EP2584230B1 - Valve, hydraulic assembly with such a valve and use of a button or switch for a valve - Google Patents

Description

The invention is based on a valve which has a position detection, a hydraulic arrangement with such a valve and a use of a button or switch for a valve.

In the DE 10 2006 049 724 A1 a valve is provided with a position detection of a valve element. The valve has a valve housing in which the valve element is slidably guided. On the valve element, a permanent magnet is arranged, which cooperates with a magnetic field sensor for detecting the position of the valve element. A disadvantage of this solution is that such a position detection device technology is extremely expensive.

Furthermore, slide valves are known from the prior art, in which a device for position detection is arranged directly on a valve slide, or cooperates with a switching magnet of the valve slide. Direct mounting on a valve spool requires sensors with a very high accuracy due to the low tolerances neutral position of the valve spool. The device for position detection must be calibrated consuming, which leads to high costs.

In the US 2003/0196618 A1 discloses a slide valve with a valve spool which is movable in at least two switching positions. Further, a sensor is provided which is activated in the one switching position and deactivated in the other switching position, wherein the sensor is activated by the valve spool.

In the US 3,921,665 A is disclosed another slide valve with a valve spool.

In contrast, the invention has for its object to provide a valve and a hydraulic arrangement with such a valve, in which the position of a valve body of the valve device is simple and inexpensive detectable. This object is achieved with regard to the valve having the features of patent claim 1 and with regard to the hydraulic arrangement having the features of patent claim 10.

According to the invention, a valve, in particular a slide valve or a seat valve, for example a conical, ball or seat valve seat, a valve body which is displaceable in at least two switching positions. In this case, a sensor is provided which is activated in an arrangement of the valve body in one of the switching positions and deactivated in the arrangement of the valve body in the other switching position.

This solution has the advantage that at least two positions of the valve body can be determined with a sensor device of extremely simple construction.

Advantageously, the sensor is designed as an electrical button or electrical switch. Such a sensor can be used in a wide variety of valve types and, unlike the prior art, does not have to be individually calibrated for a respective valve. This leads to a low production and assembly costs and is thus extremely cost-effective.

In a further embodiment of the invention, in addition to the valve body, a detection piston may be provided, via which the sensor can be activated by the valve body. The valve body is thus not directly in operative connection with the sensor and can be configured in a conventional manner.

The valve is a spool valve and the valve body is a valve spool. A switching position of the valve spool is then the neutral position in which the valve spool, for example, is spring-centered. The valve spool is then displaced from the neutral position in the direction of the other switching positions in which the sensor is activated by the valve spool.

The valve spool is displaceable from a neutral position in opposite directions in a respective switching position. There are two sensors provided. One of the sensors is then activated when the valve spool is displaced from the neutral position in one direction and the other sensor is activated when the valve spool is displaced from the neutral position in the other direction. This is on the one hand in a simple way, the arrangement of the valve spool Detectable in its neutral position and on the other hand, the direction of displacement of the valve spool is detected outside its neutral position.

Advantageously, a detection piston is provided for each sensor, which each device-wise simply coaxial with the valve spool and is movable in an end position in the direction of the valve spool. A respective detection piston can then be moved out of its end position by the valve slide, whereby then the sensor associated with the respective detection piston is activated by the detection piston.

For moving a respective detection piston into its end position, a spring can be simply used, which acts on the detection piston in the direction of its end position with a spring force.

Advantageously, the valve spool is then acted upon by the spring of the respective detection piston also with the spring force, whereby it is spring-centered in its neutral position. In the neutral position, then, both detection pistons are essentially in their end positions.

The valve may control a first pressure medium flow path and a second independent pressure medium flow path. The valve spool then has first and second control surfaces facing away from each other. When pressurizing a respective control surface of the valve spool is displaced in its switching positions. The first control surface is acted upon by the pressure in the first pressure medium flow path and the second control surface by the pressure in the second pressure medium flow path.

Each of the control surfaces of the valve slide can in this case limit a pressure chamber, in which then also a respective detection piston opens and can be mechanically brought into operative connection with the valve slide. A pressure application surface of a respective detection piston, to which a respective pressure in the respective pressure chamber in a direction of displacement of the detection piston acts away from its end position and against the spring force of the spring, is selected such that the detection piston does not counteract the spring force of the spring due to this pressure in Displaceable pressure chamber is. This avoids that the activated by the respective detection piston switch is activated by a pressure and not by the valve spool. The pressure application surface of a respective detection piston may be smaller than the respective control surface of the valve spool.

The detection piston can be designed in two parts and have a substantially circular cylindrical pin for mechanical contacting of the valve slide and a spring plate, in particular a section with a spring plate, which can activate the sensor on the one hand and on the other with the spring force of the detection piston associated spring is acted upon , A detection piston is further preserved in its end position via its spring plate, in particular, by this rests against a seat.

According to the invention, a hydraulic arrangement has a valve according to the invention, which is arranged as a check valve in a flow path between a pressure medium source and a consumer. The check valve is designed such that it is controllable only by the pressure of the pressure medium source and prevents in the closed state, a discharge of pressure medium from the consumer.

Furthermore, a flow control valve may be arranged in the pressure medium flow path between the pressure medium source and the check valve.

