DE102007034746A1 - Hydrostatic drive system for use in internal combustion engine, has non-return valve device subjected to flow position in functional position of safety valve device and subjected to locking position in safety position - Google Patents

Hydrostatic drive system for use in internal combustion engine, has non-return valve device subjected to flow position in functional position of safety valve device and subjected to locking position in safety position

Info

Publication number
DE102007034746A1
DE102007034746A1 DE200710034746 DE102007034746A DE102007034746A1 DE 102007034746 A1 DE102007034746 A1 DE 102007034746A1 DE 200710034746 DE200710034746 DE 200710034746 DE 102007034746 A DE102007034746 A DE 102007034746A DE 102007034746 A1 DE102007034746 A1 DE 102007034746A1
Authority
DE
Germany
Prior art keywords
consumer
line
safety
control
valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
DE200710034746
Other languages
German (de)
Inventor
Markus Schwab
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STILL GmbH
Original Assignee
STILL GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by STILL GmbH filed Critical STILL GmbH
Priority to DE200710034746 priority Critical patent/DE102007034746A1/en
Publication of DE102007034746A1 publication Critical patent/DE102007034746A1/en
Pending legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B66HOISTING; LIFTING; HAULING
    • B66FHOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075Constructional features or details
    • B66F9/20Means for actuating or controlling masts, platforms, or forks
    • B66F9/22Hydraulic devices or systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/05Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/163Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for sharing the pump output equally amongst users or groups of users, e.g. using anti-saturation, pressure compensation
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B20/00Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/20Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205Systems with pumps
    • F15B2211/2053Type of pump
    • F15B2211/20546Type of pump variable capacity
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/30Directional control
    • F15B2211/305Directional control characterised by the type of valves
    • F15B2211/30525Directional control valves, e.g. 4/3-directional control valve
    • F15B2211/3053In combination with a pressure compensating valve
    • F15B2211/3054In combination with a pressure compensating valve the pressure compensating valve is arranged between directional control valve and output member
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/80Other types of control related to particular problems or conditions
    • F15B2211/86Control during or prevention of abnormal conditions
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00Circuits for servomotor systems
    • F15B2211/80Other types of control related to particular problems or conditions
    • F15B2211/875Control measures for coping with failures
    • F15B2211/8755Emergency shut-down

Abstract

The invention relates to a hydrostatic drive system (1) with a pump (5) which is provided to supply a consumer group (2) having at least one consumer, wherein a delivery line (8) of the pump (5) is led to the consumer group (2) , and with a safety valve device (35) which has a functional position (35b) and a safety position (35a). To solve the problem to provide a drive system with an improved safety function, the invention proposes that in the delivery line (8) a check valve device (50) is arranged, which by means of the safety valve device (35) is controllable, wherein the check valve means (50 ) in the functional position (35b) of the safety valve device (35) in a flow position (51a) is acted upon and in the safety position (35a) of the safety valve device (35) in a blocking position (51b) can be acted upon.

