Abstract:
An electromagnetically actuatable proportional valve ( 10 ) includes a valve part ( 14 ) with an actuator that controls pressure fluid connections, an actuator solenoid ( 12 ), and with a set of control electronics ( 16 ), controls the activation of the coil. The control electronics ( 16 ) are flanged mounted onto the actuator solenoid ( 12 ) or the valve part ( 14 ) and is thereby exposed to mechanical and/or hydro-mechanical vibrations. In order to vibrationally decouple the control electronics ( 16 ) from the valve part ( 14 ) and/or the actuator solenoid ( 12 ) at least one vibration-damping means in the form of a damping plate ( 18 ) between these components and the control electronics ( 16 ) is provided.

Description:
BACKGROUND OF THE INVENTION 
     The invention is based on an electromagnetically actuatable proportional valve. Proportional valves of this kind are used, for example, as pressure controllers or flow regulators in hydraulic control circuits. 
     An electromagnetically actuatable proportional valve is already known, for example, from DE 38 29 992 A1. This known proportional valve is comprised of an actuator solenoid with a coil and armature, a valve part with a movably guided actuator that can be acted on by the armature, and a set of control electronics for controlling the activation of the armature by means of the coil. The control electronics are flange mounted to the housing of the actuator solenoid. Mechanical and/or hydro-mechanical vibrations that are produced, for example, by pumps and their pressure pulsations or by the switching processes of adjacent switching devices, are transmitted via the housing of the actuator solenoid to the wired components, the lines, and the plug connectors of the control electronics. The accelerations that occur can increase the stresses on these components, causing damage that in the extreme case can lead to the total failure of the control electronics. So that the electronic components withstand these vibrations, complex measures are taken, for example the components are cast or glued in place during the production of the control electronics. Such measures, however, are costly and often insufficient. 
     A SUMMARY OF THE INVENTION 
     An electromagnetically actuatable proportional valve has the advantage over the prior art that the transmission paths of the vibrations to the control electronics are interrupted or at least damped. The measures explained above for vibration-proof anchoring of electronic components to the circuit substrates can therefore be reduced and under some circumstances, entirely eliminated. 
     Other advantages or advantageous modifications of the invention ensue from the dependent claims and the specification. For example, embodying vibration-damping means in the form of a damping plate achieves a particularly high degree of effectiveness and a simultaneously inexpensive manufacture and simple operation. Disposing the fastening devices one above the other on the fastening flanges also permits a damping plate to be retrofitted onto existing electromagnetically actuatable proportional valves. In addition, the anchoring of the damping plate requires only a minimum of space. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Exemplary embodiments of the invention are shown in the drawings and will be explained in detail in the subsequent description. 
     FIG. 1 shows a perspective representation of an electromagnetically presettable proportional valve embodied according to the invention, 
     FIG. 2 shows several views of a damping plate as a separate part, 
     FIG. 3 shows a second exemplary embodiment for a damping plate, likewise in several different views. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The electromagnetically actuatable proportional valve  10  according to FIG. 1 is a structural unit comprised of an actuator solenoid  12 , a valve part  14  connected to it with the aid of tie bolts  13 , and a set of control electronics  16 . The control electronics  16  are attached to a side surface of the actuator solenoid  12  by means of screws  17 . Between the two components, a damping plate  18  is provided, which vibrationally decouples the actuator solenoid  12  from the control electronics  16 . The design of the damping plate  18  is shown in two exemplary embodiments in different views in FIGS. 2 and 3. 
     FIG. 2.1 shows the damping plate  18  from underneath, i.e. from its side oriented toward the actuator solenoid  12 . A first fastening flange  20  is shown, which is provided to embody a frame piece with a central opening  22 . The fastening flange  20  is preferably made of metal and is essentially rectangular in its external form. In the vicinity of the corners of this external form, grooves  24  are provided, which open toward the outside, extend along the diagonal of the fastening flange  20 , and have rounded ends. The width of the groove  24  is matched to the diameter of the shaft of the fastening screws, which are inserted into the grooves  24  from the outside in order to anchor the damping plate  18  to the actuator solenoid  12  (FIG.  1 ). The edge regions around the grooves  24  thus serve to support the screw heads. 
