DE112004000677B4 - Exhaust for an internal combustion engine and three-way valve for such an exhaust - Google Patents

Abstract

An exhaust (1) for an internal combustion engine, comprising upstream of a heat exchange device (2), in parallel with a secondary line (3), means (4) for directing the flow of exhaust gases, said means (4) being provided by a three-way valve (7). is arranged downstream of a conduit (5) which passes the exhaust gases, wherein in the three-way valve (7) a flap (8) with a first flap part (29) and a second flap part (30) is arranged, wherein the The flap (8) has a first position in which the first flap part (29) completely closes the secondary line (3) and has a second position in which the second flap part (30) completely closes the line to the heat exchanger device (2) characterized in that the first and second flap portions (29, 30) are integrally connected at an obtuse angle to each other at an axis of rotation (17), and the flap (8) has a first position in which the first K flap part (29) cooperates with a second seat for closing a second outlet opening (14), and has a second position in which the second flap part (30) cooperates with a first seat for closing a first outlet opening (13), and wherein at closed secondary line (3), the line to the heat exchange device (2) is fully open, and wherein the fully closed line to the heat exchange device (2), the secondary line (3) is fully open.

Description

The invention relates to an exhaust for an internal combustion engine and a three-way valve for such an exhaust.

The present invention relates to the field of the automotive industry and more particularly to those of the equipment which reduce the pollutant emissions resulting from the operation of an internal combustion engine.

An internal combustion engine, in particular a motor vehicle, is completed by an exhaust line, on which a catalyst is very often provided which is intended to reduce the pollutant emissions resulting from the operation of such an engine.

The US 6,141,961 A discloses an exhaust system of a motor vehicle having an internal combustion engine including a main exhaust pipe and a bypass mounted in parallel with the main exhaust pipe. Further, movable means for shutting off the main conduit and movable means for regulating the cross-section of the bypass are disclosed, which means are located in the exhaust system. Furthermore, mechanical means for synchronizing the means controlled by a single actuator are described. However, there is neither disclosed an integral valve, nor that the flap cooperates in a first position with a first seat for closing a first outlet opening and on the other hand in a second position with a second seat for closing a second outlet opening. It is also not described that when the bypass line is completely closed, the other line is fully open at the same time and vice versa.

From the DE 198 54 308 A1 For example, there is known a valve for a motor vehicle having a body having an inlet and at least one outlet connected by a passage, and a shutter in the form of a mobile flap disposed in a chamber of the passageway so as to be interposed between a passage first end position and a second end position is movable and is controlled by a control member.

The US 6,286,306 B1 describes an exhaust gas purification system for an internal combustion engine, which includes a branch from a main exhaust pipe, which is opened or closed by a valve, depending on the speed of the engine and the temperature of the exhaust gases. Furthermore, an adsorbent for the unburned components of the exhaust gases is disclosed.

In this regard, it should be noted that the proper operation of such a catalyst is highly dependent on the temperature the exhaust gases have when they arrive in such a catalyst.

Likewise, it is relatively common to find two catalysts located very close to each other at the upstream part of the exhaust pipe or very close to the engine. One of these catalysts is to treat the carbon monoxide and hydrocarbons as they exit the engine, while the other catalyst, called the "NOx trap", is downstream and more specialized in the treatment of nitrogen oxides.

In this regard, it is observed that each of these catalysts function optimally within a specific temperature range that is different for each of these catalysts.

Therefore, the combination of these catalysts often requires the use of heat exchange means which make it possible to bring these gases into the temperature range which is suitable for the proper operation of the second catalyst, in particular after they have passed through a first catalyst.

It is well understood that to the extent that the temperature of the exhaust gases is changed, especially during the transition phases of the operation of the engine, for example when starting the latter, the option to send these exhaust gases through a heat exchanger, only has to be selected when these exhaust gases have a higher temperature than the normal, or optimal, operating conditions of a catalyst. Conversely, these exhaust gases must penetrate directly into this catalyst without undergoing a cooling phase which would return them to a temperature which is below the optimum operating range.

For this purpose, it is customary to provide a bypass parallel to the heat exchanger, while means for directing the flow of exhaust gases, which are substantially formed by valves upstream of the heat exchanger and this secondary line are arranged to allow the exhaust gases, through the one or the other to flow.

