JP2013043370A - Coupling structure and coupling method for resin plate material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength when coupling a plurality of plate materials of thermoplastic resins embedded with continuous fiber sheets in a stacked state by a heat welding part.SOLUTION: When coupling a plurality of plate materials 22c, 23a of thermoplastic resins 26 embedded with continuous fiber sheets 25 in a stacked state by a heat welding part 24, since the plurality of plate materials 22c, 23a are bent into a cross-sectionally U-shape in the heat welding part 24, and the continuous fiber sheet 25 is extended in a direction orthogonal to a direction of a shearing force in that portion, strength against a shearing load or a peeling load can be improved in comparison with the case of simply carrying out the heat welding of resin of flat plate materials in the heat welding part 24. Since there is no need to form bolt holes or rivet holes in the plate materials 22c, 23a, the number of machining steps can be reduced to contribute to cost reduction, and also, a concentration of stress in the bolt holes or the rivet holes, or the exfoliation of the thermoplastic resin 26 and the continuous fiber sheet 25 at forming the bolt holes or the rivet holes can be prevented from becoming a cause of the deterioration of rigidity.

Description

  The present invention relates to a resin plate material bonding structure in which a plurality of thermoplastic resin plate materials in which a continuous fiber sheet is embedded are overlapped and bonded at a heat welding portion, and a resin plate material bonding method.

  As a conventional technique for bonding and bonding fiber reinforced resin plate materials, there are known ones in which the resin in the bonding portion is heated and melted and welded, and those using bolts or rivets that penetrate the holes formed in the bonding portion. .

  Further, when the edge portions of two thermoplastic resin plates reinforced with carbon fibers are overlapped and resistance welding is performed by passing an electric current through the portions, the orientation direction of the carbon fibers at the edge portions is determined by the thermoplastic resin. Japanese Patent Application Laid-Open Publication No. 2004-228667 discloses that the electric resistance is increased by setting in the thickness direction of the plate material, and reliable welding is possible by increasing the calorific value.

Japanese Patent No. 4289426

  By the way, in the conventional method in which the resin of the joint portion is heated and melted and welded, when a load is applied to peel off the two thermoplastic resin plates, the precious fibers hardly contribute to the improvement of the peel strength. There is a problem that the thermoplastic resin plate easily peels off from the joint surface.

  In addition, the conventional method using bolts and rivets requires the formation of bolt holes and rivet holes in the thermoplastic resin, which not only increases the number of processing steps but also increases costs, There has been a problem that the stress is concentrated and the thermoplastic resin and the fiber are peeled off during the processing of the bolt hole and the rivet hole, thereby causing a decrease in strength.

  Moreover, since the thing of the said patent document 1 needs to make the orientation direction of the carbon fiber in the edge part of the board | plate material of a thermoplastic resin different from the orientation direction of the carbon fiber in another part, a manufacturing process becomes complicated and cost. In addition to the increase factor, the carbon fiber becomes discontinuous at the portion where the orientation direction is switched, and the strength is locally reduced, which may break the portion.

  This invention is made | formed in view of the above-mentioned situation, and it aims at raising the intensity | strength at the time of laminating | stacking the board | plate material of the thermoplastic resin which embed | buried the continuous fiber sheet | seat, and couple | bonding at a heat welding part.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a resin plate bonding structure in which a plurality of thermoplastic resin plates embedded with continuous fiber sheets are overlapped and bonded at a heat welded portion. Thus, there is proposed a resin plate joining structure in which the plurality of plates are bent in a U-shaped cross section at the heat welded portion.

  According to the invention described in claim 2, in addition to the configuration of claim 1, a resin plate material coupling structure is proposed in which the heat-welded portion has an axisymmetric cup shape.

  Further, according to the invention described in claim 3, in addition to the structure of claim 1 or 2, the resin welded material bonding structure is proposed, wherein the heat welded portion has an undercut portion. .

  According to the invention described in claim 4, in addition to the structure of any one of claims 1 to 3, the plurality of plate members are joined at the heat welding portion to form a member having a closed cross section. A structure for joining resin plate materials characterized by comprising is proposed.

  According to a fifth aspect of the invention, in addition to the configuration of the fourth aspect, the member having the closed cross section is a bumper beam of an automobile or a lower member extending rearward and upward from an end portion in the vehicle width direction of the bumper beam. A bonding structure for resin plates characterized by this is proposed.

  According to the invention described in claim 6, there is provided a method for bonding resin plate materials in which a plurality of thermoplastic resin plate materials in which continuous fiber sheets are embedded are overlapped and bonded at a heat-welded portion. Resin plate bonding comprising: preheating the heat welded portion of the plate material; and pressing the preheated heat welded portion with a punch and a die to bend it into a U-shaped cross section. A method is proposed.

