DE202016005696U1 - Inlet channel with variable geometry for an internal combustion engine - Google Patents

Abstract

A variable geometry inlet duct (10) for a spark-ignited internal combustion engine (1) having at least one cylinder (4) comprising a substantially tubular wall (10) having an inlet (19) and an outlet (20) for fluid flow at least one annular seat (14) for an intake valve (12) is associated with the outlet (20); the channel (10) having an axial section at the inlet (21), an axial section at the outlet (23) and a central axial section (22), the central axial section (22) being provided with a longitudinal separating wall (24) forming the channel ( 10) in a first and in a second, respectively upper and lower, passage (25, 26), wherein the first passage (25) is substantially aligned with the outlet opening (20) and the second passage (26) in the axial section on Outlet (23) of the channel (10) laterally into the first passage (25) opens, above the valve seat (14) and a lower wall (26 a) which is adapted to the flow which flows through the second passage (26) tangentially directed towards the exit port (20) which, in use, faces the central portion of the combustion chamber (6), and wherein the axial section at the entrance (21) of the passage (10) is equipped with a flow distributor element (30); which is suitable: - a first and e to assume a second operating position, in which the flow coming from the inlet opening (19) is directed at least predominantly in the direction of the first passage (25) and respectively in the direction of the second passage (26), and a plurality of operating positions between the first and second Taking position, each intermediate position is associated with a corresponding ratio between the flow rates of the rivers flowing through the first (25) and the second passage (26).

Description

The present invention relates to a variable geometry inlet duct for a spark-ignition internal combustion engine having at least one cylinder, the duct comprising a substantially tubular wall having an inlet and an outlet for fluid flow, the outlet having at least one annular seat for an intake valve assigned.

It is known that under some operating conditions of an internal combustion engine, such. For example, in low load, low speed operation, it is advantageous to increase turbulence inside the cylinders by means of devices that change the geometry of the intake ports, such as in FIG US 2014/0165960 A1 and US Pat. No. 6,915,774 B2 described.

The increase in turbulence results in faster and more stable combustion, which generally results in a significant reduction in fuel consumption.

The increase in turbulence is generally achieved through the use of devices that allow for an increase in the motion known in the literature and in the art as "tumble" movements; H. Macro-vortex created during the intake phase (when the intake valve (s) are open) about an axis substantially perpendicular to the cylinder axis.

In order to increase the extent of tumble motions, the fluid flow flowing out of the inlet channel must be directed to increase its tangential component of velocity with respect to an axis perpendicular to the cylinder axis.

Consequently, the increase in turbulence is always associated with a flow reduction of the effective passage section through the intake valves to increase said components of the tangential velocity. This leads to a reduction of the "permeability" of the inlet channel, i. H. the flow coefficient, which limits the maximum power of the motor.

An object of the present invention is to produce a variable geometry inlet duct which, in contrast to the solutions already proposed, can be operated at high engine speeds and high loads with a maximum flow factor equal to that provided with an inflow duct designed for Maximum performance was optimized would have been achieved. Under the terms high speed and high load are z. B. in a supercharger motor speeds of the engine of greater than 4000 rpm and loads with PME (effective mean pressure) of greater than 15 bar and to understand in a naturally aspirated engine of greater than 8 bar.

worin

m_measured

der gemessene Durchfluss ist,

A_K

die oben genannte Bezugsfläche ist,

P₀₁

der Druck stromauf des Kanals ist,

R

die universelle Gaskonstante ist,

T₀₁

die Temperatur stromauf des Kanals ist,

k

das Verhältnis zwischen der spezifischen Wärme bei konstantem Druck und der spezifischen Wärme bei konstantem Volumen des Fluidflusses ist und

P₀₂

der Druck stromab des Kanals (Zylinderdruck) ist.

