WO2017021185A1

WO2017021185A1 - High-pressure assembly

Info

Publication number: WO2017021185A1
Application number: PCT/EP2016/067632
Authority: WO
Inventors: Matthias Bleeck; Bernd Gugel; Thomas KRÜGER
Original assignee: Continental Automotive Gmbh
Priority date: 2015-08-04
Filing date: 2016-07-25
Publication date: 2017-02-09
Also published as: DE102015214816A1

Abstract

The invention relates to a high-pressure assembly (32) comprising a high-pressure casing (30) and a pressure control valve (26) that includes a valve seat (36), a closing element (38) and a fluid outlet (40) for forming a valve portion (34); a portion (56) of the high-pressure casing (30) forms a valve housing portion (58) for accommodating the valve portion (34).

Description

description

The invention relates to a high-pressure arrangement for providing a high-pressure fuel, in particular in a fuel injection system.

Fuel injection systems are used to

Fuel first to pressurize a high pressure, the pressure is for example in gasoline internal combustion engines in the range of 250 bar to 400 bar and diesel engines in the range of 2000 bar to 2500 bar, and then inject this pressurized fuel into the combustion chambers of an internal combustion engine , The higher the pressure that can be generated in the respective fuel, the lower are emissions that occur during combustion of the fuel in a combustion chamber, which is particularly advantageous against the background that a reduction of emissions is increasingly desired.

In particular, the formation of carbon black as the emission at the force ^¬ fuel combustion is heavily dependent on a preparation of an air / fuel mixture in the internal combustion engine. Therefore, it is advantageous if the fuel can be injected very precisely. For this purpose, it is important to precisely regulate a predetermined pressure of the fuel in a high-pressure region of the fuel injection system. For this purpose, as is known, for example from DE 10 2011 083 154 AI, pressure control valves are used, which are arranged at the high ^¬ pressure range, and there by targeted Absteuern a KrafStoffmenge from the high-pressure region can adjust the pressure of the fuel in the high-pressure region precisely. Such pressure control valves are, as also known from DE 10 2011 083 154 AI, constructed in a so-called "cartridge design", that is, all elements that form the pressure control valve ^¬ are before mounting the pressure control valve to the high pressure area of the However, this possibility of checking the functioning of the pressure regulating valve prior to its installation is accompanied by the disadvantage that an installation situation is involved The object of the invention is therefore to propose a high-pressure arrangement, which has a pressure regulating valve, which is improved in this respect.

This object is achieved with a high-pressure assembly having the features of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims. A high-pressure arrangement for providing a high-pressure fuel has a high-pressure area defined by a high-pressure housing. Further, it has a pressure control valve for regulating the high pressure in the high ^¬ pressure range by controlling a quantity of fuel from the high pressure area. The pressure regulating valve in this case comprises a valve region with a valve seat, with a closing element and with a downstream of the valve seat in the flow direction of the fuel fluid outlet opening. Furthermore, the pressure regulating valve comprises an actuator area for moving the closing element along a movement axis. A Hochdruckgehäu ^¬ Lake area of the high pressure housing forms a valve housing for receiving at least the valve portion of the pressure control valve.

In contrast to the known pressure control valves, which are constructed in the so-called "cartridge design", now a pressure control valve is proposed, which no longer has its own housing, but whose housing is at least partially formed by the high-pressure housing, which also defines the high-pressure ^¬ area This will create a system-integrated

Pressure control valve proposed that uses components of the high-pressure ^¬ housing, so that a large number of components that were previously available in the pressure control valve, can be saved. Further, it is now possible to attach the pressure control valve flexible at a high pressure area.

The high pressure area defined by the high pressure housing may be, for example, a high pressure fuel pump in a fuel injection system, wherein the high pressure housing corresponds to a pump housing of the high pressure fuel pump. However, it is also possible that the high pressure area is formed by a pressure accumulator, a so-called "common rail", wherein the "common rail" forms the high pressure housing. Further, it is also conceivable that a high-pressure port formed at a fuel ^¬ high-pressure pump, the high pressure housing, or that an injector can be injected via the fuel from the pressure accumulator into a combustion chamber of an internal combustion engine having high-pressure housing which defines the high-pressure region.

