Composite driving system and method of excavator and excavator

Abstract

The invention discloses a composite driving system and method of an excavator and the excavator. The composite driving system comprises a controller, a first control loop and a second control loop. The first control loop comprises a movable arm driving motor and a first pile-up valve, and the second control loop comprises a composite action driving motor and a second pile-up valve; when the excavator executes the action of the movable arm, the controller controls the movable arm driving motor to convert electric energy into hydraulic energy to drive the first pile-up valve to independently control the movable arm of the excavator; when the excavator executes the composite action, the controller controls the composite action driving motor to convert electric energy into hydraulic energy to drive the second pile-up valve to control an executing mechanism of the excavator. According to the composite driving system, flow decoupling of the movable arm and other composite actions can be achieved, overflow loss is reduced, and the risk of single-point failures is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of excavator control, and in particular to a composite drive system and method for an excavator, and the excavator. Background Art

[0002] In the existing technology, the compound drive control system of the excavator may suffer a decrease in efficiency due to conflicting flow demands during compound actions, and the load-sensing valve needs to take into account the dynamic characteristics of multiple actuators. Not only may the response speed be limited due to parameter compromise, but a failure of the hydraulic pump or load-sensing valve may cause the entire system to shut down, resulting in high pollution of the excavator, delayed dynamic response, and large energy loss. Summary of the Invention

[0003] The present invention provides a compound drive system, method and excavator for an excavator. By setting two independently controlled first control loops and second control loops, when the excavator needs to perform a boom action condition, the boom action condition of the excavator is realized by controlling the boom drive motor and the first integrated valve in the first control loop; when the excavator needs to perform a compound action condition, the compound action condition of the excavator is realized by controlling the compound action drive motor and the second integrated valve in the second control loop, thereby realizing flow decoupling between the boom and other compound actions, avoiding flow competition problems during oil supply by a single pump, reducing overflow loss, and designing differentiated control strategies for the boom (high load) and compound action (high-frequency action) to avoid affecting the technical effects of other actuators.

[0004] According to a first aspect of the present invention, a compound drive system for an excavator is provided, which is applied to boom motion and compound motion of the excavator. The compound drive system comprises at least: a controller, a first control circuit, and a second control circuit; the first control circuit comprises: a boom drive motor and a first integrated valve; the second control circuit comprises: a compound motion drive motor and a second integrated valve;

[0005] The first output end of the controller is connected to the input end of the boom drive motor, and the output end of the boom drive motor is connected to the first integrated valve;

[0006] The second output terminal of the controller is connected to the input terminal of the compound action drive motor, and the output terminal of the compound action drive motor is connected to the second integrated valve;

[0007] When the excavator performs a boom action, the controller controls the boom drive motor to convert electrical energy into hydraulic energy to drive the first integrated valve to independently control the boom of the excavator;

[0008] When the excavator performs a compound action, the controller controls the compound action drive motor to convert electrical energy into hydraulic energy to drive the second integrated valve to control the excavator's actuator; wherein the actuator structure includes at least: a dipper arm, a bucket, left travel and right travel.

[0009] Optionally, the first control loop further includes: a first pump-motor and a second pump-motor;

[0010] The input end of the first pump-motor is connected to the first output end of the boom drive motor, the input end of the second pump-motor is connected to the second output end of the boom drive motor, and the output end of the first pump-motor and the output end of the second pump-motor are both connected to the first integrated valve;

[0011] The first pump-motor and the second pump-motor are used to convert the mechanical energy of the boom drive motor into hydraulic energy and transmit it to the first integrated valve to control the excavator to perform boom movements.

[0012] Optionally, the second control loop further includes: a third pump-motor and a fourth pump-motor;

[0013] The input end of the third pump-motor is connected to the first output end of the compound action drive motor, the input end of the fourth pump-motor is connected to the second output end of the compound action drive motor, and the output end of the third pump-motor and the output end of the fourth pump-motor are both connected to the second integrated valve;

[0014] The third pump-motor and the fourth pump-motor are used to convert the mechanical energy of the compound motion drive motor into hydraulic energy and transmit it to the second integrated valve to control the actuator of the excavator to perform compound motions.

