WO2009059999A1

WO2009059999A1 - Valve arrangement

Info

Publication number: WO2009059999A1
Application number: PCT/EP2008/065002
Authority: WO
Inventors: Carlos Manuel CASTAÑO GONZÁLEZ
Original assignee: Dayco Ensa, S.L.
Priority date: 2007-11-05
Filing date: 2008-11-05
Publication date: 2009-05-14
Also published as: ES2342640B1; PL2227646T3; ES2439959T3; ES2342640A1; EP2227646B1; EP2227646A1

Abstract

The present invention relates to a valve arrangement for an EGR/cooling module of an internal combustion engine including an inner chamber (13) in which a fluid is received, comprising at least a first inlet/outlet passage (14), a second inlet/outlet passage (15) and a third inlet/outlet passage (16); characterized in that the valve arrangement is adapted to open and close at least one blocking element (17, 18) pivotably assembled in the inner chamber (13) and supported on a valve seat of an inlet/outlet passage (14,15,16).

Description

VALVE ARRANGEMENT

TECHNICAL FIELD

The present invention relates to a valve arrangement controlling and regulating the exhaust gas recirculation, i.e. EGR, flow of an internal combustion engine. BACKGROUND ART

Arrangements are known in the current state of the art which allow exhaust gas recirculation from the exhaust manifold to the intake manifold of combustion engines known as EGR (Exhaust Gas Recirculation Systems) .

These systems are formed by the metal connecting tubes, EGR tubes, heat exchanger with a bypass passage, EGR cooler, bypass valve and EGR valve. Said valves are independent elements and the actuation thereof requires independent actuators.

These systems recirculate exhaust gas from the exhaust manifold to the intake manifold of the engine after subjecting such gas to a cooling process so as to reduce the amount of NOx emissions . International patent application WO2006/092401 discloses a valve which channels the exhaust gas towards a heat exchanger or towards a bypass passage according to pre-established control conditions, comprising a body with an inner chamber where the combustion gas is received through inlet passages and is directed towards outlet passages through outlet/inlet openings and an element for closing the outlet or inlet passages is formed by an actuating pin that can be axially actuated by means of an actuator, with two plates separated by a spring and which can move along the pin between two stops fixed thereto, and additionally a bellows controlled by a pneumatic actuator.

A drawback of the mentioned valve is derived from the fact that the due to the design of the valve, the latter has problems with leaks and/or seizing between the actuating pin and the valve closing plates. This valve design requires a relative movement between the closing plate and the actuating pin of the valve, having problems with wear and/or seizing between the plate and the pin in high-temperature operating conditions.

Additionally, since it is not a leak-tight joint because there has to be minimal allowance between the plate and the pin so as to be able to carry out the relative movement between the two components, it has a level of internal leaks in its closed state position due to which EGR gas cannot be precisely controlled.

The proposed design furthermore does not improve the performance in comparison with current valve insofar as preventing sticking. One of the biggest problems with EGR valve operation is the sticking of the plates to the valve seat as a result of the solidification of some condensate residues of the exhaust gas when such remains cool. Said solidification causes the moving part of the valve to stick to the seat thereof. DISCLOSURE OF INVENTION

The present invention seeks to solve one or more of the drawbacks set forth above by means of a valve arrangement such as that claimed in claim 1. Embodiments of the invention are provided in the dependent claims. An object of the present invention is to provide a valve arrangement controlling the circulating flow of a liquid or gaseous fluid between at least a first hole and a second hole preventing a valve from sticking to the seat thereof.

Another object of the invention is to provide a valve integrating the function of the EGR valve and the bypass valve by means of using a single actuator.

Yet another object of the invention is to provide a valve arrangement having high durability due to reducing the wear, preventing seizing and leaks between the pin and the plates as a result of the relative movement that must exist in the design shown between the pin and plate.

Yet another object of the invention is to prevent the plates from sticking to the valve seat, providing greater force for opening the valve. Another object of the invention is to provide an actuating motor for the valve arrangement having a reduced opening and closing force for same. Yet another object of the invention is to place the actuating motor far from the rotating shaft of the valve or closing/opening blade for the purpose of creating a high actuating moment to generate high valve actuation forces. Yet another object of the invention is to provide a leak- tight contact between the valve seat and the valve itself.

Another object of the invention is to further maintain the valve closed in the event of failure of the valve arrangement.

Another object of the invention is to prevent damages on the actuating motor due to high temperatures.

