EP2058478B1 - Adjustment device for modification of the relative position of a camshaft - Google Patents

Description

The invention relates to an adjusting device for changing the relative position of a camshaft for influencing the timing of valves of a valve train of an internal combustion engine according to the preamble of patent claim 1.

In order to optimize the power and torque of an internal combustion engine during its active phase, so-called variable adjustment comprehensive valve controls are used. With them, the position of the intake camshaft and possibly the exhaust camshaft are changed relative to the crankshaft.

Notwithstanding the camshaft adjuster type EP 1598 530 A1 is a typical and frequently used type camshaft adjuster in the swing wing-like design of a rotor and a stator between which form in size variable hydraulic chambers, in particular in a counter-rotating manner. The hydraulic chambers are filled with a hydraulic medium, wherein the rotor is held by the different pressure ratios between the chambers, in particular by pressurization on side surfaces of one or more wings, in a certain relative angular position to the stator. By a control such as a control valve, the pressure conditions in the chambers can be adjusted.

There are efforts to optimize the production of the camshaft adjuster ever further. For this purpose, for example, in the DE 10 2004 011 659 A1 proposed to produce a component blank from a continuous casting. As a suitable material is in this document, as well as in the DE 103 35 051 A1 , Aluminum or an aluminum alloy proposed. Alternatively, the EP 1 479 877 A2 be taken that a particularly hardened metal by a steel coating, for. B. in vapor-deposited form, is to use for usable wings. However, should remain in the field of aluminum alloys, so suggests the DE 100 06 269 A1 general, to use a very specific aluminum alloy, which is mechanically post-processed. The proposed alloy is said to increase strength and wear resistance. Difficulties resulting from the use of aluminum for camshaft adjusters, for example, from the US 2006/0231053 A1 in relation to the rotor return spring. The difficulties can, for example, by subsequently introduced insert body gem. DE 10 2004 062 071 A1 be countered. The US 2002/038501 A1 discloses another example of such an adjustment device.

In the DE 10 2004 062 070 A1 is explained that it is irrelevant how the actual housing of a camshaft adjuster is made. Important is the further training of a ring gear, which meets the hardness requirements as a separate part.

From the FIG. 1 of the DE 197 55 495 A1 a designer takes the opportunity to design the sprocket of a sprocket as a separate part that is to be used somehow as an additional component in the crankshaft solid component.

A variable valve timing mechanism is known EP 1 400 660 B1 in which a stator surrounding a rotor carries a sprocket. The sprocket and the housing have, on the one hand, a sprocket portion formed in a substantially circular shape and teeth on its outer periphery. On the other hand, a housing portion formed integrally with the sprocket portion as a sintered body made of a ferrous powder material.

From the DE 39 37 644 A1 is a device for the hydraulic rotation angle adjustment of a shaft relative to a drive wheel, wherein the shaft is effective as a camshaft in an internal combustion engine. The camshaft is provided with a rotor having a rotor, which is surrounded by a, also wing owning stator. The wings of the rotor and the stator are adjustable by pressurization to each other.

The above-cited prior art is incorporated by reference in its entirety into the disclosure of the present invention by reference to various embodiments of conventional swing motor type adjusting devices, thereby to present the present invention in a compact manner, particularly with respect to its mechanical shapes to be able to.

It is an object of the invention to provide an adjusting device for changing the relative position of a camshaft of an internal combustion engine, which is characterized by a comparatively low weight in effective design and good function. In this case, serving as a camshaft adjuster adjustment, known as a vane principle, also works as a vane principle, works reliably and well to produce.

According to the invention, this object is solved by the features of patent claim 1. An advantageous manufacturing method is described in claim 7.
Further, the invention ausgestaltende features are included in the subclaims.

The advantages achieved by the invention can be seen in the fact that due to the high-strength light metal alloy, consist of the essential parts of the adjustment, the latter makes a remarkable weight reducing contribution. However, the weight reduction also contributes to the fact that rotating masses are particularly favorably influenced on the camshaft of the internal combustion engine. The adjusting device, which comprises the actuator housing or the stator, the rotor and the closing covers, is a sophisticated construction which can be implemented by acceptable means. Thanks to the targeted choice of materials, elaborate coating and hardening processes can be dispensed with. Finally, the collars of the closing cover allow a simple connection with adjacent housing parts, for example, a cylinder head of the internal combustion engine.

