PRE-CHAMBER SPARK PLUG HOLDING ARRANGEMENT

Description

[0001] The invention relates to a pre-chamber spark plug receiving arrangement with a pre-chamber spark plug according to the preamble of claim 1.

[0002] DE 10 2013 210 125 A1 describes a prechamber spark plug receptacle assembly for a gas engine, in which a fuel gas-air mixture is ignited in a prechamber with the aid of a spark plug. The prechamber spark plug receptacle assembly accommodates the prechamber spark plug in a water sleeve that can be inserted into a cylinder head of the internal combustion engine. A fuel channel for supplying the fuel gas to the prechamber is guided through the wall of the water sleeve. An inflow channel for the fuel gas runs in the cylinder head and opens into an annular distributor groove that is fluidly connected to the fuel channel in the water sleeve.

[0003] DE 100 16 558 A1 describes a method for igniting very lean fuel-air mixtures using a spark-ignited prechamber spark plug located at the edge of the main combustion chamber of an internal combustion engine, which is connected to the main combustion chamber via transfer channels, with a small amount of additional fuel being introduced into the prechamber in a valve-controlled manner. DE 100 16 558 A1 further describes an arrangement, particularly for use in gas engines, with a prechamber surrounding a spark plug, which has preferably tangential transfer channels leading to the main combustion chamber, and with an extremely thin supply channel supplying additional fuel, through which high-pressure fuel is metered during the compression stroke of the internal combustion engine in a time-controlled manner, particularly by means of a solenoid valve.

[0004] WO 2010 / 009489 A1 describes a device for igniting a fuel / air mixture in the combustion chamber of an internal combustion engine, comprising an electrode which is connected to a voltage source and which extends into a prechamber, wherein the prechamber is at least partially separated from the combustion chamber by a wall, wherein a control device or regulating device is provided which regulates the voltage supply to the electrode in such a way that a corona discharge takes place in the prechamber, wherein the wall has at least one opening for the exchange of fluids between the combustion chamber and the prechamber, wherein a fluid inlet opens into the prechamber.

[0005] US 3,406,667 A describes a stratified charge ignition system for a spark-ignition internal combustion engine. The device comprises: a pre-combustion chamber coupled in fluid communication with each main combustion chamber of the engine in place of the spark plug normally associated therewith; carburetor means for supplying a relatively rich fuel-air mixture to each pre-combustion chamber; and spark ignition means for igniting the fuel-air mixture supplied to each of the chambers in timed sequence for engine operation.Fluid communication between each pre-combustion chamber and its coupled main combustion chamber is established by an orifice comprising a Borda nozzle opening into the pre-combustion chamber to define an imperforate lip extending therein; and a nozzle of substantially frusto-conical shape extending from the nozzle in diverging relationship therewith and opening into the main combustion chamber.

[0006] EP 1 203 871 A2 describes a check valve, and in particular a check valve for a fuel channel of a pre-chamber assembly of an internal combustion engine, comprising a support element, a stop element, and a ring element. The ring element is elastically arranged between the support and stop elements. The ring element is movable between a first position, in which it blocks the fluid connection between the support and stop elements, and a second position, in which it allows fluid to pass between the support and stop elements. The primary application is for applications that control the fluid passage between components, such as pre-chamber assemblies in gas engines.

[0007] The invention is based on the object of designing a pre-chamber spark plug holder arrangement with simple structural measures that is compact and has precise control of the fuel to be supplied.

[0008] This object is achieved according to the invention with the features of claim 1 or claim 11. The subclaims specify expedient further developments.

[0009] The prechamber spark plug receptacle assembly according to the invention comprises a housing bushing into which a prechamber spark plug can be inserted, via which fuel is ignitable in a prechamber. The fuel is guided to the prechamber through at least one fuel channel, wherein the fuel channel(s) are incorporated into the wall of the housing bushing. The at least one fuel channel opens, for example, on the side facing the prechamber, into a further channel, which can be designed as a distributor groove and / or annular gap and can be incorporated, for example, into a spark plug housing of the inserted spark plug. This further channel advantageously extends to the prechamber.

[0010] The pre-chamber spark plug receptacle assembly is preferably used in a gas engine and connected to the cylinder head of the engine. Accordingly, the invention also relates to a gas engine with a pre-chamber spark plug receptacle assembly in the cylinder head.

[0011] The pre-chamber spark plug receptacle assembly is equipped with at least one valve member of a switching valve for regulating the fuel flow through the at least one fuel channel. The valve member, which forms an adjustable component of the switching valve, is arranged at least partially in or on the wall of the housing bushing and forms part of the pre-chamber spark plug receptacle assembly. The adjustable valve member is arranged in or on the wall of the housing bushing and is adjustable between a closed and an open position, wherein in the closed position the fuel flow is either interrupted or at least reduced to a minimum, and in the open position the maximum fuel flow can flow. Advantageously, the valve member can assume various intermediate positions between the closed and open positions in order to be able to adjust the level of the fuel flow.However, it may also be sufficient for the valve element to only assume the closed position and the open position and to be able to be adjusted between the closed and open positions.