  According to the invention described in claim 7, in addition to the configuration of claim 6, the heat welded portion has an axisymmetric cup shape and has an undercut portion, and the die is divided into two. A method for joining resin plate materials characterized by the above is proposed.

  In addition, the 1st member 22 and the 2nd member 23 of embodiment correspond to the board | plate material of this invention.

  According to the configuration of the first aspect, the plurality of the thermoplastic resin plate materials in which the continuous fiber sheets are embedded are overlapped and bonded to each other, so that the plurality of plate materials are pulled in different directions. When a shearing load is applied to the welded portions of thermoplastic resins, or when a peeling load is applied to peel off a plurality of plate materials from each other, the continuous fiber sheet is orthogonal to the direction of the shearing force at the heat welded portion. By extending in the direction, it is possible to increase the strength against a shear load or a peeling load as compared with the case where the resin of flat plate materials is simply heat-welded. Moreover, since it is not necessary to form bolt holes and rivet holes in the plate material, not only can the processing man-hours be saved and costs can be reduced, but stress can be concentrated on the bolt holes and rivet holes, and bolt holes and rivet holes can be reduced. It is possible to prevent the thermoplastic resin and the continuous fiber sheet from being peeled off during the processing, thereby causing a decrease in strength.

  According to the second aspect of the present invention, since the heat-welded portion has an axisymmetric cup shape, it is possible to obtain a uniform strength against a tensile shear load and a peel load in an arbitrary direction.

  Moreover, according to the structure of Claim 3, since a heat welding part has an undercut part, the continuous fiber sheet | seat of several sheets of plate material mutually meshes | engages, and the intensity | strength with respect to peeling load improves further.

  Further, according to the configuration of the fourth aspect, since the plurality of plate members are joined at the heat welding portion to form a member having a closed cross section, a member having extremely high strength can be obtained in combination with the strength improvement by the closed cross section.

  Moreover, according to the structure of Claim 5, the intensity | strength of the bumper beam or lower member of a motor vehicle can be raised.

  According to the configuration of claim 6, when a plurality of thermoplastic resin plate materials in which continuous fiber sheets are embedded are overlapped and bonded together at the heat welded portion, the heat welded portion of the overlapped plate material is preheated. Since the heat welded portion is pressed with a punch and a die and bent into a U-shaped cross section, when a plurality of plate members are pulled in different directions and a shear load is applied to the welded portions of the thermoplastic resins, When a peeling load is applied that peels the sheets together, the continuous fiber sheet extends in a direction perpendicular to the direction of the shearing force at the heat-welded part, so that the resin on the flat sheet is simply heat-welded. Compared with the case where it does, the intensity | strength with respect to a shear load or a peeling load can be raised. Moreover, since it is not necessary to form bolt holes and rivet holes in the plate material, not only can the processing man-hours be saved and the cost can be reduced, but stress is concentrated on the bolt holes and rivet holes, causing a decrease in strength. Can be prevented.

  Moreover, according to the structure of Claim 7, since a heat welding part is axisymmetric cup shape and has an undercut part, it can obtain equal and high intensity | strength with respect to the tensile shear load and peeling load of arbitrary directions. it can. Moreover, since the die is divided into two, even if the heat welded portion has an undercut portion, the die can be easily removed.

The perspective view which shows the frame structure of the vehicle body front part of a motor vehicle. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. The perspective view of the metal mold | die which processes a heat welding part. Action explanatory drawing of a heat welding process.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a pair of left and right front side frames 11, 11 extending in the front-rear direction are disposed at the front of the vehicle body of the automobile. Further, on the outer side in the vehicle width direction of the front side frames 11, 11, a pair of left and right upper members 13, 13 extend forward and downward from the front ends of the pair of left and right front pillars 12, 12. A pair of left and right lower members 14, 14 extend forward and downward from the front end. Therefore, the lower members 14 and 14, the upper members 13 and 13 and the front pillars 12 and 12 are connected in series from the front lower side to the rear upper side.

  A box-shaped shock absorbing member 15 is connected to the front end of each front side frame 11, and the vehicle width direction inner surface of the front half of the lower member 14 is connected to the vehicle width direction outer surface of the shock absorbing member 15. Both ends in the vehicle width direction of the bumper beam 16 whose center in the vehicle width direction curves in an arc toward the front are connected to the front surface of the shock absorbing member 15 and the inner surface in the vehicle width direction of the front end portion of the lower member 14.

  A frame-shaped front bulkhead 20 composed of an upper beam 17 extending in the vehicle width direction, a lower beam 18 extending in the vehicle width direction, and a pair of left and right side members 19, 19 extending in the vertical direction includes the side member 19, 19 is connected to the inner surface in the vehicle width direction of the shock absorbing members 15 and 15 so that the bumper beam 16 is supported behind the bumper beam 16. The front surface of the bumper beam 16 is covered with a bumper face 21.

