The present description relates generally to methods and systems for modified intake runners including ribs in the direction of airflow.
In internal combustion engines, air is introduced into an intake manifold via an intake throttle. The intake manifold may typically consist of a plenum and intake runners. The intake runners further channel airflow from a first end of the intake runner proximal to the plenum into the engine cylinders through a second end proximal to an intake port of a cylinder. Shapes of such intake runners are adapted for improved flow pressure and air flow dynamics through the runners. In order to attain a desired shape for airflow through the intake runner, multiple molded components (shells) are welded together.
Various approaches have been developed to improve flow dynamics in an engine intake manifold. One example approach is shown by Kulkarni in U.S. Pat. No. 8,955,485. Therein, Kulkarni introduces an inlet with two radial indentations on opposite sides leading from the throttle to the plenum, in order to optimize flow in such a way to reduce noise, vibration, and harshness. The inlet maintains a wall thickness along the portion of the inlet where the radial indentations are disposed, thereby introducing no further bulk. Kulkarni also introduced a network of protruding ribs in a substantially cross-hatched manner along the intake manifold, in order to provide strength and stiffness of the intake manifold, in addition to further reducing noise, vibration, and harshness.
However, the inventors herein have recognized potential issues with such systems. While the systems of Kulkarni in U.S. Pat. No. 8,955,485 reduce noise, vibration, and harshness, they continue to rely on welding multiple, potentially thick shells together to form the intake manifold. Typically, these shells may be manufactured through injection molding. A limiting factor in the injection molding process is the processing (such as cooling) time which significantly depends on spatial dimensions (such as thickness) of the shell. Consequently, if the shell thickness is greater at certain points, manufacturing of the runners with thicker portions may be inefficient and cost ineffective. Further, stacking of layers of shells may cause thick sections in the welded shells, which adds excess weight to the intake manifold, in addition to added manufacturing costs.
In one example, the issues described above may be addressed by a system for an engine, comprising: an intake manifold adapted to couple to an intake port via an intake runner; and a plurality of negative ribs arranged on a façade of an inner portion of the intake runner. In this way, by introducing negative ribs in a direction of airflow, thickness of the intake manifold may be reduced without adversely affecting airflow through the intake runner.
As one example, for each intake runner, negative ribs may be formed along a segment in an inner portion (such as core region) of the intake runner. The segment may include a façade perpendicular to the direction of airflow proximal to the second end of the runner proximal to the cylinder. A plurality of vertical, negative ribs may be formed on the façade and a recess may be formed below the façade. Air may flow through the intake runner from the first end of the runner proximal to the throttle, to the second end of the runner proximal to the intake port of a cylinder, with the negative ribs in the direction of airflow. As air flows into the cylinder, the air may flow through the recess formed below the façade as it enters the cylinder through the intake valve. The plurality of ribs of variable length and curvature may be formed by conventional injection molding.
The inventors have recognized that the above approach may provide various advantages. In this way, by adding negative ribs to a façade in in inner portion of each intake runner, weight of each intake runner may be reduced. Further, use of conventional injection molding for forming the negative ribs allows for greater flexibility in design adaptation for optimal airflow. The addition of negative ribs allows for minimal increase in manufacturing complexity, while reducing weight and material cost. The technical effect of introducing negative ribs along the direction of flow above a recess in the intake runner is that the flow dynamics of air entering the engine cylinders may be improved. Overall, by substituting thicker, multi-layered welded sections in an inner portion of an intake runner with thinner, negative ribs, weight, and cost of an engine component may be reduced without any significant adverse effect on power and torque of the engine.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
The following description relates to systems and methods for a modified intake manifold of an engine including modified intake runners with negative ribs. An example engine system including the modified intake runners coupled to each engine cylinder is shown in
Each of the modified inner portions (such as respective portions 175,177, 179, and 181) of each intake runner may include a façade formed between an arcuate upper edge and an arcuate lower edge. The façade may be angled and may extend along a curvature of the arcuate upper edge and a plurality of negative ribs may be arranged on a façade. Along the façade, each rib of the plurality of ribs may include an elongated, rectangular indentation penetrating into a thickness of the façade. The plurality of ribs may include four central ribs and two peripheral ribs, a peripheral rib formed on each side of the central ribs. Each of the four central ribs may be identical in length, width, and thickness; and wherein each of the two peripheral ribs are identical in length, width, and thickness, while a first length of a central rib is greater than a second length of a peripheral rib, and a first width of the central rib is lower than a second width of the peripheral rib. A ledge may be formed at a base of the façade, the ledge jutting onto a base region of the inner portion, and a recess may be formed between the ledge and an inner wall of the inner portion. Intake gas may flow from the intake manifold to the intake port over the ribs and through the recess formed under the façade.
