Abstract:
Bistable high-performance miniature relay, comprising an insulating housing having a first housing chamber ( 1   b ) with a single-phase contact assembly ( 4 ) with two current bars ( 8   a,    8   b ) and a contact spring ( 13 ). The contact spring ( 13 ) being permanently connected with one leg end a current bar ( 8   a ). In a second housing chamber ( 1   a ), a bistable magnetic actuator assembly ( 3 ) with a pivotable armature ( 11 ) is placed. The contact assembly ( 4 ) and the actuator assembly ( 3 ) are located in one or two planes in the insulation material housing, the contact assembly ( 4 ) is provided with a multiplate contact spring ( 13 ) bent U-shaped to a current loop, and the actuator assembly ( 3 ) is provided with a one-part U-shaped yoke ( 14 ) with an excitation coil ( 17 ) per yoke leg and a yoke central leg ( 16 ), borne by a flat permanent magnet, supporting a rocker armature ( 11 ) formed in a slightly V-shaped.

Description:
This is an application filed under 35 USC §371 of PCT/DE2011/000395 filed on Apr. 11, 2011 and claiming priority to DE 10 2010 017 872.1 filed on Apr. 21, 2010. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a bistable high-performance miniature relay, comprising a housing made of an insulation material with a first housing chamber in which a single-phase contact assembly with two current bars and a contact spring is arranged, with the contact spring permanently connected with one leg end to one of the current bars and with the other free leg end, bearing at least one mobile contact, works to at least one fixed contact that is seated on the second current bar, wherein in a second housing chamber a bistable magnetic actuator assembly with a pivotable armature is placed that over a driving device located in the housing displaces the contact spring in order to close or break an electric circuit over the current bars. 
     Such a generic miniature relay, for example, is known from DE 10 2007 011 328 A1. In this relay the actuator assembly is placed in a housing chamber above a housing chamber for the contact assembly, with both housing chambers having different dimensions. Therefore the elongated contact spring is required. The actuator is provided with a so-called H-armature, comprising two parallel soft iron armature plates between which a permanent magnet is clamped magnetized such that the one pole is directed toward the one armature, the other pole toward the other armature. The H-armature is supported by a pivot bolt in the housing chamber of the actuator, pivoting between two sections directed toward each other of two yoke components of the magnetic circuit depending upon the excitation pulse of a solenoid coil with changeable polarity. The bolt bearing causes friction. The H-armature has a radially protruding arm reaching under a contact spring that is elongated on the whole, thus displacing the contact spring. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is based on the problem to develop a bipolar electrical miniature relay having a switching power within the range of 100 A or more that is easy to manufacture, easily adaptable to specified conditions of use and consumes only little switching energy. 
     The problem is solved by the features of claim  1 . Advantageous further developments and embodiments are given by the accompanying claims. 
     Due to its modular structure the relay according to the invention can be configured extremely variable to meet very different requirements of installation. The simple and automation-friendly components and the suitable division into an actuator assembly and a contact assembly reduce production costs. Other advantages are the small installation space with high power, and the option to minimize either the installation height or the installation width while using the same assemblies. The relay enables high switching frequencies and distinguishes itself by low contact chatter, very low contact resistance, low internal power consumption, little switching energy, long life and fast contact parting in case of a short circuit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will become apparent upon reading the following detailed description of an example of embodiment. In the accompanying drawings it is shown by: 
         FIG. 1  a bistable relay with an insulation material housing removed; 
         FIG. 2  a relay to  FIG. 1  dismantled into assemblies; 
         FIG. 3  an actuator assembly in explosive view; 
         FIG. 4  the actuator assembly to  FIG. 3  in assembled condition; 
         FIG. 5  components of a contact assembly in explosive view; 
         FIG. 6  the components to  FIG. 5  in assembled condition; 
         FIG. 7  a version of the relay with removed housing cap; 
         FIG. 8  a second version of the relay with removed housing cap; 
         FIG. 9  a third version of the relay with removed housing cap; and 
         FIG. 10  schematically shown design versions of the relay according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a first embodiment of a bistable relay according to the invention with the insulation material housing removed. The insulation material housing comprises a square housing bottom part  1  and a square housing cap  2  that enclose between each other an actuator assembly  3  and a contact assembly  4  located adjacent to the actuator assembly  3 . A partition  5  divides the housing bottom part  1  into two approximately same size housing chambers  1   a ,  1   b . The one chamber  1   a  accommodates the actuator assembly  3  by form closure, the other chamber  1   b  accommodates the contact assembly  4  by form closure, with internal housing contours not shown in the insulation material housing serving for that. The actuator assembly  3  actuates the contact assembly  4  via a driving device reaching over the chambers  1   a ,  1   b . With the insulation material housing closed, only three connector pins  7  are brought out for the control of the actuator and two current bars  8   a ,  8   b  for the consumer current to be switched, the ends of which can be configured depending upon the use of the relay. For example, the relay can be a component of an intelligent electronic energy meter. 
