A brake system for an electric wheel excavator

Abstract

The application discloses a brake system for a pure electric wheel excavator, which comprises a main controller, a power module, an electronic accelerator pedal, a walking system brake module and a rotating system brake module connected with the main controller; when the excavator is in a walking mode and the driving speed and the SOC value of the power module meet preset requirements, the driving state of the whole machine is judged according to the electronic accelerator pedal signal and the brake pressure signal in the walking system brake module, and the brake state of the walking system brake module is controlled; when the excavator is in a digging mode and the driving speed meets preset requirements, the brake state of the rotating system brake module is controlled according to the SOC value of the power module and the rotating speed of the excavator; when the walking system brake module or the rotating system brake module is in a feedback brake state, the electric energy generated is stored in the power module. The application realizes brake energy recovery during walking brake and rotating brake, and increases the whole machine endurance time of the pure electric wheel excavator.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, and specifically relates to a braking system for a pure electric wheeled excavator. Background Technology

[0002] Electric excavators are gaining increasing attention due to their advantages such as zero emissions, good environmental performance, and low operating and maintenance costs. The runtime of a fully charged machine is a crucial parameter for users. Given a fixed battery capacity, increasing the overall working efficiency of the machine is the only way to extend its runtime.

[0003] Currently available pure electric wheeled excavators directly replace diesel engines with electric motors, with the main hydraulic pump driven by the electric motor. The overall hydraulic system remains unchanged, while the travel and swing systems are still driven by hydraulic motors. Hydraulic transmission is less efficient than electric motor transmission, and the excavator cannot recover braking energy during travel and swing braking, resulting in a shorter overall operating time. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a braking system for pure electric wheeled excavators that can recover braking energy during travel braking and swing braking, thereby increasing the overall driving time of the pure electric wheeled excavator.

[0005] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0006] The present invention provides a braking system for a pure electric wheeled excavator, comprising: a main controller, and a power module, an electronic accelerator pedal, a travel system braking module and a swing system braking module connected to the main controller;

[0007] When the main controller determines that the excavator is in walking mode, and the excavator's travel speed and the SOC value of the power module meet the preset requirements, it determines the overall machine travel status based on the electronic accelerator pedal signal and the braking pressure signal in the walking system braking module, and controls the walking system braking module to be in the walking brake braking state and / or the walking motor regenerative braking state based on the overall machine travel status.

[0008] When the main controller determines that the excavator is in digging mode and the travel speed of the excavator meets the preset requirements, it controls the slewing system braking module to be in the slewing brake braking state according to the SOC value of the power module and the slewing speed of the excavator, or controls the slewing system braking module to be in the slewing brake braking state and the slewing motor regenerative braking state at the same time.

[0009] When the walking system braking module is in the walking motor regenerative braking state, or the slewing system braking module is in the slewing motor regenerative braking state, the generated electrical energy is stored in the power supply module.

[0010] Optionally, the braking system further includes a brake fluid source, which is connected to the main controller and is also connected to the travel system braking module and the slewing system braking module, respectively.

[0011] Optionally, the walking system braking module includes: a walking motor controller, a walking motor, a walking brake, a braking electromagnetic proportional valve, a brake valve, a first pressure sensor, and a third pressure sensor;

[0012] The walking motor controller is connected to the main controller, the walking motor and the power module respectively;

[0013] The travel brake is connected to the brake oil source in sequence through the brake electromagnetic proportional valve and the brake valve;

[0014] One end of the first pressure sensor is connected to the main controller, and the other end is connected to the inlet of the travel brake to detect the pressure value at the inlet of the travel brake;

[0015] One end of the third pressure sensor is connected to the main controller, and the other end is connected to the inlet of the brake electromagnetic proportional valve to detect the brake pressure signal at the inlet of the brake electromagnetic proportional valve.

[0016] Optionally, when the excavator is in walking mode, the slewing system braking module is in a braking state;

[0017] When the excavator’s travel speed is greater than or equal to the set value V1, and the SOC value of the power module is less than or equal to the set value S1, the main controller controls the operation of the travel braking system based on the electronic accelerator pedal signal and the braking pressure signal from the third pressure sensor.

