A control method of a swing platform of an excavator and the excavator

Abstract

The application discloses a control method of a rotary platform of an excavator and the excavator. The target rotating speed of the rotary platform is determined by acquiring the handle input signal of the rotary platform in real time. If the target rotating speed changes in the range (M, N), the hydraulic pump of the excavator is controlled to be always in the maximum displacement, and the displacement of the hydraulic motor of the excavator is controlled to decrease along with the increase of the target rotating speed. The rotating speed M is defined according to the maximum displacement of the hydraulic motor, and the rotating speed N is defined according to the maximum rotating speed of the rotary platform. When the target rotating speed changes in the range (M, N), different control conditions corresponding to the displacement of the hydraulic pump and the displacement of the hydraulic motor are set, so that the rotating speed requirement of the rotary platform in the starting process is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of signal processing, in particular to a control method of a rotating platform of an excavator and the excavator. BACKGROUND

[0002] At present, the rotating system of an excavator includes an open system and a closed system. In the open system, oil flows in sequence through an oil tank, a hydraulic pump, a hydraulic motor and the oil tank, so the oil tank needs to be connected to external devices through a valve port, which causes throttling loss at the valve port position. In the closed system, oil flows in sequence through a hydraulic pump, a hydraulic motor and the hydraulic pump, and no valve port needs to be arranged for connection with external devices, thereby avoiding throttling loss at the valve port position. Therefore, the closed system is usually used to control the rotating platform of an excavator.

[0003] In the process of controlling the rotation of the rotating platform in the conventional closed system, the displacement of the hydraulic motor is generally configured according to the maximum rotational speed of the rotating platform, so that the displacement of the hydraulic motor is small. Due to the flow limitation of the overflow valve, the pressure cut-off method needs to be used to avoid the hydraulic motor reaching the maximum torque. However, the use of the pressure cut-off method to control the torque of the hydraulic motor makes the maximum loadable pressure value of the hydraulic motor less than the maximum loadable pressure value of the hydraulic motor in the open system. Further, the starting acceleration of the excavator is slow in the process of starting the rotating platform, and the rotational speed of the rotating platform cannot meet the actual demand. SUMMARY

[0004] The embodiments of the present application provide a control method of a rotating platform of an excavator and the excavator, which adjusts the displacement of a hydraulic motor to ensure the rotational speed demand of the rotating platform in the starting process.

[0005] In a first aspect, the embodiments of the present application provide a control method of a rotating platform of an excavator, and the method comprises:

[0006] acquiring a handle input signal of the rotating platform in real time, and determining a target rotational speed of the rotating platform based on the handle input signal;

[0007] if the target rotational speed changes in a range of (M, N), controlling a hydraulic pump in the excavator to be always at maximum displacement, and controlling the displacement of a hydraulic motor in the excavator to decrease along with the increase of the target rotational speed; wherein the M is determined according to the maximum displacement of the hydraulic motor, and the N is determined according to the maximum rotational speed of the rotating platform.

[0008] Compared with the prior art, the application defines the rotating speed M according to the maximum displacement of the hydraulic motor, defines the rotating speed N according to the maximum rotating speed of the slewing platform, and then sets different control conditions corresponding to the displacement of the hydraulic pump and the displacement of the hydraulic motor when the target rotating speed changes in the range of (M, N), so as to ensure the rotating speed requirement of the slewing platform during the starting process.

[0009] In a possible implementation, the method further includes:

[0010] calculating a first pressure difference value of the inlet and outlet of the hydraulic pump and a second pressure difference value of the inlet and outlet of the hydraulic motor in real time;

[0011] if the target rotating speed changes in the range of (M, N), adjusting the torque of the hydraulic pump when the first pressure difference value is greater than a first threshold value, and adjusting the torque of the hydraulic motor when the second pressure difference value is greater than a second threshold value; the first threshold value is the maximum pressure value of the hydraulic pump load, and the second threshold value is the maximum pressure value of the hydraulic motor load.

[0012] The application can timely adjust the torque of the hydraulic pump and the torque of the hydraulic motor by monitoring the pressure changes of the inlet and outlet of the hydraulic pump and the pressure changes of the inlet and outlet of the hydraulic motor in real time, so as to avoid damage to the hydraulic pump and the hydraulic motor device. Meanwhile, the application can timely control the slewing platform by monitoring the pressure changes of the inlet and outlet of the hydraulic motor in real time, so as to avoid the time delay problem of controlling the slewing platform through a long pipeline by monitoring only the pressure changes of the inlet and outlet of the hydraulic pump. The pressure changes of the inlet and outlet of the hydraulic motor can also be used to more accurately control the slewing platform.

