Method for assembling a rear axle assembly for a motor vehicle, rear axle assembly and method for mounting such an assembly on a rear axle

Abstract

Method for assembling a rear axle assembly for a motor vehicle, rear axle assembly, and method for mounting such an assembly on a rear axle. The invention relates to a method for assembling a rear axle assembly for a vehicle, comprising a suspension trapezoid (1) and a suspension spring (3). According to the invention, the method includes a holding step for said spring in a compressed position, performed before mounting said assembly in said rear axle, said holding step being performed by means of a bayonet system (23) for insertion into the coils of said spring and comprising a locking member (27) and a receiving element (15) for said locking member, mounted on an upper plate (7) of said spring and adapted to cooperate with said locking member. The invention also relates to a rear axle assembly and a method for mounting such an assembly on a rear axle. Figure 3

Description

Title of the invention: Method for assembling an assembly for the rear axle of a motor vehicle, assembly for the rear axle and method for mounting such an assembly on a rear axle Technical field

[0001] The invention relates to the field of motor vehicles, in particular to the field of the ground connection of a rear axle of a motor vehicle.

[0002] The invention relates more particularly to a method of assembling an assembly for the rear axle of a motor vehicle. The invention also relates to an assembly for the rear axle and a method of mounting such an assembly on a rear axle. Prior art

[0003] A motor vehicle has a rear axle assembled to the body of the motor vehicle.

[0004] The rear axle comprises, in particular, a suspension trapezium, a cross member and a suspension spring mounted between the suspension trapezium and the cross member.

[0005] In order to absorb the different reliefs of the road, the suspension trapezium is movable in rotation about a substantially longitudinal horizontal axis of rotation, between an attack position, corresponding to an upper position of the suspension trapezium, and a relaxation position, corresponding to a lower position of the suspension trapezium. The suspension trapezium occupies a so-called reference position when the motor vehicle is in the parking position.

[0006] The transition from one to the other of the positions occupied by the suspension trapezium is obtained thanks to the suspension spring mounted between the suspension trapezium and the train crossmember.

[0007] Mounting the suspension spring between the suspension trapeze and the axle crossmember requires compression of the suspension spring.

[0008] However, in the free state, the suspension spring has a significant length. The suspension spring adopts the shape of an arc of a circle when the spring is in the free state.

[0009] The arcuate shape of the suspension spring in the free state, as well as the significant length of the suspension spring, creates a risk of the suspension spring hitting the suspension trapezium when the suspension spring is mounted in the rear axle. This is not possible, as such an impact would damage the paintwork of the suspension spring. Such damage to the paintwork of the suspension spring would create a risk of corrosion of the suspension spring, which could ultimately lead to breakage of the suspension spring.

[0010] This risk is all the higher as the architecture of the rear axle offers very little space for mounting the various elements that make it up.

[0011] Spring compression tools are also known, in particular that described in document EP 0 271 782 Bl. Such a compression tool comprises a system of jaws adapted to engage in a spring and which, when actuated, allow the spring to be compressed.

[0012] However, as previously, due to the very restricted space between the suspension trapezium and the rear axle crossmember, the risk of the tool scratching or chipping the suspension spring is high, this type of compression tool being very bulky.

[0013] Also, assuming that one manages to compress the suspension spring with the compression tool of document EP 0 271 782 B1 and to install the suspension spring in the rear axle, the space between the coils of the spring in the reference position is such that it may be complex, or even impossible, to remove the jaws between the coils. Removing the tool is thus very complicated. Statement of the invention

[0014] The present invention aims to overcome the aforementioned drawbacks, and to do so relates to a method of assembling an assembly for the rear axle of a motor vehicle, said assembly being intended to be mounted in a rear axle of a motor vehicle, said assembly comprising a suspension trapezium and a suspension spring intended to be mounted between said suspension trapezium and a cross member of said rear axle, said assembly method being remarkable in that it comprises a step of holding said suspension spring in a compressed position, said holding step being carried out before mounting said assembly in said rear axle, said holding step being carried out by means of a bayonet system, said bayonet system comprising, on the one hand, a holding tool adapted to be introduced into the turns of said suspension spring and comprising a locking member and, on the other hand,a receiving element for said locking member, said receiving element being mounted on an upper sole of said suspension spring and being adapted to cooperate with said locking member.

