Excavator hydraulic control system and excavator control method

Abstract

The present invention discloses an excavator hydraulic control system and an excavator control method. The hydraulic control system includes first and second main pumps, a swing pump, an electronically controlled main valve, a travel hydraulic motor, a swing motor, a boom cylinder, an arm cylinder, a bucket cylinder, an electronically controlled handle, an electronically controlled foot pedal, a controller, and a sensor. The first and second main pumps output hydraulic oil to the electronically controlled main valve. The swing pump and the swing motor form an independent closed swing system. The swing pump outputs hydraulic oil to the swing motor. The electronically controlled main valve includes an arm valve link, a travel valve link, a bucket valve link, and an arm valve link, which are respectively connected to the arm cylinder, the travel hydraulic motor, the bucket cylinder, and the boom cylinder. The controller calculates and controls the hydraulic oil flow rate and the power required by the load based on received action signals, speed signals, priority signals, engine speed signals, and load pressure signals. The present invention achieves precise control of each action, achieves optimal matching of compound actions, and effectively improves the operating efficiency of the excavator.

Description

Technical Field

[0001] The present invention belongs to the technical field of excavators, and in particular relates to an excavator hydraulic control system and an excavator control method. Background Art

[0002] Excavators are commonly used in construction, primarily for digging or transporting soil, sand, gravel, and coal slag. The excavator's actuators include a travel motor, a slew motor, an arm cylinder, an arm cylinder, and a bucket cylinder. These actuators can operate independently or in combination.

[0003] The hydraulic systems of excavators in the prior art mostly adopt a dual pump + open rotation + hydraulically controlled positive flow system. One main pump circuit realizes left travel, boom movement, bucket movement, and stick movement, and the other main pump circuit realizes right travel, rotation movement, boom movement, standby function, and stick movement. The compound controllability has been greatly improved, but the controllability of some compound movements is still insufficient. For example, when leveling operations or rotating and other actuators perform compound movements, uncoordinated movements often occur. However, it is difficult to achieve fine adjustment of controllability with such excavator hydraulic systems in the prior art. Summary of the Invention

[0004] In order to solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides an excavator hydraulic control system and an excavator control method.

[0005] In one aspect of the present invention, a hydraulic control system for an excavator is provided, comprising: a first main pump, a second main pump, a swing pump, an electronically controlled main valve, a travel hydraulic motor, a swing motor, a boom cylinder, an arm cylinder, a bucket cylinder, an electronically controlled handle, an electronically controlled foot pedal, a controller, and a sensor, wherein:

[0006] The first main pump, the second main pump, and the swing pump are respectively installed on three output power take-off ports of the excavator's transfer case. The first main pump, the second main pump, and the swing pump are each equipped with a proportional solenoid valve. The first main pump and the second main pump output hydraulic oil to the electronically controlled main valve. The swing pump and the swing motor form an independent closed swing system. The swing pump outputs hydraulic oil to the swing motor.

[0007] The electrically controlled main valve is an electrically controlled proportional valve, including a boom valve connection, a travel valve connection, a bucket valve connection, and a boom valve connection. The oil inlets of the boom valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection are all connected to the first main pump and the second main pump, and the oil outlets of the boom valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection are respectively connected to the boom cylinder, the travel hydraulic motor, the bucket cylinder, and the boom cylinder;

[0008] The electric control handle and the electric control foot pedal output an action requirement signal and an action speed signal to the controller according to the working condition requirements of the excavator;

[0009] The controller receives action demand signals and action speed signals from the electric control handle and the electric control foot pedal, receives engine speed signals, action priority signals, and load pressure signals of various actuators of the excavator from the sensor, receives main pump swash plate angle signals and main pump working pressure signals from the first main pump and the second main pump, and calculates and controls the hydraulic oil flow and load required power based on the various electrical signals received, sends electrical signals to the proportional solenoid valves of the first main pump and the second main pump to control the hydraulic oil output flow and pump power of the first main pump and the second main pump, sends electrical signals to the electronically controlled main valve to control the output flow of the electronically controlled main valve and output the hydraulic oil to one or more of the dipper arm valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection, and sends electrical signals to the proportional solenoid valve of the rotary pump to control the hydraulic oil output flow of the rotary pump.

