WO2015029523A1

WO2015029523A1 - Vehicle front portion structure

Info

Publication number: WO2015029523A1
Application number: PCT/JP2014/064205
Authority: WO
Inventors: Takeshi KUNIYA
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2013-08-27
Filing date: 2014-05-22
Publication date: 2015-03-05
Also published as: JP2015044439A; JP6135404B2

Abstract

There is provided a vehicle front portion structure including: a power plant that is provided within a power plant room provided at a vehicle front portion, and that has a supported portion at a vehicle rear side; a mount that supports a rear portion of the power plant by supporting the supported portion, and whose strength in a vehicle longitudinal direction is set to be lower than that of the supported portion; and an energy absorbing portion that is provided at a vehicle rear side of the supported portion, and whose strength in the vehicle longitudinal direction is set to be lower than that of the supported portion.

Description

DESCRIPTION VEHICLE FRONT PORTION STRUCTURE

Technical Field

[0001] The present invention relates to a vehicle front portion structure.

Background Art

[0002] Japanese Patent Application Laid-Open (JP-A) No. HI 1-91620 discloses a vehicle front portion structure (a mount structure of a power plant) in which, by moving a power plant toward the vehicle rear side and the vehicle lower side at the time when the vehicle is in a front collision, suppresses the power plant directly pushing a member such as the dash panel or the like. To briefly describe the technique disclosed in this document, the region at the vehicle rear side of a power plant, that is disposed at the front portion of the vehicle, is supported at the vehicle body frame via a bracket and a mount support portion, and further, a weak portion and an inclined surface are provided at the bracket. When collision load due to a front collision is applied to the power plant and the load that is applied to the power plant exceeds a predetermined value, the weak portion of the bracket breaks. Due thereto, the fixing of the power plant to the mount support portion is cancelled, and it becomes possible for the power plant to move toward the vehicle rear side. Further, when the power plant moves toward the vehicle rear side, a shaft body that is supported at the mount support portion abuts the inclined surface of the bracket. Due thereto, the power plant moves toward the vehicle lower side while moving toward the vehicle rear side.

SUMMARY OF INVENTION

Technical Problem

[0003] However, although the structure disclosed in JP-A No. 11-91620 is a technique that is advantageous from the standpoint of suppressing the power plant directly abutting the dash panel or the like at the time of a front collision, there is room for improvement from the standpoint of ensuring the performance of absorbing the collision energy that is due to a front collision, after the weak portion of the bracket breaks.

[0004] In consideration of the above-described circumstances, the present invention provides a vehicle front portion structure that can effectively absorb collision energy that is due to a front collision.

Solution to Problem [0005] A vehicle front portion structure relating to a first aspect of the present invention includes: a power plant that is provided within a power plant room provided at a vehicle front portion, and that has a supported portion at a vehicle rear side; a mount that supports a rear portion of the power plant by supporting the supported portion, and whose strength in a vehicle longitudinal direction is set to be lower than that of the supported portion; and an energy absorbing portion that is provided at a vehicle rear side of the supported portion, and whose strength in the vehicle longitudinal direction is set to be lower than that of the supported portion.

[0006] When collision load that is due to a front collision is applied to a vehicle front portion to which the vehicle front portion structure of the first aspect of the present invention is applied, that collision load is transmitted to the power plant. When the collision load that is transmitted to the power plant exceeds a predetermined value, the mount breaks, and the power plant moves toward the vehicle rear side. Further, when the power plant moves toward the vehicle rear side, the supported portion that is provided at this power plant abuts the energy absorbing portion. Then, due to the supported portion pushing the energy absorbing portion, the energy absorbing portion deforms (breaks). Due thereto, the collision energy due to the front collision is absorbed.

[0007] In a vehicle front portion structure relating to a second aspect of the present invention, in the vehicle front portion structure of the first aspect of the present invention, an inclined surface, that is inclined toward a vehicle lower side with respect to the vehicle longitudinal direction, is provided at the supported portion, and the inclined surface faces the energy absorbing portion in the vehicle longitudinal direction.

