EP2665915A1

EP2665915A1 - Air-intake line for a combustion engine, associated casing for an air filter, and motor vehicle comprising such a line

Info

Publication number: EP2665915A1
Application number: EP11818920.8A
Authority: EP
Inventors: Olivier Boucher
Original assignee: Peugeot Citroen Automobiles SA; GM Global Technology Operations LLC
Current assignee: PSA Automobiles SA; GM Global Technology Operations LLC
Priority date: 2011-01-17
Filing date: 2011-12-19
Publication date: 2013-11-27
Also published as: CN103782019B; WO2012098307A1; FR2970523A1; FR2970523B1; CN103782019A

Abstract

The invention relates to an air-intake line for a combustion engine (M), comprising, in the following order, on a main branch: an air filter (1) provided with a casing; a turbocharger compressor (2); and an air-metering valve (3), wherein the line further comprises a recirculation branch (4) bypassing the main branch between the downstream and upstream portions of the compressor (2), and a release valve (5) capable of blocking or enabling the flow of a fluid in the recirculation branch (4), characterized in that a first end (41) of the recirculation branch (4) is connected to the main branch via the air-filter (1) casing. The invention also relates to an air-filter casing that is advantageously shaped so as to implement such an air-intake line, and to a motor vehicle (V) comprising such an intake line.

Description

AIR INTAKE LINE OF A COMBUSTION ENGINE, AIR FILTER HOUSING, AND MOTOR VEHICLE

COMPRISING SUCH A LINE

The present invention claims the priority of the French application 1150341 filed January 17, 2011 whose content (text, drawings and claims) is here incorporated by reference.

The invention relates to the field of air filters for vehicles having a supercharged engine provided with a discharge valve (generally designated by the English expression "dump valve"), and the field of architecture of such engines.

[0003] The combustion engine turbochargers are equipped with a compressor discharge system, called dump valve, which protects against overpressure and the pumping phenomenon. In the "let go" phases (shutdown of the engine speed up by rapid release of the engine throttle), the air intake valve, or "throttle body" closes and then generates a peak pressure in the pressure inlet line between the turbo and the throttle body. The discharge valve allows the overpressure to be discharged to the vacuum intake circuit (before the turbocharger compressor) and thus to avoid the phenomenon of compressor pumping, as well as any peak pressure that could damage the compressor wheel.

This system is generally integrated with the compressor. Thus, in the state of the art, a dump valve architecture integrated into the compressor is known: a channel connecting, as a bypass of the compressor, the part of the vacuum air line and the part of the pressure line allows to bypass the compressor under the action of the dump valve. The discharge valve or dump-valve may for example be indifferently electric or pneumatic.

This conventional architecture causes a bulky and heavy compressor casing, because of the integration of the dump-valve. This architecture therefore limits the possibility of having a compact compressor, the discharge valve (for example of electrical or pneumatic technology) being relatively bulky. Such architecture is particularly problematic when the engine implementation constraints are important, for example in the context of an automotive application.

Such an architecture also has a second major defect. In order to ensure the best possible efficiency of the discharge valve, it is necessary to position it as close as possible to the throttle body of the engine, which is the source of the overpressures in the intake line. However, the compressor is generally fluidly away from the throttle body. Indeed, it may be necessary to integrate various elements between the compressor and the throttle body, for example a exchanger called "charge air cooler", to lower the temperature of the air at the intake of the engine . Such an element being furthermore generally positioned on the front face of a vehicle, the ducts necessary for this arrangement may have a large length.

The invention aims to solve these problems and aims to improve the overall compactness of combustion engines having a discharge valve, by proposing an intake line of an engine having an optimized architecture. The invention also relates to an air filter used in an intake line according to the invention.

More specifically, a first object of the invention therefore relates to an air intake line for combustion engine having in this order, on a main branch: · an air filter provided with a housing;

• a turbocharger compressor;

• an air metering valve; the line further comprising a recirculation branch in branch of the main branch between the downstream and the upstream of the compressor, and a discharge valve adapted to prohibit or allow the circulation of a fluid in the recirculation branch, characterized in a first end of the recirculation branch is connected to the main branch through the air filter housing. This makes it possible to obtain an optimized architecture of the air intake line, avoiding the use of a turbocharger with integrated, heavy and bulky discharge valve. Preferably, the air filter comprising a filter means between an upstream chamber and a downstream chamber, according to the direction of flow of air in the main branch, the first end of the recirculation branch is connected to the downstream chamber. Thus, the recirculation branch is disposed between two points of the main branch in which circulates air filtered by the air filter, avoiding any risk of unfiltered air passage to the engine inlet via the branch of recirculation.