  The front side frames 11, 11, the front pillars 12, 12 and the upper members 13, 13 are metal members, but the lower members 14, 14, impact absorbing members 15, 15, bumper beam 16, front bulkhead 20, and bumper face 21 is a member made of fiber reinforced resin (FRP).

  As shown in FIG. 2, the lower member 14 includes a first member 22 having a hat-shaped cross section and a second member 23 having a flat plate shape. The first member 22 includes a bottom wall 22 a, a pair of side walls 22 b and 22 b, and a pair of flanges 22 c and 22 c, and the pair of edge portions 23 a and 23 a of the second member 23 is a pair of the first member 22. Overlaid on the flanges 22c and 22c, the overlapped portion is heat-welded by a plurality of heat-welded portions 24 arranged at predetermined intervals in the longitudinal direction of the first member 22 and the second member 23 to form a square closed cross section. The

  The first member 22 and the second member 22 are composed of a continuous fiber sheet 25 made of woven fabric of glass fiber or carbon fiber, and a plate material of thermoplastic resin 26 such as polypropylene embedded so as to sandwich the continuous fiber sheet 25. The

  The heat-welded portion 24 has, for example, an axisymmetric cup shape that protrudes from the edge 23 a side to the flange 22 c side, and the thermoplastic resin 26 is stretched to be thicker than portions other than the heat-welded portion 24. Is decreasing. The continuous fiber sheet 25 bends without breaking at the heat-welded portion 24. The heat-welded portion 24 has a slightly larger diameter on the bottom side than the diameter on the opening side. That is, the heat welding part 24 has an undercut shape.

  As shown in FIG. 3, a mold 27 for processing the heat welding portion 24 includes a punch 28 and dies 29 and 30 divided into two. A convex portion 28 a protruding downward is formed on the lower surface of the punch 28, and an annular groove 28 b is formed in the middle portion of the convex portion 28. On the other hand, the dies 29 and 30 divided into two can be opened and closed in a direction perpendicular to the opening and closing direction of the mold 27 (the axial direction of the heat welding portion 24). Semi-cylindrical recesses 29a and 30a are respectively formed in the dies 29 and 30 divided into two, and reduced diameter portions 29b and 30b whose diameters are reduced are formed at the upper ends of the recesses 29a and 30a. A heater (not shown) is embedded in the mold 27, and the surface temperature can be heated to a predetermined temperature.

  Next, the process of heat-welding the flange 22c of the first member 22 and the edge 23a of the second member 23 in an overlapping manner will be described.

  First, the flange 22c of the first member 22 and the edge 23a of the second member 23 are overlapped, and the portion to be thermally welded is preheated by an IR heater (far infrared heater) or a laser. Subsequently, in a state where the pair of dies 29 and 30 of the mold 27 are opened, the upper surface of the flange 22c of the first member 22 and the edge 23a of the second member 23 are placed (FIG. 4). (See (A)). The punch 28 is lowered while the punch 28 of the mold 27 and the dies 29, 30 are heated, and the convex portion 28a of the punch 28 is inserted between the concave portions 29a, 30a of the pair of dies 29, 30 (FIG. 4B )reference). As a result, the thermoplastic resin 26, 26 and the continuous fiber sheets 25, 25 on the flange 22c of the first member 22 and the edge 23a of the second member 23 are stretched in a cup shape by the convex portion 28a of the punch 28.

  Subsequently, when the punch 28 is further lowered while the pair of dies 29 and 30 are brought close to each other, the outer surface of the cup-shaped heat welding portion 24 is formed by the dies 29 and 30, and the inner surface is formed by the punch 28. (See FIG. 4C). At this time, the undercut portion 24a (FIG. 2) is formed on the outer surface of the heat-welded portion 24 by the reduced diameter portions 29b, 30b at the upper ends of the concave portions 29a, 30a of the dies 29, 30 and the annular groove 28b of the convex portion 28a of the punch 28. 2) and an undercut portion 24b (see FIG. 2) is formed on the inner surface of the heat-welded portion 24.

  Subsequently, the pair of dies 29, 30 are opened in a direction away from each other, and the punch 28 is opened in a direction away from the pair of dies 29, 30, thereby separating the heat welding portion 24 from the mold 27. (See FIG. 4D). At this time, it is possible to release the undercut portion 24a on the outer surface of the heat welding portion 24 by the dies 29 and 30 divided into two. Further, the undercut portion 24b on the inner surface of the heat welding portion 24 protruding into the annular groove 28b of the punch 28 can be released by pulling the punch 28 before the heat welding portion 24 is completely cooled and solidified. .