The flow coefficient can be determined in a flow bank with a predetermined upstream and downstream pressure difference ΔP and, for a predetermined valve lift, as the ratio between the measured flow and the flow calculated with an isentropic flow in a reference section at the same ΔP (reference section is generally the area of a circle that has the same diameter as the engine bore):

wherein

m _measured

the measured flow is,

A _K

the above reference surface is,

P ₀₁

the pressure upstream of the channel is

R

the universal gas constant is,

T ₀₁

the temperature is upstream of the channel,

k

the ratio between the specific heat at constant pressure and the specific heat at constant volume of the fluid flow is and

P ₀₂

the pressure is downstream of the duct (cylinder pressure).

Typically, a high flow _coefficient inlet channel may have an α _k value between 0.13 and 0.18.

• – eine erste und eine zweite Betriebsstellung einzunehmen, in der der von der Eingangsöffnung kommende Fluss zumindest überwiegend in Richtung des ersten Durchgangs und jeweils in Richtung des zweiten Durchgangs geleitet wird, und
• – eine Vielzahl von Betriebsstellungen zwischen der ersten und zweiten Stellung einzunehmen, wobei jeder Zwischenstellung ein entsprechendes Verhältnis zwischen den Durchflussmengen der Flüsse, die durch den ersten und den zweiten Durchgang fließen, zugeordnet ist.

The above object is achieved according to the invention by means of a variable geometry inlet duct as initially defined which comprises
an axial section at the entrance, an axial section at the exit and a central axial section,
the central axial section being provided with a longitudinal septum dividing the channel into first and second, respectively upper and lower passages; in which
the first passage is substantially aligned with the exit port and the second passage in the axial section at the exit of the passage opens laterally into the first passage, above the valve seat and has a bottom wall adapted to flow through the second passage; tangentially in the direction of the outlet opening, which in operation faces the central part of the combustion chamber of the associated cylinder, and wherein
the axial section at the entrance of the channel is equipped with a flow distributor element which is suitable in relation to the longitudinal separation wall:

• To assume a first and a second operating position, in which the flow coming from the inlet opening is directed at least predominantly in the direction of the first passage and respectively in the direction of the second passage, and
• To occupy a plurality of operating positions between the first and second positions, each intermediate position being associated with a corresponding ratio between the flow rates of the flows flowing through the first and second passages.

Further characteristics and advantages of the invention are disclosed in the following detailed description, which is of a purely exemplary, non-limiting nature and refers to the attached figures, wherein

1 Figure 4 is a partial cross-section of a spark-ignition internal combustion engine equipped with a variable geometry intake duct according to the present invention shown in a first operating condition; and

the 2 and 3 Similar views as those in 1 are shown and show the inlet channel in two other operating states.

In the figures is with 1 Altogether a combustion engine with spark ignition of the known type referred to, a cylinder block 2 includes, at the above a head 3 is attached.

With 4 is a cylinder of the engine referred to, in which, in a manner known per se, a piston or plunger 5 is movably mounted.

In the cylinder 4 , between the piston 5 and the head 3 is a combustion chamber that with 6 is designated formed.

In the head 3 are an inlet channel 10 and an exhaust duct 11 formed, which are suitable with the combustion chamber 6 via respective valves 12 and 13 to be contacted, their position relative to the respective associated valve seats 14 and 15 in a known manner via two camshafts 16 and 17 is monitored.

The inlet channel 10 includes a substantially tubular wall 18 with an entrance 19 and an exit 20 who is the seat 14 , the intake valve 12 is assigned corresponds.

The channel 10 has an axial section at the entrance 21 and an axial section at the exit 23 on, between which there is a central axial section 22 extends.

The middle axial section 22 of the intake channel 10 is with a fixed longitudinal septum 24 equipped the channel in a first and in a second, respectively upper and lower passage 25 and 26 divides.

The first passage 25 is substantially axially on the exit opening 20 of the intake channel 10 aligned.

