POWERTRAIN ASSEMBLY EQUIPPED WITH A SYSTEM FOR REINFORCING THE MECHANICAL LINK BETWEEN AN ENGINE CRADLE AND A VEHICLE UNDERBODIES

Abstract

One aspect of the invention relates to a powertrain 1 equipped with an engine support cradle 2, a subframe 3, and a reinforcement system 8 for a mechanical connection between said engine support cradle 2 and said subframe 3. The subframe 3 comprises a front crossbar 5 extending transversely between two longitudinal members 4a, 4b, and an electrical energy storage unit 7 located at the rear of the front crossbar 5. The reinforcement system 8 further comprises: a first reinforcement element 8a integral with said front crossbar 5 and said engine support cradle 2; and a second reinforcement element 8b integral with said front crossbar 5 and said engine support cradle 2. Said first and second reinforcement elements 8a, 8b are arranged on either side of a longitudinal axis X of said powertrain 1. Figure 2

Description

Title of the invention: POWERTRAIN EQUIPPED WITH A SYSTEM FOR REINFORCING A MECHANICAL CONNECTION BETWEEN AN ENGINE CRADLE AND A VEHICLE UNDERBODY

[0001] The field of the invention relates to that of electric or hybrid motor vehicles, more particularly to their structure with a view to absorbing impact energy in the event of a shock.

[0002] An electric or hybrid vehicle usually comprises a base formed in particular by a floor, two side members extending along the two lateral edges of the floor and an electrical energy store, formed for example by a battery pack, arranged under said floor. Such a vehicle also comprises an engine support cradle mechanically linked to the base. In the event of a frontal impact, there is a significant risk that the engine support cradle will move back until it comes into contact with the electrical energy store and damage it.

[0003] In order to avoid damaging the electrical energy store during a frontal impact, document EP-A1-4021781 discloses a vehicle equipped with a reinforcement device comprising a body fixed to an underfloor front inner stretcher and two reinforcement tabs extending from the body, a first reinforcement tab connecting said body to a rear end of the engine support cradle and a second reinforcement tab connecting said body to a side member. Thus, this reinforcement device makes it possible to create a direct path for transmitting forces between the engine support cradle and the side members of the vehicle.

[0004] However, this solution does not prevent, in the event of a frontal impact, the central part of the engine support cradle from being crushed against the electrical energy store, risking damaging it.

[0005] The aim of the invention is to propose a solution making it possible to avoid damaging an electrical energy store of a vehicle during a frontal impact.

[0006] In this context, the invention thus relates, in its broadest acceptance, to a powertrain provided with an engine support cradle, a base and a system for reinforcing a mechanical connection between said engine support cradle and said base, said base comprising two side members extending along the two lateral edges of said base, a front transverse bar extending transversely between said two side members and an electrical energy store arranged at the rear of said front transverse bar.

[0007] The powertrain according to this aspect of the invention is remarkable in that the reinforcement system includes: • A first reinforcing element secured to a first end of the front crossbar and to a second end of the engine support cradle, • A second reinforcing element secured to a first end of the front crossbar and to a second end of the engine support cradle, said first and second reinforcing elements being arranged on either side of a longitudinal axis of said powertrain.

[0008] Front means the forward side of the vehicle and rear means the reverse side of the vehicle.

[0009] The powertrain according to this aspect of the invention makes it possible to protect the electrical energy store during a frontal impact.

[0010] The crossbar makes it possible, more particularly, to absorb the forces coming from a frontal impact in a direct manner over the entire width of the underbody. The electrical energy store arranged at the rear of the crossbar is thus protected.

[0011] In addition to the characteristics which have just been mentioned in the preceding paragraph, the invention may have one or more complementary characteristics among the following, considered individually or according to all technically possible combinations.

[0012] According to a non-limiting aspect of the invention, the first reinforcing element and / or the second reinforcing element is (are) formed by a plate.

[0013] According to a non-limiting aspect of the invention, the plate has a thickness of at least 1 mm.

