DE102017102109A1 - Drive device for a camshaft drive of a reciprocating internal combustion engine and piston internal combustion engine with such a drive device - Google Patents

Abstract

The drive device for a camshaft control drive of a variable compression ratio piston internal combustion engine with an eccentrically mounted adjustable crankshaft is provided with a drive wheel (16). Furthermore, the drive device has a driven wheel (26, 28) for a camshaft (17) of the piston internal combustion engine (12). The drive device is provided with a circulating traction means (24) guided around the drive wheel (16) and the driven wheel (26, 28), which has a load strand (32) and an empty strand (38). The drive device is provided with a tensioning means (36), which keeps the traction means (24) under tension in an eccentric adjustment of the crankshaft (14), and a camshaft phaser (44, 46) connected to the output gear (26, 28). is in active connection. Further, the drive device is provided with a drive unit (50) for adjusting the camshaft phaser (44, 46) to compensate for rotation of the driven gear (26, 28) in a change in the length of the load strand (32) of the traction means (24) due to a eccentric adjustment of the crankshaft (14).

Description

The invention relates to a drive device for a camshaft control drive of a reciprocating internal combustion engine with a variable compression ratio and with an eccentrically mounted adjustable crankshaft. Furthermore, the invention relates to a reciprocating internal combustion engine with such a drive device.

The development of variable compression ratio (VCR) internal combustion engines has been intensified in recent years. One way to change the top dead center of the compression piston (s) to achieve a variable compression ratio is to change the position of the crankshaft, using an adjustment drive to automatically gift an eccentric bearing device of the crankshaft, such as in FIG DE 10 2009 043 505 A1 described. The crankshaft drives in addition to the vehicle transmission also at least one circulating traction means in the form of, for example, a drive chain or a particular drive toothed belt, being driven by the traction means control and auxiliary equipment and in particular the oil and water pumps of the internal combustion engine. When changing the crankshaft position changes so that their distance to, for example, other driven shafts such as the camshafts, balancer shafts, etc. On the crankshaft is a drive wheel which is connected via the traction means with driven wheels of the control and ancillaries drive technology. By changing the relative positions of the drive wheel to output gear in an adjustment of the crankshaft, there are changes in the load and idler lengths of the traction device. Especially for the timing drive, so for the connection of the crankshaft with the camshaft control drives, thereby creating a timing error. Moreover, tensioning devices used in dynamically stressed traction means can not accomplish the load and return length compensation in part. This applies in particular to the known in the prior art clamping means in the slack side.

It is known to use parallel crank gear to compensate for the crankshaft pivoting movement. However, this is disadvantageous in terms of cost, design and friction losses.

Furthermore, it is known (see DE 10 2010 055 549 A1 ) to use an intermediate drive to compensate for the aforementioned changes. However, this intermediate drive requires additional belt / chain drive elements, an additional shaft, additional bearings and seals, which is disadvantageous in terms of design and cost.

The object of the invention is to provide a drive device for a camshaft control drive, which avoids timing errors in the control drive when used for a reciprocating internal combustion engine with variable compression ratio and with eccentrically mounted, adjustable crankshaft.

