Vehicle engine compartment hood

A vehicle engine compartment hood is provided for a vehicle body having a hood opening. A hood panel normally closes the engine compartment. A hood base panel underlies the hood panel and is pivotally mounted on the vehicle body for pivotal opening movement to lift the hood panel and allow access to the engine compartment through the hood opening. A mechanism acts between the hood panel and the hood base panel for selectively elevating the hood panel above the hood base panel and the hood opening when the vehicle is in a pedestrian rich environment. The mechanism absorbs energy when an impact is received against the hood panel.

FIELD OF THE INVENTION

The present invention relates to an engine compartment hood for a motor vehicle.

BACKGROUND OF THE INVENTION

The prior art has recognized that it may be desirable for pedestrian safety when the front end of a motor vehicle is capable of absorbing impact energy.

It would be desirable to provide a vehicle engine compartment hood that actively offers energy absorption when the vehicle is driven in a pedestrian rich environment or operating in conditions of high probability for pedestrian and vehicle collision.

SUMMARY OF THE INVENTION

A vehicle engine compartment hood is provided for a vehicle body having a hood opening. A hood panel normally closes the engine compartment. A hood base panel underlies the hood panel and is pivotally mounted on the vehicle body for pivotal opening movement to lift the hood panel and allow access to the engine compartment through the hood opening. A mechanism acts between the hood panel and the hood base panel for selectively elevating the hood panel above the hood base panel and the hood opening when the vehicle is in a pedestrian rich environment. The mechanism absorbs energy when an impact is received against the hood panel.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The following description of exemplary embodiments is merely exemplary in nature and is in not intended to limit the invention, its application, or uses.

Referring toFIG. 1, a vehicle body includes an engine compartment1that is closed by engine compartment hood2that is mounted in a hood opening2A defined between right fender2B and left fender2C at the side of the vehicle body, a header2D at the front, and a windshield2E at the rear. The right and left fenders have fender flanges13, as best seen inFIG. 4.

As seen inFIGS. 2 and 3, the hood2includes a hood outer panel3and a hood inner reinforcement panel15that are attached together by a flange around their peripheral edges to form the one-piece hood2. A hood base panel16, best seen inFIG. 4, underlies the outer panel3and the reinforcement15of the hood2. A linkage mechanism, to be described hereinafter is provided between the hood2and the hood base panel16. As seen inFIG. 4, the hood base panel16has flanges4along its edges that overlie the fender flanges13of the fenders2B and2C.

As seen inFIGS. 2 and 5, hood hinges14are provided to pivotally mount the rear end corners of the hood base panel16on the fender flanges13. A latch assembly12, including a striker12A and a latch12B are provided at the front of the hood2. The striker12A, best seen inFIG. 3, engages with the latch12B mounted on the header2D at the front of the hood opening2A to normally latch the hood2in a closed position. However, the striker12A can be unlatched from the latch12B to permit the hood2to be pivoted upwardly away from the fenders to the position ofFIG. 5for access to the engine compartment1.

Referring now toFIGS. 2 and 4, it is seen that the linkage mechanism acting between the hood2and the flanges4of the hood base panel16includes a front link5, a middle link6and a rear link7.

Front link5has a center portion5A that is pivotally mounted by a pivot5B to stanchion5C that is attached to the flange4of the hood base panel16. Link5also has an upper end5D that is pivotally mounted to the hood2by a pivot5E. And link5has a lower end5F that is pivotally mounted to the connecting rod9by a pivot5G.

Middle link6has a center portion6A that is pivotally mounted by a pivot6B to stanchion6C that is attached to the flange4of the hood base panel16. Link6also has an upper end6D that is pivotally mounted to the hood2by a pivot6E. And link6has a lower end6F that is pivotally mounted to the connecting rod9by a pivot6G.