[0008] In accordance with the vehicle front portion structure of the second aspect of the present invention, the power plant moves toward the vehicle rear side, and the supported portion that is provided at the power plant abuts the energy absorbing portion. Namely, when the inclined surface of the supported portion abuts the energy absorbing portion, the power plant moves toward the vehicle lower side while moving toward the vehicle rear side. Namely, in accordance with the present structure, the power plant can be moved toward the vehicle lower side while absorbing the collision energy due to a front collision.

[0009] In a vehicle front portion structure relating to a third aspect of the present invention, in the vehicle front portion structure of the second aspect of the present invention, a sub-frame, that spans between a pair of front side members that are disposed with an interval

therebetween in a vehicle transverse direction, is provided at the vehicle front portion, the energy absorbing portion is fixed to an upper portion of the sub-frame, and the supported portion is disposed at an upper side of the sub-frame.

[0010] In accordance with the vehicle front portion structure of the third aspect of the present invention, when the power plant moves toward the vehicle rear side, the supported portion that is provided at the power plant abuts the energy absorbing portion at the upper side of the sub-frame. Thereupon, the power plant moves toward the lower side of the sub-frame. Due thereto, the power plant abutting the sub-frame can be suppressed.

[0011] In a vehicle front portion structure relating to a fourth aspect of the present invention, in the vehicle front portion structure of the second or third aspect of the present invention, a portion of a stabilizer, that is supported at the sub-frame, is disposed at a vehicle rear side of the supported portion and the energy absorbing portion.

[0012] In accordance with the vehicle front portion structure of the fourth aspect of the present invention, when the supported portion that is provided at the power plant breaks the energy absorbing portion and the power plant moves further toward the vehicle rear side, the supported portion provided at the power plant abuts the stabilizer, and the power plant moves toward the lower side of the sub-frame. Namely, in accordance with the present structure, even after the energy absorbing portion breaks, the power plant abutting the sub-frame can be suppressed.

Advantageous Effects of Invention

[0013] The vehicle front portion structures relating to the first through fourth aspects of the present invention can effectively absorb collision energy that is due to a front collision.

BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 is a side sectional view showing a cross-section of the front portion of a vehicle, that is cut along line 1-1 shown in Fig. 2.

Fig. 2 is a perspective view showing the front portion of the vehicle to which a vehicle front portion structure of the present embodiment is applied.

DESCRIPTION OF EMBODIMENTS

[0015] A vehicle front portion structure relating to an embodiment of the present invention is described by using Fig. 1 and Fig. 2. Note that the vehicle longitudinal direction front side is denoted by arrow FR, the vehicle transverse direction outer side is denoted by arrow OUT, and the vehicle vertical direction upper side is denoted by arrow UP. Further, in the following description, when indicating merely the longitudinal and vertical directions, they mean the longitudinal of the vehicle longitudinal direction and the vertical of the vehicle vertical direction.

[0016] As shown in Fig. 2, a power plant room 14 in which a power plant 12 is

accommodated is provided at a front portion 10 of a vehicle to which the vehicle front portion structure of the present embodiment is applied. A pair of front side members 18, that extend toward the front side of a cabin 16 and are disposed with an interval therebetween in the vehicle transverse direction, are provided at the front portion 10 of the vehicle. Moreover, a pair of apron upper members 20, that are disposed at the vehicle transverse direction outer sides and vehicle upper sides of the front side members 18 and whose rear end portions are joined to unillustrated front pillars, are provided at the front portion 10 of the vehicle. A suspension tower 22, that supports the upper end portion of an unillustrated suspension, spans between the apron upper side member 20 and the front side member 18 that are disposed at the vehicle advancing direction right side. This suspension tower 22 is joined to the front side member 18 and the apron upper member 20. Further, the suspension tower 22, that is formed so as to be substantially symmetrical in the vehicle transverse direction to the above-described suspension tower 22, is joined to the front side member 18 and the apron upper member 20 that are disposed at the vehicle advancing direction left side.

