Reinforced chassis cell for motor vehicle and related manufacturing process

Abstract

To provide a chassis cell or body cell for a motor vehicle, in particular of sports type.SOLUTION: A chassis cell (2) for a motor vehicle (1) defines a passenger compartment for the motor vehicle (1) and comprises at least one shell (10) comprising carbon fibre and at least two first walls (11, 12) facing one another so as to define a cavity therebetween, is characterized in that it further comprises one or more partitions comprising carbon fibre, arranged inside the cavity according to an arrangement, each extending transversally to the first walls (11, 12) between two first ends respectively connected to the first walls (11, 12) seamlessly.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] [Cross - reference to Related Applications] This patent application claims the priority of Italian Patent Application No. 102022000012167 filed on June 8, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] The present invention relates particularly to a chassis frame or a body frame for a sports - type motor vehicle.

[0003] The present invention further relates to a method for manufacturing a chassis frame or a body frame.

Background Art

[0004] As is known, an automobile comprises a body including a support structure or a chassis that defines the skeleton of the automobile. The support structure or the chassis has the function of supporting various components of the automobile.

[0005] Furthermore, the body also includes a car body, that is, an assembly of bodies or panels such as a bonnet, doors, roof, fenders, bumpers, etc., which are supported by the chassis and define the surface and the outer contour of the automobile.

[0006] This chassis comprises a chassis frame or a body frame that defines a passenger compartment of the automobile in which the passengers and the driver of the automobile are accommodated.

[0007] This chassis frame has the function of defining the boundary of the passenger compartment, but particularly has the function of ensuring that the accommodated persons are properly protected. Therefore, the chassis frame must be particularly robust and highly rigid so that the persons in the passenger compartment are fairly safe even when a collision occurs.

[0008] Generally, automobile manufacturers consider it desirable that the chassis frame is as lightweight as possible while keeping the total weight of the automobile suppressed.

[0009] Therefore, the chassis structure is typically composed of one or more interconnected, hollow shells.

[0010] Carbon fiber is a particularly suitable material for manufacturing this shell due to its lightweight and strong properties.

[0011] Therefore, some sports cars incorporate carbon fiber into their shells.

[0012] Typically, carbon fiber shells are further reinforced or strengthened internally by structural foams and / or honeycomb structures that serve to reinforce the hollow portions of the shell.

[0013] A typical method involves bonding two half-shells that have been separately fired or polymerized, in order to allow the introduction of a structural foam or honeycomb structure containing a material different from the shell material into each of the shells. Therefore, the foam or honeycomb structure can be interposed between the half-shells before the half-shells are finally bonded together, thus forming a fully closed shell containing the structural foam and / or honeycomb structure.

[0014] Generally, it is considered necessary to improve known chassis structures, either by limiting their weight while maintaining or actually increasing their sturdiness, or simply by increasing their sturdiness alone.

[0015] Furthermore, there is a need to realize a method for manufacturing chassis structures that is an alternative to known or improved methods, for example, simpler, more cost-effective, and / or more reliable.

[0016] In particular, it is considered necessary that the method be monitorable and / or controllable. In other words, it is considered necessary to have a method that can determine or achieve the final quality of the chassis structure, or a method that allows operator intervention during execution, for example, to evaluate the state of the method or intermediate products, or to make adjustments that are useful in improving the final quality of the chassis structure. [Overview of the project] [Problems that the invention aims to solve]

[0017] The object of the present invention is to satisfy at least one of the above-mentioned needs. [Means for solving the problem]

[0018] This objective is achieved by a chassis frame for an automobile, and related manufacturing methods, as defined in each independent claim.

[0019] Each dependent claim defines a specific embodiment of the present invention. [Brief explanation of the drawing]

[0020] The following is a description of embodiments of the present invention, provided with reference to the attached drawings, as non-limiting examples, to better understand them.

