DE102014206942A1 - Camshaft adjusting device for an internal combustion engine - Google Patents

Abstract

The invention relates to a camshaft adjusting device for an internal combustion engine, having a chamber housing, a control piston which is accommodated in the chamber housing and which is pivotable about an axis concentric with the axis of the chamber housing, wherein the actuating piston has a plurality of separating flanks extending radially over a cylindrical base surface of the actuating piston, and subdividing respectively formed in the chamber housing pressure chambers into a first chamber section and a second chamber section, and sealing strips, which are radially movable in each case used in a separating flank of the actuating piston guide groove, wherein in the respective sealing strip, and / or the Guiding a guide geometry is formed and on this guide geometry, a valve member is guided such that this is displaceable in accordance with a voltage applied to the valve member oil pressure in different positions. This makes it possible in an advantageous manner to realize in conjunction with the sealing strip a precise and reliably operable valve device.

Description

Field of the invention

The invention relates to a camshaft adjusting device for an internal combustion engine for adjusting the phase position of a camshaft relative to a camshaft drive wheel, wherein the camshaft adjusting device comprises a chamber housing rotating with the camshaft drive wheel and a control piston accommodated therein. The adjusting piston is arranged concentrically to the axis of rotation of the chamber housing and pivotally mounted in the chamber housing about those axis. The actuating piston has a plurality of radially outwardly penetrating chamber flanks, which form a plurality of oil chamber sections in conjunction with radially inwardly projecting webs of the chamber housing in that chamber housing. The chamber flanks are equipped with sealing strips, whereby the oil chamber sections, each separated by a chamber flank of the actuating piston, are sealed against each other. The sealing strips are in this case used in radial grooves which are formed in the chamber flanks.

Through the use of camshaft adjusting devices, it is advantageously possible to change the phase position of a camshaft relative to a driven by a timing chain, a timing belt or other drive system drive wheel. This makes it possible to tune the timing of the valves driven by those camshaft advantageous to the current load state of the internal combustion engine. In the production of the known camshaft adjusting devices, high demands are placed on the geometry, the surface qualities and the material properties, in particular the strengths of the individual components.

Object of the invention

The invention is based on the object to provide solutions by which it is possible to provide a camshaft adjusting device, in which a required adjustment of the phase position of a camshaft relative to a drive wheel can be brought about oil hydraulic, with this camshaft adjusting device by a robust and production-technically advantageous realizable structure distinguished.

Inventive solution

• – einem Kammergehäuse
• – einem Stellkolben der in dem Kammergehäuse aufgenommen ist und der um eine zur Umlaufachse des Kammergehäuses konzentrische Achse schwenkbar ist, wobei der Stellkolben mehrere Trennflanken aufweist, die sich radial über eine zylindrischen Basisfläche des Stellkolbens erheben, und jeweils in dem Kammergehäuse gebildete Druckkammern in eine erste Kammersektion und eine zweite Kammersektion unterteilen, und
• – Dichtleisten, die radial bewegbar in jeweils eine in einer Trennflanke des Stellkolbens ausgebildete Führungsnut eingesetzt sind,
• – wobei in der jeweiligen Dichtleiste, und/oder der Führungsnut eine Führungsgeometrie ausgebildet ist und an dieser Führungsgeometrie ein Ventilglied derart geführt ist, dass dieses nach Maßgabe eines an dem Ventilglied anliegenden Öldrucks in unterschiedliche Stellungen verlagerbar ist.

The aforementioned object is achieved by a camshaft adjusting device for an internal combustion engine, with:

• - A chamber housing
• - An actuating piston which is accommodated in the chamber housing and which is pivotable about an axis concentric to the axis of the chamber housing, wherein the actuating piston has a plurality of separating flanks, which rise radially over a cylindrical base surface of the actuating piston, and each formed in the chamber housing pressure chambers in a first Subdivide chamber section and a second chamber section, and
• Sealing strips, which are inserted in a radially movable manner into a respective guide groove formed in a separating flank of the actuating piston,
• - Wherein a guide geometry is formed in the respective sealing strip, and / or the guide groove and on this guide geometry, a valve member is guided such that this is displaceable in accordance with a voltage applied to the valve member oil pressure in different positions.

