JP4524753B2 - Steering device - Google Patents

Description

  The present invention relates to a vehicle steering apparatus.

  In a vehicle steering apparatus, for convenience of layout, a steering wheel and a steering unit are not connected in a straight line by a single steering shaft, but are connected via a universal joint. Universal joints are widely used in this application because they have little rotational play and are suitable for mass production. However, because the universal joint has the property that the angular velocity ratio of the driven shaft to the drive shaft varies (inconstant velocity), if one joint has a large joint angle, the variation in angular velocity becomes the variation in steering torque. It is known to appear and cause problems in steering feeling. For this reason, it is common to use two universal joints in an arrangement that cancels both angular velocity fluctuations. In order to cancel each other's angular velocity fluctuations, it is basically necessary to set both joint angles to be the same.

  Incidentally, a vehicle steering apparatus is generally provided with a tilt mechanism that adjusts the vertical position of the steering wheel. In many cases, the tilt fulcrum is set near the oscillation center of the upper joint of the pair of universal joints as described above. On the other hand, Patent Document 1 discloses a steering device in which a tilt fulcrum is disposed above the axis of a steering shaft for the purpose of improving the assembly property to a vehicle body and the tilt trajectory.

Japanese Utility Model Publication No. 5-58552

  However, conventionally, there has been no tilt fulcrum set in consideration of maintaining the constant velocity of the pair of universal joints. For this reason, the conventional steering apparatus has a problem in that the joint angle of the upper joint is changed by the tilt operation, and the constant velocity relationship between the pair of universal joints is broken, thereby causing the steering torque fluctuation.

  If the joint angle can be originally set to be small, such a torque fluctuation does not cause a problem that affects the steering feeling. However, in recent automobiles, EPAS (Electronic Power Assist Steering), VGR (Variable Steering Gear Ratio), or a crusher configured such that the brake pedal is detached from the mount in the event of a frontal collision from the viewpoint of protecting the passenger's foot Devices such as bull brake pedals are provided around the steering device. As a result, the layout of the steering device becomes more severe, and the joint angles of the pair of universal joints tend to be set larger. Therefore, the problem of steering torque fluctuation associated with the tilt operation as described above becomes obvious.

  Therefore, an object of the present invention is to provide a steering device that can adjust the position of the steering wheel without affecting the steering feeling.

  A steering device according to an aspect of the present invention includes a steering unit that is fixed to a vehicle body and that steers the wheel, a steering wheel that is attached to the vehicle body via a tilt fulcrum so as to be adjustable in the vertical direction, the steering wheel, and the steering And a steering shaft configured to cancel torque fluctuation due to steering of the steering wheel, and the tilt fulcrum is positioned in the vertical direction of the steering wheel. The position is set to suppress the occurrence of the torque fluctuation due to the adjustment.

  Conventionally, the tilt fulcrum is set at a position that substantially coincides with the support point of the steering shaft. However, according to the above configuration, the tilt fulcrum is generated by the torque adjustment due to the vertical adjustment of the steering wheel. Therefore, even if the position of the steering wheel in the vertical direction is adjusted, the steering feeling is not adversely affected.

  According to a preferred embodiment of the present invention, it is preferable that the tilt fulcrum is set in front of the upper joints of the two universal joints. According to this configuration, good layout properties can be ensured.

  By the way, in the present invention, the “position for suppressing the occurrence of torque fluctuation by adjusting the position of the steering wheel in the vertical direction” where the tilt fulcrum is set can be a fixed position or can be displaced. It can also be a position. Here, when this position is fixed, it is necessary to make the steering shaft extendable instead. In that case, there is a high possibility that the cost will be high, for example, it is necessary to take measures to prevent the steering shaft itself from rattling.

  Therefore, according to a preferred embodiment of the present invention, the tilt fulcrum is preferably provided so as to be slidable in the front-rear direction. According to this configuration, the present invention can be implemented at a low cost.