Yet another object of the invention is to provide a high degree of leak-tightness in the closed position of the valve arrangement to prevent joints that must allow relative movements between plates, preventing leaks. Yet another object of the invention is to improve the performance due to a pressure drop in the valve arrangement because it exerts a high actuating force which allows using valve head diameters exceeding those used today. BRIEF DESCRIPTION OF THE DRAWINGS A more detailed explanation of the invention will be provided in the following description based on the attached figures :

Figure 1 shows a cross-section of a valve arrangement according to the invention, Figure 2 shows a constructive detail of an assembly of blocking elements of the valve arrangement according to the invention,

Figure 3 shows a cross-section of the valve arrangement in the open position according to the invention, Figure 4 shows another constructive detail of the blocking element assembly of the valve arrangement according to the invention,

Figure 5 shows a cross-section of another valve arrangement in the closed position according to the invention, Figure 6 shows a cross-section of another valve arrangement with a cam according to the invention, and

Figure 7 shows a cross-section of another valve arrangement with another cam according to the invention. BEST MODE FOR CARRYING OUT THE INVENTION

In relation to Figure 1, a cross-section of a valve arrangement in the closed position according to the invention is shown, which valve arrangement is located inside a body 12 with an inner chamber 13 in which a fluid, such as a liquid, a gas or the like, is received.

The body 12 comprises at least a first inlet/outlet passage 14 of the gas to the valve and at least a second inlet/outlet passage 14 and a third inlet/outlet passage 15 of the gas.

In the case at hand, the inner chamber 13 receives an inlet gas through the first inlet passage 14, coming from an inlet area and directed towards the second and third outlets 15, 16 communicating the chamber 13 with the outlet passages, or vice versa, and the inner chamber 13 comprises two inlet passages and one outlet passage.

The function of the valve arrangement is to open and close a blocking element assembly 17, 18, such as a blade or valve, which arrangement controls the gas flow amount flowing through the inlet/outlet passages 14, 15, 16 of the inner chamber 13.

Now in relation to Figures 1 and 2, the valve arrangement 11 comprises a first blade 17 and a second blade 18 which are joined at their proximal ends by means of a hinge pin 19 which is joined to a predetermined area of an inner wall of the inner chamber 13 close to a passage thereof, housed in the partition wall of the second and third outlet 15, 16 or the like for example .

The distal ends of the first and second blade 17, 18 are in physical contact with a first actuating pin 20 that can be axially actuated. Both distal ends of the first and second blade

17, 18 are kept separated by means of a first spring 21, such as a spring assembled on the first actuating pin 20.

Both the first blade 17 and the second blade 18 substantially have the same constructive shape, such as a continuous broken line.

When both blades 17, 18 are assembled on both pins, the first actuating pin 20 and the hinge pin 19, the blades 17, 18 substantially adopt an amphora-type shape ending in a tip at the proximal end and in a narrow neck at the distal end. The width of the neck of the amphora-type shape corresponds to the axial dimension of the first spring 21. This amphora-type shape can be modified depending on the available space inside the inner chamber 13 and the constructive shape of both blades may differ for the same reason, i.e. available space within the area of the inner chamber 13.

The valve operates as follows: when the valve is closed, the first blade 17 and second blade 18 block the second outlet 15 and third outlet 16 of the inner chamber 13, respectively, as a result of the force exerted by the first spring 21 on the distal ends of both blades 17, 18.

Now in relation to Figure e, to open one of the outlets 14, 15 the first actuating pin 20 is shifted a predetermined axial distance in the suitable direction by means of an actuating motor, not shown, generating and applying enough force so that the corresponding stop member 22, 23 drags the blade 17, 18, overcoming the resistance of the first spring 21. Therefore the stop 22, 23, in contact with the corresponding blade 17, 18, drags it to the opposing blade, which continues blocking its outlet, and accordingly the first spring 19 is compressed and the inlet gas exits through the corresponding outlet passage. It must be noted that both the first and second blade 17, 18 are pivotably assembled on the hinge pin 19.

One feature of the valve arrangement according to the present invention is that it can carry out the function of controlling the amount of gas to be recirculated as well as the function of selecting the circuit through which the gas must circulate, therefore it can replace two separate valves such as an EGR valve and a bypass valve generally used in common EGR systems .

The operation of the valve arrangement is likewise independent of the spatial situation of the inlet/outlet assembly 14, 15, 16.

The blades 17, 18 can be manufactured of a material such as sheet metal, casting material, machining, sintering or by means of any other manufacturing process which allows obtaining the desired blade design.

The blade-spring assembly 17, 18, 19 can be shifted along the first actuating pin 20 between the first stop and a second stop 22, 23 fixed thereto. Each blade 17, 18 is in physical contact with one of the stops 22, 23 of the first actuating pin

20, respectively.

