DE19500565B4 - valve assembly - Google Patents

Abstract

valve assembly for mixing fluids, with an inlet for a first Fluid occluding within a leadership for a second fluid arranged valve seat, one with a negative pressure acted upon actuation device for the Valve seat and a switching means for the actuator, wherein the Switching means and the actuating device form a mounting unit and arranged in a common housing are characterized in that the housing (76) has a first housing portion (78) for receiving the actuator (26) and a second housing area (80) for receiving the switching means (22), that the two housing areas (78, 80) are arranged side by side, that the first housing portion (78) is closed with a membrane lid (92), which with a joint (120) executed is that the second case area (80) is associated with a connecting piece (110) which is connected to the connecting piece (120) is detachable, so that the connecting piece (120) and the connecting piece (110) a vacuum connection (34) between the switching means (22) and the actuator (26) train.

Description

The The invention relates to a valve arrangement, in particular for an exhaust gas recirculation valve for internal combustion engines, according to the preamble of claim 1.

It is known in motor vehicles, in particular in motor vehicles, as a combustion engine using a diesel engine, exhaust gas recirculation valves use. These serve to the intake air of the internal combustion engine Add the exhaust gas of the internal combustion engine, so as to an oxygen content of the Reduce intake air. By reducing the oxygen content in the intake air is achieved in that in the internal combustion engine the incipient combustion process, the formation of nitrogen oxides can be minimized.

The DE 7313731 U shows an exhaust gas recirculation valve with a flanged to a valve body actuator and with a connection to the suction pipe controlling solenoid valve for actuating the actuator.

The US 4,919,168 shows a valve assembly consisting of a housing in which a differential pressure controlling, electromagnetically actuated pilot valve and a pressure actuated by the main valve are arranged, the closing body allows an optional connection between an output terminal and at least one input terminal.

Another exhaust gas recirculation valve is for example from the DE 42 27 739 A1 known.

in this connection is an inlet port for a first fluid, for example, a hot one Exhaust, within a guide for a second fluid, for example air, arranged. The inlet opening penetrates Here is a wall of the leadership for the second fluid. The inlet port is closed by means of a valve seat, which via an actuating device open or can be closed. For motor vehicles this usually acted upon by a negative pressure actuators used. These have a pressurizable with a negative pressure Membrane, with a valve seat closing or opening Locking body coupled is. Depending on the degree of opening and / or opening duration the valve seat is a defined admixture of the exhaust gas to the fresh air. The control of the actuator via a Switching means comprising a vacuum source with the diaphragm of the actuator combines. For example, magnetic valves or are known electropneumatic converters.

at the known valve arrangements is disadvantageous in that the actuating device and the switching means relatively distant from each other in the engine compartment of the Motor vehicle are arranged. This results in a relative long switching path for the negative pressure, so that between the operation the switching means and the triggering the actuator a time delay and / or a loss of efficiency arises, the one of the intentional mixing of the exhaust gas with the fresh air deviating mixing leads.

Advantages of invention

The Valve arrangement according to the invention with the features mentioned in claim 1 offers the other hand Advantage that the Efficiency losses in the application of the actuator be minimized so far with the negative pressure that a delay between the release of the Switching means and the opening or close of the valve seat negligible is small. Because that Switching means and the actuating device form a mounting unit, it becomes possible, this directly with each other to couple, so that a Switching path between the switching means and the actuator on the structurally necessary minimum size can be limited. By the execution as a common mounting unit is still a mounting relief of achieved entire valve assembly, since now a separate arrangement the exhaust gas recirculation valve and the switching means deleted, so that in a single assembly step, the entire compact unit mountable is.

In an advantageous embodiment of the valve arrangement is provided that the switching means and the actuating device are arranged in a common housing, which is preferably closed by a tight-closing lid, in which the switching connection between the switching means and the actuating device is integrated simultaneously. This makes it possible in a simple manner, in the assembly, the actuating device and the switching medium in the designated areas of the housing to use and lock it by means of the lid, wherein at the same time the connection between the switching means and the actuator is realized to act on the negative pressure , Thus, a complete valve assembly is achieved without any great installation effort, which can be pre-assembled with a few simple steps, so that when installing the valve assembly in a motor vehicle no additional connection costs incurred. As a result, a particularly cost-effective installation is possible. Furthermore, it is advantageous if the housing and the lid for the Actu supply device and the switching means consists of a plastic injection molded part, so that by means of known plastic injection techniques a mass and therefore inexpensive production of the housing parts of the valve assembly is possible.

