Hydraulic circuit within a hydraulic system

Abstract

The invention relates to a hydraulic circuit within a hydraulic system, comprising a tank, a pump, and at least one hydraulic joystick for controlling at least one hydraulic drive. To also enable the operation of non-hydraulic components with minimal additional components, at least one hydraulic joystick for controlling at least one non-hydraulic drive is hydraulically connected to a sensor block for controlling the non-hydraulic drive. The sensor block has at least one pilot port hydraulically connected to the joystick on its input side and at least one load-sensing port hydraulically connected to the pump on its output side. The sensor block has a check valve for each pilot port, which is provided between the respective pilot port and the load-sensing port.and wherein the sensor block has a measuring port for each pilot port, which is provided between the respective pilot port and the respective check valve and to which a pressure sensor is connected for measuring the volume flow caused by the joystick at the corresponding pilot port.

Description

[0001] The invention relates to a hydraulic circuit within a hydraulic system, comprising a tank, a pump, at least one hydraulic joystick which is connected to a control block for controlling at least one hydraulic drive, wherein the control block has at least one input connection which is hydraulically connected to the pump and has at least one pilot connection hydraulically connected to the joystick, and is hydraulically connected to the tank on the output side and has a load sensing connection which is hydraulically connected to the pump.

[0002] Hydraulic circuits are known in practice within systems that include a hydraulic joystick for controlling a hydraulic drive. These systems can, for example, be part of mobile construction machinery such as excavators. As such mobile construction machinery becomes increasingly electrified, more and more components of such mobile construction machinery are being implemented not as hydraulic but, for example, as electric.

[0003] The disadvantage here is that some non-hydraulic components of a mobile construction machine cannot be easily integrated into the existing hydraulic circuits of that mobile construction machine. For example, it is not possible to integrate electric drives into an existing hydraulic circuit within a hydraulic system without adding a large number of additional components. This often creates redundancies in the systems in question, making energy-efficient operation of the respective machine impossible.

[0004] The object of the invention is to avoid the aforementioned disadvantages and to provide a hydraulic circuit which also comprises non-hydraulic components, for example electrical components, in particular electric drives, and which can be operated efficiently with the smallest possible number of additional components.

[0005] This object is achieved in a generic hydraulic circuit in that at least one hydraulic joystick for controlling at least one non-hydraulic drive is hydraulically connected to a sensor block for controlling at least the non-hydraulic drive, wherein the sensor block has at least one pilot connection hydraulically connected to the joystick on the input side, and at least one load sensing connection on the output side, which is hydraulically connected to the pump, wherein the sensor block has a check valve for each pilot connection, which is provided between the respective pilot connection and the load sensing connection, and wherein the sensor block has a measuring connection for each pilot connection,which is provided between the respective pilot connection and the respective check valve and to which a pressure sensor is connected for measuring the volume flow caused by the joystick at the corresponding pilot connection.

[0006] Within such a system, for example within an excavator, a hydraulically operated joystick can control the hydraulic drive, for example the drive of the excavator's arm, and another hydraulic joystick can control a non-hydraulic drive, for example an electric or pneumatic drive, for example the excavator's slewing gear. It is also conceivable that within such a system, for example within an excavator, a hydraulically operated joystick controls the hydraulic drive, for example the drive of the excavator's arm, on the one hand, and the same joystick controls a non-hydraulic drive, for example an electric or pneumatic drive, for example the excavator's slewing gear, on the other hand.

[0007] Each joystick is supplied with pilot pressure from the pump. To control the arm, the joystick controlling the hydraulic drive is hydraulically connected to the control block. The control block is connected to the pump on the inlet side and transmits a power request to the pump via its load sensing connection. The sensor block, for example, has two pilot connections on the inlet side, which are hydraulically connected to the joystick controlling the hydraulic drive. If a control command for the excavator's arm is entered via the joystick controlling the hydraulic drive, this induces a volume flow in the control block and controls the hydraulic drive accordingly. This process is therefore purely hydraulic.If a control command for the excavator's slewing gear, for example an electrically operated one, is entered via the joystick controlling the non-hydraulic drive, this induces a volume flow in the sensor block. The measuring ports in the sensor block connected to the pilot ports measure the pressure of this volume flow of the joystick controlling the non-hydraulic drive. Using these measured values, the non-hydraulic drive, in this case the excavator's slewing gear, can be controlled via a suitable control unit. The volume flow triggered by the joystick controlling the non-hydraulic drive is passed on to the pump via a load sensing port on the sensor block, for example. This signals to the pump that a certain power is required to supply the pilot circuit. The pump adjusts the pressure in the system so that the maximum pilot pressure is available to the pilot circuit.For example, the joystick controlling the hydraulic drive and the joystick controlling the non-hydraulic drive can be a single joystick.