Another advantageous effect is to be seen in that with increased clocking, a stator-forming component can be produced in a die-casting process. Due to the favorable use of the self-forming casting skin as wear protection, which is in particular an oxide skin on the light metal alloy such as aluminum alloy, eliminates the usual processing steps such as grinding, broaching or calibrating after casting. For this purpose, the casting process is to be carried out in such a way that the reference point for the production of tailor-made components in the outer circumference of the adjusting device is sought. Other sides of the die-cast component may well be reworked, in particular to produce dimensional accuracy.

By choosing a forming and forming method of manufacturing a component including the gear in addition to other components such as a first closure cap, a die-cast fabrication may be a light metal alloy such as an aluminum alloy, a zinc alloy or an aluminum-based alloy with magnesium or zinc, create a dense, particularly abrasion-resistant surface. The light metal alloy, so the aluminum alloy, the zinc alloy and the Magnesium alloy, characterized by a proportion of 70% to 98% of the main alloying metal. The remaining elements are in a correspondingly low proportion of aluminum, magnesium, copper and silicon. The silicon content is in particular below 15% by volume, preferably even less than 10% by volume. The alloy is brought into the shape of the component by a die casting process. The surface is fine-pored. The surface is liquid-tight. The surface comprises an oxide layer. The surface further comprises a fine crystalline structure, which lies below the oxide layer as Stützgfüge in the outer region of the component. The surface is post-processing free. The surface is closed pore. The surface which at least partially exhibits these advantageous features is the running surface of a drive means such as a endless drive, a toothed belt drive or a chain drive. The drive means surface is counter-shaped for the drive means, for. B. by wave-shaped teeth for engagement in ribs of the toothed belt drive.

As the calibration reference point, the drive surface is selected. From this, outer, circumferentially limiting surface extending in the lateral height of the adjustment, the remaining dimensions are determined during the manufacturing process. This means that the surface, the so-called running surface, is free from post-processing. It is in the original die-cast condition. The casting skin is undamaged. The casting skin has no processing marks, except, of course, the withdrawal marks that result from the removal of the component from the die casting tool. The hardness of the component during the die casting process remains unchanged in the region of the running surface. The surface in the area of the tread is coating-free.

The manufacturing method according to the invention not only provides a quick-to-create camshaft adjuster, but the actuator housing is hydraulic fluid-tight. Especially in the case of belt adjusters, the absolute fluid-tightness of the innner-type hydraulic fluid is relevant for increasing operational safety. Furthermore, the actuator housing is resistant to abrasion and wear over the defined operating time, such as a motorized mileage of 500,000 km.

By calibrated on the outer circumference or the tread manufacturing process of untreated die casting surfaces with degrees of hardness of 80-130 HB 10 (according to Brinell) can be adjusted. The hardness is sufficient for a not further to be treated Tread. However, it may be helpful in some cases if the surface still undergoes a subsequent hot curing.

By a pure sighting of the tread, in which, for example, the position of the pores with respect to the surface is to be considered, or in which the processing marks are examined, the surface compensation of the tread according to the invention can be determined with the naked eye.

The invention is characterized by a method for producing an adjusting device. In the manufacturing method, a gear including the gear member serving as a confining member for a rotor, in particular a rotor with blades, is produced by a die-casting method, wherein no further metal-removing machining of an outer surface takes place, which is usable as a running surface of the gear. There is a maximum of processing exclusively innwandig and frontally instead of the adjustment.

The protective skin forming by the die-casting method is an oxide skin whose fine-crystalline cast structure is maintained unchanged, while another part such as the rotor or lid of the adjusting device can be subjected to machining during production.

In the drawings, embodiments of the invention are shown, which are described in more detail below.

