JP2008265696A - Manufacturing method for automobile hood - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an automobile hood enabling inexpensive manufacturing and early trial manufacturing and mass production while providing surface rigidity and pedestrian protection functions required for the automobile hood, in the automobile hood using CFRP. <P>SOLUTION: A beam-shaped inner panel is arranged inside a frame-shaped inner panel made of CFPR and jointed to it so as to form a jointed composite. Then, the outermost peripheral edge part of the jointed composite is arranged to be superposed on the outermost peripheral edge part of an outer panel, and the outer panel is bonded to the jointed composite. Alternately, the outermost peripheral edge part of the frame-shaped inner panel made of CFPR is arranged to be superposed on the outermost peripheral edge part of the outer panel and is bonded to it, so as to form a bonded composite. Then, the beam-shaped inner panel is arranged inside the frame-shaped inner panel made of CFPR, and is jointed to the bonded composite. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an automobile bonnet, and more particularly to a method for manufacturing an automobile bonnet having an outer panel and an inner panel made of CFRP.

  The bonnet for automobiles is a part that is usually located above the engine room in front of the vehicle and serves as a cover for the engine, supplementary notes, etc. in the engine room.

  As a function required for the bonnet, when opening and closing the bonnet and waxing, it does not have an inexpensive image due to a bevel when the bonnet is pushed by hand, and the outer does not deform due to wind pressure at high speed running The surface rigidity of the panel may be secured.

  In recent years, in order to protect pedestrians in the event of an accident, it is required to reduce damage to the head when the head collides with the hood. As a method of reducing the impact at the time of collision, it is conceivable to make the bonnet soft and easy to deform, but in that case, not only the surface rigidity is lowered but also the parts such as the engine existing under the bonnet. It is necessary to consider that there is a possibility that the impact of the head may be exacerbated by the secondary collision. For this reason, it is important to reduce the amount of deformation of the bonnet while reducing the impact applied to the head, particularly in the narrow part of the bonnet and the engine parts under the bonnet.

  As these measures, for example, on the back side of the bonnet, that is, on the opposite side of the design surface, the frame-shaped inner panel disposed over the entire outer periphery of the bonnet, and the vehicle inner side of the frame-shaped inner panel, that is, the frame opening An example of the inner panel in which the beam-shaped inner panel is integrated is that the surface rigidity is improved by bonding the inner panel to the outer panel (for example, Patent Document 1). At that time, considering the layout of the engine parts etc. under the bonnet for the arrangement position of the beams, for example, do not arrange the beams in the part where there is little gap with the engine parts, but install the beams in the periphery Such considerations are necessary.

  When a beam exists in a portion where the gap with the engine part is narrow, a secondary collision between the beam and the engine part occurs immediately after the head collision, and the impact applied to the head increases. Therefore, it is common not to place a beam in a portion where the gap with the engine component is small so that the deformation amount of the portion where the head collides can be as large as possible. However, if the amount of deformation of the bonnet is too large, a secondary collision with the engine will occur. Therefore, if the outer panel is deformed to some extent by installing beams around the hitting point, these beams will suppress the deformation. Secondary collision with the engine can be avoided.

  Furthermore, in recent years, lightening of automobile materials has been studied as a measure for reducing exhaust gas to the environment, and various FRP (fiber reinforced plastic) conversions are being considered for automobile bonnets. Among them, CFRP (carbon fiber reinforced plastic) is promising as the lightest, high rigidity, and high strength panel material by utilizing the high rigidity and high strength of carbon fiber for use in aircraft.

  A general CFRP bonnet is composed of an outer panel on the surface design side and a frame-shaped inner panel that is joined to the back surface side of the bonnet and disposed around the entire outer periphery of the bonnet (for example, Patent Document 2).

  In Patent Document 2, a sandwich structure in which a core material is sandwiched between CFRP single plates as an outer panel is adopted, and a bonnet structure that can ensure high rigidity and high strength only by the outer panel is provided. However, it has a structure that is very difficult to increase the cost due to the labor of manufacturing the sandwich panel and to ensure the high surface quality required by the automobile manufacturer.

