A multi-hydraulic cylinder synchronous drive system

Abstract

This invention discloses a multi-hydraulic cylinder synchronous drive system, relating to the field of hydraulic transmission. The system includes: multiple four-cavity hydraulic cylinders, multiple distributed pump control units, a valve-controlled drive circuit, a signal source, a controller, and multiple displacement sensors. The displacement sensors are used to detect the position information of the corresponding four-cavity hydraulic cylinders. The signal source is used to generate displacement command signals for each four-cavity hydraulic cylinder and transmit the displacement command signals of each four-cavity hydraulic cylinder to the controller. The controller is used to receive the position information of each four-cavity hydraulic cylinder, and based on the displacement command signals and position information of each four-cavity hydraulic cylinder, control the running speed and displacement of the corresponding four-cavity hydraulic cylinder through the distributed pump control units. The valve-controlled drive circuit drives the external load on the four-cavity hydraulic cylinders, realizing the synchronous operation of the four-cavity hydraulic cylinders and improving the energy efficiency and controllability of the multi-hydraulic cylinder synchronous system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hydraulic transmission, in particular to a multi-hydraulic cylinder synchronous driving system. BACKGROUND

[0002] Heavy equipment has complex structure, large inertia and huge load, and often needs to be driven by multiple actuators simultaneously, such as the erecting device of large-scale hoisting machinery, the lifting device of offshore drilling platform, and the jacking device of hoisting construction platform.

[0003] The existing multi-cylinder synchronous driving system is divided into mechanical passive synchronization and electro-hydraulic active synchronization. The mechanical passive synchronization ensures the synchronous operation of the system by rigidly connecting two or more hydraulic cylinders together, but it is difficult to ensure the control accuracy due to external interference factors. The active synchronization scheme of valve-controlled hydraulic cylinder using electro-hydraulic control valve and displacement sensor adopts centralized power supply, and realizes the synchronization position accuracy of the hydraulic cylinder by adjusting the valve opening. There is a great throttling loss in the whole process, and the overall energy efficiency is low. The closed pump control system changes the pressure and flow of the system by directly adjusting the variable pump / motor, eliminating the throttling loss in the valve control system and improving the system energy efficiency. For example, the Chinese patent with publication number CN109779992A discloses a new variable speed pump control direct drive multi-hydraulic cylinder synchronous control system, which uses a motor to adjust the variable pump to directly drive the hydraulic cylinder. Although this system reduces the throttling loss in the circuit, it needs to add energy storage devices such as accumulators in each actuator circuit to improve the system response speed, resulting in a complex system and increasing the system installed power and cost.

[0004] Based on the above problems, a new multi-hydraulic cylinder synchronous driving system and control method are needed to realize high energy efficiency and precise synchronization control of multi-cylinder. SUMMARY

[0005] The purpose of the present application is to provide a multi-hydraulic cylinder synchronous driving system, which can reduce the system installed power and throttling loss, and improve the energy efficiency and controllability of the multi-hydraulic cylinder synchronous system.

[0006] To achieve the above purpose, the present application provides the following solutions:

[0007] A multi-hydraulic cylinder synchronous driving system comprises: a plurality of four-cavity hydraulic cylinders, a plurality of distributed pump control units, a valve control driving circuit, a signal source, a controller and a plurality of displacement sensors;

[0008] The number of the distributed pump control units, the displacement sensors and the four-cavity hydraulic cylinders is consistent;

[0009] The distributed pump control units are connected one by one with the B cavity and the C cavity of the four-cavity hydraulic cylinders;

[0010] The valve control drive circuit is connected with the A cavity and the D cavity of the four-cavity hydraulic cylinder;

[0011] The displacement sensor is connected with the four-cavity hydraulic cylinder one by one, and is used for detecting position information of the corresponding four-cavity hydraulic cylinder.

[0012] The signal source is connected with the controller, and is used for generating a displacement instruction signal for each four-cavity hydraulic cylinder and transmitting the displacement instruction signal of each four-cavity hydraulic cylinder to the controller.

[0013] The controller is also connected with the control end of the valve control drive circuit, the control end of the plurality of distributed pump control units and the plurality of displacement sensors, and is used for:

[0014] Receiving position information of each four-cavity hydraulic cylinder;

[0015] Controlling the running speed and displacement of the corresponding four-cavity hydraulic cylinder through the distributed pump control unit based on the displacement instruction signal and the position information of each four-cavity hydraulic cylinder;

[0016] Driving the external load of the four-cavity hydraulic cylinder through the valve control drive circuit to realize the synchronous operation of the four-cavity hydraulic cylinder.

