WO2011070395A1

WO2011070395A1 - Variable geometry air intake system for internal combustion engines

Info

Publication number: WO2011070395A1
Application number: PCT/IB2009/055641
Authority: WO
Inventors: João Francisco ROMEIRO DA FONSECA PEREIRA; José Miguel CARRUSCA MENDES LOPES
Original assignee: INSTITUTO POLITéCNICO DE LEIRIA
Priority date: 2009-12-09
Filing date: 2009-12-10
Publication date: 2011-06-16
Also published as: PT104863A; PT104863B

Abstract

The present invention consists of an air intake system for engines with four cylinders or more, which has a low production cost and is easy to implement. It allows the separation or combination of cylinder intake, and hence the operation as a single conventional engine or as two or more independent two-cylinder engines, optimising the performance of internal combustion engines. Two sensors in the engine send engine speed and imposed load signals to an electronic control system. On the basis of the acquired data, the electronic control system manages the configuration of the intake system by positioning the valves in one of three available modes, in order to provide the maximum intake air flow rate into the cylinders. This invention is thus useful to increase engine torque and efficiency and may be applied to internal combustion engines for road vehicles, ships, aircraft or industrial machinery, but primarily for automobiles and motorcycles.

Description

Title of Invention: VARIABLE GEOMETRY AIR ADMISSION SYSTEM FOR COMBUSTION ENGINES

INTERNAL

Technical field of the invention

[1] The present invention relates to an engine air intake system

internal combustion engines for the propulsion of vehicles for road, naval, aeronautical or industrial use. Being a low cost and easy to implement system, it provides an increase in engine torque.

Background of the Invention

[2] Variable geometry intake systems are available on the market.

either in four-cylinder engines or in engines with six, eight or more cylinders. However, in their application to four-cylinder engines, these systems vary the length of the primary or secondary tubes in a continuous or discrete manner, tailoring the dimensions of those components to the engine operating regime. Less common, is the volume variation of the plenum chamber. In engines of six, eight or more cylinders, where there are normally two or more plenum chambers, in addition to the aforesaid geometric variation solutions, other types of solutions have been adopted which interrupt or open communication between those chambers.

[3] In the variable geometry air intake systems of four-cylinder engines described above, while improving engine performance, they do not take full advantage of the engine, since the four cylinders are attached in the same plenum chamber , there are engine speed regimes in which the cylinder intake process is mutually damaging. However, in engines with six or more cylinders, there are systems that separate the intake process from the cylinders to improve the performance of such engines. However, as in the case of four-cylinder engines, such separation does not prevent the cylinders from damaging each other in some regimes.

[4] The invention proposed here consists of an air intake system, which in rotational speed regimes of the engine in which the interference between cylinders impairs its performance, separates the cylinders two by two, causing, with respect to the the engine functions as if it were the joining of two, three or more independent twin-cylinder engines. [5] In four-cylinder engines, cylinder separation is performed by grouping the No. 4 cylinders in the plenum chamber (1) and the No. 2 and No. 3 cylinders in the plenum chamber (2) as shown in FIG. Figure 1, or alternatively, separating the No. 2 cylinders from the No. 3 and 4 cylinders, as shown in Figure 5.

[6] The application of the system to motors of six or more cylinders is performed by grouping cylinders two by two into plenum chambers, which can be isolated or put into communication, as shown in Figure 7 and Figure 8. The type of separation of cylinders to be used depends on the engine where the invention is applied.

[7] The invention proposed here is compatible with the use of variable geometry systems which vary other characteristics of the intake system as described above, as well as with variable distribution systems and / or variable geometry exhaust systems.

[8] For engines running at constant speed (or in a very narrow speed range) the principle continues to apply. The system continues to be interesting because it allows to check whether it is preferable to work with a single volume or with the total volume divided by n / 2 independent volumes (where n is the number of cylinders of the motor, always an even number).

