Vehicle front hood structure

Abstract

To enable resistance absorbing an impact load from a thigh impactor to be ensured just before a striker bracket.SOLUTION: A front hood structure includes: a hood outer panel; a hood inner panel joined to an inner surface side of the hood outer panel to form a gap between the inner surface of the hood outer panel and the hood inner panel; a striker bracket disposed on the hood inner panel and to which a striker locking a hood front part to a vehicle body is fixed; and a hood lock reinforcement disposed above the striker bracket to be opposed thereto and joined to the inner surface of the hood outer panel. The hood lock reinforcement includes: a top surface part joined to the hood outer panel; a leg part disposed at the front of the top surface part to be joined to the hood inner panel; and a beam part extending from a front end to a rear end of the top surface part and formed in a location opposed to the striker to be continuous to the leg part.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] A power unit room is provided at the front part of a vehicle such as an automobile. The upper part of this power unit room is covered with a front hood. The power unit room houses a power unit such as an electric motor or an engine. The rear part of the front hood is supported via a hinge. The front side of the front hood is openable and closable while being supported by the hinge.

[0003] The front hood has a hood outer panel and a hood inner panel. The hood outer panel is the design surface. The hood inner panel is joined to the back surface of the hood outer panel. This hood inner panel is a reinforcing member for reinforcing the hood outer panel.

[0004] Also, a striker is fixedly provided at the center in the vehicle width direction at the front part of the hood inner panel. A hood lock mechanism having a hook that engages with the striker is fixed to the front part of the vehicle body side. When the striker is engaged with the hook, the front hood is maintained in a closed state.

[0005] In a head impact test in the development stage, a head impactor is launched from an impact device toward the front panel obliquely upward from the front. This head impactor simulates the head of a pedestrian. And in the head impact test, the impact load received by the head impactor is measured, and the head injury criteria (HIC) value is evaluated.

[0006] A striker bracket for fixing the striker is fixed to the front part of the hood inner panel. This striker bracket has high rigidity. Therefore, when the head impactor collides with the striker bracket, the HIC value will become high.

[0007] In particular, the center in the vehicle width direction at the front of the front hood where the striker is located has low rigidity, and in order to reduce the HIC value, it is necessary to reinforce this part. For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2023-57237) discloses a technique in which a hood lock reinforcement is adhered to the inner surface of the hood outer panel facing the striker bracket. According to the technique disclosed in this document, when the head impactor collides with the center in the vehicle width direction at the front of the front hood, resistance can be ensured by the deformation of the hood lock reinforcement, and the HIC value can be lowered.

[0008] Also, in the development stage, a thigh impact test is also conducted. In this thigh impact test, the thigh impactor is launched toward the upper part of the front end of the vehicle body from the impact device with the thigh impactor tilted forward by a predetermined angle.

[0009] This thigh impactor simulates the thigh of a pedestrian. In the thigh impact test, the impact load received when the thigh impactor collides with the vehicle body is measured, and it is checked whether the injury value satisfies the reference value.

[0010] Conventionally, as a structure for generating resistance on the vehicle body side that receives the impact from the thigh impactor, one of the following two is often adopted. 1) The thigh impactor is made to collide with the bumper instead of the front hood, and resistance is ensured by the internal structure of the bumper. 2) The thigh impactor is made to collide with the front hood, and resistance is ensured by the deformation of the front hood.

[0011] Compared with the structure of 1), the structure of 2) has the advantage of a higher degree of design freedom. In the structure of 2), if the front hood can be crushed rearward of the vehicle body with a large stroke when the thigh impactor collides with the front hood, sufficient resistance can be ensured.

Prior Art Documents

Patent Documents

[0012] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2023-57237 [Summary of the Invention] [Problems to be Solved by the Invention]

[0013] By the way, when the front hood is closed, the striker is engaged with the hook of the hood lock mechanism and locked. The striker bracket that holds the striker has high rigidity. Therefore, it is necessary to design so that the impact load received by the thigh impactor is absorbed in front of the striker bracket.

[0014] In this case, the hood outer panel has a function as a design surface. Therefore, when trying to adjust the resistance against the impact load from the thigh impactor by deforming the hood outer panel, it is difficult to achieve because the design property is likely to be impaired.