[0013] In a possible implementation, the adjusting the torque of the hydraulic pump when the first pressure difference value is greater than a first threshold value includes:

[0014] controlling the hydraulic pump to reduce the displacement at the current moment to adjust the torque of the hydraulic pump when the first pressure difference value is greater than a first threshold value.

[0015] The application can timely adjust the torque of the hydraulic pump by controlling the displacement of the hydraulic pump, so as to avoid damage to the hydraulic pump device. Meanwhile, the application can also realize the highest pressure flow control of the hydraulic pump by adjusting the displacement of the hydraulic pump, reduce the overflow of the overflow valve, and achieve the energy-saving effect.

[0016] In a possible implementation, the adjusting the torque of the hydraulic motor when the second pressure difference value is greater than a second threshold value includes:

[0017] controlling the hydraulic motor to increase the displacement at the current moment to adjust the torque of the hydraulic motor when the second pressure difference value is greater than a second threshold value.

[0018] The application controls the displacement of the hydraulic motor, and adjusts the torque of the hydraulic motor in time to avoid damage of the hydraulic motor device. Meanwhile, by monitoring the pressure change of the inlet and outlet of the hydraulic motor in real time, the slewing platform can be controlled in time to avoid the time delay problem of controlling the slewing platform through a long pipeline by monitoring the pressure change of the inlet and outlet of the hydraulic pump. The pressure change of the inlet and outlet of the hydraulic motor can also be used to control the slewing platform more accurately.

[0019] In a possible implementation, the maximum displacement of the hydraulic motor is obtained by the following method:

[0020] The maximum displacement of the hydraulic pump is determined according to the preset maximum power of the slewing platform.

[0021] When the hydraulic pump is at the maximum displacement and the hydraulic motor is at the maximum torque, the maximum displacement of the hydraulic motor is determined.

[0022] The application defines the maximum displacement of the hydraulic motor, and can accurately adjust the displacement of the hydraulic motor in the process of controlling the displacement of the hydraulic motor.

[0023] In a possible implementation, the method further includes:

[0024] If the target rotating speed changes in the range of (0, M), the displacement of the hydraulic motor is controlled to be always at the maximum displacement, and the displacement of the hydraulic pump is controlled to increase along with the increase of the target rotating speed.

[0025] The application sets different control conditions corresponding to the displacement of the hydraulic pump and the displacement of the hydraulic motor respectively when the target rotating speed changes in different ranges, to ensure the rotating speed requirement of the slewing platform in the starting process.

[0026] In a possible implementation, the method further includes:

[0027] The first pressure difference value of the inlet and outlet of the hydraulic pump is calculated in real time.

[0028] If the target rotating speed changes in the range of (0, M), the torque of the hydraulic pump is adjusted when the first pressure difference value is greater than a first threshold value; the first threshold value is the maximum pressure value of the load of the hydraulic pump.

[0029] The application monitors the pressure change of the inlet and outlet of the hydraulic pump in real time, and adjusts the torque of the hydraulic pump in time to avoid damage of the hydraulic pump device.

[0030] In a possible implementation, if the target rotating speed changes in the range of (0, M), the torque of the hydraulic pump is adjusted when the first pressure difference value is greater than the first threshold value, including:

[0031] When the first pressure difference value is greater than the first threshold value, the hydraulic pump at the current moment is controlled to reduce displacement, and the torque of the hydraulic pump is adjusted.

[0032] The application controls the displacement of the hydraulic pump, and adjusts the torque of the hydraulic pump in time to avoid damage to the hydraulic pump device. At the same time, by adjusting the displacement of the hydraulic pump, the highest pressure flow of the hydraulic pump can be suppressed, the overflow of the overflow valve is reduced, and the energy-saving effect is achieved.

[0033] In a possible implementation, the method further includes:

[0034] When the excavator is in the parking brake stage, the hydraulic pump is controlled to be in zero displacement, and the hydraulic motor is controlled to be in maximum displacement.

[0035] The application sets the displacement of the hydraulic pump and the displacement of the hydraulic motor when the excavator is in the parking brake stage, so that when the slewing platform of the excavator is started, the rotating speed demand of the slewing platform can be ensured by adjusting the displacement of the hydraulic pump and the displacement of the hydraulic motor.

[0036] In a second aspect, the embodiments of the application provide an excavator, including: a motor, a hydraulic pump, a hydraulic motor and a slewing platform, the hydraulic pump is connected with the motor and the hydraulic motor respectively, the hydraulic motor is further connected with the slewing platform, and the motor is used to drive the slewing platform through the hydraulic pump and the hydraulic motor when the motor is used to execute any one of the embodiments of the first aspect.

[0037] In a third aspect, the embodiments of the application provide a control device of a slewing platform of an excavator, and the device includes:

[0038] An acquisition module is configured to acquire a handle input signal of the slewing platform in real time, and determine a target rotating speed of the slewing platform based on the handle input signal.

