JP4466100B2 - Hybrid vehicle body structure and manufacturing method thereof - Google Patents

Description

  The present invention relates to a hybrid vehicle body structure using a different material for a plurality of structural members joined to each other and a method for manufacturing the same.

  As a hybrid vehicle body structure, for example, the dash upper, dash lower, hood ledge and front side member are individually formed of aluminum material, and the dash side, extension member, front floor and body side are individually formed of steel material. Some are formed and these structural members are joined together.

In the conventional hybrid vehicle body structure, for example, resistance spot welding is employed for joining structural members made of the same material, and the joining of different materials, that is, the structural member made of an aluminum-based material and the structural member made of a steel-based material, For the joining, a self-piercing rivet using an adhesive was used. FIG. 6 is a cross-sectional view showing a conventional joining portion, and shows a state in which a structural member 51 made of an aluminum-based material and a structural member 52 made of a steel-based material are joined by a self-piercing rivet 52.
17th Internationaler Rohbau-Expertenkreis 22.07.2003 BMW AG, Der f · fte 5 er

  By the way, in the case of a steel body structure in which all the structural members are made of a steel-based material, each structural member can be joined by resistance spot welding. However, in the case of a hybrid vehicle body structure as described above, resistance spot welding is used for joining the same material, and self-piercing rivets are used for joining different materials, which increases the cost compared to the steel body structure. There was a point.

  In addition, since the conventional hybrid vehicle body structure employs resistance spot welding and self-piercing rivets for joining structural members, it is difficult to perform mixed production on the same production line as the steel body structure. For this reason, when producing both a hybrid vehicle body structure and a steel vehicle body structure, a dedicated production line is required, which increases the equipment cost and increases the occupied area of the production line. It was.

  The present invention has been made in view of the above-described conventional situation. In a hybrid vehicle body structure in which different materials are used for a plurality of structural members to be bonded to each other, the structural members of different materials can be bonded at low cost. A hybrid vehicle body structure capable of reducing the cost of equipment and reducing the area occupied by the production line, which can be used together with the existing steel vehicle body structure production line. The purpose is to provide.

The hybrid vehicle body structure of the present invention is a hybrid vehicle body structure using different materials for a plurality of structural members to be joined together , and at least a dash upper, a dash lower, a front side member, and a hood ledge among the plurality of structural members, the different materials used for the structural member to a composite structural member preformed member which is joined in a state of flat plate formed by molding into a three-dimensional shape. The composite structural member and the counterpart structural member corresponding to the composite structural member are joined to each other at the same material portion.

The manufacturing method for a hybrid vehicle body structure of the present invention, which uses different materials to the plurality of structural members to be joined together, a preformed member by joining the different materials used for the structural members in the form of a flat plate Then, the preformed member is formed into a three-dimensional shape by plastic working means such as a press to form a composite structure member . Then, the composite structural member and the counterpart structural member corresponding to the composite structural member are joined to each other at the same material . At this time, the dash upper, the dash lower, the front side member, and the hood ledge among the plurality of structural members constituting the vehicle body are composite structural members mainly made of an aluminum-based material, and other structural members are It is a composite structural member made mainly of steel materials. After joining aluminum materials in the engine compartment assembly process, steel materials are joined in the floor main, body side and body main assembly processes. It is characterized by performing.

  According to the hybrid vehicle body structure and the manufacturing method thereof of the present invention, the composite structural member is a preformed member formed by joining different materials used for each structural member in a flat plate state into a three-dimensional shape. Joining of different materials forming the molded member is so-called two-dimensional joining, and a joining portion with good quality and high reliability can be obtained at low cost. In addition, since the composite structural member and the counterpart structural member corresponding to the composite structural member are joined at the same material portion, the structural members are joined at a low cost by welding means such as resistance spot welding as in the case of the steel body structure. be able to. As a result, when producing both the hybrid body structure and the steel body structure, most of the production line of the hybrid body structure can be used together with the existing production line of the steel body structure. Reduction and reduction of the area occupied by the production line can be achieved.