Accordingly, the pressure regulating valve no longer has its own housing, in which the valve area is accommodated, but the valve seat and the closing element are accommodated by the high-pressure housing. The fluid outlet opening of the pressure regulating valve, via which the fuel is diverted, is no longer arranged in a separate housing of the pressure regulating valve, but in the high-pressure housing itself, which forms the valve housing. In this case, for example, a wall of the high pressure housing is broken at one point, so as to form the fluid outlet opening.

A fluid inlet opening from the high-pressure region into the pressure-regulating valve is integrated, for example, in the valve seat, for example through a bore in a valve seat body.

Advantageously, the valve seat is directly in the

Attached valve housing portion of the high-pressure housing, so that a valve seat outer surface is in direct contact with a nen ^¬ inner wall of the high-pressure housing. As a result ^¬ In nenwand the high pressure housing is not only an area of the high-pressure area, but also the valve housing area. Preferably, the valve seat on the valve seat outer surface on an external thread, which is screwed into a arranged on the inner wall of the high ^¬ pressure housing in the valve housing portion internal thread. Further advantageously, the valve seat is sealed by means of a high pressure- ^¬ sealing element, in particular by means of a biting edge, against a force acting in the high-pressure region of the pressurized high-pressure fuel. For example, the screw connection and the biting edge therefore cooperate in such a way that an axial force acts along the movement axis between the valve seat and the high-pressure housing, so that these two elements are securely sealed against one another. Thereby For example, it can be prevented that the sealing force decreases over the product life.

Advantageously, the pressure control valve is an electromagnetically actuated valve with a coil, wherein the actuator region having a pole core and an armature. As a result, a pressure of the fuel located in the high-pressure region can advantageously be regulated precisely via, for example, an electronic control unit.

Advantageously, the armature is coupled to the closing ^{element in} such a way that it can transmit a moving force to the closing ^element along the ^axis of movement. The pressure control valve can therefore advantageously be controlled simply by acting on the armature with a defined electromagnetic force, so that the closing element can move via the armature depending on the electromagnetic force used in different open positions, so that a targeted pressure control is possible. In an advantageous embodiment, the anchor and / or the

Polkern recorded directly in the valve housing portion of the high-pressure housing. Therefore, the valve housing portion of the high-pressure housing, which accommodates at least the valve region, also forms a housing part of the pressure control valve for the armature or the pole core. Depending on whether it is a normally closed pressure control valve or a normally open pressure control valve, either the armature or the pole core in the

High-pressure housing area included. However, it is also possible to include both elements in the high pressure housing area.

When recording of the armature in the formed by the Hochdruckge ^¬ häusebereich valve housing, the armature is advantageous movably supported along the axis of movement so as to be able to move the closing element along the axis of movement.

Preferably, a bobbin tube, which has the coil, plugged from the outside onto the high-pressure housing area forming the valve housing area, wherein the high-pressure housing ^¬ area extends along the axis of movement at least up to the coil arranged in the bobbin. This has the advantage that the high-pressure housing area that forms the valve housing area is not simply used as a housing so as to be able to dispense with separate housing parts of the pressure regulating valve, but can also be used in a magnetic circuit of the actuator area. Because the magnetic circuit runs through when the

High-pressure housing area extends at least up to a height of the coil along the axis of movement, even through the high pressure housing area. This makes it possible to save further components for forming the magnetic circuit of the pressure control valve. Preferably, a plug is integrally formed with the bobbin tube and in particular molded onto the bobbin tube. Further advantageously, the plugged onto the high pressure housing portion bobbin tube is so long rotationally symmetrical about the axis of rotation freely rotatable until it is firmly connected by a positive and / or cohesive fastening method with the Hochdruckge ^¬ häusebereich. An electrical connection from the outside can be ^¬ introduced at the pressure regulating valve therefore quite flexible, so that the installation situation of the pressure control valve can be designed flexibly to the high pressure housing.

A cohesive fastening method can be, for example, a welding method, while a positive fastening method can be, for example, crimping. Preferably, the actuator region has a restoring spring, which exerts on the closure element a restoring force acting along the movement axis, which counteracts a pressure force acting on the closure element from the high-pressure region

hochdruckbeaufschlagten fuel acts to push the closing ^¬ element in a closed position on the valve seat. In a closed position, the closing element has sealing contact with the valve seat. Such an arrangement advantageously forms a ^normally closed pressure regulating valve, which shuts off fuel to set a desired pressure from the high pressure region. The efficiency is higher than in a normally open designed pressure control valve.