[001 1] Preferably, the main branch further comprising a heat exchanger between the compressor and the air metering valve, a second end of the recirculation branch is connected between the heat exchanger and the metering valve. This prevents the overpressure of the heat exchanger during rapid closing of the air metering valve at the inlet, before opening the discharge valve. By connecting the second end of the recirculation branch as close as possible to the air metering valve, which is the source of the possible overpressures related to its rapid closure, it is generally possible to limit the length of the intake line that may be subjected to these pressures before opening the discharge valve.

Preferably, the discharge valve has a valve body secured to the housing of the air filter. This variant of the invention allows great simplicity in the implantation of the discharge valve.

In a preferred embodiment of the invention, the air filter housing is shaped so as to form the body of the discharge valve. This maximizes the mass gains that can be achieved by the implementation of the invention, and reduces the manufacturing and logistics costs involved in implementing the invention.

In a variant of the invention, the discharge valve is a solenoid valve. It is a reliable technology, successfully used in the field of discharge valves. In another variant, the discharge valve may comprise a pneumatic actuator.

A second object of the invention relates to an air filter housing for filtering the air at the intake of a combustion engine, characterized in that it is shaped so as to constitute the body of the discharge valve. Such an air filter housing is the main element allowing the implementation of an intake line according to the first subject of the invention. [001 6] Preferably, the housing is shaped by molding or overmoulding so as to form the body of a discharge valve.

The invention also relates to an assembly comprising a casing according to the second object of the invention, and a discharge valve whose body is constituted by said casing.

Finally, the invention relates to a motor vehicle having a combustion engine comprising an intake line according to the first object of the invention.

The invention is described in more detail below and with reference to the figures schematically showing the system in two preferred embodiments. Figure 1 schematically shows a combustion engine, as installed in a motor vehicle, and having an air intake line according to a variant of the invention.

Figures 2a and 2b show schematically an assembly comprising an air filter and a discharge valve, brought into play in a first preferred embodiment of an air intake line according to the invention. Figure 2a shows the discharge valve in the closed position, Figure 2b shows the discharge valve in the open position.

Figures 3a and 3b show schematically an assembly comprising an air filter and a discharge valve, brought into play in a second preferred embodiment of an air intake line according to the invention. Figure 3a shows the discharge valve in the closed position, Figure 3b shows the discharge valve in the open position.

Figure 1 schematically shows a combustion engine M, as implanted in a motor vehicle V and having an air intake line according to a variant of the invention. An air intake line according to the invention comprises a main branch, comprising itself and in this order according to the direction of flow of the air in the line:

an air filter 1; a compressor 2 of a turbocharger; and

- A metering valve 3 of the intake air, which may for example be a butterfly housing, as commonly used. In the invention, the line comprises a recirculation branch 4 disposed in branch of the main branch, between the downstream and the upstream of the compressor 2, the concepts of upstream and downstream meaning, as in the remainder of this document, according to the direction of flow of air in the main branch of the air intake line during normal operation of the combustion engine M that the line is intended to supply air.

A discharge valve 5 allows to prohibit or allow the circulation of a fluid in the recirculation branch. The discharge valve or "dump valve" makes it possible, in a well known manner, to discharge a too high overpressure which can be created downstream of the compressor 2, in particular during a sudden closing of the metering valve 3, towards a point of the intake line upstream of the turbocharger.

In the variant shown here, the circuit further comprises a heat exchanger 6, in this case a charge air cooler, disposed on the main branch between the compressor 2 and the metering valve 3 of the air on admission. In the invention, the recirculation branch has the particularity of having one end, said first end 41, connected to the main branch of the intake line through the housing of the air filter. Thus, the recirculation branch is in communication with the interior volume of the air filter.

In the variant of the invention shown here, the second end 42 of the recirculation branch is connected to the main branch between the heat exchanger 6 and the metering valve 3. This arrangement allows in particular to avoid the setting overpressure of the heat exchanger 6 when the rapid closure of the metering valve 3 (in particular during a sudden release of the accelerator control of the motor M) causes the opening of the discharge valve 5. [0029] Similarly, the tapping of the second end 42 of the recirculation branch on the main branch is preferably positioned closer to the metering valve 3 (but obviously upstream thereof), in order to limit the length of the main branch of the intake line put under overpressure before opening the discharge valve 5. [0030] FIGS. 2a and 2b schematically show an assembly comprising an air filter 1 and a discharge valve 5, set n game in a first variant preferential of an air intake line according to the invention. Figure 2a shows the discharge valve 5 in the closed position, Figure 2b shows the discharge valve 5 in the open position. In the variant of the invention shown in these figures 2a and 2b, the discharge valve 5 is a solenoid valve secured to the housing 1 1 of the air filter 1. More specifically, the discharge valve 5 comprises a valve body 51 and a valve 52, movable in the valve body 51 under the effect of a solenoid 53.

The valve body 51 may in particular be molded with (or overmolded on) the housing 1 1 of the air filter 1. The housing 1 1 is thus shaped to form the body 51 of the discharge valve. More simply, the discharge valve 5 (including the valve body 51) can be reported and fixed to the housing 1 1 of the air filter 1.

