Method for fixing a cover on an orifice of a power steering system

Abstract

A method for fixing a cover on an orifice of a power steering system including a step of approaching the cover to the orifice, characterized in that it includes a step of inserting at least one extension of the cover in at least one recess positioned next to the orifice and a step of deforming the at least one elongation of the cover.

Claims

1. A method for fixing a cover on an orifice of a power steering system comprising: a step of approaching the cover to the orifice; a step of inserting at least one extension of the cover in at least one recess positioned next to the orifice; and a step of deforming the at least one extension of the cover, wherein the deformation step further includes an at least partial melting phase of the at least one extension of the cover.

2. The method according to claim 1, wherein the deformation step further includes a positioning phase in which an anvil is placed in contact with an edge of a protective wall of the cover facing a first end of the at least one extension and a deforming element is placed in contact with a second end of the at least one extension.

3. The method according to claim 1, wherein the deformation step further includes a bending phase of the at least one extension, the bending phase being carried out before the insertion step.

4. A cover configured to be fixed to an orifice of a power steering system by implementing the method according to claim 1, the cover comprising: a protective wall at least partially surrounded by an edge, the at least one extension being irreversibly connected to the edge.

5. The cover according to claim 4, wherein the at least one extension extends along an orthogonal axis to a plane along which the protective wall extends.

6. The cover according to claim 4, wherein the cover is made of a material from: poly(butylene terephthalate), or polypropylene.

7. The cover according to claim 4, wherein the at least one extension has a length greater than a length of the at least one recess into which the at least one extension is configured to be inserted.

8. The cover according to claim 4, wherein the at least one extension includes two elements extending parallel to one another.

9. The cover according to claim 4, wherein one end of the at least one extension includes a protrusion.

10. The cover according to claim 4, wherein the at least one extension includes at least two legs connected to a free end of a rod.

Description

(1) The invention will be better understood from the description below, which relates to several embodiments according to the present invention, given by way of non-limiting examples and explained with reference to the appended schematic drawings, in which:

(2) FIG. 1 is a representation of a housing of a power steering system according to the state of the art;

(3) FIG. 2 is a perspective representation of a step of approaching a cover according to a first embodiment to an orifice of a housing of a steering system;

(4) FIG. 3 is a sectional view of the housing of the steering system after carrying out a step of inserting the cover according to the first embodiment;

(5) FIG. 4 is a sectional view of the housing of the steering system after carrying out a step of deforming the cover according to the first embodiment;

(6) FIG. 5 is a perspective representation of a step of approaching a cover according to a second embodiment to an orifice of a housing of a steering system;

(7) FIG. 6 is a sectional view of the housing of the steering system after carrying out a step of inserting the cover according to the second embodiment;

(8) FIG. 7 is a perspective representation of a step of approaching a cover according to a third embodiment to an orifice of a housing of a steering system;

(9) FIG. 8 is a sectional view of the housing of the steering system after carrying out a step of inserting the cover according to the third embodiment.

(10) The invention relates generally to a housing 1′, 1″ of a power steering system of a motor vehicle.

(11) The housing 1′, 1″ includes an external wall 5′, 5″ which can be metallic or made of a rigid plastic material. It accommodates a gear mechanism not represented in the figures.

(12) The mechanism is preferably a reducer comprising a reduction wheel and a worm screw which ensures a mechanical transmission between a steering assistance motor and a movable member, such as a rack or a steering column. The steering column allows changing the yaw orientation (steering angle) of the vehicle steered wheels.

(13) The housing 1′, 1″ comprises several access orifices 2, 3, 4 which pass through the external wall 5′, 5″ of said housing 1′, 1″ to allow an introduction and an assembly of all or part of the housing 1′, 1″ elements. The orifices 2, 3, 4 have a substantially circular shape.

(14) Thereafter, we will focus more particularly on the cover 6′, 6″ allowing to close the orifice 4 positioned on the reduction wheel.

(15) A first embodiment of the invention is illustrated more particularly by FIGS. 2, 3 and 4.

(16) In this embodiment, the housing 1′ comprises two recesses 9′ of substantially circular section. They are positioned diametrically opposite next to the orifice 4. The recesses 9′ are not combined with the orifice 4. The recesses 9′ pass through a thickness of the external wall 5′ of the housing 1′. They are therefore through-going recesses.

(17) The cover 6′ according to the first embodiment comprises a substantially circular protective wall 61 having a diameter substantially equal to the diameter of the orifice 4. The protective wall 61 is extended in a plane in which the protective wall extends 61 by an edge 62.

(18) The edge 62 surrounds the protective wall 61 and comprises two portions 63 positioned diametrically opposite relative to the protective wall 61. Each portion 63 comprises an extension 64′.

