Front structure of a motor vehicle

Abstract

The invention relates to a front structure of a motor vehicle comprising a bulkhead extending between an engine compartment and a passenger compartment, two front longitudinal beams (18') connected to the bulkhead (12'), a steering knuckle (20') provided in the bulkhead (12') and projecting into the engine compartment, the steering knuckle (20') having a base and an oblong hole (24') provided in the base and defining an edge (26') extending around the oblong hole (24') and facing the engine compartment, and a rack (34) mounted in the engine compartment and a rack joint (42) designed to be engaged between the rack (34) and the steering knuckle (20'). The structure further comprises an annular planar part (50) mounted on said edge (26') and extending around the oblong hole (24') so as to be able to widen the receiving bearing of the rack joint (42).

Description

[0001] The invention relates to a front structure of a motor vehicle, the front structure having a passenger compartment and an engine compartment positioned in succession with each other.

[0002] Known front structures of motor vehicles comprise a bulkhead extending transversely between the engine compartment and the passenger compartment of the vehicle. These front structures also comprise two front longitudinal beams extending parallel to each other in the longitudinal direction of the vehicle from the bulkhead in the engine compartment. These structures thus comprise a steering column and a rack connected together in the region of a steering knuckle provided in the bulkhead. The steering column extends into the passenger compartment as far as the steering wheel, while the rack extends as far as the front wheels in order to orient them.

[0003] The steering knuckle is provided in the bulkhead in line with the steering column and projects between the longitudinal beams into the engine compartment, but in the vicinity of the junction between the bulkhead and one of the longitudinal beams, in particular the left longitudinal beam in a left-hand drive motor vehicle.

[0004] The steering knuckle has a flat base in which a long circular hole is provided in order to be able to ensure the connection between the steering column and the rack. At the side of the engine compartment, the steering knuckle has an edge which extends around the long circular hole and against which the rack is pressed. Between these two is inserted a joint which, given the assembly features, is adapted to be driven in translation by the rack against the edge when compressed. This assembly requires a relatively wide edge around the long circular hole in order to ensure its implementation and to obtain an excellent seal.

[0005] For reasons of comfort in the passenger compartment, the steering column supported by the bulkhead is adjusted laterally as far as possible to the left, for example in a left-hand drive vehicle, in order to free up space for the front passengers.

[0006] However, new requirements in terms of wheel width and / or turning radius require the front longitudinal beams to be moved closer together.

[0007] Thus, if it is wished to maintain the aforementioned comfort, constraints will be imposed on the steering knuckle which will then be wedged into the angle between the bulkhead and the longitudinal beams, and the dimensions of which can no longer be maintained. This applies in particular to the width of the edge around the long circular hole.

[0008] As a result, the aforementioned assembly of the steering column and the rack is more difficult.

[0009] The problem that arises and which the invention aims to overcome is thus to provide a front structure of a motor vehicle which is able to accept front longitudinal beams which move together, while being able to normally assemble the rack and the steering column via the steering knuckle.

[0010] To this end, a front structure of a motor vehicle is proposed, the front structure having a passenger compartment and an engine compartment which extends in continuity with the passenger compartment, the structure comprising: a front bulkhead which extends transversely between the engine compartment and the passenger compartment and is adapted to support a steering column; two substantially parallel front longitudinal beams which are connected to the bulkhead and extend longitudinally within the engine compartment; a steering knuckle which is arranged in the bulkhead substantially in line with the steering column and which projects between the two longitudinal beams into the engine compartment near the connection between the bulkhead and one of the longitudinal beams, the steering knuckle having a base and an oblong hole which is provided in the base and which defines an edge which extends around the oblong hole opposite the engine compartment; a rack which is mounted within the engine compartment and a rack joint which is able to be engaged between the rack and the steering knuckle when the steering column is connected to the rack via the oblong hole. The structure further comprises an annular planar part which is mounted in a state applied to the edge and which extends around the oblong hole so as to be able to widen the receiving bearing of the rack joint.

