Energy-saving control system and excavator hydraulic control device

Abstract

The invention discloses an energy-saving control system and an excavator hydraulic control device, and relates to the technical field of hydraulic control, the energy-saving control system comprises an energy-saving motor, a differential regeneration valve, an energy-saving loop and / or a first reversing valve, the energy-saving motor is connected to the shaft end of a hydraulic pump set of the excavator hydraulic control system, and the differential regeneration valve is connected with the energy-saving loop. An oil outlet of the energy-saving motor is connected to an oil return channel through an unloading oil way, the differential regeneration valve is connected between a rodless cavity oil way and a rod cavity oil way of a movable arm oil cylinder assembly of the excavator hydraulic control system, the energy-saving loop is connected with the rodless cavity oil way of the movable arm oil cylinder assembly, and the energy-saving loop is provided with a flow extraction valve set, an oil collecting and releasing valve set and an energy accumulator. The oil collecting and discharging valve set is connected with an oil inlet of the energy-saving motor, and the first reversing valve is connected between an oil outlet of the energy-saving motor and an output oil way of a hydraulic pump set of the excavator hydraulic control system. The energy-saving control system solves the problems that an excavator hydraulic system is low in working efficiency, large in energy loss and high in temperature rise.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic control, and particularly relates to an energy-saving control system and an excavator hydraulic control device. Background Art

[0002] Currently, an excavator is usually supplied with oil to the hydraulic system by two variable pumps and one pilot fixed-displacement pump. The operation process of the excavator is divided into four stages: excavation, loading, unloading, and resetting.

[0003] In the related art, in the loading stage, in order to load the material onto the vehicle, the excavator needs to lift the working device to a certain height. In this process, in addition to doing positive work on the material, positive work is also done on the working device, causing the working device to accumulate a large amount of gravitational potential energy. Usually, this gravitational potential energy is directly lost through throttling in the hydraulic system when the working device descends. Therefore, during the operation of the excavator, a large amount of energy is lost through throttling in the hydraulic system when the working device descends. The lost energy often turns into heat loss and cannot be converted into useful work, which will lead to low working efficiency and large energy loss of the excavator hydraulic system, and cause the hydraulic system temperature to rise. Summary of the Invention

[0004] The purpose of the present application is to provide an energy-saving control system and an excavator hydraulic control device, which solve the problems of low working efficiency, large energy loss, and high temperature of the excavator hydraulic system.

[0005] To achieve the above purpose, the present application provides an energy-saving control system for an excavator hydraulic control system, including:

[0006] An energy-saving motor, which is used to be connected to the shaft end of the hydraulic pump group of the excavator hydraulic control system. The oil outlet of the energy-saving motor is connected to the return oil passage through a unloading oil circuit;

[0007] A differential regeneration valve, which is used to be connected between the rodless cavity oil circuit and the rod cavity oil circuit of the boom cylinder assembly of the excavator hydraulic control system;

[0008] An energy-saving circuit, which is used to be connected to the rodless cavity oil circuit of the boom cylinder assembly of the excavator hydraulic control system. The energy-saving circuit is provided with a flow extraction valve group, a charging and discharging valve group, and an accumulator, so that the hydraulic oil in the rodless cavity oil circuit of the boom cylinder assembly is controlled by the flow extraction valve group and flows into the accumulator through the charging and discharging valve group. The charging and discharging valve group is connected to the oil inlet of the energy-saving motor; and / or

[0009] A first reversing valve, which is used to be connected between the oil outlet of the energy-saving motor and the output oil circuit of the hydraulic pump group of the excavator hydraulic control system, so that the hydraulic oil output by the energy-saving motor flows to the output oil circuit of the hydraulic pump group.

[0010] In some embodiments, the flow extraction valve group includes a first flow extraction valve and a second flow extraction valve. The second flow extraction valve is located between the first flow extraction valve and the oil receiving and discharging valve group. The first pilot oil circuit of the second flow extraction valve is connected to the oil inlet of the first flow extraction valve, and the second pilot oil circuit of the second flow extraction valve is connected to the oil outlet of the first flow extraction valve, so as to maintain the pressure difference between the oil inlet and the oil outlet of the first flow extraction valve at a set value.

[0011] In some embodiments, the flow extraction valve group further includes a third flow extraction valve. The first pilot oil circuit of the third flow extraction valve is connected to the oil inlet of the first flow extraction valve, the second pilot oil circuit of the third flow extraction valve is connected to the oil outlet of the second flow extraction valve, and the third flow extraction valve is also connected to the oil return passage, so as to divert the hydraulic oil at the oil outlet of the second flow extraction valve to the oil return passage when the pressure difference between the oil inlet of the first flow extraction valve and the oil outlet of the second flow extraction valve meets a preset condition.

[0012] In some embodiments, the energy-saving control system further includes:

[0013] An electro-hydraulic proportional control valve for controlling the displacement of the energy-saving motor;

[0014] A first electro-hydraulic proportional pilot valve for controlling the operation of the differential regeneration valve;

[0015] A second electro-hydraulic proportional pilot valve for controlling the operation of the first flow extraction valve;

[0016] A controller communicatively connected to the electro-hydraulic proportional control valve, the first electro-hydraulic proportional pilot valve, and the second electro-hydraulic proportional pilot valve, for sending signals to the electro-hydraulic proportional control valve to control the displacement of the energy-saving motor, and also for sending signals to the first electro-hydraulic proportional pilot valve and the second electro-hydraulic proportional pilot valve to control the operations of the differential regeneration valve and the first flow extraction valve respectively.

