JP2013245823A - Hydrostatic type valve device and hydrostatic type control device including the valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a hydrostatic type valve device including a valve for blocking an inflow passage against a load informing passage without leakage so as to let the valve have a larger function range.SOLUTION: An inflow valve 64 has a meter-in restriction 28 having a valve seat, and connection between an inflow passage 46 and a pump passage 40 can be substantially blocked without leakage through the meter-in restriction. While closing the meter-in restriction 28, a load informing passage 6 is substantially blocked without leakage with respect to the inflow passage 46 through a seat valve 68, and can be connected to a returning passage 72 or to the pump passage 40.

Description

  The present invention relates to a hydrostatic valve device for supplying a pressure medium to at least one hydrostatic (hydrostatic) consumer, wherein an inflow valve is provided, and the inflow valve has a valve seat. An inflow metering throttle or a meter-in throttle (Zumessblende) having an inflow passage, and a connection between the inflow passage and the pump passage can be cut off substantially without leakage, and a load notification passage is provided. The load notification passage is related to a hydrostatic valve device that is loaded by the extracted load pressure of the consumer and further includes a seat valve.

  Furthermore, the present invention relates to a hydrostatic control device provided with such a valve device.

  In mobile work machines such as hydraulic excavators, tractors, backhoe loaders (Baggerladers) or forklift trucks, the output converted by the primary energy converter, such as a diesel engine, is a hydraulic drive / control unit. To the individual hydraulic linear or rotary consumer of the work attachment. The pump driven by the diesel engine in this case pumps the pressure medium volume flow to the valve block, which distributes the oil to the hydraulic consumer.

  In particular, in a mobile work machine, so-called load sensing control (LS) is used to supply the pressure medium independently of the load pressure, that is, without being affected by the load pressure. In load sensing control, the maximum load pressure of the consumer is notified or transmitted to a regulating pump, that is, a variable displacement pump, and this variable displacement pump is in a pump line or pump passage by a predetermined differential pressure. Control is performed so that a pump pressure higher than the load pressure is generated.

  In this case, an individual pressure compensator (Individual Druckwaage) may be arranged corresponding to the inflow metering orifice or meter-in throttle (Zumessblende) of the load sensing control unit. The individual pressure compensator maintains a constant pressure difference before and after the meter-in throttle of the hydraulic consumer with the lower load pressure, so each consumer can be controlled independently of the load pressure. It becomes possible.

  In a control device generally called “LS control unit”, an individual pressure compensator is arranged upstream of each meter-in throttle. The individual pressure compensator throttles the pressure medium volume flow between the pump line and the meter-in throttle, and the pressure upstream of the meter-in throttle is higher than the individual load pressure by a specified pressure difference regardless of the pump pressure. It is trying to become. In this case, at the time of short supply (saturation), the consumer with the maximum load pressure is decelerated. This is because the pump pressure generated on the upstream side of the meter-in throttle of the consumer is reduced, thereby reducing the pressure difference before and after the meter-in throttle. In the so-called LUDV control (lastdruckunabhaengig. Durchflussverteilung = distribution of flow quantity independent of load pressure), an individual pressure compensator is arranged downstream of the meter-in throttle, and this individual pressure compensator is located between the meter-in throttle and the consumer. The fluid flow is throttled, in which case the pressure downstream of all meter-in throttles is equal, preferably equal to or slightly higher than the maximum load pressure. In this case, the pressure on the downstream side of the meter-in throttle does not change at the time of short supply. Since the pump pressure is uniformly formed on the upstream side of all meter-in throttles, if the flow distribution between the meter-in throttles is maintained even if the pump pressure is reduced at the time of short supply, the pressure difference in all meter-in throttles Varies uniformly, and correspondingly the speed of all the consumers is reduced by an equal ratio.

  In current known prior art valves, the meter-in restrictor at the inlet is often formed through the control edges of the valve spool, so that the notification or transmission of load pressure is often performed through these control edges. Is called. In particular, in a directional switching valve that does not have an additional shut-off valve in the inflow passage, leakage from the inflow passage into the load notification passage is additionally generated through these control edges. The disadvantage is that if there is a correspondingly high leak, the consumer may fall unacceptably and the reported load will be based on the leak into the load notification path. There is a risk that the pressure may be wrong or the LS pressure in the load notification passage rises unacceptably even when the inflow valve is not operated, leading to an unacceptable increase in pump pressure. There is to be.

  Based on the specification of US Pat. No. 5,878,647, a control device having a LUDV (flow volume distribution independent of load pressure) configuration is known. In this known control device, each of two inflow valves and return valves that are operated electromagnetically has a seat valve structure. The seating structure of the main control piston achieves that the inlet passage is sealed against the pump passage without leakage if it is not desired to provide a pressure medium flow to the consumer. At this time, in order to avoid leakage from the inflow passage into the load notification passage, and thus to avoid the inconvenience of erroneous load pressure, the control device has an additional check valve. The valve body of the check valve is formed as a bush, and a large circumferential valve seat is formed through an end section of the bush.

  A disadvantage of the above-described known solution is that, due to the structure of the check valve, it takes a lot of work in terms of assembly technology and device technology to shut off the load notification passage from the consumer passage. A further disadvantage is that the check valve is limited to one such function, despite the great technical effort of the device.

US Patent Application No. 5878647

  With respect to such a known prior art, the problem that forms the basis of the present invention is to improve a hydrostatic valve device provided with a valve for shutting off the inflow passage without leakage from the load notification passage, It is to provide a hydrostatic valve device in which the valve has a larger functional range.

  Furthermore, the problem that forms the basis of the present invention is to provide a hydrostatic control device including such a valve device.

  In order to solve this problem, in the configuration of the hydrostatic (hydrostatic) valve device of the present invention, the load notification passage is substantially connected to the seat valve via the seat valve with the meter-in throttle closed. It is cut off from the inflow passage without leakage and can be connected to the return passage or the pump passage.

  Further, in order to solve the above-mentioned problem, in the configuration of the hydrostatic control device of the present invention provided with such a valve device, a hydrostatic pump is provided, and the at least 1 is provided via the pump. One consumer can be supplied with a pressure medium in relation to the load pressure.

  Claims 2 to 14 describe advantageous improvements of the hydrostatic valve device.

  A hydrostatic valve device for supplying a pressure medium to at least one hydrostatic consumer has a main seat valve or an inflow valve, which includes a meter-in throttle with a valve seat. Via this meter-in throttle, the connection between the inflow passage or the consumer passage and the pump passage can be cut off substantially without leakage. Further, the valve device has a load transmission passage or a load notification passage, and the load notification passage is loaded by a load pressure taken out by a consumer, particularly in the inflow passage. Further, the valve device has a seat valve, and in the configuration of the present invention, the load notification passage is substantially free from leakage through the seat valve with the meter-in throttle closed. And can be connected to a return passage, in particular a tank or the pump passage, and is connected in particular.

  Therefore, the functional range of the seat valve that shuts off the inflow passage from the load notification passage without leakage is expanded compared to the known prior art. In this case, the seat valve can shut off without leakage. In addition, the load notification passage can be connected to the pump passage and the return passage. Therefore, this seat valve is functionally more flexible than the known prior art seat valve. In other words, the seat valve assumes another function. Thereby, it becomes possible to reduce the whole effort concerning a hydrostatic type valve apparatus. In connection with this, the check valve conventionally used in the known prior art can be made unnecessary. This can provide a configuration space advantage on the one hand and a cost advantage on the other hand. In addition, when the seat valve is used as an inflow valve, it is possible to realize a pressure relief that can shut off the load notification passage. This is not possible using the above arrangement according to the known prior art.

