Hybrid drive slewing control system, control method and crane

Abstract

The application discloses a kind of hybrid drive rotary control systems, including control unit, hydraulic motor and rotary motor, the hydraulic motor and rotary motor are connected with rotary support respectively by two rotary speed reducers, the control unit is used to control hydraulic motor and rotary motor individual drive rotary support or control hydraulic motor and rotary motor proportional output power drive rotary support.By the hybrid drive of hydraulic motor and rotary motor, it solves the problem that the starting characteristic of hydraulic rotary system is not good and the load fluctuation resistance of motor rotary system is poor, improves the starting and stopping control characteristics and process motion stability of rotary system, and improves the product control level.

Description

TECHNICAL FIELD

[0001] The present application relates to a slewing system of a wheel crane, in particular to a hybrid drive slewing control system, a control method and a crane. BACKGROUND

[0002] The slewing system is a key operation function of the wheel crane, which can drive the superstructure operation system to rotate 360°. The traditional crane slewing system generally adopts a hydraulic drive form, i.e. a hydraulic pump drives a hydraulic motor, which is engaged with a slewing bearing through a speed reducer to realize slewing action. Due to the large hysteresis response characteristics of the slewing hydraulic system and the hysteresis loop of the slewing valve control, the slewing system is relatively difficult to control in starting and stopping, and the control characteristics are generally poor. In addition to the hydraulic drive form, in recent years, a system form of motor drive has also appeared, i.e. an electric motor drives a speed reducer to engage with a slewing support to drive slewing action. The motor slewing has the advantages of large starting torque and high control linearity, and has better start-stop control characteristics than the hydraulic drive slewing system, but the anti-load fluctuation capability is relatively poor. When the slewing load fluctuates due to factors such as deformation of the superstructure, swing inertia of the hoisted load, etc., the slewing motion speed fluctuates and is not smooth.

[0003] In the prior art, for example, a kind of electric drive hybrid power transmission crane with application number CN202310037358.0, discloses a kind of electric drive hybrid power transmission crane, provides the power source of hydraulic system by high-voltage battery, converts electric energy into hydraulic energy, drives hydraulic actuator to realize the action of superstructure, chassis hydraulic system, has the advantages of fast response, high execution efficiency, good controllability, high control precision etc. It drives the motor to further drive the actuator such as motor, and the actuator is still hydraulic element.

[0004] For example, application number CN201310131844.5 discloses a kind of hybrid power slewing drive system and engineering machinery, which converts the mechanical energy of slewing platform into electric energy, and then into hydraulic energy and stores in accumulator by first electric energy conversion unit, second electric energy conversion unit and hydraulic energy conversion unit, to realize the function of energy recovery. Application number CN201310694773.X discloses a kind of electric-hydraulic hybrid power device, excavator and method, which drives generator / pump motor to make hydraulic oil to accumulator when slewing under light load or braking, and drives pump motor / motor in accumulator under heavy load, to convert the recoverable electric energy into hydraulic energy and save and use, to realize energy recovery. Both of them convert mechanical energy, electric energy and hydraulic energy by energy conversion module to realize energy recovery and utilization, but the direct drive element of slewing is still hydraulic motor.

[0005] For example, the application number CN202021241017.3 discloses a rotary drive mechanism of excavator, which belongs to the field of hybrid excavator rotary mechanism. The rotary motor / generator replaces the hydraulic motor form, completes the rotary energy recovery of the excavator, reduces energy consumption, and saves cost. Its drive mechanism is still motor-driven. SUMMARY

[0006] The application aims to solve the above problems. The application provides a hybrid drive rotary control system, a control method and a crane for improving the start-stop control characteristics and process motion stability of a rotary system.

[0007] The application also provides a control method for the hybrid drive rotary control system and a crane using the hybrid drive rotary control system.

[0008] Technical scheme: To solve the above problems, the application adopts a hybrid drive rotary control system, which includes a control unit, a hydraulic motor and a rotary motor. The hydraulic motor and the rotary motor are connected to the rotary bearing through two rotary reducers respectively. The control unit is used to control the hydraulic motor and the rotary motor to drive the rotary bearing individually or to control the hydraulic motor and the rotary motor to drive the rotary bearing according to the power output ratio.

