DE102024111935A1 - Intake manifold assembly for a four-stroke internal combustion engine - Google Patents

Abstract

An intake manifold assembly (3) for a four-stroke internal combustion engine (1) with at least one working cylinder (2) with inlet (4) and exhaust valves (5) is provided, comprising an intake manifold device (11) which has a throttle valve assembly (12) and an intake manifold section (13) having an intake manifold end section (14), which fluidly connects the throttle valve assembly (12) to an air filter assembly (17) arranged upstream of the throttle valve assembly (12), which is arranged upstream of the intake manifold end section (14) and has an air filter element (16) and an air filter support structure (18) receiving the air filter element (16), wherein the air filter support structure (18) is a housing body (19) at least partially surrounding an air filter chamber (21) receiving cleaned intake air, which has a mounting surface (23) and is arranged upstream of the intake manifold end section (14) and the housing body (19) is provided with at least one non-return valve (20) having an air inlet opening (37), which is designed to be opened by a negative pressure occurring in the suction pipe section (13) to allow intake air to pass into an interior space (29) of the casing body (19).

Description

The present invention relates to an intake manifold arrangement for a four-stroke internal combustion engine according to the preamble of claim 1. The invention further relates to a four-stroke internal combustion engine according to claim 16 and a motorcycle according to claim 18, as well as a method for reducing the throttling noise of a throttle valve according to claim 20 and a housing body according to claim 21.

An internal combustion engine typically has an intake manifold arrangement with which a fuel-air mixture, or in the case of an internal combustion engine operated with direct fuel injection, intake air or combustion air is supplied to be introduced into the combustion chamber of the working cylinder via the open intake valves.

The intake manifold assembly can have an intake manifold structure comprising several intake manifold segments. These segments can be straight or angled pipe sections of any cross-section and diameter, and can also be designed to accommodate a throttle body. Together, the intake manifold segments form the intake manifold, which can also house a throttle valve assembly.

The intake manifold assembly can therefore extend from the intake valve(s) of the internal combustion engine to an intake manifold end section located near an air filter assembly. The intake manifold end section can be an inlet located near the air filter assembly, so that purified combustion air is introduced into the intake manifold assembly via the intake manifold end section. In the case of an internal combustion engine with direct injection, this air is then supplied to the combustion chamber as pure intake air or combustion air, or, as the intake air flows towards the combustion chamber, it is enriched with fuel. This fuel enrichment can take place via a carburetor or a throttle valve assembly, through which the fuel is metered into the intake air stream, for example, via an injection nozzle. This can also be the case with the intake manifold assembly according to the invention and the four-stroke internal combustion engine and motorcycle equipped with it.

In the following, both combustion air and an air-fuel mixture are referred to as a fluid that moves in the direction of flow towards the intake valve(s).

Internal combustion engines are subject to noise restriction regulations, which must be met, for example, due to a set of rules.

The sound emission levels of a vehicle powered by an internal combustion engine are determined, among other things, by the volume of the combustion noise from the engine, which is dampened by the exhaust system. Structural noise also contributes to the vehicle's sound emission levels; examples include noise radiated from the clutch cover of the engine's clutch assembly and intake noise, which can occur, for instance, in the area of the throttle valve of the aforementioned throttle body assembly.

These intake noises can be reduced by using large-volume intake silencers in the intake area of the internal combustion engine, but these require a significant amount of space, which, for example, is not available in a motorcycle due to its design. Furthermore, intake noise reduction is often accompanied by an undesirable loss of power from the internal combustion engine, or by a reduction in the engine torque provided by the engine at different speeds.

Based on the printed publication originating from the applicant US 10,456,638 B2 An intake manifold arrangement for a four-stroke internal combustion engine has already been discovered which has proven successful, but still has room for improvement.

Based on this, the present invention aims to provide an intake manifold arrangement which, on the one hand, enables a reduction in the intake noise of the internal combustion engine equipped with it and, on the other hand, reduces a loss of power in the internal combustion engine and is also designed in such a way that it is suitable for use on a motorcycle despite the limited installation space available on the motorcycle.

Furthermore, an internal combustion engine equipped with the intake manifold arrangement is to be created, a motorcycle equipped with the internal combustion engine is to be provided, and also a method for reducing the throttling noise of a throttle valve.

The invention, in order to solve this problem with regard to the intake manifold arrangement, comprises the features of claim 1. Advantageous embodiments thereof are described in the further claims.

Furthermore, the invention has the features of claim 16 for solving the problem with regard to the internal combustion engine and the features of claim 18 for solving the problem with regard to the motorcycle.

The invention also provides a method for reducing the throttling noise of a throttle valve with the features of claim 20 and a housing body intended for use with the intake manifold assembly.

The invention provides an intake manifold arrangement for a four-stroke internal combustion engine with at least one working cylinder with inlet and outlet valves, comprising an intake manifold device which has a throttle valve arrangement and an intake manifold section having an intake manifold end section, which fluidly connects the throttle valve arrangement to an air filter device arranged upstream of the throttle valve arrangement, which is arranged upstream of the intake manifold end section and has an air filter element and an air filter support structure receiving the air filter element, wherein the air filter support structure is a housing body at least partially surrounding an air filter chamber receiving cleaned intake air, which has a mounting surface and is arranged upstream of the intake manifold end section and the housing body is provided with at least one check valve having an air inlet opening, which is designed to be opened by a negative pressure occurring in the intake manifold section to allow intake air to pass into an interior of the housing body.

The intake manifold assembly according to the invention is intended for use with a four-stroke internal combustion engine, which has at least one working cylinder and in which the gas exchange is effected by intake and exhaust valves. The intake manifold assembly according to the invention has an intake manifold device with a throttle valve assembly and an intake manifold section, which has an intake manifold end section that fluidly connects the throttle valve assembly to an air filter device arranged upstream of the throttle valve assembly for guiding intake air to the internal combustion engine.