[0014] According to a non-limiting aspect of the invention, the plate is ribbed.

[0015] According to a non-limiting aspect of the invention, the first reinforcing element and / or the second reinforcing element is(are) formed by a bar.

[0016] According to a non-limiting aspect of the invention, the first reinforcing element is formed by two bars and / or the second reinforcing element is formed by two bars.

[0017] According to a non-limiting aspect of the invention, the first and second reinforcing elements are secured to the front transverse bar and to the engine support cradle by means of screws.

[0018] According to a non-limiting aspect of the invention, the first and second reinforcing elements are secured to the front transverse bar and to the engine support cradle by means of rivets.

[0019] According to a non-limiting aspect of the invention, the material of the reinforcing elements is steel.

[0020] Another aspect of the invention relates to an electric or hybrid motor vehicle comprising a powertrain according to any one of the aspects of the aforementioned invention.

[0021] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures.

[0022] [Fig-1] illustrates, schematically, a view from below of a motor group- propellant.

[0023] [Fig.2] illustrates, schematically, a bottom view of a powertrain according to a non-limiting aspect of the invention.

[0024] [Fig.3] illustrates, schematically, a three-dimensional view of a part of the powertrain illustrated in [Fig.2].

[0025] [Fig.4] schematically represents a part of a system for reinforcing a mechanical connection between an engine support cradle and a base according to a non-limiting aspect of the invention.

[0026] [Fig.5] schematically represents a system for reinforcing a mechanical connection between an engine support cradle and a base according to a non-limiting aspect different from the invention.

[0027] [Fig.l] illustrates a bottom view of a powertrain 1 according to a non-limiting aspect of the invention. For example, this powertrain 1 is of the electric type.

[0028] The powertrain 1 comprises an engine support cradle 2 and a base 3.

[0029] The base 3 comprises: • Two longitudinal side members 4a, 4b extending along the two lateral edges of the base 3, • A front transverse bar 5 extending transversely, at the front of the base 3, between said two side members 4a, 4b, and • A rear crossbar (not shown) extending transversely, at the rear of the base 3, between the two side members 4a, 4b.

[0030] According to this non-limiting embodiment, the front crossbar 5 is composed of: • A first part 5a extending transversely in the front part of the base 3, between a side member 4a and the tunnel 6, this first part 5a is also called the left front stretcher exterior reinforcement; • A second part 5b extending transversely in the front part of the base 3, between the other side members 4b and the tunnel 6, this second part 5b is also called the right front stretcher exterior reinforcement.

[0031] According to another embodiment not illustrated, the front crossbar 5 is in one piece, that is to say similar to the rear crossbar.

[0032] Furthermore, the base 3 comprises an electrical energy store 7 arranged between the two side members 4a, 4b, the front crossbar 5 and the rear crossbar. In other words, the electrical energy store 7 is arranged at the rear of the front crossbar 5.

[0033] This electrical energy store 7 can for example be formed by a 400V type battery pack.

[0034] [Fig. 2] illustrates a bottom view of a powertrain 1 according to a non-limiting aspect of the invention

[0035] The powertrain 1 further comprises a reinforcement system 8 for a mechanical connection between the engine support cradle 2 and the base 3.

[0036] The reinforcement system 8 comprises a first reinforcement element 8a secured to a first end of the front transverse bar 5, more particularly to the first part 5a of the front transverse bar 5, and to a second end of the engine support cradle 2.

[0037] In the illustrated embodiment, the second end of the first reinforcing element 8a is secured to a rear end of the engine support cradle 2.

[0038] The reinforcement system 8 also comprises a second reinforcement element 8b secured to a first end of the front transverse bar 5, more particularly to the second part 5b of the front transverse bar 5, and to a second end of the engine support cradle 2.

[0039] In the illustrated embodiment, the second end of the second reinforcing element 8b is secured to the rear end of the engine support cradle 2.

