Impact protection device for a system

Description

[0001] The invention relates to the field of impact protection devices for an internal combustion engine injection system, particularly for an injection system comprising at least one fuel injection rail. The invention also relates to an arrangement comprising such a protection device and a vehicle equipped with such an arrangement and / or such a protection device.

[0002] Fuel rails are used to supply an internal combustion engine with fuel, particularly gasoline. These rails are located outside the engine and allow for the storage of fuel under pressure to supply the engine's injectors.

[0003] In the event of a frontal collision, it is essential to protect the fuel rail to prevent it from shifting relative to the internal combustion engine and, consequently, from becoming detached from the injectors. Indeed, in diesel engines, for example, the fuel can reach pressures exceeding 1500 bar. Even partial detachment of the fuel rail would result in a high-pressure fuel leak into the engine and damage to various engine components. Furthermore, by spilling onto surfaces with high temperatures, as is common in a running engine, the fuel could potentially cause an engine fire.

[0004] It is known to use fuel rail protection devices, such as sheet metal or housing guards mounted on the engine, as disclosed in document US2006005800A1. However, these guards have the disadvantage of being bulky and unsuitable for engines with front-mounted injection, where space is limited. Furthermore, they do not maintain the fuel rail's position relative to the engine in the event of a significant impact.

[0005] To this end, the invention proposes a shock protection device for an internal combustion engine injection system. The protection device comprises a body configured to be mounted integrally to an engine cylinder head by means of a plurality of mounting tabs for said body. The protection device includes a hook-like element, connected to the body, having an open hook profile complementary to a profile of a fuel injection rail of the injection system. The injection rail comprises at least one flat surface facing outwards from the engine. The hook-like element is configured to extend into the engagement of said injection rail in order to ensure permanent contact with at least one flat surface of the injection rail and to prevent its movement relative to at least one injector of the engine.

[0006] Specifically, the attachment device can: be configured to prevent the displacement of the injection rail relative to at least one injector of the engine in a first direction, parallel to an extension axis of said injector, and in at least a second direction, orthogonal to the first direction; and / or be defined by an opening inscribed within an angular sector µ, relative to a principal extension direction of an injection rail, greater than or equal to 100°, in particular between 100 and 180°, or even between 100 and 150°.

[0007] The hook profile of the attachment member may include at least one free end segment configured to extend at least partially in relation to the fuel rail and / or an injector of the engine. Specifically, the free end segment may be configured to act as a stop for the fuel rail along at least one direction. In particular, the end segment may extend at least partially parallel, or substantially parallel, to a contact surface of at least one of the mounting tabs on the engine cylinder head, in order to minimize the overall size of the protective device.

[0008] Optionally, the profile of the attachment member may include a plurality of segments, of which at least the extreme, free segment, the extreme free segment of the attachment member being able to extend at least in part opposite at least one of the segments of the plurality of segments of the attachment member and the extreme segment 66 being able to have, relative to such a segment of the plurality of segments, an inclination β of between 30 and 80°, in particular between 35 and 70°, or even between 40 and 60°.

[0009] Advantageously, all or part of an internal surface of the attachment member, configured to be turned towards the injection ramp, can be equipped with a vibration absorption means, in particular made of a polymer material.

[0010] Optionally, the fastening element may include at least one means of reinforcement, such as a reinforcing edge, groove or reinforcing cord, in order to increase its rigidity.

[0011] The attachment element can be configured to be at least partially interposed between two fixing lugs of the plurality of fixing lugs, in particular along a straight line of extension of the body.

[0012] In a specific example, the attachment element can be an added part mounted as a fixed component to the body, specifically at least one of the body's mounting tabs. For example, both the attachment element and the body can be made of metallic materials, such as bent or deformed sheet steel.

[0013] The invention also relates to an arrangement comprising an internal combustion engine equipped with an injection system including at least one fuel injection rail connected by lines to injectors mounted in a cylinder head of said engine and including at least one flat surface, in particular facing outwards from the engine, the arrangement further comprising a shock protection device as described above: the body of the device being mounted securely to the cylinder head by means of the plurality of fixing lugs; the hooking member extending into contact with the injection rail so as to ensure permanent contact with at least one flat surface of the injection rail and to prevent its movement relative to at least one of the injectors.

