Small-tonnage electric excavator

Abstract

The invention discloses a small-tonnage electric excavator which comprises a cab, a rotary table, a PTC heater A, a PTC heater B, a hydraulic pump, a motor, a high-voltage junction box, a compressor, a radiator module, a heat exchanger, a hydraulic oil tank, a battery pack, a four-in-one controller, a BMS, a vehicle-mounted charger, a starting storage battery, a power main switch, a condenser assembly, an evaporator box, an electronic expansion valve and a hydraulic execution element. The cab is arranged on one side in front of the rotary table, the lower end of the cab is of a special-shaped structure, namely, a notch is formed in the lower portion of the rear side of the cab, and a double-layer support is arranged in the notch and used for supporting the cab and the rotary table. The high-voltage junction box and the compressor are arranged on the upper layer of the double-layer support, other parts are all arranged above the rotary table, the cab is designed in a special shape, the problems of insufficient space, insufficient electric quantity and disordered pipelines are solved, and the problem of poor heat management capacity of the whole machine is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery, and particularly relates to a small-tonnage electric excavator. Background Art

[0002] In recent years, the electrification process of construction machinery has developed rapidly. Compared with traditional fuel excavators, electric excavators have natural advantages in aspects such as "carbon emission reduction" and "noise reduction". However, due to the limitations of size and structure, the distance between electrical components and hydraulic components of small-tonnage electric excavators with a weight of 1.5t - 3.5t is very small, resulting in poor heat dissipation performance. The excessively high temperature environment inside the whole machine seriously affects the performance and lifespan of components such as batteries, motors, and electronic control units, and there are also certain potential safety hazards.

[0003] Patent document publication number CN117445761A discloses a layout of an electric excavator. However, for small-tonnage excavators with a whole-machine weight less than 3.5t, their height and width dimensions are limited, and it is impossible to arrange the battery pack and the motor side by side left and right as in patent document publication number CN117445761A. As a result, patent document CN 117445761 A also has the following disadvantages: (1) The heating and cooling of the battery pack, and the cooling of the motor and hydraulic components cannot be independently and precisely controlled; (2) Problems such as chaotic pipeline levels of the whole machine, abnormal heat dissipation, hot and cold air backflow, and abnormal temperature of the whole machine. Summary of the Invention

[0004] Aiming at the problems existing in the above-mentioned prior art, the present invention provides a small-tonnage electric excavator, which re-adjusts the layout of the electric excavator when the whole-machine weight is less than 3.5t, so that its temperature management is solved, and the problem of poor thermal management ability of the whole machine caused by the small space size of the mini electric excavator is solved.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a small-tonnage electric excavator, including: a cab, a turntable, PTC heater A, PTC heater B, a hydraulic pump, a motor, a high-voltage junction box, a compressor, a radiator module, a heat exchanger, a hydraulic oil tank, a battery pack, a four-in-one controller, a BMS, an on-vehicle charger, a starting battery, a main power switch, a condenser assembly, an evaporator box, an electronic expansion valve, and a hydraulic actuator. The cab is arranged on the front side of the turntable. The lower end of the cab has a special-shaped structure, that is, there is a notch at the lower part of the rear side of the cab, and a double-layer bracket is arranged in the notch for supporting between the cab and the turntable. The hydraulic pump transmits hydraulic oil to the hydraulic actuator. The motor is connected in series with the hydraulic pump and is located under the double-layer bracket. The high-voltage junction box and the compressor are arranged on the upper layer of the double-layer bracket. The rest of the components are all arranged above the turntable. When connecting the components, the principle of hierarchical layout is followed: high-voltage wires are inside, low-voltage wires are in the middle, and water circuits are on the outside.

[0006] The BMS is the battery management system. The four-in-one integrated controller includes a DCDC controller, a VCU (vehicle control unit), an MCU (motor controller), and a PDU (high-voltage distribution unit).

[0007] Further, the radiator module and the hydraulic oil tank are arranged on the turntable on one side of the cab. The compressor is arranged between the motor and the radiator module. The hydraulic pump, the motor, the compressor, and the radiator module are arranged side by side in the front-rear direction.

[0008] Further, the battery pack is arranged at the tail of the turntable and the notch of the cab. The four-in-one controller and the on-vehicle charger are located on the battery pack. The BMS is placed at the rear side of the battery pack. The four-in-one controller and the on-vehicle charger are arranged side by side in the height direction. The heat exchanger is arranged on the side of the cab notch away from the radiator module.