[0010] Furthermore, in the above-mentioned excavator hydraulic control system, the action requirement signal is the lowering boom action, raising boom action, bucket retracting action, releasing bucket action, extending stick action, retracting stick action, right rotation action, left rotation action controlled by the electronic control handle, and the forward action and backward action controlled by the electronic control foot pedal; the action speed signal is the lowering boom speed, raising boom speed, bucket retracting speed, releasing bucket speed, extending stick speed, retracting stick speed, right rotation speed, left rotation speed, forward speed, and backward speed; the action priority signal is the priority relationship between the lowering boom action, raising boom action, bucket retracting action, releasing bucket action, extending stick action, retracting stick action, right rotation action, left rotation action, forward action, and backward action.

[0011] Furthermore, in the above-mentioned hydraulic control system of the excavator, the electronically controlled handle includes an electronically controlled left handle and an electronically controlled right-left handle.

[0012] Furthermore, in the above-mentioned hydraulic control system of the excavator, the travel hydraulic motor includes a left travel hydraulic motor and a right travel hydraulic motor, and the oil outlet of the travel valve link is connected to the left travel hydraulic motor and the right travel hydraulic motor.

[0013] Furthermore, in the above-mentioned excavator hydraulic control system, the swing pump is equipped with an oil replenishment pump and an oil replenishment safety valve. The oil replenishment pump supplies hydraulic oil to the closed swing system, and the oil replenishment safety valve sets the maximum oil replenishment pressure; the low-pressure oil circuit of the swing motor is provided with a flushing valve, which returns part of the hydraulic oil directly to the oil tank for cooling.

[0014] In another aspect of the present invention, a method for controlling an excavator is provided, comprising:

[0015] The electric control handle and electric control foot pedal output action demand signals and action speed signals to the controller according to the working conditions of the excavator;

[0016] The sensor collects engine speed signals, action priority signals, and load pressure signals of each actuator of the excavator and sends them to the controller;

[0017] The controller receives a main pump swash plate angle signal and a main pump working pressure signal from the first main pump and the second main pump;

[0018] Based on the various electrical signals received, the controller calculates and controls the hydraulic oil flow and the power required by the load, sends electrical signals to the proportional solenoid valves of the first main pump and the second main pump, controls the hydraulic oil output flow and pump power of the first main pump and the second main pump, and outputs the hydraulic oil to the electronically controlled main valve, sends electrical signals to the electronically controlled main valve, controls the hydraulic oil output flow of the electronically controlled main valve, and outputs the hydraulic oil to one or more of the boom valve connection, the travel valve connection, the bucket valve connection, and the arm valve connection, and sends electrical signals to the proportional solenoid valve of the swing pump, controls the hydraulic oil output flow of the swing pump, and outputs the hydraulic oil to the swing motor, thereby realizing one of the boom action, the travel action, the bucket action, the arm action, and the swing action of the excavator, or a combined action thereof.

[0019] The excavator hydraulic control system and the excavator control method of the present invention have the following advantages and beneficial effects:

[0020] 1. The three-pump + closed-loop slewing + fully electronic control system solves the problem of difficult adjustment and uncoordinated compound movements of the excavator. It can achieve precise control of each movement, achieve the best match of compound movements, make the excavator control more intelligent, and effectively improve the excavator's operating efficiency.

[0021] 2. The electronically controlled main valve has no hydraulic pilot line and is used in combination with the hydraulic system and electronic control to achieve rapid response and energy saving, meeting the optimal fuel consumption and efficiency in different working modes such as loading, leveling, and crushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0023] Figure 1 This is a schematic diagram of the construction principle of the excavator hydraulic control system of the present invention. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, the hydraulic control system of the excavator of the present invention includes: a first main pump, a second main pump, a rotary pump, an electronically controlled main valve, a travel hydraulic motor, a rotary motor, a boom cylinder, an arm cylinder, a bucket cylinder, an electronically controlled handle, an electronically controlled foot pedal, a controller, and a sensor.

[0026] The first main pump, the second main pump and the swing pump are respectively installed on the three output power take-off ports of the excavator's transfer case. The first main pump, the second main pump and the swing pump are each equipped with a proportional solenoid valve. The proportional solenoid valves of the first main pump and the second main pump are controlled by electrical signals from the controller to realize electronically controlled displacement adjustment, pressure cut-off, pump power adjustment, and output hydraulic oil to the electronically controlled main valve.