Overview of the invention

The present invention is an inexpensive low cost production air intake system which, depending on the engine speed, separates or maintains communication via an electronic control system, the admission of engine cylinder pairs, maximizing the maximum amount of air intake air to the cylinders. When the amount of air required is less than the maximum, the system controls it according to the load imposed on the engine. This improves the performance of internal combustion engines.

[10] Separation or union of the cylinder pair admission process is performed at engine speed and / or load regimes where it is reflected in an increase in intake air flow rate for the cylinders. Likewise, the variation of the amount of air entering the system is accomplished by the actuation of only one, two or more engine load control valves, depending on the configuration that provides the largest intake air flow rate for the cylinders. The increase of the intake air flow is accompanied by an increase in the amount of fuel supplied to the cylinders, considering that the same fuel / air ratio is maintained. As a result of the increase in the amount of air and fuel, an increase of torque and yield produced by the engine results.

[11] In the application of this invention to four-cylinder engines, there are two possibilities of grouping cylinder pairs. Group No. 4 cylinders in a plenum chamber and cylinders # 2 and # 3 in another plenum chamber (see Figure 1), or Alternatively, the cylinders No. 1 and 2 can be grouped in a plenum chamber and cylinders 3 and 4 in another plenum chamber (see Figure 5), which is equivalent to grouping the cylinders No. 3 in a plenum chamber and cylinders # 2 and # 4 in another plenum chamber. In the application of the invention to six or more cylinder engines there are several possibilities of grouping cylinders, which depend on the order of ignition of each engine.

[12] The following parameters are adjusted for each type of engine and / or engine:

The dimensions of the principal organs of the invention presented.

- The number of plenum chambers.

- The number of inlet tubes.

- The number of secondary tubes.

- The speed regimes of the engine in which the process of admitting pairs of engine cylinders is separated or kept in communication.

- Speed and / or engine load regimes in which the amount of air entering the system, translated by the preprogrammed matrix in the electronic control system (13), varies.

- Possibilities of grouping of pairs of cylinders.

The number of communication valves 9 between the plenum chambers depends on the type of valve available, the space and shape of the adopted plenum chambers or otherwise deemed suitable for the purpose according to the invention.

Description of Figures

[13] Without intending to limit the scope of the invention, for the understanding of the different functionalities of the presented invention, a set of drawings representing its operating principle is attached.

[14] Figure 1: Schematic representation of the air intake system. Separation of the cylinders is carried out by insulation of cylinders 1 and 4 of cylinders 2 and 3. The system consists of four primary tubes 3, two plenum chambers 1 and 2, communication valves 9 separating the two plenum chambers 1 and 2, an actuator 10, (9), two control valves (5,6) of the engine load, two actuators (7) and (8) for controlling the two control valves (5,6) of the engine load, respectively, two secondary tubes 4, an air filter chamber 12, an inlet tube 11 and an electronic system 13 for controlling the actuators 7, 8 and 10.

[15] Figure 2: And general systemic squema of the system applied to four engines

cylinders, with all information and actuator control signals. In which (13) represents an electronic control system, (14) the signal of the motor rotation sensor, (15) the signal of the load evaluation sensor imposed on the motor, (16) the actuator control signal ) of the communication valve (9), (17) the control signal of the communication valve (7) of the load control valve (5) and, (18) the control signal of the actuator (8) of the load control valve (6).

[16] Figure 3: Experimental and simulation results obtained at full load with a system similar to that shown in Figure 1. The graph represents for the vast majority of regimes the increase in torque provided by the invention relative to the original intake system of the engine tested . In this example, up to 2066 rpm the system ran in modo mode, from 2066 rpm to 3524 rpm operated in '2 mode' and from 3524 rpm operated in 'mode 3', see section 2. of the 'Detailed description of the invention' .

Alternative configurations are shown in Figures 4 to 8 to demonstrate that the invention can be designed with different architectures, either at the level of the primary tubes, plenum chamber, secondary tubes or inlet tubes, or at the level of the array of cylinders or the number of cylinders of the engine.