[0011] In this way, the features of the invention relate to the use of an annular planar part against the edge of the knuckle opposite the base and which can extend around the oblong hole with a width which is large enough to be able to assemble the rack and the steering column according to the usual method. This is because, given the dimensional constraints imposed on the steering knuckle, the edge of the knuckle opposite the base and extending around the oblong hole is no longer large enough to be able to precisely allow such usual assembly. Thanks to the annular planar part, the receiving bearing of the rack joint is thus enlarged and such assembly is thus made possible.

[0012] According to a particularly advantageous embodiment of the invention, the two longitudinal beams define a median plane with respect to which the annular planar part is inclined. The median plane defined by the two longitudinal beams is substantially parallel to a median horizontal plane of the motor vehicle and the annular planar part is inclined with respect to this horizontal median plane, for example by a value between 40° and 50°. In what follows, how this inclination can facilitate assembly will be explained in more detail in the remainder of the description.

[0013] One of the longitudinal beams and the bulkhead thus define a bisector plane along which the oblong hole advantageously extends, the oblong hole extending along the part contained in the bisector plane. The bisector plane extends substantially vertically and is substantially inclined by 45° with respect to the longitudinal axis of the motor vehicle. The oblong hole thus extends substantially diagonally in the engine compartment, which in particular facilitates assembly of the rack and the steering column.

[0014] Furthermore, the oblong hole preferably has a lower end which is positioned towards one of the longitudinal beams and an upper end which is opposite the lower end and which is spaced apart from one of the longitudinal beams. Such an arrangement again facilitates assembly.

[0015] Furthermore, according to a particularly advantageous feature of the application, the annular planar part is connected by welds to the rim. The width of the rim of the steering knuckle enables the annular planar part to be connected by welds at this location, for example by means of a conventional welding tongs set having two opposed electrodes, the welds being regularly spaced from one another around the oblong hole.

[0016] Preferably, the structure according to the application comprises an annular mastic joint between the annular planar part and the rim. In this way, for example, mastic is applied before the annular planar part and the rim of the steering knuckle are welded. The mastic thus ensures a perfect seal between the annular planar part and the steering knuckle.

[0017] The annular planar part thus has an inner edge and an opposite outer edge, and the minimum distance between these two opposite edges is advantageously between 15 mm and 25 mm. For example, this distance is 20 mm. As will be explained below, this width enables the rack and the steering column to be installed according to the normal method, in which the joint is then compressed.

[0018] According to a particularly advantageous feature, the inner edge delimits a section identical to that of the oblong hole. The annular planar part is thus adjusted by pressing on the rim of the steering knuckle so that the inner edge of the annular planar part is perfectly coincident with the oblong hole. The annular planar part is also welded to the steering knuckle at this location.

[0019] Preferably, the annular planar part has a peripheral edge. The peripheral edge extends opposite the steering knuckle, thus enabling the rim of the joint to be housed when they are compressed during assembly of the rack and the steering column.

[0020] Other features and advantages of the application will be understood on reading the following description of particular embodiments of the application, given by way of non-limiting example, and the annexed drawings in which:

[0021] [ Figure 1 ] shows a schematic perspective top view of a part of a motor vehicle front structure according to one viewing angle;

[0022] [ Figure 2 ] shows a schematic perspective top view of another part of the front structure shown in [ Figure 1 ] ;

[0023] [ Figure 3 ] shows a schematic perspective top view of the part of the front structure shown in [ Figure 1 ] according to another viewing angle;

[0024] [ Figure 4 ] shows a schematic perspective top view of a part of the front structure shown in [ Figure 1 ] and [ Figure 2schematic perspective view of the elements in the illustrated portion;

[0025] [ Figure 5 ] shows a schematic detailed view of Figure 3 ] showing elements of the invention;

[0026] [ Figure 6 ] shows a partially schematic side view showing the assembly method of the object of Figure 4 ] on elements of the object of Figure 5 ] and

[0027] [ Figure 7 ] shows a schematic cross-sectional view of the object of Figure 4 ] and the mounting elements of the object of Figure 5 .

