EP3536976B1 - Actuator with accumulator - Google Patents

Description

The invention relates to a memory actuator and a method for operating a memory actuator.

In general, an actuator is understood to be a device or a device that converts electrical signals into mechanical movement or another physical quantity and can thus perform work. A wide variety of actuator concepts are known, such as hydraulic or pneumatic actuators. There are also so-called solid-state actuators and polymer actuators. One form of a solid-state actuator is the piezo actuator, in which a directional deformation of a piezoelectric material (piezo for short) is used to perform work. If a piezo actuator is combined with a hydraulic system, a so-called piezo hydraulic actuator is obtained. All actuator concepts have in common that when the actuator moves mechanically, it does work. The, in particular mechanical, power provided by the actuator depends essentially on the product of force and speed. This product results in a code number of the actuator that characterizes the respective actuator. If more power is required in an application than the actuator can provide, a larger variant of the actuator is usually used, for example. In the case of piezo actuators, for example, this can be a version with a larger volume, for example the drive. However, simply enlarging the actuator can lead to high costs. In addition, the space required for the corresponding actuator increases, which is undesirable or not feasible in some applications, for example in special medical applications. As an alternative to larger actuator versions, there is also the option of using actuators that have a different actuator concept. However, this is often not possible because of the desired efficiencies and thus Services cannot be realized using an alternative actuator concept either.

The U.S. 6,070,408 A discloses a hydraulic device with hydraulic supply means and an accumulator with a pressure piston and means for sensing the accumulator piston position to indicate a load request to a control means to selectively actuate the hydraulic supply device to meet the hydraulic load request and provide a relative pressure pulse-free operation by actuating the hydraulic supply device in response to the position and movement of the accumulator piston.

The EP 3 045 737 A1 discloses a hydraulic loading and propulsion system, an aircraft using the same, and corresponding methods for extending and retracting a hydraulic actuator. Furthermore, from the
DE 10 2017 205 404 A1 a hydraulic control device is known.

The object of the present invention is therefore to create a storage actuator and a method for operating such a storage actuator, the output device of which can be operated with a particularly high output.

This object is achieved by a memory actuator with the features of claim 1. Furthermore, this object is achieved by a method having the features of patent claim 12. Advantageous refinements with expedient developments of the invention are specified in the remaining claims.

A first aspect of the invention relates to a storage actuator for actuating an output device, with the output device, with at least one energy store and with a drive device. By means of the drive device, energy is in the energy store in at least one first operating state of the storage actuator storable. The storage actuator has at least one second operating state, in which at least part of the energy stored in the energy storage can be provided by the energy storage, whereby the output device can be supplied with the provided energy and can thereby be actuated. The first operating state can be referred to as the memory state. The second operating state can be referred to as the actuating state. The storage actuator according to the invention has the advantage that, due to the at least two operating states and the associated storage of the energy in the first operating state and the subsequent release of the energy in the second operating state, the output device can be operated with a particularly high output. The output device is preferably a mechanical output device.

At least one reservoir is provided for providing a hydraulic fluid. In the first operating state, the hydraulic fluid can be conveyed into the energy store by means of the drive device, whereby the energy can be stored in the energy store, with the energy store in the second operating state at least part of the hydraulic fluid stored in the energy store and thereby at least part of the hydraulic fluid stored in the energy store Provides energy, whereby the output device can be actuated by means of the hydraulic fluid provided. This means that, for example, at least one, for example mechanical, component of the energy store is moved by kinetic energy of the hydraulic fluid, i.e. by its kinetic energy, and absorbs or stores energy when the hydraulic fluid is introduced into the energy store. For example, the components can be a weight that is lifted into a storage position, the kinetic energy being converted into positional energy, that is to say potential energy. Alternatively or in addition, the component can have at least one, in particular elastic, deformable element and / or one compressible Include fluid, wherein the element is deformed and / or the fluid is compressed, the hydraulic fluid is introduced into the energy store. As a result, the component stores energy which is transmitted by means of the hydraulic fluid. As a result, energy is stored by means of the energy store. As long as the component remains in the storage position, the energy store can store the energy. For example, the energy can also be converted into pressure and / or deformation energy instead of into position energy, for example by deforming and / or compressing the component. During relaxation, in which the component changes to its original state, which the component assumed before deforming or compressing, the stored energy can be released again, in particular back into or to the hydraulic fluid. It can thus be said that energy, in particular in the form of pressure energy, can be stored in the hydraulic fluid, so that energy can be stored in the energy store by means of the hydraulic fluid. The energy store can be filled with energy particularly easily by means of the hydraulic fluid, so that the output device can be operated particularly advantageously with a particularly high output.