[0015] Optionally, the second control circuit further includes: a rotary motor and a rotary gear;

[0016] The input end of the rotary motor is connected to the third output end of the compound action drive motor, the first output end of the rotary motor is connected to the rotary gear, and the second output end of the rotary motor is connected to the second integrated valve;

[0017] The compound motion drive motor directly drives the rotary motor to make the excavator perform a rotary motion, and converts the mechanical energy generated by the excavator during the rotary motion into electrical energy and transmits it back to the second integrated valve to achieve energy recovery of the excavator.

[0018] Optionally, a third control loop is further included; the third control loop includes a third drive motor and a pilot pump;

[0019] The output end of the third drive motor is connected to the input end of the pilot pump, the first output end of the pilot pump is connected to the first integrated valve, the second output end of the pilot pump is connected to the second integrated valve, the third output end of the pilot pump is connected to the first pump motor, and the fourth output end of the pilot pump is connected to the second pump motor;

[0020] The pilot pump converts hydraulic energy into pilot pressure through a gear pump structure and transmits the pilot pressure to the first integration valve, the second integration valve, the first pump-motor, and the second pump-motor.

[0021] Optionally, the third control loop further includes: an oil charge pump;

[0022] The input end of the oil charge pump is connected to the third drive motor, and the output end of the oil charge pump is connected to the pilot pump;

[0023] The charge pump provides an open-loop oil source for the first integrated valve, the first pump-motor, and the second pump-motor.

[0024] Optionally, an inverter group is also included;

[0025] The input end of the inverter group is connected to the controller, the first output end of the inverter group is connected to the boom drive motor; the second output end of the inverter group is connected to the compound action drive motor; and the third output end of the inverter group is connected to the third drive motor.

[0026] Optionally, the first pump motor and the oil charge pump are variable displacement pumps; and the second pump motor is a fixed displacement pump.

[0027] Optionally, the third pump-motor and the fourth pump-motor are fixed-displacement pumps.

[0028] Optionally, batteries are also included;

[0029] The output end of the battery is connected to the input end of the controller, and the battery is used to provide electrical energy for the inverter group.

[0030] According to a second aspect of the present invention, a compound drive method for an excavator is provided, which is applicable to the compound drive system of the excavator described in any one of the first aspects of the present invention. The compound drive method comprises:

[0031] The battery transmits electric energy to the inverter group, and the inverter group distributes the electric energy to the first control loop, the second control loop, and the third control loop respectively;

[0032] When the excavator performs a boom action, the boom drive motor converts electrical energy into hydraulic energy to drive the first integrated valve to control the boom of the excavator;

[0033] When the excavator performs a compound action, the compound drive motor converts electrical energy into hydraulic energy to drive the second integrated valve to control the actuator of the excavator.

[0034] Optionally, the inverter group distributes the electric energy to the first control loop, the second control loop and the third control loop respectively; further comprising:

[0035] When the excavator performs a boom action and / or a compound drive action, the compound action drive motor directly drives the rotary motor to make the excavator perform a rotary action, and converts the mechanical energy generated by the excavator during the rotary action into electrical energy and transmits it back to the second integrated valve.

[0036] According to a third aspect of the present invention, there is provided an excavator comprising: a boom, an arm, a bucket, and the compound drive system of the excavator according to any one of the first aspects of the present invention.

[0037] The present invention discloses a compound drive system for an excavator, which is applied to the boom action and compound action of the excavator. The compound drive system at least includes: a controller, a first control circuit and a second control circuit; the first control circuit includes: a boom drive motor and a first integrated valve, and the second control circuit includes: a compound action drive motor and a second integrated valve; the first output end of the controller is connected to the input end of the boom drive motor, and the output end of the boom drive motor is connected to the first integrated valve; the second output end of the controller is connected to the input end of the compound action drive motor, and the output end of the compound action drive motor is connected to the second integrated valve; when the excavator performs the boom action, the controller controls the boom drive motor to convert electrical energy into hydraulic energy to drive the first integrated valve to independently control the boom of the excavator; when the excavator performs the compound action, the controller controls the compound action drive motor to convert electrical energy into hydraulic energy to drive the second integrated valve to control the excavator's actuator; wherein the actuator structure includes at least: at least one of a dipper arm, a bucket, left travel and right travel. The compound drive system of the excavator provided by the present invention is configured to set up two independently controlled first control loops and second control loops. When the excavator needs to perform a boom action condition, the boom action condition of the excavator is realized by controlling the boom drive motor and the first integrated valve in the first control loop; when the excavator needs to perform a compound action condition, the compound action condition of the excavator is realized by controlling the compound action drive motor and the second integrated valve in the second control loop, thereby realizing flow decoupling between the boom and other compound actions, avoiding flow competition problems during oil supply by a single pump, reducing overflow losses, and designing differentiated control strategies for the boom (high load) and compound actions (high-frequency actions) to avoid affecting the technical effects of other actuators.