[0039] A first control module is configured to control a hydraulic pump in the excavator to be always in maximum displacement, and control a displacement of a hydraulic motor in the excavator to decrease along with an increase of the target rotating speed if the target rotating speed changes in the range of (M, N); wherein the M is determined according to the maximum displacement of the hydraulic motor, and the N is determined according to a maximum rotating speed of the slewing platform.

[0040] In a possible implementation, the device further includes:

[0041] a first calculation module, configured to calculate a first pressure difference value of an inlet and an outlet of the hydraulic pump and a second pressure difference value of an inlet and an outlet of the hydraulic motor in real time;

[0042] a first adjustment module, configured to, if the target rotating speed changes in the range (M, N), adjust the torque of the hydraulic pump when the first pressure difference value is greater than a first threshold value, and adjust the torque of the hydraulic motor when the second pressure difference value is greater than a second threshold value; the first threshold value is a maximum pressure value of the hydraulic pump load, and the second threshold value is a maximum pressure value of the hydraulic motor load.

[0043] In a possible implementation, the first adjustment module is specifically configured to:

[0044] when the first pressure difference value is greater than the first threshold value, control the hydraulic pump at the current moment to reduce displacement and adjust the torque of the hydraulic pump.

[0045] In a possible implementation, the first adjustment module is specifically configured to:

[0046] when the second pressure difference value is greater than the second threshold value, control the hydraulic motor at the current moment to increase displacement and adjust the torque of the hydraulic motor.

[0047] In a possible implementation, the maximum displacement of the hydraulic motor is obtained by:

[0048] determining the maximum displacement of the hydraulic pump according to a preset maximum power of the slewing platform;

[0049] determining the maximum displacement of the hydraulic motor when the hydraulic pump is at the maximum displacement and the hydraulic motor is at the maximum torque.

[0050] In a possible implementation, the device further includes:

[0051] a second control module, configured to, if the target rotating speed changes in the range (0, M), control the hydraulic motor to be always at the maximum displacement, and control the displacement of the hydraulic pump to increase along with the increase of the target rotating speed.

[0052] In a possible implementation, the device further includes:

[0053] a second calculation module, configured to calculate a first pressure difference value of an inlet and an outlet of the hydraulic pump in real time;

[0054] a second adjustment module, configured to, if the target rotating speed changes in the range (0, M), adjust the torque of the hydraulic pump when the first pressure difference value is greater than a first threshold value; the first threshold value is a maximum pressure value of the hydraulic pump load.

[0055] In a possible implementation, if the target rotating speed changes in the range of (0, M), the second adjusting module is specifically configured to:

[0056] When the first pressure difference is greater than the first threshold, the hydraulic pump at the current moment is controlled to reduce displacement, and the torque of the hydraulic pump is adjusted.

[0057] In a possible implementation, the device further comprises:

[0058] When the excavator is in the parking brake stage, the hydraulic pump is controlled to be in zero displacement, and the hydraulic motor is controlled to be in maximum displacement.

[0059] In a fourth aspect, an electronic device is provided, which comprises at least a processor and a memory, and the processor is configured to execute a computer program stored in the memory to implement the control method of the excavator swing platform according to any one of the preceding aspects.

[0060] In a fifth aspect, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the control method of the excavator swing platform according to any one of the preceding aspects.

[0061] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0063] Figure 1 The internal structure diagram of the excavator provided by the embodiments of the present application is shown in the figure;

[0064] Figure 2 The flowchart of the relationship between the current 1, the current 2 and the rotating platform rotating speed provided by an embodiment of the present application is shown in the figure;

[0065] Figure 3 The device structure diagram of the excavator provided by an embodiment of the present application is shown in the figure;

[0066] Figure 4 The device structure diagram of the excavator provided by an embodiment of the present application is shown in the figure;

[0067] Figure 5A device structure schematic diagram of the excavator provided by an embodiment of the present application is shown in the figure;

[0068] Figure 6 A control method flowchart of the excavator slewing platform provided by an embodiment of the present application is shown in the figure;

[0069] Figure 7 A control device structure schematic diagram of the excavator slewing platform provided by an embodiment of the present application is shown in the figure;

[0070] The figure shows the following components: 1-motor, 2-hydraulic pump, 3-oil supplement one-way valve, 4-safety overflow valve, 5-oil supplement pressure-limiting overflow valve, 6-oil supplement pump, 7-hydraulic oil tank, 8-hydraulic pump controller, 9-hydraulic motor, 10-flushing valve, 11-flushing overflow valve, 12-hydraulic motor controller, 13-hydraulic motor reducer, 14-slewing platform, 15-hydraulic hose, 16-hydraulic pump set, 17-hydraulic motor set, 18-high-pressure pressure sensor. DETAILED DESCRIPTION

[0071] In order to make the ordinary person skilled in the art better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings.

