METHOD FOR FASTENING A COVER ON AN ORIFICE OF A POWER STEERING SYSTEM AND SUCH A COVER

Abstract

A casing of a power steering system, including at least one fastening seat of a cover, the fastening seat delimiting an orifice, the cover being intended to seal the orifice, the fastening seat including a support wall for the cover, wherein the fastening seat also includes at least one elongation portion disposed outside the support wall, the elongation portion having at least one deformation area configured to be folded over the cover.

Claims

1. A casing of a power steering system, comprising at least one seat for fastening a cover, the fastening seat delimiting an orifice, the cover being intended to seal the orifice, the fastening seat comprising a support wall for the cover, wherein the fastening seat also comprises at least one elongation portion disposed outside the support wall, the elongation portion being provided with at least one deformation area configured to be folded over the cover.

2. The casing according to claim 1, wherein the fastening seat comprises an inner surface delimiting the orifice, the support wall extending in a direction substantially transverse to the inner surface.

3. The casing according to claim 2, wherein the elongation portion extends along a direction substantially parallel to the inner surface.

4. The casing according to claim 1, wherein the elongation portion continuously surrounds the support wall.

5. The casing according to claim 1, wherein the elongation portion comprises a plurality of deformation areas evenly distributed over the elongation portion.

6. An assembly comprising a casing according to claim 1, and a cover held on the orifice by means of at least one deformation area folded over the cover.

7. A method for fastening a cover on a fastening seat of a casing according to claim 1, the cover comprising a protective wall surrounded at least partially by a holding edge, the method comprising a step of inserting the cover into the orifice so that the holding edge of the cover is in contact with the at least one support wall, the method comprising a deformation step in which the at least one deformation area is folded over the holding edge.

8. The method according to claim 7, wherein the deformation step is carried out by means of a mechanical material folding method.

9. The method according to claim 7, wherein, during the deformation step, the deformation area is folded by exerting a pressure along a direction substantially parallel to the support wall.

10. The method according to claim 7, wherein, during the deformation step, the deformation area is folded by exerting a pressure along a direction substantially transverse to the support wall.

Description

[0044] The invention will be better understood, thanks to the description below, which relates to an embodiment according to the present invention, given as a non-limiting example and explained with reference to the appended schematic drawings, in which:

[0045] FIG. 1 is a perspective representation of a cover according to the state of the art;

[0046] FIG. 2 is a representation of a casing of a power steering system comprising the cover of FIG. 1;

[0047] FIG. 3 is a sectional view of the casing of the steering system after carrying out a step of inserting the cover according to the invention;

[0048] FIG. 4 is a perspective view of the casing of the steering system after carrying out a step of deforming the cover according to the invention;

[0049] FIG. 5 is a sectional representation of an enlargement of the casing according to FIG. 4.

[0050] The casing 1′ comprises an external wall 5′ which could be metallic or made of a rigid plastic material. It accommodates a gear mechanism not represented in the figures.

[0051] The mechanism is preferably a reduction gear comprising a reduction wheel and a worm screw which ensures a mechanical transmission between a steering assist motor and a moving member, such as a rack or a steering column. The steering column allows modifying the yaw direction (steering angle) of the steered wheels of the vehicle.

[0052] The casing 1′ comprises several fastening seats 2, 3, 4 comprising an inner surface 21′ delimiting an orifice which crosses the external wall 5′ of said casing 1′ to enable the introduction and assembly of all or part of the elements of the casing 1′. The fastening seats 2, 3, 4 have a substantially circular shape.

[0053] Next, we will focus more particularly on the cover 60 allowing sealing the orifice of the fastening seat 2 positioned on the reduction wheel.

[0054] The casing 1′ comprises the fastening seat 2 of the cover 60, the fastening seat 2 comprises the inner surface 21′ delimiting the orifice, a support wall 53 extending in a direction substantially transverse to the inner surface 21′ and an elongation portion 54 extending substantially along the direction of the inner surface 21′. The support wall 53 and the elongation portion 54 are formed in a thickness of the external wall 5′. The inner surface 21′ has no recess or depression. It is cylindrical.

[0055] The cover 60 comprises a substantially circular protective wall 603 having a diameter substantially equal to the diameter of the orifice 2. The protective wall 603 is prolonged in a plane in which the protective wall 603 extends by a holding edge 602. The holding edge 602 continuously surrounds the protective wall 603.

[0056] The protective wall 603 is surrounded by an insertion edge 601 which extends in a direction substantially transverse to the protective wall 603. The insertion edge 601 comprises a location 604 intended to receive an O-ring (not represented).

[0057] A method according to the invention for fastening the cover 60 on the orifice 2 comprises a step of inserting the cover 60 into the orifice of the fastening seat 2 as represented in FIG. 3. In this step, the cover 60 is introduced into the orifice so that the insertion edge 601 is in contact with the inner surface 21′ and that the holding edge 602 of the cover 60 is in contact with the support wall 53. Thus, the protective wall 603 completely covers the orifice.

[0058] A length of the cover 60 along a direction parallel to the protective wall 603 is strictly larger than a dimension of the orifice measured between two opposite inner surfaces 21′, and strictly smaller than a dimension of the orifice measured between two increased opposite inner surfaces 21′ of the elongation wall 54. In other words, the length of the cover 60 along a direction parallel to the protective wall 603 is strictly larger than a dimension of the orifice measured between two opposite inner surfaces 21′, is smaller than or equal to a dimension of the orifice measured between two support walls 53.

[0059] The method then comprises a deformation step. During this step, deformation areas 55 of the elongation portion 54 are crushed by means of an anvil along the direction of the inner surface 21′ towards the holding edge 602. The deformation areas 55 are evenly distributed over the circumference of the cover. Alternatively, the deformation areas could be continuous on the circumference of the cover 60. The deformation areas 55 have a square shape.

[0060] FIGS. 4 and 5 illustrate the casing 1′ after completion of the fastening method according to the invention.

[0061] Of course, the invention is not limited to the embodiment described and represented in the appended figures. Modifications are still possible, in particular with regards to the constitution of the various elements or by substitution with technical equivalents, yet without departing from the scope of protection of the invention.