The present specification relates generally to engine covers and, more specifically, to engine cover grommets for connecting engine covers to engines.
Vehicle engines are covered by a hood and, in some cases, an engine cover. The hood may provide limited protection for an impacting body form to the engine by elastically and plastically deforming to absorb energy.
In one example, a substantial portion of energy from an impacting body to the hood of the vehicle may be directed toward the engine. The hood may deform toward the engine and thus absorb a limited amount of the energy from the impact. However, a substantial amount of unabsorbed energy may stroke into the engine.
Accordingly, a need exists for structures to absorb energy during hood deformation toward the engine of the vehicle.
In one embodiment, a vehicle includes an engine compartment and a hood extending over the engine compartment. An engine is situated within the engine compartment and a pin extends from a top side of the engine toward an interior surface of the hood. An engine cover extends between the top side of the engine and the interior surface of the hood. The engine cover includes at least one engine cover connection and a grommet coupled to the engine cover connection. The grommet has an entrance, a stop, and an internal cavity extending through the grommet from the entrance toward the stop. The internal cavity is divided into a passive cavity portion and an active cavity portion. The pin rests within the passive cavity portion without passing into the active cavity portion under normal operating conditions.
In another embodiment, a grommet includes a body configured to be received by an engine cover connection of an engine cover. The grommet further includes an entrance, a stop, and an internal cavity extending through the grommet from the entrance toward the stop. The passive cavity portion is configured to receive a pin. The pin rests within the passive cavity portion without passing into the active cavity portion under normal operating conditions.
In another embodiment, a method for connecting an engine cover to an engine includes installing at least one pin into a top side of an engine. The engine cover is then oriented over the pin. The engine cover comprises an engine cover connection and a grommet coupled to the engine cover connection. The grommet is configured to receive a head of the pin. The grommet includes an internal cavity extending between an entrance of the grommet toward a stop. The internal cavity includes a passive cavity portion extending from the entrance and an active cavity portion extending from the passive cavity portion toward the stop. The grommet of the engine cover is then aligned with the head of the pin. The engine cover is then attached to the pin such that the pin traverses the entrance of the grommet and rests in the passive cavity portion of the grommet. The pin rests in the passive cavity portion without passing into the active cavity portion under normal operating conditions.
These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.
The embodiments set forth in the drawings are illustrative and exemplary in nature and are not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
Vehicles according to the present specification include an engine compartment, a hood extending over the engine compartment, and an engine situated within the engine compartment. A pin extends from a top side of the engine generally toward an interior surface of the hood. An engine cover extends between the top side of the engine and the interior surface of the hood. The engine cover includes at least one engine cover connection. As will be described herein, a grommet is coupled to the engine cover connection. The grommet includes an entrance, a stop and an internal cavity extending through the grommet from the entrance toward the stop. The internal cavity may be divided into a passive cavity portion and an active cavity portion. The pin is situated within the passive cavity portion of the grommet during normal operating conditions. As will be described in further detail below, when an impact occurs to the hood, the grommet may stroke toward the top side of the engine. When this happens, the pin may pass from the passive cavity portion of the grommet and at least partially into the active cavity portion of the grommet thereby allowing some vertical movement of the grommet and the engine cover relative to the engine.
As used herein, the term “normal operating conditions” refers to a vehicle either stationary or in motion that is operating without an external force impacting a top surface of the hood of the vehicle sufficient to deform the hood toward the engine.
As used herein, the term “stroke” refers to the motion of an article from an initial position, defined in relation to a vehicle component (e.g. a hood) under normal operating conditions, to a secondary position relative to the initial position as a result of an external force impacting the vehicle. For example, when a vehicle experiences an impact to the outside surface of the hood, the hood has a tendency to plastically and elastically deflect toward the top side of the engine. Therefore, the term stroke refers to motion of vehicle components during an impact.
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The engine cover 110 may be a variety of shapes and sizes. For example, the engine cover 110 may be shaped so as to fit a certain shape of a particular engine 130 (as shown in
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The engine 130 is positioned within the engine compartment 102. The top side 132 of the engine 130 is oriented toward the hood 120. A pin 160 extends from the top side 132 of the engine 130 toward the interior surface 124 of the hood 120. The engine cover 110 extends in both the vehicle's longitudinal and lateral directions between the interior surface 124 of the hood 120 and the top side 132 of the engine 130. The grommet 140 is coupled to the engine cover connection 114 and is configured to receive the pin 160.
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The grommet 140 includes an entrance 141, a stop 142, and an internal cavity 143 extending through the grommet 140 from the entrance 141 toward the stop 142. The internal cavity 143 may be divided into at least a passive cavity portion 144 and an active cavity portion 145. Under normal operating conditions, the pin 160 rests within the passive cavity portion 144 and remains so positioned. As will be explained in more detail, under conditions where an impact 180 is occurring to the hood 120 of the vehicle 100 (as shown in
The entrance 141 of the grommet 140 is configured to receive the pin 160 therethrough, such that the head 164 and a portion of the neck 162 traverse the entrance 141 of the grommet 140. The entrance 141 may be a variety of shapes and sizes. For example, the entrance 141 may be a countersink extending internally into a body 148 of the grommet 140. In this exemplary embodiment, the width of the entrance 141 may decrease to a width of the passive cavity portion 144 of the grommet 140.