[0038] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 This is a schematic structural diagram of a composite drive system for an excavator provided by an embodiment of the present invention;

[0041] Figure 2 This is a schematic structural diagram of another composite drive system for an excavator provided by an embodiment of the present invention;

[0042] Figure 3 This is a schematic structural diagram of another composite drive system for an excavator provided by an embodiment of the present invention;

[0043] Figure 4 This is a schematic structural diagram of another composite drive system for an excavator provided by an embodiment of the present invention;

[0044] Figure 5 This is a schematic structural diagram of another composite drive system for an excavator provided by an embodiment of the present invention;

[0045] Figure 6 This is a schematic structural diagram of another composite drive system for an excavator provided by an embodiment of the present invention;

[0046] Figure 7 This is a schematic structural diagram of another composite drive system for an excavator provided by an embodiment of the present invention;

[0047] Figure 8 This is a flow chart of a compound driving method for an excavator provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0051] Figure 1 This is a schematic diagram of the structure of a composite drive system for an excavator provided by an embodiment of the present invention, with reference to Figure 1 The compound drive system for an excavator provided in an embodiment of the present invention is applied to boom and compound motions of the excavator. The compound drive system includes at least: a controller 1, a first control circuit 2, and a second control circuit 3. The first control circuit 2 includes: a boom drive motor 21 and a first integrated valve 22. The second control circuit 3 includes: a compound motion drive motor 31 and a second integrated valve 32. The first output end of the controller 1 is connected to the input end of the boom drive motor 21, and the output end of the boom drive motor 21 is connected to the first integrated valve 22. The second output end of the controller 1 is connected to the input end of the compound motion drive motor 31, and the output end of the compound motion drive motor 31 is connected to the second integrated valve 32. When the excavator performs a boom motion, the controller 1 controls the boom drive motor 21 to convert electrical energy into hydraulic energy to drive the first integrated valve 22 to independently control the boom of the excavator. When the excavator performs a compound motion, the controller 1 controls the compound motion drive motor 31 to convert electrical energy into hydraulic energy to drive the second integrated valve 32 to control the excavator's actuator. The actuator structure includes at least one of: an arm, a bucket, left travel, and right travel.

[0052] Optionally, both the first integrated valve 22 and the second integrated valve 32 adopt positive flow control valve groups.

[0053] A positive flow control valve group refers to a hydraulic system in which valve spool displacement is proportional to an input signal (such as current or pressure) to dynamically match the flow rate required by the actuator. In this embodiment of the present invention, the first and second integrated valves 22 and 32 employ the positive flow control principle to precisely control the movement of actuators (such as booms), while simultaneously adjusting the distribution of recovered energy and regenerated hydraulic energy through valve opening.

[0054] Integrated valves (such as the first integrated valve 22 and the second integrated valve 32) integrate the functional modules of multiple independent hydraulic valves (such as directional valves, pressure valves, and flow valves) into a single valve body (such as the first integrated valve 22 and the second integrated valve 32). Internal oil passages interconnect the valves to reduce piping connections. In this embodiment of the present invention, the first integrated valve 22 is dedicated to independent boom control, while the second integrated valve 32 coordinates energy distribution for complex actions (such as actuators such as the arm and bucket). Both reduce system complexity and improve response speed through modular design.

[0055] Boom movement: The driver controls the flow of hydraulic oil to the cylinder through the joystick to realize the lifting, swinging and other movements of the excavator boom.

[0056] Stick movement: The driver controls the flow of hydraulic oil to the cylinder through the operating handle to achieve the extension (outward swing) and retraction (inward retraction) of the stick.

[0057] Bucket movement: The driver controls the flow of hydraulic oil to the cylinder through the joystick to achieve digging (inward retraction) and unloading (outward flipping) of the bucket.

