Telescopic steering shaft for a motor vehicle
阅读说明:本技术 用于机动车的可伸缩转向轴 (Telescopic steering shaft for a motor vehicle ) 是由 弗洛里安·帕凯尔 丹尼斯·波铬曼 罗伯特·费尔 于 2018-05-14 设计创作,主要内容包括:用于机动车的可伸缩的转向轴(4),所述转向轴具有内轴(7),所述内轴共轴且在转向轴(4)的轴向上可移动地接入外轴(5),其中内轴(7)和外轴(5)在横截面中具有对应的轮廓以便传递扭矩,由此以简单且公差不敏感的方式配有能量吸收装置用于碰撞事故,即,通过在内轴(7)和外轴(5)之间在内轴(7)或外轴(5)上固定有轮廓轴套(22),且另一个轴配有至少一个在轮廓轴套(22)的径向区域中突出的凸起部分(25),当在碰撞事故中外轴(5)经过轴向调节区域(27)在内轴(7)上推出时,所述凸起部分(25)在动能吸收下使轮廓轴套(22)变形。(A telescopic steering shaft (4) for a motor vehicle, having an inner shaft (7), the inner shaft is coaxial and is connected to the outer shaft (5) in a movable manner in the axial direction of the steering shaft (4), wherein the inner shaft (7) and the outer shaft (5) have corresponding profiles in cross section for transmitting torque, whereby energy absorption means are provided for collision accidents in a simple and tolerance-insensitive manner, namely, by fixing a contour bush (22) to the inner shaft (7) or the outer shaft (5) between the inner shaft (7) and the outer shaft (5), and the other shaft is provided with at least one raised portion (25) projecting in the radial region of the contour sleeve (22), when the outer shaft (5) is pushed out of the inner shaft (7) through the axial adjustment region (27) in the event of a crash, the raised portion (25) deforms the profile sleeve (22) under absorption of kinetic energy.)
1. A telescopic steering shaft (4) for a motor vehicle, having an inner shaft (7), the inner shaft is coaxial and is inserted into the outer shaft (5) in a manner that the inner shaft can move in the axial direction of the steering shaft (4), wherein the inner shaft (7) and the outer shaft (5) have corresponding profiles in cross section for transmitting torque, characterized in that a profile bushing (22) is arranged between the inner shaft (7) and the outer shaft (5), wherein the contour sleeve (22) is fixed on the outer shaft (5) or the inner shaft (7), and a further shaft is provided, which is provided with at least one raised portion (25) protruding in the radial region of the contour sleeve (22), when the outer shaft (5) is pushed out of the inner shaft (7) via the axial adjustment region (27) in the event of a crash, the projections deform the profile sleeve (22) by absorbing kinetic energy.
2. Steering shaft according to claim 1, characterized in that the profile bushing (22) is fixed on the inner shaft (7) and the outer shaft (5) has at least one bulge (25) projecting radially inwards for the deformation of the profile bushing (22).
3. Steering shaft according to claim 2, characterised in that the raised portion (25) is moulded into the material of the tubular outer shaft (5).
4. A steering shaft according to claim 2 or 3, characterized in that at least two projecting portions (25) are provided which stand opposite in the circumferential direction of the outer shaft (5).
5. The steering shaft according to any one of claims 2 to 4, wherein four of the raised portions (25) are provided, two of which are arranged oppositely in the circumferential direction of the outer shaft (5).
6. Steering shaft according to any one of the preceding claims, characterized in that the profile sleeve (22) consists of plastic.
7. The steering shaft according to one of the preceding claims, characterized in that the outer shaft (5) has at least one recess (20) which is fitted in an elongated groove (21) of the inner shaft (7), a first axial region of the recess (20) being designed as an adjustment region (27) for axially adjusting the steering shaft (4), and a second axial region being designed as an energy absorption region (26) in which the recess (20) projects more radially inward than in the adjustment region and forms a bulge (25) for the deformation of the profile sleeve (22).
8. Steering column with a servo unit (2) and a load unit (3), wherein a steering shaft (4) according to any one of the preceding claims is rotatably placed in the servo unit (2).
9. Steering column according to claim 8, characterized in that the servo unit (2) is manually or motorised adjustable with respect to the load unit (3).