According to the invention, an electrical switch or an electrical switch for monitoring a neutral position and / or a switching position of a valve body of a valve can be used.

Other advantageous developments of the invention are the subject of further subclaims.

• Figur 1 einen hydraulischen Schaltplan mit einem erfindungsgemäßen Sperrventil gemäß einem ersten Ausführungsbeispiel;
• Figur 2a einen hydraulischen Schaltplan mit einem Sperrventil gemäß einem zweiten Ausführungsbeispiel;
• Figur 2b einen Ausschnitt des hydraulischen Schaltplans auf Figur 2a mit einem abgewandelten Stromregelventil;
• Figur 2c in einer vergrößerten schematischen Darstellung das Sperrventil aus Figur 2a;
• Figur 3 einen hydraulischen Schaltplan mit dem Sperrventil gemäß einem dritten Ausführungsbeispiel;
• Figur 4 in einer Draufsicht das Sperrventil gemäß dem dritten Ausführungsbeispiel;
• Figur 5 in einer Längsschnittansicht das Sperrventil gemäß dem dritten Ausführungsbeispiel;
• Figur 6 in einer Längsschnittansicht das Sperrventil gemäß dem dritten Ausführungsbeispiel;
• Figur 7 einen hydraulischen Schaltplan mit dem Sperrventil gemäß einem vierten Ausführungsbeispiel;
• Figur 8 in einer Längsschnittansicht das Sperrventil gemäß dem vierten Ausführungsbeispiel;
• Figur 9 einen hydraulischen Schaltplan mit einem Sperrventil gemäß dem dritten Ausführungsbeispiel;
• Figur 10 in einer Längsschnittansicht das Sperrventil gemäß dem vierten Ausführungsbeispiel.

In the following the invention will be explained in more detail with reference to schematic drawings. Show it:

• FIG. 1 a hydraulic circuit diagram with a check valve according to the invention according to a first embodiment;
• FIG. 2a a hydraulic circuit diagram with a check valve according to a second embodiment;
• FIG. 2b a section of the hydraulic circuit diagram FIG. 2a with a modified flow control valve;
• Figure 2c in an enlarged schematic representation of the check valve FIG. 2a ;
• FIG. 3 a hydraulic circuit diagram with the check valve according to a third embodiment;
• FIG. 4 in a plan view of the check valve according to the third embodiment;
• FIG. 5 in a longitudinal sectional view of the check valve according to the third embodiment;
• FIG. 6 in a longitudinal sectional view of the check valve according to the third embodiment;
• FIG. 7 a hydraulic circuit diagram with the check valve according to a fourth embodiment;
• FIG. 8 in a longitudinal sectional view of the check valve according to the fourth embodiment;
• FIG. 9 a hydraulic circuit diagram with a check valve according to the third embodiment;
• FIG. 10 in a longitudinal sectional view of the check valve according to the fourth embodiment.

According to FIG. 1 has a hydraulic arrangement 1, a pressure medium source in the form of a hydraulic pump 2 and a driven by this consumer in the form of a hydraulic motor 4. In the pressure fluid flow path between the hydraulic pump 2 and the hydraulic motor 4, a flow control valve 6 and an inventive valve in the form of a check valve 8 is arranged.

The pump 2 delivers via a tank line 10 pressure fluid from a tank 12 into a feed line 14. This is connected to a pressure port P of the flow control valve 6. This is a proportional adjustable 2/2-way valve, which in addition to the pressure port P has a working port A, to which a pressure medium line 16 is connected, which in turn is connected to a pressure port P of the check valve 8. A valve spool of the flow control valve 6 is acted upon by a spring 18 in the direction of a closed position with a spring force, wherein in the closed position, a pressure medium connection between the terminals P and A is interrupted. Via an actuator 20, the valve spool is then movable in its switching positions against the spring force of the spring 18, in which the pressure medium connection between the pressure port P and the working port A is opened. With the flow control valve 6 is thus a pressure medium flow rate of the funded by the hydraulic pump 2 pressure medium adjustable. To limit the pressure branches off from the feed line 14 between the hydraulic pump 2 and the flow control valve 6 from a line 22, in which a pressure relief valve 24 is arranged, which opens a connection to the tank 12 from a predetermined pressure.

The schematically illustrated check valve 8 has a valve body in the form of a valve spool 26 which is slidably guided in a valve bore 27 of a valve housing 28. With the valve spool 26 is a pressure fluid connection between the pressure port P and another working port A up and zusteuerbar. To the working port A connected to the hydraulic motor 4 working line 30 is connected, in which a in the flow direction to the hydraulic motor 4 opening check valve 32 is arranged. The valve spool 26 is biased via a spring force of a valve spring 34 in a closed position in which the pressure medium connection between the pressure port P and the working port A is interrupted, wherein one of the valve spring 34 facing away end face 36 of the valve spool 26 at a bore bottom of the valve bore 27 is substantially present. The pressure port P and the working port A open approximately radially in the valve bore 27 and are in the FIG. 1 formed approximately in a same plane approximately perpendicular to a longitudinal axis of the valve spool 26. In the in the FIG. 1 The outer side surface closes the working port A and the pressure medium connection P. The end 36 is acted upon by a pressure in the valve housing 28 pressure medium from the pressure port P, wherein the valve spool 26 then at a spring force of the valve spring 34 on the over End face 36 acting control pressure moves in an opening direction against the spring force acting on it. Here then a pressure fluid connection between the pressure port P and the working port A is opened. The check valve 8 can thus be acted upon only by the pressure medium upstream of the valve spool 26.