[0008] The check valves provided for each pilot port in the sensor block allow flow toward the corresponding load sensing port. The check valves in the sensor block prevent the maximum system pressure from entering the joystick lines of the sensor block when the hydraulic drive and the non-hydraulic drive are operating simultaneously.

[0009] The sensor block of the hydraulic circuit described above can be integrated into an excavator's existing hydraulic circuit and thus also retrofitted without the need for further extensive modifications to the existing hydraulic circuit. With this type of hydraulic circuit design, the pump only feeds as much pressure into the hydraulic circuit as is actually needed. This also enables efficient operation of the corresponding mobile construction machine. If, for example, only an electric drive is controlled, the pump only provides a pilot pressure in the system. At the same time, it is ensured that the pump provides the pilot pressure even when the hydraulic drive is not controlled.

[0010] Advantageously, the sensor block can have a nozzle for each of its pilot ports, which is provided between the respective check valve and the at least one load sensing port. A nozzle designed in this way can be used to adjust how much power the pump should deliver to the system when the electric drive is activated.

[0011] In addition, the sensor block can have a single nozzle for at least two of its pilot connections, preferably for all of its pilot connections, with the check valves upstream of the at least one load sensing connection opening into a common line, and the nozzle being provided in this common line. A nozzle designed in this way can then be used to uniformly adjust how much power the pump should deliver to the system when the electric drive is activated.

[0012] Furthermore, the load sensing connection of the control block and the load sensing connection of the sensor block can be connected to a common line connected to the pump. This can reduce the complexity and number of required components of the circuit.

[0013] Advantageously, at least one pressure sensor, and preferably all pressure sensors, can be designed redundantly. A redundant design of the pressure sensors ensures that the volume flow generated by the joystick is measured correctly. This can reduce errors in the control of the electric drive.

[0014] In addition, the control block and the sensor block can be combined into a single component. By combining the control block and the sensor block into a single component, the complexity of the hydraulic circuit can be reduced. This also reduces the number of individual components and required connecting elements.

[0015] Furthermore, the hydraulic circuit can be part of a hydraulic system of a construction machine, particularly preferably part of a hydraulic system of an excavator.

[0016] Advantageously, the at least one hydraulic joystick, which is connected to the control block for controlling at least one hydraulic drive, and the at least one joystick, which is hydraulically connected to the sensor block for controlling at least one non-hydraulic drive, can be configured as a single joystick. In this respect, it may be possible, for example, for a hydraulically operated joystick within such a system, for example within an excavator, to control a hydraulic drive, for example, the drive of the excavator's arm, on the one hand, and a non-hydraulic drive, for example, an electric or pneumatic drive, such as the excavator's slewing gear, on the other.

[0017] The single drawing shows an exemplary embodiment of a hydraulic circuit 1 within a hydraulic system. The hydraulic circuit 1 comprises a tank 2, a pump 3, and a hydraulic joystick 4. The hydraulic joystick 4 is connected to a control block 5 for controlling a hydraulic drive (not shown). The control block 5 has an input port 6 on the input side, which is hydraulically connected to the pump 3, and two pilot ports 7, which are hydraulically connected to the joystick 4. On the output side, the control block 5 is hydraulically connected to the tank 2 and has a load sensing port 8, which is hydraulically connected to the pump 3.