[0009] Further, the hydraulic oil tank is arranged at the front side of the radiator module. The condenser assembly is arranged in front of the hydraulic oil tank. The evaporator box is arranged on one side of the hydraulic oil tank and the condenser assembly and is partially embedded under the notch of the cab. The electronic expansion valve is arranged at the front side of the evaporator box.

[0010] Further, it further includes a housing A and a housing B. The housing A and the housing B are installed on the turntable and the cab. A cavity one is formed between the housing A and the turntable and the cab. A cavity two is formed between the housing B and the turntable and the cab.

[0011] Further, the hydraulic pump, the motor, the compressor, the radiator module, the high-voltage junction box, the battery pack, the four-in-one controller, the on-vehicle charger, and the BMS are arranged in the cavity one. The water inlets of the motor, the four-in-one controller, and the on-vehicle charger are connected to the radiator module through pipelines. The battery pack, the PTC heater A, and the heat exchanger are connected through water pipes. The hydraulic oil tank, the condenser assembly, the evaporator box, and the PTC heater B are arranged in the cavity two.

[0012] Further, the charging port and the wiring port of the battery pack are arranged on the housing A on the side away from the condenser assembly. The starting battery and the main power switch are arranged in the cavity one and are arranged on the same side as the condenser assembly. The main power switch is installed on the housing A.

[0013] Further, two air inlet holes are provided on the bottom plate of the turntable. One air inlet hole is also provided on the turntable of the cavity one, and the other air inlet hole is also provided on the turntable of the cavity two. The housing A is provided with an air outlet hole on the side facing the fan of the radiator module to form an air duct in the cavity one to ensure the normal operation of the radiator module. The housing B is provided with an air outlet hole on the side facing the fan of the condenser assembly to form an air duct in the cavity two to ensure the normal operation of the condenser assembly.

[0014] Furthermore, three sets of electric water pumps, namely electric water pump A, electric water pump B, and electric water pump C, are arranged near the interfaces of the battery pack, radiator module, and PTC heater B.

[0015] Furthermore, the refrigerant circuit of the air-conditioning system in the cooling mode: compressor, condenser assembly, electronic expansion valve, evaporator box and heat exchanger, compressor; The water circuit of the air-conditioning system in the heating mode: electric water pump C, PTC heater B, evaporator box, electric water pump C; The cooling (heating) water circuit of the battery thermal management system: electric water pump A, battery, heat exchanger (PTC heater A), electric water pump A; The water circuit of the electrical cooling system: electric water pump B, motor, four-in-one controller, on-board charger, radiator module, electric water pump B; The oil circuit of the hydraulic cooling system: hydraulic oil tank, hydraulic components, condenser assembly, hydraulic oil tank.

[0016] Furthermore, the refrigerant pipelines in the air-conditioning system and the battery thermal management system are integrated, and solenoid valves are provided to adjust the refrigerant distribution ratio according to the temperature sensors in the battery and the cab. The radiator module is an air-cooled radiator, which includes: a cooling core, a temperature sensor, and a fan. When the coolant flows through the cooling core, the fan takes away the excess heat. The temperature sensor is installed at the outlet of the cooling core to detect the temperature of the coolant in real time, and adjusts the fan speed of the air-cooled radiator according to the temperature to regulate the heat dissipation power and keep the coolant within a certain temperature range.

[0017] Furthermore, the front end of the cab is hinged to the turntable to make it a flip-up cab.

[0018] The beneficial effects of the present invention are: 1) The battery system and the air-conditioning system share a heat exchanger for cooling, saving costs and space; 2) The air-conditioning system, battery system, electric control cooling system, and hydraulic oil cooling system can respectively achieve thermal management of the components they are responsible for, achieving the purpose of precise temperature control and solving the problem of poor thermal management ability of the whole machine; 3) When the whole machine is connected, it follows the principle of hierarchical layout with high-voltage harnesses on the inside, low-voltage harnesses in the middle, and water circuits on the outside, improving the safety performance of the whole machine; 4) Through the special-shaped design of the cab, it is hierarchically arranged below to solve the problem of insufficient space, save volume, and at the same time use a battery instead of a counterweight to ensure the problems of insufficient power and disordered pipelines of the electric excavator; 5) Through the layout of the whole machine, the problem of poor thermal management ability of the mini electric excavator caused by its small space size, which affects the working efficiency, is solved, making it small in size, strong in thermal management ability, and stable in working efficiency. Brief Description of the Drawings