The second passage 26 opens laterally into the first passage 25 , in the axial section at the exit 23 of the intake channel 10 , above the valve seat 14 ,

The second passage 26 also has a curved lower wall 26a on, which is suitable for the flow passing through this second passage 26 flows, towards the exit opening 20 that operate the central part of the combustion chamber 6 of the associated cylinder 4 (see for example 2 ), tangentially redirect.

The axial section at the entrance 21 of the canal 10 is instead with a flow distributor element 30 equipped in the embodiment shown with the lower end in 27 to the upper end of the longitudinal septum 24 is articulated.

• – eine erste und eine zweite Betriebsstellung einzunehmen (wie jeweils in den 1 und 2 gezeigt), in der der von der Eingangsöffnung 19 kommende Fluss zumindest überwiegend, und vorzugsweise vollständig, in Richtung des ersten Durchgangs und jeweils in Richtung des zweiten Durchgangs 26 geleitet wird, sowie
• – eine Vielzahl von Betriebsstellungen zwischen der ersten und zweiten Position einzunehmen (3), wobei jeder Zwischenstellung ein entsprechendes Verhältnis zwischen den Durchflussmengen der Flüsse, die durch den ersten und den zweiten Durchgang 25 und 26 fließen, zugeordnet ist.

The flow distributor element 30 is capable of facing the septum 24 and the wall 18 of the canal 10 :

• - to occupy a first and a second operating position (as in each case in the 1 and 2 shown), in which of the entrance opening 19 incoming flow at least predominantly, and preferably completely, in the direction of the first passage and in each case in the direction of the second passage 26 is directed as well
• To assume a plurality of operating positions between the first and second positions ( 3 ), each intermediate position being a corresponding ratio between the flow rates of the rivers passing through the first and second passages 25 and 26 flow, is assigned.

The operating position of the flow distributor element 30 can by means of a connected actuator device 40 , such as As a small electric motor, are controlled by an electronic control unit 50 is controlled, to which a plurality of electrical sensors S1, ..., SN are assigned, which are suitable, this control unit 50 Signals related to the operating conditions of the engine 1 point out to deliver.

In 1 is the flow distributor element 30 shown in the position with which the highest value of the flow coefficient is obtained (maximum permeability of the inlet channel 10 ).

If instead the flow distributor element 30 in the in 2 is arranged operating position, a shape of the inlet channel 10 obtained generating very strong tumble motions in the combustion chamber 6 allows, as the flow mainly in the tangential direction into the combustion chamber 6 entry. So it is possible the turbulence in the combustion chamber 6 to increase the combustion process and the fuel consumption of the engine 1 significantly lower without affecting the performance of this engine.

The system described above also allows the flow distributor element 30 in a variety of positions between in the 1 and 2 to be shown, for example, in the position according to 3 to the ratio between the flow rates of the rivers passing through the upper passage 25 and the lower passage 26 of the canal 10 flow, control.

By proper positioning of the flow distributor element 30 it is possible to control the turbulence in the combustion chamber 6 the needs of the engine 1 so that it is possible to achieve an optimal compromise between performance and fuel consumption at all operating points of the engine.

Without prejudice to the principles of the invention, it should be understood that the embodiments and details of the embodiment may be varied substantially from what has been described and shown by way of example, not limitation, without thereby falling within the scope of the invention as defined in the appended claims.

The inlet channel comprises a tubular wall ( 10 ), which has an entrance ( 19 ) and an output ( 20 ) for a fluid flow, wherein the output ( 20 ) at least one annular seat ( 14 ) for an intake valve ( 12 ) assigned.

The channel ( 10 ) has an axial section at the entrance ( 21 ), an axial section at the exit ( 23 ) and a central axial section ( 22 ) on.

The middle axial section ( 22 ) is with a longitudinal septum ( 24 ), which is the channel ( 10 ) in a first and in a second, respectively upper and lower, passage ( 25 . 26 ).

