JP2014201112A - Vehicle front structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle front structure capable of effectively controlling vibration at a junction obtained by joining a front end part, on a vehicle front side, of a floor tunnel panel to a lower end part of a dash panel.SOLUTION: In the vehicle front structure obtained by joining a front end part 5A of a floor tunnel panel 5 to a lower end part 3a of a dash panel 3, a junction surface of the front end part 5A of the floor tunnel panel 5 is formed in an arc shape along the surface of the lower end part 3a of the dash panel 3, and a width L in a height direction of an upper stage surface part 5c of the front end part 5A with respect to a lower stage surface part 5b gradually becomes smaller toward the tip.

Description

  The present invention relates to a vehicle front structure in which a front end portion of a floor tunnel panel is joined to a lower end portion of a dash panel, and more specifically, a vehicle front portion that can suppress vibrations acting on a joining surface between the dash panel and the floor tunnel panel. Concerning structure.

  As shown in FIG. 9, in order to pass a dash panel 103 that partitions the engine room 101 and the vehicle compartment 102, an exhaust pipe in the case of an FF vehicle, and a propeller shaft in the case of an FR vehicle, A floor tunnel 104 is provided so as to extend in the direction. On the other hand, a vehicle having a dash cross member 105 having a substantially U-shaped cross section in the vehicle width direction in order to reinforce the dash panel 103 is known.

  In such a vehicle, there is a vehicle in which the lower end portion 103 a of the dash panel 103 is joined to the upper end flange portion 105 a of the dash cross member 105 and the front end portion 104 a of the floor tunnel 104 is joined to the lower end flange portion 105 b of the dash cross member 105. .

JP 2008-247346 A

  On the other hand, since a vehicle receives vibration from a road surface, an engine, or the like while traveling, it is required to suppress the vibration. In particular, a general panel (sheet metal panel) used in a conventional vehicle body structure often receives vibration in the direction perpendicular to the surface. Therefore, it is necessary to suppress the vibration in the direction perpendicular to the surface. This is a big problem at the joint.

  In the conventional vehicle shown in FIG. 9, when vibration in the vertical direction (arrow A in the drawing) is applied to the floor tunnel 104, the dash cross member 105 and the lower end portion 103a of the dash panel 103 are moved in the vehicle front-rear direction ( There is a problem that the vibration generated in the floor tunnel 104 is transmitted to the dash panel 103 as it is by being rotated and moved in the direction of arrow B). In addition, as often seen in ordinary vehicles, when the front end portion 104a of the floor tunnel 104 is abutted against the dash panel 103, there is a problem that the bent portion 104b breaks and vertical vibrations cannot be prevented.

  Furthermore, in the conventional vehicle, since the mating surface (joint surface) of the dash panel 103 extending in the vehicle height direction and the floor panel extending in the vehicle horizontal direction is close to the plane, the load due to vibration is concentrated. Therefore, vibration countermeasures in this part were important.

  Further, in the vehicle disclosed in Japanese Patent Application Laid-Open No. 2008-247346, a backbone is used as a reinforcing member for a floor tunnel, a front end portion of the backbone is joined to a rear end portion of a separate gusset, and the front end of the gusset is a dash panel. And it is the structure joined to the dash cross member. This gusset serves as a so-called refilling rod between the floor tunnel (and the floor panel) and the dash panel, but is easily bent to absorb this shock when subjected to a large impact. The structure has a bent portion. For this reason, there is a problem that this bent portion becomes a starting point at which bending due to vibration occurs.

  The present invention solves the above problems and provides a vehicle front structure capable of effectively suppressing vibration at a joint portion in which a front end portion of a floor tunnel panel is joined to a lower end portion of a dash panel. Objective.

In order to solve the above-described problems of the prior art, the present invention provides a vehicle front structure in which a front end portion of a floor tunnel panel is joined to a lower end portion of a dash panel, and a joining surface of the front end portion of the floor tunnel panel is provided. In addition, the dash panel is formed in an arc shape along the lower end surface, and the height of the upper step surface portion with respect to the lower step surface portion of the front end portion is gradually reduced toward the tip.
Further, the present invention is to join the upper and lower flange portions of the dash cross member to the back surface of the dash panel on the back side of the joining surface of the dash panel and the front end portion 5A of the floor tunnel panel, And the dash cross member formed a closed cross section.
Further, according to the present invention, the dash cross member is disposed on the back surface of the dash panel in the vehicle width direction, and the height of the dash panel in the vehicle vertical direction changes from the middle position in the vehicle width direction toward the side. The height change part is provided.
Furthermore, the present invention resides in that the front end portion of the floor panel joined to the lower step surface portion of the front end portion 5A of the floor tunnel panel and the lower end portion of the dash panel are both formed in an arc shape and joined.
Further, the present invention resides in that both lower end flange portions at the front end portion of the floor tunnel panel are sandwiched between the joint surfaces of the floor panel and the dash panel.