[0021] [Figure 1] This is a perspective view of an automobile equipped with a chassis frame according to one embodiment of the present invention. [Figure 2] This is a perspective view showing a step in a method for manufacturing a chassis frame according to a further embodiment of the present invention. [Figure 3] This is a cross-sectional view showing a further step in this manufacturing method. [Figure 4] This is an exploded view of the mold that is closed during the manufacturing process. [Figure 5] This is a perspective view showing the mold in an open configuration as shown in Figure 4. [Figure 6]It is a cross-sectional view showing subsequent steps of the manufacturing method for the step of FIG. 3.

Embodiments for Carrying Out the Invention

[0022] In FIG. 1, reference numeral 1 is used to indicate an automobile as a whole.

[0023] Similar to any automobile, the automobile 1 has a normal forward direction and includes a passenger compartment for accommodating a driver and, optionally, one or more passengers.

[0024] The automobile 1 includes a chassis frame or body frame 2 that defines or forms the passenger compartment. For example, the chassis frame 2 can be of an integral structure.

[0025] More generally, the chassis frame 2 is part of the chassis of the automobile 1, and the chassis supports a plurality of components, some of which define, for example, the outer surface of the automobile 1, that is, the surface visible to a person outside the passenger compartment.

[0026] Specifically, the components supported by the chassis include at least one of a fender 3, a side door 4, a roof 5, and a rear bumper 6 with respect to the forward direction of the automobile 1.

[0027] Specifically, FIG. 1 schematically shows the side end face 7 of the chassis frame 2. The term "side" should be understood based on the orientation in which the chassis frame 2 is arranged with respect to the automobile 1 and with respect to the forward direction of the automobile 1. Alternatively, the term "side" can also be understood based on the orientation of the passenger compartment.

[0028] The side end face 7 is open towards the passenger compartment, that is, it has an opening through which a person can enter the passenger compartment.

[0029] In particular, the opening at the side end face 7 can be closed by the side door 4, as shown in Figure 1, and the side door 4 is shown in the closed position, i.e., the position in which the side door 4 prevents a person from entering the vehicle compartment through the opening.

[0030] In other words, in the closed position, the side door 4 covers or conceals the opening and the side end face 7, according to the view from the outside of the automobile 1.

[0031] The side end face 7 is provided with a box-shaped beam in particular. This beam extends in a linear direction or along axis A, particularly parallel to the forward direction, or in any case in the longitudinal direction, i.e., adjacent to the side door 4 in the closed position.

[0032] This beam has a concave contour along axis A. In relation to the vehicle 1, the contour of this beam is concave upwards. In other words, the contour of this beam is concave toward the opening of the side end face 7.

[0033] This beam is specifically a single component and comprises two pillars 8 that define each end of the beam along axis A. Furthermore, the beam comprises longitudinal supports or door frames 9 that extend along axis A between the pillars 8.

[0034] The door frame 9 is seamlessly connected to the pillar 8, i.e., it forms a single body with the pillar 8.

[0035] In the following, the expression "seamlessly" can be understood as meaning one of the following: integrated, coherent, indistinguishable, or any combination of the aforementioned expressions, such as integrated, coherent, or indistinguishable.

[0036] Pillar 8 extends laterally with respect to axis A.

[0037] Therefore, pillar 8 forms a concave surface in the beam's contour.

[0038] In addition to the side end faces 7, the chassis frame 2 also includes a bottom (not shown) that defines the chassis or floor surface of the passenger compartment.

[0039] More specifically, the chassis frame 2 has another side end face, identical to the side end face 7, located opposite the side end face 7, particularly in the direction perpendicular to the horizontal and forward direction.

[0040] This floor surface extends between the side end face 7 and the other side end face.

[0041] Preferably, this floor surface is seamlessly connected to the side end face 7, that is, this floor surface, together with the side end face 7 and possibly the other side end face, forms a single body.

[0042] Generally, the chassis frame 2 comprises at least one shell 10 made of carbon fiber.

