WO2005084413A1

WO2005084413A1 - Supply system

Info

Publication number: WO2005084413A1
Application number: PCT/EP2005/001889
Authority: WO
Inventors: Gerhard Keuper; Peter Stachnik; Sönke Jessen
Original assignee: Bosch Rexroth Ag
Priority date: 2004-03-02
Filing date: 2005-02-23
Publication date: 2005-09-15
Also published as: RU2387889C2; RU2006130622A; EP1720397A1; DE102004010623A1

Abstract

The invention relates to a supply system (1) for a hydraulically actuated consumer (15,17) of a working device which is added to or coupled to tractor. According to the invention, a center valve (8) prefining a pressure-medium volume flow is arranged on the tractor, wherein an advance line and a return line (18,20) are connected to the center valve on the working-device side. Several consumers (15,17) are mounted in parallel in said advance line and return line. One respective consumer (15,17) is hydraulically connected to the center valve (8) by means of a distributor valve arrangement (26,27,28,29). According to the invention, the pressure-medium volume flow is adjusted on the tractor side. The pressure medium is distributed on the working device side by means of the distributor valve arrangement (26,27,28,29).

Description

description

supply system

The invention relates to a supply system for hydraulically actuated consumers mounted on a tractor or the like, of at least one working device according to the preamble of patent claim 1.

Agricultural tractors or tractors are used to pull or operate attached implements or attachments, such as a plow, baler, loading and silage wagon, or mower, which are hydraulically controlled

Actuators are operated. These actuators are supplied with pressure medium by the tractor hydraulics.

Due to different tractor hydraulic systems (constant current, load-sensing systems and occasionally also constant pressure systems), a variety of different solutions are known to transfer the hydraulic power from the tractor to the implement. The type of transmission depends crucially on the number and type of actuators, hereinafter called consumers, and the size of the pressure medium volume flow to be made available.

The standard solution for up to four consumers to be connected is the direct and separate connection of each consumer to a hydraulic socket of one control valve of the tractor. Such a solution is shown in DE 199 43 561 AI. In this solution, a hydraulic pump, a central computer and control valves assigned to a consumer are arranged on the tractor. The output connections of the control valves can be made via the hydraulic couplings can be connected to the consumers arranged on the trailer. The control valves for the pressure medium supply to the consumers are controlled via the central computer. Such a circuit can only be implemented in equipment with many consumers with a considerable amount of equipment. Another problem is that when supplying pressure medium to different work tools, care must be taken that the hydraulic system of the work tool matches that of the tractor, so that no unnecessary energy losses occur.

A supply system is known from DE 101 07 139 AI, in which a central valve block is provided on the implement attached to the tractor, in the present case a plow, via which at least one consumer of the implement can be supplied with pressure medium. The central valve block is connected to a tractor-side pump and a tractor-side tank via a bus system and hydraulic couplings. With this solution, the setting of the pressure medium volume flow and the pressure medium distribution essentially take place on the implement. This presupposes that all attachments to be attached to or attached to the tractor must be designed with a corresponding valve block - so that the investment costs for attachments of this type are relatively high compared to the solution described above, in which the pressure medium volume flow is set centrally via the tractor-side control valves are.

The development in agricultural engineering is moving towards more and more hydraulic consumers on one implement and towards ever higher-quality consumers with controlled or regulated functions. In contrast, the invention has for its object to provide a supply system through which a large number of consumers of a working device with minimal device engineering effort and low

Energy losses can be supplied with pressure medium.

This object is achieved by a supply system with the features of patent claim 1.

In the supply system according to the invention it is provided that the pressure medium volume flow setting on the tractor side takes place via a central valve, via which several consumers of a line can be supplied with pressure medium. The pressure medium volume flow distribution is carried out on the implement side with a distribution valve arrangement, via which one of the consumers connected to the central valve can be supplied with pressure medium, while the connections to the other consumers of the line are shut off.

