EP2118455B1 - Device for the combined locking and rotation angle limitation of a camshaft adjuster - Google Patents

Abstract

A locking and rotation angle device for locking and setting maximum rotational adjustability of a drive part fixed to the crankshaft and a driven part fixed to the camshaft of a camshaft adjuster. The driven part is pivotably adjusted to the drive part, which has a locking bar received in the drive or driven part, a locking bar member formed in the respectively other part, and a rotation angle limiting member formed in the correspondingly other part. Limiting wall sections serve as stops for the locking bar for adjusting a maximum rotational adjustability. The locking bar member, rotation angle limiting member, and locking bar are disposed such that the locking bar is displaced via the displacement mechanism into a locking position, engaging into the locking bar member, and into an unlocking position, in which it is released by the locking bar member and engages in the rotation angle limiting member.

Description

Field of the invention

The invention is in the technical field of internal combustion engines and relates to a combined locking and Drehwinkelbegrenzungseinrichtung a camshaft adjuster for an internal combustion engine.

State of the art

In internal combustion engines, gas exchange valves are actuated by the cams of a camshaft rotated by the crankshaft. Usually, for this purpose, the cams roll on cam followers, such as drag levers, rocker arms or bucket tappets, which counteract the spring force of a valve spring holding the gas exchange valve in a closed position. About arrangement and shape of the cam, the timing of the gas exchange valves can be specifically defined.

Against the background of thermodynamic processes, it has proved to be advantageous if, during operation of the internal combustion engine, the control times of the gas exchange valves are influenced as a function of the current operating state, such as speed or load. In particular, this can positively influence the exhaust gas behavior and reduce fuel consumption. In addition, the efficiency of the internal combustion engine, the maximum torque and the maximum power can be increased. The opening and closing times of the gas exchange valves within a working cycle of the internal combustion engine by the relative rotational position (phase) between Cam and crankshaft specified. An adjustment of the timing of the gas exchange valves within the working cycle can thus be achieved by a relative change in the rotational position between the camshaft and crankshaft.

Well known is the use of devices for changing and fixing the relative rotational position between the cam and crankshaft, hereinafter referred to as "camshaft adjuster". Via camshaft adjuster, torque can be transmitted from the crankshaft to the camshaft. In addition, can be held by camshaft adjuster during operation of the internal combustion engine, the relative rotational position between the cam and crankshaft and adjusted within a certain angular range, so as to change the timing of the gas exchange valves. Such a solution is for example in the FR 2 814 497 A1 described.

A camshaft adjuster usually comprises a driving part rotatably connected via a drive wheel to the crankshaft and a camshaft-fixed driven part, and an actuator connected between driving and driven part which transmits the torque from the drive part to the driven part and fixes and adjusts the relative rotational position between the and stripping section allows. The actuator can be operated electrically, hydraulically or pneumatically.

Hydraulically operated Nockenweckenwellenversteller are typically designed as Axialkolbenversteller or Rotationskolbenversteller, which are explained in more detail below.

In an axial piston adjuster, the drive part is toothed via a helical toothing with a piston, which in turn is toothed via a helical toothing with the output part. Between input and output part, a pressure chamber is formed, which is divided by the piston into two pressure chambers. If one of the two pressure chambers is acted upon by pressure medium, while the other is connected to a pressure medium outlet, the piston is in axial Direction shifted so that a change in the relative rotational position between the input and output part is caused by the helical gears.

In a rotary piston adjuster, the drive part formed, for example, in the form of an outer rotor, and the driven part designed, for example, in the form of an inner rotor, are arranged concentrically to each other so as to be adjustable in rotation. The outer rotor may be composed of a plurality of rotatably interconnected components, such as housing with drive wheel and on the inner rotor (hereinafter referred to as rotor) rotatably mounted stator.

In a rotary piston adjuster pressure chambers are formed in the radial gap between the stator and the rotor, for example by a plurality of circumferentially spaced cavities are formed in the stator, which extend radially outwardly from the rotor and are pressure-tight in the axial direction by side walls. In each of these pressure chambers extends radially outwardly connected to the rotor sealing element, hereinafter referred to as wings, whereby each pressure chamber is divided into two substantially pressure-tight pressure chambers. Through the wing, a flow of pressure medium from one pressure chamber into the other pressure chamber is at least largely prevented.

