WO2018154221A1

WO2018154221A1 - Leg for attaching a catalytic converter and adapted to vehicle frontal impact

Info

Publication number: WO2018154221A1
Application number: PCT/FR2018/050386
Authority: WO
Inventors: Veronica ALVAREZ-GONZALEZ; Pascal Hottebart; Roberto MIGUEL-NIETO
Original assignee: Renault S.A.S
Priority date: 2017-02-20
Filing date: 2018-02-19
Publication date: 2018-08-30
Also published as: EP3585636A1; FR3063105A1; FR3063105B1

Abstract

System (30) for attaching an accessory (15) to a crankcase (11) in an engine compartment (12) of a motor vehicle, said accessory being arranged between the crankcase (11) and a wall of the compartment (17), comprising retaining arms (19) in the form of a stretched plate which are fixed at one end to the crankcase and which via the opposite end hold the accessory, characterized in that the system (30) comprises shapings (33) designed to cause the accessory (15) to tilt about the crankcase in the event of an impact involving pressure on the wall of the compartment.

Description

FIXING STAND OF CATALYTIC POT ADAPTED TO A CRASH

FRONTAL VEHICLE

Technical field of the invention

The present invention relates to the arrangement of a power unit of a motor vehicle.

The present invention relates more particularly to a system for fixing a depollution element against a thermal engine casing.

The present invention may also relate to an attachment of an element having a controlled deformation under impact. State of the art

In known manner, a vehicle powertrain comprises all the elements allowing the motor traction. The group includes for a vehicle with an internal combustion engine also called a heat engine,

the engine with its accessories which are for example a system for supplying fuel, exhaust, cooling, ignition, pollution control;

-the transmission with a gearbox, clutch or automatic transmission;

-computers, sensors and actuators managing the combustion parameters.

Among the pollution control systems, it is known to employ a number of pollution control means in the exhaust line of combustion engines to limit the emissions of regulated pollutants. For example, an oxidation catalyst allows the treatment of carbon monoxide, unburned hydrocarbons, and under certain conditions nitrogen oxides; a particle filter can be used for the treatment of particles of soot. Specific means are also known for the treatment of nitrogen oxides or NOx, such as NOx traps or so-called SCR catalysts for "selective catalytic reduction".

These different systems form a large footprint in a motor compartment which is the space in which the powertrain elements are arranged and they are held by means of links / fasteners which are crutches, away from the motor housing. The links are rigid to ensure the operation of the powertrain and to maintain an acoustic level. However, said engine compartment space may be deformed in particular during an accident of the vehicle, said deformations are then likely to cause intrusions into the passenger compartment of the elements of said powertrain causing possible injury to passengers and driver of the vehicle. Indeed, the engine is arranged in a transverse position and the catalytic converter vis-à-vis a partition wall between the engine compartment and the cabin of the vehicle, held by rigid connection means to the engine housing. The shock for example frontal can then cause a displacement of said engine and therefore the catalytic converter along the longitudinal axis of the vehicle from the front to the rear to the passenger compartment of the vehicle.

It is known to reduce the size of the accessory parts of the GMP to have an increase in space likely to take into account the deformations in case of frontal impact. Thus, it is possible to reduce the volume and especially the diameter of said catalytic converter which has a cylindrical shape. In this way, the size of the catalytic converter along the longitudinal axis of the vehicle is substantially reduced. It should be noted that the engine is mounted in transverse position, the axis of the engine is then transverse to the longitudinal axis of the vehicle, and that the catalytic converter is also mounted substantially parallel to the axis of the engine and thus has its cross section along the longitudinal axis of the vehicle.

It is also possible to arrange a mounting system for mounting the engine block in the compartment comprising inclined bars which each connect a fastening zone on the chassis or the body of the vehicle to the engine block. said bars are capable of causing the motor to move in a direction inclined relative to the longitudinal axis of the vehicle so that the engine block can not intrude into the passenger compartment of the vehicle.

The publication FR2776244-A1 discloses such a mounting system. However, the system is substantially expensive because the sloping bars have resilient characteristics at one end and allow angular movement at the other end and are reported to the entire engine.

The object of the invention is to remedy these problems and one of the objects of the invention is a deformation of a portion of the powertrain to prevent the catalytic converter can come into contact with the wall of the passenger compartment of the vehicle and distort it accordingly with possible damage to the driver and passengers.

Presentation of the invention

The present invention relates to a system for attaching an accessory to a motor housing in a motor vehicle engine compartment, said accessory being arranged between the housing and a wall of the compartment comprising holding arms in the form of drawn plates fixed to one end to the motor housing and holding the accessory by the opposite end.