The valve spool 26 has a radially back-stepped valve spool portion 40 facing away from its end surface 36, which is guided through the valve housing 28 to the outside. The valve spool 26 defines with its end face 36 in the valve housing 28 a cylinder space and with its valve spool portion 40 a valve spring 34 having annular space 42. With the valve spool portion 40 is arranged outside the valve housing 28 sensor 44 can be actuated. This is a conventional device constructed simple electrical button or electrical switch.

By the sensor 44, the neutral position or the closed position of the valve spool 26 can be determined in an extremely simple manner, in which the pressure port P is fluidly separated from the working port A. The sensor 44 has a rod-shaped actuator 46, which in the in FIG. 1 shown position in contact or almost in contact with an end face of the valve spool portion 40 and thus mechanically engageable with the valve spool 26. Upon a displacement of the valve spool 26 from its in the FIG. 1 shown neutral position in the direction of its opening or switching positions, the actuating element 46 is also moved via the valve spool portion 40 in this direction, whereby the sensor 44 is actuated and reports a switching signal, for example, to an electronic control unit. If the valve spool 26 is moved in the direction of its neutral or closed position, the actuating element 46 is likewise displaced in this direction by a sensor spring 48 of the sensor 44. Is the valve spool 26 in the in FIG. 1 shown closed position, then the actuator 46 is in a position in which the sensor 44 is turned off.

In the valve housing 28 of the check valve 8, a leakage connection 50 is further provided, which is connected to the valve bore 27 in the region of the valve slide 26 limited annular space 42 and is connected via a tank line 52 to the tank 12. The hydraulic motor 4 is also connected on the output side via a drain line 54 to the tank 12.

FIG. 2a shows a further hydraulic arrangement 56 with a valve 58 according to the invention. In contrast to FIG. 1 the flow control valve 60 is designed as a proportionally adjustable 4/3-way valve having a pressure port P, a tank port T and two working ports A, B. To the working port A of the flow control valve 60, a first connecting line 62 is connected to a port A1 of the different FIG. 1 trained blocking valve 58 is connected and to the working port B, a second connecting line 64 is connected, which is connected to a port A2 of the check valve 58. Furthermore, the check valve 58 has a first consumer port V1, to which a first consumer line 66 is connected, and a second consumer port V2, to which a second consumer line 68 is connected. As a consumer, a differential cylinder 70 is provided with a one-sided piston rod 72 having a piston 74. The piston 74 thus separates a cylinder chamber 76 from an annular space 78. In a respective consumer line 66 and 68, a check valve 80 or 82 opening in the direction of the pressure medium flow toward the differential cylinder 70 is arranged. To unlock the check valve 80 is connected via a control line 84 to the consumer line between the check valve 58 and the check valve 82. To unlock the check valve 82, in turn, a control line 86 is provided, which branches off to the consumer line 66 between the check valve 80 and the check valve 58.

To the pressure port P of the flow control valve 60 is corresponding to the hydraulic arrangement 1 off FIG. 1 connected to the hydraulic pump 2 and it is also the pressure relief valve 24 is provided, with a connection to the tank 12 can be opened.

The flow control valve 60 has a valve spool, which is displaceable from its neutral position, in which a pressure medium connection between the terminals A, B, P and T is interrupted, via actuators in the direction of first and in the direction of second switching positions, wherein the directions are opposite to each other , In the direction of the first switching positions a, the pressure medium connection between the pressure port P and the working port A and between the tank port T and the working port B is opened, while in the second switching position b a pressure medium connection between the pressure port P and the working port B and between the working port A and the tank connection T is turned on. Furthermore, the valve spool is spring-centered in its neutral position 0.

The check valve 58 has in contrast to the check valve 8 FIG. 1 a guided in a valve housing 88 valve spool 90, which consists of a in the FIG. 2a shown neutral position in the direction of first and second switching positions is displaceable, the directions are opposite. For detecting the neutral position of the valve spool 90 and for detecting its direction of displacement from the neutral position, sensors 92 and 94 are provided, which correspond to the sensor from the FIG. 1 are designed as a device extremely simple design electrical button or electrical switch. The valve spool 90 is in this case slidably guided in a valve bore 92 in which four in the longitudinal direction of the valve bore 92 to each other spaced annular chambers 98, 100, 102 and 104 are formed. For a better explanation of the check valve 58, this is in the Figure 2c shown enlarged.

The annular chamber 98 in Figure 2c In this case, it is connected to the connection A1, the annular chamber 100 adjacent to it to the connection V1, the next chamber 102 to the connection V2, and the outer chamber 104 to the connection A2. The two middle chambers 100 and 102 are in each position of the valve spool 90 through its central radial collar 106 separated from each other. Furthermore, the valve spool 90 has a, in the Figure 2c seen from the central radial collar 106, left radial collar 108 and a right radial collar 110. With the left radial collar 108 is in the neutral position of the valve spool 90 a pressure medium connection between the annular chambers 98 and 100 controlled, while both in the first and in the second switching positions the valve spool 90, a pressure medium connection between the annular chambers 98 and 100 is opened. With the right radial collar 110, however, in the neutral position of the valve slide 90, a pressure medium connection between the annular chambers 102 and 104 is controlled and opened in the switching positions of the valve slide 90.

