PH12018000145A1

PH12018000145A1 - Steering column support structure

Info

Publication number: PH12018000145A1
Application number: PH12018000145A
Authority: PH
Inventors: Jidosha Engineering Kabushiki Kaisha Mitsubishi; Akihiro Kokura; Satoru Takahashi; Tomoki Minami; Yoichi Hisama; Shinya Tanaka; Shigeharu Ichihashi
Original assignee: Mitsubishi Motors Corp
Priority date: 2017-05-31
Filing date: 2018-05-25
Publication date: 2019-05-15
Also published as: JP6874536B2; JP2018202936A; MY194379A; PH12018000145B1

Abstract

To decrease lengths of a backward retreat amount and an upward projection amount of a rear end portion of a steering column at an occurrence of a frontal collision of a vehicle while keeping a necessary degree of freedom of layout of vehicle components. When a dash panel retreats upon occurrence of the frontal collision, a load is exerted on a first stay 30, a second stay 32 and a third stay 34, as a result of which the first stay 30 is deformed, that is, bent downward, at a deformation inducing portion 38, whereby a triangular shape formed by the stays 30, 32, and 34 is deformed. A top portion of a brake booster 14 retreats to displace a first portion 10A of the dash panel 10 up rearward. As a result, a front end portion of the first stay 30 and a front end portion of the second stay 32 which are connected to the first portion 10A of the dash panel 10 are displaced up rearward together with the first portion 10A, whereby downward displacement of a portion where the second stay 32, the third stay 34, and a front portion 16A of a steering column 16 are connected together is canceled out.

Description

S1. The brake booster 14 serves to reinforce a stepping force of the driver that is applied to a brake pedal (not shown) which is connected to the stepping force transmission shaft 1404.

A steering column 16 supports a steering shaft 20 to which a steering wheel 18 is attached. In Fig. 1, reference numeral 22 denotes a power steering device. A front portion 16A of the steering column 16 is disposed at a vehicle front position that is in the rear of the dash panel 10 and below the deck cross member 12.

Next, a support structure for the steering column 16 will be described.

The steering column 16 is supported by the deck cross member 12 and the dash panel 10 via steering column connection brackets 24, three stays 30, 32, and 34, and a bracket 36. : The steering column connection brackets 24 are spaced from each other in the vehicle width direction and attached to a rear portion of the outer circumferential surface of the deck cross member 12.

The steering column 16 is attached to the steering column connection brackets 24 by respective bolts N1. In the embodiment, the steering column 16 is attached to the steering column connection brackets 24 at its approximately middle position in the vehicle front-rear direction. Thus, the approximately middle portion, in the vehicle front-rear direction, of the steering column 16 is connected to the deck cross member 12 via the steering column connection brackets 24.

As shown in Fig. 1, each of the three stays 30, 32, and 34 connects two of three portions that are a first portion 10A that is a portion, in the vicinity of the top of the brake booster 14, of the dash panel 10 (i.e., a portion, overlapping with or adjacent to the top of the brake booster 14, of the dash panel 10 in a front view), the deck cross member 12, and the front portion 16A of the steering column 16. As such, the stays 30, 32, and 34 are like the respective sides of a triangle.

More specifically, the three stays 30, 32, and 34 are a first stay 30 which connects the first portion 10A and the deck cross member 12, a second stay 32 which connects the first portion 10A and the front portion 16A of the steering column 16, and a third stay 34 which connects the deck cross member 12 and the front portion 16A of the steering column 16.

In a plan view, the first stay 30, the second stay 32, and the third stay 34 are arranged in the vehicle front-rear direction. Since the three stays 30, 32, and 34 constitute a triangular structure, the support structure for the steering column 16 is increased in strength.

As shown in Fig. 6, the third stay 34 which connects the deck cross member 12 and the front portion 16A of the steering column 16 has a main body plate portion 3402 which is inclined so as to go down as the third stay 34 extends forward in a state that the third stay 34 is attached to the vehicle body and a pair of side plate portions 3404 which are bent downward from the main body plate portion 3402 at their two respective side edges in the vehicle width direction.