  As described above, in the heat-welded portion 24 of the present embodiment, the thermoplastic resins 26 and 26 are heat-welded to each other simply by overlapping the flange 22c of the first member 22 and the edge 23a of the second member 23. Compared to those, the bonding strength is greatly improved. That is, when tensile loads F1 and F1 in opposite directions are applied to the flange 22c of the first member 22 and the edge 23a of the second member 23 (see FIG. 2), the conventional heat-free welded portion 24 is not provided. However, in this embodiment, two layers of continuous fiber sheets 25, 25 are formed in the cup-shaped heat welding portion 24, although the thermal welding of the contact surfaces of the two layers of the thermoplastic resins 26, 26 is easily peeled off by the shearing force. Since it extends in a direction perpendicular to the direction of the shearing force, it is possible to prevent the two layers of the thermoplastic resins 26 and 26 from being peeled off by the shearing force and to increase the strength of the joint portion.

  In addition, when peeling loads F2 and F2 that peel off the two layers of the thermoplastic resins 26 and 26 are applied (see FIG. 2), two layers of continuous fibers are formed in the undercut portions 24a and 24b of the cup-shaped heat welding portion 24. Since the sheets 25 and 25 mesh with each other, it is possible to prevent the two layers of the thermoplastic resins 26 and 26 from being peeled off due to the peeling loads F2 and F2 and to increase the strength of the joint portion.

  As described above, according to the present embodiment, since the continuous fiber sheet 25 extends in the direction orthogonal to the direction of the shearing force in the heat welding portion 24, the resin of the flat plate materials is simply heat welded. The strength against shearing load and peeling load can be increased compared to. Moreover, since it is not necessary to form bolt holes and rivet holes in the flange 22c and the edge portion 23a, not only can the processing man-hours be saved and the cost can be reduced, but also stress can be concentrated on the bolt holes and rivet holes. It can be prevented from causing a decrease. In particular, since the heat-welded portion 24 has an axisymmetric cup shape, uniform strength can be obtained with respect to a tensile shear load and a peel load in an arbitrary direction.

Further, since the first member 22 and the second member 23 are heat-welded at the heat-welded portions 24 to form the lower member 14 having a closed cross section, the strength improvement due to the closed cross-section and the strength improvement due to the heat-welded portion 24 are combined, resulting in extremely strong strength. As described above, the embodiments of the present invention have been described. However, various design changes can be made without departing from the scope of the present invention.

  For example, although the heat welding part 24 of embodiment is formed in cup shape, it is applicable also to the heat welding part which has a U-shaped cross section and extends linearly.

  Moreover, although the continuous fiber sheet of embodiment is comprised with the woven fabric, the nonwoven fabric with which the long fiber was mutually entangled may be sufficient.

  In the embodiment, two plate members are combined, but the present invention can also be applied to a portion where three or more plate members are combined.

  In the embodiment, the present invention is applied to the lower member 14 of the automobile. However, it can be applied to the bumper beam 16 of the automobile and other arbitrary members.

14 Lower member 16 Bumper beam 22 First member (plate material)
23 Second member (plate material)
24 Thermally welded portion 24a Undercut portion 25 Continuous fiber sheet 26 Thermoplastic resin 28 Punch 29 Die 30 Die

Claims (7)

A resin plate material bonding structure in which a plurality of plate materials (22, 23) of thermoplastic resin (26) in which a continuous fiber sheet (25) is embedded is overlapped and bonded at a heat welded portion (24),
The resin plate joining structure characterized in that the plurality of plate members (22, 23) bend in a U-shaped cross section at the heat welding portion (24).   2. The resin plate bonding structure according to claim 1, wherein the heat-welded portion has an axisymmetric cup shape.   The said heat welding part (24) has an undercut part (24a), The joining structure of the resin board | plate material of Claim 1 or Claim 2 characterized by the above-mentioned.   The said several board | plate material (22,23) is couple | bonded by the said heat welding part (24), and comprises the member of a closed cross section, The any one of Claims 1-3 characterized by the above-mentioned. Bonding structure of resin plates.   5. The resin according to claim 4, wherein the member of the closed cross section is a bumper beam (16) of an automobile or a lower member (14) extending rearward and upward from a vehicle width direction end of the bumper beam (16). Bonding structure of plate materials. A method of joining resin plate materials in which a plurality of plate materials (22, 23) of thermoplastic resin (26) in which a continuous fiber sheet (25) is embedded are overlapped and bonded at a heat welded portion (24),
A step of preheating the heat-welded portion (24) of the plate materials (22, 23) stacked in a plurality;
A step of bending the preheated heat welded portion (24) with a punch (28) and a die (29, 30) and bending it into a U-shaped cross section;
A method for joining resin plate materials, comprising:   The said heat welding part (24) is an axisymmetric cup shape, has an undercut part (24a), and the said die | dye (29, 30) is divided into 2 parts, The 6th characterized by the above-mentioned. The method for bonding resin plate materials according to 1.

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