EP3688288B1 - Assembly comprising a camshaft phasing device - Google Patents

Description

The invention relates to a kit with a camshaft adjuster, in which a pressure fluid distributing central valve is provided, and with an actuator controlling the central valve, the camshaft adjuster being driven or drivable by means of a dry-running traction drive, for example with a belt, and one rotatable in one Has stator mounted rotor.

Kits consisting of a camshaft adjuster and a central valve are, for example, from the DE 10 2015 214 725 A1 famous. If the camshaft adjuster is driven by means of a belt, the sealing of the camshaft adjuster and the components that are actively connected to it must be ensured.

The object of the present invention is to provide a kit which is improved compared to the prior art and which ensures the seal and at the same time can be produced simply and inexpensively.

The object is achieved according to the invention by a kit having the features of claim 1. Advantageous refinements with expedient and nontrivial developments of the invention are specified in the respective subclaims.

A kit with a camshaft adjuster is proposed in which a central valve distributing a pressure fluid is provided. The kit also shows that Actuator controlling the central valve, the camshaft adjuster being driven or drivable by means of a dry-running traction drive and having a rotor rotatably mounted in a stator. Between the camshaft adjuster and the actuator there is provided a pressure fluid distribution space which can be filled with pressure fluid via the central valve and which is connected to an armature space of the actuator and is sealed off from the environment. The actuator comprises at least one armature movable by means of a coil, a pole core and a pole tube as a pole tube assembly.

According to the invention, the pressure fluid distribution space is sealed by a material-locking and / or force-locking and form-locking connection of the actuator or one or more actuator components with the central valve. Complex sealing by means of a separate sealing element can advantageously be dispensed with.

In principle, the sealing concept according to the invention is conceivable in designs in which the actuator is not connected to the central valve itself, but to a camshaft end or a component arranged on the camshaft end in a rotationally fixed and sealed manner.

According to an advantageous embodiment of the invention, the armature of the actuator can be axially displaceable in a sleeve, the sleeve being connected to the central valve in a materially bonded manner, in particular by means of welding or gluing. The sleeve allows a magnetic separation of the armature and the pole tube assembly. The armature can be turned inexpensively from free-cutting steel.

The sleeve is preferably provided as a thin, non-cutting sleeve and has a coating produced by means of plasma nitriding. The very wear-resistant sliding coating enables the sleeve to be made thin without the risk that the sleeve will wear out over a very long service life or lose its wall thickness.

According to a further advantageous embodiment, the pole tube and / or the pole core has a plurality of axial ones, preferably made of plastic, on an inner side Centering ribs made of plastic. The centering ribs allow simple and effective centering of the outer actuator components.

An alternative embodiment of the invention provides that the pole core of the actuator is cohesively connected to the central valve, in particular by means of welding or gluing. The coil and the remaining outer actuator components are radially centered on the technical unit pole tube assembly / central valve and positioned axially and positioned radially in a component fixed to the motor.
This enables the simple compensation of module-specific tolerances, so that the actuator only has to have the minimum necessary stroke. As a result, a reduction in installation space can also be achieved.
It is also not necessary to provide a backlash compensation for coaxial errors.

A particularly easy to manufacture and inexpensive embodiment of the invention provides that the pole core of the actuator is non-positively and positively connected to the central valve, in particular by means of a press fit.

The pole core can preferably form a preassembled pole tube assembly with the pole tube, with a non-magnetizable intermediate ring produced by means of a thermal process being provided between the pole tube and the pole core, which integrally connects the pole tube and the pole core. Alternatively, the pole core can form a pole tube assembly with the pole tube, in which the pole tube and the pole core are provided in one piece.

According to an advantageous embodiment of the invention, a bobbin of the coil has a plurality of axial centering ribs made of plastic, preferably made of plastic, on an inner side. The centering ribs allow simple centering and can be molded onto the coil body at low cost.