[0015] Also, the hood inner panel is formed in a shape with ridges to ensure rigidity. The ridged shape formed on this front inner panel is formed to reinforce the hood outer panel. Therefore, the shape of the hood inner panel is also limited in design. To satisfy the bending rigidity in the vehicle body front-rear direction depending on the shape of this hood inner panel, strict formability is required. It is also difficult to finely adjust the resistance against the front-rear direction load received from the thigh impactor by forming this hood inner panel.

[0016] Also, it is conceivable to try to absorb the impact load received by the thigh impactor by deforming the hood lock reinforcement disclosed in Cited Document 1. However, the hood lock reinforcement disclosed in Cited Document 1 is only adhered to the inner surface of the hood outer panel. Therefore, it is possible to generate a resistance force that absorbs the impact load from the head impactor. However, it is difficult to ensure a resistance force that absorbs the impact load of the thigh impactor that collides obliquely upward from above with respect to the front part of the vehicle body.

[0017] An object of the present invention is to provide a front hood structure of a vehicle capable of ensuring a resistance force required when absorbing an impact load from a thigh impactor before contacting a striker bracket.

Means for Solving the Problems

[0018] The present invention includes a hood outer panel, a hood inner panel joined to the inner surface side of the hood outer panel to form a gap between the inner surface of the hood outer panel, a striker bracket provided on the hood inner panel and having a striker fixed thereto for locking the front part of the hood to the vehicle body, and a hood lock reinforcement disposed in the gap, facing upward with respect to the striker bracket, and joined to the inner surface of the hood outer panel. The hood lock reinforcement includes an upper surface portion that covers the entire upper surface of the striker bracket and is joined to the hood outer panel, a leg portion provided at the front portion of the upper surface portion and joined to the hood inner panel, and a beam portion that extends from the front end to the rear end of the upper surface portion, is formed at a portion facing the striker, and is continuous with the leg portion.

Advantages of the Invention

[0019] According to the present invention, the hood lock reinforcement includes an upper surface portion that covers the entire upper surface of the striker bracket and is joined to the hood outer panel, a leg portion provided at the front portion of the upper surface portion and joined to the hood inner panel, and a beam portion that extends from the front end to the rear end of the upper surface portion, is formed at a portion facing the striker, and is continuous with the leg portion. Therefore, due to the shape of this beam portion, it becomes easy to adjust the resistance force for absorbing the impact load from the thigh impactor. As a result, it becomes possible to ensure the necessary resistance force before contacting the striker bracket by the crushing of the hood lock reinforcement.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 5C

Mode for Carrying Out the Invention

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a front hood 1 is provided at the front of a vehicle M. The upper part of the power unit room provided at the front of the vehicle M is covered by this front hood 1. The rear part of this front hood 1 is supported on the vehicle body side via a hinge (not shown). The front part of this front hood 1 is made openable and closable while being supported by the hinge. The front end part of this front hood 1 faces almost the same position as the front surface of a front grille (not shown).

[0022] As shown in FIG. 5A, the front hood 1 includes a hood outer panel 2, a hood inner panel 3, and a hood lock reinforcement 4. The hood outer panel 2 has a function as a design surface. The hood inner panel 3 is a reinforcing member for reinforcing the hood outer panel 2.

[0023] As shown in FIGS. 2 to 4, the hood inner panel 3 has ridge-shaped raised portions 3a formed at predetermined intervals. The upper surface of the raised portion 3a is joined to the inner surface side of the hood outer panel 2 by spot welding, adhesion using an adhesive, or the like. Further, the periphery of the hood outer panel and the periphery of the hood inner panel 3 are joined by hemming. A gap portion 5 is formed between the hood outer panel 2 and the hood inner panel 3 by the raised portion 3a.

[0024] Also, a striker bracket 6 is joined to the center in the vehicle width direction at the front portion of the vehicle of the hood inner panel 3 by spot welding, screwing, or the like. A striker 7 is fixedly provided at the center in the vehicle width direction of the striker bracket 6. The striker bracket 6 has a shape that is slightly horizontally long in the vehicle width direction. The striker bracket 6 is a reinforcing member that reinforces the periphery of the striker 7. Therefore, the striker bracket 6 has high rigidity.