Front end portions of the respective side plate portions 3404 are attachment plate portions 3405 through which respective bolt insertion holes 3406 are formed.

As shown in Figs. 1 and 2, the third stay 34 is connected to the deck cross member 12 by welding rear end portions of the main body plate portion 3402 and the pair of side plate portions 3404 to a front portion of the outer circumferential surface of the deck cross member 12.

As shown in Fig. 1, the third stay 34 is connected to the front portion 16A of the steering column 16 by threadedly engaging a bolt N2 being inserted in the bolt insertion holes 3406 with a boss (not shown) of the front portion 16A of the steering column 16 located in front of the power steering device 22 and thereby fastening the attachment plate portions 3405 to the boss.

As shown in Figs. 2 and 5, the second stay 32 which connects the first portion 10A and the front portion 16A of the steering column 16 has a main body plate portion 3202 which is inclined so as to go up as the second stay 32 extends forward in a state that the second stay 32 is attached to the vehicle body, a pair of side plate portions 3204 which are erected upward from the main body plate portion 3202 at its two respective sides in the vehicle width direction, and an attachment plate portion 3206 which is erected from the main body plate portion 3202 at its front edge and is continuous with front end portions of the pair of side plate portions 3204. A bolt insertion hole 3210 is formed through the attachment plate portion 3206.

As shown in Figs. 1 and 2, the second stay 32 is connected to the front portion 16A of the steering column 16 by welding rear end portions of the pair of side plate portions 3204 to the respective attachment plate portions 3405 of the third stay 34. That is, the second stay 32 is connected to the front portion 16A of the steering column 16 via the third stay 34.

As shown in Figs. 1, 2, and 3, the second stay 32 is connected to the first portion 10A by fastening the attachment plate portion 3206 of the second stay 32 to an attachment plate portion 3606 of the bracket 36 attached to the first portion 10A, by a bolt N3 being inserted in the bolt insertion hole 3210.

The bracket 36 will now be described. As shown in Figs. 1 and 2, the bracket 36 is attached to the first portion 10A.

As shown in Figs. 3 and 7A to 7D, the bracket 36 has base portions 3602 which are attached to the first portion 10A, a hollow leg portion 3604 which projects rearward from the base portions 3602, and the attachment plate portion 3606 which is continuous with the leg portion 3604 at its rear edges.

In the embodiment, the hollow leg portion 3604 is shaped like a box having approximately a truncated rectangular pyramid shape and has four side plate portions 3604A. The base portions 3602 are continuous with the leg portion 3604 at its front edges, and the attachment plate portion 3606 is continuous with the leg portion 3604 at its rear edges. The leg portion 3604 is formed in such a manner that the sectional area of its inside space decreases gradually as the leg portion 3604 extends in the direction from the base portions 3602 to the attachment plate portion 3606.

As shown in Fig. 9, the bottom wall, which is directed downward, of the leg portion 3604 is a slant wall 3604C which is inclined so as to go up gradually as the leg portion 3604 extends rearward. In this example, the bottom one of the four side plate portions 3604A is the slant wall 3604C.

Among the four side plate portions 3604A, each of the three side plate portions 3604A that are located on the two respective sides in the vehicle width direction and at the bottom is formed with, at the center in its width direction, a reinforcement bead 3608 that extends over its full length in the vehicle front-rear direction. The strength of the bracket 36 is thus increased.

The base portions 3602 are four bent plate portions which are bent outward from the four side plate portions 3604A of the leg portion 3604 at their front edges, respectively. The four bent plate portions are attached to the dash panel 10 by spot welding. In the state that the bracket 36 is attached to the dash panel 10 in this manner, the attachment plate portion 3606 is directed up rearward. In other words, as shown in Fig. 9A, the attachment plate portion 3606 is a slant wall 3606C which is inclined so as to go forward gradually as the attachment plate portion 3606 extends upward.

