Abstract:
A valve has a solenoid part and a valve part connected to the solenoid part. The valve part has a housing provided with connecting bores for a pressure medium, including a pressure connector and working connectors. The valve part has a piston and the solenoid part acts on the piston to alternatingly connect the working connectors to the pressure connector. The valve part has at least one groove extending alongside the valve part. At least one of the connecting bores is positioned in the at least one groove.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The invention relates to a valve, especially a proportional solenoid valve, comprising a solenoid part for actuating a piston of a valve part having a housing provided with connecting bores for a pressure medium. 
     2. Description of the Related Art 
     Such valves are used as cartridge valves inserted with their valve part into a receiving block, for example, an engine block of an internal combustion engine. The engine block is provided with oil channels via which oil is supplied to the connecting bores in the valve part. The oil channels in the receiving block must be drilled at precise angles so that they open into the matching connecting bores or annular grooves of the valve part. Moreover, the number of possible mounting positions of the valves in the receiving block are significantly restricted because of this. Therefore, very strict specifications with regard to manufacturing the oil channels are to be met. Moreover, the requirements with regard to the mounting position of the valve are significantly increased. 
     SUMMARY OF INVENTION 
     It is an object of the present invention to configure the valve of the aforementioned kind such that in a constructively simple way proper supply and proper return of the pressure medium to and from the valve part via the oil channels of the receiving block are ensured. 
     In accordance with the present invention, this is achieved in that at least one of the connecting bores is positioned in a groove that extends alongside the valve. 
     In the valve according to the invention, the connecting bore is located in a groove that extends alongside the valve. In this way, the oil channels in the receiving block must be arranged only such that they open into the groove. It is therefore no longer required to manufacture the oil channels such that they reach precisely the connecting bore. In this way, precise positioning of the oil channels allows greater tolerances. The oil flows from the respective oil channel first into the groove in which the oil then reliably flows into the connecting bore. Because of the configuration according to the invention, mounting of the valve on the receiving block is facilitated. 
     The groove can advantageously extend in the axial direction of the valve. However, it is also possible that the groove extends in the circumferential direction of the valve at a slant, i.e., it is inclined or has a gradient. 
     Expediently, for each connecting bore a separate groove is provided. These grooves are distributed about the circumference of the valve part. 
     Advantageously, the diameter of the connecting bore corresponds to the width of the groove. In this way, in the area of the edge of the connecting bore there is no dead space where dirt contained in the oil could collect. 
     Advantageously, the valve is a cartridge valve of the type used preferably in the automotive industry. 
     In one embodiment, the groove is provided within the valve housing. 
     In another embodiment, the groove is arranged in a sleeve (bushing) that is arranged on the valve part. This sleeve in this case forms a distributor sleeve that can also be pushed onto already existing valves. It is therefore possible to retrofit existing valves. 
     In this case, at the bottom of the groove of the sleeve a bore is provided that communicates with an annular groove of a valve member of the valve part. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a valve according to the invention in the mounted state. 
         FIG. 2  shows the valve according to the invention in a side view onto the working connectors A, B, and T. 
         FIG. 2   a  shows an end view of the valve of  FIG. 2  looking onto the T connector. 
         FIG. 3  shows the valve according to the invention in a side view onto the pressure connector P. 
         FIG. 4  is a perspective view of the valve according to the invention. 
         FIG. 5  another perspective view of the valve according to the invention rotated relative to the view of  FIG. 4 . 
         FIG. 6  shows a second embodiment of the valve according to the invention in a side view. 
         FIG. 7  shows the valve according to  FIG. 6  partially in axial section. 
         FIG. 8  is a perspective illustration of the valve according to  FIG. 6  with a bushing (sleeve). 
     
    
    
     DETAILED DESCRIPTION 
     In the illustrated embodiment, the valve is a proportional solenoid valve comprising a valve part  1  and a solenoid part  2 . The valve part  1 , as is known in the art, comprises a piston (not illustrated) that can be moved by means of a plunger (not illustrated) of the solenoid part  2  against a counter force. In this way, the working connectors A and B can be brought alternatingly into communication with the pressure connector P. The valve is inserted with its valve part  1  into a receiving block  3  ( FIG. 1 ); the receiving block can be an engine block of an internal combustion engine. At the transition from the valve part  1  into the solenoid part  2 , the valve is provided with a mounting flange  4  that projects radially past the valve part  1  and/or the solenoid part  2  and rests against the receiving block  3  in the mounted position. The mounting flange  4  has openings  5 ,  6  ( FIG. 5 ) for screws with which the valve can be fastened on the receiving block  3 . At the end of the solenoid part  2  facing away from the valve part  1 , an electrical connector  7  is provided. 