[0017] Further, a sub-frame 24, that spans between this pair of front side members 18, is provided at the lower sides of the front side members 18, and the sub-frame 24 is formed substantially in the shape of a ladder as seen in a plan view of the vehicle. In more detail, the sub-frame 24 has a pair of arm supporting portions 26 that extend in the vehicle longitudinal direction and support unillustrated suspension arms and the like, a front frame portion 28 that connects the front end portions of the pair of arm supporting portions 26 in the vehicle transverse direction, and a rear frame portion 30 that connects the rear end sides of the pair of arm supporting portions 26 in the vehicle transverse direction. Further, the front end sides of the arm supporting portions 26 are fixed to the front end sides of the front side members 18 via supporting portions 32, and the rear end sides of the arm supporting portions 26 are fixed to the rear end sides of the front side members 18.

[0018] An Fr mount 34 is fixed to the substantially central portion in the vehicle transverse direction of the front frame portion 28. An Rr mount 36 that is described in detail later is fixed to the substantially central portion in the vehicle transverse direction of the rear frame portion 30. Moreover, an Rh mount 38 is fixed to the front side member 18 that is disposed at the vehicle advancing direction right side, and an Lh mount 40 is fixed to the front side member 18 that is disposed at the vehicle advancing direction left side. Further, the power plant 12 is supported at the front side members 18 and the sub-frame 24 via the above-described Fr mount 34, Rr mount 36, Rh mount 38 and Lh mount 40.

[0019] The structures of the rear portion of the power plant 12 and the rear side of the power plant 12, that are main portions of the present embodiment, are described next.

[0020] As shown in Fig. 1, an Rr mount bracket 42, that serves as a supported portion that is supported at the Rr mount 36, is fixed to the rear portion of the power plant 12. This Rr mount bracket 42 is formed by press working a steel plate material or casting an iron-based material or the like. In more detail, the Rr mount bracket 42 has a fixing portion 44 that is fixed via unillustrated bolts to the rear portion of a transmission case 13 of the power plant 12 and that is formed in a substantially rectangular shape as seen in a rear view of the vehicle. Further, the Rr mount bracket 42 has a pair of side wall portions 46 that extend toward the vehicle rear side from the both ends in the vehicle transverse direction of the fixing portion 44 and that are formed in substantially right triangular shapes as seen in a side view of the vehicle. Further, an inclined surface that is inclined toward the vehicle lower side with respect to the vehicle longitudinal direction, i.e., an inclined surface 48 that rises toward the front as seen in a side view of the vehicle, is provided at the side wall portion 46. This inclined surface 48 faces a steering gear box 60, that is described later, in the vehicle longitudinal direction. Moreover, an insert-through hole 50, through which an unillustrated bolt is inserted, is formed in the rear end portion of the side wall portion 46.

[0021] The Rr mount 36 that serves as a mount is structured to have an annular portion 52 that is formed in an annular shape whose axial direction is the vehicle transverse direction as seen in a side view of the vehicle, flange portions 54 that are provided integrally with the annular portion 52, an unillustrated collar that is provided at the axially central portion of the annular portion 52, and an unillustrated elastic member (as an example, an elastic member that is formed by using a rubber-based material) that is provided between the annular portion 52 and the collar. Further, the region at the vehicle rear side of the annular portion 56 is made to be a weak portion 56 that is thin- walled as compared with other regions of the annular portion 52. Due thereto, the strength in the vehicle longitudinal direction of the Rr mount 36 is set to be lower than that of the Rr mount bracket 42. The above-described Rr mount 36 is fixed to the vehicle upper side surface of the rear frame portion 30 via bolts 58 that are inserted-through the flange portions 54. Further, the Rr mount bracket 42 is fixed to the Rr mount 36 via bolts or the like that are inserted-through the insert-through holes 50, that are formed in the side wall portions 46 of the Rr mount bracket 42, and the collar that is provided at the axially central portion of the annular portion 52.

