DE102009012689B4 - Valve for blowing gas - Google Patents

Abstract

Valve (7) for discharging gas into a combustion chamber (8) of an internal combustion engine (1), wherein the valve (7) comprises a housing (15), wherein in the housing (15) a discharge space (22) is provided, wherein the discharge space (22) is connected to a supply line (6) for gas, wherein the discharge space (22) has a discharge opening (23), wherein an actuator in the form of a magnetic coil (19) and a closing member (21) in the housing (15) are arranged wherein the closure member (21) is associated with the dispensing opening (23), wherein, depending on the actuation of the actuator (19), the closure member (21) opens or closes the dispensing opening (23), the closure member (21) in a guide of the housing (15) is guided, wherein the closing member (21) through the discharge space (22) to the discharge opening (23) is guided, and wherein the closing member (21) is acted upon in a closed position in the discharge chamber (22) only laterally to the direction of movement with gas pressure, characterized in that the closing member (21) part way through the magnetic coil (19) is guided, ...

Description

The invention relates to a valve for injecting gas into an internal combustion engine according to the preamble of patent claim 1.

For natural gas vehicles, gas is usually stored in cylinders with pressures of up to 200 bar. For this reason, a pressure reducer is needed, which reduces the gas from the high pressure to a low rail pressure at the inlet of the valves. The valves are designed, for example, as solenoid valves which emit the gas into a combustion chamber of the internal combustion engine depending on the energization.

In the DE 600 25 090 T2 For example, there is described an electromagnetically actuated injector for a compressed natural gas injection system for an internal combustion engine having a ferromagnetic core and a solenoid at least partially surrounding the ferromagnetic core and an armature magnetically coupled to said solenoid and moving the said solenoid reacts. The armature has a first surface at the upper end and a lower end portion with a valve closure member connected to the lower end portion of the armature and interacting with an injector having a fixed valve seat to selectively permit fuel passes through said valve seat when the element is moved to close the valve by the armature in the "valve open" position.

From the CH 671 609 A5 For example, an apparatus for preventing excessive flow of gaseous fuel through an injector of a diesel engine is known, the injector having a feed line for supplying the gaseous fuel under pressure. The injector has a housing having a passage connected to the feed line and a piston member for opening and closing the passage by means of a control fluid in dependence on the crankshaft position and the load of the diesel engine. The device additionally comprises a control valve with a valve body for closing the passage formed by the feed line and the passage in response to a reduction of the fuel pressure in the passage passage. The valve member of the injection nozzle forms the valve body of the control valve and is axially movably mounted in the housing, wherein the rod side of the piston can be acted upon by a circumferential groove surrounding the valve member in the housing with the pressure of the control liquid. A pressure sensor is arranged in the passage passage, which responds to a reduction of the fuel pressure and the passage passage and provides a signal when falling below a predetermined pressure. Further, a switching valve is provided to supply the signal to the pressure of a barrier liquid to the valve member, so that the valve member closes the channel.

The object of the invention is to provide an improved valve for discharging gas into a combustion chamber of an internal combustion engine.

The object of the invention is achieved by the valve according to claim 1.

Further advantageous embodiments of the invention are specified in the dependent claims.

An advantage of the valve according to the invention is that the closure member is movable from the closed position to the open position with little back pressure. This is achieved in that the closing member is arranged in the discharge space in such a way that the closing member is acted upon by the gas pressure in the lateral direction with respect to the direction of movement of the closing member. In this way it is possible to move the closing member from the closed position to the open position under a small gas back pressure. Thus, a lower-power actuator can be used to actuate the closing member. In addition, the design of the valve is thereby reduced. Furthermore, this results in a higher durability of the valve. In addition, when using an electric actuator simpler electronic components, in particular weaker driver output stages are sufficient.

The closing member is guided by an actuator, wherein between the closing member and the actuator, a gap is provided which serves for supplying gas to the discharge space. This makes a compact construction of the valve possible.

