Steering gear

Abstract

To provide a highly versatile steering device which may be attached regardless of a shape of a connection part between a steering shaft and a steering handle.SOLUTION: A steering device 20 is detachably attached to a travel machine body 1 and rotationally operates a steering handle 4 with power of a motor 21. The steering device 20 includes: a driven rotating body 23 fixed to the steering handle 4 side; a driving rotating body 22 which rotates the driven rotating body 23 according to driving of the motor 21; and a holding part 24 which holds multiple spokes 4b of the steering handle 4 to fix the driven rotating body 23 to the steering handle 4 side. The holding part 24 includes: multiple first holding members 31 which are provided at the driven rotating body 23 and arranged along lower parts of the multiple spokes 4b; and multiple second holding members 32 which are provided at the driven rotating body 23 and arranged along upper parts of the multiple spokes 4b.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a steering device that rotates a steering handle using the power of an actuator. [Background technology]

[0002] Steering devices that use the power of an actuator to rotate a steering wheel are known. For example, Patent Document 1 discloses a steering device that is interposed between an upper end of a steering shaft and a steering wheel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6889033 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the shape of the connection between the steering shaft and the steering wheel differs depending on the manufacturer and vehicle model, there is room for improvement in terms of versatility. [Means for solving the problem]

[0005] The present invention has been made in view of the above-described circumstances and with the aim of solving these problems. The invention of claim 1 is a steering device that is detachably mounted on a vehicle that has a steering handle attached to the upper end of a steering shaft and a steering column that covers the steering shaft below the steering handle, and that rotates the steering handle using the power of an actuator, and is characterized in that it comprises: a driven rotor fixed to the steering handle side; a driving rotor that rotates the driven rotor in response to the drive of the actuator; and a gripping portion that grips a plurality of spokes of the steering handle to fix the driven rotor to the steering handle side, the gripping portion comprising a plurality of first gripping members that are provided on the driven rotor and that follow the lower parts of the plurality of spokes, and a plurality of second gripping members that are provided on the driven rotor and that follow the upper parts of the plurality of spokes, and at least one of the first gripping member and the second gripping member is provided with a rotation restricting portion that follows the side of the plurality of spokes and restricts the relative rotation of the driven rotor around the steering shaft with respect to the steering handle. The invention of claim 2 is the steering device according to claim 1, characterized in that the first gripping member and the second gripping member are provided detachably with respect to the driven rotor. The invention of claim 3 is a steering device according to claim 1 or 2, characterized in that the driven rotor is divided into a plurality of segments and integrated by connecting the connecting portions formed on each segment, the connecting portions have a support portion that supports the base of the second gripping member so that it can swing up and down, and the plurality of second gripping members are integrally connected via a ring member with their tip portions aligned along the top of the spokes. The invention of claim 4 is the steering device according to any one of claims 1 to 3, characterized in that the first gripping member has an uneven portion that follows the shape of the lower portion of the spoke. [Effects of the Invention]