[0043] The chassis frame 2 can be understood as a single shell 10, or as multiple interconnected shells 10, regardless of the type of connection between the shells 10. For example, the shells 10 can be connected to each other seamlessly, i.e., to form a single body containing carbon fiber, i.e., a one-piece structure.

[0044] In this case, it is preferable that the beams on the side end faces 7 constitute the shell 10, and that the floor surface also constitutes the shell 10.

[0045] For the sake of brevity, the following explanation will briefly refer to only one shell 10, specifically the beam at the side end face 7.

[0046] However, the teachings given for the shell 10 described in detail can be directly applied to other shells 10 of the chassis frame 2, or to the entire chassis frame 2 as a single shell. In other words, each characteristic described for the shell 10 as described in detail herein can essentially be applied to all other shells 10 of the chassis frame 2, or to the entire chassis frame 2 as a single shell.

[0047] The shell 10 has at least two walls 11, 12 facing each other, and a cavity 13 is at least partially defined or bounded between the walls 11, 12.

[0048] Specifically, walls 11 and 12 pass across axis B, which is perpendicular to axis A, and through the sides of the passenger compartment. In other words, axis B is perpendicular to the side door 4 in the closed position, or passes through the opening of the side end face 7.

[0049] The beams of the side end faces 7, or the shell 10, may also have other walls in addition to, or instead of, the walls 11, 12, that at least partially border or define the cavity 13.

[0050] For example, each or just one of the pillars 8 is bounded according to axis A by two walls 15, 16 that are lateral to axis A. More precisely, walls 15, 16 extend lateral to walls 11, 12 between them.

[0051] In particular, walls 15 and 16 face each other.

[0052] Furthermore, each or just one of the pillars 8 is bounded by the respective wall sections 17 and 18 of the walls 11 and 12.

[0053] Therefore, the wall sections 17, 18 and the walls 15, 16 form one or each of the pillars 8.

[0054] The wall sections 17, 18 or walls 15, 16 face each other so as to at least partially define or boundary the cavity 14, which is part of the cavity 13. The cavity 14 is completely defined or boundary by the walls 15, 16 and the wall sections 17, 18. Each of the pillars 8 can define a corresponding cavity 14, for example, by the wall sections 15, 16 or the wall sections 17, 18.

[0055] A similar concept can be applied to the door frame 9, which is defined, for example, by the wall sections 19 and 20 of walls 11 and 12.

[0056] Furthermore, the door frame 9 is bounded according to axis C by two walls 21 and 22 that are perpendicular to axis C, where axis C is perpendicular to both axis A and axis B. More precisely, walls 21 and 22 extend between walls 11 and 12, and perpendicular to walls 11 and 12.

[0057] Furthermore, wall 21 extends laterally between the walls 15 of the two pillars 8, while wall 22 extends laterally between the walls 16, relative to wall 16.

[0058] In particular, walls 21 and 22 face each other.

[0059] The shell 10 further includes a plurality of partitions 24 made of carbon fiber.

[0060] Each of the partition walls 24 is provided with a particularly flat plate, or can be defined by a plate.

[0061] Each of the partition walls 24 extends laterally to walls 11 and 12 between its ends, which are seamlessly connected to walls 11 and 12, respectively, thus forming a single body with walls 11 and 12.

[0062] In particular, as will become clear below, each end of the partition wall 24 is fused to the walls 11 and 12, that is, connected by fusion, or in some cases welded, but is not bonded or fixed by any fixing device.

[0063] Alternatively, or in addition, each of the first groups of partition walls 24 extends laterally to the walls 15, 16 of one or the other pillar 8 between the ends that are seamlessly connected to the walls 15, 16, respectively, i.e., forming a single body with the walls 11, 12.

[0064] Alternatively, or in addition, each of the second group of partition walls 24 extends laterally to the walls 21 and 22 of the door frame 9 between ends that are seamlessly connected to the walls 21 and 22, respectively, i.e., forming a single body with the walls 21 and 22. Specifically, the second group of partition walls 24 consists of one of the partition walls 24.