The present invention more particularly relates to a system for fixing the accessory to the motor housing comprising holding arms in the form of stretched plates,

characterized in that the system comprises conformations adapted to cause a tilting of the accessory around the housing in the event of impact with a bearing against the wall of the compartment.

Advantageously, during a vehicle impact resulting in a contact in support of the accessory against a wall of the engine compartment, the accessory is likely to tilt around the engine housing to be in a favorable position in the compartment engine and also make the powertrain including the engine and the accessories more

30 compact to avoid intrusion into the passenger compartment of the vehicle. Also advantageously, the invention relates to the fastening system of the accessory to the motor housing and therefore less bulky and less expensive parts.

During a shock of the vehicle causing a contact with support of the accessory against the wall of the engine compartment, the fastening system comprises deformation means to cause a simple movement of the accessory to minimize the impact of the powertrain.

According to other features of the invention:

the system comprises at least one deformation arm comprising a programmed deformation zone.

Advantageously, the system comprises at least one holding arm capable of being deformed in a controlled manner. Thus the tilting of the accessory around the housing can be optimized for a minimum of impact on the powertrain environment.

the deformation arm is arranged between an end portion of the accessory and the casing.

Advantageously, the deformation arm is arranged between a portion of the housing and an end portion of the accessory to minimize the size of the powertrain and its impact against the wall of the engine compartment during impact.

the deformation arm is shaped to reduce the spacing between the accessory and the casing in the event of impact.

Advantageously, the deformation of the deformation arm makes it possible to bring the accessory closer to the casing in particular along the longitudinal axis of the vehicle and thereby reduces the impact against the wall of the engine compartment.

the deformation arm comprises a zone of weakness to allow folding of said arm in a direction transverse to the axis of said arm.

Advantageously, the deformation arm comprises a zone of weakness to allow folding of said arm in a direction transverse to the axis of said arm; said folding, however, keeps the accessory against the motor housing and thus to control the deformation.

the zone of weakness comprises a conformation of the arm in a list comprising a notch transverse to the axis of the deformation arm, a folding of the arm in a direction transverse to the axis of the arm, a zone transverse to the axis of the arm; arm having a reduced thickness compared to the nominal thickness of the arm.

Advantageously, the deformation arm comprises a conformation of the deformation arm in a direction transverse to the axis of the arm to facilitate the deformation of said arm by folding.

Said conformation is easy to achieve by adding an element of weakness in the arm to promote a folding of said arm in a given direction during an impact. The element of weakness can be:

a notch transverse to the axis of the deformation arm made for example by sawing which is a simple process. The said notch makes it possible to direct or control the deformation of the arm following an impact,

a folding of the deformation arm in a direction transverse to the axis of said arm, said arm may thus comprise a transverse corrugation which contributes to the controlled deformation of the arm following an impact,

A zone transverse to the axis of the arm having a reduced thickness relative to the nominal thickness of said arm. The deformation arm is composed of a plate having a substantially constant nominal thickness except in a transverse zone which has a reduced thickness, said transverse zone is therefore a zone of weakness for said arm to promote a

Bending in said transverse direction following an impact.

Brief description of the figures

Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments of the invention. given as non-limiting examples and shown in the accompanying drawings, in which:

FIG 1 is a schematic sectional view of a front portion of a motor vehicle.

FIG. 2 is a schematic view of a first side of the heat engine with a depollution element mounted against the engine casing.

FIG. 3 is a diagrammatic view of a second opposite side of the heat engine with a depollution element mounted against the crankcase of the engine.

FIG. 4 is a schematic view of a holding arm of the depollution element with a zone of weakness according to one embodiment.

FIG. 5 is a schematic view of a holding arm of the depollution element with a zone of weakness according to one embodiment.

FIG. 6 is a schematic view of a holding arm of the depollution element with a zone of weakness according to a second embodiment.

FIG 7 is a schematic view of a holding arm of the depollution element with a zone of weakness according to a third embodiment.

Detailed description of the figures

In the following description, like reference numerals refer to like parts or having similar functions.

Reference is made to an orthonormal reference with a longitudinal axis X parallel to the horizontal axis passing through the midpoints of the wheelsets of the vehicle, a transverse horizontal axis Y to the X axis and a vertical axis Z orthogonal to the horizontal plane. defined by the X and Y axes.

