Abstract:
The invention relates to a magnetic valve having a magnetic assembly and a capsule. An armature is disposed in the capsule and a valve insert is inserted in the capsule. A tappet is guided in a displaceable manner within the inner bore of the valve insert and sealingly immerges in a sealing seat. The valve insert is arranged at a distance from the armature via an adjustable air gap. According to the invention, the sealing seat is arranged in a sleeve which itself is disposed inside the capsule. The sleeve has at least one opening through which adjusting elements act upon the valve seat in order to regulate the magnetic flux generated by the magnetic assembly. The air gap between the valve insert and the armature is variable, whereby the adjusting elements either move the valve insert in axial direction towards the armature in order to increase the magnetic flux or move the valve insert away from the armature in order to reduce the magnetic flux.

Description:
PRIOR ART 
       [0001]    The invention is based on a magnetic valve as generically defined by the preamble to independent claim  1 . 
         [0002]    A conventional magnetic valve, particularly for a hydraulic unit, which is used for instance in an anti-lock brake system (OBOIST) or traction control system (TCS) or an electronic stability program system (ESP system), is shown in  FIG. 1 . As can be seen from  FIG. 1 , the conventional magnetic valve  110  includes a magnet assembly  5  for generating a magnetic flux  5 . 1 , which magnet assembly in turn includes a housing  5 . 2 , a coil winding  5 . 3 , a coil body  5 . 4 , and a covering disk  5 . 5 ; and a valve cartridge, which includes a capsule  60 , a valve insert  10 , a tappet  20 , a restoring spring  30 , and an armature  7 . In the production of the magnetic valve  110 , the capsule  60  and the valve insert  10  of the valve cartridge are joined together by pressing, and the valve cartridge is hydraulically sealed off from the atmosphere by a sealing weld  8 . In addition, the valve insert  10  absorbs the pressure forces that occur in the hydraulic system and carries them onward to a fluid block, via a wedging flange  10 . 1  in a wedging region, not shown. In addition, the valve insert  10  conducts the magnetic flux  5 . 1 , introduced by the joined magnet assembly  5 , axially in the direction of the armature  7  via an air gap  11 . The valve insert  10  furthermore receives the so-called valve body  40 , which includes a sealing seat  41  into which the tappet  20  dips in sealing fashion in order achieve the sealing function of the magnetic valve  110 . As can also be seen from  FIG. 1 , the tappet  20  and the restoring spring  30  are guided in the valve insert  10 . The attachment of the magnet assembly  5  at the bottom is accomplished by pressing the covering disk  5 . 5  directly onto the magnetically conductive valve insert  10  of the valve cartridge. The capsule  60 , likewise pressed onto the valve insert  10  and welded, has a lower region which is thrust in overlapping fashion onto the valve insert  10 . 
         [0003]    To adapt the conventional magnetic valve  110 , functions are as a rule established; that is, a calibration is performed, in order as much as possible to minimize and compensate for variations in such properties of the parts as their geometry, magnetic properties, and so forth. For doing so, usually components that are easily accessible from outside are displaced counter to one another in accordance with an adjustment instruction, for instance to produce an equilibrium between contrary forces, until in a final position the desired function is assured. For the adaptation, the moving components should be readily accessible, which can limit further development of the integration of the parts in optimizing valve assemblies. Hence the conventional magnetic valve  110 , before a lower valve part  12  is installed, is calibrated with simultaneous subjection of it to pressure and introduction of magnetic force. The adjustment of the magnetic flux  5 . 1  and thus of the magnetic force is done by increasing or decreasing the size of the air gap  11  by axial displacement of the valve body  40 . 
         [0004]    In German Patent Application DE 102005044672.8, not published before the priority date of the present application, of the same Applicant, a magnetic valve is described which distributes the described functions of the valve insert over a plurality of components, so that the valve insert can be designed more simply. In the described magnetic valve, the overlapping region of the capsule is lengthened in the direction of the wedging region and is wedged with a valve bush in the wedging region with the fluid block. Moreover, as the lower part of the valve cartridge, a sleeve is fitted with a sealing seat into the lengthened capsule. Because of the lengthening of the capsule into the fluid block, the sealing from the atmosphere and the wedging with the fluid block are advantageously accomplished via the valve bush, and no longer via the valve insert. As a result, the valve insert is relieved and can be designed more simply. Furthermore, one production step, for sealingly welding the capsule to the valve insert, can be dispensed with. Because the components are fitted into one another in sleevelike fashion, however, calibrating the magnetic valve is difficult to do. 