[0028] The structural context in which the problem overcome by the present invention arises will be first described with reference to Figure 1 , to Figure 2 , to Figure 3 and to Figure 4 . Fig. 1 shows a motor vehicle front structure 10. The front structure 10 has a bulkhead 12 which extends transversely and separates an engine compartment 14 located in front of the bulkhead 12 from a passenger compartment 16 located behind the bulkhead 12. The bulkhead has a bulkhead cross beam 15. Figure 1

[0029] Therefore, the motor vehicle front structure 10 illustrated in Figure 1 is oriented in an orthogonal reference system X, Y, Z so that the axis X corresponds to the longitudinal direction of the vehicle and is oriented from the front to the rear of the vehicle, the axis Y corresponds to the transverse direction and is oriented from the left to the right of the vehicle when looking towards the front of the vehicle, and the axis Z represents the vertical direction, opposite to the surface on which the vehicle rests in its normal operating condition.

[0030] [ Figure 1 ] shows a left front longitudinal beam 18 which extends in the engine compartment 14 from the bulkhead cross beam 15 substantially in the direction of the axis X, as mentioned above. It will be appreciated that the bulkhead cross beam 15 itself extends substantially in the direction of the axis Y. Moreover, in Figure 1 , it is also illustrated the steering knuckle joint 20 which protrudes into the engine compartment 14 in the area of the connection between the bulkhead cross beam 15 and the left front longitudinal beam 18.

[0031] Reference will now be made to Figure 2 ​The figure shows the bulkhead 12 as viewed from the passenger compartment 16 rather than from the engine compartment 14. The steering ball joint 20 is thus positioned within the bulkhead 12. The steering ball joint 20 is hollow and has a base 22 in which an elongated hole 24 is formed. As will be explained below, the steering ball joint 20 defines a housing large enough to accommodate the operator's hand. The elongated hole 24 opens into the engine compartment 14 located behind the bulkhead 12.

[0032] Now refer to [ Figure 3 The steering ball joint 20 is shown from the engine compartment 14. The view is along axis X in the region of the left front longitudinal beam 18. Thus, the oblong hole 24 is visible from this location, and the base 22 is visible through this hole. This defines an edge 26 extending around the oblong hole 24 in the engine compartment 14. Therefore, the edge 26 is an oblong annular shape.

[0033] In addition, in [ Figure 3 As can be seen, the intermediate plane defined by edge 26 is inclined relative to another intermediate plane defined by the left front longitudinal beam 18 and the bulkhead beam 15 connected thereto. This other intermediate plane is substantially horizontal and is also defined by the two front longitudinal beams. In other words, this intermediate plane is inclined toward the center of the engine compartment 14. For example, this intermediate plane is inclined at an angle of approximately 45° relative to the axis Z. Therefore, the oblong hole 24 extends substantially in the direction D belonging to the bisecting plane defined by the left front longitudinal beam 18 and the bulkhead beam 15 extending along the axis Z. In this way, the oblong hole 24 extends along the components in the aforementioned bisecting plane and extends at an angle of approximately 45° relative to the axis Z, for example. Therefore, the oblong hole 24 has a lower end 28 near the left front longitudinal beam 18 and an upper end 30 opposite to it.

[0034] In reference [ Figure 5 Before describing the subject matter of the invention in more detail, please refer first to [[ Figure 4 The figure shows a steering column 32 that can be mounted on a bulkhead 12 in the passenger compartment 16 and a rack 34 that is suitable for mounting in the engine compartment 14.

[0035] The rack 34 includes an elongated oval housing 36 for torque conversion. The elongated oval housing 36 is capable of converting the torque applied by the steering column.

[0036] The elongated housing 36 has an elongated opening 38 that defines an elongated edge 40, to which a compressible elongated sealing joint 42 is applied. This sealing joint 42 is annular.

[0037] The rack 34 thus has a rack shaft 44 which extends through the oblong opening 38 and protrudes in an off-center position of the oblong opening 38. As will be explained hereafter, the rack shaft 44 is adapted to be engaged by the oblong hole 24 of the steering knuckle 20, while the oblong rim 40, provided with a compressible oblong sealing joint 42, is applied against the steering knuckle 20.

[0038] At the side of the passenger compartment 16, the steering column 32 has a final segment 46 provided with a final universal joint 48. This final universal joint 48 is adapted to be connected to the rack shaft 44 within the steering knuckle 20 by means of a coupling screw 49, as will be explained hereafter.