  In the first variation of the present invention, the inflow valve is directly controlled and has a main valve body that forms the meter-in throttle. In another variation of the present invention, the inflow valve is pre-controlled or pilot-controlled, and a main valve body that forms the meter-in throttle, and a pilot valve body for pre-controlling or pilot-controlling the main valve body, Have Pilot control using a pilot valve element has the advantage that a very high operating force is not required to control the main valve element or meter-in throttle. This is advantageous especially in use with a high load pressure in the inflow passage, especially when a high flow force can be expected in the main valve body.

  In an advantageous and particularly preferred refinement, the seat valve that seals the inflow passage to the load notification passage almost without leakage is an inverse shuttle valve (invers. Wechselventil) with the opposite function of a normal shuttle valve. The inverse shuttle valve is configured to include a load notification outlet connected to the load notification passage, a consumer inlet connected to the inflow passage, and a control inlet connectable to the pump passage or the return passage. Have The inverse shuttle valve is a valve that is particularly simple in terms of equipment technology for the purpose of blocking the inflow passage from the load notification passage without substantial leakage and connecting it to the return passage or the pump passage. It is. Compared to the known prior art check valves, this inverse shuttle valve has a particularly small and simple structure and offers great cost advantages.

  In another advantageous and preferred refinement of the hydrostatic valve device, a pump connection connected to the pump passage, a return connection connected to the return passage, and a control inlet of the inverse shuttle valve And a directional control valve provided with a controlled connection. This directional control valve preferably has an operable load position, through which the control inlet of the inverse shuttle valve is connected to the pump passage and is separated from the return passage. Yes. Furthermore, the direction switching valve advantageously has a pressure relief basic position, through which the control inlet of the inverse shuttle valve is separated from the pump passage and is connected to the return passage. It is connected. Therefore, at the basic pressure release position, that is, when the direction switching valve is not operated, the control inlet of the seat valve or the inverse shuttle valve is connected to the return passage via the direction switching valve, and the load notification passage Is blocked from the inflow passage, that is, when the meter-in throttle is closed, the load notification passage is released toward the return passage or the tank. As a result, even if a leakage amount flows into the load notification path, the notified load pressure of the consumer is not increased. Said directional control valve is preferably operable electromagnetically or via a control pressure.

  In order to enable the control sequence of the directional control valve and the inflow valve to be defined particularly simply in terms of the device technology, in a further advantageous refinement of the invention, the valve body of the directional control valve comprises A connection portion (coupling) between the main valve body of the inflow valve or the pilot valve body of the inflow valve, particularly a mechanical connection portion. Based on this connection, when the valve body of the direction switching valve is operated to the load position, on the one hand, the opening control of the connection between the control inlet of the seat valve and the pump passage is performed, and at the same time, the return path or the tank is controlled. The load notification passage is shut off. On the other hand, opening control of the opening cross section of the meter-in throttle is performed through operation of the direction switching valve. The latter opening control is performed indirectly through the connected pilot valve body or directly through the main valve body connected to the inflow valve. In the case of a directly controlled inflow valve, the mechanical connection between the main valve body of the inflow valve and the valve body of the directional control valve is preferably elastic, particularly preferably a spring. Therefore, when the main valve body is still closed and pressure compensation is not performed, direct contact does not occur between the main valve body and the valve body of the direction switching valve. Thus, against the operation of the load switching position, a high pressing force acting on the main valve body in the closing direction does not act, and the operating force can be kept small. In the case of a pilot-controlled inflow valve, the mechanical connection between the pilot valve body of the inflow valve and the valve body of the directional switching valve is advantageously formed rigidly, but explained earlier For this reason, it may alternatively be formed via an elastic connection, preferably by the use of a spring. This spring advantageously has a spring stroke corresponding to an operating stroke from at least the pressure release position to the position where the pump passage is connected to the control medium by the pressure medium. In this case, the rigid connection may be formed, for example, by forming both valve bodies as a single part. However, for manufacturing and assembly technical reasons, it is advantageous to consist of several parts. As an alternative to electromagnetic operation, the directional control valve can be operated via a control pressure.

  When the meter-in throttle is opened and the load pressure is higher than the pump pressure, it is particularly advantageous if the load notification passage is blocked from the inflow passage and connected to the pump passage.

  In the inverse shuttle valve, the consumer inlet has a first valve seat and a first seal element, and the first seal element is a pressure related to the load pressure of the consumer or the load pressure of the consumer. It is advantageous if it is configured to be loaded in the closing direction. The control inlet in this refinement has a second valve seat and a second sealing element, the second sealing element being a pressure in the pump passage or a pressure related to the pressure in the pump passage. Or the pressure in the return passage or a pressure related to the pressure in the return passage is loaded in the closing direction. The valve seat is advantageously formed via a conical valve seat, a spherical valve seat or a countersunk valve seat, respectively.

  It is advantageous that the load notification outlet of the inverse shuttle valve is open to the pressure chamber between the two valve seats. The closing direction of both valve seats is such that the sealing element is lifted from the corresponding valve seat by the high pressure acting at the inlet located on the opposite side and the connection or coupling formed between these sealing elements. Or set to be loaded in the opening direction.

  It is particularly advantageous if the two sealing elements are connectable via a connecting element arranged between the two sealing elements, or are connected or connected. The connecting element can be, for example, a cylindrical pin having a particularly circular or polyhedral cross section, in particular a hexagonal cross section. Based on this connection, the force acting on each one of the sealing elements in the closing direction is transmitted directly to the other sealing element in the opening direction.

  The seat valve has a substantially cylindrical housing, which is inserted or press-fitted into another housing part of the valve device, in particular a control block or control sandwich plate or the housing of the inflow valve. When mounted or screwed, a particularly compact variant of the valve device is obtained. When a seal sheet, particularly a seal edge, is formed through one of the inlets of the inverse shuttle valve (consumer inlet or control inlet) and the housing part, the housing of the inverse shuttle valve Is sealed to the housing part in a particularly simple technical manner. In this case, alternatively or additionally, it is advantageous if at least one sealing ring, in particular an O-ring, is arranged between the seat valve housing and the housing part in the radial direction.

  In order to also seal the other of the two inlets of the inverse shuttle valve, in a further refinement of the valve arrangement, in the range of the other inlet, the other inlet and in the housing part. A sealing sheet, in particular a sealing edge, is formed via a screwed closure screw. Thus, the seat valve or inverse shuttle valve housing is simply axially fixed in the housing part and sealed at the same time via a closing screw in terms of the device technology. Furthermore, as a supplement, a sealing sheet may be formed between the closing screw and the housing part. This sealing sheet is preferably formed in the closing screw on the entire circumference in the radial direction. In order to ensure good assembly of the one or more sealing elements, it penetrates radially between the inlets and the sealing elements respectively corresponding to the inlets, in particular the housing of the inverse shuttle valve. An axial stop is arranged or formed via a fixing element, in particular a pin or a split pin. In order to allow a precise metering of the pressure medium volume flow flowing through each open cross section for a given stroke of the corresponding valve body, an advantageous refinement of the invention comprises the main valve body and The pilot valve body has a precision control geometry, in particular at least one precision control notch, especially in the pressure medium flow path from the pump passage to the inflow passage.

  The control device according to the present invention including the valve device has a hydrostatic pump. Via this hydrostatic pump, a pressure medium can be supplied in relation to the load pressure to the at least one consumer. For this purpose, the control device has at least one individual pressure compensator which is arranged upstream or downstream of the inflow valve, ie upstream or downstream of the inflow valve. As described above, the LS system or the LUDV system is configured. In both of these cases, the pump is advantageously adjustable, i.e. configured in a variable displacement manner, and the control device preferably has a pumping flow regulator. This pressure-feeding flow regulator is loaded on the one hand by the pump pressure and on the other hand by the load pressure and the pressure equivalent of the control spring (Druckaequivalent). In addition to the two variants, the control device comprises a constant displacement pump and a bypass valve loaded with load pressure in the opening direction.

