JPH05238338A - Support bracket for knee panel - Google Patents

Abstract

PURPOSE:To provide a support bracket for a knee panel, which can be easily determined of its profile, and is furnished with ideal collision energy absorbing characteristics and deforming characteristics. CONSTITUTION:Each frame forming the outer profile of a support bracket 12 is made gradually thinner in thickness starting from a pillar-to-pillar member 10 over to the mounting surface 18A of a knee panel 14. In the inner side of the frames 18, inner frames 20A, 20B, 20C, 20D and 20E are constructed using ribs 22A, 22B, 22C, 22D and the frames 18. In this case, the support bracket 12 furnished with collision energy absorbing characteristics and deforming characteristics can be easily made up by changing the profiles and the like of these ribs 22A, 22B, 22C and 22D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knee panel support bracket to which a knee panel for protecting an occupant's knee during a collision is mounted.

[0002]

2. Description of the Related Art In a vehicle, a knee panel for protecting the knees of an occupant in a collision is arranged in front of a front seat. As shown in FIG. 8, the knee panel 14 includes a support bracket 40 fixed to a pillar-shaped pillar-to-pillar member 10 having both ends connected to pillars provided on both sides of a normal vehicle.
Supported by. The support bracket 40 is configured to plastically deform and absorb the impact force when the knee of the occupant collides with the knee panel 14.

By the way, as a mode of deformation of the support bracket 40, as shown in FIG. 6, since the occupant's knee N moves upward (in the direction of arrow A) at an angle θ with respect to the horizon, It is ideal that the knee panel 14 moves in the direction of the arrow A while maintaining the facing angle with the knee N, and gradually increases the deformation resistance to absorb the impact force.

In order to obtain this ideal collision energy absorption characteristic and deformation characteristic, conventionally, as shown in FIGS. 8 and 9, a support bracket 4 formed by press molding a single plate material.
0 was provided with a crush hole 42 and a bead 44 was formed (see Japanese Utility Model Laid-Open No. 1-70657).

However, the crash hole 4
It is not clear what the deformation characteristics actually show even when the 2 or the bead 44 is formed, and the trial and error experiment is repeated to determine the shape of the support bracket 40 and the crush hole 4.
2 or the size and position of the bead 44 was determined.
As a result, a large amount of time and cost are consumed. In addition, since the plate material is bent, the weight of the support bracket 40 cannot be reduced.

[0006]

SUMMARY OF THE INVENTION In consideration of the facts described above, an object of the present invention is to provide a support bracket for a knee panel that can be easily determined in shape and has ideal collision energy absorption characteristics and deformation characteristics. ..

[0007]

A support bracket for a knee panel according to the present invention has a front side of a vehicle fixed to a vehicle body,
A knee panel support bracket to which a knee panel for protecting an occupant's knees is attached to a rear side of a vehicle, and a closed cross-section having a hollow inside and gradually thinned from the vehicle body fixing portion to the knee panel attaching portion. A plurality of closed cross-section inner frames are constructed by the frame and the partitioning frame inside the frame, and when a load acts on the knee panel, the load acts in the direction of the load and the frame and the knee panel mounting portion side to the front of the vehicle sequentially. A plurality of partition walls that undergo plastic deformation,
It is characterized by having.

[0008]

The knee bracket support bracket of the above construction has one end fixed to the front side of the vehicle body of the vehicle, for example, a pillar-to-pillar member, and the other rear side of the vehicle body supports the knee panel for protecting the occupant's knees.

When the knee of the occupant collides with the knee panel during a vehicle collision, the support bracket gradually plastically deforms and absorbs the impact load due to the load input from the knee to the knee panel. The mode of this plastic deformation is as follows.

The frame forming the outer shape of the support bracket is gradually thinned from the pillar-to-pillar member to the mounting portion of the knee panel, so that when a relatively small load is applied, the support bracket of the knee panel becomes large on the knee panel side. The amount of deformation gradually decreases as it deforms and moves toward the pillar-to-pillar member. On the other hand, when a relatively large load is applied, the support bracket of the knee panel is first positively deformed on the knee panel side, and the deformation gradually moves to the pillar-to-pillar member side, which is relatively longer than the conventional one. It takes time to transform. Also,
The cavity formed inside the frame is partitioned by partition walls to form a plurality of inner frames together with the frame. By configuring this inner frame, the support strength of the support bracket is improved, and the deformation characteristics of the support bracket can be easily changed depending on the setting form of the inner frame, so that ideal deformation characteristics can be easily realized and The impact energy absorption characteristics acting on the knee can be made ideal. That is, the inner frame is made thinner on the knee panel side, and the wall thickness is made thicker toward the pillar-to-pillar member side, and the inner frame is formed sparsely on the knee panel side. The load-deformation characteristics can be delicately changed depending on the shape or number of the inner frames as the side becomes closer.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a pole-like pillar-to-pillar member 10 having both ends attached to pillars (not shown) of a vehicle has a support bracket 12 according to this embodiment.
One end of the support bracket 12 is fixed, and the knee panel 14 is attached to the other end of the support bracket 12.

