DE102015202828A1 - Clutch actuator with pre-commutation for amplifying a clutch actuation and motor vehicle clutch - Google Patents

Abstract

The invention relates to a clutch actuator (1) for a motor vehicle clutch with a rotor (2) which is arranged concentrically and about a rotor axis (3) rotatable to a stator (4), with a rotor fixed position magnet (8) for describing the angular position the rotor (2) is arranged and configured, and with a stator-fixed position sensor (11) which is arranged and configured for detecting the angular position of the position magnet, wherein the position magnet (8) relative to the rotor (2) and the position sensor (11) relative to the stator (4) are cooperatively arranged so that a pre-commutation for amplifying an engagement operation can be generated. The invention also relates to a motor vehicle clutch with such a clutch actuator (1).

Description

The present invention relates to an electric clutch actuator for a motor vehicle clutch having a rotor which is arranged concentrically and rotatable about a rotor axis to a stator, with a rotor-fixed position magnet which is arranged and configured for describing the angular position of the rotor, and with a statorfesten position sensor, which is arranged and configured to detect the angular position of the position magnet.

Such a clutch actuator is, for example, from the still unpublished PCT / DE 2014/200462 known. This describes an actuator for a motor vehicle, comprising a housing, with a stator and a rotor rotatable relative to this stator having, electromagnetic drive means, wherein the rotor via a transducer unit is connected to a trigger element, wherein the transducer unit, the rotational movement of the rotor in a translational movement of the trigger element converts, and with an electrically connected to the drive means, the drive means controlling electronic control unit, wherein the drive means comprises at least on the control unit side facing an existing of an electrically insulating material encapsulation. In this case, the rotor may be rumspritzt on its side facing the control unit with a Umspritzung at least partially formed Rotorumspritzung. In this case, a magnet receiving cap be connected to the Rotorumspritzung that rotatably receives a centrally arranged to the rotational axis of the rotor Magnethaltering for receiving a position magnet, wherein the magnet receiving cap formed approximately integrally with the Rotorumspritzung or plugged into the Rotorumspritzung, as engaged. In this case, the magnet retaining ring can be configured with rib-shaped projections on its inner circumferential surface, wherein the position magnet is pressed against rotation in the magnet retaining ring, latched and / or glued.

It is assumed below that the generic clutch actuator includes the rotor and the stator as components of an electric motor, such as a permanent magnet synchronous motor. A permanent magnet synchronous motor is also referred to as a permanent magnet synchronous machine, as a brushless DC motor or technical language, with appropriate expression, as "electrically commutated motor". It is further assumed by way of example that the rotor includes a magnet, such as a permanent magnet, and that the stator includes a coil which can be acted upon by electric current. When the coil is commutated, i. When the coil is supplied with electric current, an electromagnetic field is generated. When the electromagnetic field of the stator is offset from the magnetic field of the rotor by an angle about the rotor axis, a torque acts on the rotor so that the rotor rotates. This angle is also referred to as displacement, and is conventionally set to π / 2. Furthermore, the displacement of π / 2 is defined as the ideal commutation angle for the following description. An actual commutation angle is the commutation angle actually applied by a power electronics / inverter / inverter to the synchronous machine. An error between an ideal and an actual commutation angle is called a commutation error. A common commutation error is tolerated in the range of ± 10 °.

The commutation is controlled by the position sensor, which detects or senses the angular position of the position magnet and thus the angular position of the rotor. Due to the shift of π / 2, there is a linear relationship between the rotational speed of the electromagnetic field, also referred to as a rotary electric field speed, and the rotational speed of the rotor, also referred to as mechanical rotational speed.

In this case, the ratio between the electric rotary field speed and the mechanical speed via the number of pole pairs of the electric machine is fixed. For example, in the case of a pole pair number of p = 1, the wave of the electromagnetic field or of the air gap field moves exactly once around the rotor axis during an electrical period, which is also referred to in technical terms as a complete revolution over the circumference of the electric machine. Under the electric period, a period of an electric oscillation which is supplied to the coil is understood. For example, with a pole pair number of p = 4, the electromagnetic rotating field moves four times around the rotor axis during a mechanical revolution, so that one revolution of the rotor about the rotor axis requires four electrical periods. Generally speaking, an "electrical angle" Φ _el corresponds to the product of the number of pole pairs p and a "mechanical angle" Φ _mech .

