DIGITAL INLET VALVE FOR A GASOLINE DIRECT INJECTION SYSTEM OF A MOTOR VEHICLE

Abstract

A digital inlet valve (DIV) for a gasoline direct injection (GDI) system of a motor vehicle is provided. The DIV includes a valve seat that seals a high pressure gasoline chamber of the GDI system against a low pressure gasoline chamber of the GDI system in a closed configuration of the DIV. A valve piston moves the valve seat between the closed configuration and an open configuration of the DIV, in which the high pressure gasoline chamber is in fluid connection with the low pressure gasoline chamber. A valve actuator actuates movement of the valve piston. The valve seat, the valve piston and the valve actuator are separate components, which are selectively plugged into each other.

Claims

1. A digital inlet valve (DIV), for a gasoline direct injection (GDI) system of a motor vehicle, comprising: a valve seat configured to seal a high pressure gasoline chamber of the GDI system against a low pressure gasoline chamber of the GDI system in a closed configuration of the DIV; a valve piston configured to move the valve seat\between the closed configuration and an open configuration of the DIV, in which the high pressure gasoline chamber is in fluid connection with the low pressure gasoline chamber; and a valve actuator configured to actuate movement of the valve piston; wherein the valve seat, the valve piston, and the valve actuator are separate components, which are selectively plugged into each other.

2. The digital inlet valve according to claim 1, further comprising: a valve hull that encloses the valve seat around an actuation direction, wherein the valve hull includes a gasoline duct for receiving gasoline from the low pressure gasoline chamber and conducting the gasoline to the valve seat.

3. The digital inlet valve according to claim 2, wherein the valve hull is plugged between the valve piston and the valve seat.

4. The digital inlet valve according to claim 3, wherein the valve seat, the valve piston, the valve actuator, and the valve hull are mounted together in a clamping connection.

5. The digital inlet valve according to claim 1, wherein the valve actuator is configured as an electromagnetic linear actuator to actuate movement of the valve piston along the actuation direction (D).

6. The digital inlet valve according to claim 1, wherein at least one of the valve seat, the valve piston, the valve actuator and the valve hull comprises a metal material.

7. The digital inlet valve according to claim 1, wherein the DIV is configured with a resonance frequency below about 5 kHz or above about 10 kHz.

8. A motor vehicle with a gasoline direct injection (GDI) system having a digital inlet valve (DIV) , wherein the DIV includes: a valve seat configured to seal a high pressure gasoline chamber of the GDI system against a low pressure gasoline chamber of the GDI system in a closed configuration of the DIV; a valve piston configured to move the valve seat\between the closed configuration and an open configuration of the DIV, in which the high pressure gasoline chamber is in fluid connection with the low pressure gasoline chamber; and a valve actuator configured to actuate movement of the valve piston; wherein the valve seat, the valve piston, and the valve actuator are separate components, which are selectively plugged into each other.

9. The motor vehicle according to claim 8, wherein the DIV further includes: a valve hull that encloses the valve seat around an actuation direction, wherein the valve hull includes a gasoline duct for receiving gasoline from the low pressure gasoline chamber and conducting the gasoline to the valve seat.

10. The motor vehicle according to claim 9, wherein the valve hull is plugged between the valve piston and the valve seat.

11. The motor vehicle according to claim 10, wherein the valve seat, the valve piston, the valve actuator, and the valve hull are mounted together in a clamping connection.

12. The motor vehicle according to claim 8, wherein the valve actuator is configured as an electromagnetic linear actuator to actuate movement of the valve piston along the actuation direction (D).

13. The motor vehicle according to claim 8, wherein at least one of the valve seat, the valve piston, the valve actuator and the valve hull comprises a metal material.

14. The motor vehicle according to claim 8, wherein the DIV is configured with a resonance frequency below about 5 kHz or above about 10 kHz.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present disclosure and together with the description serve to explain the principles of the disclosure. Other exemplary embodiments of the present disclosure and many of the intended advantages of the present disclosure will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. In the figures, like reference numerals denote like or functionally like components, unless indicated otherwise.

[0019] FIG. 1 schematically depicts a gasoline direct injection system with a digital inlet valve according to an exemplary embodiment of the present disclosure;

[0020] FIG. 2 schematically shows a motor vehicle including the gasoline direct injection system of FIG. 1 according to an exemplary embodiment of the present disclosure;

[0021] FIG. 3 shows a detailed schematic view of the digital inlet valve of FIG. 1 according to an exemplary embodiment of the present disclosure; and

[0022] FIG. 4 shows a detailed view of FIG. 3 according to an exemplary embodiment of the present disclosure.