[0027] The swing pump and swing motor form an independent closed-loop swing system. The swing pump's proportional solenoid valve, controlled by an electrical signal from the controller, controls the hydraulic oil output flow from the swing pump and delivers the oil to the swing motor, enabling the excavator's swing motion. The swing pump is equipped with a charge pump and a charge safety valve. The charge pump replenishes hydraulic oil to the closed-loop swing system, while the charge safety valve sets the maximum charge pressure to ensure system safety and reliability. The swing motor's low-pressure oil circuit is equipped with a flush valve, which directs some hydraulic oil back to the tank for cooling, ensuring the entire circuit operates within the normal temperature range.

[0028] The electrically controlled main valve is an electrically controlled proportional valve comprising an arm valve assembly, a travel valve assembly, a bucket valve assembly, and a boom valve assembly. The oil inlets of these valves are connected to the first and second main pumps, while their oil outlets are connected to the arm cylinder, travel hydraulic motor, bucket cylinder, and boom cylinder, respectively. Hydraulic oil from the first and second main pumps enters the electrically controlled main valve, pushing the valve spool of the electrically controlled main valve, opening it. Simultaneously, the electrically controlled main valve, controlled by an electrical signal from a controller, outputs hydraulic oil to one or more of the arm valve assembly, travel valve assembly, bucket valve assembly, and boom valve assembly, depending on the desired motion of the excavator's actuators. This hydraulic oil is then fed to one or more of the corresponding arm cylinders, travel hydraulic motors, bucket cylinders, and boom cylinders, achieving one or a combination of the excavator's arm, travel, bucket, and boom movements.

[0029] The electric control handle and electric control foot pedal are operated under the operator's electronic control according to the excavator's working conditions, and output action demand signals, action speed signals, etc. to the controller. For example, the action demand signals can be the lowering of the boom, raising of the boom, retracting of the bucket, lowering of the bucket, extending of the stick, retracting of the stick, right rotation, and left rotation, which are controlled by the electric control handle, and the forward and reverse movements, which are controlled by the electric control foot pedal; the action speed signals can be the lowering of the boom, raising of the boom, retracting of the bucket, lowering of the bucket, extending of the stick, retracting of the stick, right rotation, left rotation, forward speed, and reverse speed.

[0030] The controller receives action request and action speed signals from the electronic joystick and foot pedal, engine speed signals, action priority signals, and load pressure signals from the excavator's actuators from sensors, and main pump swash plate angle signals and main pump operating pressure signals from the first and second main pumps. These action priority signals can indicate the priority relationship between boom lowering, boom raising, bucket retracting, bucket lowering, arm extension, arm retraction, right swing, left swing, forward movement, and reverse movement. Based on the various electrical signals received, the controller calculates and controls the hydraulic oil flow and the power required by the load, sends electrical signals to the proportional solenoid valves of the first main pump and the second main pump, controls the hydraulic oil output flow and pump power of the first main pump and the second main pump, and outputs the hydraulic oil to the electronically controlled main valve; sends electrical signals to the electronically controlled main valve, controls the output flow of the electronically controlled main valve, and outputs the hydraulic oil to one or more of the dipper valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection; sends electrical signals to the proportional solenoid valve of the swing pump, controls the hydraulic oil output flow of the swing pump, and outputs the hydraulic oil to the swing motor.

[0031] Furthermore, in the hydraulic control system for an excavator of the present invention, the electronically controlled handle includes an electronically controlled left handle and an electronically controlled right-left handle.

[0032] Furthermore, in the hydraulic control system of the excavator of the present invention, the travel hydraulic motor includes a left travel hydraulic motor and a right travel hydraulic motor, and the oil outlet of the travel valve link is connected to the left travel hydraulic motor and the right travel hydraulic motor.

[0033] Furthermore, in the hydraulic control system of the excavator of the present invention, according to the actual operating conditions of the excavator, the electronically controlled main valve can be supplied with oil by a single pump from one of the first main pump and the second main pump, thereby reducing costs; the electronically controlled main valve can also be supplied with oil by two pumps at the same time from the first main pump and the second main pump, thereby improving operating efficiency.

