Steering system

Abstract

To provide a steering device that can generate high holding force even when the bolt axial force is small. [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 spline fitting portion 16 is formed on the inner diameter of the outer jacket 7 and the outer diameter of the inner tube 8 to spline-fit the outer jacket 7 and the inner tube 8.

Description

[Technical Field]

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

[0002] A steering apparatus includes an outer jacket supported by 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, an outer jacket (outer column) having a circular outer surface and an inner tube (inner column) having a circular outer surface are fitted into a clamp member that is disposed inside a vehicle body mounting bracket and has a circular inner surface. Then, the vehicle body mounting bracket is tightened by a bolt (tightening rod), the diameter of the outer jacket is reduced via the clamp member, and the inner tube is fixed so as not to be movable in the axial direction. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 4609203 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the steering apparatus of Patent Document 1, since both the fitting surface (inner surface) of the clamp member and the fitting surface (outer surface) of the outer jacket (outer column) are circular, a large bolt axial force (bolt tightening force) is required. In order to increase the bolt axial force, it is necessary to increase the size of the bolt, increase the number of bolts, use a special bolt, or the like.

[0005] The present invention has been made in view of such problems of the prior art. An object of the present invention is to provide a steering apparatus capable of generating a high holding force even when the bolt axial force is small. [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 the inner tube. Spline fitting portions are formed on the inner diameter of the outer jacket and the outer diameter of the inner tube to spline-fit the outer jacket and the inner tube. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a steering device that can generate a high holding force even when the bolt axial force is small. [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 an enlarged view of section A in Figure 2. [Figure 4] This is an enlarged view of section B in Figure 2. [Figure 5] This is a perspective view of the outer jacket and inner tube. [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 Figure 5, the outer jacket 7 is composed of a cylindrical portion 22 having a slit 21 extending in the longitudinal direction of the vehicle body, and a pair of clamp portions 23 hanging down from the cylindrical portion 22. The outer jacket 7 is located on the front side FR of the vehicle body relative to the fixing bracket 2, and the inner tube 8 is slidably fitted into the cylindrical portion 22 of the outer jacket 7. In addition, each clamp portion 23 is provided with a hole 24 through which a lock bolt 12 is inserted.

[0016] The inner tube 8 is formed into a cylindrical shape from metal or synthetic resin, and a bearing 17 is mounted on a rear end side portion of the inner tube 8 (see FIG. 1). The cylindrically formed inner tube 8 is inserted in the cylinder axial direction into the inner side of the cylindrical portion 22 of the outer jacket 7. Accordingly, the inner tube 8 is supported movably in the cylinder axial direction (the vehicle body front-rear direction) relative to the outer jacket 7.

[0017] In the present embodiment, the slit 21 is formed in a lower portion 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 disposed below this cylindrical portion 22. However, the present invention is not limited thereto; the slit 21 may be formed in an upper portion 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 disposed above this cylindrical portion 22.

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

[0019] As shown in FIGS. 1 to 5, the spline fitting portion 16 is formed on the inner diameter portion (inner circumferential surface) of the outer jacket 7, and has a plurality of spline grooves 18 extending in the axial direction of the outer jacket 7. The inner diameter portion of the outer jacket 7 is a part of a resin portion 50 described later, and is formed of a resin material. Further, the spline fitting portion 16 is formed on the outer diameter portion (outer circumferential surface) of the inner tube 8, and has a plurality of spline projections 19 extending in the axial direction of the inner tube 8.

[0020] Relative rotation between the outer jacket 7 and the inner tube 8 is restricted by engagement between spline grooves 18 formed on the inner diameter portion of the outer jacket 7 and spline projections 19 formed on the outer diameter portion of the inner tube 8. In addition, when tightened using the lock bolt 12, the contact surface area between the outer jacket 7 and the inner tube 8 increases, so that a high column holding force (the force for holding the inner tube 8 relative to the outer jacket 7) can be generated even when the bolt axial force is small.

[0021] In the present embodiment, the groove width of a spline groove (lower groove 18a) formed on the opening side (lower portion) where the slit 21 is located in the inner diameter portion of the outer jacket 7 is larger than the groove width of a spline groove (upper groove 18b) formed on the closed side (upper portion) where no slit 21 is provided (see FIGS. 3 and 4). Accordingly, when an axial force F (see FIG. 2) is applied to the steering column 3, the lower groove 18a formed on the opening side provided with the slit 21 can be displaced (deformed) to a greater extent, and all the spline grooves 18 can be efficiently brought into contact with the spline projections 19.

[0022] As shown in FIGS. 1, 2 and 5, 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.

[0023] The metal plate 31 is, for example, a steel plate (sheet metal), and the resin material described above is, for example, a thermoplastic resin.

[0024] The metal plate portion 30 is formed by pressing and bending a single metal plate (metal plate 31). The metal plate portion 30 has a semi-cylindrical portion 32 with an open bottom, side plate portions 33 extending downward from both the left and right sides of the semi-cylindrical portion 32, and folded portions 34 formed by folding the ends of the side plate portions 33 inward on both sides. The side plate portions 33 have convex portions 35 that protrude inward on both sides. The convex portions 35 are formed by bending the portion of the metal plate 31 corresponding to the side plate portions 33 to form a substantially trapezoidal cross-section, and the ends of the folded portions 34 have hook portions 36 that face the side surfaces of the convex portions 35 (see Figure 2). In this embodiment, there is a clearance between the side surfaces of the convex portions 35 and the hook portions 36, but the hook portions 36 may be in contact with the side surfaces of the convex portions 35. In addition, the folded portions 34 have bent portions 34a that are bent to protrude inward on both sides.