The attachment plate portion 3606 is continuous with the four side plate portions 3604A at their rear edges. A bolt insertion hole 3610 is formed through the attachment plate portion 3606, and a female screw member 3612 is welded to the inner surface of the attachment plate portion 3606 so as to be registered with the bolt insertion hole 3610.

As shown in Fig. 8, the bracket 36 is attached to the dash panel 10 so that its bottom portion coextends with a top portion of the brake booster 14 in a front view.

As shown in Figs. 2 and 4, the first stay 30 which connects the first portion 10A and the deck cross member 12 has a main body plate portion 3002 which extends in the vehicle front-rear direction and is inclined so as to go down as the first stay 30 extends forward in a state that the first stay 30 is attached to the vehicle body, a pair of side plate portions 3004 which are erected from the main body plate portion 3002 at its two side edges in the vehicle width direction,

and an attachment plate portion 3006 which is erected from the main body plate portion 3002 at its front edge. Bent plate portions 3010 are bent outward in the vehicle width direction from the side plate portions 3004 at their top edges, respectively. A bolt insertion hole 3008 is formed through the attachment plate portion 3006.

A long hole 3012 is formed through the main body plate portion 3002 at a middle position in its longitudinal direction. A recess 3014 is formed on the boundary between each of the pair of side plate portions 3004 and the associated bent plate portion 3010 in their longitudinal direction. In the embodiment, the long hole 3012 and the recesses 3014 constitute a deformation inducing portion 38 which causes an intermediate portion, in the longitudinal direction, of the first stay 30 to be deformed earlier than the other portions of the first stay 30 when it receives an impact load at the occurrence of a frontal collision. For example, the deformation inducing portion 38 has a rigidity lower than a rigidity of the other portions of the first stay 30 which are other than the deformation inducing portion 38 of the first stay 30. A single long hole or a single recess may be formed in the first stay as the deformation inducing portion 38.

Furthermore, in the embodiment, the long hole 3012 and the recesses 3014 which constitute the deformation inducing portion 38 are formed so that when the first stay 30 receives an impact load of a frontal collision an intermediate portion, in the longitudinal direction, of the first stay 30 is deformed downward more than both its end portions to form a bend there that is convex downward.

As shown in Fig. 1, the first stay 30 is connected to the deck cross member 12 by welding rear end portions of the pair of side plate portions 3004 to a top-front portion of the outer circumferential surface of the deck cross member 12 above a rear portion of the third stay 34.

As shown in Fig. 3, the first stay 30 is connected to the first portion 10A which is a portion, in the vicinity of a top portion of the brake booster 14, of the dash panel 10 by threadedly engaging the bolt N3 being inserted in the bolt insertion hole 3008 with the female screw member 3612 and thereby fastening the attachment plate portion 3006 to the attachment plate portion 3616 of the bracket 36.

In the embodiment, the attachment plate portion 3206 of the second stay 32 is placed on the attachment plate portion 3006 of the second stay 32 and the attachment plate portion 3006 of the first stay 30 is placed on the attachment plate portion 3206 of the second stay 32. And the attachment plate portion 3206 of the second stay 32 and the attachment plate portion 3006 of the first stay 30 are fastened to the attachment plate portion 3606 of the bracket 36 by the bolt

N3.

Next, a description will be made of workings and advantages. Fig. 9A shows an initial state before occurrence of a frontal collision of the vehicle.

Each of the first stay 30, the second stay 32, and the third stay 34 extends so as to form a certain angle with the vehicle front-rear direction and thereby connects two of the three portions that are the first portion 10A, the deck cross member 12, and the front portion 16A of the steering column 16. The stays 30, 32, and 34 thus form a structure having them as the respective sides of a triangle. As a result, the support structure for the steering column 16 is increased in strength.