[0015] Thus, thanks to the method according to the invention, the compression of the rear axle suspension spring is carried out before its mounting in the rear axle.

[0016] In this way, the risk of hitting the suspension spring during its assembly is limited. This therefore limits the risk of damage to the paint on the suspension spring, which would lead to a risk of corrosion of the spring, which could lead to its breakage.

[0017] Also, using a bayonet system to hold the suspension spring when the spring is in an already compressed state allows for an in introduction of the holding tool vertically. In this way, the risk of damage to the suspension spring is further limited.

[0018] Also, given that the compression of the suspension spring is carried out before its mounting in the rear axle, the mounting of the spring in the rear axle is very largely simplified compared to the prior art. Indeed, no significant manipulation of the suspension spring in the restricted space between the trapezium and the axle crossmember is then necessary.

[0019] According to optional characteristics of the assembly method according to the invention: - it comprises the following steps, prior to said step of holding said suspension spring in a compressed position, aimed at mounting said suspension spring in the free state on said suspension trapezium, compressing said suspension spring, introducing said holding tool into the turns of said suspension spring while said suspension spring is compressed, making said locking member cooperate with said receiving element; - said step of compressing said suspension spring is carried out by applying a vertical compressive force applied to said upper flange of said suspension spring; - the vertical compressive force applied to said upper sole of said suspension spring is applied by means of a jack nose or a press; - said step aimed at making said locking member cooperate with said receiving element consists of rotating said holding tool relative to said receiving element; - the method comprises an additional step, subsequent to said step aimed at making said locking member cooperate with said receiving element, consisting of stopping applying said vertical compression force to said upper sole of said suspension spring.

[0020] The invention also relates to an assembly for the rear axle of a motor vehicle, remarkable in that it is obtained by the assembly method according to the invention.

[0021] The invention also relates to an assembly for a rear axle of a motor vehicle, said assembly being intended to be mounted in a rear axle of a motor vehicle, said assembly comprising a suspension trapezium and a suspension spring mounted on said suspension trapezium, said assembly being remarkable in that said suspension spring occupies a compressed position and in that said assembly further comprises a bayonet system holding said suspension spring in said compressed position, said bayonet system comprising, on the one hand, a holding tool introduced into the turns of said suspension spring and comprising a locking member and, on the other hand, an element for receiving said locking member, said receiving element being mounted on an upper sole of said suspension spring and cooperating with said locking member.

[0022] The invention also relates to a method for mounting an assembly for the rear axle of a motor vehicle on a rear axle of a motor vehicle, said assembly being, according to the invention, remarkable in that it comprises the following steps aimed at: - positioning said assembly in said rear axle so that said suspension spring interfaces between said suspension trapezium and a cross member of said rear axle, - compress said suspension spring, - stop making said locking member cooperate with said receiving element, - stop compressing said suspension spring.

[0023] In one embodiment of the assembly method according to the invention, said step aimed at compressing said suspension spring is carried out by applying a vertical compression force applied to the lower part of said assembly. Brief description of the drawings

[0024] Other characteristics, aims and advantages of the invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the appended drawings in which:

[0025] [Fig-1] is a perspective view of a suspension trapeze of a rear axle of a motor vehicle on which a suspension spring is mounted, before assembly in the rear axle.

[0026] [Fig.2] shows the trapezoid and the suspension spring on which a compression force is applied.

[0027] [Fig.3] shows the trapeze and the suspension spring in which a bayonet system is inserted.

[0028] [Fig.4] is a detail view of an upper sole of the suspension spring.