Description

  • The The invention relates to a hydrostatic drive system with a Pump for supplying a consumer group having at least one consumer is provided, wherein a delivery line of the pump to the Consumer group, and with a safety valve device, the has a functional position and a safety position.
  • such hydrostatic drive systems are used in mobile work machines, For example, industrial trucks, used, where the consumer group is designed as working hydraulics, which is usually a lifting drive, a tilt drive and optionally at least one auxiliary drive, For example, a side shifter includes.
  • Such a generic drive system is from the EP 1 369 598 A1 known. In the from the EP 1 369 598 A1 known drive system is provided by a safety valve formed safety valve device with which the admission of an inlet pressure compensator is controllable. When the safety valve is actuated, the safety valve is in a functional position. In the functional position, a control pressure line, which branches off from the load pressure line, which controls the admission of the inlet pressure compensator in the direction of the blocking position, shut off. The inlet pressure compensator is thus acted upon in the functional position of the safety valve by the highest load pressure of the driven load of the working hydraulics in the direction of the blocking position, whereby a load pressure independent supply to the load of the working hydraulics can be achieved. If the control of the safety valve is terminated, the safety valve is acted upon in a safety position, in which the control pressure line is connected to a container and thus the load pressure line leading to the highest load pressure is relieved to the container. In this case, the inlet pressure compensator is acted upon by the delivery pressure of the pump into a flow position counter to a force of a spring acting in the direction of the blocking position, whereby the pump delivers to the container.
  • In the from the EP 1 369 598 A1 However, known drive system, it may happen that when consumers in the safety position safety valve, the load of the working hydraulics can be actuated, provided that the load pressure of the driven loads below the bias of the spring of the inlet pressure compensator and thus the inlet pressure compensator not from the self-adjusting delivery pressure of the pump in the flow position is charged.
  • Of the present invention is based on the object, a hydrostatic Drive system of the aforementioned type available to provide, which has an improved security function.
  • These The object is achieved according to the invention arranged in the delivery line a check valve device is, which is controllable by means of the safety valve device, wherein the check valve device in the functional position of the safety valve device is acted upon in a flow position and in the safety position of the Safety valve device can be acted upon in a blocking position is. According to the invention is thus one of the safety valve device controlled shut-off valve device in the guided to the consumers Delivery line arranged, depending on from the safety valve device to the flow position and the blocking position can be acted upon and thus opens the delivery line or shut off. The check valve device is in this case in the Function position befindlicher safety valve device in the Flow rate applied and is in the safety position located safety valve device is acted upon in the blocking position. In the safety position of the safety valve device is thus the delivery line by means of the check valve device shut off, causing an actuation of the consumer Consumer group is not allowed. Thus, a Drive system with an effective safety function achieved at in the safety position of the safety valve device an activation of consumers of the consumer group safely is excluded.
  • Conveniently, is to control consumers of the consumer group respectively a control valve device provided to the delivery line is connected, wherein the check valve device in the delivery line upstream of the connections of the control valves to the delivery line is arranged. This is achieved in a simple manner that when in the blocking position befindlicher check valve device the to the control valve devices guided conveyor line is shut off and thus an actuation of the consumer can be effectively avoided in a simple manner.
  • According to one preferred embodiment of the invention is the check valve device as a control valve with a flow position and a blocking position educated. Such, for example as a longitudinal slide valve trained control valve has a low construction cost.
  • Particular advantages arise when the check valve device according to a preferred embodiment of the invention by a spring in the direction of the blocking position can be acted upon and in response to the delivery pressure of the pump in Direction of the flow position can be acted upon, the application of the check valve device in the direction of the flow position by the delivery pressure of the pump by means of the safety valve device is controllable. As a result, the check valve device can be controlled by the safety valve device in a simple manner and the spring can be used to ensure that the check valve device is acted upon in the blocking position.
  • According to one preferred embodiment of the invention is in a direction the flow position acting control surface of the check valve device one from the delivery line upstream of the check valve device branched control pressure line out, wherein the control pressure line is in communication with a pilot pressure branch line connected to the Safety valve device is connected. This can be done on simple Make the safety valve device of the delivery pressure the pump in the direction of the flow position are applied and the application of the delivery pressure in the direction the flow position of the check valve device by means of the safety valve device to be controlled.
  • Provided the safety valve device in the safety position the Control pressure branch line connects to a container and in the functional position, the connection of the control pressure branch line shut off with the container can be achieved in a simple manner be that the check valve device in the safety position the safety valve device of the spring in the blocking position and in the functional position of the safety valve device of the pending in the control pressure line delivery pressure of the Pump is acted upon in the flow position.