The air filter assembly is arranged upstream of the throttle valve assembly and comprises an air filter element and an air filter support structure that accommodates the air filter element.

The air filter device has an air filter chamber with cleaned intake air, which is located downstream of the air filter element, and an air filter chamber with uncleaned intake air, which is located upstream of the air filter element.

The air filter support structure of the intake pipe arrangement according to the invention is a casing body that at least partially surrounds the air filter chamber which receives the cleaned intake air and has a mounting surface and is arranged upstream of the intake pipe end section.

The mounting surface allows the housing to be attached, for example, to a segment, area, or housing of the air filter assembly or intake manifold, within which the cleaned intake air filter chamber is located. This allows the housing to at least partially enclose the cleaned intake air filter chamber. An air filter element that cleans the intake air can therefore be positioned upstream of the housing.

The invention also includes a configuration in which the air filter element is arranged downstream of the casing body, so that intake air that has not yet been cleaned can pass through the casing body.

The casing has at least one check valve with an air inlet opening, which is designed to be opened by a negative pressure occurring in the intake manifold section, allowing intake air to pass into an interior of the casing. Thus, the negative pressure in the intake manifold section can open the check valve, allowing intake air, whether cleaned or uncleaned, to enter the interior of the casing.

In a configuration where the air filter element is located upstream of the housing, already cleaned intake air enters the interior of the housing, while in a configuration where the air filter element is located downstream of the housing, uncleaned intake air enters the interior of the housing.

The intake manifold arrangement according to the invention allows combustion air, which is required by the internal combustion engine, to be supplied to it. The internal combustion engine has at least one intake valve, so that in the following we refer to the intake valve, which also includes a configuration with more than one intake valve.

The intake air required for combustion is supplied through the intake manifold assembly by a vacuum wave that is created when the intake valve opens.

The intake air passes through the throttle valve assembly and exits past the throttle valve, resulting in high flow velocities in the area of the throttle valve's opening cross-section, which are accompanied by the development of strong throttle noise. This airborne noise can propagate towards the air filter assembly and is significantly reduced by the intake manifold assembly designed according to the invention.

It has been shown that the sound pressure generated by the intake noise of an internal combustion engine during a full-load curve, operated with a known intake manifold arrangement without a check valve and an exhaust system, is several decibels higher than the sound pressure of the identical internal combustion engine with the intake manifold arrangement according to the invention and an identical exhaust system.

Conversely, this means that the sound pressure level can be reduced by several decibels with the intake manifold arrangement according to the invention compared to a known intake manifold arrangement. This is accompanied by only a slight reduction in the maximum drive power of the internal combustion engine at full load. A comparable reduction in sound pressure level can only be achieved without the intake manifold arrangement according to the invention with a completely enclosed air filter housing, which, however, requires a volume that is not available in a motorcycle.

The vacuum wave created when the intake valve is open opens at least one check valve, allowing intake air to be directed towards the internal combustion engine, as a pressure difference forms at the check valve, which leads to the opening of the check valve.

When the intake valve of the internal combustion engine closes, the vacuum wave is reflected at the closed intake valve and travels back as a pressure wave towards the intake manifold end section, passing through it into the interior of the housing. The check valve is of the normally closed type and is configured to be closed in its initial state. This means that when the vacuum inside the housing decreases, and the pressure level acting on the check valve increases, the check valve is actuated to close, thus ending the opening movement of the check valve caused by the vacuum wave.

When the aforementioned pressure wave enters the interior of the housing, the check valve is actively actuated by the pressure wave, thus closing it. The sound waves entering the interior of the housing with the pressure wave are prevented from escaping into the environment via the check valve's air inlet opening by the closed check valve. This reduces the amount of airborne noise from the intake manifold assembly reaching the surrounding area and dampens the intake noise.

The casing thus prevents the sound waves from exiting the casing through the air inlet of the check valve. The sound waves are at least partially reflected back into the interior of the casing at the closed check valve.

According to a further development of the invention, the intake manifold device has a housing element that at least partially surrounds the air filter chamber, and the housing body is designed to be detachably connected to the housing element.

This configuration ensures that the housing body with the check valve and any air filter element arranged upstream on the housing body can be easily removed from the intake manifold assembly as a complete unit, for example for the purpose of cleaning the air filter element.

This configuration also eliminates the need for a flame screen, which is typically located downstream of the air filter element. In a conventional intake manifold arrangement, this flame screen is required to prevent a flame front from flowing back from the internal combustion engine through the intake manifold towards the air filter element – a phenomenon commonly referred to as backfire. In such a backfire, the flame front, having passed through the end section of the intake manifold, encounters the housing, which is closed and also contains a closed check valve. This prevents the flame front from passing through the housing towards the air filter element, which is typically coated with filter oil.

This reduces the installation space required in the airspace area with purified intake air, i.e., the cleanroom area, because fewer components, such as the flame screen, are needed, and the mass of the components required in the cleanroom area is also reduced, thus reducing the overall mass of the intake pipe assembly.

According to a further development of the invention, the casing body has a circumferential bottom edge designed as a mounting surface with surface elements extending from the plane of the bottom edge, which are arranged converging towards each other and form a closed dome-shaped configuration, wherein at least one surface element has a recess for receiving the check valve.

The surrounding base edge, designed as a mounting surface, allows the housing body to be detachably attached, for example, to a housing component or a component of the intake manifold assembly that at least partially encloses the cleanroom. Surface elements extend from the base edge of the housing body, converging to form a closed, dome-shaped configuration. This dome-shaped configuration of the outer contour of the housing body simultaneously creates a receiving surface for an air filter element, such as a foam element, thus eliminating the need for a support structure for the air filter element, which is required in a conventional intake manifold assembly.

The casing body thus ensures functional integration, namely the function of the flame screen and the function of the support body, by eliminating the need for both the flame screen and the support body, so that the intake manifold assembly according to the invention has fewer components than the known intake manifold assembly and the overall mass of the intake manifold assembly can also be reduced as a result.