[0029] [Fig.5] shows a locking step of the bayonet system.

[0030] [Fig.6] shows the assembly obtained at the end of the assembly process according to the invention.

[0031] [Fig.7] shows a first step of mounting the assembly of the invention on a rear axle of a motor vehicle.

[0032] [Fig.8] shows a second step of mounting the entire invention on the rear axle.

[0033] [Fig.9] shows a third step of mounting the entire invention on the rear axle. Description of the embodiments

[0034] In the remainder of the description, elements having an identical structure or similar functions are designated by the same reference.

[0035] Reference is made to [Fig.l] showing a suspension trapezoid 1 of a rear axle of a motor vehicle on which a suspension spring 3 is mounted, before assembly in a rear axle of a motor vehicle, the rear axle being for example a multi-link axle.

[0036] In the lower part, the suspension spring 3 comprises a lower sole 5 and, in the lower part, the suspension spring 3 comprises an upper sole 7.

[0037] The lower sole 5 comprises a centering cone 9 adapted to hold the suspension spring 3 in position when the suspension spring 3 is mounted on the trapeze.

[0038] The lower sole 5 further comprises an orifice 11 which, as will be seen in the remainder of the description, is adapted to allow the passage of a holding tool.

[0039] The upper sole 7 also includes an orifice 13 adapted to allow the passage of the holding tool.

[0040] The upper sole 7 further comprises a receiving element 15 for a locking member of a bayonet system which, as will be seen in the remainder of the description, is adapted to hold the suspension spring 3 in a compressed position.

[0041] In the assembly method according to the invention, the suspension spring 3 is mounted in the free state on the suspension trapeze 1, as shown in [Fig.l].

[0042] The suspension trapeze 1, carrying the suspension spring 3 mounted in the free state, is positioned horizontally on a frame 17, as visible in [Fig.2] to which reference is made.

[0043] The suspension spring 3 is then compressed. The compression of the suspension spring 3 is thus carried out while neither the suspension spring 3 nor the suspension trapezoid 1 are mounted in the rear axle.

[0044] In one embodiment, the compression of the suspension spring 3 is achieved by applying a vertical compression force applied to the upper flange 7 of the suspension spring 3, as represented by the arrow 19.

[0045] In one embodiment, the vertical compression force is applied to the upper sole 7 of the suspension spring 3 by means of a nose 21 of a jack or a press.

[0046] Once the suspension spring occupies its compressed position illustrated in [Fig.2], the assembly method comprises a step aimed at maintaining the suspension spring 3 in its compressed position.

[0047] Referring to [Fig.3]. In order to maintain the suspension spring 3 in its position previously compressed, the assembly process provides for the use of a bayonet system 23.

[0048] The bayonet system comprises a holding tool 25 adapted to be introduced into the coils of the suspension spring 3.

[0049] The holding tool 25 further comprises at an upper end a locking member 27 adapted to cooperate with the receiving element 15 mounted on the upper sole 7 of the suspension spring 3 when the holding tool 25 is introduced into the turns of the suspension spring 3.

[0050] In the embodiment illustrated in the figures, the holding tool 25 comprises a tubular body 29 extending longitudinally.

[0051] The locking member 27 comprises, for example, two diametrically opposed locking lugs 31 extending from the tubular body 29 towards the outside of the tubular body 29.

[0052] In the lower part, the holding tool 25 comprises a retaining jaw 33 adapted to cooperate with an external face of the suspension trapezium 1.

[0053] The retaining jaw 33 comprises a frustoconical portion adapted to partially penetrate the orifice 11 of the lower sole 5 of the suspension spring 3. The retaining jaw 33 also comprises a shoulder radially extending the frustoconical portion and bearing against the external face of the suspension trapezium when the holding tool 25 is introduced into the suspension spring 3.

[0054] Reference is made to [Fig.4] showing an enlargement of the upper sole 7 of the suspension spring 3.