       ADVANTAGES OF THE INVENTION 
       [0005]    The magnetic valve of the invention having the characteristics of independent claim  1  has the advantage over the prior art that a sealing seat is disposed in a sleeve which is fitted into a capsule and has at least one opening, through which adjusting elements act on a valve insert for adjusting a magnetic flux generated by a magnet assembly. As a result, an air gap between the valve insert and an armature can be varied, and the adjusting elements move the valve insert axially toward the armature to increase the magnetic flux or move the valve insert axially away from the armature to decrease the magnetic flux. The adjusting elements according to the invention, which act via existing openings on the poorly accessible components, that is, the valve insert, advantageously make it possible for even magnetic valves with components fitted into one another in sleevelike fashion to be easily calibrated and adjusted for function without major additional effort or expense. The invention makes use of the geometric properties, created by functional integration, of the magnetic valve so as to advantageously enable the calibration and function adjustment even via poorly accessible internal components. 
         [0006]    By the provisions and refinements recited in the dependent claims, advantageous improvements to the magnetic valve disclosed in the independent claim are possible. 
         [0007]    It is especially advantageous that the capsule is wedged with a valve bush in a wedging region with a fluid block, thereby greatly simplifying the valve insert. For adjusting the air gap between the valve insert and the armature, a tappet dips sealingly into the sealing seat of the sleeve; that is, the sealing seat of the sleeve is closed during the calibration process. 
         [0008]    In a feature of the magnetic valve of the invention, at least one check valve seat bore and/or at least one radial bore is used as the at least one opening in the sleeve. The adjusting elements act on the valve insert for instance via a nonpositive engagement and/or a positive engagement. For producing a positive engagement, the valve insert for instance has receiving means, which are preferably embodied as an annular groove that is engaged by the at least one adjusting element. 
         [0009]    In a further feature of the magnetic valve of the invention, at least one adjusting element is solidly connected to the valve insert and acts on the valve insert through a first opening, and the at least one adjusting element, after the adjustment of the air gap, can be disconnected from the valve insert by means of a tool, for instance by means of a cutting tool, introduced through a second opening. Alternatively, at least one adjusting element can be embodied as a pair of grippers which can be introduced axially into the sleeve through two openings and acts axially on the valve insert. 
         [0010]    In a further feature of the magnetic valve of the invention, at least one adjusting element can be introduced into the sleeve radially through at least one opening and acts, axially guided, on the valve insert. Alternatively, the at least one radially introduced adjusting element can act in a rotationally leverlike fashion on the valve insert. 
     
    
     
       DRAWINGS 
         [0011]    Advantageous embodiments, described below, of the invention as well as the conventional exemplary embodiment described above for better comprehension of the invention, are shown in the drawings. Shown are: 
           [0012]      FIG. 1 , a schematic sectional view of a conventional magnetic valve; 
           [0013]      FIG. 2 , a schematic sectional view of a valve cartridge for a magnetic valve of the invention; 
           [0014]      FIG. 3 , a schematic sectional view of a valve cartridge for a magnetic valve of the invention, with a first exemplary embodiment of an adjusting element; 
           [0015]      FIG. 4 , a schematic sectional view of a valve cartridge for a magnetic valve of the invention, with a second exemplary embodiment of an adjusting element; 
           [0016]      FIG. 5 , a schematic sectional view of a valve cartridge for a magnetic valve of the invention, with a third exemplary embodiment of an adjusting element; and 
           [0017]      FIG. 6 , a schematic sectional view of a valve cartridge for a magnetic valve of the invention, with fourth and fifth exemplary embodiments of an adjusting element. 
       
    
    
     DESCRIPTION 
       [0018]    As can be seen from  FIG. 2 , a valve cartridge  100  for a magnetic valve according to the invention, which valve cartridge is wedged via a valve bush  9  in a wedging region, not show, with a fluid block, includes a capsule  6 , a sleeve  4 , a valve insert  1 , a tappet  2  guided in an inner bore of the valve insert  1 , a restoring spring  3  which is braced against the valve insert  1  in the inner bore and restores the tappet  2 , and an armature  7 . The capsule  6  is pushed in overlapping fashion onto the valve insert  1  and is embodied as a valve component that provides sealing from the atmosphere. In a distinction from the conventional magnetic valve  110  shown in  FIG. 1 , the capsule  6  is lengthened in the direction of the wedging region. As a result, the conventional sealing weld  8  of  FIG. 1  can be omitted. Furthermore, the fluid forces and wedging forces are no longer absorbed by the valve insert  1  but rather by the valve bush  8  and are transmitted to the fluid block via the wedging region, not shown. In the capsule  6 , the armature  7 , which is unchanged from the conventional magnetic valve  110  of  FIG. 1 , acts and sets the tappet  2 , which is unchanged in its function, into motion counter to the restoring spring  3 . The lower part of the valve cartridge  100  and a sealing seat  4 . 1  are formed by the sleeve  4 , which is fitted into the capsule  6 . The valve cartridge  100  shown furthermore includes a flat filter  14  and an annular filter  16 , which are connected to the sleeve  4 . As can also be seen from  FIG. 2 , the sleeve  4  has radial bores  16 . 1  and a check valve seat bore  15 , which with a check valve ball  15 . 1  forms a check valve. For constructing the magnetic valve of the invention, a magnet assembly, not shown, which for instance is equivalent to the conventional magnet assembly  5  of  FIG. 1 , is pushed onto the wedging region. A magnetic flux, introduced into the valve insert  1  via a wall of the capsule  6  by the magnet assembly, not shown, is conducted axially in the direction of the armature  7  by the valve insert  1  via an air gap  11 . By varying the air gap  11  between the valve insert  1  and the armature  7 , the magnetic flux and thus the magnetic force can be adjusted. 