[0009] Further, the hydraulic motor is powered by a hydraulic oil pump. A free rotation valve is arranged between the hydraulic oil pump and the hydraulic motor. The opening of the free rotation valve is adjusted to realize the conduction or cut-off of the hydraulic motor oil supply circuit. The rotary motor is powered by a battery. The rotary motor has a motor floating control function to realize the switching between free rotation and normal work of the rotary motor.

[0010] Further, the input end of the rotary reducer connected to the rotary motor is connected with a rotary brake. The rotary brake brakes or unlocks the rotary reducer.

[0011] Further, the input end of the rotary reducer connected to the hydraulic motor is connected with a rotary brake. The rotary brake brakes or unlocks the rotary reducer.

[0012] Further, the input end of the two rotary reducers connected to the rotary motor and the hydraulic motor respectively is connected with a rotary brake. The rotary brake brakes or unlocks the rotary reducer.

[0013] Further, the application also includes an operation unit and a detection unit. The operation unit is used to send operation instructions to the control unit. The detection unit is used to obtain the working parameters of the hydraulic motor and the working parameters of the rotary motor.

[0014] The application also adopts a hybrid drive rotary control method. The control method in the starting stage includes the following steps:

[0015] (1) receiving a start operation instruction;

[0016] (2) starting the rotary motor according to the start operation instruction, and starting the rotary system through the rotary motor;

[0017] (3) receiving a control operation instruction, starting the hydraulic motor according to the control operation instruction, and controlling the power distribution ratio of the hydraulic motor and the rotary motor according to the rotary load size, so as to gradually increase the power output of the hydraulic motor while reducing the power output of the rotary motor;

[0018] (4) according to the control operation instruction, the hydraulic motor completely drives the rotary system, and the rotary motor enters a floating state and no longer provides power for the rotary system.

[0019] Further, the control method for decelerating to the stop stage comprises the following steps:

[0020] (1) receiving a deceleration operation instruction;

[0021] (2) starting the rotary motor according to the deceleration operation instruction, and controlling the power distribution ratio of the hydraulic motor and the rotary motor, so as to gradually reduce the power output of the hydraulic motor while increasing the power output of the rotary motor;

[0022] (3) according to the deceleration operation instruction, the rotary motor completely drives the rotary system, and the hydraulic motor no longer provides power for the rotary system;

[0023] (4) according to the stop operation instruction, slowly closing the rotary motor.

[0024] The application also adopts a crane, which adopts the above-mentioned hybrid drive rotary control system.

[0025] Advantages: Compared with the prior art, the application has the remarkable advantages that through the hybrid drive of the hydraulic motor and the rotary motor, the problems of poor start-up characteristics of the hydraulic rotary system and poor load fluctuation resistance of the motor rotary system are solved, the start-stop control characteristics and process motion stability of the rotary system are improved, and the product control level is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a composition schematic diagram of the hybrid drive rotary control system in the application.

[0027] Figure 2 is a control timing diagram of the rotary system in the application.

[0028] Figure 3 is a control flowchart of the rotary system in the application. DETAILED DESCRIPTION

[0029] Example 1

[0030] As Figure 1 shown, a hybrid drive rotary control system in this embodiment includes a hydraulic rotary actuator, a motor rotary actuator, and a hybrid drive control device.

[0031] (1) Hydraulic rotary actuator

[0032] It includes a hydraulic oil pump 1, a hydraulic motor 2, a rotary reducer 3, and a free rotary valve 4. The hydraulic oil pump is connected to the hydraulic motor to provide power; the hydraulic motor is connected to the rotary reducer, and the output shaft of the rotary reducer is provided with a gear connected to the rotary bearing 5; the free rotary valve has the function of reverse proportional adjustment opening, and the off state is on and the maximum current state is off. By adjusting the opening of the valve, the oil circuit at both ends of the hydraulic motor is gradually connected or cut off, realizing the function of switching between free rotation and normal work of the motor. The hydraulic rotary system can also use a positive proportional control free rotary valve, and the control method can be adjusted accordingly.