[0017] The application discloses a multi-hydraulic cylinder synchronous driving system, which comprises a plurality of four-cavity hydraulic cylinders, a plurality of distributed pump control units, a valve control drive circuit, a signal source, a controller and a plurality of displacement sensors. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0019] Figure 1The first schematic view of the multi-hydraulic cylinder synchronous driving system provided by the present application;

[0020] Figure 2 The second schematic view of the multi-hydraulic cylinder synchronous driving system provided by the present application;

[0021] Figure 3 The third schematic view of the multi-hydraulic cylinder synchronous driving system provided by the present application.

[0022] Symbol explanation:

[0023] Load mechanism - 1, first four-chamber hydraulic cylinder - 2-1, second four-chamber hydraulic cylinder - 2-2, first overflow valve - 3, second overflow valve - 4, first oil supplementing check valve - 5, second oil supplementing check valve - 6, first electric motor - 7, first motor - 8, first accumulator - 9, first three-position four-way proportional valve - 10, second three-position four-way proportional valve - 11, second electric motor - 12, second motor - 13, first oil tank - 14, third overflow valve - 15, signal source - 16, controller - 17, first displacement sensor - 18, second displacement sensor - 19, first proportional throttle valve - 20, second proportional throttle valve - 21, third proportional throttle valve - 22, fourth proportional throttle valve - 23, fifth proportional throttle valve - 24, sixth proportional throttle valve - 25, seventh proportional throttle valve - 26, eighth proportional throttle valve - 27, first pressure sensor - 28, second pressure sensor - 29, third pressure sensor - 30, fourth pressure sensor - 31, first three-position four-way control valve - 32, second three-position four-way control valve - 33, bypass proportional valve - 34, second accumulator - 35, shuttle valve - 36, second oil tank - 37, third oil tank - 38, third electric motor - 39, third motor - 40, fourth electric motor - 41, fourth motor - 42, fourth overflow valve - 43, fifth overflow valve - 44, first distributed pump control unit - 100-1, second distributed pump control unit - 100-2, valve control driving circuit - 200. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0025] The purpose of the present application is to provide a multi-hydraulic cylinder synchronous driving system, which can reduce system installed power and throttling loss, and improve energy efficiency and controllability of the multi-hydraulic cylinder synchronous system.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Example 1

[0028] like Figure 1 As shown, a multi-hydraulic cylinder synchronous drive system in this embodiment includes: multiple four-chamber hydraulic cylinders, multiple distributed pump control units, valve-controlled drive circuit 200, signal source 16, controller 17, and multiple displacement sensors.

[0029] All of the four-cavity hydraulic cylinders are connected to the load mechanism 1; the number of the distributed pump control unit, the displacement sensor, and the four-cavity hydraulic cylinders are the same.

[0030] The distributed pump control unit is connected one-to-one with chambers B and C of the four-chamber hydraulic cylinder.

[0031] The valve-controlled drive circuit 200 is connected to chambers A and D of the four-chamber hydraulic cylinder.

[0032] The displacement sensors are connected one-to-one with the four-chamber hydraulic cylinders.

[0033] The signal source 16 is connected to the controller 17 and is used to generate displacement command signals for each four-chamber hydraulic cylinder and transmit the displacement command signals of each four-chamber hydraulic cylinder to the controller 17.

[0034] The controller 17 is also connected to the control terminal of the valve-controlled drive circuit, the control terminals of the multiple distributed pump control units, and the multiple displacement sensors, respectively, for: receiving the position information of each four-cavity hydraulic cylinder; controlling the running speed and displacement of the corresponding four-cavity hydraulic cylinder through the distributed pump control unit based on the displacement command signal and position information of each four-cavity hydraulic cylinder; and driving the external load on the four-cavity hydraulic cylinder through the valve-controlled drive circuit to achieve synchronous operation of the four-cavity hydraulic cylinder.

[0035] The distributed pump control unit includes: a first electric motor 7, a first motor 8, a first replenishing check valve 5, a second replenishing check valve 6, a first overflow valve 3, a second overflow valve 4, and a first accumulator 9; the first motor 8 is a bidirectional variable motor or a bidirectional variable pump motor.