  According to a preferred embodiment of the present invention, the telescopic mechanism further enables the steering wheel to be adjusted in the front-rear direction, and the telescopic mechanism is configured to move the upper and lower positions of the upper joints of the two universal joints during telescopic operation. Is preferably configured to move in synchrony with its telescopic motion.

  According to this configuration, since the vertical position of the upper joint can be displaced in synchronization with the telescopic operation, it is possible to suppress the occurrence of steering torque fluctuations associated with the front-rear position adjustment of the steering wheel. Become.

  Further, according to a preferred embodiment of the present invention, the steering shaft includes an upper shaft that connects the steering wheel and the upper joints of the two universal joints, and an upper joint and a lower joint of the two universal joints. It is preferable that the tilt fulcrum is set between an extension line of the upper shaft in the upper joint direction and the intermediate shaft.

  According to this configuration, while ensuring good layout, it is possible to reliably ensure the effect that the steering feeling is not adversely affected even if the position of the steering wheel in the vertical direction and / or the longitudinal direction is adjusted. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the steering apparatus which can adjust the position of a steering wheel without affecting a steering feeling is provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a steering device according to the embodiment.

  A dash lower panel 6 is provided in the front part of the vehicle compartment 5, and the engine room 7 and the vehicle compartment 5 are partitioned in the front-rear direction by the dash lower panel 6. A cowl box 8 having a closed sectional structure extending in the vehicle width direction (direction perpendicular to the drawing) is attached to the upper portion of the dash lower panel 6. The cowl box 8 is a vehicle body rigid member in which a cowl panel 9 and a dash lower panel 10 are joined to form a cowl closed section 11 extending in the vehicle width direction. Further, a floor panel 12 extending substantially horizontally rearward is joined to the lower portion of the above-described dash lower panel 6, thereby forming a floor portion.

  Below the cowl box 8 on the driver's seat side, a substantially cylindrical outer tube 15 that constitutes a steering column is provided in a slanted shape that is lowered forward. The outer tube 15 is supported by a steering support member 13 as a vehicle body rigid member extending in the vehicle width direction. This steering support member 13 is welded and fixed to a support bracket 31 described later, and this support bracket 31 is welded and fixed to a steering support bracket 48 attached to the dash floor panel 10 constituting the cowl box 8. Has been.

  An upper shaft 14 as a first steering shaft is rotatably fitted in the outer tube 15, and a steering wheel 27 is attached to the upper end portion of the upper shaft 14. The lower end portion of the upper shaft 14 is connected to the upper end portion of the intermediate shaft 20 as the second steering shaft via a first universal joint (hereinafter referred to as “upper joint”) 19. On the other hand, the lower end portion of the intermediate shaft 20 is connected to the upper end portion of the lower shaft 22, which is a third steering shaft, via a second universal joint (hereinafter referred to as “lower joint”) 21. Thereby, the intermediate shaft 20 transmits the steering force (rotational force) by the steering wheel 27 to the lower shaft 22 via the upper joint 19 and the lower joint 21.

  The lower shaft 22 extends forward and downward from the opening 6 a of the dash lower panel 6. A worm 25 is provided at the extended end, and a steering gear is formed by engaging the worm 25 with a sector or a rack. Furthermore, a steering unit (steering device) 26 for steering the left and right front wheels is configured by connecting the steering gear to the left and right sides with tie rods.

  Reference numeral 28 denotes an EPAS (electronic power assist steering) unit, and reference numeral 29 denotes a VGR (variable steering gear ratio) unit.

  As described above, the steering apparatus according to the present embodiment has a configuration in which two universal joints are interposed between the steering wheel 27 and the steering unit 26. In the case of an automobile in recent years, especially when it is an FF vehicle and has the above EPS unit, VGR unit, etc., the layout of the steering device is severe, and the lower shaft 22 looks quite upright. Yes. For this reason, the joint angle of the universal joint becomes large, and the above-described problem of steering torque fluctuation becomes obvious. Therefore, in the present embodiment, the two universal joints of the upper joint 19 and the lower joint 21 are used in an arrangement that can cancel the mutual angular velocity fluctuation and maintain the constant velocity. In order to cancel each other's angular velocity fluctuations, it is basically necessary to make both joint angles equal.