In one embodiment, an end piece of the closing member is cylindrical, wherein the end piece protrudes into a cylindrical discharge opening. The cylindrical design of the end piece is easy to manufacture and provides adequate sealing in cooperation with the cylindrical inner contour of the discharge opening. Thus, a cost-effective and simple construction of the valve is possible.

In a further embodiment, the end piece of the closing member has a channel which is guided from an outlet opening at a lower end of the end piece upwards to an inlet opening arranged laterally at the end piece. In the closed position, the lateral inlet opening is covered by the cylindrical inner contour of the discharge opening and thus sealed. In the Open position, the side entrance opening is released from the discharge opening, so that the inlet opening opens into the discharge space. Due to this embodiment, a closing member is provided, which can be moved with a small stroke in an open position. In addition, a precise definition of the opening cross section of the open valve is possible by the formation of the input opening. Furthermore, the closing member can continue to be guided in the dispensing opening in the open position. Thus, the valve is designed to be stable overall management.

In a further embodiment, the closing member is sleeve-shaped at least in the lower end region. The sleeve shape provides a simple and inexpensive form of education for the tail of the closure member.

In a further embodiment, the closing member has a cylindrical outer contour, which is guided by a coil carrier of a magnetic coil with an angular inner contour. Due to the angular inner contour of the bobbin and the cylindrical outer contour of the closing member, a sufficiently large gap for supplying gas to the discharge space is formed in a small design.

In a further embodiment, the closing member is cylindrical and protrudes in the closed position into a cylindrical dispensing opening, wherein the closing member closes the dispensing opening in the closed position. In the open position, the closing member releases the discharge opening at least partially.

An advantage of a method for injecting gas by means of such a valve is that the gas pressure in the inlet to the valve is adjusted depending on a parameter of the internal combustion engine, in particular depending on the load of the internal combustion engine. In this way it is possible to set a relatively low gas pressure at the valve. Thus, the valve with respect to the seal, in particular with respect to the seal in the region of the closing member of the valve can be made simpler. Due to the adaptation of the gas pressure, it is not always necessary to seal a high gas pressure.

The invention will be explained in more detail below with reference to FIGS. Show it:

1 a schematic structure of a Gaseinblassystems,

2 a schematic representation of a valve for blowing gas,

3 a cross section through the valve according to 2 ,

1 shows a schematic representation of a gas injection system of an internal combustion engine 1 , It is a gas storage 2 provided, the gas with a predetermined pressure, for example, stored at a pressure of 200 bar. The gas storage is via a switching valve 3 with a gas pipe 4 connected. The gas line 4 is via a pressure control valve 5 with a supply line 6 in connection. The supply line 6 is to a valve 7 The result is a combustion chamber 8th the internal combustion engine 1 assigned. Furthermore, there is a sensor 9 on the internal combustion engine 1 provided, via a sensor line 10 with a control unit 11 connected is. The control unit 11 also stands with a first control line 12 with the switching valve 3 and via a second control line 13 with the pressure control valve 5 in connection. Furthermore, there is the control unit 11 with a data store 14 in connection.

In a simple embodiment, instead of the pressure regulating valve 5 a pressure reducer may be provided which reduces the gas pressure from the predetermined storage pressure of, for example, 200 bar to an injection pressure of, for example, 8 bar.

The control unit 11 controls the switching valve 3 in an open or closed state depending on whether gas from the gas storage 2 the valve 7 should be led. Furthermore, the control unit detects 11 over the sensor 9 at least one parameter of the internal combustion engine 1 , For example, as a parameter of the internal combustion engine 1 the load and / or an accelerator pedal position of a vehicle in which the internal combustion engine 1 is arranged to be detected. Depending on the load and / or the accelerator pedal position, the controller provides 11 different gas pressures in the supply line 6 one. This is the control unit 11 with the data store 14 connected, in which tables and / or curves are stored, which a gas pressure in the supply line 6 associated with the load and / or accelerator pedal position. In this way it is achieved that the gas pressure in the supply line 6 to the arrangement of a pressure reducer instead of the gas control valve 5 is set lower on average by the controller. Thus, lower requirements for the pressure tightness of the valve 7 given.