[18] Figure 4: Alternative configuration to that shown in Figure 1 while maintaining the same cylinder grouping. This variant differs from Figure 1 in that it allows the use of straight primary tubes or with high (soft) beam curves. In this variant the two plenum chambers were packed into a single piece (19). The grouping of cylinders 1 and 4 is separated from the grouping of cylinders 2 and 3 by a bulkhead and the communication valve (s) 9 when they are closed.

[19] Figure 5: Alternative configuration to that represented in Figure 1 with another

grouping of cylinders. This variant differs from Figure 1 in that the cylinder grouping is changed between the cylinders No. 2 in a plenum chamber 22 and the cylinders No. 3 and No. 4 in another plenum chamber 23, .

[20] Figure 6: Alternative configuration to that shown in Figure 1 while maintaining the same grouping of cylinders. This variant differs from Figure 1 in that it has only one secondary tube (26) and has two inlet tubes (28). The plenum chambers 24 and 25 differ from the plenum chambers 1 and 2 shown in Figure 1 in view of the new geometry of the secondary tube 26. The air filter chamber 27 differs from the air filter chamber 12 shown in Figure 1, due to the new geometry of the secondary tube 26 and the existence of two inlet tubes 28. The diameter of the inlet tubes 28 differs from the diameter of the inlet tube 11 shown in Figure 1 so that the sum of the cross-sectional areas of the two tubes is equal to the cross-sectional area of the inlet tube 11.

[21] Figure 7: Alternative configuration to that shown in Figure 1. This variant differs from Figure 1 in that it represents the concept of this invention applied to six-cylinder engines. The primary tubes 29 are grouped into three plenum chambers 30, 31 and 32 so that the cylinders connected to the same chamber have 360 degrees of mismatch in the ignition order. The air is drawn from the air filter chamber (33) to the plenum chambers through three secondary tubes (34). The engine load control is accomplished by opening one, two or three engine load control valves 35, 36 and 37, driven by three actuators 38, 39 and 40, , respectively.

[22] Figure 8: Alternative configuration to that shown in Figure 1. This variant differs from Figure 1 in that it represents the concept of this invention applied to eight-cylinder engines. The primary tubes 41 are grouped into four plenum chambers 42, 43, 44 and 45 so that the cylinders connected to the same chamber have 360 degrees of mismatch in the ignition order. The air is drawn from the air filter chambers 46 and 47 into the plenum chambers through four secondary tubes 48. The engine load control is performed by opening one, two, three or four engine load control valves 49, 50, 51, 52, driven by four actuators 53, 54, 55, and (56), respectively.

Detailed description of the invention

[23] The invention proposed here consists of an air intake system, which in engine speed regimes in which the interference of the intake process between cylinders impairs its performance, separates the intake process from the cylinders two by two, making it possible for the engine to function as if it were the joining of two or more independent twin-cylinder engines. The invention is based essentially on two main components exemplified below for the application to four-cylinder engines:

1. An air intake system consisting of primary tubes 3, two plenum chambers 1 and 2, two secondary tubes 4, an air filter chamber 12 and a tube of the inlet (11). The primary tubes (3) are dimensionally the same as each other, having the same length and diameter. The length and diameter of the primary tubes (3) must be adjusted to the type of engine where the invention is applied and its use. The ends of the primary tubes 3 of each pair of cylinders connected to the plenum chambers 1 and 2 must be positioned at the same distance from the air inlet in the plenum chamber, which was not followed in Figure 1 and Figure 5 for a better understanding thereof. This specification implies that the primary tubes have curved shapes. The use of a plenum chamber as shown in Figure 4 enables the use of rectilinear primary tubes. The plenum chambers (1) and (2) have the same volume, which must also be adjusted to the type of engine where the invention is applied and its use. The communication valve (s) (9), in the closed position (s), must be sufficiently leakproof so that there is no interference between the pressure in the two chambers. The secondary tubes (4) must have the same length and diameter, they may be rectilinear or curves depending on the deployment of the system in the space in the engine compartment. The geometric shape of all components must be adjusted to the space available in the engine compartment of the vehicle where the invention is applied.

