WO2013120969A1

WO2013120969A1 - Support bearing with spring element

Info

Publication number: WO2013120969A1
Application number: PCT/EP2013/053019
Authority: WO
Inventors: Jens-Hauke MÜLLER; Alexander Kogan; Sven Kirschbaum
Original assignee: Tedrive Steering Systems Gmbh
Priority date: 2012-02-14
Filing date: 2013-02-14
Publication date: 2013-08-22
Also published as: DE102012101147A1

Abstract

The invention relates to a support bearing (1) for the mounting of a steering column (13) in a steering housing (14), having: a support bearing body (2) which has a central aperture (6), which defines an inner wall (5), for receiving the steering column (13) so as to enable the steering column (13) to be moved relative to the steering housing (14) by means of a steering gear (12), and an outer wall (4) for abutment against the steering housing (14); and at least one spring element (3, 3'), which is arranged between the inner wall (5) and outer wall (4), for supporting the steering column (13) with an elastic restoring action in at least one main spring direction perpendicular to the inner wall (5).

Description

Designation: Support bearing with spring element

The invention relates to a support bearing for a steering of a motor vehicle and an associated steering gear. Steering gears have an essentially tubular steering housing, a steering rod displaceably guided in the steering housing by means of at least two support bearings, and a transmission in order to effect a rotating steering movement into an axial movement of the steering rod via its gear engagement. Steering gears are used in motor vehicles to convert the applied over the steering wheel rotating steering movement in a rectilinear movement for pivoting the vehicle wheels to be steered. To assist steering this case, a servo drive can be used, which can be arranged at suitable locations within the steering power flow.

Conventional steering gear are designed as so-called rack and pinion steering. In the rack and pinion steering, the end of the steering column is connected to a pinion, which engages in the teeth of the handlebar, which is also called rack, and this moves laterally when turning the steering. At each end of the rack, a tie rod is connected via a ball joint. The simple construction has ensured the widespread use of rack and pinion steering. Rack and pinion steering has good feedback and very good resilience. It is known to provide a thrust piece to bias the engagement of the transmission components so that wear-related play between these components is prevented. For example, the pressure piece is screwed by spring force in a cylindrical pressure piece seat of the steering housing and it acts in the installed position under spring tension with its front contact surface on the outer surface of the handlebar so that the handlebar is pressed with its teeth against the pinion. Such plungers increase the design complexity of the steering gear, increase the effort in the assembly of the steering gear, increase the weight and the overall volume and can be disadvantageous cause of undesirable noise during steering. There is therefore a need for a steering gear in which the gear engagement, for example, the engagement between the pinion and the toothing of the handlebar, comparatively structurally simple can be set under bias and in particular can be adjusted, in particular at the same time advantageous removal of a pressure piece or the like.

The object of the present invention is therefore to be able to reduce the assembly costs, the costs, the overall volume and also the weight for a steering gear while still causing a preloaded engagement of the associated transmission components and in particular to be able to adjust these, in particular by omission of a pressure piece, also called sliding block. This object is achieved by a support bearing according to claim 1. A correspondingly advantageous steering gear and its use in a motor vehicle are each subject of the independent claims. Advantageous embodiments are the subject of the dependent claims. It should be noted that the features listed individually in the claims can be combined with each other in any technologically meaningful manner and show further embodiments of the invention. The description, in particular in connection with the figures, additionally characterizes and specifies the invention.

The support bearing according to the invention is provided for the storage of a handlebar in a steering housing. The support bearing comprises a support bearing body with an opening defining an inner wall for receiving the handlebar. For example, the aperture is arranged to penetrate at least the geometric center of the support bearing. The support bearing body may have various configurations of the inner wall. For example, the cross-sectional shape of the aperture defined by the inner wall is adapted to the cross section of the handlebar, for example, both have a circular cross section. In another embodiment, the cross section defining the inner wall is drop-shaped, ie. partially V-shaped with a part-circular transition between the legs of the V. The breakthrough is provided in order to move the handlebar relative to the steering housing by means of a steering gear can. The outer wall of the support bearing body is generally positively against the steering housing to support the handlebar via the support bearing on the steering housing. The support bearing according to the invention is characterized in that, between the inner wall and the outer wall, at least one spring element for elastically restoring support of the handlebar is arranged in at least one of the inner wall, preferably radially. directed, main spring direction has. "Spring element" in the sense of the invention is to be interpreted broadly, and thus comprises a separate spring element inserted into the support bearing material and a spring element provided by a special shaping of the support bearing made of the material of the support bearing In addition, means for limiting the spring travel, such as beads or the like can be provided.