This makes it possible in an advantageous manner to realize in conjunction with the sealing strip a precise and reliably operable valve device.

According to a particularly preferred embodiment of the invention, the camshaft adjusting device is designed such that a drive wheel is provided which is connected as such to the chamber housing. The camshaft is then connected to the actuator piston. The drive wheel can be designed in particular as a chain or toothed belt wheel or as a gear for a gear drive. The drive wheel can take over the function of a housing part, in particular a cover plate of the chamber housing. As an alternative to the embodiment described above, it is also possible, in the manner of a kinematic reversal, to connect the said drive wheel to the control piston and the camshaft to the chamber housing. In this variant, the adjusting piston can then be guided in an advantageous manner on an end portion of the camshaft precisely rotatable.

According to a particularly preferred embodiment of the invention, the sealing strip can be designed such that the guide geometry guides the valve member so as to be radially displaceable relative to the revolving axis. The valve member may be designed so that this has a non-circular cross-section, in which case in the sealing strip with respect to the cross-sectional complementary guide pocket is formed. A manufacturing technology particularly advantageous alternative to the above-mentioned variant is that the valve member is designed so that this has a circular cross-section. In the sealing strip then a cylindrical blind hole is formed in which the valve member with the typical fits for slide valves fits smoothly displaced.

Advantageously, the valve member and the sealing strip are supported against each other via a spring device. This spring device can be configured as a slightly axially preloaded screw or cylinder spring, wherein the spring device can be positioned in a pocket formed in the sealing strip.

The realized in the interaction between sealing strip and valve member valve assembly is preferably designed so that the valve member is exposed to the bottom portion of the sealing strip and the loading of the valve member with pressure oil from the region of the groove bottom of the formed in the actuating piston guide groove. From this area can then be inserted into the sealing strip during assembly of the camshaft adjusting the valve member.

The invention is based essentially on a camshaft adjuster for a timing drive, in particular in the form of a chain or belt drive. Here, in each case a valve element is integrated into the sealing strips or wings via which a hydraulic freewheel and in particular a central locking can be brought, which is needed if necessary. The valve elements are controlled by oil pressure and are biased by a compression spring into a starting position.

The use of the valve elements (also control piston) in the sealing strips results in an advantageous use of the space and the material of the sealing strips. According to the invention, the function of a valve mechanism is thus integrated into the required sealing strips.

According to the invention, a movable additional component is inserted into a sealing strip in its interior and guided displaceably therein. The position of the additional component is determined by the oil pressure and a compression spring. As a result of the movement of the inner component, a channel, in particular a bore, which is in the rotor blade, is opened and closed, and thus the function of a control piston is depicted. The movement of the control member takes place in the radial direction. As a result, a compact design of the camshaft adjuster can be realized. The control member may be square or round. or intermediate shapes (e.g., rounded edges) which allow for better manufacturability and function. An advantageous geometry is the square shape for the control member when using a narrow sealing strip. The control member may e.g. be guided in a groove in the sealing strip. The control member can form an assembly with the sealing strip.

Brief description of the figures

Further details and features of the invention will become apparent from the following description taken in conjunction with the drawings. It shows:

1 a radial sectional view for explaining the structure of a camshaft adjusting device according to the invention;

2 an axial sectional view of the camshaft adjusting device according to the invention 1 ;

3 a detail sectional view for explaining the structure and the arrangement of an inventively incorporated in a sealing strip of a camshaft adjusting device valve device;

4 a further detail sectional view of the present invention incorporated in a sealing strip of a camshaft adjusting valve means, now in a state with maximum pressurized by pressurized oil valve member;

5a . 5b . 5c . 5d . 5e a group of representations to illustrate the structure of the sealing strip, the valve element and the compression spring of a variant in which the valve element is made as a block or cuboid structure and formed in the sealing strip guide structure is formed as a laterally open pocket on both sides;

6a . 6b . 6c . 6d . 6e a group of representations to illustrate the construction of the sealing strip, the valve element and the compression spring of a variant in which the valve element is made as a cylinder-pin-like structure and formed in the sealing strip guide structure is formed as a blind hole-like bag;