As shown in Fig. 9B, at the occurrence of a frontal collision of the vehicle, when the dash panel 10 retreats toward the vehicle compartment S1 side due to an impact load applied from the front side, a load is exerted on the second stay 32, and the third stay 34 from the dash panel 10 via the bracket 36. In Figs. 9B and 9C, two-dot chain lines indicate the positions of the respective members and portions in the initial state.

Because of the reception of the impact load, as shown in Fig. 9B, the first stay 30 is deformed, that is, the first stay 30 is bent downward, at the deformation inducing portion 38, whereby the triangular shape formed by the stays 30, 32, and 34 is deformed so as to be compressed in the vehicle front-rear direction as indicated by solid lines from the initial state indicated by the two-dot chain lines.

Since the triangular shape formed by the stays 30, 32, and 34 is deformed so as to be compressed in the vehicle front-rear direction, the retreat length of the rear end of the steering column 16, that is, the steering wheel 18, is decreased.

During that course, since the triangular shape formed by the stays 30, 32, and 34 is deformed so as to be compressed in the vehicle front-rear direction, the portion where the second stay 32, the third stay 34, and the front portion 16A of the steering column 16 are connected together is displaced downward. In response, the steering column 16 is forced to rotate in such a manner that its rear portion is displaced upward with its portion connected to the deck cross member

12 via the steering column connection brackets 24 as a supporting point.

At this time, as shown in Fig. 9C, the main body 1402 of the brake booster 14 retreats, whereupon the top portion of the main body 1402 deforms the first portion 10A of the dash panel 10 up rearward. As a result, the front end portion of the first stay 30 and the front end portion of the second stay 32 which are connected to the first portion 10A are displaced up rearward together with the first portion 10A. In response, the portion where the second stay 32, the third stay 34, and the front portion 16A of the steering column 16 are connected together is displaced upward to cancel out the above-mentioned downward displacement of the same portion. In this manner, the upward projection length of the rear end portion of the steering column 16, that is, the upward projection length of the steering wheel 18, is decreased.

Since the retreat length and the upward projection length of the rear end portion of the steering column 16, that is, the retreat length and the upward projection length of the steering wheel 18, are decreased, which is advantageous in lowering the degree of injury.

Furthermore, unlike in the conventional technique, it is not necessary to dispose plural vehicle components such as the engine unit, the cross member, and the steering gear box at particular positions for the purpose of decreasing the retreat length and the upward projection length of the steering wheel 18. This is advantageous in keeping a necessary degree of freedom of layout of vehicle components.

The embodiment is such that the first stay 30 is bent downward so as to have a convex shape when its deformation inducing portion 38 receives an impact load of a frontal collision of the vehicle. Alternatively, the first stay 30 may be such as to be bent upward so as to assume a convex shape when its deformation inducing portion 38 receives an impact load of a frontal collision of the vehicle.

However, in the embodiment, when the first stay 30 is deformed at the deformation inducing portion 38 at the occurrence of a frontal collision, the deformation inducing portion 38 does not interfere with the instrument panel which is located above the first stay 30. Thus, the first stay 30 is deformed reliably at the deformation inducing portion 38 without any restrictions and the first stay 30, and the second stay 32, and the third stay 34 are displaced reliably without any restrictions. As such, the embodiment is more advantageous in decreasing the retreat length and the upward projection length of the rear end portion of the steering column 16, that is, the retreat length and the upward projection length of the steering wheel 18.

The top portion of the brake booster 14 and the bottom portion of the bracket 36 need not always coextend with each other in a front view. However, where they coextend with each other as in the embodiment, at the occurrence of a frontal collision the bottom portion of the bracket 36 is displaced up rearward reliably by the top portion of the brake booster 14, the front end portion of the first stay 30 and the front end portion of the second stay 32 are displaced up rearward efficiently. As such, the embodiment is more advantageous in decreasing the upward projection length of the rear end portion of the steering column 16, that is,

the steering wheel 18, and hence in lowering the degree of injury.