[0065] Preferably, portions between the partition walls 24 can be grouped together to form a complex geometric shape in some cases.

[0066] For example, two of the partition walls 24 have surfaces 25 and 26 that are lateral to walls 11 and 12, and these surfaces extend along their respective incident surfaces at acute angles so that the two of the partition walls 24 form a V-shaped or crocodile-mouth structure, as can be seen better in Figure 4.

[0067] Furthermore, three of the partition walls 24 have surfaces 27, 28, and 29 that are oriented laterally to walls 11 and 12, and these surfaces 27 and 29 face each other and are both oriented laterally to surface 28, so that the three of the partition walls 24 form a C-shaped structure, or an omega-shaped structure, or a U-shaped structure, as seen in Figure 4.

[0068] In Figure 4, the surface 30 of the partition wall 24 is visible, and the surface 30 is connected in a particularly direct manner, that is, in contact with the wall 11.

[0069] Generally, the shape and / or arrangement of the bulkheads 24 are optimized, for example, using a computer program that assists the design based on calculations, particularly on the completed elements, with the aim of maximizing the robustness of the shell 10 against impact and / or optimizing the ratio of robustness to the total weight of the shell 10.

[0070] As can be seen more clearly in Figure 2, the partition wall 24 is positioned to divide the cavity 13 into several separate compartments 32.

[0071] Furthermore, at least the majority of the bulkhead 24 is positioned within the pillar 8, that is, inside the cavity 14 of the pillar 8.

[0072] According to a particular embodiment, the chassis frame 2 further comprises a plurality of bags 60, each positioned inside the compartment 32.

[0073] In some cases, the number of bags 60 may be less than the number of compartments 32. Therefore, the chassis frame 2 may have only one bag 60 in the corresponding compartment 32.

[0074] The following describes the manufacturing method for the chassis frame 2.

[0075] More precisely, the manufacturing method of the shell 10 having internal partition walls 24 described above will be explained in detail, but since the manufacturing methods of other shells 10 are substantially the same as those described, a detailed explanation will not be given.

[0076] In other words, each of the characteristics of the methods described can be individually and directly applied to each manufacturing method of the shell 10, or to the entire chassis frame 2, which can be considered as a single shell.

[0077] This method involves providing a mold 40 having an inner wall configured or adapted to define the cavity 13. In other words, the inner wall of the mold 40, which is clearly understood as a sealed mold, encloses the same cavity as the cavity 13. In other words, the inner wall of the mold 40 borders the cavity containing the cavity 13.

[0078] With this in mind, the term cavity 13 is used herein to refer to both the actual cavity 13 in the shell 10 at the end of this method and the cavity 13 inside the sealing mold 40.

[0079] The mold 40 comprises, in particular, at least two parts 41 and 42. More specifically, the mold 40 is closed when the two parts 41 and 42 are joined together to surround the cavity 13.

[0080] Therefore, the inner wall of the mold 40 includes a first inner wall 43 of part 41 and a second inner wall 44 of part 42.

[0081] As shown in Figure 2, which illustrates a portion 41 of the mold 40, the method includes fixing pre-cured and therefore finished partitions 24 to the mold 40. These partitions are fixed in accordance with their actual arrangement within the cavity 13 and the inner wall 43.

[0082] Therefore, the partition wall 24 is positioned inside the mold 40, dividing the cavity 13 into sections 32.

[0083] Therefore, more precisely, the partition wall 24 is fixed to part 41 of the mold 40.

[0084] For example, the partition walls 24 are fixed by screw members 31 such as bolts, i.e., held in place in their arrangement. Alternatively, the partition walls 24 can be fixed by other fastening means, such as structural foam or adhesive material.

[0085] Therefore, the method may further include arranging a plurality of foils or sheets 46 of raw carbon fibers on the inner wall 43 at positions adapted to form at least one wall 12.

[0086] Therefore, the inner wall 43 is configured to form at least the wall 12.