As shown in FIG. 2, the support bracket 12 is manufactured, for example, by extruding a lightweight material such as aluminum and then cutting it into a predetermined width (cut by a two-dot chain line). As described above, by extruding the lightweight member to manufacture the support bracket 12, it is possible to reduce the cost such as the die cost and the weight of the member as compared with the press working. Further, it becomes easy to change the shape or the mounting position of the rib 22 of the support bracket 12.

As shown in FIG. 3, the support bracket 1
2 is a long frame 18 having a closed cross-section with a cavity inside and curved slightly upward, and a plurality of truss-shaped inner frames 20A, 20B, 20C, 20D, 20E arranged inside are respectively formed with the frame 18. Ribs 22A, 22 to be constructed
B, 22C, 22D.

The frame 18 forming the outer shape of the support bracket 12 is gradually thinned from the pillar-to-pillar member 10 to the mounting surface 18A of the knee panel 14 (T1> T).
2). Thus, when an impact load is applied to the knee panel 14, the support bracket 12 is gradually deformed from the knee panel 14 side.

Pillar-to-pillar member 10 of frame 18
On the side, a semicircular bracket 18B having an inner diameter equal to the outer diameter of the pillar-to-pillar member 10 is formed. Both ends of the bracket 18B are welded to the outer peripheral surface of the pillar-to-pillar member 10 to firmly fix the support bracket 12 to the pillar-to-pillar member 10.

On the other hand, as shown in FIG.
The mounting surface 18A formed on the side of the knee panel 14 of 8 has a wall thickness (> T2) for maintaining the posture of the knee panel 14 (the mounting angle with respect to the pillar-to-pillar member 10),
Further, the inner frame 2 is reinforced by the ribs 22D and is not easily deformed.
0E is configured. On the mounting surface 18A, a support plate 26 integrally formed with a cushioning body 24 such as styrofoam forming the knee panel 14, a bolt 28 and a nut 30.
Is fixed by.

The ribs 22A, 22B, 22C and 22D arranged inside the frame 18 are truss-shaped inner frames 20A, 20B, 20C and 2 with the frame 18, respectively.
It composes 0D and 20E. The rib 22A (pillar-to-pillar member 10 side) has a large thickness, and the rib 22B,
22C and 22D (on the side of the knee panel 14) are successively thinned. In this way, the ribs 22A, 22B, 22C, 22
By disposing D, the frame 18 can be reinforced, and the deformation direction and deformation characteristics of the support bracket 12 can be easily set.

Next, a modification of the support bracket 12 will be described with reference to FIGS. As shown in FIG. 6, when the vehicle collides, the occupant moves forward due to inertial force, and the knee N hits the knee panel 14 (solid line). When the occupant further moves forward, the knee N moves upward (angle θ) to the knee panel 1.
Move in the direction to push 4 up (two-dot chain line). Therefore,
It is ideal for the knee panel 14 to move in the direction of arrow A while maintaining the initial posture in order to absorb the impact force.

Immediately after the knee N hits the knee panel 14 (see FIG. 6), the support bracket 12 supports the knee panel 14 in a state before deformation as shown in FIG.

Next, as shown in FIG. 4, when a load acts on the knee panel 14, the side of the support bracket 12 on which the rigidity is low, that is, the inner frames 20C and 20D on the side of the knee panel 14 is largely deformed, and the pillar-to-pillar structure is used. Since the inner frames 20A and 20B on the member 10 side have high rigidity, the inner frames 20A and 20B move in the direction of arrow A while maintaining their sectional shapes. Due to this plastic deformation, the initial impact force is absorbed on the knee panel side of the support bracket 12. The inner frame 20E forming the mounting surface 18A is
Only by deforming the rib 22D, a constant cross-sectional shape is maintained. Thereby, the posture of the knee panel 14 is maintained.

Next, as shown in FIG. 5, when a relatively large load is applied to the knees of the occupant, the load continues to be applied to the knee panel 14, and the support bracket 12 is fixed to the inner frame of the knee panel 14 side. 20C and 20D are crushed, and the inner frames 20A and 20B on the pillar-to-pillar member 10 side are moved upward while being curved upward. in this way,
When the plastic deformation of the knee panel 14 gradually occurs, the plastic deformation continues for a relatively long time as compared with the conventional one without a large reaction force acting on the knees of the occupant, and the support bracket 12 is completely crushed. Alternatively, the deformation stops when the load on the knees of the occupant stops. by this,
It is possible to stop the movement of the occupant without giving a large impact to the occupant's knees. The inner frame 20E forming the mounting surface 18A bends the rib 22D, but still maintains the cross-sectional shape. Thereby, the posture of the knee panel 14 is maintained.

The ribs 22A, 22B, 22C,
The shape of 22D, the mounting position, etc. are not limited to the structure of this embodiment, but when the shape of the support bracket 12 is determined, the shape of the frame 18 is first determined, and then the time is changed by a destructive test or the like. It can be easily added by extrusion. This makes it possible to sufficiently reduce the time and cost.

