Abstract:
A module for in-line arrangement on at least one further module in a fluid power valve cluster ( 10 ) including modules placed in a row adjacent to one another in an in-line direction, comprising communicating means for communication with the at least one further module of the valve cluster ( 10 ). For the there is such that the means are designed as waveguide communication means ( 19, 21  and  23 ) for communication via a waveguide ( 14 ) of the valve cluster ( 10 ).

Description:
FIELD OF THE INVENTION 
     The invention relates to a module for in-line arrangement on at least one further module in a fluid power valve cluster including modules lined up in a line adjacent to one another in an in-line direction, comprising communicating means for communication with the at least one further module of the valve cluster. 
     BACKGROUND OF THE INVENTION 
     Such a module is for example disclosed in the German patent publication 198 01 243 D2. The modules of the valve cluster are placed in line. The modules respectively laterally bear electrical contacts. In the assembled state of the valve cluster such electrical contacts engage each other. Accordingly the modules are electrically connected with each other. By way of the electrical connections data, for example, are transmitted for control of the valves present in the modules. For data and energy transmission several contacts are necessary. The modules are therefore expensive to manufacture. Mechanical damage and/or oxidation impairs the contact properties of conventional spring contacts. 
     The German patent publication 199 42 508 A1 discloses the supply to a pneumatic device, for example a valve, by way of a pneumatic line of pressure and, additionally, by the intermediary of pressure changes, microwaves or acoustic signals using the gaseous medium in the line, the transmission of control signals to the pneumatic device. The German patent publication 199 42 509 A1 discloses in the case of a pneumatic device of the same type as in the said German patent publication 199 42 508 A1 the supply by acoustic waves, microwaves or pressure changes, of electrical energy. The pneumatic devices are respectively individual pneumatic cylinders, which are connected by way of the pneumatic line with a control device. A separate compressed air line leads to each device. The devices are not suitable for a cluster-like structure. 
     SUMMARY OF THE INVENTION 
     Accordingly one object of the present invention is to increase the reliability of the communication means in the case of a module of the type initially mentioned. 
     This object is achieved in the case of the module of the type initially mentioned since the communication means are designed in the form of a waveguide communication means for communication by way of a waveguide of the valve cluster. 
     The communication by way of the waveguide or hollow conductor is simple and reliable. Using a waveguide transmission may take place at comparatively high transmission frequencies of, for example 1 GHz so that communication with the valve cluster may be performed with a single waveguide. In principle however several waveguides are possible as well. 
     Preferably the communication means comprise at least one antenna. Such antenna it is for example a question of a slotted waveguide. 
     The waveguide advantageously renders possible a transmission in the uplink and downlink direction: it is bidirectional. 
     Preferably the waveguide is designed in the form of a transmission channel separate from the fluid power and supply channels. The waveguide may employed for its intended purpose as a communication channel, in a for example geometrically optimum manner. 
     It is an advantage for the communication means to be designed for the transmission of energy. In this respect the fact is made use of that comparatively large energy amounts may be transmitted using a waveguide. For instance, approximately one to two watts of electrical power may be transmitted to each module of the valve cluster. The energy received by the communication means is preferably employed for the operation of a valve drive. The valve drive preferably constitutes a component of the module. 
     The waveguide may for example have a rectangular, round or elliptical cross section. 
     In order to ensure having a reflection-free termination, a terminating resistance or an electrically conductive termination element is provided for the waveguide. Such element is best comprised in the module in accordance with the invention. For low electrical power levels for example foils are suitable, for example of carbon or a metal coated material. For higher power levels terminating resistances of a ferrite or a graphite and sand composite are suitable. In principle however the waveguide may also have an open end. 
     Such electrical terminating resistances prevent reflection in the waveguide. The electrical field strength is accordingly evenly distributed in the waveguide. The waveguide is simple to adjust. 
     Preferably a waveguide section is contained in the module to constitute the waveguide. The waveguide is constituted by an in-line arrangement of the modules. 
     The waveguide section is preferably enhanced by being electroplated. It is for example electroplated with silver, copper or gold. The electroplated material is preferably in the interior of the waveguide section. 
     On the waveguide section there is preferably a plug-in end for the production of plug connection with the adjacent waveguide section. It is convenient such plug-in ends are plated at both ends of the waveguide section. The modules can therefore be plugged together in a line to extend or form the waveguide. 
