DE102007050578B4 - Transmission actuator and gearbox - Google Patents

Abstract

Motor vehicle-suitable actuator (1, 1 ', 1' ', 1' '', 1 '' ''), which is equipped with a piezoelectric element (3), which is to be used as a piezo-voltage path converter, wherein the actuator (1, 1 ', 1' ', 1' '', 1 '' '') has a surface converter (17) with an immediate hydraulic transmission (15) for receiving the voltage-dependent path lengthening (7) of the piezoelectric element (3), characterized in that a Reinforcement of Weglängung (7) through the area converter (17) on a conventional clutch path (13) is feasible, wherein in the actuator (1, 1 ', 1' ', 1' '', 1 '' '') on piston ( 31, 33) hydraulic pressure is exercised, with which two clutches (112, 114) are simultaneously controllable in a vehicle.

Description

The present invention relates to a motor vehicle suitable actuator, in particular for a transmission, and the design of a suitable transmission with such a motor vehicle suitable actuator, such as a yaw damping gear or a dual clutch transmission.

Gierdämpfungsgetriebe are such transmissions that want to promote the driving stability by actively influencing the torque of the output axles. The gearboxes are denoted by the English keywords "torque vectoring" or "active yaw", other common names are the linguistic summary of the function of the transmission as a transmission for torque distribution on a vehicle axle or transmission for active torque distribution.

In the last two decades prior to the filing date of this proprietary right, numerous concepts have been devised by transmission designers of how to distribute the torque of an input shaft to at least two output shafts according to the desired requirement. By usually electronically assisted torque distribution calculation, which can be performed for example in a dedicated controller, a different torque is applied to the one wheel of an axle compared to the second wheel of the same motor vehicle axle. Often, the calculation of the torque distribution takes place as a function of the chosen steering angle. In order to avoid under- or oversteer, the wheel, which covers a smaller radius path at the selected steering angle, in short travels a shorter distance, are usually subjected to a lower torque than the wheel rotating on the road of the same axis, the the larger Radienweg, in short the longer way, travels. In the event of an uncontrolled yaw of the vehicle is then trying to restore the stability of the vehicle by a conscious torque shift using the appropriate vehicle control unit. Thus, depending on the dependence of the understeer or oversteer, the torque on the inside wheel can be reduced or increased. For this purpose, the corresponding control unit is equipped with suitable sensors and works together via a network network such as a CAN network with other control devices.

Clutches in gearboxes are designed to lower the torque on the output side, which can reach a maximum of the input torque, than to pass on the torque applied to the input side to an output shaft. For the purposes of the following invention also brake-like systems are subsumed under the term clutch. Brakes, in contrast to clutches, ensure the static stability of one of the two sides to be coupled. Embodiments are also conceivable in the yaw damping transmissions in which parts of the transmission are braked against the housing in order to accelerate other parts of the transmission. As a result, the output-side wheel is thus accelerated. This is possible, for example, with a planetary gear set. Also in such a kind of coupling systems, the present invention is applicable.

By way of example, some driving force distribution devices are to be cited, for which the actuator according to the invention can be used. The concepts can be subdivided into satellite transmission concepts, coupling concepts and combined concepts. Instead of a planetary gear train concepts are also known in which a normal gear set is used. As the translations of a planetary gear set can be designed low, the figure description of EP 0 575 151 B1 (Patentee: Mitsubishi Jidosha Kogyo Kabushiki Kaisha, priority date: June 15, 1992). In 2 are shown parallel to the clutch discs hydraulic piston for actuating the clutch. The hydraulic fluid must be brought to the hydraulic pistons via connecting pieces in the housing. By springs, the pistons are moved back to their rest position with hydraulic pressure freedom. A similar planetary concept can be the US 2005 / 247,511 A1 (Owner: Magna Powertrain USA Inc, filing date: May 7, 2004). Clutches influence the torque distribution in the gearboxes shown schematically. Suitable actuators for the actuation of the couplings are needed. A distribution gearbox equipped with two clutches is schematically shown in FIG US 2004 / 058,774 A1 (Applicant: Vistion Global Technology Inc., filing date: 25th September 2002). The actuating force on the clutches is also disclosed only schematically by double solid arrows. In terms of design, a hydrostatic distribution gearbox based on planetary gears can be used in a more detailed manner EP 1 788 284 A1 (Applicant: Hofer Getriebetechnik GmbH, priority date: 19 November 2005). Despite the wealth of detail of the swash plate pump also this document does not show the implementation of the hydraulic control. From the numerous omissions the expert takes the hint that the quite promising concepts require the active torque distribution of a motor vehicle-compatible actuator.