In each of the pressure chambers pressure medium lines open to supply and / or discharge of pressure medium to and from the pressure chambers. By targeted pressurization of the pressure chambers, that is, by generating a pressure difference across the pair of pressure chambers of a respective pressure chamber, the wings can be pivoted within the pressure chambers, so that via the rotatably connected to the camshaft rotor rotation of the camshaft and consequently a change in the relative rotational position between Camshaft and crankshaft is effected. On the other hand, the rotational position can be maintained by a corresponding equal pressurization of the two pressure chambers of a respective pressure chamber.

A control of the hydraulic camshaft adjuster is effected by a control unit which controls the inflow and outflow of pressure medium to and from the individual pressure chambers on the basis of detected characteristics of the internal combustion engine, such as speed and load. The pressure medium flows are regulated for example by a control valve.

In order to prevent occurring at the camshaft alternating or drag torque is transmitted to the stator at an insufficient pressure medium supply, a locking device for non-rotatable locking of the stator and rotor in a so-called base position is provided in which stator and rotor a desired rotational position, in particular an optimal rotational position for the start or idle of an internal combustion engine, take.

A conventional locking device for locking rotor and stator in base position comprises, for example, a piston received in a recess of the rotor, which is urged by a spring in the axial direction of the inner rotor and can engage for locking in the base position in a gate formed by the gate, whereby a positive mechanical connection between rotor and stator is created. Depending on the application of the camshaft phaser to an intake or exhaust camshaft, the base position is usually one of the maximum relative rotational positions (final rotational positions) from rotor to stator, referred to as the "early" or "late" position of the rotor. The retarded position corresponds to an end rotational position of the rotor in a twisting direction, which is directed counter to the (on the drive by the crankshaft) rotor rotational direction, while the early position of a final rotational position of the rotor in a twisting direction, which is the same direction to the rotor rotational direction, equivalent.

The maximum possible rotation angle range is predetermined by the early or late stop of the wings within the pressure chambers or by a separate rotation angle limiting device, as is the case with camshaft adjusters made of sheet metal parts.

While a late position of the rotor with insufficient pressure medium supply is automatically taken by a transmitted to the rotor, inherent drag torque of the camshaft special precautions have to be taken for the adjustment of the rotor in the early position or, for example, in an intermediate position between early and late position, as the provision a spring element acting on the rotor.

A disadvantage of conventional camshaft adjusters is the fact that their assembly is therefore already relatively time consuming and costly, since the adjustment of the locking device of the desired base position corresponding rotary position of the rotor is to be considered, which in turn already with tolerances, for example by a rotational angle limiting device, afflicted is, so that the locking device can be adjusted in industrial mass production only with a relatively large locking clearance. As a result, this leads to a poorly defined rotational position of the rotor in base position and consequently to poorly set timing of the gas exchange valves.

In order to realize a relatively low locking clearance, the pairing of further components is required. Very small locking games can only be realized by sorting out corresponding camshaft adjuster.

Summary of the invention Object of the invention

In contrast, the object of the present invention is to provide a locking device of a camshaft adjuster for an internal combustion engine, by which the above-mentioned disadvantage of a relatively large locking play can be avoided. In addition, the locking device should be produced in a simple and cost-effective manner.

Solution of the task

These and other objects are achieved according to the proposal of the invention by a combined locking and Drehwinkelbegrenzungseinrichtung a camshaft adjuster for an internal combustion engine having the features of the independent claim. Advantageous embodiments of the invention are indicated by the features of the subclaims.

According to the invention, a combined locking and rotational angle limiting device for non-rotatable locking and limiting the relative rotational adjustability of a crankshaft fixed or can be brought into drive connection with a crankshaft drive part and a rotatably adjustable thereto, camshaft fixed or can be brought into a drive connection with a camshaft output part of a camshaft adjuster for an internal combustion engine. As usual, the camshaft adjuster serves as a device for transmitting a torque between the input and output part as well as for adjusting and fixing the relative rotational position (phase position) between the crankshaft and the camshaft. Drive and driven part may be formed, for example in the form of an outer rotor with a drive wheel formed thereon, which is in drive connection with the crankshaft, and an inner rotor concentrically arranged to the outer rotor.

The combined locking and rotational angle limiting device according to the invention comprises a locking element accommodated in the driving or driven part, hereinafter referred to as "bolt", which is displaceable by a displacement mechanism. To lock the bolt a bolt gate is formed in the corresponding other part, by which the bolt is positively received in the circumferential direction, so as to connect input and output member rotation with each other.