[0025] Also, a hood lock mechanism (not shown) is fixed to the front portion of the vehicle body. This hood lock mechanism is fixed to, for example, the radiator upper panel. When the front hood 1 covers the upper portion of the power unit room, the striker 7 is engaged with the hook of the hood lock mechanism. When the striker 7 is engaged with the hook, the front portion of the front hood 1 is locked to the vehicle body.

[0026] The hood lock reinforcement 4 faces the upper side of the striker bracket 6. The hood lock reinforcement 4 is interposed in the gap portion 5 between the hood outer panel 2 and the hood inner panel 3. The hood lock reinforcement 4 is made of sheet metal processed from a metal plate such as a steel plate or an aluminum plate.

[0027] As shown in FIGS. 2 to 4 and 5A, the upper surface portion 4a of the hood lock reinforcement 4 has a shape that covers the entire upper surface of the striker bracket 6. The center in the width direction of the hood lock reinforcement 4 is located above the striker 7.

[0028] A front leg portion 4b is formed at the front end portion of the upper surface portion 4a of the hood lock reinforcement 4. This front leg portion 4b is bent downward from three locations, namely the central portion and both end portions of the upper surface portion 4a. Further, a flange portion 4c is formed at the lower end of each front leg portion 4b. This flange portion 4c is bent forward from the lower end of the front leg portion 4b.

[0029] Also, a rear leg portion 4d is formed at the rear end portion of the upper surface portion 4a of the hood lock reinforcement 4. This rear leg portion 4d is bent downward from both end portions at the rear end of the upper surface portion 4a. A flange portion 4e is formed at the lower end of this rear leg portion 4d. This flange portion 4e is bent rearward from the lower end of the rear leg portion 4d.

[0030] The front front leg portion 4b and the rear rear leg portion 4d are arranged front and rear across the striker bracket 6. Further, the flange portion 4c formed on the front leg portion 4b is joined to the hood inner panel 3 in front of the striker bracket 6. On the other hand, the flange portion 4e formed on the rear leg portion 4d is joined to the hood inner panel 3 behind the striker bracket 6.

[0031] Also, a rear extension portion 4f is integrally formed on the upper surface portion 4a of the hood lock reinforcement 4. The rear extension portion 4f extends rearward from between the left and right rear leg portions 4d formed at the rear end portion of the upper surface portion 4a. Openings 4g, 4h are respectively formed in the upper surface portion 4a and the rear extension portion 4f. These openings 4g, 4h are formed at symmetric positions with the center in the vehicle width direction in between.

[0032] Furthermore, a beam portion 4i is formed on the upper surface portion 4a and the rear extension portion 4f. This beam portion 4i is formed at the center in the vehicle width direction sandwiched by the openings 4g, 4h. This beam portion 4i is continuous with the front leg portion 4b at the center in the vehicle width direction. Beads (ribs) 4j are formed on this beam portion 4i and the front leg portion 4b at the center in the vehicle width direction. The bead 4j is formed at the center in the width direction of the beam portion 4i and the front leg portion 4b at the center in the vehicle width direction. The bead 4j is formed linearly from the front to the rear across the beam portion 4i and the front leg portion 4b at the center in the vehicle width direction. The cross section of this bead 4j is, for example, concave.

[0033] The upper surface portion 4a and the rear extension portion 4f are joined to the inner surface of the hood outer panel 2 via an adhesive 8. Note that reference numeral 21 denotes a head impactor, and 22 denotes a thigh impactor. The head impactor 21 simulates the head of a pedestrian. The thigh impactor 22 simulates the thigh of a pedestrian.

[0034] Next, the operation of the front hood structure having such a configuration will be described.

[0035] [Head Impact Test]

[0036] In the head impact test, the impact device launches the head impactor 21 from diagonally upward in the front direction at the center in the vehicle width direction of the front hood 1. Then, as shown in FIG. 5B, the upper surface portion 4a of the hood lock reinforcement 4 adhesively bonded to the inside of the hood inner panel 3 via the adhesive 8 deforms together with the hood outer panel 2.

[0037] The deformation of the upper surface portion 2a of the hood lock reinforcement 4 is gradually enlarged by the inertial mass when the head impactor 21 collides with the hood outer panel 2. When the upper surface portion 2a of the hood lock reinforcement 4 deforms, a resistance force is generated, and the impact load Fh received by the head impactor 21 is absorbed. Note that the hood outer panel is a design surface, and the resistance force characteristics against the impact load are hardly considered.