According to another advantageous embodiment of the invention, at least the coil with a coil body and a housing of the actuator are centered radially on the pole tube assembly by means of one or more slide bearings. The slide bearing or bearings allow the gap between the pole tube assembly and the pole disks to be minimized. Know that or the plain bearings as an additional material PFTE, a particularly low-wear bearing can also be achieved for high circumferential speeds. An advantageous embodiment provides that a single plain bearing made of a non-ferrous base material is arranged between the coil body and the pole tube assembly. This can, for example, be encapsulated with the remaining outer actuator components. The arrangements in the area of the coil body allow the gap between the pole tube assembly and the pole disks to be easily minimized without additional installation space.

According to an alternative advantageous embodiment, two plain bearings made of a ferrous base material are arranged axially outside a magnetic circuit. A sealing element can preferably be provided for further sealing between the camshaft adjuster, in particular between the stator and the central valve.

According to an advantageous embodiment, a bearing element can be provided between the camshaft adjuster, in particular between the stator and the central valve.

Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and on the basis of the drawing.

Figur 1

in schematischer Darstellung einen Ausschnitt eines ersten Ausführungsbeispiels eines erfindungsgemäßen Bausatzes im Längsschnitt;

Figur 2

in schematischer Darstellung einen Ausschnitt eines zweiten Ausführungsbeispiels eines erfindungsgemäßen Bausatzes im Längsschnitt;

Figur 3

eine Zentralventil/Aktuator-Baugruppe des Bausatzes gemäß Fig. 2 im Längsschnitt;

Figur 4

einen Querschnitt A-A der Zentralventil/Aktuator-Baugruppe des Bausatzes gemäß Fig. 2;

Figur 5

einen vergrößerten Ausschnitt X des Querschnitts A-A gemäß Fig. 4;

Figur 6

einen Ausschnitt eines dritten Ausführungsbeispiels eines erfindungsgemäßen Bausatzes im Längsschnitt und

Figur 7

einen Ausschnitt eines vierten Ausführungsbeispiels eines erfindungsgemäßen Bausatzes im Längsschnitt.

In the drawing show:

Figure 1

in a schematic representation a detail of a first embodiment of a kit according to the invention in longitudinal section;

Figure 2

in a schematic representation a detail of a second embodiment of a kit according to the invention in longitudinal section;

Figure 3

a central valve / actuator assembly of the kit according to Fig. 2 in longitudinal section;

Figure 4

a cross section AA of the central valve / actuator assembly of the kit according to Fig. 2 ;

Figure 5

an enlarged detail X of the cross section AA according to Fig. 4 ;

Figure 6

a section of a third embodiment of a kit according to the invention in longitudinal section and

Figure 7

a section of a fourth embodiment of a kit according to the invention in longitudinal section.

Fig. 1 shows a first embodiment of a kit 1 with a basically known camshaft adjuster 2, in which a pressure fluid distributing central valve 3 is provided.

The camshaft adjuster 2 is used to adjust an in Fig. 1 not shown camshaft formed. The central valve 3 has a piston 10 which is axially movable in a valve housing 11 and which with the aid of an electromagnetic actuator 4 is moved. Several working connections are provided in the valve housing 11 for the hydraulic supply of the camshaft adjuster 2.
The central valve 3 and the actuator 4 are in Fig. 1 only partially and schematically formed. Details are accordingly Fig. 2 can be seen which shows a further embodiment of the kit 1.

The camshaft adjuster 2 allows a change in the opening and closing times of gas exchange valves of the internal combustion engine to be brought about during the operation of an internal combustion engine that includes a cylinder head and is not shown in detail. For this purpose, with the help of the camshaft adjuster 2, a relative angular position of a camshaft (not shown) of the internal combustion engine rotatably received in the cylinder head compared to a crankshaft (not shown) of the internal combustion engine is continuously changed, the camshaft being rotated relative to the crankshaft. By turning the camshaft, the opening and closing times of the gas exchange valves are shifted so that the internal combustion engine can achieve its optimum performance at the respective speed.
The camshaft adjuster 2 is driven or drivable by means of a dry-running traction mechanism drive, for example with a belt, and for this purpose has a stator 5 that is non-rotatably connected to a belt wheel 12 as a drive wheel. The belt pulley 12 is guided over the belt as a drive element. The stator 5 is drive-connected to the crankshaft in a known manner via the belt and the belt pulley 12. The stator 5 and the belt pulley 12 can consist of separate components or can be formed in one piece. The belt pulley 12 can form, for example, a cylindrical stator base body and a cover.