[0017] In some embodiments, the energy-saving control system further includes a first pressure sensor and a second pressure sensor. The first pressure sensor and the second pressure sensor are respectively used to detect the pressures of the oil receiving and discharging valve group and the accumulator. The third flow extraction valve, the first pressure sensor, and the second pressure sensor are all communicatively connected to the controller. The controller is further used to control the operation of the third flow extraction valve according to the pressures detected by the first pressure sensor and the second pressure sensor, so as to divert the hydraulic oil at the oil outlet of the second flow extraction valve to the oil return passage.

[0018] In some embodiments, the energy-saving control system further includes a second reversing valve connected between the oil outlet of the energy-saving motor and the oil receiving and discharging valve group, so that the hydraulic oil output by the energy-saving motor flows through the oil receiving and discharging valve group to the accumulator.

[0019] In some embodiments, a third reversing valve is provided on the unloading oil path, and the energy-saving control system further includes a solenoid valve. The solenoid valve is connected to the third reversing valve to unload when the hydraulic oil pressure at the oil outlet of the energy-saving motor exceeds the threshold value by means of the third reversing valve and the solenoid valve.

[0020] In some embodiments, the energy-saving control system further includes a pressure relief valve connected in parallel with the third reversing valve.

[0021] In some embodiments, a check valve group is connected to the oil inlet of the energy-saving motor. The check valve group is connected to the oil return passage and the oil tank so that the oil inlet of the energy-saving motor sucks oil from the oil tank or the oil return passage through the check valve group.

[0022] The present application further provides an excavator hydraulic control device, which includes an excavator hydraulic control system. The excavator hydraulic control system includes a hydraulic pump group, a boom cylinder assembly, and a multi-way valve. The multi-way valve is connected to the output oil path of the hydraulic pump group, the rodless cavity oil path, and the rod cavity oil path of the boom cylinder assembly to control the action of the boom cylinder assembly. The energy-saving control system according to any one of the above is further included. The energy-saving motor of the energy-saving control system is connected to the shaft end of the hydraulic pump group of the excavator hydraulic control system. The differential regeneration valve of the energy-saving control system is connected between the rodless cavity oil path and the rod cavity oil path of the boom cylinder assembly of the excavator hydraulic control system. The energy-saving circuit of the energy-saving control system is connected to the rodless cavity oil path of the boom cylinder assembly. The first reversing valve of the energy-saving control system is connected between the oil outlet of the energy-saving motor and the output oil path of the hydraulic pump group.

[0023] Compared with the above background art, the energy-saving control system provided by the embodiments of the present application is used for an excavator hydraulic control system. The energy-saving control system includes an energy-saving motor, a differential regeneration valve, an energy-saving circuit, and / or a first reversing valve. Among them, the energy-saving motor is used to be connected to the shaft end of the hydraulic pump group of the excavator hydraulic control system. The oil outlet of the energy-saving motor is connected to the oil return passage through the unloading oil path. The differential regeneration valve is used to be connected between the rodless cavity oil path and the rod cavity oil path of the boom cylinder assembly of the excavator hydraulic control system. The energy-saving circuit is used to be connected to the rodless cavity oil path of the boom cylinder assembly of the excavator hydraulic control system. Further, the energy-saving circuit is provided with a flow extraction valve group, a charge and discharge valve group, and an accumulator so that the hydraulic oil in the rodless cavity oil path of the boom cylinder assembly is controlled by the flow extraction valve group and flows into the accumulator through the charge and discharge valve group. The charge and discharge valve group is connected to the oil inlet of the energy-saving motor. The first reversing valve is used to be connected between the oil outlet of the energy-saving motor and the output oil path of the hydraulic pump group of the excavator hydraulic control system so that the hydraulic oil output by the energy-saving motor flows to the output oil path of the hydraulic pump group.

[0024] In this way, when the excavator is in the energy-saving mode, the energy-saving motor, differential regeneration valve, flow extraction valve group, oil collection and release valve group, accumulator and / or the first reversing valve are opened. Specifically, when the operator operates the boom cylinder assembly of the excavator hydraulic control system to descend, the differential regeneration valve acts, and the rodless chamber and the rod chamber of the boom cylinder assembly are differentially connected. At this time, the rodless chamber and the rod chamber of the boom cylinder assembly are communicated. On the one hand, in the differential state of the boom cylinder assembly, the rodless chamber of the boom cylinder assembly supplies oil to the rod chamber. On the other hand, the excess high-pressure oil in the rodless chamber of the boom cylinder assembly enters the oil collection and release valve group through the flow extraction valve group and finally enters the accumulator, completing the energy recovery during the descent process of the boom cylinder assembly. When the excavator is in the energy release process, when the accumulator reaches the release condition, the accumulator releases the recovered high-pressure oil. The high-pressure oil enters the oil inlet of the energy-saving motor and flows to the oil return passage through the oil outlet of the energy-saving motor via the unloading oil circuit. During the operation of the energy-saving motor, the energy-saving motor provides torque assistance to the shaft end of the engine-hydraulic pump group of the excavator hydraulic control system to balance the engine load, reduce the engine output, and achieve energy saving; and / or, the high-pressure oil released by the accumulator enters the oil inlet of the energy-saving motor and supplies oil from the oil outlet of the energy-saving motor to the output oil circuit of the hydraulic pump group of the excavator hydraulic control system through the first reversing valve. In this way, by providing hydraulic energy to the excavator hydraulic control system, energy saving is achieved.

