WO2016116150A1

WO2016116150A1 - Steering assembly for an automotive vehicle and automotive vehicle comprising such a steering assembly

Info

Publication number: WO2016116150A1
Application number: PCT/EP2015/051157
Authority: WO
Inventors: Olivier CHEVÉ; Jérôme CARNAC
Original assignee: Aktiebolaget Skf
Priority date: 2015-01-21
Filing date: 2015-01-21
Publication date: 2016-07-28

Abstract

This steering assembly (A) for an automotive vehicle comprises a kingpin (2), a steering knuckle (4) pivotably mounted around the kingpin (2), a sensor unit (10) for sensing the angular position of the knuckle (4) with respect to the kingpin (2), comprising a target ring (100) coupled in rotation to the kingpin (2) and sensing elements (102) mounted in a sensing element holder (104) mounted on a printed circuit board (106), and a cover (8) screwed on the knuckle (4) so as to close an internal volume (V) in which an axial end (20) of the kingpin (2) extends. The sensing elements (102), the sensing element holder (104) and the printed circuit board (106) are mounted in a non-rotatable manner in the cover (8). The cover (8) comprising a shaft (87) extending in the interior volume (V) along a rotation axis (X-X') of the kingpin (2). The target ring (100) is mounted in a rotatable manner on the shaft (87) and comprises axially extending tongues (118) which cooperate in a sliding manner with a protruding portion (24) of the kingpin (2) so as to couple in rotation the target ring (100) to the kingpin (2).

Description

STEERING ASSEMBLY FOR AN AUTOMOTIVE VEHICLE AND AUTOMOTIVE VEHICLE COMPRISING SUCH A STEERING ASSEMBLY

TECHNICAL FIELD OF THE INVENTION

The invention relates to a steering assembly for an automotive vehicle. The invention also concerns an automotive vehicle, such as a truck, comprising such a steering assembly.

BACKGROUND OF THE INVENTION

Automotive vehicles, such as trucks, generally comprise a steering mechanism which includes a steering knuckle rotatably mounted with respect to a kingpin. In some applications, in particular for articulated trucks, in order to know the actual wheel angle of the steered wheel and to provide the driver with feedback information, a sensor unit is provided to control the angular position of the knuckle relative to the kingpin.

It is known from WO-A-2010/055370, to provide a steering assembly with a cover screwed on the knuckle. This cover contains some sensing elements and some processing means of the sensor unit, and comprises a shaft on which a target ring of the sensor unit is rotatably mounted. The target ring of the sensor unit is coupled in rotation to the kingpin.

Such a technique implies alignment issues between the kingpin and the shaft of the cover, because of the manufacturing tolerances and the centering of the thread of the cover. Moreover, this solution takes up an important space and is designed for a drum brake. Today disc brakes are more commonly used and offer less mounting space due to the brake calipers of the disc brake.

In addition, blind mounting is today requested to improve the mounting time and costs. Such an assembly cannot be blind mounted as it requests handling of some elements inside the knuckle.

SUMMARY OF THE INVENTION

The aim of the invention is to provide a new steering assembly whose mounting is easier and more accurate.

To this end, the invention concerns a steering assembly for an automotive vehicle, said steering assembly comprising a kingpin, a steering knuckle pivotably mounted around the kingpin, a sensor unit for sensing the angular position of the knuckle with respect to the kingpin, comprising a target ring coupled in rotation to the kingpin and sensing elements mounted in a sensing element holder mounted on a printed circuit board, a cover screwed on the knuckle so as to close an internal volume in which an axial end of the kingpin extends, the sensing element, the sensing element holder and the printed circuit board being mounted in a non-rotatable manner in the cover, the cover comprising a shaft extending in the interior volume along a rotation axis of the kingpin, the target ring being mounted in a rotatable manner on the shaft. This steering assembly is characterized in that the target ring comprises axially extending tongues which cooperate in a sliding manner with a protruding portion of the kingpin so as to couple in rotation the target ring to the kingpin.

Thanks to the invention, the target ring can be connected to the kingpin by sliding self-adjusting means which allows mounting the sensor unit as a unique element integrated in the cover without having to handle the connection of the kingpin with the target ring. Moreover, the mechanical connection with tongues permits to compensate for misalignments between the kingpin and the target ring.

According to further aspects of the invention which are advantageous but not compulsory, such a steering assembly may incorporate one or several of the following features:

- The free ends of the tongues comprise radial teeth which cooperate with ribs provided on the protruding portion of the kingpin, so as to couple in rotation the target ring to the kingpin and to allow a sliding movement of the target ring with respect to the kingpin along the rotation axis of the kingpin.

- The teeth of the free ends of the tongues comprise a chamfer on their side opposed to the cover.

- The ribs comprise a chamfer on their side oriented towards the cover.

- The protruding portion of the kingpin is provided on a pin mounted in a recess of the kingpin, and which comprises a radial surface on which the ribs are provided.

