DE102015208456A1 - Cam Phaser System - Google Patents

Abstract

Proposed is a device (1) for adjusting the relative angular position between at least one camshaft (2) and a crankshaft (3) of an internal combustion engine having a camshaft (2), a crankshaft (3) and an adjusting mechanism (4, 9, 15) for Adjusting the relative angular position between at least one camshaft (2) and a crankshaft (3) of an internal combustion engine, characterized in that a first adjusting mechanism (4) on the crankshaft (3) is arranged.

Description

Field of the invention

The invention relates to a device for adjusting the relative angular position between at least one camshaft and a crankshaft.

Background of the invention

Camshaft adjusters are used in internal combustion engines for varying the timing of the combustion chamber valves in order to make the phase relation between a crankshaft and a camshaft in a defined angular range, between a maximum early and a maximum late position, variable. Adjusting the timing to the current load and speed reduces fuel consumption and emissions. For this purpose, camshaft adjuster are integrated into a drive train, via which a torque is transmitted from the crankshaft to the camshaft. This drive train may be formed for example as a belt, chain or gear drive.

In a hydraulic camshaft adjuster, the output element and the drive element form one or more pairs of mutually acting pressure chambers, which can be acted upon by hydraulic fluid. The drive element and the output element are arranged coaxially. By filling and emptying individual pressure chambers, a relative movement between the drive element and the output element is generated. The rotationally acting on between the drive element and the output element spring urges the drive element relative to the output element in an advantageous direction. This advantage direction can be the same or opposite to the direction of rotation.

One type of hydraulic phaser is the vane phaser. The vane cell adjuster comprises a stator, a rotor and a drive wheel with an external toothing. The rotor is designed as a driven element usually rotatably connected to the camshaft. The drive element includes the stator and the drive wheel. The stator and the drive wheel are rotatably connected to each other or alternatively formed integrally with each other. The rotor is coaxial with the stator and located inside the stator. The rotor and the stator are characterized by their, radially extending wings, oppositely acting oil chambers, which are acted upon by oil pressure and allow relative rotation between the stator and the rotor. The wings are either formed integrally with the rotor or the stator or arranged as "inserted wings" in designated grooves of the rotor or the stator. Furthermore, the vane cell adjusters have various sealing lids. The stator and the sealing lids are secured together via several screw connections.

Another type of hydraulic phaser is the axial piston phaser. Here, a displacement element is axially displaced via oil pressure, which generates a helical gear teeth relative rotation between a drive element and an output element.

Another design of a camshaft adjuster is the electromechanical camshaft adjuster having a three-shaft gear (for example, a planetary gear). One of the shafts forms the drive element and a second shaft forms the output element. About the third wave, the system by means of an adjusting device, such as an electric motor or a brake, rotational energy supplied or removed from the system. A spring may additionally be arranged, which supports or returns the relative rotation between the drive element and output element.

Summary of the invention

The object of the invention is to provide a device for adjusting the relative angular position between at least one camshaft and a crankshaft, which has an improved performance.

According to the invention, this object is solved by the features of claim 1.

The adjusting mechanism according to the invention contains the components of the known camshaft adjuster and the same also in the function of the adjustment with the known camshaft adjusters.

This achieves several effects. On the one hand several camshafts can be adjusted with a single adjustment mechanism, whereby the number of adjustment mechanisms and thus the costs are reduced. On the other hand, a direct start of the internal combustion engine can be realized by means of the adjusting mechanism arranged on the crankshaft. The engine is started up without a starter when starting directly. The engine control unit uses a sensor to identify in which cylinder the piston occupies the most favorable position after top dead center (measured in degrees crank angle). Then it is injected directly into this combustion chamber and ignited. In this way, enough torque is generated to set the engine in motion.

