EP3390870A1

EP3390870A1 - Double flapped switch valve for controlling the re-circulation exhaust passage

Info

Publication number: EP3390870A1
Application number: EP16875043.8A
Authority: EP
Inventors: Ritesh Duhan; Suraj Sharma; Hitoshi Kawai; Takuo IWAHASHI; Kabir BHANDARI; Sandeep ANTIL
Original assignee: Padmini VNA Mechatronics Pvt Ltd
Current assignee: Padmini VNA Mechatronics Pvt Ltd
Priority date: 2015-12-18
Filing date: 2016-12-19
Publication date: 2018-10-24
Also published as: WO2017103901A1; EP3390870A4

Abstract

The switch valve assembly comprises of at least two butterfly flaps, at least one primary outer bigger flap and at least one secondary smaller inner flap, mounted coaxially to the rotatable shaft, the bigger flap overlaying the smaller flap to control the EGR flow path more effectively and efficiently by effectively sealing the EGR flow path for an extended period of time; the additional flap allows complete sealing of the passage and further allows exposure of comparatively less surface area so that the soot deposited on the housing of the switch valve would be exposed to a lesser surface area therefore the breakaway force required is less; and the angle of the double flapped butterfly flap is customizable to cover all angles less than 90 degree, or the housing centre wall and stopper wall is optimized accordingly

Description

"DOUBLE FLAPPED SWITCH VALVE FOR CONTROLLING THE RECIRCULATION EXHAUST PASSAGE"

FIELD OF THE INVENTION

The present invention provides a double napped switch valve for controlling the re-circulation exhaust passage. More specifically, the present invention provides switch valve assembly comprises of at least two butterfly flaps, mounted coaxially, the bigger flap overlaying the smaller flap to seal the re-circulation exhaust passage of the EGR flow path more effectively and efficiently, over an extended period of time.

BACKGROUND OF THE INVENTION An EGR valve reduces the harmful gases such as Nitrogen oxides and keeps the vehicular emission under check. One of the main challenges while applying an EGR valve is mixing of the hot and temperature controlled exhaust gas for more efficient burning of the fuel. A switch valve is installed to help in switching between the hot and temperature controlled exhaust gas. A switch valve is installed between the exhaust manifold and intake manifold. The switch valve has 2 passages, allowing gases directly from the exhaust manifold or indirectly through a cooler. The purpose of two channels of intake is to precisely regulate the temperature of the intake exhaust. However, sometimes the temperature has to be stepped up, especially during winter or when an engine has just started running. The temperature required during such operation. Therefore, when the recycled gases are required at a higher temperature then the passage (passage 1) is opened to directly allow the gases from the exhaust manifold. Similarly, when less temperature is required then the other passage (passage 2) is opened allowing the cooled exhaust gas. This process has to be carefully regulated, therefore precise channelling is required. At present most of the switch valve provides two passages that is being regulated by an L or a V-shaped flap that is attached to an actuator that selectively blocks one passage to regulate the temperature of the re-circulated gas, when the actuator is rotated in its axis. The L shaped flap provides simplicity of design and avoids installing two flaps. This further reduces the work load on the actuator as the shaft having the L shaped flap or a V-shaped flap does not have to rotate completely, thus reducing the load on the actuator.

Although, the prior art has several advantages, however there are some key aspects that are missing. One of the key aspects is that the L-shaped flap or a V- shaped flap is constantly being rotated to regulate the temperature of the exhaust re-circulated. Over a period of time due to the soot deposition, the flap sticks on the housing of the switch valve, therefore the breakaway force required by the actuator increases manifold. Further, due to constant impact on the housing the shape changes that leads to incomplete sealing of the passage. Although, the prior art have sighted sealants to be affixed, but high temperature, pressure and constant impact renders them useless.

The following prior art:

US7438062B2 provides flow passage switching valve provided with a swing arm type valve element comprises a housing formed with a first passage communicated with an inlet port, a second passage communicated with an outlet port, a bypass passage for providing communication between the first passage and the second passage, an introduction port through which a fluid flowing in the first passage is introduced into an external part, and a discharge port through which the fluid introduced into the external part is discharged into the second passage; and

US6484703B1 provides a valve for use in an EGR system for an internal combustion engine has a housing having an exhaust inlet, an EGR outlet, an exhaust outlet and a bleed air inlet. A butterfly plate is pivotally connected to the housing. The butterfly plate has at least a first position and a second position, wherein the first position defines a first fluid path between the exhaust inlet and the EGR outlet and defines a second fluid path between the bleed air inlet and the exhaust outlet, and wherein the second position defines a third fluid path between the exhaust inlet and the exhaust outlet and defines a fourth fluid path between the bleed air inlet and the EGR outlet.