In order to achieve such a result, it has been customary to resort to two valves which operate synchronously to close a flow path of the exhaust gases and at the same time open another.

If the presence of these two valves also complicates a little the execution of the exhaust pipe, since their control must be perfectly synchronous, dangers of deterioration are possible in case of malfunction.

It is an object of the invention to find an answer to this difficulty. This object is achieved by an exhaust and a three-way valve having the features of the independent claims. Advantageous embodiments are described in the dependent claims.

To this end, the invention relates to an exhaust for an internal combustion engine, comprising upstream of a heat exchange device, which is associated in parallel with a secondary line, means for directing the flow of exhaust gases, characterized in that said means are defined by a three-way valve, downstream of a conduit is disposed, which forwards the exhaust gases and comprises a flap with two positions, which is arranged such that it passes these gases through the heat exchange device in a first position and in a second position, these gases through the secondary line passes.

More particularly, the invention relates to a three-way valve for an exhaust pipe of an internal combustion engine intended to direct exhaust gases coming from an upstream pipe in two different directions, especially in the direction of a heat exchange device and a secondary pipe, characterized in that the valve comprises a valve body which is divided into an upstream part of the valve body, comprising an inlet opening for the exhaust gases, and a downstream part of the valve body, which is provided with two outlet openings, wherein these two valve body parts are designed such that, after installation of a flap, the is provided, on the one hand with a first seat for closing a first outlet opening and on the other hand cooperate with a second seat for closing a second outlet opening, can be assembled, wherein each of the seats at least partially vo n is formed at least a portion of the upstream and / or downstream part of the valve body.

The invention will be better understood from the study of the following description, which refers to an embodiment illustrated in the accompanying drawings, in which:

1 is a schematic representation of an exhaust pipe according to the invention;

2 is a schematic representation in the exploded perspective view of a three-way valve according to the invention;

3 an exploded plan view of a valve;

4 is a plan view in section, which corresponds to a particular embodiment of a valve according to the invention after assembly;

5 FIG. 3 is a schematic perspective view corresponding to a detail of the flap corresponding to that in FIG 4 illustrated valve includes.

The present invention relates to the field of the automotive industry and more particularly to those of the equipment that can reduce the emissions of pollutants resulting from the operation of an internal combustion engine.

Thus, the present invention relates to, as in 1 presented an exhaust 1 for an internal combustion engine, with such an exhaust 1 on the one hand a heat exchange device 2 and a secondary line 3 parallel to this heat exchange device 2 is arranged, and on the other hand means 4 to steer the flow of exhaust gases from an upstream pipe 5 come, it includes, these means 4 to steer, these gases, as the case may be, through the heat exchange device 2 or the secondary line 3 to steer the temperature of these exhaust gases when, for example, at a downstream catalyst 6 arrive, to control optimally.

Advantageously, the means 4 for directing this flow of exhaust gases from a three-way valve 7 formed downstream to the upstream line 5 is arranged and a flap 8th comprising two positions, which is arranged such that in a first position, these gases through the heat exchange device 2 be directed and in a second position, these gases through the secondary line 3 be directed.

In particular, the three-way valve includes 7 further a valve body 9 coming from an upstream valve body part 10 of the valve body 9 and a downstream valve body part 11 of the valve body 9 is formed. The upstream valve body part 10 of the valve body 9 includes an inlet opening 12 for the exhaust gases coming from the upstream pipe 5 come while the downstream valve body part 11 of the valve body 9 on the one hand, a first outlet opening 13 that allows, for example, these exhaust gases to the heat exchange device 2 to arrive, and on the other hand, a second outlet opening 14 includes these gases through the bypass 3 to lead.

These upstream 10 and downstream valve body parts 11 are designed so that they can be assembled to the valve body 9 define. For this purpose and as in 2 can be seen, the downstream valve body part 11 a connecting flange 15 intended to be provided with a similar connecting flange 16 cooperate in the region of the upstream valve body part 10 the valve body is defined. Such an assembly is especially after insertion of the flap 8th in the valve body 9 guaranteed.

Another feature of the invention is that this valve body 9 further means, in particular a rotation axis 17 , for the articulation of the flap 8th includes.