If a piston is not exactly at top dead center, so the crankshaft can be moved in the locked state according to the device according to the invention in the position of top dead center or another meaningful for this ignition position by the adjusting mechanism, which, for example, electrically driven to then go through the above process to start the engine. To support a conventional - albeit a small and adapted to the direct start - starter motor may be present. Advantageously, such a start-stop operation can be realized very easily and with a reduction in weight.

In one embodiment of the invention, the adjusting mechanism is arranged at one end of the crankshaft. Compared with the arrangement of the adjusting mechanism between the crank weights, the end-side arrangement of the adjusting mechanism has the advantage of easy installation. In addition, access to the control drive is facilitated to adjust the camshaft or the camshaft in the angular position to the crankshaft.

In an advantageous embodiment, the adjusting mechanism has a stator with a toothed ring arranged thereon in a rotationally fixed manner, the toothed rim being in engagement with the control drive, which transmits a torque from the crankshaft to the at least one camshaft and the adjusting mechanism has a rotor arranged so as to be relatively rotatable relative to the stator, which is rotatably connected to the crankshaft.

The sprocket may be designed for engagement with a chain, a belt or a gear. The timing drive can thus be designed as a chain drive, belt drive or gear drive, whereby the torque can be transmitted from the crankshaft to the camshaft or camshaft. An angular position adjustment between the stator and the rotor, wherein either the stator or the rotor is connected to the crankshaft and the corresponding other component with the ring gear is rotatably connected, thus affecting the angular position between the crankshaft and the camshaft and the camshaft.

In a particularly preferred embodiment, the power source of the adjusting mechanism for adjusting electrically, hydraulically or mechanically. If a plurality of adjusting mechanisms are arranged within the device according to the invention, different adjusting mechanisms can be operated by different energy sources, which effect the adjustment of the angular position.

The use of hydraulically operated adjustment mechanisms lends itself, for example, to the position of the crankshaft, since the oil paths to the tank are short. Thus, the oil does not have to be pumped through a complex oil gallery and thus not overcome unnecessary heights within the internal combustion engine. The hydraulic adjusting mechanism can therefore be controlled very quickly and therefore also reacts very quickly to the operating parameters. Likewise, the short oil paths avoid the accumulation of air in the oil since the oil gallery can be made simpler and flow-optimized to supply the hydraulic adjustment mechanism.

Electromechanically operated adjusting mechanisms draw their energy for adjusting the angular position of an electric motor, which rotates via an adjusting the stator relative to the rotor. Such an electric motor can, as already described, be used for the direct start of the internal combustion engine.

In one embodiment of the invention, the device has a further adjusting mechanism, which is arranged on the at least one camshaft. Advantageously, the adjustment range between crankshaft and camshaft can thus be increased. The further adjusting mechanism or the second adjusting mechanism can be arranged on the intake camshaft or on the exhaust camshaft.

In a preferred embodiment, the ring gear of the adjusting mechanism has a non-circular shape. Advantageously, with a targeted angular arrangement of a non-circular sprocket on the adjusting the oscillations occurring in the timing drive, which arise, for example. By camshaft alternating torques can be reduced or eliminated. The sprocket can here, as described above, be designed for engagement with a chain, a belt or a gear.

In a further embodiment of the invention, the device comprises two camshafts, wherein two adjusting mechanisms are arranged on the crankshaft and each adjusting mechanism can set the relative angular position to one of the camshafts. Advantageously, the axial length can be saved on the respective camshafts, each camshaft can be adjusted relative to the crankshaft in its angular position. The two adjusting mechanisms on the crankshaft may preferably be attached to the end of the crankshaft, respectively.

In one embodiment of the invention, the device comprises two camshafts, wherein an adjusting mechanism is arranged on each of the camshafts. In this embodiment of the invention is on each existing camshaft arranged an adjusting mechanism. Thus, the timing between the camshaft and the crankshaft as a whole is determined by the adjusting mechanism disposed on the crankshaft, and a timing shift or valve lift overlap can be realized between the intake camshaft and the exhaust camshaft.