For the sake of more compact presentation of the present invention, reference is made to the above-mentioned publications, so that the transmission in its variety richness itself for a active torque distribution does not need to be fully described, and yet sufficiently disclosed.

For the actuators, either hydraulic pistons or electromechanical solutions have been considered in the previously developed transmissions. Another approach is a magnetorheological coupling. Because over the entire automotive typical operating temperature range of -40 ° C to + 150 ° C a fast (between 50 ms and 150 ms) actuation of the torque setting is desired in the hydraulic systems usually a correspondingly large hydraulic pump is kept, so that the required hydraulic fluid quantities can be added and removed. Large pumps have correspondingly large power losses and increase the total weight of the torque distribution gearbox.

Thus, attempts have been made several times in the past to design geared controls by using piezo elements. To DE 44 45 606 A1 (Applicant: LuK Lamellen- und Kupplungsbau GmbH, priority date: 5 January 1994), a piezoelectric actuator alone should not be sufficient to apply the necessary coupling power. It is therefore proposed to combine hitherto known hydraulic systems with a piezoactuator with a superimposition of an inertial force addition in the clutch. The piezoactuator offers fast reactivity, while the basic power is applied classically. To take advantage of the fast reactivity of a piezoelectric element, is in the US 4,636,679 A (Applicant: United States of America, filing date: 15 January 1986) proposed hydraulic pumping in a piezostack into a rotating disk. The longitudinal movement of the piezo stack, which undergoes an elongation in a preferred direction as a function of the exciting high DC voltage is converted by means of hydraulic fluid in a rotational movement through a coupling ring. To compensate for the lack of elongation of the piezo element is one of the solved tasks of the EP application EP 0 790 145 A2 (Applicant: Hydraulik-Ring GmbH, priority date: 19 January 1996), proposing a reversal of a lever arm. For a very small quantity pump, the proposed deflection amplification concept via a lever deflection makes sense; a direct application for clutches and transmissions with two output strands of the EP 0 790 145 A2 not be removed.

Alternatively, one can also look into the technical field of injectors, which work with fuel as the fluid to be controlled. The fuel charge of now common injectors is in a much higher range. At the same time working with very small amounts of fuel. To US 2003 / 150,432 A1 (Applicant: Siemens VDO Automotive Inc., Filing date: February 13, 2003), the minimum elongation of a piezoelectric element, which is less than 0.035 mm, can be increased in an injector by diameter translation up to 6 mm. Should be a level like US 2003 / 150,432 A1 not be possible, so suggests DE 10 2005 022 137 A1 (Applicant: Denso Corporation, priority date: 13 May 2004) to provide a two-stage hydraulic transmission device with a small-diameter valve piston, which uses the fuel hydraulically reinforced for movement extension.

Further explanations of the use of piezoelectric elements in the motor vehicle can be z. B. the DE 196 31 203 A1 (Applicant: Hydraulik-Ring Antriebs- und Steuerungstechnik GmbH, filing date: 02.08.1996). There, it is proposed to pressurize a brake hydraulic means with a piezoelectric translator utilizing the inverse piezoelectric effect. This pressure is generated in a pressure chamber. Due to a hydraulic transmission, a brake piston of a wheel brake cylinder is to be loaded. The piezo elements should enable fast control.

The DE 195 11 811 B4 (Patent owner: Lucas Industries p.I.C., filing date: 30.03.1995) also relates to a motor vehicle brake. The piezoelectric actuator should be used in the form of a linear motor using a hydraulic ratio. How should be built in such wheel brake the piezo interrupter, can be, inter alia, the description of the DE 198 18 156 A1 (Applicant: Robert Bosch GmbH, filing date: 23.04.1998).

From other fields of application it is known that piezoelectric actuators can be used as actuators for modulating additional movements. The way offered by the actuators is too low. Therefore, the actual path is covered by another mechanism. By way of example, the DE 10 2006 008 674 A1 (Applicant: LuK Lamellen and Kupplungsbau Beteiligungs KG; Priority Date: 31.03.2005) that according to a superposition principle, fluid volume is actuated in a clutch actuation by a main release system and by a piezoelectric actuator, the actuator being referred to as an add-on system. Thus, juddering vibrations can be counteracted more effectively. The temperature compensation of a spindle chuck is based on a similar principle DE 198 54 348 C1 (Applicant: Fortuna-Werke Maschinenfabrik GmbH, filing date: 25.11.1998) a mechanical clamping and a for Compensation of thermal expansion additionally provided piezoelectric clamping holds.