On the inside of the stator 5 or the stator base body 13, webs extending radially inward are formed at regular intervals, such that an intermediate space is formed between each two adjacent webs. A wing 14 of a rotor hub of a rotor 6 of the camshaft adjuster 2 rotatably mounted in the stator 5 is arranged protruding into the intermediate space. The rotor hub has a number of vanes 14 corresponding to the number of gaps. Thus, with the help of the wings, each space can be divided into two pressure chambers. In A pressure medium, generally a hydraulic fluid, is introduced into these sub-spaces in a controlled manner with the aid of the central valve 3.

A pressure chamber is assigned to each working connection. The first pressure chamber is assigned to the first working connection and the second pressure chamber is assigned to the second working connection. To the angular position between

To change the camshaft and the drive wheel and thus the crankshaft, the rotor is rotated relative to the stator. For this purpose, hydraulic fluid is fed into the pressure chambers depending on the desired direction of rotation, while the other pressure chambers are relieved towards a tank. In order to pivot the rotor counterclockwise with respect to the stator, a first working connection is pressurized by the central valve and a second working connection is relieved. In contrast, in order to pivot the rotor clockwise, the central valve pressurizes the second working connection and relieves the first working connection. The discharge takes place via at least one tank connection, the hydraulic fluid being able to flow off via this tank connection.

The piston 10 of the central valve 3 is moved with the aid of a tappet 15 of the actuator 4, which is fixed in an armature 16 and can be axially displaced with the armature 16 along a longitudinal axis of the actuator 4.

The actuator 4 comprises an in Fig. 1 Pole tube assembly 17, not shown, which is arranged within a cylindrical, magnetic field-generating coil 18, and a housing 19 which is fastened directly or with the aid of an adapter in a component 20 fixed to the engine, such as a cylinder head. Together with pole disks 31, 32, the coil 18 and the pole tube assembly 17 form a magnetic circuit. One or both pole disks 31, 32 can be formed in one piece with the housing 19. It is also conceivable to encapsulate the housing 19 and the pole disks 31, 32 and the coil 18 with an additional plastic housing.

The coil 18 is received in a coil body 21 made of plastic, which at least partially surrounds the pole tube assembly.

In the first, in Fig. 1 The embodiment shown, the armature 16 is provided in a sleeve 22 so as to be axially displaceable. For the magnetic separation of armature 16 and pole tube assembly 17, the sleeve 22 is preferably provided as a thin, non-cutting sleeve and has, for example, a coating produced by means of plasma nitriding. The armature 16 can be turned inexpensively from free-cutting steel. The very wear-resistant sliding coating enables the sleeve 22 to be made thin without the risk that the sleeve 22 will wear out over a very long service life or lose its wall thickness.

Between the camshaft adjuster 2 and the actuator 4 there is a pressure fluid distribution space 7 which can be filled with pressure fluid via the central valve 3 and which is connected to an armature space 8 of the actuator 4. As can be seen, the pressure fluid distribution space 7 is provided within the valve housing 11 and extends between the piston 10 and the armature space 8. The pressure fluid distribution space 7 is sealed off from the environment in order to keep the belt drive area free of hydraulic fluid / pressure fluid and thus ensure the drive is operationally reliable.

The first exemplary embodiment provides for the sealing of the pressure fluid distribution space 7 by means of a material connection of the actuator 4 or one or more actuator components with the central valve 3 or a central valve component.
How out Fig. 1 is apparent, for a material connection of the actuator 4 to the central valve 3, a circumferential collar 23 of the sleeve 22 is tightly welded or glued to an axial end face 24 of the valve housing 11. Laser welding, for example, can be used as a welding process. The sleeve 22 is thus embodied in a rotationally fixed manner with the central valve 3 and thus with the camshaft 9.

The sleeve 22, which is integrally connected to the valve housing 11, is rotatably supported by the connection in the pole tube assembly 17 (not shown), which can be formed in one piece or in several parts and which, like the remaining external components of the actuator 4, is statically attached to the motor-fixed component 20.