The separate spring element is for example made of elastomer, rubber, such as synthetic or natural rubber, in particular vulcanized rubber. According to a preferred embodiment, the spring element is made of a spring steel.

Due to the resilient properties of the spring element occurring during operation of the steering gear motion fluctuations between the pinion and handlebar (dynamic tolerances), which are caused mainly by manufacturing tolerances can be compensated, so that whipping noise after lifting the handlebar of the pinion through will be caused later, if not avoided so at least be mitigated.

According to a further embodiment, a plurality of spring elements per main spring direction are provided. For example, two spring elements are provided. Due to the mating according to the invention, the total spring action per main spring direction is modulated by the spring retention of the individual spring elements. For example, we the overall spring behavior result from the mating of spring elements with a linear spring behavior but different elasticity in a non-linear spring behavior

In a variant thereof, for example, a separate spring element and one integral with the support bearing body spring element is provided per main spring direction. Preferably, the integrally formed with the support bearing body spring element is in the radial direction of the support bearing innermost of the at least two spring elements per main spring direction. Preferably, the at least one spring element is arranged so that the elastically restoring support has a preferred direction with respect to the radial directions of the support bearing, for example, because the spring element does not extend fully around the inner wall. Due to the preferred direction, the direction of the elastic support can be preset or adjusted by turning the support bearing.

According to a preferred embodiment, the inner wall is arranged eccentrically to the outer wall. This means, for example, that the geometric center of the inner wall cross-section does not coincide with the geometric center of the Außenwandungsquerschnitts. Due to the eccentricity a displacement possibility of the handlebar with respect to the steering housing by turning the support bearing is made possible to adjust the engagement of the transmission by the rotation of the support bearing and optionally the contact pressure by means of the spring element. By means of an eccentric breakthrough, it is possible to ensure manufacturing tolerances, dimensional tolerances by the different components and thus adjustability required for mounting in a steering gear, especially at the same time omitting a pressure piece or sliding block and its mounting means.

The arrangement of the spring element in the circumferential direction is not necessarily fixed, for example, it is arranged so that its main spring direction is on the line connecting the two geometric centers so on the direction of eccentricity. The spring element is arranged offset according to a further variant about 90 ° to the eccentricity in the circumferential direction.

The arrangement of the spring elements in the circumferential direction with respect to the eccentricity will be chosen according to a preferred variant, that results in an optimal variation of the contact pressure based on a statistically to be determined average rotational position of the support bearing, which is determined over several assembly and adjustment processes.

For simplicity, the average position between maximum and minimum engagement between the handlebar and pinion is considered as the average rotational position. When using two spring elements, these are arranged so that their main spring direction by the connecting line of the two middle points defined axis (Exzentrizitätsrichtung) at an angle in the range of 45 ° to 90 ° intersects.

The spring element defined according to a preferred embodiment, at least partially the inner wall. D.h. the spring element is thus arranged adjacent to the outer circumference of the handlebar, thus abuts against the handlebar. In this case, the spring element is preferably formed integrally with the support bearing body, which has the advantage that in the sliding relative movement between the support bearing and rack, the spring element can be separated from the support bearing difficult. For example, this spring element as the support bearing body to improve the sliding properties between the support bearing and rack made of plastic.

According to a further advantageous embodiment, means are also provided,

Preferably, a cavity in the support bearing body is arranged between the spring element and outer wall to ensure a controlled, defined yielding of the spring element. In this cavity may further be used a damping element to dampen the stop of the spring element to the boundary of the cavity.

