VEHICLE EQUIPPED WITH A REAR CHASSIS UNIT MADE BY MOLD AND WITH IMPROVED REPAIRABILITY

Abstract

The invention relates to a vehicle equipped with at least one rear chassis unit (1A) produced by molding using the so-called gigacasting process, said unit (1A) comprising, distributed symmetrically on each side, two central portions (2) for the wheel arches, two upstream portions (4) located between each central portion (2) and a removable rear shock absorber (7, 8), and two downstream portions (3) located between each central portion (2) and the front portion of the vehicle chassis. Said rear unit (1A) comprising at least one cut line (9, 10) in a portion (4, 20) of the unit (1A), characterized in that at least one first cut line (9) is formed on each upstream portion (4) and a second cut line (10) is formed on each central portion (2). Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: VEHICLE WITH A REAR CHASSIS UNIT MADE BY MOLDING AND WITH IMPROVED REPAIRABILITY

[0001] The invention relates to a vehicle equipped with a rear chassis unit made by molding and with improved repairability.

[0002] Here the term vehicle means a car, a van, a truck, a public transport vehicle, a piece of public works or agricultural machinery, the vehicle being motorized by an electric motor, a thermal engine or a hybrid motorization.

[0003] Many manufacturers have adopted a process for manufacturing vehicle chassis parts using a molding process known as gigacasting. This involves replacing several welded parts with a single large cast piece. This solution saves manufacturing time, as the number of assembly and welding lines is reduced. However, this manufacturing technique creates problems when repairing the chassis, for example, after an impact. Indeed, a large part must then be replaced, which increases repair time and costs to such an extent that some vehicle leasing companies exclude vehicles with gigacasting chassis from their fleets. Insurance premiums for this type of vehicle also increase. Moreover, from an environmental perspective, the production and recycling of such large parts are not optimal.US-A-2023 0356 293 describes a part manufactured by gigacasting comprising a main body and so-called replaceable parts. Cut lines define the parts that can be replaced with a new part. CN-A-116 984 593 describes a repair method consisting of locating the damaged portion of the part and defining a cut line around it. Once removed, the damaged portion is replaced with an undamaged one, and replacement parts are manufactured based on the removed damaged portion. With certain chassis parts, particularly the rear unit, in a rear-end collision, the damage to the rear unit varies depending on the force of the impact, and therefore on the speed. Some damage, such as cracks, may necessitate a complete replacement of the rear unit when it is manufactured using the gigacasting technique.The invention aims to provide a solution for repairing a vehicle rear unit obtained by gigacasting using conventional repair techniques, following a rear-end collision, while adapting to the violence, and therefore the speed, of the impact.

[0004] To this end, the invention relates to a vehicle equipped with a rear chassis unit produced by molding according to the so-called gigacasting process, said unit comprising, distributed symmetrically on each side, two central parts for the passage of the wheels, two upstream parts located between each central part and a removable rear shock absorber, two downstream parts located between each central part and the front part of the vehicle chassis, said rear unit comprising at least one cut line of a part of the unit, characterized in that at least a first cut line is provided on each upstream part and a second cut line is provided on each central part.

[0005] Thanks to the invention, a vehicle is obtained in which the rear unit, produced by the gigacasting technique, is repairable by known repair methods, namely cutting, grinding, welding with filler material, or screwing. Thanks to the invention, the repair is adapted to the speed of the impact received and therefore makes it possible to limit the repair to only those areas of the unit likely to have been impacted by the shock, namely the shock absorber, at least an upstream portion, or a zone of the central section. It is therefore no longer necessary to replace the entire part, but only certain parts, depending on the speed, and therefore the force, of the impact received.

[0006] According to advantageous, but not mandatory, aspects of the invention, such a vehicle may include one or more of the following features:

[0007] At least one first cutting line is provided at the junction between each upstream part and each central part.

[0008] At least one second cutting line formed in each central part divides each central part into at least two parts.

[0009] The second cutting line divides each central part into two unequal parts.

[0010] The second cutting line is formed in one-third of each central part located near the junction with the upstream section.

[0011] The cutting lines are provided with a visual marking.

[0012] Each upstream part comprises at least two cutting lines.

[0013] The cutting lines are made by a technique chosen at least from overmolding, making a groove.

[0014] The invention will be better understood and other advantages thereof will become more apparent upon reading the following description, given solely by way of non-limiting example and with reference to the accompanying drawings in which:

[0015] [Fig-1] is a side view of one side of a rear unit of a state vehicle of the technique, starting from the outer face of the unit,

[0016] [Fig.2] is a view similar to [Fig.1] and to the same scale, of one side of a rear unit of a vehicle according to an embodiment of the invention,

[0017] [Fig.3] is a side view, similar to [Fig.2] and at the same scale, after separation of the parts along a first cutting line and,

[0018] [Fig.4] is a side view, similar to [Fig.3], after separation of the parts according a second cutting line.

