PROCESSES FOR MANUFACTURING LOAD-BEARING STRUCTURES FOR VEHICLE DOORS

Abstract

Process for manufacturing a load-bearing structure for tailgates of vehicles by thermoforming, the process comprises obtaining a thermoforming press comprising a male mold and a female mold, wherein the male mold and the female mold comprise variable maximum distances between the male mold and the female mold, heat a sheet of thermoplastic material with dimensions equivalent to the load-bearing structure for tailgates of vehicles, cooling down the male mold and the female mold, placing the sheet of thermoplastic material between the male mold and the female mold, adjusting the male mold and the mold female causing the pressing of the sheet of thermoplastic material to obtain the load-bearing structure and dimensionally stabilize the load-bearing structure.

Claims

1. A process for manufacturing a load-bearing structure for a tailgate of a vehicle by thermoforming, the process comprising: obtaining a thermoforming press comprising a male mold and a female mold, wherein the male mold and the female mold comprise variable maximum distances between the male mold and the female mold; calculating at least one first maximum distance between the male mold and the female mold, wherein the at least one first maximum distance is equivalent to the thickness of the load-bearing structure in flat areas of the load-bearing structure; calculating at least one second maximum distance between the male mold and the female mold, wherein the at least one second maximum distance is the thickness of the load-bearing structure in curvilinear areas of the load-bearing structure, wherein the at least one second maximum distance is less than the at least one first maximum distance in one or more areas of the load-bearing structure; heating to a temperature between 200 C. and 400 C. a sheet of thermoplastic material with dimensions equivalent to the load-bearing structure for the tailgate of the vehicle; cooling down the male mold and the female mold at a temperature between 30 C. and 50 C.; placing the sheet of thermoplastic material between the male mold and the female mold; actuating the male mold and the female mold causing the pressing of the sheet of thermoplastic material at a temperature between 180 C. and 210 C. and with pressures between 50 Kg/cm.sup.2 and 100 Kg/cm.sup.2 to obtain the load-bearing structure, wherein the flat and curvilinear areas of the load-bearing structure are proportional to the at least one first maximum distance and the at least one second maximum distance, and stabilizing dimensionally the load-bearing structure.

2. The process for manufacturing a load-bearing structure for a tailgate of a vehicle according to claim 1, further comprising: inserting an internal metallic substructure comprising profiles and/or tubes in the load-bearing structure by means of joining means.

3. The process for manufacturing a load-bearing structure for a tailgate of a vehicle according to claim 1, further comprising: obtaining an opening configured for housing a glass of the tailgate during the actuation step, wherein obtaining said opening generates a piece of additional thermoplastic material; and obtaining auxiliary elements of the tailgate structure by thermoforming from the piece of additional thermoplastic material.

4. A load-bearing structure for a tailgate of a vehicle obtained by the manufacturing process of claim 1.

5. (canceled)

6. A process for manufacturing a load-bearing structure for a tailgate of a vehicle by thermoforming, wherein the load-bearing structure comprises an upper substructure and a lower substructure, the manufacturing process comprises for each of the substructures: obtaining a thermoforming press comprising a male mold and a female mold, wherein the male mold and the female mold comprise variable maximum distances between the male mold and the female mold; calculating at least one first maximum distance between the male mold and the female mold, wherein the at least one first maximum distance is equivalent to the thickness of the upper or lower substructure in flat areas of the upper or lower substructure; calculating at least one second maximum distance between the male mold and the female mold, wherein the at least one second maximum distance is the thickness of the load-bearing structure in curvilinear areas of the upper or lower substructure structure, wherein the at least one second maximum distance is less than the at least one first maximum distance in one or more areas of the upper or lower substructure; heating to a temperature between 200 C. and 400 C. a sheet of thermoplastic material with dimensions equivalent to the upper or lower substructure for the tailgate of the vehicle; cooling down the male mold and the female mold at a temperature between 30 C. and 501 C.; placing the sheet of thermoplastic material between the male mold and the female mold; actuating the male mold and the female mold causing the pressing of the sheet of thermoplastic material at a temperature between 180 C. and 210 C. and with pressures between 50 Kg/cm.sup.2 and 100 Kg/cm.sup.2 to obtain the upper or lower substructure, wherein the flat and curvilinear areas of the upper or lower substructure are proportional to the at least one first maximum distance and at least one second maximum distance, and assembling the upper substructure and the lower substructure to obtain the load-bearing structure by joining means.