[0034] In summary, in the hydraulic control system of the excavator of the present invention, the controller controls the hydraulic oil output flow and pump power of the first main pump and the second main pump, and controls the hydraulic oil output flow of the rotary pump according to the excavator working condition requirements represented by the electric control handle, the electric control foot pedal, and the electrical signals input by the sensor. The first main pump and the second main pump output the hydraulic oil to the electric control main valve. Under the control of the controller, the electric control main valve outputs the hydraulic oil to one or more of the dipper valve connection, the walking valve connection, the bucket valve connection, and the boom valve connection. The rotary pump outputs the hydraulic oil to the rotary motor, thereby realizing one or a combined action of the dipper valve connection, the walking valve connection, the bucket valve connection, the boom valve connection, and the rotary motor of the excavator, and at the same time, under the regulation of the hydraulic oil output flow of the first main pump, the second main pump and the rotary pump and the pump power of the first main pump and the second main pump, the speed adjustment and precise control of various actions are realized.

[0035] In another aspect of the present invention, a method for controlling an excavator is provided. The excavator is equipped with the excavator hydraulic control system described above. The method for controlling the excavator includes:

[0036] The electric control handle and electric control foot pedal output action demand signals and action speed signals to the controller according to the working conditions of the excavator;

[0037] The sensor collects engine speed signals, action priority signals, and load pressure signals of each actuator of the excavator and sends them to the controller;

[0038] The controller receives a main pump swash plate angle signal and a main pump working pressure signal from the first main pump and the second main pump;

[0039] Based on the various electrical signals received, the controller calculates and controls the hydraulic oil flow and the power required by the load, sends electrical signals to the proportional solenoid valves of the first main pump and the second main pump, controls the hydraulic oil output flow and pump power of the first main pump and the second main pump, and outputs the hydraulic oil to the electronically controlled main valve; sends electrical signals to the electronically controlled main valve, controls the output flow of the electronically controlled main valve, and outputs the hydraulic oil to one or more of the dipper valve connection, the travel valve connection, the bucket valve connection, and the arm valve connection; sends electrical signals to the proportional solenoid valve of the swing pump, controls the hydraulic oil output flow of the swing pump, and outputs the hydraulic oil to the swing motor, thereby realizing one or a combination of the dipper valve connection, the travel valve connection, the bucket valve connection, the arm valve connection, and the swing motor of the excavator.

[0040] Furthermore, in the excavator control method of the present invention, the action requirement signal includes the lowering boom action, raising boom action, bucket retracting action, releasing bucket action, extending stick action, retracting stick action, right rotation action, left rotation action controlled by the electronic control handle, and the forward action and backward action controlled by the electronic control foot pedal; the action speed signal includes the lowering boom speed, raising boom speed, bucket retracting speed, releasing bucket speed, extending stick speed, retracting stick speed, right rotation speed, left rotation speed, forward speed, and backward speed; the action priority signal includes the priority relationship between the lowering boom action, raising boom action, bucket retracting action, releasing bucket action, extending stick action, retracting stick action, right rotation action, left rotation action, forward action, and backward action.

[0041] In summary, compared with the prior art, the excavator hydraulic control system and the excavator control method of the present invention have the following advantages and beneficial effects:

[0042] 1. The three-pump + closed-loop slewing + fully electronic control system solves the problem of difficult adjustment and uncoordinated movements of the excavator's compound movements. It can achieve precise control of each movement, achieve the best match for the compound movements, make the excavator's control more intelligent, and effectively improve the excavator's operating efficiency.

[0043] 2. The electronically controlled main valve has no hydraulic pilot line and is used in combination with the hydraulic system and electronic control to achieve rapid response and energy saving, meeting the optimal fuel consumption and efficiency in different working modes such as loading, leveling, and crushing.