[0038] The hood lock reinforcement 4 has front legs 4b and 4d formed at the front and rear ends of the upper surface portion 4a. Flange portions 4c and 4e bent at the lower ends of the front legs 4b and 4d are joined to the hood inner panel 3. The resistance force characteristics of the hood lock reinforcement 4 due to the collision of the head impactor 21 are adjusted by the shape and number of the openings 4g and 4h and the lateral width of the front legs 4b and 4d.

[0039] By adjusting to obtain optimal resistance force characteristics, the impact load Fh received by the head impactor 21 is absorbed before the upper surface portion 4a of the hood lock reinforcement 4 contacts the striker bracket 6.

[0040] In particular, for the hood lock reinforcement 4, the flange portions 4c and 4e of the front legs 4b and 4d are joined to the hood inner panel 3. Therefore, optimal impact resistance characteristics can be obtained only by the shape of the hood lock reinforcement 4 without modifying the hood outer panel 2 forming the design surface. As a result, the HIC value can be made smaller.

[0041] In addition, the central portion in the vehicle width direction at the front part of the front hood 1 is reinforced by this hood lock reinforcement 4. Thereby, it is possible to prevent the dent in the said part when a hand, an elbow, etc. of a pedestrian etc. lightly strike the said part.

[0042] [Thigh impact test]

[0043] In the thigh impact test, the impact device fires the thigh impactor 22 downward from an obliquely upper direction in front of the vehicle M with respect to the center in the vehicle width direction at the front end of the front hood 1. The reason why the impact device fires the thigh impactor downward from an obliquely upper direction in front of the vehicle M will be briefly described. When the leg of a pedestrian collides with the front part of the vehicle M, this leg is lifted up by the bumper or the front grille. Then, the upper body of the pedestrian falls toward the front hood 1. At this time, the thigh of the pedestrian falls from an obliquely upper position in front of the vehicle M to the front end of the front hood 1. The impact device fires the thigh impactor simulating this.

[0044] When the thigh impactor 22 collides with the center in the vehicle width direction at the front end of the front hood 1, as shown in FIG. 5C, the front end of the hood outer panel 2 is bent downward by the impact load Ft from the thigh impactor 22. Subsequently, the front end of the hood outer panel 2 that has received the impact load Ft from the thigh impactor 22 presses the front part of the hood lock reinforcement 4.

[0045] At the front center of the hood lock reinforcement 4, a front leg portion 4b is provided. The front leg portion 4b at the front center receives the impact load Ft from the thigh impactor 22 and is pressed rearward of the vehicle body.

[0046] A flange portion 4c bent and formed at the lower end of the front leg portion 4b at the front center is joined to the hood inner panel 3. Also, the upper surface portion 4a continuous with the front leg portion 4b is adhered to the hood inner panel 3. Since the front leg portion 4b at the front center is structured to receive the impact load Ft from the thigh impactor 22, the initial resistance can be increased.

[0047] The front leg portion 4b at the front center is linearly continuous with a beam portion 4i formed on the upper surface portion 4a of the hood lock reinforcement 4. The beam portion 4i and the hood outer panel 2 adhered to the upper surface portion 4a are crushed by receiving the impact load Ft from the thigh impactor 22. The impact load Ft from the thigh impactor 22 is absorbed by the resistance force generated by the crushing of the beam portion 4i and the upper surface portion 4a.

[0048] Beads 4j are formed on the front leg portion 4b at the front center and the beam portion 4i. The resistance characteristics of the hood lock reinforcement 4 against the impact load Ft of the thigh impactor 22 are adjusted by the widths of the front leg portion 4b at the front center and the beam portion 4i and the shape of the beads 4j. When the hood lock reinforcement 4 receives the impact load Ft from the thigh impactor 22, it crushes the front leg portion 4b at the front center and the beam portion 4i to generate a resistance force. By adjusting this resistance force, the front leg portion 4b at the front center absorbs the impact load Ft from the thigh impactor 22 before reaching the front end of the striker bracket 6. Thereby, the injury value evaluated by the load applied to the thigh impactor 22 is made equal to or less than the reference value.