[0006] According to the invention of claim 1, the device can be attached regardless of the shape of the connection between the steering shaft and the steering handle, thereby enhancing versatility. Furthermore, the device is provided with a gripping portion that fixes the driven rotor to the steering handle by gripping multiple spokes of the steering handle, making it easy to fix and align the driven rotor to the steering handle. Furthermore, at least one of the first gripping member and the second gripping member is provided with a rotation restricting portion along the side of the multiple spokes that restricts relative rotation of the driven rotor around the steering axis with respect to the steering handle, thereby preventing misalignment of the driven rotor around the steering axis with respect to the steering handle. Furthermore, according to the invention of claim 2, the first gripping member and the second gripping member constituting the gripping portion are detachably attached to the driven rotor, so that by simply preparing the first gripping member and the second gripping member corresponding to various steering handles, it becomes possible to appropriately attach the gripping portion to various vehicles. Furthermore, according to the invention of claim 3, not only can the spokes be easily and reliably gripped by multiple second gripping members, but the second gripping members can be swingably supported by utilizing the connecting portions of the driven rotor. According to the invention of claim 4, the first gripping member has an uneven portion that conforms to the shape of the lower portion of the spoke, so that misalignment between the steering handle and the driven rotor can be further suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an overall side view of a tractor equipped with a steering device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a plan view of the main parts of the tractor equipped with the steering device. [Figure 3] FIG. 2 is a side view of the main part of the tractor equipped with the steering device. [Figure 4] FIG. 2(a) is a perspective view of the main part of a tractor equipped with a steering device, and FIG. 2(b) is an exploded perspective view of the steering device. [Figure 5] FIG. 10 is a perspective view showing the final installation process of the steering device to the steering handle. [Figure 6]FIG. 2 is a perspective view of a steering device attached to a steering handle. [Figure 7] FIG. 2(a) is a plan view of a steering device attached to a steering handle, and FIG. 2(b) is a side view of the steering device attached to a steering handle. [Figure 8] 8 is a cross-sectional view taken along the line AA in FIG. 7. [Figure 9] 7A is a cross-sectional view taken along line BB in FIG. 7, and FIG. 7B is a cross-sectional view taken along line CC in FIG. [Figure 10] (a) is a front view of the first gripping member, (b) is a plan view of the first gripping member, (c) is a rear view of the first gripping member, (d) is a side view of the first gripping member, (e) is an oblique view of the first gripping member from the front side, and (f) is an oblique view of the first gripping member from the rear side. [Figure 11] (a) is a DD cross-sectional view of Figure 7, (b) is a DD cross-sectional view showing a modified first gripping member, (c) is a DD cross-sectional view showing a modified first gripping member applied to a steering handle with a different spoke cross-sectional shape, (d) is a DD cross-sectional view showing a modified first gripping member applied to a steering handle with a different spoke cross-sectional shape, and (e) is a DD cross-sectional view showing a modified first gripping member applied to a steering handle with a different spoke cross-sectional shape. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the present invention will be described below with reference to the drawings. In Fig. 1, reference numeral 1 denotes a running machine body (vehicle) of a tractor, and the running machine body 1 includes an engine mounting section 2 on which an engine (not shown) is mounted, a transmission case 3 that changes the speed of engine power, left and right front wheels 5 that are driven to rotate by the running power transmitted from the transmission case 3 and are steered in response to the rotation of a steering handle 4, left and right rear wheels 6 that are also driven to rotate by the running power transmitted from the transmission case 3, a control section 7 on which an operator rides, and a working machine coupling section 8 to which various working machines (not shown) can be coupled so that they can be raised and lowered.

[0009] The control section 7 includes a driver's seat 9 where an operator sits. Various operating tools for traveling and working, including the steering wheel 4, are arranged in front of and to the sides of the driver's seat 9. The steering wheel 4 is attached to the upper end of a steering shaft (not shown) so as to be rotatable together with the steering wheel 4. When the steering shaft rotates in response to the rotation of the steering wheel 4, the steering angle of the front wheels 5 is changed via a power steering mechanism (not shown) connected to the lower end of the steering shaft. The steering shaft is covered by a steering column 10 provided below the steering wheel 4.

[0010] 1 to 9, a steering device 20 that rotates the steering wheel 4 using the power of a motor 21 (actuator) is detachably attached to the steering wheel 4. The steering wheel 4 of this embodiment includes a hub 4a that is connected to the steering shaft so as to be integrally rotatable therewith, three spokes 4b that extend outward from the hub 4a, and an annular rim 4c that connects the tips of the spokes 4b, but the object to which the steering device 20 is attached is not limited to this.

[0011] As shown in FIGS. 3 to 11, the steering device 20 includes a motor 21, a driving rotor 22, a driven rotor 23, a grip portion 24, a cover body 25, and a bracket 26.