• – einem Antriebsrad, das zum Drehen durch die Kurbelwelle an dieser anbringbar ist,
• – mindestens einem Abtriebsrad, das in Wirkverbindung mit einer Nockenwelle der Kolbenbrennkraftmaschine bringbar ist,
• – einem um das Antriebsrad und das Abtriebsrad geführten umlaufenden, insbesondere in Form einer Antriebskette oder eines Antriebsriemens, vorzugsweise eines Antriebszahnriemens, ausgeführten Zugmittel, das ein Lasttrum, welches in Antriebsbewegungsrichtung des Zugmittels betrachtet dessen jeweiligen Abschnitt zwischen dem Antriebsrad und dem Abtriebsrad oder dem ersten Abtriebsrad bildet, und ein Leertrum aufweist, welcher in Antriebsbewegungsrichtung des Zugmittels betrachtet dessen jeweiligen Abschnitt zwischen dem Abtriebsrad oder dem letzten Abtriebsrad und dem Antriebsrad bildet,
• – einem Spannmittel, das das Zugmittel bei einer bei einer exzentrischen Verstellung der Kurbelwelle erfolgenden Verschiebung des Antriebsrads relativ zum Abtriebsrad unter Spannung hält,
• – einem Nockenwellen-Phasensteller, der mit dem Abtriebsrad in Wirkverbindung steht und mechanisch mit dem Nockenwellensteuerantrieb verbindbar ist, und
• – einer Ansteuereinheit zum Verstellen des Nockenwellen-Phasenstellers zum Ausgleich einer Verdrehung des Abtriebsrads bei einer Veränderung der Länge des Lasttrums des Zugmittels infolge einer bei einer exzentrischen Verstellung der Kurbelwelle erfolgenden Verschiebung des Antriebsrads relativ zum Abtriebsrad.

To solve this problem, the invention proposes a drive device for a camshaft control drive of a reciprocating internal combustion engine with variable compression ratio and with an eccentrically mounted adjustable crankshaft, wherein the drive device is provided with

• A drive wheel attachable thereto for rotation by the crankshaft,
• At least one driven wheel, which can be brought into operative connection with a camshaft of the reciprocating internal combustion engine,
• - A guided around the drive wheel and the driven wheel rotating, in particular in the form of a drive chain or a drive belt, preferably a drive belt, running traction means, a load strand, which viewed in the drive movement direction of the traction means whose respective section between the drive wheel and the output gear or the first output gear forms, and has an empty strand, which forms in the drive movement direction of the traction means whose respective section between the output gear or the last driven gear and the drive wheel,
• - A tensioning means, the traction means at a at a eccentric adjustment of the crankshaft takes place displacement of the drive wheel relative to the output gear under tension,
• - A camshaft phaser, which is operatively connected to the output gear and mechanically connected to the camshaft control drive, and
• - A drive unit for adjusting the camshaft phaser to compensate for a rotation of the driven wheel with a change in the length of the load strand of the traction mechanism as a result of a successful in an eccentric adjustment of the crankshaft displacement of the drive wheel relative to the driven wheel.

According to the invention, therefore, a basically unintentional relative rotation of the output gear of a camshaft control drive relative to the drive wheel is compensated for by a corresponding adjustment automatic adjustment of the eccentrically mounted crankshaft, that between the output gear and the camshaft drive a camshaft phaser is connected, via a drive unit to compensate a rotation of the output gear is changed in a change in the length of the load strand of the traction means as a result of a successful in an eccentric adjustment of the crankshaft displacement of the drive wheel relative to the output gear.

If the reciprocating internal combustion engine has a plurality of camshaft control drives, then there is one camshaft phaser of the aforementioned type per camshaft control drive. In this variant of the invention, the traction device then runs around the driven wheels of all camshaft control drives.

In another variant of the invention with likewise a plurality of camshaft control drives of the reciprocating internal combustion engine, it is provided that the driven wheels of these camshaft control drives are in operative connection with one another by another traction means. One of these traction means is also connected via a traction means with the drive wheel of the camshaft. In this constellation, only a camshaft phaser for the above-described torsional compensation of the driven wheels of all camshaft control drives in a change in the length of the load of the traction device between the drive wheel and a driven wheel due to a successful in an eccentric adjustment of the crankshaft displacement of the drive wheel relative to this driven wheel is required ,

To change the closing and opening times of the intake and exhaust valves of a reciprocating internal combustion engine, it is known to use camshaft phaser. These camshaft phasers can now also be used to prevent the above-mentioned timing error in a relative change in the position of the piston shaft relative to the camshaft.