[0049] Thus, in this embodiment, the impact load Ft from the thigh impactor 22 is absorbed by crushing the hood lock reinforcement 4 provided in the front hood 1. When the thigh impactor 22 collides with the center of the front part of the front hood 1 from the front, the impact load Ft is received by the front leg part 4b formed at the center of the front part of the hood lock reinforcement 4.

[0050] The flange part 4c formed at the lower end of the front leg part 4b is joined to the hood inner panel 3. Therefore, the front leg part 4b at the center of the front part can increase the initial resistance by receiving the impact load Ft from the thigh impactor 22.

[0051] A beam part 4i is formed at the center in the width direction of the upper surface part 4a and the rear extension part 4f of the hood lock reinforcement 4, and beads 4j are formed on the beam part 4i. By adjusting the width of the beam part 4i and the shape of the beads 4j, the resistance characteristics obtained by crushing the hood lock reinforcement 4 against the impact load Ft of the thigh impactor 22 can be adjusted to an optimal value. As a result, it becomes easy to ensure the resistance required when absorbing the impact load Ft from the thigh impactor 22 before the hood lock reinforcement 4 contacts the striker bracket 6.

[0052] Also, by providing the hood lock reinforcement 4 according to this embodiment above the striker bracket 6, the skeletal rigidity of the front part of the front hood 1 is improved. As a result, the striker 7 provided on the front hood 1 can be accurately engaged with the hook provided in the hood lock mechanism fixed to the front part of the vehicle body.

[0053] Note that the present invention is not limited to the above-described embodiment. For example, the beads 4j formed on the beam part 4i of the hood lock reinforcement 4 may be formed only on the beam part 4i of the upper surface part 4a and the rear extension part 4f. Also, the beads 4j may not be formed on the hood lock reinforcement 4. In this case, the resistance for absorbing the impact load Ft from the thigh impactor 22 is adjusted by the width of the beam part.

[0054] Furthermore, when it is possible to secure the necessary resistance against the impact load only with the upper surface portion 4a, the rear extension portion 4f can be omitted.

Description of Reference Numerals

[0055] 1… Front hood, 2… Hood outer panel, 3… Hood inner panel, 3a… Raised portion, 4… Hood lock ring reinforcement, 4a… Upper surface, 4b… Front leg portion 4c, 4e… Flange portions, 4d… Rear leg portion, 4f… Rear extension portion, 4g, 4h… Openings, 4i… Beam portion, 4j… Bead, 5… Gap portion, 6… Striker bracket, 7… Striker, 8… Adhesive, 21… Head impactor, 22… Thigh impactor, Fh, Ft… Impact loads, M… Vehicle

Claims

1. A hood outer panel, a hood inner panel joined to the inner surface side of the hood outer panel and forming a gap between the inner surface of the hood outer panel, a striker bracket provided on the hood inner panel and having a striker fixed thereto for locking the front part of the hood to the vehicle body, and a hood lock reinforcement disposed in the gap, facing upward with respect to the striker bracket, and joined to the inner surface of the hood outer panel A front hood structure of a vehicle comprising: The hood lock reinforcement includes: an upper surface portion covering the entire upper surface of the striker bracket and joined to the hood outer panel, a leg portion provided at the front portion of the upper surface portion and joined to the hood inner panel, and a beam portion extending from the front end to the rear end of the upper surface portion, formed at a portion facing the striker, and continuous with the leg portion A front hood structure of a vehicle, characterized by comprising the above.

2. Openings are formed on the left and right in the vehicle width direction of the upper surface portion, and the beam portion is formed between the openings The front hood structure of a vehicle according to claim 1, characterized by the above.

3. A bead is formed along the beam portion on the beam portion The front hood structure of a vehicle according to claim 1, characterized by the above.

4. Beads are continuously formed along the beam portion and the leg portion on the beam portion and the leg portion The front hood structure of a vehicle according to claim 1, characterized by the above.

5. A rear extension portion is integrally formed at the rear end of the upper surface portion, the rear extension portion is joined to the inner surface of the hood outer panel, and the beam portion formed on the upper surface portion is continuously formed on the rear extension portion The front hood structure of a vehicle according to any one of claims 1 to 4, characterized by the above.

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