[0012] The motor 21 rotates the driving rotor 22 by outputting motor power. The driving rotor 22 meshes with the driven rotor 23 and rotates the driven rotor 23 in response to the driving of the motor 21. As shown in Fig. 6 , the driving rotor 22 in this embodiment is configured as a roller pinion that meshes with the driven rotor 23 via a plurality of rollers 22a arranged in the circumferential direction, but is not limited to a roller pinion as long as it can rotate the driven rotor 23 in response to the driving of the motor 21.

[0013] The driven rotor 23 is fixed to the steering wheel 4 via a grip 24 so as to be rotatable integrally therewith, and rotates the steering wheel 4 in response to the drive of the motor 21. In this embodiment, the driven rotor 23 is formed of a ring gear having sprocket-like outer teeth that can mesh with the driving rotor 22, which is made up of a roller pinion.

[0014] 4 and 9, the driven rotor 23 is divided into a plurality of segments 27, which are integrated by connecting the connecting portions 27a formed on the segments 27. With this divided configuration, it is not necessary to remove the steering wheel 4 from the steering shaft when attaching the driven rotor 23 along the lower part of the steering wheel 4 (spokes 4b).

[0015] The connecting portion 27a of each divided piece 27 includes a fitting portion 27b that fits into the adjacent divided piece 27, a screw fixing portion 27c that is fixed to the adjacent divided piece 27 via a screw 28, and a second support portion 27d that detachably supports a second gripping member 32 (described later) so that the second gripping member 32 can swing up and down. Also, a first support portion 27e is formed in the middle portion on the inner periphery of each divided piece 27 to detachably support a first gripping member 31 (described later).

[0016] The gripping portion 24 grips the multiple spokes 4b of the steering handle 4, thereby fixing the driven rotor 23 to the steering handle 4. The gripping portion 24 of this embodiment includes a first gripping member 31, a second gripping member 32, and a ring member 33. Note that in this embodiment, the number of first gripping members 31 is three, but this can be changed depending on the number of spokes 4b. Furthermore, the second gripping member 32 is divided into three parts to match the number of divisions of the driven rotor 23, but the number of second gripping members 32 can also be changed.

[0017] 4 and 9 to 11, the first gripping members 31 are detachably attached to the driven rotor 23 so as to fit along the lower parts of the multiple spokes 4b. The steering device 20 of this embodiment is equipped with three first gripping members 31, and each first gripping member 31 integrally includes an attachment portion 31a that is L-shaped in side view and is attached along the first support portion 27e of the driven rotor 23, a pair of fitting portions 31b that fit into the first support portion 27e of the driven rotor 23, and spoke abutment portions 31c that fit along the lower parts of the spokes 4b and can abut against the lower parts of the spokes 4b.

[0018] As shown in Figure 11(a), the first gripping member 31 of this embodiment can linearly contact the lower part of the spokes 4b, but may also be provided with recesses 31d and protrusions 31e aligned in the direction around the steering axis at the portion where it contacts the lower part of the spokes 4b, as in modified first gripping member 31B shown in Figures 11(b) to 11(e). Such modified first gripping member 31B can not only accommodate spokes 4b having various cross-sectional shapes, as shown in Figures 11(b) to 11(e), but also suppress displacement of the driven rotor 23 relative to the steering wheel 4 in the direction around the steering axis by engaging with the recesses 4d and protrusions 4e of the spokes 4b.

[0019] The second gripping member 32 is detachably attached to the driven rotor 23 so as to fit along the upper parts of the multiple spokes 4b. The second gripping member 32 of this embodiment includes a base 32a that is detachably attached to the second support part 27d of the driven rotor 23 and supported so as to be able to swing up and down, spoke abutting parts 32b that fit along the upper parts of the spokes 4b and can abut against the upper parts of the spokes 4b, rotation restricting parts 32c that fit along the side parts of the spokes 4b and can abut against the side parts of the spokes 4b, and a ring member fixing part 32d to which the ring member 33 is fixed via a screw 34.