  • Special Benefits arise when, according to a preferred Development of the invention in the control pressure line a throttle device, in particular a panel is arranged. This achieves that at in the safety position located safety valve device the control pressure branch line safely relieved to the container and the check valve device is acted upon by the spring in the blocking position so that the delivery line is securely shut off.
  • The Safety valve device is according to an embodiment the invention of a spring in the direction of the safety position acted upon and by means of an actuator operable in the direction of the functional position. This can the safety valve device in a simple manner in the functional position be actuated, being sure that at termination the control of the actuator, the safety valve device is acted upon by the spring in the safety position.
  • The Actuating device is expediently as a magnet, in particular switching magnet, is formed, whereby the Safety valve device in a simple manner in the functional position can be operated.
  • Special Benefits can be achieved if the consumer group as working hydraulics is formed, which is a lifting drive and / or a tilt drive and / or at least one auxiliary drive, wherein the lifting drive a discharge pressure balance for load-independent control of Lowering speed of the lifting drive is assigned and the discharge pressure balance is controllable by means of the safety valve device. By the Control of the discharge pressure balance by means of the safety valve device can be easily achieved that in the safety position the safety valve device with the pressure compensator a drop the load applied to the lifting drive is prevented.
  • For this is in accordance with an embodiment of the invention provided that in the safety position of the safety valve device a control surface acting in the direction of a blocking position the discharge pressure compensator depending on one in one Load pressure line guided load pressure of the lifting drive acted upon is. This achieves a simple way that in the safety position the safety valve device, the discharge pressure balance of the load pressure the lifting drive is acted upon in the blocking position, whereby a drop in the load can be safely avoided.
  • Conveniently, is here to act on in the direction of the blocking position acting control surface of the discharge pressure balance a control pressure line provided in the safety position of the safety valve device is connected to the load pressure line and in the functional position relieved to a container. This will be on easy Mode allows that in the functional position of the safety valve device the admission of the discharge pressure balance in the direction of the blocking position is canceled by the load pressure of the linear actuator and by means of Discharge pressure compensator the function of the load-independent control the lowering speed of the lifting drive is made possible.
  • In addition, it is provided according to an advantageous development of the invention that in the neutral position of the lifting drive controlling control valve device acting in the direction of a flow position control surface of the discharge pressure balance is relieved to a container. This ensures that the discharge pressure compensator is safely loaded in the safety position in the safety position device by the load pressure of the linear actuator in the locked position and thus avoid a drop in the upcoming lifting drive load that will.
  • According to one preferred embodiment of the invention is another at least a consumer group having consumers can be supplied by the pump, wherein a guided to the further consumer group conveyor branch line to the delivery line upstream of the check valve device connected. By the arrangement of the check valve device in the support line led to the consumer group may be an upstream of the check valve means by means of a delivery branch line connected to the support line further consumer group also in the safety position befindlicher safety valve device and thus with acted upon in the blocking position blocking valve device Pressure medium to be supplied, with the by the safety valve device controlled shut-off valve device actuation of the consumer the consumer group is effectively avoided.
  • The another consumer group may be a steering hydraulics and / or at least another consumer, in particular a fan drive of a Cooling circuit, include.
  • The Pump is according to an embodiment of the invention is designed as a variable displacement pump whose delivery volume depending on the highest load pressure of the driven consumers of the consumer group and / or others Consumer group is adjustable. With such a load-sensing Regulated pump can with low losses the consumers the consumer group and the wider consumer group. However, it is also possible, as a pump, a constant pump to use with constant displacement, each one Consumer group is associated with an inlet pressure compensator.
  • to Forwarding of the load of consumers of the consumer group Each load is associated with a load pressure signaling line, the in the neutral position of the corresponding consumer controlling Control valve device is relieved to a container. This is achieved in a simple manner that when not driven Consumers load the load pressure lines of the consumer to the container are relieved and thus the pump in the direction of the minimum delivery volume is set. Instead of relieving the load pressure signaling lines via the control valve means to the container may also the highest load pressure of consumers of the consumer group leading load pressure signaling line by means of the safety valve device be relieved in the safety position to the container, wherein the connection of the load pressure signaling line to the container shut off in the functional position of the safety valve device is.
  • Further Advantages and details of the invention will be described with reference to the schematic figures illustrated embodiment explained in more detail. This shows
  • 1 the circuit diagram of a drive system according to the invention and