[0018] When there is an electronic accelerator pedal signal but no brake pressure signal, the excavator is in normal driving mode. At this time, the travel system braking module is not in the travel brake braking state or the travel motor regenerative braking state.

[0019] When there is no electronic accelerator pedal signal or brake pressure signal, the excavator is in a coasting state, and at this time the travel system braking module is only in the travel motor regenerative braking state.

[0020] When there is only a brake pressure signal and no electronic accelerator pedal signal, the excavator is in a braking state. At this time, the travel system braking module is simultaneously in the travel brake braking state and the travel motor regenerative braking state.

[0021] When the driving speed is less than the set value V1, or the SOC value of the power battery is greater than the set value S1, the regenerative braking state of the walking motor is not allowed to work.

[0022] Optionally, when the walking system braking module is in the walking brake braking state, the main controller controls the brake oil source to provide pressure oil. The pressure oil flows through the brake valve to the third pressure sensor and the brake electromagnetic proportional valve. At this time, the current output by the main controller to the brake electromagnetic proportional valve is zero, the oil port of the brake electromagnetic proportional valve is fully open, and the pressure oil acts on the walking brake, so that the walking brake generates braking torque.

[0023] When the travel system braking module is in the regenerative braking state of the travel motor, the main controller controls the brake oil source to supply pressurized oil. The pressurized oil flows through the brake valve to the third pressure sensor and the brake solenoid proportional valve. At this time, the current output by the main controller to the brake solenoid proportional valve is the rated value, the oil port of the brake solenoid proportional valve is closed, no pressurized oil acts on the travel brake, and no braking torque is generated. The pressure value detected by the third pressure sensor is input to the main controller. When the main controller determines that the regenerative braking conditions are met based on the excavator's travel speed and the SOC value of the power module, the main controller outputs a control signal to the travel motor controller to control the travel motor to be in the regenerative braking state and generate braking torque.

[0024] Optionally, when the travel system braking module is in the travel motor regenerative braking state, the main controller calculates the required braking torque based on the excavator's travel speed, the machine's allowable braking torque limit, and the pressure signal from the third pressure sensor. It then outputs a control signal to the travel motor controller to control the travel motor to be in the regenerative braking state, generating braking torque and achieving the machine's travel motor regenerative braking state. Simultaneously, the main controller outputs a corresponding current to the brake solenoid proportional valve to control the travel brake to operate in the corresponding working state. If an abnormal pressure signal from the first pressure sensor is detected, the travel regenerative braking stops, and the current output to the brake solenoid proportional valve is stopped, allowing the machine to operate entirely in the normal hydraulic braking state. When the excavator's travel speed is less than the set value V1, the travel regenerative braking stops.

[0025] Optionally, the slewing system braking module includes: a slewing motor controller, a slewing motor, a slewing brake, a slewing electromagnetic proportional valve, and a second pressure sensor;

[0026] The rotary motor controller is connected to the main controller, the rotary motor, and the power module, respectively.

[0027] The rotary brake is connected to the brake oil source through the rotary electromagnetic proportional valve.

[0028] One end of the second pressure sensor is connected to the main controller, and the other end is connected to the inlet of the rotary brake to detect the pressure value at the inlet of the travel brake.

[0029] Optionally, when the main controller determines that the excavator is in digging mode:

[0030] When the excavator's travel speed is greater than the set value V2, the travel system braking module is controlled to enter travel regenerative braking mode.

[0031] When the excavator's travel speed is less than or equal to the set value V2, the slewing system braking module is controlled to be in the slewing motor regenerative braking state. The main controller detects the SOC value of the power module. When the SOC value is less than or equal to the set value S1, the main controller detects the excavator's slewing speed. When the slewing speed is greater than or equal to the set value V3, the main controller controls the slewing system braking module to be in both the slewing brake braking state and the slewing motor regenerative braking state. When the SOC value is greater than the set value S1, the slewing system braking module is controlled to be in the slewing brake braking state. When the excavator's slewing speed is less than the set value V3, the slewing system braking module is controlled to be in the slewing brake braking state.

[0032] Optionally, the slewing brake is always in a braking state when no external pressure oil is connected;

[0033] When the slewing system braking module is in the slewing brake braking state, the operator stops operating the slewing handle, the current output by the main controller to the slewing solenoid proportional valve is zero, the oil port of the slewing solenoid proportional valve is closed, and the slewing brake generates braking torque because it is in the braking state.