• Fig.1 eine perspektivische Explosionszeichnung einer ersten Ausführungsform einer Verstelleinrichtung nach der Erfindung,
• Fig.2 einen Längsschnitt der Verstelleinrichtung nach Fig. 1,
• Fig. 3 eine Ansicht entsprechend Fig. 2 mit einer zweiten Ausführungsform der Verstelleinrichtung,
• Fig. 4 eine Schrägansicht einer dritten Ausführungsform einer Verstelleinrichtung,
• Fig. 5 einen Längsschnitt der Verstelleinrichtung nach Fig. 4,
• Fig. 6 eine Ansicht in Längsrichtung einer vierten Ausführungsform einer Verstelleinrichtung,
• Fig. 7 einen Schnitt nach der Linie VII-VII der Fig. 6,
• Fig. 8 eine Ansicht in Längsrichtung einer vierten Ausführungsform einer Verstelleinrichtung,
• Fig. 9 einen Schnitt nach der Linie IX-IX der Fig. B.

Show it

• Fig.1 an exploded perspective view of a first embodiment of an adjusting device according to the invention,
• Fig.2 a longitudinal section of the adjusting device according to Fig. 1 .
• Fig. 3 a view accordingly Fig. 2 with a second embodiment of the adjusting device,
• Fig. 4 an oblique view of a third embodiment of an adjusting device,
• Fig. 5 a longitudinal section of the adjusting device according to Fig. 4 .
• Fig. 6 a view in the longitudinal direction of a fourth embodiment of an adjusting device,
• Fig. 7 a section along the line VII-VII of Fig. 6 .
• Fig. 8 a view in the longitudinal direction of a fourth embodiment of an adjusting device,
• Fig. 9 a section along the line IX-IX of Fig. B.

An internal combustion engine, not shown, comprises an adjusting device 1 - first embodiment: Fig. 1 and 2 - Which is arranged coaxially with a camshaft 2 and connected to the latter. The camshaft 2 operates in a combustion chamber of the internal combustion engine acting valves that belong to a valve train of said internal combustion engine - not shown -. With the adjusting device 1, the relative position of the camshaft 2 for influencing the timing of the valves of the valve train is variable. The adjusting device 1 is provided with a stator 3 which is coupled to a drive device in the form of a coupled to a crankshaft of the internal combustion engine Endlostriebs example. Zahnriemenrieb - is not shown -. The stator 3, which is part of an actuator housing 4, surrounds a rotor 5, which is fixedly connected to the camshaft 2. At the outer periphery 6 of the cylindrical actuator housing 4, a gear wheel 7 designed as a toothed belt wheel is provided, which cooperates with the toothed belt drive. The stator 3 is provided with wings 8, 9 and 10; the rotor 5 with wings 11, 12 and 13. In the axial direction AA, the actuator housing 4 is limited by first and second closing lids 14 and 15, which are designed like a disk.

The gear 7 and the actuator housing 4 are made of a high-strength light metal alloy with a high silicon content. In this case, at least the actuator housing 4 and the gear 7 are produced as a unit 16 by die casting, which comprises at least the first closing cover 14. In addition, the assembly 16 or parts thereof, for example. Gear 7, actuator housing 4 or the like. Not uncured or uncoated. In the exemplary embodiment, the actuator housing 4, the gear 7 and the first closing cover 14, which form the assembly 16, made in one piece same from this light metal alloy may consist of the rotor 5 and the second closing cover 15, ie, the The last-mentioned components are similar in material to the first closing lid 14. It is also conceivable, however, to produce the second closure lid 15 made of iron-metallic material, plastic or a glass fiber reinforced material.

The second closing cover 15 is connected to the actuator housing 4 by means of axially extending screws 17, 18 and 19. The screws 17, 18 and 19 are arranged adjacent to an outer periphery 20 of the second closing cover 15 and screwed into corresponding threaded bores 21 in the actuator housing 4. Between the second closing cover 15 and the actuator housing 4, an annular sealing body 22 is effective. For receiving the sealing body 22, a groove 23 is provided, which is incorporated in the actuator housing 4; but it is also possible to form this groove 23 in the second closing cover 15. The first closing cover 14 and the second closing cover 15 are provided with coaxial with the central longitudinal axis AA of the adjusting device 1 extending first and second sleeve-like collars 24 and 25 - Fig. 2 -, Which are designed as axial extensions 26 and 27 of the first and second closing lids 14 and 15. Via the second collar 25 of the second closing cover 15, the camshaft 2 connected to the rotor 5 is introduced. In the end position of the adjusting device 1, an outer diameter 28 of the second collar 25 is installed with the interposition of a sealing ring 29 in a housing shown as a cylinder head 30 of the internal combustion engine. In a bore 31, which penetrates the first collar 24 of the first closing cover 14, rests a closure pin 31 ', which cooperates via a thread 32 with the first collar 24.