In a particularly preferred embodiment of the invention, the device has at least two camshafts, wherein only the intake valves can be adjusted to the crankshaft in the control time. Especially with V or W engines, multiple camshafts are available to operate the intake valves.

In a further embodiment of the invention, the device comprises at least two camshafts, wherein only the exhaust valves can be adjusted in the control time to the crankshaft. Especially with V or W engines, there are multiple camshafts to operate the exhaust valves.

The invention also relates to a device for adjusting control times between a camshaft and a crankshaft of the internal combustion engine, wherein a camshaft actuates both inlet and exhaust valves (rotated valve star).

By the device according to the invention a space savings in the upper part of the engine, a component reduction and thus a cost saving is achieved. In addition, a direct start is made possible by the device according to the invention.

Brief description of the drawings

Embodiments of the invention are illustrated in the figures.

Show it:

1 a first embodiment of the invention,

2 A second embodiment of the invention,

3 A third embodiment of the invention and

4 the first embodiment of the invention with a different motor architecture.

Detailed description of the drawings

1 shows a first embodiment of the invention.

The left side of the 1 shows a first device according to the invention 1 , where the right side of the 1 the effects of the first embodiment on the timing of the intake and exhaust valves of this first device 1 clarified.

The device 1 has a crankshaft 3 and two camshafts 2 wherein the one camshaft may control the intake valves and the second camshaft may control the exhaust valves. Alternatively, both camshafts 2 operate both intake and exhaust valves (turned valve star). The adjustment mechanism 4 is on the crankshaft 3 arranged and stands over the control drive 5 in torque transmitting connection with those on the two camshafts 2 arranged sprockets 6 , Instead sprockets and pulleys or gears can be applied, resulting in the shape of the timing drive 5 change accordingly. The view of the camshafts 2 is through the sprockets 6 locked, because the respective sprocket 6 end to the respective camshaft 2 is arranged. The camshafts 2 are (each) behind the respective sprocket 6 where a camshaft 2 and the respective sprocket 6 aligned with each other, that is, both axes of rotation are largely concentric with each other, are arranged. The adjustment mechanism 4 is also end to the crankshaft 3 and aligned with the crankshaft 3 arranged.

The adjustment mechanism 4 is formed in this embodiment as a hydraulically actuated adjusting mechanism, which is a drive element 8th and an output element 7 Has. The peculiarity of a hydraulic actuatable adjusting mechanism is the formation of hydraulic chambers between the drive element 8th and the output element 7 , whereby a relative rotation between the drive element 8th and the output element 7 can be effected. The hydraulic actuation is effected by a control valve which controls the inflow of hydraulic fluid from a (not shown here) hydraulic fluid pump and the outflow of hydraulic fluid to a (not shown here) reservoir so that the hydraulic chambers are filled and / or emptied to a rotation between the drive element 8th and the output element 7 to effect or even achieve a hydraulic clamping, in which the relative angular position between the drive element 8th and the output element 7 hydraulically fixed. The actuation is thus analogous to a known from the prior art hydraulic camshaft adjuster, which are fixed to the camshaft. Advantageously, the connection to the oil gallery, which directs the hydraulic fluid through the internal combustion engine, facilitates and shortens the oil paths to the adjustment mechanism.

Alternatively, instead of a hydraulically actuated adjusting mechanism 4 an electromechanically actuated adjusting mechanism can be used. The electromechanically actuable adjusting mechanism is modeled on an electromechanically actuable camshaft adjuster, which is attached according to the prior art to a camshaft. An electromechanically actuable adjusting mechanism also has a drive element 8th and an output element 7 ,

The output element 7 the adjustment mechanism 4 is non-rotatable with the crankshaft 3 connected. The drive element 8th is non-rotatable with the timing drive 5 connected. The tax drive 5 is formed in this embodiment as a chain drive, after which the drive element 8th , analogous to the sprockets 6 , has a suitable for a chain toothing, which is in communication with a chain. Will the adjustment mechanism 4 operated, so there is a relative rotation between the drive element 8th and the output element 7 , This relative rotation affects the timing drive 5 and the sprockets 6 on the angular position of the camshafts 2 relative to the crankshaft 3 out. The effect of relative rotation is extremely variable in the direction of adjustment 12 the valve lift curves 10 . 11 , which are shown in the diagrams.