In another application of motor vehicle technology, the injection technology, the fuel control by means of piezo actuators is also known (see DE 199 39 478 C1 (Applicant: Robert Bosch GmbH, filing date: 20.08.1999)).

Leaving the field of automotive engineering, you will also find piezo actuators in other applications, such. B. in the DE 10 2006 023 036 A1 (Applicant: Paczyniski et al., Filing date: 17.05.2006) for the robot control, in the DE 37 14 337 C2 (Patentee: Mannesmann Rexroth GmbH, filing date: 29.04.1987) as part of a servo valve and in the DE 199 53 244 A1 (Applicant: ITT Manufacturing Enterprises Inc., filing date: 04.11.1999) as part of a press control. In the DE 37 14 337 C2 and in the DE 199 53 244 A1 In addition, the proposal is made to extend too short distances of the piezoelectric element by parallel switching or by hydraulic translations.

The purpose of being able to influence the drive torque on the different wheels of a motor vehicle, can be with devices such. B. the US 2005 247 511 A1 (Applicant: Kirkwood, filing date: 07.05.2004) and z. B. the US 2004 058 774 A1 (Applicant: Perkins, filing date: 25.02.2002). The synchronizations and controls are often done by control units and synchronized calculation processes in the control units.

The present invention is based on the object to build gear with two output shafts, such as driving force distribution devices as yaw damping or dual clutch transmission without hydraulic pumps for the actuators and still achieve the highest possible control quality.

The object of the invention is achieved by a motor vehicle suitable actuator according to claim 1. The advantageous use or the advantageous use of an actuator according to the invention in corresponding transmissions can be found in claims 7, 12 and 13.

As stated above, the lengthening of a piezoelectric element is very small depending on the voltage applied to it. The piezoelectric element can undergo a longer path length by layer-by-layer construction of individual piezoelectric cells. The piezo element generates the greatest elongation in a preferred direction. The Weglängungsrichtung of the piezoelectric element and the normal clutch travel are superimposed according to the invention. Coupling and Weglängungsrichtung can run in one embodiment in the same axial direction. By means of hydraulics, however, a change in direction of the directions of movement of the piezoelectric element and the pressure plate can also take place relative to one another. In such an orientation can be filled by using a hydraulic ratio completed otherwise, which can be filled with a special hydraulic means such as a hydraulic oil, the relatively short path of the piezoelectric element in dependence on the applied voltage to the usual coupling of 2 to 6 mm, preferably 4 mm, are reacted. The actuator has its own hydraulic chamber. According to a further embodiment, the actuator may also have a plurality of completely closed hydraulic chambers. The powerful deflection of the piezoelectric element is amplified so far over the completed hydraulic translator that an actuating piston can cover a sufficient clutch travel.

The completed hydraulic translator can be considered as a surface converter. The translation takes place through the two hydraulic surfaces. The translation can act through the projected surfaces acting parallel to each other. In an alternative embodiment can be accomplished simultaneously by means of hydraulics, the force directional deflection. It is particularly favorable if the area converter is configured in the manner of a cylinder. The area converter has a first surface, which is clamped parallel to the piezo element, and on which the piezo element can act. The area converter has a second hydraulic surface which is adjacent to a pressure piston. The pressure piston is designed to exert a force on a clutch. The hydraulic surface, which acts on the pressure piston, is smaller than the hydraulic surface, which adjoins directly to the piezoelectric element. The closed hydraulic volume is such a large volume that the translation in the form of a rigid composite can be exercised. The hydraulic ratio with two movable, projecting hydraulic surfaces, which are different in size, is considered as a single-stage translation, provided a conversion and path reinforcement or extension by a single hydraulic step is brought about. According to one embodiment, the moving surface of the piezoelectric element may be parallel to the surface of the coupling.

The piezoelectric element has a multilayer structure. Several individual piezo cells can be laid one on top of the other. By stacking the individual piezo cells, the elongation can be increased. The piezoelectric cells are arranged one above the other flatly. A single piezo cell is relatively flat. Even a piezo stack has a very low height.