       FIG. 2  shows the same establishment of a relay, again with the insulation material housing removed, with the actuator assembly  3 , the contact assembly  4  and the driving device shown separated from each other for better visibility of details. In the relay version shown, the driving device is established as rotative double-arm rocker element  6  supported in the insulation material housing. A hole  9  is provided, centered at the level of the partition  5  of the housing chambers  1   a ,  1   b  in the housing bottom part  1 , to support the rocker element  6 . Using a gripper arm  6   a  the rocker element  6  grips a force application member  10  of a rocker armature  11  of the actuator assembly  3 , using the other gripper arm  6   b  a force application member  12  of a contact spring  13  of the contact assembly  4 . Both gripper arms  6   a ,  6   b  are equal in length so that same force-way ratios follow. But also other lever ratios are possible. 
     In  FIG. 3  an actuator assembly  3  is shown detailed in an explosive view. A U-shaped yoke  14  is one-part with both yoke legs stamped and bent from soft iron sheet. On the central part of the yoke  14  a flat permanent magnet  15  is arranged, bearing a soft iron central leg  16 . So an E-shaped magnetic core is formed. On the outer yoke legs there are separately controllable excitation coils  17  carried by an insulating body  18 . The insulating bodies  18  of the excitation coils  17  are connected by one or several film hinges  19 , therefore can be wound in one operation while bringing out the inner line ends. The inner line ends are soldered to one of the three connector pins  7 , the outer line ends separately to the other two connector pins  7 . On the central leg  16  the slightly V-shaped rocker armature  11  is knife-edge mounted. Such an armature support is very poor in friction, therefore requires only little control power. The magnetic force of the extremely flat permanent magnet  15  is sufficient to hold all four magnetic components  14 ,  15 ,  16  and  11  without any other fastening means, excepting a lateral guide of the rocker armature  11  at the insulating body  18 . At a wing of the rocker armature  11  the force application member  10  for the gripper arm  6   a  of the double-arm rocker element  6  is mounted or formed on. Depending upon the switching position of the rocker armature  11  the relay closes or breaks a load circuit led over the two current bars  8   a ,  8   b.    
     In  FIG. 4  the actuator assembly  3  is again shown in assembled condition, with the same reference marks used for equal-function components like in all other drawings. The specially flat design of the actuator assembly  3  and the small number of components is seen. 
     In a preferred version the actuator assembly  3  is controlled over the connector pins  7  such that for switching over the rocker armature  11  from one switching position into the other the permanent magnetic holding flux through the parallel magnetic circuit closed over the rocker armature  11  commutates at an electromagnetic control flux generated by the excitation coil  17  of this magnetic circuit at a direction opposed to the permanent magnetic holding flux into the other parallel magnetic circuit that carries the unexcited excitation coil  17 . For switching over, always that excitation coil  17  is driven that is in the magnetic circuit with the attracted armature wing of the rocker armature  11 . This reduces the driving power. 