[0019] Figure 1 illustrates one side of a rear chassis unit 1 produced by the so-called gigacasting technique, which consists of molding large parts in one piece, whereas traditionally these parts are made by assembling and welding individual elements. The unit 1 is made of metal, for example, aluminum, steel, or, advantageously, a metal alloy. A rear unit comprises a central body with two identical and symmetrical sides, the whole having an overall U-shape. In the various Figures 1 to 4, only one side of the unit is viewed laterally from the external face, that is, from outside the vehicle on which the unit 1 is mounted. Thus, the side of the unit 1 shown corresponds to the right side of the rear unit, according to the direction of travel of the vehicle represented by arrow F.For the sake of simplicity, only the right side of the unit will be described and referred to as the unit, it being understood that the invention relates to both sides of a rear unit, in an identical manner.

[0020] Unit 1 illustrates a prior art unit. It comprises a central concave portion 2 defining the passage of a wheel, not shown. A downstream portion 3 extends the central portion 2 towards the front of the vehicle, therefore here to the right of [Fig. 1], in the direction of arrow F. The portion 3 is elongated, with an overall rectangular cross-section in the illustrated example. An upstream portion 4 extends from the central portion 2 towards the rear of the vehicle, therefore here to the left. The upstream portion 4 is also elongated and has an overall rectangular cross-section.

[0021] It is understood that the shapes and dimensions of parts 2 to 4 are adapted to each vehicle. In all cases, the two sides of the rear unit of a vehicle are identical, and therefore, what is described for the illustrated unit 1 applies to the other side of the vehicle. The free end 5 of the upstream part 4, that is, the end opposite that 6 connected to the central part 2, supports a shock absorber 7. Such an absorber is known in itself, and its function is to absorb an impact on the rear bumper 8 of the vehicle, preserving the chassis from any deformation as much as possible. Hereafter, when the absorber 7, 8 is referred to, this will also include the bumper 8 attached to the absorber 7.

[0022] In a rear-end collision, also known as an urban collision, i.e., at a speed below 16 km / h, the impact is deformed and absorbed by elements 7 and 8, without the upstream part 4 being affected. In this case, it is easy to dismantle and replace elements 7 and 8 using techniques commonly practiced in automotive repair, at an acceptable cost and with an acceptable vehicle downtime. On the other hand, in a rear-end collision at a speed above 16 km / h, not only Elements 7 and 8 need to be replaced, but cracks and / or deformations may appear on the upstream part 4, or, depending on the force of the impact, on a portion of the central part 2. In this case, with a state-of-the-art rear unit 1, it is necessary to replace not only the absorber 7, 8 but also the entire rear unit 1, therefore the whole of the central part 2, downstream part 3 and upstream part 4 which generates significant costs and significant vehicle downtime.

[0023] Figure 2 illustrates one side of a rear unit IA according to an embodiment of the invention. The configuration and dimensions of unit IA are similar to those of unit 1, with Figure 2 also illustrating unit IA laterally from outside the vehicle. Elements common to and identical with those of Figure 1 will be designated by the same reference numerals for ease of reference. Thus, the central part 2, the downstream part 3 and upstream part 4, the shock absorber 7, and the bumper 8 are similar. The invention utilizes the fact that a part produced by gigacasting can be repaired using known repair techniques, for example, by cutting, grinding, welding with filler material, or screwing, due to the nature of the alloys used to produce the part. The object of the invention is to allow the repair of unit IA in a manner adapted to the impact received.For this purpose, at least two cutting lines 9, 10 are provided on each side of the rear unit IA. These cutting lines allow the damaged section to be cut out and then the replacement element to be welded or screwed in. Here, a cutting line is defined as areas within the unit IA that allow for easy cutting of the damaged section and its replacement with a new, or at least undamaged, section, using welding techniques with filler material or screwing techniques known per se. Such cutting lines are advantageously formed, for example, but not limited to, by overmolding or by creating grooves approximately one millimeter deep so as not to affect the strength and structural characteristics of the unit IA. It should be noted that, in one embodiment, the cutting lines 9, 10 are provided with visual markings. These markings may be a color code, an alphanumeric code, or a pictogram.Lines 9 and 10 are formed on both faces on either side of unit IA, and not just on the face shown in Figures 2 to 4. Thus, lines 9 and 10 cover the entire cross-section of the upstream and central parts on which they are formed. The cut can be made from either face of parts 2 and 4.