[0036] The first motor 7 is connected with the motor to transmit power; two cavities of the first motor 8 are respectively communicated with B cavity and C cavity of the four-cavity hydraulic cylinder; control ends of the first motor 7 and the first motor 8 are connected with the controller 17; oil outlets of the first oil supplementing check valve 5 and the second oil supplementing check valve 6 are respectively communicated with two cavities of the motor, and oil inlets of the first oil supplementing check valve 5 and the second oil supplementing check valve 6 are communicated with the first accumulator 9; oil inlets of the first overflow valve 3 and the second overflow valve 4 are respectively communicated with two cavities of the motor, and oil outlets of the first overflow valve 3 and the second overflow valve 4 are communicated with the first accumulator 9; when pressures of B cavity and C cavity of the four-cavity hydraulic cylinder are lower than pressure of the first accumulator 9, the first accumulator 9 supplements oil for the four-cavity hydraulic cylinder through the first oil supplementing check valve 5 or the second oil supplementing check valve 6, so as to prevent air suction phenomenon of the hydraulic cylinder oil cavity.

[0037] As an embodiment, the valve control drive circuit 200 comprises: a plurality of three-position four-way proportional valves, a second motor 12, a second motor 13, a first oil tank 14 and a third overflow valve 15; the second motor 13 is a hydraulic pump motor or a hydraulic motor.

[0038] The number of the three-position four-way proportional valves is consistent with the number of the four-cavity hydraulic cylinder.

[0039] The second motor 12 is connected with the second motor 13 to obtain power; an oil inlet of the second motor 13 is connected with the first oil tank 14; an oil inlet of the third overflow valve 15 is connected with an oil outlet of the second motor 13, and an oil outlet of the third overflow valve 15 is connected with the first oil tank 14; two cavities of the three-position four-way proportional valve are respectively connected with A cavity and D cavity of the four-cavity hydraulic cylinder in one-to-one correspondence, oil inlets of a plurality of the three-position four-way proportional valves are connected with the oil outlet of the second motor 13, and oil return ports of a plurality of the three-position four-way proportional valves are connected with the first oil tank 14; control ends of a plurality of the three-position four-way proportional valves, the second motor 12 and the second motor 13 are connected with the controller 17.

[0040] As Figure 1As shown, the multi-cylinder synchronous driving system in this embodiment includes a first four-cylinder hydraulic cylinder 2-1, a second four-cylinder hydraulic cylinder 2-2, a first distributed pump control unit 100-1, a second distributed pump control unit 100-2, a valve control driving circuit 200, a signal source 16, a controller 17, a first displacement sensor 18, and a second displacement sensor 19. The B and C chambers of the first four-cylinder hydraulic cylinder 2-1 and the second four-cylinder hydraulic cylinder 2-2 are connected to the first distributed pump control unit 100-1 and the second distributed pump control unit 100-2, respectively, and the A and D chambers of the first four-cylinder hydraulic cylinder 2-1 and the second four-cylinder hydraulic cylinder 2-2 are connected to the valve control driving circuit 200. The first displacement sensor 18 and the second displacement sensor 19 are connected to the first four-cylinder hydraulic cylinder 4-1 and the first four-cylinder hydraulic cylinder 4-2, respectively, to collect position information of the hydraulic cylinders. The signal source 16 is connected to the controller 17, and the controller 17 is connected to the first distributed control unit 100-1, the second distributed control unit 100-2, and the valve control driving circuit to control the operation of the hydraulic synchronous driving system.

[0041] The first distributed pump control unit 100-1 and the second distributed pump control unit 100-2 have the same connection mode.

[0042] Taking the first distributed pump control unit 100-1 as an example, the first distributed pump control unit 100-1 includes a first motor 7, a first motor 8, a first oil supplement check valve 5, a second oil supplement check valve 6, a first overflow valve 3, a second overflow valve 4, and a first accumulator 9.

[0043] The first motor 7 is connected to the first motor 8 to transmit power. The two chambers of the first motor 8 are in communication with the B and C chambers of the first four-cylinder hydraulic cylinder 2-1. The forward and reverse rotation of the first motor 7 controls the extension and retraction of the first four-cylinder hydraulic cylinder 2-1, and the first motor 8 controls the movement speed of the first four-cylinder hydraulic cylinder 2-1 by adjusting the swash plate angle.