[0034] When the slewing system braking module is in the slewing motor regenerative braking state, the operator stops operating the slewing handle, the main controller outputs the rated current to the slewing solenoid proportional valve, the slewing solenoid proportional valve port is fully open, the pressure oil acts on the slewing brake to release the slewing brake, the slewing brake does not generate braking torque, at this time the main controller determines that the regenerative braking condition is met, and outputs a control signal to the main motor controller to control the slewing motor to work in the regenerative braking state, generate regenerative braking torque, and realize the whole machine slewing electro-regenerative braking.

[0035] Optionally, when the slewing system braking module is in the slewing motor regenerative braking state, the main controller calculates the required braking torque based on the slewing speed, the allowable braking torque limit of the whole machine, and the pressure signal from the second pressure sensor. It then outputs a control signal to the slewing motor controller to control the slewing motor to be in the regenerative braking state, generating braking torque. Simultaneously, the main controller outputs a corresponding current to the slewing solenoid proportional valve to control the slewing brake to operate in the corresponding working state. If an abnormal pressure signal from the second pressure sensor is detected, the slewing motor regenerative braking state is stopped, and the current output to the brake solenoid proportional valve is also stopped, ensuring that the whole machine's slewing action operates entirely in the normal brake braking state, achieving normal braking of the whole machine's slewing. When the excavator's travel speed is less than the set value V3, the slewing motor regenerative braking state is stopped.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] Based on the braking system for a pure electric wheeled excavator proposed in this invention, when the main controller determines that the excavator is in walking mode, and the excavator's travel speed and the SOC value of the power module meet preset requirements, it determines the overall machine travel state based on the electronic accelerator pedal signal and the braking pressure signal in the walking system braking module, and controls the walking system braking module to be in walking brake braking state and / or walking motor regenerative braking state based on the overall machine travel state; when the main controller determines that the excavator is in digging mode, and the excavator's travel speed meets preset requirements, it then... Based on the SOC value of the power module and the swing speed of the excavator, the swing system braking module is controlled to be in the swing brake braking state, or the swing system braking module is controlled to be in both the swing brake braking state and the swing motor regenerative braking state simultaneously. When the travel system braking module is in the travel motor regenerative braking state, or the swing system braking module is in the swing motor regenerative braking state, the generated electrical energy is stored in the power module. The excavator can recover braking energy during travel gliding and travel braking. The recovered energy is stored through the power battery, increasing the overall range of the pure electric wheeled excavator. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. 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 effort, wherein:

[0039] Figure 1 This is a schematic diagram of the braking system for a pure electric wheeled excavator according to an embodiment of the present invention;

[0040] Figure 2 This is a schematic flowchart of a braking method for a braking system of a pure electric wheeled excavator according to an embodiment of the present invention.

[0041] in:

[0042] 1-Power battery, 2-High voltage junction box, 3-Active motor controller, 4-Walking motor controller, 5-Main pump motor, 6-Slewing motor, 7-Electronic accelerator pedal, 8-Walking motor, 9-Pressure oil source, 10-Main controller, 11-Slewing solenoid proportional valve, 12-Slewing brake, 13-First pressure sensor, 14-Drive system, 15-Brake valve, 16-Second pressure sensor, 17-Slewing reduction mechanism, 18-Third pressure sensor, 19-Brake solenoid proportional valve, 20-Walking brake. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may include different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0045] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0046] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The application principle of the present invention will be described in detail below with reference to the accompanying drawings.

[0048] This invention provides a braking system for a pure electric wheeled excavator, such as... Figure 1 As shown, it includes: a main controller 10, and a power module, an electronic accelerator pedal 7, a walking system braking module and a turning system braking module connected to the main controller 10;

[0049] When the main controller 10 determines that the excavator is in walking mode, and the excavator's travel speed and the SOC value of the power module meet the preset requirements, it determines the overall machine travel status based on the electronic accelerator pedal signal and the braking pressure signal in the walking system braking module, and controls the walking system braking module to be in the walking brake braking state and / or the walking motor regenerative braking state based on the overall machine travel status.