2 shows a schematic representation of the structure of the valve 7 where the valve 7 a housing 15 having. A gas flow direction is shown by arrows. In the case 15 is a supply room 16 provided with the supply line 6 connected is. The supply room 16 is through a guide section 17 limited. In the leadership section 17 is a recess 18 provided in which a magnetic coil 19 is arranged. The magnetic coil 19 has a central recess 20 on, in which a closing member 21 is arranged. The closing element 21 protrudes from the central recess 20 through a delivery room 22 with a tail in a dispensing opening 23 , The delivery room 22 is in the case 15 arranged. The discharge opening 23 stands with a combustion chamber 8th the internal combustion engine 1 in connection. Depending on the chosen embodiment may be on the supply space 16 be dispensed with and the supply line 6 directly into the delivery room 22 be guided.

The closing element 21 has a cylindrical outer contour, which in a cylindrical inner contour of the discharge opening 23 is guided sealingly. Furthermore, the closing member 21 a channel 24 on that from an exit opening 25 to an entrance opening 26 is guided. The exit opening 25 is on a lower side of the end piece of the closing member 21 formed in the discharge opening 23 empties. The entrance openings 26 are laterally in a cylinder outer wall of the closing member 21 brought in. In the illustrated position, the closing member is located 21 in the open position. In this position, the channel connects 24 the delivery room 22 with the discharge opening 23 , Thus, there is a gas flow between the discharge space 22 and the delivery port 23 instead of. In the closed position is the closing member 21 so deep into the discharge opening 23 plugged in that the channel 24 is closed, ie the entrance openings 26 laterally from the cylindrical walls of the discharge opening 23 are closed.

Depending on the chosen embodiment may be on the channel 24 be waived. In this embodiment, in the open position, the closing member 21 completely out of the delivery opening 23 pulled out and thus the discharge opening 23 open. The closing element 21 consists in the illustrated embodiment of a magnetic material which, when energized, the magnetic coil 19 via electrical supply lines 27 is operable in the height position. An advantage of the illustrated valve 7 is that the closing member 21 in the closed position only laterally, as indicated by arrows, with gas pressure is applied. Thus, a relatively easy operation of the closing member 21 in the direction of actuation possible, since this is not acted upon by the gas pressure.

The gas flow to the delivery room 22 can either be directly via the supply line 6 or over a gap 28 (please refer 3 ) between the solenoid 19 and the closing member 21 , ie starting from the supply space 16 respectively. This is a gap 28 (please refer 3 ) between the housing 15 and the magnetic coil 19 and / or between the magnetic coil 19 and the closing member 21 intended.

An upper end of the closing member 21 protrudes into a cylindrical chamber 32 in which a spring element 30 is arranged. The spring element 30 clamps the closing element 21 towards a closed position and thus towards a stop 31 in front, at the lower end of the discharge opening 23 is arranged. When the solenoid is not energized 19 sits the closing member 21 on the stop 31 on and the entrance openings 26 are in the delivery port 23 arranged and through the housing 15 sealed. Will now be the solenoid 19 energized, then becomes the closing element 21 from the stop 31 towards the chamber 32 pulled, with the entrance openings 26 with the delivery room 22 are connected. The chamber 32 is either via sealing gaps or via a central recess of the closing member 21 with the delivery room 22 connected. That over the supply line 6 and the supply room 16 supplied gas is at the side of the chamber 32 past. The closing element 21 For example, as a sleeve with side entry openings 26 be educated. In this embodiment, the spring element is located 32 on an upper annular edge of the closing member 21 on.

3 shows in a cross section through the closing member 21 an embodiment in which the magnetic coil 19 in the recess 18 is arranged and sealing on the housing 15 is applied. The magnetic coil 19 has a coil carrier 29 on, which is angular in the inner contour. In the illustrated embodiment, the bobbin is 29 formed on the inside octagonal and limits the central recess 20 , In the central recess 20 is the cylinder-shaped closure member 21 arranged. Between the outer contour of the closing member 21 and the coil carrier 29 is a gap 28 educated. The gap 28 represents a gas line that the supply room 16 with the delivery room 22 combines.

