JP5797496B2 - Bonding structure of resin plate material and bonding method of resin plate material - Google Patents

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.

To achieve the above object, according to the invention described in claim 1, each other at first, heat-welded portion of the second member superposed two sheets made of plate material is embedded continuous fiber sheet thermoplastic resin a coupling structure of the resin sheet to be coupled to the first, the second member is bent to have a U-shaped cross section in the heat welded portion having the undercut portion, in the heat welded portion, wherein the first, The continuous fiber sheets forming the two layers of the second member are continuously bent without breaking, bent in a U-shaped cross section so as to be orthogonal to the direction of the shear load applied to the heat welded portion, and the action of the peeling load A joint structure of resin plate materials characterized by having undercut shapes that mesh with each other in a direction is proposed.

According to the invention described in claim 2, in addition to the structure of claim 1, the first and second members are coupled to each other at the heat welded portion, so that the vehicle width direction end of the bumper beam of the automobile is obtained. coupling structure of a resin plate member lower member of closed cross section extending rearwardly upwardly from section is equal to or formed is Ru been proposed.

According to the invention described in claim 3 , two sheets of the first and second members made of the thermoplastic resin plate material in which the continuous fiber sheet is embedded are overlapped with the thermoplastic resin plate material in which the continuous fiber sheet is embedded, a method of binding resin sheet material a axisymmetric cup attached at the heat seal parts having undercut portions, the superposed two first, step of the portions of the heat welding of the second member is preheated And a pressing step of pressing the preheated portion with a punch and a die divided into two to obtain the heat-welded portion. In the pressing step , the thermoplastic resin of the first and second members and When the two-layer continuous fiber sheet is stretched in a cup shape by the punch, the two-layer continuous fiber sheet is continuously continuous without breaking, and orthogonal to the direction of the shear load acting on the heat-welded portion. The two-layer continuous fiber sheets are mutually bent in the direction of action of the peeling load on the heat-welded portion between the punch and the two divided dies that are close to each other. binding method of a resin sheet material, characterized in that undercut shape is formed which meshes with the Ru been proposed.

According to the configuration of claim 1, in the resin plate material bonding structure in which two first and second members made of a thermoplastic resin plate in which a continuous fiber sheet is embedded are overlapped and bonded to each other at the heat welded portion, The first and second members are bent in a U-shaped cross section at the heat welding portion having an undercut portion, and the continuous fiber sheets forming the two layers of the first and second members are each broken at the heat welding portion. Without having an undercut shape that is continuously bent in a U-shaped cross section so as to be orthogonal to the direction of shear load acting on the heat welded part, and meshing with each other in the direction of peel load acting , When the first and second members are pulled in different directions and a shear load is applied to the heat- welded portion between the thermoplastic resins, or when a peeling load is applied to separate the first and second members from each other, the heat-welded portion Underscore Continuous fiber sheet 2 layers have if bite each other in the direction of action of the peeling load in parts, and that the continuous fiber sheet of a two-layer in the heat welded portion extends in a direction perpendicular to the direction of shear forces, The strength against shearing load and peeling load can be increased as compared with the case of simply heat-welding flat plate materials. That is, since the two layers of continuous fiber sheets continuously extend in a direction perpendicular to the direction of the shearing force without breaking at the U-shaped cross-section, the two layers of thermoplastic resin are peeled off by the shearing force. It can prevent and increase the strength of the joint, and when a peeling load acts on the heat welded part, the two layers of continuous fiber sheets are continuously peeled without breaking at the undercut part of the heat welded part. Since they mesh with each other in the acting direction of the load, it is possible to prevent the two layers of the thermoplastic resin from peeling off due to the peeling load, and to further increase the strength of the joint.

Moreover , since it is not necessary to form bolt holes and rivet holes in the first and second members , not only can the processing man-hours be saved and the cost can be reduced, but stress can be concentrated on the bolt holes and rivet holes, It is possible to prevent the thermoplastic resin and the continuous fiber sheet from peeling off at the time of processing the bolt holes and the rivet holes and causing a decrease in strength .

Further, according to the configuration of claim 2 , since the first and second members made of the plate material are joined at the heat-welded portion to constitute a member having a closed cross section, a member having extremely high strength coupled with strength improvement by the closed cross section , That is, a lower member of a car can be obtained .

