JP2020079038A - Vehicle front part structure - Google Patents

Abstract

To provide a vehicle front part structure which enables reduction of deformation of a dash panel occurring when a cross member moves to the vehicle rear side to contact with the dash panel.SOLUTION: In an opening cross sectional part 33 of a cross member 30, a deformation induction bead 36 which induces deformation in a vehicle fore and aft direction is provided extending in a vehicle width direction. Thus, when intrusion of a barrier causes the cross member 30 to move to the vehicle rear and contact with a dash panel 48, the cross member 30 deforms relatively easily in a manner that the cross member 30 crashes in the vehicle fore and aft direction. Therefore, deformation of the dash panel 48 can be reduced. In particular, since the deformation induction bead 36 is provided at the opening cross sectional part 33 formed in an opening cross sectional shape, the cross member 30 can be efficiently deformed, compared to a case where the deformation induction bead is provided at a portion formed in a closed cross sectional shape.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle front structure having a cross member for supporting a motor and other accessories (inverters, etc.) in an electric vehicle, a hybrid vehicle including an internal combustion engine and a motor, and the like.

  Patent Document 1 (JP-A-2018-114785) has a cross member that extends in the vehicle width direction and has a closed cross section in a cross-sectional view orthogonal to the vehicle width direction, and the cross member is below the cross member. A structure for supporting a motor unit and auxiliary machinery (inverter and charger) above it is disclosed.

However, the structure disclosed in Patent Document 1 has the following problems.
Since the cross member has a closed cross section, it has relatively high rigidity. Therefore, when the cross member moves to the rear of the vehicle while maintaining its shape and comes into contact with the dash panel behind the cross member due to barrier intrusion during the vehicle front collision test, the amount of deformation of the dash panel may increase. There is.

  By the way, Patent Document 2 (Japanese Patent Laid-Open No. 2005-255070) does not relate to a cross member that supports motors and auxiliaries, but a suspension cross member 1 that supports left and right suspensions, as shown in FIG. A technique for providing the beads 2a is disclosed. Further, by providing the bead 2a, even if the suspension cross member 1 moves rearward of the vehicle and comes into contact with the dash panel 4, the bead 2a is condensed in the vehicle front-rear direction to suppress damage to the dash panel 4. ing.

  However, in the technique disclosed in Patent Document 2, the suspension cross member 1 has not only the fragile portion 2 due to the bead 2a but also the closed cross-sectional portion 3 in a sectional view orthogonal to the vehicle width direction. Therefore, the rigidity of the suspension cross member 1 is still high, and when the suspension cross member 1 contacts the dash panel 4, the deformation amount of the dash panel 4 may increase.

JP, 2018-114785, A JP, 2005-255070, A

An object of the present invention is to provide a vehicle front structure that can reduce the amount of deformation of the dash panel when the cross member moves rearward of the vehicle and contacts the dash panel.

The present invention that achieves the above object is as follows.
(1) A pair of left and right side members provided at intervals in the vehicle width direction and extending in the vehicle front-rear direction,
A cross member that extends in the vehicle width direction, is fixed to the pair of side members, and supports a motor and/or auxiliary machinery;
A vehicle front structure having:
The cross member has an open cross-section portion having an open cross-sectional shape in a cross-sectional view orthogonal to the vehicle width direction in at least a part of the vehicle width direction, and induces deformation in the vehicle front-rear direction in the open cross-section portion. A vehicle front structure in which a deformation-inducing bead that extends is provided in the vehicle width direction.

According to the vehicle front structure of (1) above, the following effects can be obtained.
A deformation-inducing bead that induces deformation in the vehicle front-rear direction is provided on the open cross-section of the cross member so as to extend in the vehicle width direction. When it comes into contact with a dash panel behind the cross member, the cross member deforms relatively easily in the front-rear direction of the vehicle. Therefore, the deformation amount of the dash panel can be reduced. In particular, since the deformation-inducing bead is provided in the open cross-section having the open cross-sectional shape, the cross member can be deformed more efficiently than in the case where the deformation-inducing bead is provided in the closed cross-section. it can.

  Therefore, the amount of deformation of the dash panel at the time of the collision test can be effectively reduced by setting the open cross-section portion where the deformation-inducing beads are provided at the cross member portion predicted to interfere with the dash panel.