The valve spool 90 is radially stepped back at its end portions 112 and 114 and each has an annular end surface 116 and 118 formed by the radial collar 108 and the end portion 112 and the radial collar 110 and the end portion 114, respectively. Furthermore, the valve slide 90 has end faces 120 and 122 respectively formed on its end section 112 and 114.

The valve spool 90 is actuated at a shift from his in the Figure 2c shown neutral position to the left via a coaxially to the detection piston 124 arranged thereon the sensor 92 and a shift to the right via a further detection piston 126, the sensor 94. A respective detection piston 124 and 126 has a radial collar 128 and 130, each about in the central region the detection piston 124 or 126 is formed. A respective piston section 132 or 134 extends from the radial collar 128 and 130 of a respective detection piston 124 or 126 to the valve spool 90. A respective end face of the piston section 132 or 134 facing the valve spool 90 has a substantially dome-shaped configuration and rests in the neutral position of the valve spool 90 its respective end face 120 and 122 from. The piston portions 132 and 134 thereby collar into the annular chamber 98 and 104, respectively. Furthermore, extending from a respective radial collar 128 and 130, away from the valve spool 90, another piston portion 136 and 138. These limit each case in the valve housing 88 an annular spring chamber 140 and 142 and extend through the Valve housing 88 outwardly for actuating a respective actuating element 46 of the sensor 92 and 94. In the respective spring chamber 140 and 142, a valve spring 144 and 146 is arranged, which surrounds the respective piston portion 136 and 138, respectively supported on the valve housing 88 and the respective radial collar 128 and 130 acted upon by a spring force in the direction of the valve spool 90. The valve spool 90 is then spring-centered via the valve spring 144 or 146 in its neutral position. The spring chambers 140 and 142 are each connected to the tank 12 via a leakage channel 150 or 152.

The operation of the check valve 58 will now be described with reference to FIGS. 2a and 2c explained. By the flow control valve 60 either the port A1 or A2 with the hydraulic pump 2 is connectable, while the other is connected to the tank 12. If the port A1 connected to the hydraulic pump 2, that is, the flow control valve 60 is in its switching positions a, then builds up in the annular chamber 98 of the check valve 58 by a therein conveyed pressure fluid pressure, causing the valve spool 90 via his to Ring chamber 98 facing annular end face 116 and end face 120 acts a compressive force. The other annular chamber 104, however, is relieved to the tank 12. If the pressure force acting on the valve spool 90 exceeds the spring force of the valve spring 146, the valve spool 90 shifts into its switching positions in which a pressure medium connection between the ports A1 and V1 and between the ports V2 and A2 is opened. Downstream of the connection V1 of the check valve 58 then the check valves 80 and 82 are opened, in which case the cylinder chamber 76 with the hydraulic pump 2 and the annular space 78 with the tank 12 are in fluid communication. When moving the valve spool 90 of the check valve 58 in the switching position described, the detection piston 126 is also moved by the end face 122 of the valve spool 90 abuts the end face of the piston portion 134. The displacement of the detection piston 126 also takes place counter to the spring force of the valve spring 146 in the direction of the actuating element 46. Since this rests against an end face of the piston portion 138, it is moved in the direction of the sensor 94, whereby it is actuated. The other sensor 92 remains unconfirmed because the detection piston 124 remains in its end position by the valve spring 144 assigned to it, in which the radial collar 128 abuts an annular surface of the valve housing 58 substantially abuts. Since only the sensor 94 is actuated, it can be concluded that the valve spool 90 is displaced in its direction from its neutral position.

If the fluid connection between the check valve 58 and the hydraulic pump 2 is interrupted by an adjustment of the valve spool of the flow control valve 60 in its neutral position, then pressure fluid flows from the annular chamber 98 as leakage to the tank 12, whereby a pressure in this chamber 98 is reduced. The check valves 80 and 82 are closed, leaving the differential cylinder 70 in position substantially. If the pressure in the annular space 98 decreases to such an extent that the pressure force acting on the valve spool 90 against the spring force of the valve spring 146 is smaller than the spring force, then the valve spool 90 is displaced by the valve spring 146 and the detection piston 126 into its neutral position. When the valve spool 90 reaches its neutral position, the actuating element 46 of the sensor 94 is likewise returned to its initial position by the sensor spring 48, in which the sensor 94 is unactuated. Since the sensor 92 is also unconfirmed in the neutral position of the valve spool 90, it can thus be concluded in a simple manner that the valve spool 90 is also in its neutral position.

Upon a displacement of the valve spool of the flow control valve 60 in the switching positions b, the annular chamber 104 is connected to the hydraulic pump 2 and the annular chamber 98 to the tank 12. Here, the valve spool 90 is shifted at appropriate pressure ratios in its switching positions in the figures to the left, which in turn the sensor 92 is actuated via the detection piston 132. The sensor 94 remains unconfirmed. In the switching positions of the valve spool 90, the port A2 is connected to the port V1 and the port A1 to the port V1. If the pressure in the annular chamber 104 decreases after the valve spool of the flow control valve 60 has been shifted to its neutral position 0, the valve spool 90 is spring-centered again into its neutral position, and the sensor 92 is again inactive.