[0019] Figure 1 This is a schematic diagram of a part of the cavity for the overall machine component layout of the present invention; Figure 2 This is a schematic diagram of the cavity for the overall machine component layout of the present invention; Figure 3 This is a schematic diagram of the second cavity for the overall machine component layout of the present invention; Figure 4 This is a schematic diagram of the front side of the overall structure of the cavity for the overall machine component layout of the present invention; Figure 5 This is a schematic diagram of the rear side of the overall structure of the cavity for the overall machine component layout of the present invention; In the figure: 1. Cab; 2. Slewing platform; 31. Electronic water pump A; 32. Electronic water pump B; 33. Electronic water pump C; 41. PTC heater A; 42. PTC heater B; 5. Hydraulic pump; 6. Motor; 7. High-voltage junction box; 8. Compressor; 9. Radiator module; 10. Heat exchanger; 11. Hydraulic oil tank; 12. Battery pack; 13. Four-in-one controller; 14. BMS; 15. On-vehicle charger; 16. Starting battery; 17. Main power switch; 18. Condenser assembly; 19. Evaporator box; 20. Electronic expansion valve. Detailed Description of the Preferred Embodiment

[0020] To make the objectives, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention.

[0022] Such as Figures 1-5As shown in the figure, a small-tonnage electric excavator includes: a cab 1, a turntable 2, a PTC heater A41, a PTC heater B42, a hydraulic pump 5, an electric motor 6, a high-voltage junction box 7, a compressor 8, a radiator module 9, a heat exchanger 10, a hydraulic oil tank 11, a battery pack 12, a four-in-one controller 13, a BMS14, an on-vehicle charger 15, a starting battery 16, a main power switch 17, a condenser assembly 18, an evaporator box 19, an electronic expansion valve 20, and hydraulic actuators. The cab 1 is arranged on the front side of the turntable 2. The lower end of the cab 1 has a special-shaped structure, that is, there is a notch at the lower part of the rear side of the cab 1, and a double-layer bracket is arranged in the notch for supporting between the cab 1 and the turntable 2. The hydraulic pump 5 transfers hydraulic oil to the hydraulic actuators. The electric motor 6 is connected in series with the hydraulic pump 5 and is located under the lower layer of the double-layer bracket. The high-voltage junction box 7 and the compressor 8 are arranged on the upper layer of the double-layer bracket. The rest of the components are all arranged above the turntable 2.

[0023] For the convenience of maintenance, the front end of the cab 1 is hinged to the turntable 2 to make the cab 1 rotatable, which is convenient for maintaining the components below the cab 1. The lower end of the corresponding double-layer bracket is fixed to the turntable 2, and the upper end is used to support the cab 1 and is fixed to the cab 1 in a detachable manner, such as buckles, locks, etc.

[0024] The four-in-one controller 13, the on-vehicle charger 15, and the high-voltage junction box 7 can be interchanged in position.

[0025] The hydraulic actuators are used to control the working device of the excavator. The working device is installed on the turntable 2. The fan of the condenser assembly 18 is a blowing type, and the radiator module 9 is a suction type. The battery pack 12 is arranged with multiple batteries in the up-and-down direction.

[0026] In this example, the cab 1 is located at the left front of the turntable 2. The radiator module 9 and the hydraulic oil tank 11 are arranged on the turntable 2 on the right side of the cab 1. The compressor 8 is arranged between the electric motor 6 and the radiator module 9. The hydraulic pump 5, the electric motor 6, the compressor 8, and the radiator module 9 are arranged side by side in the front-rear direction.

[0027] The battery pack 12 is arranged at the tail of the turntable 2 and at the notch of the cab 1. The four-in-one controller 13 and the on-vehicle charger 15 are located on the battery pack 12. The BMS14 is placed at the rear side of the battery pack 12. The four-in-one controller 13 and the on-vehicle charger 15 are arranged side by side in the height direction. The BMS14 is electrically connected to the battery pack 12. The heat exchanger 10 is arranged on the side of the notch of the cab 1 away from the radiator module 9, that is, between the battery pack 12 and the hydraulic pump 5 and close to the left side of the whole machine.

[0028] The hydraulic oil tank 11 is arranged on the front side of the radiator module 9, the condenser assembly 18 is arranged in front of the hydraulic oil tank 11, the evaporator box 19 is arranged on the left side of the hydraulic oil tank 11 and the condenser assembly 18 and partially embedded under the notch of the cab 1, and the electronic expansion valve 20 is arranged on the front side of the evaporator box 19.

[0029] The small-tonnage electric excavator further includes a housing A and a housing B. The housing A and the housing B are installed on the slewing platform 2 and the cab 1. A cavity one is formed between the housing A and the slewing platform 2 and the cab 1, and a cavity two is formed between the housing B and the slewing platform 2 and the cab 1.