According to the third aspect, the first consisting of plate material is embedded continuous fiber sheet thermoplastic resin, when the second member superposed 2 sheets bonded by heat welding portion, overlapped two said first, a portion of the heat welding of the second member preheated, the moiety that preheated by pressing a punch and 2 split die, the having an undercut portion a axisymmetric cup A press process for obtaining a heat-welded portion, and in the press process , the thermoplastic resin of the first and second members and the two-layer continuous fiber sheet are stretched into a cup shape by a punch, whereby the two-layer continuous fibers Each of the sheets is continuously bent without breaking and bent in a U-shaped cross section so as to be orthogonal to the direction of the action of the shear load on the heat-welded portion, and the two layers between the punch and the two-part dies approaching each other. Continuous fiber The fiber sheet is formed with an undercut shape that meshes with each other in the direction of the action of the peeling load on the heat- welded portion, so that the shear load is applied to the heat- welded portion between the thermoplastic resins by pulling the first and second members in different directions. When applied, or when a peeling load is applied to separate the first and second members from each other, the two layers of continuous fiber sheets mesh with each other in the direction of the action of the peeling load at the undercut portion of the heat-welded portion, and heat Since the two continuous fiber sheets extend in the direction perpendicular to the direction of the shearing force at the welded portion, the strength against shearing load and peeling load can be increased compared to the case where the resin of flat plate materials is simply heat welded. Can be increased. That is, since the two continuous fiber sheets continuously extend in the direction perpendicular to the direction of the shear force without breaking at the cup-shaped heat welded portion, the two layers of thermoplastic resin are prevented from peeling off due to the shear force. The strength of the joint portion can be increased, and when a peeling load acts on the heat welded portion, the continuous fiber sheet of the two layers in the undercut portion of the heat welded portion is continuously peeled without breaking. Since they mesh with each other in the direction of action, it is possible to prevent the two layers of the thermoplastic resin from being peeled off due to the peeling load, thereby further increasing the strength of the joint.

In addition , since it is not necessary to form bolt holes and rivet holes in the first and second members , not only can the processing man-hours be saved and costs can be reduced, but also stress can be concentrated on the bolt holes and rivet holes to increase the strength. It can be prevented from causing a decrease. Moreover, since the heat welding part is an 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. 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, and the pair of left and right upper members 13, 13 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 is continuous without breaking at the heat-welded portion 24 and is bent into a U-shaped cross section . 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. Is bent in a U-shaped cross section and extends in a direction perpendicular to the direction of the shearing force, so that the two layers of the thermoplastic resins 26 and 26 are prevented from being peeled off by the shearing force and the strength of the joint can be increased.

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 in the acting direction of the peeling loads F2 and F2, it is possible to prevent peeling of the two layers of the thermoplastic resins 26 and 26 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 24b Undercut portion 25 Continuous fiber sheet 26 Thermoplastic resin 28 Punch 29 Die 30 Die

Claims (3)

A resin plate material in which two sheets of first and second members (22, 23) made of a thermoplastic resin (26) plate in which a continuous fiber sheet (25) is embedded are stacked and bonded to each other at a heat welded portion (24). A combined structure,
The first and second members (22, 23) are bent in a U-shaped cross section at the heat welded portion (24) having undercut portions (24a, 24b) ,
In the heat welded part (24) , the continuous fiber sheets (25) forming the two layers of the first and second members (22, 23) are continuous without being broken, and the heat welded part (24). A resin plate material coupling structure characterized by having an undercut shape that is bent in a U-shaped cross section so as to be orthogonal to the direction of action of the shearing load on the surface and meshes with each other in the direction of action of the peeling load . The first and second members (22, 23) are coupled to each other at the heat welded portion (24), and the lower member (with a closed cross section extending rearward and upward from the vehicle width direction end portion of the bumper beam (16) of the automobile). 14), characterized in that it consists, binding structure of the resin sheet of claim 1. First made of plate material is embedded continuous fiber sheet (25) a thermoplastic resin (26), a second member (22, 23) superposed two sheets, undercut a axisymmetric cup (24a, 24b) a method for joining resin plate materials to be joined at a heat welded part (24),
The superimposed two first, the steps of the part of the heat welding of the second member (22, 23) is preheated,
Pressing the preheated portion with a punch (28) and a die (29, 30) divided into two to obtain the heat welded portion (24) ,
In the pressing step, the thermoplastic resin (26) of the first and second members (22, 23) and the two-layer continuous fiber sheet (25) are stretched in a cup shape by the punch (28). The two-layer continuous fiber sheet (25) is continuously bent without breaking, and is bent into a U-shaped cross section so as to be orthogonal to the direction of the shear load applied to the heat-welded portion (24). (28) and between the two divided dies (29, 30) approaching each other, the continuous fiber sheet (25) of the two layers is mutually connected in the direction of the action of the peeling load on the heat welded part (24). An undercut shape that meshes with the resin plate is formed .

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