[0050] When the main controller 10 determines that the excavator is in digging mode and the travel speed of the excavator meets the preset requirements, it controls the slewing system braking module to be in the slewing brake braking state according to the SOC value of the power module and the slewing speed of the excavator, or controls the slewing system braking module to be in both the slewing brake braking state and the slewing motor regenerative braking state at the same time.

[0051] When the walking system braking module is in the walking motor regenerative braking state, or the slewing system braking module is in the slewing motor regenerative braking state, the generated electrical energy is stored in the power supply module.

[0052] In one specific embodiment of the present invention, the braking system further includes a brake fluid source, which is connected to the main controller 10 and connected to the travel system braking module and the slewing system braking module, respectively. In a specific implementation, the brake fluid source includes a connected main pump motor 5 and a pressure oil source 9. The main pump motor 5 is connected to the main pump controller, and the pressure oil source 9 is connected to the oil circuits of the slewing electromagnetic proportional valve 11 and the brake valve 15, respectively. In a specific implementation, the main pump controller and the slewing motor controller are integrated into a main motor controller 3.

[0053] In one specific embodiment of the present invention, the walking system braking module includes: a walking motor controller 4, a walking motor 8, a walking brake 20, a braking electromagnetic proportional valve 19, a brake valve 15, a first pressure sensor 13, a third pressure sensor 18, and a drive system 14.

[0054] The walking motor controller 4 is connected to the main controller 10, the walking motor 8 and the power module respectively;

[0055] The travel brake 20 is connected to the brake oil source in sequence through the brake electromagnetic proportional valve 19 and the brake valve 15.

[0056] The drive system 14 is connected between the travel brake 20 and the travel motor 8;

[0057] One end of the first pressure sensor 13 is connected to the main controller 10, and the other end is connected to the inlet of the travel brake 20 to detect the pressure value at the inlet of the travel brake 20.

[0058] One end of the third pressure sensor 18 is connected to the main controller 10, and the other end is connected to the inlet of the brake electromagnetic proportional valve 19 to detect the brake pressure signal at the inlet of the brake electromagnetic proportional valve 19.

[0059] In one specific embodiment of the present invention, the power module includes a connected power battery 1 and a high-voltage junction box 2. The power battery 1 is connected to the main controller 10, and the walking motor controller 4 and the main motor controller 3 are both connected to the high-voltage junction box 2.

[0060] When the excavator is in walking mode, the slewing system braking module is in braking state;

[0061] When the excavator’s travel speed is greater than or equal to the set value V1 and the SOC value of the power module is less than or equal to the set value S1, the main controller 10 controls the operation of the travel braking system based on the electronic accelerator pedal signal and the braking pressure signal of the third pressure sensor 18.

[0062] When there is an electronic accelerator pedal signal but no brake pressure signal, the excavator is in normal driving mode. At this time, the travel system braking module is not in the travel brake braking state or the travel motor regenerative braking state.

[0063] When there is no electronic accelerator pedal signal or brake pressure signal, the excavator is in a coasting state, and at this time the travel system braking module is only in the travel motor regenerative braking state.

[0064] When there is only a brake pressure signal and no electronic accelerator pedal signal, the excavator is in a braking state. At this time, the travel system braking module is simultaneously in the travel brake braking state and the travel motor regenerative braking state.

[0065] When the driving speed is less than the set value V1, or the SOC value of the power battery is greater than the set value S1, the regenerative braking state of the walking motor is not allowed to work.

[0066] When the walking system braking module is in the walking brake braking state, the main controller 10 controls the brake oil source to provide pressure oil. The pressure oil flows through the brake valve 15 to the third pressure sensor 18 and the brake electromagnetic proportional valve 19. At this time, the current output by the main controller 10 to the brake electromagnetic proportional valve 19 is zero, the oil port of the brake electromagnetic proportional valve 19 is fully open, and the pressure oil acts on the walking brake 20, so that the walking brake 20 generates braking torque.