  A tilt mechanism for adjusting the vertical position of the steering wheel 27 is provided at the lower end of the outer tube 15. A tilt joint 42 serves as a tilt fulcrum. Hereinafter, the tilt mechanism in the present embodiment will be described in detail with reference to FIGS. 2 and 3. FIG. 2 is a perspective view showing an example of the tilt mechanism, and FIG. 3 is an upper cross-sectional view showing the structure around the upper joint 19 and the lower joint 21. In the figure, arrow F indicates the front of the vehicle, and arrow R indicates the rear of the vehicle.

  Reference numeral 30 denotes a steering mounting bracket that fixes the outer tube 15 and the steering support member 13. The steering mounting bracket 30 enables steering to be tilted. The steering mounting bracket 30 includes the following components including a pair of left and right support brackets 31 and 31 having a gate shape in cross section that are welded and fixed to the steering support member 13 at both left and right portions with the outer tube 15 therebetween.

  Reference numeral 35 denotes a U-shaped bracket that is joined and fixed to the front end portion of the outer tube 15 and does not interfere with the upper joint 19. On both the left and right sides of the U-shaped bracket 35 with the outer tube 15 therebetween, long holes 34 are formed as guide holes that extend so as to gradually move downward toward the front of the vehicle.

  Reference numeral 39 denotes a pair of left and right mounting brackets that are formed in an L shape and are provided so as to sandwich the outer tube 15 at the rear part of the support bracket 31 and have guide holes 36 extending in the vertical direction. A nut 37 is welded and fixed to the side of the mounting bracket 39 in contact with the support bracket 31, and is fastened and fixed using bolts 38 from below the support bracket 31.

  Reference numeral 41 denotes a pair of left and right mounting brackets formed in an L shape so as to extend between the front portion of the support bracket 31 and the U-shaped bracket 35. A guide hole 34 having the same shape as the guide hole 34 formed with the U-shaped bracket 35 is also formed on the side of the mounting bracket 41 in contact with the U-shaped bracket 35. The holes 34 are fixed at the matching positions. Specifically, the nut 40 is welded and fixed to the side of the mounting bracket 41 that contacts the support bracket 31, and is fastened or welded from below the support bracket 31 using bolts (not shown).

  Then, a bolt 42 is inserted into the guide hole 34 of the mounting bracket 41 located on the front side and the guide hole 34 of the U-shaped bracket 35, and the bolt 42 is fastened and fixed with a lock nut so that the bolt 42 does not fall out of the guide hole 34. . The bolt 42 can move along the guide hole 34.

  On the other hand, the mounting bracket 39 located on the rear side is provided with a shaft member 43 that passes through the guide hole 36 in the vertical direction and the outer tube 15, and a nut 44 that is welded and fixed to the one mounting bracket 39. The adjustment lever 45 integrally connected to the other end side of the shaft member 43 is configured to be tightened and loosened.

  With this configuration, by operating the lever 45 to loosen the shaft member 43, the steering wheel 27 attached to the upper shaft 14 is adjusted in the vertical direction within the guide hole 36 with the bolt 42 as a tilt fulcrum. sell. Then, at the desired tilt position, the lever 45 is operated to tighten the shaft member 43, whereby the steering wheel 27 is locked at the tilt position.

  Referring to FIG. 3, the arrangement position of the upper joint 19 that did not appear in FIG. 2 will be clearly understood. As shown in the drawing, the upper bracket 19 that connects the upper shaft 14 and the intermediate shaft 20 is disposed so as to be accommodated in a U-shaped bracket 35. The upper joint 19 and the lower joint 21 are each provided with yoke members 87 and 88 and a cross member 89 for connecting the yoke members 87 and 88 as shown in the figure.