We also speak of a longitudinal axis X 'of an arm axis along the greater length of the arm, said longitudinal axis X' of the arm can then vary according to the arrangement of the arm. According to FIG. 1, the motor vehicles 10 equipped with heat engines 1 1 comprise for the most part a motor compartment 1 2 arranged at the front 13 of the vehicle in which is housed a power unit. By powertrain 14 is meant the assembly formed to ensure the movement of the vehicle, that is to say:

the engine 1 1 with its accessories which are for example a system for supplying fuel, exhaust, cooling, ignition, pollution control (15);

transmission with a gearbox, clutch or automatic gearbox (not shown);

-computers, sensors and actuators managing the combustion parameters (not shown).

The engine is mounted in transverse position, that is to say along a transverse horizontal axis Y with respect to the longitudinal axis X of the vehicle passing through

15 the center points of the wheel axles. It is known that the engines comprise accessory pollution control systems 15 arranged along a transverse side 16 of the engine through which the exhaust gases are directed and called the exhaust side of the engine. The transverse exhaust side 16 according to our invention is turned towards a wall 17 of the engine compartment separating said

20 compartment of the cockpit 18 of the vehicle in which the driver and the passengers are.

To reduce the pollution generated by the exhaust gases of the heat engines, it is known to associate said engine with pollution control systems including a catalyst pot SCR 15 for "selective catalytic reduction".

The latter technology consists of reducing NOx by introducing a reducing agent (or a precursor of such a reducing agent) into the exhaust gas. Said pot can also be associated with a particle filter or "FAP". In order to best treat the pollution generated by the exhaust gases, these pollution control systems are arranged on the side

The engine exhaust therefore between said engine and the partition wall of the passenger compartment of the vehicle. According to Figures 2 and 3, the catalyst pot 15 according to the invention is substantially cylindrical and is held substantially parallel to the longitudinal axis Y of the motor by holding arms 19 or crutches 20 which are a combination of two arms of holding 19 as shown in FIG.

The catalyst pot 1 5 is held away from the engine 1 1 for example by a fastening system 30 comprising at least three holding arms 1 9 and generally by four arms arranged at the ends of the catalyst pot along the longitudinal axis Y of the engine. In our example embodiment it can be maintained by two stands and therefore four holding arms.

As shown in Figures 4 to 7, the holding arm 19 is composed of a plate 27 of a nominal thickness e to ensure the rigidity of said arm, with fixing devices 21 at each of the two ends. For example, an end may comprise an orifice for the passage of a fixing screw 22 or a fork-shaped end which is adapted to grip the cylindrical body of a fixing screw 22. The attachment arm 19 is fixed at one end to the motor housing and holding at the opposite end an end portion of the accessory member 15 which in this embodiment is the catalyst pot. The end portion 23 of the catalyst pot 15 is preferred for example a middle portion for better holding the catalyst pot in position relative to the motor housing.

During a frontal impact of the vehicle during an accident, the front face 1 3 of the vehicle is depressed and pushes the power train 14 from the front to the rear of the vehicle bringing the catalyst pot 15 against the partition wall 14 the engine compartment 12 with the cockpit 18. Said catalyst pot 1 5 is little deformable and may therefore break down said partition wall 17 and impact the driver or passengers of the vehicle. Subsequently, when we speak of shock, it is a frontal impact of the vehicle causing a displacement of the engine 1 1 along the longitudinal axis X of the vehicle passing through the midpoint of the wheel axles, having for consequence a strong contact of the accessory 1 5 against the partition wall 17 between the engine compartment 12 and the passenger compartment of the vehicle 18.

The invention proposes a deformable fastening system 30 to make the powertrain 14 more compact during an impact and reduce the impact on the passenger compartment 1 8 of the vehicle.

According to the invention, the fastening system 30 comprises conformations 33 adapted to cause a tilting of the accessory around the casing in the event of impact with a bearing against the wall of the compartment. For this purpose, the fastening system comprises at least one deformation arm 31 among the holding arms 19 of the pot, said deformation arm having a programmed deformation zone 32. Said deformation arm is preferably arranged in an area where the space between said catalyst pot 15 and the partition wall 17 is small including the spacing between the wall of the catalyst pot and the partition wall; in our exemplary embodiment, said deformation arm is arranged between the motor housing and an upper part 25 of the catalyst pot 15. However, said deformation arm 31 can also be arranged between the motor housing and a lower part 24 of the pot catalyst.

The deformation arm 31 comprises means for causing a deformation of said arm in a predefined shape following the impact.

According to a preferred embodiment shown in Figure 6, the deformation arm 31 has a notch 34 between the two attachment ends of said arm. Said notch 35 is substantially oriented in a direction transverse to the axis of the arm. It can be a cutoff from a side edge of said arm or preferably a groove dug on the plate 27 over the width of said arm. Thus the deformation arm comprises a zone called programmed deformation 28 or weakness having less rigidity mechanical characteristics than in the rest of the plate 27. The notch can be obtained easily by sawing the plate 27 forming the deformation arm .