[0044] The oil outlets of the first oil supplement check valve 5 and the second oil supplement check valve 6 are in communication with the two chambers of the first motor 8, the oil inlets of the first oil supplement check valve 5 and the second oil supplement check valve 6 are in communication with the first accumulator 9, the oil inlets of the first overflow valve 3 and the second overflow valve 4 are in communication with the two chambers of the first motor 8, and the oil outlets of the first overflow valve 3 and the second overflow valve 4 are in communication with the first accumulator 9. When the pressure of the two chambers of the first four-cylinder hydraulic cylinder 2-1 is lower than the pressure of the first accumulator 9, the first accumulator 9 supplements oil to the first four-cylinder hydraulic cylinder 2-1 through the first oil supplement check valve 5 or the second oil supplement check valve 6 to prevent the first four-cylinder hydraulic cylinder 2-1 from being vacuumed.

[0045] The valve control driving circuit 200 includes a second motor 12, a second motor 13, a first oil tank 14, a third overflow valve 15, a first three-position four-way proportional valve 10, and a second three-position four-way proportional valve 11.

[0046] The second motor 12 is connected with the second motor 13, and the oil inlet of the second motor 12 is connected with the first oil tank 14 and the oil outlet of the third overflow valve. The oil inlet of the third overflow valve 15 is connected with the oil outlet of the second motor 13. The working oil port A of the first three-position four-way proportional valve 10 and the working oil port A of the second three-position four-way proportional valve 11 are respectively connected with the A cavity of the first four-cavity hydraulic cylinder 2-1 and the A cavity of the second four-cavity hydraulic cylinder 2-2. The working oil port B of the first three-position four-way proportional valve 10 and the working oil port B of the second three-position four-way proportional valve 11 are respectively connected with the D cavity of the first four-cavity hydraulic cylinder 2-1 and the D cavity of the second four-cavity hydraulic cylinder 2-2. The oil inlet of the first three-position four-way proportional valve 10 and the oil inlet of the second three-position four-way proportional valve 11 are connected with the oil outlet of the second motor 13. The oil return port of the first three-position four-way proportional valve 10 and the oil inlet of the second three-position four-way proportional valve 11 are connected with the oil return port of the second motor 13. The output flow of the second motor 13 drives the first four-cavity hydraulic cylinder 2-1 and the second four-cavity hydraulic cylinder 2-2 through the first three-position four-way proportional valve 10 and the second three-position four-way proportional valve 11. Since the valve-controlled drive circuit is only used to match the load borne by the actuator and is not used to adjust the position of the actuator, the opening of the control valve is as large as possible, and the throttling loss is reduced.

[0047] As an embodiment, as shown in Figure 2 The valve-controlled drive circuit 200 includes a third motor 39, a third motor 40, a second oil tank 37, a fourth overflow valve 43, and a plurality of proportional throttle valve groups. The third motor 40 is a hydraulic pump motor or a hydraulic motor.

[0048] The number of proportional throttle valve groups is consistent with the number of four-cavity hydraulic cylinders.

[0049] The third motor 39 is connected with the third motor 40 to obtain power. The oil inlet of the third motor 40 is connected with the second oil tank 37. The oil inlet of the fourth overflow valve 43 is connected with the oil outlet of the third motor 40, and the oil outlet of the fourth overflow valve 43 is connected with the second oil tank 37. Two cavities of the proportional throttle valve group are connected with the A cavity and the D cavity of the four-cavity hydraulic cylinder one by one. The oil inlet of the proportional throttle valve group is in communication with the oil outlet of the third motor 40, and the oil outlet of the proportional throttle valve group is connected with the second oil tank 37. The control ends of the third motor 39 and the third motor 40 are connected with the controller 17.

[0050] The proportional throttle valve group includes a first proportional throttle valve 20, a second proportional throttle valve 21, a third proportional throttle valve 22, and a fourth proportional throttle valve 23.

[0051] The outlet of the first proportional throttle valve 20 and the inlet of the second proportional throttle valve 21 are connected to the D chamber of the four-chamber hydraulic cylinder. The outlet of the third proportional throttle valve 22 and the inlet of the fourth proportional throttle valve 23 are connected to the A chamber of the four-chamber hydraulic cylinder. The inlet of the first proportional throttle valve 20 and the inlet of the third proportional throttle valve 22 are connected to the outlet of the third motor 40. The outlets of the second proportional throttle valve 21 and the fourth proportional throttle valve 23 are connected to the second oil tank 37. The control terminals of the first proportional throttle valve 20, the second proportional throttle valve 21, the third proportional throttle valve 22, and the fourth proportional throttle valve 23 are all connected to the controller 17.