[25] 2. An electronic system (13) that controls the system configuration in three possible modes, designated 'mode', 'mode 2' and 'mode 3', depending on the motor speed and the load imposed on the motor. In the 'mode' the inlet of the four cylinders is in communication through the opening of the communication valve (s) (9) and the engine load is controlled only by a motor load control valve (5), maintaining the second engine load control valve (6) is closed. In 'mode 2' the inlet of the four cylinders is separated through the closure of the communication valve (s) (9) and the engine load is controlled by the two engine load control valves (5) and (6) ). In 'mode 3' the inlet of the four cylinders is in communication through the opening of the communication valve (s) (9) and the engine load is controlled by the two engine load control valves (5) and ( 6). The electronic system (13) has a matrix which determines at each instant the 'mode' in which the system operates. The matrix depends on the speed of rotation of the engine and the load imposed on it by the driver and must be programmed to suit the operation and type of use of the engine where the invention is applied.

Application examples

[26] The invention proposed here has been tested experimentally with a

Figure 3 presents the results of these tests, where there were increases of torque with respect to the original engine system tested, standing out the range of 2250 rpm at 3500 rpm, where there was an increase of the most significant torque reaching a maximum of 6.3% at 3050 rpm. The invention has also been tested with a computational model in engine simulation software. The computational model was calibrated with experimentally obtained motor operating parameters. Figure 3 presents the results of the tests with the computational model, with a good approximation with the experimental results. The computational model was further used to optimize the concept of the invention, obtaining torque increases in the order of 10% by varying the length of the primary tubes and the distribution diagram.

Claims

[Claim 1] A variable geometry air intake system for

internal combustion engines, for the propulsion of vehicles for road, naval, aeronautical or industrial use, characterized by separating or keeping in communication the process of cylinder admission, operating as a conventional engine or as two or more independent twin-cylinder engines, depending on position of communication valves of the plenum chambers, controlled electronically by an electronic control system (13), according to a matrix which defines its position in relation to the imposed load and the speed of the motor.

Claim 2 An air intake system according to claim 1, characterized in that, in its application to four-cylinder engines, it consists of the following components, the geometric shape of which is to be adjusted to the available space in the engine compartment of the vehicle where the invention is applied:

- Four primary inlet tubes (3) connected at one end to each of the four engine cylinders and in the other two plenum chambers (1) and (2);

- Two plenum chambers (1) and (2) separated by one or more communication valves (9) and connected to the primary tubes (3) and the secondary air supply tubes (4);

- One or more communication valves (9) which isolate the two plenum chambers (1) and (2), driven by servo motors (10) electronically controlled by the electronic control system (13) or alternatively actuated by pneumatic actuators (10) electronically controlled by the electronic control system (13) via control solenoid valves;

- Two independently actuated load control valves (5,6) (7,8) electronically controlled by the electronic control system (13);

- Two secondary tubes (4) between the two plenum chambers and the air filter case (12);

An air filter housing (12) which receives air from the outside or a second air intake system through the inlet pipe (11);

An electronic control system (13) which receives information from the the engine speed sensor 14 and the load rating imposed on the engine 15 and which manages the positioning of the load control valves 5 and 6 and the communication valves 9 according to the invention. with a preprogrammed matrix.

Air intake system according to claim 2, characterized in that the primary tubes (3) are dimensionally the same as each other, having the same length and diameter, which must be adjusted to the type of engine where the invention is applied and its use.

Air intake system according to claims 1, 2 and 3, characterized in that the primary tubes (3) are curved or rectilinear in shape, wherein the ends of the primary tubes of each pair of cylinders connected to the plenum chambers (1) ) and (2) are positioned at the same distance from the air inlet in the plenum chamber.

Air intake system according to claim 2, characterized in that the plenum chambers (1) and (2) have an equal volume, which must be adjusted to the type of engine where the invention is applied and to its use.