  • 2 the circuit diagram in an enlarged view.
  • In the 1 is a circuit diagram of a hydrostatic drive system according to the invention 1 shown for a trained as a forklift truck. The drive system 1 includes a consumer group formed by a working hydraulics of the forklift truck 2 , which includes, for example, a linear actuator, a tilt drive and an auxiliary drive, and another consumer group 3 for example, having a steering hydraulic and a fan drive for a refrigeration cycle.
  • To supply the consumer group 2 and the wider consumer group 3 is one with a prime mover 4 , For example, an internal combustion engine, in driving connection pump 5 provided, the input side by means of a container line 6 with a container 7 is in communication and on the output side in a delivery line 8th promotes. The support line 8th is to the consumer group 2 connected, wherein upstream of the connection of the delivery line 8th to the working hydraulics forming consumer group 2 to the support line 8th a conveyor branch line 9 connected to the second consumer group 3 is guided.
  • From the support line 8th branches within the consumer group 2 a conveyor branch line 10 from, leading to a lifting drive controlling control valve device 11 is guided. By means of another from the delivery line 8th branching conveyor line 12 is via a control valve device 13 a tilt drive controllable. For controlling an auxiliary drive designed, for example, as a side slide, a control valve device is provided 14 provided, which also with the delivery line 8th communicates. The control valve devices 11 . 13 . 14 are mechanically operated here. However, it is also possible, the control valve devices 11 . 13 . 14 hydraulically or electrically operated.
  • The pump 5 is configured as adjustable in the delivery volume variable displacement pump whose delivery volume in dependence on the highest load pressure of the driven consumers of the consumer group 2 or the further consumer group 3 is controllable. For this purpose, an example designed as a demand flow regulator displacement adjusting device 15 connected to the actuator of the pump pe 5 is in operative connection, one of the highest load pressure of the driven consumers of the consumer group 2 respectively. 3 leading load pressure signaling line 16 connected. The load pressure signaling line 16 stands with the output of a shuttle valve device 17 in connection, on the input side, the highest load pressure of the other consumer group 3 leading load pressure signaling line 18 and one of the highest load pressure of the consumer group 2 leading load pressure signaling line 19 connected. The selection of the highest load pressure of consumers of the consumer group 2 takes place by means of one of shuttle valve devices 20 and 21 formed shuttle valve chain. To the shuttle valve device 20 Here is the output side, the load pressure signaling line 19 connected. On the input side is the shuttle valve device 20 with a load pressure signaling line leading the load pressure of the lifting drive 22 and a load pressure signaling line 23 connected to the output of the shuttle valve device 21 connected. The shuttle valve device 21 is the input side with the load pressure of the tilt drive detecting load pressure signaling line 24 and a load pressure detection line detecting the load pressure of the auxiliary drive 25 in connection.
  • The lifting drive controlling control valve device 11 connects here in the illustrated neutral position, the load pressure signaling line 22 with a container line 26 leading to the container 7 is guided. Accordingly, in the illustrated neutral position of the tilt drive controlling control valve device 13 the load pressure signaling line 24 with the container line 26 connected and in the neutral position of the auxiliary drive controlling control valve device 14 the load pressure signaling line 25 with the container line 26 and thus the container 7 connected.
  • In the control valve device controlling the lifting drive 11 to the lifting cylinder not shown guided pressure medium line 30 is a discharge pressure balance 31 arranged, which is provided for load-independent control of the lowering speed of the lifting drive. The discharge pressure balance 31 is - as in the 2 is shown - as throttling in intermediate positions control valve with a flow position 31a and a blocking position 31b formed and by means of a spring 32 and one in a control pressure line 33 pending control pressure in the direction of the flow position 31a acted upon. In the neutral position of the control valve device 11 is the control pressure line 33 with one in the direction of the flow position 31a acting control surface of the discharge pressure balance 31 communicates with the container line 26 connected and thus to the container 7 relieved.
  • Towards the blocking position 31b is the discharge pressure balance 31 from the pressure between the discharge pressure balance 31 and the control valve device 11 acted upon. For this purpose, one of the pressure medium line 30 branching control pressure line 34 provided to one in the direction of the blocking position 31b acting control surface of the discharge pressure balance 31 is guided.
  • For controlling the admission of the discharge pressure balance 31 in the direction of the blocking position 31b is also designed as a switching valve safety valve device 35 provided a security position 35a and a functional position 35b having. The safety valve device 35 is from a spring 36 towards the security position 35a acted upon. For actuating the safety valve device 35 in the functional position 35b is an actuating device designed as a magnet, in particular as a switching magnet 37 intended.
  • In the security position 35a the safety valve device 35 Here is a load pressure line leading to the load pressure of the linear actuator 38 with a control pressure line 39 connected to a piston-side control pressure chamber of a piston device 40 connected to the in the direction of the blocking position 31b acting control surface of the discharge pressure balance 31 is in active connection. A piston rod side control pressure chamber of the piston device 40 is by means of a container branch line 41 to the container line 26 connected. In the functional position 35b the safety valve device 35 is the load pressure line 38 shut off and the control pressure line 39 with the container branch line 41 connected.