In Fig. 3 is a substantially comparable with the adjusting device 1 second embodiment of an adjusting 33 shown, which includes a rotor 34 and a stator 35. The stator 35, which is part of a actuator housing 36, comprises a first integrated closing cover 37. A second closing cover 38 is screwed to the actuator housing 36, the first closing cover 37 having a first axial collar 39 and the second closing lid 38 having a second axial collar 40 , which are designed in the manner of sockets. In this embodiment, a camshaft 41 is inserted via the first collar 39 of the first closure lid, which is inserted with an outer diameter 42 with the interposition of a sealing ring 43 in a housing shown as a cylinder head 44.

A third embodiment of an adjusting device 45 according to the Fig. 4 and 5 instructs Steller housing 46 with a stator 47 and a rotor 48 on. The stator 47, which has a circular cylindrical shape, surrounds the rotor 48 connected to a camshaft and is delimited on the one hand by a first closure cover 49 produced in one piece with the actuator housing 46 and on the other hand by a second closure cover 50 in the axial direction AA which is independent of the actuator housing 46 and the stator 47 produced by the second closure lid 50, and said second closure lid 50 are interconnected by means of axial screws 51, 52, 53 and 54. The screws 51, 52, 53 and 54 are provided with a countersunk head 55, Fig. 5 - And from the second closing cover 50 is screwed into threaded holes 56 of the first closing cover 49.

The FIGS. 6 and 7 give a fourth embodiment of an adjustment 57 again, which in principle comprises the features of the adjusting device 1, with a actuator housing 58 with structurally united first closing cover 59 and attached second closing cover 60. In the actuator housing 58 and the first closing cover 59, consisting of a Alloy, iron-metallic inserts 61 and 62 are provided, which are cast around the light metal. The insert is used for local reinforcement, for example. A bore 63 for a locking device of a rotor to a stator 64, the z. B. during cold start of the equipped with the adjusting device 57 engine is effective. The insert 62 is disposed in an annular housing portion 65 and has a flat rectangular cross-section 66, the longer side 67 extends in the radial direction of the cylindrical adjustment device 57 and serves for sectional or circumferential reinforcement in the circumferential direction of the actuator housing 58.

Within a gear 68 of the actuator housing 58, one or more part-ring-like recesses 69, 70, 71, 72, 73, and 74 are incorporated in the annular housing portion 65, which contribute to the additional weight reduction of the adjusting device 57. At least the recesses 72 and 73 are brought with radial boundaries 75 and 76 relatively close to an axial bore 77 in the housing portion 65. In addition, at least in wings 78, 79 and 80 of the stator 64 weight reducing recesses 81, 82 and 83 are provided.

From the Fig. 8 and 9 shows a fifth embodiment of an adjusting device 84, which shows a actuator housing 85 in the axial direction AA limiting first and second closing covers 86 and 87. The actuator housing 85 is made of a high-strength Made of light alloy and carries adjacent to an outer periphery 88 a gear 89, which is designed as a sprocket 90 for a cooperating with a crankshaft endless chain drive - not shown.

The sprocket 90 is made independently or separately from the actuator housing 85 as a prefabricated component and consists of a suitable steel; but it is also conceivable to use a high-strength light metal alloy for the sprocket. To connect the annular sprocket 90 with the actuator housing 85 are non-positive methods, for example. Shrinking, which is shown at 91. For this purpose, a bore 92 of the sprocket 90 is fixed on a pin 95 of the first closing cover 86 of the actuator housing 85. It is also possible to provide the sprocket 90 with a sprocket portion 96, shown at 97, which forms a radial extension of the sprocket 90 into which the actuator housing 85 projects to form positive fit and which is encapsulated by the material of said actuator housing 85. In the sprocket 96 an axial bore 97 is incorporated, which is penetrated by the light metal material. Finally, it is also conceivable, the annular sprocket 90 with the actuator housing 85 by means of adhesive bond, z. As soldering welding or the like., To connect.