[0087] In practice, specifically as shown in Figure 2, the raw carbon fiber sheets 46 are also placed on the inner wall 43 to form the respective walls 15 and 16 of the pillar 8, and similarly to form the walls 21 and 22 of the door frame 9.

[0088] Therefore, the inner wall 43 is further configured to also form walls 15, 16 and walls 21, 22.

[0089] Further carbon fiber sheets 46 can also be placed on the partition wall 24, particularly independently of each of their surfaces.

[0090] Furthermore, preferably, the partition wall 24 is connected to the raw carbon fiber sheet 46 by an adhesive film configured to melt or at least soften during firing in the autoclave, in order to facilitate bonding between the carbon fiber sheet 46 and the partition wall 24 during firing.

[0091] The carbon fiber sheet 46 is composed of carbon fiber fabric impregnated with a resin, more specifically a thermosetting resin.

[0092] As can be seen in Figures 2 and 3, portion 41 defines its inner cavity, which substantially includes the cavity 13.

[0093] Part 41 includes an outer contour 47 configured to face part 42 during the closing of the mold 40 in accordance with the mold closing direction H.

[0094] Furthermore, portion 42 also has a contour configured to coincide with the outer contour 47 when the mold 40 is closed.

[0095] As can be seen in Figures 4 and 5, part 42 includes an inner wall 44 and a plate 50 configured to close the cavity 13 when the contour of part 42 coincides with the contour 47, i.e., as soon as the mold 40 is closed.

[0096] If necessary, the method includes first firing the raw carbon fiber sheet 46 placed on the inner wall 43 in an autoclave. In the first firing, the raw carbon fiber sheet 46 is fired together with the partition wall 24 fixed to the portion 41 in the inner wall 43.

[0097] Therefore, the first firing is carried out in an autoclave with the portion 41 and partition wall 24, which include the raw material carbon fiber sheet 46, placed without the portion 42.

[0098] More specifically, before placing the raw material carbon fiber sheet 46 and the portion 41 with the partition wall 24 into the autoclave, the portion 41 with the raw material carbon fiber sheet 46 and the partition wall 24 is sealed inside a vacuum bag 55 under vacuum (Figure 3).

[0099] For example, the vacuum bag 55 can be made of polyamide fibers, particularly aliphatic compounds, or silicone.

[0100] The vacuum bag 55 includes at least one valve device 56 configured to connect the vacuum bag 55 to a vacuum pump 57.

[0101] The vacuum pump 57 is connected to the vacuum bag 55 by a valve device 56. Thus, the vacuum pump 57 is used to suck air from inside the vacuum bag 55, which contains the raw carbon fiber sheet 46 and the portion 41 with the partition wall 24. In this way, the portion 41 with the raw carbon fiber sheet 46 and the partition wall 24 is vacuum sealed.

[0102] At this point, the vacuum bag 55 containing the raw material carbon fiber sheet 46 and the section 41 with the partition wall 24 is placed inside the autoclave and the first firing is performed.

[0103] Clearly, the initial firing is performed by operating the autoclave.

[0104] After the first firing, the vacuum bag 55 is removed, for example, by reintroducing air into the vacuum bag 55 using a valve device 56, and then by destroying it or simply removing it.

[0105] At this point, the method includes arranging a plurality of raw carbon fiber sheets 58 on the inner wall 44 in positions adapted to form at least one wall 11.

[0106] The raw material carbon fiber sheet 58 is preferably of the same type as the raw material carbon fiber sheet 46.

[0107] For example, the raw carbon fiber sheets 58 and / or raw carbon fiber sheets 46 can be held in place by an adhesive film configured to melt or at least soften during firing in an autoclave.

[0108] Therefore, the mold 40 can enclose the raw material carbon fiber sheet 58, the partition wall 24, and optionally the carbon fiber sheet fired by the first firing, inside itself.