[0058] Specifically, such as Figure 1 As shown, the compound drive system of the excavator provided by the embodiment of the present invention includes a first control loop 2 and a second control loop 3;

[0059] The first output terminal of the controller 1 is connected to the input terminal of the boom drive motor 21, and the output terminal of the boom drive motor 21 is connected to the input terminal of the first integrated valve 22 to form a first control loop 1. When the excavator needs to perform a boom movement, the controller 1 sends a control instruction to the boom drive motor 21, and the boom drive motor 21 controls the opening of the first integrated valve 22 to control the excavator's boom movements, such as lifting, lowering, and swinging.

[0060] The second output end of the controller 1 is connected to the input end of the compound action drive motor 31, and the output end of the compound action drive motor 31 is connected to the input end of the second integrated valve 32 to form a second control loop 3; when the excavator needs to perform a compound action, the controller 1 sends a control instruction to the compound action drive motor 31, and the compound action drive motor 31 controls the opening of the second integrated valve 32 to control the excavator to perform a compound action, wherein the compound action includes but is not limited to: dipper arm, bucket, left walking, right walking and other actions you want to perform.

[0061] The compound drive system of the excavator provided by the embodiment of the present invention is realized by setting two independently controlled first control loops and second control loops. When the excavator needs to perform a boom action condition, the boom action condition of the excavator is realized by controlling the boom drive motor and the first integrated valve in the first control loop; when the excavator needs to perform a compound action condition, the compound action condition of the excavator is realized by controlling the compound action drive motor and the second integrated valve in the second control loop. On the one hand, the flow decoupling between the boom and other compound actions is realized, the flow competition problem when a single pump supplies oil is avoided, the overflow loss is reduced, and differentiated control strategies are designed for the boom (high load) and compound action (high frequency action) to avoid affecting the technical effects of other actuators. On the other hand, due to the modular setting (such as the boom drive motor, the first integrated valve, the compound action drive motor, and the second integrated valve), the excavator can be easily repaired and maintained when a failure occurs.

[0062] Figure 2 This is a schematic diagram of the structure of another composite drive system for an excavator provided by an embodiment of the present invention. Figure 2 Optionally, the first control circuit 2 in the compound drive system of the excavator provided by the embodiment of the present invention further includes: a first pump-motor 23 and a second pump-motor 24;

[0063] The input end of the first pump-motor 23 is connected to the first output end of the boom drive motor 21, the input end of the second pump-motor 24 is connected to the second output end of the boom drive motor 21, and the output end of the first pump-motor 23 and the output end of the second pump-motor 24 are both connected to the first integrated valve 22;

[0064] The first pump-motor 23 and the second pump-motor 24 are used to convert the mechanical energy of the boom drive motor into hydraulic energy and transmit it to the first integrated valve 22 to control the excavator to perform boom movements.

[0065] Specifically, the first control circuit 2 of the compound drive system of the excavator provided by the embodiment of the present invention further includes: a first pump motor 23 and a second pump motor 24, such as Figure 2 As shown, the input end of the first pump-motor 23 is connected to the first output end of the boom drive motor 21, and the output end of the first pump-motor 23 is connected to the input end of the first integrated valve 22; the input end of the second pump-motor 24 is connected to the second output end of the boom drive motor 21, and the output end of the second pump-motor 24 is connected to the first integrated valve 22. The boom drive motor 21 converts electrical energy into mechanical energy and transmits it to the first pump-motor 23 and the second pump-motor 24. The first pump-motor 23 and the second pump-motor 24 convert mechanical energy into hydraulic energy and transmit it to the first integrated valve 22 together, thereby controlling the opening of the first integrated valve 22 to realize the boom action condition of the excavator.

[0066] Optionally, the first pump-motor 23 and the oil charge pump (mentioned below) are variable displacement pumps.

[0067] A variable displacement pump / motor changes its displacement by adjusting the swashplate angle or plunger stroke. In this embodiment, the first pump-motor 23 (the boom-driving main pump) and the charge pump (described below) employ variable displacement pumps. The former dynamically adjusts displacement based on boom movement requirements to achieve flow matching, while the latter adaptively adjusts charge flow in an open circuit according to system pressure changes, jointly optimizing energy efficiency.