Furthermore, the combined locking and rotational angle limiting device according to the invention comprises a correspondingly different part shaped Drehwinkelbegrenzungskulisse, through which the same bar in the circumferential direction is receivable with distance from the boundary wall. In the circumferential direction spaced apart, substantially radial boundary wall sections of the boundary wall of the rotation angle limiting link serve as stops for recorded in the Drehwinkelbegrenzungskulisse latch at a relative rotational adjustment of drive and driven part in the two directions of rotation for adjusting a maximum rotational adjustability of drive and driven part.

In the combined locking and rotational angle limiting device according to the invention, the bolt gate, the rotation angle limiting link and the bolt are arranged so that the bolt by the displacement mechanism in a locking position, in which he engages in the bolt gate and is guided by the bolt gate, and in an unlocking position, in he is released from the bar gate, only engages the Drehwinkelbegrenzungskulisse and can be guided by the Drehwinkelbegrenzungskulisse, is displaced.

In the embodiment of the combined locking and rotational angle limiting device according to the invention, the locking linkage is arranged within an (imaginary) extension in the direction of displacement of the bolt of the (limiting wall of) the rotational angle limiting link.

The inventive combined locking and rotational angle limiting device thus locking of drive and driven part can be achieved with a compared to conventional locking devices very low locking clearance, since only an adjustment of the same bolt within the bolt gate and the rotational angle limiting link is required. In contrast to conventional camshaft adjusters with separate rotation angle limiting device, it is not necessary to take into account any tolerances concerning the separate rotation angle limiting device.

In this case, the bolt slide and the rotational angle limiting slide are particularly advantageously arranged offset axially relative to each other so that the bolt slide is located within an axial extension of the rotational angle limiting slide.

In the aforementioned embodiment of the locking and rotational angle limiting device according to the invention, it may be advantageous if a in the direction of rotation of driven by the crankshaft drive part trailing, substantially radial boundary wall portion of the locking link in the circumferential direction closer to a particular axial extension of a trailing in the direction of rotation of the driven part, substantially radial Boundary wall portion of the rotational angle limiting link is arranged as to a leading in the direction of rotation of the driven part radial boundary wall portion of the rotational angle limiting link. Particularly advantageous is a trailing in the direction of rotation of the driven part, substantially radial boundary wall portion of the locking slide in particular arranged axially aligned with a trailing in the direction of rotation of the driven part, substantially radial boundary wall portion of the rotation angle limiting link. This corresponds to a lock in the early position of the driven part.

In the aforementioned embodiment of the locking and rotational angle limiting device according to the invention, it may also be advantageous if a leading in the direction of rotation of the driven part, substantially radial Begrenzungswandabschnitt the locking link in the circumferential direction closer to a particular axial extension of a leading in the direction of rotation of the driven part, substantially radial Begrenzungswandabschnitts the rotational angle limiting link is arranged as a trailing in the direction of rotation of the driven part radial boundary wall portion of the Drehwinkelbegrenzungskulisse. Particularly advantageous is a leading in the direction of rotation of the driven part, substantially radial boundary wall portion of the locking link in particular axially aligned with a leading in the direction of rotation of the driven part, substantially radial boundary wall portion of the rotational angle limiting link arranged. This corresponds to a locking in late position of the driven part.

In the aforementioned embodiment of the locking and rotational angle limiting device according to the invention, it may also be advantageous if the locking slide substantially centrally between particular axial extensions of a trailing in the direction of rotation of the driven part, substantially radial Begrenzungswandabschnitts and a leading in the direction of rotation of the driven part, substantially radial Begrenzungswandabschnitts the rotational angle limiting link is arranged. This corresponds to a lock in the middle position of the driven part.

In a further particularly advantageous embodiment of the combined locking and rotational angle limiting device according to the invention, the locking linkage and the rotational angle limiting link are in the form of a particularly axially stepped link, hereinafter referred to as "step link".

In particular, in the aforementioned case, it is particularly advantageous in view of the achievable (low) locking clearance, when the bolt gate and the rotation control gate are integrally formed.