Furthermore, the storage actuator according to the invention comprises at least the drive device having a drive actuator for conveying the hydraulic fluid. Furthermore, the storage actuator comprises the energy store for storing hydraulic fluid or energy that can be transmitted by the hydraulic fluid. Furthermore, the, in particular hydraulic, accumulator actuator comprises a chamber with a piston element arranged movably in the chamber, which divides the chamber into a first chamber area, in which the hydraulic fluid can be conveyed by means of the drive device, and a second chamber area. The piston element can be moved from a first position into a second position by means of or by conveying the hydraulic fluid into the first chamber region. In the second position the piston element releases a first through-flow opening and blocks a second through-flow opening, so that the hydraulic fluid conveyed into the first chamber area can be introduced into the energy store from the first chamber area via the first through-flow opening. Furthermore, the storage actuator according to the invention comprises at least one resetting device, by means of which the piston element can be moved from the second position into the first position, in which the piston element releases the second flow opening and blocks the first flow opening, so that at least part of the hydraulic fluid introduced into the energy storage device is released from the Energy store can be introduced into the second chamber region via the second through-flow opening. Furthermore, the storage actuator has an output device which can be supplied and thereby driven with at least part of the hydraulic fluid introduced into the second chamber area. The first position in which the piston element can be located can also be referred to as the actuation position and characterizes an actuation phase or the actuation state of the entire storage actuator. The second position can also be referred to as the storage position, in which the storage actuator, in particular its drive device comprising the drive actuator, provides mechanical energy by means of which the hydraulic fluid is supplied to the energy store, so that energy is stored in the energy store by means of the hydraulic fluid. If the piston element is in the storage position, the actuator, in particular the piston element, is in the storage state or the first operating state.

A particularly large mechanical output can be provided by the storage actuator. In particular, the piston element according to the invention, which divides the chamber into a first chamber area and a second chamber area, makes it possible to store a particularly large, predeterminable amount of energy and a corresponding amount in the form of power through the first position and second position that it can occupy on the output device of the storage actuator to provide or to deliver. The storage actuator works in two phases, or it has at least the two mentioned operating states: the storage state, during which the piston element is in the second position or storage position, and the actuation state, during which the piston element is in the first position or actuation position . The storage actuator according to the invention is particularly suitable for applications in which a trigger time of the storage actuator plays a secondary role, but in which a particularly high output with as constant a force and speed as possible over the entire actuation phase is desired on the output device. The period during which the actuation takes place, that is to say the duration of the actuation phase, is the actuation time, that is to say the time during which a position or movement takes place on the output device. The trigger time is the time that elapses from the first actuation of the drive actuator or its switching on until the actuation begins. The start of the actuation is the start of a movement on the output device.

In the second position of the piston element or in the storage state, the in particular mechanical energy provided by the drive device or the at least one drive actuator, for example in the form of hydraulic energy, is stored in the in particular hydraulic energy store. For this purpose, the hydraulic fluid is conveyed or moved into the first chamber area of the chamber by means of the drive actuator.

If the piston element is initially in the first position and the hydraulic fluid is conveyed to or into the first chamber area by means of the drive actuator, the piston element is thereby moved from the first position into the second position. The piston element provides the first through-flow opening, which extends from the first chamber area at least indirectly to that for storage the hydraulic fluid formed energy storage leads freely. As a result, the hydraulic fluid can flow from the first chamber area into the energy store. By releasing the first through-flow opening, the hydraulic fluid or the energy contained in the hydraulic fluid can thus be stored in the energy store, in particular by introducing the hydraulic fluid into the energy store. The energy contained in the hydraulic fluid is generated, in particular, by applying a pressure to the hydraulic fluid, by means of which, in particular, mechanical work, in particular on the output device, can be brought about or performed.

If the hydraulic fluid is now not conveyed or the hydraulic fluid is not introduced into the first chamber area by the drive device, i.e. if the hydraulic fluid conveyed into the first chamber area by means of the drive device is ended, the piston element can move from the second position to the first position can be moved. In the second position, the second through-flow opening is released and the first through-flow opening is blocked. By blocking the first through-flow opening, no hydraulic fluid can flow or flow back from the energy store into the first chamber area. The hydraulic fluid can now flow from the energy store into the second chamber region through the released second through-flow opening, or the hydraulic fluid can be introduced or conveyed into it. During the actuation state, the hydraulic fluid introduced or conveyed into the second chamber area via the second through-flow opening or a part of this hydraulic fluid can be conveyed or conveyed further into the output device. In other words, the output device can be supplied with at least part of the hydraulic fluid and can be driven by it, so that the storage actuator on the output device and thus can perform mechanical work on its output. As already mentioned above, the storage actuator is particularly suitable for applications in which the tripping time plays a secondary role. Therefore, the storage phase or the storage state is not time-critical, whereby it can be guaranteed to a particularly large extent that the energy store can be filled with sufficient energy to provide the required power for the actuation state or the actuation itself. As a result, the storage actuator according to the invention can provide a particularly large power or a comparatively small drive actuator can experience a particularly large increase in power, which in alternative actuator concepts would be associated with particularly high costs and / or can lead to a particularly large amount of installation space. Furthermore, the memory actuator according to the invention can be designed such that it has a particularly high force density, which can represent a boundary condition for operating the memory actuator. The required power density cannot be provided by alternative actuator concepts either. For example, with a piezo-hydraulic actuator without a storage component, a variation of the force range and, at the same time, the speed range is possible so that, for example, a size of the stroke available at the output or an output device is also changed, with the output of a piezo actuator always only from the piezo or Piezo actuator itself depends. The force density can be selected particularly advantageously through the energy store of the storage actuator according to the invention. The force density can be understood as the ratio of the volume of the output device that can be filled with hydraulic fluid in relation to the entire volume of the storage actuator, that is, a total of all components that can be filled with hydraulic fluid, such as the chamber and the energy store.