[0020] The ring member 33 integrally connects the second gripping members 32 that are fitted along the upper portions of the spokes 4b, and restricts the up and down swing of the second gripping members 32. Such a structure of the gripping portion 24 allows attachment regardless of the shape of the connection between the steering shaft and the steering handle 4, thereby enhancing the versatility of the steering device 20. Furthermore, the gripping portion 24 fixes the driven rotor 23 to the steering handle 4 by gripping the multiple spokes 4b of the steering handle 4, making it easy to fix and align the driven rotor 23 with the steering handle 4. Furthermore, the second gripping member 32 includes a rotation restricting portion 32c that fits along the side of the spokes 4b, thereby preventing the driven rotor 23 from shifting relative to the steering handle 4 in the direction around the steering shaft.

[0021] The rotation restricting portions 32c along the sides of the spokes 4b may be provided on the first gripping member 31, or on both the first gripping member 31 and the second gripping member 32. The first gripping member 31 and the second gripping member 32 may grip the spokes 4b via a cushioning material such as a rubber sheet rather than directly gripping the spokes 4b. This allows for easy adaptation to steering handlebars 4 with spokes 4b of different thicknesses and cross-sectional shapes. The first gripping member 31 and the second gripping member 32 may be made of a thermoplastic resin and heated to soften it before gripping the spokes 4b. This allows the first gripping member 31 and the second gripping member 32 to deform to fit the shape of the spokes 4b, improving adhesion to the spokes 4b. The first gripping member 31 and the second gripping member 32 may be made of a thermosetting resin and molded to fit the spokes 4b to be gripped, and then heated to harden. In this way, the first gripping member 31 and the second gripping member 32 that can be adapted to various shapes of the spokes 4b can be obtained.

[0022] 4, 6, etc., the cover body 25 includes a semicircular annular first cover member 41 that covers the outer periphery of the driven rotor 23, a second cover member 42 that houses the motor 21 and the driving rotor 22, and a pair of bolts 43 that connect the first cover member 41 and the second cover member 42. When one of the bolts 43 is removed, the first cover member 41 and the second cover member 42 become rotatable relative to each other with the other bolt 43 as a fulcrum, making it possible to open and close the accommodation space for the driven rotor 23.

[0023] Three rollers 44 are provided on the inner periphery of the first cover member 41, aligned at predetermined intervals in the circumferential direction. The three rollers 44 support the driven rotor 23 so that it can rotate in the circumferential direction but cannot move up and down. In other words, the cover body 25, motor 21, and drive rotor 22 are supported by the driven rotor 23 via the three rollers 44 so that they can rotate in the circumferential direction but cannot move up and down. In addition, a detent pin 45 extending downward is provided on the front end of the first cover member 41.

[0024] 3 and 7, the bracket 26 is fixed to the steering column 10 on the front side of the vehicle body via a screw 51. The bracket 26 has an engagement portion 26a through which the anti-rotation pin 45 of the first cover member 41 passes or engages. This restricts the co-rotation of the cover body 25 around the steering axis, making it possible to rotate the steering wheel 4 in response to the drive of the motor 21. Note that the engagement portion 26a is provided with a spacer 52 such as a rubber ring that fills the gap between the anti-rotation pin 45 and the bracket 26, preventing rattling noise caused by the anti-rotation pin 45 and the bracket 26.

[0025] According to the present embodiment configured as described above, the steering device 20 is detachably mounted on a traveling machine body 1 which has a steering handle 4 attached to the upper end of the steering shaft and a steering column 10 which covers the steering shaft below the steering handle 4, and which rotates the steering handle 4 using the power of a motor 21. The steering device 20 comprises a driven rotor 23 fixed to the steering handle 4 side, a driving rotor 22 which rotates the driven rotor 23 in response to the drive of the motor 21, and a gripping portion 24 which grips a plurality of spokes 4b of the steering handle 4 to fix the driven rotor 23 to the steering handle 4 side. The gripping portion 24 comprises a plurality of first gripping members 31 which are provided on the driven rotor 23 and which extend along the lower parts of the plurality of spokes 4b, and a plurality of second gripping members 32 which are provided on the driven rotor 23 and which extend along the upper parts of the plurality of spokes 4b. Therefore, the steering device 20 can be mounted regardless of the shape of the connection between the steering shaft and the steering handle 4, and the versatility of the steering device 20 is improved. Furthermore, by providing a grip portion 24 for fixing the driven rotor 23 to the steering handle side, fixing and aligning the driven rotor 23 with respect to the steering handle 4 becomes easy.