  The configuration of the steering device in the present embodiment is generally as described above. A feature of this configuration is that the bolt 42 as a tilt fulcrum is configured to be movable along the guide hole 34. Conventionally, since the position of the tilt fulcrum is fixed at a position near the upper joint 19, the joint angle of the upper joint is changed by the tilt adjustment, but the effect is not exerted on the joint angle of the lower joint. For this reason, the angle difference between the two joint angles is widened, and the constant velocity cannot be maintained. In this respect, in the present embodiment, the tilt fulcrum 42 is configured to be movable along the guide hole 34. Therefore, the tilt fulcrum 42 is moved in accordance with the tilt adjustment, and thereby the joint angle between the two joint angles is changed. It is possible to adjust to a smaller angle.

  More specifically, for example, when the steering wheel 27 is tilted downward, the tilt fulcrum 42 is tilted as described above as the steering wheel 27 is moved downward. It moves upward and backward along 34. Then, the upper joint 19 moves downward and rearward as shown by 19a in FIG. The increase in the joint angle of the upper joint 19 due to this movement is small compared to the conventional configuration. Further, the movement of the upper joint 19 increases the joint angle while the lower joint 21 is also driven. By such an operation, the angle difference between the joint angle of the upper joint 19 and the joint angle of the lower joint 21 can be kept small.

  Conversely, when the steering wheel 27 is tilted upward, the tilt fulcrum 42 moves downward and forward along the guide hole 34 as the steering wheel 27 is moved upward. Then, the upper joint 19 moves upward and forward as shown by 19b in FIG. Due to this movement, the decrease in the joint angle of the upper joint 19 is small compared to the conventional configuration. Further, the movement of the upper joint 19 reduces the joint angle while the lower joint 21 is also driven. By such an operation, the angle difference between the joint angle of the upper joint 19 and the joint angle of the lower joint 21 can be kept small.

  That is, the tilt fulcrum is set to a position that suppresses the occurrence of steering torque fluctuation due to the vertical position adjustment of the steering wheel 27. For example, as shown in FIG. 4, if the tilt fulcrum is set at least within a range S that is forward of the upper joint 19 in the extending direction of the intermediate shaft 20, the angle difference between the joint angles of both can be kept small. And the occurrence of steering torque fluctuations can be suppressed. From the viewpoint of layout, it is more preferable to set between the extension line of the upper shaft 14 in the direction of the upper joint 19 and the intermediate shaft 20.

  According to the operation described above, the occurrence of steering torque fluctuation due to tilt adjustment is suppressed, and therefore the position of the steering wheel can be adjusted without affecting the steering feeling.

  As another embodiment, the position of the tilt fulcrum is not variable as described above, but the position of the tilt fulcrum is fixed, and instead, the intermediate shaft 20 is configured to be extendable and retractable. An effect can be obtained.

  Specifically, for example, as shown in FIG. 5, the U-shaped bracket 35 and the mounting bracket 41 do not have a guide hole 34 through which a bolt 42 as a tilt fulcrum can be moved. Is fixed. Instead, as shown in FIG. 6, the intermediate shaft 20 is composed of an outer shaft 20A and an inner shaft 20B that are connected to each other. According to this configuration, as shown in FIG. 7, even when the position of the tilt fulcrum is fixed, the intermediate shaft 20 is expanded and contracted to a length that can keep the angle difference between the two joint angles small along with the tilt adjustment. It is possible. Also in this case, as shown in the drawing, the upper joint 19 moves in the vertical direction in accordance with the tilt adjustment. Further, if the tilt fulcrum is set at least within the range S that is forward of the upper joint 19 in the extending direction of the intermediate shaft 20, the angle difference between the two joint angles can be kept small. However, from the viewpoint of layout properties, it is more preferable to set between the extension line of the upper shaft 14 in the direction of the upper joint 19 and the intermediate shaft 20.