In the storage actuator according to the invention, the storage unit of the actuator, the energy store, is implemented or designed in such a way that the power stored in it in the form of energy, in particular due to the storage position of the piston element, is not released during the storage of the energy provided by the drive device.

If, for example, the energy store is sufficiently filled with hydraulic fluid, so that, for example, a predeterminable or desired and thus sufficient amount of energy is stored in the energy store, which is sufficient, for example, to actuate the output device, then, for example, the delivery of the hydraulic fluid to the or ended in the first chamber area. In particular directly afterwards, the piston element releases, in particular automatically, the energy stored in the energy store, in particular in that the piston element is moved from the second position into the first position by means of the resetting device. The energy is thus released passively, that is to say without further action, for example by a user and / or the drive device of the storage actuator.

The storage actuator according to the invention can deliver particularly constant output parameters, in particular in terms of force and / or speed, during the actuation phase, in particular when a certain amount of energy is already contained in the energy storage device before the storage state preceding the actuation phase. That is, the storage actuator is filled with hydraulic fluid or with a corresponding amount of hydraulic fluid, so that during the storage process only enough volume of the hydraulic fluid has to be pumped into the energy store to ensure a required stroke ΔS of the output or the output device. The amount of hydraulic fluid required or the volume of hydraulic fluid required ΔV depends on the Product of ΔS and an output cross section A of the output device.

By combining the drive device with the energy store of the storage actuator according to the invention, the energy can advantageously be stored and only released when a sufficient amount is available. Another advantage is that the energy is released automatically and without a separate triggering unit, ie in a passive manner. By using the energy store, the actual drive actuator can provide little actual power to the drive device, which means that costs can be kept particularly low. In addition, installation space can be saved by the storage actuator according to the invention. Furthermore, a particularly high, realizable energy density can be generated with the storage actuator and this can be integrated particularly advantageously in possible application scenarios. Overall, the storage actuator can be designed to be able to provide a particularly high mechanical power.

In an advantageous embodiment of the invention, the drive actuator is designed as a solid-state actuator, in particular as a piezo actuator, and / or a polymer actuator. In other words, the actuator concept of the drive device can be selected from a large number of actuator concepts. Solid body and polymer actuators often have in common that they have a travel path or travel path which is particularly short, which means that certain applications cannot be implemented with these actuator concepts. In the case of a piezocator, for example, the travel range is limited by the maximum deformability of the piezo. A piezo actuator can, for example, provide a particularly high force density for this purpose. The storage actuator according to the invention can advantageously enlarge an application range of, for example, solid-state actuators, such as the piezo actuator. In addition, a combination of force density and power can be designed particularly advantageously. The memory actuator according to the invention can thus in particular be designed as a piezo-hydraulic storage actuator.

In an advantageous embodiment of the invention, the storage actuator has a check valve which is arranged in the first throughflow opening and which blocks in the direction of the first chamber region. As a result, a flow or backflow of the hydraulic fluid from the energy store back into the first chamber area is kept as low as possible or prevented, whereby, for example, a particularly efficient storage of the energy or the hydraulic fluid or the energy contained in the hydraulic fluid can be carried out. In addition, especially when changing from the first position to the second position of the piston element or vice versa, backflow is kept particularly small or avoided, as a result of which a particularly high efficiency of the storage actuator can be achieved.

In an advantageous embodiment of the invention, the drive device has a drive chamber that can be supplied with the hydraulic fluid and a drive piston element that partially delimits the drive chamber and that can be driven by the drive actuator, by means of which the hydraulic fluid from the drive chamber into the first chamber area and via the first chamber area and the first flow opening is to be promoted in the energy store. In other words, if the drive piston element is driven by means of the drive actuator and thereby moved, at least part of the hydraulic fluid initially received in the drive chamber is conveyed out of the drive chamber by means of the drive piston element. In short, the drive device has a hydraulic cylinder which is at least partially formed by the drive chamber and the drive piston element and which functions as a so-called working cylinder. The energy from the hydraulic fluid is converted into an effective force that is particularly easy to control or handle implemented, by means of which the energy store can be particularly advantageously filled with energy or hydraulic fluid. In this way, for example, a particularly simple and therefore low-maintenance drive device can be implemented.