- The pin is press-fitted in a bore provided on a bottom of the recess of the kingpin.

- The target ring comprises a disc-shaped portion which joins, on its outer side, a magnetic ring, and on its inner side, a tubular portion mounted on the shaft of the cover, whereas the tongues extend from the disc-shaped portion remotely from the tubular portion.

-The target ring comprises four tongues.

The invention also relates to an automotive vehicle, such as a truck, comprising a steering assembly as mentioned here-above. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in reference to the annexed figures, as an illustrative example. In the annexed figures:

- figure 1 is a longitudinal sectional view of a steering assembly according to the invention,

- figure 2 is a view at a larger scale of detail II on figure 1 ;

- figure 3 is a perspective view of a target ring belonging to the steering assembly of figures 1 and 2,

- figure 4 is a partially sectioned perspective view of an end portion of a kingpin belonging to the steering assembly of figures 1 and 2,

- figure 5 is an exploded perspective view of a portion of the steering assembly of figure 1 ,

- figure 6 is an exploded perspective view, from a different angle, of a portion of the steering assembly of figure 1 .

DETAILED DESCRIPTION OF SOME EMBODIMENTS

A steering assembly A represented on figures 1 to 5, which may belong to an automotive vehicle such as a truck, includes a kingpin 2 and a steering knuckle 4 which supports a non-shown steered wheel. The steering knuckle 4 is pivotably mounted around the kingpin 2 which is considered to be fixed with respect to the truck chassis for this description. X-X' denotes the central longitudinal axis of the kingpin 2, which is also the rotation axis of the steering knuckle 4 with respect to the kingpin 2. At least one roller bearing 6 allows the pivoting movement of the steering knuckle 4 with respect to the kingpin 2 around axis X-X'.

In this description, the words "axial" and "radial" are used in reference to axis X-X'. An "axial surface" is a surface perpendicular to axis X-X', and a "radial surface" is a surface centered on axis X-X'.

According to a non-shown embodiment of the invention, the steering assembly A may comprise rolling bearings having rolling elements different from rollers, for example balls or needles.

Towards one end 20 of the kingpin 2, the steering assembly A comprises a cover 8 which is screwed on the steering knuckle 4. This cover 8 closes an internal volume V filled with a lubricant and in which the end 20 of the kingpin 2 extends. The cover 8 has a circular shape and comprises a tubular portion 81 having an outer threaded surface 83. The threaded surface 83 is screwed in an inner threaded surface 40 of the steering knuckle 4, so that the cover 8 is firmly and tightly fastened to the steering knuckle 4. In order to detect a rotation parameter, such as the angular position, of the steering knuckle 4 with respect to the kingpin 2, the steering assembly A comprises a sensor unit 10 which is mounted inside the internal volume V. The sensor unit 10 comprises a target ring 100 which is coupled in rotation to the kingpin 2, sensing elements 102 mounted in a sensing element holder 104 and processing means for handling the signals delivered by the sensing element 102, integrated in a printed circuit board 106 fixed to the holder 104. The sensing element 10, the holder 104 and the printed circuit board 106 are mounted in a non-rotatable manner in an annular cavity of the cover 8 extending between the tubular portion 81 and an internal tubular portion 85 of the cover 8.

The cover 8 comprises a shaft 87 which may be, as represented on figure 1 , an independent element non-removably fixed within the cover 8, which extends along the axis X-X' inside the interior volume. The shaft 87 may be a metallic part overmoulded in the cover 8. The target ring 100 is mounted in a rotatable manner on the shaft 87, thanks to non-shown means which may be one or more bearings, for example plain bearings.

The target ring 100 is formed by a disc shaped portion 1 10 which joins a tubular portion 1 12 provided on its outer side and on which a magnetic ring 1 14 is provided, and an inner tubular portion 1 16 located on the inner side of target ring 100, and which is mounted on the shaft 87. The magnetic ring 1 14 extends around the axis X-X' and is radially aligned with the sensing elements 102, which detects the magnetic field generated by the rotation of the target ring 100 through the internal tubular portion 85 of the cover 8.

The target ring 100 is retained on the shaft 87 thanks to a washer 89 and an elastic ring or circlip 90 mounted inside a groove of the shaft 87.

To implement the coupling in rotation of the target ring 100 with the kingpin 2, the target ring 10 comprises four axially extending tongues 1 18 which cooperate in a sliding manner with a protruding portion of the kingpin 2 so as to couple in rotation the target ring 100 to the kingpin 2. The free ends 1 18b of the tongues 1 18 comprise radial teeth 1 18b which cooperate with ribs 22 provided on the protruding portion of the kingpin 2. The protruding portion of the kingpin 2 is provided on a cylindrical pin 24 which is mounted in a recess 26 of the kingpin 2. The tongues 1 18 also extend in the recess 26. The pin 24 comprises a radial surface on which the ribs 22 are provided. As an optional feature, the pin 24 may be press fitted in a bore 27 provided on a bottom 28 of the recess 26. Alternatively, the pin 24 may be screwed in the bore 27.