Hereinafter, an embodiment of a hybrid vehicle body structure and a manufacturing method thereof according to the present invention will be described with reference to the drawings.
A hybrid vehicle body structure 1 shown in FIGS. 1 and 2 is composed of an engine compartment 2 in a dotted frame forming an engine room, a front floor assembly 3, a pair of left and right body sides 4 and 5, and a vehicle body rear half portion (not shown). is there.

  The engine compartment 2 includes, as structural members, a dash upper 10 and a dash lower 11 that partition the engine room and the passenger compartment, a pair of left and right dash sides 12 and 13, a pair of left and right hood ledges 14 and 15, a suspension housing 16, 17, a pair of left and right front side members 18 and 19, and a pair of left and right extension members 20 and 21.

  The front floor assembly 3 includes a front floor 22 as a passenger compartment floor and a pair of left and right side sill inners 23 and 24 as structural members. The front floor assembly 3 forms a front door frame on both sides thereof. The body sides 4 and 5 are joined.

  In the hybrid vehicle body structure 1 described above, among the structural members, the dash upper 10, the dash lower 11, the hood ledges 14 and 15, the suspension housings 16 and 17 and the front side members 18 and 19 are mainly made of an aluminum-based material. The dash sides 12, 13 which are other structural members, the extension members 20, 21, the front floor assembly 3 (22-24) and the body sides 4, 5 are mainly made of steel.

  In this embodiment, the dash upper 10, the dash lower 11, the hood ledges 14 and 15, the front side members 18 and 19, and the extension members 20 and 21 are made of different materials, that is, an aluminum material and a steel material in a flat plate state. It is a composite structural member obtained by molding the joined preformed member into a three-dimensional shape, and the other structural members are formed of a single material of an aluminum-based material or a steel-based material, which will be described in detail below. In this way, the composite structural member and the counterpart structural member corresponding thereto are joined to each other at the same material.

  The dash upper (composite structural member) 10 includes a main body portion 10a made of an aluminum-based material, which is a main material, and joint flange portions made of a steel-based material, which is the main material of the mating structural member, on both left and right sides of the main body portion 10a. 10b, 10c. This dash upper 10 forms a preformed member by joining the main body portion 10a and the joining flange portions 10b and 10c in a flat plate state to form a preformed member, and the preformed member is formed into a three-dimensional shape by plastic working means such as press molding. The joining flange portions 10b and 10c made of a steel-based material are joined to the dash sides 12 and 13 which are counterpart structural members also made of a steel-based material.

  The dash lower (composite structural member) 11 includes a main body portion 11a made of an aluminum-based material, which is a main material, and a joint made of a steel-based material, which is the main material of the mating structural member, on both the left and right sides and the lower side of the main body portion 11a. Flange portions 11b to 11d are provided. The dash lower 11 is formed by a tailored blank method similar to the dash upper 10, and the joining flanges 11b and 11c on both the left and right sides made of a steel-based material are dash side which is a counterpart structural member also made of a steel-based material. 12 and 13, and the lower flange portion 11 d made of steel material is joined to the front floor 22, which is a counterpart structural member made of steel material.

  In the food ledges (composite structural members) 14 and 15, the front half portions 14a and 15a correspond to a main body portion made of an aluminum-based material as a main material, and the rear half portions 14b and 15b are main materials of a mating structural member. It corresponds to a joining flange portion made of a steel material, and is formed by a tailored blank method similar to the dash upper 10. The hood ledges 14 and 15 join the rear half portions 14b and 15b made of a steel material to the dash sides 12 and 13 and the body sides 4 and 5 which are counterpart structural members made of the same steel material.

  In addition, the hood ledges 14 and 15 join suspension housings 16 and 17 made of aluminum material to the front half portions 14a and 15a made of aluminum material. Since the suspension housings 16 and 17 are formed of a single material, the suspension housings 16 and 17 are not limited to press-formed products, and it is possible to improve performance and reduce costs by integrating components by using a casting.

  The front side members (composite structural members) 18 and 19 include main body portions 18a and 19a made of an aluminum-based material that is a main material, and joint flange portions 18b and 19b made of a steel-based material that is a main material of a mating structural member. In the same manner as the dash upper 10, the tailored blank method is used. The front side members 18 and 19 join the joining flange portions 18b and 19b made of a steel material to the dash sides 12 and 13 which are counterpart structural members made of the same steel material.