In a further advantageous embodiment of the invention, the drive piston element executes strokes caused by the drive actuator to convey the hydraulic fluid at a frequency of less than 10,000 Hertz, in particular less than 1000 Hertz. This low frequency for a drive actuator, in particular designed as a piezo actuator, enables, for example, particularly energy-efficient and low-wear operation of the piezo actuator and thus of the entire, in particular piezo-hydraulic, storage actuator.

In an advantageous embodiment of the invention, the output device has an output chamber into which the hydraulic fluid can be introduced, and an output piston element which partially delimits the output chamber and which has an output surface that can be acted upon by the hydraulic fluid introduced into the output chamber. The output piston element can be driven by subjecting the output surface of the output piston element to the hydraulic fluid introduced into the output chamber. In other words, the output piston element and the output chamber at least partially form a hydraulic cylinder which particularly advantageously converts or uses the hydraulic fluid stored in the energy store to operate the actuator, whereby, for example, a desired output speed and / or a desired output force are provided by the storage actuator in a particularly advantageous manner can. In other words, the output piston element has a hydraulically effective output surface which can be acted upon by the hydraulic fluid introduced into the output chamber. As a result of this loading of the output surface with the hydraulic fluid introduced into the output chamber, during the actuation state the driven piston element can be driven and thus moved, in particular in a translatory manner. Due to the described design of the output device, for example, a particularly large amount of power can be made available at the output or the output piston element.

In an advantageous embodiment of the invention, the restoring device has at least one spring which is tensioned more strongly in the second position than in the first position and thereby provides a spring force or restoring force at least in the second position, by means of which the piston element moves from the second position, the storage position , is movable into the first position, the actuating position. In this case, during the storage position or the storage state, the piston element is acted upon with hydraulic fluid in the first chamber part in such a way that the spring is tensioned in such a way, especially when the storage position is reached, that a restoring force prevails in the spring, which is particularly passive, i.e. without further control or regulation, at the end of the storage, the piston element is moved into the actuating position, so that the second throughflow opening is opened, through which the hydraulic fluid can flow into the output device via the second chamber region. By using a spring as at least a part of the resetting device, a particularly simple and thus low-maintenance and low-cost design of the resetting device can be implemented, as a result of which the storage actuator can be or can be operated particularly inexpensively.

In an advantageous embodiment of the invention, the energy store is designed as a bellows pressure accumulator which has at least one storage chamber and at least one bellows arranged in the storage chamber, which can be elastically compressed by introducing the hydraulic fluid into the storage chamber. By introducing hydraulic fluid into the energy store by means of the drive device, the bellows is compressed, in particular elastically, whereby energy can be stored in the memory. In the actuation state, in which no hydraulic fluid is conveyed in the energy store, the bellows compressed in the storage state relaxes so that the energy of the bellows is transferred to the hydraulic fluid in order to drive the output device. The energy store, which is thus designed as a so-called gas pressure store, can, for example, have an inner and an outer bellows, each of which is in particular at least partially formed from metal. Furthermore, the bellows can have a stop, in particular a mechanical stop, by means of which it is prevented that energy is already given off during the storage state. By using a bellows pressure accumulator as an energy store, the storage actuator according to the invention can be designed, for example, to be particularly compact and / or particularly inexpensive. Other types of hydraulic and / or gas pressure accumulators can additionally or alternatively be used as energy stores.

In an advantageous embodiment of the invention, a second check valve is provided, via which the hydraulic fluid can be introduced from the drive device into the first chamber area. A backflow of hydraulic fluid into the drive device can be prevented in a particularly advantageous manner by the second check valve, as a result of which the energy store can be charged particularly efficiently. Furthermore, when changing from the storage state to the actuating state, in particular by means of the resetting device, hydraulic fluid can additionally be introduced into the energy store instead of flowing back into the drive device.

In an advantageous embodiment of the invention, a third check valve is provided, via which the output device can be supplied with the hydraulic fluid from the second chamber area. Through the third check valve a backflow of the hydraulic fluid from the output device, in particular from the output chamber, into the second chamber area is prevented or kept particularly low, which means that the output device can be actuated particularly efficiently and, when changing from the actuation position to the storage position, for example, prevents or prevents the output piston element from moving back can be kept particularly low. By using the third check valve, a particularly advantageous operation can be implemented during the actuation state, since, for example, a drop in performance during actuation can be particularly small.