To center the sleeve 22 in the pole tube assembly, several, preferably three, axial centering ribs made of plastic, evenly distributed over the circumference, can be injection-molded onto an inside of the pole tube assembly. These enable exact alignment and centering during the assembly of the remaining actuator components (coil 18, pole tube assembly 17, housing 19) and ensure that the necessary small air gap is maintained. Separate sealing elements and a process-intensive production of sealing surfaces between the actuator 4 and the camshaft adjuster 2 can thus be dispensed with.

In order to increase the robustness of the kit 1, part of the pole tube assembly 17, in particular a pole core, can be connected to the end face 24 of the central valve 3 in a materially bonded manner, in particular by means of welding or gluing. A sealing element 25 can be provided between the stator 5 and the central valve 3 for further sealing. Furthermore, a bearing by means of a suitable bearing 26 can be provided between the stator 5 and the central valve 3.

According to the Figures 2 to 5 The embodiment shown differs from the first embodiment according to FIG Fig. 1 in that the actuator 4 has no sleeve and the armature 16 in this case is mounted displaceably in the pole tube assembly 17.
Between the camshaft adjuster 2 and the actuator 4 there is the pressure fluid distribution space 7 which can be filled with pressure fluid via the central valve 3 and which is connected to an armature space 8 of the actuator 4. As can be seen, the pressure fluid distribution space 7 is provided within a pole core 27 of the pole tube assembly 17 and extends between the piston 10 of the central valve 3 and the armature space 8. The pressure fluid distribution space 7 is also sealed off from the environment in this exemplary embodiment in order to keep the belt drive area free of hydraulic fluid / pressure fluid and thus to ensure the drive is operationally safe.

To seal off the pressure fluid distribution space 7, the pole core 27 of the actuator 4 is non-positively and positively locked, in particular by means of a press fit with the central valve 3, ie connected to the valve housing 11 in a rotationally fixed manner. In this exemplary embodiment, the pole tube assembly 17 comprises the pole core 27, a pole tube 28 and a base 29 which is tightly connected to the pole tube 28. An additional material connection of the pole core 27 to the valve housing 11 is conceivable.

Advantageously, a non-magnetizable intermediate ring 30 produced by means of a thermal process can be provided between the pole tube 28 and the pole core 27, which connects the pole tube 28 and the pole core 27 in a materially bonded manner.

The pole tube assembly 17, which is positively and non-positively connected to the valve housing 11, is rotatably supported by the connection in that of the coil 18, i.e. in its bobbin 21, which like the housing 19 and the pole disks 31, 32 are statically attached to the component 20 fixed to the motor.

To center the bobbin 21 of the bobbin 18, several, preferably three, axial centering ribs 36 made of plastic are injection-molded on an inside of the bobbin 21, evenly distributed over the circumference. These enable exact alignment and centering during the assembly of the remaining actuator components (coil 18, coil body 21, housing 19) and ensure that the necessary small air gap is maintained. Separate sealing elements and a process-intensive production of sealing surfaces between the actuator 4 and the camshaft adjuster 2 can thus be dispensed with.

The housing 19 of the actuator 4, which, as already described, can be overmolded by means of an additional plastic housing, is also fastened in this exemplary embodiment directly or with the aid of an adapter in a component 20 fixed to the engine, such as a cylinder head.

Fig. 6 shows a section of a third exemplary embodiment of a kit 1 according to the invention, in which, similar to the previous exemplary embodiment, the pole core 27 of the pole tube assembly 17 is connected to the central valve 3, not shown, in a rotationally fixed manner. The pole tube assembly 17 is designed in one piece here and forms a technical unit with the central valve 3. The remaining External components of the magnetic circuit (coil 18, coil body 21, housing 19 and pole disks 31, 32 are statically fastened directly or with the aid of an adapter in the engine-fixed component 20 such as a cylinder head.

The coil 18 with its coil body 21, the pole disks 31, 32 and the housing 19 of the actuator 4 are radially centered on the pole tube assembly 17 by means of a sliding bearing 33 and axially fixed with minimal play. In this embodiment, the plain bearing 33 is made of a non-ferrous base material (e.g. bronze) with PTFE and can preferably be overmolded with the remaining components.

