Abstract:
The invention relates to a vacuum system, in particular a vacuum gripping system having at least one vacuum gripping apparatus for gripping workpieces and/or a vacuum component, in particular having a sensor for sensing states in the vacuum gripping system and/or one of the components and for generating state data, wherein the vacuum gripping apparatus and/or at least one of the components is equipped with an energy generation device for generating new electrical energy, which is not stored in the vacuum system, for operating a module consuming electrical energy.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application No. PCT/EP2006/007818 filed on Aug. 8, 2006, which claims the benefit of DE 10 2005 047 385.7-22, filed Sep. 28, 2005, DE 10 2006 016 235.8, filed Mar. 31, 2006 DE 10 2006 016 236.6, filed Mar. 31, 2006, and PCT/EP2006/004968, filed Mar. 24, 2006. The disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The invention relates to a vacuum system, in particular a vacuum gripping system having at least one vacuum gripping device for gripping workpieces and/or a vacuum component. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0004]    Vacuum systems are used for the production of low pressure and the handling of objects. An example of a device for the production of low pressure is an ejector, which is operated with compressed air and to which vacuum consumers are connected. An example of a vacuum consumer of this type is a suction gripper, by means of which an object is sucked in so that it can be picked up and transported to another place. There are, however, also known gripping systems which are used for gripping workpieces, so that the workpieces can be processed. The individual vacuum gripping devices and the components which work with them are subject to wear and must accordingly be monitored in order to ascertain whether they show leaks and/or still work properly. It may also be necessary to ascertain particular data on the status of these components—for example, the level of the partial vacuum which prevails within them—in order to enable them to continue to operate. Thus, for example, a workpiece which has been sucked in can only be picked up when the partial vacuum in the suction gripper has reached a predetermined value. 
         [0005]    To this end, sensors are provided, which record the statuses and convert them into status data, whereby the status data can then be transmitted by cable to a receiver. In addition, cables are required in order to provide the sensors with electrical energy; however, effort and expense are required for cabling. For example, providing cabling for status requires that not only that the compressed air and partial vacuum devices be installed, but also the energy supply cables and the data transmission cables. 
       SUMMARY 
       [0006]    The invention is accordingly based on the task of producing a vacuum system of simpler construction. 
         [0007]    The vacuum gripping device of the present disclosure and/or at least one of the components exhibits an energy generation device for the production of new electrical energy, which is not stored in the vacuum system, for the operation of an electrical energy-consuming component. 
         [0008]    The device according to the invention does not require electrical supply lines for energy supply, because the energy is generated on site by means of the energy generation device. This electrical energy is preferably not taken from an original energy storage unit included in the vacuum system; rather, it is converted from a form of energy existing in the environment or derived from another form of energy which exerts an effect on the vacuum system, such as, for example, motion energy or light. 
         [0009]    The vacuum system of the present invention may have an element for the recording of statuses in the vacuum system, which may be located within the vacuum gripping system and/or in one of the components, for the generation of status data. 
         [0010]    According to the invention, the electrical energy required for recording of the statuses and the generation of the status data is no longer required to be supplied to the vacuum system by means of cables, because the vacuum gripping device and/or at least one of the components used by it is provided with an energy generation device, so that the required electrical energy is generated on site. This electrical energy is not taken from an original energy storage unit; rather, it is converted from another form of energy and may be taken from the environment. 
         [0011]    Preferably, the electrical energy-consuming component is a sensor, a transmitter, an optical and/or acoustic display, a valve, an actuator, or a data storage unit. Should the status data be transmitted in a wireless manner by means of a transmitter, the transmitter in question will also be provided with energy by the energy generation device. In other words, it will require no cabling for transmission of the status data to a receiver located outside the vacuum system, because these status data are transmitted to it in a wireless manner by means of a transmitter. Accordingly, the entire cabling of the system becomes unnecessary, so that only the air supply lines must be installed. In this way, the effort and expense required for construction are significantly reduced, and repairs and maintenance operations can be performed more quickly and simply. In addition, the weight and size of the system are reduced. 
         [0012]    The vacuum gripping device may consist of a suction gripper, a vacuum clamping system, or another device capable of directly or indirectly holding a workpiece by means of partial vacuum. Suction grippers are used to suck in objects, so that they can be picked up and moved to another place. Vacuum clamping systems allow components to be held fast, so that they can subsequently be processed. These components can be equipped with the energy generation device, so that their status data—for example, switching cycles, partial vacuum applied, amounts of air supplied and so forth—can be recorded and either stored in the component and/or transmitted to an external receiver. Storage of the data can be implemented, for example, by an RFID (Radio Frequency Identification Device), which is fastened to a suitable place on the suction gripper or the vacuum clamping system. In this way, the usage history of the component is not lost and can be called up at any time. 