[0044] It should be noted that, in this document, unless otherwise expressly specified or limited, the term "connected" or its synonyms should be interpreted broadly. For example, "connected" can mean a fixed or removable connection; a mechanical or electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication between two elements or the interaction between two elements. A person of ordinary skill in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances. Furthermore, expressions such as "first" and "second" are used solely to distinguish one entity or operation from another and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Furthermore, the terms "front," "rear," "left," "right," "upper," and "lower" herein are used with reference to the positions shown in the accompanying drawings.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An excavator hydraulic control system, characterized in that: The hydraulic control system of the excavator includes: a first main pump, a second main pump, a rotary pump, an electronically controlled main valve, a travel hydraulic motor, a rotary motor, a boom cylinder, an arm cylinder, a bucket cylinder, an electronically controlled handle, an electronically controlled foot pedal, a controller, and a sensor, wherein: The first main pump, the second main pump, and the swing pump are respectively installed on three output power take-off ports of the excavator's transfer case. The first main pump, the second main pump, and the swing pump are each equipped with a proportional solenoid valve. The first main pump and the second main pump output hydraulic oil to the electronically controlled main valve. The swing pump and the swing motor form an independent closed swing system. The swing pump outputs hydraulic oil to the swing motor. The electrically controlled main valve is an electrically controlled proportional valve, including a boom valve connection, a travel valve connection, a bucket valve connection, and a boom valve connection. The oil inlets of the boom valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection are all connected to the first main pump and the second main pump, and the oil outlets of the boom valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection are respectively connected to the boom cylinder, the travel hydraulic motor, the bucket cylinder, and the boom cylinder; The electric control handle and the electric control foot pedal output an action requirement signal and an action speed signal to the controller according to the working condition requirements of the excavator; The controller receives action demand signals and action speed signals from the electric control handle and the electric control foot pedal, receives engine speed signals, action priority signals, and load pressure signals of various actuators of the excavator from the sensor, receives main pump swash plate angle signals and main pump working pressure signals from the first main pump and the second main pump, and calculates and controls the hydraulic oil flow and load required power based on the various electrical signals received, sends electrical signals to the proportional solenoid valves of the first main pump and the second main pump to control the hydraulic oil output flow and pump power of the first main pump and the second main pump, sends electrical signals to the electronically controlled main valve to control the output flow of the electronically controlled main valve and output the hydraulic oil to one or more of the dipper arm valve connection, the travel valve connection, the bucket valve connection, and the boom valve connection, and sends electrical signals to the proportional solenoid valve of the rotary pump to control the hydraulic oil output flow of the rotary pump.

2. The hydraulic control system for an excavator according to claim 1, characterized in that: The action requirement signal is the lowering boom action, raising boom action, bucket retracting action, bucket releasing action, stick extending action, stick retracting action, right rotation action, left rotation action controlled by the electric control handle, and the forward action and backward action controlled by the electric control foot pedal; the action speed signal is the lowering boom speed, raising boom speed, bucket retracting speed, bucket releasing speed, stick extending speed, stick retracting speed, right rotation speed, left rotation speed, forward speed, and backward speed; the action priority signal is the priority relationship between the lowering boom action, raising boom action, bucket retracting action, bucket releasing action, stick extending action, stick retracting action, right rotation action, left rotation action, forward action, and backward action.

3. The hydraulic control system for an excavator according to claim 1, characterized in that: The electric control handle includes an electric control left handle and an electric control right-left handle.

4. The hydraulic control system for an excavator according to claim 1, characterized in that: The travel hydraulic motor includes a left travel hydraulic motor and a right travel hydraulic motor, and the oil outlet of the travel valve link is connected to the left travel hydraulic motor and the right travel hydraulic motor.

5. The hydraulic control system for an excavator according to any one of claims 1 to 4, characterized in that: The rotary pump is equipped with an oil replenishment pump and an oil replenishment safety valve. The oil replenishment pump supplies hydraulic oil to the closed rotary system, and the oil replenishment safety valve sets the maximum pressure of the replenishment oil; the low-pressure oil circuit of the rotary motor is provided with a flushing valve, which returns part of the hydraulic oil directly to the oil tank for cooling.

6. A method for controlling an excavator, wherein the excavator is equipped with the excavator hydraulic control system according to any one of claims 1 to 5, the method comprising: The electric control handle and electric control foot pedal output action demand signals and action speed signals to the controller according to the working conditions of the excavator; The sensor collects engine speed signals, action priority signals, and load pressure signals of each actuator of the excavator and sends them to the controller; The controller receives a main pump swash plate angle signal and a main pump working pressure signal from the first main pump and the second main pump; Based on the various electrical signals received, the controller calculates and controls the hydraulic oil flow and the power required by the load, sends electrical signals to the proportional solenoid valves of the first main pump and the second main pump, controls the hydraulic oil output flow and pump power of the first main pump and the second main pump, and outputs the hydraulic oil to the electronically controlled main valve, sends electrical signals to the electronically controlled main valve, controls the hydraulic oil output flow of the electronically controlled main valve, and outputs the hydraulic oil to one or more of the boom valve connection, the travel valve connection, the bucket valve connection, and the arm valve connection, and sends electrical signals to the proportional solenoid valve of the swing pump, controls the hydraulic oil output flow of the swing pump, and outputs the hydraulic oil to the swing motor, thereby realizing one of the boom action, the travel action, the bucket action, the arm action, and the swing action of the excavator, or a combined action thereof.

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