In a further particularly advantageous embodiment of the combined locking and rotational angle limiting device according to the invention, but in particular can not be realized exclusively in conjunction with a stage link, the bolt is guided by the Drehwinkelbegrenzungskulisse with the interposition of a slider, so that instead of the bolt, the slider against the plant the circumferentially spaced apart, substantially radial boundary wall sections of the boundary wall of the rotational angle limiting link passes. The bolt is slidably received for this purpose in the slider, so that it can be moved to its locking position and in its unlocked position. The slider engages in the Drehwinkelbegrenzungskulisse and is so received in the rotational angle limiting link or in a formed on the rotational angle limiting track recording, that, guided by the bolt, it can reach the abutment against the essentially radial boundary wall sections of the boundary wall of the rotational angle limiting cam which serve as stops. With the interposition of the slider abutting the substantially radial boundary walls of the rotational angle limiting link, a maximum rotational adjustability (relative final rotational positions) of the input and output part can be set in a rotational adjustment of the input and output part in the two directions of rotation.

The provision of a slider has the particular advantage that a clamping of the bolt in early or late position due to a friction torque, which results from a frictional engagement between the bolt and the substantially radial boundary wall portion of the rotational angle limiting link, can be avoided and the bolt thus easy and safe can be brought into its locking position by moving within the substantially radial boundary wall portion of the Drehwinkelbegrenzungskulisse fitting slider.

Particularly advantageously, the locking slide and the rotation angle limiting link are formed in the drive part, wherein these can be formed, in particular, in a sealing element arranged between a housing component and the driven part, such as a sealing plate. In this case, the bolt gate and the Drehwinkelbegrenzungskulisse may be formed, for example in the form of a radial recess of a central bore of the sealing element, which serves to mount a central screw for fixing the output member and camshaft.

The invention further extends to a camshaft adjuster provided with a combined locking and rotational angle limiting device as described above.

In addition, the invention extends to an internal combustion engine which is equipped with such a camshaft adjuster, and to a motor vehicle with such a phaser.

Brief description of the drawings

Fig. 1

eine perspektivische Teilschnittansicht eines Nockenwellenverstel- lers mit erfindungsgemäßer kombinierter Verriegelungs- /Drehwinkelbegrenzungseinrichtung;

Fig. 2

einen Axialschnitt gemäß Linie I-I in Fig. 1;

Fig. 3

einen Schnitt senkrecht zur Axialen gemäß Linie II-II in Fig. 2;

Fig. 4

eine perspektivische Ansicht einer Dichtplatte mit Stufenkulisse zur Verriegelung in Frühstellung;

Fig. 5

eine perspektivische Ansicht einer Dichtplatte mit Stufenkulisse zur Verriegelung in Mittenstellung.

The invention will now be explained in more detail by means of embodiments, reference being made to the accompanying drawings. Identical or equivalent elements are denoted by the same reference numerals in the drawings. Show it:

Fig. 1

a partial perspective sectional view of a camshaft adjuster with inventive combined locking / rotation angle limiting device;

Fig. 2

an axial section along line II in Fig. 1 ;

Fig. 3

a section perpendicular to the axial line II-II in Fig. 2 ;

Fig. 4

a perspective view of a sealing plate with step link for locking in the early position;

Fig. 5

a perspective view of a sealing plate with stepped gate for locking in the center position.

Detailed description of the drawings

In the figures, a combined locking and rotational angle limiting device of a vane-type camshaft adjuster for the variable adjustment of the timing of the gas exchange valves of an internal combustion engine is shown.

The vane-type camshaft adjuster includes, as the drive part, an outer rotor 1 drivingly connected to a crankshaft via a drive wheel 24 and an inner rotor 2 concentrically disposed within the outer rotor 1, hereinafter referred to as a rotor, which is non-rotatably connected to a camshaft 19.

The outer rotor 1 is in turn made up of a plurality of rotatably interconnected components. Thus, the outer rotor 1 comprises a stator 3, for example designed as a sheet-metal part, whose inner lateral surface 4 is provided with a plurality of radial recesses 5, each of which is delimited by radial side walls 6, 7. The inner circumferential surface 4 of the stator 3 is thus circumferentially extending, inner peripheral walls 27 and circumferentially extending, outer peripheral walls 28, and the inner and outer peripheral walls each interconnecting radial side walls 6, 7, subdivided. The stator 3 is rotatably mounted on the rotor 2 via its inner peripheral walls 27, which abut an outer circumferential surface 8 of the rotor 2. The stator 3 may for example be made of sheet steel by means of a chipless forming process, such as a deep drawing process.