[0067] When the travel system braking module is in the regenerative braking state of the travel motor, the main controller 10 controls the brake oil source to provide pressurized oil. The pressurized oil flows through the brake valve 15 to the third pressure sensor 18 and the brake solenoid proportional valve 19. At this time, the current output by the main controller 10 to the brake solenoid proportional valve 19 is the rated value, the oil port of the brake solenoid proportional valve 19 is closed, no pressurized oil acts on the travel brake 20, and no braking torque is generated. The pressure value detected by the third pressure sensor 18 is input to the main controller 10. When the main controller 10 determines that the regenerative braking conditions are met based on the excavator's travel speed and the SOC value of the power module, the main controller 10 outputs a control signal to the travel motor controller 4 to control the travel motor 8 to be in the regenerative braking state, generating braking torque. Specifically:

[0068] When the travel system braking module is in the travel motor regenerative braking state, the main controller 10 calculates the required braking torque based on the excavator's travel speed, the machine's allowable braking torque limit, and the pressure signal from the third pressure sensor 18. It then outputs a control signal to the travel motor controller 4 to control the travel motor 8 in the regenerative braking state, generating braking torque and achieving the machine's travel motor regenerative braking state. Simultaneously, the main controller 10 outputs a corresponding current to the brake solenoid proportional valve 19 to control the travel brake 20 to operate in the corresponding working state. If an abnormal pressure signal is detected from the first pressure sensor 13, the travel regenerative braking stops, and the current output to the brake solenoid proportional valve 19 is stopped, allowing the machine to operate entirely in the normal hydraulic braking state. When the excavator's travel speed is less than the set value V1, the travel regenerative braking stops.

[0069] In one specific embodiment of the present invention, such as Figure 1 As shown, the slewing system braking module includes: a slewing motor controller, a slewing motor 6, a slewing brake 12, a slewing electromagnetic proportional valve 11, a second pressure sensor 16, and a slewing deceleration mechanism 17;

[0070] The rotary motor controller is connected to the main controller 10, the rotary motor 6 and the power module respectively;

[0071] The rotary brake 12 is connected to the brake oil source through the rotary electromagnetic proportional valve 11;

[0072] The rotary deceleration mechanism 17 is mechanically connected to the rotary brake 12;

[0073] One end of the second pressure sensor 16 is connected to the main controller 10, and the other end is connected to the inlet of the rotary brake 12 to detect the pressure value at the inlet of the rotary brake 12.

[0074] When the main controller 10 determines that the excavator is in digging mode:

[0075] When the excavator's travel speed is greater than the set value V2, the travel system braking module is controlled to enter travel regenerative braking mode.

[0076] When the excavator's travel speed is less than or equal to the set value V2, the slewing system braking module is controlled to be in the slewing motor regenerative braking state. The main controller 10 detects the SOC value of the power module. When the SOC value is less than or equal to the set value S1, the main controller 10 detects the excavator's slewing speed. When the slewing speed is greater than or equal to the set value V3, the main controller 10 controls the slewing system braking module to be in both the slewing brake braking state and the slewing motor regenerative braking state. When the SOC value is greater than the set value S1, the slewing system braking module is controlled to be in the slewing brake braking state. When the excavator's slewing speed is less than the set value V3, the slewing system braking module is controlled to be in the slewing brake braking state.

[0077] The rotary brake 12 is always in a braking state when no external pressure oil is connected;

[0078] When the slewing system braking module is in the slewing brake braking state, the operator stops operating the slewing handle, the current output by the main controller 10 to the slewing electromagnetic proportional valve 11 is zero, the oil port of the slewing electromagnetic proportional valve 11 is closed, and the slewing brake 12 generates braking torque because it is in the braking state.

[0079] When the slewing system braking module is in the slewing motor regenerative braking state, the operator stops operating the slewing handle. The current output from the main controller 10 to the slewing solenoid proportional valve 11 is at its rated value, the oil port of the slewing solenoid proportional valve 11 is fully open, and the pressurized oil acts on the slewing brake 12 to release the slewing brake. The slewing brake 12 does not generate braking torque. At this time, the main controller 10 determines that the regenerative braking condition is met, and outputs a control signal to the main motor controller 3 to control the slewing motor 6 to work in the regenerative braking state, generating regenerative braking torque, thereby realizing the overall machine slewing electro-regenerative braking. Specifically:

[0080] When the slewing system braking module is in the slewing motor regenerative braking state, the main controller 10 calculates the required braking torque based on the slewing speed, the allowable braking torque limit of the whole machine, and the pressure signal of the second pressure sensor 16. It then outputs a control signal to the slewing motor controller to control the slewing motor 6 to be in the regenerative braking state, generating braking torque. Simultaneously, the main controller 10 outputs a corresponding current to the slewing solenoid proportional valve 11 to control the slewing brake 12 to operate in the corresponding working state. If an abnormal pressure signal is detected from the second pressure sensor 16, the slewing motor regenerative braking state is stopped, and the current output to the braking solenoid proportional valve 19 is stopped, ensuring the whole machine's slewing action operates entirely in the normal braking state, achieving normal braking of the whole machine's slewing. When the excavator's travel speed is less than the set value V3, the slewing motor regenerative braking state is stopped.

[0081] The following is combined with Figure 2 right Figure 1The detailed working process of the braking system in the middle is explained.

[0082] Excavator operating modes are divided into walking mode and working mode.

[0083] When the excavator is in walking mode, it can only perform walking operations. At this time, the main controller 10 restricts the whole machine's excavation operations, including slewing.

[0084] When the excavator's travel speed is greater than or equal to the set value V1, and the SOC value of the power module (which can be the power battery 1) is less than or equal to the set value S1, the main controller 10 controls the operation of the travel system braking module according to the electronic accelerator pedal signal and the braking pressure signal from the third pressure sensor 18. Specifically: when there is an electronic accelerator pedal signal but no braking pressure signal, the excavator is in normal travel mode, and neither the travel brake nor the travel regenerative brake works; when there is neither an electronic accelerator pedal signal nor a braking pressure signal, the excavator is in coasting mode, and only the travel regenerative brake works; when there is only a braking pressure signal but no electronic accelerator pedal signal, the excavator is in normal travel braking mode, and both the travel brake and the travel regenerative brake work simultaneously.

[0085] When the excavator's travel speed is less than the set value V1, or the SOC value of the power module (which can be the power battery 1) is greater than the set value S1, the travel system braking module is not in the travel motor regenerative braking state.

[0086] During regenerative braking, the main controller 10 calculates the required braking torque based on the excavator's travel speed, the machine's permissible braking torque limit, and the braking pressure signal from the third pressure sensor 18. It then outputs a control signal to the travel motor controller 4, thereby controlling the travel motor 8 to enter regenerative braking mode and generate braking torque, achieving regenerative braking of the entire machine. Simultaneously, the main controller 10 outputs a corresponding current to the brake solenoid proportional valve 19 to control the travel brake 20 in the appropriate operating state. If an abnormal pressure signal is detected from the first pressure sensor 13, the regenerative braking stops, and the current output to the brake solenoid proportional valve 19 is stopped, ensuring the machine operates entirely in normal travel brake mode and guaranteeing safe vehicle operation. The regenerative braking stops when the excavator's travel speed is less than the set value V1.

[0087] When the excavator is in digging mode, it can perform both traveling and full-machine digging operations, including slewing. In this mode, when the excavator's traveling speed is greater than the set value V2, the traveling regenerative braking is activated. The main controller 10 detects the excavator's slewing speed and SOC value. When the SOC value is less than or equal to the set value S1, the main controller 10 further detects the slewing speed. When the slewing speed is greater than or equal to the set value V3, the slewing brake 12 and the slewing motor regenerative braking operate simultaneously. When the SOC value is greater than the set value S1, the slewing motor regenerative braking is not allowed to operate, and only the slewing brake 12 applies braking. When the excavator's slewing speed is less than the set value V3, the slewing motor regenerative braking is not allowed to operate, and only the slewing brake 12 applies braking.

[0088] When the rotary motor regenerative braking is in operation, the main controller 10 calculates the required braking torque based on the rotational speed, the allowable braking torque limit of the entire machine, and the pressure signal from the second pressure sensor 16. It then outputs a control signal to the rotary motor controller to control the rotary motor 6 into a regenerative braking state, generating braking torque and achieving regenerative braking of the entire machine's rotary motor. Simultaneously, the main controller 10 outputs a corresponding current to the rotary solenoid proportional valve 11 to control the rotary brake 12 to operate in the correct state. If an abnormal pressure signal from the second pressure sensor 16 is detected, the rotary motor regenerative braking stops, and the current output to the brake solenoid proportional valve 19 is stopped, ensuring the entire machine's rotational action operates entirely in the normal rotary brake braking state, achieving normal braking of the entire machine's rotation. When the rotational speed is less than the set value V3, the rotary motor regenerative braking stops operating.