(19) The extension 64′ is irreversibly fixed to the portion 63. More specifically, the cover 6′, comprising the protective wall 61, the edge 62 and the extensions 64′, is produced in a single material injection operation. The extension 64′ has a substantially cylindrical shape having a diameter substantially equal to a diameter of the recess 9′ into which it is intended to be inserted. The extension 64′ extends along an axis orthogonal to the plane in which the protective wall 61 extends. The extension 64′ has a length greater than the length of the recess 9′ in which it is intended to be inserted.

(20) The two extensions 64′ are positioned on the same face of the cover 1′, hereinafter called inner face. So that the two extensions 64′ can be inserted into the corresponding recess 9′.

(21) A method for fixing according to the invention the cover 6′ on the orifice 4 comprises a step of approaching the cover 6′ to the orifice 4 as represented in FIG. 2. In this step, the cover 6′ is positioned away from the housing 1′, facing the orifice 4. More precisely, the inner face of the cover 6′ is positioned facing the orifice 4 so that the extensions 64′ are each facing a recess 9′.

(22) Then, a step of inserting the extensions 64′ of the cover 6′ into the recesses 9′ is carried out. When the insertion step is complete, the protective wall 61 covers the orifice 4 and the edge 62 is in contact with the external wall 5′ of the housing 1′.

(23) Furthermore, each extension 64′ is positioned in a recess 9′ as represented in FIG. 3. Each extension 64′ protrudes from the corresponding recess 9′.

(24) The fixing method then comprises a step of deforming the extensions 64′, and more precisely, a positioning phase and then a melting phase.

(25) During the positioning phase, an anvil is placed in contact with the portion 63 of the cover 6′. Thus, the anvil is positioned on one face of the cover 1′ opposite to the inner face.

(26) Furthermore, a deforming element is positioned in contact with a free end of the extension 64′, that is to say the end which has passed through the recess 9′.

(27) During the melting phase, the deforming element on the one hand increases the inner energy of the extension 64′ so as to make the extension 64′ liquid, and on the other hand exerts pressure on the extension 64′ towards the anvil so that the length of the extension 64′ is reduced and that a head 65′ is created at the extension 64′.

(28) The head 65′ has a substantially circular shape with a diameter greater than the diameter of the recess 9′. The head 65′ is in contact with the outer wall 5′ of the housing 1′.

(29) After cooling, the head 65′ hardens and can no longer pass through the recess 9′. Thus, the head 65′ prevents a withdrawal of the extension 64′ from the recess 9′ and therefore a withdrawal of the cover 6′ from the orifice 4.

(30) The deformation step is carried out on the two extensions 64′ simultaneously or on the contrary successively.

(31) A second embodiment of the invention is illustrated more particularly by FIGS. 5 and 6.

(32) In this embodiment, the housing 1″ comprises two recesses 9″ of substantially square or circular section. They are positioned diametrically opposite next to the orifice 4. The recesses 9″ are not merged with the orifice 4. The recesses 9″ pass through a thickness of the outer wall 5″ of the housing 1″. They are therefore through-going recesses.

(33) The cover 6″ according to the second embodiment comprises a substantially circular protective wall 61 having a diameter substantially equal to the diameter of the orifice 4. The protective wall 61 is extended in a plane in which the protective wall 61 extends by an edge 62.

(34) The edge 62 surrounds the protective wall 61 and comprises two portions 63 positioned diametrically opposite relative to the protective wall 61. Each portion 63 comprises an extension 64″.

(35) The extension 64″ is irreversibly fixed to the portion 63. More specifically, the cover 6″, comprising the protective wall 61, the edge 62 and the extensions 64″, is made in a single injection material operation. The extension 64″ extends along an axis orthogonal to the plane in which the protective wall 61 extends. The extension 64″ has a length slightly greater than the length of the recess 9″ in which it is intended to be inserted. The extension 64″ comprises a first element 67 and a second element 66 extending parallel to each other. The first element 67 has a smooth surface. The second element 66 comprises, at a free end, that is to say the end opposite an end in contact with the edge 62, a protrusion 65″.

(36) The protrusion 65″ comprises a relief angle α, that is to say an angle formed between an axis X transverse to the elongation axis of the extension and an edge of the protrusion 65″. The relief angle α is comprised between 5° and 15°.

(37) The two extensions 64″ are positioned on the same face of the cover 1″, hereinafter called the inner face. So that the two extensions 64″ can be inserted in the corresponding recess 9″.

(38) A method for fixing according to the invention the cover 6″ on the orifice 4 comprises a step of approaching the cover 6″ to the orifice 4 as represented in FIG. 5. In this step, the cover 6″ is positioned away from the housing 1″, facing the orifice 4. More precisely, the inner face of the cover 6″ is positioned facing the orifice 4 so that the extensions 64″ are each facing a recess 9″.