Whether the valve is reported or that its body 51 is integrally formed with the housing 1 1, it can be advantageously positioned on the cover of the air filter (which is an element of the housing 1 1). Compared to a conventional cover, the cover can be advantageously reinforced at the connection with the recirculation branch 4.

Figures 3a and 3b show schematically an assembly comprising an air filter and a discharge valve, brought into play in a second preferred embodiment of an air intake line according to the invention. Figure 3a shows the discharge valve in the closed position, Figure 3b shows the discharge valve in the open position. In this variant of the invention, the discharge valve 5 is not integral with the housing 1 1 of the air filter 1, but is positioned at another point of the recirculation branch 4. The simplification of the intake line is smaller, but this variant offers greater freedom in the positioning of the discharge valve January 1, which can allow the use of any volume along the recirculation leg 4 to position the discharge valve 5.

In Figures 2b and 3b, the flow of air flowing in the recirculation branch 4 following the opening of the valve 52 of the discharge valve 5 is represented by dashed arrows. Preferably, and as represented in the variants shown in FIGS. 2a / 2b and 3a / 3b, the air filter 1 comprises a filtration means 12 between a upstream chamber 13 and a downstream chamber 14 of the air filter. The upstream chamber 13 corresponds to the internal volume of the air filter housing on the "dirty" air side (before filtration), the downstream chamber 14 corresponds to the internal volume of the clean air-side air filter housing (after filtration). Thus, the recirculation branch being mounted between two points of the main branch located on clean air side, it avoids any risk of unfiltered air passage to the inlet of the motor M via said recirculation branch 4 (for example in case of poor sealing of the discharge valve 5).

The invention thus proposes a device offering multiple advantages. It is thus possible to optimize the architecture of the intake line of an engine. In particular, the adoption of a turbocharger whose compressor has no valve and integrated discharge conduit reduces the volume and implementation constraints, allowing a general optimization of the intake line. The implementation of the invention is however easy, especially since it retains the conventional operation of the discharge valve, which can impose a standard control (in the case of course where the discharge valve is a pilot valve).

By positioning the dump valve closer to the throttle body, it ensures a quick response and avoids the pressurization of a large part of the air intake line (including the air cooler of supercharging if the engine is equipped with it)

Other advantages arise from the use of an intake line according to the invention. In particular, it is possible to mention a saving in mass (in particular because the valve can be located in a less constrained environment, in particular thermally). In an automotive application, the use of the invention can also optimize the distribution of masses in the under-hood space of the engine, for example by relating the discharge valve behind the front end of the vehicle.

Claims

claims

1. Air intake line for combustion engine (M) comprising in this order, on a main branch:

An air filter (1) provided with a casing (1 1); "A compressor (2) turbocharger;

• a metering valve (3) for the air; the line further comprising a recirculation branch (4) in branch of the main branch between the downstream and the upstream side of the compressor (2), and a discharge valve (5) able to prohibit or allow the circulation of a fluid in the recirculation branch (4), characterized in that a first end (41) of the recirculation branch (4) is connected to the main branch through the housing (1 1) of the air filter (1) .

2. Inlet line according to claim 1, the air filter (1) comprising a filtering means (12) between an upstream chamber (13) and a downstream chamber (14), according to the direction of flow of the air in the main branch, wherein the first end (41) of the recirculation branch (4) is connected to the downstream chamber (14).

Air intake line according to claim 1 or claim 2, the main branch further comprising a heat exchanger (6) between the compressor (2) and the metering valve (3) of the air, in a second end (42) of the recirculation branch (4) is connected between the heat exchanger (6) and the metering valve (3).

4. Air intake line according to one of claims 1 to 3, wherein the discharge valve (5) has a valve body (51) integral with the housing (1 1) of the air filter (1). .

5. Air intake line according to claim 4, wherein the housing (1 1) of the air filter (1) is shaped so as to constitute the body (51) of the discharge valve.

6. Air intake line according to one of claims 1 to 5, wherein the discharge valve (5) is a solenoid valve.

7. Air intake line according to one of claims 1 to 5, wherein the discharge valve (5) comprises a pneumatic actuator.

8. Carter (1 1) of air filter (1) for filtering the air at the intake of a motor (M) combustion, characterized in that it is shaped so as to constitute the body ( 51) of a discharge valve (5).

9. Carter (1 1) of air filter (1) according to claim 8, shaped by molding or overmoulding so as to constitute the body (51) of a discharge valve.

1 0. An assembly comprising a housing (1) according to claim 8 or claim 9 and a discharge valve (5) whose body (51) is constituted by said housing (1 1).

1 1. Motor vehicle (V) having a combustion engine (M) having an intake line according to any one of claims 1 to 6.