[0109] This method further includes performing a second firing in an autoclave on the raw material carbon fiber sheet 58, which is placed inside the mold 40, more precisely on the inner wall 44, together with the partition wall 24 and, in particular, the carbon fiber sheet fired in the first firing.

[0110] More specifically, the method includes placing the bags 60 inside the compartments 32 within the mold 40 before the second firing.

[0111] The mold 40 has at least one corresponding opening 61 for each of the compartments 32, especially when it is closed, and each opening 61 establishes a connection between the compartment 32 and the outside of the mold 40.

[0112] In other words, the mold 40 is configured to define, or to define, openings 61 for establishing connections between compartment 32 and the outside of the mold 40, respectively.

[0113] Clearly, the opening 61 is a through opening, and in particular, it penetrates the inner wall 43 or the inner wall 44.

[0114] The bag 60 has air inlets 63 that allow the bag 60 to be inflated with pressurized air. The air inlets 63 are suitable for bringing pressurized air into the inside of the bag 60.

[0115] Even when the bag 60 is closed through the opening 61 as shown in Figure 6, it is positioned inside the compartment 32 with the air inlet 63 located outside the mold 40.

[0116] Therefore, the air inlet 63 is exposed to the outside of the mold through the opening 61 even when the mold 40 is closed.

[0117] In this way, during the second firing, the mold 40 houses the bag 60, and the bag 60 is inflated by the pressurized air of the autoclave. In practice, the pressurized air flows into the bag 60 through an air inlet 63 that is outside the mold 40 via an opening 61.

[0118] Due to this expansion, during the second firing, the bag 60 presses the raw material carbon fiber sheet 58 against the inner wall 44.

[0119] Therefore, due to the dimensions of the bag 60, it is possible for the bag 60 to expand under the pressure of the pressurized air in compartment 32, thereby occupying a volume equal to the volume of compartment 32.

[0120] The bag 60 can be made of polyamide fibers, particularly aliphatic compounds or silicones, i.e., particularly thermoplastic plastic resins, so that it is heat-sealable.

[0121] The mold 40, more specifically part 41, may have an opening 65 to allow the bag 60 to be removed from the mold 40 after the second firing.

[0122] The opening 65 is a through-opening that penetrates the inner wall 43.

[0123] Bag 60 can be considered reusable, especially for further firing.

[0124] Alternatively, the bag 60 can remain inside compartment 32, thereby remaining in compartment 32 of the shell 10 or chassis frame 2. In this case, the opening 65 can be made particularly small, or even eliminated.

[0125] The result of the second firing is specifically shell 10.

[0126] Preferably, as shown in Figure 5, the surface 30 and optionally the outer contour 47 are covered with an adhesive film 70 so that the raw material carbon fiber sheet 58 on the inner wall 44 can be bonded to the partition wall 24 when the mold 40 is closed, in this case before the second firing.

[0127] In particular, Figure 5 shows the bag 60 introduced inside compartment 32, more specifically, section 41.

[0128] Conveniently, as shown in Figure 6, the mold 40 is sealed under vacuum during the second firing inside the vacuum bag 71.

[0129] Therefore, before placing the mold 40, which includes the raw material carbon fiber sheet 58 and the partition wall 24, into the autoclave, the mold 40 is sealed inside a vacuum bag 71 under vacuum.

[0130] For example, the vacuum bag 71 can be made of polyamide fibers, particularly aliphatic compounds, or silicone.

[0131] The vacuum bag 71 includes at least one valve device 72 configured to connect the vacuum bag 71 to the vacuum pump 73.

[0132] The use of the vacuum bag 71, valve device 72, and vacuum pump 73 is the same as the use of the vacuum bag 55, valve device 56, and vacuum pump 57, respectively, and therefore no further detailed explanation will be provided.

[0133] The vacuum bags 71 are liquid-tightly connected to each of the bags 60 outside the mold 40.

[0134] The air inlet 63 of bag 60 is located outside vacuum bag 71 so that it can perform its function.