To reduce the sliding friction is in accordance with a further advantageous embodiment in the support bearing body, an inner wall of the opening at least partially defining sliding insert, for example made of plastic, used.

Furthermore, to reduce the manufacturing cost of the support bearing body is at least partially made of plastic.

The spring element is designed for example as a leaf spring, corrugated spring or plate spring. The spring element may be formed as a separate component which can be inserted into the support bearing body. Preferably, however, the spring element and the support bearing body are integrally formed.

According to a further preferred embodiment, the support bearing comprises at least two circumferentially offset spring elements. This can be done by Aligning the support bearing, in particular by rotating the support bearing of the support bearing used in the steering housing, the spring action can be adjusted. Preferably, the main spring direction intersect at an angle of 90 °.

The function of the support bearing according to the invention is not limited to the support function of the rack, but can also serve the impact (lock stop) of the sliding movement of the rack. Preferably, the at least one spring elements additionally serves the elastic impact of the sliding movement of the rack.

The invention further relates to a steering gear, which has a substantially tubular steering housing, a steering rod displaceably guided in the steering rod and a transmission in order to effect via its gear engagement a rotating steering movement in an axial movement of the handlebar.

The steering gear according to the invention is characterized by at least one, for example one or two, support bearing for the mounting of the handlebar in the steering housing in one of the previously described embodiments. Preferably, the transmission comprises a handlebar side toothing and a pinion meshing therewith.

The steering gear according to the invention is not limited in terms of the technical design and the nature of the transmission, preferably the transmission comprises a pinion arranged in the so-called pinion tower of the steering housing and a toothing arranged on the handlebar side. According to the invention, the steering gear can have no as well as one, for example an electromechanical, power assistance. For example, a hydraulic power assisting gear is provided. Steering gears with a hydraulic support have a mechanical range and a hydraulic range of the steering box. The mechanical area is the area in which the area of the rack moves, which is provided with teeth and which engages with the pinion. The pinion engagement area is thus located in the mechanical area of the steering housing. By contrast, the hydraulic region is the region in which the toothed rack also extends but usually has no toothing. Within the hydraulic range is the Rack connected to a displaceably mounted piston element, on whose end faces each have a cylinder chamber is formed. Upon rotation of the steering wheel of the vehicle, a control valve is actuated so that pressure oil flows into each one of the cylinder chambers, whereby the piston and thus the rack in the cylinder experiences a force that displaces the rack supportive. The displacement of the piston due to the pressure oil serves as a force reinforcement for the rack movement. For this purpose, the control valve and the rack housing are connected to each other via hydraulic lines, so that depending on the direction of rotation of the steering wheel one or the other cylinder chamber can be acted upon with pressure oil.

In one embodiment of the steering gear according to the invention, the support bearing described above in one of the embodiments described above replaces a so-called sliding block, ie a biased, in sliding contact with the steering rod support of the steering rod in the engagement between the steering pinion and handlebar to bias the engagement.

The invention further relates to an advantageous for the aforementioned reasons use of the steering gear in a motor vehicle.

The invention will be explained in more detail with reference to the following figures. The figures are to be understood as exemplary only and represent only preferred embodiments. The respective reference numerals of the embodiments have been retained in functional identity of the relevant component. Show it :

Fig. 1 is a sectional view of a first embodiment of the support bearing according to the invention;

Fig. 2 is a side view of a second embodiment of the support bearing according to the invention;

3 shows a side view of a third embodiment of the support bearing according to the invention;

Fig. 4 is a sectional view of a steering gear (10) with the third embodiment of the support bearing of Fig. 3;

5 shows a perspective view of the third embodiment of the support bearing according to the invention from FIG. 3; 6a shows a side view of an insertable into the opening 9 of the support bearing 1 according to the figures 1 to 5, additional spring element 3 ^λ ;

Fig. 6b is a plan view of the additional spring element 3 ^λ of FIG. 6a;

7 shows a side view of a fourth embodiment of the support bearing according to the invention;

8 shows a perspective view of the fourth embodiment of the support bearing according to the invention from FIG. 7;

9 shows a side view of a fifth embodiment of the support bearing according to the invention;

Fig. 10 shows a curve of the rotational position-dependent contact force between the handlebar and pinion.