According to the invention, the volume flow adjusting and volume flow distributing elements are thus separated, the volume flow adjustment using the central valve on the tractor and the volume flow distribution, ie the pressure medium supply to a selected consumer using the distribution valve arrangement arranged on the implement. In a departure from the systems described at the outset, according to the invention, a plurality of consumers are connected to the volume-flow-adjusting tractor-side central valve, so that virtually any number of consumers can be supplied via this central valve. The distribution valve arrangement is preferably controlled electrically or electronically as a function of control signals which are emitted by at least one control device. Depending on the requirement, one or more control devices can be arranged on the tractor and / or on the working device, the signal transmission to the tractor or to the working device preferably taking place via a bus system. The signal transmission is not only possible via cable connections, but wireless solutions can also be implemented via radio (Bluetooth). In the case of high-quality consumers with controlled or regulated functions, it is advantageous if operating parameters of the supply system or of the consumer are detected by suitable sensors and processed by the control device. These sensors can be connected to the assigned control device directly or via the bus system.

In a preferred variant of the supply system, the distribution valve arrangement has at least one

Switching valve, via which a flow or return line to the assigned consumer can be shut off or opened. In the case in which double-acting consumers are to be controlled, the distribution valve arrangement assigned to each double-acting consumer preferably has in each case a switching valve for shutting off or opening the inlet or return line. In principle, however, it is also sufficient for double-acting consumers

Switch valve off.

If several consumers of the implement are to be controlled simultaneously with the supply system according to the invention, several central valves are combined on the tractor side to form a valve block, whereby Each central valve is assigned a flow and return line on the device side, to which several consumers are connected in parallel in the manner described above. Each of the consumers is assigned a distribution valve arrangement - preferably two switching valves in the case of a double-acting consumer - via which one consumer can be connected to the flow and return line and the other consumers can be blocked.

In LS systems, each central valve has a variable orifice plate and an associated one

Pressure compensator for setting the pressure medium volume flow and with control edges for setting the pressure medium flow direction.

Other advantageous developments of the invention are the subject of further dependent claims. Preferred exemplary embodiments of the invention are explained in more detail below with the aid of schematic representations. Show it:

Figure 1 is a circuit diagram of a supply system for a tractor on which a working device, such as a plow or a baler is attached or attached and

Figure 2 shows a simplified embodiment of a supply system.

The supply system 1 shown in FIG. 1 is composed of a part 2 on the tractor side and a part 4 on the implement side, with an electrical and hydraulic connection of the implement being attached to or attached to the tractor tractor-side and implement side part 2, 4 of the supply system.

The supply system 1 shown is designed as a load-sensing system. As mentioned at the beginning, however, other concepts, for example a regulation of a constant pressure medium volume flow or a constant pressure medium pressure, can also be implemented. The part 2 of the supply system 1 on the tractor side has an LS pump 6, via which pressure medium can be drawn in from a pressure medium tank T of the tractor. The pressure connection of the LS pump 6 is connected to an input connection of an LS valve block 8, which in the exemplary embodiment shown is composed of a plurality of valve segments 8a, 8b, 8c. Each of these valve segments 8a, 8b, 8c is assigned to a large number of consumers and has at least two working connections A, B, which are connected via hydraulic working lines 10, 12 to hydraulic sockets (couplings) 14, 16 arranged on the tractor.

In FIG. 1, for example, two consumers 14, 16 of the implement can be supplied with pressure medium via the valve segment 8a. Of course, more than these two consumers 15, 17 can also be connected to the valve segment 8a and additional consumers can also be connected to the other two valve segments 8b, 8c.

In the embodiment shown, a double branch line is connected to the hydraulic sockets 14, 16, through which a feed line 18 and a return line 20 are formed, via which the consumers 14, 16 can be supplied with pressure medium. The flow and return lines 18, 20 are when mounting or Attach the implement via coupling elements 22, 24 to the hydraulic sockets 14, 16 connected. The two consumers 15, 17 are each connected via a flow branch line 22 or 23 and a return branch line 24 or 25 to the flow line 18 or the return line 20. There is a distribution valve in each branch line 22, 23, 24, 25

26, 27, 28 and 29 respectively. These are designed as switching valves and can be brought from a spring-loaded basic position (see FIG. 1) into an open position by means of an electromagnet 30. In FIG. 1, by way of example only the electromagnet 30 of the distribution valve 29 is provided with a reference number. The consumers 15, 17 connected to the two flow and return lines 18, 20 and possibly all other consumers connected to this line are thus connected in parallel to each other to the valve segment 8a.

