EP0197314A1 - Hydraulic arrangement for selecting and transmitting a pressure signal in a directional stacking valve - Google Patents

Abstract

1. Hydraulic arrangement (37) for selecting and transmitting a pressure signal in a directional block valve (11), the housing (10) of which has, in a flange surface (12), a recess (15) which resembles a blind hole and can be covered by the flange surface (14) of an adjacent control-block element (13) and up to the bottom (16) of which lead two control ducts (18, 21) in the housing, whilst a third control duct (24) opens from the adjacent control-block element (13) into the recess (15) receiving an exchangeable insert body (27) for a change-over function, in order to block the lower signal of two pressure signals of differing size supplied ans transmit the higher signal, the middle connection of th change-over valve receiving the higher signal being selectively communicalble by means of the insert body (27) with a control duct in the directional block valve (11) or in the adjacent control-block element (13), characterized in that the control duct (18) picking up the pressure signal in the directional block valve (11) leads centrally into the bottom (16) of the recess (15), in that its mouth opening into the bottom (16) is designed as a spherical valve seat (19), and in that the insert body (27, 41) is guided radially in the recess (15) and performs the function of a closing member (32 ; 48) moveable in the longitudinal axis of the recess (15).

Description

State of the art

The invention relates to a hydraulic device for selecting and forwarding a pressure signal in a block directional valve according to the preamble of the main claim. Such a device is already known from DE-OS 33 09 998, with which a left-hand version and a right-hand version can be achieved with identical housings of the block directional control valves by installing different inserts in a blind hole-like recess in the flange surface. These inserts each consist of a multi-part structure, which has a shuttle valve with a spherical closing element inside, which can be moved parallel to the flange surface. The disadvantage is that this multi-part construction is relatively complex and expensive and molds for raw parts are required for their production.

Advantages of the invention

The hydraulic device according to the invention for selecting and forwarding a pressure signal in a block path til with the characterizing features of the main claim has the advantage that it allows a simpler and cheaper design while maintaining the same housing and the possibility of a left and right version. In both types of implementation, the number of components required is reduced. In addition, the different insert bodies for left and right-hand versions work essentially with an axial seal. The insert bodies can largely be designed as simple turned parts with preferably axial internal and external machining. Any form tools for raw parts are no longer required.

Advantageous further developments and improvements of the device specified in the main claim are possible through the measures listed in the subclaims. According to claims L and 7 can be built particularly space-saving and inexpensive facilities that ensure safe operation.

drawing

Embodiments of the invention are shown in the drawing and explained in more detail in the following description. 1 shows a partial cross section through a block directional control valve with a first device for selecting and forwarding a pressure signal in a left-hand version, and FIG. 2 shows a second device in the right-hand version matching FIG. 1. FIG. 3 shows in section a third device for left-hand execution and in FIG. 4 the right-hand execution suitable for this. FIG. 5 shows in section a fifth device with a double arrangement of a left and a right version in adjacent flange surfaces.

Description of the embodiments

1 shows a simplified representation of a partial cross section through the housing 10 of a first block directional control valve 11, on the first flange surface 12 of which a second block directional control valve 13 with its second flange surface 14 is attached.

From the first flange surface 12, a blind hole-like recess 15 is arranged in the housing 10, the bottom 16 of which extends at a distance from a slide bore 17. A first control channel 18 leads into the floor 16 and transmits a pressure signal Y1 from the slide bore 17. The first control channel 18 runs coaxially with the cylindrically shaped recess 15, its opening into the bottom 16 being designed as a conical valve seat 19.

A second control channel 21 runs in the housing 10 parallel to the first control channel 18 and connects a second flange surface 22 on the housing 10 to the bottom 16 of the recess 15. This second control channel 21 runs at a distance from the slide bore 17 and opens between the tapered valve seat 19 and the outer diameter of the recess 15 in the bottom 16. Coaxial with this second control channel 21, a third control channel 24 runs in the housing 23 of the flanged second block directional valve 13 third control channel 24 leads into the second flange surface 14 and transmits a pressure signal Y2 from a device (not shown in more detail) for the selection and forwarding of a pressure signal in the second block directional valve 13. In the housing 10, the recess 15 is widened towards the first flange surface J2 by a recess 25, in which an O-ring 26 is arranged for sealing to the outside, which at the same time has a function as a captive device.