Further, as shown in FIG. 7, as a method of fixing the support bracket 12 to the pillar-to-pillar member 10, the bracket 34 of the support bracket 12 is formed into a substantially cylindrical shape, and the outer shape of the pillar-to-pillar member 10 is formed. The pins 36 may be crimped so as to surround the.

In this embodiment, the support bracket 12
The thickness of the frame 18 and the inner frames 20A, 20B, 20
Although the load deformation characteristics were controlled by the wall thicknesses of C and 20D, the inner frame arranged inside the frame 18 was formed sparsely on the knee panel side and gradually became closer to the pillar-to-pillar member 10 side. You may control by forming densely.

Next, a destructive test of a conventional knee panel support bracket 50 made by press-molding an aluminum material as shown in FIG. 10 and a support bracket 12 made by extrusion-molding of this embodiment as shown in FIG. The difference in the amount of displacement (mm) of the load surface F with respect to the applied load (kg · f) will be described.

As shown in FIG. 12, in this destructive test, a pipe-shaped fixing jig 54 provided on the fixing base 52 is used.
While fixing the brackets 18B and 56 (see FIGS. 10 and 11) of the respective support brackets 12 and 50 to the load face F (corresponding to the mounting portion of the knee panel), the load face P The displacement amount δ is measured.

As shown in the graph of FIG. 13 and the table of FIG. 14, the conventional support bracket 50 formed by press molding has a larger peak load (425 kg · f) than the support bracket 12 formed by extrusion molding, but after that, It can be seen that the load decrease is large (in other words, the load decrease gradient is large) (indicated by). As can be judged from the graph of the ideal energy absorption characteristics shown in FIG. 15, this is far from the ideal displacement characteristics where the load decreases from the peak load U with a substantially horizontal gradient, and this is a relatively large peak. When the load is not reached, the support bracket 50 is less deformed, a large reaction force is generated, and the energy absorption characteristic is not good.

On the other hand, in the support bracket 12 of this embodiment, the peak load (381 kg · f) is small, but the load decrease thereafter is small (in other words, the load decrease gradient is small) ( Is displayed). This is shown in FIG.
As can be judged from the graph, since the peak load is relatively small, the support bracket 12 is easily deformed,
In addition, since the deformation also gradually changes, the load is always absorbed by plastic deformation, and the reaction force is small, so it shows that the energy absorption characteristics are good, without giving a large impact to the occupant's knees. From this test result, it can be judged that the energy acting on the knees of the occupant can be absorbed.

The support bracket 12 of this embodiment has a width B as shown in the graph of FIG. 13 and the table of FIG.
The energy absorption characteristics of the support bracket 12 can be easily adjusted by changing the above.

[0030]

The knee bracket support bracket of the present invention can change the load deformation characteristics by deforming the thickness of the support bracket or devising the shape of the inner frame, and a large collision, a small collision and the collision form thereof. Regardless of the above, it is possible to always plastically deform the support bracket of the knee panel so that a large reaction force is not generated from the knee panel to the occupant's knee and ideally absorb the collision energy.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a support bracket of a knee panel according to the present invention is assembled.

FIG. 2 is a perspective view showing a manufacturing process of a support bracket for a knee panel according to the present invention.

FIG. 3 is a side view showing a state before the support bracket of the knee panel according to the present invention is deformed.

FIG. 4 is a side view showing a state after the support bracket of the knee panel according to the present invention is deformed.

FIG. 5 is a side view showing a state after the support bracket of the knee panel according to the present invention is deformed.

FIG. 6 is a side view showing a relative movement relationship between a knee panel and a knee.

FIG. 7 is a side view showing a state in which the support bracket of the knee panel according to the present invention is attached to the pillar-to-pillar member.

FIG. 8 is a perspective view showing a state in which a support bracket of a conventional knee panel is assembled.

FIG. 9 is a perspective view showing a support bracket of a conventional knee panel.

FIG. 10 is a perspective view showing a support bracket of a conventional knee panel for performing a destructive test.

FIG. 11 is a perspective view showing a support bracket of the knee panel according to the present invention for performing a destructive test.

FIG. 12 is a side view showing a state in which the support bracket of the knee panel according to the present invention is set in the destruction test device.

FIG. 13 is a graph showing the relationship between the applied load and the amount of displacement of the applied surface as the experimental results of the destructive test.

FIG. 14 is a table showing the experimental results of a destructive test.

FIG. 15 is a graph showing ideal energy absorption characteristics.

[Explanation of symbols]

 12 Support bracket 18 Frame 20 Inner frame 22 Rib (partition wall)

Claims (1)

[Claims] 1. A support bracket for a knee panel, in which a front side of a vehicle is fixed to a vehicle body, and a knee panel for protecting a knee of an occupant is attached to a rear side of the vehicle, the support bracket having a cavity inside thereof from the vehicle body fixing portion. A plurality of closed cross-section inner frames are constructed by a frame having a closed cross section gradually thinned toward the mounting portion of the knee panel and a partitioning frame on the inner side of the frame, and when a load acts on the knee panel, the action of the load And a plurality of partition walls that are plastically deformed sequentially with the frame toward the front of the vehicle from the side where the knee panel is mounted, the support bracket for the knee panel.