  Further, as the CFRP bonnet, a bonnet having an outer panel made of a single CFRP plate is conceivable. In that case, to ensure the surface rigidity of the outer panel, increase the thickness of the outer panel, or set an inner panel with a beam structure as in Patent Document 1 or an inner panel with corrugated beads over the entire panel. There must be. When the thickness of the outer panel is increased, the weight is significantly increased, and the lightening effect by CFRP is offset.

  Therefore, a CFRP bonnet may have a structure in which an outer panel is joined to a CFRP single plate panel, and an inner panel is joined to a panel having a beam as in Patent Document 1. However, when a CFPR inner panel having a beam is formed as in Patent Document 1, first, a shaping operation is required in which a carbon fiber unidirectional material or a cloth material is arranged in a forming die. When the beam shape is complicated, the shaping work becomes complicated, the productivity deteriorates, and the cost increases. Further, for example, when carrying out RTM (resin transfer molding) molding, if the final shape is complicated, the resin fluidity is poor, and molding defects frequently occur and the yield may be deteriorated.

Further, when a change in the engine layout or the like occurs, it is necessary to change the beam shape, and the mold repair of the CFRP mold is necessary. The mold for the inner panel is very large, and it has a temperature adjustment mechanism for resin curing, so a large amount of cost and a long correction period are required for mold repair, and the temperature adjustment mechanism is reviewed. If it is necessary, it is expected that a CFRP mold will be newly produced, and it may not be possible to meet the needs of short-term development and prototype production.
JP 2005-96685 A JP 2002-284038 A

  Therefore, an object of the present invention is to provide an automobile bonnet using CFRP, which has surface rigidity and a pedestrian protection function required for an automobile bonnet, but is inexpensive and can be manufactured at an early stage in trial production and mass production. It is providing the manufacturing method of the bonnet for motor vehicles used as this.

  In order to solve the above problems, a CFRP outer panel, a CFRP frame inner panel, and a beam inner panel are used, and at least a part of the back side of the CFRP outer panel and the CFRP frame shape are used. A method of manufacturing an automobile bonnet for bonding a part of an inner panel, wherein the beam-shaped inner panel is arranged inside a frame-shaped inner panel made of CFRP and bonded to form a bonded composite, Provided is a method for manufacturing an automobile bonnet, wherein an outermost peripheral end portion of the bonded composite is disposed so as to overlap an outermost peripheral end of the outer panel, and the outer panel is bonded to the bonded composite.

  Furthermore, as another method for solving the above-described problem, a CFRP outer panel, a CFRP frame-shaped inner panel, and a beam-shaped inner panel are used, and at least a part of the back surface side of the CFRP outer panel; An automobile bonnet manufacturing method for bonding a part of the CFRP frame-shaped inner panel to an outermost peripheral end of the CFRP frame-shaped inner panel overlapping an outermost peripheral end of the outer panel. An automobile bonnet manufacturing method is provided in which the beam-shaped inner panel is disposed inside the CFRP frame-shaped inner panel after being arranged and bonded to form an adhesive composite, and is joined to the adhesive composite. To do.

  The bonnet for automobiles manufactured by the manufacturing method of the present invention is, for example, a change in the arrangement position of engines / auxiliaries, surface rigidity is smaller than originally expected, or pedestrian head protection performance that was initially expected If it is necessary to change the design of the beam shape part of the bonnet due to the failure to achieve the above, it is possible to cope with it by simply modifying and newly installing the beam shape inner panel mold. As a result, it is possible to respond to design changes at an early stage and at a lower cost than the conventional bonnet in which the frame-shaped inner panel and the beam-shaped inner panel are integrated, and it is possible to keep prototype and development costs low.