[0072] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0073] At present, the slewing system of the excavator includes open system and closed system. In the open system, the oil flows in sequence through the oil tank-hydraulic pump-hydraulic motor-oil tank, so the oil tank needs to be connected to the external device through the valve port, which will cause throttling loss at the valve port position. In the closed system, the oil flows in sequence through the hydraulic pump-hydraulic motor-hydraulic pump, and no valve port needs to be set for connection with the external device, avoiding throttling loss at the valve port position, so the closed system is usually used to control the slewing platform of the excavator.

[0074] Traditional closed-loop systems typically configure the hydraulic motor's displacement based on the slewing platform's maximum speed when controlling its rotation, resulting in a relatively small displacement. Furthermore, due to the flow restriction imposed by the relief valve, a pressure cutoff method is required to prevent the hydraulic motor from reaching its maximum torque. However, using a pressure cutoff method to control the hydraulic motor's torque results in a lower maximum loadable pressure than that of an open-loop system. Consequently, when starting the excavator's slewing platform, acceleration is slow, and the slewing platform's speed falls short of the required speed.

[0075] To this end, the present application provides a control method for an excavator slewing platform and an excavator, by defining the speed M according to the maximum displacement of the hydraulic motor and defining the speed N according to the maximum speed of the slewing platform, and then when the target speed varies within the range of (M, N), by setting different control conditions corresponding to the displacement of the hydraulic pump and the displacement of the hydraulic motor, the speed requirement of the slewing platform during the startup process is guaranteed.

[0076] After introducing the design concept of the embodiment of the present application, the following is a detailed description of this in conjunction with the accompanying drawings and specific implementation methods. Although the embodiment of the present application provides the method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on routine or no creative work. In steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided in the embodiment of the present application.

[0077] like Figure 1 As shown, an embodiment of the present application provides a schematic diagram of the internal structure of an excavator, the excavator including: a motor 1, a hydraulic pump 2, a hydraulic motor 9 and a rotary platform 14, the hydraulic pump 2 is connected to the motor 1 and the hydraulic motor 9 respectively, and the hydraulic motor 9 is also connected to the rotary platform 14.

[0078] Optionally, when the excavator is in operation, to prevent the hydraulic pump 2 from exceeding the pressure limit due to the hydraulic pump 2 being at its maximum displacement under high pressure, the excavator may further include a safety relief valve 4 and an oil-supply pressure-limiting relief valve 5. The safety relief valve 4 is used to monitor the flow rate of the oil circuit in the excavator in real time, and the oil-supply pressure-limiting relief valve 5 is used to monitor the pressure of the oil circuit in the excavator in real time.

[0079] In order to ensure that there is sufficient oil in the excavator during the oil flow process, the excavator can also include: an oil replenishing one-way valve 3 and an oil replenishing pump 6, the oil replenishing pump 6 is used to deliver oil to the hydraulic pump 2, and the oil replenishing one-way valve 3 is used to control the oil delivery direction.

[0080] In order to solve the problem of heat dissipation of the hydraulic motor 9 in the working state of the excavator, the excavator can also include a flushing valve 10 and a flushing overflow valve 11. The flushing valve 10 is used to control whether the hydraulic motor 9 is flushed, and the flushing overflow valve 11 is used to control the pressure limiting of the oil flowing out of the hydraulic motor 9.

[0081] In the running state of the excavator, the handle input signal of the slewing platform 14 is obtained in real time, and the target rotating speed of the slewing platform 14 is determined based on the handle input signal. Then the motor 1 drives the hydraulic pump set 16 at a fixed rotating speed, and the hydraulic pump set 16 generates oil through the swash plate angle of the hydraulic pump 2. The oil is transmitted to the hydraulic motor set 17 through the upper side of the hydraulic hose 15. The hydraulic motor set 17 transmits the output of the hydraulic motor 9 to the motor reducer 13, and then to the slewing platform 14. At the same time, the oil flowing out of the hydraulic motor 9 is transmitted to the hydraulic pump set 16 through the lower side of the hydraulic hose 15, and the oil is absorbed by the hydraulic pump 2 in the hydraulic pump set 16.

[0082] When the hydraulic motor 9 is in a high pressure state, the high pressure oil will drive the flushing valve 10 to start working, thereby generating a small amount of oil flow, and the oil flow is limited by the flushing overflow valve 11 and flows out to the hydraulic oil tank 7 for heat dissipation. The oil on the other side of the hydraulic oil tank 7 can be supplemented by the oil supplementing pump 6, limited by the oil supplementing pressure limiting overflow valve 5, and transmitted to the oil suction side of the hydraulic pump 2 through the oil supplementing check valve 3 to prevent the oil suction side of the hydraulic pump 2 from being empty.

