JP2015131568A - vehicle steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that enhances the rigidity of a tilt mechanism connecting an instrument panel reinforcement with a steering column in a vehicle steering device.SOLUTION: Steering columns 37, 38 include: a steering assist motor 24; a worm deceleration mechanism coaxially connected with a steering shaft 14; housings 42, 44 covering the worm deceleration mechanism; and a second column tube 38 which extends from the housings 42, 44 to the steering wheel side and into which the steering shaft 14 is inserted. A tilt mechanism includes: a first bracket 36 which protrudes outward from a trunk line 34a of an instrument panel reinforcement and is connected with the second column tube 38; an attachment part 46 which extends from the second housing 44 outward in a radial direction; and a tilt rotation shaft part 48 which is integrally provided with an outer peripheral surface of the trank line 34a of the instrument panel reinforcement and rotatably connects the attachment part 46 with the trank line 34a of the instrument panel reinforcement.

Description

  The present invention relates to a vehicle steering apparatus having a tilt mechanism capable of changing the position of a steering wheel.

  The vehicle steering device includes an EPS (Electric Power Steering) device for assisting the driver's steering, and realizes smooth and comfortable steering for the driver. In addition, the vehicle steering device includes a tilt mechanism that changes the tilt of the steering shaft and the steering column, and can adjust the position of the steering wheel in the vertical direction.

  A column assist type electric power steering apparatus described in Patent Document 1 includes a steering column that is supported by an instrument panel force and is capable of tilting operation, and a steering force assisting motor that is disposed integrally with the steering column. And. The steering column includes a cylindrical column tube, a steering main shaft that is rotatably supported by an axial center portion of the column tube, and a worm wheel that is disposed coaxially with the steering main shaft. The steering column and the instrument panel reinforcement are connected to the outer peripheral surface of the steering tube and the lower bracket on the lower side of the worm wheel by a steering support fixed to the peripheral surface of the instrument panel reinforcement. A rotating shaft for tilting the steering column is provided on the lower bracket and is located below the worm wheel.

JP 2008-247160 A

  The reaction force of the assist force transmitted from the steering force assist motor is generated so as to be twisted in the outer peripheral direction of the worm wheel. This reaction force is received by the instrument panel force through the steering support and the lower bracket. Therefore, it is desirable to increase the rigidity of the tilt mechanism, specifically, the rigidity of the connecting portion between the instrument panel reinforcement and the steering column that are connected to perform the tilt operation.

  The present invention has been made in view of such circumstances, and provides a technique for increasing the rigidity of a tilt mechanism that connects an instrument panel force and a steering column in a vehicle steering apparatus.

  In order to solve the above-described problems, an aspect of the present invention provides a vehicle steering apparatus capable of changing the position of a steering wheel by changing the inclination of a steering column and a steering shaft supported by an instrument panel force. A steering column connected to the reinforcement, and a tilt mechanism that changes the position of the steering wheel connected to the steering shaft by changing the inclination of the steering column and the steering shaft. The steering column includes a motor for applying an assist force for assisting a driver's steering, a worm reduction mechanism that is coaxially connected to the steering shaft and provided with an assist force from the motor, a housing that covers the worm reduction mechanism, A column tube extending from the housing toward the steering wheel and into which the steering shaft is inserted. The tilt mechanism protrudes outward from the main panel of the instrument panel reinforcement, and is provided integrally with the bracket connected to the column tube, the mounting portion extending radially outward from the housing, and the outer peripheral surface of the main panel of the instrument panel reinforcement. And a tilt rotation shaft portion that rotatably connects the attachment portion and the main panel of the instrument panel reinforcement.

  According to this aspect, since the tilt rotation shaft portion is integrally provided on the outer peripheral surface of the main line of the instrument panel reinforcement, the rigidity can be enhanced against the twisting force generated in the housing.

  According to the present invention, in the vehicle steering apparatus, the rigidity of the tilt mechanism that connects the instrument panel force and the steering column can be increased.