Further advantageous embodiments of the invention will become apparent from the rest in the dependent claims mentioned features.

drawings

The Invention will be described below in an embodiment with reference to the accompanying drawings explained in more detail. It demonstrate:

1 schematically an exhaust gas recirculation of an internal combustion engine, which simultaneously reflects the prior art;

2 a sectional view through a valve assembly according to the invention and

3 a plan view of the valve assembly with the cover removed.

description of the embodiment

In the 1 is the schematic diagram of an exhaust gas recirculation shown. This schematic diagram simultaneously illustrates the criticized state of the art. The main component of exhaust gas recirculation is one here in general 10 designated exhaust gas recirculation valve. Furthermore, a cylinder chamber 12 an internal combustion engine shown, on the one hand with an intake 14 and on the other hand with an exhaust passage 16 connected is. The intake channel 14 and the exhaust duct 16 be in well known manner via valves 18 with the cylinder chamber 12 connected. From the exhaust duct 16 leads a bypass 20 to the intake passage 14 , In the bypass 20 is the exhaust gas recirculation valve 10 arranged, thus connecting the bypass 20 to the intake passage 14 can open or close. The exhaust gas recirculation valve 10 is via a switching means 22 controlled, which is a vacuum source 24 with an actuating device 26 the exhaust gas recirculation valve 10 combines. The switching means 22 is from a control unit 28 activated, with an injection pump 30 and an accelerator pedal 32 a motor vehicle, not shown, is connected. The switching means 22 is via a first vacuum connection 34 with the actuator 26 and a second vacuum connection 36 with the vacuum source 24 connected. The switching means 22 can thus in dependence on one of the control unit 28 provided control signal, the vacuum source 24 on the actuator 26 switch through, so that the actuator 26 the exhaust gas recirculation valve 10 opens or closes.

During operation of the internal combustion engine is via the intake passage 14 Fresh air sucked into the fuel by means of the injection pump 30 is injected. In which the intake duct 14 opening valve 18 the fuel-air mixture flows into the cylinder chambers 12 , There, the well-known combustion process takes place by the fuel-air mixture is ignited by means of an ignition source. After completion of the combustion process is over the the exhaust duct 16 associated valve 18 the exhaust gas in the exhaust duct 16 pushed out. Part of the exhaust gas is passing through the bypass 20 on the exhaust gas recirculation valve 10 directed. Depending on an engine management and an operating state of the motor vehicle, such as an engine speed, a coolant temperature, a boost pressure, etc., is of the control unit 28 a switching pulse for the switching means 22 provided, thus the actuator 26 the exhaust gas recirculation valve 10 actuated. With the exhaust gas recirculation valve open 10 will connect the bypass 20 and the intake channel 14 made so that over the bypass 20 a partial flow of the exhaust gas of the fresh air can be added.

As a result, for example, the proportion of oxygen in the fresh air can be reduced, so that in the cylinder chambers 12 running combustion processes a smaller amount of nitrogen oxides. In order to achieve the most accurate possible metered addition of the fresh air zugemengten exhaust gas, must between that of the control unit 28 provided control pulse and the opening of the exhaust gas recirculation valve 10 by means of the actuating device 26 a timely relationship exist. This is essentially due to the length of the first vacuum connection 34 determines that via the second vacuum connection 36 at the switching means 22 applied negative pressure on the actuator 26 turns on. The switching means 22 In this case, for example, it may be a solenoid valve or an electropneumatic converter, which, depending on their switching state, the vacuum connections 34 and 36 separate or connect with each other.

In the 2 is a common with 38 designated valve assembly according to the invention. The valve arrangement 38 on the one hand, the exhaust gas recirculation valve 10 and on the other hand, the switching means 22 on. The exhaust gas recirculation valve 10 has a valve sleeve 40 on that a wall area 42 of the intake duct 14 be upheld. The wall area 42 this can be an immediate part of intake duct 14 may, however, also as a separate sleeve, that is as Ansaugkanalabschnitt 1 into a suction channel 14 be fitted. In this case, both sides would be here with 44 designated wall area a fresh air side area 46 and an engine-side area 48 of the intake duct 14 connect.

The valve sleeve 40 has a larger diameter guide section 50 by a flange 52 is guided. The flange 52 has for this purpose a passage opening 54 into which the valve sleeve 40 with her leadership section 50 is fitted. The flange 52 in turn is at a neck 56 attached to the wall area 42 of the intake duct 14 arises. The stub 56 has a passage opening 58 through which the valve sleeve 40 in the exhaust duct 14 protrudes. A diameter of the passage opening 58 is chosen larger than a diameter of the valve sleeve 40 so that between the neck 56 and the valve sleeve 40 an annulus 60 results. The annulus 60 stands with an interior 62 of the intake duct 14 in connection. The valve sleeve 40 has an air guide element 64 leading to the fresh air side area 46 of the intake duct 14 extends. At the intake port 14 opposite side 66 the valve sleeve 40 is the in 1 shown bypass 20 connected.