         [0013]    The component may consist of an ejector, a vacuum pump, a vacuum bellows, a valve, a data storage unit, a suction gripper, a spring-loaded plunger, a vacuum switch, or a display, by way of example. The valve may be an electromagnetic valve, a pneumatic valve, or a touch valve, by way of example. In these components as well—whereby the abovementioned list is intended by way of example only—an energy generation device may be provided, which supplies the energy for the sensors for recording the individual status data, and the data may be directly transmitted to and stored in a data storage unit on site and/or transmitted to an external receiver. The energy used in storage and transmission is similarly provided by the energy generation device. In addition, it should be noted a rechargeable energy storage unit, for example, a battery, an accumulator, a condenser, or a fuel cell, may also be provided, so that small quantities of energy generated by the energy generation device can be accumulated. 
         [0014]    In one preferred form, the energy generation device may be a piezoelectric element. It is also, however, contemplated that thermocouples, oscillation converters, induction generators, or turbines with generator or photovoltaic cells, may be used, by way of example. The individual components may subjected to mechanical stress, for example, when handling objects, whereby these mechanical movements can be converted by the piezoelectric elements or induction generators into electrical energy, so that the electrical energy for sensors, transmitters and storage units can be provided. In this context, the piezoelectric element and/or the induction generator is preferably located in or on a section which is moved mechanically—for example, on a piston, a cylinder wall, or a touch valve—which, when attached to a workpiece, is inserted into the suction device. The section, for example, can also be transformed in shape when the workpiece is gripped. This transformation energy accomplishes the transformation of the piezoelectric element and/or the induction generator, which converts the mechanical energy into electrical energy. In another variation, a turbine may be used, which may be located in the suction or air blast stream, and which may drive a generator. 
         [0015]    The sensor is preferably a vacuum sensor, a flow sensor, an air quantity sensor, a counter, a movement sensor, a temperature sensor, a distance sensor, a presence sensor, or a force sensor. In this way, an extremely wide variety of statuses can be determined and corresponding data can be generated. Thus, for example, the wear limit of a suction gripper can be recognized before the suction gripper stops working. In addition, it is also possible to recognize when an object is not correctly sucked in or gripped, and thereby to prevent accidents. 
         [0016]    The transmitter can be a radio transmitter, an infrared transmitter, an ultrasound transmitter, or a wired signal generator, by way of example. The data may be encrypted or unencrypted and may be combined with component-dependent original features. In this way, it is possible to determine, at any time, where and when the data were generated. 
         [0017]    The vacuum gripping device and/or the vacuum component may exhibit a data storage unit for the storage of status data and/or data relevant to the vacuum gripping device and/or the vacuum component. This data storage unit can be read out during operation and/or in cases requiring service or repair. This may enable the more rapid tracing of any causes of error. 
         [0018]    The vacuum gripping device and/or the vacuum component may be driven by means of the data stored in the component. These data can be predetermined; they can also, however, be generated in the course of the current operation and can thereby have an affect on the following operation. 
