KR20070032315A - Electrically driven camshaft adjuster - Google Patents

Abstract

The invention relates to an adjusting device (1) for adjusting the position of the rotational angle of the camshaft (3) relative to the crankshaft. This adjusting device comprises a drive unit 4 fixedly mounted to the crankshaft and a drive unit 5 fixedly mounted to the camshaft. The adjusting device 1 includes an adjusting motor 2 as a primary adjusting device and an auxiliary drive 11 as a secondary adjusting device. When the regulating motor 2 fails, the camshaft 3 can be adjusted by the auxiliary drive 11 to a fixed rotational angle position, that is, an emergency position.

Crankshaft, Camshaft, Flywheel, Drive Wheel, Clutch, Brake Disc

Description

Electrically Driven Camshaft Adjuster {ELECTRICALLY DRIVEN CAMSHAFT ADJUSTER}

The present invention relates to an adjusting device for adjusting the relative rotational angular position of the camshaft with respect to the crankshaft of the combustion device having the adjusting gear formed of three-axis gear, the adjustment of the crankshaft fixed drive unit, the camshaft fixed output unit and the adjustment motor An adjustment shaft coupled with the motor shaft.

In order to ensure safe engine starting in combustion engines with hydraulic or electric camshaft adjustment systems, the camshaft is positioned in the so-called base or emergency position. It is usually located at the "late" position in the inlet camshaft and at the "early" position in the outflow camshaft. In normal operation of the vehicle, the camshaft is driven to the foundation position upon stopping of each engine and adjusted to be fixed or fastened thereto.

Conventionally, hydraulically actuated rotary piston adjusting devices, such as impellers, swing or split impellers, include locking units. This holds the hydraulic adjustment device in the foundation position until sufficient oil pressure is established for adjustment of the camshaft. In the case of engine stalling, the camshaft may be positioned at an undefined position other than the foundation position.

In a hydraulic camshaft adjustment system having a "late" foundation position, the camshaft is automatically adjusted to the late foundation position at the next start of the combustion engine and when the oil pressure is insufficient due to the camshaft friction moment acting against the camshaft rotational direction. In the "early" position, the camshaft is adjusted to the "early" position as opposed to the camshaft friction moment when oil pressure is insufficient. This is most often caused by a compensating spring which generates a moment opposite to the camshaft friction moment.

Such a conventional method of hydraulic camshaft adjustment for adjustment to the base position after stalling of the combustion engine cannot be applied in an electrically propelled camshaft adjustment device. These are not necessary as long as the camshaft can be adjusted in a combustion engine in which the regulating motor system is intact and the camshaft is stationary or at a new start to a separate foundation position. However, in the electric coordination motor system, the coordination motor and / or its control unit may fail and thus may not reach the base position.

In German patent DE 41 10 195 A1 the adjustment of the rotational angular position between the crankshaft and the camshaft of the combustion engine is described as having an adjustment mechanism formed by a three-axis gear, which is connected to the driveshaft and camshaft connected to the crankshaft. It includes an adjustment shaft connected to the output shaft and the electric adjustment motor, and there is a static gear ratio (I0) between the drive shaft and the output shaft in the stationary adjustment shaft, which is based on the individual direction or shift of the cam shaft's adjustment direction and shift (negative or plus shift). Determine the emergency position.

In such an adjusting device, the adjusting shaft needs to be easily moved and precisely adjusted. If a limitation of the adjustment angle is provided when the regulating motor system fails, the function of the combustion engine can be at least temporarily achieved. However, there is no criterion for reaching the base or emergency position in such a situation. In such a configuration the foundation position must be provided at one of the two ends of the camshaft adjustment device. The camshaft adjuster always leads to a fast or late stop.

However, it is desirable to select any central position as the base position under certain thermodynamic criteria.

It is therefore an object of the present invention to provide an adjusting device for the adjustment of the rotational angular position of the camshaft with respect to the crankshaft of the combustion device, which can be displaced to an arbitrary position, in particular a central emergency position, in case the regulating motor fails. To provide. The adjusting device should then be maintained in this position.

According to the invention, this object is solved by a combustion device having the features of the preamble of claim 1, wherein the adjustment device comprises an adjustment motor as the primary adjustment device and an auxiliary drive as the secondary adjustment device, thus providing an auxiliary drive. The camshaft adjusts the camshaft to a fixed angle of rotation, that is, an emergency position in case of an adjustment motor failure.