[0023] Although specific exemplary embodiments are illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific exemplary embodiments shown and described without departing from the scope of the present disclosure. Generally, this application is intended to cover any adaptations or variations of the specific exemplary embodiments discussed herein.

DETAILED DESCRIPTION

[0024] It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, combustion, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum).

[0025] Although exemplary embodiment is described as using a plurality of units to perform the exemplary process, it is understood that the exemplary processes may also be performed by one or plurality of modules. Additionally, it is understood that the term controller/control unit refers to a hardware device that includes a memory and a processor. The memory is configured to store the modules and the processor is specifically configured to execute said modules to perform one or more processes which are described further below.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0027] Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from the context, all numerical values provided herein are modified by the term “about.”

[0028] FIG. 1 schematically depicts a gasoline direct injection (GDI) system 10 with a digital inlet valve (DIV) 1 according to an exemplary embodiment of the present disclosure. The GDI system 10 may be integrated into an internal combustion engine 101, in particular an engine running on gasoline, e.g. to power the vehicle depicted in FIG. 2. The various components (e.g., pumps etc. may be operated by a controller)

[0029] Since modern vehicles have to meet highest demands concerning consumption, emission and performance standards, gasoline vehicles are mostly equipped with direct fuel injecting systems. Gasoline direct injection indicates that the fuel is injected by an injector directly into a combustion chamber (not depicted) of the engine 101, which then realizes an internal gas mixture. Accordingly, the present system 10 may include a low pressure fuel pump (also not depicted here), configured to pump the gasoline at low pressures (e.g. about 3 bar) via a low pressure gasoline inlet 12 into a low pressure gasoline chamber 7 of the GDI system 10. The digital inlet valve 1 shown in FIG. 1 regulates transfer of the gasoline from the low pressure gasoline chamber 7 to a high pressure gasoline chamber 6 of a high pressure fuel pump 20, from where the gasoline is ejected via a high pressure gasoline outlet 13 into a rail (not depicted) and injected into the combustion chamber of the engine 101.

[0030] The high pressure pump 20 may be configured to compress the demanded fuel quantity for the injection to a required pressure level, e.g. about 50 bar up to about 500 bar. Accordingly, the high pressure pump 20 may be driven with a plunger 15 resiliently connected to a tappet 21 via a return spring 17, the tappet 21 in turn being connected to a camshaft 18 of the engine 101. Thus, a pump frequency of the high pressure pump 20 may be driven by the speed of the internal combustion engine 101 (cf. arrow at the plunger 15 in FIG. 1 that indicates an oscillating movement of the plunger 15). The DIV 1 thus has to be actuated at a specific time to deliver an adequate amount of fuel within a predetermined period of time. Accordingly, the DIV 1 may be operated by an engine control unit (ECU) of the engine 101 (not depicted) based on various sensor data.

[0031] The DIV 1 may be accommodated inside a DIV housing 16 and may include four separate functional components: a valve seat 2, a valve piston 3, a valve actuator 4 and a valve hull 5 (see left side in FIG. 1). The functional components are shown in FIG. 3 in a mounted arrangement and in a detailed view in FIG. 4.

[0032] The valve seat 2 may be configured to seal the high pressure gasoline chamber 6 of the GDI system 10 against the low pressure gasoline chamber 7 of the GDI system 10 in a closed configuration of the DIV. The valve piston 3 may be configured to move the valve seat 2 between the closed configuration and an open configuration of the DIV 1, in which the high pressure gasoline chamber 6 is in fluid connection with the low pressure gasoline chamber 7. The valve actuator 4 may operate as an electromagnetic linear actuator powered via electric connection 9 to actuate movement of the valve piston 3 along an actuation direction D. The valve hull 5 may enclose the valve seat 2 around the actuation direction D and may include a gasoline duct 8 for receiving gasoline from the low pressure gasoline chamber 7 and conducting the gasoline to the valve seat 2 (see FIG. 3).

[0033] The four functional components, namely the valve seat 2, the valve piston 3, the valve actuator 4 and the valve hull 5, are separate components made from a soft and lightweight metal alloy. In conventional DIV these functional elements are usually provided together as one fully integrated single structural element to save manufacturing costs and simplify the supplier chain. This means that in common DIV the functional elements are rigidly connected within one piece, e.g. by welding several steel components together. In the present disclosure however, four separate components are provided, which are plugged into each other as shown in FIG. 4 and are mounted in a clamping connection, e.g. by a bracket or the like (not depicted). This provision enables significant reduction in sound emissions, as will be described below.