     It is convenient for the waveguide section to possess electrically conductive contact means for the production of an electrical connection with the adjacent waveguide section. Such contact means may for example be constituted by plug ends with a suitable electrical conductivity. Furthermore the contact means may comprise a rosette or a flange. Preferably the contact means comprise silver and/or copper plated conductive resilient elements or such elements rendered electrically conductive in some other way. Same ensure optimum contact reliability. 
     Preferably the waveguide section possesses a sealing ring or a seal groove. Such sealing means prevent the access of pressure medium or the action of other environmental effects likely to impede transmission quality in the interior of the waveguide. The sealing means preferably comprise elastic elements, as for example of a silicone such as a silicone rubber. 
     Preferably at the end there are central transmitting and/or receiving means at the end on the waveguide. Such means may be present in a module in accordance with the invention. 
     It shall be noted that more than one waveguide may be provided, whereby for example one waveguide may be provided for each transmission direction. 
     Preferably again information and/or energy is transmitted with at least two transmission frequencies in the waveguide. For instance, a first and a second transmission frequency for transmission in the downlink direction and, respectively, in the uplink direction. It is clear that furthermore different frequencies may be provided for the energy and data transmission. 
     It is admittedly preferred for the waveguide to possess the same cross section from end to end. However for forming transitions the waveguide may have a waveguide union for connection to join waveguides together which have different cross sections. The length of the transition or join is preferably large in comparison with the length of the waveguide. There may also be a so-called twist union for rotation of the planes of polarization, for example through 90 degrees. The valve cluster in accordance with the invention (for example a module as well) may also comprise a coaxial transition as a join between a waveguide and a coaxial cable. 
     In the case of the module various different geometries are possible: 
     Preferably the module comprises a central control unit for the control of additional modules of the valve cluster. It constitutes for example the bus master of a data or energy bus formed on the waveguide. Such a module can be termed a central control module of the valve cluster. 
     The module may also be a central diagnostic module. It then preferably comprises a central diagnostic module for monitoring further modules of the valve cluster. 
     In the case of a further version of the invention the module is a local control module or a valve module. Such a module comprises control and/or diagnostic means for control or, respectively, monitoring at least one valve and/or valve drive. The valve or, respectively, the valve drive may constitute a separate subassembly, which is controlled or, respectively, monitored. Such subassemblies are preferably arranged in line in the row direction. A preferred version of the invention provides for the valve or, respectively, the valve drive is comprised in the module in accordance with the invention. It is then designed as valve module. In connection with a valve cluster it is possible to speak of a valve disk too. 
     In a further form of the invention the module is designed in the form of a terminating module for terminating the waveguide. The terminating module can be a sort of passive module which for example comprises the above mentioned terminating resistance. It may however also be a sort of active terminating module that comprises the above mentioned central control unit. 
     More particularly in the case of the latter central control module it preferably on the one hand contains the waveguide communication means for communication with the further modules of the valve cluster and on the other hand possesses second waveguide communication means for communication with a master control. 
     In the case of the valve cluster in accordance with the invention several different modules of the above mentioned modules may be placed in line, as for example a central control module, several valve modules and a terminating module. 
     In the following the invention will be described on the basis of one working example with reference to the drawing in more detail: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a first working embodiment of a valve cluster in accordance with the invention having two waveguides in a perspective elevation. 
         FIG. 2  shows a highly diagrammatic cross sectional view of a valve cluster with a waveguide that is formed between a central control module and furthermore decentral control modules. 
         FIG. 3  shows a highly diagrammatic cross sectional view of a valve cluster with a waveguide that is formed between a central control module and valve modules. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the case of a valve cluster  10  in accordance with  FIG. 1  a central control module  11 , a diagnostic module  12  and valve modules  13  are joined by a waveguide  14 . The central control module  11  controls and monitors the valve modules  13 . The diagnostic module  12  provides diagnostic tools, as for example for detecting and visualizing wear, faults or the like in the valve modules  13 . The valve modules  13  comprise valve drives, not illustrated, valve drives and pneumatic valves, not illustrated either, which are controlled and monitored by control means  20 . The control means  20  comprise a processor for example and also memories. They are for example in the form of application specific integrated circuits (ASICs) or comprise ASICs. 