Despite seals that can be arranged parallel to the piston or circumferentially to the piston, occur in hydraulic systems basically any leaks. Thus, the hydraulic fluid to replace or refill the leaked amount. The same piezoelectric element can be used, in particular via an additional pressure rod or a pressure piston, to refill the lost hydraulic amount as needed.

The piezohydraulic actuator is suitable for yaw damping transmissions and dual-clutch transmissions because of its double design in one and the same housing. Both types of transmission are designed so that in normal operation to the extent that a piston is to extend, a second piston is retracting exactly opposite. To the same extent means that the individual piston paths may differ from each other by a factor determined by the clutches. So it is also possible that a piston travels only half of the absolute way as the other piston. The actuator can hydraulically exert pressure on both the one and the other pistons. The pistons work in opposite directions in one embodiment. The pistons can also act in a change of direction in one embodiment. With a piezo element thus several pressure plates and thus (hydraulic or clutch) control points can be controlled simultaneously. Thus, the force or pressure control can be adjusted so that either one or the other piston can only exert the pressure. The pressure is then applied alternately.

The pressure of the piston or the distance traveled by the piston serves to actuate clutches, such as multi-disc clutches. The couplings transmit the torques in a drive train. By an appropriate electronic interconnection of the actuator or alternatively by an unlocking or mutual blocking of the hydraulic interconnection of the hydraulic translator can be extremely compact, with high control quality acting in the reverse direction actuator for two coupling strands realize.

Couplings age in the course of their operation. In the course of operation, the clutch travel to be covered increases, not least because of the abrasion of the clutch linings. Thus, a pure distance measurement, especially at the end of the operating period, meaningless. The hydraulic booster with the at least two mutually parallel hydraulic surfaces can be well used, in particular by measuring the pressure in the section with the smaller diameter to determine the pressure exerted by the piston or - converted to the active surface - force.

Common to most yaw damping transmissions is that the torque distribution of an input torque application is divided into two output shafts as a function of a steering angle or as a function of vehicle stability. Each output shaft opens into at least one road wheel. Thus, the torque at the respective road wheel is influenced by the yaw damping gear. The yaw damping gear should normally give a larger torque to the wheel with the longer radius path during normal operation. The yaw damping gear consists of numerous components. One of the components is a gearbox that works as a differential gearbox. In some yaw damper gears, a differential gear is actually used for torque distribution. The piezoactuator influences the torque transmission on at least one of the two output shafts. The piezo actuator can act on couplings for this purpose.

Such a clutch may be a multi-plate clutch comprising at least two clutch plates. The transmission system comprises the multi-plate clutch.

The transmission system may also include a planetary gear. It is particularly advantageous if the power flow is performed by an external planetary gear on the inner planetary gears. In that case, no unnecessary deflection of the power flows is to be provided. According to a further embodiment, of course, the inner sun gear can be surrounded by the outer planetary gears so that a power flow direction takes place from the inside to the outside.

According to one embodiment, the mechanical-hydraulic torque distribution device may be configured such that the torque on one wheel increases to the same extent as the torque on the other wheel is to be reduced, with two different factors implementing the measure, as stated above. The operation can therefore also be alternately.

The piezo actuator requires a relatively high voltage. The electrical system of the motor vehicle usually provides the voltage is not available. Incidentally, a high DC voltage is considered hazardous. For this reason, it is proposed to provide an electronic voltage transformer. As a voltage transformer, a boost converter can be arranged immediately before the piezoelectric actuator. The piezoactuator can be realized together with the built-up of electronic components, in particular coil-free voltage transformer as a closed component. The electric Berührgefährdung a motor vehicle driver or motor vehicle mechanic during repair is excluded.

Dual-clutch transmissions also functionally fall back on two different coupling strands, one of which is intended to open one coupling strand to the extent that the second coupling strand should transmit the torque with the connected transmission shaft. Also dual-clutch transmissions can be advantageously controlled and operated by the actuator according to the invention.

Through a continuous adjustment of the drive voltage of the actuator according to the invention can perform a continuous control of the clutches. The couplings can be opened and closed as desired within a very short time. It must be pumped no unnecessary volumes of hydraulic fluid in the vehicle.