1 is a plan view showing a vehicle front structure and its vicinity according to an embodiment of the present invention. FIG. 1 is a front view showing a vehicle front structure and its vicinity according to an embodiment of the present invention. It is a top view of a cross member in the vehicle front part structure of the example of the present invention. It is an AA line expanded sectional view of FIG. However, for the sake of clarity of the drawing, only the cross member is shown in cross section, and the others are omitted. FIG. 3 is a schematic bottom view showing a vehicle front structure of the embodiment of the present invention and the vicinity thereof, showing (a) before collision and (b) after collision. It is a schematic sectional drawing which shows the conventional vehicle front part structure.

  A vehicle front structure according to an embodiment of the present invention will be described below with reference to the drawings. In the figure, FR indicates the front (vehicle front) and UP indicates the upper side (vehicle upper side). W indicates the vehicle width direction.

  As shown in FIGS. 1 and 2, the vehicle front structure 10 of the embodiment of the present invention includes a pair of left and right side members 20 that are provided to extend in the vehicle front-rear direction (front-rear direction) at intervals in the vehicle width direction. The cross member 30 extends in the vehicle width direction and is fixed to the pair of side members 20.

  The side members 20 are front side members, and are provided on both left and right sides of the vehicle. The side member 20 is a skeletal member of a vehicle having a closed cross-sectional shape such as a rectangular cross-sectional shape (transverse cross-sectional shape) orthogonal to the extending direction (vehicle front-rear direction). A radiator support 40 that supports a radiator (not shown) is attached to the vehicle front end of the side member 20 or in the vicinity thereof via a bracket 40a. The lower end of the suspension tower 42 is joined to the vehicle rear end of the side member 20 or in the vicinity thereof. The suspension tower 42 is formed so as to cover a front suspension (not shown) that supports the front wheels of the vehicle, and an upper end portion of the front suspension (not shown) is fastened and fixed to an upper wall 42a of the suspension tower 42.

  As shown in FIG. 5A, a bumper reinforcement 46 extending in the vehicle width direction via a crash box 44 is attached to the vehicle front side of the side member 20. The crash box 44 is provided for axial compression deformation and absorption of energy when an impact load in the vehicle front-rear direction is received. The bumper reinforcement 46 has a curved shape in a plan view so that the central portion 46a in the vehicle width direction is located on the vehicle front side with respect to both vehicle width direction end portions 46b.

  The vehicle rear side of the side member (front side member) 20 is joined to the dash panel 48. The dash panel 48 is provided upright from the end of the floor panel 50 on the vehicle front side, and separates the passenger compartment (cabin) and the engine compartment 52 in the vehicle front-rear direction. Since the engine compartment 52 is a space in which the motor 60 is arranged as described later, it may be called a motor compartment or a motor room.

  As shown in FIGS. 1 and 2, the cross member 30 is an engine compartment cross member (may be referred to as a motor compartment cross member) on which a motor (motor generator) 60 and/or accessories 70 are supported. Therefore, it is a component different from the suspension cross member that supports the front suspension (not shown). In the illustrated example of the present invention, the cross member 30 supports both the motor 60 and the auxiliary machines 70. The accessories 70 are devices necessary for driving the motor 60, and are not particularly limited, but are, for example, inverters that control electric power from a battery (not shown) to the motor 60.

  The cross member 30 is provided so as to extend in the vehicle width direction between the vehicle front-rear direction intermediate portions of the pair of left and right side members 20. The cross members 30 are fixed to the pair of side members 20 either directly or via brackets 31 at both ends in the extending direction (vehicle width direction). The vertical position of the cross member 30 is the same as or substantially the same as the vertical position of the fixed side member 20, and spaces S1 and S2 are provided below and above the cross member 30 in the engine compartment 52, respectively.

The motor 60 is arranged in the space S1 below the cross member 30. As shown in FIG. 4, the motor 60 is supported by the cross member 30 via a motor mount 61. In FIG. 4, only the motor mount 61 is shown and the motor 60 is not shown. The motor 60 is supported by the cross member 30 by fastening and fixing the motor mount 61 to the cross member 30 using bolts 62. The bolt 62 has a front bolt 62a and a rear bolt 62b provided at a distance from the front bolt 62a to the rear of the vehicle in the vicinity of both ends of the cross member 30 in the vehicle width direction. Therefore, the motor 60 is bolted to the cross member 30 at four points 60a (see FIG. 3) on the front, rear, left and right.
In FIG. 4, reference numeral 63 is a collar that functions as a spacer that forms a gap S3 between the cross member 30 and the motor mount 61 (motor 60) in the vertical direction. Further, reference numeral 64 is a washer.