At least one surface element of the casing has a recess for receiving the check valve, so that the check valve can be detachably integrated into the casing, for example, and together with the casing forms a one-piece assembly for easy mounting on the motorcycle.

According to a further development of the invention, it is also provided that the casing body has a cover surface which is arranged largely opposite the mounting surface and has a recess for receiving the check valve.

This configuration creates a housing body that, for example, has the aforementioned surface elements and can also have a top surface that does not extend from the surrounding base edge, but is located on the outer circumference of the housing body, largely opposite the base edge or mounting surface, and has a recess for receiving the check valve. In this configuration as well, the housing body and check valve can be formed as a single unit for easy mounting on the motorcycle.

According to a further development of the invention, it is also provided that the check valve has at least one diaphragm valve with a diaphragm holder having at least one contact surface and at least one diaphragm tongue which can be detachably fixed to the diaphragm holder, in particular which rests against the contact surface in the blocking state and releases a flowable area between the contact surface and the diaphragm tongue in the non-blocking state.

Due to the arrangement of the check valve upstream of the throttle valve assembly on the housing, the diaphragm valve experiences low thermal and mechanical stress, resulting in a long service life.

The remote positioning of the diaphragm valve from the engine also reduces pressure peaks occurring in the intake manifold assembly. This is achieved by the large volume of the intake manifold assembly, from the intake valve of the working cylinder to the check valve. This large volume acts as a calming volume, thus reducing the stress on the diaphragm valve(s) by lowering the pressure peak magnitude. This, in turn, extends the service life of the check valve.

During the intake stroke of the internal combustion engine, a vacuum is created in the intake manifold. This vacuum causes the reed valve to lift away from the mating surface, opening a flow-through area between the mating surface and the reed valve. The reed valve can be pre-tensioned towards the mating surface, causing it to close relative to the mating surface as soon as the intake manifold vacuum drops below a predetermined threshold. This prevents any subsequent backflow in the intake manifold, which can be triggered, for example, by the closing of the intake valves, from causing the fuel carried along with the backflow to flow upstream of the reed valve. The air filter element can be accessed from the body. On a motorcycle, such as an off-road motorcycle, the air filter element is often designed as a foam air filter that is coated with filter oil.

When the internal combustion engine is started in a cold operating state, a cold-start enrichment is typically used, meaning the engine is operated with a fuel-air mixture containing excess fuel when cold. This is also referred to as a rich fuel-air mixture, which, in a non-inventive intake manifold arrangement, can flow back into the area of the air filter element and cause contamination there. This creates the risk that the foam air filter will become saturated with fuel and its filtering efficiency will decrease.

This problem is also solved by the intake manifold arrangement according to the invention, since the rich fuel-air mixture can no longer spread into the foam air filter located in the area upstream of the casing.

According to a further development of the invention, it is also provided that the membrane holder has a wedge-shaped configuration and has two contact surfaces and two membrane tongues which, in the blocking state, rest against the contact surfaces and, in the non-blocking state, release a respective flowable area between the contact surface and the membrane tongue.

Compared to a check valve with only one diaphragm holder, this configuration allows for a symmetrical configuration of the diaphragm holder and thus a stiffer configuration of the diaphragm holder, since the two diaphragm tongues can be positioned opposite each other on a wedge-shaped retaining body of the diaphragm holder and the retaining body can have a support surface in the area of the middle of the two contact surfaces, which leads to the aforementioned stiffer configuration of the diaphragm holder.

According to a further development of the invention, it is also provided that the check valve has two diaphragm holders, each with two diaphragm tongues.

Such a configuration allows the air inlet opening of the check valve to be enlarged, resulting in a compact design and easy insertion into the housing body during assembly of the assembly consisting of the housing body with check valve.

As mentioned above, it is advantageous if the check valve has two diaphragm holders, each with two diaphragm reeds, because this allows for a high total flow area of the diaphragm reeds and still enables a high flow velocity in the intake manifold assembly at low engine speeds, thereby increasing the output torque of the internal combustion engine in this operating range.

According to a further development of the invention, the diaphragm tongue has a largely flat configuration in the closed state. The diaphragm tongue can be configured to bear against the contact surface with preload, thus creating a normally closed check valve whose diaphragm tongue only opens at a predetermined threshold of the vacuum level inside the housing body, thereby creating defined suction conditions such that the diaphragm valve reliably comes into contact with the contact surface and is thus closed when the pressure inside the housing body increases.

The vacuum wave created when the intake valves open generates a pressure differential across the reed valve (or reeds). When the intake valve closes, a pressure wave travels through the intake manifold to the interior of the valve body. This pressure wave then acts upon the reed valve, exerting an additional closing force. This ensures that the reed valve comes into contact with the sealing surface and creates a tight seal. This effect leads to improved cylinder filling with fluid, as it reduces the backflow of the fuel-air mixture into the intake manifold. Furthermore, it reduces noise levels and pressure, since the pressure wave is significantly dampened by the closing reed valve.

When the flow opening formed between the membrane tongue and the contact surface closes, the membrane tongue strikes the contact surface; the closing impulse when the membrane tongue hits the contact surface can be reduced by an impact-damping coating provided on the contact surface according to a further development of the invention, which is in particular provided with a polyurethane material.

According to a further development of the invention, the check valve is provided to be largely oriented in the direction of the flow-through area. The fluid flow is arranged on the casing body in the direction of the suction pipe end section.

The flowable area is formed between the contact surface and the diaphragm tongue. When the diaphragm tongue is lifted from the contact surface, a flowable area is created between the diaphragm tongue and the contact surface, through which intake air can enter the interior of the housing. The intake air then flows towards the intake manifold end section of the intake manifold assembly. A fluid flow is thus established between the flowable area and the intake manifold end section. This fluid flow can be laminar, and the arrangement of the check valve relative to the housing is selected according to the invention such that the fluid flow between the flowable area and the intake manifold end section proceeds at least largely without deflections, thus preventing disturbances to the laminar fluid flow.