The term "commutation quality" refers to the precision in positioning a signaling sensor to the stator. The smaller the commutation error, the greater the commutation quality.

If the commutation error of 0 ° is not adhered to, a pre-commutation or pre-commutation or a subsequent commutation or subsequent commutation may occur. While pre-commutation results in an increase in the torque that can be delivered by the rotor and in the speed of the rotor, post-commutation results in a reduction in torque and a reduction in speed. However, a reduction in the torque of the rotor has the consequence that a suitable for delivering a stronger torque and thus larger and heavier Kupplungsbetätiger is provided. Both an increase in the space of the clutch actuator as well as an increase in the weight of the clutch actuator are extremely undesirable in the automotive industry.

It is therefore the object of the present invention to eliminate the disadvantages known from the prior art, and in particular to keep the manufacturing costs low and / or to provide the smallest possible and / or as easy as possible Kupplungsbetätiger.

This object is achieved in a generic Kupplungsbetätiger according to the invention that the position magnet relative to the rotor and the position sensor relative to the stator are arranged cooperatively so that a pre-commutation for amplifying an engagement movement can be generated. Thus, a self-opening or normally-open or depressed automobile clutch may be actuated by a clutch actuator in spite of reduced commutation efficiency, i. can be achieved with a lower requirement for the detection tolerance, be realized with constant space requirements and / or weight requirements of the clutch actuator.

It can be provided independently claimable, a motor vehicle clutch with a clutch actuator according to one of the above aspects. Such a motor vehicle clutch has the advantages of each clutch actuator, so in particular reduced costs, reduced space and / or reduced weight.

The two preceding solutions of the object of the invention also have the advantageous consequence that a smaller and / or lighter clutch actuator can be used in the case of a constant requirement on the quality of the commutation and constant demands on the engagement force or disengaging force to be applied.

The term "engagement operation" may be described as an operation engaging the vehicle clutch or as an operation for engaging a motor vehicle clutch, wherein engagement operation means an engagement operation of the clutch actuator.

Advantageous embodiments are claimed in the subclaims and are explained below. The aspects mentioned there can also be pursued individually, independently of each other and from the main aspect.

In one aspect, the rotor and the stator may be elements of an electric motor. Furthermore, the rotor-fixed position magnet can also be described as a rotor-fixed position magnet whose polarization is arranged and configured to describe the angular position of the rotor or of the rotor about the rotor axis. Furthermore, the stator-fixed position sensor can be described as a stator-type position sensor which is used for sensing, i.e., detecting, sensing. Recording, such as with a sensor or sensor, the angular position of the position magnet is arranged and configured.

If the relative arrangement of the position magnet to the rotor and the position sensor to the stator with an asymmetrical tolerance position against a commutation error of 0 ° is provided, the tolerance limit in the direction of the amplifying unbalanced commutation amount is greater than the opposing tolerance limit, this has, for example in that due to reduced accuracy requirements in the manufacture of the clutch actuator, the manufacturing costs can be reduced in a manner that is easy to implement.

It can be provided that the tolerance limitation in the direction of the pre-commutation is 15 ° φ _el and in the direction of the post-commutation is -5 ° φ _el . In the direction of the amplifying commutation, the tolerance limitation can be + 6 ° and in the opposite direction -2 °, together 8 °, so that, for example, with a number of pole pairs of p = 5, the requirement for the commutation error can be reduced to ± 20 °. It may further be provided that the tolerance limitation in the direction of the amplifying commutation is 3 ° and in the opposite direction -1 °, together 4 °, so that advantageously the commutation error can be limited to ± 10 °. It may also be provided that the tolerance limit in the opposite direction the amplifying commutation is 0 °, so that even slight Nachkommutierung is reliably prevented. The above measures all have the consequence that a more powerful actuator can be produced. The weight can be reduced and the space used better.