Rear link7has a center portion7A that is pivotally mounted by a pivot7B to stanchion7C that is attached to the flange4of the hood base panel16. Link7also has an upper end7D that is pivotally mounted to the hood2by a pivot7E. And link7has a lower end7F that is pivotally mounted to the connecting rod9by a pivot7G.

Thus each of these links5,6and7has a lower end that is pivotally connected to the connecting rod9so that the links are linked together and caused to pivot in unison about their respective pivot points. It will be appreciated that one of these linkage mechanisms is provided at each side of the hood2.

An actuator8has one end pivotally connected to the flange4of the hood base panel by stanchion8A and pivot8B. Actuator8also has a second end that is pivotally connected to the lower end6F of the middle link6and/or the connecting rod9, by a pivot8C.

As seen inFIGS. 2 and 4, the actuator8and the linkage mechanism, including the links5,6, and7and the rod9, cooperate to establish the hood2in a normal position in which the hood2fits flush within the hood opening2A of the vehicle body.

However, upon energization of the actuator8, the actuator8and the links5,6, and7act as an elevator mechanism to elevate the hood2. In particular, the actuator8is extended in length and pushes on the connecting rod9to cause the links5,6, and7to pivot from their retracted positions ofFIGS. 2 and 4to an elevated position shown inFIGS. 6 and 7so that the hood2is elevated a few inches above the hood opening. When the actuator8is reversed, the actuator8will contract in length and pull the connecting rod9to cause the links5,6and7to pivot down and return the hood2to the normal condition ofFIGS. 2 and 4. The normal position of the hood2is established by a cushion10mounted on the rear edge of the base panel16. The rear end of the hood2comes to rest upon the cushion10. In addition a stop11is provided at the front of the base panel16and the lower end5F of the front link5and/or the connecting rod9comes to rest upon the stop11.

One example of the actuator8is shown in U.S. Pat. No. 6,302,458. In this actuator, a tube is powered out to an extended position, or retracted to a retracted position by an electric motor. The actuator also includes a lock to lock the tube in the extended position, as well as an energy absorbing device that will allow forced retraction of the tube in the event that a certain level of force is exerted against the actuator in the retracting direction. The electric motor is connected with sensors and controllers and functions according to an algorithm that is designed for the particular application of the actuator.

OPERATION

In the present invention, the vehicle is equipped with pedestrian sensors such as radar or vision sensor or infrared sensor or laser sensor, or a contact sensor. The vehicle also has conventional speed sensors and steering sensors and braking sensors and other sensors that gather information relating to the operation of the motor vehicle. A controller processes information from these sensors, as well as perhaps manual controls operated by the driver, and energizes the actuator8to elevate the hood2when the an algorithm determines that the vehicle is being driven in a pedestrian environment.

In operation, during normal highway operation of the vehicle, the hood outer panel3will be retracted to its normal position within the hood opening2A. But when the controller determines that the vehicle has entered a pedestrian environment, the actuator8and the linkage mechanism will activate to elevate the hood outer panel3to the elevated position ofFIGS. 6 and 7. As seen inFIGS. 6 and 7, whenever the hood outer panel3is elevated, the hood base panel16remains at its position ofFIGS. 2 and 3so that access to the engine compartment remains closed by the hood base panel16.

When the vehicle leaves the pedestrian environment, the hood outer panel3is again lowered to its normal position ofFIGS. 1 and 2.

In the event that an impact is imposed upon the hood2while it is elevated, the hood outer panel3can collapse in a controlled manner via the energy absorbing retraction of the actuator8. Or energy can be absorbed by flexure or deformation of the links5,6, and7and/or deformation of the hood2. Thus the hood2yields to the imposed force and absorbs energy in a controlled manner.

In the event that the engine compartment needs to be accessed in order to service the engine, the latch12B is released to release the striker12A so that the hood2and the hood base panel16can be pivoted upwardly about the hinges14, as seen inFIG. 5.