[0012] The integration of at least the valve element of the switching valve into or on the wall of the housing bushing results in a compact design. Furthermore, the fuel flow can be controlled with high precision, as the distance between the valve element and the prechamber is shorter than with switching valves positioned outside the housing bushing. Switching operations therefore have a faster effect on the filling of the prechamber with fuel.

[0013] Other, particularly non-adjustable, components of the switching valve, such as valve housing parts, can also be connected to the pre-chamber spark plug receptacle assembly, particularly arranged in or on the wall of the housing bushing. If necessary, all components of the switching valve are connected to the pre-chamber spark plug receptacle assembly. Alternatively, it is also possible to arrange individual components of the switching valve outside the pre-chamber spark plug receptacle assembly.

[0014] The valve member is located in the flow path of at least one fuel channel in the wall of the housing bushing that accommodates the spark plug. The switching valve also comprises an actuator, via which the valve member can be adjusted. The actuator is advantageously arranged in or on the wall of the housing bushing. It may be expedient for the actuator and the valve member to form a coherent structural unit that is inserted into the wall of the housing bushing, for example, fully or partially inserted into a recess in the wall, or arranged on one side of the wall.

[0015] However, designs are also possible in which the actuator is not integrated into the wall of the housing bushing, but is located on one side of the wall, for example, on the outside of the wall, for example, on the front side of the wall of the housing bushing. The actuator can optionally be connected to the valve element via an actuating rod and adjust it, or, in a further design, adjust the valve element electromagnetically. In this case, it is possible, for example, to arrange the actuator on the outside of the wall of the housing bushing and to effect the adjustment of the valve element via an electromagnetic field generated by the actuator.

[0016] The actuator is advantageously electrically controllable, so that the desired adjustment of the valve member is achieved by energizing the actuator. According to the invention, the actuator is electromagnetically designed and has an energizable solenoid coil, which, when energized, generates an electromagnetic field that adjusts the valve member made of a soft magnetic material.

[0017] The valve member is advantageously biased by a spring element into an end position, particularly the closed position, so that without energizing the actuator, the switching valve remains in the closed position and the fuel flow is interrupted or reduced to a minimum. When the actuator is energized, the valve member is moved toward the open position against the force of the spring element acting on it.

[0018] In the inventive embodiment of the actuator as a magnetic coil, the magnetic coil runs in a ring-like manner within the wall of the housing bushing. The windings of the magnetic coil thus have at least approximately the same diameter as the preferably cylindrical housing bushing. The magnetic coil is located, in particular, directly on the outside of the housing bushing and has several windings arranged one above the other, extending in the axial direction of the spark plug.

[0019] According to a further advantageous embodiment, the switching valve has a valve housing in which at least the valve member and, if appropriate, also the actuator are arranged. In a preferred embodiment, the valve housing can be connected to the housing bushing, in particular, it can be placed onto the housing bushing and thus encompasses the outer side of the housing bushing. The valve housing can, for example, be screwed onto the housing bushing. When the valve housing is placed onto the housing bushing, the valve member enters the flow path through the fuel channel.

[0020] According to a further expedient embodiment, several fuel channels are incorporated into the wall of the housing bushing, distributed around the circumference. This includes both designs in which all fuel channels are assigned a common valve element, the adjustment of which between the closed and open positions closes or opens the flow path through each fuel channel, and designs with one valve element per fuel channel. In any case, it is expedient for the valve element or elements to be adjusted by a common actuator, although designs are possible in which each valve element is assigned an actuator. In the latter case, a switching valve is provided for each fuel channel.

[0021] According to yet another advantageous embodiment, the housing bushing forms a water-cooled water bushing. The cooling circuit for the water bushing is designed independently of the switching valve, so that the cooling function and the switching function do not interfere with each other.

[0022] According to a further advantageous embodiment, the adjustable valve element of the switching valve is formed by the actuator. When energized, the actuator moves between the closed and open positions. In the electromagnetic version of the actuator, when energized, it is pulled against the wall of the housing bushing, which is designed to be soft magnetic for this purpose, against the force of a spring element acting on it. If necessary, a soft magnetic component can be integrated into the wall of the housing bushing, against which the actuator moves when energized.

[0023] The actuating movement of the valve member is preferably a translational movement. However, rotary actuating movements or pivoting movements of the valve member are also possible, which open or close the flow path through the fuel channel.

