Integrated vehicle structure and power-plant exhaust

TECHNICAL FIELD

0001The invention relates to a vehicle structure integrated with a power-plant exhaust system.

BACKGROUND

0002Typically, a vehicle includes a structure for enclosing and supporting various vehicle systems, as well as the vehicle passengers. Heavy-duty vehicles, such as pick-up trucks and vans, commonly employ a frame to support a body and a powertrain of the vehicle. On the other hand, light-duty vehicles, such as a majority of passenger cars, often employ a monocoque or unibody construction that eschews a separate body and frame, in favor of a lighter, integrated structure. Additionally, some lighter-duty vehicles employ a combination monocoque structure with a subframe for carrying the vehicle's powertrain. Frequently, additional structural members are used to buttress the vehicle structure, as well as for supporting various chassis and powertrain subsystems.

SUMMARY

0003A frame is disclosed for a vehicle having a vehicle body, a vehicle suspension, and a power-plant configured to generate torque and an exhaust gas stream by-product. The frame includes a tubular frame rail in fluid communication with the power-plant, wherein the rail is defined by a fully-closed cross-section that provides a fluid passage. The frame rail is configured to support the vehicle body and the vehicle suspension. The fluid passage is configured to channel the exhaust gas stream through the frame rail and away from the vehicle body. A vehicle employing such a frame is also disclosed.

0004The frame rail may include two substantially parallel rails spaced apart by a distance.

0005The fluid passage may include an inside surface in direct contact with the exhaust gas stream, wherein the inside surface may include a coating configured to minimize corrosion of the frame rail.

0006The coating may be generated via a galvanization or a galvannealing process. Additionally, the coating may either be a rubberized or an epoxy compound.

0007The frame rail may be formed from an aluminized stainless steel.

0008The frame rail cross-section may have either a substantially parallelogram “boxed” shape or a substantially round shape.

0009The frame rail may be formed by a process of extrusion or hydro-forming.

0010A vehicle employing such a frame is also disclosed.

0011The power-plant may be a hydrogen fuel-cell, while the vehicle may then also include a hydrogen fuel tank in fluid communication with the fuel-cell. In such a case, the frame may also be configured to support the hydrogen fuel tank.

0012The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of the embodiment(s) and best mode(s) for carrying out the described invention when taken in connection with the accompanying drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

0013<figref idref="DRAWINGS">FIG. 1</figref> is a schematic plan view of a vehicle structure including a frame, a powertrain including a power-plant, a transmission, fuel tanks, and integrated vehicle frame rails and exhaust passages.

0014<figref idref="DRAWINGS">FIG. 2</figref> is a close-up view of the power-plant being supported by and connected to the frame rails that are configured to direct power-plant exhaust away from the vehicle, as shown in <figref idref="DRAWINGS">FIG. 1</figref>.

0015<figref idref="DRAWINGS">FIG. 3</figref> is an illustration of a cross-section of the frame rails shown in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>.

DETAILED DESCRIPTION

0016Referring to the drawings, wherein like reference numbers refer to like components, <figref idref="DRAWINGS">FIG. 1</figref> shows a schematic view of a motor vehicle <b>10</b> positioned relative to a road surface <b>12</b>. The vehicle <b>10</b> includes a vehicle structure <b>14</b>, which includes a vehicle body <b>16</b> and a vehicle frame <b>18</b>. The vehicle <b>10</b> also includes a powertrain <b>20</b> configured to propel the vehicle. The frame <b>18</b> is configured to support the vehicle body <b>16</b> and also to channel an exhaust stream away from the body, as set forth in detail below with respect to <figref idref="DRAWINGS">FIG. 3</figref>.

0017As shown in <figref idref="DRAWINGS">FIG. 1</figref>, the powertrain <b>20</b> includes a power-plant <b>22</b> configured to generate torque to power the vehicle <b>10</b> and a transmission assembly <b>24</b>. As a by-product of the generated torque, the power-plant <b>22</b> generates an exhaust gas stream <b>25</b>. In <figref idref="DRAWINGS">FIG. 1</figref> the vehicle <b>10</b> is depicted as a fuel-cell type vehicle, and the power-plant <b>22</b> is depicted as a fuel-cell. Alternatively, the vehicle <b>10</b> may be a gas/electric hybrid (not shown) and employ a powertrain <b>20</b> that includes one or more motor/generators in conjunction with an internal combustion (IC) engine. Furthermore, the vehicle <b>10</b> may be a conventional type (not shown) powered only by an IC engine. Although neither the gas/electric hybrid nor the conventional vehicle types are specifically shown, such configurations are well known and would be easily envisioned by those skilled in the art.