[0083] The hydraulic pump controller 8 can control the displacement of the hydraulic pump 2, and the hydraulic motor controller 12 can control the displacement of the hydraulic motor 9. The high pressure sensor 18 can send a pressure signal to the hydraulic pump 2 and the hydraulic motor 9 to adjust the torque.

[0084] Here, the hydraulic pump set 16 includes the hydraulic pump 2, the oil supplementing check valve 3, the safety overflow valve 4, the oil supplementing pressure limiting overflow valve 5 and the high pressure sensor 18. The hydraulic motor set 17 includes the hydraulic motor 9, the flushing valve 10, the flushing overflow valve 11 and the high pressure sensor 18. The motor 1 can also be a diesel engine or other device with a power source. It should be noted that, Figure 1 The connection relationship of each device of the excavator is only an example and can be adjusted according to actual conditions.

[0085] Next, the control method of the excavator slewing platform is introduced from controlling the displacement of the hydraulic pump, controlling the displacement of the hydraulic motor, adjusting the torque of the hydraulic pump and adjusting the torque of the hydraulic motor respectively:

[0086] I. Control the displacement of the hydraulic pump and the displacement of the hydraulic motor

[0087] When the excavator is in the parking brake phase, the hydraulic pump 2 is controlled to zero displacement, while the hydraulic motor 9 is controlled to maximum displacement. The parking brake is then released, and during the startup phase, the handle input signal of the slewing platform 14 is acquired in real time, and the target speed of the slewing platform 14 is determined based on the handle input signal.

[0088] The maximum displacement of the hydraulic pump 2 can then be determined based on the preset maximum power of the slewing platform 14. When the hydraulic pump 2 is at its maximum displacement and the hydraulic motor 9 is at its maximum torque, the maximum displacement of the hydraulic motor 9 can be determined. For example, in addition to the preset maximum power of the slewing platform 14, the maximum displacement of the hydraulic pump 2 can also be calculated in conjunction with the speed parameters of the motor 1. The maximum torque of the hydraulic motor 9 is determined based on the maximum acceleration of the hydraulic motor 9, which is pre-set based on the excavator's requirements. Furthermore, when the hydraulic pump 2 is at its maximum displacement and the slewing platform 14 is at its maximum speed, the minimum displacement of the hydraulic motor 9 can be determined.

[0089] like Figure 2 As shown, when the hydraulic motor 9 is at maximum displacement, the maximum speed of the hydraulic motor 9 is M, N is the maximum rotational speed of the rotary platform 14, and N is greater than M. Figure 2 The figure shows the change process of the current 1 of the hydraulic pump 2 controlled by the hydraulic pump controller 8, the change process of the current 2 of the hydraulic motor 9 controlled by the hydraulic motor controller 12, and the change process of the rotation speed of the rotary platform 14. Figure 2 The changes of current 1, current 2 and the rotation speed of the rotary platform 14 are only shown for reference. The slope of each change can be adjusted according to actual conditions.

[0090] After determining the target speed of the slewing platform 14, if the target speed changes within the range (0, M), the swash plate angle of the hydraulic motor 9 is controlled to remain at its maximum slew rate, while the swash plate angle of the hydraulic pump 2 is controlled to increase as the target speed increases. In other words, the hydraulic motor 9 is controlled to maintain its maximum displacement, while the displacement of the hydraulic pump 2 is controlled to increase as the target speed increases.

[0091] If the target speed changes within the range (M, N), the swash plate angle of hydraulic pump 2 is controlled to remain at its maximum swivel position, while the swash plate angle of hydraulic motor 9 is controlled to decrease as the target speed increases. This means that hydraulic pump 2 is controlled to maintain its maximum displacement, while the displacement of hydraulic motor 9 is controlled to decrease as the target speed increases. Once the target speed reaches the maximum speed N, the slewing platform 14 can continue operating at the maximum speed N.

[0092] 2. Adjust the torque of the hydraulic pump and adjust the torque of the hydraulic motor

[0093] Considering that the oil return port pressure of the hydraulic motor 9 will increase when the slewing platform 14 is braked, the inlet pressure of the hydraulic motor 9 is set as the main control torque when the slewing platform 14 is started, and the outlet pressure of the hydraulic motor 9 is set as the main control torque when the slewing platform 14 is braked.

[0094] During the adjustment of the displacement of the hydraulic pump 2 and the adjustment of the displacement of the hydraulic motor 9, the input pressure signal of the inlet of the hydraulic pump 2, the output pressure signal of the outlet of the hydraulic pump 2, the input pressure signal of the inlet of the hydraulic motor 9, and the output pressure signal of the outlet of the hydraulic motor 9 can be obtained in real time through the high-pressure pressure sensor 18. Then, based on the input pressure signal of the inlet of the hydraulic pump 2 and the output pressure signal of the outlet of the hydraulic pump 2, the first pressure difference value of the hydraulic pump 2 is determined; and based on the input pressure signal of the inlet of the hydraulic motor 9 and the output pressure signal of the outlet of the hydraulic motor 9, the second pressure difference value of the hydraulic motor 9 is determined.