[0018] The hydraulic joystick 4 is hydraulically connected to a sensor block 9 for controlling an electric drive (not shown), i.e., a non-hydraulic drive. The sensor block 9 has two pilot connections 10 on the input side, which are hydraulically connected to the joystick 4. On the output side, the sensor block 9 has a load sensing connection 11, which is hydraulically connected to the pump 3.

[0019] In this respect, the hydraulic joystick 4 is connected to the control block 5 on the one hand to control the hydraulic drive and on the other hand to the sensor block 9 for controlling the non-hydraulic drive, in this case the electric drive.

[0020] The sensor block 9 includes a check valve 12 for each pilot port 10, which is provided between the respective pilot port 10 and the load sensing port 11. The check valves 12 are permeable toward the load sensing port 11.

[0021] The sensor block 9 also has a measuring port 13 for each pilot port 10, which is provided between the respective pilot port 10 and the respective check valve 12. A pressure sensor 14 is connected to each measuring port 13 for measuring the volume flow generated by the joystick 4 at the corresponding pilot port 10.

[0022] The sensor block 9 has a single nozzle 15 for all of its pilot connections 10, wherein the check valves 12 open into a common line upstream of the load sensing connection 11 and the nozzle 15 is provided in this common line.

[0023] The load sensing connection 8 of the control block 5 and the load sensing connection 11 of the sensor block 9 open into a common line 16 which is connected to the pump 3.

Claims

1. Hydraulic circuit (1) within a hydraulic system, comprising a tank (2), a pump (3), at least one hydraulic joystick (4) which is connected to a control block (5) for controlling at least one hydraulic drive, wherein the control block (5) has at least one input connection (6) which is hydraulically connected to the pump (3) and has at least one pilot connection (7) hydraulically connected to the joystick (4), and is hydraulically connected on the output side to the tank (2) and has a load sensing connection (8) which is hydraulically connected to the pump (3), characterized in thatat least one hydraulic joystick (4) for controlling at least one non-hydraulic drive is hydraulically connected to a sensor block (9) for controlling at least the non-hydraulic drive, wherein the sensor block (9) has at least one pilot connection (10) hydraulically connected to the joystick (4) on the input side, and at least one load-sensing connection (11) on the output side, which is hydraulically connected to the pump (3), wherein the sensor block (9) has a check valve (12) for each pilot connection (10), which is provided between the respective pilot connection (10) and the load-sensing connection (11), and wherein the sensor block (9) has a measuring connection (13) for each pilot connection (10),which is provided between the respective pilot connection (10) and the respective check valve (12) and to which a pressure sensor (14) is connected for measuring the volume flow caused by the joystick (4) at the corresponding pilot connection (10).

2. Hydraulic circuit (1) according to the preceding claim, characterized in that the sensor block (9) has a nozzle (15) for each of its pilot connections (10), which is provided between the respective check valve (12) and the at least one load sensing connection (11).

3. Hydraulic circuit (1) according to claim 1, characterized in that the sensor block (9) has a single nozzle (15) for at least two of its pilot connections (10), preferably for all of its pilot connections (10), wherein the check valves (12) open into a common line upstream of the at least one load sensing connection (11) and the nozzle (15) is provided in this common line.

4. Hydraulic circuit (1) according to one of the preceding claims, characterized in that the load sensing connection (8) of the control block (5) and the load sensing connection (11) of the sensor block (9) open into a common line (16) which is connected to the pump (3).

5. Hydraulic circuit (1) according to one of the preceding claims, characterized in that at least one pressure sensor (14) is designed, preferably all pressure sensors (14) are designed redundantly.

6. Hydraulic circuit (1) according to one of the preceding claims, characterized in that the control block (5) and the sensor block (9) are combined in one component.

7. Hydraulic circuit (1) according to one of the preceding claims, characterized in that the hydraulic circuit (1) is a component of a hydraulic system of a construction machine, particularly preferably a component of a hydraulic system of an excavator.

8. Hydraulic circuit (1) according to one of the preceding claims, characterized in that the at least one hydraulic joystick (4), which is connected to the control block (5) for controlling at least one hydraulic drive, and the at least one joystick (4), which is hydraulically connected to the sensor block (9) for controlling at least one non-hydraulic drive, are designed as a single joystick (4).

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