All of the prior art enumerated have butterfly valve or plate having single butterfly flaps, where a new switch valve is required that provides at least one additional flap allowing complete sealing of the passage and further allowing exposure of comparatively less surface area so that the soot deposited on the housing of the switch valve would be exposed to a lesser surface area therefore the breakaway force required shall be less. The lesser breakaway force means reducing the operational load on the actuator, that further obviates the need of complex seals to be attached on the flap.

OBJECT OF THE INVENTION

The primary object of the invention is to provide a double flapped switch valve for controlling the re-circulation exhaust passage.

Yet another object of the invention is to provide a switch valve with at least one flap mounted either coaxially, non-coaxially or eccentrically. Yet another object of the invention is to provide a double flapped switch valve for efficient sealing of the gas passages to accurately control the temperature of the fluid entering the EGR valve, even after prolonged usage.

Yet another object of the invention is to provide a double flapped switch valve acting as an effective sealant due to two flaps effectively avoiding any leakage, by changing the design of the switch valve, which is not affixed, rather is a permanent installation that increases the longevity of the product, by holding its shaped under high pressure, temperature and impact. Yet another object of the invention is to provide double flapped switch valve wherein one flap is preferably smaller than the other or some.

Yet another object of the invention is to provide double flapped switch valve, preferably one flap smaller than the other to allow the contact of the smaller flap with the housing of switch valve to reduce the surface area in contact to decrease the breakaway force provided by the actuator.

Yet another object of the invention is to provide a double flapped switch valve that is independent of angle i.e. the working of the flap is not affected by the angle between them as the housing centre wall and stopper wall are optimized accordingly.

Yet another object of the invention is to provide double flapped switch valve with high longevity due to enhanced actuator life.

Yet another object of the invention is to provide double flapped switch valve that can be used in one passage to split in two passages or two passages to direct in one passage.

Yet another object is to mount the smaller flap with bigger flap for providing structural rigidity.

Yet another object is to mount the smaller flap with bigger flap for providing additional recoil breakaway force due to its spring action. Yet another object is to mount the smaller flap with bigger flap for reducing leakage through valve.

Yet another object is to mount the smaller flap with bigger flap for providing better fatigue life.

Still another object of the invention is to provide a double flapped switch valve that has a primary flap that is bigger and a secondary flap that is smaller, attached co-axially, to effectively seal the hot gas passages and the temperature controlled gas passage for a longer duration; and further negating the effect of soot deposition by providing a flap exposing lesser surface area to minimize the breakaway force exerted by the actuator.

SUMMARY OF THE INVENTION The present invention provides a double flapped switch valve for controlling the re-circulation exhaust passage. The switch valve comprising of two flaps, at least one primary outer flap and at least one secondary inner flap, mounted coaxially to the rotatable shaft, the bigger flap overlaying the smaller flap to control the EGR flow path more effectively and efficiently by effectively sealing the Exhaust gas re-circulation passage for an extended period of time.

In an embodiment of the current invention the present invention provides double flapped switch valve that is attached coaxially to the rotatable shaft for additional sealing of the selective passage, (passage 1 or passage 2). The shaft attached to an actuator, for controlled rotation, covering the passage, selectively and alternately. In yet another embodiment of the current invention, the angle of the wing portion of the double flapped switch valve is independent of the angle, that it can be customized to cover all angles less than 90 degree, as the housing centre wall and stopper wall is optimized accordingly.

In yet another embodiment of the current invention, the flow path double flapped switch valve selectively allows passage 1 while completely blocking passage 2 or blocks passage 1 while completely allowing passage 2 wherein the additional flap allows complete sealing of the passage as applied and further allows exposure of comparatively less surface area so that the soot deposited on the housing of the switch valve would be exposed to a lesser surface area therefore the breakaway force required shall be less. The lesser breakaway force means reducing the operational load on the actuator. This further obviates the need of complex seals to be attached on the flap. In yet another embodiment of the present invention the smaller flap mounted with bigger flap also provides structural rigidity, provides additional recoil breakaway force due to its spring action, reduces leakage through valve and provides better fatigue life.

BRIEF DESCRIPTION OF THE DRAWINGS

A complete understanding of the system and method of the present invention may be obtained by reference to the following drawings:

Figure 1 provides the exploded view of the double flapped switch valve; Figure 2 provides the plan view of the double flapped switch valve;

Figure 3 provides the cross sectional view of the double flapped switch valve showing the working on passage 1 ;

Figure 4 provides the cross sectional view of the double flapped switch valve showing the working on passage 2; and Figure 5 provides the cross sectional view of the double flapped switch valve at an intermittent position.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art. Figure 1 provides the exploded view of the double flapped switch valve, elucidating the main components of the most preferred embodiment. The double flapped switch valve comprising of a shaft 102, at least one primary flap 103 and at least one secondary flap 104. This assembly is further connected to an actuator 101 to rotate the shaft 102 and to an EGR housing having passage 1, 105 and passage 2, 106. The modified EGR valve with double flapped switch valve wherein at least one primary flap 103 and at least one secondary flap 104 is mounted co-axially as shown in the diagram.