[0030] The hydraulic pump 5, the motor 6, the compressor 8, the radiator module 9, the high-voltage junction box 7, the battery pack 12, the four-in-one controller 13, the on-vehicle charger 15, and the BMS 14 are arranged in the cavity one. The water ports of the motor 6, the four-in-one controller 13, and the on-vehicle charger 15 are connected to the radiator module 9 through pipelines. The battery pack 12, the PTC heater A 41, and the heat exchanger 10 are connected through water pipes. The hydraulic oil tank 11, the condenser assembly 18, the evaporator box 19, and the PTC heater B 42 are arranged in the cavity two.

[0031] Among them, the cavity one and the cavity two refer to relatively enclosed spaces, and the shape of the cavity can be adjusted according to the overall machine shape. In this example, the cavity one is an L-shaped cavity, and the cavity two is a cubic structure.

[0032] The charging port and the wiring port of the battery pack 12 are arranged on the right side housing A of the whole machine far from the condenser assembly 18. The starting battery 16 and the main power switch 17 are arranged in the left side of the cavity one and on the same side as the condenser assembly 18. The starting battery 16 is arranged near the tail of the slewing platform 2, and the main power switch 17 is installed on the housing A.

[0033] Two air inlet holes are arranged on the bottom plate of the slewing platform 2. One air inlet hole is also arranged on the slewing platform 2 of the cavity one, and the other air inlet hole is also arranged on the slewing platform 2 of the cavity two. The housing A is provided with an air outlet hole on the side facing the fan of the radiator module 9 to form an air duct in the cavity one to ensure the normal operation of the radiator module 9. The housing B is provided with an air outlet hole on the side facing the fan of the condenser assembly 18 to form an air duct in the cavity two to ensure the normal operation of the condenser assembly 18.

[0034] To control the flow rate of the coolant, three groups of electronic water pumps, namely electronic water pump A 31, electronic water pump B 32, and electronic water pump C 33, are arranged near the interfaces of the battery pack 12, the radiator module 9, and the PTC heater B 42.

[0035] Refrigerant circuit in the refrigeration mode of the air-conditioning system: compressor 8, condenser assembly 18, electronic expansion valve 20, evaporator box 19, heat exchanger 10, compressor 8; Heating mode water circuit of the air conditioning system: Electric water pump C33, PTC heater B42, evaporator box 19, electric water pump C33; Refrigeration (heating) water circuit of the battery thermal management system: Electric water pump A31, battery, heat exchanger 10 (PTC heater A41), electric water pump A31; Water circuit of the electrical cooling system: Electric water pump B32, motor 6, four-in-one controller 13, on-vehicle charger 15, radiator module 9, electric water pump B32; Oil circuit of the hydraulic cooling system: Hydraulic oil tank 11, hydraulic components, condenser assembly 18, hydraulic oil tank 11.

[0036] The air conditioning system, battery thermal management system, and hydraulic cooling system are connected in the pipeline according to the above circuits.

[0037] The air conditioning system and the battery thermal management system adopt refrigerant pipeline integration. Solenoid valves are set to adjust the refrigerant distribution ratio according to the temperature sensors in the battery and the cab 1. For example, when the battery in the battery pack 12 generates high heat during charging and needs to be cooled, the refrigerant ratio allocated to the battery is increased; after the refrigerant passes through the condenser assembly 18, it can reach a lower temperature. When passing through the heat exchanger 10 along the pipeline, it exchanges heat with the coolant water of the battery, reducing the water temperature and realizing the cooling of the battery; the refrigeration principle of the air conditioner is the same as that of the air conditioner of a fuel excavator. Among them, the air conditioning system and the battery are equipped with independent heaters and pipelines, namely PTC heater A41 and PTC heater B42. In the heating mode, PTC heater A41 and PTC heater B42 start to work to heat the water; The radiator module 9 is an air-cooled radiator. The air-cooled radiator includes: a cooling core, a temperature sensor, and a fan. Among them, the coolant used in the electrical cooling system is water, and the coolant used in the hydraulic cooling system is hydraulic oil. Therefore, the cooling core is divided into a water cooling core and an oil cooling core for use in the electrical cooling system and the hydraulic cooling system. The fan is set according to the number and area of the cooling cores, and the temperature sensor is set according to the number of cooling cores. When the coolant flows through the cooling core, the fan takes away the excess heat. The temperature sensor is installed at the outlet of the cooling core to detect the temperature of the coolant in real time, adjust the fan speed of the air-cooled radiator according to the temperature, regulate the heat dissipation power, and keep the coolant within a certain temperature range.

[0038] When connecting a small-tonnage electric excavator, the principle of layered layout with high-voltage wiring harnesses inside, low-voltage wiring harnesses in the middle, and water circuits on the outside must be observed to improve the overall safety performance of the machine.