     The valve modules  13  are arranged on a distributor block  15  in whose interior a channel system, not illustrated, is located, for example for supplying the valves of the valve module  13  with compressed air. At the front side of the valve block  15  there are supply connections  16 , pilot control connections  17  and furthermore load or, respectively, power connections  18 . The compressed air supplied at such supply connections  16  compressed air flows in a fashion dependent on the position of the valves of the valve modules  13  out at the power connections  18 . These valves of the valve modules  13  are operated by pilot control valves, for whose operation pilot control compressed air is supplied by way of the pilot control connections  17 . For driving the valve members of the pilot control valve use is made of electrical drives, as for example electromagnetic and/or electrostatic drives, which are driven by the control means  20 . 
     A central control means  9 , as for example a processor and memory, in the central control module transmits, by way of an antenna  19  in the so-called downlink direction, control signals through the waveguide  14 . The antenna  19  constitutes a component of waveguide communication means of the control module  11 . The control signals are received by the control means  20  by means of antennas  21 . In the present case all control means  20 , that are connected with the waveguide  14 , receive the control signals. Accordingly a bus is formed. For instance using suitable address data in the control signals the respective control means  20  of the valve modules  13  can detect whether the respective control signal is intended for them. 
     In the reverse direction, that is to say in the so-called uplink direction, the control means  20  transmit data by way of the waveguide  14 . The control means  20  use the antennas  21  to transmit message information for example as received from the central control means  9 . Furthermore the message information is received by diagnostic means  22  with the aid of an antenna  23 . The diagnostic means  22  comprise for example a processor and a memory for the evaluation of the received message signals and also a display device, as for example an LCD display, for visualizing the information. On the display device faults or other operational states of the valve modules  13  are displayed. 
     In the present case the waveguide  14  is a waveguide with a circular cross section. It is constituted by the modules  11  through  13 . In same respective waveguide sections are present. Owing to the lining up of the waveguide sections the waveguide  14  is formed. The length of the waveguide sections is preferably optimized to suit the cross section of the waveguide  14  and the transmission and reception frequencies employed. 
     The waveguide  14  extends in the present case, in addition to the modules  12  and  13  participating in the communication by way of the waveguide  14 , also through muffler modules  30 . One muffler module  30  is located between the diagnostic module  12  and the valve module group constituted by the valve modules  13 . The other silencer module  30  is located on the opposite side of the valve module group. To the fore on the silencer modules  30  spent air connections  91  are provided. 
     The central control means  9  communicates with a very diagrammatically shown master control  24  with the aid of a second waveguide  25 . The waveguide  25  also has a circular cross section. In the present case it is formed by a rigid waveguide section  26  and a flexible waveguide section  27 , as for example an electrically conductive hose. The control means  9  transmits and receives data by means of an antenna  28  on the waveguide  25 . 
     As a further—as it were, conventional—possibility of communication a connection, for example having a serial bus protocol, may be produced with the control means  9 . By way of a plug  29  an electrical connection may be produced to the serial interface. 
     In the case of one valve cluster  40  in accordance with  FIG. 2  a central control module  41 , valve modules  42  and furthermore a terminating module  43  are placed in line. The control module  41  and also the valve modules  42  communicate with each other via a wavegude  44 . The waveguide is formed by waveguide sections  45 ,  46  and  47  of the modules  41  through  43 . 
     The valve modules  42  comprise so-called decentral control modules  48  that contain the waveguide sections  46  to form the waveguide  44  and valve component groups  49  having pneumatic valve  50 . The valves  50  are illustrated in a highly diagrammatic manner. 
     Unlike the valve manifold or cluster  10  in the case of the valve cluster  40  there is no fluid or, respectively, compressed air distributor block or manifold. Instead of it the valve modules  42  are designed in the form of so-called solid board valves having ducts having ducts and duct sections for the distribution and supplying the compressed air. For disposing of pressure medium or venting in the case of the valve component groups  49  supply ducts  51  are provided through which input of compressed air is possible by way of supply connections  51 ′ at the terminating module  43 . Dependent on the position of the pneumatic valves  50  such compressed air flows through power ducts  52  opening at the front at power connections generally of the same type as power connections  18  at the front on the valve cluster  40 . 
     At an electrical interface  53  the central control module  41  receives control instructions from a master control, not illustrated. Such control instructions are converted by a control means  54  into control instructions for the valve modules  42 . The control means  54  sends the control instructions by means of an antenna  55  on the waveguide  44 . The local control modules  48  receive, by means of antennas  56 , the control instructions. In accordance with the control instructions control means  57  which for example comprise ASICs, valve drives  58 , as for example electromagnets. The valve drives  58  actuate valve members of the pneumatic valves  50 . 