In the following like those shown in the embodiments FIGS. 1 to 9 together and in parallel to facilitate the emphasis on certain aspects.

The adjusting device 1, 33, 45, 57, 84 is suitable for changing the relative position of a camshaft 2, 41 for influencing the timing of valves of a valve train of an internal combustion engine. The adjusting device 1, 33, 45, 57, 84 has a stator 3, 35, 47 coupled to a drive device. The adjusting device 1, 33, 45, 57, 84 has a rotor 5, 34 permanently connected to the camshaft 2, 41. The stator 3, 35, 47, 64 is designed in the manner of a rotor housing 5, 34 surrounding the actuator housing 4, 36, 46, 85. The actuator housing 4, 36, 46, 58, 85 is provided at its outer periphery 6, 20 with a gear 7, 68, 89. It is in the axial direction of the adjusting device 1, 33, 45, 57, 84 as seen by closing lids 14, 15, 37, 38, 49, 50, 59, 60, 86, 87 limited. The gear wheel 7, 68, 89 of the adjusting device 1, 33, 45, 57, 84 and a first closing cover 14, 37, 49, 59, 86 and a second closing cover 15, 38, 50, 60, 90 carrying and with the Cam shaft 2, 41 connected rotor 5, 34 receiving actuator housing 4, 36, 46, 58, 85 are made of a high-strength light metal alloy.

The light metal alloy for the gear 7, 68, 89 and the actuator housing 4, 36, 46, 58, 85 is an aluminum alloy having a high silicon content. Due to the silicon content of the lightweight aluminum alloy is provided with a special hardness.

The actuator housing 4, 36, 46, 58, 85 and the gear wheel 7, 68, 89 of the adjusting device 1, 33, 45, 57, 84 have been formed by die casting to form a structural unit 16.

The assembly 16 of the adjusting device 1, 33, 45, 57, 84 comprises at least a first closing cover 38, 50, 60, 90th

The actuator housing 4, 36, 46, 58, 85, the gear 7, 68, 89 and the first closing cover 14, 37, 49, 59, 86 may be made in one embodiment in one piece.

The assembly 16 or at least parts thereof (eg gear wheel 7, 68, 89 actuator housing 4, 36, 46, 58, 85) are designed uncoated, they get their suitability for use without any further coating.

The assembly 16 or at least parts thereof (eg gear wheel 7, 68, 89, actuator housing 4, 36, 46, 58, 85) may also be uncured.

The second closing cover 15, 38, 50, 60, 90 may be in an embodiment material similar to the first closing cover 14, 37, 49, 59, 86 executed. The closure covers 14, 15, 37, 38, 49, 50, 86, 87 can be connected to the actuator housing 4, 36, 46, 58, 85 by means of screws 17, 18 and 19, 51, 52 and 53.

Alternatively, the second closure lid 15, 38, 50, 87 of a different material than a light metal alloy, for example. Steel, plastic or the like. Even then, with the intermediary of screws 17, 18 and 19, 51, 52 and 53 of the latter with the actuator housing 4, 36, 46, 58, 85 is connected. The screws 17, 18, 19, 51, 52, 53 can evenly distributed over a circumference produce a uniform surface pressure.

Between the second closing cover 15, 38, 50, 87 and the actuator housing 4, 36, 46, 58, 85, an annular sealing body 22 may be provided.

To receive the sealing body 22, a groove 23 may be provided which, for example, is incorporated in the actuator housing 4, 36, 46, 58, 85.

The first closing cover 14, 37, 49, 59, 85 and the second closing cover 15, 38, 50, 87 are arranged coaxially with a central longitudinal axis (AA) of the adjusting device 1, 33, 45, 57, 84 first and second sleeve-like cylindrical collars 24, 25, 39, 40, which are designed as axial extensions of the closure cover 26, 27.