The recess 15 in the housing 10 receives an insert body 27 which, in the left-hand version shown in FIG. 1, is designed as a one-piece rotating part. In the region of a collar-shaped section 28, the insert body 27 is axially guided in the recess 15, the resulting radial gap 29 being dimensioned so large that it can easily transmit pressure signals. On its inner end face 31, the insert body 27 has the actual closing member 32, the spherical sealing surface 33 of which cooperates with the conical valve seat 19 fixed to the housing. A circular sealing strip 35 is formed on an outer end face 34 of the insert body 27 and cooperates with the second flange surface 14 of the adjacent block directional control valve 13 in the manner of a seat valve. The diameter of the sealing strip 35 is chosen to be as large as possible, and almost corresponds to the outer diameter of the insert body 27, so that the opening of the third control channel 24 into the second flange surface 14 lies within the area enclosed by the sealing strip 35.

The insert body 27 is biased by a weak spring 36, which is supported on the second flange surface 14, in the direction of a preferred position in which its sealing surface 33 bears against the conical valve seat 19, while the sealing strip 35 lifts off the second flange surface 14.

The insert body 27 and the associated, correspondingly designed recess 15 are parts of a first device 37 for selecting and forwarding a pressure signal in a block directional valve 11. The one-piece insert body 27 forms the valve member of a shuttle valve, in which the first (18) and the third control channel 24 form the side connections, while the second control channel 21 represents the center connection of the shuttle valve, via which the higher of the two incoming pressure signals YJ, Y2 continues is conducted as a pressure signal Y. The insert body 27 delimits an annular space 38 in the recess 15, which is connected to the second control channel 21 and whose connections to the side connections 18, 24 can be switched on or off alternately.

• In lastdruckkompensierten Steuereinrichtungen mit mehreren Blockwegeventilen muß das jeweils maximale Lastdrucksignal ausgewählt und an die Druckmittelversorgungseinrichtung weitergeleitet werden, damit auch der maximal belastete Motor steuerbar ist. Zu diesem Zweck wird im ersten Blockwegeventil 11 über den ersten Steuerkanal 18 ein Drucksignal Y1 aus der Schieberbohrung 17 abgegriffen, wobei dieses Drucksignal der gerade maximalen Belastung des angeschlossenen Motors entspricht. Dieses Drucksignal YJ wird in die erste Einrichtung 37 eingegeben. In entsprechender Weise wird im benachbarten zweiten Blockwegeventil 13 ein Drucksignal Y2 abgegriffen, das z.B. der maximalen Belastung des vom zweiten Blockwegeventil 13 gesteuerten Motors entsprechen kann. Auch dieses Drucksignal Y2 wird der Einrichtung 37 eingegeben.

The mode of operation of the first device 37 in the first block directional control valve 11 is explained as follows:

• In load pressure-compensated control devices with several block directional control valves, the maximum load pressure signal in each case must be selected and forwarded to the pressure medium supply device so that the maximum loaded motor can also be controlled. For this purpose, a pressure signal Y1 is tapped from the slide bore 17 in the first block directional valve 11 via the first control channel 18, this pressure signal corresponding to the maximum load of the connected motor. This pressure signal YJ is input into the first device 37. In a corresponding manner, a pressure signal Y2 is tapped in the adjacent second block directional control valve 13, which may correspond, for example, to the maximum load on the motor controlled by the second block directional control valve 13. This pressure signal Y2 is also input to the device 37.

If the incoming pressure signal Y2 is greater than the pressure signal Y1_and the insert body 27 is in the preferred position just drawn in FIG. 1, the higher pressure signal Y2 can also build up in the annular space 38 via the opened sealing strip 35 and the radial gap 29 and will be via transmit the second control channel 21 to the second flange surface 22 as a pressure signal Y. The annular space 38 is blocked by the closing member 32 from the first control channel 18. Apart from the weak force of the spring 36, the insert body 27 becomes pressed with a force on the conical valve seat 19, which results from the pressure difference between the two pressure signals Y2 and Y1 in connection with a pressurized surface, which is determined by the effective seat diameter on the closing member 32.

If the pressure signal Y1 is now greater than the signal Y2, after overcoming the force of the spring 36, the insert body 27 is pressed to the right, with its sealing strip 35 being supported on the second flange surface 14 of the adjacent block directional valve 13. Now this sealing strip 35 determines the effective, pressurized area. The connection from the third control channel 24 to the second control channel 21 is hereby interrupted. At the same time, the closing member 32 lifts off its valve seat 19, so that the higher pressure signal Y1 can now pass the sealing surface 33 into the annular space 38 and is passed on to the second flange surface 22 via the second control channel 21.