Preferably, the restoring force can be overcome by an active opening movement of the closing element induced by the actuator region. Alternatively, however, the restoring force can also be overcome by a positive pressure in the high-pressure region which exceeds a predetermined maximum pressure. Thus, on the one hand an active pressure control ^valve is ^{bereitge ¬} provides that can actively set a desired pressure in the high pressure area by an active opening movement of the

On the other hand, however, at the same time a safety valve is provided which can control a non-desired overpressure in the high-pressure region.

An advantageous embodiment of the invention will be explained in more detail with reference to the accompanying drawings. It shows:

Fig. 1 is a fuel injection system with a plurality of high-pressure assemblies to which pressure control valves are attached; and FIG. 2 is a detailed longitudinal sectional view of a pressure regulating valve attached to one of the high pressure assemblies of FIG. 1. FIG. Fig. 1 shows a fuel injection system 10, with the fuel 12 on the one hand is subjected to high pressure, and on the other hand is stored for injection, to then as needed in

Be combusted combustion chambers of an internal combustion engine. The fuel injection system 10 has for storing the

Kraftstoffes 12 a tank 14, from which via a backing pump 16 of the fuel 12 of a high-pressure fuel pump 18 is supplied. In this case, an inlet valve 20 is arranged in the flow direction of the fuel 12 in front of the high-pressure fuel pump 18, which admits the fuel 12 in the high-pressure fuel pump 18 or can prevent an inlet.

In the high-pressure fuel pump 18, the fuel 12 is then subjected to a high pressure, and then fed to a pressure accumulator 22, the so-called "common rail", where the

pressurized fuel 12 is stored. In fluid communication with the pressure accumulator 22 are a plurality of injectors 24, which then inject the high-pressure fuel 12 into combustion chambers of an internal combustion engine. In order to be able to provide the injectors 24 with a high-pressure fuel 12 with a defined high pressure, the fuel injection system 10 has at least one pressure regulating valve 26 which is located downstream of the high-pressure fuel pump 18 in the flow direction of the fuel 12

High-pressure region 28 of the fuel injection system 10 is arranged ^¬ is. However, it is also possible for a plurality of pressure regulating valves 26 to be arranged in the high-pressure region 28, for example on a pump housing, not shown, of the high-pressure fuel pump 18, at a high-pressure connection of the high-pressure fuel line. In any case, at least part of the high-pressure region 28 is defined by a high-pressure housing 30, for example, by said pump housing, by the pressure accumulator 22 or by a housing of an injector 24 can be formed.

The respective high-pressure housing 30 together with the pressure regulating valve 26 forms a high-pressure arrangement 32, which is designed to provide a pressurized fuel 12 be ^¬ , wherein the fuel 12 in this case has a defined high pressure.

FIG. 2 shows a longitudinal sectional view of the pressure regulating valve 26 of FIG. 1 connected to the respective high pressure housing 30 for forming the high pressure assembly 32.

The pressure control valve 26 has a valve region 34, which takes over the actual valve function of the pressure regulating valve 26, and to a valve seat 36, a closing element 38 and a fluid outlet opening 40 comprises downstream of the valve seat 36 in the flow direction, and the fuel 12 when opening the Pressure control valve 26 can be disabled. In order to move the closing element 38 along a movement axis 42, the pressure regulating valve 26 further has an actuator region 44, which comprises a pole core 46 and an armature 48. Since the pressure control valve 26 further comprises a coil 50 which is arranged around the pole core 46 and the armature 48, and which can be driven from outside via, for example, a plug 52, this is

Pressure control valve 26 is formed as an electromagnetically actuated valve. In this case, the armature 48 is coupled to the closing element 38 so that it along the axis of movement 42 of the

Closing element 38 a motive force on the closing element 38 can transmit. For example, the closing element 38 is screwed into the armature 48 for this purpose. However, it is also an indirect coupling between the armature 48 and closing element 38 conceivable.

The high-pressure housing 30 does not end where the pressure control valve 26 begins, as was the case with the conventional cartridge designs, but forms a valve housing area 58 with a high-pressure housing area 56, in which at least the valve area 34, that is the valve seat 36 Closing element 38, and the fluid outlet opening 40, are received.