7. The process for manufacturing a load-bearing structure for a tailgate of a vehicle according to claim 6, further comprising: introducing an internal metallic substructure formed by profiles and/or tubes to the load-bearing structure by means of joining means.

8. The process for manufacturing a load-bearing structure for a tailgate of a vehicle according to claim 6, further comprising: obtaining an opening configured for housing a glass of the tailgate during the actuation step, wherein obtaining said opening (generates a piece of additional thermoplastic material; and obtaining auxiliary elements of the tailgate structure by thermoforming from the piece of additional thermoplastic material.

9. A load-bearing structure for a tailgate of a vehicle obtained by the manufacturing process of claims 6.

10. (canceled)

11. A tailgate for a vehicle comprising the load-bearing structure according to claim 4.

12. The tailgate for a vehicle according to claim 11, further comprising one or more of the following elements: glass or plastic glazing; plastic or metal outer skin; one or more motors; electronics; at least one lock; shock absorbers; windshield wiper; spoilers for aerodynamic improvement; lights; sensors; wiring; and/or components for improving the vibroacoustic properties of the tailgate.

13. The process for manufacturing a load-bearing structure for a tailgate of a vehicle according to claim 1, further comprising: obtaining an opening configured for housing a glass of the tailgate during a cutting step subsequent to the actuation step, wherein obtaining said opening generates a piece of additional thermoplastic material; and -obtaining auxiliary elements of the tailgate structure by thermoforming from the piece of additional thermoplastic material.

14. The process for manufacturing a load-bearing structure for a tailgate of a vehicle according to claim 6, further comprising: obtaining an opening configured for housing a glass of the tailgate during a cutting step subsequent to the actuating step, wherein obtaining said opening generates a piece of additional thermoplastic material; and obtaining auxiliary elements of the tailgate structure by thermoforming from the piece of additional thermoplastic material.

15. A tailgate for a vehicle comprising the load-bearing structure according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To complement the description that is being made and in order to help a better understanding of the features of the manufacturing processes in accordance with a preferred example of its practical embodiment, a set of drawings is attached as an integral part of said description, wherein, by way of illustration and not limitation, the following has been represented:

[0033] FIG. 1 shows the manufacturing process according to the present invention.

[0034] FIG. 2 shows the load-bearing structure obtained by the manufacturing process according to the present invention.

[0035] FIG. 3 shows the load-bearing structure integrated as part of a vehicle tailgate.

[0036] FIG. 4 shows a first exploded view of an example of a load-bearing structure obtained by the manufacturing process according to the present invention and wherein the load-bearing structure comprises an internal metallic substructure formed by profiles and/or tubes.

[0037] FIG. 5 shows a second exploded view of the example of the load-bearing structure obtained by the manufacturing process according to the present invention and wherein the load-bearing structure comprises an internal metallic substructure formed by profiles and/or tubes.

[0038] FIG. 6 shows the example of the load-bearing structure that comprises an internal metallic substructure formed by profiles and/or tubes.

[0039] FIG. 7 shows a vehicle tailgate comprising a load-bearing structure obtained by the manufacturing process according to the present invention.

DETAILED DESCRIPTION

[0040] FIG. 1 shows the manufacturing process (1000) of a load-bearing structure (100) for a vehicle tailgate (200) by thermoforming.

[0041] The manufacturing process (1000) comprises obtaining (1100) a sheet of thermoplastic material (1010) with dimensions equivalent to the load-bearing structure (100) for a tailgate (200) of a vehicle, as well as obtaining a thermoforming press that comprises a male mold (1050a) and a female mold (1050b), wherein the male mold and the female mold (1050a, 1050b) comprise variable maximum distances between the male mold and the female mold (1050a, 1050b).