(39) Then a step of deforming the extensions 64″ is carried out and more precisely a bending phase. In said bending phase, the two elements 66, 67 of each extension 64″ are elastically brought together. To carry out this bending step, a force is exerted on the two elements 66, 67 of each extension 64″. The deformation step is simultaneously carried out on the two extensions 64″.

(40) After the deformation step, a step of inserting the extensions 64″ of the cover 6″ in the recesses 9″ is carried out. When the insertion step is complete, the protective wall 61 covers the orifice 4 and the edge 62 is in contact with the outer wall 5″ of the housing 1″. Furthermore, each extension 64″ is positioned in a recess 9″ as represented in FIG. 6. Each extension 64″ protrudes from the corresponding recess 9″.

(41) No force is being exerted on the two elements 66, 67, these come in a holding position. The protrusion 65″ of the second element 66 comes into contact with the external wall 5″ of the housing 1″. The relief angle α making it possible to make an assembly of the cover on the orifice without creating an axial backlash, that is to say a spacing between the cover and the wall of the orifice along the elongation axis of the extension.

(42) The protrusion 65″ is not positioned in an axis of the recess 9″. It is offset relative to said axis of the recess 9″. Thus, the protrusion 65″ can no longer pass into the recess 9″. The protrusion 65″ prevents a withdrawal of the extension 64″ from the recess 9″ and therefore a withdrawal of the cover 6″ from the orifice 4.

(43) A third embodiment of the invention is illustrated more particularly by FIGS. 7 and 8.

(44) In this embodiment, the housing 1′″ comprises two recesses 9′″ of a substantially rectangular section. They are positioned diametrically opposite next to the orifice 4. The recesses 9′″ are not merged with the orifice 4. The recesses 9′″ pass through a thickness of the external wall 5′″ of the housing 1′″. They are therefore through-going recesses.

(45) The cover 6′″ according to the third embodiment comprises a substantially circular protective wall 61 having a diameter substantially equal to the diameter of the orifice 4. The protective wall 61 is extended in a plane in which the protective wall 61 extends by an edge 62.

(46) The edge 62 surrounds the protective wall 61 and comprises two portions 63 positioned diametrically opposite relative to the protective wall 61. Each portion 63 comprises an extension 64′″.

(47) The extension 64′″ is irreversibly fixed to the portion 63. More specifically, the cover 6′″, comprising the protective wall 61, the edge 62 and the extensions 64′″, is produced in a single material injection operation. The extension 64′″ extends along an axis orthogonal to the plane in which the protective wall 61 extends. The extension 64′″ has a length greater than the length of the recess 9′″ in which it is intended to be inserted. The extension 64′″ comprises two legs 68 connected to a free end of a rod 69.

(48) The rod 69 is substantially rectilinear. A first end of the rod is fixed to the edge 62 of the protective wall 61 and the two legs 68 are fixed to a second end of the rod 69.

(49) The two legs 68 are substantially symmetrical and flexible. The two legs 68 extend on either side of the rod 69. The legs 668 form an acute angle with the rod 69.

(50) The two extensions 64′″ are positioned on the same face of the cover 1′″, hereafter called the inner face. So that the two extensions 64′″ can be inserted into the corresponding recess 9′″.

(51) A method for fixing according to the invention the cover 6′″ on the orifice 4 comprises a step of approaching the cover 6″ to the orifice 4 as represented in FIG. 7.

(52) In this step, the cover 6′″ is positioned at a distance from the housing 1′″, facing the orifice 4. More precisely, the inner face of the cover 6′″ is positioned facing the orifice 4 so that the extensions 64′″ are each facing a recess 9′″.

(53) Then a step of deforming the extensions 64′″ is carried out and more precisely a bending phase. In said bending phase, the two legs 68 of each extension 64′″ are elastically brought together and are brought closer to the rod 69. To carry out this bending step, a force is exerted on the two legs 68 of each extension 64′″. The deformation step is simultaneously carried out on the two extensions 64′″.

(54) After the deformation step, a step of inserting the extensions 64′″ of the cover 6′″ is carried out in the recesses 9′″. When the insertion step is complete, the protective wall 61 covers the orifice 4 and the edge 62 is in contact with the outer wall 5′″ of the housing 1′″. Furthermore, each extension 64′″ is positioned in a recess 9′″ as represented in FIG. 8. Each extension 64′″ protrudes from the corresponding recess 9′″.

(55) No force is being exerted on the two legs 68, these come in a holding position and prevent a withdrawal of the extension 64′″ from the recess 9′″ and therefore a withdrawal of the cover 6′″ from the orifice 4.

(56) Of course, the invention is not limited to the embodiments described and represented in the appended figures. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.