[0024] The valve element can also be adjusted hydraulically or pneumatically, if necessary. The adjustment is carried out via an actuating medium, either liquid or gaseous. The actuating medium can, if necessary, be supplied to the valve element from outside the switching valve.

[0025] Further advantages and practical embodiments can be found in the further claims, the description of the figures, and the drawings. They show: Fig. 1 shows a pre-chamber spark plug receptacle arrangement with a pre-chamber spark plug in a water bushing, into which a switching valve for regulating the fuel flow is also introduced, shown in longitudinal section, Fig. 2 shows a pre-chamber spark plug receptacle arrangement in longitudinal section with a switching valve shown in detail.

[0026] In the figures, identical components are provided with identical reference symbols.

[0027] How Fig. 1 combined with Fig. 2 As can be seen, a pre-chamber spark plug receptacle assembly 1 is arranged on a cylinder head 2 of a gas engine, which serves to ignite a fuel gas-air mixture in a pre-chamber 6 using an ignition assembly 7. A spark plug 3 of the pre-chamber spark plug receptacle assembly 1 is accommodated in a spark plug housing 4, which is inserted into a housing bushing 5, which is also a component of the pre-chamber spark plug receptacle assembly 1. The housing bushing 5 is designed as a water bushing and is water-cooled.

[0028] The spark plug housing 4 of the spark plug 3 is constructed in several parts and comprises two housing parts 4a and 4b, which rest against the inner wall of the receiving housing bushing 5. Both housing parts 4a and 4b are sleeve-shaped, with the first housing part 4a enclosing the second housing part 4b.

[0029] A fuel channel 8 is introduced into the wall of the water bushing 5, which extends - with respect to the longitudinal axis 9 of the spark plug 3 - in the axial direction through the wall and is connected to a distributor groove 10, which is introduced in a ring-shaped circumferential manner into the wall of the water bushing and is in turn flow-connected to an inflow channel 11 in the cylinder head 2, via which the fuel is supplied.

[0030] The fuel is thus guided via the inflow channel 11 and the distributor groove 10 into the fuel channel 8 in the wall of the water bushing 5 in the direction of the pre-chamber 6.

[0031] On the side facing the prechamber 6, the fuel channel 8 opens via a further distributor groove 12, which can be designed as a channel, into a circumferential annular gap 13 that extends to the prechamber 6. There, the fuel can be ignited via the ignition arrangement 7.

[0032] The distributor groove 12 on the side facing the prechamber 6 is incorporated into the first housing part 4a of the spark plug 3 and extends in the radial direction. The annular gap 13, into which the distributor groove 12 opens, runs in the axial direction and is located between the encompassing first housing part 4a and the radially inner, second housing part 4b. On the side facing the prechamber 6, the annular gap 13 bends radially inward in the manner of a truncated cone and opens into the prechamber 6.

[0033] In the flow path of the fuel channel 8, a switching valve 14 is located in the wall of the water sleeve 5, with which the fuel flow through the fuel channel 8 can be regulated. The fuel channel 8 runs above the switching valve 14 in the axial direction and below the switching valve 14 - on the side facing the prechamber 6 - at an angle inward until it reaches the radially further inward distributor groove 12.

[0034] The switching valve 14 is inserted into a recess in the wall and fully integrated into the wall of the water bushing 5. In an alternative embodiment, the switching valve 14 is only partially integrated into the wall of the water bushing 5 and protrudes beyond the wall of the water bushing 5 either on the radial inside or on the radial outside. Furthermore, a design is also possible in which the switching valve 14 is arranged on the outside or inside of the wall of the water bushing 5; in this case, for example, the fuel channel 8 opens into the switching valve 14 and continues in the wall of the water bushing 5 on the side of the switching valve 14 facing the prechamber 6.

[0035] The switching valve 14 comprises an adjustable valve member that can be adjusted by an actuator between a closed position blocking the fuel channel and an open position releasing the fuel channel. In a preferred embodiment, the actuator is integrated into the switching valve 14.

[0036] The actuator can also be located outside the switching valve. Fig. 1 An actuator 15 is shown in dashed lines on the axial end face of the pre-chamber spark plug receptacle assembly 1, in particular on the end face of the water bushing 5. The actuator 15 is connected to the valve member of the switching valve 14 via a connecting member 16, for example a connecting rod. The actuator movement of the actuator 15 is transmitted to the valve member of the switching valve 14 via the connecting member 16.

[0037] Distributed around the circumference, several fuel channels 8 can be incorporated into the wall of the water sleeve 5. Each fuel channel 8 is blocked or opened by a switching valve 14, whereby, if necessary, a common switching valve can be provided for all fuel channels 8. However, it is also possible to arrange one switching valve 14 for each fuel channel 8.