According to the present invention, the following effects can be obtained.
In the vehicle body front structure according to the present invention, the joint surface of the front end portion of the floor tunnel panel is formed in an arc shape along the lower end surface of the dash panel, and the height of the upper step surface portion with respect to the lower step surface portion of the front end portion The width in the direction is formed so as to gradually decrease toward the tip. Thus, the vibration in the vehicle vertical direction received by the front end portion of the floor tunnel panel is received and absorbed in the direction perpendicular to the dash panel (in the shear direction) at the joint surface with the dash panel. That is, since the vibration can be received and dispersed on the surface and the load can be prevented from being concentrated, the effect of suppressing the propagation of the vibration can be obtained. Further, even in the vehicle longitudinal direction vibration received by the dash panel, the load can be smoothly transmitted to the front end portion of the floor tunnel panel without concentrating the load, thereby suppressing the vibration. Can be obtained. Furthermore, by forming the width in the height direction of the upper step surface portion of the front end portion of the floor tunnel panel to gradually decrease toward the tip, the load received by the upper step surface portion is applied to the lower step surface portion and the dash panel. Therefore, the reinforcing effect can be enhanced.

  In the vehicle body front structure according to the present invention, the upper and lower flange portions of the dash cross member are joined to the back surface of the dash panel on the back side of the joining surface of the dash panel and the front end portion of the floor tunnel panel, Since the closed cross section is formed by the dash panel and the dash cross member, the closed cross section structure can increase the strength of the joint between the dash panel and the front end of the floor tunnel panel. The strength in the direction perpendicular to the panel can be increased. As a result, the dash cross member can be prevented from moving in the rotational direction due to vertical vibration of the front end portion of the floor tunnel panel, and vibration suppression at the joint portion can be achieved.

  In the vehicle body front structure according to the present invention, the dash cross member is disposed on the back surface of the dash panel in the vehicle width direction, and the height of the dash panel in the vehicle vertical direction from the middle position in the vehicle width direction toward the side. Since the height changing portion is provided so as to change, the bent portion serves as a change point of the vibration phase, so that the vibration suppressing effect can be enhanced.

  In the vehicle body front structure according to the present invention, the front end portion of the floor panel joined to the lower step surface portion of the front end portion of the floor tunnel panel and the lower end portion of the dash panel are both formed in an arc shape and joined. Therefore, each panel can receive vibration in a wide area, and as a whole, a structure that easily absorbs vibration can be obtained.

  In the vehicle body front structure according to the present invention, the flanges on both sides at the front end of the floor tunnel panel are sandwiched between the joint surfaces of the floor panel and the dash panel. It is possible to prevent the dash panel from being deformed by the vibration generated at the portion.

It is the perspective view which looked at the principal part of the vehicle front part structure concerning the embodiment of the present invention from the cabin side. It is a perspective view which expands and shows the principal part of the vehicle front part structure which concerns on embodiment of this invention. It is the perspective view which looked at the principal part of the vehicle front part structure concerning the embodiment of the present invention from the engine room side. It is CC sectional view taken on the line in FIG. It is a perspective view which expands and shows the front edge part vicinity of the floor tunnel panel in the vehicle front part structure which concerns on embodiment of this invention. FIG. 3 is a cross-sectional view taken along line D-D in FIG. It is a perspective view which shows the mode of joining of the front-end part of a dash panel, a floor panel, and a floor tunnel panel in the vehicle front part structure which concerns on embodiment of this invention. It is a perspective view which shows the mode of joining of the front-end part of a dash panel, a floor panel, and a floor tunnel panel in the vehicle front part structure which concerns on embodiment of this invention. FIG. 5 shows a conventional vehicle front part structure and is a cross-sectional view corresponding to FIG. 4.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 8 show a vehicle front structure according to an embodiment of the present invention. In this structure, a floor panel 4 is joined to the lower end portion 3a of the dash panel 3 that partitions the engine room 1 and the vehicle compartment 2 at the front part of the seat surface of the driver seat and the passenger seat (see FIGS. 1 to 4). .