FIG. 1 therefore shows a left-hand version of the first control device 37, in which the higher signal is selected and continued from two incoming pressure signals Y1 and Y2, while the lower pressure signal is blocked. A control block is referred to as a left-hand version if the pressure medium inflow, viewed from the operating side, is arranged to the left of the individual block valves 11 and 13 and the maximum control pressure signal must therefore be fed back there.

FIG. 2 shows a second device 40 for selecting and forwarding a pressure signal in a block directional control valve in a simplified representation and in a construction as a right-hand version. In the second device 40, the housings 10 and 23 of the two block directional valves 11 or 13 retained unchanged as in Figure 1; however, the recess 15 accommodates another, second insert body 41 in the housing 10.

The second insert body 41 differs from the first insert body 27 according to FIG. 1 primarily in that it no longer assumes the function of a closing element itself, but instead has additional components inside for the shuttle valve function. The second insert body 41 is now firmly arranged in the housing 10. It is centered in the recess 15 with a collar 42, a sealing ring 43 ensuring radial sealing. With an end-side sealing cone 44, the second insert body 41 is pressed tightly and firmly onto the conical valve seat 19, as a result of which the annular space 38 is shut off.

The sealing cone 44 encloses a recessed blind hole 45, which is introduced from the inner end face 31 and whose shoulder forms an inner valve seat 46. In an outer section 47 of the blind bore 45, a spherical closing member 48 is guided, which is assigned to the shuttle valve function. The outer section 47 is chosen larger in diameter than the first control channel 18, so that the valve seat 19 fixed to the housing can also cooperate with the spherical closing member 48. A transverse bore 51 extends from an inner section 49 of the blind bore 45 into the annular space 38, which is connected to the second control channel 21. Furthermore, an oblique bore 52 leads from the outer section 47 of the blind hole 45 to the outer end face 34 of the second insert body 41, where it has a connection with the third control channel 24 in the second block directional valve 13 via a flat recess 53. A weak spring 54 arranged in the blind bore 45 brings about a preferred position of the spherical closing member 48 in the position shown.

• Die Wechselventilfunktion in dem gehäusefest angeordneten zweiten Einsatzkörper 41 wird nun vom kugeligen Schließglied 48 wahrgenommen. Während das Drucksignal Y1 wie bisher im ersten Steuerkanal 18 ansteht, wird das zweite ankommende Drucksignal Y2 über den zweiten Steuerkanal 21 der zweiten Einrichtung 40 zugeführt. Ist das zweite Drucksignal Y2 größer als das erste Drucksignal Y1, so kann sich dessen Druck über den Ringraum 38, die Querbohrung 51, den inneren Ventilsitz 46, die Schrägbohrung 52 und die Ausnehmung 53 auch im dritten Steuerkanal 24 des zweiten Blockwegeventils 13 aufbauen, wo es als Drucksignal Y nach rechts zum nächsten Blockwegeventil bzw. zur Anschlußplatte oder zur Druckmittelversorgung weitergeleitet wird. Das Schließglied 48 liegt dabei am Ventilsitz 19 an und sperrt den ersten Steuerkanal 18 ab.

The mode of operation of the second device 40 according to FIG. 2 differs from the first device 37 according to FIG. 1 primarily in the following points:

• The shuttle valve function in the second insert body 41 arranged fixed to the housing is now performed by the spherical closing element 48. While the pressure signal Y1 is present in the first control channel 18 as before, the second incoming pressure signal Y2 is supplied to the second device 40 via the second control channel 21. If the second pressure signal Y2 is greater than the first pressure signal Y1, its pressure via the annular space 38, the transverse bore 51, the inner valve seat 46, the oblique bore 52 and the recess 53 can also build up in the third control channel 24 of the second block directional valve 13, where it is forwarded as pressure signal Y to the right to the next block directional valve or to the connecting plate or to the pressure medium supply. The closing member 48 rests on the valve seat 19 and shuts off the first control channel 18.

If the signal Y1 is greater than the two incoming pressure signals, the spherical closing member 48 lies against its force against the weak spring 54 on its inner valve seat 46 and blocks the connection to the second control channel 2J. At the same time, the closing member 48 opens the connection from the first control channel 18 via the valve seat 19, the oblique bore 52 and the recess 53 to the third control channel 24, so that the larger pressure signal Y is in turn continued to the right there.