It is a figure for explaining the outline of the composition of the vehicle steering device of the embodiment, and its circumference. FIG. 2A is a view for explaining the tilt mechanism of the embodiment, and FIG. 2B is a cross-sectional view of a part of line AA of the vehicle steering apparatus shown in FIG. It is. FIG. 3A is a view for explaining a tilt mechanism of the comparative technique, and FIG. 3B is a cross-sectional view of the tilt mechanism shown in FIG.

  FIG. 1 is a diagram for explaining an outline of a vehicle steering device 10 according to an embodiment and a configuration around the vehicle steering device 10. The vehicle steering apparatus 10 includes a steering wheel 12, a steering shaft 14, a steering column 16, an intermediate shaft 17, a pinion shaft 19, a rack and pinion mechanism 20, a rack bar 22, a first universal joint 30, and a second universal joint 32. . An instrument panel force 34 is provided as a member that supports the steering wheel 12, the steering shaft 14, and the steering column 16. A front wheel FR and a front wheel FL are connected to the rack bar 22.

  The steering wheel 12 is steered by the driver. One end of the steering shaft 14 is connected to the steering wheel 12 so as to rotate together with the steering wheel 12, and functions as a rotating shaft that transmits the rotation of the steering wheel 12. The other end of the steering shaft 14 is connected to the intermediate shaft 17 and the pinion shaft 19 via the first universal joint 30 and the second universal joint 32.

  The pinion shaft 19 is connected to a rack and pinion mechanism 20 including a rack bar 22 that extends in the left-right direction (vehicle width direction) of the vehicle and slides in the axial direction. The rack and pinion mechanism 20 is configured by meshing pinion teeth formed at one end of the pinion shaft 19 with a rack shaft.

  When the driver operates the steering wheel 12, the rotation of the steering shaft 14 is transmitted to the rack and pinion mechanism 20 through the intermediate shafts 17 and 19, and the rack and pinion mechanism 20 converts the rack bar 22 into a linear motion in the horizontal direction. The One end of a tie rod (not shown) is connected to each end of the rack bar 22. The other end of the tie rod is connected to a knuckle arm (not shown) that supports the right front wheel FR and the left front wheel FL. When the rack bar 22 moves linearly, the right front wheel FR and the left front wheel FL are steered.

  The vehicle steering device 10 includes an EPS device on the column side. The EPS apparatus includes a steering wheel 12 that is steered by a driver, a steering shaft 14 that is coupled to the steering wheel 12, and a steering column 16 that applies an assist force to assist the steering operation to the steering shaft 14.

  The steering column 16 includes a worm reduction mechanism 41 provided at the lower end of the steering shaft 14, a steering assist motor 24 whose output shaft is connected to the worm reduction mechanism 41, and a first column tube 37 into which the steering shaft 14 is inserted. And a second column tube 38. The steering assist motor 24 provides an assist force that assists the driver's steering.

  The worm reduction mechanism 41 is coaxially connected to the steering shaft 14 and is given an assist force from the steering assist motor 24. Inside the worm reduction mechanism 41, a worm gear for transmitting the assist force is provided. The worm speed reduction mechanism 41 is covered with a small-diameter first housing 42 and a large-diameter second housing 44 that are integrally formed. The first housing 42 and the second housing 44 are integrally formed in a disc shape. When the first housing 42 and the second housing 44 are not distinguished, they are called worm gear housings or simply housings.

  When the first column tube 37 and the second column tube 38 are not distinguished, they are called column tubes. The column tube extends from the first housing 42 toward the steering wheel 12 and the steering shaft 14 is inserted. The second column tube 38 and the first bracket 36 are connected. The column tube and the worm gear housing are integrally formed.

  The steering column 16 is connected to and supported by the instrument panel force 34. The instrument panel reinforcement 34 is a vehicle body reinforcing member that is fixed to the vehicle body, and is disposed inside the instrument panel. The steering column 16 is connected to the instrument panel force 34 at two locations. Specifically, the first bracket 36 on the side of the steering wheel 12 projecting outward from the trunk line 34a of the instrument panel reinforcement 34 and the column tube are coupled, and the coupling mechanism 40 and the worm gear fixed to the trunk line 34a of the instrument panel reinforcement 34. The outer peripheral surface of the housing is connected. The main line 34a of the instrument panel line 34 is a central cylindrical member that extends in the vehicle width direction of the instrument panel line 34 as shown in FIG.