The upper diagram on the right side of the 1 schematically illustrates an adjustment of the timing of the gas exchange valves at the inlet and the outlet in the illustrated adjustment 12 , triggered by the adjustment mechanism 4 , in the direction of "early," that is, the valve lift curves 10 . 11 the intake and exhaust valves have been shifted to the same extent - ie by the same crankshaft angle on the abscissa - to the left. The lower diagram on the right side of the 1 schematically illustrates an adjustment of the timing of the gas exchange valves in the illustrated adjustment 12 , triggered by the adjustment mechanism 4 , in the direction of "late", that is, the valve lift curves 10 . 11 , the intake and exhaust valves have been displaced to the right to the same extent - ie the same crankshaft angle on the abscissa. In this embodiment, the output angular position (solid line) is between the two end angle positions (dashed line), wherein the maximum early angular position in the upper diagram and the maximum late angular position in the lower diagram is shown as a dashed line. Advantageously, with a single adjustment mechanism 4 on the timing of the gas exchange valves at the inlet and at the outlet (intake and exhaust valves) are influenced, wherein the displacement of the valve lift curves 10 . 11 , at the same time as the crankshaft 3 and synchronously under the two camshafts 2 to each other.

2 shows a second embodiment of the invention.

The left side of the 2 shows a second device according to the invention 1 , where the right side of the 2 the effects of the second embodiment on the timing of the intake and exhaust valves of this second device 1 clarified.

Basically, the second embodiment is based on the first embodiment. The second embodiment was a second adjustment mechanism 9 , which on the camshaft 2 is arranged, the exhaust valves actuated. The structure and operation of the second adjustment mechanism 9 is that of the first adjustment mechanism 4 equal. However, it is also possible to use two differently actuable adjusting mechanisms 4 . 9 , For example, one as hydraulically actuated and one as electromechanically operable adjusting mechanism, be provided, which then differ in structure accordingly.

Due to the additional second adjustment mechanism 9 There are further functions and effects of the second embodiment of the device according to the invention 1 over the first embodiment.

The upper diagram on the right side of the 2 schematically illustrates an adjustment of the timing of the gas exchange valves at the inlet and the outlet in the illustrated adjustment 12 , triggered by the adjustment mechanism 4 , in the direction of "early," that is, the valve lift curves 10 . 11 , inlet and outlet valves to the same extent ie at the same crankshaft angle on the abscissa - have been moved to the left. The output angular position is shown as a solid line, while that by the first adjustment mechanism 4 achievable position is shown by the short dashed line. Now, through the second adjustment mechanism 9 the valve lift curve 10 the exhaust valves are additionally shifted. In the diagram, the timing of the exhaust valves (valve lift curve 10 ) by the second adjustment mechanism 9 in an adjustment direction 13 which oppositely directed the adjustment 12 That is through the adjustment mechanism 4 was moved back towards "late".

The lower diagram on the right side of the 1 schematically illustrates an adjustment of the timing of the gas exchange valves in the illustrated adjustment 12 , triggered by the adjustment mechanism 4 , also in the direction of "early", that is, the valve lift curves 10 . 11 , the intake and exhaust valves have been shifted to the same extent - ie the same crankshaft angle on the abscissa - to the left. The output angular position is shown as a solid line, while that by the first adjustment mechanism 4 achievable position is shown by the short dashed line. Now, through the second adjustment mechanism 9 the valve lift curve 10 the exhaust valves are additionally shifted. In the diagram, the timing of the exhaust valves (valve lift curve 10 ) by the second adjustment mechanism 9 continue in adjustment 12 , which by the adjustment mechanism 4 was effected, shifted in the direction of "early".