As already mentioned above, acts on the traction means a clamping means, which may have one or more tension rollers. Such clamping means are known in principle. The tensioning means can be arranged either in the load strand or in the slack side. It is also conceivable that each attack on one of the two strands of the traction means when using two tension rollers. The clamping means may be resiliently biased against the traction means or may be positively controlled in the direction of the clamping means or away from this movable, which then advantageously takes place in dependence on the change in position of the crankshaft.

The clamping device can basically be designed as an eccentric tensioner. As a rule, however, such tensioning devices have a relatively short lever arm. Possibly this is not sufficient to compensate for the change in length of the traction means in a change in the crankshaft position and to keep the traction means always under sufficient tension. Therefore, it is expedient if the clamping means as a long stroke, so with a lever arm which is longer than in the known Exzenterspannern executed.

In order to use the camshaft phaser used for setting the valve timing within the scope of the invention, they should have a sufficient adjustment range, in order to compensate for the additional "error" in the timing drive in addition to the desired extreme values of the valve timing by the respective combustion process. Basically, any known design (hydraulic, electric, CTA, etc.) is suitable as a phaser.

The combination of long arm tensioner in the slack side and camshaft phaser is basically sufficient to avoid both a control timing error and to maintain the operability of the timing gear (keeping the tension means under tension).

To compensate for the change in length of the traction means for ancillaries and in particular the oil pump, it is sufficient to use automatic clamping elements in the respective empty belt. A tensioner in the oil pump drive is required to keep this drive always functional.

• – einem Gehäuse,
• – mindestens einem in dem Gehäuse angeordneten Pleuel mit einem in einem Zylinderhohlraum des Gehäuses vor- und zurückbewegbar geführten Kolben,
• – einer mit dem mindestens einen Pleuel gelenkig verbundenen Kurbelwelle, die in und/oder an dem Gehäuse zur automatischen, motorischen Verstellung exzentrisch gelagert ist,
• – mindestens einem Nockenwellensteuerantrieb und
• – einer Antriebsvorrichtung gemäß einer der obigen Ausführungen.

Finally, the invention also provides a reciprocating internal combustion engine with variable compression ratio, which is provided with

• A housing,
• At least one connecting rod arranged in the housing with a piston that can be moved back and forth in a cylinder cavity of the housing,
• A crankshaft hingedly connected to the at least one connecting rod and mounted eccentrically in and / or on the housing for automatic, motorized adjustment,
• - At least one camshaft drive and
• - A drive device according to one of the above embodiments.

The invention will now be described with reference to two embodiments and with reference to the drawings. In detail, they show:

1 a perspective view of the drive device for a camshaft drive of a reciprocating internal combustion engine according to a first embodiment,

2 a schematic representation of the camshaft control drives of the reciprocating internal combustion engine according to 1 with appropriate control,

3 a variant of a drive device for a camshaft drive of a reciprocating internal combustion engine in perspective view and

4 schematically the control of only one camshaft phaser.

In 1 is in perspective the housing 10 a reciprocating internal combustion engine 12 shown. In the case 10 at least one connecting rod is arranged, one in a cylinder cavity of the housing 10 movable piston carries forward and zurückbewegbar. The connecting rod is in a known manner with a crankshaft 14 connected, the front side or at her from the housing 10 outstanding end of a drive wheel 16 having. The piston internal combustion engine 12 has camshafts in a known manner 17 with camshaft control drives 18 . 20 for the intake and exhaust valves.