The physical contact between the first pin 20 and blade 17, 18 inevitably occurs in the moment the valve is actuated for the purpose of opening the blade 17, 18.

In the event that the valve is in the closed position, the stops 22, 23 being in contact option or the stops 22, 23 not being in contact option can be selected by design. The design of both stops 22, 23 is a function of the design of the distal end of the blade 17, 18 and of the design of the first actuating pin 20 so that when the first actuating pin 20 moves in the valve opening direction, the stop comes into contact with the corresponding blade 17, 18, the first pin 20 transmitting the desired opening force.

In addition, when the first pin 20 axially shifts in the blade 17, 18 closing direction, there is no contact or transmission of force between the pin 20 and the blades.

To obtain the foregoing, the first pin 20 can have two different diameters, the central part of the first pin 20 having a smaller diameter than the diameter of the ends of the pin 20 so as to abut with the blades 17, 18 only in the blade 17, 18 opening direction.

In another embodiment, the diameter of the first pin 20 is constant, stops such as washers integral with the pin 20 located in the outer parts of the blades 17, 18, being installed, obtaining the same effect as that described above.

The designer has a certain degree of liberty to make a design allowing a blade 17, 18 to come into contact so that it can open with the first pin 20, transmitting the necessary force to overcome the closing forces of the spring 19, preventing the axial movement from tending to close the blade 17, 18; in this case there is no contact between the pin 20 and the blade 17, 18, and accordingly there is no transmission of force between pin 20 and blade 17, 18. The blades 17, 19 are closed by means of the action of the spring 19, which always tends to close them.

In relation to Figure 4, a torsion spring 41 can additionally be located in the hinge pin 19 to help the spring

19 assembled on the first actuating pin 20 in its task of placing both the first and second blades 17, 18 on the corresponding valve seat.

Obviously the spring 19 or the torsion spring 41, or both, will be assembled, depending on the desired precision of the control of the gas flow through both second and third outlets

14, 15. It must also be noted that the existence of the spring 19 or the torsion spring 41 prevents the simultaneous opening of the second and third outlets 14, 15.

The stop 22, 23, that is no longer in physical contact with its corresponding blade 17, 18 limits the movement of the first actuating pin 20 when it comes into contact with the corresponding inner wall of the body 12.

However, the end of travel is not necessarily marked by the physical contact between the stop 22, 23 and the inner wall of the body 12, but rather the movement of the actuating pin 20 is controlled by the movement of the actuating motor. Therefore, a blade 17, 18 can be located between the ends of a shift range of the first actuating pin 20, one of its ends being the rest, non-opening position of the valve, and the other end the maximum shift of the actuating pin 20, maximum opening of the valve. The degree of opening of a blade is related to the magnitude of the shift of the actuating pin 20, which defines the amount of gas going through the valve.

This valve arrangement with an inlet area 14 and two outlet areas 15, 16 is particularly applicable, for example, for a heat exchanger of an EGR system with a bypass passage, the inlet area 14 being connected to the exhaust manifold and the outlet areas

15, 16 to the cooling module and to the bypass passage.

The valve arrangement 11 with two inlet areas and one outlet area is also applicable for a heat exchanger of an EGR system with a bypass passage, the two inlet areas being connected to the cooling module and to the bypass passage, and the outlet area to the intake manifold. The valve arrangement 11 can have two inlet areas and one outlet area such that the operation of the valve such that the gas flows from an inlet passage to the outlet passage and from the other inlet passage to the same outlet passage is by means of the same dynamics as that of the valve shown in Figures 1 to 4.

In relation to Figure 5, a blade 17, 18 additionally includes a sealing means 51, 52 to provide an improved sealing of the outlets 15, 16. The sealers 51, 52 can have a circular type shape or the like. The sealing disc 51, 52 is fixed to the blade 17, 18 by means of a ball joint type joint at both ends of the joint, one end corresponding to the joint to the disc and the other end to the joint to the blade 17, 18, allowing a degree of movement of the disc 51, 52 with regard to the blade, and in turn providing a sealed seat in the valve seat made in the body 12.

A second spring can likewise be installed in the joint fixing the disc 51, 52 to the blade 17, 18 to prevent vibration of the disc caused by pressure pulses generated in the gas recirculation system. The described valve arrangement 11 can be installed in a body 12 comprising a single inlet and a single outlet, for example, for the EGR valve function in which only the amount of gas to be recirculated is controlled.

The first actuating pin 20 can be axially shifted by means of, for example, a motor with a reduction gearbox coupled to an outlet in a rack and pinion system.