Via the second collar 25 of the second closing cover 15, 38, 50, 60, 87, the camshaft 2, 41 connected to the rotor 5, 34 is introduced.

An outer diameter 28 of the second collar 25 works with the interposition of a sealing ring 29 with a housing, for example. A cylinder head 30, 44, the internal combustion engine together.

In a bore 31, 63, 77, 92, which penetrates the first collar 24 of the first closing cover 14, 37, 49, 59, 86, rests a closure pin 31 '.

The camshaft 2, 41 connected to the rotor 5, 34 is introduced via the first collar 24 of the first closing cover 14, 37, 49, 59, 86.

An outer diameter 42 of a first collar 39 of an adjusting device 1, 33, 45, 57, 84 with the interposition of a bearing 43 works with a housing, for example. A cylinder head 44, the internal combustion engine together.

A rotor 5, 34, 48 is surrounded by a stator 3, 35, 47, 64 inserted in a actuator housing 36, 46, 58, 85, on the one hand by a first closing cover 14, 37, 49, 59, 86 and on the other hand by a second closing lid 15, 38, 50, 60, 87 is limited.

The actuator housing 4, 36, 46, 58, 85 and the first closure cover 14, 37, 49, 59, 86 are made in one piece.

The first closing cover 14, 37, 49, 59, 86, the stator 3, 35, 47, 64, and the second closing cover 15, 38, 50, 60, 87 are mediated by axial screws 17, 18, 19, in particular four screws 51, 52, 53, 54, connected together.

The screws 51 to 54 rest in threads 56 of the first closure cover 49.

At least one actuator housing 4, 36, 46, 58, 85 of an adjusting device 1, 33, 45, 57, 84, one or more iron-metallic inserts 61, 62 are provided.

The inserts 61, 62 are encapsulated by the light metal alloy.

The insert 61 serves for local reinforcement, for example in the region of a bore 63, 77, 92 of a first closing cover 14, 37, 49, 59, 86 or of the actuator housing 4, 36, 46, 58, 85.

The insert 62 is used at least for sectional reinforcement, z. B. in the circumferential direction of the actuator housing 4, 36, 46, 58, 85th

Within an outer circumference of a gear 7, 68, 89 of the actuator housing 4, 36, 46, 58, 85, in an annular housing portion 65, one or more partially ring-like, weight-reducing recesses 69, 70, 71, 72, 73, 74, 81, 82, 83 provided.

Especially in the FIGS. 6 ff. illustrated design example can also be described by the fact that at least a portion of the recesses 69 to 74 with radial boundaries 75, 76 are brought relatively close to axial holes 77 in the housing portion 65.

At least in the wings 78, 79, 80 of the stator 64 weight reducing recesses 81, 82, 83 may be incorporated.

In the adjusting device 1 33, 45, 84 for changing the relative position of a camshaft 2, 41 for influencing the timing of valves of a valve train of an internal combustion engine, wherein the adjusting device 1, 33, 45, 57, 84 a coupled to a drive device stator. 3 , 35, 47, 64 and a rotor 5, 34 fixedly connected to the camshaft 2, 41, the stator 3, 35, 47, 64 is designed in the manner of a stator housing 4 surrounding the rotor 5, 34. The actuator housing 4, 36, 46, 58, 85 is provided at its outer periphery 6, 20, with a gear wheel 7, 68, 89. In the axial direction of the adjusting device 1, 33, 45, 57, 84 seen the actuator housing 4, 36, 46, 58, 85 of Closing covers 14, 15, 37, 38, 49, 50, 59, 60, 86, 87 limited. A first closure lid 86 and a second closure lid 87 are fastened to the actuator housing 85 in a load-bearing manner, wherein the actuator housing 85 is designed such that it can accommodate the rotor 5, 34 connected to the camshaft 2, 41. The actuator housing 86 of the adjusting device 84 is made of a high-strength light metal alloy, wherein the actuator housing 86 is provided with a gear formed as a sprocket 90 7, 68, 89. The gear 7, 68, 89 is prefabricated separately from the actuator housing 4, 36, 46, 58, 85.