The first round ( 25 ) is essentially at the exit opening ( 20 ) and the second pass ( 26 ) flows in the axial section at the exit ( 23 ) of the channel ( 10 ) laterally into the first passage ( 25 ), above the valve seat ( 14 ) and has a bottom wall ( 26a ), which is suitable for the flow through the second passage ( 26 ) flows, tangentially in the direction of the exit opening ( 20 ) operating in the central part of the combustion chamber ( 6 ), redirect.

• – eine erste und eine zweite Betriebsstellung einzunehmen, in der der von der Eingangsöffnung (19) kommende Fluss in Richtung des ersten Durchgangs (25) und jeweils in Richtung des zweiten Durchgangs (26) geleitet wird, und
• – eine Vielzahl von Betriebsstellungen zwischen der ersten und zweiten Stellung einzunehmen, wobei jeder Zwischenstellung ein entsprechendes Verhältnis zwischen den Durchflussmengen der Flüsse, die durch den ersten (25) und den zweiten Durchgang (26) fließen, zugeordnet ist.

The axial section at the entrance ( 21 ) of the channel ( 10 ) is connected to a flow distributor element ( 30 ), which is suitable:

• - occupy a first and a second operating position, in which the one from the inlet opening ( 19 ) coming river in the direction of the first passage ( 25 ) and in each case in the direction of the second passage ( 26 ), and
• To assume a plurality of operating positions between the first and second positions, each intermediate position having a corresponding relationship between the flow rates of the flows passing through the first 25 ) and the second passage ( 26 ) flow, is assigned.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2014/0165960 A1 [0002]
• US 6915774 B2 [0002]

Claims (4)

Inlet channel with variable geometry ( 10 ) for a spark-ignition internal combustion engine ( 1 ) with at least one cylinder ( 4 ) comprising a substantially tubular wall ( 10 ), with an input ( 19 ) and an output ( 20 ) for a fluid flow, wherein the output ( 20 ) at least one annular seat ( 14 ) for an intake valve ( 12 ) assigned; where the channel ( 10 ) has an axial section at the entrance ( 21 ), an axial section at the exit ( 23 ) and a central axial section ( 22 ), wherein the middle axial section ( 22 ) with a longitudinal septum ( 24 ), which is the channel ( 10 ) in a first and in a second, respectively upper and lower, passage ( 25 . 26 ), the first passage ( 25 ) substantially onto the exit opening ( 20 ) and the second pass ( 26 ) in the axial section at the exit ( 23 ) of the channel ( 10 ) laterally into the first passage ( 25 ), above the valve seat ( 14 ) and a lower wall ( 26a ), which is adapted to the flow through the second passage ( 26 ) flows, tangentially in the direction of the exit opening ( 20 ) operating in the central part of the combustion chamber ( 6 ), and redirecting the axial section at the entrance ( 21 ) of the channel ( 10 ) with a flow distributor element ( 30 ), which is capable of: - assuming a first and a second operating position, in which the one from the inlet opening ( 19 ) incoming flow at least predominantly in the direction of the first passage ( 25 ) and in each case in the direction of the second passage ( 26 ), and - to take a plurality of operating positions between the first and second positions, each intermediate position having a corresponding ratio between the flow rates of the flows passing through the first ( 25 ) and the second passage ( 26 ) flow, is assigned. Inlet duct according to claim 1, wherein the flow distributor element ( 30 ) in a rotatable manner to the longitudinal septum ( 24 ) is articulated. Inlet duct according to one of the preceding claims, wherein the flow distributor element ( 30 ) an electrically controlled actuator ( 40 ), which is suitable to cause the movement between the above-mentioned operating positions. Inlet duct according to claim 3, wherein the actuator device ( 40 ) by an electronic control unit ( 50 ) is dependent on signals and data supplied by measuring devices (S1, ..., SN), which in operation the operating conditions of the internal combustion engine ( 1 ), the inlet channel ( 10 ) is assigned.

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