The up-rearward displacement of the bracket 36 can be made more reliable by setting the overlap range of the brake booster 14 and the bracket 36 to at most the bottom half region of the front end of the bracket 36.

In the embodiment, the bracket 36 has the base portions 3602 which are attached to the dash panel 10, the hollow leg portion 3604 which projects rearward from the base portions 3602, and the attachment plate portion 3606 which is continuous with the leg portion 3604 at its rear edges. The bracket 36 thus assumes a box shape. This structure is advantageous in increasing the strength of the bracket 36.

As a result, at the occurrence of a frontal collision, an impact load that is exerted from the top portion of the brake booster 14 to the bottom portion of the bracket 36 can be transmitted up rearward via the bracket 36.

The leg portion 3604 of the bracket 36 need not always assume a hollow box shape. However, the bracket 36 having a hollow box shape can increase its strength while decreasing its weight.

The bottom wall of the leg portion 3604 of the bracket 36 is the slant wall 3604C which is inclined so as to go up gradually as the bracket 36 extends rearward. As a result, at the occurrence of a frontal collision, an impact load that is exerted from the top portion of the brake booster 14 to the bottom portion of the bracket 36 is transmitted up rearward efficiently along the slant wall 3604C of the leg portion 3604.

The attachment plate portion 3606 is the slant wall 3606C which goes forward gradually as the attachment plate portion 3606 extends upward. Thus,

at the occurrence of a frontal collision, an impact load that is exerted from the top portion of the brake booster 14 to the bottom portion of the bracket 36 is transmitted up rearward efficiently past the attachment plate portion 3606.

This is more advantageous in displacing the front end portion of the first stay 30 and the front end portion of the second stay 32 are displaced up rearward efficiently at the occurrence of a frontal collision. As such, the embodiment is even more advantageous in decreasing the upward projection length of the rear end portion of the steering column 16, that is, the steering wheel 18, and hence in lowering the degree of injury.

In the embodiment, among the four side plate portions 3604A constituting the leg portion 3604, each of the three side plate portions 3604A that are located on the two respective sides in the vehicle width direction and at the bottom is formed with a reinforcement bead 3608. This is advantages in increasing the strength of the bracket 36 and hence is advantages in transmitting an impact load up rearward efficiency that is applied from the top portion of the brake booster 14 to the bottom portion of the bracket 36 at the occurrence of a frontal collision.

Thus, this is more advantageous in displacing the front end portion of the first stay 30 and the front end portion of the second stay 32 are displaced up rearward efficiently at the occurrence of a frontal collision. As such, the embodiment is even more advantageous in decreasing the upward projection length of the rear end portion of the steering column 16, that is, the steering wheel 18, and hence in lowering the degree of injury.

In the embodiment, the first stay 30 to connect the first portion 10A and the deck cross member 12 is connected to the dash panel 10 by attaching the first stay 30 to the bracket 36 which is attached to the dash panel 10.

However, the bracket 36 may be omitted, that is, the first stay 30 may be attached to the dash panel 10 directly.

However, where the distance between the second stay 32 and the top portion of the brake booster 14 is short, the use of the bracket 36 is advantageous in securing a necessary distance between the second stay 32 and the top portion of the brake booster 14, preventing the second stay 32 from being bent early by the top portion of the brake booster 14 at the occurrence of a frontal collision, and suppressing increase of the upward projection length of the rear end portion of the steering column 16, that is, the steering wheel 18.

STEERING COLUMN SUPPORT STRUCTURE

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a steering column support structure. 2. Description of the Related Art

Various steering column support structures have been proposed conventionally which lower the degree of injury of the driver by decreasing the lengths of a backward retreat amount and an upward projection amount of a rear end portion of a steering column, that is, a steering wheel, occurring at the occurrence of a frontal collision of the vehicle.

JP-A-2006-44309 discloses a support structure that a steering column is supported rotatably by a deck cross member extending in the vehicle width direction and a steering gear box which is provided in front of the steering column is disposed between an engine unit provided in a vehicle front space and a cross member extending in the vehicle width direction.