[0089] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention.

[0090] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A braking system for a pure electric wheeled excavator, characterized in that, include: The main controller, and a power module, an electronic accelerator pedal, a walking system braking module, and a turning system braking module connected to the main controller; When the main controller determines that the excavator is in walking mode, and the excavator's travel speed and the SOC value of the power module meet the preset requirements, it determines the overall machine travel status based on the electronic accelerator pedal signal and the braking pressure signal in the walking system braking module, and controls the walking system braking module to be in the walking brake braking state and / or the walking motor regenerative braking state based on the overall machine travel status. When the main controller determines that the excavator is in digging mode and the travel speed of the excavator meets the preset requirements, it controls the slewing system braking module to be in the slewing brake braking state according to the SOC value of the power module and the slewing speed of the excavator, or controls the slewing system braking module to be in the slewing brake braking state and the slewing motor regenerative braking state at the same time. When the walking system braking module is in the walking motor regenerative braking state, or the slewing system braking module is in the slewing motor regenerative braking state, the generated electrical energy is stored in the power supply module. The braking system also includes a brake fluid source, which is connected to the main controller and is also connected to the travel system braking module and the slewing system braking module, respectively. The slewing system braking module includes: a slewing motor controller, a slewing motor, a slewing brake, a slewing electromagnetic proportional valve, and a second pressure sensor; The rotary motor controller is connected to the main controller, the rotary motor, and the power module, respectively. The rotary brake is connected to the brake oil source through the rotary electromagnetic proportional valve. One end of the second pressure sensor is connected to the main controller, and the other end is connected to the inlet of the rotary brake to detect the pressure value at the inlet of the rotary brake; When the main controller determines that the excavator is in digging mode: When the excavator's travel speed is greater than the set value V2, the travel system braking module is controlled to enter travel regenerative braking mode. When the excavator's travel speed is less than or equal to the set value V2, the slewing system braking module is controlled to be in the slewing motor regenerative braking state. The main controller detects the SOC value of the power module. When the SOC value is less than or equal to the set value S1, the main controller detects the excavator's slewing speed. When the slewing speed is greater than or equal to the set value V3, the main controller controls the slewing system braking module to be in both the slewing brake braking state and the slewing motor regenerative braking state. When the SOC value is greater than the set value S1, the slewing system braking module is controlled to be in the slewing brake braking state. When the excavator's slewing speed is less than the set value V3, the slewing system braking module is controlled to be in the slewing brake braking state.

2. The braking system for a pure electric wheeled excavator according to claim 1, characterized in that: The walking system braking module includes: a walking motor controller, a walking motor, a walking brake, a braking electromagnetic proportional valve, a brake valve, a first pressure sensor, and a third pressure sensor. The walking motor controller is connected to the main controller, the walking motor and the power module respectively; The travel brake is connected to the brake oil source in sequence through the brake electromagnetic proportional valve and the brake valve; One end of the first pressure sensor is connected to the main controller, and the other end is connected to the inlet of the travel brake to detect the pressure value at the inlet of the travel brake; One end of the third pressure sensor is connected to the main controller, and the other end is connected to the inlet of the brake electromagnetic proportional valve to detect the brake pressure signal at the inlet of the brake electromagnetic proportional valve.

3. A braking system for a pure electric wheeled excavator according to claim 2, characterized in that: When the excavator is in walking mode, the slewing system braking module is in braking state; When the excavator’s travel speed is greater than or equal to the set value V1, and the SOC value of the power module is less than or equal to the set value S1, the main controller controls the operation of the travel braking system based on the electronic accelerator pedal signal and the braking pressure signal from the third pressure sensor. When there is an electronic accelerator pedal signal but no brake pressure signal, the excavator is in normal driving mode. At this time, the travel system braking module is not in the travel brake braking state or the travel motor regenerative braking state. When there is no electronic accelerator pedal signal or brake pressure signal, the excavator is in a coasting state, and at this time the travel system braking module is only in the travel motor regenerative braking state. When there is only a brake pressure signal and no electronic accelerator pedal signal, the excavator is in a braking state. At this time, the travel system braking module is simultaneously in the travel brake braking state and the travel motor regenerative braking state. When the driving speed is less than the set value V1, or the SOC value of the power battery is greater than the set value S1, the regenerative braking state of the walking motor is not allowed to work.