7 a detail sectional view to further illustrate the structure of the arrangement according to the 6a to 6e ;

8a . 8b . 8c . 8d . 8e a group of representations to illustrate the construction of the sealing strip, the valve element and the compression spring of a variant in which the valve element is made as a flattened on both sides cylinder pin-like structure and formed in the sealing strip guide structure is formed as a double-sided open cylinder bore;

9a . 9b . 9c . 9d . 9e a group of representations to illustrate the construction of the sealing strip, the valve element and the compression spring of a variant in which the Valve element is made as a prismatic flattened on both sides pin-like structure and formed in the sealing strip guide structure is designed as a complementary prismatic, on both sides, edge open pocket;

Detailed description of the figures

The representation after 1 shows in the form of a radial sectional view of a camshaft adjusting device according to the invention for an internal combustion engine. This includes a chamber housing 1 , an actuator piston 2 in the chamber housing 2 is received and the one to the axis of rotation X of the chamber housing 1 concentric axis is pivotable, wherein the actuating piston 2 several cutting edges 2a which extends radially across a cylindrical base surface 2 B raise, and in each case in the chamber housing 1 divided pressure chambers C into a first chamber section C1 and a second chamber section C2. In addition, the camshaft adjusting device according to the invention also comprises sealing strips 3 , which are radially movable in each case one in a separating flank 2a of the adjusting piston 2 trained guide groove 2c are used, wherein in the respective sealing strip 3 , and / or the guide groove 2c a leadership geometry 3a is formed and on this leadership geometry 3a a valve member 4 is guided so that this in accordance with a on the valve member 4 adjacent oil pressure in different positions can be displaced.

In the embodiment shown here is further a drive wheel 5 provided, this drive wheel 5 here to the chamber housing 1 rotatably connected and not shown here camshaft to the actuator piston 2 is connected. In principle, a kinematic reversal of the involvement of the camshaft adjusting device in a corresponding valve train is possible, then the drive wheel would be 5 to the actuator piston 2 and the camshaft to the chamber housing 1 tethered.

In the embodiment shown here, the invention is in the sealing strip 3 used valve device with a radially displaceable valve member 4 Mistake. Through this valve member 4 For example, a fluid communication path between the two chamber sections C1, C2 of a chamber C is released or closed. The setting condition of the valve member 4 is adjusted by influencing the oil pressure in the bottom area of the sealing strips 3 is taken. If the oil pressure is increased there, then the valve member 4 applied on the bottom side with a pressure and migrates in the radial direction, wherein the valve spring 6 loaded and compressed according to the oil pressure.

The valve mechanism according to the invention offers in particular the function of a center lock in a camshaft adjuster. In the case of a central locking, the valve mechanism is actuated via an additional oil channel which is not short-circuited to the working chambers C1, C2. The pressure in this additional oil passage determines when to unlock and lock without influence from the working chambers C1, C2. A particular embodiment additionally includes the function when needed to short the working chambers. This short circuit creates a hydraulic freewheel. For this specific short circuit, the valve device according to the invention is used and controlled via the third oil passage in which it is depressurized. In addition, the oil drain can be turned off for a working chamber. This therefore serves as a support chamber when using the hydraulic freewheel and receives oil only via the short circuit between C1 and C2. The oil drain is additionally prevented in this support chamber by a check valve V1, V2, thus the short circuit between C1 and C2 takes place only in one direction. Depending on the reverse direction of the check valve V1, V2 thus a support direction is generated after early or late. There is ever a support chamber C1, C1 'in the direction of "Early and a support chamber C2, C2' in the direction" Late. Which support chamber is used, is decided by the position of the rotor relative to the locking position. If this is e.g. in the late position relative to the Verrieglungsposition so by the Verrieglungskolben which is to lock in the direction of early, the oil removal of the support chamber, which is to adjust in the direction of early, locked. This is done by immersing the locking piston in a groove. This groove extends from the late stop to the central locking position. The Verrieglungskolben thus serves as a valve piston. However, if the rotor is in the "early position" with respect to the center locking position, the locking piston can not penetrate into the groove whichever locking direction "early", since this only extends from "late" to center locking position. In the "early" position, however, the locking piston "late" can engage in a groove which extends from "early" to the central locking position. As a result, the oil removal for the support chamber, which acts in the direction of late, closed.