In this case, in the present embodiment, the valve seat 36 is mounted directly in the valve housing portion 58 of the high-pressure housing 30, in such a way that a valve seat outer surface 60 is in direct contact with an inner wall 62 of the high ^¬ pressure housing 30. For example, while the valve seat 36 at its valve seat outer surface 60 has an external thread 46, and the inner wall 62 of the high-pressure housing 30 has an internal thread 66, so that the valve seat 36 can be screwed directly into the high-pressure housing 30.

In order to prevent high-pressure fuel 12 from unintentionally leaking out of the high-pressure region 28, the valve seat 36 is sealed by means of a high-pressure sealing element 68 against a pressure force of the high-pressure fuel 12 acting in the high-pressure region 28. Such a high-pressure sealing element 68 can be provided, for example, by a biting edge 70. Such a biting edge 70, with the threads 64, 66 bolted together, may provide a sealing force between the valve seat 36 and the high pressure housing 30 along the movement 42 which provides a secure, high pressure, high pressure seal force available over the life of the elements. The coil 50 of the pressure control valve 26 is housed in a bobbin tube 72 which is formed so that it can be easily plugged onto a housing from the outside. Therefore, the bobbin tube 72 with the coil 50 is simply plugged from outside onto the valve housing portion 58 formed by the high-pressure housing 30. The bobbin tube 72 is rotatable about the movement axis 42 until it firmly with the

High-pressure housing portion 56 is connected, for example by welding or by crimping. Integral with the bobbin tube 72, the plug 52 is formed, for example, by injection, so that this is freely rotatable about the movement axis 42 until the final attachment of the bobbin tube 72 to the high-pressure housing portion 56. This flexible to ^¬ circuit geometry is possible.

The high-pressure housing portion 56, which forms the valve housing portion 58, extends along the movement axis 42 to the coil 50. Thus, a magnetic circuit 74 induced by the coil 50 also penetrates the high-pressure housing portion 56, so that the high-pressure housing 30 not only the

Valve housing portion 58 forms for accommodating elements of the pressure control valve 26, but at the same time can be used for the magnetic circuit 74. As a result, additional elements for forming the necessary magnetic circuit 74 in the pressure regulating valve 26 can be dispensed with.

In the present embodiment, the armature 48 of the pressure regulating valve 26 is directly in the valve housing portion 58, which is formed by the high-pressure housing 30 is added.

If not the armature 48 follows in the flow direction of the fuel 12 directly to the valve seat 36, but the pole core 46, it is also possible to include the pole core 46 in the valve housing portion 58. Depending on the design of the high-pressure housing 30 is However, it is also possible to allow a recording of both armature 48 and pole core 46 of the pressure control valve 26.

The armature 48 is coupled to the closure element 38 so that it can move it along the movement axis 42 by transmitting a motive force to the closure element 38. For this purpose, the armature 48 is movable along the axis of movement 42 in the

Valve housing portion 58 stored. In addition, a return spring 76 is disposed in the actuator region 44, which is located between the armature 48 and the pole core 46. The return spring 76 in this case exerts a restoring force on the armature 48 and the locking element 38 coupled to the armature 48, so that the closing element 38 is pressed onto the valve seat 36 and thus into a closed position. The restoring force therefore acts against a pressure force acting on the closing element 38 from the other side, that is to say from the high-pressure region 28, of the high-pressure fuel 12 located therein.

By this arrangement, a normally closed pressure ^¬ control valve 26 is realized, which can regulate the high pressure in the high ^¬ pressure range 28 with a high efficiency. The restoring force of the return spring 26 can be overcome by energizing the coil 50 and pulling the armature 48 onto the pole core 46. As a result, the closing element 38 is pulled out of the valve seat 36 and the pressure regulating valve 26 is thus opened. Therefore, an actively induced opening movement of the closing element 38 is possible via the actuator region 44.