  The tilt mechanism including the first bracket 36 and the coupling mechanism 40 can change the tilt of the steering column 16 and the steering shaft 14 so that the vertical position of the steering wheel 12 can be adjusted. The tilt mechanism will be described in detail with reference to FIG.

  Fig.2 (a) is a figure for demonstrating the tilt mechanism of embodiment, FIG.2 (b) is a cross section of some line segments AA of the vehicle steering apparatus 10 shown to Fig.2 (a). FIG.

  The first bracket 36 is composed of two plate-like members, projects outward in the radial direction from the main line 34 a of the instrument panel force 34, and is connected to the second column tube 38. The second bracket 39 is also provided with a second bracket 39 in parallel with the first bracket 36. The first bracket 36 projects toward the steering wheel 12, and the second bracket 39 projects toward the intermediate shaft 17 side.

  The connection mechanism 40 includes a tilt rotation shaft portion 48, a main line side attachment portion 46, a worm side attachment portion 49, and a bolt 47. As shown in FIG. 2B, the tilt rotation shaft portion 48 is inserted with a cylindrical tilt rotation shaft 48a like a hinge. The tilt rotation shaft portion 48 is integrally provided on the outer peripheral surface of the main line 34 a of the instrument panel force 34. The tilt rotation shaft portion 48 may be fixed to the main line 34a by welding or may be integrally formed with the main line 34a. The tilt rotation shaft portion 48 is located between the two second brackets 39. The main line side attachment portion 46 is a plate-like member connected to the tilt rotation shaft portion 48, and can be rotated by the tilt rotation shaft portion 48.

  The worm side mounting portion 49 is a plate-like member and extends radially outward from the second housing 44. The worm side mounting portion 49 may extend radially outward from the first housing 42. The worm side mounting portion 49 is formed integrally with the housing. The main line side attaching portion 46 and the worm side attaching portion 49 are connected by a bolt 47. That is, the tilt rotation shaft portion 48 rotatably connects the worm side attachment portion 49 and the main line 34a of the instrument panel reinforcement 34 via the main line side attachment portion 46. Thus, by providing the tilt rotation shaft portion 48 integrally with the main line 34a, the reaction force of the assist force of the steering assist motor 24 can be received in the shear direction, and the rigidity of the tilt mechanism can be increased. 2A, the vehicle steering device 10 can be roughly divided into an instrument panel force-side member supported by the instrument panel force 34 and a column-side member supported by the steering column 16. As shown in FIG. If the fastening of the bolt is released, the connection between the steering column 16 and the instrument panel force 34 can be released. Here, a description will be given using the technique to be compared shown in FIG.

  FIG. 3A is a view for explaining a tilt mechanism of the comparative technique, and FIG. 3B is a cross-sectional view of the tilt mechanism shown in FIG. In the tilt mechanism of the comparative technique, the position of the tilt rotation shaft 62 is different from the tilt rotation shaft portion 48 of the embodiment. The steering support 60 connects the second bracket 39 and the lower surface of the second housing 44. The steering support 60 has a tilt rotation shaft 62. The tilt rotation shaft 62 is located below the second housing 44, that is, on the intermediate shaft 17 side.

  As shown in FIG. 3A, the reaction force of the assist force transmitted from the steering assist motor 24 is generated in the outer peripheral direction of the housing. This reaction force is transmitted to the instrument panel force 34 via the steering support 60 and the second bracket 39. Since the rigidity and weight of the second bracket 39 and the steering support 60 affect the steering feeling of the driver, it is preferable to increase the rigidity and weight.

  In the tilt mechanism of the comparative technique, since the tilt rotation shaft 62 is located below the second housing 44, the tilt rotation shaft 62 is offset from the main line 34 a of the highly rigid instrument panel reinforcement 34. For this reason, the torsional rigidity is lower than that of the tilt mechanism of the embodiment against the reaction force of the assist force, that is, the force that twists around the outer periphery of the housing.