When the clutch actuator is prepared for anti-clockwise and clockwise rotation, the clutch actuator can actuate both an engagement movement and a disengagement movement of the vehicle clutch.

The relative arrangement of the position magnet to the rotor and the position sensor to the stator can be designed so that the amplifying commutation a speed increase and / or torque increase of at least 10%, more preferably at least 25% and even more preferably at least 33%, compared to a Commutation error of 0 °, causes. Thus, with a consistent applied force for engagement or disengagement, a significantly lighter and / or smaller clutch actuator can be used. A smaller and / or a lighter clutch actuator is usually cheaper to manufacture.

It may be provided in the intended "pre-commutation to enhance an engagement movement" that the relative arrangement of the position magnet to the rotor and the position sensor to the stator is designed so that a Nachkommutierung a speed reduction and / or torque reduction of at most 15%, more preferably from at most 10%, and even more preferably at most 5%, compared to a commutation error of 0 °. In other words, the pre-commutation should optionally be selectively selected in such a way that a speed and / or torque drop arising on rotation of the rotor in the opposite direction is limited. As a result, a motor vehicle coupling designer must provide a lower safety margin so that a significantly smaller and / or significantly lighter clutch actuator can be used. This saves costs.

The amplifying commutation may be prepared and adjusted such that the amplification by the amplifying commutation compensates for a hysteresis when operating the motor vehicle clutch, or preferably that the amplification by the amplifying commutation exceeds the hysteresis when operating the motor vehicle clutch in amount. The notion that "the amplification by the amplifying commutation exceeds the hysteresis when operating the motor vehicle clutch" can also be described as "an additional torque caused by the amplification by the amplifying commutation, a torque to be applied by or due to the hysteresis on actuation of the motor vehicle clutch in terms of amount "or the like will be described. If the hysteresis is compensated when operating the motor vehicle clutch, a developer of the motor vehicle clutch need not provide a safety margin to overcome the hysteresis. If the amplifying commutation exceeds the hysteresis when operating the motor vehicle clutch in terms of amount, a again reduced in size and / or weight clutch actuator can be provided.

It can further be provided that the rotor has a spindle for actuating the motor vehicle clutch, wherein the reinforcement can be provided by the reinforcing commutation, the spindle pitch at least balancing. Instead of the term "spindle pitch" also one of the terms "self-locking of the spindle" or "inhibition" or "friction of the spindle" can be used. The notion that "the reinforcement is at least compensating for the lead through the amplifying commutation may be represented by the notion that" an additional torque caused by amplification by the amplifying commutation is applied by the spindle pitch upon actuation of the motor vehicle clutch Torque is provided at least balancing "is described or the like.

Further, it can be provided that the rotor has a spindle with a spindle nut arranged or attachable thereto for actuating the motor vehicle clutch. If the spindle pitch or the self-locking or friction of the spindle is taken into account in this way, the clutch actuator according to the invention can be designed even more precisely on the operation of the same, so that the size and / or weight of the clutch actuator can be further reduced.

It is proposed to design the commutation quality taking into account an actuator connected to the clutch actuator, such as, for example, taking into account a spindle and / or taking into account a hysteresis when operating the motor vehicle clutch. This means that the mounting tolerances of the sensor system can be defined on the basis of the entire actuator system or clutch actuation system or the entire motor vehicle clutch.