[0025] The resin portion 50 is composed of an inner tube support portion 51, which is a first resin portion covering the rear end portion of the metal plate portion 30, and a steering shaft support portion 52, which is a second resin portion covering the front end portion of the metal plate portion 30. The first resin portion (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 (inner tube support portion 51) covers up to the inner circumference of the semi-cylindrical portion 32. In addition, the aforementioned hole portion 24 is provided at the lower part of the first resin portion (inner tube support portion 51) (see Figure 5). Furthermore, a plurality of resin protrusions 53 are arranged on the upper part of the first resin portion (inner tube support portion 51).

[0026] 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.

[0027] 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).

[0028] 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.

[0029] Next, the tilt position adjustment operation and telescopic position adjustment operation of the steering device 1 of this embodiment will be described.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] The effects and advantages of this embodiment will be explained below.

[0035] (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 spline fitting portion 16 is formed on the inner diameter of the outer jacket 7 and the outer diameter of the inner tube 8 to spline-fit the outer jacket 7 and the inner tube 8.

[0036] The spline fitting portion 16 engages (fits) the inner diameter portion of the outer jacket 7 with the outer diameter portion of the inner tube 8, thereby restricting relative rotation between the outer jacket 7 and the inner tube 8. Furthermore, the increased contact surface area between the inner diameter portion of the outer jacket 7 and the outer diameter portion of the inner tube 8 allows for the generation of a high column holding force (the force that holds the inner tube 8 relative to the outer jacket 7) even when the bolt axial force is small.

[0037] As described above, according to this embodiment, a steering device 1 can be provided that can generate a high holding force even when the bolt axial force is small.

[0038] (2) In the steering device 1, the outer jacket 7 has a slit 21 that opens upward or downward and extends in the longitudinal direction of the vehicle body. The spline fitting portion 16 has a plurality of spline grooves 18 formed on the inner diameter portion of the outer jacket 7 and extending in the axial direction of the outer jacket 7, and a plurality of spline projections 19 formed on the outer diameter portion of the inner tube 8 and extending in the axial direction of the inner tube 8. The groove width of the spline groove (lower groove 18a) formed on the side of the outer jacket 7 with the inner slit 21 is greater than the groove width of the spline groove (upper groove 18b) formed on the side of the outer jacket 7 without the inner slit 21.

[0039] In this embodiment, the groove width of the spline groove (lower groove 18a) formed on the opening side (lower part) of the inner diameter portion of the outer jacket 7 is larger than the groove width of the spline groove (upper groove 18b) formed on the closed side (upper part) of the inner diameter portion of the outer jacket 7. Therefore, when an axial force F (see Figure 2) is applied to the steering column 3, the lower groove 18a formed on the opening side where the slit 21 is located can be displaced (deformed) more significantly, and all spline grooves 18 can be efficiently brought into contact with the spline projections 19.

[0040] (3) 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.

[0041] 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, the increase in manufacturing costs due to the welding process can be suppressed, and thermal distortion and other factors that affect the dimensional accuracy of the outer jacket 7 can be avoided.

[0042] (4) In the steering device 1, the resin material is a thermoplastic resin.

[0043] Since the resin portion 50, which is part of the outer jacket 7, 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 a metal plate.

[0044] (5) In the steering device 1, the inner diameter portion of the outer jacket 7 is formed of a resin material.

[0045] Since the inner diameter portion of the outer jacket 7 is made of resin material, 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 formed from a metal plate.

[0046] (6) In the steering device 1, the resin material is a thermoplastic resin.

[0047] Since the inner diameter portion of the outer jacket 7 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 formed from a metal plate.

[0048] (7) In the steering device 1, the outer jacket 7 has a slit 21 that opens downward and extends in the longitudinal direction of the vehicle body.

[0049] When an axial force F (see Figure 2) is applied to the steering column 3, the opening side (lower part) of the outer jacket 7 with the slit 21 can be displaced (deformed) more significantly, allowing the outer jacket 7 to efficiently come into contact with the inner tube 8.

[0050] 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]

[0051] 1. Steering system 7 Outer Jacket 8 Inner Tubes 9. Steering shaft 16 Spline mating section 18 spline grooves 18a Lower groove 18b Top groove 19 Spline protrusions 21 slits 30 Metal plate part 31 Metal plate 50 Resin part

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, The inner diameter portion of the outer jacket and the outer diameter portion of the inner tube are formed with spline fitting portions for spline fitting the outer jacket and the inner tube. Steering system.

2. The outer jacket has a slit that opens upward or downward and extends in the longitudinal direction of the vehicle body. The aforementioned spline fitting portion is A plurality of spline grooves are formed in the inner diameter portion of the outer jacket and extend in the axial direction of the outer jacket, The inner tube has a plurality of spline projections formed on the outer diameter portion of the inner tube and extending in the axial direction of the inner tube, The groove width of the spline groove formed on the side of the outer jacket with the slit between the upper and lower parts is greater than the groove width of the spline groove formed on the side of the outer jacket without the slit between the upper and lower parts. The steering device according to claim 1.

3. The aforementioned outer jacket is A metal plate portion made of metal plates, It is composed of a 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 or 2.

4. The steering device according to claim 3, wherein the resin material is a thermoplastic resin.

5. The steering device according to claim 1 or 2, wherein the inner diameter portion of the outer jacket is formed of a resin material.

6. The steering device according to claim 5, wherein the resin material is a thermoplastic resin.

7. The steering device according to claim 1, wherein the outer jacket has a slit that opens downward and extends in the longitudinal direction of the vehicle body.

Images