The recesses 5 together with an outer circumferential surface 8 of the rotor 2 and two axial sealing surfaces, which will be explained in more detail below, circumferentially distributed pressure chambers 10th

In each pressure chamber 10 protrudes, starting from the rotor 2, radially outwardly a wing 11, whereby the pressure chambers 10 are each divided into two oppositely acting pressure chambers 12, 13, one of which precedes in the direction of rotation of the rotor 2 and the other nachläuft accordingly. In the example of a vane-type camshaft adjuster shown, the vanes 11 are each received in axial grooves 29, which are formed in the outer circumferential surface 8 of the rotor 2. At the groove bottom of each axial groove 29 a wing 11 radially outwardly loading spring element is arranged, thereby causing the wings 11 of the outer peripheral wall 28 of the stator 3 sealingly abut. equally It would be possible to form the wings 11 in the form of projections integrally with the rotor 2.

The outer rotor 1 further comprises a stator 3 and the rotor 2 pressure-tight encapsulating housing, which is composed of a cup-shaped first housing part 15 and a disk-shaped second housing part 16 connected thereto. The two housing parts 15, 16 may for example be made of sheet steel by means of a chipless forming process, such as a deep-drawing process.

The first housing part 15 is provided on a side facing the camshaft 19 with a bottom surface 17, in which a through collar 18 is formed for receiving the camshaft 19. The stator 3 is accommodated centered within the first housing part 15. The inner circumferential surface 30 of the first housing part 15 is provided with radial projections 20 which engage in respective recesses between the side walls 6, 7 of the inner circumferential surface 4 of the stator 3, whereby a circumferentially positive connection between the stator 3 and the first housing part 15 is made. On the side facing away from the camshaft 19 of the first housing part 15, a radial first flange 21 is formed with axial bores 22.

Coaxially disposed to the first housing part 15, second housing part 16 forms a second flange 31 which is complementary to the first flange 21 of the first housing part 15 is formed. Further, the second flange 31 is provided with axial bores, which are arranged axially in alignment with the axial bores 22 of the first flange 21. The two housing parts 15, 16 are interconnected by connecting means, here screws 23 which engage through the aligned axial bores.

The drive wheel 24 is rotatably connected via the screws 23, which additionally engage through holes 14 which are formed on a radially inwardly extending collar 48 of the drive wheel 24, with the two housing parts 15, 16.

Furthermore, a central bore 26 is formed in the second housing part 16, which makes it possible to fasten the rotor 2 to the camshaft 19 by means of a central screw. The bore 26 is closed by means of a cover 25 to the outside.

The above-mentioned axial sealing surfaces for forming the circumferentially distributed pressure chambers 10 are formed by a arranged on the opposite side of the camshaft 19 sealing plate 9 and on the facing side of the camshaft 19 through the bottom surface 17 of the first housing part 15, which the pressure chambers or Close the pressure chambers axially in a pressure-tight manner.

The sealing plate 9 is rotatably connected to the first housing part 15. For rotationally fixed connection with the stator 3, a radial outer circumferential surface 38 of the sealing plate 9 is provided with indentations 39 into which engage the projections 20 formed by the inner lateral surface 30 of the first housing part 15. The sealing plate 9 also serves to compensate for any tolerances between the two housing parts 15, 16. Alternatively, the sealing of the pressure chambers or pressure chambers could be done to the outside through the second housing part 16.

In the pressure chambers 12, 13 open pressure medium lines through which pressure medium can be supplied to the pressure chambers or derived from these. By targeted application of pressure medium, a pressure gradient can be established between the pair of pressure chambers of each pressure chamber, which causes a pivoting of the wings 11 and thus a change in the relative rotational position of the rotor 2 to the stator 3. At a same hydraulic pressure between a pressure chamber pair of each pressure chamber, the relative rotational position between the rotor 2 and stator 3 is maintained.

In order to avoid transmission of alternating and drag torque of the camshaft 19 to the stator 3 with insufficient pressure medium supply, is a locking device for locking rotor 2 and stator 3 is provided in a desired rotational position. This comprises a piston 33 received in a recess 32 of the rotor 2, which is urged by a spring element 34 in the direction of the sealing plate 9. In a selectable relative rotational position of the rotor 2 to the stator 3, the piston 33 can engage in a recess formed by the sealing plate 9 or gate, whereby a positive connection between the rotor 2 and the stator 3 rotatably connected to the sealing plate 9 is made.

In order to prevent an insufficient supply of pressure medium striking the wings 11 to the side walls 6, 7 of the pressure chambers 10, also a rotation angle limiting means for setting relative Enddrehlagen of rotor 2 to stator 3 is provided in the two directions of rotation.