0018With continued reference to <figref idref="DRAWINGS">FIG. 1</figref>, the vehicle <b>10</b> also includes a plurality of wheels <b>26</b> and <b>28</b>. As shown, each of the plurality of wheels <b>26</b>, <b>28</b> may include an inflatable tire <b>30</b> mounted thereon. Although four wheels <b>26</b>, <b>28</b> with tires <b>30</b> are shown in <figref idref="DRAWINGS">FIG. 1</figref>, a vehicle with fewer or greater number of wheels and tires is also envisioned. Depending on the specific configuration of the powertrain <b>20</b>, torque of the power-plant <b>22</b> may be transmitted to the road surface <b>12</b> through the wheels <b>26</b>, the wheels <b>28</b>, or through all the wheels <b>26</b> and <b>28</b>.

0019As shown in <figref idref="DRAWINGS">FIG. 1</figref>, a vehicle suspension system <b>32</b> operatively connects the frame <b>18</b> to the wheels <b>26</b>, <b>28</b> for maintaining contact between the wheels and the road surface <b>12</b>, and for maintaining handling of the vehicle <b>10</b>. As shown, the suspension system <b>32</b> may include a plurality of upper control arms <b>34</b> and lower control arms <b>36</b>, wherein one upper and one lower control arm is connected to one of the wheels <b>26</b>, <b>28</b>. Although a specific configuration of the suspension system <b>32</b> is shown in <figref idref="DRAWINGS">FIG. 1</figref>, other vehicle suspension designs are similarly envisioned. The suspension system <b>32</b> also includes springs <b>38</b> and dampers <b>40</b>. Each spring <b>38</b> and damper <b>40</b> is configured to control deflection of the respective wheel <b>26</b>, <b>28</b> as the vehicle <b>10</b> traverses the road surface <b>12</b> and the subject wheel's subsequent rebound.

0020As shown, the frame <b>18</b> may be separate from the body <b>16</b>, as is typically employed in heavier-duty work vehicles, such as pick-up trucks and vans, or be a part of a unibody structure, as is typically employed in lighter duty vehicles. In the case of separate vehicle body <b>16</b> and frame <b>18</b>, the frame additionally supports the body, while in the case of a unibody structure, the frame and the body each carry a portion of the structural load. In either the separate frame or the unibody case, the frame <b>18</b> is configured to withstand considerable stress without experiencing structural damage, while supporting the vehicle powertrain <b>20</b>, absorbing vibration thereof, and withstanding the torque generated by engine <b>18</b> during propulsion. Additionally, whether in the separate frame or the unibody case, the frame <b>18</b> is configured to support the load of vehicle passengers and cargo, and any additional loads passed through the suspension system <b>32</b>. The frame <b>18</b> may be attached to the body <b>16</b> by any known means such as welding or via appropriate fasteners.

0021In the specific case where the power-plant <b>22</b> is a fuel-cell, as shown in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the vehicle <b>10</b> also includes one or more hydrogen fuel tanks <b>42</b>. The hydrogen fuel tank <b>42</b> is in fluid communication with the power-plant <b>22</b> and configured to supply the hydrogen fuel thereto. When the vehicle <b>10</b> employs the hydrogen fuel tank <b>42</b>, the frame <b>18</b> may additionally support the hydrogen fuel tank. In the case that the power-plant <b>22</b> is a gas/electric hybrid (not shown) and includes motor/generators and/or an IC engine, the vehicle <b>10</b> may include a fuel tank for the IC engine and an energy storage device, such as one or more batteries. Accordingly, in the gas/electric hybrid vehicle, the frame <b>18</b> may additionally support the fuel tank and the energy storage device. In the case that the power-plant <b>22</b> is an IC engine, the frame <b>18</b> may be configured to support the engine and the fuel tank.

0022As shown in <figref idref="DRAWINGS">FIG. 3</figref>, the frame <b>18</b> includes a tubular frame rail defined by a fully-closed cross-section <b>44</b>. As shown in <figref idref="DRAWINGS">FIG. 1</figref>, the frame <b>18</b> includes two substantially parallel frame rails, <b>46</b> and <b>48</b>, separated in the vehicle structure <b>14</b> by a distance D. Although two frame rails are specifically shown and described herein, the frame <b>18</b> may include only one or any other number of frame rails, as deemed necessary for supporting the above-noted vehicle subsystems. The frame rails <b>46</b> and <b>48</b> may be formed from an appropriate high-strength material, such as steel, by any appropriate method, e.g., extrusion, hydro-forming, roll-forming, as well as stamping and welding.