Fig. 11 is a sectional view of an arrangement of a rack, a steering housing and a support bearing according to the invention in a sixth embodiment.

FIG. 1 shows a first embodiment of the support bearing 1 according to the invention. This has a support bearing body 2 with a central opening 6. The support bearing body 2 is positively received in a steering housing, not shown, wherein the outer periphery 4 comes to rest on the inner wall of the steering housing. In the opening 6 of the support bearing body is a sliding insert 7, for example made of a plastic, used to reduce friction. The defined by the sliding insert 7 of the support bearing body opening 6 serves to receive a handlebar, not shown, which is slidably received in the steering housing, not shown. The outer circumference 4 of the support bearing body 2 is adapted to the shape of the inner cross section of the steering housing, for example, the support bearing body 2 is elliptical or circular. The inner wall 5 is offset according to the figure 1 with a horizontal eccentric offset to the outer wall 4, wherein the eccentric offset refers to the geometric center of the outer wall 4 and the inner wall 5. Laterally to this direction of eccentricity, a spring element 3 is arranged in the form of a leaf spring made of spring steel, whose main spring direction perpendicular to FIG. 1 runs. By turning the support bearing body in the steering housing, for example, for adjustment after assembly and before the determination of the support bearing in the steering housing, can be through the eccentric arrangement of the handlebar in the support bearing body, the handlebar to the pinion pivot and simultaneously bias by building a contact force by means of the spring element 3 due to its elastic supporting effect.

2 shows a second embodiment of the support bearing 1 according to the invention, wherein the support bearing body 2 is annular and has an offset with respect to the outer wall 4 eccentric aperture 6. With regard to the eccentricity with the eccentricity X, which is perpendicular in FIG. 2, the spring element 3 is arranged laterally, ie offset in the circumferential direction by approximately 90 °. The leaf spring-shaped spring element 3 is formed integrally with the support bearing body 2 and results as an inner web, which is defined by the provided between the outer wall 4 and inner wall 5 opening 9. Again, by the rotation of the support bearing 1 in the steering housing, not shown, the engagement of the steering gear but due to the spring element 3, the bias is set. In order to allow the application of a tool for the twisting, associated recesses 8 are provided on the support bearing body 2. In the opening 9 of the support bearing body 2, a further separate spring element 3 ^λ can be used, as shown for example in Figures 6a and 6b.

3 shows a third embodiment of the support bearing 1 according to the invention, which differs essentially only from the second embodiment described above, that the leaf spring-shaped spring element 3 has been replaced by two, one-sided with the support bearing body integrally connected, a free end having leaf springs. Again, in the opening 9 another, separate spring element, as shown for example in Figures 6a and 6b, if necessary, be used. In the following, a further description of functionally identically acting components is dispensed with and reference is hereby made to the above description in this regard.

FIG. 4 shows the steering gear 10 according to the invention with a support bearing in the third embodiment according to the invention, as known from FIG. The support bearing body 2 is received positively in the steering housing 14, wherein the outer periphery 4 comes to rest on the inner wall of the steering housing 14. The defined by the support bearing body 2 opening 6 serves to receive a handlebar 13, which is slidably received on the support bearing body 2 in the steering housing 14. The outer circumference 4 of the support Bearing body 2 is adapted to the shape of the inner cross section of the steering housing 14. The inner wall 5 is offset according to the figure 4 with a horizontal eccentric offset relative to the outer wall 4, wherein the eccentric offset refers to the geometric centers of the outer wall 4 and the inner wall 5. Laterally to this direction of eccentricity two spring element 3 are formed in the form of two leaf springs whose main spring direction extend horizontally in Fig. 1. The steering housing 14 has a pinion tower 11. In the pinion tower 11 which is rotatably driven by the steering column pinion 12 is arranged, which is in gear engagement with the not shown in Figure 4 toothing of the handlebar 13. By rotating the support bearing body 2 relative to the steering housing 13 can be through the eccentric arrangement of the handlebar 13 in the support bearing body 2, the handlebar 13 pivot on the pinion 12 and simultaneously bias by building a contact force by means of the spring elements 3 due to their elastic supporting effect.