Another embodiment of the invention is shown inFIGS. 8 and 9. A hood base panel116underlies hood102. The hood base panel116has flanges104along its edges that overlie the fender flanges113of the fenders. A linkage mechanism, to be described hereinafter, is provided between the hood102and the flange104of hood base panel116. Hood hinge114pivotally mounts the rear end corners of the hood base panel116on the fender flanges113or other vehicle body structure.

The linkage mechanism acting between the hood102and the flanges104of the hood base panel116includes a front link105and a rear link107.

Front link105has a center portion105A that is pivotally mounted by a pivot105B to stanchion105C that is attached to the flange104of the hood base panel116. Link105also has an upper end105D that is pivotally mounted to the hood102by a pivot105E. And link105has a lower end105F that forms a hook105H that reaches into a slot116A provided in the flange104of the hood base panel116and a slot113A provided in the fender flange113.

Rear link107has a center portion107A that is pivotally mounted by a pivot107B to stanchion107C that is attached to the flange104of the hood base panel116. Rear link107also has an upper end107D that is pivotally mounted to the hood102by a pivot107E. And link107has a lower end107F that forms a hook107H that reaches into a slot116A provided in the flange104of the hood base panel116and a slot113A provided in the fender flange113.

An actuator108has one end pivotally connected to the flange104of the hood base panel116by stanchion108A and pivot108B. Actuator108also has a second end that is pivotally connected to the lower end107F of the rear link107by a pivot108C.

As seen in8, the actuator108and the linkage mechanism, including the links105and107cooperate to establish the hood102in a normal position in which the hood102fits flush within the hood opening of the vehicle body. In the event that an impact force against the front of the hood were to attempt rearward excursion of the hood102, the hooks105H and107H will engage against the wall of the slots113A in the fender flanges104to restrain the hood102and the hood base panel116against such rearward excursion.

Upon energization of the actuator108, the actuator108and the links105and107act as an elevator mechanism to elevate the hood102to the position ofFIG. 9. In the event that an impact is imposed upon the hood102while it is elevated, the hood102can collapse in a controlled manner via the energy absorbing retraction of the actuator8. Or energy can be absorbed by flexure or deformation of the links105and106and/or deformation of the hood102. However, if the impact load also attempts to move the hood base panel116rearwardly toward the windshield, the hooks105H and107H will engage against the wall of the slots113A in the fender flanges104so that the links restrain the hood102and the hood base panel116against such rearward excursion.

In the event that the engine compartment needs to be accessed in order to service the engine, the hood102is unlatched so that the hood102and the hood base panel106can be pivoted upwardly about the hinges114, as permitted by the hook portions105H and107H being pivoted upwardly with the hood base panel116and being withdrawn from the slots113A in the fender flanges104.

It will be understood that the foregoing description of the invention is merely exemplary in nature and, thus, variations thereof are intended to be within the scope of the invention. For example, the actuator8may be of various mechanical, hydraulic or pneumatic designs. Or the linkage mechanism can be replaced by hydraulic or pneumatic cylinder or by inflatable air bags or a pyrotechnic actuator. The actuator may be connected to any of the links, or to a connecting rod. The extent to which the hood2will be elevated is determined by the length of the links5,6, and7. All of the links can be of the same length so that the front and rear will be elevated the same distance, as shown in the drawings. Or, for example, the front link5can be 2 inches, the middle link6can be 4 inches and the rear link7can be 6 inches, so that the hood2will be higher at the rear than at the front. Alternatively, the front link can be replaced by a simple front pivot so that the hood elevates by links at the rear of the hood for pivoting the hood about the front pivot.

It will be appreciated that inFIGS. 6 and 7, showing the hood2elevated, the hood base panel16remains in place to cover the engine compartment. However, it may be desirable to lighten the vehicle by having a hood base panel16that is a rectangular frame shape with side flanges4for mounting the links, but with a large central opening, in which case the engine compartment will be somewhat exposed to view when the hood2is elevated.

And, the hooks105H and107H can be employed on some or all or none of the links.