       FIG. 5  shows a version of the contact assembly in an explosive view. Three plates of a contact spring  13  bent in U-shape are shown. The three plates of different length are solely at their ends mechanically and electrically connected to each other. The shorter U-legs are attached with their ends to one of the current bars  8   a , the longer ends bear a movable contact  20  that interacts with a fixed contact  21  on the other current bar  8   b . Formed at the free ends of the upper and lower contact spring plates there are force application members  12  in form of cut-out flexible tongues serving as application point of a driving device. Shape elements not shown in detail of the current bars  8   a ,  8   b  engage with corresponding shape elements in the housing chamber  1   b  of the housing bottom part  1  to make a form closure. In addition, both ends of the current bars  8   a ,  8   b  are configured to enable conductors to be connected. 
     In  FIG. 6  a contact assembly  4  is again drawn in assembled condition. The U-shape of the contact spring  13  allows to achieve a force-way characteristic well-tuned to the actuator, despite of the short design length and high current carrying capacity required. The requirement is supported by the multiplate structure of the contact spring  13 , while it is advantageous for heat removal, length compensation of manufacture tolerances, length compensation of thermal expansion of the plates and flexibility of the contact spring  13 , if in the U-bending zone the single plates fan out in a self-aligning manner. It can also be provided that the single plates have different spring and conductivity properties. Due to the U-shape of the contact spring  13  the current flows through the contact spring sections, that are parallel next to the other, of the U-legs in opposite directions so that in case of a short-circuit current the contacts  20 ,  21  advantageously are broken at a low delay by the electrodynamic forces acting on the contact spring  13 . 
       FIG. 7  shows another version of the relay. The relay has already been assembled excepting putting on the housing cap  2 . The fundamental structure corresponds to that of the basic version to  FIG. 1 . But as distinct from  FIGS. 1 ,  2 ,  5  and  6 , a version of a contact assembly  4  is represented having two contacts  20  on the contact spring  13  and two fixed contacts  21  on the current bar  8   b . If there are two contacts for one switching pole, the transition resistance between the contacts  20 ,  21  is cut in half, which has a positive effect on the heating, internal power consumption and service life of the contact system. The multiplate contact spring  13  is slotted at its contacts bearing end so that each of both movable contacts  20  is flexibly moving on its own, capable to compensate for any manufacture tolerances toward the fixed contacts  21 . Moreover, the chatter liability, hence contact burn-up reduces. The dimensions of the two housing chambers  1   a ,  1   b  are not changed compared to the dimensions in  FIG. 1 . In the rotative bearing  9  at the level of the partition  5  the double-arm rocker element  6  is supported as driving device. 
     In  FIG. 8  another relay version is shown. The version comprises a long extending three-plate contact spring  13  bent U-shaped that is slotted longitudinally over a longer length to form two spring arms. Again the plates are connected to each other at both ends. The shorter U-leg of the contact spring  13  is mounted with its end to a current bar  8   a , the longer U-leg of the contact spring  13  bears a movable contact  20  at each end of its spring arms. The movable contacts  20  interact with fixed contacts  21  attached to the second current bar  8   b . In contrast to the previous contact assemblies the contacts  20 ,  21  are on the other switching side, away from the U-bend. For that, the current bar  8   b  bearing the fixed contacts  21  is offset in the housing chamber  1   b  for the contact assembly  4 . In the shown closing position of the contacts  20 ,  21  a current flows over the first current bar  8   a , the shorter U-leg of the contact spring  13 , the U-bend zone of the contact spring  13 , the longer U-leg of the contact spring  13 , the contacts  20 ,  21  to the second current bar  8   b . The U-shape of the contact spring  13  allows to achieve a force-way characteristic well-tuned to the actuator, despite of the short design length of the contact spring  13  and the high current carrying capacity required. This requirement is supported by the multiplate structure of the contact spring  13 , wherein it is advantageous for the heat removal and flexibility of the contact spring  13  that the single plates of the contact spring  13  fan out in the U-bend zone due to their different lengths. Also here the single plates can be provided to have different flexibility and conductivity properties. Due to the U-shaped contact spring  13  the current flows through the contact spring sections that are parallel next to the other, of the U-legs in opposite directions. In the closed position of the contacts  20 ,  21 , when high currents flow, the contacts  20 ,  21  are advantageously pressed onto each other, in addition to the contact force, by the occurring electrodynamic forces acting on the contact spring  13 . Again a double-arm rocker element  6  serves to operate the contact spring  13  over the actuator assembly  3 . 