         [0019]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0020]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
           [0021]      FIG. 1  a schematic diagram of a vacuum gripping system, according to the principles of the present invention; 
           [0022]      FIG. 2  is a schematic diagram of a suction device having a battery-free radio module and an external storage unit, in accordance with the principles of the present invention; 
           [0023]      FIG. 3  is a schematic diagram of suction grippers having an external storage unit, according to the principles of the present invention; 
           [0024]      FIG. 4  is a schematic diagram of a process showing the suction and lifting of an object, in accordance with the principles of the present invention; 
           [0025]      FIG. 5  is a schematic diagram of a suction gripper having an integrated storage unit, according to the principles of the present invention; 
           [0026]      FIG. 6  is a schematic diagram of a suction device having a battery-free radio module and an internal storage unit, in accordance with the principles of the present invention; 
           [0027]      FIG. 7  is another schematic diagram of the suction device of  FIG. 6 ; 
           [0028]      FIG. 8  is a schematic diagram of a suction device  42  having a radio module and an energy buffer, in accordance with the principles of the present invention; 
           [0029]      FIG. 9  is a schematic diagram of a mechanical vacuum switch having a radio module, according to the principles of the present invention; 
           [0030]      FIG. 10  is a schematic diagram of a mechanical vacuum switch having a radio module with a buffer, in accordance with the principles of the present invention; 
           [0031]      FIG. 11  is a schematic diagram of an electrical vacuum switch having a radio module, according to the principles of the present invention; 
           [0032]      FIG. 12  is a schematic diagram of an ejector having a turbine located in its air stream, in accordance with the principles of the present invention; 
           [0033]      FIG. 13  is another schematic diagram of the ejector of  FIG. 12 ; 
           [0034]      FIG. 14  is a schematic diagram of a touch valve having an induction generator and a radio transmitter, in accordance with the principles of the present invention; 
           [0035]      FIG. 15  is a schematic diagram of a valve cluster, according to the principles of the present invention; 
           [0036]      FIG. 16  is a schematic diagram of spring-loaded plunger having immersion depth monitoring, in accordance with the principles of the present invention; and 
           [0037]      FIG. 17  is another schematic diagram of the spring-loaded plunger of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
         [0039]      FIG. 1  is a schematic diagram of a vacuum gripping system generally designated at  10 , in which is located an energy generation device  22 , which is connected to an electrical energy-consuming component  8 , for example, a display, a sensor, a valve, a wired signal generator, a transmitter, or a data storage unit, by way of example. This component  8  communicates with an external unit  6 , for example, in order to read, write, evaluate or display. In addition, the vacuum gripping system  10  is provided with an additional energy buffer  4 , for example, a battery, an accumulator, or a condenser, for example, to which may be connected an additional optional signal generator  2 , for example, a switch, a cable, a (radio) receiver, a sensor, or a timer, by way of example. 
         [0040]    In  FIG. 1 , the solid arrows represent a flow of electrical energy, the dot-and-dashed arrows represents a flow of non-electrical energy, the dashed arrows symbolize a flow of information over a physical connection, and the dashed arrow with concentric arcs symbolize a flow of information with no cable, line or hose. Arrow  38  symbolizes energy which has an effect on the vacuum gripping system  10 . For activation of the consumer  8 , either a signal from the signal generator  2  or an electrical pulse from the energy generation device  22  may be used. Finally, the element  40  represents another mechanical actuation. 
         [0041]      FIG. 2  shows a schematic diagram of a suction device  42  with a battery-free radio module and an external storage unit. Element  44  is an induction generator or a piezoelectric element which operates a radio transmitter  26 . The energy generator  22 , in the form of an induction generator or piezoelectric element  44 , emits an electrical pulse which represents a signal. The unit  6  is an external data storage unit  20 . 
         [0042]      FIG. 3  shows the vacuum gripping system  10  with three suction grippers  12 , by means of which workpieces  14  can be sucked in. The suction grippers  12  are connected, by means of a partial vacuum line  16 , to a partial vacuum supply device  18 , for example, a partial vacuum pump or an ejector. In addition, it may be seen that an external data storage unit  20  is provided. Accordingly, the ejector itself represents a vacuum component. 
         [0043]    Integrated into each individual suction gripper  12  is an energy generation device  22 , a so-called energy converter, and a sensor  24 . This sensor  24  records statuses of the suction gripper  12 , for example, the partial vacuum prevailing in the suction gripper  12  or the number of load cycles; it then generates status data and transmits them, by way of a transmitter  26 , to the data storage unit  20 . The electrical energy required to operate the sensor  24  and to operate the transmitter  26  is generated by the energy generation device  22 , which, for example, maybe a piezoelectric element or an induction generator, a photovoltaic cell, a turbine, an oscillation converter, or a thermocouple, by way of example. 
         [0044]      FIG. 4  shows one variation of a process for the handling of a workpiece  14 , in which the suction gripper  12  is first lowered in the direction of the arrow  28  onto the workpiece  14 , until the suction gripper  12  is attached to the workpiece  14 . In the process, the suction gripper  12  is transformed in shape, whereby the mechanical transformation energy is converted into electrical energy by the energy generation device  22 . This activates the transmitter  26 , which sends an activation signal to the receiver located in the data storage unit  20 , as indicated by means of the arrow  30 . 
         [0045]    This has the effect of setting the partial vacuum supply device  18  in operation and thereby providing the partial vacuum line  16  with a partial vacuum. The workpiece  14  is sucked in. Once the required suction pressure has been obtained, as determined by the sensor  24 , an additional signal is issued, indicating that the object  14  can now be picked up (arrow  32 ), because the partial vacuum prevailing in the suction gripper  12  is strong enough. Should the partial vacuum in the suction gripper  12  become weaker, this will also be recognized by the sensor  24 , so that an additional signal can be transmitted. When the partial vacuum reaches its required value, the partial vacuum supply device  18  can be switched off or the partial vacuum line  16  can be blocked. 