  Next, an implementation example of the telescopic mechanism when the bolt 42 as the tilt fulcrum is configured to be movable along the guide hole 34 as described above will be described with reference to FIG.

  The configuration shown in FIG. 8 is substantially the same as the configuration shown in FIG. 2, but in the example of FIG. 8, a pair of left and right brackets 33 each having a guide hole 32 extending in the front-rear direction of the vehicle It is fixed to the joint. The bracket 33 is formed with a long hole 32 as a guide hole extending in the extending direction of the upper shaft 14. In the upper part of the outer tube 15, a shaft member 43 is provided so as to integrally penetrate the guide holes 36 and the guide holes 32 on both the left and right sides.

  With this configuration, by operating the lever 45 to loosen the shaft member 43, the upper shaft 14, that is, the steering wheel 27 can be adjusted not only in the vertical direction within the guide hole 36 as described above, but also in the guide The position is adjusted in the front-rear direction within the range of the hole 32.

  At the time of telescopic adjustment by such a mechanism, the bolt 42 which is a tilt fulcrum is also driven along the guide hole 34 as the outer tube 15 moves along the guide hole 32. As described above, since the guide hole 34 is inclined so as to gradually go downward as it goes toward the front of the vehicle, the joint angle of the universal joint also changes by this telescopic adjustment. By operation, it is possible to move the bolt 42 as a tilt fulcrum so as to keep the angle difference between the joint angles of the upper joint 19 and the lower joint 21 small.

  More specifically, for example, when the steering wheel 27 is telescopically adjusted rearward, the shaft member 43 moves rearward along the guide hole 34, and the tilt fulcrum 42 moves along the guide hole 34. Move up and backward. Then, the upper joint 19 moves downward and rearward as shown by 19a in FIG. This movement increases the joint angle of the upper joint 19, but increases the joint angle while the lower joint 21 is also driven. By such an operation, the angle difference between the joint angle of the upper joint 19 and the joint angle of the lower joint 21 can be kept small.

  On the contrary, when the steering wheel 27 is telescopically adjusted forward, the shaft member 43 moves forward along the guide hole 34, and the tilt fulcrum 42 moves downward and forward along the guide hole 34. To do. Then, the upper joint 19 moves upward and forward as shown by 19b in FIG. By this movement, the joint angle of the upper joint 19 decreases, but the joint angle decreases while the lower joint 21 is also driven. By such an operation, the angle difference between the joint angle of the upper joint 19 and the joint angle of the lower joint 21 can be kept small.

  Thus, during the telescopic operation in the present embodiment, the tilt fulcrum 42 moves to a position where the occurrence of steering torque fluctuation is suppressed in synchronization with the telescopic operation. With this movement, the upper and lower positions of the upper joint 19 are configured to move. With this configuration, it is possible to suppress the occurrence of steering torque fluctuation. For example, as shown in FIG. 9, if the tilt fulcrum is set within a range S ′ between the extension line of the upper shaft 14 in the direction of the upper joint 19 and the intermediate shaft 20, The angle difference can be kept small, and the occurrence of steering torque fluctuation accompanying the position adjustment of the steering wheel 27 in the front-rear direction can be suppressed.

It is a figure which shows the structure of the steering device in embodiment of this invention. It is a perspective view which shows an example of the tilt mechanism in embodiment of this invention. It is an upper section showing the structure of the upper joint and lower joint periphery in the embodiment of the present invention. It is a schematic diagram explaining the operation | movement of tilt adjustment and the setting position of a tilt fulcrum in embodiment of this invention. It is a perspective view which shows an example of the tilt mechanism in other embodiment of this invention. It is a figure which shows the structural example of the intermediate shaft in other embodiment of this invention. It is a schematic diagram explaining operation | movement at the time of setting the tilt fulcrum in the other embodiment of this invention to a fixed position. It is a perspective view which shows an example of the telescopic mechanism in another embodiment of this invention. It is a schematic diagram explaining the operation | movement of telescopic adjustment and the setting position of a tilt fulcrum in embodiment of this invention.