  Further, in the manufacturing method of the present invention, as in the past, several bonnets in which the frame-shaped inner panel and the beam-shaped inner panel are integrated are prepared, and the pedestrian head protection performance is not evaluated, but the beam shape Since it is possible to evaluate pedestrian head protection performance by preparing only a few inner panels, the number of production days and costs can be greatly reduced, and development costs can be reduced, resulting in low cost and light weight performance. A bonnet having Furthermore, it is possible to provide an inexpensive product by manufacturing the beam-shaped inner panel with a material cheaper than CFRP, that is, metal or resin.

  The automobile hood obtained by the production method of the present invention will be described with reference to FIG.

  As shown in FIG. 1, an automobile hood obtained by the manufacturing method of the present invention includes an outer panel 1 made of CFRP that constitutes an outer surface of a vehicle, that is, a surface that appears as an appearance when used in an automobile, and an outer panel. The frame-shaped inner panel 2 made of CFRP and the beam-shaped inner panel 3 disposed at the opening of the frame-shaped inner panel 2 are formed over the entire outer periphery of the frame 1. Here, the fact that the CFRP frame-shaped inner panel 2 exists over the entire outer periphery of the outer panel 1 means that the outermost peripheral end of the CFRP frame-shaped inner panel 2 overlaps the outermost peripheral end of the outer panel 1. Means. Note that the outermost peripheral end of the CFRP frame-shaped inner panel 2 overlaps with the outermost peripheral end of the outer panel 1 is a figure formed by the outermost peripheral end of the CFRP frame-shaped inner panel 2. Means that the figure formed by the outermost peripheral end portion of the outer panel 1 is congruent, but as long as the object of the present invention is not impaired, a part of the outermost peripheral end portion of the CFRP frame-shaped inner panel 2 Alternatively, there may be a portion that does not overlap with the outermost peripheral end portion of the outer panel 1 in all.

  CFRP refers to a resin reinforced with carbon reinforced fibers. Examples of the CFRP matrix resin include thermosetting resins such as epoxy resins, unsaturated polyethylene resins, vinyl ester resins, and phenol resins, and polyamide resins, polyolefin resins, dicyclopentadiene resins, polyurethane resins, and the like. These thermoplastic resins can also be used. The mechanical properties of CFRP can be appropriately set by selecting and combining the matrix resins as described above, the orientation and volume content of the reinforcing fibers, and the laminated structure.

  The frame-shaped inner panel 2 is a frame-shaped member that exists over the entire outer periphery of the outer panel 1. As shown in FIG. 2, the frame-shaped inner panel 2 has a hat-shaped cross-sectional shape (not shown, but a cross-sectional shape having two hat-shaped shapes at least at both ends when viewed in the full width of the cross-sectional view). The flange portion 2a at both ends of the hat-shaped cross section can be bonded to the back surface of the outer panel 1, that is, the surface on the lower side of the vehicle (the surface that does not appear as an appearance when used in an automobile). It is preferable.

  The beam-shaped inner panel 3 is configured by combining a plane portion or a curved surface portion inside the frame opening portion 9 of the frame-shaped inner panel 2 in FIG. 6, and one or a plurality of beams having a hat-shaped cross section are overlapped. A combined structure is preferable. The number of beams to be overlapped, the shape of the beam, and the position of the beam are determined in consideration of the surface rigidity required by the vehicle and the size of the gap between the engine and other parts existing under the bonnet and the beam. It is what is done. In addition, the beam-shaped inner panel 3 has a structure that can be bonded to the lower surface of the outer panel 1 in the flange portion 3a at both ends of the hat-shaped cross section, and a portion that requires surface rigidity of the bonnet. The beam-shaped inner panel 3 can be bonded to the outer panel 1.

  The beam-shaped inner panel 3 is preferably made of metal, resin, or FRP. Examples of the metal include steel that is inexpensive and excellent in formability, and aluminum that can be lighter than steel and has good formability. The metal beam-shaped inner panel 3 is preferably formed by press molding. In addition to the resins that can be used as the matrix resin, thermoplastic resins such as nylon 6, nylon 6,6, ABS (acrylonitrile-butadiene-styrene), and polypropylene are preferably used as the resin. In general, ABS is particularly preferably used because the molding technique has been established.