  In the following, one embodiment of the control device according to the present invention will be described with reference to one drawing, four embodiments of the valve device according to the present invention will be described in detail with reference to seven drawings, and the control according to two drawings. Two embodiments of the device or the inverse shuttle valve used in the valve device will be described in detail.

1 is a significantly simplified circuit diagram illustrating a first embodiment of a hydrostatic control device. FIG. It is a general circuit diagram which shows 1st Embodiment of the valve apparatus used in the control apparatus shown in FIG. It is a longitudinal cross-sectional view of the valve apparatus shown in FIG. FIG. 4 is a detailed circuit diagram of the valve device shown in FIGS. 2 and 3. It is a longitudinal cross-sectional view which shows 2nd Embodiment of a valve apparatus. It is a detailed circuit diagram of the valve apparatus shown in FIG. It is a longitudinal cross-sectional view which shows 3rd Embodiment of a valve apparatus. It is a longitudinal cross-sectional view which shows 4th Embodiment of a valve apparatus. It is a longitudinal section showing a 1st embodiment of an inverse shuttle valve. It is a longitudinal cross-sectional view which shows 2nd Embodiment of an inverse shuttle valve.

  In the following, one embodiment of the control device according to the invention and four embodiments of the valve device according to the invention will be described in detail with reference to the seven drawings, and further two embodiments of shuttle valves used in the control device or valve device. Will be described in detail with reference to the two drawings.

  The control device and the valve device described below perform load notification or load transmission to a separate load notification passage of a hydraulic consumer unit corresponding to the inflow valve. In this case, this load notification or load transmission is performed. Is performed so that the load passage or the inflow passage can be sealed without leakage when the inflow valve is not operated. Further, it is given that the load notification passage is released to the return passage when the corresponding inflow valve is not operated, and this release pressure is released when the inflow valve is operated. In this case, the inflow valve is arranged as a proportionally adjustable seat valve in the inflow part of the consumer.

  FIG. 1 schematically shows a highly simplified circuit diagram of an embodiment of a hydrostatic or hydrostatic control device 1. The hydrostatic control device 1 is used to supply a pressure medium to a plurality of consumers provided in one mobile work machine such as a hydraulic excavator, a tractor, a backhoe loader, or a forklift truck. In this embodiment, the consumers 2 and 4 are illustrated as differential cylinders, for example. Supply of the pressure medium to the consumers 2 and 4 is performed via the control block 5. This control block 5 has two valve sandwich plates or directional valve sections 6, 8. The two-way switching valve sections 6 and 8 correspond to one consumer 2 and 4 respectively. The directional valve sections 6 and 8 each have two working connections A and B. Both work connection portions A and B can be connected to the connection portions P, T, and LS of the control block 5 through a valve device described below.

  The control device 1 has a pump, which is a variable displacement pump 10 in this embodiment. The discharge connection portion of the variable displacement pump 10 is connected to the pressure connection portion P of the control block 5 via the pressure line 12. Unlike the embodiment shown in FIG. 1 and the subsequent embodiments, a constant displacement pump with a bypass valve can be used instead of the variable displacement pump. In the illustrated embodiment, the variable displacement pump 10 is configured as an axial piston pump, for example. The tilt angle of this axial piston pump can be adjusted via the working cylinder 14. Control of the working cylinder 14 is performed via a pressure feed flow rate regulator (regulator) 16. In the illustrated embodiment, the tilt angle is adjustable via a return device 18 which is loaded with the pressure in the pressure line 12 in the direction of the maximum tilt angle and this maximum. In the opposite direction to the tilt angle, it is loaded with a spring force, whereas the working cylinder 14 can be adjusted against the force of the return device 18 to reduce the tilt angle. The pumping flow rate regulator 16 is preloaded or preloaded in the direction of reducing the load on the working cylinder 14 by the spring force of the control spring 20 and the control pressure in the load notification line 22. In this case, the control oil connection portion from the working line 24 opened in the working chamber of the working cylinder 14 toward the tank T is controlled to open. In the load notification line 22, the maximum load pressure of the controlled consumers 2 and 4 is applied, and this maximum load pressure is taken out at the LS connection portion of the control block 5. The tank connection portion T of the control block 5 is connected to the tank T via the tank pipe line 26.

  The pump pressure taken out by the pressure line 12 acts on the valve spool of the pumping flow rate regulator 16 against the spring force of the control spring 20 and the maximum load pressure. This pump pressure is also applied to the pressure connection P of the pumping flow rate regulator 16. When the variable displacement pump 10 is controlled, the pump volume flow rate, and hence the pump pressure in the pressure line 12, increases. In this case, the pump volume flow rate or the pump pressure in the pressure line 12 is increased by the pumping flow rate regulator 16. Until the pressure balance between the pressing pressure of the pump pressure, the load pressure of the consumer with the highest load pressure and the spring force of the control spring 20 occurs. In that case, the pump pressure is set higher than the maximum load pressure by a differential pressure defined by the spring force of the control spring 20. Since the basic function of such pump control is known based on the known prior art, for example, European Patent Application No. 2171285, further detailed description is omitted.

  Each of the valve sandwich plates 6 and 8 includes a consumer connecting portion A, B, a pressure connecting portion P, a tank T, and a load notification connecting portion LS. In this case, the connecting portions P, T , LS are connected in pressure medium to the adjacent valve sandwich plates 8, 6 respectively.

  In the valve sandwich plates 6 and 8 to be described below, an inflow metering throttle or meter-in throttle 28 and 30 and a single descent brake valve 32 and 34 are respectively arranged corresponding to the consumer connecting portions A and B. For load compensation, at least one individual pressure compensator 36 is arranged corresponding to the meter-in throttles 28 and 30. Via this individual pressure compensator 36, the pressure drop around each meter-in throttle 28, 30 can be kept constant. In the solution shown in FIG. 1, the valve sandwich plates 6, 8 are configured as an LS system. In this case, only one individual pressure compensator 36 is arranged corresponding to both meter-in throttles 28, 30. The inlet connection of the spring preloaded individual pressure compensator 36 is connected via a pressure passage 38 to the pressure connection P of the valve sandwich plates 6, 8. The outlet of the individual pressure compensator 36 is connected to one pressure connection portion P of each of the meter-in throttles 28 and 30 via a branched pump passage 40. The individual pressure compensator 36 is pressed by the pressure upstream of the meter-in throttles 28 and 30 in the closing direction, and is pressed by the individual load pressures of the connected consumers 2 and 4 in the opening direction. This load pressure is taken out via the LS passage 42. The LS passage 42 communicates with one inlet of the shuttle valve 44, and the highest load pressure of the other consumer 2, 4 is applied to the other inlet of the shuttle valve 44. In the case of another hydrostatic consumer, the maximum load pressure is taken through the shuttle valve cascade. Since the outlet of the shuttle valve 44 is connected to the LS connection portion of the valve block 5, the maximum load pressure among all the load pressures is notified or transmitted to the pumping flow rate regulator 16 described at the beginning.

  Both meter-in throttles 28 and 30 having the same structure are formed as proportionally adjustable seat valves that can be electrically controlled. The work connection portions A and B of the seat valve are connected to the work connection portions A and B of the valve sandwich plates 6 and 8 through a passage. In the following description of the control of the inflow volume flow rate performed through the hydrostatic valve devices 29 and 31 having the meter-in throttles 28 and 30, the consumer connection part A is located on the inflow side, and the consumer connection part B Is located on the outflow side. Corresponding to this assumption, the passage leading to the consumer connecting portion A will be referred to as “inflow passage 46”, and the passage leading to the consumer connecting portion B will be referred to as “outflow passage 48”. The end faces of both inflow valves 29 and 31 are pressure compensated at the start of opening the throttle cross section of the meter-in throttles 28 and 30.