Technical Field
The invention relates to a telescopic steering shaft for a motor vehicle, comprising an inner shaft which is coaxially and displaceably inserted into an outer shaft in the axial direction of the steering shaft, wherein the inner shaft and the outer shaft have corresponding contours in cross section for transmitting torque.
Background
From EP2910451a1, steering axles are known which have an inner shaft which is telescopically inserted into an outer shaft and which has an axial adjustment region and an energy absorption region connected thereto. If the inner shaft is pushed into the outer shaft via the axial adjustment region, the inner shaft reaches the energy absorption region, which is characterized in that a higher force is required there for the axial displacement. Such forces occur during a crash event. In the event of a collision, the force transmitted into the steering shaft via the steering wheel will exceed a predetermined force, so that an axial displacement takes place under energy absorption. A portion of the kinetic energy will be absorbed in the energy absorbing region. The disadvantage of this solution is that the inner and outer shafts are expensive to manufacture and are subject to high tolerance requirements to ensure smooth, uniform adjustment and predefined crash characteristics.
Disclosure of Invention
The object of the invention is to provide an adjustable steering spindle with an energy absorption section, which is easy and inexpensive to produce and has a low tolerance sensitivity.
This object is solved by the features of claim 1. Advantageous embodiments are described in the dependent claims.
The solution according to the invention provides that a profile sleeve is arranged between the inner shaft and the outer shaft, wherein the profile sleeve is fixed to the outer shaft or the inner shaft, and the other shaft is provided with at least one bulge which projects in a radial region of the profile sleeve and which deforms the profile sleeve under absorption of kinetic energy when the outer shaft is pushed out of the inner shaft through the axial adjustment region in the event of a crash.
In contrast to the prior art, the energy is absorbed not by deformation of the outer shaft itself but by deformation of the contour sleeve. The deformation of the sleeve for energy absorption can be carried out by deformation and/or destruction of the contour sleeve. Only minor changes to existing manufacturing tools are required for manufacturing. The outer and inner shafts do not have to be matched with such a high precision that the solution according to the invention is not susceptible to manufacturing tolerances. The profile sleeve, which is arranged between the inner shaft and the outer shaft, transmits the torque introduced into the steering shaft between the outer shaft and the inner shaft, in other words, a force flow occurs between the inner shaft and the outer shaft via the profile sleeve.
In an advantageous development, the inner shaft can be designed as a solid shaft or as a hollow shaft.
In an advantageous development, the contour sleeve is advantageously fixed on the inner shaft and the outer shaft has at least one bulge which projects radially inwards for the deformation of the contour sleeve. The radially inwardly projecting bulge part is manufactured in a simple manner.
The embodiment is therefore particularly advantageous in terms of manufacturing costs.
The raised portion is molded into the material of the tubular outer shaft. The male part and the outer shaft are therefore preferably designed as a one-piece integral component. A boss portion protruding radially inward is formed inside the outer shaft by being molded into the outer shaft from the outside. This shaping can be formed in the outer shaft in a simple and cost-effective manner, for example by means of a deformation tool.
In a first preferred embodiment, at least two raised portions are provided, which are opposite in the circumferential direction of the outer shaft. This arrangement ensures a symmetrical force distribution, thereby ensuring a perfect function. The asymmetric force distribution may cause the inner shaft to jam within the outer shaft.
As long as the excess (ü berma β) is the same for an embodiment with two and four lobes, i.e., two lobes project into the interior of the outer shaft to the same extent as four lobes, greater deformation forces and absorption of more energy can be provided by a double number of lobes than in the case of two lobes.
In an advantageous development, the contour sleeve consists of plastic. It is particularly preferred that the contour sleeve consists entirely of plastic. This material on the one hand allows the inner shaft to slide in the outer shaft with as little friction as possible in the axial region provided for the steering shaft adjustment. Furthermore, the different plastic materials have different hardnesses, which makes it possible to easily adapt the energy absorbed by the inner shaft during a movement in the energy absorption region as required by a corresponding selection of the plastic materials. In a further particularly advantageous development, the contour sleeve is composed of Polyetheretherketone (PEEK) or Polyoxymethylene (POM).
In another embodiment, the contour sleeve is composed of a fiber-reinforced plastic. It is particularly preferred that the fiber-reinforced plastic contains carbon fibers or glass fibers.
In an alternative embodiment, the contour sleeve is composed of a metallic material. For this purpose, the contour sleeve can be made of brass or bronze, for example.
In a particularly preferred embodiment there is provided: the outer shaft has at least one recess which engages in an elongated groove of the inner shaft, a first axial region of the recess being designed as an adjustment region for adjusting the steering shaft in the axial direction and a second axial region as an energy absorption region in which the recess projects radially further inward or outward than in the adjustment region and forms a bulge for the deformation of the profile sleeve.
In the embodiment in which the projecting section of the outer shaft is designed by shaping, a wide range of embodiments which can be used for the outer shaft are advantageous, which preferably have four recesses running parallel to the axis of rotation of the steering shaft, which are distributed uniformly over the circumference and engage in corresponding four elongated grooves of the inner shaft, wherein a profiled bushing is arranged between the inner shaft and the outer shaft. In order to improve upon these known and widespread structural designs according to the invention, the shaping tool designated for shaping the groove in the outer shaft only has to be adjusted to a smaller circumference so that the radially inwardly projecting bulge can be formed at the same time as the groove is shaped.
The at least one recess and an indentation for the formation of the raised portion are preferably formed by a common shaping tool.
In an advantageous embodiment it can be provided that one or more of the raised portions has a ramp-shaped elevation. By this measure the absorption level of kinetic energy is increased and the outer shaft is pushed further on the inner shaft.
The invention also relates to a steering column with a servo unit and a load unit, wherein a steering shaft according to the invention is rotatably placed in the servo unit according to the above description.
Preferably, the servo unit is manually or mechanically adjustable relative to the load unit. So that energy absorption can be used in a manually or motor-adjustable steering column in a simpler and less costly manner by means of the steering shaft according to the invention.
Drawings
Embodiments of the invention are explained in detail below with the aid of the figures. The figures show in detail;
FIG. 1: a perspective view of a steering column having a load unit and a servo unit, in which a steering shaft according to the present invention is placed;
FIG. 2: fig. 1 is a longitudinal sectional view of a steering column with a steering shaft according to the invention;
FIG. 3: enlarged detail of fig. 2;
FIG. 4: a perspective view of the inner shaft, the contour bush, and the outer shaft of the steering shaft according to the present invention, which are unfolded from each other;
FIG. 5: a perspective view of an enlarged detail of the outer shaft;
FIG. 6: a partial perspective view of the cut outer shaft;
FIG. 7: enlarged detail of fig. 6;
FIG. 8: a partial cross-sectional view of a steering shaft according to the invention, wherein the inner shaft is located in an axially adjustable region;
FIG. 9: fig. 8 shows a partial cross-sectional view of a steering shaft according to the invention, but with the inner shaft in the energy absorption region.
Detailed Description
Fig. 1 and 2 show a steering column 1 according to the invention with a
The steering shaft 4 is rotatably placed in the
The load unit 3 is articulated on a vehicle chassis, not shown, by means of a
In order to fix the load unit 3 in the direction of rotation, a
To lock in the desired vertical position, the operating
Fig. 4 shows how the
In the radial region between the
The
If, in the event of a crash, the steering wheel, not shown, is displaced by a strong axial force in the direction of the
Fig. 9 shows the situation when the
The strength of the braking force can be adapted as desired by changing the number of raised
For production techniques, the raised
By means of the invention, the steering shaft can be equipped with an energy absorption device according to a general structural model in a simple and tolerance-insensitive manner.
List of reference numerals
1. Steering column
2. Servo unit
3. Load cell
4. Steering shaft
5. Outer shaft
6. Rotating shaft
7. Inner shaft
8. End point on one side of steering wheel
9. Ball bearing
10. Ball bearing
11. Ball bearing
12. Clamp apparatus
13. Operating rod
14. Turntable bearing
15. Support frame
16. Sliding block
17. Sliding block
18. Breach
19. Clamping bolt
20. Groove
21. Elongated slot
22. Contour shaft sleeve
23. Nose
24. Nose
25. Raised portion
26. Energy absorbing region
27. Adjustment area
28. Arrow head