         [0019]    Below, in conjunction with  FIGS. 3 through 6 , the procedure for varying the air gap  11  between the valve insert  1  and the armature  7  for adjusting the magnetic flux will be described. For adjusting the magnetic flux generated by the magnet assembly, not shown, adjusting elements  17 . 1  through  17 . 5  act on the valve insert  1  through at least one opening  15 ,  16 . 1  in the sleeve  4 , and by that means the air gap  11  between the valve insert  1  and the armature  7  can be varied. Hence the adjusting elements  17 . 1  through  17 . 5  move the valve insert  1  axially toward the armature  7 , to increase the magnetic flux. To decrease the magnetic flux, the adjusting elements  17 . 2  through  17 . 5  can move the valve insert  1  axially away from the armature  7 . 
         [0020]      FIG. 3  shows a further schematic sectional view of a valve cartridge  101 , which essentially corresponds to the valve cartridge  100  of  FIG. 2 , but in the valve cartridge  101 , in a distinction from the valve cartridge  100  shown in  FIG. 2 , the flat filter  14  and the check valve ball  15 . 1  of  FIG. 2  have not yet been installed, so that access to the valve insert  1  is possible via the check valve seat bore  15 . As can be seen from  FIG. 3 , an adjusting element, embodied as a pin  17 . 1 , is introduced via the check valve seat bore  15  and displaces the valve insert  1  axially upward, as a result of which the air gap  11  between the valve insert  1  and the armature  7  decreases in size, and the resultant magnetic flux and hence the magnetic force are increased. An enlargement of the air gap  11  with a resultant decrease in the magnetic flux and hence in the magnetic force is not possible with the first adjusting element  17 . 1 . In the assembly of valve cartridge  100 , the air gap  11  can therefore be set to a maximum value, which can be reduced in the calibration by the first adjusting element  17 . 1  until full functionality is achieved. After that, the other components, such as the check valve ball  15 . 1  and the flat filter  14 , can be installed in order to complete the valve cartridge  101 . The calibration of the valve cartridge  101  is effected with simultaneous pressure subjection  13  and introduction of magnetic force, or in other words with a closed sealing seat  4 . 1 . 
         [0021]      FIG. 4  shows a further schematic sectional view of a valve cartridge  102 , which essentially corresponds to the valve cartridge  100  of  FIG. 2 , but in the valve cartridge  102 , in a distinction from the valve cartridge  100  shown in  FIG. 2 , the flat filter  14 , the annular filter  16 , and the check valve ball  15 . 1  of  FIG. 2  have not yet been installed, so that access to the valve insert  1 ′ is possible via the check valve seat bore  15  and the radial bores  16 . 1 . As can be seen from  FIG. 4 , as a further distinction, an adjusting element embodied as a tie rod  17 . 2  is integrally formed onto the valve insert  1 ′ of the valve cartridge  102 ; it acts on the valve insert  1 ′ via the check valve seat bore  15  and can pull the valve insert  1 ′ axially downward, as a result of which the air gap  11  between the valve insert  1  and the armature  7  is enlarged, and the resultant magnetic flux and hence the magnetic force are lessened. A reduction of the size of the air gap  11  with a resultant increase in the magnetic flux and hence the magnetic force is likewise possible with the second adjusting element  17 . 2 , since the valve insert  1 ′ can be pressed upward in the direction of the armature  7  via the tie rod  17 . 2  to decrease the size of the air gap  11 . Therefore in the assembly of the valve cartridge  100 , the air gap  11  can be set for instance to an arbitrary value, preferably a minimal value, which can be increased or decreased in the calibration by the second adjusting element  17 . 2  until full functionality is reached. After the calibration, the tie rod  17 . 2  is disconnected from the valve insert  1 ′, for instance by means of a cutting tool  19  introduced into the sleeve  4  via the radial bore  16 . 1 . Next, the other components, such as the annular filter  16 , the check valve ball  15 . 1 , and the flat filter  14 , can be installed in order to complete the valve cartridge  102 . The calibration of the valve cartridge  102  is again effected with simultaneous pressure subjection  13  and introduction of magnetic force, or in other words with a closed sealing seat  4 . 1 . 