A diameter of the valve spool 90 facing piston portions 132 and 134 of the detection piston 124 and 126 is selected such that a pressure force acting on it due to a pressure in the annular chamber 98 and 104 is smaller than the spring force of the valve spring 144 or 146, so that the detection piston 124 or 126 is displaceable only by the valve spool 90.

To determine the neutral position of the valve spool 90, the sensors 92 and 94 advantageously have a comparatively low precision, whereby simple switches are sufficient as a device for position detection, resulting in a very cost-effective valve with position monitoring.

In the FIG. 2b is a flow control valve 154 as a variant of the flow control valve 60 FIG. 2a shown. This has, in contrast to the flow control valve 60, a neutral position 0, in which the working ports A and B are each throttled connected to the tank port T. As a result, in the neutral position of the flow control valve 154, pressure medium, in particular from the annular chambers 98 and 104 of the check valve 58, can flow to the tank 12.

According to FIG. 3 the hydraulic assembly 156 is separate from the FIG. 2b differing flow control valve 158. The connections between the pressure port P and the working port A or B are in each case throttled. Furthermore, branches off from the feed line 14, a channel with a pressure relief valve 160, the spring force of the valve spring 162 is adjustable in contrast to the previous embodiments. In the FIG. 3 In addition, a hydraulic pump 2 driving motor 164 is shown.

The check valve 193 is according to another embodiment as a block diagram in the FIG. 3 shown. Downstream of the check valve 58 are in the FIG. 3 two different variations for connection of the differential cylinder 70 is provided. The right variation, unlike the embodiment in the FIG. 2a Check valves 166 and 168, the valve body are each acted upon by a spring 170 and 172 with a spring force in the direction of its closing direction. In the second variant, left in the FIG. 3 is provided in parallel to a respective check valve 166 and 168, a valve 174 and 176, respectively. These are each a proportional 2/2-way valve. A valve spool of the respective valve 174 and 176 is acted upon via a spring force of a spring in the closing direction. On the respective valve spool of the valve 174 or 176 additionally acts in the closing direction, the pressure of its associated consumer line 66 or 68 between the check valve 193 and the respective valve 174 and 176, respectively, for each of which a branch of the consumer line 66 and 68 control line 178 and 180 is provided. In the opening direction, a respective valve slide of the valve 174 or 176 is acted upon by a pressure between a respective valve 174 or 176 and the differential cylinder 70 via a control line 182 or 184. Further, the valve spool of the right valve 176 in its opening direction via a control line 186 from the pressure of the consumer line 66 between check valve 193 and the left valve 174 and the valve spool of the left valve 174 in its opening direction via the control line 188 from the pressure of the consumer line 68 between check valve 193 and the right valve 176 acted upon.

The block diagram of the check valve 193 schematically shows the sensors 92 and 94 which are actuated by the valve spool of the check valve 193. Furthermore, the leakage channels 150, 152 opening in the tank 12 are shown. A pressurization of the valve spool of the check valve 193 takes place through the control lines 190 and 192, which branch off respectively from the connecting line 62 and 64 respectively.

In the illustration according to FIG. 4 has the check valve 193 off FIG. 3 formed in the valve housing 88 working ports V1 and V2. The sensors 92 and 94 are laterally screwed into the valve housing 88 and each have two electrical contacts 194 and 196 for electrical contacting.

FIG. 5 shows in a longitudinal sectional view along a sectional plane AA FIG. 4 the check valve 193. The working ports V1 and V2 are here introduced as blind holes in the valve housing 88. At the bottom of the hole of a respective port V1 and V2 leads a slant channel 198 or 200 to the annular chamber 100 and 102. The ports A1 and A2 are introduced as slanted channels 202 and 204 in the valve housing 88 and open respectively in the annular channel 98 and 104. In contrast to the check valve 58th from the Figure 2c is a respective detection piston 206 or 208 designed in two parts. Here each of the radial collar 128 or 130 leading to the valve spool 90 piston portion 210 and 212 is configured in one piece and rod-shaped. The respective piston section 210 and 212 can then be supported on the piston section 136 or 138 with its end face facing away from the valve slide 90. Each with its facing the valve spool 90 face the piston portion 210 and 212 may be supported on the valve spool 90. This has in contrast to the check valve 58 from the Figure 2c A respective blind bore 214 or 216 extends approximately to the radial collar 108 or 110 of the valve slide 90 and has a larger diameter than that of its respective end face 120 and 122 ago introduced, approximately coaxially to the longitudinal axis of the valve spool 90 extending blind holes respective rod-shaped piston portion 210 and 212, respectively. By means of the detection pistons 206 and 208 constructed in two parts, a statically overdetermined guidance is avoided so that a clamping of the respective detection piston 206 or 208 is substantially avoided.