In order to achieve both a locking of rotor 2 and stator 3 and an adjustment of the relative end rotational positions of rotor 2 to stator 3 with the same piston 33, the sealing plate 9 is provided with an axially stepped stile 37 for the piston 33. The step link 37 is formed as a radial recess of the radial boundary wall 53 of a central bore 36 of the sealing plate 9. The central bore 36 allows attachment of the rotor 2 by means of a central screw on the camshaft 19th

The step link 37 is composed of two mutually offset in the axial direction scenes: a greater axial distance from the camshaft 19 arranged first link 35 ("bolt gate"), which serves the positive reception of the piston 33, and one with a smaller axial distance from the camshaft 19 arranged second link 40 ("rotational angle limiting link"), which serves to set the maximum relative Enddrehlagen rotor 2 to stator 3 in the two directions of rotation of the rotor 2.

The bolt gate 35 and the Drehwinkelbegrenzungskulisse 40 are separated in the axial direction by the step 41 from each other. While the bolt gate 35 is formed in the form of an opening of the sealing plate 9, the Drehwinkelbegrenzungskulisse 40 merely as axial depression of the camshaft 19 facing sealing surface 42 of the sealing plate 9 is formed.

The radial boundary wall sections 43, 44 of the locking link 35 are located within an (imaginary) axial extension of the radial boundary wall sections 45, 46 of the rotational angle limiting link 40.

The bolt gate 35 extends in the circumferential direction in such a way that its radial boundary wall sections 43, 44 bear against the outer surface of the piston 33 engaging in the bolt gate 35 in the circumferential direction, so that the piston accommodated in the recess 32 of the rotor 2 and engaging in the bolt gate 35 at the same time 33 is a positive connection in the circumferential direction between the rotor 2 and the stator 3 is made.

The two radial boundary wall sections 43, 44 of the bolt gate 35 are connected to each other by a circular segment-shaped, substantially in the circumferential direction extending boundary wall portion 49.

The cylindrical piston 33 is slidably received in the cavity 54 of a piston sleeve 51. The engaging in the rotational angle limiting link 40 piston sleeve 51 is in turn slidably received in the circumferential direction in a not-shown recess between the sealing plate 9 and rotor 2. The piston 33 engages in the locking position through the piston sleeve 51 therethrough. In unlocking position, the piston 33 engages in the piston sleeve 51. The piston sleeve 51 is moved with the engaging in unlocking position in it piston 33 at a change in the relative rotational position of the rotor 2 to stator 3 in the circumferential direction.

In contrast to the bolt gate 35, the Drehwinkelbegrenzungskulisse 40 extends in the circumferential direction, that their radial Begrenzungswandabschnitte 45, 46 of the outer surface of the same time in the recess 32 of the rotor 2 and (only) in the Drehwinkelbegrenzungskulisse engaging piston 33 are not present in the circumferential direction, but rather Form stops for the piston 33 and the intermediate piston sleeve 51 for defining respective maximum Enddrehlagen from rotor 2 to stator 3. In the two relative Endrehlagen the outer circumferential surface 52 of the piston sleeve 51 comes to rest against the radial boundary wall sections 45, 46 of the Drehwinkelbegrenzungskulisse 40. Insofern, by the circumferential distance of the radial boundary wall sections 45, 46 of the Drehwinkelbegrenzungskulisse 40 a maximum angle of rotation for rotational adjustment of rotor 2 to stator 3 are set. The radial boundary wall portions 45, 46 of the rotation angle limiting link 40 are connected to each other by a substantially circumferentially extending boundary wall portion 50.

The provision of the piston sleeve 51 has the advantage that when locking in Endrehlage no frictional torque between the outer circumferential surface of the piston 33 and the radial boundary wall sections 45, 46 of the Drehwinkelbegrenzungskulisse 40 may occur, so that the piston 33 without risk of jamming / wedging safely into the bar scenery 35 can be moved.

The piston 33 can be displaced by a displacement mechanism between a locking position, in which it engages the locking link 35, and an unlocking position, in which it (only) engages in the rotational angle limiting link 40 with the interposition of the piston sleeve 51.

In the example shown, the piston 33 is urged by the spring element 34 in the bolt backdrop 35. Only in a selectable relative rotational position (base position) of the rotor 2 to the stator 3, the piston 33 can engage in the bolt gate 35.