[0038] The switching valve 14 is located, for example, in a recess in the wall of the water sleeve 5. The recess may extend annularly around the outside of the wall as a groove. Alternatively, instead of a recess or a groove, it is also possible to arrange the switching valve 14 on the outside of the water sleeve 5 and to attach a valve housing of the switching valve to the water sleeve or another housing component of the prechamber spark plug receptacle assembly.

[0039] A concrete realization of a switching valve 14 in a pre-chamber spark plug holder arrangement 1 is shown in Fig. 2 The switching valve 14 is arranged in a sleeve-shaped valve housing 17, which is placed on the water sleeve 5 and connected to it, for example, by screwing it. The switching valve 14 has a solenoid coil as an actuator 18, the windings of which are arranged in a ring-shaped manner within the switching valve 14 and engage around the wall of the water sleeve 5.

[0040] The switching valve 14 further comprises a valve member 19 and one or more spring elements 20, which force the valve member 19 into a closed position in which the fuel channel(s) 8 are blocked. The valve member 19 is preferably designed as a circumferential ring that is pressed axially into the closed position by one or more spring elements 20. The spring elements 20 are designed, for example, as coil springs.

[0041] The solenoid coil 18 acts as an actuator, axially spaced from the valve member 19 and the spring element(s) 20. When the solenoid coil 18 is energized, a force is exerted on the valve member 19, which moves the valve member 19 into the open position against the force of the spring element 20, thereby releasing the fuel channel 8 and allowing fuel to flow through the fuel channel 8 toward the prechamber 6. When the solenoid coil 18 is no longer energized, the valve member 19 is moved back into the closed position by the force of the spring element(s) 20.

[0042] The switching valve 14, including the valve housing 17, forms a coherent structural unit that is placed on the water bushing 5. The valve housing 17, together with the switching valve 14, surrounds the water bushing 5. Connection channels for the flow connection to the upper and lower sections of the fuel channel 8 run within the valve housing 17, so that when the valve member 19 is open, the fuel can flow without leakage from the upper section of the fuel channel 8 via the switching valve 14 into the lower section of the fuel channel.

Claims

1. Prechamber spark plug receiving arrangement for receiving a prechamber spark plug (3) in a housing bushing (5), comprising at least one fuel duct (8), which is made in the wall of the housing bushing (5), for supplying fuel to a prechamber (6), wherein at least one adjustable valve member (19) of a switching valve (14) is introduced into the wall of the housing bushing (5) for regulating the fuel flow through the fuel duct (8) or is arranged on the wall, wherein the valve member (19) in or on the wall of the housing bushing (5) can be adjusted between a closed position and an open position, and wherein a plurality of fuel ducts (8) are made in the wall of the housing bushing (5) in a manner distributed over the periphery, characterized in that the actuator (18), for adjusting the valve member (19) of the switching valve (14), is designed as a solenoid (18) which can be energized, wherein the solenoid (18) is arranged peripherally in the form of a ring in or on the wall of the housing bushing (5).

2. Prechamber spark plug receiving arrangement according to Claim 1, characterized in that the valve member (19) of the switching valve (14) can be adjusted by an actuator (15, 18) which is arranged in or on the wall of the housing bushing (5).

3. Prechamber spark plug receiving arrangement according to Claim 2, characterized in that the actuator (18) is integrated into the wall of the housing bushing (5).

4. Prechamber spark plug receiving arrangement according to Claim 2, characterized in that the actuator (15) is arranged on the end side of the wall of the housing bushing (5).

5. Prechamber spark plug receiving arrangement according to Claim 4, characterized in that the valve member (19) is connected to the actuator (15) by means of a connecting rod which is routed through the wall of the housing bushing (5).

6. Prechamber spark plug receiving arrangement according to any of Claims 1 to 5, characterized in that the valve member (19) of the switching valve (14) is forced into the closed position by a spring element (20) which is integrated into the wall of the housing bushing (5).

7. Prechamber spark plug receiving arrangement according to Claim 1, characterized in that in each case one valve member (19) of a switching valve (14) is associated with each fuel duct (8).

8. Prechamber spark plug receiving arrangement according to Claim 7, characterized in that the valve members (19) can be adjusted by means of a common actuator.

9. Prechamber spark plug receiving arrangement according to any of Claims 1 to 8, characterized in that the switching valve (14) has a valve housing (17) which can be connected to the housing bushing (5), in particular can be fitted onto the housing bushing (5).

10. Prechamber spark plug receiving arrangement according to any of Claims 1 to 9, characterized in that the housing bushing (5) is designed as a water-cooled bushing.

11. Gas engine comprising a prechamber spark plug receiving arrangement (1) according to any of Claims 1 to 10 which is inserted into a cylinder head (2).