The arrangement of the check valve(s) relative to the housing is thus selected such that the central axis between the air inlet opening of the check valve and the flow-through area is aligned towards the center of the housing's interior. In a preferred embodiment of the intake manifold arrangement with more than one check valve according to the invention, the center of the housing's interior is located opposite the intake manifold end section, resulting in a funnel-shaped bundling of the fluid flows through the respective flow-through areas between the flow-through areas and the intake manifold end section. This allows for an improvement in the cylinder filling efficiency and the achievement of high specific power output from the internal combustion engine.

According to a further development of the invention, the check valve is also designed as a component that can be detached from the housing body. This means that if a diaphragm tongue of the check valve is damaged, the damaged check valve can be easily replaced.

According to a further development of the invention, it is also provided that the ratio of the area of the air inlet opening of the check valve to the surface of the casing body has a value in the range of 0.0375 to 0.375, in particular a value in the range of 0.075.

The value mentioned in particular enables a significant reduction in intake noise and at the same time a high power output from the internal combustion engine, and therefore counteracts a significant loss of power that usually occurs with closed small-volume air filter systems compared to an open air filter system.

According to a further development of the invention, it is also provided that the check valve has at least one diaphragm valve which is arranged on a surface element or a cover surface of the casing body, wherein the diaphragm tongue of the check valve is located at least largely in the plane of the surface element or the cover surface in the blocking state.

With this configuration, the membrane tongue is integrated into the plane of the surface element or cover surface and, in the closed state, lies at least largely within this plane. When the internal combustion engine is located in the intake manifold, a negative pressure wave is created in the intake manifold assembly. This wave causes the membrane tongue to move slightly out of the plane of the surface element or cover surface, opening a flow-through area. A gap then opens between the membrane tongue and the stop or contact surface surrounding it in the closed state, allowing intake air to flow through the outer contour of the housing towards the interior of the housing. This configuration therefore represents a surface membrane integrated into the surface element or cover surface.

In this configuration, the diaphragm tongue can be arranged on a diaphragm holder similarly to the aforementioned configuration of the check valve with a wedge-shaped configuration of the diaphragm holder, such that the diaphragm tongue is fixed at an axial end region on the diaphragm holder, for example by means of a screw connection, and the end region of the diaphragm tongue opposite the axial end region can detach from the contact surface in order to open the flowable area or the flowable gap for the passage of intake air.

According to a further development of the invention, it is also provided that the check valve equipped with a surface membrane has a contact surface with a shock-absorbing coating, which is in particular provided with a polyurethane material.

This configuration has the same advantages as those already explained above in connection with the check valve with a wedge-shaped diaphragm holder.

According to a further development of the invention, it is also provided that the air filter element is designed as a foam element, which is arranged upstream or downstream of the casing body.

The foam element can therefore be provided in the direction of flow of the intake air on the outer circumferential area or on the inner circumferential area of the casing body, i.e., in the case of an arrangement of the foam element upstream of the casing body, it can be arranged on the outer circumferential area of the casing body and in the case of an arrangement downstream of the casing body, on the inner circumferential area of the casing body.

The arrangement of the foam element upstream of the casing body has the advantage that already purified intake air passes through the check valve(s) of the suction pipe arrangement according to the invention.

The arrangement of the foam air filter downstream of the casing has the advantage that the casing can be designed with a larger total outer surface area, which can be particularly advantageous in a configuration with surface membranes, as this increases the flowable area of the flowable region of the respective check valve.

The invention also provides a four-stroke internal combustion engine with at least one working cylinder with inlet and outlet valves and an intake manifold arrangement as described above.

The internal combustion engine according to the invention has the advantage that the intake manifold arrangement significantly reduces the intake noise of the engine in operation compared to an engine without the intake manifold arrangement according to the invention. For example, it has been shown that this makes it possible to meet the noise regulations required in the homologation test cycle for off-road motorcycles without having to expect significant power losses from the engine, as was previously the case. Until now, the noise regulations could only be met by making considerable reductions in the cross-sectional area of the intake tract, which led to significant power losses compared to an engine that could be operated without cross-sectional reductions in the intake tract.

The intake manifold arrangement according to the invention and the four-stroke internal combustion engine operated with it solve this problem, since on the one hand the noise regulations can be complied with and on the other hand only slight losses in performance with regard to the peak power of the internal combustion engine operated with it occur.

In a further development of the internal combustion engine according to the invention, the throttle valve arrangement comprises at least one throttle valve and at least one fuel injection device, and the device introduces the fuel into an area between the throttle valve and the intake valve. This ensures that the fuel is introduced downstream of the throttle valve, thus reducing the backflow of fuel towards the check valve.

The invention also provides a motorcycle with a rider's saddle and a front wheel, as well as a rear wheel and an internal combustion engine driven by an internal combustion engine, as described above. The check valve in the intake manifold assembly of the motorcycle according to the invention is thus provided upstream of the throttle valve assembly and upstream of the intake manifold end section, and the internal combustion engine for driving the motorcycle is a four-stroke internal combustion engine.

According to a further development of the motorcycle according to the invention, it is also provided that the throttle valve arrangement has at least one throttle valve and at least one device for injecting fuel, and that the device introduces the fuel into an area between the throttle valve and the intake valve.

The invention also provides a method for reducing the throttling noise of a throttle valve coupled to an intake manifold assembly, the intake manifold assembly having a fluid flow direction in a passage direction of the throttle valve and an intake manifold end section spaced apart from the throttle valve, wherein the throttling noise is dampened by means of an air filter device comprising an air filter element and an air filter support structure accommodating the air filter element, wherein the air filter support structure is a housing body at least partially surrounding an air filter chamber accommodating cleaned intake air, which has a mounting surface and is arranged upstream of the intake manifold end section, and the housing body is equipped with at least one check valve having an air inlet opening. It can be seen that it is designed to allow intake air to pass into an interior of the casing by means of a negative pressure occurring in the intake manifold section.