  • In the promotion line 8th is downstream of the connection of the delivery branch line 9 and upstream of the ports of the control valve devices 11 . 13 . 14 by means of the delivery branch lines 10 . 12 to the support line 8th a check valve device 50 arranged. The check valve device 50 is here as a control valve 51 with a flow position 51a and a blocking position 51b educated.
  • The check valve device 50 is by means of a spring 52 in the direction of the blocking position 51b acted upon. In the direction of the flow position 51a is the check valve device 50 from the one in the delivery line 8th upstream of the check valve device 50 Pending delivery pressure of the pump 5 acted upon. For this purpose, an acting in the direction of flow position control surface of the check valve device 50 one from the support line 8th branching control pressure line 53 guided in which a trained example as a diaphragm throttle device 54 is arranged.
  • The admission of the check valve device 50 is still using the safety valve direction 35 controllable. For this purpose, a control pressure branch line 55 provided by the control pressure line 53 downstream of the throttle device 54 branches off to an input of the safety valve device 35 is guided. In the functional position 35b the safety valve device 35 is the control pressure branch line 55 shut off. In the security position 35a the safety valve device 35 is the control pressure branch line 55 to the container branch line 41 connected and thus the direction of the flow position 51a acting control surface of the check valve device 50 to the container 7 relieved.
  • In the security position 35a the safety valve device 35 is thus the check valve device 50 from the spring 52 in the locked position 51b applied. The throttle device 54 in the control pressure line 53 ensures that by means of the safety position 35a located safety valve device 35 the control pressure branch line 55 to the container 7 is relieved and thus the check valve device 50 safely in the locked position 51b is charged. In the functional position 35b the safety valve device 35 is the connection of the control pressure branch line 55 with the container 7 shut off, causing the in the control pressure line 53 Pending delivery pressure of the pump 5 the check valve device 50 in the flow position 51a applied.
  • The drive system according to the invention operates as follows:
    Upon actuation of the safety valve device 35 by a control of the actuating device 37 For example, in a presence of an operator detecting seat contact switch, the safety valve device 35 in the functional position 35b actuated, in which the connection of the control pressure branch line 55 with the container 7 is locked. The check valve device 50 is thus by the in the control pressure line 53 Pending delivery pressure of the pump 5 in the flow position 51b applied. At the same time is in the functional position 35b the safety valve device 35 the load pressure signaling line 38 shut off and the control pressure line 39 to the container branch line 41 connected. The piston rod-side control pressure chamber and the piston-side control pressure chamber of the piston device 40 are thus to the container 6 relieved.
  • Upon actuation of the control valve devices 11 . 13 . 14 thus consumers can be the consumer group 2 be operated. Upon actuation of the lifting drive controlling control valve device 11 in the in the 2 On the left shown auxiliary position is in the drain pressure scale 31 controlling control pressure lines 33 and 34 in each case the pressure downstream of a throttle point of the control valve device 11 on, causing the pressure compensator 31 from the spring 32 in the flow position 31a is charged. Upon actuation of the control valve device 11 in the in the 2 lowering position shown on the right is the discharge pressure balance by means of the control pressure lines 33 and 34 from at the throttle point of the control valve device 11 adjusting pressure difference controlled, the discharge pressure balance 31 controls the lowering speed of the lifting drive independent of the load.
  • In in the functional position 35b located safety valve device 35 continue to be the consumers of the wider consumer group 3 actuated.
  • Upon completion of the actuation of the actuator 37 For example, by an operator no longer actuating the seat contact switch, the safety valve device becomes 35 from the spring 36 in the in the 1 and 2 illustrated safety position 35a applied.
  • The control pressure line 39 is here to the load pressure line 38 connected, whereby by means of the piston device 40 the discharge pressure balance 31 from the load pressure of the lifting drive in the blocking position 31b is charged. The discharge pressure balance 31 thus prevents a drop in a load applied to the lifting drive.
  • At the same time is in the security position 35a the safety valve device 35 the control pressure branch line 55 by means of the container branch line 41 to the container 7 relieved, causing the check valve device 50 from the spring 52 in the locked position 51b is charged.
  • In this safety position 35a the safety valve device 35 are the consumers of the wider consumer group 3 actuated. The pump 5 is in this case of the in the load pressure message line 18 upcoming highest load pressure of the driven consumers of the further consumer group 3 controlled. The connection of the delivery line 8th with the control valve devices 11 . 13 . 14 is through the in the locked position 51b applied check valve device 50 but shut off, causing an actuation of consumers of the consumer group 2 irrespective of this in the case of an actuation of the consumers of the further consumer group 3 adjusting delivery pressure of the pump 5 is prevented.
  • As a result, an improved safety function of the drive system is achieved because in the safety position 35b the safety valve device 35 an activity of consumers of the consumer group 2 is not possible and thus the functions lifting, lowering or tilting and the Zu set hydraulics of the working hydraulics of a truck forming consumer group 2 can not be executed.
  • QUOTES INCLUDE IN THE DESCRIPTION
  • This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.
  • Cited patent literature
    • - EP 1369598 A1 [0003, 0003, 0004]