In the base position, the bolt gate 35 communicates with at least one pressure medium line for supplying or discharging pressure medium to or from the bolt gate 35, so that an axial end face of the piston 33 can be acted upon hydraulically and the piston 33 against the spring force of the spring element 34 from the bolt gate 35 can be pressed.

The displacement mechanism is in this case designed so that the piston 33 can only be pushed so far in the direction of its recess 32 in the rotor 2 due to hydraulic loading, that it always engages in the unlocking position in the rotational angle limiting link 40 and the engaging in the Drehwinkelbegrenzungskulisse 40 locking sleeve 51 in order to realize in cooperation with the entrained piston sleeve 51, a rotation angle limitation between the rotor 2 and stator 3.

In Fig. 4 are the leading in the rotor rotational direction, radial boundary wall sections 43, 45 of the locking link 35 and the rotational angle limiting link 40 are arranged approximately axially aligned with each other. This causes a locking of the rotor 2 in the early position, in which the wings 41 are arranged in the locking position closer to the leading edge in the rotor rotational direction side walls 6 than to the corresponding trailing side walls 7 of the pressure chambers 10.

To adjust the rotor in the early position, a spring element 47 is arranged, which is connected both to the outer rotor 1 and to the inner rotor 2. The forces exerted by the spring element 47 on the rotor 2 are directed so that the rotor 2 and stator 3 are rotated in insufficient pressure medium filling the pressure chambers in such a relative rotational position (base position), in which the piston 33 can engage in the bolt backdrop 35.

Instead of locking in the early position would equally locking in late position possible. For this purpose, it is only necessary to form the stepped link 37 so that the trailing in the rotor rotational direction, radial boundary wall sections 44, 46 of the locking link 35 and the rotational angle limiting link 40 are arranged approximately axially aligned with each other.

Instead of a lock in early or late position would equally lock in the middle position possible.

Fig. 5 illustrates a sealing plate 9 of another embodiment of the locking device according to the invention with locking in the center position. In order to effect a central locking, it is only necessary that the radial boundary wall sections 43, 44 of the bolt gate 35 are arranged approximately centrally in the circumferential direction between an (imaginary) axial extension of the radial boundary wall sections 45, 46 of the rotational angle limiting track 40.

Advantageously, the sealing plate 9 is made of a hardenable steel, so that it can be subjected to a hardening process after shaping to ensure that the forces transmitted via the piston 33 can be reliably absorbed.

Although the bar scenery 35 in 4 and 5 is formed in the form of an opening, it would equally possible that it is formed only in the form of an axial depression of the sealing surface 42 of the sealing plate 9.

Although the step pattern 37 in 4 and 5 formed in the sealing plate 9, it would be equally possible to form the step link in the second housing part 16 or another component of the outer rotor 1

Although a displacement mechanism is illustrated in which the spring-urged piston 33 is hydraulically unlockable, another displacement mechanism, such as displacement of the piston 33 by an electric servomotor, may equally be provided.

LIST OF REFERENCE NUMBERS

1

outer rotor

2

Inner rotor (rotor)

3

stator

4

Inner surface area

5

recess

6

Side wall

7

Side wall

8th

Outer casing surface

9

sealing plate

10

pressure chamber

11

wing

12

pressure chamber

13

pressure chamber

14

drilling

15

first housing part

16

second housing part

17

floor area

18

collar

19

camshaft

20

head Start

21

first flange

22

drilling

23

screw

24

Drive wheel.

25

cover

26

drilling

27

inner peripheral wall

28

outer peripheral wall

29

axial groove

30

Inner surface area

31

second flange

32

recess

33

piston

34

spring element

35

bar slot

36

drilling

37

stages setting

38

Outer casing surface

39

indentation

40

End limits setting

41

step

42

sealing surface

43

radial boundary wall section

44

radial boundary wall section

45

radial boundary wall section

46

radial boundary wall section

47

spring element

48

Federation

49

circumferential boundary wall section

50

circumferential boundary wall section

51

piston sleeve

52

Outer shell surface of the piston sleeve

53

radial boundary wall

54

cavity

Claims (16)