  As shown in FIG. 2A, in the tilt mechanism of the embodiment, since the tilt rotation shaft portion 48 is provided integrally with the main line 34a, it is in a state of being close to the highly rigid main line 34a. Thereby, torsional rigidity can be increased against a twisting force on the outer periphery of the housing. Moreover, since the main line side attaching part 46 has a flat plate-like cross section, the cross-sectional secondary pole moment can be increased more than the steering support 60 having a U-shaped cross section of the comparative technique. The connection between the instrument panel line 34 and the main line 34a can be simplified to reduce the weight. Further, since the tilt mechanism of the embodiment is connected to the instrument panel force 34 on the outer surface of the steering column 16, it can be compatible with a telescopic mechanism for expanding and contracting the steering shaft 14 and a mechanism for removing the steering shaft 14.

  In the above, this invention was demonstrated based on each embodiment. It is to be understood by those skilled in the art that these embodiments are exemplifications, and various modifications can be made to each component and process combination, and such modifications are also within the scope of the present invention. Such modifications will be described below.

  In the embodiment, the cylindrical second column tube 38 is shown as the column side member to which the first bracket 36 is connected, but the present invention is not limited to this mode. For example, the column side member to which the first bracket 36 is connected may be a plate-like member extending from the first column tube 37. That is, the column side member for connecting the first column tube 37 and the first bracket 36 is not limited to a cylindrical shape like the second column tube 38, and extends from the first column tube 37 along the steering shaft 14. Any shape can be used.

  In the embodiment, the mode in which the first bracket 36 is formed by two plate-like members has been described, but the present invention is not limited to this mode. For example, the aspect formed with one member may be sufficient. The first bracket 36 may have a shape that is fixed to the outer periphery of the main line of the instrument panel reinforcement 34, extends to the steering wheel 12 side, and extends to above the second column tube 38.

  In the embodiment, the aspect in which the tilt rotation shaft portion 48 is directly welded to the trunk line of the instrument panel force 34 has been described. However, the embodiment is not limited thereto, and the tilt rotation shaft portion 48 is fixed to the second bracket 39. Good. That is, the tilt rotation shaft portion 48 is fixed to the instrument panel force 34 via the second bracket 39. The tilt rotation shaft portion 48 may be fixed not to the steering column 16 side but to the instrument panel force 34 side.

  DESCRIPTION OF SYMBOLS 10 Vehicle steering device, 12 Steering wheel, 14 Steering shaft, 16 Steering column, 17 Intermediate shaft, 19 Pinion shaft, 20 Rack and pinion mechanism, 22 Rack bar, 24 Steering assist motor, 30 First universal joint, 32 2 universal joints, 34 instrument panel reinforcement, 36 first bracket, 37 first column tube, 38 second column tube, 39 second bracket, 40 coupling mechanism, 42 first housing, 44 second housing, 41 worm speed reduction mechanism, 46 trunk side attachment part, 49 worm side attachment part, 47 bolt, 48 tilt rotation shaft part, 48a tilt rotation axis, 34a trunk line, 62 tilt rotation axis, 60 stearin Support.

Claims (1)

A vehicle steering device capable of changing the position of a steering wheel by changing the inclination of a steering column and a steering shaft supported by an instrument panel force,
The steering column coupled to the instrument panel force;
A tilt mechanism that changes a position of a steering wheel coupled to the steering shaft by changing an inclination of the steering column and the steering shaft;
The steering column
A motor for providing an assisting force to assist the steering of the driver;
A worm reduction mechanism that is coaxially connected to the steering shaft and is provided with an assist force from the motor;
A housing covering the worm reduction mechanism;
A column side member extending from the housing to the steering wheel side,
The tilt mechanism is
A bracket projecting outward from the main line of the instrument panel force and connected to the column side member;
A mounting portion extending radially outward from the housing;
A vehicle steering apparatus comprising: a tilt rotation shaft portion that is integrally provided on an outer peripheral surface of a main line of the instrument panel force and that rotatably connects the attachment portion and the main line of the instrument panel force.

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