The cooperation between the teeth 1 18b of the tongues 1 18 and the ribs 22 couple in rotation the target ring 100 to the kingpin 2 and allow a sliding movement of the target ring 100 with respect to the kingpin 2 along the rotation axis X-X'. When the sensor unit 10, which forms with the cover 8 a unique element, is to be mounted on the steering knuckle 4 and connected to the kingpin 2, an operator only needs to put the cover 8 in position in the threaded surface 40 and to start screwing the cover 8 in the threaded surface 40. Thanks to the fact that the target ring 10 is rotatable with respect to the cover 8, this screwing operation provokes the translation of the target ring 100 along axis X-X' along an arrow F1 , so that the teeth of the tongues 1 18 become meshed with the ribs 22 of the kingpin 2, thereby coupling in rotation the kingpin 2 with the target ring 100 without any intervention from an operator in the internal volume V of the steering assembly A. The sensor unit 10 can therefore be blind mounted in only one step by an operator, allowing a fast and low cost assembly.

According to an optional embodiment, the teeth 1 18b comprise a chamfer 1 18c on their side opposed to the cover 8, so that when the teeth 1 18b enter for the first time in contact with the ribs 22, the meshing cooperation between the ribs 22 and the teeth 1 18b is made easier and provokes less friction.

In the same way, as an optional embodiment, the ribs 22 comprise a chamfer 22a on their side oriented towards the cover 8, to further ease the cooperation between the ribs 22 and the teeth 1 18b.

The shape of the tongues 1 18 provide them with a relatively flexible property which permits to compensate for axial misalignments between the kingpin 2 and the target ring 100.

According to a non-shown embodiment of the invention, the target ring 100 may comprise only three tongues, or more than four tongues.

The features of the above disclosed embodiments and variants may be combined to form new embodiments of the invention.

Claims

1 . A steering assembly (A) for an automotive vehicle, said steering assembly comprising :

- a kingpin (2),

- a steering knuckle (4) pivotably mounted around the kingpin (2),

- a sensor unit (10) for sensing the angular position of the knuckle (4) with respect to the kingpin (2), comprising a target ring (100) coupled in rotation to the kingpin (2) and sensing elements (102) mounted in a sensing element holder (104) mounted on a printed circuit board (106),

- a cover (8) screwed on the knuckle (4) so as to close an internal volume (V) in which an axial end (20) of the kingpin (2) extends, the sensing elements (102), the sensing element holder (104) and the printed circuit board (106) being mounted in a non-rotatable manner in the cover (8), the cover (8) comprising a shaft (87) extending in the interior volume (V) along a rotation axis (Χ-Χ') of the kingpin (2), the target ring (100) being mounted in a rotatable manner on the shaft (87),

wherein the target ring (100) comprises axially extending tongues (1 18) which cooperate in a sliding manner with a protruding portion (24) of the kingpin (2) so as to couple in rotation the target ring (100) to the kingpin (2).

2. Steering assembly according to claim 1 , wherein the free ends (1 18a) of the tongues (1 18) comprise radial teeth (1 18b) which cooperate with ribs (22) provided on the protruding portion (24) of the kingpin (2), so as to couple in rotation the target ring (100) to the kingpin (2) and to allow a sliding movement of the target ring (100) with respect to the kingpin (2) along the rotation axis (Χ-Χ') of the kingpin (2).

3. Steering assembly according to claim 2, wherein the teeth (1 18b) of the free ends (1 18a) of the tongues (1 18) comprise a chamfer (1 18c) on their side opposed to the cover

(8).

4. Steering assembly according to any of claims 2 and 3, wherein the ribs (22) comprise a chamfer (22a) on their side oriented towards the cover (8).

5. Steering assembly according to any of claims 2 to 4, wherein the protruding portion of the kingpin (2) is provided on a pin (24) mounted in a recess (26) of the kingpin (2), and which comprises a radial surface on which the ribs (22) are provided.

6. Steering assembly according to claim 5, wherein the pin (24) is press-fitted in a bore (27) provided on a bottom (28) of the recess (26) of the kingpin (2).

7. Steering assembly according to any preceding claim, wherein the target ring (100) comprises a disc-shaped portion (1 10) which joins, on its outer side, a magnetic ring (1 14), and on its inner side, a tubular portion (1 16) mounted on the shaft (87) of the cover (8), and wherein the tongues (1 18) extend from the disc-shaped portion (1 10) remotely from the tubular portion (1 16).

8. Steering assembly according to any preceding claim, wherein the target ring (100) comprises four tongues (1 18).

9. An automotive vehicle, such as a truck, comprising a steering assembly (A) according to one of the previous claims.