With unchanged housings 10, 23 of the two block directional control valves 11, 13, a right-hand version can thus be realized using another insert body 41, which is to be understood as meaning such a control block in which - with the operating side facing the viewer - the Connection plate containing pressure medium inflow comes to the right of the individual block directional control valves and therefore the maximum pressure signal must also be directed there.

FIG. 3 shows a third device 60 in the left-hand version, which differs from that according to FIG. 1 as follows, the same reference symbols being used for the same components.

The first block directional control valve 11 has a different housing 61, in which the conical valve seat 19 is now reached through a valve seat bore 62. This valve seat bore 62 is designed in terms of depth and outer diameter in such a way that it forms with the spherical closing element required for a right-hand version the alternating valve function can work together.

The second block directional control valve 13 has a different housing 63, with a countersink 64 in the second flange surface 14, the countersink 64 cutting the third control channel 24, which ends at a distance from the second flange surface 14.

The recess 15 receives a third insert body 65 which, in addition to its sealing strip 35 on the outer end face 34, is also formed on the inner end face 31 with a flat seat 66. The diameter of this flat seat 66 is larger than the valve seat bore 62, but smaller than the diameter of the sealing strip 35. The third insert body 65 is in turn guided with a radial gap 29 in the recess 15 and, due to its axial mobility, can itself function the closing member in a shuttle valve take over.

The mode of operation of the third device 60 therefore largely corresponds to that of the first device 37 according to FIG. 1, the flat seat 66 interacting with the base 16 determining an effective pressure area. The coaxial rotation 64 in the housing 63 is intended to accommodate unevenness on the outer end face 34 on the third insert body 65, as is e.g. in the case of one-sided turning machining can arise from turning sleeves. Since the third control channel 24 no longer has to be drilled into the second flange surface 14, it can lie on the same diameter with the sealing strip 35, which favors a more compact design of the third device 60.

FIG. 4 shows, in a simplified manner, a section through a fourth device 70 in a right-hand embodiment, the same housings 61 and 63 as in FIG. 3 being used. The right-hand version 70 differs from the associated left-hand version 60 only by a different, fourth insert body 71.

The fourth insert body 71 is arranged in a manner corresponding to the second insert body 41 according to FIG. 2 in the recess 15 of the housing 61, for which purpose it has the collar 42 with the sealing ring 43. Furthermore, the fourth insert body 71 correspondingly has a blind hole 45 with an inner valve seat 46, an inner section 49 and a transverse hole 51 leading from the latter to the annular space 38. An outer section 72 of the blind hole 45 is now shorter, so that it just closes the closing member 48 can record. This outer section 72 opens into a recess 73 delimited by the flat seat 66, from which a longitudinal bore 74 running parallel to the blind hole bore 45 extends to the outer end face 34 on the fourth insert body 71.

The mode of operation of the fourth device 70 corresponds essentially to that of the right-hand version 40 according to FIG. 2, although the spherical closing member 48 can alternately assume its end positions in the valve seat bore 62 fixed to the housing or in the outer section 72 of the fourth insert body 71. The recess 73 assumes the function of a center connection in the shuttle valve, via which the selected, higher pressure is passed on.

FIG. 5 shows a fifth device 80 with a double arrangement of shuttle valves, which is required when a shuttle function is required in each of the adjacent flange surfaces. 5, the second device 40 according to FIG. 2 is arranged as a right-hand version, to which two pressure signals Y1 and Y2 are input. A first insert body 27 according to FIG. 1 is inserted in an adjacent connecting plate 81 with the same recess 15. A pressure signal Y3 can thus be entered in the connection plate 81 via a first control channel 82, e.g. can come from an associated steering committee. At a control output 83, the maximum signal Y can finally be tapped from the pressure signals Y1 to Y3 and passed on to the controller of a variable displacement pump.