[0014] In particular, the attachment element can extend by gripping at least part of an extreme portion of the injection rail, along a main direction of extension of the injection rail.

[0015] Optionally, the injection rail can be defined by a total length, along the main direction of extension of the injection rail, the attachment member including an attachment part, configured to be at least partly in permanent contact with the injection rail, which may have a width, along said direction, greater than 3% of the total length of the injection rail, in particular between 3 and 15% of the total length, or even between 5 and 10%.

[0016] Optionally, the injection system may further include an LPG supply rail for the internal combustion engine, the supply rail being arranged to be interposed between the injection rail and at least a part of the body along one direction of travel of the vehicle, the attachment member being arranged to be at least partially interposed between the injection rail and the supply rail.

[0017] The invention finally relates to a motor vehicle comprising at least one internal combustion engine equipped with a crash protection device according to the invention and / or comprising at least one arrangement according to the invention.

[0018] Further details, features and advantages will become clearer upon reading the detailed description given below, which is indicative and not exhaustive, in relation to the various implementation examples illustrated in the following figures: [Fig. 1 ] There figure 1 is a schematic view of an embodiment of a disassembled arrangement comprising an internal combustion engine and a protection device according to the invention. Fig. 2 ] There figure 2 is a schematic view of the arrangement according to the figure 1 when it is assembled. Fig. 3 ] There figure 3 is a perspective view of a first embodiment of the protection device. Fig. 4 ] There figure 4 is a perspective view of the first embodiment of the protection device. Fig. 5 ] There figure 5 is a longitudinal cross-sectional view taken at the level of a fastening element of the protective device according to the first embodiment when it is integrated into the arrangement. Fig. 6 ] There figure 6 is a longitudinal cross-sectional view taken at the level of the attachment point of the protective device according to the first embodiment when it is integrated into the arrangement. Fig. 7 ] There figure 7 is a perspective view of the attachment point illustrated in the figure 5 . [ Fig. 8 ] There figure 8 is a perspective view of a second embodiment of the protection device. Fig. 9 ] There figure 9 is a perspective view of the second embodiment of the protection device. Fig. 10 ] There figure 10 is a perspective view of the attachment element of the protective device according to the second embodiment.

[0019] THE figures 1 et 2 These diagrams schematically illustrate one embodiment of an arrangement 1 for a motor vehicle. Arrangement 1 comprises an internal combustion engine 2 and a crash protection device 3. With reference to the orientations and directions defined below, the longitudinal direction is represented by the Ox axis and corresponds to the direction of travel of the vehicle, while the Oy and Oz axes represent the vertical and transverse directions, respectively. These axes together define a coordinate system Oxyz, shown in the relevant figures.

[0020] The engine 2 is equipped with an injection system 4 comprising at least one fuel injection rail 41, in particular for gasoline, as illustrated in figures 1 à 7 for a first embodiment of the invention. According to a second embodiment, further detailed below with reference to figures 8 à 10 The injection system 4 may further include a fuel rail 42 for the LPG-powered internal combustion engine 2. As is known, the fuel rail 41 is mounted on a cylinder head 21 of the engine 2 and located between an injection pump (not shown) and injectors 22 mounted in the cylinder head 21. The fuel rail 41 is supplied with fuel under high pressure by the pump and is connected to the injectors 22 by lines 23 or any other similar connecting means.

[0021] The fuel rail 41 has an elongated structure, in particular at least partially cylindrical or substantially cylindrical, and includes at least one flat surface. In particular, said flat surface may face outwards from the engine, i.e., away from the cylinder head 21 and / or the injectors 22. For example, a "flat surface" is understood to mean a side of the profile of the fuel rail 41, as illustrated, or, alternatively (not shown), a flat section integrated into a fuel rail 41 that may have a circular, oblong, or elliptical profile. Optionally, the fuel rail may include a plurality of flat surfaces. In particular, the fuel rail 41 extends along a principal direction of extension 410, in this case substantially parallel to the Oz axis, and is centered on this same direction. By way of example, the fuel rail 41 is made of a metallic material, such as aluminum.The injection rail 41 further includes a fuel supply orifice, not shown, and distributes fuel to the injectors 22 via a plurality of connecting orifices at which the lines 23 are arranged.