  As shown in FIG. 2, the auxiliary machinery (inverter) 70 is arranged in the space S2 above the cross member 30. The accessories 70 are fastened and fixed to the cross member 30 with bolts 71. As shown in FIG. 3, the auxiliary machines 70 are also bolted to the cross member 30 at four points 70a on the front, rear, left and right. When the size of the auxiliary machine 70 with respect to the cross member 30 is large and the fastening point 70a deviates from the cross member 30 in the vehicle front-rear direction, a protrusion protruding in the vehicle front-rear direction to the cross member 30 to secure the fastening point. The piece 32 may be provided.

  As shown in FIG. 4, the cross member 30 has an open cross-sectional shape that does not have a closed cross-sectional shape and has an open cross-sectional shape as a whole in a cross-sectional view (transverse cross-sectional view) orthogonal to the vehicle width direction. It has a part 33. The open cross-section portion 33 is continuously provided over the entire region of the cross member 30 in the vehicle width direction (extension direction). That is, the cross member 30 has an open cross-sectional shape over the entire vehicle width direction (extension direction). However, it suffices that the open cross section 33 is provided at least in a part of the cross member 30 in the vehicle width direction (extension direction).

  In the open cross-section portion 33, the cross member 30 has flange portions 34, 34 that are bent and extend downward at both end portions in the vehicle front-rear direction in order to enhance rigidity in the vehicle width direction. Therefore, the cross member 30 has an open cross-sectional shape that opens downward.

  A space between the flange portions 34, 34 in the vehicle front-rear direction is a single plate-shaped portion 35 extending in the vehicle front-rear direction. A motor 60 and accessories 70 are fastened and fixed to the plate-shaped portion 35. A deformation inducing bead 36 is provided at an intermediate portion of the plate-like portion 35 in the vehicle front-rear direction to induce deformation of the cross member 30 in the vehicle front-rear direction when a load in the vehicle front-rear direction is applied to the cross member 30 ( Has been formed).

  As shown in FIG. 3, the deformation inducing beads 36 are provided between the front two points and the rear two points of the four fastening points 60a of the motor 60 to the cross member 30 between the front and rear directions of the vehicle. Of the four fastening points 70a to the cross member 30 of the machinery 70, they are provided between the front two points and the rear two points in the vehicle front-rear direction.

  The deformation inducing bead 36 is provided so as to extend in the vehicle width direction, and is continuously provided over the entire area of the open cross section 33 in the vehicle width direction. In the illustrated example, since the open cross-section portion 33 is continuously provided over the entire region of the cross member 30 in the vehicle width direction, the deformation inducing beads 36 are also continuously provided over the entire region of the cross member 30 in the vehicle width direction. ing. Although only one deformation induction bead 36 is provided in the illustrated example, a plurality of deformation induction beads 36 may be provided at different positions in the vehicle front-rear direction.

  As shown in FIG. 4, the deformation inducing bead 36 has a shape in which the vehicle front-rear direction intermediate portion of the plate-shaped portion 35 is recessed downward. The reason why the deformation inducing bead 36 is not formed so that the vehicle longitudinal direction intermediate portion of the plate-like portion 35 is convex upward is that the deformation inducing bead 36 interferes with the auxiliary machines 70 on the cross member 30. This is to suppress The deformation inducing bead 36 having a shape recessed downward is located in the gap S3 between the cross member 30 and the motor mount 61 (motor 60), and the deformation inducing bead 36 is connected to the motor mount 61 (motor 60). Interference is suppressed.

  Since the deformation-induced bead 36 has a shape in which the vehicle longitudinal direction intermediate portion of the plate-shaped portion 35 is recessed downward, the deformation-induced bead 36 reduces the rigidity of the cross member 30 in the vehicle longitudinal direction, The rigidity of the cross member 30 in the vehicle width direction (the rigidity in the vertical direction) is improved.

  The deformation inducing bead 36 includes a bead front side wall 36a extending in the vertical direction, a bead rear side wall 36b located rearward of the bead front side wall 36a in the vehicle and parallel or substantially parallel to the bead front side wall 36a, and a lower end portion of the bead front side wall 36a. And a bead bottom wall 36c that connects the lower ends of the bead rear side walls 36b and extends in the vehicle front-rear direction. Therefore, the deformation inducing bead 36 has a U-shaped cross section (or U shape) that opens upward.

  5A and 5B show before and after a collision in the vehicle frontal collision test. The vehicle frontal collision test is not particularly limited as long as it is a collision test in which the cross member 30 moves to the rear of the vehicle due to the entry of a barrier (collision barrier) not shown, and may be a full-lap frontal collision test. The offset frontal collision test may be performed, or the oblique frontal collision test may be performed in which the barrier intrudes obliquely from the front.