  By energizing the proportional solenoids 50 and 52, the meter-in throttles 28 and 30 are moved from the illustrated cutoff position, that is, from the cutoff position where the outflow from the consumers 2 and 4 toward the individual pressure compensator 36 is blocked without leakage. It can be adjusted in the opening direction. In this case, the open cross section is related to the energization of the proportional solenoids 50, 52. The pressure on the upstream side of each meter-in throttle 28, 30 is taken out at the LS connection portion of the meter-in throttle 28, 30. This pressure is applied to the inlet of another shuttle valve 54. The outlet of the shuttle valve 54 is connected to the LS passage 42. The load pressure at the LS connection portion of the meter-in throttle 28 is also notified or transmitted to the connection portion B, that is, the signal pressure chamber of the descending brake valve 34 disposed on the outflow side, via the load take-out passage 56. Correspondingly, the load pressure at the LS connection portion of the other meter-in throttle 30 is connected to the signal pressure chamber of the inflow-side descent brake valve 32 via the load pressure extraction passage 58. Correspondingly, both signal pressure chambers of the lowering brake valves 32, 34 are separated from each other via the shuttle valve 54. Since the functions of the lowering brake valves 32 and 34 are described in detail in German Patent Application No. 102012203386.6 filed on the same day as the present application by the same applicant, further description will be omitted.

  In the illustrated embodiment, the pressure limiting valve that limits the pressure in the inflow passage 46 and the outflow passage 48 is not shown. When the predetermined maximum pressure adjusted in these pressure limiting valves is exceeded, the pressure limiting valve opens the pressure medium connection to the pressure relief passage connected to the tank connection T.

  In the following, with reference to FIG. 2, the same double valve devices 29, 31 having meter-in throttles 28, 30 will be described in detail. FIG. 2 shows a general circuit diagram of the valve device 29 in various degrees of detail. On the right-hand side of FIG. 2 there is shown a significantly simplified switching symbol showing the valve device 29 in the control device 1 in a form cut out from FIG. It can be connected to the consumer connection part A connected to the inflow passage 46, the pump connection part P connected to the pump passage 40, the tank connection part T connected to the tank, and the LS passage 42 shown in FIG. A load notification connection LS is illustrated. The meter-in throttle 28 can be proportionally adjusted, and has a seat valve structure. In the shut-off position (a), the inflow passage 46 is shut off from the pump passage 40 without leakage, and the load notification passage 60 is released toward the tank. Even if inflow occurs, there is no fear that a pressure increase including an error in the load notification passage 60 will occur. The valve device 29 has an inflow position (b). In the inflow position (b), the pump passage 40 is connected to the inflow passage 46 via the meter-in restrictor 28. On the downstream side of the meter-in throttle 28, the load pressure applied in the inflow passage 46 is taken out and transmitted to the load notification passage 60. The valve device 29 has a blocking position (a) preloaded via a spring 62. In order to switch the shut-off position (a) to the inflow position (b), the valve device 29 has a proportional solenoid 50.

  On the left side of FIG. 2, a circuit diagram depicting the valve device 29 in more detail is shown. Below, the functional form in this invention of the valve apparatus 29 or the valve apparatus 31 is demonstrated about this circuit diagram. The valve device 29 represents a solution using a proportionally adjustable main seat valve or inlet valve 64 for the supply of pressure medium to the inlet of the consumer. In this solution, the load notification passage 60 is sealed against the inflow passage 46 without leakage when the inflow valve 29 is not operated. Further, this solution means the pressure release of the load notification passage 60 to the tank when the inflow valve 29 is not operated and the release of the pressure release when the inflow valve 29 is operated.

  As shown on the left side of FIG. 2, the inflow valve 29 includes a main seat valve 64, a direction switching valve 66, and an inverse shuttle valve 68 (a function reverse to the function of a normal shuttle valve, that is, a high pressure in both inlets. The inverse shuttle valve 68 has a seat valve structure or is formed as a seat valve. The main seat valve 64 shuts off the inflow passage 46 from the pump passage 40 without leakage through the spring preloaded shut-off position (a), and enters the inflow position (b) through the proportional solenoid 50. Can be adjusted. In relation to the pressure generated at the consumer inlet V of the inverse shuttle valve 68 and the control connection S via the inverse shuttle valve 68, the lower pressure of both pressures is selected, Notification or transmission to the load notification path 60 is possible. In this case, the inverse shuttle valve 68 blocks the consumer inlet V from the load notification passage 60 and the control passage 70 without leakage. The main valve 64 is mechanically coupled to the direction switching valve 66. The direction switching valve 66 is formed as a four-port three-position direction switching valve, and connects the control passage 70 to the return passage 72 in the illustrated initial position with the main valve 64 closed. In the illustrated embodiment, the return passage 72 is released toward the tank. When the load pressure in the inflow passage 46 is larger than the return pressure in the control passage 70, the first and second seal elements 74 and 76 of the inverse shuttle valve 68 remain at the illustrated positions, and the load notification passage 60 is in the return passage. The pressure is released toward 72. Therefore, the leakage that has flowed into the load notification passage 60 can be derived, and an unintended pressure increase in the load notification passage 60 does not occur. As can be seen from the left side of FIG. 2, the direction switching valve 66 has a valve body 78, and this valve body 78 is mechanically firmly connected to the main valve body 80 of the main seat valve 64. Therefore, when the proportional solenoid 50 is operated, the direction switching valve 66 changes its position together with the main seat valve 64, and this time connects the control passage 70 to the pump passage 40. Therefore, during this first control phase, the load notification passage 60 is directly connected to the pump passage 40 based on the open connection between the control passage 70 and the load notification passage 60. The short circuit (see reference numerals 16 and 10 in FIG. 1) formed in the pump flow rate regulator 16 in this way causes an increase in the suction capacity of the pump in the LS system and the LUDV system. This is because the pressure does not drop at this point through the open cross section of the main seat valve 64 which is still closed. Accordingly, the pump flow rate regulator has reached the limit position or the maximum position. When the pump pressure reaches the value of the load pressure taken out in the inflow passage 46, the seal elements 74 and 76 provided in the inverse shuttle valve 68 are switched, and at this time, the lower load pressure is applied to the load notification passage 60. Informed. What can be said about all the illustrated embodiments is that the control sequence is such that the directional control valve 66 first connects the control passage 70 to the pump passage 40, and then the main valve 64 passes through its meter-in restrictor 28 to the pump passage 40. It is advantageous if it is adjusted so that the open cross section between the inlet and the inlet passage 46 can be opened.

  FIG. 3 shows the valve device 29 shown in FIGS. 1 and 2 in a longitudinal sectional view. The valve device 29 is formed in the same structure as the valve device 31 of the drawing. The valve device 29 integrates an inflow valve or main seat valve 64, an inverse shuttle valve 68, and a direction switching valve 66. In this case, the valve device 29 is incorporated in the valve sandwich plate 6 shown in FIG. 1 of the hydrostatic valve device 1 and has a valve housing 82. A main valve body 84 is accommodated in the valve housing 82 so as to be movable in the axial direction on the left side in FIG. Further, the valve device 29 has a front control valve body or a pilot valve body 86 that is accommodated in an axial hole provided in the main valve body 84 so as to be slidable in the axial direction. The valve sandwich plate 6 has a pump passage 40, an inflow passage 46, a load notification passage 60, and a return passage 72. In these passages mentioned above, ports or connecting portions P, A, LS, T formed in the valve housing 82 of the valve device 29 are connected to the pressure medium, that is, the pressure medium flows. It is connected. The main valve body 84 is hydraulically and mechanically coupled to the pilot valve body 86.