[0052] The multi-hydraulic cylinder synchronous drive system in this embodiment has the same structure and working principle as... Figure 1 The system is identical except that the first three-position four-way proportional valve 10 and the second three-position four-way proportional valve 11 in the valve-controlled drive circuit are replaced with the first proportional throttle valve 20, the second proportional throttle valve 21, the third proportional throttle valve 22, the fourth proportional throttle valve 23, the fifth proportional throttle valve 24, the sixth proportional throttle valve 25, the seventh proportional throttle valve 26, and the eighth proportional throttle valve 27. Figure 2 As shown. The connection method is as follows: the oil outlet of the first proportional throttle valve 20 and the oil inlet of the second proportional throttle valve 21 are connected to chamber D of the first four-chamber hydraulic cylinder 2-1; the oil outlet of the third proportional throttle valve 22 and the oil inlet of the fourth proportional throttle valve 23 are connected to chamber A of the first four-chamber hydraulic cylinder 2-1; the oil outlet of the fifth proportional throttle valve 24 and the oil inlet of the sixth proportional throttle valve 25 are connected to chamber D of the second four-chamber hydraulic cylinder 2-2; and the oil outlet of the seventh proportional throttle valve 26... The inlet of the eighth proportional throttle valve 27 is connected to chamber A of the second four-chamber hydraulic cylinder 2-2; the inlets of the first proportional throttle valve 20, the third proportional throttle valve 22, the fifth proportional throttle valve 24, and the seventh proportional throttle valve 26 are connected to the outlet of the third motor 40; and the outlets of the second proportional throttle valve 21, the fourth proportional throttle valve 23, the sixth proportional throttle valve 25, and the eighth proportional throttle valve 27 are connected to the second oil tank 37. By using independent proportional valves to control the pressure and flow of the inlet and outlet of the four-chamber hydraulic cylinder, the efficiency of the synchronization system and the motion performance of the hydraulic cylinder can be further improved.

[0053] As one example, such as Figure 3 As shown, the valve-controlled drive circuit 200 includes: a fourth motor 41, a fourth motor 42, a third oil tank 38, a fifth relief valve 44, multiple three-position four-way control valves, a bypass proportional valve 34, a shuttle valve 36, multiple pressure sensor groups, and a second accumulator 35; the fourth motor 42 is a hydraulic pump motor or a hydraulic motor.

[0054] The number of the three-position four-way control valves and the number of the pressure sensor groups are consistent with the number of the four-cavity hydraulic cylinders.

[0055] The fourth motor 42 is connected with the fourth electric motor 41 to obtain power, an oil suction port of the fourth motor 42 is communicated with the third oil tank 38; an oil outlet port of the fourth motor 42 is communicated with an oil inlet port of the fifth overflow valve 44, an oil outlet port of the fifth overflow valve 44 is communicated with the third oil tank 38; the working oil ports A and B of the three-position four-way control valve are connected with the D cavity and the A cavity of the four-cavity hydraulic cylinder respectively, an oil inlet port of the three-position four-way control valve is communicated with the outlet of the fourth motor 42, an oil outlet port of the three-position four-way control valve is communicated with the third oil tank 38; the pressure sensor groups are connected with the A cavity and the D cavity of the four-cavity hydraulic cylinder respectively, for detecting the pressure values of the A cavity and the D cavity of the four-cavity hydraulic cylinder; the load ends of the multiple three-position four-way control valves are communicated with the shuttle valve 36, the shuttle valve 36 is used for detecting the highest load pressure of the four-cavity hydraulic cylinder; the first working oil port of the bypass proportional valve 34 is communicated with the third oil tank 38; the second working oil port of the bypass proportional valve 34 is communicated with the second accumulator 35; the third working oil port of the bypass proportional valve 34 is communicated with the oil outlet port of the fourth motor 42; the spring end of the bypass proportional valve 34 is connected with the shuttle valve 36, the spring end of the bypass proportional valve 34 is used for detecting the maximum load feedback pressure of the four-cavity hydraulic cylinder; the pressure detection end of the bypass proportional valve 34 is communicated with the oil outlet port of the fourth motor 42, the pressure detection end of the bypass proportional valve 34 is used for detecting the outlet pressure of the hydraulic pump motor.

[0056] The valve control drive circuit 200 comprises a pressure sensor group comprising a first pressure sensor 28 and a second pressure sensor 29.

[0057] The first pressure sensor 28 is connected with the D cavity of the four-cavity hydraulic cylinder, for detecting the D cavity pressure value of the four-cavity hydraulic cylinder; the second pressure sensor 29 is connected with the A cavity of the four-cavity hydraulic cylinder, for detecting the A cavity pressure value of the four-cavity hydraulic cylinder.