     Whereas in the  FIGS. 1 ,  2 ,  7  and  8  relay versions were described with the actuator assembly  3  and the contact assembly  4  arranged in one plane in the insulation material housing, that is side by side in the housing chambers  1   a ,  1   b  of the housing bottom part  1 ,  FIG. 9  shows another relay version with the actuator assembly  3  placed above the contact assembly  4  in the insulation material housing  1 . The assemblies  3 ,  4  themselves basically have the same structure and same size compared to the previous assemblies. But in this example the current bars  8   a ,  8   b  are led out of the insulation material housing at right angle. Also the housing chambers  22   a ,  22   b  have the same dimensions. Now the insulation material housing  22  is no longer square in its cross-section but rectangular, the housing cap, not shown in detail, is L-shaped. The insulation material housing is twice as high and, therefore, half as wide as the insulation material housing having a square cross-section. The contact assembly  4  is inserted into the lower housing chamber  22   b . The actuator assembly  3  is inserted into the upper housing chamber  22   a . The driving device includes a slide  23  that on a narrow side is guided by contours of the housing bottom part  22   b . The slide  23  has gripper arms  23   a ,  23   b  on both sides that grip, first, a force application member  10  of a rocker armature  11  of the actuator assembly  3  and second, a force application member  12  of a contact spring  13  of the contact assembly  4 . A further special feature is that each excitation coil  17  is led to a couple of connector pins  7 . 
     The assembly drawing with the  FIGS. 10   a ) to  10   e ) shows purely schematically some versions of a relay structure, wherein to  FIG. 10   a ) to  FIG. 10   d ) the housing chamber  1   a  for the actuator assembly  3  and the housing chamber  1   b  for the contact assembly  4  are placed side by side in one plane in an insulation material housing in each case, but to  FIG. 10   e ) in two planes above each other. In the examples, the current bars  8   a ,  8   b  are in all versions led out parallel to each other. The relay arrangements to the  FIGS. 1   a ) and  1   e ) are preferred because of the compact design. If the installation conditions, however, do not allow another option, a relay version to the  FIGS. 10   b ) to  10   d ) can easily be used. Depending upon the demands of the individual versions, rockers, slides, levers, pins etc. can be used as driving devices, and the current bars  8   a ,  8   b  can be flat, raised on edge, parallel or at an angle to each other. For special cases of application relays can be made having one actuator assembly and more than one contact assembly. For example, following  FIG. 10   e ), relays with two contact assemblies located above each other can be configured, or following  FIG. 10   a ), relays with contact assemblies located on both sides of an actuator assembly. For example, the actuator assembly can actuate a make contact assembly and a break contact assembly. Also a switching over contact assembly can be configured in that on both sides of the contact spring there is a movable contact that interacts with a fixed contact each. In this case three current bars lead out of the insulation material housing. 
     NOMENCLATURE 
     
         
           1  square housing bottom part 
           1   a  housing chamber for actuator assembly 
           1   b  housing chamber for contact assembly 
           2  square housing cap 
           3  actuator assembly 
           4  contact assembly 
           5  partition 
           6  double-arm rocker element as driving device 
           6   a  gripper arm 
           6   b  gripper arm 
           7  connector pins 
           8   a  current bar 
           8   b  current bar with fixed contact 
           9  rotative bearing in the housing bottom part 
           10  force application member at the rocker armature 
           11  rocker armature 
           12  force application member at the contact spring 
           13  contact spring 
           14  U-shaped soft iron yoke 
           15  permanent magnet 
           16  central leg 
           17  excitation coils 
           18  insulating body 
           19  film hinge 
           20  movable contact 
           21  fixed contact 
           22  rectangular housing bottom part 
           22   a  upper housing chamber for the actuator assembly 
           22   b  lower housing chamber for the contact assembly 
           23  slide as driving device 
           23   a  upper gripper arm at the slide 
           23   b  lower gripper arm at the slide