     The successful or unsuccessful performance of the control instructions is communicated by the control means  57  to the central control module  41  by way of the waveguide  44 . For this purpose they send via the antenna  56  corresponding message instructions, which are received with the antenna  55  and are interpreted by the control means  54 . The messages are visualized or displayed at a display means  59 , for example an LCD display. 
     The waveguide  44  is terminated by terminating resistances  90 . The terminating resistances  90  are matched to the wave resistance of the waveguide and comprise an electrically conductive material. The terminating resistances  90  are provided in the case of the central control module  41  and also the terminating module  43 . They are located in the present case on the terminal face of the waveguide sections  45  and, respectively,  47 . 
     The waveguide  44  has, for example, a rectangular cross section. The inner side of the waveguide  44  is in the present case electrically conductive, and for instance it is electroplated with a conductive surface layer. The housing of the control modules  48  otherwise comprise plastic for example. 
     In the case of a valve cluster  60  in accordance with  FIG. 3  the modular configuration is somewhat less emphasized than in the case of the valve cluster  40 . However to the extent that the valve cluster  60  has similar or identically functioning components like in the valve cluster  40 , same are provided with the same reference numeral and are not described again in the following. 
     In the case of the valve cluster  60  a central module  61  and valve modules  62  and  63  are placed in line. The modules  61  through  63  communicate by way of a waveguide  64 . Furthermore by way of the waveguide  64  energy is transmitted. The valve modules are essentially the same as the valve modules  42 , there being no separation between the control module and the valve component groups. The valve modules  52  and  63  contain the control means  75 , valve drives  58  and pneumatic valves  50 . Moreover, in the valve modules  62  and  63  there are duct sections like opening to form supply and power ducts  51  and  52 . Like the valve modules  42  the valve modules  62  and  63  are also lined up in a pressure-tight manner. Compressed air is fed into the supply channels  51  via supply connections  51 ″, which are provided on the control module  61 . The central control module  61  and also the valve module  63  constitute terminating modules of the valve cluster  60 . 
     The waveguide  64  is constituted by the waveguide sections  65 ,  66  and  67  of the modules  61  through  63 . On the outer end sides of the waveguide  64 , in the waveguide sections  65  and  67  terminating resistances  68  and  69  are arranged that terminate the waveguide  64  electrically. The waveguide sections  65  through  67  are for example plugged into one another. It is also possible for them to abut together with flat surfaces in engagement. Preferably they are connected together in an electrically conductive fashion. 
     In the present case communication takes place with different transmission frequencies via the waveguide. Furthermore the control module  61  transmits the electrical supply energy along the waveguide  64  for the valve modules  62  and  63 . 
     The control module  61  receives control instructions at an interface  71  from a master control, not illustrated. These master control instructions are interpreted by the control means  79  as local control instructions that it transmits with the aid of an antenna  72  and by way of to the to the valve modules  62  and  63 . The antenna  68  is a terminal transmission means. It extends through the terminating resistance  68 . The control instructions are transmitted by way of the antenna  72  at a first transmission frequency  73 . 
     For receiving the data at the first transmission frequency  73  receiving antennas (extending into the waveguide  64 ) are provided at the valve modules  62  and  63 . In accordance with the received control instructions the control means  75  control valve drives  58  for driving the valve members of the valves  50 . 
     In the present case all valve modules  62  and  63  receive the instructions transmitted via the antenna  72 . For transmission of the instructions a bus protocol is for example utilized. The control means analyses address particulars contained in the control messages. It is also possible however for each of the valve modules  62  and  63  to use a different transmission frequency and for the valve modules  62  and  63  to only receive instructions transmitted at the frequency assigned to them and to convert them for control of the drives  50 . 
     Moreover the control module sends, at the transmission frequency  73 , the electrical supply energy necessary for the operation of the valve modules  62  and  63 . Such energy is obtained from the received electromagnetic waves by energy converters  76 . 
     In the uplink direction the control means  75  send message information at a second transmission frequency  77 . For transmission at the second frequency  77  antennas  78  are provided at the valve modules  62  and  63 . The control module  61  receives the messages of the valve modules  62  and  63  with the aid of an antenna  79 . The antennas  78  and  79  are tuned to the second transmission frequency  77 . The messages of the valve modules  62  and  63  are displayed by the central control module  61  using display means  80 . 
     It is also possible for the waveguides  14 ,  44 , and  64  to be termed microwave buses. The electromagnetic waves serving for communication between the connected modules and if necessary for the transmission of energy are preferably so-called microwaves. Their wave length is for example in a range extending from a few millimeters to centimeters.