  If the coil 88 of the proportional solenoid 50 is not energized, the pressure-compensated solenoid armature 90 is in its rest position. At this time, the solenoid armature 90 and the valve body 78 of the direction switching valve 66 are pressed to the initial position or the priority position by the spring 92 that is slightly preloaded. The preload force or preload force of the spring 92 can be easily changed by the adjusting screw 94. Thus, manufacturing errors can be compensated, and a desired solenoid current when the valve body 78 of the direction switching valve 66 and the pilot valve body 86 mechanically connected to the valve body 78 start to move is adjusted. obtain.

  In a state where the coil 88 is not energized, the pilot valve body 86 is pressed against the seal sheet 98 formed of a conical seat structure via another spring 96. If the pressure in the pump passage 40, and hence the pressure in the pump connection P of the valve housing 82, is lower than the load pressure in the inflow passage 46 or the load pressure in the inflow connection A of the valve housing 82, the shuttle valve 100 is higher. Is transmitted to the back chamber 106 of the pilot valve body 86 through the radial passage 102 and the axial passage 104 formed in the pilot valve body 86. Thereby, the pilot valve body 86 receives an additional force, and this force presses the pilot valve body 86 against the seal sheet 98. The pressure in the back chamber 106 is notified or transmitted to the back chamber 110 of the main valve body 84 by the throttle 108. The resulting pressing force acting on the rear end face of the main valve body 84 presses the main valve body 84 against a corresponding seal sheet 112 that is also formed of a conical seat structure having a valve housing 82. . Further, via the valve body 78 of the direction switching valve 66, the load notification passage 60 passes through the LS connection portion of the inverse shuttle valve 68, the control connection portion S, the control passage 70, and the tank connection portion T of the valve housing 82. Thus, the pressure medium connection leading to the return passage 72 or the tank T is controlled to be opened. Thereby, at this position of the valve body 78, the pressure in the return passage 72 is notified or transmitted to the control inlet S of the inverse shuttle valve 68. Since the load pressure notified or transmitted from the inflow passage 46 to the consumer inlet V of the inverse shuttle valve 68 via the inflow connection portion A of the valve housing 82 is larger than the pressure in the return passage 72, the inverse shuttle valve 68 is The consumer inlet V is blocked without leakage by the sealing sheet of the first sealing element 74. Therefore, on the one hand, the load notification passage 60 is released toward the tank via the inverse shuttle valve 68, and on the other hand, the inflow passage 46 is blocked from the load notification passage 60 without leakage.

  Next, when the coil 88 of the proportional solenoid 50 is energized, a force in the opening direction acts on the solenoid armature 90. Against this force, it is generated from the force of the spring 96 and the pressure in the back chamber 106 of the pilot valve body 86 via the valve body 78 and the pilot valve body 86 connected to the valve body 78. The pressing force acts. The generated combined pressing force acts only when the pilot valve body 86 is not pressure-compensated and when the pressure in the pump passage 40 is smaller than the load pressure in the inflow passage 46. A high solenoid current must be set such that the valve body 78 closes the connection between the control passage 70 and the return passage 72. At about the same time, a connection between the pump passage 40 and the control passage 70 is formed. In order to be able to measure the position of the solenoid armature 90 at this time, it is possible to rely on a sensorless stroke detection concept regardless of the illustrated embodiment. For example, the position of the solenoid armature 90 can be estimated for the change in the inductance of the coil 88 and the detection of the solenoid current at the same time, and thus the open cross section of the seal sheet 112 can be estimated. In order to significantly reduce the magnetic force at the time of switching of the valve body 78, the mechanically rigid coupling between the valve body 78 and the pilot valve body 86 is discarded and, alternatively, an elastic coupling, It can advantageously be replaced by an elastic coupling realized by a spring (similar to the solution shown in FIG. 8-directly operated valve). Thus, the magnetic force only has to work against the spring force newly added between the valve body 78 and the pilot valve body 86. In this case, a significantly smaller magnetic force is required to move the valve body 78 and realize a pressure medium connection between the pump passage 40 and the control passage 70. When the pressure medium is connected between the pump passage 40 and the control passage 70, the pump pressure is notified or transmitted into the LS passage, and the pump can tilt. When the pump pressure reaches a value higher than the load pressure, the pilot valve body 86 is compensated for pressure, and when the proportional solenoid 50 is continuously energized, the pilot valve body 86 is opened by the valve body 78 in proportion to the magnetic force. obtain. In this case, there must be direct mechanical contact between the valve body 78 and the pilot valve body 86.

  Due to the pressure medium connection between the pump passage 40 and the control passage 70 formed in this way, the short circuit occurs in the pumping flow rate regulator 16 (see FIG. 1). This short circuit results in increased pump tilt and increased pumped capacity flow. Thereafter, when the pressure in the pump passage 40 increases until it becomes larger than the load pressure in the inflow passage 46, the inverse shuttle valve 68 is switched, and the lower pressure, that is, the load pressure in the inflow passage 46 is loaded. Informs or transmits to the informing passage 60. Next, the pump pressure higher than the load pressure by a predetermined differential pressure is adjusted via the individual pressure compensator (36, see FIG. 1) of the control device.

  Almost at the same time, the shuttle valve 100 is switched, and at this time, the higher pressure, that is, the pump pressure in the pump passage 40 is supplied to the pilot valve body through the passages 114, 116 and 104 formed in the pilot valve body 86. The 86 back rooms 106 are notified. The pressure in the back chamber 106 is also notified in the back chamber 110 of the main valve body 84 via the throttle 108. As a result, the main valve body 84 receives a combined force in the closing direction. This is because the end face of the main valve body 84 defining the back chamber 110 is completely loaded with pump pressure, and a load pressure lower than the pump pressure is applied to a part of the end face arranged on the opposite side. Because it works.

  The operation point at which the pilot valve body 86 is pressure compensated can be detected by the sensorless stroke detection mentioned above. This applies when the pump pressure is higher than the load pressure. The position of the solenoid armature 90 is controlled to a value at which load notification or load transmission from the inflow passage 46 to the load notification passage 60 is performed, but the axial hole provided in the main valve body 84 and the pilot valve body are controlled. A precision control geometry 118 formed through a radial extension provided at 86 still controls the connection between the inlet passage 46 and the pump passage 40 open. Therefore, the pressure medium volume flow returning from the inflow passage 46 to the pump passage 40 does not flow. If the pilot valve body 86 is pressure compensated, a significantly lower solenoid current need only be applied to maintain this input controlled position. When the solenoid current approaches a value such that the combined pressing force in the back chamber 106 only needs to act against the force of the spring 96, it can be estimated that the pilot valve body 86 is pressure compensated. As the coil 88 continues to be energized, the solenoid armature 90 moves further and the connection between the inlet passage 46 and the pump passage 40 is controlled open via the precision control geometry 118. In this way, a load or load drop at the start of exercise is avoided. This is because the pump pressure does not become lower than the load pressure at the start of exercise. Therefore, an additional check valve can be dispensed with. The precise control of the inflow volume flow rate is realized via the precise control geometry 118 of the pilot valve body 86.

  After a predefined stroke of the pilot valve body 86, the throttle cross section is controlled to open via the precision control geometry 120. The back chamber 110 of the main valve body 84 is connected to the intermediate passage 124 via a passage hole 122 formed in the main valve body 84 through the throttle cross section. Due to the voltage divider formed in this way, the pressure in the back chamber 110 of the main valve body 84 is reduced. Thereby, the direction of the synthetic pressing force with respect to the main valve body 84 changes until the main valve body 84 is moved. This movement of the main valve body 84 results in a reduction of the throttle cross section in the precision control geometry 120 until a pressing force balance occurs. Thus, the main valve body 84 follows the movement of the pilot valve body 86 and the open crossing between the pump passage 40 and the inflow passage 46 via the conical seal sheet 112 which the main valve body 84 forms with the valve housing 82. Open the face. Through this throttle cross section, a much larger inflow volume flow rate of the pilot valve body 86 can flow than through the throttle cross section formed in the seal sheet 98.