Engine exhaust 108 includes an exhaust manifold 148 leading to an exhaust passage 135 that routes exhaust gas to the atmosphere. The exhaust manifold 148 channels exhaust gas from the cylinders 172 via the exhaust valves 147 into respective exhaust runners 184, 186, 188, and 190. Engine exhaust 108 may include one or more emission control devices 170 mounted in a close-coupled position. The one or more emission control devices may include a three-way catalyst, lean NOx trap, diesel particulate filter, oxidation catalyst, etc. It will be appreciated that other components may be included in the engine such as a variety of valves and sensors, as further elaborated in herein. In some embodiments, wherein engine system 100 is a boosted engine system, the engine system may further include a boosting device, such as a turbocharger (not shown).
Engine system 106 is coupled to a fuel system 168. Fuel system 168 includes a fuel tank 121 coupled to a fuel pump 171, the fuel tank supplying fuel to an engine 10 for combustion in the engine cylinders. Fuel pump 171 is configured to pressurize fuel delivered to the injectors of engine 10, such as example injector 166. While only a single injector 166 is shown, additional injectors are provided for each cylinder.
Vehicle system 102 may further include control system 114. Control system 114 is shown receiving information from a plurality of sensors 116 (various examples of which are described herein) and sending control signals to a plurality of actuators 118 (various examples of which are described herein). As one example, sensors 116 may include exhaust gas sensor 131 located upstream of the emission control device, temperature sensor 133, and pressure sensor 137. Other sensors such as additional pressure, temperature, air/fuel ratio, and composition sensors may be coupled to various locations in the vehicle system 102. As another example, the actuators may include fuel injector 166, and throttle 162.
Controller 112 may be configured as a conventional microcomputer including a microprocessor unit, input/output ports, read-only memory, random access memory, keep alive memory, a controller area network (CAN) bus, etc. Controller 112 may be configured as a powertrain control module (PCM). The controller may be shifted between sleep and wake-up modes for additional energy efficiency. The controller may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on instruction or code programmed therein corresponding to one or more routines.
In some examples, vehicle system 102 may be a hybrid vehicle system with multiple sources of torque available to one or more vehicle wheels 155. In other examples, vehicle system 102 is a conventional vehicle with only an engine, or an electric vehicle with only electric machine(s). In the example shown, vehicle system 102 includes engine 10 and an electric machine 153. Electric machine 153 may be a motor or a motor/generator. Crankshaft of engine and electric machine 153 are connected via a transmission 157 to vehicle wheels 155 when one or more clutches 154 are engaged. In the depicted example, a first clutch 154 is provided between crankshaft and electric machine 153, and a second clutch 154 is provided between electric machine 153 and transmission 157. Controller 112 may send a signal to an actuator of each clutch 154 to engage or disengage the clutch, so as to connect or disconnect crankshaft from electric machine 153 and the components connected thereto, and/or connect or disconnect electric machine 153 from transmission 157 and the components connected thereto. Transmission 157 may be a gearbox, a planetary gear system, or another type of transmission. The powertrain may be configured in various manners including as a parallel, a series, or a series-parallel hybrid vehicle.
Electric machine 153 receives electrical power from a traction battery 158 to provide torque to vehicle wheels 155. Electric machine 153 may also be operated as a generator to provide electrical power to charge battery 158, for example during a braking operation.
During combustion in the combustion chamber 14, air may enter the intake manifold 144 through the intake throttle 162, passing through a plenum 145 and then flowing to the intake valve 150 via an intake runner 178. The intake runner may include an inner portion (core) 179 formed with negative ribs along the direction of airflow. Details of the structure of the inner portion 179 are shown in
The cylinder may, for example, operate in a standard four-stroke cycle as part of the engine 10. A four-stroke cycle consists of an intake stroke, a compression stroke, a power stroke, and an exhaust stroke. During the four-stroke cycle, air may enter the combustion chamber an air/fuel mixture and be ignited by a spark plug 192. Upon combustion within the combustion chamber, the residual gas may then be expelled as exhaust through the exhaust valve 156 and the exhaust passage 148.