After a in 2 illustrated preferred embodiment, these receiving means, in particular a rotation axis 17 , in the region of the downstream valve body part 11 of hemispherical elements 18 . 19 (which are defined in particular by a ceramic or the like), which are arranged diametrically opposite and in which hemispherical or conical parts 20 . 21 can insert, which is also diametrically opposite the flap 8th includes.

As in 2 are one and / or the other of the hemispherical elements 18 . 19 Retractable provided to insert the flap 8th after the intervention of the latter 8th in the downstream valve body part 11 of the valve body 9 to allow more accurate. This downstream valve body part 11 takes through appropriate openings 22 the hemispherical elements 18 . 19 , which are made of ceramic in particular.

It will be readily understood that the invention in no way refers to such an embodiment of this receiving means of the flap 8th is limited. As in 4 can be seen, such recording means 17 also from a rotary axis 17 or the like.

Finally, according to the invention in the valve body 9 provided two seats, which are arranged so that on one of these seats in a first position (shown in broken lines in 4 ) the flap 8th comes to rest, around the first outlet opening 13 to close, in a second position of this flap 8th (Representation in solid lines in 4 ) these 8th on the other seat comes to rest, around the second outlet opening 14 to close.

In this regard, it should be noted that each of these receiving seats is at least in part of at least a portion of the upstream valve body portion 10 and / or a portion of the downstream valve body portion 11 of the valve body 9 is formed.

According to a particular embodiment of the invention, each of these receiving seats of the flap 8th partly from the upstream valve body part 10 and the downstream valve body part 11 of the valve body 9 educated. In summary, a seat of a flap is formed by two half-seats, one of which is in the upstream valve body part 10 of the valve body 9 is located while the other in the downstream valve body part 11 of the valve body is located.

In the 3 is a valve body 9 represented and in the 4 a particular embodiment of a valve body according to the invention 9 shown, comprising on the one hand a first output line 23 , which is intended to a heat exchange device 2 to be connected, and on the other hand, a second output line 24 , which is intended to a secondary line 3 to be connected.

So shows 3 a valve body 9 wherein the downstream valve body part 11 of the valve body 9 assumes a "Y-shape" and the first and second output lines 23 . 24 assume a substantially symmetrical shape to a plane (not shown), at least through the downstream valve body part 11 this valve body 9 runs.

In 4 is a particular embodiment of a valve body according to the invention 9 illustrated, the upstream valve body part 10 an input line 25 which is connected to an upstream pipe 5 is connected and essentially along an axis 26 extends.

According to an embodiment, not shown, the second output line extends 24 (to the secondary line 3 connected) actually along an axis 27 which are essentially to the axis 26 the input line 25 of the valve body 9 parallel or aligned with this.

However, after a in 4 illustrated preferred embodiment of the invention, this second output line extends 24 along an axis 27 that are essentially oblique to the axis 26 the input line 25 of the valve body 9 is aligned.

What the first output line 23 relates (to the heat exchange device 2 connected), this extends laterally (for example in Essentially perpendicular) to the axis 26 the input line 25 especially along an axis 28 that are essentially perpendicular to this axis 26 is aligned.

Such an embodiment favors the flow of gases in the direction of the secondary line 3 (which most of the time and more often than the heat exchange device 2 is used, especially during the full engine load operating phases) and allows the pressure exerted by the incoming gases to be applied to a first flap portion 29 the flap 8th that the second output line 24 closes that to the secondary line 3 is connected, is higher than on a second flap part 30 the flap 8th that is attached to the heat exchange device 2 connected first output line 23 closes.

In addition, it allows the fact that the first output line 23 connected to the heat exchange device 2 is connected, laterally to the axis 26 the input line 25 is defined, due to the preferential discharge of the gases in the to the secondary line 3 connected second output line 24 , a negative pressure in the region of the heat exchanger device 2 connected first output line 23 to produce when this through the flap 8th is closed, this negative pressure causes the stop of the flap 8th in the position for closing this first output line 23 is reinforced.

Furthermore, it allows the execution of these first and second output lines 23 . 24 , the load loss caused by the to the heat exchange device 2 connected first output line 23 caused to decrease, since this first output line 23 used only occasionally (heating the bodywork during a cold start) and under conditions of low gas flow rates.

Furthermore, this embodiment preferably makes it possible, advantageously, to close the heat exchanger device 2 connected first output line 23 to ensure, in the event of failure of a control system of the flap 8th with which the three-way valve 7 can be provided (safety position).