[0022] As seen at the figure 5 When the arrangement 1 is assembled under normal, or "reference," conditions, for each pair of injectors and lines connected, an extension axis 220 of the injector and a main extension axis 230 of the line are coincident or substantially coincident. In other words, under normal conditions, the injector and the line cooperating together are at least partially coaxial or substantially coaxial. In a vehicle lacking a protective device 3 according to the invention, in the event of a collision, the front-mounted components may crush, tear, or shear the fuel rail 41, thereby causing the lines 23 and injectors 22 to separate.This can then result in a displacement of the injection rail 41 and the lines 23, in particular by the rotation of the injection rail 41 around its axis, such that the main extension axis 230 of the line then extends transversely to the extension axis 220 of the injector in question. Their connection is then weakened, or even interrupted, and the sealing of such a connection may be compromised.

[0023] To prevent such detachment and to protect the injection system 4 against impacts, particularly the fuel rail 41, the protective device 3 comprises a body 5 and a mounting element 6. The body 5 is configured to be mounted securely to the cylinder head 21 of the engine 2 by means of a plurality of mounting tabs 51 of said body 5. In particular, the body 5 includes at least two mounting tabs 51. The body 5 is specifically configured to be floating relative to the fuel rail 41, that is, it extends at a non-zero distance from the fuel rail 41 under normal conditions. In other words, the body 5 is fixed to the cylinder head 21 of the engine 2 at its mounting tabs 51, and at least one base 52 of the body 5 extends at a distance from the cylinder head 21, without making direct contact with it. Thus, at least one of the fixing tabs 51 is connected to said base 52.In this way, the body 5 exerts no direct mechanical stress on the injection system 4, in particular the injection rail 41, under normal conditions. In the illustrated, non-limiting example, the protective device 3 comprises three mounting tabs 51 mounted at separate points on the cylinder head 21.

[0024] The mounting lugs 51 extend transversely to the base 52, in particular at least partly perpendicular to it, in the direction of the cylinder head 21. They include at least one flat or substantially flat portion defining a contact surface with the cylinder head 21 of the engine.

[0025] According to the illustrated embodiments, at least two mounting lugs 51 may be positioned oppositely along an extension line 520 of the base 52 and the body 5. In this case, such a line extends parallel or substantially parallel to the main extension direction 410 of the fuel rail 41 and / or to the Oz axis. In other words, at least two mounting lugs 51 of the plurality of mounting lugs 51 of the protective device 3 may be connected to opposite portions of the base 52 along the extension line 520 of said base 52. Such a positioning of the mounting lugs 51 allows for proper retention of the mounting device on the cylinder head 21 while limiting the number of attachment points.

[0026] The gripping member 6 is connected to the body 5 and is configured to extend into the injection rail 41 in order to ensure permanent contact with at least one flat surface thereof. "Permanent contact" here means at least one point of contact between the gripping member 6 and the injection rail 41 that exists at all times, even in the event of an impact. The gripping member 6, in combination with the body 5, thus ensures that the injection rail is held in its normal, or reference, position. In this case, it advantageously prevents its movement relative to the injectors 22 of the engine 2 in a first direction, parallel to the extension axis 220 of at least one of the injectors 22, and in at least a second direction, orthogonal to the first direction. In particular, the second direction is also orthogonal to the extension direction of the injection rail 41.As a consequence, the protection device 3 prevents the movement of the injection rail 41 along the vertical axis Oy and along the longitudinal axis Ox, and therefore the rotation of the injection rail 41.

[0027] In general, the attachment member 6 comprises an attachment part 61, configured to cooperate with the injection rail 41, in particular to be at least partly in permanent contact with said rail, and a linking part 62, carrying said attachment part 61 and through which the attachment member 6 is connected to the body 5 of the protection device 3.