  FIG. 4 shows a schematic circuit diagram of the valve device 29 described with reference to FIG.

  FIG. 5 shows a second embodiment of a valve device 229 according to the present invention that includes a main seat valve 264, a direction switching valve 266, and an inverse shuttle valve 68 having a reverse configuration. Further, the valve device 229 has a stroke detector 326 for measuring the position of the main valve body 284. The stroke detector 326 is connected to the control unit 332 via the signal line 330, and this control unit 332 is connected to the coil 88 of the proportional solenoid 50 via the current line 334. In the present embodiment, there is no hydraulic or mechanical coupling between the main valve body 284 and the pilot valve body 286. This is because the valve bodies 284 and 286 do not form a throttle cross section together. Unlike the case of the first embodiment of the valve device 29 shown in FIG. 3, both valve bodies 284 and 286 are arranged in directions orthogonal to each other or non-coaxially with each other. Alternatively, the valve bodies 284, 286 may be arranged coaxially with each other, in particular concentrically with each other. For this purpose, the two valve bodies 284, 286 are advantageously arranged one after the other. In this case, the main valve body 284 is accommodated in a cylindrical hole 203 provided in the valve housing 282 so as to be movable in the axial direction, and the pilot valve body 286 is disposed in the cylindrical hole 202 provided in the valve housing 283. It is housed so that it can move in the direction.

  In a state where the proportional solenoid 50 is not energized, the preload force or preload force of the spring 297 and the pressing force generated in the back chamber 306 of the pilot valve body 286 act on the pilot valve body 286. As a result, the pilot valve body 286 is pressed against the seal sheet 98 provided in the housing 283. A shuttle valve 200 is disposed on the main valve body 284, and the shuttle valve 200 selects a higher pressure from the pump pressure in the pump passage 40 and the load pressure in the inflow passage 46. This maximum pressure is notified to the back chamber 310 of the main valve body 284 via an axial passage 304 provided in the main valve body 284 and a throttle 308 disposed in the axial passage 304. This pressure in the back chamber 310 generates a pressing force of the main valve body 284 against the end surface defining the back chamber 310, and this pressing force is combined with the preload force of the spring 296 to cause the main valve body 284 to move. Then, the seal sheet 312 provided in the housing 282 is pressed. At this time, the pressure in the back chamber 310 can be propagated into the back chamber 306 of the pilot valve body 286 via the housing hole connecting both the valve housings 282 and 283 and another throttle.

  Further, the control passage 70 is connected to the return passage or the tank passage 72 through the valve body 78 of the direction switching valve 266. As a result, a return pressure is applied to the control inlet S of the inverse shuttle valve 68 and a load pressure is applied to the consumer inlet V of the inverse shuttle valve 68. Therefore, the load notification passage 60 is located at the switching position shown in FIG. A state in which the pressure is released into the return passage or the tank through the control passage 70 is shown.

  When the proportional solenoid 50 is energized, the proportional solenoid 50 first causes the control passage 70 to no longer be connected to the pressure medium in the return passage 72, and the pressure is applied to the pump passage 40 through the connection passage penetrating both valve housings 282 and 283. The valve body 78 is moved to a position where the medium is connected. At the same time, since the precise control geometry 320 provided on the pilot valve body 286 is still closed, the throttle cross section is not yet opened between the back chamber 310 of the main valve body 284 and the intermediate passage 324. The intermediate passage 324 is already connected to the return passage 72 through the seal sheet 98 with the pilot valve body 286 opened. Accordingly, the return pressure can be propagated into the back chamber 306 of the pilot valve body 286 through the radial hole and the axial hole formed in the pilot valve body 286. The condition in this case is that the throttle cross section of the throttle disposed in the pressure medium flow path leading from the back chamber 310 of the main valve body 284 to the back chamber 306 of the pilot valve body 286 is the back chamber 310 of the main valve body 284. Is connected to the inflow passage 46 or is formed to be significantly smaller than the throttle cross section of the throttle 308 connecting to the pump passage 40. As a result, the pilot valve body 286 is pressure compensated.

  At this time, the load notification passage 60 is connected to the pump passage 40 through the control inlet S opened by the inverse shuttle valve 68. In this case, the short circuit occurs in the pumping flow regulator (in the case of LS and LUDV valves) and in the predecessor individual pressure compensator possible in the LS system. When the pump pressure rises and the pump pressure becomes higher than the load pressure in the inflow passage 46, the inverse shuttle valve 68 is switched, and this time, the load pressure from the inflow passage 46 is notified or transmitted to the load notification passage 60. To do. Similarly, the shuttle valve 200 is switched to notify or transmit the pressure in the pump passage 40 into the back chamber 310 of the main valve body 284. In order to be able to open the main valve body 284 or its seal sheet 312, the proportional solenoid 50 is continuously energized. This opens the precision control geometry 320 of the pilot valve body 286, thereby opening the throttle cross section between the back chamber 310 of the main valve body 284 and the intermediate passage 324. This diaphragm cross section is variable. A pressure divider circuit is created through the restriction 308 and the restriction having a variable cross-section formed by the precision control geometry 320 so that the pressure in the back chamber 310 can be varied. As pressure limits in the back chamber 310, pump pressure (with the precision control geometry 320 closed) and nearly return pressure (with the precision control geometry 320 fully open) are obtained. Due to the pressure drop in the back chamber 310 of the main valve body 284, a composite force is generated in the main valve body 284 in the opening direction. The main valve body 284 moves away from the seal sheet 312 formed with the housing 282 to open the throttle cross section between the pump passage 40 and the inflow passage 46. Thus, a predetermined incoming volume flow can flow to the consumer.

  The position of the main valve body 284 is determined via a stroke detector 326 connected to the main valve body 284 via a shaft 328. The position signal is transmitted to the control unit 332 via the signal line 330. The control unit 332 compares this actual value with a predetermined target value and controls the coil 88 of the proportional solenoid 50 for controlling the direction switching valve 266 and the pilot valve body 286 via the current line 334 accordingly. . Thus, the position of the main valve body 284 or the open cross section of the seal sheet 312 can be controlled in a closed loop manner in accordance with the predetermined target value. The proportional solenoid 50 is otherwise formed in the same structure as the proportional solenoid 50 of the valve device 29 shown in FIG.

  FIG. 6 shows a schematic circuit diagram of the valve device 229 described with reference to FIG.

  FIG. 7 shows a third embodiment of the valve device 429. The third embodiment mainly corresponds to the second embodiment of the valve device 229 shown in FIGS. 5 and 6. The only difference is that the main valve body 484 additionally has a precision control geometry 420. In a state where the main valve seat or the seal sheet 312 is opened, the pressure medium volume flow rate from the pump passage 40 toward the inflow passage 46 is precisely metered and controllable through the precision control geometry 420. The precision control geometry 420 is formed on the main valve body 484 side via a radially extended control collar. To form the precision control geometry 420, the valve housing 482 has been modified, in which case the valve housing 482 has a radial collar that radially narrows the cylindrical hole 203 within the control collar. This radial collar is flush with the control collar of the main valve body 484. This control collar has a control notch towards the pressure chamber connected to the pressure passage in the pump passage 40. Through the precision control geometry 420, the pressure medium volume flow from the pump passage 40 to the inflow passage 46 is more precise than if only the main valve seat 312 of the main valve body 484 having the valve housing 482 is provided for control. Can be controlled.