1. Combined locking and rotational angle limiting device for locking and setting a maximum rotational adjustability of a drive input part (1), which is fixed with respect to a crankshaft, and a drive output part (2), which is rotatably adjustable relative to said drive input part (1) and which is fixed with respect to a camshaft, of a camshaft adjuster for an internal combustion engine, having a bar (33) which is held in the drive input or drive output part and which can be moved by a movement mechanism, having a bar slot (35) which is formed in the corresponding other part and by means of which the bar (33) can be held in a positively locking fashion in the circumferential direction, and having a rotational angle limiting slot (40) which is formed in the corresponding other part and by means of which the bar (33) can be held in the circumferential direction with a spacing, with substantially radial boundary wall sections (45, 46) which are spaced apart in the circumferential direction serving as stops for the bar in order to set a maximum rotational adjustability of the drive input and drive output parts, with the bar slot, the rotational angle limiting slot and the bar being arranged in such a way that the bar can be moved by the movement mechanism into a locked position, in which said bar can be guided by the bar slot, and into an unlocked position, in which said bar can be guided by the rotational angle limiting slot, characterized in that the bar slot (35) is arranged within an in particular axial elongation, in the bar movement direction, of the rotational angle limiting slot (40).
2. Combined locking and rotational angle limiting device according to Claim 1, characterized in that the bar slot (35) and the rotational angle limiting slot (40) are arranged so as to be offset in the axial direction.
3. Combined locking and rotational angle limiting device according to one of Claims 1 or 2, characterized in that the bar slot (35) and the rotational angle limiting slot (40) are formed in the manner of a stepped slot (37).
4. Combined locking and rotational angle limiting device according to one of Claims 2 or 3, characterized in that a substantially radial boundary wall section (44), which runs behind in the rotational direction of the drive output part (2), of the bar slot (35) is arranged closer in the circumferential direction to an axial elongation of a substantially radial boundary wall section (46), which runs behind in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40) than to an axial elongation of a substantially radial boundary wall section (45), which runs ahead in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40).
5. Combined locking and rotational angle limiting device according to Claim 4, characterized in that a substantially radial boundary wall section (44), which runs behind in the rotational direction of the drive output part (2), of the bar slot (35) is arranged in axial alignment with a substantially radial boundary wall section (46), which runs behind in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40).
6. Combined locking and rotational angle limiting device according to one of Claims 2 or 3, characterized in that a substantially radial boundary wall section (43), which runs ahead in the rotational direction of the drive output part (2), of the bar slot (35) is arranged closer in the circumferential direction to an axial elongation of a substantially radial boundary wall section (45), which runs ahead in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40) than to an axial elongation of a substantially radial boundary wall section (46), which runs behind in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40).
7. Combined locking and rotational angle limiting device according to Claim 6, characterized in that a substantially radial boundary wall section (43), which runs ahead in the rotational direction of the drive output part (2), of the bar slot (35) is arranged in axial alignment with a substantially radial boundary wall section (45), which runs ahead in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40).
8. Combined locking and rotational angle limiting device according to one of Claims 2 or 3, characterized in that the bar slot (35) is arranged substantially centrally between the axial elongations of a substantially radial boundary wall section (46), which runs behind in the rotational direction of the drive output part (2), and a substantially radial boundary wall section (45), which runs ahead in the rotational direction of the drive output part (2), of the rotational angle limiting slot (40).
9. Combined locking and rotational angle limiting device according to one of Claims 1 to 8, characterized in that the bar and rotational angle limiting slots (35, 40) are formed in the drive input part (1).
10. Combined locking and rotational angle limiting device according to Claim 9, characterized in that the bar and rotational angle limiting slots (35, 40) are formed in a sealing element (9) which is arranged between a housing component (16) and the drive output part (2).
11. Combined locking and rotational angle limiting device according to Claim 10, characterized in that the bar and rotational angle limiting slots (35, 40) are formed in each case in the manner of a radial recess of a central bore (36) of the sealing element (9).
12. Combined locking and rotational angle limiting device according to one of Claims 1 to 11, characterized in that the bar (33) is guided by the rotational angle limiting slot (40) with the interposition of a sliding member (51) which engages into the rotational angle limiting slot (40), with the bar (33) being held in the sliding member (51) so as to be movable in its movement direction.
13. Combined locking and rotational angle limiting device according to Claim 12, characterized in that the sliding member (51) is formed in the manner of a sleeve.
14. Camshaft adjuster having a combined locking and rotational angle limiting device according to one of Claims 1 to 13.
15. Internal combustion engine having a combined locking and rotational angle limiting device according to one of Claims 1 to 13.
16. Motor vehicle having an internal combustion engine according to Claim 15.

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