Abstract:
The invention relates to a magnetic valve which is caulked on a caulking area by means of a fluid block. The valve includes a capsule, a magnetic assembly, an anchor and a valve insert which guides a magnetic flux which starts from the magnetic assembly in an axial manner via an airgap in the direction of the anchor. The capsule includes a lower area which is displaced in an overlapping manner on the valve insert. The overlapping area of the capsule extends in the direction of the caulking area, the magnetic assembly guides the magnetic flux via the capsule into the valve insert, the capsule is caulked with a valve bushing on the caulking area by means of a fluid block and a bushing is inserted into the capsule.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a 35 USC 371 application of PCT/EP 2006/064970 filed on Aug. 2, 2006. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is directed to an improved solenoid valve of the type used, for example, in a hydraulic system such as a vehicle brake system. 
     2. Description of the Prior Art 
       FIG. 6  shows a conventional solenoid valve, in particular for a hydraulic unit that is used, for example, in an antilock brake system (ABS), a traction control system (TCS), or an electronic stability program system (ESP). As is clear from  FIG. 6 , the conventional solenoid valve  600  has a magnet unit  7  with a covering washer  19 , and a valve cartridge, which includes a capsule  1 , valve insert  5 , a tappet  9 , a return spring  10 , and an armature  8 . During manufacture of the solenoid valve  600 , the capsule  1  and the valve insert  5  of the valve cartridge are joined to each other by being press-fitted and the valve cartridge is hydraulically sealed in relation to the atmosphere by means of a seal weld  4 . In addition, the valve insert  5  absorbs the compressive forces occurring in the hydraulic system and conveys them via a caulking flange  20  to a caulking region  2  on a fluid block  3 . In addition, the valve insert  5  conducts a magnetic flux, which is introduced by the magnet unit  7 , axially via an air gap  17  in the direction of the armature  8 . In addition, the valve insert  5  accommodates the so-called valve body, which constitutes the valve seat  11  into which the tappet  9  is inserted in a sealed fashion in order to perform the sealing function of the solenoid valve  600 . As is also clear from  FIG. 6 , the tappet  9  is guided in the valve insert  5  by a tappet guide  18  and the return spring  10 . The lower attachment of the magnet unit  7  is produced by the covering washer  19  being pressed directly against the magnetically conductive valve insert  5  of the valve cartridge. The capsule  1 , which is likewise pressed onto the valve insert  5  and welded, has a lower region that is slid in overlapping fashion onto the valve insert  5 . In order to be pressed into place, the capsule  1  is slid onto the valve insert  5  by means of a frontal insertion bevel  13 . A second insertion bevel is provided for pressing the magnet unit  7  onto the valve insert  5 . 
     SUMMARY AND ADVANTAGES OF THE INVENTION 
     The solenoid valve according to the present invention has the advantage over the prior art that an overlap region of a capsule is elongated in the direction of a caulking region, a magnet unit introduces a magnetic flux into a valve insert via the capsule, the capsule is caulked by means of a valve bushing to a fluid block in the caulking region, and a sleeve is inserted into the capsule. This advantageously permits a significant simplification of the individual components. By elongating the capsule into the fluid block, the sealing in relation to the atmosphere and the caulking to the fluid block advantageously occur by means of the valve bushing and no longer by means of the valve insert. As a result, it is possible to eliminate a manufacturing step for seal welding the capsule to the valve insert. Eliminating the welding seam and an insertion bevel for press-fitting the capsule onto the valve insert also results in a reduced structural height of the solenoid valve above the fluid block, which can have a positive effect on a housing volume of a subassembly into which the fluid block with the solenoid valve can be integrated. The sleeve design in the lower part of the valve also advantageously results in a reduced structural height in the fluid block, thus reducing the thickness of the fluid block and therefore also permitting an advantageous reduction in the weight and volume of the fluid block. 
     Advantageous improvements of the solenoid valve are disclosed. It is particularly advantageous that the movement of a tappet of the solenoid valve according to the present invention is guided by the valve insert and/or by the sleeve by means of an associated tappet guide. The guidance of the tappet by means of the sleeve has the advantage that no offset of the guide in relation to the sealing seat is caused by the assembly of two components. It is then possible for the valve insert to have a simple annular form and to serve only for conducting the magnetic flux, which is introduced by the magnet unit, via the air gap to the armature. If the tappet is guided by the valve insert, then the valve insert can have a round internal bore and the tappet can have volume compensation grooves let into it between a tappet top and a tappet bottom. In an alternative embodiment, the tappet can be embodied as fully round and the valve insert can have volume compensation grooves let into it between the tappet top and tappet bottom. 