[0040] The first and second reinforcing elements 8a, 8b are arranged on either side of a longitudinal axis X of the powertrain 1, in other words on either side of the tunnel 6.

[0041] As can be seen in [Fig. 3] which schematically represents a three-dimensional view of a part of the powertrain 1, and in particular the first reinforcing element 8a, the first and second reinforcing elements 8a, 8b are formed by a folded plate having a thickness greater than 1 mm. The material is for example high elastic limit steel.

[0042] This plate is illustrated in isolation in [Fig.4]. It can be seen that the reinforcing element 8a is formed by a folded plate. Depending on the configuration of the engine support cradle 2 and the base 3, this reinforcing element 8a could be flat or stamped.

[0043] The first and second reinforcing elements 8a, 8b are intended to be fixed to the front transverse bar 5 of the underbody 3 and to the engine support cradle 2 by screwing or riveting and comprise for this purpose a plurality of holes 9 for the passage of fixing means.

[0044] The powertrain 1 according to this aspect of the invention makes it possible to protect the electrical energy store 7 during a frontal impact. The front crossbar 5 allows, more particularly, to absorb the forces coming from a frontal impact in a direct manner over the entire width of the underbody 3. The electrical energy store 7 arranged at the rear of the front transverse bar 5 is thus protected. Indeed, the sinking of the engine support cradle 2 towards the electrical energy store 7 is limited by the first reinforcing element 8a and the second reinforcing element 8b.

[0045] According to an embodiment not illustrated, the first and second reinforcing elements are formed by a ribbed plate. Thus, a less rigid material can be used, for example aluminum.

[0046] According to another embodiment illustrated in [Fig.5], the first reinforcing element 8a is formed by two bars and the second reinforcing element 8b is formed by two bars.

[0047] According to another embodiment not illustrated, the first reinforcing element is formed by a bar and the second reinforcing element is formed by a bar.

Claims

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2.

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5.

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7. Claims Powertrain (1) provided with an engine support cradle (2), a base (3) and a reinforcement system (8) for a mechanical connection between said engine support cradle (2) and said base (3), said base (3) comprising two side members (4a, 4b) extending along the two lateral edges of said base (3), a front transverse bar (5) extending transversely between said two side members (4a, 4b) and an electrical energy store (7) arranged at the rear of said front transverse bar (5), said powertrain (1) being characterized in that the reinforcement system (8) comprises: - A first reinforcing element (8a) secured to a first end of said front crossbar (5) and to a second end of said engine support cradle (2), - A second reinforcing element (8b) secured to a first end of said front transverse bar (5) and to a second end of said engine support cradle (2), said first and second reinforcing elements (8a, 8b) being arranged on either side of a longitudinal axis (X) of said powertrain (1). Powertrain (1) according to the preceding claim, characterized in that the first reinforcing element (8a) and / or the second reinforcing element (8b) is (are) formed by a plate. Powertrain (1) according to the preceding claim, characterized in that the plate has a thickness of at least 1 mm. Powertrain (1) according to any one of claims 2 or 3, characterized in that the plate is ribbed. Powertrain (1) according to claim 1, characterized in that the first reinforcing element (8a) and / or the second reinforcing element (8b) is (are) formed by a bar. Powertrain (1) according to claim 1, characterized in that the first reinforcing element (8a) is formed by two bars and / or the second reinforcing element (8b) is formed by two bars. Powertrain (1) according to any one of the preceding claims, characterized in that the first and second elements of

8.

9.

10. reinforcement (8a, 8b) are secured to the front crossbar (5) and to the engine support cradle (2) by means of screws. Powertrain (1) according to any one of claims 1 to 6, characterized in that the first and second reinforcing elements (8a, 8b) are secured to the front transverse bar (5) and to the engine support cradle (2) by means of rivets. Powertrain (1) according to any one of the preceding claims, characterized in that the material of the first and second reinforcing elements (8a, 8b) is steel. Electric or hybrid motor vehicle, characterized in that it comprises a powertrain (1) according to any one of the preceding claims.

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