[0033] (2) Motor rotary actuator

[0034] It includes a battery 6, a rotary motor 7, a rotary reducer 8, and a rotary brake 9. The battery is connected to the rotary motor to provide power; the rotary motor is connected to the rotary reducer, and the output shaft of the rotary reducer is provided with a gear connected to the rotary bearing 5; the rotary brake is connected to the input end of the rotary reducer, which can brake or unlock the rotation of the reducer; the rotary motor has the function of motor floating control, which can realize the function of smooth switching between free rotation and normal work of the motor.

[0035] (3) Hybrid drive control device

[0036] It includes an operation unit 10, a control unit 11, and a detection unit 12. The operation unit is connected to the control unit to provide rotary control intent information; the detection unit can obtain hydraulic motor pressure information and motor torque, power, etc. Signals, and is connected to the control unit to provide rotary load state information to the control unit; the control unit is also connected to the hydraulic oil pump, the free rotary valve, the rotary motor and other execution components, which can control the hydraulic rotary actuator and the motor rotary actuator to work independently or cooperatively according to the control intent and the rotary load state.

[0037] The motor rotary system is provided with a rotary brake, while the hydraulic rotary system is not provided with a rotary brake. A brake can also be provided in the hydraulic rotary system while the motor rotary system is not provided with a brake, or both systems are provided with a brake.

[0038] Example 2

[0039] The hybrid drive rotary control method in the embodiment controls the rotary system by taking advantage of hydraulic drive and motor drive respectively, and the control mode is divided into three types: motor rotary mode, hydraulic rotary mode and hybrid drive rotary mode.

[0040] (1) Motor rotary mode: In this mode, the rotary brake connected with the rotary reducer of the rotary motor is opened, the rotary motor normally outputs, and the hydraulic pump and the free rotary valve have no output.

[0041] (2) Hydraulic rotary mode: In this mode, the rotary brake connected with the rotary reducer of the hydraulic motor is opened, the hydraulic pump and the free rotary valve normally output, and the rotary motor is floating controlled. The motor floating control means that the motor is freely rotated in both directions and does not generate driving force.

[0042] (3) Hybrid drive mode: In this mode, the rotary brake is opened, the rotary motor has output with the hydraulic pump and the free rotary valve, and power distribution of the two modes is performed according to the rotary load size.

[0043] The control timing diagram is as shown in Figure 2 , s1 is an operation instruction signal, s2 / s4 is a motor control signal, and s3 is a hydraulic pump control signal. The motor rotary mode is mainly used in the rotary start stage (t1) and the stop stage (t5), the hydraulic rotary mode is mainly used in the large load and high speed rotary stage (t3), and the hybrid drive mode is mainly used in the process speed regulation stage (t2, t4).

[0044] Taking a typical control method as an example, the control method between different modes is specifically explained according to different operation stages. The control flow chart is as shown in Figure 3 :

[0045] (1) Start stage

[0046] After the control unit receives the start operation instruction issued by the operation unit, the rotary brake is opened, the rotary motor is started, and the rotary motor is started through the motor rotary system; at this time, the hydraulic pump and the free rotary valve have no control output.

[0047] (2) Motion stage

[0048] During the continuous increase of the operation instruction, the detection unit monitors the motor load and the hydraulic motor load in real time, increases the control output of the free rotary valve and the hydraulic pump, gradually increases the power output of the hydraulic rotary system, so that the hydraulic rotary system gradually participates in the rotary system work, and at the same time, the control output of the rotary motor is reduced, so that the power output of the motor rotary system is gradually reduced, and the power distribution ratio of the two systems is controlled according to the rotary load size. The two systems enter the hybrid drive state.

[0049] (3) Hydraulic independent control stage

[0050] When the operation instruction reaches a certain value or the load reaches a certain value, the free rotation valve control value reaches the maximum, the valve opening is completely closed, the hydraulic rotation system completely participates in the rotation system work, and the motor enters a floating state and no longer provides power for the rotation system, and the system enters a hydraulic rotation independent work state.