The actuation of the electromagnets 30 of the distribution valves 26, 27, 28, 29 takes place via a control device 32 which is arranged on the implement in the exemplary embodiment shown. The electromagnets 30 of the distribution valves 26, 27, 28 and 29 are energized via signal lines 34 connected to the signal connections of the control unit 32 (only the signal line 34 of the distribution valve 29 is provided with a reference symbol in FIG. 1), always with a consumer 15, 17 associated distribution valves 26, 28;

27, 29 are simultaneously de-energized or energized to actuate one of the consumers 15, 17.

Depending on the type of implement, different sensors can be provided to

Operating parameters of the supply system or the Movement of the consumer 15, 17 to be detected. There are a variety of options for arranging these sensors. 1 shows a variant according to which the sensors (pressure, current, stroke, volume flow, etc.) 36 are connected to the control unit 32, in which the sensor signals are processed and, if necessary, in actuating signals for actuating the consumers 15, 17 and the LS pump 6 are implemented. A control unit 38 can also be provided on the tractor, as shown in FIG. 1, which is connected to the control unit 32 on the implement side and to the distribution valves 26, 27, 28, 29 and the LS valve block 8 via a bus system 40. In such a variant, the or some of the sensors 42 can also be connected to the tractor-side control unit 38 via the bus system 40. Furthermore, it is also possible to provide sensors 44 on the tractor side, the signals of which are supplied directly by the control unit 38. Alternatively, sensors 46 arranged on the tractor can also be connected via bus system 40 to control unit 32 on the implement side or control unit 38 on the tractor side. The LS valve block is controlled directly via the signals output by the control unit 38 or via the bus system 40 depending on the control unit 32.

When one of the consumers 15, 17 (hydraulic motor 15, differential cylinder 17) is actuated, a pressure medium volume flow request is transmitted to the tractor-side hydraulic system via the bus 40 and this is fulfilled by the LS pump 6 and the LS valve block 8. In other words, the orifice plate is brought into an open position to set a predetermined pressure medium volume flow and, for example, the supply line 18 with the LS pump 6 and the return line 20 with the Tank T connected. At the same time, the electromagnets 30, for example the distribution valves 27, 29, are energized via the control devices 32 or 38, so that they are brought into their open position. The two distribution valves 26, 28 facing the hydraulic motor 15 remain in the closed position. Correspondingly, a cylinder space 48 of the differential cylinder 17 is supplied with pressure medium via the feed line 18, while pressure medium is displaced from an annular space 50 via the return line 20 and returned to the tank T - the piston rod of the differential cylinder 17 extends. To retract the piston rod, the two distribution valves 27, 29 are also brought into their through position and the directional part of the valve segment 8a is reversed so that the line 20 then becomes the flow line and the line 18 becomes the return line.

The same control device architecture as in the case of control devices 32, 38 on the tractor side can be used in such a control of one of several consumers of a line. As mentioned, the two distribution valves 26, 28 remain in their closed position, so that the hydraulic motor 15 or other consumers are not supplied with pressure medium. If a further consumer of the implement is to be controlled in parallel, this had to be connected to the valve segment 8b or 8c in the same way as described above.

In the event that a single-acting consumer is to be actuated, it can be connected to the flow or return line 18, 20 via a single distribution valve. The main advantage of the circuit according to the invention is that several consumers can be assigned to a single valve segment 8a, 8b, 8c, so that the cost-intensive individual connection of the consumers to a hydraulic socket is eliminated. In the event that several consumers are controlled simultaneously, they can be connected to further valve segments on the tractor valve side, which are supplied with pressure medium via a common LS pump 6. I.e. According to the invention, the valve segments on the tractor side are used several times, the volume flow distribution being carried out by the very cheap distributor valves 26, 27, 28 and 29 on the implement side, so that a large number of consumers can be controlled with minimal expenditure on control and device technology.

In the exemplary embodiment shown in FIG. 1, the consumers are each clamped between two distribution valves 26, 28 and 27, 29 when they are not activated. To control the consumers 15, 17 both distribution valves 26, 28 or 27, 29 must then be opened. Functionally, this solution is very elegant, but the circuitry complexity is relatively high.

FIG. 2 shows a simplified system in which the essential advantages of the invention are retained, but the circuitry complexity is reduced.