[0055] In the embodiment illustrated in the figures, the receiving element 15 of the upper sole 7 comprises a locking cross comprising a recess zone 37 in which a recess is made over the entire height of the receiving element 15. The recess zone 37 is adapted to allow the locking lugs 31 of the holding tool 25 to pass through.

[0056] The locking cross further comprises an axial retaining zone 39 adapted to receive the locking lugs 31 of the holding tool 25 when the holding tool 25 is rotated relative to the receiving element 15 of the upper sole 7, as shown by the arrow 41 in [Fig. 5]. In the illustrated embodiment, locking is obtained when the holding tool 25 is rotated by a quarter turn.

[0057] In an alternative embodiment not shown in the figures, the receiving element 15 of the upper sole 7 comprises a locking system adapted to cooperate with a locking member carried by the holding tool 25.

[0058] When the locking lugs 31 of the locking member 27 of the holding tool 25 are received by the axial retaining zone 39 of the receiving element 15 of the upper sole 7 of the suspension spring 3 and when the retaining jaw 33 cooperates with the external face of the suspension trapezoid 1, the suspension spring 3 is held in the compressed position. The holding tool 25 then prevents any relaxation movement of the suspension spring 3.

[0059] Reference is made to [Fig.6] showing the assembly obtained at the end of the assembly process according to the invention.

[0060] At this stage, the holding tool 25 prevents any relaxation movement of the suspension spring 3 mounted on the suspension trapeze 1.

[0061] It is thus no longer necessary to apply the vertical compression force on the suspension spring 3 previously applied in the exemplary embodiment by means of the nose 21 of a jack or a press.

[0062] Thus, the assembly method of the invention provides a step consisting of stopping the application of the vertical compression force, after the step aimed at making the locking member 27 of the holding tool 25 cooperate with the receiving element 15 of the upper sole 7 of the suspension spring 3.

[0063] The assembly 43 thus obtained is then capable of being transported to a rear axle assembly line.

[0064] The assembly 43 comprises the suspension trapezoid 1, the suspension spring 3 mounted on the suspension trapezoid 1 in the compressed position, and the bayonet system 23 holding the suspension spring 3 in the compressed position.

[0065] The compressed position of the suspension spring 3 in the assembly 43 is not total, that is to say that the suspension spring 3 can still be compressed further, this to allow the removal of the holding tool 25 during the assembly 43 in a rear axle, as will be seen in the remainder of the description.

[0066] Reference is made to figures 7 to 9 showing the mounting of the assembly 43 on a rear axle of a motor vehicle.

[0067] The rear axle comprises, among other things, a 45 axle cross member.

[0068] When the assembly 43 arrives on the train assembly line, an operator positions the assembly 43 in the rear train so that the suspension spring 3 interfaces between the suspension trapeze 1 and the train crossmember 45.

[0069] When the assembly 43 is positioned in the rear axle, the suspension spring 3 does not push on the axle crossmember 45.

[0070] The assembly method then comprises a step shown in [Fig.8] aimed at further compressing the suspension spring 3, as shown by the arrow 47, this being made possible taking into account the fact that the compressed position of the suspension spring 3 in the assembly 43 is not total.

[0071] In one embodiment, the compression of the suspension spring 3 is achieved by applying a vertical compression force applied to the lower part of set 43.

[0072] The assembly method then continues by stopping the locking member 27 of the holding tool 25 from cooperating with the receiving element 15 of the upper sole 7 of the suspension spring 3 and by driving the holding tool 25 in rotation relative to the receiving element 15 of the upper sole 7, as shown by the arrow 49 in [Fig.9].

[0073] The holding tool 25 can be removed, vertically relative to the suspension spring 3, and the step of further compressing the suspension spring 3 can at this point be stopped. Once the compression has stopped, the suspension spring 3 relaxes in the space provided between the suspension trapezium 1 and the landing gear crossmember 45.

[0074] The assembly of the assembly 43 in the rear axle is completed, and the suspension spring 3 occupies its reference position in the rear axle.