[0025] The beneficial effects of the energy-saving control system configured in this way mainly include: through the energy-saving control system provided by the embodiments of the present application, the excavator can work in the energy-saving mode for a long time, thereby maximizing the energy recovery and utilization of the boom cylinder assembly of the excavator hydraulic control system. For the recovered energy, it can be used to drive the energy-saving motor to reverse and output torque to the engine of the excavator hydraulic control system, or it can be directly used to supply oil to the excavator hydraulic control system, achieving the energy-saving effect throughout the process of the motor, so as to ensure that the recovered hydraulic energy is utilized to the greatest extent, thereby reducing the engine power output of the excavator hydraulic control system, reducing the heat generation of the excavator hydraulic control system, reducing energy consumption, and improving the operation efficiency, solving the problems of low working efficiency, large energy loss, and high temperature rise of the excavator hydraulic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0027] Figure 1 It is the hydraulic schematic diagram of the first energy-saving control system of the present application and the excavator hydraulic control system;

[0028] Figure 2 This is the hydraulic schematic diagram of the second energy-saving control system of this application and the hydraulic control system of the excavator;

[0029] Figure 3 This is the hydraulic schematic diagram of the third energy-saving control system of this application and the hydraulic control system of the excavator;

[0030] Figure 4 is Figure 1 The flow block diagram of the energy recovery of the energy-saving control system shown;

[0031] Figure 5 is Figure 1 The flow block diagram of the energy release of the energy-saving control system shown.

[0032] Wherein:

[0033] 10 - Energy-saving control system, 11 - Energy-saving motor, 12 - Unloading oil circuit, 13 - Oil return channel, 14 - Differential regeneration valve, 15 - Energy-saving circuit, 16 - Flow extraction valve group, 161 - First flow extraction valve, 162 - Second flow extraction valve, 163 - Third flow extraction valve, 17 - Oil charging and discharging valve group, 18 - Accumulator, 19 - First reversing valve group, 191 - First reversing valve, 192 - Second reversing valve, 110 - Second reversing valve group, 1101 - Third reversing valve, 1102 - Solenoid valve, 1103 - Pressure relief valve, 111 - Check valve group, 112 - Electro-hydraulic proportional valve, 113 - First electro-hydraulic proportional pilot valve, 114 - Second electro-hydraulic proportional pilot valve, 115 - Controller, 116 - First pressure sensor, 117 - Second pressure sensor, 118 - Third pressure sensor, 119 - Fuel tank;

[0034] 20 - Hydraulic control system of the excavator, 21 - First pump, 211 - Fourth pressure sensor, 22 - Second pump, 221 - Fifth pressure sensor, 23 - Boom cylinder assembly, 24 - Multi-way valve, 241 - Boom confluence valve, 242 - Boom control valve, 25 - Engine. Specific embodiments

[0035] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0036] In order to enable those skilled in the art of this technology to better understand the solution of this application, the following further detailed description of this application will be given in conjunction with the accompanying drawings and specific embodiments.

[0037] Please refer to Figure 1 、 Figure 4 and Figure 5 The energy-saving control system 10 provided by the embodiments of the present application is used for the hydraulic control system 20 of an excavator. The energy-saving control system 10 includes an energy-saving motor 11, a differential regeneration valve 14, an energy-saving circuit 15 and / or a first reversing valve 191.

[0038] It should be noted that the hydraulic control system 20 of the excavator includes a hydraulic pump set, a boom cylinder assembly 23 and a multi-way valve 24. The multi-way valve 24 is connected to the output oil circuit of the hydraulic pump set and the rodless cavity oil circuit and the rod cavity oil circuit of the boom cylinder assembly 23 to control the movement of the boom cylinder assembly 23. Among them, the hydraulic pump set includes a first pump 21 and a second pump 22. An energy-saving motor 11 (also called a variable displacement motor) is directly connected in series at the shaft ends of the first pump 21 and the second pump 22. The oil outlet of the energy-saving motor 11 is connected to the oil return channel 13 through an unloading oil circuit 12. A differential regeneration valve 14 is added between the multi-way valve 24 and the boom cylinder assembly 23. The differential regeneration valve 14 is connected between the rodless cavity oil circuit and the rod cavity oil circuit of the boom cylinder assembly 23. The energy-saving circuit 15 of the energy-saving control system 10 is connected to the rodless cavity oil circuit of the boom cylinder assembly 23. The first reversing valve 191 of the energy-saving control system 10 is connected between the oil outlet of the energy-saving motor 11 and the output oil circuit of the hydraulic pump set.

[0039] Furthermore, the energy-saving circuit 15 is provided with a flow extraction valve group 16, a charging and discharging valve group 17 and an accumulator 18, so that the hydraulic oil in the rodless cavity oil circuit of the boom cylinder assembly 23 is controlled by the flow extraction valve group 16 and flows into the accumulator 18 through the charging and discharging valve group 17. The charging and discharging valve group 17 is connected to the oil inlet of the energy-saving motor 11. The first reversing valve 191 is used to be connected between the oil outlet of the energy-saving motor 11 and the output oil circuit of the hydraulic pump set of the hydraulic control system 20 of the excavator, so that the hydraulic oil output by the energy-saving motor 11 flows to the output oil circuit of the hydraulic pump set.