This method enables the reduction of the throttle valve noise and also an overall reduction of the intake port noise, which was explained above.

Finally, the invention also provides a casing body for use in a suction pipe arrangement as described above, wherein the casing body has a circumferential bottom edge with surface elements extending out of the plane of the bottom edge, which are arranged converging towards each other and form a closed dome-shaped configuration, wherein at least one surface element has a recess for receiving a check valve.

According to a further development of the invention, the casing body has a cover surface which is arranged largely opposite the surrounding bottom edge and has a recess for receiving the check valve.

• 1 eine teilweise geschnittene schematische Ansicht einer Viertaktbrennkraftmaschine mit einem Arbeitszylinder und einer Saugrohranordnung nach einer Ausführungsform gemäß der vorliegenden Erfindung;
• 2 eine Explosionsdarstellung von Bauteilen einer Ausführungsform einer erfindungsgemäßen Saugrohranordnung;
• 3 eine Ansicht auf die Unterseite eines Hüllkörpers gemäß einer Ausführungsform der vorliegenden Erfindung;
• 4 eine Explosionsdarstellung eines Rückschlagventils;
• 5 eine perspektivische Darstellung von zwei Rückschlagventilen;
• 6 eine perspektivische Darstellung eines Hüllkörpers mit Flächenmembranen in einer Ansicht auf die Außenseite des Hüllkörpers;
• 7 eine perspektivische Darstellung eines Hüllkörpers mit Flächenmembranen in einer Ansicht auf die Innenseite des Hüllkörpers;
• 8 eine perspektivische Darstellung eines Hüllkörpers mit Flächenmembranen in einer modifizierten Ausführungsform;
• 9 eine teilweise geschnittene Seitenansicht eines Motorrads mit einer Brennkraftmaschine mit einer Saugrohranordnung einer Ausführungsform gemäß der Erfindung und eine Detailansicht dazu; und
• 10 ein Diagramm der Leistung und des Abtriebsmoments einer Viertaktbrennkraftmaschine mit einer Saugrohranordnung nach der Erfindung im Vergleich zu einer Viertaktbrennkraftmaschine ohne die erfindungsgemäße Saugrohranordnung.

The invention will be explained in more detail below with reference to the drawing. This shows:

• 1 a partially cutaway schematic view of a four-stroke internal combustion engine with a working cylinder and an intake manifold arrangement according to an embodiment according to the present invention;
• 2 an exploded view of components of an embodiment of an intake manifold arrangement according to the invention;
• 3 a view of the underside of a casing body according to an embodiment of the present invention;
• 4 an exploded view of a check valve;
• 5 a perspective view of two check valves;
• 6 a perspective view of an envelope with surface membranes in a view of the outside of the envelope;
• 7 a perspective view of an envelope with surface membranes in a view of the inside of the envelope;
• 8 a perspective view of a shell body with surface membranes in a modified embodiment;
• 9 a partially cutaway side view of a motorcycle with an internal combustion engine with an intake manifold arrangement of an embodiment according to the invention and a detailed view thereof; and
• 10 a diagram of the power and output torque of a four-stroke internal combustion engine with an intake manifold arrangement according to the invention compared to a four-stroke internal combustion engine without the intake manifold arrangement according to the invention.

1 The drawing shows a partially cut-away schematic view of a four-stroke internal combustion engine 1 with a working cylinder 2 and an intake manifold arrangement 3 according to an embodiment according to the present invention.

As can be readily seen, the internal combustion engine has 1 inlet valves 4 and 1 outlet valve 5, with two inlet valves 4 and two outlet valves 5 being provided, of which only one valve is visible in each case due to the chosen representation.

The valves 4, 5 are actuated to open via a camshaft 7 and a valve train 8 arranged in the cylinder head 6 of the internal combustion engine 1, in order to carry out the gas exchange in the working cylinder 2 of the internal combustion engine 1 when the valves are open.

The camshaft 7 is actuated to rotate via a timing chain (not shown in detail), and the internal combustion engine 1 also has a starter motor 9 and a gearshift transmission 10.

The intake manifold assembly 3 comprises an intake manifold device 11, which includes a throttle valve assembly 12 with a throttle valve 50 and an intake manifold section 13, which has an intake manifold end section 14. The intake manifold section 13 and the intake manifold end section 14 are formed in one piece and can be made of an elastic material, preferably a rubber or plastic material.

Arrow 15 indicates the direction of flow of intake air or combustion air when the internal combustion engine 1 is in the intake stroke, i.e., when the intake valves 4 are open.

The air flows over a structure that is further detailed by... 2 The air filter element 16 shown, which may be a foam filter, is wetted with filter oil to improve the filtering effect of the foam element and from there towards the internal combustion engine 1.

The air filter assembly 17, which includes the air filter element 16, comprises, in addition to the air filter element 16, an air filter support structure 18, which in the illustrated embodiment is a housing body 19, for example in 1 and 2 as shown in the drawing.

The air filter element 16, which is located in the housing 19, can be attached to the casing 19. 2 as shown in the drawing.

The casing 19 thus simultaneously fulfills a supporting function for the air filter element 16.

Once the intake air or combustion air has passed through the air filter element 16, it can be filtered through a 2 The check valve 20 shown in the drawing enters a cleaned intake air intake air filter chamber 21 and then moves via the intake pipe end section 14 in the direction of the flow direction 15 to the inlet valves 4.

The casing 19 at least partially surrounds the air filter chamber 21, which receives the cleaned intake air, as can be seen from 1 and 2 as can be seen in the drawing and can be detachably fixed at a section 22, for example a housing section 22 or housing element 22 formed in one piece with the intake pipe end section 14.