[0075] As goes without saying, the present invention is not limited to the sole embodiments of this method of assembling an assembly for the rear axle of a motor vehicle, of this assembly for the rear axle and of this method of mounting such an assembly on a rear axle, described above solely as illustrative examples, but on the contrary it embraces all the variants involving the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

Claims

Claims

1. Method for assembling an assembly (43) for a rear axle of a motor vehicle, said assembly (43) being intended to be mounted in a rear axle of a motor vehicle, said assembly (43) comprising a suspension trapezium (1) and a suspension spring (3) intended to be mounted between said suspension trapezium (1) and a cross member (45) of said rear axle, said assembly method being characterized in that it comprises a step of holding said suspension spring (3) in a compressed position, said holding step being carried out before mounting said assembly (43) in said rear axle, said holding step being carried out by means of a bayonet system (23), said bayonet system (23) comprising, on the one hand, a holding tool (25) adapted to be introduced into the turns of said suspension spring (3) and comprising a locking member (27) and, on the other hand,a receiving element (15) for said locking member (27), said receiving element (15) being mounted on an upper sole (7) of said suspension spring (3) and being adapted to cooperate with said locking member (27).,

2. Method according to claim 1, characterized in that it comprises the following steps, prior to said step of holding said suspension spring (3) in a compressed position, aimed at: - mounting said suspension spring (3) in the free state on said suspension trapezium (1), - compressing said suspension spring (3), - introducing said holding tool (25) into the turns of said suspension spring (3) while said suspension spring (3) is compressed, - making said locking member (27) cooperate with said receiving element (15).

3. Method according to claim 2, characterized in that said step of compressing said suspension spring (3) is carried out by applying a vertical compressive force applied to said upper sole (7) of said suspension spring (3).

4. Method according to claim 3, characterized in that the vertical compressive force applied to said upper sole (7) of said suspension spring (3) is applied by means of a jack nose (21) or a press.

5. Method according to any one of claims 2 to 4, characterized in that said step aimed at making said locking member (27) cooperate with said receiving element (15) consists of rotating said holding tool (25) relative to said receiving element (15).

6. Method according to one of claims 3 or 4 or according to claim 5 combined with claim 3, characterized in that it comprises an additional step, subsequent to said step aimed at making said locking member (27) cooperate with said receiving element (15), consisting of stopping applying said vertical compression force on said upper sole (7) of said suspension spring (3).

7. Assembly (43) for the rear axle of a motor vehicle, characterized in that it is obtained by the assembly method according to any one of claims 1 to 6.

8. Assembly (43) for a rear axle of a motor vehicle, said assembly (43) being intended to be mounted in a rear axle of a motor vehicle, said assembly (43) comprising a suspension trapezium (1) and a suspension spring (3) mounted on said suspension trapezium (1), said assembly (43) being characterized in that said suspension spring (3) occupies a compressed position and in that said assembly (43) further comprises a bayonet system (23) holding said suspension spring (3) in said compressed position, said bayonet system (23) comprising, on the one hand, a holding tool (25) introduced into the turns of said suspension spring (3) and comprising a locking member (27) and, on the other hand, a receiving element (15) for said locking member (27), said receiving element (15) being mounted on an upper sole (7) of said suspension spring (3) and cooperating with said locking member (27).

9. Method for mounting an assembly (43) for a rear axle of a motor vehicle on a rear axle of a motor vehicle, said assembly (43) being according to one of claims 7 or 8, characterized in that it comprises the following steps aimed at: - positioning said assembly (43) in said rear axle so that said suspension spring (3) interfaces between said suspension trapezium (1) and a cross member (45) of said rear axle, - compressing said suspension spring (3), - stopping said locking member (27) from cooperating with said receiving element (15), - stopping compressing said suspension spring (3).

10. Mounting method according to claim 9, characterized in that said step aimed at compressing said suspension spring (3) is carried out by applying a vertical compression force applied to the lower part of said assembly (43).

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