The secondary drive can be formed in an active or passive manner. Active secondary drives require controllers, switches and actuators. It is connected if necessary, thus taking energy. At this time, the actual displacement with respect to the emergency position is known, the adjusted energy input is derived from the actual displacement, and the emergency position is controlled. It is desirable when the connection takes place via separate working media of the secondary drive. This may relate to a pneumatic motor in the auxiliary motor, for example separated from the adjusting shaft in a steady state via a spring. If the regulating motor fails, the connection is made via compressed air.

The passive auxiliary drive is permanently combined with the main drive. The basic position of the camshaft corresponds to the equilibrium with the auxiliary drive of the system three-axis gear. In normal operation, energy is transferred into the secondary drive with each rotation angle adjustment from the foundation position. If the main drive operating with respect to the auxiliary drive fails, adjust the angular position of rotation of the camshaft into the emergency position. For a passive auxiliary drive, only one actuator is needed. The controller and switch can be removed.

It is desirable that no energy is transferred from the active auxiliary drive to the auxiliary drive during normal operation, so that no reaction in the form of vibration usually occurs. Adjustment of the passive auxiliary drive is a simpler and more economical means of realization. Two auxiliary drives can be connected to the mixed drive, in which manual adjustment, which can be carried out via friction, can be carried out in a certain direction, the adjustment taking place in the opposite direction under the connection of an active system operating in only one direction. .

Auxiliary drives can be operated in two main ways. Firstly, it can act on the adjusting shaft, and torque support occurs on the chainwheel or camshaft. At this time, a small moment of the auxiliary drive is required, but a large rotation speed must be provided. For example, five rotations of the adjustment shaft are required at a deceleration of the adjustment mechanism of 1:60 at a maximum camshaft adjustment, typically 30 degrees.

The auxiliary drive can then act directly on the chainwheel or the camshaft, where torque support occurs between each other. In this case, a large moment is needed. However, the friction effect or bearing failure at this time has a greater influence on the moment adjustment between the camshaft and the chain wheel.

Specifically, the auxiliary drive is implemented by means of a hydraulic motor, pneumatic motor, electrical auxiliary motor, brake, centrifugal motor, three-axis gear, adjustable freewheel, flywheel, for example via a torsion spring or by using the moment of inertia of the regulating motor. Can be.

If the auxiliary drive is formed of a torsion spring, it is arranged between the adjusting shaft and the chain wheel or between the chain wheel or the cam shaft. These may be formed as torsion springs which work in double or have speed reducers. These systems require a small technical cost and the switching time depends on the design.

If the auxiliary drive is formed of a hydraulic motor, this can produce a large moment. The switching time depends on the viscosity of the operating medium, for example oil, required for the operation. This disadvantage is compensated by small reactions both in the case of failure and in normal operation, since the auxiliary drive can be operated without oil. It needs energy only in case of failure. If the auxiliary drive is formed of a pneumatic motor, the dependence of the viscous switching time cannot be applied. However, this allows for worse efficiency compared to hydraulic motors when the electric motor fails.

Auxiliary drives formed as electrically controlled drives can be, for example, emergency coils or combined electric motors, but additionally have batteries or capacitors, exhibit short switching times and use less energy if necessary. If the auxiliary drive is for example combined with a three-axis gear or formed of a brake such as a brake lining or an eddy current brake, it has the same advantages as an electrical auxiliary motor at smaller reactions to normal operation.

For simplicity, the auxiliary drive consists of an adjustment axis with a flywheel. These systems have a small response in case of failure. This is because this small response to normal operation is significant because of the large inertia.

The auxiliary drive may be formed of a centrifugal motor. A passive or active system can be implemented, whose switching time depends on the design and camshaft revolutions. Since the response in normal operation increases with the rotational speed of the camshaft, there is almost no response in case of failure. This mechanism is operable as soon as the drive wheel exceeds a predetermined minimum speed.

The arrangement of the auxiliary drive provided according to claim 2 can be done spatially between the drive and the output but is not limited thereto. An arrangement for power flow as can be seen from some of the above particularly preferred embodiments described in detail. For example, if the regulating motor consists of an electric motor, it is arranged axially before the camshaft.

In summary, the passive system acts on normal operation under displacement due to its simplicity in structure due to permanent power reception and discharge. Active systems avoid these drawbacks but are complex in structure.

If the auxiliary drive is to be used in the event of a failure, maintenance of the emergency position is possible in three different ways. Force through active control, for example through form coupling with a fixed pin operated in axial or radial direction and operating in oil pressure, air pressure or electromagnetically, or for example a switchable flywheel It is possible through a combination.

An overload clutch can be arranged between this and the camshaft to protect the adjusting shaft or adjusting mechanism from overload when the adjusting shaft of the electrical regulating motor is suddenly blocked. Such overload clutches can be formed, for example, as slip clutches or shear pins.