         [0046]    After the workpiece  14  has been gripped, which is again registered by the sensor  24 , the partial vacuum line  16  is supplied with air, so that the suction gripper  12  can be removed from the object  14  in the direction of the arrow  34 . 
         [0047]    The vacuum system according to the invention requires no electrical lines for provision of energy to the sensor  24  and the transmitter  26 ; instead, the vacuum system may be provided merely with the supply of a partial vacuum to the suction gripper  12 . 
         [0048]      FIG. 5  shows an example of a suction gripper  12 , in which the data storage unit  20  is integrated into the suction gripper  12 , for example, in the form of an RFID tag. This suction gripper  12  likewise transmits data (arrow  30 ) to an external receiver  36 ; however, the usage history is stored in the internal storage unit  20  and can also be read out later. In addition to the usage history, identification numbers, the manufacturing date, the manufacturer, material designations, and the like may also be stored. In this way, it is possible to draw conclusions with regard to incorrect operation, faulty manufacture, and the like. 
         [0049]      FIGS. 6 and 7  illustrate a suction device  42  having a battery-free radio module and an internal storage unit. Located in the suction device is an induction generator or piezoelectric element  44 , which, for example, is actuated by means of a plunger  46  or by means of an elastic section of the suction device  42 , and which supplies a data storage unit  48  and a radio transmitter  26  with electrical energy. Instead of the external data storage unit  20 , it is also possible to provide an external display  50  or a signal converter, for example, for a programmable controller, a robot controller or another superordinate controller, by way of example. 
         [0050]      FIG. 8  illustrates of a suction device  42  having a radio module and an energy buffer. The suction device  42  contains a photovoltaic cell  52 , by means of which electrical energy is generated. This energy is stored in an energy buffer  56  in the form of a condenser  54 . The plunger  46  activates an electromechanical switch  58 . 
         [0051]      FIG. 9  is a schematic diagram of a mechanical vacuum switch  60  with a radio module. Located in the vacuum switch  60  is an induction generator or piezoelectric element  44 ; the actuation element consists of a bellows  62  or a piston, to which a partial vacuum  64  can be supplied by sucking out the air in the direction of the arrow  66 . This embodiment is used in process control and automation. 
         [0052]      FIG. 10  shows a sketch in principle of a mechanical vacuum switch  60  with a radio module and a buffer  56 , which is formed by a condenser  54 . Located in the vacuum switch  60  is a photovoltaic cell  52 , by means of which electrical energy is produced from light  68 . This energy is stored in an energy buffer  56  in the form of a condenser  54 . 
         [0053]      FIG. 11  is a schematic diagram of an electrical vacuum switch  66  with a radio module  26  and a buffer  56 . Transmission pulses are generated by the vacuum switch  66  upon the obtaining of a switching threshold  70  determined by either an excess or a shortfall, whereby the vacuum switch  66  is connected by means of a hose  72  to the partial vacuum to be monitored. In one variant, the transmission pulses are controlled by means of a timer  74 . The sensor measures the vacuum value, for example, every two seconds, and sends an analog signal to a superordinate controller. 
         [0054]      FIGS. 12 and 13  illustrate an ejector  76 , in whose air stream a turbine  78  is located. The air stream is either an air blast stream  80  or a suction stream  82 . The turbine  78  drives a generator  84  for production of electrical energy. The turbine  78  located at the outlet of the air blast stream  80  thereby works as a muffler, because it slows the air stream. 
         [0055]      FIG. 14  illustrates a touch valve  86  having an induction generator  44  and a radio transmitter  26 . The sent and received data are processed in the signal converter  88  for a robot controller. When the touch valve  86  touches the object, a plunger is immersed and the induction generator  44  is actuated, so that the radio transmitter  26  is supplied with electrical energy for transmission. 
         [0056]      FIG. 15  is a schematic diagram of a valve cluster  90 , in which a suction or air blast stream is used to drive the turbine  78 . 
         [0057]      FIGS. 16 and 17  show a sketch in principle of a spring-loaded plunger with adjustable immersion depth monitoring. In  FIG. 17 , the solid line represents the extended position  94 , and the dotted line represents the immersed position  96 , of the spring-loaded plunger  92 . 
         [0058]    It should be noted that the disclosure is not limited to the embodiment described and illustrated as examples. A large variety of modifications have been described and more are part of the knowledge of the person skilled in the art. These and further modifications as well as any replacement by technical equivalents may be added to the description and figures, without leaving the scope of the protection of the disclosure and of the present patent.