1 and 2 The drawing shows that the casing 19 is provided with four check valves 20, which are described in more detail below. 5 as can be seen in the drawing.

The more detailed information based on 3 The housing body 19 shown in the drawing has a mounting surface 23, which is formed by a circumferential base edge 24 that is complementary in shape and surface to the housing element 22, as can be seen from the following: 2 as can be seen in the drawing.

2 The drawing further shows that the casing 19 has two recesses 26 on a cover surface 25, into which the check valves 20 can be inserted, as can be seen from the 2 as can be seen in the drawing, and are spanned by a cover frame 27, which can be detachably fixed to the housing body 19 by means of screws 28. The configuration thus formed is then further spanned by the air filter element 16.

Although in 2 In a modified embodiment, if the air filter element 16 is shown upstream of the housing body 19 in the direction of the flow direction 15, it is also possible for the air filter element 16 to be located downstream of the housing body 19 in the direction of the flow direction of the arrow 15, i.e. closer to the air filter chamber 21, so that uncleaned intake air enters the interior 29 of the housing body 19 through the check valves 20, which then passes through the filter element 16 to enter the air filter chamber 21 which receives the cleaned intake air.

3 The drawing shows a view of the interior 29 of the casing 19 with the four check valves 20 extending towards the interior 29.

2 and also 3 show that surface elements 30 extend from the circumferential base edge 24 of the casing body 19, converging towards each other and forming a closed dome-shaped configuration, wherein the casing body 19 in the illustrated embodiment has a cover surface 31 which has the aforementioned recesses 26 into which the check valves 20 can be inserted, as shown by 2 as can be seen in the drawing.

This can be illustrated, for example, by... 5 The check valve 20 shown in the drawing has a diaphragm valve 32 with a wedge-shaped diaphragm holder 33 and a further description by means of 4 The mounting surface 34 shown in the drawing, to which the membrane tongue 35 can be detachably fixed, which in the locking configuration, as shown in 5 as shown in the drawing, it rests on the contact surface 34 and, in the non-blocking state, releases a flowable area 36 formed between the contact surface 34 and the membrane tongue 35.

The check valve 20 has an air inlet opening 37 through which air can enter the check valve 20 to flow through the open flowable area 36 in the open state of the check valve 20 in order to flow towards the air filter chamber 21, as already mentioned above.

At the in 4 In the embodiment of the check valve 20 shown in the drawing, it has two wedge-shaped diaphragm holders 33, each with two contact surfaces 34 against which diaphragm tongues 35, of which the check valve 20 has four, come into contact when closed. The diaphragm holder 33 and the diaphragm tongues 35, which can be brought into contact with the respective contact surface 34, form a diaphragm valve 32. As shown in the drawing, the contact surfaces 34 can be used to adjust the valve. 4 The drawing schematically shows a coating bead 51, and each has an impact-damping coating 38 made of a polyurethane material arranged. where the respective membrane tongue 35 comes into contact with the contact surface 34. An impact-damping coating 38 can also be provided on the membrane tongue 35 instead of the impact-damping coating 38 on the contact surface 34, as shown in 4 is stylized with a coating bead 51.

When the diaphragm valve 32 or check valve 20 is opened by the aforementioned vacuum wave and the intake vacuum, the diaphragm tongue 35 is opened from the contact surface to form the flowable area 36. The diaphragm tongue thus lifts away from the contact surface 34 and the coating 38 to open the flowable area 36. The intake air can then flow through the flowable area 36, as has already been mentioned several times above. When the intake valves 4 of the internal combustion engine 1 are closed, the check valves 20 are closed, the diaphragm tongues 35 come into contact with the respective contact surface 34 on the impact-damping coating 38, and the backflowing overpressure wave towards the check valves is prevented from exiting the interior 29 of the housing 19 because the check valves 20 are closed, thus damping the intake noise.

4 and also 5 show that the membrane tongue 35 has a largely flat configuration in the locking state, with the membrane tongues 35 being able to rest on the contact surface 34 with preload, as already mentioned, to assist the closing movement of the membrane tongues 35.

1 The drawing shows that the check valves 20 are arranged largely in the direction of the fluid flow from the flowable area 36 towards the suction pipe end section 14 on the casing body 19.

The check valves 20 can be controlled via the following: 2 The screws 28 shown in the drawing are detachably fixed to the casing 19, which conversely means that the check valves 20 are designed as assemblies that can be detachably separated from the casing 19.

6 The drawing shows a modified embodiment of the check valve 20. In this embodiment, the check valve has a diaphragm valve 32 in the form of a surface diaphragm 39, the diaphragm tongue 40 of which, in the blocking state, is arranged at least largely in the plane of the respective surface element 30 of the housing body 19.

7 shows a view from below of the interior 29 of the shell body 19 with the surrounding bottom edge 24 and a plurality of surface membranes 39, which have already been mentioned above.

The surface membranes 39 also lie with the membrane tongues 40 in the blocking state on corresponding contact surfaces 34, which each have an impact-damping coating, which is provided in particular with a polyurethane material.

8 The drawing shows a further modified embodiment of a casing body 19 with check valves 20, which are arranged in lateral surface elements 30 of the casing body 19 and each have an air inlet opening through which, when the check valve 20 is open, intake air or combustion air can flow in the direction of the air filter chamber 21.

9 The drawing shows a side view of a motorcycle 41, which has a four-stroke internal combustion engine 1, as described above, and also a front wheel 42, a rear wheel 43, a rider's seat 44, and handlebars 45. The internal combustion engine 1 is equipped with the intake manifold assembly 3 according to the invention, as can be seen from the detailed view of the internal combustion engine 1. The housing 19 has four check valves through which intake air can flow towards the air filter chamber 21 and from there further in the direction of arrow 15 to the throttle valve assembly 12.