[0039] Reference will now be made to Figure 5 , which shows a more constraining structural environment than the one shown in Figure 1 , in Figure 2 , in Figure 3 , and in Figure 4 , and which demonstrates the use of the invention. Thus, the elements present in Figure 5 and which are equivalent to the elements in the previous figures will have the same reference number, assigned with an apostrophe: "'".

[0040] Thus, in this Figure 5 , and when viewed from the engine compartment, the bulkhead 12', the steering knuckle 20' located at the junction of the bulkhead cross member 15' and the left front longitudinal beam 18' can be seen in more detail. In this way, the steering knuckle 20' is substantially more compact than the one illustrated in the previous figures, enabling the left front longitudinal beam 18' to be configured in a position closer to its counterpart (the right front longitudinal beam). In other words, if the relative positions of the steering knuckle 20' and the steering column are maintained, the left front longitudinal beam 18' is moved closer in the transverse direction of the axis Y to the steering knuckle 20' which must be configured in a more compact manner.

[0041] This is because it is necessary to move the front longitudinal beams closer together by using a front wheel structure shell of larger dimensions. In Figure 5 , the oblong hole 24' extending from the upper end 30' to the lower end 28' and its annular rim 26' covered by the annular planar part 50 can also be seen. This annular planar part 50 is also oblong and is mounted so as to be applied on the annular rim 26'.

[0042] Thus, the annular planar part 50 is defined so as to have an oblong central aperture 52 defined by an inner rim 54 and of the same dimensions as the oblong hole 24' of the steering knuckle 20'. In other words, the inner rim 54 delimits the same section or surface as the one delimited by the oblong hole 24'.

[0043] Furthermore, the annular planar part 50 has an outer edge 56 which is spaced apart from the inner edge 54 by a substantially constant distance d . The distance d is preferably between 15 mm and 25 mm. For example, the distance is equal to 20 mm.

[0044] Furthermore, the annular planar part 50 has a peripheral edge 58 which continuously follows the outer edge 56.

[0045] In this way, the annular planar part 50 defines an annular receiving bearing 60 which is oblong and planar and is wider than the annular edge 26’ of the steering knuckle joint 20’. Thus, the annular planar part 50 extends beyond the annular edge 26’ and the steering knuckle joint 20’ in order to be able to provide the annular receiving bearing 60 which is larger in size than the annular edge 26’.

[0046] Furthermore, the annular planar part 50 must be connected to the steering knuckle joint 20’ in a fluid-tight manner. Thus, a not shown annular joint of mastic is first formed on the annular edge 26’ around the oblong hole 24’ and close to the edge of the oblong hole 24’. Then, the annular planar part 50 is pressed flat against the annular edge 26’ so that the oblong hole 24’ coincides exactly with the oblong central aperture 52 of the annular planar part 50, the joint of mastic is flattened. Then, the annular planar part 50 is connected to the annular edge 26’ around the flattened joint of mastic by means of spot welds which are formed by a spot welder group. In this way, the sealing is ensured due to the mastic and the annular planar part 50 is fixedly joined to the steering knuckle joint 20’ due to the spot welds. Advantageously, 6 to 10 spot welds are produced around the annular joint of mastic. For example, eight spot welds are produced.

[0047] In this way, the sealing assembly of the oblong housing 36 of the rack 34 is greatly facilitated due to the oblong and planar annular receiving bearing 60, as will be explained below with reference to Figure 6 and Figure 7 and in support of Figure 4 and Figure 5 .

[0048] In this way, the rack 34 can be seen schematically in Figure 6 with the oblong sealing joint 42 of mastic on top of the oblong housing 36 of the rack 34. It can also be seen that the rack shaft 44 protrudes from the oblong opening 38 of the oblong housing 36.

[0049] Furthermore, in Figure 6The steering knuckle 20' can be seen in part in the figure, provided with an annular planar part 50 applied against the annular edge 26' of the steering knuckle 20'.

[0050] In a first phase, the oblong housing 36 is thus adjusted in an inclined manner with respect to the oblong hole 24', and more particularly the rack shaft 44 is aligned with the lower end 28' of the oblong hole.

[0051] Next, in a second movement phase, the oblong housing 36 is translated along the vertical axis Z against the annular planar part 50 so that the rack shaft 44 passes through the lower end 28' of the oblong hole 24', while the compressible oblong sealing joint 42 is in planar contact with the annular receiving bearing 60 of the annular planar part 50.