[0058] The multi-hydraulic cylinder synchronous drive system structure and working principle in the embodiment are consistent with those of the multi-hydraulic cylinder synchronous drive system structure and working principle Figure 1 The first three-position four-way proportional valve 10 and the second three-position four-way proportional valve 11 in the valve control drive circuit are replaced by the first three-position four-way control valve 32 and the second three-position four-way control valve 33 with load pressure feedback function, and further, the shuttle valve 17, the first pressure sensor 28, the second pressure sensor 29, the third pressure sensor 30, the fourth pressure sensor 31, the bypass proportional valve 34 and the second accumulator 35 are added, as shown in Figure 3The working oil port A of the first three-position four-way control valve 32 is connected with the D cavity of the first four-cavity hydraulic cylinder 2-1, and the working oil port B of the first three-position four-way control valve 32 is connected with the A cavity of the first four-cavity hydraulic cylinder 2-1, the working oil port A of the second three-position four-way control valve 33 is connected with the D cavity of the second four-cavity hydraulic cylinder 2-2, and the working oil port B of the second three-position four-way control valve 33 is connected with the A cavity of the second four-cavity hydraulic cylinder 2-2, the oil inlet of the first three-position four-way control valve 32 and the oil inlet of the second three-position four-way control valve 33 are communicated with the outlet of the fourth motor 42, and the oil return port of the first three-position four-way control valve 32 and the oil return port of the second three-position four-way control valve 33 are communicated with the third oil tank 38.

[0059] The shuttle valve 36 is communicated with the load end of the control valve corresponding to each four-cavity hydraulic cylinder, and the shuttle valve 36 is used for detecting the highest load pressure of the four-cavity hydraulic cylinder.

[0060] The first pressure sensor 28 is connected with the D cavity of the first four-cavity hydraulic cylinder 2-1, the second pressure sensor 29 is connected with the A cavity of the first four-cavity hydraulic cylinder 2-1, the third pressure sensor 30 is connected with the D cavity of the second four-cavity hydraulic cylinder 2-2, and the fourth pressure sensor 31 is connected with the A cavity of the second four-cavity hydraulic cylinder 2-1.

[0061] The bypass proportional valve 34 is provided with a first working oil port D, a second working oil port E, a third working oil port F, a spring end and a pressure detection end; the first working oil port of the bypass proportional valve 34 is communicated with the third oil tank 38; the second working oil port of the bypass proportional valve 34 is communicated with the second accumulator 35; the third working oil port of the bypass proportional valve 34 is communicated with the oil outlet of the fourth motor 42; the spring end of the bypass proportional valve 34 is connected with the shuttle valve 36, and the spring end of the bypass proportional valve 34 is used for detecting the maximum load feedback pressure of each four-cavity hydraulic cylinder; the pressure detection end of the bypass proportional valve 34 is communicated with the oil outlet of the fourth motor 42, and the pressure detection end is used for detecting the outlet pressure of the fourth motor 42. The bypass proportional valve 34 is controlled by the outlet pressure of the fourth motor 42, the load feedback pressure and the spring force, so that the outlet pressure of the fourth motor 42 is always higher than the load pressure by a fixed value.

[0062] Embodiment 2

[0063] The application also provides a kind of multi-hydraulic cylinder synchronous drive system control method, a kind of multi-hydraulic cylinder synchronous drive system control method is applied to a kind of multi-hydraulic cylinder synchronous drive system, and multi-hydraulic cylinder synchronous drive system control method includes:

[0064] The controller controls the driving pressure in each four-cavity hydraulic cavity to balance the external load by controlling the motor speed, hydraulic pump motor displacement and each control valve spool displacement in the valve control drive circuit according to the signal source signal.

[0065] The position information of each four-cavity hydraulic cylinder is collected by the displacement sensor.

[0066] The controller controls the forward and reverse rotation of the motor in the distributed pump control unit to realize the extension and retraction of the four-cavity hydraulic cylinder according to the position information of each four-cavity cylinder, inputs a variable signal to the motor in the distributed pump control unit to control the movement speed of the hydraulic cylinder, and then realizes the precise closed-loop control of the position of the hydraulic cylinder.

[0067] The multi-hydraulic-cylinder synchronous driving control method further comprises:

[0068] By controlling the bypass proportional valve, the outlet pressure of the fourth motor is higher than the highest load pressure by a fixed value, and the opening of each joint control valve is maximized.