[0051] (4) deceleration stage

[0052] After the control unit receives the deceleration operation instruction issued by the operation unit, the free rotation valve and the hydraulic oil pump control output are reduced, the hydraulic rotation system power output is gradually reduced, the rotation motor control output is increased, the motor rotation power output proportion is increased, and the system power mode is switched to the motor rotation system mode.

[0053] (5) stop stage

[0054] After the control unit receives the stop operation instruction issued by the operation unit, the hydraulic oil pump and the free rotation valve control output are closed, the rotation motor is slowly closed, and after the rotation is completely stopped, the rotation brake is closed.

[0055] The control process disclosed in the application is only one of the cases, and different power modes can be selected for the rotation system control according to different scenes.

[0056] The application also provides a crane applying the above-mentioned hybrid drive rotation control system, solves the problems of poor hydraulic rotation system starting characteristics and poor motor rotation system load fluctuation resistance, and improves the product control level.

Claims

1. A hybrid drive slewing control method applied to a slewing system of a crane, characterized in that, The control method of the starting stage comprises the following steps: (1) receiving a starting operation instruction; (2) starting the rotary motor according to the starting operation instruction, and starting the rotary system through the rotary motor; (3) receiving a control operation instruction, starting the hydraulic motor according to the control operation instruction, and controlling the power distribution ratio of the hydraulic motor and the rotary motor according to the rotary load size, gradually increasing the power output of the hydraulic motor while reducing the power output of the rotary motor; (4) according to the control operation instruction, the hydraulic motor completely drives the rotary system, and the rotary motor enters a floating state and no longer provides power for the rotary system; The control method of the deceleration to stop stage comprises the following steps: (1) receiving a deceleration operation instruction; (2) starting the rotary motor according to the deceleration operation instruction, and controlling the power distribution ratio of the hydraulic motor and the rotary motor, gradually reducing the power output of the hydraulic motor while increasing the power output of the rotary motor; (3) according to the deceleration operation instruction, the rotary motor completely drives the rotary system, and the hydraulic motor no longer provides power for the rotary system; (4) according to a stop operation instruction, slowly turning off the rotary motor.

2. A hybrid drive slewing control system employing the control method according to claim 1, characterized by The control unit (11), the hydraulic motor (2) and the rotary motor (7) are connected to the rotary support (5) through two rotary reducers, respectively, and the control unit (11) is used to control the hydraulic motor (2) and the rotary motor (7) to drive the rotary support (5) individually or to control the hydraulic motor (2) and the rotary motor (7) to drive the rotary support (5) in proportion.

3. The hybrid drive swing control system according to claim 2, characterized by The hydraulic motor (2) is powered by the hydraulic oil pump (1), and a free rotation valve (4) is arranged between the hydraulic oil pump (1) and the hydraulic motor (2), and the opening of the free rotation valve (4) is adjusted to realize the conduction or cut-off of the hydraulic motor oil supply circuit.

4. The hybrid drive swing control system according to claim 2, characterized by The rotary motor (7) is powered by the battery (6), and the rotary motor (7) has a motor floating control function to realize the switching between free rotation and normal work of the rotary motor.

5. The hybrid drive swing control system according to claim 2, characterized by The input end of the rotary reducer connected with the rotary motor (7) is connected with a rotary brake (9), and the rotary brake (9) brakes or unlocks the rotary reducer.

6. The hybrid drive swing control system according to claim 2, characterized by The input end of the rotary reducer connected with the hydraulic motor (2) is connected with a rotary brake, and the rotary brake brakes or unlocks the rotary reducer.

7. The hybrid drive swing control system according to claim 2, characterized by The input end of the two rotary reducers connected with the rotary motor (7) and the hydraulic motor (2), respectively, is connected with a rotary brake, and the rotary brake brakes or unlocks the rotary reducer.

8. The hybrid drive swing control system according to claim 2, characterized by It also includes an operation unit (10) and a detection unit (12), the operation unit is used to send operation instructions to the control unit, and the detection unit is used to obtain hydraulic motor working parameters and rotary motor working parameters.

9. A crane, characterized in that The hybrid drive rotary control system of any one of claims 2 to 8 is adopted.

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