[0052] Next, in a third movement phase, the compressible oblong sealing joint 42 is compressed between the oblong edge 40 of the oblong housing 36 and the annular receiving bearing 60, while the oblong edge 40 is driven in sliding movement against the annular receiving bearing 60. In this way, the rack shaft 44 is driven in translation towards the upper end 30' of the oblong hole 24', while moving away from the front left longitudinal beam 18', while the compressed compressible oblong sealing joint 42 is adjusted around the oblong hole 24'.

[0053] In other words, the annular receiving bearing 60 is wide enough to be able to receive the compressible oblong sealing joint 42 by friction until it is fully adjusted around the oblong hole 24'.

[0054] In this way, as illustrated in the cross-sectional view in [ Figure 7 ], between the oblong edge 40 and its oblong sealing joint 42, showing the rack shaft 44 extending in the upper end 30' of the oblong hole 24', the compressible oblong sealing joint 42 is fully compressed between the oblong edge 40 of the oblong housing 36 and the annular receiving bearing 60 and thus ensures a good seal between the oblong housing 36 of the rack 34 and the steering knuckle 20'.

[0055] The oblong housing 36 is thus fixed in this position, in which it is pressed against the annular planar part 50, while, on the other hand, the final universal joint 48 is connected to the rack shaft 44 using the coupling screw 49. In this way, the connection between the final universal joint 48 and the rack shaft 44 enables the oblong housing 36 to remain abutted by the force against the annular planar part 50, while the compressible oblong sealing joint 42 is compressed. In this way, the seal between the oblong housing 36 and the steering knuckle 20' is fully ensured.

Claims

1. A front structure of a motor vehicle, the front structure having a passenger compartment and an engine compartment, the engine compartment being continuous and extending from the passenger compartment, the front structure comprising: - A bulkhead (12') that extends laterally between the engine compartment and the passenger compartment and is adapted to support the steering column; - Two generally parallel front longitudinal beams (18') which are connected to the bulkhead (12') and extend longitudinally within the engine compartment; - A steering ball joint (20') arranged in the bulkhead (12') and substantially in line with the steering column, and the steering ball joint protruding into the engine compartment between the two front longitudinal beams near the connection between the bulkhead (12') and one of the front longitudinal beams (18'), the steering ball joint (20') having a base and an elongated hole (24') disposed in the base and defining an edge (26') extending around the elongated hole (24') opposite to the engine compartment; - Rack (34) and rack connector (42), the rack being installed in the engine compartment, the rack connector being able to engage between the rack (34) and the steering ball joint (20') when the steering column is connected to the rack via the elongated hole (24'); The front structure is characterized by further including an annular planar member (50) which is mounted in a state of application to the edge (26') and extends around the elongated hole (24') so as to widen the receiving support portion of the rack joint (42).

2. The front structure as described in claim 1, characterized in that, The two front longitudinal beams define a mid-plane, and the annular planar component (50) is inclined relative to the mid-plane.

3. The front structure as described in claim 1 or 2, characterized in that, One of these front longitudinal beams (18') and the partition (12') define a bisecting plane, and the elongated hole (24') extends along the components contained in the bisecting plane.

4. The front structure as described in claim 1 or 2, characterized in that, The elongated hole (24') has a lower end (28') positioned toward one of the front longitudinal beams (18') and an upper end (30') opposite to the lower end and spaced apart from one of the front longitudinal beams.

5. The front structure as described in claim 1 or 2, characterized in that, The annular planar component (50) is connected to the edge (26') by a solder joint.

6. The front structure as described in claim 1 or 2, characterized in that, The front structure includes an annular mastic joint between the annular planar component (50) and the edge (26').

7. The front structure as described in claim 1 or 2, characterized in that, The annular planar component (50) has an inner edge (54) and an opposite outer edge (56), and the minimum distance between the two opposite edges is between 15 mm and 25 mm.

8. The front structure as described in claim 7, characterized in that, The inner edge (54) defines the same cross section as the elongated hole (24').

9. The front structure as described in claim 1 or 2, characterized in that, The annular planar component (50) has a peripheral edge (58).

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