[0024] A first cutting line 9 is formed on the upstream part 4, in the vicinity of the junction 11 between part 4 and the central part 2. This cutting line 9 makes it possible to separate the upstream part 4 from the rest of the unit IA, as illustrated in [Fig. 3]. Such separation is necessary during an impact at a so-called average speed, at Speeds exceeding 16 km / h and below 40 km / h are known to occur. In such cases, not only is the shock absorber 7, 8 damaged, but the upstream part 4 is also frequently affected, for example, by cracking. Once the damaged part 4 has been removed, an undamaged part 4 can be reattached, as indicated by arrow Fl, to the central part 2. Part 4 is attached using techniques known per se, for example, by peripheral welding with filler material. Alternatively, parts 2 and 4 are joined by screws. At least four screws are placed around the periphery of the opposing faces of parts 2 and 4 to secure them. Advantageously, centering and positioning devices such as lugs on one face of part 2 or 4 and holes on the opposing face of the other part 4 or 2 are provided.Similarly, since in such a shock absorber 7, 8 is also damaged, a new absorber 7, 8 can be fixed, according to arrow F2, to the end 5 of the undamaged part 4. It is understood that this fixing is advantageously carried out once the new upstream part 4 is in place on the unit IA or, alternatively, prior to fixing the new part 4.

[0025] Figure 4 illustrates the case of a so-called high-speed rear-end collision, therefore greater at 40 km / h. In this case, not only the absorber 7, 8 and the upstream section 4 are damaged, but also the central section 2. It is generally the area near the end 6 of the upstream section 4 that is damaged, therefore the area near the junction 11 between sections 2 and 4. In other words, it is the third of the central section 2 located closest to the upstream section 4 that sustains the most damage. The second cut line 10 is positioned so as to define, overall, this area 20 of section 2 that is susceptible to damage in the event of a high-speed impact.

[0026] As before, it is then possible to remove, after cutting along line 10, the damaged parts 7, 8, 4, 20, advantageously in one go. Alternatively, depending on the force of the impact, it may be necessary to first cut part 4 along line 9 and then the portion of part 2 along line 10, after possibly separating the absorber 7, 8 from part 4. It is then possible to reattach, along arrow F3, a new or at least undamaged assembly of upstream part 4 and portion 20 of part 2 to unit IA. Such attachment is carried out by peripheral welding with filler material or by screwing, as before. Similarly, a new absorber 7, 8 is attached along arrow F4 to this assembly, either before or after mounting the upstream part 4 and portion 20 of part 2 onto unit IA.

[0027] Depending on the geometric configuration and / or dimensions of unit IA, it is possible to provide cutting lines other than lines 9 and 10. For example, in the case of a long upstream section 4, it is possible to provide another cutting line in addition to line 9 on the upstream section 4. Similarly, other cutting lines can be provided on section 2 in order to replace portions that are more or less important aspects of part 2 depending on the force of the impact. In all cases, the cutting lines, regardless of their number and / or configuration, must not weaken the resistance or alter the structural characteristics of unit IA.

Claims

Demands

1. Vehicle having a rear chassis unit (AI) produced by molding according to the so-called gigacasting process, said unit (AI) comprising, distributed on each side and symmetrically, two central parts (2) for the passage of the wheels, two upstream parts (4) located between each central part (2) and a removable rear shock absorber (7, 8), two downstream parts (3) located between each central part (2) and the front part of the vehicle chassis, said rear unit (AI) comprising at least one cutting line (9, 10) of a part (4, 20) of the unit (AI), characterized in that at least a first cutting line (9) is provided on each upstream part (4) and a second cutting line (10) is provided on each central part (2).

2. Vehicle according to claim 1, characterized in that at least one first cutting line (9) is provided at the junction (11) between each upstream part (4) and each central part (2).

3. Vehicle according to claim 1, characterized in that at least one second cutting line (10) formed in each central part (2) divides each central part into at least two parts (20).

4. Vehicle according to claim 3, characterized in that the second cutting line (10) divides each central part (2) into two unequal parts (20).

5. Vehicle according to claim 4, characterized in that the second cutting line (10) is formed in the third (20) of each central part (2) located in the vicinity of the junction (11) with the upstream part (4).

6. Vehicle according to at least one of the preceding claims, characterized in that the cutting lines (9, 10) are provided with a visual marking.

7. Vehicle according to claim 1, characterized in that each upstream part (4) comprises at least two cutting lines (9).

8. Vehicle according to any one of the preceding claims, characterized in that the cutting lines are made by a technique selected from overmolding, making a groove.

Images