Through the solution according to the invention, the stability of the adjusting device is substantially increased. Thus, it is possible to operate a simply constructed passive system or to use an active system with a small reaction to the operation.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic view of an adjusting device with a regulating motor fixed to a cylinder head.

2 is a schematic diagram of an adjusting device having an adjusting motor formed of a flywheel.

3A is a schematic illustration of an auxiliary drive formed of a torsion spring and arranged between the chainwheel and the camshaft.

3b is a schematic view of an auxiliary drive formed with a spring and operating between the chainwheel and the adjustment shaft;

4 is a schematic view of an adjusting device having a pneumatic or hydraulic motor arranged between the adjusting shaft and the chain wheel.

Fig. 5A is a cross sectional view of an auxiliary drive formed of a centrifugal force motor positioned in a foundation position;

Fig. 5B is a sectional view of an auxiliary drive formed of a centrifugal force motor, not located in the foundation position.

6A is a schematic diagram of an adjusting device having an auxiliary drive and a brake arranged therein;

6B is a schematic diagram of an adjusting device having an auxiliary drive and a brake arranged externally.

7A is a schematic diagram of an adjusting device having an auxiliary drive provided through a condenser.

7B is a schematic diagram of an adjusting device having an auxiliary drive provided through an external voltage source.

7C is a schematic diagram of an adjusting device having an external auxiliary drive formed of an electric motor.

8 is a schematic view of an adjusting device having an overload clutch.

9 is a sectional view of an adjusting device having a locking unit.

1 shows an embodiment of the present invention as an adjusting device having an adjusting mechanism 13 and an adjusting motor 2, which essentially consists of a rotor 8 and a stator 9. This is used for adjustment of the rotational angular position between the crankshaft and the camshaft 3 of the combustion apparatus, not shown. The adjusting gear 13 is formed as a three-axis gear having a drive part 4, an output part 5, and an adjusting shaft 6. The drive unit 4 has a drive wheel 7 which is fixedly connected to the crankshaft by means of a gear wheel, drive belt or toothed chain, not shown. The output part 5 is fixedly connected to the camshaft 3 and the adjustment shaft 6 is fixedly connected to the rotor 8 of the regulating motor 2. The stator 9 of the regulating motor 2 is fixedly connected to the cylinder head 10 and is stationary. The camshaft 3 has a base or emergency position, which must be achieved for certain start and limited operation. Because the regulating motor 2 adjusts the camshaft 3 to a stationary combustion engine or during a new start in the basic position, the regulating motor 2 is an undamaged regulating motor 2, which is possible without the auxiliary drive 11. It is operated after stalling of the combustion engine (see Fig. 2). However, without the auxiliary drive 11, control of the rotational angular position is no longer possible in the defective regulating motor 2.

2 shows an auxiliary drive 11 designed as a flywheel 12, which is arranged directly on the adjusting shaft 6 and is thus fixedly connected to the adjusting motor 2. The drive wheel 7 is thereby connected to the adjustment shaft 6 on the one hand and to the camshaft 3 on the other hand. The flywheel 12 can be integrated into the adjusting device 1 to save space, and it is particularly preferable to arrange the mass as far as possible from the axis of rotation so that the smallest possible mass can be applied at a given moment of inertia. However, if the rotor 8 of the regulating motor 2 already has a greater mass, the additional flywheel 12 can be removed if the rotor 8, which can act as a torque reservoir, has a sufficiently high torque. have.

In figure 3a an auxiliary drive 11 is shown which is formed from a torsional spring 14 actuating dually. This operates between the camshaft 3 and the drive wheel 7. At this time, the base position is formed by the rotation angle between the camshaft position and the drive wheel position, and there is a moment equilibrium state without the influence of the adjusting motor 2 at the rotation angle. In normal operation the electric regulating motor 2 changes the equilibrium state and thus moves the torsion spring 14. At this time, if the regulating motor 2 fails, the torsion spring is released from deformation to the rest position. Thus, the torsion springs 14 can operate in one or in dual. In FIG. 3B a spring 18 is arranged between the drive wheel 7 and the adjustment shaft 6. At this time, the moment is transmitted from the adjusting shaft 6 through the reduction unit 15, otherwise the actuation mechanism corresponds to the acting furniture of Fig. 3A. In particular here a single acting spring 18 can be used, or a spiral spring can be used.