[0135] Therefore, the air inlet 63 continues to bring pressurized air from the autoclave into the bag 60, causing the bag 60 to expand.

[0136] At the same time, since the vacuum bag 71 is liquid-tightly connected to the bag 60, pressurized air does not flow into the vacuum bag 71, and the vacuum inside the vacuum bag 71 can be maintained.

[0137] The vacuum bag 71 compresses the mold 40 from the outside, particularly due to the vacuum generated within it, but the pressurized air of the autoclave allows the bag 60 to expand from the inside of the mold 40.

[0138] Preferably, a liquid-tight connection between the bag 60 and the vacuum bag 71 is made by a sealing adhesive 75, more specifically a rubber adhesive.

[0139] At the end of the second firing, the vacuum bag 71 can be removed, for example, by breaking it, or in any case, in a manner similar to the method used to remove the vacuum bag 55.

[0140] Once the vacuum bag 71 is removed, the shell 10, or possibly the chassis frame 2, is manufactured.

[0141] The first firing is optional and can therefore be omitted. In this case, the second firing is the only firing of all carbon fiber sheets 46, 58 with partitions 24 within the sealed mold 40.

[0142] All the characteristics described for the second firing can be applied to a single firing as well. Therefore, bags 60 and vacuum bags 71 can be used according to the above description.

[0143] When a single firing is performed, the raw material carbon fiber sheets 46 and 58 are placed in the inner walls 43 and 44, respectively, to form at least walls 11 and 12.

[0144] The mold 40 is closed with the raw material carbon fiber sheets 46 and 58 inside the cavity 13 together with the partition wall 24.

[0145] Based on the above, the advantages of the chassis frame 2 and the method according to the present invention are clear.

[0146] The bulkheads 24 contain carbon fiber, and therefore they are lightweight and durable at the same time. In this way, the chassis frame 2 can be made lighter without compromising its strength.

[0147] Furthermore, the seamless bonding of the bulkhead 24 to the shell 10 enhances the robustness of the chassis frame 2 compared to possible cases where the bulkhead 24 is simply glued or held in place by structural foam.

[0148] This manufacturing method is highly effective and versatile. In fact, it is simplified by performing a single firing. On the other hand, by performing a two-firing method, it becomes possible to better control the pressure inside the mold 40.

[0149] Furthermore, since part 41 is fully visible after the first firing, manufacturing defects can be identified. In this way, the second firing can be performed while taking into account the results of the first firing. That is, if the intermediate product of the first firing is waste, i.e., has unacceptable quality, the second firing can be omitted.

[0150] Using bag 60 ensures improved control of the internal pressure in each of the compartments 32 during the second firing.

[0151] Using Bag 60 is even more advantageous if they are to be reused.

[0152] Finally, modifications and alterations can be made to the chassis frame 2 and method according to the present invention, and it is clear that these will not deviate from the scope of protection as defined by the claims.

[0153] In particular, the number and shape of the components described and illustrated may differ and can be changed with a particularly large degree of freedom.

[0154] Furthermore, numerical adjectives such as "first" and "second" are used to enhance clarity in the explanation, but should not be understood as strictly limiting. In fact, the first and second firings may coincide with a single firing.

Claims

1. A chassis frame (2) for an automobile (1), comprising at least one shell (10) that defines a passenger compartment for the automobile (1) and includes carbon fiber and at least two first walls (11, 12) facing each other so as to define a cavity (13) between them, A chassis frame (2) further comprising one or more carbon fiber partition walls (24) aligned inside the cavity (13) according to the arrangement, and extending laterally with respect to the first walls (11, 12) between two first ends, each seamlessly connected to the first walls (11, 12).

2. The partition wall (24) is arranged to divide the cavity (13) into a plurality of separate compartments (32). The chassis frame according to claim 1.

3. The chassis frame according to claim 2, further comprising a plurality of bags (60) arranged inside each of the compartments (32).