In this support structure, the positions of the engine unit, the cross member, and the steering gear box are set so that the steering gear box is put between the engine unit and the cross member and thereby pushed out upward when the engine unit retreats at the occurrence of a frontal collision. Thus, at the occurrence of a frontal collision, the steering gear box is pushed out upward, whereby a front portion of the steering column is rotated upward and a rear portion of the steering column is rotated downward about the axis of the deck cross member. As a result, the lengths of a backward retreat amount and an upward projection amount of a rear end portion of the steering column, that is, the steering wheel, are decreased.

However, in the above conventional technique, it is necessary to dispose plural vehicle components such as the engine unit, the cross member, and the steering gear box at particular positions. This means a disadvantage that the degree of freedom of layout of vehicle components is lowered.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstances, and an object of the invention is therefore to provide a steering column support structure which is advantageous in decreasing the lengths of a backward retreat amount and an upward projection amount of a rear end portion of the steering column, that is, the steering wheel, at the occurrence of a frontal collision while keeping a necessary degree of freedom of layout of vehicle components.

To attain the above object, the invention provides a steering column support structure of the following items (1) to (5): (1) A steering column support structure comprising: a deck cross member which is disposed in a rear of a dash panel and extends in a vehicle width direction of a vehicle; a steering column attached to the deck cross member; a first stay which connects the dash panel and the deck cross member,

a second stay which connects the dash panel and a front portion of the steering column; and a third stay which connects the front portion of the steering column and the deck cross member,

wherein a brake booster is disposed in front of the dash panel;

wherein the first stay and the second stay are attached to a first portion, which is positioned above the brake booster, of the dash panel; and wherein the first stay has a deformation inducing portion at which the first stay is deformed earlier than the other portions of the first stay when the first stay receives an impact load of a frontal collision of the vehicle.

(2) The steering column support structure according to item (1), wherein the deformation inducing portion causes the first stay to be bent downward so as to have a convex shape when the first stay receives the impact load of the frontal collision of the vehicle.

(3) The steering column support structure according to item (1) or (2), wherein the first stay and the second stay are attached to a bracket which is mounted on the first portion of the dash panel to connect the first portion to the first stay and the second stay; and wherein a top portion of the brake booster and a bottom portion of the bracket are overlapped with each other in view from a front of the vehicle.

(4) The steering column support structure according to item (3), wherein the bracket has a base portion which is mounted on the dash panel, a leg portion which projects rearward from the base portion, and an attachment plate portion which is continuous with a rear end of the leg portion and is attached to the first stay and the second stay;

wherein a bottom portion, which is directed downward, of the leg portion has a slant face which goes up gradually as the bottom portion extends rearward; and wherein the attachment plate portion has a slant face which goes forward of the vehicle gradually as the attachment plate portion extends upward. (5) The steering column support structure according to any one of items (1) to (4), wherein the deformation inducing portion is at least one of a long hole and a recess formed in the first stay. (6) The steering column support structure according to item (5), wherein the first stay has a main body plate portion which extends a front-rear direction of the vehicle and a pair of side plate portions which stand from both side edges of the main body plate portion in the vehicle width direction; and wherein the long hole is formed in a middle part of the main body plate portion in its longitudinal direction and the recess is formed in a middle part of each of the pair of side plate portions in its longitudinal direction.

In the steering column support structure recited in item (1), when the dash panel retreats due to an impact load coming from the front side at the occurrence of a frontal collision of the vehicle, a load is exerted from the dash panel to the three stays. The first stay is deformed, that is, bent, at the deformation inducing portion by the load, and the triangular shape formed by the three stays is deformed so as to be compressed in the vehicle front-rear direction.

As a result, the retreat length of a rear end portion of the steering column, that is, a steering wheel, is decreased.