[0040] At the same time, all the solenoid valves in the system are controlled by the signals output by the controller 115.

[0041] When the excavator is in the energy-saving mode, the energy-saving motor 11, differential regeneration valve 14, flow extraction valve group 16, oil collection and release valve group 17, accumulator 18 and / or the first reversing valve 191 are opened. Specifically, when the operator operates the boom cylinder assembly 23 of the excavator hydraulic control system 20 to descend, the differential regeneration valve 14 acts, and the rodless cavity and the rod cavity of the boom cylinder assembly 23 are differentially connected. At this time, the rodless cavity and the rod cavity of the boom cylinder assembly 23 are communicated. On the one hand, when the boom cylinder assembly 23 is in the differential state, the rodless cavity of the boom cylinder assembly 23 supplies oil to the rod cavity. On the other hand, the excess high-pressure oil in the rodless cavity of the boom cylinder assembly 23 enters the oil collection and release valve group 17 through the flow extraction valve group 16 and finally enters the accumulator 18 to complete the energy recovery during the descent process of the boom cylinder assembly 23.

[0042] Please refer to Figure 2 simultaneously. When the excavator is in the energy release process, when the accumulator 18 reaches the release condition, as the first energy release method: the accumulator 18 releases the recovered high-pressure oil, and the high-pressure oil enters the oil inlet of the energy-saving motor 11 and flows to the oil return passage 13 through the oil outlet of the energy-saving motor 11 by the unloading oil circuit 12. During the operation of the energy-saving motor 11, the energy-saving motor 11 provides torque assistance to the shaft end of the engine 25 - hydraulic pump group of the excavator hydraulic control system 20 to balance the load of the engine 25 and reduce the output of the engine 25 to achieve energy saving. Please refer to Figure 3 simultaneously. As the second energy release method: the accumulator 18 releases the recovered high-pressure oil, and the high-pressure oil enters the oil inlet of the energy-saving motor 11 and supplies oil to the output oil circuit of the hydraulic pump group of the excavator hydraulic control system 20 through the oil outlet of the energy-saving motor 11 by the first reversing valve 191. In this way, by providing hydraulic energy to the excavator hydraulic control system 20, energy saving is achieved.

[0043] This application can use the first energy release method and / or the second energy release method for energy release.

[0044] Through the energy-saving control system 10 provided by the embodiment of this application, the excavator can work in the energy-saving mode for a long time, so as to maximize the energy recovery and utilization of the boom cylinder assembly 23 of the excavator hydraulic control system 20. For the recovered energy, it can be used to drive the energy-saving motor 11 to output torque in the reverse direction to the engine 25 of the excavator hydraulic control system 20, or directly used to supply oil to the excavator hydraulic control system 20, realizing the energy-saving effect of the whole process of the motor, ensuring that the recovered hydraulic energy is utilized to the greatest extent, thereby reducing the power output of the engine 25 of the excavator hydraulic control system 20, reducing the heat generation of the excavator hydraulic control system 20, reducing energy consumption, improving the operation efficiency, and solving the problems of low working efficiency, large energy loss and high temperature rise of the excavator hydraulic system.

[0045] The following is combined with Figure 1 and Figure 4and Figure 5 , specifically describing the structure of the energy-saving control system 10.

[0046] The flow extraction valve group 16 includes a first flow extraction valve 161 and a second flow extraction valve 162. The second flow extraction valve 162 is connected between the first flow extraction valve 161 and the oil intake and discharge valve group 17. The first pilot oil circuit of the second flow extraction valve 162 is connected to the oil inlet of the first flow extraction valve 161, and the second pilot oil circuit of the second flow extraction valve 162 is connected to the oil outlet of the first flow extraction valve 161, so as to maintain the pressure difference between the oil inlet and the oil outlet of the first flow extraction valve 161 at a set value.

[0047] During the energy recovery process, the second flow extraction valve 162 controls the pressures of the oil inlet and the oil outlet of the first flow extraction valve 161 through the first pilot oil circuit and the second pilot oil circuit respectively, so as to control the passing flow of the first flow extraction valve 161. That is to say, the second flow extraction valve 162, as the post-valve pressure compensation valve of the first flow extraction valve 161, can stably control the pressure difference before and after the first flow extraction valve 161 to control the passing flow of the first flow extraction valve 161, so as to control the boom lowering speed and the recovered high-pressure flow.

[0048] Moreover, the flow extraction valve group 16 further includes a third flow extraction valve 163. The first pilot oil circuit of the third flow extraction valve 163 is connected to the oil inlet of the first flow extraction valve 161, the second pilot oil circuit of the third flow extraction valve 163 is connected to the oil outlet of the second flow extraction valve 162, and the third flow extraction valve 163 is also connected to the oil return channel 13, so as to divert the hydraulic oil at the oil outlet of the second flow extraction valve 162 to the oil return channel 13 when the pressure difference between the oil inlet of the first flow extraction valve 161 and the oil outlet of the second flow extraction valve 162 meets a preset condition.