Air intake system according to claim 2, characterized in that the communication valve (s) (9) in the closed position (s) is sufficiently leaktight so that there is no interference between the pressure in both chambers.

Air intake system according to claim 2, characterized in that the secondary pipes (4) are of equal length and diameter and can be rectilinear or curved depending on the system being installed in the space in the engine compartment.

A system according to claim 1, characterized in that it is applied to four-cylinder engines and to engines with an even number of cylinders greater than four, whatever the order of ignition used in the propulsion of vehicles.

The system according to claim 1, characterized in that it can be used in fully electric propulsion vehicles having internal combustion engines coupled to generators, in which the plenum chamber can be operated as a single volume or with separate volumes.

The system according to claim 1, characterized in that to allow more intake air into the engine due to the less destructive interference of the air intake process between the cylinders, reflecting an increase in torque.

Claim according to claim 1, characterized in that it has an electronic control system (13) which constantly evaluates the speed of rotation and the load imposed on the engine and which generates the positioning of the load control valves and the valves according to a pre-programmed matrix.

Claim 12 An electronic system (13) controlling the configuration of the variable geometry air intake system of internal combustion engines for the propulsion of motor vehicles described in the preceding claims, characterized in that depending on the speed of the engine and the load imposed to operate in three possible modes:

(a) 'mode', where the four cylinders are in

communicating via the opening of the communication valve (s) (9) and the engine load is controlled only by an engine load control valve (5), the second control valve (6) of the engine load;

b) 'mode 2', wherein the inlet of the four cylinders is separated through the closure of the communication valve (s) (9) and the engine load is controlled by the two engine load control valves (5). ) and (6); c) 'mode 3', where the four cylinders are in

communicating via the opening of the communication valve (s) (9), and the engine load is controlled by the two engine load control valves (5) and (6).

Claim according to claims 1, 8 and 11, characterized in that it is adapted to the conditions of use according to the following possibilities:

- dimensions of the main organs, translated in the form of the length and diameter of the primary tubes, the secondary tubes and the inlet tube (s), in the volume and shape of the plenum chambers and the chamber (s) of the air filter ;

- Number of plenum chambers;

- Number of secondary tubes;

- Number of inlet tubes;

- Preprogrammed matrix in the electronic control system (13) which defines the speed regimes of the motor in which it separates or maintains in communication the process of admitting pairs of engine cylinders through the plenum chambers, and the actuation of the charge control valve (s) (6);

- Pre-programmed matrix in the electronic control system (13) and defining the engine speed and / or load regimes in which the amount of maximum air entering the system varies;

- Possibilities of grouping of pairs of cylinders;

- Number, shape and type of actuation of the communication valves (9);

- Compatibility with fixed or variable geometry admission systems on the market.

The system according to claims 1, 8 and 13, characterized in that the motor can have two inlets (11) and two filter chambers (46, 47), with secondary inlets (49, 50, 51, 52) being that the eight cylinders (1,2,3,4,5,6,7,8) are grouped two by two considering a 360 ° lag in the order of ignition, and the plenum chambers (42,43,44,45 ) are separated by four communication valves (9), and the pairs of cylinders (5, 3), (1,6), (2,8) and (4,7) being in connection with the respective cams plenum (42,43,44,45).

The system according to claims 1, 8 and 13, characterized in that the engine is able to have an air inlet (11) and a filter chamber (33), with three secondary inlets (34), the six cylinders ( 1,2,3,4,5,6) are grouped two by two considering a 360 ° offset in the order of ignition, and the plenum chambers (30,31,32) are separated by two communication valves (9) , the pairs of cylinders (1,5), (4,3) and (2,6) being in connection with the respective plenum chambers (30,31,32).

Claim according to claims 14 and 15, characterized in that it has an electronic control system (13) controlling the eight-cylinder engine charge control valves (49,50,51,52), or the valves (35,36,37) of the six cylinder engine, and further controls all communication valves (9).