In an advantageous embodiment of the invention, the energy store can be at least predominantly, in particular completely, filled with the hydraulic fluid within a maximum of 10 seconds, in particular within a maximum of one second, during which the piston element is continuously in the second position or the storage position. That is, the energy store can be charged with the energy at least predominantly, in particular completely, during the storage state, in particular within a maximum of one second, in order to be able to operate the output device with the required power during the following actuation state. As already mentioned, a time interval that occurs between the switching on of the drive actuator for storing the energy and the actual switchover of the storage actuator to the actuation state can be understood as a so-called trigger time. This means that the trigger time of the memory actuator according to the invention is less than ten or one second and is therefore particularly short, which results in a particularly wide range of applications for using the memory actuator according to the invention.

A second aspect of the invention relates to a method for actuating an output device by means of a storage actuator, in which, in a first operating state of the storage actuator, at least one energy storage device is by means of a drive device of the storage actuator is supplied with energy, whereby the energy is stored in the energy store, wherein in a second operating state of the storage actuator the energy store provides at least part of the energy stored in the energy store, whereby the output device is supplied with the energy provided and thereby by means of the energy provided is operated.

The method according to the invention can advantageously be carried out in such a way that the stored energy is automatically released. As an alternative to this, the energy can be held available or stored, that is to say a storage state or the storage state can be locked until, for example, the energy is released manually. Furthermore, the energy can be stored up to a certain, in particular predeterminable, amount of energy. If this amount is reached, the output device can be driven automatically, for example.

The memory actuator according to the invention is operated by means of the method according to the invention or the method according to the invention is carried out on the memory actuator according to the invention. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa.

Further advantages, features and details of the invention emerge from the following description of at least one preferred exemplary embodiment and with reference to the drawings. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination, but also in other combinations or on their own, without the scope of Invention to leave.

FIG 1

eine schematische Schnittansicht eines erfindungsgemäßen Speicheraktors; und

FIG 2

eine weitere Ausführungsform des Speicheraktors, mit einem Balgdruckspeicher.

It shows:

FIG 1

a schematic sectional view of a memory actuator according to the invention; and

FIG 2

another embodiment of the memory actuator, with a bellows pressure accumulator.

FIG 1 shows, in a schematic sectional view, a storage actuator 10 which has an output device 32. The output device 32 represents an output of the storage actuator 10. The storage actuator 10 is designed to operate the output device 32 and comprises at least one energy store 18 and a drive device 14, by means of which energy can be stored in the energy store 18 in at least one first operating state of the storage actuator 10. The storage actuator 10 can have at least one second operating state in which at least part of the energy stored in the energy storage device 18 can be provided by the energy storage device 18, whereby the output device 32 can be supplied with the energy provided and can thereby be actuated.

The drive device 14 comprises a drive actuator 12. The drive actuator 12 is advantageously designed as a piezo actuator, for example, alternatively, it can be designed as a different solid-state actuator and / or as a polymer actuator. In principle, any actuator concepts are possible as drive actuator 12.

A hydraulic fluid can be conveyed by means of the drive actuator 12 and thus by means of the drive device 14. The storage actuator 10 further comprises a chamber 16 and the energy store 18. A piston element 20 is arranged in the chamber 16 such that it can be moved in translation and divides the chamber 16 into a first chamber area 22 and a second chamber area 24. Here is the hydraulic fluid can be conveyed into the first chamber region 22 by means of the drive device 14.

At least one reservoir 38, in particular in the form of a tank, is provided to provide the hydraulic fluid, which in the first operating state can be conveyed into the energy store 18 by means of the drive device 14, whereby the energy can be stored in the energy store 18. In the second operating state, the energy store 18 can provide at least part of the hydraulic fluid stored in the energy store 18 and thereby at least part of the energy stored in the energy store 18, whereby the output device 32 can be actuated by means of the provided hydraulic fluid.

By conveying the hydraulic fluid into the first chamber region 22, the piston element 20 can be moved from a first position, which is also referred to as the actuating position, into a second position, which is also referred to as the storage position. The piston element is in the storage position in the first operating state and in the actuating position during the second operating state. The first operating state is therefore referred to as the memory state and the second operating state as the actuating state. In the second position, the piston element 20 releases a first throughflow opening 26 of the accumulator actuator 10. In addition, the piston element 10 blocks a second throughflow opening 28 of the storage actuator 10 in the second position, so that in the second position the hydraulic fluid conveyed into the first chamber area 22 can be introduced or flows from the first chamber area 22 via the first throughflow opening 26 into the energy store 18.

Furthermore, the storage actuator 10 has at least one resetting device 30, by means of which the piston element 20 can be moved from the second position into the first position, in which the piston element 20 releases the second throughflow opening 28 and blocks the first throughflow opening 26, so that at least part of the hydraulic fluid introduced into the energy store 18 can be introduced from the energy store 18 via the second through-flow opening 28 into the second chamber region 24. In addition, the storage actuator 10 includes the output device 32, which can be supplied with at least part of the hydraulic fluid introduced into the second chamber region 24 and can thereby be driven.