[0042] To obtain said variable distances, the manufacturing process (1000) comprises calculating at least one first maximum distance (d1) between the male mold (1050a) and the female mold (1050b), wherein (d1) is equivalent or proportional to the thickness of the load-bearing structure (100) in flat areas of the load-bearing structure (100) and calculating at least one second maximum distance (d2) between the male mold (1050a) and the female mold (1050b), wherein d2 is the thickness of the load-bearing structure (100) in curvilinear areas of the load-bearing structure (100), wherein (d2) is less than (d1) in one or more areas of the load-bearing structure (100).

[0043] The manufacturing process (1000) comprises heating (1200) the sheet of thermoplastic material (1010) at a temperature between 200 C. to 400 C.

[0044] The manufacturing process (1000) comprises cooling down the male mold and the female mold (1050a, 1050b) at a temperature range between 30 C. to 50 C.

[0045] The manufacturing process (1000) comprises placing the sheet of thermoplastic material (1010) between the male mold and the female mold (1050a, 1050b) as shown in reference (1300).

[0046] The manufacturing process (1000) comprises actuating (1300, 1400) the male mold and the female mold causing the pressing of the sheet of thermoplastic material at a temperature range between 180 C. to 210 C. and at a pressure range between 50 Kg/cm.sup.2 to 100 Kg/cm.sup.2 to obtain the load-bearing structure (100), wherein the flat and curvilinear areas of the load-bearing structure are equivalent to d1 and d2.

[0047] Finally, the manufacturing process (1000) comprises dimensionally stabilizing (1500) the load-bearing structure (100).

[0048] The advantages of this manufacturing process (1000) are multiple:

[0049] The cost is much lower than other manufacturing processes that use injection or metal stamping, especially in large parts such as a tailgate of an automobile such as the one described in the present invention. Another advantage is the lower cost of thermoforming molds compared to injection molds.

[0050] In a particular example, the manufacturing process (1000) comprises the step of introducing an internal metallic substructure (160) formed by profiles and/or tubes in the load-bearing structure (100) by means of joining means.

[0051] FIG. 2a shows the load-bearing structure (100) obtained through the manufacturing process (1000).

[0052] In another example, the load-bearing structure (100) can be obtained by assembling an upper substructure and a lower substructure to obtain the load-bearing structure (100). The upper and lower substructure can also be obtained by the manufacturing process (1000) and assembled by joining means.

[0053] The load-bearing structure (100) may comprise an opening (150) obtained during the pressing step configured for housing a glass of the tailgate (200) (the tailgate (200) shown in FIG. 4). From the additional or surplus thermoplastic material of said opening (150) a set of auxiliary elements (150a) of thermoplastic material can be obtained as shown in FIG. 2b. The set of auxiliary elements (150a) can be used as an integral part of the structure of the tailgate (200).

[0054] In another example, said opening (150) can be obtained during a cutting step subsequent to the pressing step.

[0055] FIG. 2c shows the load-bearing structure (100) obtained through the manufacturing process (1000) and wherein the opening (150) can be seen without the set of auxiliary elements (150a) obtained from the additional thermoplastic material.

[0056] FIG. 3 shows the integral parts of the tailgate (200) such as the load-bearing structure (100) and a set of parts (200a) such as glass, plastic or metallic outer skin, motors and/or electronics.

[0057] FIGS. 4 and 5 show two exploded views of another example of a load-bearing structure (100) obtained by the manufacturing process (1000) according to the present invention. The load-bearing structure (100) comprises the opening (150) and a set of auxiliary elements ( ) obtained from the additional or surplus thermoplastic material of said opening (150). In addition, this example of load-bearing structure (100) comprises an internal metallic substructure (160) formed by profiles and/or tubes by means of joining means to increase the rigidity of the tailgate (200) and allow the structural load of the thermoformable plastic to be reduced.

[0058] FIG. 6 shows the example of the load-bearing structure (100) of FIGS. 4 and 5, which comprises the internal metal substructure (160) formed by profiles and/or tubes and joined to the load-bearing structure (100) by means of joining means.

[0059] FIG. 7 shows the tailgate (200) comprising the load-bearing structure (100) obtained by the manufacturing process (1000).