  Furthermore, when FRP is used for the beam-shaped inner panel 3, the reinforcing fiber is preferably a reinforcing fiber made of inorganic fibers such as carbon fibers and glass fibers, or organic fibers such as Kepler fibers, polyethylene fibers, and polyamide fibers. Among them, a reinforcing fiber made of carbon fiber is particularly preferably used. As the FRP matrix resin, for example, a thermosetting resin such as an epoxy resin, an unsaturated polyethylene resin, a vinyl ester resin, or a phenol resin is preferably used. Furthermore, a polyamide resin, a polyolefin resin, a dicyclopentadiene resin, or a polyurethane resin is used. A thermoplastic resin such as is also preferably used. Further, the mechanical properties of FRP can be appropriately set depending on the selection and combination of the matrix resins as described above, the orientation and volume content of the reinforcing fibers, and the laminated structure.

  In the manufacturing method of the present invention, first, the beam-shaped inner panel 3 formed of the above-described material is disposed on the frame opening inner side 9 of the frame-shaped inner panel 2 made of CFRP, and then these are bonded to each other. The body 4 is produced.

  Here, the joined composite 4 means a member obtained by joining the frame-shaped inner panel 2 and the beam-shaped inner panel 3 by mechanical fastening such as bolts and rivets, or adhesive joining using an adhesive. As shown in FIG. 4 or 5, the joint composite 4 has a flange portion that can join both members at the portion where the beam-shaped inner panel 3 and the frame-shaped inner panel 2 are in contact with each other. It is preferable that it can be fastened or adhesively bonded with an adhesive.

  When considering the weight reduction of the bonnet and the appearance of the back side of the bonnet, it is desirable that the bonded composite 4 is manufactured by adhesive bonding. In addition, the back surface of a bonnet said here means the surface opposite to the design surface (surface which appears as an external appearance when used for a motor vehicle) of a bonnet.

  As the adhesive, epoxy resin adhesive, urethane resin adhesive, phenol resin adhesive, acrylic resin adhesive, etc. are preferably used, but urethane resin adhesive generally used for automobile members It is particularly preferable to use an agent.

  Then, the joining composite 4 is attached to the outer panel 1 so that the end of the flange portion 2a forming the outermost peripheral end of the joining composite 4 overlaps with the outer peripheral end of the outer panel 1 at the same position. After arranging on the back surface, that is, the surface that is the lower side of the vehicle (the surface that does not appear as an appearance when used in an automobile), the flange portion 2a and the outer panel 1 that form the outermost peripheral end portion of the frame-shaped inner panel 2, The bonnet for automobiles can be completed by performing adhesive bonding using an adhesive.

  Here, when it is desired to increase the torsional rigidity and bending rigidity of the bonnet, the other flange part 2a existing on the side opposite to the flange part 2a forming the outermost peripheral end in the cross section of the frame-shaped inner panel 2 is used as the outer panel. It is more preferable to perform adhesive bonding to 1.

  Furthermore, when it is necessary to improve the surface rigidity of the bonnet, it is more preferable to bond the flange portion 3 a existing in the beam-shaped inner panel 3 to the outer panel 1.

  As a 2nd form of this invention, the edge part of the flange part 2a which forms the outermost periphery edge part of the frame shape inner panel 2, and the position of the outermost periphery edge part of the CFRP outer panel 1 overlap, and a frame After the shape inner panel 2 is arranged on the back surface of the outer panel 1, that is, the surface on the lower side of the vehicle (the surface that does not appear as an appearance when used in an automobile), the outermost peripheral end of the frame shape inner panel 2 is formed. The flange portion 2a and the outer panel 1 are bonded and bonded with an adhesive to manufacture the bonded composite body 5.

  And after arrange | positioning the beam-shaped inner panel 3 in the frame opening inner part 9 of the frame-shaped inner panel 2 in this adhesion composite body 5 in a predetermined position, the junction part of the frame-shaped inner panel 2 and the beam-shaped inner panel 3 Can be joined by mechanical fastening such as bolts and rivets, adhesive bonding using an adhesive, or the like to complete the bonnet.