On the outer circumference, the chamber 16 and a second chamber 34 of the storage actuator 10 connected to the chamber 16 in a fluidically conductive manner can be essentially cylindrical. The, in particular hydraulic, storage actuator 10 is, while the piston element 20 is in the storage position, in a first phase (storage phase) or the first operating state, which is also referred to as the storage state. In the storage state, the storage actuator 10, in particular its drive device 14, provides mechanical energy, which is stored in the energy store 18 by means of the hydraulic fluid. If the piston element 20 is in the actuation position, the storage actuator 10 is in a second phase (actuation phase) or the second operating state, which is also referred to as the actuation state. In the actuation state, the output device 32 is actuated by means of the energy stored in the energy store 18 and thereby moved, for example, whereby an actuation can be effected by means of the output device 32.

The storage actuator 10 can be operated in such a way that the storage state or the storage of energy is not time-critical, that is, sufficient energy can be stored to provide the power required or required in the actuation state for the complete actuation phase. As a result, the storage actuator 10 shown is of interest for applications in which, for example, an increase in the performance of an actuator would be associated with excessive costs and alternative actuator concepts compared to the Piezo actuator designed drive actuator 12, for example, can not achieve the desired force density.

In the storage state, the drive actuator 12 of the drive device 14 in the embodiment shown pumps the hydraulic fluid from the drive device 14 into the first chamber area 22 via a second check valve 36, so that the hydraulic fluid can be introduced into the first chamber area 22. In order to convey the hydraulic fluid, the drive device 14 in the exemplary embodiment shown has a drive chamber which can be supplied with the hydraulic fluid and a drive piston element which partially delimits the drive chamber and which can be driven by the drive actuator 12, by means of which the hydraulic fluid from the drive chamber into the first chamber area 24 by driving the drive piston element and is to be conveyed via the first chamber region 24 through the first flow opening 26 into the energy store 18. For the sake of clarity, the drive chamber and the drive piston element are shown in FIG FIG 1 Not shown. The hydraulic fluid can be provided, for example, by the tank designed as a reservoir 38, which is located in the blocking direction on the same side of the second check valve 36 as the drive device 14. A first check valve 40, which blocks in the direction of the first chamber region 24, is advantageously arranged in the first through-flow opening 26.

If the piston element 20 is now in the storage position, the hydraulic fluid is pumped or conveyed into the first chamber region 22 of the chamber 16 via the second check valve 36 and an opening 42 by means of the drive device 14. Due to the low compressibility of the hydraulic fluid, the piston element 20 is pressed against the restoring device 30, as a result of which the first throughflow opening 26 and thus the first check valve 40 are released. For this purpose, the restoring device 30 advantageously has at least one spring 44. The spring 44 is in the second position, i.e. in the storage position, tensed more than in the actuating position, as a result of which the spring 44 provides a spring force, at least in the storage position, by means of which the piston element 20 can be moved from the storage position into the actuation position. However, as long as the hydraulic fluid is conveyed by means of the output device 32, it flows via the first check valve 40 at least indirectly into the energy store 18, which is connected to the first chamber area 22 via the chamber 34 and a further opening 46 in a fluidically conductive manner during the storage state. The first check valve 40 prevents hydraulic fluid from flowing back from the second chamber 34 into the first chamber region 22. Due to the position of the piston element 20 in the storage position, the second throughflow opening 28 is blocked, in particular automatically, as a result of which no hydraulic fluid can flow out of the second chamber 34 and thus the energy storage device 18 into the second chamber region 24. If the hydraulic fluid is not conveyed by the drive device 14, the piston element 20 is moved translationally within the first chamber by the restoring force of the spring 44, so that the piston element 20 is shifted from the storage position into the actuating position, in particular translationally.

The piston element 20 is designed in such a way that leakage through the, in particular radial, gap between the piston element 20 and a wall of the chamber 16 is particularly small. That is to say, a fluidic exchange of the hydraulic fluid between the first chamber region 22 and the second chamber region 24 past the piston element 20 is particularly small, in particular negligible. The in FIG 1 The energy store 18 shown is designed, for example, as a pneumatic and / or hydraulic store, that is, the more fluid or hydraulic fluid the drive actuator 12 pumps via the second check valve 36, the more energy is stored in the energy store 18. Advantageously, the energy store 18 is already filled with sufficient hydraulic fluid or contains sufficient energy before the start of the storage state, so that only as much fluid volume ΔV has to be pumped into the energy store 18 or the second chamber 34 to ensure a required stroke ΔS of the output device 32 . In other words, the pressure within the components of the, in particular hydraulic, storage actuator 10 to be filled with hydraulic fluid, such as in particular the energy store 18, should reach or apply a certain initial pressure, which is, for example, above an ambient pressure in the vicinity of the storage actuator 10. As a result, constant output parameters for force and speed can be maintained during the actuation state in which the output device 32 performs the mechanical work, so that, for example, an output piston element 50 does not fall below a desired minimum speed towards the end of its translational movement. In the embodiment shown, the output device 32 has an output chamber 48 into which the hydraulic fluid can be introduced. Furthermore, the output device 32 has the output piston element 50 which partially delimits the output chamber 48 and which has an output surface 52 that can be acted upon by the hydraulic fluid introduced into the output chamber 48. By subjecting the output surface 52 to the hydraulic fluid introduced into the output chamber 48, the output piston element 50 can be driven.