[0026] Furthermore, at least one of the first gripping member 31 and the second gripping member 32 is provided with a rotation restricting portion 32c along the side of the plurality of spokes 4b, which restricts the relative rotation of the driven rotor 23 around the steering axis relative to the steering handle 4, thereby preventing the driven rotor 23 from shifting around the steering axis relative to the steering handle 4.

[0027] Furthermore, since the first gripping member 31 and the second gripping member 32 are detachably attached to the driven rotor 23, it becomes possible to appropriately attach them to various vehicles simply by preparing the first gripping member 31 and the second gripping member 32 that correspond to various steering handles 4.

[0028] In addition, the driven rotor 23 is divided into multiple segments 27 and is integrated by connecting the connecting portions 27a formed on each segment 27, and the connecting portions 27a have second support portions 27d that support the base 32a of the second holding member 32 so that it can swing up and down.The multiple second holding members 32 are connected together via ring members 33 with their tip portions aligned with the top of the spokes 4b.This not only makes it easy and reliable for the multiple second holding members 32 to grip the spokes 4b, but also allows the connecting portions 27a of the driven rotor 23 to be used to support the second holding members 32 in a swinging manner.

[0029] Furthermore, the first gripping member 31B of the modified example has recessed portions 31d and protruding portions 31e that fit the shape of the lower portions of the spokes 4b, so that misalignment between the steering handle 4 and the driven rotor 23 can be further suppressed. [Explanation of symbols]

[0030] 1 Running body (vehicle) 4 Steering handle 4b spoke 10. Steering column 20 Steering gear 21 Motor 22 Drive rotor 23 Driven Rotor 24 Gripping part 25 Cover body 26 Bracket 27 Split pieces 27a Connecting part 27b Mating part 27c Screw fixing part 27d 2nd support part 27e 1st support part 31 first gripping member 31d Recess 31e Convex part 32 second gripping member 32a base 32b Spoke contact area 32c Rotation restriction part 33 Ring member

Claims

1. A steering device that is detachably mounted on a vehicle having a steering handle attached to an upper end of a steering shaft and a steering column that covers the steering shaft below the steering handle, and that rotates the steering handle using power from an actuator, a driven rotor fixed to the steering handle; a driving rotor that rotates the driven rotor in response to driving of the actuator; a gripping portion that grips a plurality of spokes of the steering handle to fix the driven rotor to the steering handle side, The gripping portion is a plurality of first gripping members provided on the driven rotor and arranged along the lower portions of the plurality of spokes; a plurality of second gripping members provided on the driven rotor and arranged along upper portions of the plurality of spokes; A steering device characterized in that at least one of the first gripping member and the second gripping member is provided with a rotation restricting portion along the side of the plurality of spokes, which restricts relative rotation of the driven rotor with respect to the steering handle in a direction around the steering axis.

2. 2. The steering device according to claim 1, wherein the first gripping member and the second gripping member are detachably provided to the driven rotor.

3. The driven rotor is divided into a plurality of segments, and the segments are integrated by connecting the connecting portions formed on the segments, the connecting portion has a support portion that supports a base portion of the second gripping member so that the base portion can swing up and down, 3. The steering device according to claim 1, wherein the second gripping members are integrally connected via a ring member with their tip portions aligned along the upper portions of the spokes.

4. 4. The steering device according to claim 1, wherein the first gripping member has an uneven portion that conforms to the shape of the lower portion of the spoke.

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