     FIG. 1 indicates the outer contour of an elastomer part  26 , depicting it with dashed lines because it is only indirectly visible in this view, which is vulcanized onto the side of the fastening flange  20  oriented away from the plane of the drawing. This elastomer part  26  protrudes partly into the opening  22  and constitutes a circumferential collar  28  that protrudes beyond the fastening flange  20  and seals the parting plane between the actuator solenoid  12  and the damping plate  18 . In the vicinity of the comers, the elastomer part  26  is provided with recesses so that the grooves  24  of the damping plate  18  are left unobstructed. 
     The top view of the damping plate  18  depicted in FIG. 2.2 shows a second fastening flange  30 , which is disposed on the opposite side of the elastomer part  26  from the first fastening flange  20  and is likewise vulcanized onto the elastomer part  26 . As a result of this connection, the two fastening flanges  20  and  30  can move in relation to each other so that vibrations, which are introduced into the system by the first fastening flange  20  are transmitted to the second fastening flange  30  in a sharply damped form, if at all. The outer contours of the two fastening flanges  20 ,  30  are congruent and threaded sleeves  32  are provided in the vicinity of the comers of the second fastening flange  30 . These threaded sleeves are placed concentric to the rounded ends of the grooves  24  of the first fastening flange  20  and are likewise accommodated in recesses in the elastomer part  26 . The threaded sleeves  32  are advantageously connected to the second fastening flange  30  by means of caulking. They abut the second fastening flange  30  and extend toward the first fastening flange  20  without touching it. This assures the relative mobility of the fastening flanges  20 ,  30 . Between the end of the threaded sleeves  32  and the first fastening flange  20 , a space is left, which is greater than the height of the screw head of a screw accommodated in the groove  24  of the first fastening flange  20 . 
     The second fastening flange  30  is oriented toward the control electronics  16 , which are anchored to the damping plate  18  by screws, which are screwed into the threaded sleeves  32 . Before this screw-mounting procedure takes place, the screws accommodated in the grooves  24  of the first testing flange  20  must be screwed into the screw threads provided for them in the actuator solenoid  12  by means of a tool that is not shown. Advantageously, a tool can be used for this, which can be inserted through the core hole of the threaded sleeves  32  of the second fastening flange  30 . 
     The concentric placement of grooves  20  in relation to the threaded sleeves  32  in connection with a screw-mounting procedure that takes place through the opening of the threaded sleeves  32  achieves a particularly space-saving design of the damping plate  18 . In addition, this permits a damping plate  18  of this kind to be retrofitted onto existing electromagnetically actuatable proportional valves  10 . 
     The cross section through the damping plate  18 , which is depicted in FIG. 2.3 and runs along the sectional line A—A according to FIG. 1, shows that the fastening flanges  20  and  30  are comprised of angle sections. These angle sections are disposed point-symmetrically opposite each other and with their legs, at least partially define the inner and outer contours of the damping plate  18 . The intermediary space between the two angle sections is filled by the elastomer part  26  so that the damping plate  18  as a whole has a solid rectangular cross section. Naturally, the fastening flanges  20 ,  30  are not limited to the equal-sided angle sections shown. If need be, hollow spaces can also be provided in the elastomer part  26  whose shape and disposition can be used to influence the elasticity of the elastomer part  26  in a manner specific to the intended use. 
     Furthermore, instead of being made of angle sections, the fastening flanges  20 ,  30  can also be made of flat band material. FIG. 3 shows an embodiment of this kind. This second embodiment differs from the above-described first embodiment also in that instead of the grooves  24  in the fastening flange  20 , through openings  34  are provided on the side oriented toward the actuator solenoid  12 . These through openings  34  are embodied in the region of the first fastening flange  20  enclosed inside the elastomer part  26  and this fastening flange  20  has an opening  22 , which is correspondingly smaller in size than in the first exemplary embodiment. In order to anchor the control electronics  16  onto the damping plate  18 , threaded sleeves  32  are likewise provided in the comer regions of the second fastening flange  30 , but are not shown in FIG.  3 . 
     Naturally, other changes or additions to the exemplary embodiments described above are possible without venturing beyond the scope of the invention.