Conventional electrically commutated motors or synchronous machines or servomotors generally have to meet the same requirements both in left-hand rotation and on the right-hand rotation, so that the sensor system must conventionally satisfy symmetrical tolerances. Depending on the direction of rotation, motor vehicle couplings have different requirements with regard to the rotational speed and the torque to the clutch actuator or clutch actuator. This has its cause, for example, in the actuator connected to the clutch actuator, such as, for example, the spindle and a clutch load characteristic which is subject to hysteresis. It is further proposed that the fact that a clutch actuator or clutch actuator depending on use in a rotor rotation direction must apply a greater force than in the other direction of rotor rotation, exploit. For example, when a self-opening clutch in the direction of engagement or in the clutch closing direction, a higher force than in the disengaging or opening direction must be applied, as with a self-closing clutch a greater force in the disengagement or opening direction than in the direction of engagement or Closing direction must be applied. It is proposed according to this invention that the sensor can be mounted with a "preferred direction", so that there are synergy effects with the properties of, for example, a vehicle coupling to be driven. In particular, the combined consideration of the actuating direction-dependent applied force, the spindle pitch and / or the clutch characteristic offers synergy effects.

Formulated in yet other words, the invention provides a deliberate and possibly even increased tolerance, wherein according to the invention it is provided that the system of position magnet, position sensor and electric motor is designed such that an unequally distributed tolerance of -a% to + b% is provided with the amount of a not equal to the amount of b. The arrangement of the participating parts of the tolerance chain can and should be provided to each other, that in particular when taking into account spindle pitch, hysteresis and / or actuation direction dependent applied force either a pre-commutation or Nachkommutierung the coil, the stator or generally the electric motor at an operation, such as a clutch actuation, because of the tolerance defined according to the invention is deliberately greater than a commutation in the opposite direction.

The invention will be described in more detail below with reference to an embodiment. Show it:

1 a cut along a rotor axis representation by a clutch actuator,

2 a comparison of rotational speeds in a left-hand rotation and in a clockwise rotation with different commutation angles,

3 a comparison of torques for a left-hand rotation and a clockwise rotation with different commutation angles,

4 an overview of exemplary achievable maximum torques at different commutation angles, and

5 three exemplary and hysteresis clutch characteristics.

The figures are merely schematic in nature and are only for the understanding of the invention. The same elements or similar elements are provided with the same reference numerals, and a description will be omitted in general.

The 1 shows a cross section through a clutch actuator 1 who has a rotor 2 Has. The rotor 2 is about a rotor axis 3 rotatable. Further, the rotor 2 concentric with a stator 4 arranged. The rotor 2 has a rotor shaft 5 , in sections as a spindle 6 is configured, and further has one with the rotor shaft 5 firmly connected permanent magnets 7 , as well as one fixed to the rotor shaft 5 connected position magnets 8th , The stator 4 has a housing 9 and a variety of coils 10 , Furthermore, a position sensor 11 stuck to the stator 4 connected. In addition to other attachments is one on the spindle 6 along the rotor axis 3 in the manner of a spindle displaceable and to the spindle 6 opposite spindle nut 12 shown.

In the 2 a comparison of different speeds is shown, which were measured at a different commutation angle with an otherwise same clutch actuator in the left and right. In this case, U denotes the rotational speed plotted along the ordinate axis, and t denotes the test time plotted along the abscissa axis. Alternatively, the speed, as usual with n or the angular velocity with ω can be specified.

The speed measurement designated U0 was recorded with a commutation angle of 0 °, the U10 speed measurement was recorded with a Kommutierungsfehler of 10 °, the U20 speed measurement was recorded with a Kommutierungsfehler of 20 °, the U30 speed measurement was with a Commutation error of 30 ° recorded, the U40 speed measurement was recorded with a commutation error of 40 °, the U50 speed measurement was recorded with a commutation error of 50 ° and the U60 speed measurement was recorded with a commutation error of 60 °. In this case, from time t1 to time t2, a pre-commutation occurs, for example, anticlockwise, and from t3 to t4 there is an after-commutation, for example, a clockwise rotation. In the 3 a comparison of corresponding torque measurements is shown, wherein the torque measurement T0 at a commutation error of 0 °, the torque measurement T10 at a commutation error of 10 °, the torque measurement T20 at a commutation error of 20 °, the torque measurement T30 at a commutation angle of 30 °, the torque measurement T40 with a commutation error of 40 °, the torque measurement T50 was recorded at a commutation error of 50 ° and the torque measurement T60 at a commutation error of 60 °. The 2 and 3 show exemplary measurement results to illustrate the principle and effects of the invention.