     In the embodiment of the solenoid valve according to the present invention, a return spring for the tappet can rest against the sleeve or valve insert. With a positioning of the return spring between the armature and the valve insert in the vicinity of the air gap and a support of it against the valve insert, the flow guidance in the valve seat region can be advantageously improved since the fluid flow no longer subjects the return spring to the flow forces in the vicinity of the sealing seat. 
     In another embodiment of the solenoid valve according to the present invention, the stroke of the tappet can be advantageously adjusted by axially sliding the capsule and/or sleeve into one another. The air gap between the valve insert and the armature can be changed by sliding the valve insert in the capsule with the inserted armature. In addition, the sleeve can include an outflow bore. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will become apparent from the description contained herein below, taken in conjunction with the drawings, in which: 
         FIG. 1  is a schematic sectional depiction of a first embodiment of a solenoid valve according to the present invention, 
         FIG. 2  is a schematic sectional depiction of a second embodiment of a solenoid valve according to the present invention, 
         FIG. 3  is a schematic cross-sectional depiction along a line A-A from  FIG. 2  to show a first variant of a tappet guide, 
         FIG. 4  is a schematic cross-sectional depiction along a line A-A from  FIG. 2  to show a second variant of a tappet guide, 
         FIG. 5  is a schematic sectional depiction of a third embodiment of a solenoid valve according to the present invention, and 
         FIG. 6  is a schematic sectional depiction of a conventional solenoid valve. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As is clear from  FIG. 1 , a first embodiment of a solenoid valve  100  according to the present invention, which is caulked to a fluid block  3  in a caulking region  102  by means of a valve bushing  106 , has a magnet unit  7  equipped with a covering washer  19  and a valve cartridge that includes a capsule  101 , a sleeve  112 , a valve insert  105 , a tappet  109  guided by the valve insert  105  by means of a tappet guide  18 , a return spring  110  that rests against the sleeve  112 , and an armature  8 . The capsule  101  has a lower region that is slid in overlapping fashion onto the valve insert  105 . The capsule  101  of the valve cartridge is embodied in the form of a valve component that produces a seal in relation to the atmosphere and in comparison to the conventional solenoid valve  600  shown in  FIG. 6 , the overlap region of the capsule  101  is elongated in the direction of the caulking region  102  of the fluid block  3 . This makes it possible to eliminate the conventional seal weld  4  from  FIG. 6 . The fluid forces and caulking forces are no longer absorbed by the valve insert  105  but are instead absorbed by the valve bushing  106 . The armature  8 , which is unchanged compared to the conventional solenoid valve  600  from  FIG. 6 , operates inside the capsule  101  and sets the functionally unchanged tappet  109  into motion in opposition to the return spring  110 . The lower part of the valve cartridge and a sealing seat  111  are constituted by the sleeve  112  with an outflow bore  116 , which is inserted into the capsule  101 . The sealing of the two parts of the valve can be produced by means of a plastic insert or by means of a sealed press-fitting into a seat in the fluid block  3 . The stroke of the tappet  109  can be adjusted by axially sliding the capsule  101  and sleeve  112  into each other. A magnetic flux MF that the magnet unit  7  introduces into the valve insert  105  via a wall of the overlap region of the capsule  101  is conducted by the valve insert  105  axially via an air gap  17  in the direction of the armature  8 . The air gap  17  between the valve insert  105  and the armature  8  can be changed by sliding the valve insert  105  into the capsule  101  with the inserted armature  8 . The elimination of the seal welding seam  4  and an insertion bevel  13  gives the first embodiment of the solenoid valve  100  according to the present invention a reduced structural height above the fluid block in comparison to the conventional solenoid valve  600  in  FIG. 6  and has a positive effect on the housing volume of the subassembly into which the fluid block with the solenoid valve is integrated. The sleeve design likewise permits the lower part of the solenoid valve  100  to be embodied with a reduced structural height inside the fluid block  3 . It is thus possible to reduce the thickness of the fluid block  3  and to also advantageously reduce the weight and volume of the fluid block  3 . 