[0069] According to the flow matching principle, the required flow of each four-cavity hydraulic cylinder is calculated.

[0070] According to the required flow, the swash plate swing angle of the hydraulic pump motor is adjusted to control the output flow of the hydraulic pump motor to be consistent with the required flow.

[0071] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0072] The principles and implementation modes of the present application are described by using specific examples in this paper, and the above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A multi-cylinder synchronous drive system, characterized by, The system comprises a plurality of four-cavity hydraulic cylinders, a plurality of distributed pump control units, a valve control drive circuit, a signal source, a controller and a plurality of displacement sensors; The number of the distributed pump control units, the displacement sensors and the four-cavity hydraulic cylinders is consistent; The distributed pump control units are connected with the B cavity and the C cavity of the four-cavity hydraulic cylinders one by one; The valve control drive circuit is connected with the A cavity and the D cavity of the four-cavity hydraulic cylinders; The displacement sensors are connected with the four-cavity hydraulic cylinders one by one and are used for detecting position information of the corresponding four-cavity hydraulic cylinders; The signal source is connected with the controller and is used for generating displacement instruction signals of each four-cavity hydraulic cylinder and transmitting the displacement instruction signals of each four-cavity hydraulic cylinder to the controller; The controller is further connected with the control end of the valve control drive circuit, the control end of the plurality of distributed pump control units and the plurality of displacement sensors respectively and is used for: receiving position information of each four-cavity hydraulic cylinder; controlling the running speed and displacement of the corresponding four-cavity hydraulic cylinder through the distributed pump control unit based on the displacement instruction signal and the position information of each four-cavity hydraulic cylinder; controlling the external load of the four-cavity hydraulic cylinder through the valve control drive circuit to realize the synchronous operation of the four-cavity hydraulic cylinder; The distributed pump control unit comprises a first motor, a first motor, a first oil supplement check valve, a second oil supplement check valve, a first overflow valve, a second overflow valve and a first accumulator; the first motor is a bidirectional variable motor or a bidirectional variable pump motor; The first motor is connected with the first motor to transmit power; the two cavities of the first motor are communicated with the B cavity and the C cavity of the four-cavity hydraulic cylinder; the control end of the first motor and the first motor is connected with the controller; the oil outlet of the first oil supplement check valve and the second oil supplement check valve is communicated with the two cavities of the first motor, and the oil inlet of the first oil supplement check valve and the second oil supplement check valve is communicated with the first accumulator; the oil inlet of the first overflow valve and the second overflow valve is communicated with the two cavities of the first motor, and the oil outlet of the first overflow valve and the second overflow valve is communicated with the first accumulator; when the pressure of the B cavity and the C cavity of the four-cavity hydraulic cylinder is lower than the pressure of the first accumulator, the first accumulator supplements oil to the four-cavity hydraulic cylinder through the first oil supplement check valve or the second oil supplement check valve; The controller controls the forward and reverse rotation of the first motor in the distributed pump control unit according to the position information of each four-cavity hydraulic cylinder to realize the extension and retraction of the four-cavity hydraulic cylinder, inputs the variable signal of the first motor in the distributed pump control unit to control the movement speed of the four-cavity hydraulic cylinder, and then realizes the precise closed-loop control of the position of the four-cavity hydraulic cylinder; The controller controls the motor speed, the displacement of the hydraulic pump motor and the displacement of each control valve spool in the valve control drive circuit according to the signal source signal, and then controls the driving pressure in each four-cavity hydraulic cylinder to balance the external load. The valve control drive circuit comprises a plurality of three-position four-way proportional valves, a second motor, a second motor, a first oil tank and a third overflow valve; the second motor is a hydraulic pump motor or a hydraulic motor; 2. The multiple hydraulic cylinder synchronous drive system of claim 1, wherein, ​ The number of the three-position four-way proportional valves is consistent with the number of the four-cavity hydraulic cylinders; The second motor is connected with the second motor to obtain power; the oil inlet of the second motor is connected with the first oil tank; the oil inlet of the third overflow valve is connected with the oil outlet of the second motor, and the oil outlet of the third overflow valve is connected with the first oil tank; two cavities of the three-position four-way proportional valve are connected with A cavity and D cavity of the four-cavity hydraulic cylinder one by one, the oil inlets of multiple three-position four-way proportional valves are connected with the oil outlet of the second motor, and the oil return ports of multiple three-position four-way proportional valves are connected with the first oil tank; the control ends of multiple three-position four-way proportional valves, the second motor and the second motor are connected with the controller.