10 The drawing shows a diagram of the power and output torque of the four-stroke internal combustion engine 1 with an intake manifold arrangement 3 according to the invention in comparison to a four-stroke internal combustion engine without the intake manifold arrangement according to the invention.

Curve 46 shows the drive power of the internal combustion engine without the intake manifold arrangement according to the invention, and curve 47 shows the drive power of the internal combustion engine with the intake manifold arrangement according to the invention, plotted against engine speed. As is readily apparent, the drive power 47 is only slightly lower than the drive power 46, while curve 48 shows the drive power of the internal combustion engine with another known intake manifold arrangement, which is significantly lower than the drive power shown in curve 47. The lower curve 46A shows the torque curve of the internal combustion engine without the intake manifold arrangement according to the invention, while curve 47A shows the torque curve of the internal combustion engine with the intake manifold arrangement according to the invention. The intake manifold arrangement is shown, and the curve shown for comparison 48A shows the course of the torque of the internal combustion engine with the other known intake manifold arrangement.

The respective curves show full-load curves of the identical internal combustion engine, wherein the noise level of the intake manifold noise measured during the recording of curve 47 is up to 5 dB below the noise level of the intake manifold noise measured during the recording of curve 46, and thus the intake manifold arrangement according to the invention enables a significant reduction of the intake manifold noise without significantly reducing the drive power provided by the internal combustion engine.

The intake manifold arrangement according to the invention enables a significant reduction in the intake noise of the internal combustion engine. The intake air required for combustion is drawn in through the air filter assembly by a vacuum wave generated when the intake valves open. The intake manifold arrangement according to the invention is characterized by an air filter support structure comprising a housing designed to accommodate at least one check valve and simultaneously serving as a support for an air filter element, for example, a foam air filter.

During the intake process when the intake valves open, a pressure difference arises at the check valve(s), which can be designed as a diaphragm valve with a tongue diaphragm or as diaphragm valves with tongue diaphragms or as diaphragm valves with flat diaphragms, between the ambient pressure and the pressure in the intake manifold assembly. This allows air from the environment to flow through the diaphragm valve, which is opened due to the pressure difference, towards the interior of the housing. From there, it flows through an intake manifold section towards the throttle body with the throttle valve and finally enters the combustion chamber of the internal combustion engine via the intake valves.

When the intake valves close, overpressure builds up in the intake manifold, and a pressure wave travels towards the check valves. The diaphragm reeds of the check valves can be pre-tensioned relative to the valve mating surfaces, so that the closing movement of the diaphragm reeds begins as soon as the vacuum inside the housing decreases. When the diaphragm reeds contact the valve mating surfaces, the pressure wave is prevented from escaping the interior of the housing towards the environment. The airborne noise carried by the pressure wave is therefore also prevented from escaping the interior of the housing, thus effectively dampening and reducing the intake noise of the internal combustion engine.

The housing simultaneously serves as a carrier for an air filter element, allowing the housing and air filter element to be easily replaced, for example, for cleaning purposes. This is a significant advantage when using the intake manifold arrangement according to the invention on an off-road motorcycle or mountain bike. At the same time, the configuration according to the invention eliminates the need for a flame screen typically found downstream of the air filter element, as explained in detail above.

The diaphragm reeds of the check valves according to the invention can be manufactured using a glass fiber reinforced plastic material, and additionally, the respective edge region of the diaphragm reeds, which comes into contact with the contact surface of the check valve, can be provided with a shock-absorbing coating. The configuration of the diaphragm reeds can thus have such a shock-absorbing coating, for example in the form of a polyurethane coating, via which the diaphragm reeds come into contact with the contact surface of the respective check valve body.

It was mentioned above that such a shock-absorbing coating can be provided on the contact surface of the check valve body, i.e., for example, the diaphragm holder.

Instead of providing a shock-absorbing coating on the contact surface of the check valve body, a shock-absorbing effect can also be provided on the respective diaphragm tongue, specifically on an area of the diaphragm tongue that comes into contact with the contact surface of the check valve body.

It is also possible to provide a shock-absorbing coating on both the contact surface of the check valve body and on the diaphragm tongue.

With regard to features of the invention not explained in detail above, explicit reference is made to the patent claims and the drawing.

List of reference symbols

1

four-stroke internal combustion engine

2

Working cylinder

3

Intake manifold assembly

4

Intake valves

5

exhaust valves

6

cylinder head

7

camshaft

8

Valve train

9

Starter motor

10

Gearbox

11

Intake pipe device

12

Throttle valve arrangement

13

Intake manifold section

14

Intake manifold end section

15

Flow direction

16

air filter element

17

Air filter system

18

Air filter support structure

19

Enclosing body

20

check valve

21

Air filter compartment

22

Housing element

23

Mounting surface

24

surrounding ground edge

25

Cover surface

26

Exclusion

27

Cover frame

28

screw

29

Interior

30

Surface element

31

Cover surface

32

Diaphragm valve

33

Membrane holder

34

Site area

35

Membrane tongue

36

Flowable area

37

air inlet

38

Coating

39

Surface membrane

40

Membrane tongue

41

motorcycle

42

front wheel

43

rear wheel

44

Driver's seat

45

handlebar

46

Curve

47

Curve

48

Curve

46A

Curve

47A

Curve

48A

Curve

50

throttle

51

Coating bead

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• US 10,456,638 B2 [0009]

Claims (22)