[0049] It should be noted that the so-called pressure difference between the oil inlet of the first flow extraction valve 161 and the oil outlet of the second flow extraction valve 162 meeting a preset condition means that the pressure difference between the oil inlet of the first flow extraction valve 161 and the oil outlet of the second flow extraction valve 162 is less than a certain minimum value, or in other words, the oil outlet pressure of the second flow extraction valve 162 is greater than a certain maximum value.

[0050] It can be understood that when the oil outlet pressure of the second flow extraction valve 162 or the oil inlet pressure of the oil intake and discharge valve group 17 is greater than a certain maximum value, it means that the accumulator 18 has stored the set pressure. At this time, in order to ensure that the oil outlet pressure of the second flow extraction valve 162 or the oil inlet pressure of the oil intake and discharge valve group 17 does not exceed the set pressure stored in the accumulator 18, it is necessary to unload the hydraulic oil in the energy-saving circuit 15.

[0051] In this way, the third flow extraction valve 163, as the differential pressure compensation valve for the oil inlet and outlet of the flow extraction valve group 16, controls the pressures of the oil inlet of the first flow extraction valve 161 and the oil outlet of the second flow extraction valve 162 through its first pilot oil circuit and second pilot oil circuit respectively, so as to divert the hydraulic oil at the oil outlet of the second flow extraction valve 162 to the oil return passage 13 when the differential pressure between the oil inlet of the first flow extraction valve 161 and the oil outlet of the second flow extraction valve 162 is less than a certain minimum value, or in other words, when the oil outlet pressure of the second flow extraction valve 162 is greater than a certain maximum value, thereby ensuring that the oil outlet pressure of the second flow extraction valve 162 or the oil inlet pressure of the oil receiving and discharging valve group 17 does not exceed the storage set pressure of the accumulator 18.

[0052] It should be emphasized that the flow extraction valve group 16 is a flow control valve group with double differential pressure control. During the energy recovery process, on the one hand, the second flow extraction valve 162, as the valve rear pressure compensation valve of the first flow extraction valve 161, can stably control the differential pressure before and after the first flow extraction valve 161 to control the flow rate passing through the first flow extraction valve 161, so as to control the boom lowering speed and the recovered high-pressure flow rate; on the other hand, the third flow extraction valve 163, as the differential pressure compensation valve for the oil inlet and outlet of the flow extraction valve group 16, can ensure that the oil outlet pressure of the second flow extraction valve 162 or the oil inlet pressure of the oil receiving and discharging valve group 17 does not exceed the storage set pressure of the accumulator 18.

[0053] Therefore, by controlling the opening degree of the differential regeneration valve 14 and the first flow extraction valve 161 in the flow extraction valve group 16, it is possible to control the boom lowering speed while realizing the energy recovery of the boom lowering, and at the same time ensure that the energy storage of the accumulator 18 does not overload, which not only ensures the controllability of the whole machine but also stably realizes the energy recovery.

[0054] In some embodiments, the energy-saving control system 10 further includes an electro-hydraulic proportional control valve 112, a first electro-hydraulic proportional pilot valve 113, a second electro-hydraulic proportional pilot valve 114 and a controller 115.

[0055] Among them, the electro-hydraulic proportional control valve 112 is connected to the energy-saving motor 11 and is used to control the displacement of the energy-saving motor 11; the first electro-hydraulic proportional pilot valve 113 is connected to the differential regeneration valve 14 and is used to control the action of the differential regeneration valve 14; the second electro-hydraulic proportional pilot valve 114 is connected to the first flow extraction valve 161 and is used to control the action of the first flow extraction valve 161; the controller 115 is communicatively connected to the electro-hydraulic proportional control valve 112, the first electro-hydraulic proportional pilot valve 113 and the second electro-hydraulic proportional pilot valve 114. The controller 115 is used to send signals to the electro-hydraulic proportional control valve 112 to control the displacement of the energy-saving motor 11, and is also used to send signals to the first electro-hydraulic proportional pilot valve 113 and the second electro-hydraulic proportional pilot valve 114 to control the actions of the differential regeneration valve 14 and the first flow extraction valve 161 respectively.

[0056] Moreover, the energy-saving control system 10 further includes a first pressure sensor 116 and a second pressure sensor 117. The first pressure sensor 116 and the second pressure sensor 117 are respectively used to detect the pressures of the oil intake and discharge valve group 17 and the accumulator 18. The third flow extraction valve 163, the first pressure sensor 116 and the second pressure sensor 117 are all communicatively connected to the controller 115. The controller 115 is further configured to control the operation of the third flow extraction valve 163 according to the pressures detected by the first pressure sensor 116 and the second pressure sensor 117, so as to divert the hydraulic oil at the oil outlet of the second flow extraction valve 162 to the oil return passage 13.

[0057] When the pressure values detected by the pressure sensors corresponding to the oil intake and discharge valve group 17 and the accumulator 18 reach the corresponding settings, the controller 115 can automatically control the operation of the third flow extraction valve 163, so that the excess flow in the energy-saving circuit 15 is diverted from the third flow extraction valve 163 to the oil return passage 13.

[0058] In some embodiments, the energy-saving control system 10 further includes a second reversing valve 192. The second reversing valve 192 is connected between the oil outlet of the energy-saving motor 11 and the oil intake and discharge valve group 17, so that the hydraulic oil output by the energy-saving motor 11 flows to the accumulator 18 through the oil intake and discharge valve group 17.