The present invention may be better understood by reference to the accompanying figures, wherein

1 in a schematic representation shows a yaw damping gear,

2 an approach shows how existing systems can be conveniently equipped with hydraulic cylinders,

3 shows a first part of an embodiment according to the invention,

4 an embodiment of the invention shows

5 a second embodiment of the invention shows

6 a development of an embodiment of the invention shows and

7 a development of an embodiment of the invention shows.

Similar items have been designated by the same reference numerals for ease of understanding, although slight variations are apparent between embodiments.

1 shows a torque transmission device 100 , The torque transmission device 100 can be used as yaw damping gear on at least one axle of a motor vehicle. The torque transmission device 100 is shown schematically. From an input shaft 106 The torque is applied to two half-waves as the first output shaft 108 and as a second output shaft 110 work, transfer. The output shafts 108 . 110 may be partially, so in sections, intermeshing, parallel waves. The input shaft 106 opens into an input shaft bevel gear 118 , The input shaft bevel gear 118 drives an input driven gear 120 at. The input driven wheel 120 encloses a differential gear 104 , The differential gear 104 is seitlings through a first camp 122 and a second camp 124 supported. Camps 122 and 124 carry the two half-waves, which are the output shafts 108 . 110 represent. The output shafts 108 . 110 open into a first disc-like flange 128 and a second disc-like flange 130 on which the road wheels are screwed. The input driven wheel 120 directs the rotational movement on a transmission gear 102 further. The transmission gearbox 102 translated into the fast. The slower rotation of the input shaft 106 is via a gear ratio of the transmission gear 102 accelerated. Kraftflußmäßig behind the transmission gear 102 follows a two clutches 112 . 114 comprehensive coupling device attached to a third bearing 126 is stored. The couplings 112 . 114 are to be closed differently depending on the torque distribution. The actuator according to the invention is used for this purpose 1 , for example, in parts 3 is shown. The couplings 112 . 114 in the transmission 1 are to be actively influenced by a control unit.

A way of influencing the clutches 112 . 114 is in 2 shown. The embodiment according to 2 relies on a classic hydraulic pusher box, which is a hydraulic circuit 132 represents. The hydraulic circuit 132 is via a pump 136 that have a motor 134 powered, supplied. A filter 138 For example, it may retain abrasion in the hydraulic oil, which may be engine oil, for example. By the hydraulic circuit 132 the hydraulic flows are split, so that hydraulic fluid 41 both on a first printing plate 35 as well as on a second printing plate 37 for exerting pressure on a clutch 112 respectively. 114 arrives. The printing plates 35 . 37 press the clutches 112 . 114 against pressure springs 142 , As typical couplings 112 . 114 can be multi-plate clutches with fins 140 be used. By the hydraulic circuit 132 it is determined on which pressure plate which pressure should be applied. Thus there are two hydraulic pistons 31 . 33 , The hydraulic pistons 31 . 33 are in hydraulic cylinder bearings 43 stored. The pump 136 must be able to promote such a sufficient amount of hydraulic that within a very short time - with couplings switching times of less than 150 ms required - the respective clutch 112 . 114 can open and close completely.

A part of an embodiment of an actuator according to the invention 1 can in 3 to be considered in a schematic representation. The piezo element 3 consists of several piezo cells 5 together. In fact, several hundred piezo cells can be combined to form a piezo stack. For manufacturing reasons, piezoelectric cells are requested by manufacturing specialists 5 in low double-digit number next to each other brought together. By electrical voltage undergoes the piezoelectric element 3 an elongation in the direction of elongation 9 , The direction of elongation 9 creates a pressure on a first, covered by a plate hydraulic surface 19 that have a first diameter 23 Has. The cylindrical surface converter 17 , wherein indicated by the dots only the two ends are shown, with the two hydraulic surfaces 19 . 21 is with a hydraulic fluid 41 filled. The cylindrical surface converter 17 represents a closed, with hydraulic means 41 filled space. The hydraulic translator 15 works with two different diameters 23 . 25 , The second diameter 25 is smaller than the first diameter 23 , For longitudinal alignment is in front of the first pressure plate 35 a hydraulic cylinder bearing 43 provided so that the first pressure plate 35 has only one degree of freedom in one direction. In the illustrated embodiment, the direction of movement coincides with the direction of elongation 9 together. By the movement of the pressure plate 35 in the direction of elongation 9 becomes the necessary clutch travel 13 kilometer. Alternatively, of course, at the same time also a change in direction between the direction of elongation 9 and the clutch path 13 realize by a hydraulic deflection. The slats 140 can be supported against the bearing of the pressure spring 142 be brought closer together. The electro-hydraulic actuator can be made very compact due to the few components. The as a pressure piston 29 designed hydraulic piston 31 creates a responsive, the necessary clutch travel during the entire operating life guaranteed actuator with very short space-length extension, which has few moving components.