The valve sleeve 40 diametrically opposite is at the intake 14 the actuating device 26 for the exhaust gas recirculation valve 10 arranged. The actuating device 26 has a valve stem 68 on, which is a jack 70 of the intake duct 14 be upheld. The socket 70 has one on both sides of the Wandabschittes 44 cantilevered, sleeve-shaped Be rich 72 respectively 74 , The area 74 is integral with a housing 76 formed, which has a first housing portion 78 and a second housing portion 80 has. Within the first housing area 76 is one with the valve stem 68 firmly connected diaphragm plate 82 arranged, which is a membrane 84 wearing. The membrane 84 has on its outer periphery a sealing portion 86 which is in a recess 88 of the housing area 78 intervenes. The diaphragm plate 82 supports against the force of an elastic spring element 90 on a membrane lid 92 from. The membrane lid 92 forms a dome for this purpose 94 out, at the bottom of it 96 a guide section 98 for the spring element 90 is provided. The diaphragm plate 82 in turn has a ring collar 100 that is the spring element 90 fixed. The membrane lid 92 is on the case 76 latched, with a circumferential latch 102 at the same time against the sealing portion 86 the membrane 84 press and thus this in the recess 88 fixed. At his the diaphragm plate 82 opposite side carries the valve stem 68 a valve ring 104 that with the valve sleeve 40 a valve seat 106 formed.

In the housing area 80 of the housing 76 is the switching means 22 arranged, which may be for example a solenoid valve or an electro-pneumatic converter. The switching means 22 has a connecting piece 108 to which the in 1 shown second vacuum connection 36 is connectable. Furthermore, the switching means has 22 a second connecting piece 110 that of a trunk 112 of the membrane lid 92 is overruled. The trunk 112 has a coupling part for this purpose 113 that the connecting piece 110 can embrace. The trunk 112 also has a passage opening 114 that have an interior 116 the actuator 26 with the connecting piece 110 combines. The passage opening 114 can be formed by staggered holes, punctures or the like. The passage opening 114 can sections 120 having different diameters. The trunk 112 is with the membrane lid 92 formed integrally, which preferably consist of a plastic injection molded part, so that the passage opening 114 can be provided during the injection process. The passage opening 114 forms the in 1 shown first vacuum connection 34 , Between the trunk 112 and the connecting piece 110 is a sealing element 116 ' , For example, an O-ring provided. The switching means 22 also has a connection area 118 about this with the controller 28 can be contacted.

In the 2 shown valve assembly 38 performs the following function:
During operation of the internal combustion engine, not shown, the intake passage 14 constantly flushed with fresh air. At the same time the valve sleeve 40 over the bypass 20 acted upon by the exhaust gas of the internal combustion engine. The exhaust gas in this case, for example, has a temperature of about 400 ° C, while the intake passage 14 passing fresh air has approximately ambient temperature. In the initial state of the valve assembly 38 is the valve seat 106 closed, that is, the valve ring 104 is over the valve stem 68 and the diaphragm plate 82 by means of the force of the spring element 90 against the opening of the valve sleeve 40 pressed, so that an exit of the exhaust gas in the intake passage 14 not possible. The the intake channel 14 passing fresh air flows around the valve sleeve 40 , wherein by means of the air guide element 64 a part of the fresh air into the annulus 60 is directed. This ensures that the valve sleeve 40 in her directly on the wall area 42 the exhaust duct 14 lying region is cooled, so that the intake passage 14 may consist of a less heat-resistant material, such as plastic, without this coming into direct contact with the hot exhaust gas.