  The extension members (composite structural members) 20 and 21 are opposite in structure to the structural members such as the dash upper 10 described above, and include main body portions 20a and 21a made of a steel-based material as a main material. The front end portions of the main body portions 20a and 21a are provided with joint flange portions 20b and 21b made of an aluminum-based material that is a main material of the mating structural member. The extension members 20 and 21 are formed by the tailored blank method similarly to the dash upper 10, and the joining flange portions 20b and 21b made of an aluminum-based material are replaced with the front side which is a mating structural member also made of an aluminum-based material. The members 18 and 19 and the dash lower 11 are joined.

  In the hybrid vehicle body structure and the manufacturing method thereof according to the present invention, since a plurality of structural members are joined to each other, the front side members 18 and 19 previously described as composite structural members are extensions that are composite structural members as described above. The members 20 and 21 may be mating structural members.

  Here, in general, when an aluminum-based material and a steel-based material are to be joined in a vehicle body structure of an automobile, both of them are joined by fusion welding such as resistance spot welding and arc welding that are conventionally used for body assembly. I can't.

  On the other hand, in the hybrid vehicle body structure and the manufacturing method thereof, the dash upper 10, the dash lower 11, the hood ledges 14 and 15, the front side members 18 and 19 and the extension members 20 and 21 which are composite structural members are made of different materials. After forming the preformed member by joining them in a flat plate state, the preform is molded into a three-dimensional shape by plastic working means such as press molding. Different materials can be joined by stirring joining or mash seam joining.

  FIG. 3 is a diagram showing a case where the steel-based material 30 on the thin plate side and the aluminum-based material 31 on the thick plate side are joined by friction stir welding, FIG. 3 (a) shows the state before joining, and FIG. ) Shows after joining.

  In the friction stir welding, the flat steel-based material 30 and the flat aluminum-based material 31 are abutted so that their upper surfaces are continuous and constrained by jigs, and then the tool 35 is rotated at high speed while the tool 35 is rotated at high speed. By pressing the pin 37 provided at the tip against the end of the aluminum material 31, the aluminum material 31 is mainly heated by the frictional heat to cause plastic flow. Then, the pins 37 are inserted into the aluminum-based material 31 until the shoulder portion 36 of the tool 35 reaches the vicinity of the surface of the material, and in this state, the tool 35 is moved along the joining surface 32 of both the materials 30, 31 to thereby join the material. An agitating layer 33 of the aluminum-based material 31 is formed in the vicinity of the surface 32, and the agitating layer 33 is pressed against the joining surface of the steel-based material 30, so that the two materials 30, 31 are joined in a linear form without melting each other. .

  FIG. 4 is a diagram showing a case where the steel material 40 on the thin plate side and the aluminum material 41 on the thick plate side are joined by mash seam joining, FIG. 4 (a) shows the state before joining, and FIG. 4 (b). Indicates after bonding.

  In mash seam joining, the end of the flat aluminum-based material 41 is overlapped with the upper surface of the end of the flat steel-based material 40, and then the energized portion is energized while being relatively pressed by the upper and lower electrodes 43, 44. In addition, the electrodes 43 and 44 are moved along the joint surfaces 42 of both materials 40 and 41 while rotating. Thereby, the superposition | polymerization part of the aluminum-type material 41 deform | transforms so that the edge part of the steel-type material 40 may be embraced, and it will be in the state which the lower surfaces of both materials 40 and 41 continued, and each other shown to Fig.4 (a) A joining portion 46 shown in FIG. 4B is formed on the joining surface 42, and both materials 40 and 41 are joined in a linear shape.

  In this way, when different materials constituting the preformed member are joined to each other, if the two-dimensional joining in the flat plate state is performed using the friction stir welding or the mash seam joining described above, the joining surfaces are joined to each other. It is easy to control to the required pressure and temperature, and it is possible to efficiently and inexpensively obtain a joint portion with good quality and high reliability.