4 shows a particularly suitable actuator 1' , via an electronic control device 116 can be operated. A DC high voltage generator 148 can be executed multiple times both in the control device 116 be placed, as well as immediately before the piezoelectric element 3 (not shown). The actuator 1' consists of two hydraulic pistons 31 . 33 together, to each other due to the electronic control of the drive device 116 can interact. Between the drive device 116 and the piezo elements 3 are electrical cables 150 intended. The drive device 116 controls the piezo elements 3 due to information coming from control statements 146 can come from other control devices or on sensor data 144 based. Such sensor data are pressure, speed or temperature sensors. Other sensors may be tilt angle sensors. Each piezo element 3 of the actuator 1' may be due to over the cable 150 applied electrical voltage summed elongation direction 9 the individual piezo cells 5 Experienced. Every piezo cell 5 leads to an elongation 7 out, which adds to the overall longitudinal direction. The elongation 7 the piezo elements 3 affects the hydraulic piston 31 . 33 on the printing plates 35 . 37 out. Here are the hydraulic pistons 31 . 33 like stepped translators 27 built up. The movement of the printing plates 35 . 37 serves to engage and disengage the clutch 112 . 114 , Because of the bearings 43 learns the respective hydraulic piston 31 . 33 only one movement in the axial direction 11 , The axial direction 11 acts the spring direction of the return spring 142 opposite. As previously shown are exemplary multi-plate clutches 140 has been chosen.

The in 5 illustrated actuator 1'' also consists of two hydraulic pistons 31 . 33 together, with the same input-side pressure plate between piezo element 3 and hydraulic means 41 for both printing plates 35 . 37 is provided. By means of hydraulic circuit 132 passing through a control unit 116 via electrical cables 150 is controllable, the pressure of the piezoelectric element 3 made up of numerous piezo cells 5 composed, on the first printing plate 35 the first clutch 112 and the second pressure plate 37 the second clutch 114 divided up. Every printing plate 35 . 37 is in a warehouse 43 guided. The control unit 116 collects its information from other ECUs via control data and control statements 146 or via sensor data 144 , The hydraulic circuit 132 can be constructed with different valves. Thus, a hydraulic priority circuit or negative feedback blocking circuit can be realized. The fluids in the piping is a hydraulic fluid 41 , The path extension for generating the necessary clutch travel via the ratio of at least two hydraulic surfaces 19 and 21 per actuation direction.

In 6 is an actuator 1''' shown, which is the elongation in the longitudinal direction 9 of the piezoelectric element 3 not just for applying pressure to the lamellae 140 the clutch 112 against the spring 142 used, but also, for example, via a pushrod 45 , the hydraulic fluid lost via leakage hydraulic fluid 140 Pumping over two check valves 39 refills. The individual piezo cells 5 of the piezoelectric element 3 both exert pressure on the plunger 29 as well as a pressure on the working as a pressure transducer pressure rod 45 out. The pressure of the pressure rod serves to convey the hydraulic fluid 41 against the two check valves. Between the pressure piston 29 and the printing plate 35 The one-level forms over a step 27 realized first hydraulic piston 31 out.

The leakage of hydraulic fluid 41 that is between the first pressure plate 35 and the plunger 29 is clamped in a closed space can, as in 7 represented by the promotion of the pump 136 by a motor 134 powered, be refilled in an alternative way. The printing plate 35 and the plunger 29 are ideally provided with seals to reduce leakage. The coupling 112 gets over the pressure plate 35 opened and closed. Again, the piezoelectric element sits down 3 from numerous piezo cells 5 together. clutch travel 13 , Degree of freedom, in the camp 43 stored pressure plate 35 , and main movement direction of the piezoelectric cell 5 are rectified. Of course, they can also be redirected in their orientation direction.

The translation, which is done hydraulically by a cylinder-like surface converter, may have a transmission ratio of 1:10. With such a gear ratio, a surface area ratio of about 3.14: 1 should be selected on both sides of the hydraulic chamber due to the cylindrical surfaces.