Intake manifold assembly (3) for a four-stroke internal combustion engine (1) with at least one working cylinder (2) with inlet (4) and outlet valves (5), with an intake manifold device (11) which has a throttle valve assembly (12) and an intake manifold section (13) having an intake manifold end section (14), which fluidly connects the throttle valve assembly (12) to an air filter assembly (17) arranged upstream of the throttle valve assembly (12), which is arranged upstream of the intake manifold end section (14) and has an air filter element (16) and an air filter support structure (18) receiving the air filter element (16), characterized in that the air filter support structure (18) is a housing body (19) at least partially surrounding an air filter chamber (21) receiving cleaned intake air, which has a mounting surface (23) and is arranged upstream of the intake manifold end section (14) and the housing body (19) is provided with at least one check valve (20) having an air inlet opening (37), which is designed to be opened by a negative pressure occurring in the suction pipe section (13) to allow intake air to pass into an interior space (29) of the casing body (19). Intake manifold arrangement (3) according to Claim 1 , characterized in that the intake manifold device (11) has a housing element (22) that at least partially surrounds the air filter chamber (21) and the casing (19) is designed to be detachably connected to the housing element (22). Intake manifold arrangement (3) according to Claim 1 or 2 , characterized in that the casing body (19) has a circumferential bottom edge (24) designed as a mounting surface (23) with surface elements (30) extending out of the plane of the bottom edge (24), which are arranged converging towards each other and form a closed dome-shaped configuration, wherein at least one surface element (30) has a recess (26) for receiving the check valve (20). Suction pipe arrangement (3) according to one of the preceding claims, characterized in that the casing body (19) has a cover surface (25) which is arranged largely opposite the mounting surface (23) and has a recess (26) for receiving the check valve (20). Suction pipe arrangement (3) according to one of the preceding claims, characterized in that the check valve (20) has at least one diaphragm valve (32) with a diaphragm holder (33) having at least one contact surface (34) and at least one diaphragm tongue (35) which can be detachably fixed to the diaphragm holder (33), in particular which rests against the contact surface (34) in the blocking state and in the non-blocking state releases a flowable area (36) between contact surface (34) and diaphragm tongue (35). Intake manifold arrangement (3) according to Claim 5 , characterized in that the membrane holder (33) has a wedge-shaped configuration and two contact surfaces (34) and two membrane tongues (35) which, in the blocking state, bear against the contact surfaces (34) and, in the non-blocking state, release a respective flowable area (36) between contact surface (34) and membrane tongue (35). Intake manifold arrangement (3) according to Claim 6 , characterized in that the check valve (20) has two diaphragm holders (33) each with two diaphragm tongues (35). Intake manifold arrangement (3) according to one of the Claims 5 until 7 , characterized in that the membrane tongue (35) has a largely planar configuration in the blocking state. Intake manifold arrangement (3) according to one of the Claims 5 until 8 , characterized in that the contact surface (34) and/or the membrane tongue (35) has an impact-damping coating (38), which is in particular provided with a polyurethane material. Intake manifold arrangement according to one of the Claims 5 until 9 , characterized in that the check valve (20) is arranged largely in the direction of the fluid flow from the flowable area (36) towards the suction pipe end section (14) on the casing body (19). Intake manifold arrangement (3) according to one of the Claims 5 until 10 , characterized in that the check valve (20) is designed as an assembly that can be detached from the casing body (19). Intake pipe arrangement (3) according to one of the preceding claims, characterized in that the ratio of the area of the air inlet opening (37) to the surface of the casing body (19) has a value in the range of 0.0375 to 0.375, in particular a value in the range of 0.075. Intake manifold arrangement (3) according to one of the preceding Claims 1 until 5 , characterized in that the check valve (20) has at least one diaphragm valve which is attached to a surface element (30) or a cover surface (25) of the casing body (19), wherein a diaphragm tongue (40) of the check valve (20) is located in the blocking state at least largely in the plane of the surface element (30) or the cover surface (25). Intake manifold arrangement (3) according to Claim 13 , characterized in that the check valve (20) has a contact surface (34) with a shock-absorbing coating (38), which is in particular provided with a polyurethane material. Intake manifold arrangement (3) according to one of the preceding claims, characterized in that the air filter element (16) is designed as a foam element and is arranged upstream or downstream of the casing body (19). Four-stroke internal combustion engine (1) with at least one working cylinder (2) with inlet (4) and outlet valves (5) and an intake manifold arrangement (3) according to one of the preceding claims. four-stroke internal combustion engine (1) according to Claim 16 , characterized in that the throttle valve arrangement (12) has at least one throttle valve and at least one device for injecting fuel and the device introduces the fuel into an area between the throttle valve and the intake valve (4). Motorcycle (41) with a rider's seat (44) and a front wheel (42) and a rear wheel (43) driven by an internal combustion engine (1), characterized in that the internal combustion engine (1) is an internal combustion engine according to Claim 16 is. Motorcycle (41) after Claim 18 , characterized in that the throttle valve arrangement (12) has at least one throttle valve and at least one device for injecting fuel and the device introduces the fuel into an area between the throttle valve and the intake valve (4). A method for reducing the throttling noise of a throttle valve assembly (12) comprising a throttle valve (50) coupled to an intake manifold assembly, the intake manifold assembly having a flow direction for fluid in a passage direction of the throttle valve (50) and an intake manifold end section (14) spaced apart from the throttle valve (50), characterized in that the throttling noise is dampened by means of an air filter device (17) comprising an air filter element (16) and an air filter support structure (18) receiving the air filter element (16), wherein the air filter support structure (18) is a housing body (19) at least partially surrounding an air filter chamber (21) receiving cleaned intake air, which has a mounting surface (23) and is arranged upstream of the intake manifold end section (14), and the housing body (19) is provided with at least one check valve (20) having an air inlet opening (37), which is opened by a (13) the negative pressure occurring to allow intake air to pass into an interior space (29) of the casing body (19) is designed to be openable. Enclosure body (19) for use in a suction pipe assembly (3) according to one of the Claims 1 until 15 , characterized by a circumferential base edge (24) with surface elements (30) extending out of the plane of the base edge (24), which are arranged converging towards each other and form a closed dome-shaped configuration, wherein at least one surface element (30) has a recess (26) for receiving a check valve (20). Enclosure body (19) according Claim 21 , characterized in that the casing body (19) has a cover surface (25) which is arranged largely opposite the circumferential bottom edge (24) and has a recess (26) for receiving the check valve (20).