The main difference to the above

Embodiment is that in these

Solutions each consumer 15, 17 is assigned only one distribution valve 26 or 27. In other words, when there is no actuation

Consumer 15, 17 is only clamped on one side, which is acceptable in certain applications. If the consumer is designed as a hydraulic motor 15, it is in principle irrelevant whether the distribution valve is arranged in the feed branch line or in the return branch line. For consumers with different pressurized surfaces, such as a hydraulic cylinder 17, it is preferred if the cut-in valve 27 is arranged in the feed branch line 23 to the larger cylinder space 48, so that there is no pressure transmission between the cylinder space 48 and the annular space 50 at the consumer 17 and consequently with one Pressure build-up in the return line 20 no power transmission to the return branch line 25 occurs. Otherwise corresponds to that shown in FIG. 2

Embodiment the above

Embodiment, so that further explanations are unnecessary. Disclosed is a supply system for hydraulically actuated consumers of an implement attached or attached to a tractor or the like. According to the invention, a central valve which specifies the pressure medium volume flow is arranged on the tractor, to which a supply and return line on the implement side is connected. In this flow and return line, several consumers are connected in parallel to one another, one consumer in each case being hydraulically connectable to the central valve via a distribution valve arrangement. According to the invention, the pressure medium volume flow is thus set on the tractor side, while the pressure medium distribution is carried out on the implement side via the distribution valve arrangement. LIST OF REFERENCE NUMERALS supply system tractor side part working device side part LS pump LS-Ventilblocka Ventilsegmentb Ventilsegmentc Ventilsegment0 Arbeitsleitung2 Arbeitsleitung4 hydraulic Steckdose5 Verbraucher6 hydraulic Steckdose7 Verbraucher8 Vorlaufleitung0 Rücklaufleitung2 VorlaufZweigleitung3 VorlaufZweigleitung4 RücklaufZweigleitung5 RücklaufZweigleitung6 Verteilventil7 Verteilventil8 Verteilventil9 diverting 0 Elektromagnet2 control unit (working device) 4 signal line 6 sensor8 control unit (tractor) 0 Bussystem2 Sensoren4 Sensors6 sensors8 cylinder chamber0 annulus

Claims

claims

1. Supply system for hydraulic consumers of a tractor mounted or attached to a tractor

Tool, with a continuously adjustable

Central valve (8) through which at least two consumers

(15, 17) can be supplied with pressure medium, in one

Flow and return lines (18, 20) between the central valve (8) and the consumers (15, 17) each have a distribution valve arrangement (26, 28; 27, 29) for opening or closing the connection to the associated consumer (15, 17) is provided, characterized in that the central valve (8) is arranged on the tractor and the distribution valve arrangement (26, 28; 27, 29) on the implement.

2. Supply system according to claim 1, wherein the distribution valve arrangement (26, 28; 27, 29) and the central valve (8) can be controlled electrically or electronically as a function of a control signal emitted by at least one control unit (32, 38).

3. Supply system according to claim 2, wherein a control device (38) on the tractor and / or a control device

(32) is arranged on the implement and the signal transmission between the tractor and implement takes place via a bus system (40).

4. Supply system according to claim 2 or 3, with sensors (36, 42, 44, 46) for detecting operating parameters of the supply system.

5. Supply system according to claim, wherein the sensors (36, 42, 44, 46) are connected directly or via the bus system (40) to a control device (32, 38).

6. Supply system according to claim 1, wherein the distribution valve arrangement has at least one switching valve (26, 28; 27, 29) via which the flow or return line (18, 20) to the respective double or single-acting consumer (15, 17) can be shut off.

7. Supply system according to claim 1 or 2, wherein the consumer (15, 17) is double-acting and the associated distribution valve means each a switching valve (26, 28; 27, 29) for shutting off or opening a connection to the supply and return lines (18, 20) has.

8. Supply system according to one of the preceding claims, with further central valves (8b, 8c), which are combined with the first-mentioned central valve (8a) to form an LS valve block (8), each central valve (8a, 8b, 8c) having a flow on the implement side - And return line (18, 20) with each of the consumers (15, 17) assigned distribution valve arrangements (26, 28; 27, 29) is assigned.

9. Supply system according to one of the preceding claims, wherein the valve block is a LS valve block with at least one variable orifice, one of these pressure compensators and control edges for adjusting the pressure medium flow direction.