Alternatively, the two diagrams may depict a timing different from the above-described and described respective diagrams in that the first adjustment mechanism 4 caused displacement of the valve lift curves 10 . 11 in the direction of "late", so contrary to the adjustment shown here 12 ,

3 shows a third embodiment of the invention.

The left side of the 3 shows a third device according to the invention 1 , where the right side of the 3 the effects of the third embodiment on the timing of the intake and exhaust valves of this third device 1 clarified.

Basically, the third embodiment is based on the second embodiment. The third embodiment has been a third adjustment mechanism 15 , which on the other camshaft 2 is arranged, the inlet valves actuated. The structure and operation of the third adjustment mechanism 15 is that of the first adjustment mechanism 4 equal. However, it can also be differently actuated adjustment mechanisms 4 . 9 . 15 , For example, two as hydraulically actuated and one as electromechanically operable adjusting mechanism, be provided, which then differ in structure accordingly.

Due to the additional third adjustment mechanism 15 There are further functions and effects of the third embodiment of the device according to the invention 1 over the first embodiment.

The upper diagram on the right side of the 3 schematically illustrates an adjustment of the timing of the gas exchange valves at the inlet and the outlet in the illustrated adjustment 12 , triggered by the adjustment mechanism 4 , in the direction of "early," that is, the valve lift curves 10 . 11 , the intake and exhaust valves have been shifted to the same extent - ie the same crankshaft angle on the abscissa - to the left. The output angular position is shown as a solid line, while that by the first adjustment mechanism 4 achievable position is shown by the short dashed line. Now, through the second adjustment mechanism 9 the valve lift curve 10 the exhaust valves are additionally shifted. In the diagram, the timing of the exhaust valves (valve lift curve 10 ) by the second adjustment mechanism 9 in an adjustment direction 13 which oppositely directed the adjustment 12 That is through the adjustment mechanism 4 has been moved back toward "late", thereby achieving the long-dashed position at the outlet. In addition, now by the third adjustment mechanism 15 the valve lift curve 11 at the inlet also opposite to the adjusting mechanism 4 caused adjustment 12 in adjustment 14 in the direction of "late", whereby the long-dashed position is reached at the inlet.

The lower diagram on the right side of the 1 schematically illustrates an adjustment of the timing of the gas exchange valves in the illustrated adjustment 12 , triggered by the adjustment mechanism 4 , also in the direction of "early", that is, the valve lift curves 10 . 11 , the intake and exhaust valves have been shifted to the same extent - ie the same crankshaft angle on the abscissa - to the left. The output angular position is shown as a solid line, while that by the first adjustment mechanism 4 achievable position is shown by the short dashed line. Now, through the second adjustment mechanism 9 the valve lift curve 10 the exhaust valves are additionally shifted. In the diagram, the timing of the exhaust valves (valve lift curve 10 ) by the second adjustment mechanism 9 continue in adjustment 12 , which by the adjustment mechanism 4 was effected, and thus in the adjustment 13 moved to "early". In addition, now by the third adjustment mechanism 15 the valve lift curve 11 at the inlet also along the through the adjustment mechanism 4 caused adjustment 12 in adjustment 14 in the direction of "early", whereby the long-dashed position at the inlet is reached.

Alternatively, the two diagrams may depict a timing different from the above-described and described respective diagrams in that the first adjustment mechanism 4 caused displacement of the valve lift curves 10 . 11 in the direction of "late", so contrary to the adjustment shown here 12 ,

4 shows the first embodiment of the invention with a different motor architecture.

The left side of the 4 shows the first device according to the invention 1 at one of 1 different engine architecture, with the right side of the 4 the effects of this embodiment on the timing of the intake and exhaust valves of this engine architecture illustrates.