[0068] The second pump-motor 24 is a fixed displacement pump.

[0069] Fixed displacement pump: A hydraulic pump / motor with non-adjustable displacement (output flow rate per unit speed). In this embodiment, the second pump-motor 24 utilizes a fixed displacement pump design, driven directly by an electric motor in a closed circuit. The output flow rate is strictly proportional to the motor speed, ensuring consistent movement of actuators such as the boom under stable load conditions while reducing control complexity.

[0070] Figure 3 This is a schematic diagram of the structure of another composite drive system for an excavator provided by an embodiment of the present invention. Figure 3 Optionally, the second control circuit 3 in the compound drive system of the excavator provided by the embodiment of the present invention further includes: a third pump-motor 33 and a fourth pump-motor 34;

[0071] The input end of the third pump-motor 33 is connected to the first output end of the compound action drive motor 31, the input end of the fourth pump-motor 34 is connected to the second output end of the compound action drive motor 31, and the output end of the third pump-motor 33 and the output end of the fourth pump-motor 34 are both connected to the second integration valve 32;

[0072] The third pump-motor 33 and the fourth pump-motor 34 are used to convert the mechanical energy of the compound motion drive motor 31 into hydraulic energy and transmit it to the second integrated valve 32 to control the actuator of the excavator to perform compound motions.

[0073] Specifically, such as Figure 3 As shown, the input end of the third pump-motor 33 is connected to the first output end of the compound action drive motor 31, and the output end of the third pump-motor 33 is connected to the second integration valve 32; the input end of the fourth pump-motor 34 is connected to the second output end of the compound action drive motor 31, and the output end of the fourth pump-motor 34 is connected to the second integration valve 32;

[0074] The compound motion drive motor 31 converts electrical energy into mechanical energy and transmits it to the third pump motor 33 and the fourth pump motor 34. The third pump motor 33 and the fourth pump motor 34 convert mechanical energy into hydraulic energy and transmit it to the second integrated valve 32 together, thereby controlling the opening of the second integrated valve 32 to realize the compound motion working condition of the excavator.

[0075] Optionally, the third pump-motor 33 and the fourth pump-motor 34 are fixed displacement pumps.

[0076] In the embodiment of the present invention, the third pump-motor 33 and the fourth pump-motor 34 are designed as fixed-displacement pumps and are directly driven by motors in a closed loop. The output flow rate strictly corresponds to the motor speed, ensuring the consistency of the movements of actuators such as walking and buckets under stable load conditions, while reducing control complexity.

[0077] Closed circuit: Hydraulic oil forms a closed loop between the pump and the actuator (such as a motor), which is an efficient energy transfer method without the intervention of the oil tank. Figure 2 and Figure 3 In the embodiment of the present invention, the first pump-motor 23 (variable pump), the second pump-motor 24 (fixed displacement pump), the third pump-motor 33 (fixed displacement pump) and the fourth pump-motor 34 (fixed displacement pump) all operate in a closed loop, directly driving actuators such as the boom, reducing throttling losses and improving energy utilization, and are particularly suitable for energy recovery requirements during braking of the rotary motor.

[0078] Figure 4 This is a schematic diagram of the structure of another composite drive system for an excavator provided by an embodiment of the present invention. Figure 4 , Optionally, the second control circuit 3 in the compound drive system of the excavator provided by the embodiment of the present invention further includes: a rotary motor 35 and a rotary gear 36;

[0079] The input end of the rotary motor 35 is connected to the third output end of the compound action drive motor 31 , the first output end of the rotary motor 35 is connected to the rotary gear 36 , and the second output end of the rotary motor 35 is connected to the second integrated valve 32 ;

[0080] The compound motion drive motor 31 directly drives the rotary motor 35 to make the excavator perform a rotary motion, and converts the mechanical energy generated by the excavator during the rotary motion into electrical energy and transmits it back to the second integrated valve 32 to achieve energy recovery of the excavator.

[0081] Specifically, such as Figure 4 As shown, the second control circuit 3 in the compound drive system of the excavator provided by the embodiment of the present invention further includes: a rotary motor 35 and a rotary gear 36;

[0082] The compound action drive motor 31 can also directly drive the rotary motor 35 to realize the rotary action of the excavator. During the rotation of the excavator, the generated mechanical energy is converted into electrical energy and transmitted back to the second integrated valve 32 to realize energy recovery of the excavator.