Despite the reduction of the hydraulic fluid to be used of the hydraulic fluid 41 it becomes apparent that with the piezo elements 3 constructed actuators 1 . 1' . 1'' . 1''' . 1'''' no longer rely on circulating significant amounts of hydraulic. The pump is relieved. Ideally, no pump is needed for the piezohydraulic actuators. Even the leakage can be compensated hydraulically via the piezo elements. The transmissions, such as yaw damping or dual clutch transmissions, exhibit a much higher response speed than known, initially presented, transmission implementations.

Although only four embodiments have been disclosed, it will be understood by those skilled in the art that these embodiments are in principle to disclose the spirit of the invention, which is not deviated from, even if more or less piezo elements are installed in an actuator. According to an interesting aspect, the elongation is amplified in the same direction without any translational conversion. According to an alternative aspect, the elongation is reoriented by the hydraulic next to the reinforcement simultaneously in the absolute direction. In another aspect, hydraulically sealed systems are used. Instead of liquids, such as fuels, particularly suitable hydraulic oils can be used. According to another aspect, several clutches can be infinitely adjusted to one another as desired.

LIST OF REFERENCE NUMBERS

1, 1 ', 1' ', 1' '', 1 '' ''

Actuator, in particular as a piezo actuator

3

piezo element

5

piezo cell

7

elongation

9

elongation direction

11

Axial direction

13

clutch travel

15

Hydraulic translation

17

Cylindrical surface converter

19

First hydraulic surface, especially larger hydraulic surface

21

Second hydraulic surface, especially smaller hydraulic surface

23

First diameter, in particular smaller diameter

25

Second diameter, in particular larger diameter

27

Level of translation

29

Pressure piston, in particular first pressure piston

31

First hydraulic piston

33

Second hydraulic piston

35

First printing plate

37

Second printing plate

39

check valve

41

Hydraulic means, in particular hydraulic oil

43

Hydraulic cylinder bearings

45

Pressure transmitter, such as pressure rod

100

Torque transfer device

102

up gear

104

differential gear

106

input shaft

108

First output shaft

110

Second output shaft

112

First clutch

114

Second clutch

116

Control device, in particular electronic control unit

118

Eingangswellenstirnrad

120

Eingangsabtriebsrad

122

First camp

124

Second camp

126

Third camp

128

First flange

130

Second flange

132

hydraulic circuit

134

engine

136

pump

138

filter

140

slats

142

pressure spring

144

sensor data

146

control statements

148

DC high voltage generator

150

Ansteuerkabel

Claims (13)