     The valve part  1  has a valve housing  8  which is provided in the illustrated embodiment with axially extending oil guiding grooves  9  to  11 . At the bottom of the oil guiding grooves  9  to  11 , a bore ( 23  to  25 ) is provided, respectively. By means of these grooves  9  to  11  and bores  23  to  25 , the hydraulic oil is supplied to the connecting bores A, B, and P. The connecting bores A and B form working connectors, the connecting bore P the pressure connector, and the connecting bore T the tank connector. 
     The receiving block  3  is provided with oil channels.  FIG. 1  shows the oil channels  12  and  13 . In the valves according to the prior art, these oil channels must be aligned exactly with the connecting bores or annular grooves in the valve part  1  when the valve is in the mounted position. This requires a very precise manufacture of the oil channels in the receiving block  3  as well as of the arrangement of the connecting bores in the valve part  1 . In the valve of the present invention, this precise positional alignment is no longer necessary. When mounting the valve, it must only be ensured that the oil channels  12 ,  13  of the receiving block  3  open into the corresponding oil guiding grooves  9  to  11  of the valve part  1 . Within the oil guiding grooves the oil can flow to the corresponding connecting bores in any case. On the other hand, the oil reliably returns from the valve part  1  into the respective oil channels  12 ,  13 . 
     As a result of the axial extension of the oil guiding grooves  9  to  11 , the oil channels  12 ,  13  in the receiving block  3  can extend at different angles or slants without this impairing the reliable supply of the oil. The solid lines indicate the oil channels  12 ,  13  in an extreme slanted position in which they open into the lower end of the oil guiding grooves  9 ,  10 . By means of the dashed lines, the other extreme slanted position of these oil channels is illustrated in which they open into the upper end of the oil guiding groove  9 ,  10 , respectively. Accordingly, the oil channels  12 ,  13  in the receiving block  3  can be positioned at different slants varying within the indicated angle α without this impairing the supply or return of the oil. 
     Because of the oil guiding grooves  9  to  11 , a high positional precision or accuracy of the oil channels  12 ,  13  to be drilled into the receiving block  3  is no longer required. The slant of the oil channels  12 ,  13  can vary by the angle α. Because of the oil guiding grooves  9  to  11 , the variability of the mounting position of the valve in the receiving block  3  is significantly increased. Moreover, the oil guiding grooves  9  to  11  widen the tolerance range for the angular position of the oil channels  12 ,  13 . 
     In the illustrated embodiment, the different oil guiding grooves  9  to  11  extend axially, respectively. However, it is possible easily to provide the oil guiding grooves  9  to  11  also slanted at an angle relative to the valve housing  8 . In this case, a high positional precision of the oil channels  12 ,  13  in the receiving block  3  is also not required. 
       FIGS. 6 through 8  show an embodiment of a valve in which the oil guiding grooves  9  to  11  are provided in a bushing (sleeve)  14  that is pushed onto a valve member  15 . The valve member  15  has annular grooves  16  to  18  that are delimited by annular webs  19  to  22 . The different connectors A, B, P of the valve open into the annual grooves  16  to  18 . The webs  19  to  22  are positioned on the inner wall of the sleeve or bushing  14  so that the oil cannot flow across the annular webs into the neighboring oil grooves  16 – 18 . 
     At the bottom of the oil guiding grooves  9  to  11 , a bore  23  to  25  is provided, respectively, through which the oil can reach the respective annular groove  16 – 18 . The bores  23  to  25  of neighboring oil guiding grooves  9  to  11  are axially staggered relative to one another. 
     The bushing  14  is pushed onto the valve member  15  to such an extent that it rests with its end face against the fastening flange  4 . The bushing  14  forms a distributor sleeve with which valves can be retrofitted in order to also obtain the advantage of a variable mounting position of the valve in the receiving block  3 . In deviation from the illustrated embodiment, the oil guiding grooves  9  to  11  in the bushing  14  can be positioned inclined at an angle In other respects, the valve according to  FIGS. 6 to 8  is identical to the preceding embodiment. 
     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.