  FIG. 8 shows a fourth embodiment of the valve device 629. In the fourth embodiment, the port or connecting portions A, P, L, S and T, the proportional solenoid 50, the direction switching valve 66 and the inverse shuttle valve 68 are the same as those in the first embodiment of the valve device 29 shown in FIG. It is almost equivalent. Unlike the first embodiment shown in FIG. 3 and the second and third embodiments shown in FIGS. 5 to 7, the main seat valve or the inflow valve 664 is not directly controlled but directly controlled. Is done. The main change accompanying this is that the coupling between the valve body 78 of the direction switching valve 66 and the main valve body 684 of the main seat valve 664 is no longer rigid, but is formed flexibly via a spring 699, and A spring 96 is disposed in the back chamber 110 of the main valve body 684 and acts on the main valve body 684 in the closing direction. Further, the shuttle valve 100 is no longer disposed on the pilot valve body, but is disposed directly on the main valve body 684. Accordingly, the axial passage 104 is not directly on the pilot valve body, but directly on the main valve body 684. It opens to the back chamber 110 of the valve body 684. Another difference is that the main valve body 684 shown in FIG. 8 has a radially expanded control collar at approximately the center and the valve housing 682 is approximately radially reduced at this location. With a controlled collar. The radially expanded control collar provided on the main valve body 684 further has a control notch. When the proportional solenoid 50 is energized, a magnetic force acts on the valve body 78. This magnetic force works against the spring 699. Based on the energized solenoid, the valve body 78 can move and simultaneously disconnect the pressure medium connection between the control passage 70 and the tank passage 72 and at the same time the pressure medium between the control passage 70 and the pump passage 40. Release the connection. Due to the short circuit already described in the individual pressure compensator 36 and the pumping flow regulator 16 of the pump 10, the pump 10 can be tilted and consequently the pressure in the pump passage 40 increases. . When the pressure in the pump passage 40 becomes higher than the load pressure in the consumer passage or the inflow passage 46, the inverse shuttle valve 68 notifies the load pressure to the load notification passage 60, and the shuttle valve 100 sends the pump pressure to the main valve body. Informs the back room 110 of 684. The main valve body 684 is pressure compensated at this time, and can be opened by energizing the proportional solenoid 50 continuously. In this case, the valve body 78 is in direct contact with the main valve body 684 (direct mechanical rigidity coupling).

  The next two figures, FIGS. 9 and 10, show two embodiments of an inverse shuttle valve 68 that was only schematically shown in the previous figures. As shown in FIG. 9, the inverse shuttle valve 168 is press-fitted into the valve housing (assuming it is the valve housing 82 of the first embodiment shown in FIG. 3). The inverse shuttle valve 168 has a cylindrical valve housing 802, and the valve housing 802 is inserted into a cylindrical hole 804 provided in the valve housing 82. On the left side of FIG. 9, a connecting passage 806 follows the cylindrical hole 804. As shown in FIG. 3, the connection passage 806 is connected to the inflow passage 46 through a pressure medium via an inflow connection portion A provided in the valve housing 82. In the approximate center of the valve housing 802, the valve housing 82 has a radial hole, through which an LS connection as schematically shown in FIG. 3 is formed. This LS connection portion is connected to the load notification passage 60 shown in FIG. The LS connection portion of the valve housing 802 is connected to the annular chamber 808 with a pressure medium, and the annular housing 808 surrounds the valve housing 802 in a predetermined section in the circumferential direction. Therefore, the load pressure generated in the load notification passage 60 acts on the valve housing 802 uniformly from all sides. On the right side of FIG. 9, the valve housing 802 has a control inlet S. The valve housing 802 is fixed in the valve housing 82 in the axial direction via a closing screw 812 having a hexagonal hole 810. In order to allow a pressure medium connection (see FIG. 3) from the control inlet S to the control passage 70, a closing screw 812 is provided with an axial connection passage 814 formed as a blind hole and a radius from this connection passage 814. And a radial hole 816 branched in the direction. The radial hole 816 is connected to the control passage 70 by a pressure medium. Via the closing screw 812, the valve housing 802 of the inverse shuttle valve 168 is not only axially fixed in the valve housing 82 but also a first seal provided at two seal seats, namely the consumer inlet V. A seal sheet 818 and a second seal sheet 820 provided at the control inlet S are also formed. Thereby, when the tightening torque of the closing screw 812 is sufficiently strong, leakage in the seal sheets 818 and 820 is prevented. Further, in order to prevent leakage occurring through the outer peripheral surface 822 of the valve housing 802, a plurality of annular grooves are provided in the outer peripheral surface 822, and an O-ring 824 is inserted into these grooves. ing. Each of the inlets V and S of the inverse shuttle valve 168 has one ball-shaped sealing element 74 and 76, and one conical valve seat 75 and 77 corresponding to the sealing element 74 and 76, respectively. A connecting element 826 is arranged between the two seal elements 74, 76, and only the pressing force is transferred from the first seal element 74 to the second seal element 76 or vice versa via the connection element 826. Transmission from the second seal element 76 to the first seal element 74 is possible. In order to prevent the sealing elements 74, 76 from slipping out of the valve housing 802 during normal operation after the sealing elements 74, 76 have been assembled into the radially expanded inlets V, S, Seal elements 74 and 76 are secured via retainer pins or position fixing pins 828 that act as stoppers. The position fixing pin 828 penetrates the valve housing 802 in the radial direction or the lateral direction. Position locking pin 828 is coupled to valve housing 802 via a press fit, allowing very little leakage through the corresponding coupling location. In order to further improve the sealing of the connection passage 806 or the inflow passage 46 and the control passage 70 to the load notification passage 60, the O-ring 824 is an alternative to the illustrated embodiment in that the longitudinal axis of the inverse shuttle valve 168 is With respect to the position fixing pin 828.

  FIG. 10 shows a second embodiment of an inverse shuttle valve 268 according to the present invention. First, the second embodiment differs from the first embodiment shown in FIG. 9 in that the inverse shuttle valve is screwed into the valve housing 82 and not press-fitted. . For this purpose, the valve housing 82 has a cylindrical bore 904 with a female thread section 905 that is radially reduced in diameter. Correspondingly, the valve housing 902 of the inverse shuttle valve 268 has a male thread section 907 that is radially expanded on the left side in FIG. The inverse shuttle valve 268 also has both seal elements 74 and 76 with valve seats 75 and 77. Further, a connecting element 826 is also provided. The connecting element 826 is movable in the axial direction and has a play as in the case of the first embodiment of the inverse shuttle valve shown in FIG. It is slidably supported in the narrow part of the direction. Also in the embodiment shown in FIG. 10, the sealing elements 74, 76 are not rigidly coupled to the connecting element 826, so that one sealing element 74 can be transferred from one sealing element 74 to the other sealing element 76. Only the pressing force can be transmitted to 74. Further, the position fixing type of the seal elements 74 and 76 in the valve housing 902 via the position fixing pin 828 is also formed in the same way. Unlike the embodiment shown in FIG. 9, the control inlet S of the inverse shuttle valve 268 has a hexagonal hole. The inverse shuttle valve 268 can be screwed into the valve housing 82 through the hexagonal hole. A seal sheet 918 is formed through the valve housing 902 and the valve housing 82 in the range of the end section on the left side of the valve housing 902 as viewed in FIG. Leakage into the annular gap disposed between the valve housings 902 and 82 is prevented through the seal sheet 918. Therefore, in the embodiment shown in FIG. 10, the O-ring 824 as shown in FIG. 9 can be dispensed with. Also at the control inlet S of the inverse shuttle valve 268, the seal concept is changed with respect to the first embodiment shown in FIG. In this range, the valve housing 902 is tapered conically. This conical outer peripheral surface of the valve housing 902 forms a seal sheet 920 with an annular seal edge provided on the closing screw 912. A radial seal sheet 921 is additionally formed in the region on the radially outer side of the closing screw 912 based on the force acting on the conical section when the closing screw 912 is screwed. Yes. Thus, the seal sheets 920 and 921 ensure that the inverse shuttle valve 268 is sealed without leakage at the control inlet S. The closure screw 912 also has a radial hole 816. The control inlet S is connected to the control passage 70 via a pressure medium via the radial hole 816. As an alternative to the connecting element that transmits only the pressing force shown in FIGS. 9 and 10, the sealing elements may be firmly connected to each other via the connecting element.