According to the principle of pre-commutation or Nachkommutierung, also referred to as field weakening, while the angle or the relative arrangement of the position magnet to the rotor and the position sensor to the stator is deliberately set so that, depending on the set angle in the pre-commutation an increase in Speed and torque follows. This has a Nachkommutierung a reduction in the rotational speed of the result. It is particularly clear that the change in speed and / or torque in the left-hand rotation and the right-hand rotation is not symmetrical. If, for example, the angle between the position sensor and the stator, such as the relative arrangement between the rotor and the position magnet and the position sensor and the stator, adjusted in a clockwise direction, there is a Nachkommutierung in a clockwise rotation of the rotor, and is at a rotation of the Rotor counterclockwise before a pre-commutation. In this case, for example, the rotational speed increases counterclockwise by 10 ° in the case of a rotation of the rotor, and the rotational speed of the rotor decreases by 25% in a clockwise rotation. Below is an overview table given by way of example measured maximum torques given example set commutation. commutation Max. torque -0 ° (post-commutation) -0.889 Nm -10 ° -0.840 Nm -20 ° -0.769 Nm -30 ° -0.665 Nm -40 ° -0.553 Nm -50 ° -0.418 Nm -60 ° -0.293 Nm -0 ° (pre-commutation) +0.909 Nm + 10 ° +0.947 Nm + 20 ° +0.944 Nm + 30 ° +0.898 Nm + 40 ° +0.815 Nm + 50 ° +0.694 Nm + 60 ° +0.587 Nm

These maximum torques achieved as a function of the commutation angle during the measurement are in 4 shown graphically again. In this case, the respective commutation angles K are represented over the abscissa axis, and the measured maximum torques Tmax are shown over the ordinate axis. The characteristic curve TmaxVK designates the exemplary maximum torques measured during the pre-commutation, and the characteristic curve TmaxNK designates the exemplary maximum torques measured during post-commutation.

The spindle 6 is formed, for example, with a clockwise slope. At this point it should be noted that instead of the spindle 6 Also, a Planetenwälzgetriebe (not shown) with a example. Right-handed slope can be used. The clutch actuator is set up and prepared to close a self-opening clutch (not shown) torque-controlled. The clutch has a hysteresis clutch characteristic. In the 5 characteristic curves of three exemplary clutches A, B and C are shown, wherein on the abscissa an actuation path x, which is also referred to as Einrückweg, and the ordinate an operating force F are registered. The clutch A is engaged along the characteristic Ae, and is disengaged along the characteristic Aa. The clutch B is engaged along the characteristic Be, and is disengaged along the characteristic line Ba. The clutch C is engaged along the characteristic Ce, and is disengaged along the characteristic Ca.

Because with the clutch actuator 1 the position magnet relative to the rotor and the position sensor are arranged cooperatively relative to the stator so that the position sensor detected the angular position of the rotor in a clockwise or clockwise direction, a Vorkommutation at an engagement operation or at a vehicle clutch engaging operation generated. This leads to an amplification of the output from the clutch actuator in the engagement operation torque. Thus, the clutch actuator receives an increased performance in that the clutch actuator is faster when closing the clutch and can apply a higher torque to close the clutch. When opening the clutch, the clutch actuator is supported by the self-opening feature of the clutch. When opening the clutch or when driving up the clutch actuator less force is needed than when closing the clutch.

Therefore, by providing an asymmetrical tolerance position of the relative arrangement of the position magnet to the rotor and the position sensor to the stator advantageously a magnitude greater tolerance can be provided. As an example may be called instead of a conventional tolerance demand on the angular position of the sensor of ± 2 ° a tolerance position of -1 ° to + 3 ° is required. Furthermore, instead of the conventional tolerance requirement of ± 2 °, which corresponds to a tolerance range of 4 ° in total, a tolerance limitation of -2 ° to + 6 ° is sufficient, which corresponds to a tolerance field size of 8 ° in total.