  As shown in (b) of FIG. 5, the bumper reinforcement 46 is pushed rearward of the vehicle by a barrier (not shown) that has entered during the collision test, the crash box 44 is axially compressed and deformed (crushed), and the side members are also compressed. A load is also applied to 20, and the side member 20 is plastically deformed with buckling. Then, the cross member 30 attached to the side member 20 moves rearward of the vehicle and comes into contact with the dash panel 48 of the cross member 30 rearward of the vehicle.

  Here, the cross member 30 is provided with a deformation inducing bead 36 extending in the vehicle width direction for inducing deformation in the vehicle front-rear direction at the open cross-section portion 33 of the cross member 30. The rigidity is reduced. Therefore, when the cross member 30 moves rearward of the vehicle and comes into contact with the dash panel 48 due to the entry of the barrier, the deformation inducing bead 36 deforms the cross member 30 to be crushed over the entire vehicle front-rear direction. That is, the cross member 30 is pushed by the dash panel 48 and deforms in a direction away from the dash panel 48.

  Next, effects of the embodiment of the present invention will be described.

(A) Since the deformation-induced bead 36 that induces deformation in the vehicle front-rear direction is provided on the open cross-sectional portion 33 of the cross member 30 so as to extend in the vehicle width direction, the cross member 30 is located behind the vehicle during a collision test. When the cross member 30 is moved to and comes into contact with the dash panel 48, the cross member 30 is deformed relatively easily in the longitudinal direction of the vehicle. Therefore, not only at least a part of the collision energy can be absorbed, but also the contact area with the dash panel 48 can be increased. Therefore, the deformation amount of the dash panel 48 can be reduced. In particular, since the deformation inducing bead 36 is provided in the open cross-section portion 33 having the open cross-sectional shape, the cross member 30 is more efficiently arranged than when the deformation-inducing bead 36 is provided in the portion having the closed cross-sectional shape. It can be transformed. Therefore, the amount of deformation of the dash panel 48 during the collision test is effectively set by setting the open cross-section portion 33 provided with the deformation inducing bead 36 at the portion of the cross member 30 predicted to interfere with the dash panel 48. It can be reduced.

(B) When the open cross-section portion 33 provided with the deformation inducing bead 36 is continuously provided over the entire area of the cross member 30 in the vehicle width direction (extension direction), the cross member 30 in the vehicle width direction (extension direction). Whichever part of the cross member 30 abuts the dash panel 48, the cross member 30 can be relatively easily crushed in the vehicle front-rear direction. Therefore, the amount of deformation of the dash panel 48 when the cross member 30 contacts the dash panel 48 can be effectively reduced regardless of the type of collision test.

(C) Since the deformation-induced bead 36 has a shape in which the vehicle longitudinal direction intermediate portion of the plate-shaped portion 35 is recessed downward, the deformation-induced bead 36 causes the cross member 30 to have a rigidity in the vehicle width direction (in the vertical direction). (Rigidity) can be improved. Therefore, even when the cross member 30 has the open cross-section portion 33 having the open cross-sectional shape (even when the rigidity in the vehicle width direction is lower than that in the case where the cross member 30 has the closed cross-sectional shape). The rigidity of the cross member 30 when supporting the motor 60 and the accessories 70 (heavy weight) by the cross member 30 can be secured (guaranteed).

10 Vehicle Front Structure 20 Side Member 30 Cross Member 31 Bracket 33 Open Cross Section 34 Flange 35 Plate-like Part 36 Deformation-Inducing Bead 40 Radiator Support 42 Suspension Tower 44 Crash Box 46 Vamparin Force 48 Dash Panel 50 Floor Panel 52 Engine Compartment 60 Motor 60a Motor fastening point to cross member 61 Motor mount 70 Auxiliary equipment 70a Fastening point to accessory cross member S1, S2 Space S3 Clearance

Claims (1)

A pair of left and right side members provided to extend in the vehicle front-rear direction at intervals in the vehicle width direction,
A cross member that extends in the vehicle width direction, is fixed to the pair of side members, and supports a motor and/or auxiliary machinery;
A vehicle front structure having:
The cross member has an open cross-section portion having an open cross-sectional shape in a cross-sectional view orthogonal to the vehicle width direction in at least a part of the vehicle width direction, and induces deformation in the vehicle front-rear direction in the open cross-section portion. A vehicle front structure in which a deformation-inducing bead that extends is provided in the vehicle width direction.

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