[0095] If the target rotating speed changes in the range of (0, M), the torque of the hydraulic pump 2 is adjusted when the first pressure difference value is greater than the first threshold value. If the target rotating speed changes in the range of (M, N), the torque of the hydraulic pump 2 is adjusted when the first pressure difference value is greater than the first threshold value, and the torque of the hydraulic motor 9 is adjusted when the second pressure difference value is greater than the second threshold value.

[0096] Here, the first threshold value is the maximum pressure value of the load of the hydraulic pump 2, and the second threshold value is the maximum pressure value of the load of the hydraulic motor 9.

[0097] Optionally, when the first pressure difference value is greater than the first threshold value, the displacement of the hydraulic pump 2 at the current moment is controlled to decrease, and the torque of the hydraulic pump 2 is adjusted. When the second pressure difference value is greater than the second threshold value, the displacement of the hydraulic motor 9 at the current moment is controlled to increase, and the torque of the hydraulic motor 9 is adjusted.

[0098] During the control of the increase of the displacement of the hydraulic pump 2, if the torque of the hydraulic pump 2 needs to be adjusted, the swing angle value of the swash plate angle of the hydraulic pump 2 is reduced. During the control of the decrease of the displacement of the hydraulic pump 2, if the torque of the hydraulic pump 2 needs to be adjusted, the swing angle value of the swash plate angle of the hydraulic pump 2 is increased. Similarly, during the control of the increase of the displacement of the hydraulic motor 9, if the torque of the hydraulic motor 9 needs to be adjusted, the swing angle value of the swash plate angle of the hydraulic motor 9 is reduced. During the control of the decrease of the displacement of the hydraulic motor 9, if the torque of the hydraulic motor 9 needs to be adjusted, the swing angle value of the swash plate angle of the hydraulic motor 9 is increased.

[0099] By adjusting the torque of the hydraulic pump 2 and adjusting the torque of the hydraulic motor 9, the balance of the slewing platform 14 in the two performance indexes of the starting braking acceleration and the maximum speed can be achieved.

[0100] When the slewing platform 14 is adjusted from the working state to the stop working state, the hydraulic motor 9 is dragged into the working condition of the hydraulic pump 2 due to the rotational kinetic energy of the slewing platform 14, and the hydraulic pump 2 drives the motor 1 to be dragged, at this time, the power of the reverse dragging can be calculated according to the inlet and outlet pressures of the hydraulic pump 2, and the oil injection of the motor 1 is reduced to avoid the motor 1 from appearing the runaway phenomenon, thereby the kinetic energy of the slewing brake can be effectively utilized to achieve the energy-saving effect.

[0101] In one possible embodiment, Figure 1 The system in which the slewing platform of the excavator is shown is a closed slewing system, and the excavator can be a hydraulic excavator of more than 50 tons. Figure 3 Another structure schematic diagram of an excavator is shown, wherein the excavator comprises a motor 301, a hydraulic pump 302, a hydraulic motor 303, a hydraulic motor 304, a motor reducer 305, a motor reducer 306 and a slewing platform 307. The hydraulic pump 302 is connected with the motor 301, the hydraulic motor 303 and the hydraulic motor 304 respectively, the motor reducer 305 is further connected with the hydraulic motor 303 and the slewing platform 307 respectively, and the motor reducer 306 is further connected with the hydraulic motor 304 and the slewing platform 307 respectively.

[0102] Here, the excavator can also comprise Figure 1 The oil supplementing check valve 3, the safety overflow valve 4, the oil supplementing pressure limiting overflow valve 5, the oil supplementing pump 6, the hydraulic oil tank 7, the hydraulic pump controller 8, the flushing valve 10, the flushing overflow valve 11, the hydraulic motor controller 12, the hydraulic hose 15 and the high-pressure pressure sensor 18 in the above-mentioned embodiment are not limited to the specific connection relationship between the above-mentioned devices, and the number of each device is not limited, which can be adjusted according to the actual situation.

[0103] Figure 4 Another structure schematic diagram of an excavator is shown, wherein the excavator comprises a motor 401, a drive transfer case 402, a hydraulic pump 403, a hydraulic pump 404, a hydraulic motor 405, a hydraulic motor 406, a motor reducer 407, a motor reducer 408 and a slewing platform 409. The drive transfer case 402 is connected with the motor 401, the hydraulic pump 403 and the hydraulic pump 404 respectively, the hydraulic motor 405 is connected with the hydraulic pump 403 and the motor reducer 407 respectively, the hydraulic motor 406 is connected with the hydraulic pump 404 and the motor reducer 408 respectively, the motor reducer 407 is further connected with the slewing platform 409, and the motor reducer 408 is further connected with the slewing platform 409.