However, the restoring force of the return spring 76 can also be overcome by acting from the high-pressure region 28 on the closing element 38, a pressure force which is greater than that Restoring force of the return spring 76. This is the case, for example, when a maximum pressure in the high-pressure region 28 is exceeded. Therefore, the pressure regulating valve 26 not only provides a function of actively controlling a high pressure in the high pressure area 28, with which a desired high pressure can be adjusted in the fuel 12, but also constitutes a safety valve which, in the case of the high pressure in the high pressure area 28 exceeds a maximum pressure applicable to elements of the

Fuel injection system 10 could be dangerous

Fuel 12 absteuert to the outside.

The pressure control valve 26 is therefore used to regulate system pressures in the high pressure region 28 as needed. As a result, the system pressure can be adjusted as needed for combustion in an internal combustion engine. On the other hand, it is possible by the pressure regulating valve 26 to prevent the system from being damaged by an overpressure in an emergency.

Currently, it is known to provide pressure control valves 26 as individual modules in cartridge design, in the existing systems in the high pressure area, that is, at pressures up to 3000 bar and higher, for example in a

Fuel pump or be screwed into a pressure accumulator 22. The valve seat 36 is integrated in the pressure control valve 26, since the pressure control valves 26 due to

Wear minimizations have high hardness. The system assemblies, that is, the high pressure areas 28, in which the pressure control valves 26 are screwed in as a whole, however, are softer and tough, so that the high-pressure region 28 can withstand high pressure pulsations. Because of these contrasting properties are the

Pressure control valves 26 constructed in known systems separated from the system modules of the high-pressure region 28. As a result, however, a large number of components is required. In addition, the orientation of the electrical connector 52 within an overall assembly of a pressure control valve 26 is not flexible.

So far, the pressure control valve 26 and the high-pressure housing 30 are constructed separately from each other, wherein the pressure control valve 26 is screwed as a whole into the high-pressure housing 30 and seals axially against the high-pressure housing 30. The hydraulic pressure in the high-pressure region 28 is regulated by the fact that the pressure regulating valve 26 opens at certain times in order to reduce or regulate the pressure. The hydraulic fluid drains into a low pressure area.

The plug position of the plug 52 within an overall assembly of the pressure control valve 26 has been solved so that the thread is aligned with the high-pressure housing 30 to the pressure control valve 26, and at the same time the thread of the

Pressure control valve 26 is aligned with the position of the plug 52. As a result, a relatively large variation of the position of the electrical connector 52 to the overall assembly of the pressure regulating valve 26 may occur, since this position of the accuracy of alignment of the thread in the high pressure housing 30, the accuracy of the position of the thread of the pressure control valve 26 to the position of the electrical connector 52 and the Einschraubparametern the pressure control valve 26 of the overall assembly is dependent. Now, however, proposed that the pressure regulating valve 26 sys ^¬ temintegriert be integrated into the high-pressure casing 30th The valve seat 36 is integrated in the high pressure housing 30 directly via an external thread 64 and a Hochdruckabdichtelement 68 in the form of a biting edge 70 in the high pressure housing 30. This Hochdruckabdichtelement 68 seals by an axial force exerted by the screw directly against the

High pressure housing 30 from. By the axial force of the valve seat 36 and the external thread 64, a sealing force is exerted on the Hochdruckabdichtelement 68. This prevents the sealing force from decreasing over the product's life and the sealing force being lost. The pressure regulating valve 26 is pressurized axially from the high pressure area 28 ago. Since medium can flow through the pressure regulating valve 26. In operation of the

Pressure control valve 26, there are two operating states. In the first operating state, a closing element 38, which is subjected to a force, seals against the valve seat 36. This force can be generated by an electromagnet or a compression spring such as the return spring 76. In the second operating state, the closing element 38 lifts off from the valve seat 36. As a result, a cross section is released, can flow through the medium. The case of lifting off the closing element 38 can be produced by the hydraulic pressure from the high-pressure region 28 being greater than the force by the electromagnet or the return spring 76. In a second case, an actuator region 44, for example an electromagnet with a coil 50, the spring force of the return spring 76 are actively canceled, so that the hydraulic cross section between the closing element 38 and valve seat 36 is released for the hydraulic medium.