[0028] Preferably, the fastening member 6 is arranged within the protective device 3 so as to be at least partially interposed between two of the fastening lugs 51 of the plurality of fastening lugs 51 along a third direction, orthogonal to the first and second directions. In particular, said third direction extends parallel, or substantially parallel, to the Oz direction and / or to the extension line 520 of the base 52. In other words, the fastening member 6 is configured to extend at least partially into an intermediate volume 300 delimited by the body 5, in particular by at least two of the fastening lugs 51 and the base 52 supporting them, relative to the breech 21. Thus, in the event of mechanical stress or an impact exerted along the third direction, at least part of the impact is first absorbed by one of the fastening lugs 51.The attachment element 6, and by extension its connection to the injection rail 41, is thus protected from direct impact. Furthermore, this positioning helps to limit the bulk generated by the protective device 3.

[0029] Preferably, the gripping member 6 is arranged within the protective device 3 so as to extend by gripping at least part of an extreme portion of the injection rail 41. "Extreme" means the portion of the injection rail 41 corresponding to 5 to 25%, in particular 10 to 20%, of the total length of the injection rail 41, such length being defined along the main extension direction 410 of the injection rail 41. In other words, at least one flat surface may be included, at least in part, within the extreme portion of the injection rail 41, in particular within all or part of said extreme portion. In particular, such an extreme portion may be the one furthest from the injection pump. Indeed, it has been observed that the extreme portions of the injection rail 41 are likely to suffer more stress, and by extension more damage, than a central part of the latter.

[0030] In this respect, the attachment member 6 can advantageously be connected to one of the mounting tabs 51. In particular, according to an example of an embodiment illustrated in figures 3 et 4 The attachment member 6 can be connected to an inner face, facing the injection rail 41, of the mounting bracket in question. The attachment member 6 can thus be partially offset relative to the mounting bracket 51 supporting it, particularly along the third direction. According to an alternative (not shown), the attachment member 6 can be connected to the base 52, or alternatively to the base 52 and at least one of the mounting brackets 51.

[0031] As illustrated in figures 1 à 7 The attachment member 6, in particular its attachment part 61, extends to engage with the injection rail 41. By "engaged" is meant, in particular, in the embodiment illustrated in the figure 6 , that the shape and dimensions of the attachment member 6 are adapted to the injection rail 41 in order to ensure sufficient permanent contact to prevent movement of the injection rail 41 relative to at least one injector 22.

[0032] In particular, the hook member 6 advantageously has an open hook profile suitable for receiving the injection rail 41. Such a shape aims to ensure that the injection rail 41 is held in position while allowing simple assembly of the hook member 6 onto the rail.

[0033] The attachment member 6 can thus, preferably, have a shape at least partly complementary to that of the injection rail 41. In particular, a profile of the attachment member 6, here defined at the level of the attachment part 61 along a longitudinal plane, is at least partly complementary to the profile of the injection rail 41. It is understood that "profile" means a definition of the shape of the attachment member in a two-dimensional plane but that said member extends in three dimensions, in particular, in the illustrated example, also in the transverse direction of the vehicle.

[0034] In particular, the attachment member 6 can be defined by a profile having an opening suitable for allowing the passage of the injection rail 41 without affecting the retention of the injection rail 41 in position. The opening lies within an angular sector µ greater than or equal to 100°, specifically between 100 and 180°, or even between 100 and 150°. Such an angular sector µ is defined relative to the principal extension direction 410 of the injection rail 41 and delimited by two half-lines originating at said direction and passing through points of the profile delimiting said opening. In other words, the hooked profile of the attachment member 6 then lies within an angular sector complementary to the angular sector µ, which may be less than 260°, for example, between 180 and 260°, or even between 180 and 230°.Such an arrangement makes it possible, in particular for the example of the injection rail 41 illustrated, to ensure that the hooking member forms a stop, or extends into contact, with the injection rail on two opposite sides of the injection rail 41 or, in the case of a rail with a circular profile, from two diametrically opposite points of said rail while allowing simple positioning of the hooking member 6 on the injection rail 41.

[0035] In particular, according to a specific, non-limiting embodiment, the attachment member 6, specifically the profile of the attachment portion 61, may comprise a plurality of segments, including at least one free end segment 66 that helps to define the opening. Here, "segment" is understood to mean a portion or part of a whole, in this case, the attachment member 6, specifically the profile of the attachment portion 61. Each segment may, for example, have a curved or straight shape.