4 shows an adjusting device 1 with an auxiliary drive 11 formed of a pneumatic motor 16. The housing 20 of the pneumatic motor is rotatably connected with the drive wheel 7 and the chamber, and the pneumatic motor rotor 21 is rotatably connected with the adjustment shaft 6. As soon as the regulating motor 2 fails, the pneumatic motor 16 can continue to delegate its function as an active drive, or can adjust the regulating device 1 only within the foundation position, as in a passive auxiliary drive, the foundation position being It remains fixed via the locking unit 19 (Fig. 9). The approximate configuration of the pneumatic motor 16 is, for example, a laminate or gear motor.

Instead of the pneumatic motor 16 the auxiliary drive 11 can be formed as a hydraulic motor 17, whereby it is particularly suitable to use a roll vane pump, an internal gear pump or a flow pump.

Figures 5a and 5b consist essentially of an internal gear 23 having a connecting link 24, for example showing a centrifugal force motor 22 which can be fixed on the drive wheel 7 and rotate about it. .

The inner gear wheel 23 is located above the planetary gear 25, and the planetary gear 25 is arranged on the web shaft 26, which is rigidly connected to the drive wheel 7, and the line arranged on the adjusting shaft 6. The wheel 27 is in an effective shift coupling state. In the connecting link 24 the run case 28 is guided through a mass 30 rigidly connected to it, the mass 30 being simultaneously guided in the slot hole 29, the slot hole being driven wheel 7. ) And extend radially. A slide ring may be disposed instead of the run case 28. If the connecting link 24 does not extend exactly in the radial direction and the base position of the device corresponds to the run case position and is radially distanced as far as possible from the center of the inner gear wheel 23, the link 24 is essentially arbitrary. It may be in the form of phosphorus. In particular, the connection link 24 is preferably configured in a parabolic or V shape.

The centrifugal force motor 22 is operable as soon as the drive wheel 7 reaches the minimum speed. At this time, when the adjustment of the rotation angle of the adjusting motor 2 is started, it rotates the drive wheel 7 via the adjusting shaft 6 and the sun wheel 27. At the same time, the inner gear wheel 23 is rotated through engagement with the planetary gear 25, through which the mass 30 is pulled radially inward through the connecting link (see FIG. 5B). If the regulating motor 2 fails, the mass 30 moves to the position furthest outward due to the centrifugal force. The output flow is returned and the adjusting device 1 is adjusted to the basic position. There the adjusting device 1 can be fixed with the locking unit 19 (Fig. 9) if necessary.

In Figs. 6A and 6B, the auxiliary drive 11 is formed of a brake 31, which in Fig. 5A is a brake 31 which is integrated into the electric regulating motor. It may for example consist of a short circuit brake coil and stops the regulating motor through induction. Another possibility could be a separate coil that can be used as an emergency coil. In addition, the brake 31 may be arranged externally (FIG. 6B), for example a brake disc 32 arranged on the adjustment shaft 32, which may be hydraulically or electromagnetically actuated brake block. Braking in case of failure via (33). Another possible embodiment of the brake 31 is a band, disc or shoe brake. The brake 31 can act directly on the output 5 and on the camshaft 3, or indirectly on an axis which is connected, for example, via engagement with an adjustment shaft.

7A and 7B show an auxiliary drive 11 formed of an electric motor 34, the rotor of which is formed by the rotor of the adjusting device 2. A separate coil is performed as the emergency coil 35 around the stator of the electric motor 34. The energy supply of the electric motor 34 is stably provided through the capacitor 36 or the external power unit 37. A battery may be used instead of the capacitor 36. Alternatively, the drive may be performed by a belt or chain. It is clear from FIG. 7C that the electric motor 34 can be implemented as an external component.

8 shows an adjusting device 1 with an adjusting motor 2, whereby an overload clutch 38 is arranged between the adjusting motor 2 and the output shaft 5. If the adjusting shaft 6 is blocked, then the blocking does not have any suppressive effect on the camshaft 3. Preferably, the auxiliary drive 11 is arranged behind the overload clutch 38, so that the failed adjusting device 2 can not operate opposite to the auxiliary drive 11. The overload clutch 38 can be selected as a clutch known in the art, for example clutch disks 40, 41 with compression springs 39 are used or are formed to operate magnetically.

9 illustratively shows a possible arrangement of the locking unit 19, which is essential in the manual system described above to fix the angle of rotation in the event of a failure. The locking unit 19 is here formed of a spring element operating in the radial direction. Fixing and releasing are done via the oil pressure supplied by the oil channel 42 in this figure. Alternatively, the locking unit 19 can use the centrifugal force, magnetic force or angular moment of the adjustment axis to be identified. The arrangement of the locking unit 19 can be done in the axial direction and the radial direction in the adjusting device.