  A hydrostatic valve device for supplying a pressure medium to at least one hydrostatic consumer with an inflow valve with a meter-in throttle having a valve seat and a control device with such a valve device are disclosed. ing. Via the meter-in throttle, the connection between the inflow passage and the pump passage can be cut off almost without leakage. Furthermore, the valve device has a load notification passage, which can be loaded by the load pressure of the consumer taken out in the inflow passage. In this case, in the closed meter-in throttle, the load notification passage is blocked from the inflow passage through the seat valve with almost no leakage, and can be connected to the return passage or the pump passage through the same seat valve. .

DESCRIPTION OF SYMBOLS 1 Hydrostatic type control device 2,4 Hydrostatic type consumer 5 Control block 6,8 Valve sandwich plate 10 Variable displacement pump 12 Pressure line 14 Actuating cylinder 16 Pressure feed flow rate regulator 18 Return device 20 Control spring 22 Load Notification line 24 Actuation line 26 Tank line 28, 30 Meter-in throttle 29, 31, 229, 429, 629 Hydrostatic valve device 32, 34 Descent brake valve 36 Individual pressure compensator 38 Pressure path 40 Pump path 42 LS Passage 44 Shuttle valve 46 Inflow passage 48 Outflow passage 50, 52 Proportional solenoid 54 Shuttle valve 56, 58 Load take-out passage 60 Load notification passage 62 Spring 64, 264, 664 Main seat valve 66, 266 Directional switching valve 68, 168, 268 Inverse Shuttle valve 0 control passage 72 return passage 74 seal element 75 valve seat 76 seal element 77 valve seat 78 valve body 80 main valve body 82,282,283,482,682 valve housing 84,284,484 main valve body 86,286 pilot valve body 88 Coil 90 Solenoid armature 92 Spring 94 Adjustment screw 96, 296 Pilot valve body 98 Seal sheet 100, 200 Shuttle valve 102, 202 Radial hole 104, 304 Axial passage 106, 306 Back chamber 108, 308 Restriction 110, 210, 310 Back chamber 112, 312 Seal sheet 114, 116, 216 Passage 118 Precision control geometry 120, 320, 420 Precision control geometry 122 Passage hole 124, 324 Intermediate passage 326 Stroke detector 202, 203 Cylindrical hole 2 7 Spring 326 Stroke detector 328 Axis 330 Signal line 334 Current line 332 Control unit 699 Spring 802, 902 Valve housing 804, 904 Cylindrical hole 806 Connection passage 808 Annular chamber 810 Hexagonal hole 812, 912 Closing screw 814 Connection passage 816 Radial direction Hole 818, 820, 918, 920, 921 Seal sheet 822 Outer peripheral surface 824 O-ring 826 Connection element 828 Position fixing pin 905 Female thread section 907 Male thread section

Claims (15)

  Hydrostatic valve device for supplying pressure medium to at least one hydrostatic consumer (2, 4), provided with an inflow valve (64; 264; 464; 664), said inflow valve Has a meter-in throttle (28, 30) with a valve seat, through which the connection between the inflow passage (46) and the pump passage (40) can be cut off substantially without leakage. , A load notification passage (60) is provided, and the load notification passage is loaded by the extracted load pressure of the consumer, and further, a seat valve (68; 168; 268) is provided. In the hydrostatic valve device, the load notification passage (60) is connected to the seat valve (68; 168; 268) with the meter-in throttle (28, 30) closed. The hydrostatic valve device is cut off from the inflow passage (46) substantially without leakage and can be connected to the return passage (72) or the pump passage (40). .   The inflow valve (664) is directly controlled and has a main valve body (684) forming the meter-in throttle (28), or the inflow valve (64; 264; 464) is pilot controlled. The valve device according to claim 1, comprising a main valve body (84; 284; 484) forming the meter-in throttle (28) and a pilot valve body (86; 286; 486).   The seat valve is formed as an inverse shuttle valve (68; 168; 268). The inverse shuttle valve includes a load notification outlet (LS) connected to the load notification passage (60) and the inflow passage (46). The valve device according to claim 1 or 2, comprising a consumer inlet (V) connected to the pump passage (40) or a control inlet (S) connectable to the return passage (72).   A directional control valve comprising a pump connection portion connected to the pump passage (40), a return connection portion connected to the return passage (72), and a control connection portion connected to the control inlet (S). (66) is provided, the direction switching valve (66) has an operable load position, and the control inlet (S) is connected to the pump passage (40) via the load position. The direction switching valve (66) has a pressure relief basic position, and the control inlet (S) is connected to the pressure release basic position via the pressure relief basic position. The valve device according to claim 3, wherein the valve device is separated from the pump passage (40) and connected to the return passage (72).   The valve body (78) of the direction switching valve (66) has a connection portion with a main valve body (684) of the inflow valve (664) or a pilot valve body (86) of the inflow valve (64). Item 5. The valve device according to Item 2 or 4.   The consumer inlet (V) has a first valve seat (75) and a first sealing element (74), so that the first sealing element (74) is loaded in the closing direction by a load pressure. The control inlet (S) has a second valve seat (77) and a second seal element (76), and the second seal element (76) is connected to the pump passage (40). 6. The valve device according to claim 3, wherein the valve device is loaded in a closing direction by an internal pressure or a pressure in the return passage (72).   The valve device according to claim 6, wherein the load notification outlet (LS) opens to a pressure chamber between the valve seats (75, 77).   The two sealing elements (74, 76) are connectable or connected via a connecting element (826) arranged between the sealing elements (74, 76). 7. The valve device according to 7.   The seat valve (68; 168; 268) has a substantially cylindrical housing (802; 902), which housing part (82; 282; 482) of the valve device (29; 229; 429; 629). 682) a valve device according to any one of claims 1 to 8, which is inserted into, press-fitted or screwed into.   One seal seat (818; 918) between one of the inlets (V) of the inverse shuttle valve (68; 168; 268) and the housing part (82; 282; 482; 682) And / or at least one seal member (824) is disposed radially between the housing (802) and the housing portion (82) of the seat valve (168). The valve device according to 3 or 9.   In the range of the other inlet (S) of the inlets of the inverse shuttle valve (168; 268), the other inlet (S) and a closing screw (812; screwed into the housing part (82)). The valve device according to claim 10, wherein one sealing sheet (820; 920) is formed between the first sealing sheet (912 and 912).   A stopper (828) is arranged between each inlet (V, S) and the sealing element (74, 76) corresponding to each inlet (V, S). The valve device according to any one of the above.   13. The main valve body (484; 684) and / or the pilot valve body (86; 286) have a precisely controlled geometry (120; 320; 420; 620). Valve device.   An individual pressure compensator (36) is disposed in the pump passage (40) upstream of the meter-in restrictors (28, 30), and the individual pressure compensator (36) is arranged in the meter-in restrictor (36) in the closing direction. 28, 30) and is loaded by the load pressure of the consumer (2, 4) in the open direction, or in the inflow passage downstream of the meter-in restrictor. A compensator is arranged, the individual pressure compensator being loaded by the maximum load pressure of the one or more consumers in the closing direction and by the pressure downstream of the meter-in throttle in the opening direction. The valve device according to any one of claims 1 to 13.   A hydrostatic control device comprising the valve device (29; 31; 229; 429; 629) according to any one of claims 1 to 14, wherein a hydrostatic pump (10) is provided. The hydrostatic control device is characterized in that a pressure medium can be supplied to the at least one consumer (2, 4) in relation to a load pressure via the pump.

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