Figure 2 provides the plan view of the double flapped switch valve in an EGR valve. The figure illustrates the actual arrangement of the double flapped switch valve in an EGR valve, accurately representing the position of the actuator 101, relative to the double flapped switch valve installed on the shaft 102 to rotate the shaft.

Figure 3 provides the cross sectional view of the double flapped switch valve showing the working on passage 1 where the temperature of the re-circulated exhaust gases are regulated by allowing the gases at a higher temperature to directly enter the switch valve from the exhaust manifold from the passage 105 (passage 1), shown open and the other passage 106 (passage 2) shown closed. The rotatable double flapped switch valve is attached to a shaft 102 and has 2 flaps, primary flap 103 and secondary flap 104 co-axially mounted. Further, the secondary flap 104 is shown blocking the central valve.

Figure 4 provides the cross sectional view of the double flapped switch valve showing the working on passage 2 where the temperature of the re-circulated exhaust gases are maintained by allowing the cooled exhaust gas from the passage 106 (passage 2) to directly allow the gases from the exhaust manifold and the other passage 105 (passage 1) is closed. The rotatable double flapped switch valve is attached to a shaft 102 and has 2 flaps, primary flap 103 and secondary flap 104 co-axially mounted. Further, the secondary flap 104 is shown blocking the central valve. Figure 5 provides the cross sectional view of the double flapped switch valve at an intermittent position, facilitating partial allowance of the gases at a higher temperature to directly enter the switch valve from the exhaust manifold from the passage 105 (passage 1) and of the cooled exhaust gas from the passage 106 (passage 2). The rotatable double flapped switch valve is attached to a shaft 102 and has 2 flaps, primary flap 103 and secondary flap 104 co-axially mounted.

In an embodiment of the current invention a double flapped EGR valve comprising of a housing with an inlet and an outlet constituting the EGR flow path; a switch valve assembly enclosed in the housing controlling the inlet and outlet with a butterfly flap mounted on a rotatable shaft powered by an actuator; wherein: the switch valve assembly comprises of at least two butterfly flaps, at least one primary outer bigger flap and at least one secondary smaller inner flap, mounted coaxially to the rotatable shaft, the bigger flap overlaying the smaller flap to control the EGR flow path more effectively and efficiently by effectively sealing the EGR flow path for an extended period of time; the additional flap allows complete sealing of the passage and further allows exposure of comparatively less surface area so that the soot deposited on the housing of the switch valve would be exposed to a lesser surface area therefore the breakaway force required is less; and the angle of the double flapped butterfly flap is customizable to cover all angles less than 90 degree, or the Housing Centre wall and stopper wall is optimized accordingly.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

CLAIMS We Claim:

1. A double flapped EGR valve comprising of a housing with an inlet and an outlet constituting the EGR flow path; a switch valve assembly enclosed in the housing controlling the inlet and outlet with a butterfly flap mounted on a rotatable shaft powered by an actuator; wherein: the switch valve assembly comprises of at least two butterfly flaps, at least one primary outer bigger flap and at least one secondary smaller inner flap, mounted coaxially to the rotatable shaft, the bigger flap overlaying the smaller flap to control the EGR flow path more effectively and efficiently by effectively sealing the EGR flow path for an extended period of time; the additional smaller flap allows complete sealing of the passage and further allows exposure of comparatively less surface area so that the soot deposited on the housing of the switch valve would be exposed to a lesser surface area therefore the breakaway force required is less; the smaller flap mounted with bigger flap also provides structural rigidity, provides additional recoil breakaway force due to its spring action, reduces leakage through valve and provides better fatigue life; and the angle of the double flapped butterfly flap is customizable to cover all angles less than 90 degree, or the housing centre wall and stopper wall is optimized accordingly.

2. The double flapped EGR valve as claimed in the claim 1, wherein the shaft is attached to an actuator for controlled rotation, covering the passage, selectively and alternately.

3. The double flapped EGR valve as claimed in the claim 1, wherein which said butterfly flaps are aluminum or an aluminum alloy, stainless steel or other heat resistant metals or non metals.

4. The double flapped EGR valve as claimed in the claim 1, wherein the switch valve with at least one flap mounted to the rotatable shaft either coaxially, non-coaxially or eccentrically.

5. The double flapped EGR valve as claimed in the claim 1, wherein the double flapped switch valve accurately controls the temperature of the fluid entering the EGR valve even after prolonged usage.

6. The double flapped EGR valve as claimed in the claim 1, wherein the one flap is smaller than the other to allow the contact of the smaller flap with the housing of the switch valve to reduce the surface area in contact to decrease the breakaway force provided by the actuator.

7. The double flapped EGR valve as claimed in the claim 1, wherein the smaller flap mounted with bigger flap also provides structural rigidity by providing additional force due to its spring action, reduced leakage through valve and better fatigue life.