  In this embodiment, friction stir welding and mash seam joining are exemplified as means for joining different materials. However, joining of different materials in the hybrid vehicle body structure and the manufacturing method thereof is limited to the joining means described above. Instead, other joining means such as adhesion and brazing can be used.

  Next, based on FIG. 5, the manufacturing method of a vehicle body structure is demonstrated in order of an assembly process. Here, a case where both a hybrid vehicle body structure using a different material as a structural member and an existing steel vehicle body structure in which all the structural members are formed of a steel-based material is shown. FIG. A manufacturing method according to the invention is shown, and FIG. 5B shows a conventional manufacturing method. As for the hybrid vehicle body structure, both the dash upper (10), the dash lower (11), the hood ledge (14, 15), the suspension housing (16, 17), and the front side member (18) are used in both the embodiment and the conventional example. 19) uses aluminum-based material as the main material, and other structural members use steel-based material as the main material.

  In general, the vehicle body structure manufacturing method includes an engine compartment assembly process, a floor main assembly process, a body side assembly process, and a body main assembly process. Here, in the manufacture of the steel body structure, since all are joined by the same material, fusion welding such as resistance spot welding or arc welding is used. However, in the production of the hybrid vehicle body structure, the same material and the different material are joined. At this time, the above-mentioned fusion welding cannot be used for joining the different materials.

  In manufacturing a conventional hybrid vehicle body structure, as described in the background section, after forming each structural member, a self-piercing rivet (see FIG. 6) is used to join the structural members made of different materials. Therefore, in the conventional example shown in FIG. 5B, the engine compartment assembly process S51, the floor main assembly process S52 and the body side assembly process S53 of the hybrid vehicle body structure, and the assembly processes S101 to S103 of the steel vehicle body structure are different. This is a production line, and only the body main assembly process S61 is a common process.

  More specifically, in the manufacture of the conventional hybrid vehicle body structure, in the engine compartment assembling step S101, as an example, there is a joining of a dash upper made of an aluminum-based material and a dash side made of a steel-based material. In the step S102, as an example, there is a joining of a dash lower made of an aluminum material and a front floor made of a steel material, and in the body side assembly step S103, a hood ledge made of an aluminum material is taken as an example. Since there is a joint with the body side made of a steel-based material, it is necessary to separate the assembly steps S101 to S103 including these dissimilar material joints from the assembly steps S51 to S53 for the steel body structure. For this reason, the equipment cost increased and the occupation area of the production line increased.

  On the other hand, in the hybrid vehicle body structure and manufacturing method of the present invention, the dash upper 10, the dash lower 11, the hood ledges 14 and 15 and the front side members 18 and 19, which are mainly made of an aluminum-based material, The pre-formed member joined in the state is a composite structural member formed into a three-dimensional shape, and these joining flange portions 10b, 10c, 11b to 11d, 14b, 15b, 18b, 19b are connected to the mating structural member (4, 4). 5, 12, 13, 22), and the extension members 20, 21 made of the steel material as the main material are also composite structural members, and the joint flange 20 b. , 21b are formed of an aluminum-based material that is the main material of the mating structural member (18, 19), Since hand-structured members are joined with the same material, it is only necessary to join aluminum-based materials and steel-based materials together. For these, fusion welding such as resistance spot welding or arc welding is used. it can.

  Accordingly, in the embodiment of the present invention shown in FIG. 5A, only the engine compartment assembly process S1 of the hybrid vehicle body structure 1 and the engine compartment assembly process S2 of the steel vehicle body structure are separate processes. The assembly process S3, the body side assembly process S4, and the body main assembly process S5 can be made a common production line. In other words, most of the production line of the hybrid vehicle body structure can be used together with the existing production line of the steel vehicle body structure, and the equipment cost can be reduced or produced as compared with the conventional example shown in FIG. It is clear that the area occupied by the line can be reduced, and the degree of freedom for producing a plurality of vehicle types is high.