The sprocket 90 may be made of a suitable steel. A steel is suitable if it is sufficiently wear-resistant. The wear resistance can be created by hardening or coating. Therefore, steels are used, which are to be considered as steels for flame or induction hardening, as case hardening steels, as nitriding steels or as tempering steels. The Ketterad 90 may also be made of a sintered metal.

The sprocket 90 may also be made of a suitable high strength light metal alloy. A light metal alloy is considered to be high strength if it can withstand the operating life of the requirements, eg. B. abrasion of less than 1/10 mm per 500,000 km.

The annular sprocket 90 in one embodiment is shrink-connected to the actuator housing 86.

The sprocket 90 protrudes into the actuator housing 85 with a sprocket portion 96. It is encapsulated by the material of the said actuator housing 85 in a further embodiment.

As in the Figures 2 . 3 . 5 . 7 and 9 As can be seen, the tread 93, which can be laterally closed and bounded by one or two guide stops 94, is in the uncalibrated, post-processing, cast condition. By the mold of the injection molding tool, the surface is contoured and shaped so that the corresponding drive means can engage well in elevations of the tread 93. The tread 93, their surface, is gated. The tread 93 is in the original structural state. A fine-pored surface is a surface whose coarser, inner pores created by the die-casting process remain closed. If the surface were reworked, then experience would show that pores extend from the inside to the outside, which are also detrimental to the tightness. LIST OF REFERENCE NUMBERS reference numeral importance 1 adjustment 2 camshaft 3 stator 4 actuator housing 5 rotor 6 Circumference, in particular outer circumference 7 Pinion 8th First wing, especially in the stator 9 Second wing, especially in the stator 10 Third wing, especially in the stator 11 First wing, especially rotor blades 12 Second wing, in particular rotor wing 13 Third wing, especially rotor blades 14 First closing cover 15 Second lock cover 16 unit 17 First screw, in particular axially extending screw 18 Second screw, in particular axially extending screw 19 Third screw, in particular axially extending screw 20 Circumference, in particular outer circumference 21 threaded hole 22 Sealing body, in particular annular sealing body 23 groove 24 First collar, especially cylindrical collar 25 Second collar, especially cylindrical collar 26 First extension of the closure lid 27 Second extension of the closure lid 28 outer diameter 29 seal 30 cylinder head 31 drilling 31 ' Verschlusszapfen 32 thread 33 adjustment 34 rotor 35 stator 36 actuator housing 37 First closing cover, in particular integrated closing cover 38 Second lock cover, in particular bolted lock cover 39 First collar 40 Second collar 41 camshaft 42 outer diameter 43 Bearing, which can simultaneously take over sealing ring functions 44 cylinder head 45 adjustment 46 actuator housing 47 stator 48 rotor 49 First closing cover 50 Second lock cover 51 First screw, especially axial screw 52 Second screw, especially axial screw 53 Third screw, especially axial screw 54 Fourth screws, especially axial screw 55 countersunk 56 Thread or threaded holes 57 adjustment 58 actuator housing 59 First closing cover 60 Second lock cover 61 Insert, in particular iron-metallic insert 62 Insert, in particular iron-metallic insert 63 drilling 64 stator 65 Housing area, in particular annular housing area 66 Cross section, in particular rectangular cross section 67 Longer side 68 Pinion 69 First recess, in particular part-ring-like recess 70 Second recess, in particular part-ring-like recess 71 Third recess, in particular part-ring-like recess 72 Fourth recess, in particular part-ring-like recess 73 Fifth recess, in particular part-ring-like recess 74 Sixth recess, in particular part-ring-like recess 75 First boundary, in particular radial boundary 76 Second boundary, in particular radial boundary 77 Bore, in particular axial bore 78 First wing 79 Second wing 80 Third wing 81 First recess 82 Second recess 83 Third recess 84 adjustment 85 actuator housing 86 First closing cover 87 Second lock cover 88 outer periphery 89 Pinion 90 Sprocket 91 Connection, in particular a non-positive connection 92 drilling 93 Tread, in particular round, circumferential surface 94 Guide limit, in particular lateral guide limit 95 spigot 96 Kettenradabschnitt 97 drilling AA central longitudinal axis

Claims (8)