[0036] In particular, in the illustrated example, the attachment member 6 comprises a first segment 63 and a second segment 64, connected to each other by at least one intermediate segment 65. The second segment 64 carries the free segment 66 while the first segment participates in defining, with the extreme segment 66, the "open" shape of the profile of the attachment member 6. In other words, it extends at a non-zero distance from the extreme segment 66 of the attachment part 61.

[0037] The first segment 63 is configured to extend at least partially into contact with a first side 411 on the two opposite sides of the injection rail 41, and / or the second segment 64 is configured to be at least partially in contact with a second side 412 of the rail, opposite the first side 411, thus forming various points of contact with sides of the injection rail 41. In particular, and preferably, such points of contact may be permanent points of contact. The intermediate segment 65 may additionally extend into contact with a third side 413 of the injection rail 41, which connects the first side 411 and the second side 412, in particular to define a permanent point of contact between the injection rail 41 and the attachment member 6.Thus, in the illustrated example, the first side 411, the second side 412 and the third side 413 are flat surfaces of the injection rail 41, the hooking member 6 being configured to ensure permanent contact with the first side 411 and / or the second side 412 and / or the third side 413.

[0038] The first segment 63 forms a stop for the injection rail 41, in particular on the first side 411 of the injection rail 41, in a direction of the second direction, while the second segment 64 forms a stop for the injection rail 41, here on the second side 412 of the injection rail 41, in an opposite direction of this same direction, each of said segments comprising points of contact with the injection rail 41.

[0039] The free end segment 66 is configured here to act as a stop for the injection rail 41 along the first direction and / or along the second direction. Specifically, the intermediate segment 65 acts as a stop for the injection rail 41 along one direction of the first direction, while the end segment 66 limits its movement in the opposite direction. In this case, the end segment 66 helps to maintain the injection rail 41 along the first direction. The end segment 66 thus secures the grip of the attachment member 6 on the injection rail 41, that is, it ensures continuous contact between the injection rail 41 and the attachment member 6.In addition to the second segment 64, it ensures the maintenance of the injection rail 41 relative to the engine 2 when significant stresses are exerted on the protection device 3, in particular to contribute to the permanent contact between the injection rail 41 and the attachment element 6.

[0040] Within arrangement 1, the free end segment 66 of the attachment member 6 thus extends at least partially opposite the injection rail 41 and / or the injector along the second direction. In this case, the end segment 66 extends partially opposite the second side 412 and a fourth side 414, opposite the third side 413, of the injection rail 41.

[0041] In other words, the free end segment 66 of the attachment member 6 extends at least partially opposite at least one of the segments of the plurality of segments of the attachment member 6. In particular, the end segment 66 may have, relative to such a segment of the plurality of segments, an inclination β of between 30 and 80°, in particular between 35 and 70°, or even between 40 and 60°. In the illustrated example, the end segment 66 extends opposite the intermediate segment 65 along the first direction and opposite the first segment 63 along the second direction, and the inclination β is defined relative to the intermediate segment 65.

[0042] In order to ensure this safety function, and depending on the size of the engine environment 2, the outermost segment 66 may, alternatively or additionally, have an inclination α relative to the second segment 64 of between 10 and 60°. In this respect, the outermost segment 66 may, alternatively or additionally, extend at least partially parallel, or substantially parallel, to the contact surface of at least one of the mounting tabs 51 of the device on the cylinder head as illustrated in the figure 8 .

[0043] The protective device 3 is essentially made of a metallic material, for example, bent or deformed sheet steel, to ensure adequate resistance to mechanical stresses. In particular, the body 5 of the protective device 3 may be composed of a plurality of attached metal parts, held together by means of fasteners, such as rivets, and / or by welding. Alternatively, at least one of the mounting tabs 51 and the base 52 may form a single unit, meaning that they cannot be separated from each other without resulting in their degradation or even destruction.