[0059] In this way, when it is necessary to discharge the energy of the accumulator 18, in addition to adopting the above first energy discharge method and / or the second energy discharge method, a third energy discharge method can also be adopted. As the third energy discharge method: the accumulator 18 releases the recovered high-pressure oil, and the high-pressure oil enters the oil inlet of the energy-saving motor 11, and flows from the oil outlet of the energy-saving motor 11 through the second reversing valve 192 and the oil intake and discharge valve group 17 to the accumulator 18.

[0060] It can be understood that when the pressures detected by the fourth pressure sensor 211 at the pump port of the first pump 21 and the fifth pressure sensor 221 at the pump port of the second pump 22 exceed the corresponding set values or the oil discharge of the motor cannot enter due to the too high oil pressure in the output oil circuits of the first pump 21 and the second pump 22, the controller 115 controls the second reversing valve 192 to work, and the flow at the motor outlet can be recycled to the oil intake and discharge valve group 17 again, and then to the accumulator 18.

[0061] In some embodiments, a third reversing valve 1101 is provided on the unloading oil circuit 12. The energy-saving control system 10 further includes a solenoid valve 1102. The solenoid valve 1102 is connected to the third reversing valve 1101 to perform unloading by the third reversing valve 1101 and the solenoid valve 1102 when the hydraulic oil pressure at the oil outlet of the energy-saving motor 11 exceeds the threshold value.

[0062] That is to say, if the flow rate at the motor outlet cannot enter the accumulator 18 at this time, that is, the pressure detected by the third pressure sensor 118 at the oil outlet of the energy-saving motor 11 exceeds the corresponding set value, the controller 115 sends a signal to the solenoid valve 1102 to unload through the third reversing valve 1101.

[0063] In some embodiments, the energy-saving control system 10 further includes a pressure relief valve 1103 connected in parallel with the third reversing valve 1101. In this way, when the pressure at the oil outlet of the energy-saving motor 11 reaches the set pressure of the pressure relief valve 1103, the oil flow rate at the oil outlet of the energy-saving motor 11 flows through the pressure relief valve 1103 to the unloading oil circuit 12 and then flows into the oil return passage 13.

[0064] In some embodiments, a check valve group 111 is connected to the oil inlet of the energy-saving motor 11. The check valve group 111 is connected to the oil return passage 13 and the fuel tank 119 so that the oil inlet of the energy-saving motor 11 sucks oil from the fuel tank 119 or the oil return passage 13 in the valve through the check valve group 111.

[0065] In this way, the oil inlet of the energy-saving motor 11 sucks oil from the fuel tank 119 or the internal valve oil return passage 13 through the check valve group 111 to prevent the motor from sucking air.

[0066] The working process of the energy-saving control system 10 will be specifically described below:

[0067] After the vehicle starts, the controller 115 sends a signal to the electro-hydraulic proportional control valve 112 to control the swashplate angle of the energy-saving motor 11 to swing to the minimum. The oil inlet of the energy-saving motor 11 sucks oil from the fuel tank 119 or the internal valve oil return passage 13 through the check valve group 111 to prevent the motor from sucking air. The system can select the conventional or energy-saving mode (input the signal to the controller 115 through the touch screen). When the excavator is in the conventional mode, the first reversing valve group 19 including the first reversing valve 191 and the second reversing valve 192, the differential regeneration valve 14, the flow extraction valve group 16, and the oil collection and discharge valve group 17 have no action signals, and the energy-saving system is in the closed state. At this time, the second reversing valve group 110 including the third reversing valve 1101, the solenoid valve 1102, and the pressure relief valve 1103 acts to unload the oil outlet of the energy-saving motor 11, and the energy-saving motor 11 maintains standby operation at the lowest load.

[0068] When the excavator is in the energy-saving mode and the operator operates the boom cylinder assembly 23 to descend, the first electro-hydraulic proportional pilot valve 113 receives a signal from the controller 115, and the differential regeneration valve 14 acts. The rod chamber and the rodless chamber of the boom cylinder assembly 23 are differentially connected, and at this time, the rod chamber and the rodless chamber of the boom cylinder assembly 23 are communicated with each other. On the one hand, when the boom cylinder assembly 23 is in the differential state, the rodless chamber of the boom cylinder assembly 23 supplies oil to the rod chamber. On the other hand, the excess high-pressure oil in the rodless chamber of the boom cylinder assembly 23 enters the oil collection and discharge valve group 17 through the flow extraction valve group 16 and finally enters the accumulator 18, completing the energy recovery process of the boom cylinder assembly 23 descending. Among them, the flow extraction valve group 16 is a flow control valve group controlled by double pressure differences. During the energy recovery process, on the one hand, the second flow extraction valve 162 serves as the valve rear pressure compensation valve of the first flow extraction valve 161, which can stably control the pressure difference before and after the first flow extraction valve 161 to control the flow passing through the first flow extraction valve 161, so as to control the boom descending speed and the recovered high-pressure flow. On the other hand, the third flow extraction valve 163 serves as the pressure difference compensation valve of the oil inlet and outlet of the flow extraction valve group 16, which can ensure that the outlet pressure of the second flow extraction valve 162 or the inlet pressure of the oil collection and discharge valve group 17 does not exceed the storage set pressure of the accumulator 18. When the pressure values detected by the pressure sensors corresponding to the oil collection and discharge valve group 17 and the accumulator 18 reach the corresponding settings, the controller 115 can automatically control the third flow extraction valve 163 to act, so that the excess flow in the energy-saving circuit 15 is diverted from the third flow extraction valve 163 to the oil return passage 13. Therefore, by controlling the opening degree of the differential regeneration valve 14 and the first flow extraction valve 161 in the flow extraction valve group 16, it is possible to control the boom descending speed while realizing the energy recovery of the boom descending, and at the same time ensure that the energy storage of the accumulator 18 does not overload, which not only ensures the controllability of the whole machine but also stably realizes the energy recovery.