     A second embodiment of a solenoid valve  200  according to the present invention in  FIG. 2  is embodied analogously to the first embodiment of the solenoid valve  100  according to the present invention in  FIG. 1  and is caulked to a fluid block in a caulking region by means of a valve bushing. In order to describe the differences between the first and second embodiments of the solenoid valve  100 ,  200  according to the present invention,  FIG. 2  shows only the valve cartridge, which is composed of the capsule  101  and sleeve  112 , and the associated components. The essential difference between the first and second embodiments of the solenoid valve  100 ,  200  according to the present invention is that in the second embodiment of the solenoid valve  200 , the return spring  210  for the tappet  209  is inserted into the vicinity of the air gap  17  between the armature  8  and the valve insert  205 . In addition, the return spring does not rest against the sleeve  112 , but rather against the valve insert  205 . As a result, the fluid flow no longer subjects the return spring  210  to the flow forces in the vicinity of the sealing seat  111 , thus improving the flow properties. Analogous to the first embodiment of the solenoid valve  100  according to the present invention in  FIG. 1 , the overlap region of the capsule  101  is also elongated in the direction of the caulking region with the fluid block in the second embodiment of the solenoid valve  200  according to present invention in  FIG. 2 , as a result of which the magnetic flux MF of the magnet unit that the valve insert  205  conducts axially via the air gap  17  in the direction of the armature  8  is introduced into the valve insert  205  via the wall of the overlap region of the capsule  101 . In the second embodiment of the solenoid valve  200  according to the present invention, the movement of the tappet  209  in opposition to the return spring  210  is likewise guided by the valve insert  205  by means of the tappet guide  18 . The second embodiment of the solenoid valve  200  according to the present invention has the same advantages in terms of structural height as the first embodiment of the solenoid valve  100  according to the present invention. 
       FIGS. 3 and 4  each show a cross-sectional depiction along a line A-A from  FIG. 2  in order to depict the tappet guide  18  by means of the valve inserts  105 ,  205 .  FIGS. 3 and 4  show only the cross sections through the tappets  109 ,  209  and valve inserts  105 ,  205 . As is clear from  FIGS. 1 and 2 , in the first and second embodiments of the solenoid valve  100 ,  200  according to the present invention, the movement of the tappet  109 ,  209  is guided by the valve insert  105 ,  205  by means of an associated tappet guide  18 . As is clear from  FIG. 3 , the valve inserts  105 ,  205  according to the first exemplary embodiment of the tappet guide  18  can have a round internal bore and the tappets  109 ,  209  can have volume compensation grooves  121  let into them between a tappet top  15  and a tappet bottom  14 . As is clear from  FIG. 4 , in the second exemplary embodiment of the tappet guide  18 , the tappets  109 ,  209  can be embodied as fully round and the valve insert  105 ,  205  can have volume compensation grooves  122  let into it between the tappet top  15  and tappet bottom  14 . 
     A third embodiment of a solenoid valve  300  according to the present invention in  FIG. 5  is embodied analogously to the first embodiment of the solenoid valve  100  according to present invention in  FIG. 1  and is caulked to a fluid block in a caulking region by means of a valve bushing. In order to describe the differences between the third exemplary embodiment of the solenoid valve  300  according to the present invention and the first embodiment of the solenoid valve  100  according to the present invention,  FIG. 5  likewise shows only the valve cartridge, which is composed of the capsule  101  and sleeve  312 , and the associated components. The essential difference between the third embodiment of the solenoid valve  300  according to the present invention and the first embodiment of the solenoid valve  100  according to the present invention is that in the third embodiment of the solenoid valve  300 , the sleeve  312  assumes the function of the tappet guide  18  for the tappet  309  and the valve insert  305  has a simple annular form. The only function of the valve insert  305  is to conduct the magnetic flux MF, which the magnet unit introduces via a wall of the overlap region of the capsule  101 , axially via the air gap  17  in the direction of the armature  8 . Analogous to the first embodiment of the solenoid valve  100  according to the present invention in  FIG. 1 , the overlap region of the capsule  101  is also elongated in the direction of the caulking region with the fluid block in the third embodiment of the solenoid valve  300  according to present invention in  FIG. 3 . In addition, the return spring  310  rests against the sleeve  312 . In an alternative embodiment that is not shown, the return spring for the tappet  309  can, analogously to the second embodiment of the solenoid valve  200  according to the present invention, be inserted in the vicinity of the air gap  17  between the armature  8  and the valve insert  305  so that the return spring does not rest against the sleeve  312 , but rather against the valve insert  305 . The third embodiment of the solenoid valve  300  according to the present invention has the same advantages with regard to the structural height as the first and second embodiments of the solenoid valve  100 ,  200  according to the present invention. 
     The solenoid valve according to the present invention has a capsule that is elongated in the direction of the caulked attachment to the fluid block, is embodied with an inserted sleeve as a valve component that produces a seal in relation to the atmosphere, and contains a valve bushing that absorbs the fluid forces and caulking forces and transmits them to the fluid block. This makes it possible to reduce the structural height of the solenoid valve in comparison to conventional solenoid valves. 
     The solenoid valve according to the present invention can, for example, be embodied in the form of a 2/2-way valve that is open when without current or closed when without current and preferably can be used in hydraulic units that are components of an antilock brake system (ABS), a traction control system (TCS), or an electronic stability program system (ESP). 
     The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.