3. The multiple hydraulic cylinder synchronous drive system of claim 1, wherein, The valve control drive circuit comprises a third motor, a third motor, a second oil tank, a fourth overflow valve, and a plurality of proportional throttle valve groups; The number of the proportional throttle valve groups is consistent with the number of the four-cavity hydraulic cylinders; The third motor is connected with the third motor to obtain power; the oil inlet of the third motor is connected with the second oil tank; the oil inlet of the fourth overflow valve is connected with the oil outlet of the third motor, and the oil outlet of the fourth overflow valve is connected with the second oil tank; two cavities of the proportional throttle valve group are connected with A cavity and D cavity of the four-cavity hydraulic cylinder one by one, the oil inlets of the proportional throttle valve group are connected with the oil outlet of the third motor, and the oil outlets of the proportional throttle valve group are connected with the second oil tank; the control ends of multiple proportional throttle valve groups, the third motor and the third motor are connected with the controller.

4. The multiple hydraulic cylinder synchronous drive system of claim 3, wherein, The proportional throttle valve group comprises a first proportional throttle valve, a second proportional throttle valve, a third proportional throttle valve and a fourth proportional throttle valve; The oil outlet of the first proportional throttle valve, the oil inlet of the second proportional throttle valve and the D cavity of the four-cavity hydraulic cylinder are connected, the oil outlet of the third proportional throttle valve, the oil inlet of the fourth proportional throttle valve and the A cavity of the four-cavity hydraulic cylinder are connected, the oil inlet of the first proportional throttle valve and the oil inlet of the third proportional throttle valve are connected with the oil outlet of the third motor, the oil outlet of the second proportional throttle valve and the oil outlet of the fourth proportional throttle valve are connected with the second oil tank; the control ends of the first proportional throttle valve, the second proportional throttle valve, the third proportional throttle valve and the fourth proportional throttle valve are connected with the controller.

5. The multiple hydraulic cylinder synchronous drive system of claim 1, wherein, The valve control drive circuit comprises a fourth motor, a fourth motor, a third oil tank, a fifth overflow valve, a plurality of three-position four-way control valves, a bypass proportional valve, a shuttle valve, a plurality of pressure sensor groups and a second accumulator; the fourth motor is a hydraulic pump motor or a hydraulic motor; The number of the three-position four-way control valve is consistent with the number of the four-cavity hydraulic cylinder and the pressure sensor group; The fourth motor is connected with the fourth electric motor to obtain power, and an oil suction port of the fourth motor is communicated with the third oil tank; an oil outlet port of the fourth motor is communicated with an oil inlet port of a fifth overflow valve, and an oil outlet port of the fifth overflow valve is communicated with the third oil tank; working oil ports A and B of the three-position four-way control valve are connected with D cavity and A cavity of the four-cavity hydraulic cylinder respectively, an oil inlet port of the three-position four-way control valve is communicated with the outlet of the fourth motor, and an oil outlet port of the three-position four-way control valve is communicated with the third oil tank; a pressure sensor group is connected with A cavity and D cavity of the four-cavity hydraulic cylinder respectively, and is used for detecting pressure values of A cavity and D cavity of the four-cavity hydraulic cylinder; load ends of a plurality of three-position four-way control valves are communicated with the shuttle valve, and the shuttle valve is used for detecting the highest load pressure of the four-cavity hydraulic cylinder; a first working oil port of the bypass proportional valve is communicated with the third oil tank; a second working oil port of the bypass proportional valve is communicated with the second accumulator; a third working oil port of the bypass proportional valve is communicated with the oil outlet port of the fourth motor; a spring end of the bypass proportional valve is connected with the shuttle valve, and the spring end of the bypass proportional valve is used for detecting the maximum load feedback pressure of the four-cavity hydraulic cylinder; a pressure detection end of the bypass proportional valve is communicated with the oil outlet port of the fourth motor, and the pressure detection end of the bypass proportional valve is used for detecting the outlet pressure of the hydraulic pump motor.

6. The multiple hydraulic cylinder synchronous drive system of claim 5, wherein, The valve control drive circuit comprises a pressure sensor group comprising a first pressure sensor and a second pressure sensor; The first pressure sensor is connected with D cavity of the four-cavity hydraulic cylinder, and is used for detecting a D cavity pressure value of the four-cavity hydraulic cylinder; and the second pressure sensor is connected with A cavity of the four-cavity hydraulic cylinder, and is used for detecting an A cavity pressure value of the four-cavity hydraulic cylinder.

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