Due to the constant inflow of new oil due to the short circuit of the chambers C1 and C2, the camshaft adjuster is adjusted against the support direction. The inflow is triggered by the alternating moments which try to swing the rotor back and forth with respect to the stator. This process continues until the camshaft adjuster has reached the locked position. It is therefore possible on the basis of the inventive concept, two separate, respectively seated in a wing valve devices 4 to control via separate control channels and in this case in each case controlled unlockable or closable fluid path to use a check valve device. If the check valves are oriented in opposite directions, an adjustment of the phase position of the control piston relative to the chamber housing can be initiated as a result of the changing load moments.

As shown 2 it can be seen in the sealing strip 3 trained guide geometry designed such that the valve member 4 is radially displaceable relative to the revolving axis X. Here is the valve member 4 through a directly in the sealing strip 3 trained guide geometry guided radially displaceable. The valve member 4 may have a non-circular cross-section, or be formed as a cylindrical pin. In the latter case is then in the sealing strip 3 formed with respect to the cross-section, blind hole-like leadership pocket. The spring device is as recognizable as a cylinder spring 6 trained and sitting in one in the sealing strip 3 trained bag. The valve member 4 lies to the bottom area of the sealing strip 3 is exposed and the pressurization of the valve member takes place from the region of the groove bottom in the actuating piston 2 trained guide groove 2a ,

In 3 This is the structure of the camshaft adjusting device according to the invention in the surrounding area of the sealing strip 3 further illustrated. In this illustration, in particular, the sealing strip 3 transversely passing transverse bore 3b recognizable. This transverse bore 3b is through the valve member 4 controlled lockable or releasable. The valve spring 6 is in the region of their axial ends on both sides in the valve member 4 or the sealing strip 3 secured. The sealing strip 3 is urged radially outward by another, designed here as a curved leaf spring spring. The at the bottom side of the sealing strip 3 applied oil pressure urges the sealing strip 3 also radially outwards, so that in particular when a high sealing effect of the sealing strip 3 this is also required with an increased radial force radially outward against the chamber housing 1 is urged. The chamber housing 1 is axially closed on both sides on one side of the chamber housing 1 sits a sealing lid 8th , on the axially opposite side sits here designed as a sprocket drive wheel 5 , The oil supply of the valve device 4 via oil channels here u. A. one in the sprocket and the actuator piston 2 trained oil groove 9 . 10 include.

The representation after 4 shows a detailed representation analogous to 3 However, here is the in 3 recognizable transverse or through hole through the valve member 4 locked. The position of the valve member shown here 4 was achieved by the valve member 4 bottom was pressurized with oil. This pressure oil was behind the sealing strip 3 and thus on the exposed back of the valve member 4 directed. The direct bridging path between the in 1 recognizable chamber sections C1, C2 is thus interrupted and the camshaft adjuster can be adjusted in the direction of early or late normal oil pressure in the working chambers C1, C2. Incidentally, the comments on the previously described figures apply mutatis mutandis.

The group of 5a to 5e shows an embodiment of the sealing strip 3 and the associated valve member 4 in which the valve member 4 designed as a parallelepiped piston whose side surfaces 4a . 4b laterally flush with the side surfaces 3c . 3d complete the sealing strip. In the embodiment shown here are then blocked by the valve member or shared channels in the control piston 2 , However, it is also possible to form these channels in such a way that these partially through the sealing strip 3 and / or the valve member 4 run.

The group of 6a to 6e shows an embodiment of the sealing strip 3 and the associated valve member 4 in which the valve member 4 designed as a cylindrical pin, in one in the sealing strip 3 trained blind hole drilling 3e slidably guided. In the sealing lead 3 are transverse holes 3b formed by the valve member 4 are closable. On the valve member 4 is a spacer pin 4m formed which ensures that the valve member 4 from the bottom not completely on the bottom of the groove 2c (see. 1 ) or the leaf spring 7 (see. 3 ) is seated. On the side facing away from the spacer pin of the valve member 4 is in this the for receiving the spring 6 provided bag pocket 4k educated.