Claims (17)

  1. Hydrostatic drive system with a pump which is provided for supplying a consumer group having at least one consumer, wherein a delivery line of the pump is guided to the consumer group, and with a safety valve device which has a functional position and a safety position, characterized in that in the delivery line ( 8th ) a check valve device ( 50 ) arranged by means of the safety valve device ( 35 ) is controllable, wherein the check valve device ( 50 ) in the functional position ( 35b ) of the safety valve device ( 35 ) into a flow position ( 51a ) and in the safety position ( 35a ) of the safety valve device ( 35 ) in a blocking position ( 51b ) can be acted upon.
  2. Hydrostatic drive system according to claim 1, characterized in that for controlling the consumers of the consumer group ( 2 ) each have a control valve device ( 11 ; 13 ; 14 ) which is to be sent to the 8th ) is connected, wherein the check valve device ( 50 ) in the support line ( 8th ) upstream of the connections of the control valves ( 11 ; 13 ; 14 ) to the support line ( 8th ) is arranged.
  3. Hydrostatic drive system according to claim 1 or 2, characterized in that the check valve device ( 50 ) as a control valve ( 51 ) with a flow position ( 51a ) and a blocking position ( 51b ) is trained.
  4. Hydrostatic drive system according to one of claims 1 to 3, characterized in that the check valve device ( 50 ) of a spring ( 52 ) in the direction of the blocking position ( 51b ) can be acted upon and in dependence on the delivery pressure of the pump ( 5 ) in the direction of the flow position ( 51a ) can be acted upon, wherein the loading of the check valve device ( 50 ) in the direction of the flow position ( 51a ) by the delivery pressure of the pump ( 8th ) by means of the safety valve device ( 35 ) is controllable.
  5. Hydrostatic drive system according to claim 4, characterized in that in the direction of the flow position ( 51a ) acting control surface of the check valve device ( 50 ) one of the support line ( 8th ) upstream of the check valve device ( 50 ) branching control pressure line ( 53 ), wherein the control pressure line ( 53 ) with a control pressure branch line ( 55 ) connected to the safety valve device ( 35 ) connected is.
  6. Hydrostatic drive system according to claim 5, characterized in that the safety valve device ( 35 ) in the security position ( 35a ) the control pressure branch line ( 55 ) with a container ( 7 ) and in the functional position ( 35b ) the connection of the control pressure branch line ( 55 ) with the container ( 6 ) locks.
  7. Hydrostatic drive system according to claim 5 or 6, characterized in that in the control pressure line ( 53 ) a throttle device ( 54 ), in particular a diaphragm, is arranged.
  8. Hydrostatic drive system according to one of claims 1 to 7, characterized in that the safety valve device ( 35 ) of a spring ( 36 ) towards the safety position ( 35a ) is acted upon and by means of an actuating device ( 37 ) in the direction of the functional position ( 35b ) is operable.
  9. Hydrostatic drive system according to claim 8, characterized in that the actuating device ( 37 ) is designed as a magnet, in particular switching magnet.
  10. Hydrostatic drive system according to one of claims 1 to 9, characterized in that the consumer group ( 2 ) is designed as working hydraulics, which comprises a lifting drive and / or a tilt drive and / or at least one auxiliary drive, wherein the lifting drive a discharge pressure balance ( 31 ) is assigned to the load-independent control of the lowering speed of the lifting drive and the discharge pressure balance ( 31 ) by means of the safety valve device ( 35 ) is controllable.
  11. Hydrostatic drive system according to claim 10, characterized in that in the safety position ( 35a ) of the safety valve device ( 35 ) one in the direction of a blocking position ( 31b ) acting control surface of the discharge pressure balance ( 31 ) as a function of one in a load pressure line ( 38 ) guided load pressure of the lifting drive can be acted upon.
  12. Hydrostatic drive system according to claim 11, characterized in that for acting in the direction of the blocking position ( 31b ) acting control surface of the discharge pressure balance ( 31 ) a control pressure line ( 39 ), which in the safety position ( 35a ) of the safety valve device ( 35 ) to the load pressure line ( 38 ) is connected and in the functional position ( 35b ) to a container ( 7 ) is relieved.
  13. Hydrostatic drive system according to one of claims 10 to 12, characterized in that in the neutral position of the control device controlling the lifting drive ( 11 ) one in the direction of a flow position ( 31a ) acting control surface of the discharge pressure balance ( 31 ) to the container ( 7 ) ent is lasted.
  14. Hydrostatic drive system according to one of claims 1 to 13, characterized in that a further consumer group having at least one consumer ( 3 ) from the pump ( 5 ), one to the other consumer group ( 3 ) guided conveyor branch line ( 9 ) to the support line ( 8th ) upstream of the check valve device ( 50 ) connected.
  15. Hydrostatic drive system according to claim 14, characterized in that the further consumer group ( 3 ) comprises a steering hydraulics and / or at least one further consumer, in particular a fan drive of a cooling circuit.
  16. Hydrostatic drive system according to one of claims 1 to 15, characterized in that the pump ( 5 ) is designed as a variable displacement pump whose delivery volume in dependence on the highest load pressure of the driven consumers of the consumer group ( 2 ) and / or the wider consumer group ( 3 ) is adjustable.
  17. Hydrostatic drive system according to one of claims 2 to 16, characterized in that for the forwarding of the load to the load of the consumer group ( 2 ) each load a load pressure signaling line ( 22 ; 24 ; 25 ), which in the neutral position of the corresponding consumer controlling control valve device ( 11 ; 13 ; 14 ) to a container ( 7 ) is relieved.
DE200710034746 2007-07-25 2007-07-25 Hydrostatic drive system for use in internal combustion engine, has non-return valve device subjected to flow position in functional position of safety valve device and subjected to locking position in safety position Pending DE102007034746A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE200710034746 DE102007034746A1 (en) 2007-07-25 2007-07-25 Hydrostatic drive system for use in internal combustion engine, has non-return valve device subjected to flow position in functional position of safety valve device and subjected to locking position in safety position