Furthermore, when the brake booster retreats to displace the first portion of the dash panel up rearward, a front end portion of the first stay and a front end portion of the second stay which are connected to the first portion are displaced up rearward together with the first portion. As a result, a portion where the second stay, the third stay, and the front portion of the steering column are connected together is displaced upward. Thus, downward displacement of that portion is canceled out, whereby the length of an upward projection portion of a rear end portion of the steering column, that is, a steering wheel, is decreased.

Still further, it is not necessary to dispose plural vehicle components at particular positions for the purpose of decreasing the retreat length and the upward projection length of the steering wheel. This is advantageous in keeping a necessary degree of freedom of layout of vehicle components.

In the steering column support structure recited in items (2), (5) and (6), at the occurrence of a frontal collision of the vehicle, the first stay is deformed reliably at the deformation inducing portion without any restrictions and the first stay and the three stays are displaced reliably without any restrictions. As such, this steering column support structure is more advantageous in decreasing the retreat length and the upward projection length of the rear end portion of the steering column, that is, the steering wheel, at the occurrence of a frontal collision.

In the steering column support structure recited in item (3), at the occurrence of a frontal collision, the bottom portion of the bracket is displaced up rearward reliably by the top portion of the brake booster. As such, this steering column support structure is more advantageous in decreasing the upward projection length of the rear end portion of the steering column, that is, the steering wheel.

In the steering column support structure recited in item (4), at the occurrence of a frontal collision, an impact load that is exerted from the top portion of the brake booster to the bottom portion of the bracket is transmitted up rearward efficiently via the bracket. As such, this steering column support structure is even more advantageous in decreasing the upward projection length of the rear end portion of the steering column, that is, the steering wheel.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a side view of a steering column support structure according to an embodiment.

Fig. 2 is a plan view of the steering column support structure shown in

Fig. 1.

Fig. 3 is a perspective view, as viewed from direction A in Fig. 2, of the steering column support structure and shows a portion where a first stay, a second stay, and a bracket are connected together.

Fig. 4 is a perspective view of the first stay.

Fig. 5 is a perspective view of the second stay.

Fig. 6 is a perspective view of a third stay.

Fig. 7A is a perspective view of the bracket, Fig. 7B is a plan view of the bracket, Fig. 7C is front view, as viewed from direction C in Fig. 7A, of the bracket, and Fig. 7D is a side view, as viewed from direction D in Fig. 7A, of the bracket.

Fig. 8 is an explanatory diagram as viewed from the vehicle front side and illustrates a positional relationship between the bracket and a brake booster.

Figs. 9A to 9C are schematic explanatory diagrams illustrating states of the steering column support structure at the occurrence of a frontal collision;

Fig. 9A shows a state before the frontal collision, Fig. 9B shows how the first stay is deformed at the occurrence of the frontal collision, and Fig. 9C shows how downward displacement of the steering column is suppressed at the occurrence of the frontal collision.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

An embodiment of the present invention will be hereinafter described with reference to the drawings. In Figs. 1 to 3 and 7A to 9C, symbols “FR, “UP,” and “RH” denote the vehicle forward direction, upward direction, and rightward direction (in the width direction), respectively.

As shown in Fig. 1, a vehicle compartment S1 and a vehicle front space SO located in front of it are separated from each other by a dash panel 10 which extends in the vehicle width direction and the vertical direction.

A deck cross member 12 is disposed in the vehicle compartment S1 at a front position, that is, in the rear of the dash panel 10 below an instrument panel (not shown), so as to extend in the vehicle width direction. The deck cross member 12 is a steel pipe and its two ends in the longitudinal direction are connected to respective front pillars (not shown).

A brake booster 14 is disposed in the vehicle front space SO at a position that is in front of the dash panel 10 and below the deck cross member 12.