  More specifically, in the hybrid vehicle body structure manufacturing method, in the engine compartment assembling step S1, for example, a combination of structural members mainly made of an aluminum-based material, such as a combination of a dash upper 10 and a dash lower 11, is performed. At the same time, as in the combination of the dash upper 10 and the dash sides 12 and 13, a structural member mainly made of an aluminum-based material and a structural member mainly made of a steel-based material are joined. At this time, the former combination is a joining of aluminum-based materials, and the latter combination is a joining of steel-based materials since the joining flange portions 10b and 10c of the dash upper 10 are steel-based materials.

  Existing aluminum resistance spot welding, inert gas arc welding, laser welding, and other welding means can be used for joining aluminum materials, and existing resistance spots are also used for joining steel materials. Welding means such as welding, arc welding, and laser welding can be used. In any case, a high-quality joint can be obtained easily and at low cost.

  Thus, in the engine compartment assembling step S1 of the hybrid vehicle body structure 1, the dash upper 10, the dash lower 11, the hood ledges 14, 15, the front side members 18, 19 and the extension members 20, 21 which are composite structural members Thus, the engine compartment 2 including the dash sides 12 and 13 made of a steel material and the suspension housings 16 and 17 made of an aluminum material is obtained. In the engine compartment assembling step S2 of the steel body structure, the same engine compartment can be obtained only by joining the steel-based materials.

  Thereafter, in the floor main assembly step S3, the front floor assembly 3 is welded to the engine compartment 2 described above. In the next body side step S4, the body sides 4 and 5 are welded and joined. In the next body main step S5, Other body panels will be welded together, and in these assembling processes, basically only steel-based materials are joined together, so both the hybrid body structure and the steel body structure are the same.

  As described above, in the hybrid vehicle body structure and the manufacturing method thereof described in the above embodiment, the joining of different materials is a so-called two-dimensional joining, and a joining portion with good quality and high reliability can be obtained efficiently and at low cost. In addition, since the composite structural member and the corresponding counterpart structural member are joined by the same material portion, the structural members are joined by welding means such as resistance spot welding as in the case of the steel body structure. This enables efficient and low-cost operation, which makes it possible to use most of the production line of the hybrid body structure together with the existing production line of steel body structure, reducing equipment costs and occupying the production line. Realize area reduction.

  Further, in the hybrid vehicle body structure 1, at least the dash upper 10, the dash lower 11, the front side members 18 and 19 and the hood ledges 14 and 15 among the structural members are combined structural members, and in addition, the extension members 20 and 21. Since the composite structural member is used only in the engine compartment 2 as a composite structural member, the joining work of the aluminum-based materials can be concentrated in the engine compartment assembling step S1, which is apparent from FIG. 5 (a). As described above, it is possible to manufacture a hybrid vehicle body structure by simply adding one assembly step S1 upstream of the existing steel vehicle body structure production line, further reducing the equipment cost and occupying the production line area. It can contribute to further reduction.

  Further, the main material of the dash upper 10, the dash lower 11, the front side members 18, 19 and the hood ledge 14, 15 is made of an aluminum material, and the main material of the other structural members is made of a steel material. Thus, it is possible to obtain a vehicle body structure that can reduce the weight of the engine compartment 2 on which the engine and the transmission are mounted and can sufficiently ensure the rigidity of the passenger compartment.

  It should be noted that the hybrid vehicle body structure and the manufacturing method thereof according to the present invention are not limited to the above-described embodiment in details of the configuration. For example, the composite structure member and the counterpart structure member in the above-described embodiment are reversely related. It is also possible to make it. Specifically, the steel-based material extension members 20 and 21 are made of a single material, and the front-side members 18 and 19 of the aluminum-based material are provided with a joining flange portion of the steel-based material, and both of the steel-based materials are made of each other. Or providing a joint flange portion made of an aluminum-based material on the front floor 22 of a steel-based material, and making the dash lower 11 made of an aluminum-based material as a single material and joining both of the aluminum-based materials together Is also possible.

  However, if the joining of the engine compartment 2 and the front floor assembly 3 includes joining of aluminum-based materials, the floor main assembly process S3 also requires the work of joining different materials, so that the production line can be simplified. Therefore, it is desirable to use a composite structural member for the engine compartment 2 as in the above embodiment.