Basically, the effect is the same in the 1 described operation of one on the crankshaft 3 arranged adjusting mechanism 4 , By arrangement of the adjustment mechanism 4 in a V-engine, the camshafts can 2 the desired cylinder bank with the adjustment mechanism 4 operate.

In addition, other adjustment mechanisms analogous to the 2 and 3 be provided, which in 2 and 3 can develop described effects.

By the embodiments of the device according to the invention 1 to 2 and 3 may be an additional area by the displacement of the intake valve lift curve 11 and exhaust valve lift curve 10 be opened, which previously remained unattainable by the arrangement of only one adjusting mechanism.

By the embodiments of the device according to the invention 1 to 1 and 4 can a smaller adjustment mechanism 4 on the crankshaft 3 be arranged, which can reduce weight and at the same time with an adjustment mechanism 4 the synchronous shift of the valve lift curves 10 . 11 achieved at the inlet and the outlet.

LIST OF REFERENCE NUMBERS

1

 contraption

2

 camshaft

3

 crankshaft

4

 first adjustment mechanism

5

 Timing

6

 Sprocket

7

 output element

8th

 driving element

9

 second adjustment mechanism

10

Valve lift curve inlet

11

Valve lift curve outlet

12

adjustment

13

adjustment

14

adjustment

15

third adjustment mechanism

Claims (10)

Contraption ( 1 ) for adjusting the relative angular position between at least one camshaft ( 2 ) and a crankshaft ( 3 ) an internal combustion engine with a camshaft ( 2 ), a crankshaft ( 3 ) and an adjusting mechanism ( 4 . 9 . 15 ) for adjusting the relative angular position between at least one camshaft ( 2 ) and a crankshaft ( 3 ) of an internal combustion engine, characterized in that a first adjusting mechanism ( 4 ) on the crankshaft ( 3 ) is arranged. Contraption ( 1 ) according to claim 1, characterized in that the adjusting mechanism ( 4 ) at one end of the crankshaft ( 3 ) is arranged. Contraption ( 1 ) according to claim 1, characterized in that the adjusting mechanism ( 4 . 9 . 15 ) a stator ( 8th ) with a toothed ring arranged for this purpose in a rotationally fixed manner, the toothed ring being in engagement with the control drive ( 5 ), which torque from the crankshaft ( 3 ) on the at least one camshaft ( 2 ) transmits and the adjusting mechanism ( 4 ) one to the stator ( 8th ) rotatably mounted rotor ( 7 ), wherein the rotor ( 7 ) with the crankshaft ( 3 ) is rotatably connected. Contraption ( 1 ) according to one of the preceding claims, characterized in that the energy source of the adjusting mechanism ( 4 . 9 . 15 ) is to adjust electrically, hydraulically or mechanically. Contraption ( 1 ) according to claim 1, characterized in that the device has a further adjusting mechanism ( 9 . 15 ), which on the at least one camshaft ( 2 ) is arranged. Contraption ( 1 ) according to claim 1, characterized in that the sprocket of the adjusting mechanism ( 4 ) has a non-circular shape. Contraption ( 1 ) according to claim 1, characterized in that the device has two camshafts ( 2 ), wherein two adjustment mechanisms ( 4 ) on the crankshaft ( 3 ) are arranged and each adjustment mechanism ( 4 ) the relative angular position to one of the camshafts ( 2 ). Contraption ( 1 ) according to claim 1, characterized in that the device ( 1 ) two camshafts ( 2 ), wherein on each of the camshafts ( 2 ) an adjusting mechanism ( 4 . 9 . 15 ) is arranged. Contraption ( 1 ) according to claim 1, characterized in that the device ( 1 ) at least two camshafts ( 2 ), wherein only the intake valves in the control time to the crankshaft ( 3 ) can be adjusted. Contraption ( 1 ) according to claim 1, characterized in that the device ( 1 ) at least two camshafts ( 2 ), only the Exhaust valves in the control time to the crankshaft ( 3 ) can be adjusted.

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