[0069] During the energy release process, the cylinder pressure in the accumulator 18 is collected by the second pressure sensor 117, and information on the current operating conditions is received. The controller 115 calculates and determines whether the recovered high-pressure oil in the accumulator 18 reaches the release condition. When the release condition is reached, the controller 115 sends a signal to the oil collection and discharge valve group 17 for energy release and reuse. When the accumulator 18 releases the recovered high-pressure oil, the high-pressure oil enters the oil inlet of the energy-saving motor 11, and the motor runs. The controller 115 sends a signal to the electro-hydraulic proportional valve 112 that controls the displacement adjustment of the energy-saving motor 11, and the displacement of the energy-saving motor 11 increases. At the same time, an action signal is sent to the first reversing valve 191 to supply oil to one of the output oil paths of the first pump 21 and the second pump 22. When the pump port pressures of the first pump 21 and the second pump 22 exceed the corresponding set values or the output circuit pressures of the first pump 21 and the second pump 22 are too high and the motor oil discharge cannot enter, the second reversing valve 192 operates, and the motor outlet flow can be recycled to the oil collection and discharge valve group 17 and then to the accumulator 18 again. If the motor outlet flow cannot enter the accumulator 18 at this time, that is, the outlet oil pressure of the energy-saving motor 11 exceeds the corresponding set value, the controller 115 sends a signal to the solenoid valve 1102, and unloading will be performed through the third reversing valve 1101.

[0070] When the pressure of the high-pressure oil released by the accumulator 18 gradually decreases to insufficient during the release process and the outlet load pressure of the energy-saving motor 11 is relatively high, at this time, the main shafts of the first pump 21 and the second pump 22 drive the motor to rotate, and at this time, the energy-saving motor 11 changes to the pump working condition. By absorbing the torque of the engine 25, it is converted into hydraulic energy output in the hydraulic pump working condition and directly supplies oil to the output circuits of the first pump 21 and the second pump 22. The one-way valve group 111 at the oil inlet of the energy-saving motor 11 sucks oil from the oil return passage 13 or the fuel tank 119 to avoid cavitation problems when the energy-saving motor 11 is converted to the hydraulic pump working condition.

[0071] In summary, by setting the above energy-saving control system 10, the switching between the conventional and energy-saving modes of the excavator can be realized, and it can also work in the energy-saving mode for a long time, maximizing the recovery and utilization of the boom energy. For the recovered energy, it can be used to drive the energy-saving motor 11 to output torque in the reverse direction to the engine 25, or it can be directly used to supply oil to the hydraulic system, or it can be stored again in the accumulator 18 to achieve the energy-saving effect of the entire process of the motor, ensuring that the recovered hydraulic energy is utilized to the greatest extent, reducing the power output of the engine 25, reducing the heat generation of the hydraulic system, reducing energy consumption, and improving the operation efficiency.

[0072] An excavator hydraulic control device provided by the present application includes an excavator hydraulic control system 20, and the excavator hydraulic control system 20 includes a hydraulic pump set, a boom cylinder assembly 23 and a multi-way valve 24. Among them, the hydraulic pump set includes a first pump 21 and a second pump 22 connected to each other. The boom cylinder assembly 23 includes at least two boom cylinders. The multi-way valve 24 is connected to the output oil circuit of the hydraulic pump set and the rodless cavity oil circuit and the rod cavity oil circuit of the boom cylinder assembly 23. Specifically, the multi-way valve 24 includes a boom confluence valve 241 and a boom control valve 242. The flow rate of the first pump 21 can enter the rodless cavity of the boom cylinder assembly 23 under the control of the boom confluence valve 241, and the flow rate of the second pump 22 can enter the rodless cavity of the boom cylinder assembly 23 under the control of the boom control valve 242 to achieve the control of the rising action of the boom cylinder assembly 23.

[0073] In addition, the excavator hydraulic control device further includes the energy-saving control system 10 described in the above specific embodiment. The energy-saving motor 11 of the energy-saving control system 10 is connected in series at the shaft end of the hydraulic pump set. The differential regeneration valve 14 of the energy-saving control system 10 is connected between the rodless cavity oil circuit and the rod cavity oil circuit of the boom cylinder assembly 23. The energy-saving circuit 15 of the energy-saving control system 10 is connected to the rodless cavity oil circuit of the boom cylinder assembly 23. The first reversing valve 191 of the energy-saving control system 10 is connected between the oil outlet of the energy-saving motor 11 and the output oil circuit of the hydraulic pump set.