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE200710034746 DE102007034746A1 (en) 2007-07-25 2007-07-25 Hydrostatic drive system for use in internal combustion engine, has non-return valve device subjected to flow position in functional position of safety valve device and subjected to locking position in safety position

Publications (1)

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DE102007034746A1 true DE102007034746A1 (en) 2009-01-29

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DE200710034746 Pending DE102007034746A1 (en) 2007-07-25 2007-07-25 Hydrostatic drive system for use in internal combustion engine, has non-return valve device subjected to flow position in functional position of safety valve device and subjected to locking position in safety position

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3252003A1 (en) * 2016-06-03 2017-12-06 STILL GmbH Hydraulic drive system of an industrial truck
EP3385215A1 (en) * 2017-04-06 2018-10-10 STILL GmbH Hydraulic raising control of a mobile working machine, in particular an industrial truck

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1369598A1 (en) 2002-06-03 2003-12-10 HAWE Hydraulik GmbH & Co. KG Electro-hydraulic lifting control device for industrial use vehicles

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1369598A1 (en) 2002-06-03 2003-12-10 HAWE Hydraulik GmbH & Co. KG Electro-hydraulic lifting control device for industrial use vehicles

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3252003A1 (en) * 2016-06-03 2017-12-06 STILL GmbH Hydraulic drive system of an industrial truck
EP3385215A1 (en) * 2017-04-06 2018-10-10 STILL GmbH Hydraulic raising control of a mobile working machine, in particular an industrial truck

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