4. The chassis frame (2) is provided with a beam which is part of the side end face (7), The side end face (7) has an opening that allows a person to enter the vehicle interior and can be occupied by the side door (4) of the automobile (1) in the closed position, and in this closed position, the side door (4) prevents the person from entering the vehicle interior through the opening. A chassis frame according to any one of claims 1 to 3, wherein the beam extends along the linear direction (A) between two beam ends defined by pillars (8) that cross the linear direction (A), the beam further comprises a door frame (9) between the pillars (8) along the linear direction, and the door frame (9) forms a single component with the pillars (8).

5. The beam defines one boundary of the pillar (8) according to the linear direction (A), and comprises two second walls (15, 16) that extend laterally between the first walls (11, 12) and the first walls (11, 12). The partition wall (24) extends further inward into the pillar (8) between the second ends which are seamlessly connected to the second walls (15, 16), respectively. The chassis frame according to claim 4.

6. A method for manufacturing the chassis frame (2) according to claim 1, a. A step of providing a mold (40) having mold inner walls (43, 44) configured to define the cavity (13), b. The steps of fixing the pre-hardened partition wall (24) to the mold (40) in accordance with the arrangement, on the inside of the cavity (13) and on the first mold inner wall (43) of the mold inner walls (43, 44), c. The step of placing a plurality of raw material carbon fiber sheets (58) on the second mold inner wall (44) of the mold inner wall (43, 44) at a position adapted to form at least one of the first walls (11, 12), d. A method comprising the step of firing the raw material carbon fiber sheet (58) placed inside the mold (40) together with the partition wall (24) in an autoclave.

7. The partition wall (24) is positioned inside the mold (40) and divides the cavity (13) into a plurality of separate compartments (32). The method according to claim 6.

8. The mold (40) has a plurality of through openings (61) that establish connections between the compartment (32) and the outside of the mold (40), The method further includes the step of positioning each of the bags (60) inside the compartment (32) of the mold (40) such that each bag (60) has an air inlet (63) outside the mold (40) through the through opening (61), The air inlet (63) is adapted to allow pressurized air to flow into the bag (60), and the mold (40) houses the bag (60) inside the compartment (32) during step d, so that the bag (60) expands due to the pressurized air of the autoclave during firing, thereby pressing the raw material carbon fiber sheet (58) against the inner wall (44) of the second mold during firing. The method according to claim 7.

9. During step d, the mold (40) is sealed under vacuum inside a first vacuum bag (71) which is connected in a liquid-tight manner to each of the bags (60) outside the mold (40), with the air inlet (63) outside the first vacuum bag (71), so that the first vacuum bag (71) compresses the mold (40) from the outside, but the pressurized air of the autoclave causes the bags (60) to expand from the inside of the mold (40). The method according to claim 8.

10. The mold (40) comprises first and second parts (41, 42) each having the first and second mold inner walls (43, 44), e. The step of placing a further raw material carbon fiber sheet (46) on the first mold inner wall (43) in a position adapted to form the other of the first walls (11, 12), f. The further step of firing the additional raw material carbon fiber sheet (46), which is placed on the inner wall (43) of the first mold, together with the partition wall (24), in a further autoclave or within the autoclave, Steps c. and d. are performed after step f. The method according to any one of claims 6 to 9.

11. The mold (40) comprises first and second parts (41, 42) each having the first and second mold inner walls (43, 44), e. The step of placing a further raw material carbon fiber sheet (46) on the first mold inner wall (43) in a position adapted to form the other of the first walls (11, 12), f. Under vacuum, with the partition wall (24) and the further raw material carbon fiber sheet (46) on the inner wall (43) of the first mold, the first portion (41) is sealed inside the second vacuum bag (55), g. A step of firing the additional raw material carbon fiber sheet (46), which is sealed under vacuum in the second vacuum bag (55) together with the partition wall (24), in a further autoclave or within the autoclave, h. The process further includes, after step g, removing the second vacuum bag (55): Steps c. and d. are performed after step h. The method according to any one of claims 6 to 9.

Images