0023As shown in <figref idref="DRAWINGS">FIG. 2</figref>, each of the rails <b>46</b>, <b>48</b> defines a hermetically sealed volume along the particular rail's length. The rails <b>46</b>, <b>48</b> are connected at first distal ends <b>46</b>-<b>1</b> and <b>48</b>-<b>1</b>, respectively, to the power-plant <b>22</b>. Therefore, the entire length of each rail <b>46</b> and <b>48</b> is in fluid communication with power-plant <b>22</b>. The rails <b>46</b>, <b>48</b> are also open to the atmosphere at second distal ends <b>46</b>-<b>2</b> and <b>48</b>-<b>2</b>, respectively. When the power-plant is operating and generating torque, the exhaust gas stream <b>25</b> is channeled from the power-plant <b>22</b> via the manifolds <b>50</b>, through the frame rails <b>46</b>, <b>48</b>, and away from the vehicle body <b>16</b> to the atmosphere. Therefore, in addition to functioning as structural members that are part of the frame <b>48</b>, the frame rails <b>46</b>, <b>48</b> additionally operate as fluid passages for channeling the exhaust gas stream <b>25</b> away from the power-plant <b>22</b>. As such, the fluid passages provided in the frame rails <b>46</b>, <b>48</b> include inside surfaces, <b>46</b>-<b>3</b> and <b>48</b>-<b>3</b>, respectively, configured for direct contact with the exhaust gas stream <b>25</b>. Additionally, the frame rails <b>46</b> and <b>48</b> may be connected to cross members <b>50</b>-<b>1</b> and <b>50</b>-<b>2</b> via couplings <b>51</b>. Couplings <b>51</b> may include drainage provisions to expel any condensate that would otherwise collect inside the rails <b>46</b>, <b>48</b> from the exhaust gas stream <b>25</b> during operation of the power-plant <b>22</b>.

0024The frame rails <b>46</b>, <b>48</b> may be formed from steels ranging from typical low-grade carbon steel to high-grade type, for example GMW3032M-ST-S hot-rolled HR550 or cold-rolled CR560, while using a wide range of material gauges appropriate to the particular loads seen by the frame rails in the vehicle <b>10</b>. Furthermore, the frame rails <b>46</b>, <b>48</b> may be formed from a robust material, such as aluminized stainless steel. The cross-section <b>44</b> may have a substantially parallelogram “boxed”, i.e., closed section, shape or a substantially round shape. The frame rails <b>46</b>, <b>48</b> may be subsequently bent or routed to accommodate the packaging of other components and subsystems in the vehicle <b>10</b> while maintaining the required load bearing characteristics. As such, the above mentioned material selection and the external form of the rails <b>46</b>, <b>48</b> are typically a function of expected vehicle loads, durability, and packaging requirements.

0025In the case of the rails <b>46</b>, <b>48</b> being formed from aluminized stainless steel or stainless steel that is either galvanized or treated with a Galva anneal process, i.e., galvannealed. The inside surfaces <b>46</b>-<b>3</b>, <b>48</b>-<b>3</b> of the rails may include a temperature-resistant coating <b>52</b> applied thereto (shown in <figref idref="DRAWINGS">FIG. 3</figref>). In such a case, the exhaust gas stream <b>25</b> will traverse the coated surfaces <b>46</b>-<b>3</b>, <b>48</b>-<b>3</b> along the length of the rails <b>46</b>, <b>48</b> on the way to the atmosphere. The coating <b>52</b> may be a urethane or rubberized compound configured to protect the inside surfaces <b>46</b>-<b>3</b> and <b>48</b>-<b>3</b> from corrosion or oxidation due to various particles present in the exhaust gas stream <b>25</b>. The coating <b>52</b> may be an epoxy resin, formulated from a silicone, or any other suitable temperature-resistant compound configured to achieve the same result. Additionally, to generate the coating <b>52</b>, a protective layer of zinc may be generated by galvanization or the subject surfaces may be galvannealed via a combined process of galvanizing and annealing.

0026In the embodiment where the power-plant <b>22</b> is a hydrogen fuel-cell, the temperature of the exhaust gas stream <b>25</b> may be below 100 degrees Celsius. On the other hand, wherein the power-plant <b>22</b> is an IC engine, the temperature of the exhaust gas stream <b>25</b> may exceed 800 degrees Celsius. As such, the thermal stresses and corrosion on the inside surfaces <b>46</b>-<b>3</b>, <b>48</b>-<b>3</b> are likely to be significantly lower in the case of the fuel-cell as compared with the IC engine. Accordingly, in the case where the power-plant <b>22</b> is a hydrogen fuel-cell, the inside surfaces <b>46</b>-<b>3</b>, <b>48</b>-<b>3</b> of the rails <b>46</b>, <b>48</b> may be coated with the high-temperature rubberized compound or the epoxy. In the case where the power-plant <b>22</b> is an IC engine, the rails <b>46</b>, <b>48</b> may be formed from an aerospace-grade stainless steel, while the components coated with the rubberized compound or epoxy may be additionally thermally isolated via any known methods. The above-mentioned selection of stainless steel for the rails <b>46</b>, <b>48</b> may allow the rails to durably withstanding sustained elevated temperatures in the presence of the exhaust gas stream <b>25</b>, as well as retain the long-term structural support of vehicle subsystems noted above.

0027The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims.