Abstract:
A valve controlled fluid power actuator arrangement having a fluid power valve arrangement ( 61 ) controlled by an electronic control means ( 63  through  65 ) being connected by means of at least one plastic fluid power line ( 11 ) with at least one actuator ( 62 ). In the plastic line ( 61 ) electrical line strands and/or light guides are integrated for the transmission of sensor signals. The at least one plastic line ( 11 ) is connected with the respective actuator ( 62 ) with the aid of a connection member ( 10 ) having a connection cable ( 29 ) with at least one sensor ( 30 ) in or on the actuator ( 62 ). Accordingly in the case of a valve arrangement separate from the actuators a rapid and simple fluid power and electrical or, respectively, optical assembly may take place.

Description:
This application is the National Stage of PCT Application No. PCT/EP01/12012 filed on Oct. 17, 2001 which claims priority to German Application No. 100 54 561.0 filed on Oct. 31, 2000. 
     FIELD OF THE INVENTION 
     The invention relates to a valve controlled fluid power actuator arrangement comprising a fluid power valve arrangement controlled by an electronic control means plastic fluid power lines being provided having integrated line strands and/or light guides for the transmission of sensor signals. 
     BACKGROUND OF THE INVENTION 
     The European patent publication 0803653 A1 discloses an arrangement, in which the transmission of the working pressure and of sensor signals from position sensors to power cylinders takes place by way of electropneumatic plastic lines. In this case the electropneumatic plastic lines are connected by way of connection members with valve arrangements, which are arranged on the power cylinders. The position sensors are connected by way of electrical lines with the valve arrangements. The connection members are plugged into the valves and retained by holding screws in them. Owing to the electrical line strands in the plastic lines screwing in of the connection members is not possible. Moreover, the valves are required as connection members between the sensor lines and the line strands in the plastic lines. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a valve controlled fluid power actuator arrangement in which the valve arrangement is positioned separated in space from the actuator arrangement and in which the plastic lines between the valve arrangement and the actuator arrangement on the actuator arrangement may be quickly and simply connected up with little work of the fitter so that fluid power connections and sensor connections are produced. 
     This object is attained in accordance with the invention using a valve controlled actuator arrangement with the features of claim  1  herein. 
     In an advantageous manner the connection members on the actuator or actuators automatically constitute both the fluid power connection and also the electrical or, respectively, optical connection with the sensors without optical or electrical connection having to be separately mounted. Simply the mechanical connection by itself of the plastic lines by way of the connection members with the actuators is sufficient to produce all necessary connections automatically. The danger of wrong electrical connections and confusion of connections in the case of the sensors is thereby out of the question. Replacement of sensors is also quickly and simply possible. It is possible for customary actuators, such as power cylinders, to be employed, which are adapted for valves mounted on them so that the arrangement of the line in the actuators is simplified. 
     The features recited in the dependent claims represent advantageous further developments and improvements in the valve controlled actuator arrangement as defined in claim  1 . 
     The actuator arrangement appropriately comprises at least one actuator designed a power cylinder, the at least one sensor being designed in the form of a position sensor for the position of the piston in the power cylinder. In the case of an advantageous form of design the valve arrangement is connected by way of two plastic fluid power lines with the at least one power cylinder. Each of the two connection members then has a position sensor to find the terminal positions. 
     Quick and simple fitting is also enhanced if the at least one plastic line is connected by way of a further connection member with the valve arrangement, the electrical and/or optical connection cable of the connection member being connected with the electronic control means, which is preferably at least partly mounted on the valve arrangement. Accordingly simply by insertion of the at least one plastic line by means of the connection members both the fluid power and electrical or, respectively, optical sensor connections are automatically produced without the wrong connections being made possible. 
     In accordance with an advantageous development the at least one connection member possesses a line connection socket for the plastic line, which is connected with a fluid power line in the connection member and which possesses coupling means for the electrical and/or optical connection with the at least one electrical line strand and/or the light guide in the plastic line, the coupling means being connected with the electrical and/or optical connection cable on the connection member. This arrangement as well contributes to preventing wrong electrical connections and confusion of connections in the case of the sensors. 
     In an advantageous manner on the floor of the non-radially symmetrical line connection socket, which is adapted to the cross section of the plastic line, at least one electrical contact spike is so arranged as a coupling means that on insertion of the plastic line into the line connection socket it is aligned with the at least one electrical line strand and contacts into the latter. Accordingly by simple insertion of the plastic fluid power line into the line connection socket the electrical connections themselves are produced automatically, even despite a plurality of line strands being present in the wall of the plastic line. No additional production of electrical connections or later production thereof is required at all. Since on insertion of the plastic line into the line connection socket the contact spikes directly penetrate into the line strands a secure electrical connection is ensured, more especially since the contact spikes are inserted in the longitudinal direction into the line strands and accordingly give rise to a contact area which is longer than in the case of transverse insertion. 
     As an alternative or in addition the wall of the plastic line may also possess at least one light guide, optical transmitters or optical transducers then being present at the floor of the line connection socket instead of contact spikes. The advantages disclosed occur with this design as well. 
     The line connection socket preferably possesses piece of tube arranged parallel to the contact spike and adapted to penetrate the fluid power duct of the plastic line or consists essentially of such a piece of tube. On joining the plastic line with the piece of tube there is on the one hand the production of a sealing fluid power connection and on the other hand this piece of tube serves to center and align the plastic line and accordingly renders possible secure positioning in relation to the contact spike or spikes. 
     For the mechanical attachment in place a clamping fixing means is advantageous, more particularly in the form of a clamping screw means. The clamping screw means is in this case best made up of a screw thread around the line connection socket and a corresponding union nut, a wedge member, able to be moved along an oblique face by the union nut being provided to retain the plastic line by a clamping action and more particularly for clamping in place between the piece of tube and the wedge member. On screwing in the union nut there is accordingly not only the desired clamping action but furthermore in addition a pressing 
     of the plastic line into the line connection socket so that the electrical contact between the contact spikes and the line strands is improved by compacting the material of the hose cable (contact pressure by way of the material of the hose cable). 
     In accordance with an advantageous design the flexible wedge member is designed in the form of a clamping ring and possesses an internal shape corresponding to the external form of the plastic line, the external diameter tapering like a wedge toward the floor of the line connection socket. This means that the clamping screw means simultaneously leads to a water-proof connection in connection with suitable sealing means. 
     The connection member is connected by way of an internal duct arrangement in a fluid conducting manner with the fluid power actuator or the valve arrangement, the connection member preferably having a fluid power connection screw means for screwing into the actuator or valve arrangement or being integrally formed thereon. 
     A particularly simple and reliable assembly and arrangement is made possible if the sensor arrangement and the electrical and/or optical connection cables are permanently connected with one another, and more particularly molded on one another. Furthermore, the at least one connection cable is preferably permanently molded on the connection member, since then a water-tight arrangement sealed off from the environment is produced. It is naturally possible for the connection cable to be connected with the connection member using a plug-in or screw connection. 
     One working example of the invention is represented in the drawing and will be explained in detail in the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates in longitudinal section a connection member with a molded on connection cable and a sensor, in the case of which a plastic fluid power line with three electrical line strands in the wall is plugged in position. 
         FIG. 2  shows a cross sectional elevation of the plastic fluid power line. 
         FIG. 3  shows the connection member in accordance with  FIG. 1  with the completely inserted plastic line as secured by a clamping screw means. 
         FIG. 4  depicts a further design of a connection member for optical signal transmission in a longitudinal section. 
         FIG. 5  is a diagrammatic representation of the working example of the invention having four power cylinders as an actuator arrangement. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The connection member  10  illustrated in  FIGS. 1 and 3  serves essentially for connection with a flexible plastic fluid power line  11 , in whose wall three electrical line strands  12  through  14  extend which for instance are in the form of fine flexible wires. The number of the line strands  12  through  14  is naturally able to be selected freely between one and a plurality of line strands. 
     The plastic line  11  possesses a non-radially symmetrical cross section so that insertion into a line connection socket  15  with a matching cross section of the principal body  16  of the connection member is only possible in a predetermined angular position. The line connection socket  15  is in this case surrounded by a tubular wall portion  18 , having an external screw thread  17 , of the principal body  16 . A part of the wall portion  18  adjacent to the part with the line connection socket  15  is tapered toward its axial end so that at its internal side a circularly conical oblique face  19  is formed. The line connection socket  15  is delimited radially inward by a piece  20  of tube, which is secured or molded on or in the principal body  16  in a sealing manner, a piece  20  of tube extending in the axial direction past the free end of the wall portion  18 . The external diameter of the piece  20  of tube is in this case slightly larger than the internal diameter of a fluid duct  21  in the interior of the plastic line  11 . 
     Electrical contact spikes extend from the floor of the line connection socket  22  in a direction parallel to the piece  20  of tube into the line connection socket  15 , the number and arrangement of the contact spike  22  being the same as the number and arrangement of the line strands  12  through  14  in the plastic line  11  so that on insertion of the plastic line  11  into the line connection socket  15  the contact spikes  22  slip in between the line strands  12  through  14  and create an electrically conductive connection, as is illustrated in  FIG. 3 . Owing to the sectional view only the contact spike  22  in contact with the middle line strand  13  is visible. Here a sealing washer  23  is placed between the floor of the socket  15  and the terminal face of the plastic line  11 . 
     For securing the inserted plastic line  11  in the line connection socket  15  use is made of a union nut  24  provided with a screw thread  17 , through which a flexible elastic clamping ring  25  like a clamping tongs or collet is able to be moved axially. The internal shape of this clamping ring  25  is in this case the same as the external shape of the plastic line  11 , whereas the external form of this clamping ring  25  is circularly conical so as to be complementary at least at the circularly conical oblique face  19  of the wall portion  18  with the result that on screwing in the union nut  24  the clamping ring  25  is thrust by a wedge action against the plastic line  11  and clamps it between it and the piece  20  of tube. In this case screwing in the union nut  24 , owing to the clamping ring  25  a force acts on the plastic line  11  in the insertion direction S, by which the plastic line  11  is thrust against the floor of the line connection socket  15  and consequently against the sealing washer  23 . Simultaneously the contact spike  22  bite more deeply into the plastic line  11  and, respectively, the line strand  12  through  14  if they have not already penetrated fully into it during insertion. In addition owing to the compaction of the elastic material of the hose cable the contact pressure is increased. 
     Instead of the above described clamping sensor means it is also possible to utilize other known clamping or detent connection means or furthermore internal screw means. In the simplest case it is for instance possible to only provide the piece  20  of tube on its external side and/or wall portion  18  on its internal side with annular retaining projections for securing the inserted plastic line  11 . Such retaining projections may also in addition be employed in the connection member described. Furthermore, the contact spikes  22  can be differently arranged or replaced by other contact means. 
     The terminal portion of the principal body  16  axially opposite to the wall portion  18  is designed in the form of a screw means for screwing into a fluid power device such as a valve, a power cylinder or the like. For this purpose this tubular screw threaded portion  27  is provided with an external or male thread  26 , an internal duct  28  producing the fluid power connection from the end as far as the piece  20  of tube. 
     As shown in  FIG. 1  an electric cable  29  is peripherally mounted or molded on the principal body  16 , such cable producing the electrical connection between a sensor arrangement  30  and the contact spikes  22 . If the sensor arrangement  30  should only require two lines for signal transmission, then the cable  29  may have two cores instead of three cores so that one of the contact spikes  22  is left unconnected or is omitted. The electric cable  29  may in this case be molded in a sealing manner both on the sensor arrangement  30  and also on the principal body  16 . Such a sensor arrangement is for example for detecting a position, for detecting a pressure or for detecting a temperature. In this case the sensor arrangement will comprise sensors suitable for the respective detection to be performed, as for example a Hall elements for of position or other sensors responsive to magnetic and/or electrical fields. 
     Instead of a molded on electric cable  29  the means may also be in the form of an electrical plug-in or screw connection. Furthermore, in an alternative design a plurality of electric cables  29  may be mounted or molded on the principal body  16  or they may be connected using several plug-in or screw connection means, for example to connect a plurality of sensor arrangements or other devices with the line strands  12  through  14  in the plastic line  11 . 