[0083] Energy recovery and regeneration refers to the process of converting braking or gravitational potential energy into reusable energy. In this embodiment of the present invention, when the swing motor is operating, the compound-action drive motor 31 converts mechanical energy into electrical energy and transmits it back to the second integrated valve 32. Simultaneously, the first integrated valve 22 and the second integrated valve 32 group redistribute excess hydraulic energy to other actuators (such as boom lift) through positive flow control, achieving multi-stage conversion and recycling of mechanical energy, electrical energy, and hydraulic energy.

[0084] Figure 5 This is a schematic diagram of the structure of another composite drive system for an excavator provided by an embodiment of the present invention. Figure 5 Optionally, the compound drive system of the excavator provided by the embodiment of the present invention further includes a third control circuit 4; the third control circuit 4 includes a third drive motor 41 and a pilot pump 42;

[0085] An output end of the third drive motor 41 is connected to an input end of the pilot pump 42, a first output end of the pilot pump 42 is connected to the first integration valve 22, a second output end of the pilot pump 42 is connected to the second integration valve 32, a third output end of the pilot pump 42 is connected to the first pump-motor 23, and a fourth output end of the pilot pump 42 is connected to the second pump-motor 24;

[0086] The pilot pump 42 converts hydraulic energy into pilot pressure through a gear pump structure and transmits the pilot pressure to the first integration valve 22 , the second integration valve 32 , the first pump-motor 23 , and the second pump-motor 24 .

[0087] Specifically, the third drive motor 41 sends a control instruction to the pilot pump 42, and the pilot pump 42 converts the hydraulic energy into a pilot pressure (low-pressure oil pressure used to control the action of the main valve, controlling large flow with small pressure) through the gear pump structure, and transmits it to the first integrated valve 22, the second integrated valve 32, the first pump motor 23 and the second pump motor 24, and provides pressure balance for the first pump motor 23 and the second pump motor 24.

[0088] Figure 6 This is a schematic diagram of the structure of another composite drive system for an excavator provided by an embodiment of the present invention. Figure 6 , Optionally, the third control circuit 4 in the compound drive system of the excavator provided by the embodiment of the present invention further includes: an oil charge pump 43;

[0089] The input end of the oil charge pump 43 is connected to the third drive motor 41 , and the output end of the oil charge pump 43 is connected to the pilot pump 42 ;

[0090] The charge pump 43 provides an open-circuit oil source for the first integrated valve 22 , the first pump-motor 23 , and the second pump-motor 24 .

[0091] Optionally, the oil charge pump 42 is a variable displacement pump.

[0092] Open circuit: A circulation method in which the return oil of the actuator (such as the cylinder) in the hydraulic system returns directly to the oil tank and the oil is in contact with the atmosphere.

[0093] Specifically, the oil replenishment pump 43 adopts an open loop design, completes oil cooling and impurity precipitation through the oil tank, provides stable low-pressure oil replenishment for the first pump-motor 23, the second pump-motor 24, the third pump-motor 33 and the fourth pump-motor 34, and avoids pressure fluctuations caused by the compressibility of the oil in the closed loop.

[0094] Figure 7 This is a schematic diagram of the structure of another composite drive system for an excavator provided by an embodiment of the present invention. Figure 7 , the compound drive system of the excavator provided by the embodiment of the present invention further includes an inverter group 5;

[0095] The input end of the inverter group 5 is connected to the controller 1, the first output end of the inverter group 5 is connected to the boom drive motor 21; the second output end of the inverter group 5 is connected to the compound action drive motor 31; the third output end of the inverter group 5 is connected to the third drive motor 41.

[0096] Specifically, the inverter group 5 is a collection of multiple inverters, and the inverter group 5 is used for converting between direct current and alternating current to match the power voltages of the boom drive motor 21 , the compound motion drive motor 31 and the third drive motor 41 .

[0097] Optional, continue to refer to Figure 7 , the compound drive system of the excavator provided by the embodiment of the present invention further includes a battery 6;

[0098] The output end of the battery 6 is connected to the input end of the controller 1 , and the battery 6 is used to provide electrical energy to the inverter group 5 .