[0104] Similarly, the excavator can also comprise Figure 1The oil supplementing check valve 3, the safety overflow valve 4, the oil supplementing pressure limiting overflow valve 5, the oil supplementing pump 6, the hydraulic oil tank 7, the hydraulic pump controller 8, the flushing valve 10, the flushing overflow valve 11, the hydraulic motor controller 12, the hydraulic hose 15 and the high pressure sensor 18 are not limited in the specific connection relationship between the above devices, and the number of each device is not limited, and can be adjusted according to the actual situation.

[0105] Figure 5 Another structure diagram of the excavator is shown, wherein the excavator comprises a motor 501, a motor 502, a hydraulic pump 503, a hydraulic pump 504, a hydraulic motor 505, a hydraulic motor 506, a motor reducer 507, a motor reducer 508 and a slewing platform 509. The hydraulic pump 503 is connected with the motor 501 and the hydraulic motor 505 respectively, the hydraulic pump 504 is connected with the motor 502 and the hydraulic motor 506 respectively, the motor reducer 507 is connected with the hydraulic motor 505 and the slewing platform 509 respectively, and the motor reducer 508 is connected with the hydraulic motor 506 and the slewing platform 509 respectively.

[0106] Similarly, the excavator can also comprise Figure 1 The oil supplementing check valve 3, the safety overflow valve 4, the oil supplementing pressure limiting overflow valve 5, the oil supplementing pump 6, the hydraulic oil tank 7, the hydraulic pump controller 8, the flushing valve 10, the flushing overflow valve 11, the hydraulic motor controller 12, the hydraulic hose 15 and the high pressure sensor 18 are not limited in the specific connection relationship between the above devices, and the number of each device is not limited, and can be adjusted according to the actual situation.

[0107] In summary, the present application defines the rotation speed M according to the maximum displacement of the hydraulic motor, defines the rotation speed N according to the maximum rotation speed of the slewing platform, and then sets different control conditions corresponding to the displacement of the hydraulic pump and the displacement of the hydraulic motor when the target rotation speed changes in the range of (M, N), so as to ensure the rotation speed demand of the slewing platform during the starting process. By adjusting the torque of the hydraulic pump and the torque of the hydraulic motor, the balance of the slewing platform in the starting braking acceleration and the maximum speed performance indicators can be realized.

[0108] In an embodiment of the present application, as shown in Figure 6 The control method of the slewing platform of the excavator provided by the embodiment of the present application comprises the following steps:

[0109] S601, acquiring a handle input signal of the slewing platform in real time, and determining a target rotation speed of the slewing platform based on the handle input signal;

[0110] S602, if the target rotating speed changes in the range (M, N), control the hydraulic pump in the excavator to be always at the maximum displacement, and control the displacement of the hydraulic motor in the excavator to decrease along with the increase of the target rotating speed; wherein M is determined according to the maximum displacement of the hydraulic motor, and N is determined according to the maximum rotating speed of the rotating platform.

[0111] In an embodiment of the present application, as shown in Figure 7 The control device of the rotating platform of the excavator provided by the embodiment of the present application comprises:

[0112] The acquisition module 701 is configured to acquire the handle input signal of the rotating platform in real time, and determine the target rotating speed of the rotating platform based on the handle input signal.

[0113] The first control module 702 is configured to, if the target rotating speed changes in the range (M, N), control the hydraulic pump in the excavator to be always at the maximum displacement, and control the displacement of the hydraulic motor in the excavator to decrease along with the increase of the target rotating speed; wherein M is determined according to the maximum displacement of the hydraulic motor, and N is determined according to the maximum rotating speed of the rotating platform.

[0114] In a possible implementation, the device further comprises:

[0115] The first calculation module is configured to calculate the first pressure difference value of the inlet and outlet of the hydraulic pump and the second pressure difference value of the inlet and outlet of the hydraulic motor in real time.

[0116] The first adjustment module is configured to, if the target rotating speed changes in the range (M, N), adjust the torque of the hydraulic pump when the first pressure difference value is greater than a first threshold value, and adjust the torque of the hydraulic motor when the second pressure difference value is greater than a second threshold value; the first threshold value is the maximum pressure value of the load of the hydraulic pump, and the second threshold value is the maximum pressure value of the load of the hydraulic motor.

[0117] In a possible implementation, the first adjustment module is specifically configured to:

[0118] When the first pressure difference value is greater than the first threshold value, control the hydraulic pump at the current time to decrease the displacement and adjust the torque of the hydraulic pump.