     The modified connection member  51  as shown in  FIG. 4  is substantially similar to the connection member  10  illustrated in  FIGS. 1 and 3 , identical or functionally identical components being provided with the same reference numerals and not being described over again. In contradistinction to the connection member  10  there is in this case a plastic line  52  with a suitable cross section, in whose wall instead of electrical line strands  12  through  14  there are now light guides  53 . On the floor of the line connection socket  15  the contact spikes  22  are now replaced by optical transmitters  54 , which, when the plastic line  52  is inserted make optical contact with the end sides of the light guides  53 . The electric lines connected with the contact spike  22  and extending internally of the principal body  16  are in this case replaced by suitably arranged internal light guides  55 . The workings of the connection member  51  represented in  FIG. 4  are essentially the same as those of the connection member  10 , only the electrical signal transmission being replaced by optical signal transmission. 
     With a modification of the connection member  51  it is possible, in a simpler design, for the optical transmitters  54  to be dispensed with the result that the light guides  53  in the connection member  52  come directly into optical contact with the internal light guides  55 . Alternatively, the optical transmitters  54  may also be replaced by optical transducers so that in this case optical signals may be converted into electrical ones and the internal light guides  55  are replaced by electrical conductors again. 
     In principle hybrid designs are also possible, that is to say a plastic line may in part comprise electrical line strands and in part light guides, suitable contact spike and optical transmitters or, respectively, optical transducers being arranged in the line connection socket  15 . For instance one light guide for the signal transmission and two electrical line strands for electrical amplifiers or, respectively, power supply, may be provided. 
     In the case the working embodiment depicted in  FIG. 5  four fluid power valves  60  in the form of plate valves, of a valve station  61  are connected by way of plastic lines  11  with an actuator arrangement, which comprises fourth power cylinders  62 . The number of valves  60  and of power cylinders  62  may naturally be freely selected, it being possible for other actuators to be utilized, as for example linear motors, fluid power rotary drives, fluid power gripping means or the like. If the double acting power cylinders  62  are replaced by single acting ones, then it is naturally possible to have only one respective plastic line  11 . 
     An electronic control  63 , for example in the form of a processor control, for the valve station  61  or, respectively, the power cylinders  62  is connected by way of a bus line  64  (for example an ASI bus) with a bus station  65 , which is arranged athwart the planes of the plate-like valves  60  on the valve station  61 , for example by plugging and is internally connected by way of lines or, respectively, plug connecting means with the solenoid coils of the individual valves  60 . A fluid power line  66 , as for example a pneumatic pressure line, is connected with the valve station  61  for pressure supply. 
     Each power cylinder  62  is connected by way of two electropneumatic plastic lines  11  with the respectively associated valve  60 , the plastic lines  11  respectively being connected at the end with the power cylinders  62  using connection members  10 , and with the valves  60  using modified connection members  9 , which essentially comprise the wall portion  18  and the line connection socket  15  in accordance with  FIGS. 1 and 3  and for example are plugged or molded for connection with the valves  60 , the contact spikes  22  being connected by way of internal electrical lines with the valve station  61  in order to supply same with sensor signals. In principle it is also possible to employ a screw-in connection member  10  in this case. 
     The two plastic lines  11  for each power cylinder  62  serve to put the piston, not illustrated, under pressure in the opposite direction in order to have two directions of motion. The sensors  30  connected by way of electric cable  29  are designed as position sensors and are attached to the power cylinders  62  to detect the desired terminal positions or other position, conventional attachment means being employed. The connection members  10  may also respectively be connected with a plurality of sensors, as for example a plurality of position sensors and/or pressure sensors and/or temperature sensors and the like in order to obtain data in relation to the power cylinders  62 . For sensor signal transmission in the plastic lines  11  the necessaary number of stands  13  is provided. 
     Obviously it is possible for the plastic lines  11  and the and the connection members  9  and  10  may also be optical in design, as for instance in accordance with  FIG. 4 . Hybrid designs are possible as well. 
     Although in the case of  FIG. 5  each valve  60  is only illustrated with one connection member  9 , naturally for the respectively two plastic lines  11  two tandem arranged connection members  9  are present. In principle however combined connection members could be utilized, which are designed for the connection of two fluid power lines.