[0034] In general, all vibrating surfaces transfer their movement into the air, which in turn generates spherical outspreading waves. These waves have nearly the same frequency as the vibrating body. The resulting sound or acoustic noise is also referred to as solid-borne sound. In simplified conditions, solid-borne sound corresponds to the resonance frequency of the whole body, including its physical boundaries of mass, stiffness and damping.

[0035] Vehicle noise emission remains one of the key challenges to meet end-user satisfaction. Powertrain acoustics influences, by positive association, in case of “sportive” sound and negative perception in case for harsh sounds. Studies show that common GDI systems are one major source for mechanic noise emission. Especially in idle condition, this circumstance may be annoying or inconvenient to both driver and pedestrians. Particularly the high pressure pump in modern gasoline direct injection engines may be perceived as acoustically annoying due to a “ticking” noise, which is emitted over the otherwise very smooth operation of these engines. The ticking sound is mainly caused by the rapid closing and opening movement of the digital inlet valve regulating fuel inlet into the high pressure pump.

[0036] Studies reveal that GDI system noise covers a range between about 1.6 kHz up 16 kHz. In other words, this range may be split in two major areas for pump function. Pressure generation impacts the area from roughly about 1.6 to 5 kHz, while the digital inlet valve impacts the area from about 5 to 10 kHz. The range of about 5 to 10 kHz may also be described as “ticking” noise.

[0037] The underlying principle of the exemplary embodiment of FIGS. 1 to 4 is to decouple all functional elements and provide a dismountable digital inlet valve 1. Therefore, the functional components do not interact as one integrated part, but as smaller parts within the assembly. In other words, the sound emissions of the valve 1 while closing are not transferred through the whole component as solid borne sound. Since the functional components, including the vale seat 2, the valve piston 3, the valve hull 5 and the valve actuator 4, are selectively plugged together (or otherwise connected together in a separable manner), these parts have different contact points, which already inhibits spreading of sound across the DIV 1.

[0038] Moreover, since the DIV 1 is less rigid due to the separation of the functional components, a “natural” noise damping effect is established across the assembly. By targeting these effects with additional damping material (e.g. rubber layers, light & soft metallic alloy), the ticking sound emission may be completely suppressed. Accordingly, the material and geometric configuration of the functional components and their different contact and/or fixture points within the assembly may be configured such that the resulting resonance frequencies of the assembly are outside of the ticking range between 5 kHz and 10 kHz. As a consequence, the actuation of the DIV 1 will not lead to solid-borne sound emissions of the DIV 1, since the resonance frequency does not match the actuation frequency.

[0039] In particular, the valve seat 2 and the valve piston 3 may be decoupled from each other in the exemplary embodiment of FIGS. 3 and 4, as the valve hull 5 is plugged in-between the valve seat 2 and the valve piston 3 (see FIG. 4 in particular). Since the valve seat 2 and the valve piston 3 are often considered to be the main cause for sound emission during operation of the DIV 1, the present solution thus ensures that no direct connection exists between these components. The present disclosure thus is able to significantly reduce the ticking noise of common digital inlet valves by decoupling the functional elements of the digital inlet valve from each other.

[0040] In the foregoing detailed description, various features are grouped together in one or more examples or examples with the purpose of streamlining the disclosure. It is to be understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents of the different features and embodiments. Many other examples will be apparent to one skilled in the art upon reviewing the above specification. The exemplary embodiments were chosen and described in order to explain the principles of the disclosure and its practical applications, to enable others skilled in the art to utilize the disclosure and various exemplary embodiments with various modifications as are suited to the particular use contemplated.

REFERENCE LIST

[0041] 1 digital inlet valve (DIV) [0042] 2 valve seat [0043] 3 valve piston [0044] 4 valve actuator [0045] 5 valve hull [0046] 6 high pressure gasoline chamber [0047] 7 low pressure gasoline chamber [0048] 8 gasoline duct [0049] 9 electric connection [0050] 10 gasoline direct injection (GDI) system [0051] 11 magnetic coil [0052] 12 low pressure gasoline inlet [0053] 13 high pressure gasoline outlet [0054] 14 GDI system housing [0055] 15 plunger [0056] 16 DIV housing [0057] 17 return spring [0058] 18 engine camshaft [0059] 19 gasoline flow [0060] 20 high pressure pump [0061] 21 tappet [0062] 100 motor vehicle [0063] 101 internal combustion engine [0064] D actuation direction