[0099] According to the same inventive concept, an embodiment of the present invention further provides a compound drive method for an excavator, which is applicable to the compound drive system of the excavator in any of the above-mentioned embodiments of the invention. Figure 8 This is a flow chart of a compound driving method for an excavator provided by an embodiment of the present invention, with reference to Figure 8 , the composite drive method includes:

[0100] S101: The battery transmits electric energy to the inverter group, and the inverter group distributes the electric energy to the first control loop, the second control loop, and the third control loop respectively.

[0101] Specifically, the battery transmits electrical energy to the inverter group, the inverter group converts direct current into alternating current to match the voltage required by each motor, and then transmits the electrical energy to the first control loop, the second control loop and the third control loop respectively to provide electrical energy for each control loop.

[0102] S102: When the excavator performs a boom action, the boom drive motor converts electrical energy into hydraulic energy to drive the first integrated valve to control the boom of the excavator.

[0103] Specifically, when the excavator wants to perform a boom movement, the driver in the cab issues a control command, the controller receives the control command, and controls the boom drive motor to convert electrical energy into hydraulic energy, and controls the lifting, swinging and other movements of the excavator boom by controlling the opening of the first integrated valve.

[0104] S103: When the excavator performs a compound action, the compound drive motor converts electrical energy into hydraulic energy to drive the second integrated valve to control the actuator of the excavator.

[0105] Specifically, when the excavator wants to perform a compound action, the driver in the cab issues a control command, the controller receives the control command, and controls the compound drive motor to convert electrical energy into hydraulic energy, and controls the excavator's execution structure by controlling the opening of the second integrated valve. The execution mechanism includes but is not limited to: dipper arm, bucket, left and right travel, etc.

[0106] The compound driving method for an excavator provided by an embodiment of the present invention can achieve the same technical effect as the compound driving system for an excavator provided by any of the above-mentioned embodiments of the invention, and will not be described in detail here.

[0107] Optionally, the inverter group distributes the electric energy to the first control loop, the second control loop, and the third control loop respectively; and further includes:

[0108] When the excavator performs a boom action and / or a compound drive action, the compound action drive motor directly drives the swing motor to make the excavator perform a swing action, and converts the mechanical energy generated by the excavator during the swing action into electrical energy and transmits it back to the second integrated valve.

[0109] Specifically, when the excavator performs boom operation and / or compound drive action, the compound drive motor can also directly drive the rotary motor to realize the rotary action of the excavator. The mechanical energy generated during the rotary action of the excavator can also be converted into electrical energy and retransmitted to the second integrated valve to realize energy recovery and utilization of the excavator.

[0110] According to the same inventive concept, an embodiment of the present invention further provides an excavator, comprising: a boom, a dipper arm, a bucket, and the compound drive system of the excavator in any of the above-mentioned embodiments of the invention.

[0111] The excavator provided by the embodiment of the present invention can achieve the same technical effects as the composite drive system of the excavator provided by any of the above-mentioned embodiments of the invention, and will not be described in detail here.

[0112] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A compound drive system for an excavator, characterized in that: Applicable to boom motion and compound motion of excavator, the compound drive system comprises at least: a controller, a first control circuit and a second control circuit; the first control circuit comprises: a boom drive motor and a first integrated valve, the second control circuit comprises: a compound motion drive motor and a second integrated valve; The first output end of the controller is connected to the input end of the boom drive motor, and the output end of the boom drive motor is connected to the first integrated valve; The second output terminal of the controller is connected to the input terminal of the compound action drive motor, and the output terminal of the compound action drive motor is connected to the second integrated valve; When the excavator performs a boom action, the controller controls the boom drive motor to convert electrical energy into hydraulic energy to drive the first integrated valve to independently control the boom of the excavator; When the excavator performs a compound action, the controller controls the compound action drive motor to convert electrical energy into hydraulic energy to drive the second integrated valve to control the excavator's actuator; wherein the actuator structure includes at least: a dipper arm, a bucket, left travel and right travel.

2. The compound drive system for an excavator according to claim 1, characterized in that: The first control loop further includes: a first pump-motor and a second pump-motor; The input end of the first pump-motor is connected to the first output end of the boom drive motor, the input end of the second pump-motor is connected to the second output end of the boom drive motor, and the output end of the first pump-motor and the output end of the second pump-motor are both connected to the first integrated valve; The first pump-motor and the second pump-motor are used to convert the mechanical energy of the boom drive motor into hydraulic energy and transmit it to the first integrated valve to control the excavator to perform boom movements.