As a result, the manufacturing cost of Kupplungsbetätigers invention are significantly reduced. Furthermore, because of the above-described torque increase of the clutch actuator in the clutch closing direction, a particularly powerful or improved performance Kupplungsbetätiger can be used.

LIST OF REFERENCE NUMBERS

1

 clutch actuator

2

 rotor

3

 rotor axis

4

 stator

5

 rotor shaft

6

 spindle

7

 permanent magnet

8th

 position solenoid

9

 casing

10

 Kitchen sink

11

 position sensor

12

 spindle nut

U

 rotation speed

U0, U10, U20, U30, U40, U50, U60

 Speed measurement

T

 torque

T0, T10, T20, T30, T40, T50, T60

 torque measurement

t

 Time

p

 number of pole pairs

Tmax

 maximum torque

TmaxVK

 at a pre-commutation measured maximum torque

TmaxNK

 at a Nachkommutierung measured maximum torque

A, B, C

 clutch

Aa, Ba, Ca

 Coupling characteristic when disengaged

Ae, Be, Ce

 Coupling characteristic when engaged

F

 operating force

x

 actuating

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 2014/200462 [0002]

Claims (9)

Clutch actuator ( 1 ) for a motor vehicle clutch with a rotor ( 2 ) concentric and about a rotor axis ( 3 ) rotatable to a stator ( 4 ) is arranged, with a rotor-fixed position magnet ( 8th ) used to describe the angular position of the rotor ( 2 ) is arranged and configured, and with a stator-fixed position sensor ( 11 ), which is arranged and configured for detecting the angular position of the position magnet, characterized in that the position magnet ( 8th ) relative to the rotor ( 2 ) and the position sensor ( 11 ) relative to the stator ( 4 ) are cooperatively arranged so that a pre-commutation for amplifying an engagement operation can be generated. Clutch actuator ( 1 ) according to claim 1, characterized in that the relative arrangement of the position magnet ( 8th ) to the rotor ( 2 ) and the position sensor ( 11 ) to the stator ( 4 ) is provided with an asymmetrical tolerance position, compared with a commutation error of 0 °, wherein the tolerance limit in the direction of the pre-commutation is greater in magnitude in the direction of the pre-commutation than the opposing tolerance limit. Clutch actuator ( 1 ) according to claim 2, characterized in that the tolerance limit in the direction of the pre-commutation of + 15 ° Φ _el and in the direction of Nachkommutierung -5 ° Φ _el . Clutch actuator ( 1 ) according to one of claims 1 to 3, characterized in that the clutch actuator ( 1 ) is prepared for counterclockwise and clockwise rotation. Clutch actuator ( 1 ) according to one of claims 1 to 4, characterized in that the relative arrangement of the position magnet ( 8th ) to the rotor ( 2 ) and the position sensor ( 11 ) to the stator ( 4 ) is configured so that the pre-commutation causes a speed increase and / or a torque increase of at least 10%, more preferably at least 25% and even more preferably at least 33% compared to a commutation error of 0 °. Clutch actuator ( 1 ) according to one of claims 1 to 5, characterized in that the relative arrangement of the position magnet ( 8th ) to the rotor ( 2 ) and the position sensor ( 11 ) to the stator ( 4 ) is configured so that a Nachkommutierung a speed reduction and / or a torque reduction of at most 15%, compared with a commutation error of 0 ° causes. Clutch actuator ( 1 ) according to one of claims 1 to 6, characterized in that the pre-commutation is prepared and adjusted so that the gain compensates by the Vorkommutierung a hysteresis when operating the motor vehicle clutch in amount, or, preferably, that the gain by the Vorkommutierung the hysteresis during actuation The motor vehicle clutch exceeds the amount. Clutch actuator ( 1 ) according to one of claims 1 to 7, characterized in that the rotor ( 2 ) a spindle ( 6 ) for actuating the motor vehicle clutch, wherein the gain is prepared by the Vorkommutierung the spindle pitch compensating. Motor vehicle clutch with a clutch actuator ( 1 ) according to one of claims 1 to 8.

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