[0119] In a possible implementation, the first adjustment module is specifically configured to:

[0120] When the second pressure difference value is greater than the second threshold value, control the hydraulic motor at the current time to increase the displacement and adjust the torque of the hydraulic motor.

[0121] In a possible implementation, the maximum displacement of the hydraulic motor is obtained in the following manner:

[0122] The maximum displacement of the hydraulic pump is determined according to the preset maximum power of the rotating platform.

[0123] determining the maximum displacement of the hydraulic motor when the hydraulic pump is at the maximum displacement and the hydraulic motor is at the maximum torque.

[0124] In a possible implementation, the device further comprises:

[0125] the second control module is configured to control the hydraulic motor to be at the maximum displacement and control the displacement of the hydraulic pump to increase with the target rotating speed when the target rotating speed changes in the range of (0, M).

[0126] In a possible implementation, the device further comprises:

[0127] the second calculation module is configured to calculate the first pressure difference between the inlet and the outlet of the hydraulic pump in real time.

[0128] the second adjustment module is configured to adjust the torque of the hydraulic pump when the first pressure difference is greater than a first threshold value when the target rotating speed changes in the range of (0, M), the first threshold value being the maximum pressure value of the hydraulic pump load.

[0129] In a possible implementation, when the target rotating speed changes in the range of (0, M), the second adjustment module is specifically configured to:

[0130] control the hydraulic pump to reduce the displacement and adjust the torque of the hydraulic pump when the first pressure difference is greater than the first threshold value.

[0131] In a possible implementation, the device further comprises:

[0132] controlling the hydraulic pump to be at zero displacement and the hydraulic motor to be at the maximum displacement when the excavator is in the parking brake phase.

[0133] Although the preferred embodiments of the present application have been described, those skilled in the art who understand the basic inventive concept can make further changes and modifications to the embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0134] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A control method of a swing platform of a shovel, characterized by, The method comprises: Real-time acquisition of the handle input signal of the slewing platform, and determination of a target rotating speed of the slewing platform based on the handle input signal; Real-time calculation of a first pressure difference value of the inlet and outlet of the hydraulic pump and a second pressure difference value of the inlet and outlet of the hydraulic motor; If the target rotating speed changes within the range (M, N), the hydraulic pump in the excavator is controlled to be always at maximum displacement, and the displacement of the hydraulic motor in the excavator is controlled to decrease along with the increase of the target rotating speed; wherein the M is determined according to the maximum displacement of the hydraulic motor, and the N is determined according to the maximum rotating speed of the slewing platform; when the first pressure difference value is greater than a first threshold value, the displacement of the hydraulic pump at the current time is controlled to decrease, and the torque of the hydraulic pump is adjusted; when the second pressure difference value is greater than a second threshold value, the displacement of the hydraulic motor at the current time is controlled to increase, and the torque of the hydraulic motor is adjusted; the first threshold value is the maximum pressure value of the load of the hydraulic pump, and the second threshold value is the maximum pressure value of the load of the hydraulic motor.

2. The method of claim 1, wherein, The maximum displacement of the hydraulic motor is obtained in the following manner: The maximum displacement of the hydraulic pump is determined according to the preset maximum power of the slewing platform; The maximum displacement of the hydraulic motor is determined when the hydraulic pump is at maximum displacement and the hydraulic motor is at maximum torque.

3. The method of claim 1, wherein, The method further comprises: If the target rotating speed changes within the range (0, M), the hydraulic motor is controlled to be always at maximum displacement, and the displacement of the hydraulic pump is controlled to increase along with the increase of the target rotating speed.

4. The method of claim 3, wherein, The method further comprises: Real-time calculation of a first pressure difference value of the inlet and outlet of the hydraulic pump; If the target rotating speed changes within the range (0, M), the torque of the hydraulic pump is adjusted when the first pressure difference value is greater than a first threshold value; the first threshold value is the maximum pressure value of the load of the hydraulic pump.

5. The method of claim 4, wherein, If the target rotating speed changes within the range (0, M), the torque of the hydraulic pump is adjusted when the first pressure difference value is greater than a first threshold value, which comprises: When the first pressure difference value is greater than a first threshold value, the displacement of the hydraulic pump at the current time is controlled to decrease, and the torque of the hydraulic pump is adjusted.

6. The method according to any one of claims 1 to 5, characterized in that, The method further comprises: When the excavator is in the parking brake stage, the hydraulic pump is controlled to be at zero displacement, and the hydraulic motor is controlled to be at maximum displacement.

7. An excavator characterized by comprising: It comprises: A motor, a hydraulic pump, a hydraulic motor and a slewing platform, the hydraulic pump is connected with the motor and the hydraulic motor respectively, the hydraulic motor is further connected with the slewing platform, and the motor is used to drive the slewing platform through the hydraulic pump and the hydraulic motor when the method in any one of claims 1-6 is executed.

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