FIG. 6 shows the check valve 193 in a longitudinal sectional view, wherein the sectional plane approximately perpendicular to the sectional plane AA FIG. 4 runs. In this view, leakage channels 150 and 152 can be seen, the spring chambers 140 and 142 with the tank 12 from FIG. 3 connect fluidly. The spring chambers 140 and 142 are each accommodated in a housing cartridge 218 or 220 screwed into the valve housing 88. These are the same design, so for the sake of simplicity only in the FIG. 6 left housing cartridge 218 is described below. The housing cartridge 218 has an inner portion 222 immersed in the valve housing 88 and a larger diameter outer portion 224. The outer portion 224 has, see FIG. 4 an edge-shaped outer circumferential surface, which is configured for engaging a tool corresponding to a nut. The valve housing 88 has a continuous valve bore 226 with two different diameters. In its middle region, in which the valve slide 90 in the valve bore 226 is slidably guided, the diameter is smaller than in their end regions 228 and 230, respectively, in which the housing cartridge 218 or 220 is immersed. In a respective end region 228 and 230 of the valve bore 226th an internal thread 232 is introduced into which the respective housing cartridge 218 or 220 is screwed with an external thread 234. A screw-in depth of the housing cartridge 218 is limited by an annular end face 238 formed between the inner and outer sections 222, 224, which essentially abuts the valve housing 88 in the screwed-in state.

The spring chamber 140 is introduced as a blind hole in the housing cartridge 218, in which case the radial collar 128 of the detection piston 206 from FIG. 5 as spring plate is slidably guided in the spring chamber 140. An end position of the spring plate 128 is formed by the bore bottom of the blind hole of the spring chamber 140, wherein the bottom of the bore points away from the valve slide 90. For closing the spring chamber 140, an annular closing element 240 is provided, by the inner circumferential surface of which the valve spool 90 facing away piston portion 136 is sealingly and slidably received and abuts with its outer lateral surface on an inner circumferential surface of a bore in the housing cartridge 218, which has a slightly larger diameter as the spring chamber 140 has. Seen in the longitudinal direction after the closing element 240, the housing cartridge 218 has an internal thread 242 into which a sensor housing 244 of the sensor 92 is then screwed. The closing element 240 is then supported on an end face of the sensor housing 244 and the valve spring 144 in turn is supported on an annular end face of the closing element 240 and acts on the radial collar 128 of the detection piston 206, see FIG. 5 with the spring force in the direction of the valve spool 90. The closing element 240 has an inner and outer sealing ring, wherein the outer sealing ring on the housing cartridge 218 and the inner sealing ring on the piston portion 136 abuts and the spring chamber 140 seals substantially to the outside. The spring chamber 140 is connected via a radial channel 246 introduced in the housing cartridge 218 with an annular space 248, which surrounds the housing cartridge 218 and is inserted into the valve housing 88, which in turn is connected to the leakage channel 150. The radial channel 246 is spaced from the bore base of the spring chamber 140 so that in the illustrated arrangement of the radial collar 128 in its voltage applied to the bottom of the hole end position of the radial channel 246 is not covered by this.

The formed as a cylindrical pin piston portion 210 is slidably guided in a pin bore 250 of the housing cartridge 218, wherein the housing cartridge 218 has in the region of the piston portion 210 at its outer periphery and in the region of the pin bore sealant to seal the annular space 98 to the outside.

The construction of the sensors 92 and 94 is based on the in the FIG. 6 right sensor 94 explained in more detail. As an actuating element, the sensor 94 has an actuating ball 252, which is mounted on the end side in a sensor housing 254. In the non-actuated state, the actuating ball 252 bears against a conical seat 256 of the closing element 240 and the piston section 138 is somewhat spaced with its end face from the actuating ball 252. The sensor housing 254 is stepped and has a threaded portion 256 with an external thread, which is screwed into the internal thread 242 of the housing cartridge 220.

FIG. 7 shows a hydraulic arrangement 258 in a further embodiment, in contrast to the embodiment of FIG. 3 a differently designed check valve 260 has. Here, the working ports V1 and V2 in the neutral position of the valve spool of the check valve 260 via a leakage channel 262 and a tank line 264, to which the leakage channels 150 and 152 are connected, connected to the tank 12. Hereby an unintentional displacement of the valve spool of the check valve 260 from its neutral position due to a high consumer-side pressure is additionally avoided.

In the FIG. 8 is the check valve 258 shown, in which the valve spool 266 additionally has two valve spool channels 268 and 270, in the neutral position of the valve spool 260, the annular spaces 100, 102 to the tank 12 from FIG. 7 to connect via the introduced in the valve housing 88 tank channel 262. The valve spool channels 268 and 270 are each introduced obliquely and parallel to each other in the valve spool 90 in the region of the radial collar 106 as a blind hole from a formed by the radial collar 106 of the valve spool 90 end face 272 and 274 ago. The valve slide channels 268 and 270 then each end approximately in the center of the valve slide 90 seen in the longitudinal direction and are each connected to a centrally introduced into the radial collar 106 radial bore 276 and 278. In The illustrated neutral position of the valve spool 90, the radial bores are fluidly connected to a valve housing 88 between the annular chambers 100 and 102 introduced further annular chamber 280, in turn, the leakage channel 262 opens. Upon a displacement of the valve spool 90 from its neutral position in the direction of the first or second switching positions, the radial bores 276 and 278 are displaced away from the annular chamber 280, whereby the fluidic connection between the annular chamber 280 and the radial bores 276 and 278 and thus to the annular chambers 100 and 102 is interrupted via the oblique valve slide channels 268 and 270, respectively.