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The stop 142 of the grommet 140 may have a grommet pressure release aperture 156. The grommet pressure release aperture 156 extends from the active cavity portion 145 of the grommet 140 to the cover pressure release aperture 111 of the engine cover 110. When the engine cover 110 is installed onto the pin 160 air pressure may build up within the internal cavity 143 of the grommet 140. Therefore, it may be desirable to relieve the pressure within the grommet 140 by allowing the buildup of air, or other fluids to escape first through the grommet pressure release aperture 156 and then through the cover pressure release aperture 111 of the engine cover 110. As such, the grommet pressure release aperture 156 may be substantially aligned with the cover pressure release aperture 111 of the engine cover 110. In some embodiments, the cover pressure release aperture 111 of the engine cover 110 may be substantially congruent to the grommet pressure release aperture 156. There may be a plurality of grommet pressure release apertures 156. In some cases, the number of grommet pressure release apertures 156 may be equal to the number of pressure release apertures 111 of the engine cover 110.
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In some embodiments, the active cavity portion 145 of the grommet 140 may further include a catch structure 155 connecting the active cavity portion 145 and the passive cavity portion 144 of the grommet 140 to inhibit the head 164 of the pin 160 from passing into the active cavity portion 145 of the grommet 140 under lower loading conditions, i.e., normal operating conditions. In some embodiments, the width of the catch structure 155 is less than that of the head 164 of the pin 160. The width of the active cavity portion 145 of the grommet 140 may be substantially uniform with the width of the catch structure 155. The width of the catch structure 155 and the active cavity portion 145 of the grommet 140 may be tuned to provide a preselected amount of resistance against passage of the head 164 of the pin 160 from the passive cavity portion 144 to the active cavity portion 145 of the grommet 140. For example, where the width of the active cavity portion 145 of the grommet 140 is much smaller than the width of the passive cavity portion 144, a greater amount of energy from the impact may be absorbed. In doing so, however, the stroke of the grommet 140 to the engine 130 may be shortened. In an opposite example, where the width of the active cavity portion 145 of the grommet 140 is not much smaller than the width of the passive cavity portion 144 of the grommet 140, a lesser amount of energy from the impact may be absorbed. In this case, the additional stroke provided between the grommet 140 and the engine 130 may be lengthened. It is desirable to both absorb energy from the impact 180 while maximizing the stroke experienced by the grommet 140.
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As such, to connect the engine cover 110 to the engine 130, at least one pin 160 is installed into the top side 132 of the engine 130. The engine cover 110 may then be oriented over the pin 160, such that the grommet 140 is aligned with the pin 160. The engine cover 110 is then attached to the pin 160. When attaching the engine cover 110 to the engine 130, the pin 160 traverses the entrance 141 of the grommet 140 and rests in the passive cavity portion 144 of the grommet 140. Under normal operating conditions, the pin 160 remains in the passive cavity portion 144 of the grommet 140. Generally, the engine cover 110 may be attached by pressing the engine cover 110 down on top of the pin 160 until the pin 160 rests in the passive cavity portion 144 of the grommet 140.
When an object impacts the hood of a vehicle, the hood may elastically or plastically deform or stroke toward the engine and as such absorbs some of the energy of the impact. The impact may be of such a magnitude that the hood continues stroking such that it contacts an engine cover of the vehicle. The engine cover may also begin to stroke toward the engine. The engine cover may be designed to accommodate the introduction of the energy of the impact, such that the engine cover may provide increased energy absorption. This absorption of energy may decrease the magnitude of acceleration experienced when the object causing the impact comes in contact with the engine itself. Particularly, the grommets of the engine cover described herein may be tuned to dissipate the energy associated with the impact and decrease the acceleration experienced once the impacting object reaches the engine.
As the energy of the impact 180 continues to force the grommet 140 toward the base 163 of the pin 160, the catch structure 155 may begin to deform about the head 164 of the pin 160 as the head 164 of the pin 160 passes into the active cavity portion 145 of the grommet 140. The deformation allows for some of the energy of the impact 180 to be absorbed.
The active cavity portion 145 of the grommet 140 continues to absorb the energy of the impact as the head 164 of the pin 160 passes further into the active cavity portion 145 of the grommet 140 and more of the active cavity portion 145 of the grommet 140 deforms about the head 164 of the pin 160. It should be noted that the pin 160 need not pass completely into the active cavity portion 145 of the grommet 140. The stroking of the grommet 140 may stop prior to the head 164 of the pin 160 fully passing into the active cavity portion 145 of the grommet 140. The amount of stroking that occurs is dependent on the force of the impact 180 as well as the specific tuning of the grommet 140. For example, if the grommet 140 has a stiffer configuration the amount of stroking may be lessened. In some embodiments, the grommet 140 may be capable of stroking at least up to 10 mm toward the top side 132 of the engine 130 in response to an impact with a 5 kg weight.
If the grommet 140 continues to stroke toward the base 163 of the pin 160, the head 164 of the pin 160 may eventually contact the stop 142 of the active cavity portion 145 of the grommet 140. Once the pin 160 comes in contact with the stop 142, the grommet 140 may not stroke toward the engine 130 further. Acceleration may be lessened due to the additional stroking ability provided by the grommet 140 of the present specification.
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The above-described engine cover and grommet provides additional structure that may be used to absorb impact energy when a head form impacts a hood of a vehicle. As such, the grommet provides additional stroke which allows more of the impact energy to be dissipated before the energy of the impact reaches the engine of the vehicle. While the grommets are described in the context of impacts to the hood of the car, similar grommets could be used to allow for additional stroke in the event of an impact to other vehicle panels.
In is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.