[0044] Similarly, the fastening member 6 is preferably made of a metallic material, for example, sheet steel. The fastening member 6 may be an added part mounted integrally to the body 5, in particular, as described above, by at least one mounting tab 51. By way of non-limiting example, the fastening member 6 may be mounted to the body 5 by means of rivets. The body 5, here the mounting tab 51, may then optionally include at least one oblong hole to allow adjustment of the position of the fastening member 6 relative to the body 5 during the assembly of the protective device 3. Alternatively, the fastening member 6 may be fixed to the body 5 by welding. According to yet another alternative, not shown, the fastening member 6 and at least a part of the body 5, in this case one of the mounting tabs 51, may form a single unit.

[0045] Optionally, but preferably, all or part of an internal surface 600 of the attachment member 6, configured to face the injection ramp 41 within the arrangement 1 and, in particular, to maintain permanent contact with the injection ramp 41, is equipped with a vibration-absorbing means. Such an absorption means may, for example, be made of a polymer material such as an elastomeric foam. Preferably, the absorption means 67 has a thickness greater than 1 mm, in particular between 1.5 and 5 mm, or even between 1.5 and 3 mm. The absorption means 67 may extend at least partially into the first segment 63 and / or the second segment 64. In addition, the absorption means 67 may extend into the intermediate segment 65. Optionally, the absorption means 67 may extend into the outermost segment 66.

[0046] The absorption means 67 advantageously allows for limiting direct contact between elements made of metallic materials, in this case the attachment member 6 and the injection rail 41, and allows for at least partial absorption of vibrations generated by the internal combustion engine 2 and likely to be transmitted to the attachment member 6 via the injection rail 41.

[0047] THE figures 8 à 10 illustrate an example of a second embodiment of the invention in which the injection system 4 comprises, in addition to the fuel injection rail 41, a fuel supply rail 42 for the internal combustion engine 2 using LPG, for "liquefied petroleum gas". This results in an arrangement 1 substantially similar to the arrangement previously described, except that, in the present embodiment, the fuel supply rail 42 is positioned to be interposed between the injection rail 41 and at least a portion of the body 5, in particular the base 52, along the Ox direction of travel of the vehicle. In other words, the fuel supply rail 42 extends into the intermediate volume 300 delimited by the protective device 3.

[0048] The entirety of the preceding description applies mutatis mutandisin the present embodiment. Within arrangement 1, the attachment member 6 extends, as previously described, into contact with the injection rail 41 and is positioned to be at least partially interposed between the injection rail 41 and the supply rail 42, particularly along the Ox direction of vehicle movement. For example, the attachment portion 61, in particular the intermediate segment 65, can be interposed between the injection rail 41 and the supply rail 42 along the Ox direction.

[0049] The protective device 3 is substantially identical to that previously described, except that it is shaped and dimensioned to accommodate, within the intermediate volume 300, at least partially the LPG supply rail 42. Specifically, the length of at least one mounting bracket, corresponding to the dimension measured along the Ox direction, is increased compared to a mounting bracket as described with reference to the first embodiment. Consequently, the structure of at least one of the mounting brackets 51 can be reinforced, for example, by increasing the thickness of said brackets or, as illustrated, by adding reinforcing edges 53.

[0050] In the illustrated example, in order to accommodate such modifications of the fixing lug, the connection of the hook member 6 to the fixing lug can be modified so that the connecting part 62 of the hook member 6 is fixed on an extreme portion, along the Ox direction, of the fixing lug closest to the cylinder head 21, that is to say in the vicinity of the contact surface of the fixing lug on the cylinder head 21.

[0051] Optionally, and in order to optimize the resistance of the hooking element to mechanical stresses, it may include at least one reinforcing means 68. According to the illustrated, non-limiting example, such a reinforcing means 68 is configured to increase the resistance of the hooking element to mechanical stresses and may include a flange closing at least partially the hook profile of the hooking portion 61, that is, closing at least partially the hooking portion 61 along the third direction. The reinforcing means 68 extends transversely, in particular perpendicularly, to the first segment 63 and / or the second segment 64 and / or the intermediate segment 65. Such a feature may advantageously extend to the first embodiment. Alternatively, or in combination, the reinforcing means 68 may include a groove or a reinforced cord 68' extending over all or part of the profile of the hooking element 6 in order to increase its rigidity.