FIG. 9 shows a hydraulic arrangement 282 according to another embodiment, in which the check valve 283 substantially in accordance with the hydraulic arrangement of FIG. 3 is educated and unlike FIG. 3 the flow control valve 284 has another configuration. This is designed as 7/3-way valve. In addition to the working ports A and B, the pressure port P and the tank port T, the flow control valve 284 has two output ports Y1 and Y2 and an input port X, which are each connected to a further proportionally adjustable 3/3-way valve 286. With these, a pressure medium volume flow to the pressure port P of the flow control valve 284 is additionally controlled.

The port X of the flow control valve 284 is connected to the feed line 14, and the output ports Y1 and Y2 are connected to a common supply line 288 which is connected to an input port X of the directional control valve 286. Via a first output connection Y1, the directional control valve 286 is connected to a pressure line 290, which is connected to the pressure connection P of the flow control valve 284 via a check valve 292 which opens toward the flow control valve 284. Via a further output port Y2, the directional control valve 286 is connected to a control line 294 via which a valve spool of the directional control valve 286 can be acted upon with pressure medium in the direction of a closed position. In the closed position, the input terminal X and the output terminals Y1 and Y2 are separated from each other. In the direction of a first switching position of the valve spool of the directional control valve 286 via a control line 296 with pressure medium of the supply line 288 between the flow control valve 284 and the directional control valve 286 can be acted upon, wherein in the first switching positions a, the input terminal X is connected in a throttled manner to the output terminal Y1. In a further displacement of the valve spool of the directional control valve 286 after the first switching positions to second switching positions b in addition a connection between the input terminal X and the output terminal Y2 is opened.

In the in the FIG. 9 shown neutral position 0 of the valve spool of the flow control valve 284, the working ports A and B are throttled connected to the tank port, while the other ports X, P, Y1 and Y2 are separated from each other. In a displacement of the valve spool of the flow control valve 284 in the direction of the switching positions a, the input terminal X, which is connected to the feed line 14, throttled connected to the output terminal Y1, the pressure port P to the working port A and the working port B to the tank port T. Bei a shift of the valve spool of the flow control valve 284 in its switching positions b, in turn, the input terminal X to the output terminal Y2, the working port A to the tank port T and the pressure port P to the working port B is connected. If the valve spool of the directional valve 286 then in the switching positions a or b, the pressure port P of the flow control valve 284 with the feed line 14 via the input terminal X and the output terminal Y1 or Y2 of the flow control valve 284, via the supply line 288, via the directional valve 286 and connected via the pressure line 290.

In the FIG. 10 the check valve 283 is off FIG. 9 shown in a longitudinal sectional view. This corresponds essentially to the check valve 193 from the FIG. 6 , For the sake of simplicity, in the FIG. 10 only the left sensor 92 is shown. The valve spool 90 is in the FIG. 10 shown in a switching position, in which on the one hand, the annular chamber 98 is connected to the annular chamber 100 and the annular chamber 104 with the annular chamber 102. The displacement of the valve spool 90 is limited by the fact that its end face 120 rests against an end face of the housing cartridge 218. The pin-shaped piston portion 210 of the detection piston 206 is immersed in the switching position in the spring chamber 140, whereby this displaces the piston portion 136 against the spring force in the direction of the sensor 92, which in turn the actuating ball 252 in a in the FIG. 10 not shown actuating position is shifted, in which the sensor 92 is actuated or turned on. exceeds the spring force of the valve spring 144 acting on the valve spool 90 compressive forces, the valve spool 90 is moved by the spring force of the valve spring 144 in its neutral position.

Disclosed is a valve, in particular a slide valve or a seat valve, which has a valve body. This is movable at least in two switching positions. In order to detect the position of the valve body in one of the switching positions, a sensor is provided which is activated in a switching position and deactivated in the other switching position.