According to a second embodiment shown in FIG. 5, the deformation zone 28 of the deformation arm 31 is substantially transverse to the longitudinal axis X 'of said arm and has a plate thickness e1 reduced compared to the average nominal thickness e of the plate, which introduces a weakness of said arm 31 during an impact along the longitudinal axis X' of the arm. Indeed, this lower thickness has no impact on the maintenance of the accessory 1 5 in range of the motor housing 1 1 but promotes a deformation of the deformation arm 31 during a shock substantially along the longitudinal axis X ' of the arm. The zone of lesser transverse thickness forms a zone of programmed deformation 28 or weakness and can be easily obtained by stamping the plate 27 forming the deformation arm.

According to a third embodiment shown in FIG. 7, the plate

27 forming the deformation arm 31 has a fold 29 along an axis transverse to the axis X 'of the arm 31. Said fold 29 may be a transverse corrugation which makes it possible to promote a folding of the arm 31 during a longitudinal impact. Said transverse zone comprising the fold 29 forms a zone of programmed deformation or weakness 28. The fold 29 can be easily obtained by stamping the plate 27 forming the deformation arm 31.

It is naturally possible to produce several sawn or stampings of the plate 27 in order to obtain a deformation of said plate according to an optimal predefined shape following the impact.

The accessory 15 is mounted substantially parallel to the axis X of the engine and held close to the housing of the engine 1 1 by the holding arms 19 of which at least one arm is the deformation arm 31. Under the force of a shock with a bearing against the partition wall 17, the deformation zone 28 of the deformation arm 31 promotes the folding of said arm without breaking, the other arms deforming little, which causes the accessory to tilt around the motor housing 31 and to approach said casing to make the entire powertrain more compact and minimize the impact of said group against the partition wall 17, the accessory 15 is little deformable. The passenger compartment 18 of the vehicle is therefore substantially preserved to minimize the consequences of the impact on the driver and the passengers. The objective is achieved: the fixing system 30 of the accessory 15 which can be a catalyst pot makes it possible to make the power train more compact with a heat engine during a collision of the motor vehicle to minimize the impact of the impact on the partition wall 17 between the engine compartment 12 and the passenger compartment 18 of the vehicle.

As goes without saying, the invention is not limited to the embodiments of this deformation arm, described above as examples, it encompasses all variants. As has been recalled, the accessory can be held by a stand which is a combination of two arms, said stand can comprise a deformation arm as described above. The deformation arm 31 may also comprise a deformation zone with greater elastic mechanical characteristics compared to the remainder of the plate.

Claims

claims

1. System for fixing (30) an accessory (15) to a motor housing (1 1) in a motor vehicle compartment (12), said accessory being arranged between the housing (1 1) and a wall of the compartment

(17), comprising stretched plate-shaped holding arms (19) attached at one end to the motor housing and holding the accessory by the opposite end,

Characterized in that the system (30) comprises conformations (33) adapted to cause a tilting of the accessory

(15) around the casing in the event of impact with a bearing against the wall of the compartment to bring said accessory to said motor housing to make the entire powertrain more compact during a shock bearing on the wall of the compartment.

2. Fixing system (30) according to claim 1, characterized in that the system comprises at least one deformation arm (31) having a deformation zone (28) programmed. 3. Fixing system (30) according to claim 2, characterized in that the deformation arm (31) is arranged between an end portion of the accessory (15) and the motor housing (1 1).

4. Fastening system (30) according to one of claims 2 or 3, characterized in that the deformation arm (31) is shaped to reduce the spacing between the accessory (15) and the motor housing (1). 1) in case of shock. Fastening system (30) according to any one of the claims

2 to 4, characterized in that the deformation arm (31) has a zone of weakness (28) to allow folding of said arm in a direction transverse to the axis X 'of said arm.

6. Fastening system (30) according to claim 5, characterized in that the zone of weakness (28) comprises a transverse notch (35) to the axis (Χ ') of the deformation arm.

7. Fastening system (30) according to claim 5, characterized in that the zone of weakness (28) comprises a fold (29) transverse to the axis (Χ ') of the deformation arm.

8. Fastening system (30) according to claim 5, characterized in that the zone of weakness (28) comprises a zone transverse to the axis of the arm, of reduced thickness (e1) with respect to the nominal thickness ( e) plate (27) of said arm.

9. Fixing system (30) according to any one of claims 1 to 8, characterized in that the accessory (15) is in a list comprising a catalytic converter, a particulate filter, a NOx trap.

Motor vehicle engine with an accessory (15) according to claim 9.