In summary, the configuration according to the invention of the auxiliary drive 11 enables a controlled active or passive reset to the base position in the event of a failure of the adjusting device 2, and the combustion device between the crankshaft and the camshaft 3. It can be operated more reliably by the rotation angle at.

1. Adjustment device

2. adjustable motor

3. Camshaft

4. Driving part

5. Output

6. Adjustable shaft

7. Drive wheel

8. Rotor

9. Stator

10. Cylinder head

11. Auxiliary Drive

12. Flywheel

13. Adjustment mechanism

14. Torsion Spring

15. Reducer

16. Pneumatic motor

17. Hydraulic motor

18. Spring

19. Locking Unit

20. Housing

21. Pneumatic motor rotor

22. Centrifugal force motor

23. Internal gear

24. Link

25. Planetary Gear

26. Web shaft

27. Sun Wheel

28.Run case

29. Slot hole

30. Mass

31.Brake

32. Brake Disc

33. Brake Block

34. Electric motor

35. Emergency Coil

36. Condenser

37. External Network

38. Overload Clutch

39. Compression Spring

40. Clutch Disc

41. Clutch Disc

42. Oil Channel

Claims (20)

In the adjusting device 1 for adjusting the relative rotational angular position of the camshaft 3 with respect to the crankshaft of the combustion device, comprising a drive section 4 fixed to the crankshaft and an output section 5 fixed to the camshaft. ,  The adjusting device 1 comprises an adjusting motor 2 as a primary adjusting device and an auxiliary drive 11 as a secondary adjusting device, in which the camshaft 3 causes the auxiliary drive 11 to fail when the adjusting motor 2 fails. Adjusting device characterized in that the adjustable rotation angle position through, that is, adjustable to the emergency position. 2. The adjusting device according to claim 1, wherein the auxiliary drive (11) is arranged between the drive part (4) and the output part (5). 2. The adjusting device according to claim 1, wherein after the arrival of the emergency position the locking unit (19) makes a form-coupled or force-coupled connection between the drive (4) and the output (5). 4. The adjusting device according to claim 3, wherein the locking unit (19) is formed of a pin, wedge, taper or ball, and the locking unit (19) is operated electromagnetically, hydraulically or pneumatically. The auxiliary drive (11) according to claim 1, characterized in that the auxiliary drive (11) is permanently coupled with the regulating motor (2) and adjusts the rotation angle to the emergency position without external energy supply when the regulating motor (2) fails. Adjusting device. 6. The adjusting device according to claim 5, wherein the auxiliary drive (11) is formed of a torsion spring (14) acting singly or dually. 6. The adjusting device according to claim 5, wherein the auxiliary drive (11) is formed of a torsion spring (14) having a deceleration part. 8. The adjusting device according to claim 6 or 7, wherein the torsion spring (14) is preloaded at engine start, is disconnected in the preload state and is connected by an actuator when the regulating motor (2) fails. 6. The adjusting device according to claim 5, wherein the auxiliary drive (11) is formed of a centrifugal force motor (22). 6. The adjusting device according to claim 5, wherein the adjusting motor (2) is formed of an electric motor and the rotor (8) of the electric motor simultaneously forms an auxiliary drive (11). 6. The adjusting device according to claim 5, wherein the auxiliary drive (11) is formed of a flywheel (12). 2. The auxiliary drive (11) according to claim 1, wherein the auxiliary drive (11) is not permanently coupled with the regulating motor (2) and / or adjusts the rotation angle to the emergency position by external energy supply in case the regulating motor (2) has failed. Features adjusting device. 2. The adjusting device according to claim 1, comprising an adjusting gear 13 formed as a three-axis gear, wherein the auxiliary drive 11 is formed as a brake 31 coupled to one of the members of the three-axis gear. . 14. The adjusting device according to claim 13, wherein the brake (31) is formed of a disk arranged in the adjusting motor (2). 13. The adjusting device according to claim 12, wherein the auxiliary drive (11) is formed of a hydraulic motor (17) or a pneumatic motor (16). 13. The adjusting device according to claim 12, wherein the auxiliary drive (11) is formed of an electric auxiliary motor (34) or an emergency coil (35). 17. The adjusting device according to claim 16, wherein the energy supply of the electric auxiliary motor (34) or emergency coil (35) is provided through a condenser (36), an external power unit (37), a battery, a chain or a belt. 2. The adjusting device according to claim 1, wherein the auxiliary drives (11) are each formed of two auxiliary drives operating in reverse. 2. The adjusting device according to claim 1, wherein the overload clutch (38) is arranged between the adjusting motor (2) and the output part (5). 20. The adjusting device according to claim 19, wherein the overload clutch (38) is formed by a slide clutch or a shear pin.

Images