4. A braking system for a pure electric wheeled excavator according to claim 2 or 3, characterized in that: When the braking module of the walking system is in the walking brake braking state, the main controller controls the brake oil source to provide pressure oil. The pressure oil flows through the brake valve to the third pressure sensor and the brake electromagnetic proportional valve. At this time, the current output by the main controller to the brake electromagnetic proportional valve is zero, the oil port of the brake electromagnetic proportional valve is fully open, and the pressure oil acts on the walking brake, so that the walking brake generates braking torque. When the travel system braking module is in the regenerative braking state of the travel motor, the main controller controls the brake oil source to supply pressurized oil. The pressurized oil flows through the brake valve to the third pressure sensor and the brake solenoid proportional valve. At this time, the current output by the main controller to the brake solenoid proportional valve is the rated value, the oil port of the brake solenoid proportional valve is closed, no pressurized oil acts on the travel brake, and no braking torque is generated. The pressure value detected by the third pressure sensor is input to the main controller. When the main controller determines that the regenerative braking conditions are met based on the excavator's travel speed and the SOC value of the power module, the main controller outputs a control signal to the travel motor controller to control the travel motor to be in the regenerative braking state and generate braking torque.

5. A braking system for a pure electric wheeled excavator according to claim 4, characterized in that: When the travel system braking module is in the travel motor regenerative braking state, the main controller calculates the required braking torque based on the excavator's travel speed, the machine's allowable braking torque limit, and the pressure signal from the third pressure sensor. It then outputs a control signal to the travel motor controller to control the travel motor in the regenerative braking state, generating braking torque and achieving regenerative braking of the entire machine's travel motor. Simultaneously, the main controller outputs a corresponding current to the brake solenoid proportional valve to control the travel brake in the appropriate operating state. If an abnormal pressure signal from the first pressure sensor is detected, the travel regenerative braking stops, and the current output to the brake solenoid proportional valve is stopped, ensuring the machine operates entirely in normal hydraulic braking mode. When the excavator's travel speed is less than the set value V1, the travel regenerative braking stops.

6. A braking system for a pure electric wheeled excavator according to claim 1, characterized in that: The rotary brake is always in a braking state when no external pressure oil is connected. When the slewing system braking module is in the slewing brake braking state, the operator stops operating the slewing handle, the current output by the main controller to the slewing solenoid proportional valve is zero, the oil port of the slewing solenoid proportional valve is closed, and the slewing brake generates braking torque because it is in the braking state. When the slewing system braking module is in the slewing motor regenerative braking state, the operator stops operating the slewing handle, the main controller outputs the rated current to the slewing solenoid proportional valve, the slewing solenoid proportional valve port is fully open, the pressure oil acts on the slewing brake to release the slewing brake, the slewing brake does not generate braking torque, at this time the main controller determines that the regenerative braking condition is met, and outputs a control signal to the main motor controller to control the slewing motor to work in the regenerative braking state, generate regenerative braking torque, and realize the whole machine slewing electro-regenerative braking.

7. A braking system for a pure electric wheeled excavator according to claim 6, characterized in that: When the slewing system braking module is in the slewing motor regenerative braking state, the main controller calculates the required braking torque based on the slewing speed, the allowable braking torque limit of the whole machine, and the pressure signal from the second pressure sensor. It then outputs a control signal to the slewing motor controller to control the slewing motor in the regenerative braking state, generating braking torque. Simultaneously, the main controller outputs a corresponding current to the slewing solenoid proportional valve to control the slewing brake in the corresponding working state. If an abnormal pressure signal from the second pressure sensor is detected, the slewing motor regenerative braking state is stopped, and the current output to the brake solenoid proportional valve is also stopped, ensuring the whole machine's slewing action operates entirely in the normal braking state, achieving normal braking of the whole machine's slewing. When the excavator's travel speed is less than the set value V3, the slewing motor regenerative braking state is stopped.

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