The storage actuator 10 advantageously has a third check valve 54, via which the output device 32 can be supplied with the hydraulic fluid from the second chamber region 24. If the energy storage is ended, i.e. the drive actuator 12 stops conveying the hydraulic fluid via the check valve 36 into at least the first chamber region 22, the hydraulic fluid can then flow into the output device 32 after the piston element 20 has been reset by the reset device 30, whereby the output force and the output speed and thus the power, in particular at the output piston element 50, are provided. In this case, the, in particular translational, movement of the output piston element 50 takes place when the hydraulic fluid acts on the hydraulically effective output surface 52.

Advantageously, the drive piston element of the drive device 14, which executes the strokes caused by the drive actuator 12 to convey the hydraulic fluid, can be moved back and forth at a frequency of less than 1000 Hertz, whereby the drive actuator 12 and thus the entire drive device 14, for example, are particularly wear-resistant and thus can be operated with little maintenance.

The storage state and thus the storage of energy advantageously take less than a second. During this second, the piston element 20 is continuously in the second position, and the energy store 18 is at least predominantly, in particular completely, filled with the hydraulic fluid or can be filled with it during the period of time mentioned. The period mentioned is also referred to as the trigger time, so that the trigger time of the memory actuator 10 can be less than one second. The change between the storage state and the actuation state occurs passively, i.e. no action is required on the part of a user or a special device to actuate the storage actuator 10, in particular on its output piston element 50, in particular artificially, but the actuation phase starts alone by stopping the conveyance of the drive device 14, in particular its drive actuator 12, and by automatically resetting the piston element 20 by means of the resetting device 30, in particular by the resetting force of its spring 44.

FIG 2 shows a schematic sectional view of a further embodiment of the, in particular piezo-hydraulic, storage actuator 10, the second chamber 34 or the energy store 18 being designed as a bellows pressure accumulator which has at least one storage chamber, the second chamber 34, and at least one bellows 56 arranged in the storage chamber which is elastically compressible by introducing the hydraulic fluid into the storage chamber, the second chamber 34. The FIG 2 shows only one half of the chambers of the memory actuator 10, since for reasons of symmetry, in particular due to a cylindrical design of the chamber 16 or 34 of the embodiment, no further information in FIG FIG 2 could be won. Furthermore, the bellows pressure accumulator in FIG 2 an inner metal bellows 58 and an outer metal bellows 60, as a result of which, for example, a gas pressure accumulator or pressure accumulator which is particularly unsusceptible to malfunctions can be realized. In addition, the embodiment shows a mechanical stop 62 of the bellows 56. This stop 62 can ensure that a certain amount of energy in the hydraulic fluid can already be held, so that only the fluid volume ΔV in the chamber region 22 or in the chamber 16 and thus in the energy store 18 must be introduced, which is required to ensure the required stroke ΔS on the output piston 50, the required volume being calculated over the area A of the output area 52 and the length ΔS of the stroke. The mechanical stop 62 serves to prevent the already stored energy from being released during the storage state.

Furthermore, hydraulic fluid can be applied to the stop 62 in such a way that the bellows 56 can be compressed or is compressed by the application of the action. During the storage state in which the hydraulic fluid is transferred by means of the drive device 14, in particular from the reservoir 38 or tank, via the second check valve 36 and the opening 42 into the first chamber region 22 and further via the through-flow opening 26, respectively the first check valve 40 is introduced into the chamber 34 and thus into the energy store 18, it elastically deforms the bellows 56 there, whereby energy can be stored by means of the hydraulic fluid by compressing the bellows 56.

Through the shown, in particular piezo-hydraulic, storage actuator 10, in which the energy store 18 is combined with the drive device 14 and the output device 32 in such a way that the storage actuator 10 can be operated by means of two phases, the storage phase and the actuation phase, a lot of power can be generated which the drive actuator 12 itself cannot provide, which opens up a wide range of possibilities for using the memory actuator 10.