  Further, in the above embodiment, the front side members 18 and 19 are composite structural members, but the front side members 18 and 19 can be cast parts made of an aluminum-based material for the purpose of component integration. In this case, another connecting component formed by a tailored blank method using an aluminum-based material and a steel-based material at a portion where the front side members 18, 19 and the dash side 12, 13 made of a steel-based material are joined. (Not shown) can be added.

  Furthermore, in the above embodiment, the case where an aluminum-based material and a steel-based material are used for the structural member has been described. However, the material of the structural member is not limited to this, and a combination of a magnesium-based material and a steel-based material can be used. A combination of a titanium-based material and a steel-based material may be used. Furthermore, in the above embodiment, the case where the composite structural member is used in the engine compartment has been described, but it goes without saying that the composite structural member is used for other structural members and other subassemblies constituting the rear portion of the vehicle body. The configuration can be changed as appropriate without departing from the concept of the present invention.

It is a disassembled perspective view explaining one Example of the hybrid vehicle body structure of this invention. It is a perspective view which shows the state which assembled the engine compartment from the state of FIG. It is sectional drawing (a) which shows the state before joining of friction stir welding, and sectional drawing (b) which shows the state after joining. It is sectional drawing (a) which shows the state before joining of mash seam joining, and sectional drawing (b) which shows the state after joining. FIG. 2 is a block diagram (a) showing the manufacturing method of the hybrid vehicle body structure of the present invention in the order of assembly steps and a block diagram (b) showing the manufacturing method of the conventional hybrid vehicle body structure in the order of the assembly steps. It is sectional drawing which shows the junction part of the structural member in the conventional hybrid vehicle body structure.

Explanation of symbols

1 Hybrid body structure 4 5 Body side (mating structure member)
10 Dash upper (composite structural member)
10a body part 10b 10c joint flange part 11 dash lower (composite structure member)
11a body part 11b-11d joint flange part 12 13 dash side (mating structure member)
14 15 Food ledge (composite structural member)
14a 15a body part 14b 15b latter half part (joining flange part)
18 19 Front side member (composite structural member)
20 21 Extension member (composite structural member)
20a 21a Main body 20b 21b Joint flange 22 Front floor (mating structure member)

Claims (5)

A hybrid vehicle body structure using different materials for a plurality of structural members joined together,
At least dash upper dash lower, a front side member and hood ledge, formed by molding a three-dimensional shape of the preform member the different materials are joined in a state of flat plate used for each structural member composite structure of the plurality of structural members As a member,
A hybrid vehicle body structure in which a composite structural member and a counterpart structural member corresponding to the composite structural member are joined to each other at the same material portion. Of the plurality of structural members, the dash upper, dash lower, front side member, hood ledge, and extension member are composite structural members obtained by molding the preformed member into a three-dimensional shape, and are composed of the main material of the composite structural member. The hybrid vehicle body structure according to claim 1, further comprising a main body portion and a joining flange portion made of a main material of the mating structural member . The hybrid vehicle body structure according to claim 2, wherein the main material of the dash upper, the dash lower, the front side member, and the hood ledge is an aluminum-based material, and the main material of the extension member is a steel-based material . A method for manufacturing a hybrid vehicle body structure using different materials for a plurality of structural members joined together,
After different materials used for each structural member are joined in a flat plate state to form a preformed member,
A preformed member is molded into a three-dimensional shape by plastic working means to form a composite structure member,
When joining the composite structural member and the counterpart structural member corresponding to this with the same material part,
The dash upper, dash lower, front side member, and hood ledge of the plurality of structural members constituting the vehicle body are composite structural members mainly made of an aluminum-based material, and other structural members are steel-based materials. Is a composite structural member made mainly of
After joining aluminum materials in the assembly process of the engine compartment,
A method for manufacturing a hybrid vehicle body structure, comprising joining steel materials in an assembly process of a floor main, a body side, and a body main. 5. The hybrid vehicle body according to claim 4, wherein different materials are joined by friction stir welding or mash seam joining when different materials used for each structural member are joined in a flat plate state to form a preformed member. Structure manufacturing method.

Images