The brake booster 14 is equipped with a main body 1402 and a stepping force transmission shaft 1404. The main body 1402 is attached to the dash panel 10 by a metal fitting (not shown), and the stepping force transmission shaft 1404 penetrates through the dash panel 10 and projects into the vehicle compartment

Claims

WHAT IS CLAIMED IS:

1. A steering column support structure comprising: a deck cross member which is disposed in a rear of a dash panel and extends in a vehicle width direction of a vehicle; a steering column attached to the deck cross member; a first stay which connects the dash panel and the deck cross member; a second stay which connects the dash panel and a front portion of the steering column; and a third stay which connects the front portion of the steering column and the deck cross member, wherein a brake booster is disposed in front of the dash panel; wherein the first stay and the second stay are attached to a first portion, which is positioned above the brake booster, of the dash panel; and wherein the first stay has a deformation inducing portion at which the first stay is deformed earlier than the other portions of the first stay when the first stay receives an impact load of a frontal collision of the vehicle.

2 The steering column support structure according to claim 1, wherein the deformation inducing portion causes the first stay to be bent downward so as to have a convex shape when the first stay receives the impact load of the frontal collision of the vehicle.

3. The steering column support structure according to claim 1 or 2,

wherein the first stay and the second stay are attached to a bracket which is mounted on the first portion of the dash panel to connect the first portion to the first stay and the second stay; and wherein a top portion of the brake booster and a bottom portion of the bracket are overlapped with each other in view from a front of the vehicle.

4. The steering column support structure according to claim 3, wherein the bracket has a base portion which is mounted on the dash panel, a leg portion which projects rearward from the base portion, and an attachment plate portion which is continuous with a rear end of the leg portion and is attached to the first stay and the second stay; wherein a bottom portion, which is directed downward, of the leg portion has a slant face which goes up gradually as the bottom portion extends rearward; and wherein the attachment plate portion has a slant face which goes forward of the vehicle gradually as the attachment plate portion extends upward.

5. The steering column support structure according to claim 1 or 2, wherein the deformation inducing portion is at least one of a long hole and a recess formed in the first stay.

6. The steering column support structure according to claim 5, wherein the first stay has a main body plate portion which extends a front-rear direction of the vehicle and a pair of side plate portions which stand from both side edges of the main body plate portion in the vehicle width direction; and wherein the long hole is formed in a middle part of the main body plate portion in its longitudinal direction and the recess is formed in a middle part of each of the pair of side plate portions in its longitudinal direction.

, CLAIMS FOR PROSECUTION WHAT IS CLAIMED IS:

1. A steering column support structure comprising: a deck cross member which is disposed in a rear of a dash panel and extends in a vehicle width direction of a vehicle; a steering column attached to the deck cross member; a first stay which connects the dash panel and the deck cross member; a second stay which connects the dash panel and a front portion of the steering column; and a third stay which connects the front portion of the steering column and the deck cross member, wherein a brake booster is disposed in front of the dash panel, wherein the first stay and the second stay are attached to a first portion, which is positioned above the brake booster, of the dash panel; and wherein the first stay has a deformation inducing portion at which the first stay is deformed earlier than the other portions of the first stay when the first stay receives an impact load of a frontal collision of the vehicle.

2. The steering column support structure according to claim 1, wherein the deformation inducing portion causes the first stay to be bent downward so as to have a convex shape when the first stay receives the impact load of the frontal collision of the vehicle.

3. The steering column support structure according to claim 1 or 2,

wherein the first stay and the second stay are attached to a bracket which is mounted on the first portion of the dash panel to connect the first portion to the first stay and the second stay; and wherein a top portion of the brake booster and a bottom portion of the bracket are overlapped with each other in view from a front of the vehicle. 4, The steering column support structure according to claim 3, wherein the bracket has a base portion which is mounted on the dash panel, a leg portion which projects rearward from the base portion, and an attachment plate portion which is continuous with a rear end of the leg portion and is attached to the first stay and the second stay; wherein a bottom portion, which is directed downward, of the leg portion has a slant face which goes up gradually as the bottom portion extends rearward; and wherein the attachment plate portion has a slant face which goes forward of the vehicle gradually as the attachment plate portion extends upward.