About the connection piece 108 is constantly one from the vacuum source 24 ( 1 ) provided negative pressure. The switching means 22 is in a closed state, that is, the connecting piece 108 is from the connecting piece 106 separated, for example, by a closing body, not shown, the connection path between the connecting piece 108 and 110 within the switching means 22 closes. Now via the control unit 28 a control signal is provided which supplies a certain amount of exhaust gas to the intake passage 14 passing fresh air is to be mixed, via the switching means 22 the connecting pieces 108 and 110 separated from each other closing body led out of the connection, so that the on the second vacuum connection 36 fitting negative pressure on the interior 116 of the actuating means 26 is switched through. Due to the extremely short connection path via the first vacuum connection 34 is the at the connecting piece 108 applied negative pressure without time delay and without relevant loss of efficiency immediately in the interior 116 issue. As a result of in the interior 116 adjacent negative pressure is the diaphragm plate 82 against the force of the spring 90 moved so that over the coupling of the valve stem 68 the valve ring 104 from the valve sleeve 40 is moved away, so that the valve seat 106 is opened. Through the open valve seat 106 can now via the bypass 20 the exhaust gas into the inside of the intake duct 14 reach prevailing fresh air flow. Due to the prevailing flow, the exhaust gas is injected and mixed on its transport path to the cylinder chambers 12 with the fresh air. Over a period of time and a height of the interior 116 prevailing negative pressure is the opening duration and the opening degree of the valve seat 106 certainly. Thus, the amount of the exhaust gas mixed in the fresh air is directly related to the time duration and the opening degree of the valve seat 106 dependent. As a result of the short connection path between the constantly on the connecting piece 108 applied vacuum and the actuating means 26 a substantially delay-free actuation of the valve seat 106 can take place, is a defined high-precision admixture of the exhaust gas 20 possible to the fresh air flow.

Overall, the valve assembly 38 constructed as a very compact unit, which is for example formed integrally as a plastic injection molded part, which the Ansaugkanalabschnitt 15 including its neck 56 and socket 70 as well as the housing 76 includes. This plastic base can easily with the valve sleeve 40 , the actuating device 26 and the switching means 22 be completed, so that when installed in a motor vehicle, only a connection to the bypass 20 , the second vacuum connection 36 and the controller 28 must be done. The assembly effort is thus drastically reduced compared to the previous solutions, so that a cost saving occurs. By the integration of the first vacuum connection 34 in the membrane lid 92 Furthermore, a source of errors for leaks is avoided, since a leak test can be carried out before installation in motor vehicles.

In the 3 is the intake passage section 15 with the molded housing 7b shown again in a front view. In this illustration is the membrane lid 92 not shown. Same parts as in 2 are provided with the same reference numerals and not explained again. On the basis of this view, once again the compact construction of the intake passage section 15 clearly, at the same time the housing areas 78 respectively 80 having. Thus, in a confined space, the necessary actuator 26 and the necessary switching means 22 be housed. This intake passage section 15 can after completion - as in 2 shown - are provided as a structural unit, so that the necessary installation effort in the installation, for example in the engine compartment of a motor vehicle, limited to a necessary minimum. Here are only the Ansaugkanalabschnitt 15 on its fresh air side area 46 and its cylinder chamber side area 48 in a suction channel 14 fit. This can be done for example by simply snapping the individual areas or sections, since these parts are made of plastic with a sufficiently high elasticity.

Claims (8)

A valve assembly for mixing fluids, comprising a valve seat closing a first fluid inlet within a second fluid guide, a valve seat actuator actuatable by a vacuum, and a control means for the actuator, the switch means and the actuator forming a mounting unit and are arranged in a common housing, characterized in that the housing ( 76 ) a first housing area ( 78 ) for receiving the actuating device ( 26 ) and a second housing area ( 80 ) for receiving the switching means ( 22 ), that the two housing areas ( 78 . 80 ) are arranged side by side, that the first housing area ( 78 ) with a membrane lid ( 92 ), which is connected to a connector ( 120 ) is executed, that the second housing area ( 80 ) a connecting piece ( 110 ) associated with the connector ( 120 ) is detachable, so that the connecting piece ( 120 ) and the connecting piece ( 110 ) a vacuum connection ( 34 ) between the switching means ( 22 ) and the actuating device ( 26 ) train. Valve arrangement according to Claim 1, characterized in that the connecting piece has a trunk ( 112 ), which can be coupled with the connection piece. Valve arrangement according to one of the preceding claims, characterized in that the housing ( 76 ) integral with a Ansaugkanalabschnitt ( 15 ) of an intake duct ( 14 ) is designed for guiding the second fluid. Valve arrangement according to claim 2, characterized in that the trunk ( 112 ) via a sealing element ( 116 ) at the connecting piece ( 110 ) is present. Valve arrangement according to claim 2, characterized in that the membrane cover ( 92 ) and the trunk ( 112 ) are integrally formed. Valve arrangement according to claim 2, characterized in that the membrane cover ( 92 ) and the trunk ( 112 ) are formed as a plastic injection molded part. Valve arrangement according to one of the preceding claims, characterized in that the passage opening ( 114 ) of the trunk ( 112 ) Sections ( 120 ) having different cross section. Valve arrangement according to one of the preceding claims, characterized in that over the sections ( 120 ) a throttling or amplification of the negative pressure effect of the actuating device ( 26 ) is adjustable.