[0022] Further, the steering gear box 60 that serves as an energy absorbing portion is provided at the vehicle rear side of the Rr mount bracket 42. This steering gear box 60 is structured to include a steering gear box case 62, that structures the contour of the steering gear box 60 and is formed by casting of an aluminum alloy or the like, and unillustrated gears and a shaft 64, that are disposed within the steering gear box 60, and the like. Further, the steering gear box case 62 is structured to have a base portion 66 that is fixed to the vehicle upper side surface of the rear frame portion 30, and a tubular portion 68 that extends toward a vehicle transverse direction outer side from a vehicle transverse direction end portion of the base portion 66. Moreover, the tubular portion 68 faces the Rr mount bracket 42 in the vehicle longitudinal direction and is disposed at the upper side of the Rr mount 36 as seen in a side view of the vehicle.

[0023] Further, in the present embodiment, the strength in the vehicle longitudinal direction of the steering gear box 60 is set to be lower than that of the Rr mount bracket 42. Namely, the tubular portion 68 of the steering gear box case 62 is set so as to break before the Rr mount bracket 42 breaks, at the time when the Rr mount bracket 42 pushes the steering gear box 60.

[0024] Further, a portion 72 of a stabilizer 70, that connects an arm supported at the arm supporting portion 26 (see Fig. 2) at the vehicle advancing direction right side and an arm supported at the arm supporting portion 26 at the vehicle advancing direction left side, is disposed at the vehicle rear side of the Rr mount bracket 42 and the steering gear box 60. This stabilizer 70 is formed by bending processing or a heat treatment or the like being carried out on a solid rod material that is made of steel, or the like. The stabilizer 70 is supported at the rear frame portion 30 via a supporting portion 74. Moreover, as seen in a side view of the vehicle, the portion 72 of the stabilizer 70 is disposed further toward the vehicle lower side than the center of the tubular portion 68 of the steering gear box case 62 and further toward the vehicle upper side than the center of the annular portion 52 of the Rr mount 36 (the center of the collar).

[0025] (Operation and Effects of Present Embodiment)

The operation and effects of the present embodiment are described next.

[0026] As shown in Fig. 2, when collision load due to a front collision is applied to the front portion 10 of the vehicle to which the vehicle front portion structure of the present

embodiment is applied, this collision load F is transmitted to the power plant 12 as shown in

Fig. 1. When the collision load F that is transmitted to the power plant 12 exceeds a predetermined value, the region at the vehicle rear side of the annular portion 52 of the Rr mount 36, i.e., the weak portion 56 of the annular portion 52, breaks, and the power plant 12 moves toward the vehicle rear side. Further, when the power plant 12 moves toward the vehicle rear side, the Rr mount bracket 42, that is provided at that power plant 12, abuts the steering gear box 60. Then, due to the Rr mount bracket 42 pushing the steering gear box 60, the steering gear box 60 deforms. In more detail, the tubular portion 68 of the steering gear case 62, that structures a portion of the steering gear box 60, breaks. Due thereto, the collision energy that is due to the front collision can be absorbed effectively.

[0027] Further, in the present embodiment, the above-described inclined surfaces 48 are provided at the Rr mount bracket 42. Therefore, when the power plant 12 moves toward the vehicle rear side and the inclined surfaces of the Rr mount bracket 42 abut the tubular portion 68 of the steering gear box case 62, the power plant 12 moves toward the vehicle lower side while moving toward the vehicle rear side, i.e., while the Rr mount bracket 42 deforms (breaks) the tubular portion 68 of the steering gear box case 62. Due thereto, while the collision energy due to a front collision is absorbed, the power plant 12 can be moved toward the vehicle lower side, and the power plant 12 abutting the front end side of the rear frame portion 30 can be suppressed.