         [0022]      FIG. 5  shows a further schematic sectional view of a valve cartridge  103 , which corresponds essentially to the valve cartridge  100  of  FIG. 2 , but in a distinction from the valve cartridge  100  shown in  FIG. 2 , a sleeve  4 ′ of the valve cartridge  103  includes two check valve bores  15  for receiving check valve balls  15 . 1 , and a valve insert  1 ″ of the valve cartridge  103  has receiving means which are embodied as an annular groove  18 . In the valve cartridge  103  shown, the flat filter  14  and the check valve balls  15 . 1  have not yet been installed, so that access to the valve insert  1 ″ is possible via the check valve seat bores  15 . As can be seen from  FIG. 5 , an adjusting element embodied as a pair  17 . 3  of grippers can act on the receiving means  18 , introduced into the valve insert  1 ″, by means of a positive engagement and can pull the valve insert  1 ″ axially downward, as a result of which the air gap  11  between the valve insert  1 ″ and the armature  7  is enlarged, and the resultant magnetic flux and hence the magnetic force are reduced, or can slide the valve insert  1 ″ upward, as a result of which a reduction in the size of the air gap  11  and a resultant increase in the magnetic flux and hence the magnetic force are attained. Therefore upon the assembly of the valve cartridge  103 , the air gap  11  can be set for instance to an arbitrary value, preferably a minimal value, which can be increased or decreased in the calibration by the third adjusting element  17 . 3  until full functionality is achieved. Next, the other components, such as the check valve balls  15 . 1  and the flat filter  14 , can be installed in order to complete the valve cartridge  103 . Once again, the calibration of the valve cartridge  103  is effected with simultaneous pressure subjection  13  and introduction of magnetic force, or in other words with a closed sealing seat  4 . 1 . Alternatively, the encompassing annular groove  18  on the valve insert  1 ″ can be dispensed with, and the pair  17 . 3  of grippers protruding through the check valve bores  15  can act on the valve insert  1 ″ via a nonpositive engagement. However, the receiving means  18  make access to the valve insert  1 ″ easier. 
         [0023]      FIG. 6  shows a further schematic sectional view of a valve cartridge  104 , which essentially corresponds to the valve cartridge  100  of  FIG. 2 , but in a distinction from the valve cartridge  100  shown in  FIG. 2 , a valve insert  1 ′ of the valve cartridge  104  has receiving means embodied as an annular groove  18 , and in the valve cartridge  104 , the annular filter  16 , the flat filter  14 , and the check valve ball  15 . 1  have not yet been mounted, so that access to the valve insert  1 ″ is possible via the check valve seat bores  15  and the radial bores  16 . 1 . As can be seen from  FIG. 6 , adjusting elements  17 . 4 ,  17 . 5  embodied as grippers or pins can act via the radial bores  16 . 1  by means of a positive engagement on the receiving means  18  inserted into the valve insert  1 ″ and can slide the valve insert  1 ″ axially downward, as a result of which the air gap  11  between the valve insert  1 ″ and the armature  7  increases in size, and the resultant magnetic flux and hence the magnetic force are decreased, or can slide the valve insert  1 ″ axially upward, by means of which a reduction in size of the air gap  11  and a resultant increase in the magnetic flux and thus in the magnetic force are attained. In the assembly of the valve cartridge  104 , the air gap  11  can therefore be set for instance to an arbitrary value, preferably a minimal value, which can be increased or decreased in the calibration by the fourth and/or fifth adjusting element  17 . 4 ,  17 . 5  until full functionality is reached. To illustrate various possible embodiments, as can also be seen from  FIG. 6 , the fourth adjusting element  17 . 4  acts on the valve insert  1 ″ via a leverlike, rotational motion, and the fifth adjusting element acts on the valve insert  1 ″ via a purely axially executed motion. Next, the further components, can be installed, such as the annular filter  16 , the check valve ball  15 . 1 , and the flat filter  14 , in order to complete the valve cartridge  104 . The calibration of the valve cartridge  104  is again effected with simultaneous pressure subjection  13  and introduction of magnetic force, or in other words with a closed sealing seat  4 . 1 . 
         [0024]    In the embodiments of the invention described, the bores integrated into the sleeve for the check valve seats and/or the radial outflow bores are advantageously used for axially displacing the valve insert. As a result, the remanent air gap and thus the magnetic force can be adjusted in turn. As a consequence of the functional integration, the sleeve carries both the primary valve sealing seat and the seat for one or more check valves.