Motor vehicle-compatible actuator ( 1 . 1' . 1'' . 1''' . 1'''' ), which is equipped with a piezo element ( 3 ) which is to be used as a piezo voltage path converter, wherein the actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) a surface converter ( 17 ) with an immediate hydraulic ratio ( 15 ) for receiving the voltage-dependent path lengthening ( 7 ) of the piezo element ( 3 ), characterized in that an amplification of the path lengthening ( 7 ) through the area converter ( 17 ) to a usual coupling path ( 13 ) is feasible, wherein in the actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) on pistons ( 31 . 33 ) hydraulic pressure is exercisable, with which two clutches ( 112 . 114 ) are controllable in a vehicle. Actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) according to claim 1, characterized in that the hydraulic transmission ( 15 ) in the area converter ( 17 ) is feasible, the a hydraulically sealed, in particular cylinder-like area converter ( 17 ), whereby the translation ( 15 ) of a larger, in particular to the piezo element ( 3 ) adjacent, hydraulic surface ( 19 ) on a smaller, in particular to a pressure piston ( 29 ) adjacent, hydraulic surface ( 21 ), wherein preferably the piezo element ( 3 ) direct pressure, in particular in the form of a rigid composite, on the hydraulic surface ( 19 . 21 ) and the hydraulic transmission ( 15 ) a one-step translation ( 27 ). Actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) according to one of the preceding claims, characterized in that the piezo element ( 3 ) is a multilayer element which consists of individual piezo cells ( 5 ) in flat, in particular in the direction of elongation ( 9 ) stacked flat arrangement, which via a check valve ( 39 ), in particular simultaneously to the pressure build-up of the actuator ( 1''' ), Leaks of a hydraulic fluid ( 41 ), preferably a hydraulic oil, in the hydraulic booster ( 15 ) can be refilled. Actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) according to one of the preceding claims, characterized in that the pressure on the mutually opposing pistons ( 31 . 33 ) can be applied in such a way that as much as a first pressure on the first piston ( 31 ), a pressure on the second piston ( 33 ) is degraded. Actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) according to one of the preceding claims, characterized in that the hydraulic transmission ( 15 ) the voltage-dependent path lengthening ( 7 ) of the piezo element ( 3 ) in the axial direction ( 11 ) of elongation ( 7 ) of the piezo element ( 5 ), in particular the couplings ( 112 . 114 ), which are of a lamella type ( 140 ), for adjustable torque transmission in a drive train ( 100 ) serve. Actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) according to one of the preceding claims, characterized in that on the basis of the hydraulic pressure in the hydraulic booster ( 15 ), preferably by measuring the pressure in the section with a smaller diameter ( 23 ) of two diameters ( 23 . 25 ), the pressure on the piston ( 31 . 33 ) is determined. Mechanical-hydraulic device ( 100 ) of a motor vehicle output train, which determines the torque distribution of a torque of at least one input shaft ( 106 ) on at least two output shafts ( 108 . 110 ), which open in road wheels, depending on a steering angle by means of a transmission system ( 112 . 114 . 102 . 104 ) can influence so that the output shaft ( 108 respectively. 110 ) of the longer Radienweg reclining road wheel with a different, in particular larger, torque is provided as the output shaft ( 110 respectively. 108 ) of the road wheel laying the shorter radius path, in particular with a comparatively smaller torque, the device ( 100 ) as a differential gear ( 104 ) working gear ( 102 ), characterized in that the influencing of the transmission system ( 112 . 114 . 102 . 104 ) an output shaft near torque transmission by a piezo actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) according to one of the preceding claims 1 to 6 is feasible. Apparatus according to claim 7, characterized in that the transmission system a multi-plate clutch ( 112 . 114 ) with at least two clutch discs ( 140 ). Device according to claim 7, characterized in that the transmission system ( 112 . 114 . 102 . 104 ) comprises a planetary gear with a power flow direction from the outer planetary gear, such as a sun gear, to internal planetary gears. Device according to one of the preceding claims 7 to 9, characterized in that the torque arising from the device ( 100 ) to the road wheel of a longer radius path is increasing as the torque decreases, which is to be delivered from the device to the road wheel of the shorter radius path, decreases. Device according to one of the preceding claims 7 to 10, characterized in that the piezo actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) is a piezohydraulic actuator, which is its triggering for influencing by an electrical pulse ( 150 ), in particular an electrical voltage, on the piezoelectric element ( 3 ) while a stroke path ( 7 ) of the piezoactuator ( 1 . 1' . 1'' . 1''' . 1'''' ) by a hydraulic pressure-way converter ( 15 ) is amplified, wherein the voltage from an electronic voltage transformer ( 148 ) in the form of high-voltage direct voltage. Mechanical-hydraulic device of a motor vehicle drive train ( 100 ), which determines the torque distribution of a torque of at least one input shaft ( 106 ) on at least two output shafts ( 108 . 110 ), which alternately via a gear transmission ( 102 ), which performs a speed ratio, and by means of one of the respective output shafts ( 108 . 110 ) associated clutch ( 112 . 114 ) on the input shaft ( 106 ) are switchable, with an actuator ( 1 . 1' . 1'' . 1''' . 1'''' ), characterized in that the actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) a piezohydraulic actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) with several piezo elements ( 3 ), which is designed according to one of claims 1 to 6, in which at least one of the pressure plates ( 35 . 37 ) is moved. Mechanical-hydraulic device ( 100 ) of a motor vehicle output train, which determines the torque distribution of a torque of at least one input shaft ( 106 ) on at least two output shafts ( 108 . 110 ), which alternately via a gear transmission ( 102 ), which performs a speed ratio, and by means of one of the respective output shafts ( 108 . 110 ) associated clutch ( 112 . 114 ) on the input shaft ( 106 ) are switchable, with an actuator ( 1 . 1' . 1'' . 1''' . 1'''' ), characterized in that the actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) a piezohydraulic actuator ( 1 . 1' . 1'' . 1''' . 1'''' ) with several piezo elements ( 5 ), which is designed according to one of claims 1 to 6, wherein a pressure plate ( 35 ) moves to the extent in an open position, such as a second pressure plate ( 37 ) moves into a closed position.

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