In this example, inner portion 179 within the second intake runner 178 is discussed in detail, however, each intake runner including a first intake runner 180 and a third intake runner 176 may comprise substantially identical ribbed inner portions (first inner portion 181 and second inner portion 177).
The second intake runner 178 may include a first end 322 proximal to and emanating from a plenum (such as 145 of
The façade may be arcuate and follow the curvature of the upper edge 342. The façade may have a higher cross-sectional area at the upper edge 342 with tapering sides. Said another way, the façade 333 of the second inner portion 179 including the one or more negative ribs may be arcuate with a width of the façade being higher at a center of the wall and the width of the wall decreasing towards two ends. In one example, the façade 333 may be angled along the direction of airflow indicated by arrow 311. The second segment 330 may further include an open base area 365 positioned directly below the façade 333. Air may flow to the second end 348 of the second runner 178 via the base area 365.
The façade 333 may include a plurality of negative ribs formed within the façade. In this example, six evenly spaced ribs 334 are shown. However, in alternate embodiments, there may be lower or higher number of ribs. Each rib 334 may be a negative rib such as an indentation formed into the façade 333. Each rib 334 may be a rectangular, elongated negative indentation (along the z-axis of the coordinate system 390) with a central opening 332 lined with four walls projecting inwards into the façade 333. Air may flow over the ribs and also through the central opening 332.
The plurality of ribs 334 may include four central ribs which are identical and two peripheral ribs which may be shortened relative to the central ribs. In this way, the negative ribs may include a first set of coplanar central ribs and a second set of peripheral ribs, each rib in the first set of coplanar central ribs being longer than each rib in the second set of peripheral ribs. As one example, the height of the peripheral ribs may be 80% of that of the central ribs. The plurality of ribs 334 may be formed by injection molding. The technical effect of the addition of a plurality of ribs 334 is the elimination of thicker sections in the intake manifold runners, which reduces complex manufacturing procedures.
The inner portion of intake runner 179 may be formed of three stacked segments, which are stacked along the z axis. The three stacked shells may be welded together by ultrasonic welding. The stacked segments may include a first section 364 positioned directly below the rim 324 (along the direction of negative z-axis). A second section 366 may be positioned vertically below (along the direction of negative z-axis) the first section 364, the second section 366 separated from the first section 364 via a first flange 326. An additional third section 368 may be positioned vertically below (along the direction of negative z-axis) the second section 366, and the third section 368 may be separated from the second section 366 via a second flange 328. Each end of the arcuate upper edge 342 of the second segment 330 is coplanar with the first flange 326 and may end at the first flange 326. Additionally, the arcuate lower edge 346 is coplanar with a second flange 328 and may end at the second flange 328. As an example, the façade 333 may be positioned vertically below (along the direction of negative z-axis) the first flange 326, between the first flange 326 and the second flange 328. Each of the rim 324, first section 364, the flange 326, and the second section 366 may have a substantially similar curvature with the first section 364.
The airflow from the intake runner 178 to a cylinder (such as cylinder 172 of
Similar to the second inner portion 179 of the second intake runner 178 as described in
As seen from the cross-sectional view of the façade 498, a ledge 422 may be formed under the façade 498. The ledge 422 may jut out onto the open base area 465. As will be elaborated with reference to
Due to the presence of the recess 668, as air flows into an intake valve of the cylinder via the inner portion of an intake runner, the air may flow through the recess formed below the façade. The combination of the ribs and the recess may improve the flow dynamics of air and allow improved air flow into the cylinder.
In this way, air in the intake system may flow from a plenum of an intake manifold to an intake port of a cylinder via each of a plurality of negative ribs formed on a façade of an inner portion of an intake runner and a recess formed below the façade of the inner portion. The addition of negative ribs within an inner portion of the intake runners may have several advantages. The technical effect of the production of negative ribs is to reduce excess material use within the intake runners of the intake manifold without sacrificing air flow dynamics. Typically, the intake manifold may be manufactured through the stacking of several shells formed through injection molding, which may then be sonically welded together. During the injection molding process, cooling time is a limiting time scale, which depends significantly on spatial dimensions (such as thickness). Additionally, during the manufacturing process, several shells may be ultrasonically welded together, which may create thick portions within the intake runners. Previous solutions modified thick portions in subsequent manufacturing processes to reduce excess thickness. Therefore, addition of negative ribs may reduce the cooling time and remove the need for subsequent manufacturing processes, reducing manufacturing time and cost. An additional technical effect of the addition of negative ribs is to allow for further range of design in the shape of the intake runner, allowing for greater airflow optimization with negligible effect on power and torque.