5 shows the third embodiment of the support bearing 1 according to the invention in a perspective view. In this view, the defined by a cross-sectional expansion of the outer peripheral surface bead 18 can be seen, which ensures a positional fixation in the axial direction of the support bearing 1 in the steering housing, not shown.

FIG. 7 shows a further, fourth embodiment of the support bearing 1 according to the invention that differs from the embodiment shown in FIG. 2 in that a plurality of spring elements 3 arranged offset by approximately 90 ° are provided whose main spring directions are at an angle of 90 ° to cut. The openings 9 between the spring elements 3 and the outer wall 4 can in turn, if necessary, be equipped with additional, separate, not shown in Figure 7 spring elements, as shown for example in Figures 6a and 6b. 8 shows the fourth embodiment in associated perspective view.

A fifth embodiment of the support bearing 1 according to the invention is shown in FIG. This is based on the fourth embodiment and takes up the specific embodiment of the spring elements of Figures 3 to 5. The fifth embodiment thus comprises two spring element pairs 3, each pair, two integrally formed with the support bearing body 2, each having a free end on includes pointing leaf springs. The pairs are arranged offset by about 90 ° to each other, wherein the main spring direction intersect the direction defined by the eccentricity at an angle of 45 °.

In Figure 10, the curve of the contact pressure, more precisely its normal component, the handlebar in the direction of pinion in dependence on the rotational position of the support bearing is applied. The dotted line corresponds to the force curve of the third embodiment, wherein the O-degree representation corresponds to the middle position between maximum and minimum engagement due to the eccentric mounting of the rack. By rotating the support bearing in the positive direction to 5 °, 10 °, 15 ° .... due to the eccentricity of the engagement increases or the engagement clearance is reduced, upon rotation in the other direction, the engagement is reduced or dissolved. At the same time, the offset by 90 ° to the eccentricity arranged spring element increases the contact pressure. A maximum of the normal component of the contact force is reached at about 20 °. Thereafter, the contact force of the rack falls back on the pinion, although the distance between the pinion and handlebar due to the eccentricity is further reduced.

The dashed line shows this in comparison the course of the contact pressure, more precisely its normal component (based on the engagement between the handlebar and pinion), the handlebar in the direction of pinion in dependence of the rotational position of the fifth embodiment of the support bearing. Due to the two offset by 90 ° spring elements results in relation to the dotted graphs an overall flatter course with a higher angle of rotation shifted maximum. By using the two circumferentially offset spring elements thus results in a wider range of adjustment for the contact force with almost constant maximum force. By dividing the force in two directions, this can be adjusted so that the Normalkompenente is reduced, so as to reduce the frictional forces during the sliding movement of the handlebar in the support bearing over a spring elementless support bearing. An oblique force acting on the engagement between the handlebar and the pinion also has the advantage that when external impulse action on the handlebar this no longer removed in the normal direction from the engagement with the pinion, but along the resulting direction of force, ie obliquely. A part of the acting force is therefore absorbed by the other force component, which is vertical to the normal direction, and thus reduces the rebounding momentum. ment and thus also the impact sound at reunion of the components rack and pinion.

11 shows an arrangement of a steering housing 14, a steering rod 13 and a further embodiment of the support bearing 1. This support bearing 1 comprises a support bearing body 2 made of plastic and two pairs of spring elements 3, 3 "f .. The support bearing body 2 is in the steering housing 14 The central opening 5 serves to receive and slide the steering rod 13. The steering rod 13 is mounted eccentrically in the steering housing 14 by the support bearing 1. Means are provided for relative rotatability of the support bearing 1 in the steering housing 14, wherein the support bearing 1 remains fixed at least in the axial direction of the steering housing 14. Means may also be provided for preventing the support bearing 1 from rotating in the steering housing 14. Each pair of spring elements 3, 3 "comprises an inner fitting to and integral with the rack 13 Support bearing body 2 formed spring element. 3 and an outer separate spring element 3 "made of spring steel, which is bent opposite to the loading direction. The inner spring element 21 has a region 21 which is adapted to the contour of the outer circumference of the steering rod 13 in each case in the area of contact with the steering rod 13. There is a cavity 9 between the separate spring element 3 "and The outer circumferential circumference of the support bearing body 2 defining the free spring travel of the outer spring element 3 "A damping element 20 arranged in the cavity 9 serves for impact damping The main spring direction of each pair 3, 3" intersects the axial course of the steering rod perpendicularly, with the main spring directions of the pairs relative to each other stand vertically. With rotation of the support bearing body 1, the direction of the resultant is rotated from the two main spring direction. The direction of the resultant varies with respect to the engagement between the handlebar 13 and pinion. Due to the eccentric arrangement of the handlebar 13 in the steering housing 14 varies simultaneously with the rotation of the support bearing 2, the engagement or the bias of the engagement between the handlebar 13 and pinion.

Claims

claims

1. Support bearing (1) for the storage of a handlebar (13) in a steering housing (14) comprising: a support bearing body (2) defining an inner wall (5) opening (6) for receiving the handlebar (13) to the Handlebar (13) relative to the steering housing (14) by means of a steering gear (12) to move, and an outer wall (4) for abutment with the steering housing (14); at least one between the inner wall (5) and outer wall (4) arranged spring element (3, 3 ^λ ) for elastically restoring support of the handlebar (13) in at least one of the inner wall (5) perpendicular main spring direction.

2. Support bearing (1) according to the preceding claim with at least two circumferentially offset spring elements (3).

3. Support bearing (1) according to the preceding claim, wherein the main spring directions of the offset spring elements (3) are at an angle of 90 ° to each other.

4. Support bearing (1) according to one of the preceding claims, wherein the at least one spring element (3, 3 ^λ ) is arranged so that the elastically restoring support has a preferred direction with respect to the radial directions of the support bearing.

5. Support bearing (1) according to one of the preceding claims with a plurality of cooperating spring elements (3, 3 ") per main spring direction.

6. Support bearing (1) according to one of the preceding claims, wherein the inner wall (5) is arranged eccentrically to the outer wall (4).

7. Support bearing (1) according to one of the preceding claims with means for rotatable mounting of the support bearing (1) relative to the outer wall of the steering housing.

8. Support bearing (1) according to one of the preceding claims, wherein the spring element (3) at least partially defines the inner wall.

9. Support bearing (1) according to one of the preceding claims, wherein between spring element (3) and outer wall (4) in the support bearing body (2) has a cavity (9) is arranged.

10. Support bearing (1) according to one of the preceding claims, wherein the at least one spring element (3 ^λ ) is made of a spring steel.

11. Support bearing (1) according to one of the preceding claims, wherein the support bearing body (2) comprises an inner wall (5) of the opening (6) at least partially defining sliding insert (7), for example made of plastic.

12. Support bearing (1) according to one of the preceding claims, wherein the support bearing body (2) is at least partially made of plastic.

13. Support bearing (1) according to one of the preceding claims, wherein the spring element is designed as a leaf spring (3, 3 ^λ ), corrugated spring or disc spring.

14. Support bearing (1) according to one of the preceding claims, wherein the spring element (3) and the support bearing body (2) are integrally formed.

15. Steering gear (10) comprising: a substantially tubular steering housing (14), a in the steering housing (14) displaceably guided steering rod (13), a transmission (12), via the gear engagement a rotating steering movement in an axial movement of the handlebar (13) in the steering housing (14), and at least one support bearing (1) for the mounting of the steering rod (13) in the steering housing (14) according to one of the preceding claims.

16, steering gear according to the preceding claim, wherein the transmission comprises a handlebar side toothing and a pinion engaged therewith.

17. Use of the steering gear (10) according to one of the two preceding claims in a motor vehicle.