As in the enclosed 4 can be seen, includes the valve body 9 also here an upstream valve body part 10 and a downstream valve body part 11 , which are intended to be assembled in particular by interlocking, to such a valve body 9 to build. In this regard, it should be noted that the input line 25 in the region of the upstream valve body part 10 is defined while the second output line 24 attached to the secondary line 3 is connected, in the region of the downstream valve body part 11 is defined. The first output line 23 connected to the heat exchange device 2 is partially in the area of the upstream valve body part 10 and partly in the region of the downstream valve body part 11 of the valve body 9 Are defined. In particular in the region of the upstream valve body part 10 this first output line 23 the negative pressure prevails, which causes the stop of the flap 8th in the position for closing this first output line 23 is reinforced.

According to a further feature of the invention, the flap takes 8th an asymmetric geometry, as in the 4 and 5 you can see.

In this regard, it is observed that this flap 8th is actually defined such that the surface of the incoming gases offered in the region of the first flap part 29 this flap 8th which is arranged so that the to the secondary line 3 connected second output line 24 is closed, larger than in the area of the second flap part 30 this flap 8th is arranged such that the to the heat exchange device 2 connected first output line 23 is closed.

Such an embodiment also allows (and with the above-mentioned effects) that the pressure exerted by the incoming gases on the first flap part 29 the flap 8th who sent the to the secondary line 3 connected second output line 24 closes, is larger than on the second flap part 30 the flap 8th that is attached to the heat exchange device 2 connected first output line 23 closes.

An additional feature is that the flap 8th Means, which are arranged so that they are a guide of the input line 25 Ensuring incoming gas flow, in the direction of the to the secondary line 3 connected second output line 24 , Such a guide is at least in the Verschließstellung of the heat exchange device 2 connected first output line 23 through the fold 8th guaranteed.

Such guide means preferably make it possible on the flap 8th , But also on the means for articulated recording, in particular a rotation axis 17 , the flap 8th on the valve body 9 reduce incoming heat flow.

These guide means also make it possible to detach the flap 8th from the seat on which it rests, to the heat exchanger device 2 connected first output line 23 to close, to reduce.

As in particular in 5 As can be seen, these guide means are actually of a concave deformation 31 that shut the door 8th has, in particular in the region of its first flap part 29 who sent the to the secondary line 3 connected second output line 24 to close.

Such a concave deformation 31 it also allows the flap 8th a higher stiffness against the thermal stresses from the gases on the flap 8th to be exercised, in particular in the position of closure by the latter.

Finally, the receiving means define the flap 8th a rotation axis 17 this flap 8th , where this axis of rotation 17 is arranged in the input cone, the circumference of this flap 8th represents. Thereby, it is preferably possible to minimize the bow chain, which results in the dispersion of the positioning, in order to improve its tightness.

It should be noted that the invention described above finds particular (but by no means limiting) application when it comes to using the exhaust gases to ensure the heating of the bodywork of a vehicle, in particular recourse to a heat exchange device as mentioned above ,

Claims (10)