Due to the formation of the gap 28 is a compact construction of the valve 7 possible.

Claims (6)

Valve ( 7 ) for discharging gas into a combustion chamber ( 8th ) an internal combustion engine ( 1 ), whereby the valve ( 7 ) a housing ( 15 ), wherein in the housing ( 15 ) a delivery room ( 22 ), the delivery room ( 22 ) with a supply line ( 6 ) is connected to gas, the delivery room ( 22 ) a discharge opening ( 23 ), wherein an actuator in the form of a magnetic coil ( 19 ) and a closing member ( 21 ) in the housing ( 15 ) are arranged, wherein the closing member ( 21 ) the discharge opening ( 23 ), wherein, depending on the actuation of the actuator ( 19 ) the closing member ( 21 ) the discharge opening ( 23 ) opens or closes, wherein the closing member ( 21 ) in a guided tour of the housing ( 15 ) is guided, wherein the closing member ( 21 ) through the delivery room ( 22 ) to the discharge opening ( 23 ) is guided, and wherein the closing member ( 21 ) in a closed position in the delivery room ( 22 ) is acted upon only laterally to the direction of movement with gas pressure, characterized in that the closing member ( 21 ) partially by the magnetic coil ( 19 ), wherein a gap ( 28 ) between the magnetic coil ( 19 ) and the closing member ( 21 ), wherein the intermediate space ( 28 ) the delivery room ( 22 ) with an inflow space ( 16 ) and where the space ( 28 ) for supplying gas to the delivery room ( 22 ) serves. Valve according to claim 1, wherein the closing member ( 21 ) has a cylindrical outer contour, wherein the closing member by a coil carrier ( 29 ) of the magnetic coil ( 19 ) is guided with an angular inner contour, wherein intermediate spaces ( 28 ) between the round outer contour and the angular inner contour for the supply of gas to the discharge space ( 22 ) are formed. Valve according to claim 1, wherein at least one end piece ( 33 ) of the closing member ( 21 ) has a cylindrical outer contour, wherein the discharge opening ( 23 ) has a cylindrical inner contour, wherein the closing member ( 21 ) at least in the closed position with the cylindrical end piece ( 33 ) into the delivery opening ( 23 ) protrudes and the cylindrical outer contour of the tail ( 33 ) the cylindrical inner contour of the discharge opening ( 23 ), whereby in the tail ( 33 ) a channel ( 24 ) is introduced, wherein the channel from an exit opening ( 25 ) at the lower end of the tail ( 33 ) up to an entrance opening ( 26 ), wherein the input opening ( 26 ) on the side of the end piece ( 33 ) is formed, wherein in the closed position, the input opening ( 26 ) through the cylindrical inner contour of the discharge opening ( 23 ) is sealed, wherein in an open position of the closing member ( 21 ) the entrance opening ( 26 ) into the delivery room ( 22 ) opens. Valve according to claim 3, wherein at least two inlet openings ( 26 ) are provided with the output port ( 25 ) are connected. Valve according to one of claims 3 or 4, wherein the closing member ( 21 ) at least in the region of the end piece ( 33 ) is sleeve-shaped. Valve according to one of claims 1 and 4 to 5, wherein an end piece ( 33 ) of the closing member ( 21 ) has a cylindrical outer contour, wherein the discharge opening ( 23 ) has a cylindrical inner contour, wherein in the closed position, the tail ( 33 ) into the delivery opening ( 23 ) protrudes and the cylindrical outer contour of the tail ( 33 ) sealingly on the cylindrical inner contour of the discharge opening ( 23 ) and the discharge opening ( 23 ), and wherein in an open position the tail ( 33 ) the discharge opening ( 23 ) at least partially releases.

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