  In the center of the vehicle, a tunnel portion that is one step higher than the floor panel 4 is provided so as to extend in the vehicle front-rear direction in order to allow the exhaust pipe to pass through. The tunnel portion is formed by a floor tunnel panel 5 which is a separate panel at the tip. The floor tunnel panel 5 is formed in an inverted U-shaped cross section and has a front end portion 5 </ b> A connected to the dash panel 3. The front end portion 5A of the floor tunnel panel 5 constitutes a lower step surface portion 5b provided with flange portions 5a serving as a joint surface with the floor panel 4 on both sides and the tip, a surface higher than the lower step surface portion 5b, and a ceiling portion of a U-shaped portion. The upper step surface portion 5c, and the height surface portion 5d constituting both side surfaces continuous so as to connect the lower step surface portion 5b and the upper step surface portion 5c are configured (see FIG. 5). The height surface portion 5d is formed so as to gradually narrow toward the front end of the front end portion 5A of the floor tunnel panel 5, and to be substantially flush with the flange portion 5a at the front end of the lower step surface portion 5b.

  Further, on the engine room 1 side of the dash panel 3, a dash cross member 6 having a substantially U-shaped cross section is joined as a reinforcing member for reinforcing the dash panel 3 via upper and lower flange portions 6a and 6b. The panel 3 is disposed over almost the entire region in the vehicle width direction (see FIGS. 1 to 4).

  The lower end portion 3a of the dash panel 3 is formed in a smooth arc shape so as to protrude toward the vehicle front side, while the front end portion 5A on the vehicle front side of the floor tunnel panel 5 is a lower step surface portion along the surface of the dash panel 3 The flange portion 5a of 5b is formed in a smooth arc shape so as to be substantially parallel to the surface angle of the dash panel 3. Further, the height surface portion 5d of the front end portion 5A is tapered, that is, the width L in the height direction of the upper step surface portion 5c with respect to the lower step surface portion 5b is gradually reduced toward the tip, and the lower end of the dash panel 3 is formed. The flange portion 5a of the front end portion 5A of the floor tunnel panel 5 is joined to the portion 3a in an arc shape (see FIGS. 1 to 4). A closed cross-section S1 with a slight gap is formed between the lower end 3a of the dash panel 3 and the flange 5a of the front end 5A of the floor tunnel panel 5.

  As a result, the front end portion 5A of the floor tunnel panel 5 is coupled to the dash cross member 6 in the shearing direction, so that the vibration in the vehicle vertical direction (arrow E in FIG. 1) received by the front end portion 5A of the floor tunnel panel 5 is reduced. Since the vibration is received in the plane 7 (shear direction) of the dash panel 3 at the joint 7 with the dash panel 3 and can be absorbed by the surface, propagation of vibration can be suppressed. Further, the vibration in the vehicle front-rear direction received by the dash panel 3 can be smoothly transmitted to the front end portion 5A of the floor tunnel panel 5 in the surface direction, so that the effect of suppressing the vibration can be obtained. .

  Further, the front end portion 5A of the floor tunnel panel 5 is formed so that the width L in the height direction of the height surface portion 5d gradually decreases toward the front end of the vehicle body. The load received by the upper step surface portion 5c can be smoothly propagated to the lower step surface portion 5b and the dash panel 3 toward the tip as shown in FIG. Generation can be suppressed, and the reinforcing effect can be enhanced.

  In this structure, the upper and lower flange portions 6a and 6b of the dash cross member 6 are joined to the back surface of the joint portion between the dash panel 3 and the front end portion 5A of the floor tunnel panel 5, and the dash panel 3 and the floor tunnel are combined. A closed cross section S2 is formed in a direction perpendicular to the plane of the joint 7 of the front end 5A of the panel 5 and the dash cross member 6 (see FIGS. 2 and 4). With this closed cross-section S2 structure, it is possible to obtain a reinforcing action in the direction perpendicular to the surface of the dash panel 3 that is easily affected by vibration from the back side of the joint surface, thereby suppressing vibration and increasing the strength of the joint portion 7. it can. Further, the upper and lower flange portions 6a and 6b of the dash cross member 6 are joined together with the front end portion 5A of the floor tunnel panel 5 in three pieces, so that the upper and lower flange portions 6a and 6b are joined to different members. As a result, the strength is increased, and the rotational movement that occurs in the dash cross member 6 can be suppressed. Since the closed cross section S2 is formed between the dash panel 3 and the dash cross member 6, and the closed cross section S1 is formed between the dash panel 3 and the flange portion 5a of the lower step surface portion 5b of the floor tunnel panel 5. The rigidity can be improved.