Because the valve seat 36 is integrated directly in the high pressure housing 30, it is possible to use elements of the high pressure housing 30 for the pressure control valve 26. Areas of this high pressure housing 30 may be in the magnetic circuit 74 of the

Aktorbereiches 44 of the pressure control valve 26 are used. The assembly is simple and robust. All components of the pressure control valve 26 are integrated into the high-pressure housing 30. Similarly, the magnetic circuit 76, wherein the course of the magnetic Flow of the electromagnet in the high-pressure housing 30 is inte ^¬ grated. The magnetic circuit 74 runs like a torus around the coil 50 in the metallic components such as the pole core 46, the armature 48, and the high pressure housing portion 56. This makes it possible to save components.

Another advantage is that the location of the electrical connector 52 is defined to the overall assembly. The coil 50 is attached directly to the high-pressure housing 30. Therefore, the position of the electrical connector 52 in the overall assembly can be exactly posi ^¬ tioned.

Claims

claims

A high pressure assembly (32) for providing a high pressure fuel (12), comprising:

- A defined by a high pressure housing (30) high pressure area (28);

a pressure regulating valve (26) for regulating the high pressure in the high pressure area (28) by venting an amount of fuel from the high pressure area (28), the pressure regulating valve (26) having a valve area (34) with a valve seat (36)

Closing element (38) and with a valve seat (36) downstream in the flow direction of the fuel (12)

Fluid outlet opening (40), and an actuator region (44) for moving the closing element (38) along a movement axis (42);

wherein a high pressure housing portion (56) of the high pressure housing (30) forms a valve housing portion (58) for receiving at least the valve portion (34) of the pressure regulating valve (26).

2. High-pressure arrangement (32) according to claim 1,

characterized in that the valve seat (36) is mounted directly in the valve housing portion (58) of the high pressure housing (30) such that a valve seat outer surface (60) is in direct contact with an inner wall (62) of the high pressure housing (30), the valve seat (36) on the valve seat outer surface (60) in particular ^{¬ a} special external thread (64) which is screwed into a on the inner wall (62) of the high-pressure housing (30) in the Ventilge ^¬ housing area (58) arranged internal thread (66).

3. High-pressure arrangement (32) according to any one of claims 1 or 2, characterized in that the valve seat (36) by means of a Hochdruckabdichtelements (68), in particular by means of a biting edge (70) against one in the high-pressure region (28) acting Compressive force of hochdruckbeaufschlagten fuel (12) from ^¬ sealed.

4. High-pressure arrangement (32) according to one of claims 1 to 3, characterized in that the pressure regulating valve (26) is an electromagnetically operable valve with a coil (50), wherein the actuator region (44) has a pole core (46) and an armature (46). 48).

5. High-pressure arrangement (32) according to claim 4,

characterized in that the armature (48) is connected to the closing element (38) is coupled such that it can transmit a moving force on the closing element (38) along the BEWE ^¬ supply axis (42).

6. high-pressure assembly (32) according to any one of claims 4 or 5, characterized in that the armature (48) and / or the pole core (46) is received directly in the valve housing portion (58) of the high-pressure housing (30), wherein the armature ( 48) is movably mounted in the valve housing region (58), in particular along the movement axis (42).

7. High-pressure arrangement (32) according to one of claims 4 to 6, characterized in that a coil sleeve (72) having the coil (50), from the outside on the valve housing portion (58) forming the high-pressure housing portion (56) is attached, wherein the high-pressure housing region (56) extends along the movement axis (42) at least as far as the coil (50) arranged in the bobbin tube (72).

8. High-pressure arrangement (32) according to claim 7,

characterized in that a plug (52) integral with the bobbin tube (72) formed, in particular molded onto the bobbin tube (72), and / or that on the Hochdruckge- Housing (56) plugged bobbin tube (72) as long ro ^¬ tion symmetric about the movement axis (42) is freely rotatable until it is firmly connected by a positive and / or cohesive fastening ^¬ gungsverfahren with the high-pressure housing portion (56).

9. High-pressure arrangement (32) according to one of claims 1 to 8, characterized in that the actuator region (44) a

Return spring (76) which exerts on the closing element (38) along the movement axis (42) acting restoring force against a on the closing element (38) of the high pressure area (28) acting pressure force of

pressurized fuel (12) acts to the

To press closing element (38) in a closed position on the valve seat (36).

10. High-pressure arrangement (32) according to claim 9,

characterized in that the restoring force by a by the actuator area (44) induced active opening movement of the closing element (38) or by a predetermined one

Maximum pressure exceeding overpressure in the high pressure region (28) can be overcome.