  Also here, when it is desired to increase the torsional rigidity of the bonnet, the other flange portion 2a existing on the side opposite to the flange portion 2a forming the outermost peripheral end portion in the cross section of the frame-shaped inner panel 2 is used as the outer panel 1. More preferably, it is adhesively bonded.

  Furthermore, when it is necessary to improve the surface rigidity of the bonnet, it is more preferable to bond the flange portion 3 a existing in the beam-shaped inner panel 3 to the outer panel 1.

  The bonnet for automobiles manufactured in this way achieves pedestrian head protection performance that was initially expected, such as changes in the position of engines and accessories, surface rigidity is smaller than originally expected, etc. If it is necessary to change the design of the beam shape due to the failure, it is possible to cope with it only by correcting and newly installing the beam shape inner panel 3. As a result, it is possible to respond to design changes at an early stage and at a lower cost than the conventional bonnet in which the frame-shaped inner panel and the beam-shaped inner panel are integrated, and it is possible to keep prototype and development costs low.

  Further, in the manufacturing method of the present invention, as in the prior art, several bonnets in which the frame-shaped inner panel 2 and the beam-shaped inner panel 3 are integrated are prepared, and pedestrian head protection performance is not evaluated. Since it is possible to evaluate the pedestrian head protection performance by preparing only a few beam-shaped inner panels 3, the number of days and costs for mold production can be greatly reduced, and development costs can be reduced. A bonnet with lightweight performance can be provided. Furthermore, it is possible to provide an inexpensive product by manufacturing the beam-shaped inner panel with a material cheaper than CFRP, that is, metal or resin.

It is a disassembled perspective view of the hood for motor vehicles of this invention. It is sectional drawing (AA) of the hood for motor vehicles of this invention. It is sectional drawing (BB) of the hood for motor vehicles of this invention. It is a joining figure by adhesion | attachment of a frame shape inner panel and a beam-shaped inner panel. It is a joint figure by the bolt nut of a frame shape inner panel and a beam shape inner panel. It is a perspective view of a frame shape inner panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer panel 2 Frame shape inner panel 2a Flange part 3 Beam shape inner panel 3a Flange part 4 Joining composite body 5 Adhesive composite body 6 Adhesive 7 Bolt 8 Nut 9 Inside frame opening part

Claims (6)

A CFRP outer panel, a CFRP frame inner panel and a beam inner panel are used to bond at least a part of the back side of the CFRP outer panel and a part of the CFRP inner panel. A method for manufacturing an automobile bonnet, wherein the beam-shaped inner panel is arranged inside a frame-shaped inner panel made of CFRP and joined to form a joined composite, and then the outermost peripheral end of the joined composite A method for manufacturing an automobile bonnet, wherein a portion is disposed so as to overlap an outermost peripheral end portion of the outer panel, and the outer panel is bonded to the joint composite. A CFRP outer panel, a CFRP frame inner panel and a beam inner panel are used to bond at least a part of the back side of the CFRP outer panel and a part of the CFRP inner panel. A method for manufacturing an automobile bonnet, wherein the outermost peripheral end of the CFRP frame-shaped inner panel is arranged so as to overlap the outermost peripheral end of the outer panel, and bonded to form an adhesive composite, A method of manufacturing an automobile bonnet, wherein the beam-shaped inner panel is arranged inside a CFRP frame-shaped inner panel and joined to the adhesive composite. The manufacturing method of the bonnet for motor vehicles of Claim 1 or 2 with which the cross section of the said beam-shaped inner panel is formed in the hat shape. The manufacturing method of the bonnet for motor vehicles in any one of Claims 1-3 whose said beam-shaped inner panel is metal. The manufacturing method of the bonnet for motor vehicles in any one of Claims 1-3 whose said beam-shaped inner panel is resin. The manufacturing method of the bonnet for motor vehicles in any one of Claims 1-3 whose said beam-shaped inner panel is a product made from CFRP.

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