In 1 is the tax drive 22 the reciprocating internal combustion engine 12 , So the drive device for the camshaft control drives 18 . 20 shown. The tax drive 22 has a circulating traction means 24 exemplified in the form of a drive belt on. This traction device 24 runs around the drive wheel 16 and about driven wheels 26 . 28 for the two camshaft control drives 18 . 20 , Furthermore, the tax drive includes 22 a pulley 30 in the load area 32 of the traction device 24 and a long-arm tensioner 34 as a clamping device 36 in the empty section 38 ,

The crankshaft 14 is stored eccentrically, which is at 40 should be indicated. To the compression ratio at which the piston internal combustion engine 12 is operable to change, now becomes the position of the crankshaft 14 relative to the housing 10 changed what with the double arrow 42 is indicated. In such an adjustment of the crankshaft 14 there is a relative displacement of the drive wheel 16 relative to the driven wheels 26 . 28 , In addition, the empty and Lasttrumlängen the traction device change 24 , All this leads to an unintentional relative rotation of the driven wheels 26 . 28 for the camshaft control drives 18 . 20 , which in turn leads to timing errors for the valve control. This should be avoided.

According to the invention, to compensate for these unintentional relative rotations of the driven wheels 26 . 28 for the camshaft control drives 18 . 20 relative to the drive wheel 16 one camshaft phaser per camshaft control drive 44 . 46 used (see 2 ). Such phase adjusters exist in modern reciprocating internal combustion engines and are known in this respect. They are in these known reciprocating internal combustion engines via the engine control 48 driven.

It is new that these camshaft phasers 44 . 46 also be used for the compensation of tax times as described above. For this purpose, a drive unit is used 50 which is also part of the engine control 48 can be. The drive unit 50 receives a drive signal 52 , In accordance with the drive signal for the (not shown) adjustment of the (also not shown) eccentric bearing device of the crankshaft 14 with a change in the compression ratio. The drive unit 50 then controls the camshaft phaser 44 . 46 to compensate for a rotation of the driven wheels due to the change in Lasttrumlänge when adjusting the crankshaft 14 at. Thus, timing errors are compensated or prevented from forming.

In addition to the two camshaft phasers used in the invention 44 . 46 As a further advantage of the invention, the use of the long-arm tensioner 34 to be viewed as. This long-arm tensioner 34 ensures instead of known eccentric tensioner for sufficient tension of the traction device 24 , regardless of the current adjustment position of the crankshaft 14 ,

In the 3 and 4 an alternative concept of the drive device according to the invention is shown. Identical or functionally identical elements are in the 1 to 4 each provided with the same reference numerals.

In the embodiment according to 3 wraps around the traction device 24 only one of the driven wheels of the camshaft control drives, namely in this embodiment, the output gear 26 , and the drive wheel 16 , The two camshaft control drives are interconnected by another traction means 54 connected with each other. As based on 4 can be seen, now controls the drive unit 50 only the camshaft phaser 44 , the output wheel 26 assigned. The second camshaft phaser 46 Depending on the respective desired combustion process, only the engine control system will still be used 48 driven. Due to the fact that the drive unit 50 only the camshaft phaser 44 controls, immediately also timing errors in the second camshaft control drive 20 prevented because the two camshaft control drives 18 . 20 over the second traction means 54 are synchronized.

The drive signal 52 could also be derived from a displacement or position detector / sensor, the adjustment of the tensioner 34 and preferably, among other things, also recognizes the set compression ratio.

LIST OF REFERENCE NUMBERS

10

casing

12

Piston internal combustion engine

14

crankshaft

16

Drive wheel on the crankshaft

17

camshafts

18

Camshaft timing drive

20

Camshaft timing drive

22

Timing

24

traction means

26

Output gear for camshaft control drive

28

Output gear for camshaft control drive

30

idler pulley

32

Lasttrum of the traction device

34

Long sleeve tensioner

36

clamping means

38

Slack side of the traction device

40

Eccentric bearing of the crankshaft

42

double arrow

44

Camshaft phaser

46

Camshaft phaser

48

motor control

50

control unit

52

control signal

54

traction means

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009043505 A1 [0002]
• DE 102010055549 A1 [0004]

Claims (6)