Exhaust ( 1 ) for an internal combustion engine, comprising upstream of a heat exchange device ( 2 ), which has a secondary line ( 3 ), means ( 4 ) for directing the flow of exhaust gases, these means ( 4 ) by a three-way valve ( 7 ) downstream of a conduit ( 5 ) is arranged, which forwards the exhaust gases, wherein in the three-way valve ( 7 ) a flap ( 8th ) with a first flap part ( 29 ) and a second flap part ( 30 ), wherein the flap ( 8th ) has a first position in which the first flap part ( 29 ) the secondary line ( 3 ) completely closes, and has a second position in which the second flap part ( 30 ) the line to the heat exchange device ( 2 ) completely closed, characterized in that the first and second flap parts ( 29 . 30 ) at an obtuse angle integral with each other at a rotational axis ( 17 ) and the flap ( 8th ) has a first position in which the first flap part ( 29 ) with a second seat for closing a second outlet opening ( 14 ) cooperates, and has a second position in which the second flap part ( 30 ) with a first seat for closing a first outlet opening ( 13 ) and with fully closed secondary line ( 3 ), the line to the heat exchange device ( 2 ) is fully open and wherein with the line completely closed to the heat exchange device ( 2 ), the secondary line ( 3 ) is completely open. Three-way valve ( 7 ) in an exhaust line of an internal combustion engine, which is intended to exhaust gases from an upstream line ( 5 ), in two different directions, in particular in the direction of a heat exchange device ( 2 ) and a secondary line ( 3 ), the three-way valve ( 7 ) a valve body ( 9 ) with seats that fit into an upstream valve body part ( 10 ) of the valve body ( 9 ), comprising an inlet opening ( 12 ) for the exhaust gases, and a downstream valve body part ( 11 ) of the valve body ( 9 ), which has two outlet openings ( 13 . 14 ), these two valve body parts ( 10 . 11 ) are designed such that one in the valve body ( 9 ) arranged flap ( 8th ) a first flap part ( 29 ) and a second flap part ( 30 ), wherein the two valve body parts ( 10 . 11 ) are mountable in such a way that each of the seats is at least partially offset by at least a portion of the upstream ( 10 ) and / or downstream part ( 11 ) of the valve body ( 9 ), characterized in that the first and second flap parts ( 29 . 30 ) at an obtuse angle integral with each other at a rotational axis ( 17 ) and the flap ( 8th ) has a first position in which the first flap part ( 29 ) with a second seat for closing a second outlet opening ( 14 ) cooperates, and has a second position in which the second flap part ( 30 ) with a first seat for closing a first outlet opening ( 13 ) and with fully closed secondary line ( 3 ), the line to the heat exchange device ( 2 ) is completely open and that when the line is completely closed to the heat exchange device ( 2 ), the secondary line ( 3 ) is completely open. Three-way valve ( 7 ) according to claim 2, characterized in that on the one hand in the region of the upstream valve body part ( 10 ), the entrance opening ( 12 ), an input line ( 25 ) connected to the upstream pipe ( 5 ) and on the other hand in the region of the downstream part ( 11 ), the outlet openings ( 13 . 14 ), a first output line ( 23 ) connected to a heat exchange device ( 2 ), and a second output line ( 24 ) connected to a secondary line ( 3 ) connected. Three-way valve ( 7 ) according to claim 3, characterized in that the downstream part ( 11 ) assumes a "Y-shape" and that the two output lines ( 23 . 24 ) has a substantially symmetrical shape to a plane passing through at least this downstream part ( 11 ), accept. Three-way valve ( 7 ) according to claim 3, characterized in that on the one hand the input line ( 25 ) along an axis ( 26 ) and on the other hand, the second output line ( 24 ) to a secondary line ( 3 ) is connected and along an axis ( 27 ) substantially parallel to an axis ( 26 ) of the input line ( 25 ) is parallel or aligned with it or substantially oblique to the axis ( 26 ) of this input line ( 25 ) is aligned. Three-way valve ( 7 ) according to one of claims 4 or 5, characterized in that the to the heat exchanger ( 2 ) connected output line ( 23 ) laterally to the axis ( 26 ) of the input line ( 25 ) along an axis ( 28 ) substantially perpendicular to this axis ( 26 ) is aligned. Three-way valve ( 7 ) according to one of claims 3 to 6, characterized in that the flap ( 8th ) has an asymmetric geometry and is defined such that the area provided for the incoming gases in the region of a first flap part ( 29 ) of this flap ( 8th ), which is arranged in such a way that to the secondary line ( 3 ) connected second output line ( 24 ) is larger than in the area of a second flap part ( 30 ) of this flap ( 8th ), which is arranged in such a way that the heat exchanger ( 2 ) connected first output line ( 23 ), whereby the pressure exerted by the incoming gases on the first flap part ( 29 ) is greater than on the second flap part ( 30 ). Three-way valve ( 7 ) according to one of claims 3 to 6, characterized in that the flap ( 8th ) Comprises means provided for directing a guide from the input line ( 25 ) in the direction of the to the secondary line ( 3 ) connected second output line ( 24 ). Three-way valve ( 7 ) according to claim 8, characterized in that the guide means of a concave deformation ( 31 ), the flap ( 8th ), in the region of the first flap part ( 29 ), which is designed such that it is connected to the secondary line ( 3 ) connected second output line ( 24 ), are formed. Three-way valve ( 7 ) according to one of claims 2 to 9, characterized in that each of the seats is partly of each of the upstream and downstream valve body parts ( 10 . 11 ) of the valve body ( 9 ) is formed.

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