hole 60 and arranging them accordingly, the insertion load of the steering shaft 9 into the through-hole 60 can be adjusted.

[0053] (8) In the steering device 1, the resin material is a thermoplastic resin.

[0054] Since the steering shaft support portion 52 is made of thermoplastic resin, the outer jacket 7 can be made lighter, and the degree of freedom in its shape can be improved compared to when the entire outer jacket 7 is made of metal plate.

[0055] Although this embodiment has been described above, this embodiment is not limited to these, and various modifications are possible within the scope of the gist of this embodiment. [Explanation of Symbols]

[0056] 1. Steering system 7 Outer Jacket 8 Inner Tubes 9. Steering shaft 30 Metal plate part 31 Metal plate 50 Resin part 52 Steering shaft support 60 Through hole 61 Protrusion 61a Slope 62 Groove 62a groove

Claims

1. An outer jacket supported by the vehicle body, An inner tube slidably fitted to the outer jacket, The system comprises a steering shaft housed inside the outer jacket and the inner tube, A steering shaft support portion made of resin material is formed at the front end of the outer jacket on the vehicle body side. The steering shaft support portion has a through hole portion that directly supports the steering shaft. Steering system.

2. The aforementioned outer jacket is A metal plate portion made of metal plates, It is composed of the aforementioned resin material and comprises a resin portion that covers at least a part of the metal plate portion, The steering device according to claim 1.

3. The steering device according to claim 1 or 2, wherein a projection for fixing the steering shaft in the longitudinal direction of the vehicle body is formed on the inner circumferential surface of the through-hole, in the direction of the through-hole.

4. The steering device according to claim 3, wherein an inclined surface is formed on the portion of the projection that is on the rear side of the vehicle body.

5. On the inner circumferential surface of the through-hole, a groove portion is formed by arranging multiple grooves in the circumferential direction of the through-hole, with grooves extending in the axial direction of the through-hole. The aforementioned protrusions are arranged alternately with the grooves in the circumferential direction of the through-hole. The steering device according to claim 3.

6. The steering device according to claim 1 or 2, wherein a groove portion is formed on the inner circumferential surface of the through-hole portion, with a plurality of grooves extending in the axial direction of the through-hole portion arranged in the circumferential direction of the through-hole portion.

7. On the inner circumferential surface of the through-hole, a projection extending in the circumferential direction of the through-hole is formed. The grooves are arranged alternately with the protrusions in the circumferential direction of the through hole. The steering device according to claim 6.

8. The steering device according to claim 1 or 2, wherein the resin material is a thermoplastic resin.

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