Drive device for a camshaft control drive of a variable compression ratio piston internal combustion engine with an eccentrically mounted adjustable crankshaft, comprising - a drive wheel ( 16 ), which can rotate through the crankshaft ( 14 ) is attachable to this, - at least one driven wheel ( 26 . 28 ) operatively connected to a camshaft ( 17 ) of the reciprocating internal combustion engine ( 12 ), - one to the drive wheel ( 16 ) and the driven wheel ( 26 . 28 ) guided circulating, in particular in the form of a drive chain or a drive belt, preferably a drive belt, running traction means ( 24 ), which is a 32 ), which in the drive movement direction of the traction means ( 24 ) considers its respective section between the drive wheel ( 16 ) and the driven wheel ( 26 . 28 ) or the first output gear ( 26 . 28 ), and an empty strand ( 38 ), which in the drive movement direction of the traction means ( 24 ) considers the respective section between the output gear ( 26 . 28 ) or the last output gear ( 26 . 28 ) and the drive wheel ( 16 ), - a tensioning means ( 36 ), which the traction means ( 24 ) at one at an eccentric adjustment of the crankshaft ( 14 ) displacement of the drive wheel ( 16 ) relative to the output gear ( 26 . 28 ), - a camshaft phaser ( 44 . 46 ), which is connected to the driven wheel ( 26 . 28 ) is in operative connection and mechanically with the camshaft control drive ( 18 . 20 ), and - a control unit ( 50 ) for adjusting the camshaft phaser ( 44 . 46 ) to compensate for a rotation of the output gear ( 26 . 28 ) with a change in the length of the load tube ( 32 ) of the traction means ( 24 ) as a result of an eccentric adjustment of the crankshaft ( 14 ) displacement of the drive wheel ( 16 ) relative to the output gear ( 26 . 28 ). Drive device according to claim 1, characterized in that when the reciprocating internal combustion engine a plurality of camshaft control drives ( 18 . 20 ), the traction means ( 24 ) around the multiple camshaft control drives ( 18 . 20 ) associated output wheels ( 26 . 28 ) and each output gear ( 26 . 28 ) in operative connection with a camshaft phaser ( 44 . 46 ), wherein the drive unit ( 50 ) the camshaft phasers ( 44 . 46 ) to compensate for rotations of the driven wheels ( 26 . 28 ) with a change in the length of the load tube ( 32 ) of the traction means ( 24 ) as a result of an eccentric adjustment of the crankshaft ( 14 ) displacement of the drive wheel ( 16 ) relative to the output gear ( 26 . 28 ). Drive device according to claim 1, characterized in that when the reciprocating internal combustion engine a plurality of camshaft control drives ( 18 . 20 ), the traction means ( 24 ) around the drive wheel ( 16 ) and with one of the camshaft phasers ( 44 . 46 ) in operative connection driven wheel ( 26 . 28 ) and that with the camshaft phaser ( 44 . 46 ) in operative connection driven wheel ( 26 . 28 ) by means of one around this and the output wheels ( 26 . 28 ) for the other camshaft control drives ( 18 . 20 ) guided, circulating, in particular in the form of a drive chain or a drive belt, preferably a drive belt, running traction means ( 24 ) are in operative connection. Drive device according to one of claims 1 to 3, characterized in that the clamping means against the traction means ( 24 ) resiliently biased or in response to an adjustment of the crankshaft ( 14 ) and thus a displacement of the drive wheel ( 16 ) relative to the output gear ( 26 . 28 ) positively controlled on the traction means ( 24 ) is movable toward or away from it. Drive device according to one of claims 1 to 4, that the tensioning means on the load strand ( 32 ) and / or on the empty strand ( 38 ) attacks. Piston internal combustion engine with variable compression ratio, with - a housing ( 10 ), - at least one in the housing ( 10 ) arranged with a connecting rod in a cylinder cavity of the housing ( 10 ) guided back and forth guided piston, - one with the at least one connecting rod articulated crankshaft ( 14 ) in and / or on the housing ( 10 ) is mounted eccentrically for adjustment, - at least one camshaft control drive ( 18 . 20 ) and - a drive device according to one of the preceding claims.

Images