3. The compound drive system for an excavator according to claim 1, characterized in that: The second control loop further includes: a third pump-motor and a fourth pump-motor; The input end of the third pump-motor is connected to the first output end of the compound action drive motor, the input end of the fourth pump-motor is connected to the second output end of the compound action drive motor, and the output end of the third pump-motor and the output end of the fourth pump-motor are both connected to the second integrated valve; The third pump-motor and the fourth pump-motor are used to convert the mechanical energy of the compound motion drive motor into hydraulic energy and transmit it to the second integrated valve to control the actuator of the excavator to perform compound motions.

4. The compound drive system for an excavator according to claim 3, characterized in that: The second control circuit further includes: a rotary motor and a rotary gear; The input end of the rotary motor is connected to the third output end of the compound action drive motor, the first output end of the rotary motor is connected to the rotary gear, and the second output end of the rotary motor is connected to the second integrated valve; The compound motion drive motor directly drives the rotary motor to make the excavator perform a rotary motion, and converts the mechanical energy generated by the excavator during the rotary motion into electrical energy and transmits it back to the second integrated valve to achieve energy recovery of the excavator.

5. The compound drive system for an excavator according to claim 2, characterized in that: Also includes a third control circuit; the third control circuit includes a third drive motor and a pilot pump; The output end of the third drive motor is connected to the input end of the pilot pump, the first output end of the pilot pump is connected to the first integrated valve, the second output end of the pilot pump is connected to the second integrated valve, the third output end of the pilot pump is connected to the first pump motor, and the fourth output end of the pilot pump is connected to the second pump motor; The pilot pump converts hydraulic energy into pilot pressure through a gear pump structure and transmits the pilot pressure to the first integration valve, the second integration valve, the first pump-motor, and the second pump-motor.

6. The compound drive system for an excavator according to claim 5, characterized in that: The third control loop further includes: an oil charge pump; The input end of the oil charge pump is connected to the third drive motor, and the output end of the oil charge pump is connected to the pilot pump; The charge pump provides an open-loop oil source for the first integrated valve, the first pump-motor, and the second pump-motor.

7. The compound drive system for an excavator according to claim 5, characterized in that: Also includes inverter group; The input end of the inverter group is connected to the controller, the first output end of the inverter group is connected to the boom drive motor; the second output end of the inverter group is connected to the compound action drive motor; and the third output end of the inverter group is connected to the third drive motor.

8. The compound drive system for an excavator according to claim 6, characterized in that: The first pump motor and the oil charge pump are variable displacement pumps; the second pump motor is a fixed displacement pump.

9. The compound drive system for an excavator according to claim 3, characterized in that: The third pump-motor and the fourth pump-motor are fixed-displacement pumps.

10. The compound drive system for an excavator according to claim 7, characterized in that: Also includes batteries; The output end of the battery is connected to the input end of the controller, and the battery is used to provide electrical energy for the inverter group.

11. A compound driving method for an excavator, characterized in that: The compound drive system of the excavator according to any one of claims 1 to 10, wherein the compound drive method comprises: The battery transmits electric energy to the inverter group, and the inverter group distributes the electric energy to the first control loop, the second control loop, and the third control loop respectively; When the excavator performs a boom action, the boom drive motor converts electrical energy into hydraulic energy to drive the first integrated valve to control the boom of the excavator; When the excavator performs a compound action, the compound drive motor converts electrical energy into hydraulic energy to drive the second integrated valve to control the actuator of the excavator.

12. The compound driving method of an excavator according to claim 11, characterized in that: The inverter group distributes electric energy to the first control loop, the second control loop and the third control loop respectively; and further comprises: When the excavator performs a boom action and / or a compound drive action, the compound action drive motor directly drives the rotary motor to make the excavator perform a rotary action, and converts the mechanical energy generated by the excavator during the rotary action into electrical energy and transmits it back to the second integrated valve.

13. An excavator, characterized in that: include: A boom, an arm, a bucket, and a composite drive system for an excavator as claimed in any one of claims 1 to 10.

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