In one example, a system for an engine in a vehicle, comprises: an intake manifold adapted to couple to an intake port via an intake runner, and a plurality of negative ribs arranged on a façade of an inner portion of the intake runner. In the preceding example, additionally or optionally, the intake runner adapted to flow intake gas from the intake manifold to a cylinder via the negative ribs and the intake port. In any or all of the preceding examples, additionally or optionally, the inner portion of the intake runner includes the façade formed between an arcuate upper edge and an arcuate lower edge. In any or all of the preceding examples, additionally or optionally, the façade is angled and extends along a curvature of the arcuate upper edge. In any or all of the preceding examples, additionally or optionally, each rib of the plurality of ribs include an elongated, rectangular indentation penetrating into a thickness of the façade. In any or all of the preceding examples, additionally or optionally, the plurality of ribs include four central ribs and two peripheral ribs, a peripheral rib formed on each side of the central ribs. In any or all of the preceding examples, additionally or optionally, each of the four central ribs are identical in length, width, and thickness; and each of the two peripheral ribs are identical in length, width, and thickness. In any or all of the preceding examples, additionally or optionally, a first length of a central rib is greater than a second length of a peripheral rib, and a first width of the central rib is lower than a second width of the peripheral rib. In any or all of the preceding examples, additionally or optionally, the system further comprising, a ledge formed at a base of the façade, the ledge jutting onto a base region of the inner portion, and a recess formed between the ledge and an inner wall of the inner portion. In any or all of the preceding examples, additionally or optionally, intake gas flows from the intake manifold to the intake port over the ribs and through the recess formed under the façade. In any or all of the preceding examples, additionally or optionally, the engine includes a plurality of the intake runners with each intake runner including the plurality of negative ribs arranged on the façade of the inner portion of the intake runner.
In another example, a system for an engine in a vehicle, comprises: an intake manifold including a plenum coupled to a plurality of intake runners, each intake runner including negative ribs formed along a wall of an inner portion of the intake runner and a recess formed under the wall allowing air flow from the plenum to an intake port of a cylinder. In the preceding example, additionally or optionally, the inner portion of the intake runner includes a rim lining the perimeter of the intake runner, a plurality of vertically stacked segments, and an intake port formed at a second end of the intake runner, a first end of the intake runner being proximal to the plenum. In any or all of the preceding examples, additionally or optionally, the wall of the inner portion including the one or more negative ribs is arcuate with a width of the wall being higher at a center of the wall and the width of the wall decreasing towards two ends. In any or all of the preceding examples, additionally or optionally, the recess is formed between a base of the wall and another wall of the vertically stacked segments, the base of the wall projecting outward towards the second end of the intake runner from the another wall of the vertically stacked segments. In any or all of the preceding examples, additionally or optionally, negative ribs include a first set of coplanar central ribs and a second set of peripheral ribs, each rib in the first set of coplanar central ribs being longer than each rib in the second set of peripheral ribs. In any or all of the preceding examples, additionally or optionally, six negative ribs are formed along the wall of the inner portion of the intake runner.
In yet another example, a method for an engine in a vehicle, comprising: flowing air from a plenum of an intake manifold to an intake port of a cylinder via each of a plurality of negative ribs formed on a façade of an inner portion of an intake runner and a recess formed below the façade of the inner portion. In the preceding example, additionally or optionally, each negative rib includes a trapezoidal cross section along a direction of air flow, each negative rib extending through a thickness of the façade. In any or all of the preceding examples, additionally or optionally, the recess is a rectangular area formed between a lower surface of the façade and an inner wall of the inner portion of the intake runner.
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. Moreover, unless explicitly stated to the contrary, the terms “first,” “second,” “third,” and the like are not intended to denote any order, position, quantity, or importance, but rather are used merely as labels to distinguish one element from another. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
As used herein, the term “approximately” is construed to mean plus or minus five percent of the range unless otherwise specified.
The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
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