[0052] Thus, the protective device according to the invention provides shock protection for the fuel rail of an internal combustion engine and prevents its detachment from the injectors. In the event of an impact, this protection is achieved through two main mechanisms: firstly, passive protection via the device body mounted on the cylinder head, which extends freely relative to the fuel rail; and secondly, active protection and retention via the attachment element, which engages with the fuel rail and maintains constant contact with it, thus preserving its position relative to the engine and its injectors, even in the event of an impact. Consequently, the invention thus prevents, at a lower cost, the risk of fuel leaks commonly observed following a frontal impact on the vehicle.

[0053] The present invention is not limited to the means and configurations described and illustrated herein. It also extends to any equivalent means or configuration, as well as any technically feasible combination of such means, insofar as they fulfill the described functionalities. In any event, the scope of the invention shall be determined in light of the following claims.

Claims

1. Shock protection device (3) for an injection system (4) of an internal combustion engine (2), the protection device (3) comprising a body (5) configured to be mounted integrally with a cylinder head (21) of an engine (2) by means of a plurality of fixing tabs (51) of the body (5), characterised in that the protection device (3) comprises a hooking member (6), connected to the body (5), having an open hook-shaped profile complementary to a profile of a fuel injection rail (41) of the injection system (4), the injection rail (41) comprising at least one flat surface, in particular facing outwardly of the engine (2), the hooking member (6) being configured to extend in engagement with the injection rail (41) so as to ensure permanent contact with the at least one flat surface of the injection rail (41) and to prevent displacement thereof relative to at least one injector (22) of the engine (2).

2. The protection device (3) according to the preceding claim, wherein the hook-shaped profile of the hooking member (6) comprises at least one free end segment (66) configured to extend at least partly opposite an injection rail (41) and / or an injector (22) of the engine (2).

3. The protection device (3) according to one of the preceding claims, wherein all or part of an internal surface (600) of the hooking member (6), configured to face an injection rail (41), is provided with vibration-absorbing means (67), the vibration-absorbing means being made, in particular, of a polymer material.

4. The protection device (3) according to one of the preceding claims, wherein the hooking member (6) is configured to be at least partly interposed between two fixing tabs (51) of the plurality of fixing tabs (51), in particular along an extension line (520) of the body (5).

5. The protection device (3) according to one of the preceding claims, wherein the hooking member (6) is a separate part mounted integrally with the body (5), in particular with at least one fixing tab (51) of the body (5).

6. An assembly (1) comprising an internal combustion engine (2) provided with an injection system (4) comprising at least one fuel injection rail (41), the injection rail (41) being connected by conduits (23) to injectors (22) mounted in a cylinder head (21) of the engine (2) and comprising at least one flat surface, in particular facing outwardly of the engine (2), the assembly (1) further comprising a shock protection device (3) according to one of the preceding claims: - the body (5) of the device being mounted integrally with the cylinder head (21) by means of the plurality of fixing tabs (51), - the hooking member (6) extending in engagement with the injection rail (41) so as to ensure permanent contact with the at least one flat surface of the injection rail (41) and to prevent displacement thereof relative to at least one of the injectors (22).

7. The assembly (1) according to the preceding claim, wherein the hooking member (6) extends in engagement with at least part of an end portion of the injection rail (41), along a main extension direction (410) of the injection rail (41).

8. The assembly according to one of claims 6 or 7, wherein the injection rail (41) is defined by a total length along a main extension direction (410) of the injection rail (41), the hooking member (6) comprising a hooking portion (61), configured to be at least partly in permanent contact with the injection rail (41), the hooking portion (61) having a width (601), along the direction (410), greater than 3% of the total length of the injection rail (41), in particular between 3% and 15% of the total length, preferably between 5% and 10%.

9. The assembly (1) according to one of claims 6 to 8, wherein the injection system (4) further comprises a supply rail (42) of an LPG internal combustion engine (2), the supply rail (42) being arranged so as to be interposed between the injection rail (41) and at least part of the body (5) along a vehicle forward direction (Ox), the hooking member (6) being arranged so as to be at least partly interposed between the injection rail (41) and the supply rail (42).

10. A motor vehicle comprising at least one internal combustion engine (2) provided with a shock protection device (3) according to one of claims 1 to 5 and / or comprising at least one assembly (1) according to one of claims 6 to 9.