1. A shifting device (1, 33, 45, 57, 84) for changing the relative position of a camshaft (2, 41) to influence control times of valves of a valve drive of an internal combustion engine, which shifting device (1, 33, 45, 57, 84) comprises a stator (3, 35, 47, 64), which is coupled to a drive device and a rotor (5, 34), which is fixed permanently to the camshaft (2, 41), wherein the stator (3, 35, 47, 64) is configured in the manner of an actuator housing (4, 36, 46, 58, 85), which surrounds the rotor (5, 34), is provided on its outer circumference (6, 20) with a gearwheel (7, 68) having a drive means surface (93) and is delimited as viewed in an axial direction of the shifting device (1, 33, 45, 57, 84) by closing covers (14, 15, 37, 38, 59, 60, 86, 87),
   wherein the gearwheel (7, 68) of the shifting device (1, 33, 45, 57, 84) and the actuator housing (4, 36, 46, 58, 85), which accommodates the rotor (5, 34) to be connected to the camshaft (2, 41), are produced by die casting to form a single-piece, coherent structural unit (16), which in particular comprises at least one first closing cover (14, 49, 59, 86),
   characterised in that
   the structural unit (16) is produced from a high-strength, lightweight metal alloy, that is, an aluminium alloy, a zinc alloy or a magnesium alloy having aluminium, zinc or magnesium as the main alloy metal with a proportion of 70 % to 98 %, wherein the calibration reference point for producing the dimensional accuracy of the structural unit (16) of the shifting device (1, 33, 45, 57, 84) is on the drive means surface (93), which is free of post-processing.
2. The shifting device (1, 33, 45, 57, 84) according to Claim 1, characterised in that the lightweight metal alloy for the gearwheel (7, 68) and the actuator housing (4, 36, 46, 58, 85) is an aluminium alloy that has a high proportion of silicon.
3. The shifting device (1, 33, 45, 57, 84) according to any one of the preceding claims, characterised in that the structural unit (16) is at least partially uncoated, in particular on a surface of a drive running surface, such as a belt drive running surface or a chain drive running surface, and is preferably joined untreated but hardened after die casting to form the shifting device (1,33,45,57,84).
4. The shifting device (1, 33, 45, 57, 84) according to one or more of the preceding claims, characterised in that one or more ferric insertion parts (61 and 62) are provided at least in the actuator housing (4, 36, 46, 58, 85) of an shifting device (1, 33, 45, 57, 84), in particular the gearwheel (7, 68) as a chain wheel (90) extends with a chain wheel section (96) into the actuator housing (4, 36, 46, 58, 85), and the material of the actuator housing (4, 36, 46, 58, 85) is cast around said gearwheel.
5. The shifting device (1, 33, 45, 57, 84) according to Claim 4, characterised in that the lightweight metal alloy is cast around the insertion parts (61 and 62), wherein in particular the insertion parts (61, 62) serve for local reinforcement, such as in the region of a bore (31, 63, 92) of a first closing cover (14, 49, 59, 86).
6. The shifting device (1, 33, 45, 57, 84) according to any one of the preceding claims, characterised in that a casting skin that forms owing to the die casting, in particular on the outer surface of the shifting device (1, 33, 45, 57, 84), left untreated, like left unground or unhardened as a wear-resistant protective skin, constitutes a running surface (93) for a drive means.
7. A method for producing an shifting device (1, 33, 45, 57, 84), in particular according to any one of the preceding claims, in which a component (16) that comprises the gearwheel (7, 68) and serves as an enclosing component for a rotor (5, 34), in particular for a rotor (5, 34) having blades (11, 12, 13), is produced by means of a die casting method, and can be used as a running surface of the gearwheel (7, 68) without further processing of an outer surface, in which method processing steps are preferably only carried out on the inner walls and end walls of the shifting device (1, 33, 45, 57, 84).
8. The method according to Claim 7, characterised in that the protective skin that forms owing to the die casting method is an oxide skin, the fine-crystalline casting structure of which is kept unchanged, while a further part such as the rotor (5, 34) or cover (14, 15, 59, 60) of the shifting device (1, 33, 45, 57, 84) undergoes a chip removing process during production.

Images