LIST OF REFERENCE NUMBERS

1

hydraulic arrangement

2

hydraulic pump

4

hydraulic motor

6

Flow control valve

8th

check valve

10

tank line

12

tank

14

feeder

16

Pressure medium line

18

feather

20

actuator

22

management

24

Pressure relief valve

26

valve slide

27

valve bore

28

valve housing

30

working line

32

check valve

34

valve spring

36

front

38

lever

40

Spool section

42

annulus

44

sensor

46

actuator

48

sensor spring

50

leakage line

52

tank line

54

drain line

56

hydraulic arrangement

58

check valve

60

Flow control valve

62

first connection line

64

second connection line

66

consumer line

68

consumer line

70

differential cylinder

72

piston rod

74

piston

76

cylinder space

78

annulus

80

check valve

82

check valve

84

control line

86

control line

88

valve housing

90

valve slide

92

sensor

94

sensor

96

valve bore

98

annular chamber

100

annular chamber

102

annular chamber

104

annular chamber

106

radial collar

108

radial collar

110

radial collar

112

end

114

end

116

Annular face

118

Annular face

120

face

122

face

124

detection piston

126

detection piston

128

radial collar

130

radial collar

132

piston section

134

piston section

136

piston section

138

piston section

140

spring chamber

142

spring chamber

144

valve spring

146

valve spring

150

leakage channel

152

leakage channel

154

Flow control valve

156

hydraulic arrangement

158

Flow control valve

160

Pressure relief valve

162

feather

164

engine

166

check valve

168

check valve

170

feather

172

feather

174

Valve

176

Valve

178

control line

180

control line

182

control line

184

control line

186

control line

188

control line

190

control line

192

control line

193

check valve

194

electric contact

196

electric contact

198

oblique channel

200

oblique channel

202

oblique channel

204

oblique channel

206

detection piston

208

detection piston

210

piston section

212

piston section

214

Blind hole

216

Blind hole

218

housing cartridge

220

housing cartridge

222

inner portion

224

outer portion

226

valve bore

228

end

230

end

232

inner thread

234

inner thread

236

external thread

238

Annular face

240

closing element

242

inner thread

244

sensor housing

246

radial channel

248

annulus

250

pin hole

252

actuating ball

254

sensor housing

256

valve seat

258

hydraulic arrangement

260

check valve

262

leakage channel

264

leakage line

266

valve slide

268

Valve slide channel

270

Valve slide channel

272

Annular face

274

Annular face

276

radial bore

278

radial bore

280

annular chamber

282

hydraulic arrangement

283

check valve

284

Flow control valve

286

way valve

288

supply line

290

pressure line

292

check valve

294

control line

Claims (12)

1. Slide valve with a valve slide (26; 90) which is movable into at least two switching positions, a sensor (44; 92, 94) being provided which is activated in one of the switching positions of the valve slide (26; 90) and is deactivated in the other switching position, one switching position of the valve slide (90) being a neutral position, out of which the valve slide (90) can be displaced in the direction of the further switching position in which the sensor (92, 94) is activated by the valve slide (90), characterized in that the valve slide (90) can be displaced out of the neutral position in opposite directions in each case into a switching position, two sensors (92, 94) being provided, one sensor (92) being activatable in the first switching position of the valve slide (90) and the other sensor (94) being activatable in the second switching position of the valve slide (90).
2. Valve according to Claim 1, the sensor (44; 92, 94) being designed as a button or as a switch.
3. Valve according to Claim 1 or 2, a detection piston (124, 126) being provided, via which the sensor (92, 94) can be activated by the valve slide (90).
4. Valve according to one of the preceding claims, a detection piston (124, 126) being provided in each case for a respective sensor (92, 94), which detection pistons extend essentially coaxially with respect to the valve slide (90) and have an end position in each case in a direction of displacement towards the valve slide (90), a respective detection piston (124, 126) being displaceable out of its end position by the valve slide (90) in order to activate the respective sensor (92, 94).
5. Valve according to Claim 4, a respective detection piston (124, 126) being tensionable into its end position via a spring force of a spring (144, 146).
6. Valve according to Claim 5, the valve slide (90) being spring-centred in its neutral position via the spring force of the springs (144, 146) of the detection pistons (124, 126).
7. Valve according to Claims 4 to 6, the slide valve (58) controlling a first and a second pressure-medium flow path (A1, V1; A2, V2) the valve slide (90) having two first and second control faces (116, 120; 118, 122), pointing away from one another, for acting with pressure upon the valve slide (90) in the direction of its switching positions, the first control face (116, 120) being capable of being acted upon with the pressure medium of the first pressure-medium flow path (A1, V1), and the other, second control face (118, 122) being capable of being acted upon with the pressure medium of the second pressure-medium flow path (A2, V2).
8. Valve according to Claim 7, the control faces (116, 120; 118, 122) of the valve slide (90) in each case delimiting a pressure space (98, 104) in which in each case a detection piston (124, 126) issues and in which the valve slide (90) mechanically contacts the respective detection piston (124, 126) for displacement, a pressure engagement face of a respective detection piston (124, 126), at which face a pressure in the respective pressure space acts in a direction of displacement of the detection piston (124, 126) away from the end position of the latter, and the spring force of the spring (144, 146) assigned to the respective detection piston (124, 126) being selected in such a way that the detection pistons (124, 126) cannot be displaced via the pressure in the respective pressure space (98, 104) counter to the spring force.
9. Valve according to Claims 5 to 8, the detection piston (124, 126) being constructed in two parts with a first piston portion, designed as a pin (210, 212), for the mechanical contacting of the valve slide (90) and with a piston portion which is designed as a spring plate (128, 130) for activating the sensor (92, 94) and on which the respective spring (144, 146) engages, and the spring plate (128, 130) being tensionable into the end position of the detection piston (124, 126) by the spring force of the spring (144, 146), the pin (210, 212) being supportable on a supporting face of the spring plate (128, 130), the said supporting face facing away from the spring.
10. Hydraulic arrangement with a valve according to one of the preceding claims, which is arranged as a stop valve (8, 58) in a pressure-medium flow path between a pressure medium source (2) and a consumer (4, 78).
11. Hydraulic arrangement according to Claim 10, the stop valve (8, 58) being capable of being acted upon, upstream of its valve body (26, 90) in the direction of its switching positions, by a pressure in the pressure-medium flow path connected to the pressure-medium source (2).
12. Hydraulic arrangement according to Claim 10 or 11, a flow-regulating valve (6, 60) being arranged in the pressure-medium flow path between the stop valve (8, 58) and the pressure-medium source (2).

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