The representation after 7 shows those in the group of 6a to 6e shown components in installed condition. In this illustration, the valve member is located 4 in a starting position in which the spring 6 only slightly biased and the transverse holes 3e are released. The leaf spring 7 urges the sealing strip 3 radially slightly outwards in contact with the inner surface of the chamber housing 1 ,

The group of 8a to 8e shows an embodiment of the sealing strip 3 and the associated valve member 4 in which the valve member 4 is designed as a primarily cylindrical, but laterally flattened piston whose side surfaces 4a . 4b laterally flush with the side surfaces 3c . 3d complete the sealing strip. In the embodiment shown here are similar to the variant according to the 5a to 5e through the valve member 4 blocked or released channels in the actuator piston 2 , However, it is also possible here to form these channels in such a way that these partially through the sealing strip 3 and / or the valve member 4 run.

The group of 9a to 9e shows an embodiment of the sealing strip 3 and the associated valve member 4 in which the valve member 4 is designed as a prismatic, laterally flat piston whose side surfaces 4a . 4b turn laterally flush with the side surfaces 3c . 3d complete the sealing strip. Also in the embodiment shown here are similar to the variant according to the 5a to 5e through the valve member 4 blocked or released channels in the actuator piston 2 , However, it is also possible here, these channels in such a way that these partially through the sealing strip 3 and / or the valve member 4 run.

Claims (10)

Camshaft adjusting device for an internal combustion engine, comprising: - a chamber housing ( 1 ) - an actuating piston ( 2 ) in the chamber housing ( 1 ) and the one about the axis of rotation (X) of the chamber housing ( 1 ) concentric axis is pivotable, wherein the actuating piston ( 2 ) several separating flanks ( 2a ), which rise radially over a cylindrical base surface, and in each case in the chamber housing ( 1 ) divided pressure chambers (C) into a first chamber section (C1) and a second chamber section (C2), and - sealing strips ( 3 ), which are radially movable in each case in a separating edge ( 2a ) of the adjusting piston ( 2 ) formed guide groove ( 2c ) are used, - wherein in the respective sealing strip ( 3 ) a guide geometry is formed and at this guide geometry a valve member ( 4 ) is guided such that this in accordance with a on the valve member ( 4 ) adjacent oil pressure in different positions can be displaced. Camshaft adjusting device according to claim 1, characterized in that a drive wheel ( 5 ) is provided, and that this drive wheel ( 5 ) to the chamber housing ( 1 ) is connected and the camshaft to the actuating piston ( 2 ) is attached. Camshaft adjusting device according to claim 1, characterized in that a drive wheel ( 5 ) is provided, and the drive wheel ( 5 ) to the adjusting piston ( 2 ) and the camshaft to the chamber housing ( 1 ) is attached. Camshaft adjusting device according to at least one of claims 1 to 3, characterized in that the guide geometry is designed such that the valve member ( 4 ) is radially displaceable relative to the revolving axis (X). Camshaft adjusting device according to at least one of claims 1 to 4, characterized in that the valve member ( 4 ) in the sealing strip ( 3 ) is guided radially displaceable. Camshaft adjusting device according to at least one of claims 1 to 5, characterized in that the valve member ( 4 ) has a non-circular cross-section and in the sealing strip ( 3 ) is formed with respect to the cross-sectional complementary guide pocket. Camshaft adjusting device according to at least one of claims 1 to 5, characterized in that the valve member ( 4 ) has a circular cross-section and in the sealing strip ( 3 ) A cylindrical blind hole is formed. Camshaft adjusting device according to at least one of claims 1 to 7, characterized in that the valve member ( 4 ) and the sealing strip ( 3 ) via a spring device ( 6 ) are supported against each other, and that the spring device ( 6 ) in one in the sealing strip ( 3 ) trained bag is included. Camshaft adjusting device according to claim 8, characterized in that the spring device ( 6 ) is designed as a cylindrical spring. Camshaft adjusting device according to at least one of claims 1 to 9, characterized in that the valve member ( 4 ) to the bottom area of the sealing strip ( 3 ) is exposed and the admission of the valve member ( 4 ) with pressure oil from the region of the groove bottom in the actuating piston ( 2 ) formed guide groove ( 2c ) he follows.

Images