[0074] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0075] The above has introduced in detail the energy-saving control system and the excavator hydraulic control device provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the solution and its core idea of the present application. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. An energy-saving control system for an excavator hydraulic control system, characterized in that: include: An energy-saving motor is used to be connected to the shaft end of the hydraulic pump group of the hydraulic control system of the excavator, and the oil outlet of the energy-saving motor is connected to the oil return channel through a load-relief oil circuit; A differential regeneration valve is used to connect between the rodless chamber oil circuit and the rod chamber oil circuit of the boom cylinder assembly of the hydraulic control system of the excavator; An energy-saving circuit, used for connecting to the rodless chamber oil circuit of the boom cylinder assembly of the hydraulic control system of the excavator, the energy-saving circuit is provided with a flow extraction valve group, an oil retracting and releasing valve group and an accumulator, so that the hydraulic oil in the rodless chamber oil circuit of the boom cylinder assembly is controlled by the flow extraction valve group and flows into the accumulator through the oil retracting and releasing valve group, and the oil retracting and releasing valve group is connected to the oil inlet of the energy-saving motor; and / or The first reversing valve is used to connect between the oil outlet of the energy-saving motor and the output oil circuit of the hydraulic pump group of the hydraulic control system of the excavator, so that the hydraulic oil output by the energy-saving motor flows to the output oil circuit of the hydraulic pump group.

2. The energy-saving control system according to claim 1, characterized in that: The flow extraction valve group includes a first flow extraction valve and a second flow extraction valve, the second flow extraction valve is located between the first flow extraction valve and the oil retractable and release valve group, the first pilot oil circuit of the second flow extraction valve is connected to the oil inlet of the first flow extraction valve, and the second pilot oil circuit of the second flow extraction valve is connected to the oil outlet of the first flow extraction valve, so as to maintain the pressure difference between the oil inlet and the oil outlet of the first flow extraction valve at a set value.

3. The energy-saving control system according to claim 2, characterized in that: The flow extraction valve group also includes a third flow extraction valve, the first pilot oil circuit of the third flow extraction valve is connected to the oil inlet of the first flow extraction valve, the second pilot oil circuit of the third flow extraction valve is connected to the oil outlet of the second flow extraction valve, and the third flow extraction valve is also connected to the return oil channel to divert the hydraulic oil at the oil outlet of the second flow extraction valve to the return oil channel when the pressure difference between the oil inlet of the first flow extraction valve and the oil outlet of the second flow extraction valve meets a preset condition.

4. The energy-saving control system according to claim 3, characterized in that: The energy-saving control system further comprises: An electric proportional control valve, used for controlling the displacement of the energy-saving motor; A first electric proportional pilot valve, used to control the action of the differential regeneration valve; a second electric proportional pilot valve, used to control the action of the first flow extraction valve; A controller is communicatively connected to the electric proportional control valve, the first electric proportional pilot valve and the second electric proportional pilot valve, and is used to send signals to the electric proportional control valve to control the displacement of the energy-saving motor, and is also used to send signals to the first electric proportional pilot valve and the second electric proportional pilot valve to respectively control the operation of the differential regeneration valve and the first flow extraction valve.

5. The energy-saving control system according to claim 4, characterized in that: The energy-saving control system also includes a first pressure sensor and a second pressure sensor, wherein the first pressure sensor and the second pressure sensor are respectively used to detect the pressure of the oil-retracting and -discharging valve group and the accumulator, and the third flow extraction valve, the first pressure sensor and the second pressure sensor are all communicatively connected with the controller, and the controller is also used to control the action of the third flow extraction valve according to the pressure detected by the first pressure sensor and the second pressure sensor, so as to divert the hydraulic oil at the oil outlet of the second flow extraction valve to the return oil channel.

6. The energy-saving control system according to claim 1, characterized in that: The energy-saving control system also includes a second reversing valve, which is connected between the oil outlet of the energy-saving motor and the oil-retracting and releasing valve group, so that the hydraulic oil output by the energy-saving motor flows to the accumulator through the oil-retracting and releasing valve group.

7. The energy-saving control system according to claim 6, characterized in that: A third reversing valve is provided on the unloading oil circuit, and the energy-saving control system also includes a solenoid valve, which is connected to the third reversing valve so that the third reversing valve and the solenoid valve can unload when the hydraulic oil pressure at the oil outlet of the energy-saving motor exceeds a threshold.

8. The energy-saving control system according to claim 7, characterized in that: The energy-saving control system further includes a pressure relief valve connected in parallel with the third reversing valve.

9. The energy-saving control system according to claim 1, characterized in that: The oil inlet of the energy-saving motor is connected to a one-way valve group, and the one-way valve group is connected to the oil return channel and the oil tank, so that the oil inlet of the energy-saving motor absorbs oil from the oil tank or the oil return channel through the one-way valve group.

10. An excavator hydraulic control device, comprising an excavator hydraulic control system, the excavator hydraulic control system comprising a hydraulic pump group, a boom cylinder assembly and a multi-way valve, the multi-way valve is connected to the output oil circuit of the hydraulic pump group and the rodless chamber oil circuit and the rod chamber oil circuit of the boom cylinder assembly to control the action of the boom cylinder assembly, characterized in that: It also includes an energy-saving control system as described in any one of claims 1 to 9, the energy-saving motor of the energy-saving control system is connected to the shaft end of the hydraulic pump group, the differential regeneration valve of the energy-saving control system is connected between the rodless chamber oil circuit and the rod chamber oil circuit of the boom cylinder assembly, the energy-saving circuit of the energy-saving control system is connected to the rodless chamber oil circuit of the boom cylinder assembly, and the first reversing valve of the energy-saving control system is connected between the oil outlet of the energy-saving motor and the output oil circuit of the hydraulic pump group.

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