With existing devices, left and right-hand versions can thus be realized with the same housings, the insert bodies being essentially designed as simple turned parts, as can be produced by preferably axial internal and external machining. While a one-piece rotating part is sufficient for the left-hand version, the insert part for a right-hand version must accommodate the actual closing element of the shuttle valve function. The simple construction of the insert body is achieved in a particularly expedient manner by the essentially axial seal, preferably metallic sealing compound be used. In the case of the first insert body 27, a possible radial impact error can be absorbed in an advantageous manner by the spherical sealing surface 33, whose associated ball diameter is smaller than the maximum diameter of the insert body 27. In the shuttle valves according to FIG. 1 and FIG. 2, their closing elements can be easily pretensioned on one side by a weak spring into a preferred position. Furthermore, the insert bodies are designed in such a way that they can be arranged against one another if required if two changing functions are necessary in a flange surface. A simple and compact design of the devices is favored according to FIG. 3 and if the flange surface covering a recess is provided with a suitable countersink in order to compensate for inaccurate shapes of the insert bodies. In the second device 40, protection against loss of the spherical closing member 48 can be achieved in a simple manner if the associated sealing cone 44 is slightly caulked inwards. Likewise, the 0-rings 26 in the recesses 25 simultaneously take on the function of securing against loss, as long as the block directional control valves 11 are not combined to form a control block composed of several valves.

Of course, changes to the illustrated embodiment are possible without departing from the spirit of the invention. It is particularly expedient if the sealing cone 44 according to FIG. 2 is designed in the manner of a ball dome.

Claims (10)

1.Hydraulic device for selecting and forwarding a pressure signal in a block directional control valve, the housing of which has a blind hole-like recess in a flange surface, which can be covered by the flange surface of an adjacent control block element and at the bottom of which two control channels lead into the housing, while a third control channel from the adjacent one Control block element opens into the recess, which receives an interchangeable insert body for an alternating function in order to shut off the lower signal from two supplied, differently sized pressure signals and to forward the higher signal, with the insert body of the center connection of the shuttle valve, which derives the higher signal, optionally having a control channel in the Block directional valve or in the adjacent control block element can be connected, characterized in that the control channel (18) tapping the pressure signal in the block directional valve (11) leads centrally into the bottom (16) of the recess (15) such that its mouth location in the bottom (16) is designed as a conical valve seat (19) and that the insert body (27, 41) is guided radially in the recess (15) and the function of a closing member (32; 48). 2. Hydraulic device according to claim 1, characterized in that the insert body (27) is integrally formed, on its inner end face (31) Central locking member (32) and on the outer end face (34) has an annular sealing strip (35). 3. Hydraulic device according to claim 2, characterized in that the insert body (27) is guided with radial play (29) in the recess (15) and in particular the diameter of the pressurizable surface enclosed by the sealing strip (35) almost the outer diameter of the insert body (27) corresponds. 4. Hydraulic device according to claim 2 or 3, characterized in that the closing member (32) has a spherical sealing surface (33) which is opposite the valve seat (19) in the housing (10). 5. Hydraulic device according to claim 2 or 3, characterized in that the insert body (65) as a closing member has an n salmon seat (66) which faces the bottom (16) and whose diameter is larger than the valve seat (19) in the housing (61). 6. Hydraulic device according to claim 1, characterized in that the insert body (41; 71) with an end annular bead (44; 66) lies tightly and firmly against the housing-fixed base (16) and the annular bead (44; 66) has a blind hole (45 ) encloses, in which a spherical closing member (48) is guided, on the one hand the valve seat (19) fixed to the housing and on the other hand an inner valve seat (46) are assigned, the latter (46) of which is connected to an annular space (38) which in the recess (15) between the annular bead (44; 66) and a radial sealing point (43) of the insert part (41, 71) is limited and into which the second control channel (21) leads, and that a transverse connection of the blind hole (45) 52, 53; 73, 74) in the leads to the annular bead (44; 66) opposite end face (34) of the insert body (41; 71). 7. Hydraulic device according to claim 6, characterized in that the annular bead is a sealing cone (44) which immediately surrounds the blind bore (45) and abuts the conical valve seat (19) in the housing (10), and that the cross connection as a transverse bore ( 52) is formed. 8. Hydraulic device according to claim 6, characterized in that the blind hole (45) in the insert body (71) opposite a valve seat bore (62) in the housing (61) and between the two (45, 62) a flat, radial chamber (73) extends, which is enclosed by the annular bead (66) and from which a longitudinal bore (74) forming the transverse connection extends. 9. Hydraulic device according to one of claims 1 to 8, characterized in that in the adjacent control block element (13, 63) coaxial with the recess (15) is a countersink (64) and that its control channel (24) at a distance from the flange surface (14th ) ends and this countersink (64) snows, det, in particular the control channel (24) on the diameter of the sealing strip (35). 10. Hydraulic device according to one of claims 1 to 9, characterized in that the in the flange surface (12) lying 0-ring (26) is designed as a loss protection for the insert body (27, 41).

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