  In this structure, the dash cross member 6 has left and right height changing portions 6c whose side portions change downward in the vehicle vertical direction (height) toward the vehicle side portion as compared to the intermediate position in the vehicle width direction. (See FIGS. 2 and 3), the height changing portion 6c becomes a change point of the vibration phase, and the vibration suppressing effect by the dash cross member 6 is exhibited over the entire width of the dash panel 3. Can do.

  In this structure, the front end portion 4a of the floor panel 4 and the lower end portion 3a of the dash panel 3 joined to the lower step surface portion 5b of the front end portion 5A of the floor tunnel panel 5 are both formed in a smooth arc shape and joined to each other. Since it is configured (see FIG. 2 and FIG. 4), each panel can receive vibrations over a wide area, and vibrations are not easily propagated to other parts not only in the front end portion 5A of the floor tunnel panel 5 but also in the entire vehicle structure. It can be set as the structure which has a vibration suppression effect.

  In the structure, in the portion where the floor panel 4 and the dash panel 3 are joined, both side flange portions 5a of the front end portion 5A of the floor tunnel panel 5 are sandwiched between the floor panel 4 and the dash panel 3 on the vehicle rear side. The configuration is used (see FIGS. 5 to 8). Thereby, it is possible to prevent the dash panel 3 from being deformed by the vibration generated at the rear end portion of the front end portion 5A of the floor tunnel panel 5, and the vibration propagated through the front end portion 5A of the floor tunnel panel 5. Can be suppressed by the dash panel 3 and the floor panel 4 sandwiched therebetween, and a reinforcing effect can be obtained. Furthermore, since the vibration received by the dash panel 3 and the floor panel 4 joined in a state close to the orthogonal direction can be received in the surface direction of the other panel, the vibration suppressing effect can be enhanced. With respect to the vibration in the vehicle front-rear direction applied to the dash panel 3, the vibration is propagated in the surface direction of the front end portion 5A of the floor panel 4 and the floor tunnel panel 5. The vibration in the vehicle vertical direction applied to the floor panel 4 is propagated in the surface direction of the dash panel 3 via the front end portion 5 </ b> A of the floor tunnel panel 5. By propagating vibration in the surface direction of the panel in this way, adverse effects such as rotation due to vibration can be prevented as much as possible, and the effect of suppressing vibration can be effectively exhibited.

  In FIGS. 5, 7, and 8, “*” indicates a spot welding point.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention. . For example, the front end portion 5A of the floor tunnel panel 5 may be formed integrally or may be formed of a separate part, and in any case, the same effect as the present proposal can be obtained.

DESCRIPTION OF SYMBOLS 1 Engine room 2 Car compartment 3 Dash panel 3a Lower end part 4 Floor panel 5 Floor tunnel panel 5A Front end part 5a Flange part 5b Lower stage surface part 5c Upper stage part 5d Height surface part 6 Dash cross member 6a Upper end part 6b Lower end part 6c Height change part 7 Joint S1, S2 Closed section

Claims (5)

In the vehicle front structure in which the front end portion of the floor tunnel panel is joined to the lower end portion of the dash panel, the joining surface of the front end portion of the floor tunnel panel is formed in an arc shape along the lower end surface of the dash panel In addition, the vehicle front portion structure is characterized in that the height in the height direction of the upper step surface portion with respect to the lower step surface portion of the front end portion is gradually reduced toward the tip. The upper and lower flange portions of the dash cross member are joined to the back surface of the dash panel on the back side of the joining surface between the dash panel and the front end portion 5A of the floor tunnel panel, so that three pieces are combined, and the dash panel, the dash cross member, The vehicle front part structure according to claim 1, wherein a closed cross section is formed. The dash cross member is disposed on the back surface of the dash panel in the vehicle width direction, and is provided with a height changing portion in which the height in the vehicle vertical direction changes from the middle position in the vehicle width direction of the dash panel toward the side. The vehicle front structure according to claim 1 or 2, wherein The front end portion of the floor panel joined to the lower step surface portion of the front end portion 5A of the floor tunnel panel and the lower end portion of the dash panel are both formed in an arc shape and joined. Vehicle front structure. The vehicle front part structure according to claim 4, wherein both side lower end flange portions at a front end portion of the floor tunnel panel are sandwiched between joint surfaces of the floor panel and the dash panel.

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