Now in relation to Figures 6 and 7, the opening and closing of the blades 17, 18 can be carried out by means of using a cam which would replace the first actuating pin 20, spring 21 and stops 22, 23 assembly.

The cam 61 has a second actuating pin 62 longitudinally parallel to the sides of the blades 17, 18. The joint of the cam 61 to the second actuating pin 62 is done at a predetermined off-centered point of the cam 61 so that the assembly thereof is pivotable, which allows carrying out the actuation of the two blades 17, 18 when the rotation of the second actuating pin 62 occurs. The blades 17, 18 have a substantially clip type shape in this arrangement.

Therefore the use of the cam 61 prevents converting a rotational movement of the motor into a linear movement, reducing the number of necessary components and allowing placing the electric motor above the valve 11 instead of on one side thereof .

The cam 61 includes two stops 63, 64 such that each stop is in permanent or intermittent contact with the corresponding blade 17, 18. The cam 61 can have different shapes causing the opening and closing of the blades 17, 18. Depending on the shape of the cam 61, the second actuating pin 62 can be centered or off- centered in the cam 61.

As a person skilled in the art will understand, the outer shape of the body 11 of the valve arrangement has a shape that can be inserted in the suitable place of the EGR system and may require as many additional elements as needed to carry out the corresponding couplings.

The force that the actuating motor, not shown, must develop depends on the lever developing the leverage that the designer designs for said valve arrangement 11, meaning that, in summary, the opening force is increased by increasing the leverage.

Therefore without increasing the motor, which increase has drawbacks such as heavier weight, greater cost, greater complexity for introducing it in the available space, greater electric consumption, with the subsequent increased consumption of fossil fuels, C02 emissions are reduced.

In another embodiment, the valve arrangement 11 can be used in a system comprising a two-pass EGR cooler for the gas flow such that when the second blade 17 is in the open position, the gas is removed through the second EGR outlet 16, and when the first blade 15 opens, the first inlet 14 is communicated directly with the second EGR outlet 16, thereby performing the bypass function of the EGR cooler.

The embodiment and example provided in this specification is presented as the best explanation of the present invention and its practical application, and to thus allow a person skilled in the art to put the invention into practice and use it. Nevertheless, the person skilled in the art will know that the description and previous example have been presented for the purpose of illustrating the invention only as an example.

Claims

1.- A valve arrangement for an EGR/cooling module of an internal combustion engine including an inner chamber (13) in which a fluid is received, comprising at least a first inlet/outlet passage (14) , a second inlet/outlet passage (15) and a third inlet/outlet passage (16) ; characterized in that the valve arrangement is adapted to open and close at least one blocking element (17, 18) pivotably assembled in the inner chamber (13) and supported on a valve seat of an inlet/outlet passage (14, 15, 16) .

2.- A valve arrangement according to claim 1, characterized in that the blocking element (17, 18) has a continuous broken line type shape such that its proximal end is joined by means of a hinge pin (19) to a partition wall of the second and third outlet (15, 16) and its distal end is in physical contact with a first actuating pin (20) which can be axially actuated.

3.- A valve arrangement according to claim 2, characterized in that the distal ends of the blocking element (17, 18) is kept in physical contact with the valve seat of the corresponding inlet/outlet passage (16, 15, 14) by means of a first spring (21) assembled on the first actuating pin (20) .

4.- A valve arrangement according to claim 3, characterized in that the distal end of the blocking element (17, 18) is kept in physical contact with the valve seat of the corresponding inlet/outlet passage (16, 15, 14) by means of a first spring (21) assembled on the first actuating pin (20) .

5.- A valve arrangement according to claim 4, characterized in that the distal end of the blocking element (17, 18) is adapted to come into physical contact with an end of the first spring (21) and a stop member (22, 23) assembled on the first actuating pin (20) .

6.- A valve arrangement according to claim 1, characterized in that the blocking element (17, 18) has a continuous broken line type shape such that its proximal end is joined by means of a hinge pin (19) to a partition wall of the second and third outlet (16, 15) and its distal end is in physical contact with a cam (61) joined by means of a second actuating pin (62) which is rotatably actuated.

7.- A valve arrangement according to claim 6, characterized in that the cam (61) is adapted to be pivotably assembled to the second actuating pin (62) .

8.- A valve arrangement according to claims 5 and 7, characterized in that the valve arrangement comprises two blocking elements (17, 18) having an amphora-type shape ending in a tip at their proximal end and in a narrow neck at their distal end, being pivotably assembled in the inner chamber (13) .