In a fourth embodiment according to Fig. 7 on the other hand, two plain bearings 34, 35 made of a ferrous base material are arranged axially outside the magnetic circuit. That is, the two slide bearings 34, 35 are each axially adjacent to the pole disks 31, 32 outside the magnetic circuit.

In principle, the sealing concept according to the invention is also conceivable in embodiments not shown, in which the sleeve 22 or the pole core 27 is not rotatably attached to the central valve 3 itself, but to a camshaft end or a component arranged on the camshaft end as described.

Claims (14)

1. Kit (1) with a camshaft adjuster (2), in which a central valve (3) which distributes a pressure fluid is provided, and with an actuator (4) which controls the central valve (3), the camshaft adjuster (2) being driven or being capable of being driven by means of a dry-running flexible drive and having a rotor (6) which is mounted rotatably in a stator (5), a pressure fluid distribution space (7) which can be filled with pressure fluid via the central valve (3) being provided between the camshaft adjuster (2) and the actuator (4), which pressure fluid distribution space (7) is connected to an armature space (8) of the actuator (4) and is sealed towards the surroundings, and the actuator (4) comprising at least one armature (16) which can be moved by means of a coil (18), a pole core (27) and a pole tube (28) as a pole tube assembly (17), characterized in that the sealing of the pressure fluid distribution space (7) takes place by way of an integrally joined and/or non-positive and positively locking connection of the actuator or one or more actuator components to the central valve.
2. Kit (1) according to Claim 1, characterized in that the armature (16) of the actuator (4) can be displaced axially in a sleeve (22), the sleeve (22) being connected to the central valve (3) in an integrally joined manner, in particular by means of welding or adhesive bonding.
3. Kit (1) according to Claim 2, characterized in that the sleeve (22) is provided as a sleeve which is manufactured to be thin without the removal of material, and has a coating which is produced by means of plasma nitriding.
4. Kit (1) according to Claim 2 or 3, characterized in that the pole tube (28) and/or the pole core (27) have/has, on an inner side, a plurality of axial centring ribs which are made from plastic and are preferably moulded on from plastic.
5. Kit (1) according to Claim 1, characterized in that the pole core (27) of the actuator (4) is connected to the central valve in an integrally joined manner, in particular by means of welding or adhesive bonding.
6. Kit (1) according to Claim 1 or 5, characterized in that the pole core (27) of the actuator (4) is connected to the central valve (3) in a non-positive and positively locking manner, in particular by means of an interference fit.
7. Kit (1) according to Claim 6, characterized in that the pole core with the pole tube forms a pole tube assembly (17) which can be preassembled, and a non-magnetizable intermediate ring which is produced by means of a thermal method is provided between the pole tube and the pole core, which intermediate ring connects the pole tube and the pole core in an integrally joined manner.
8. Kit (1) according to Claim 6, characterized in that the pole core with the pole tube forms a pole tube assembly (17), in the case of which the pole tube and the pole core are provided in one piece.
9. Kit (1) according to one of Claims 6 to 8, characterized in that a coil body (21) of the coil (18) has, on an inner side, a plurality of axial centring ribs (36) which are made from plastic and are preferably moulded on from plastic.
10. Kit (1) according to one of Claims 6 to 8, characterized in that at least the coil (18) is centred radially on the pole tube assembly (17) by way of a coil body (21), and a housing (19) of the actuator (4) is centred radially on the pole tube assembly (17) by means of one or more plain bearings (33, 34, 35).
11. Kit (1) according to Claim 10, characterized in that a single plain bearing (33) consisting of a non-ferrous basic material is arranged between the coil body (21) and the pole tube assembly (17).
12. Kit (1) according to Claim 10, characterized in that two plain bearings (34, 35) consisting of a ferrous basic material are arranged axially outside a magnetic circuit.
13. Kit (1) according to one of the preceding claims, characterized in that a seal element (25) is provided between the camshaft adjuster (2), in particular between the stator (5) and the central valve (3).
14. Kit (1) according to one of the preceding claims, characterized in that a mounting element is provided between the camshaft adjuster (2), in particular between the stator (5) and the central valve (3).

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