Claims (12)

1. A storage actuator (10) for actuating an output device (32), with the output device (32), with at least one energy storage (18), with a drive device (14) by means of which energy can be stored in the energy storage (18) in at least one first operating state of the storage actuator (10), wherein the storage actuator (10) has at least one second operating state in which at least a part of the energy stored in the energy storage (18) can be provided from the energy storage (18) whereby the output device (32) can be supplied with the provided energy and can thereby be actuated, wherein at least one reservoir (38) for providing a hydraulic fluid is provided which can be conveyed into the energy storage (18) by means of the drive device (14) in the first operating state, whereby the energy can be stored in the energy storage (18), and wherein the energy storage (18) provides at least a part of the hydraulic fluid stored in the energy storage (18) and thereby at least the part of the energy stored in the energy storage (18) in the second operating state, whereby the output device (32) can be actuated by means of the provided hydraulic fluid, wherein the storage actuator further comprises:

   - the drive device (14) including at least one drive actuator (12) for conveying the hydraulic fluid;

   - a chamber (16);

   - a piston element (20) movably arranged in the chamber (16), the piston element (20) dividing the chamber (16) into a first chamber area (22) into which the hydraulic fluid can be conveyed by means of the drive device (14), and a second chamber area (24), and the piston element (20) being, by conveying the hydraulic fluid into the first chamber area (22), movable from a first position into a second position in which the piston element (20) unblocks a first through-flow opening (26) and blocks a second through-flow opening (28) such that the hydraulic fluid conveyed into the first chamber area (22) can be introduced from the first chamber area (22) via the first through-flow opening (26) into the energy storage (18);

   - at least one return device (30) by means of which the piston element (20) is movable from the second position into the first position in which the piston element (20) unblocks the second through-flow opening (28) and blocks the first through-flow opening (26) such that at least a part of the hydraulic fluid introduced into the energy storage (18) can be introduced from the energy storage (18) via the second through-flow opening (28) into the second chamber area (24); and

   - the output device (32) which can be supplied with at least a part of the hydraulic fluid introduced into the second chamber area (24) thereby driving the output device (32).
2. The storage actuator (10) according to claim 1, wherein the drive actuator (12) is formed as a solid-state actuator, in particular as a piezo actuator, and/or polymer actuator.
3. The storage actuator (10) according to claim 1 or 2, wherein a first check valve (40), which blocks towards the first chamber area (22), is arranged in the first through-flow opening (26).
4. The storage actuator (10) according to claim 1 to 3, wherein the drive device (14) comprises a drive chamber capable of being supplied with the hydraulic fluid and a drive piston element partially bounding the drive chamber and drivable by the drive actuator (12), by means of which the hydraulic fluid can be conveyed from the drive chamber into the first chamber area (22) and via the first chamber area (22) and the first through-flow opening (26) into the energy storage (18) by driving the drive piston element.
5. The storage actuator (10) according to claim 4, wherein the drive piston element carries out strokes effected by the drive actuator (12) for conveying the hydraulic fluid with a frequency of less than 10000 Hertz, in particular smaller than 1000 Hertz.
6. The storage actuator (10) according to claim 1 to 5, wherein the output device (32) comprises an output chamber (48), into which the hydraulic fluid can be introduced, and an output piston element (50) partially bounding the output chamber (48), which comprises an output surface (52) capable of being applied with the hydraulic fluid introduced into the output chamber (48) and can be driven by applying the output surface (52) with the hydraulic fluid introduced into the output chamber (48).
7. The storage actuator (10) according to claim 1 to 6, wherein the return device (30) comprises at least one spring (44), which is more severely tensioned in the second position than in the first position and thereby provides a spring force at least in the second position, by means of which the piston element (20) is movable from the second position into the first position.
8. The storage actuator (10) according to claim 1 to 7, wherein the energy storage (18) is formed as a bellows pressure storage, which comprises at least one storage chamber (34) and at least one bellows (56) arranged in the storage chamber (34), which is elastically compressible by introducing the hydraulic fluid into the storage chamber (34).
9. The storage actuator (10) according to claim 1 to 8, wherein a second check valve (36) is provided, via which the hydraulic fluid can be introduced from the drive device (14) into the first chamber area (22).
10. The storage actuator (10) according to claim 1 to 9, wherein a third check valve (54) is provided, via which the output device (32) can be supplied with the hydraulic fluid from the second chamber area (24).
11. The storage actuator (10) according to claim 1 to 10, wherein the energy storage (18) can be at least predominantly, in particular completely, filled up with the hydraulic fluid within at most 10 seconds, in particular within at most one second, during which the piston element (20) is continuously in the second position.
12. A method for actuating an output device (32) by means of a storage actuator (10) according to any one of the preceding claims, in which at least one energy storage (18) is supplied with energy by means of a drive device (14) of the storage actuator (10) in a first operating state of the storage actuator (10), whereby the energy is stored in the energy storage (18), wherein the energy storage (18) provides at least a part of the energy stored in the energy storage (18) in a second operating state of the storage actuator (10), whereby the output device (32) is supplied with the provided energy and thereby is actuated by means of the provided energy.

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