[0028] Moreover, in the present embodiment, when the Rr mount bracket 42 that is provided at the power plant 12 breaks the tubular portion 68 of the steering gear box case 62, and the power plant 12 moves further toward the vehicle rear side, the inclined surfaces 48 of the Rr mount bracket 42 abut the stabilizer 70, and the power plant 12 moves toward the lower side of the rear frame portion 30. Namely, in accordance with the present structure, even after the tubular portion 68 of the steering gear box case 62 breaks, the power plant 12 abutting the front end side of the rear frame portion 30 can be suppressed.

[0029] Note that the present embodiment has described an example in which the portion 72 of the stabilizer 70 is disposed at the vehicle rear side of the Rr mount bracket 42 and the steering gear box 60, but the present invention is not limited to this. For example, it is possible to not provide the stabilizer, or to dispose the portion of the stabilizer at a position that the Rr mount bracket 42 does not abut. In this way, it suffices to decide whether or not to provide a stabilizer, or where to dispose the portion of the stabilizer, appropriately in consideration of the steering stability of the vehicle and the clearance with other vehicle body structural parts and the like.

[0030] Further, the present embodiment has described an example in which the collision load due to a front collision is absorbed by deforming the steering gear box 60 that is fixed to the sub-frame 24, but the present invention is not limited to this. For example, there may be a structure in which an energy absorbing portion, that has a honeycomb structure or the like, is fixed to a vehicle body skeleton member, and the collision energy due to a front collision is absorbed by causing this energy absorbing portion to be deformed by the Rr mount bracket 42.

[0031] Moreover, the present embodiment has described an example in which the inclined surfaces 48 are provided at the Rr mount bracket 42, but the present invention is not limited to this, and, for example, an Rr mount bracket that does not have the inclined surfaces 48 can be used. It suffices to decide whether or not to provide the inclined surfaces 48 at the Rr mount bracket 42 in this way, appropriately in consideration of the positional relationship between the Rr mount bracket 42 and the sub-frame 24, or the like.

[0032] Further, the present embodiment has described an example in which the Rr mount bracket 42 that is supported at the Rr mount 36 is fixed to the rear portion of the power plant 12, but the present invention is not limited to this. For example, there may be a structure in which a region corresponding to the Rr mount bracket 42 is formed integrally with the power plant.

[0033] An embodiment of the present invention has been described above, but the present invention is not limited to the above, and, of course, can be implemented by being modified in various ways other than the above within a scope that does not deviate from the gist thereof.

[0034] The disclosure of Japanese Patent Application No. 2013-175629, filed August 27, 2013, is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

Claim 1. A vehicle front portion structure comprising:

a power plant that is provided within a power plant room provided at a vehicle front portion, and that has a supported portion at a vehicle rear side;

a mount that supports a rear portion of the power plant by supporting the supported portion, and whose strength in a vehicle longitudinal direction is set to be lower than that of the supported portion; and

an energy absorbing portion that is provided at a vehicle rear side of the supported portion, and whose strength in the vehicle longitudinal direction is set to be lower than that of the supported portion.

Claim 2. The vehicle front portion structure of claim 1, wherein an inclined surface, that is inclined toward a vehicle lower side with respect to the vehicle longitudinal direction, is provided at the supported portion, and the inclined surface faces the energy absorbing portion in the vehicle longitudinal direction.

Claim 3. The vehicle front portion structure of claim 2, wherein:

a sub-frame, that spans between a pair of front side members that are disposed with an interval therebetween in a vehicle transverse direction, is provided at the vehicle front portion, the energy absorbing portion is fixed to an upper portion of the sub-frame, and the supported portion is disposed at an upper side of the sub-frame.

Claim 4. The vehicle front portion structure of claim 2 or claim 3, wherein a portion of a stabilizer, that is supported at the sub-frame, is disposed at a vehicle rear side of the supported portion and the energy absorbing portion.