Explanation of symbols

5 ... Vehicle compartment 6 ... Dash lower panel 7 ... Engine room 8 ... Cowl box 12 ... Floor panel 13 ... Steering support member 14 ... First steering shaft (upper shaft)
15 ... Outer tube 19 ... First universal joint (upper joint)
20 ... Second steering shaft (intermediate shaft)
21 ... Second universal joint (lower joint)
22 ... Third steering shaft (lower shaft)
26 ... Steering unit 27 ... Steering wheel 30 ... Steering mounting bracket

Claims (4)

A steering device for steering a wheel,
A steering unit that is fixed to the vehicle body and steers the wheels;
A steering wheel provided rearward and upward in the vehicle longitudinal direction with respect to the steering unit, and attached to the vehicle body via a tilt fulcrum so as to be adjustable in the vertical direction;
Wherein the steering wheel and the steering unit, together with the coupling via two universal joints composed of the upper joint and a lower joint, the lower and the upper joint as the steering torque fluctuation caused by the steering wheel is offset A steering shaft configured such that the joint angle with the side joint is set to incline the respective upper ends toward the rear of the vehicle ;
With
The steering shaft is
An upper shaft connecting the steering wheel and the upper joint;
An intermediate shaft connecting the upper joint and the lower joint;
The tilt fulcrum, slidable in the longitudinal direction of the vehicle,
The tilt fulcrum moves upward and rearward of the vehicle so that the upper joint moves downward and rearward of the vehicle by adjusting the position of the steering wheel downward, and the upper joint is moved upward by adjusting the position of the steering wheel upward. In order to move the tilt fulcrum downward and forward of the vehicle so as to move forward of the vehicle, the sliding direction of the tilt fulcrum is inclined downward toward the front of the vehicle with respect to an extension line of the upper joint direction of the upper shaft. steering device, characterized in that constructed. A steering device for steering a wheel,
A steering unit that is fixed to the vehicle body and steers the wheels;
A steering wheel provided behind and above the vehicle front-rear direction with respect to the steering unit, and attached to the vehicle body via a tilt fulcrum so as to be adjustable in the vertical direction;
The steering wheel and the steering unit are connected via two universal joints composed of an upper joint and a lower joint, and the upper joint and the lower unit are arranged so that torque fluctuations caused by steering of the steering wheel are offset. A steering shaft configured such that the joint angle with the side joint is set to incline each upper end toward the rear of the vehicle;
With
The steering shaft is
An upper shaft connecting the steering wheel and the upper joint;
An intermediate shaft connecting the upper joint and the lower joint;
The tilt fulcrum is provided so as to be slidable in the vehicle longitudinal direction,
The steering wheel is supported at a position closer to the steering wheel side than the tilt fulcrum so that the front-rear position can be adjusted via a guide hole extending in the vehicle front-rear direction with respect to the steering support bracket.
In synchronization with the position adjustment of the steering wheel toward the rear of the vehicle, the tilt fulcrum moves upward and toward the rear of the vehicle so that the upper joint moves downward and toward the rear of the vehicle, thereby adjusting the position of the steering wheel toward the front of the vehicle. Synchronously, the tilt fulcrum slide direction inclines toward the vehicle front lower side with respect to the guide hole so that the tilt fulcrum moves downward and forward of the vehicle so that the upper joint moves upward and forward of the vehicle. Configured
A steering device characterized by that. The tilt fulcrum, the steering apparatus according to claim 1 or 2 than the prior SL upper side joint, characterized in that it is set forward. Before Symbol tilt fulcrum, the steering device according to any one of claims 1 to 3, characterized in that it is set between the upper joint direction of extension and the intermediate shaft of the upper shaft.

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