[0039] The battery pack 12, the four-in-one controller 13, the on-vehicle charger 15, and the starting battery 16 are all arranged at the rear of the whole vehicle, replacing the counterweight of the traditional excavator, reducing the front-back sway during the operation of the excavator. The motor 6, the hydraulic pump 5, the high-voltage junction box 7, and the compressor 8 are arranged at the notch of the cab 1, making the center of the slewing platform 2 have a certain weight and making it more stable during operation. At the same time, the hydraulic oil tank 11, the condenser assembly 18, the evaporator box 19, and the radiator module 9 are all arranged on one side of the cab 1, balancing part of the weight of the cab 1, making the left and right forces on the slewing platform 2 more uniform, reducing the left-right sway during the operation of the excavator, and at the same time, better balancing the working device, reducing the front-back sway during the operation of the excavator, and making it more stable during operation.

[0040] The hierarchical arrangement of the motor 6, the hydraulic pump 5, the high-voltage junction box 7, and the compressor 8, and the hierarchical arrangement scheme of the battery, the four-in-one controller 13, and the on-vehicle charger 15 solve the problem of insufficient space. Replacing the traditional counterweight with the battery solves the problem of insufficient power, and at the same time, solves the problem of disordered pipelines.

[0041] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, or improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A small tonnage electric excavator, characterized in that: include: Cab, turntable, PTC heater A, PTC heater B, hydraulic pump, motor, high-voltage junction box, compressor, radiator module, heat exchanger, hydraulic oil tank, battery pack, four-in-one controller, BMS, on-board charger, starting battery, main power switch, condenser assembly, evaporator box, electronic expansion valve, hydraulic actuator. The cab is arranged on the front side of the turntable, and the lower end of the cab is a special structure, that is, a notch is provided at the lower rear part of the cab, and a double-layer bracket is provided in the notch for support between the cab and the turntable. The hydraulic pump transfers the hydraulic oil to the hydraulic actuator. The motor and the hydraulic pump are connected in series on the lower layer of the double-layer bracket. The high-voltage junction box and the compressor are arranged on the upper layer of the double-layer bracket. The remaining components are arranged above the turntable. When connecting the components, the principle of layered arrangement of the high-voltage wiring harness inside, the low-voltage wiring harness in the middle, and the water channel on the outside is followed.

2. A small tonnage electric excavator according to claim 1, characterized in that: The radiator module and the hydraulic oil tank are arranged on a turntable on one side of the cab, the compressor is arranged between the motor and the radiator module, and the hydraulic pump, the motor, the compressor and the radiator module are arranged side by side in the front-to-back direction.

3. A small tonnage electric excavator according to claim 1, characterized in that: The battery pack is arranged at the tail of the turntable and the opening of the cab. The four-in-one controller and the on-board charger are located on the battery pack. The BMS is placed at the rear of the battery pack. The four-in-one controller and the on-board charger are arranged side by side in the height direction. The heat exchanger is arranged on the side of the cab opening away from the radiator module.

4. A small tonnage electric excavator according to claim 1, characterized in that: The hydraulic oil tank is arranged on the front side of the radiator module, the condenser assembly is arranged in front of the hydraulic oil tank, the evaporator box is arranged on one side of the hydraulic oil tank and the condenser assembly and is partially embedded under the notch of the cab, and the electronic expansion valve is set on the front side of the evaporator box.

5. The small-tonnage electric excavator according to claim 1, characterized in that: It also includes a shell A and a shell B. The shell A and the shell B are installed on the turntable and the cab. A cavity one is formed between the shell A, the turntable and the cab, and a cavity two is formed between the shell B, the turntable and the cab.

6. A small tonnage electric excavator according to claim 5, characterized in that: The hydraulic pump, motor, compressor, radiator module, high-voltage junction box, battery pack, four-in-one controller, on-board charger, and BMS are arranged in cavity one. The water inlets of the motor, four-in-one controller, and on-board charger are connected to the radiator module through pipelines. The battery pack, PTC heater A, and heat exchanger are connected through water pipes; the hydraulic oil tank, condenser assembly, evaporator box, and PTC heater B are arranged in cavity two.

7. A small tonnage electric excavator according to claim 6, characterized in that: The charging port and wiring port of the battery pack are arranged on the shell A on the side away from the condenser assembly. The starting battery and the main power switch are arranged in cavity 1 and are arranged on the same side as the condenser assembly. The main power switch is installed on the shell A.

8. A small tonnage electric excavator according to claim 6, characterized in that: Two air inlet holes are arranged on the bottom plate of the turntable, one air inlet hole is arranged on the turntable of cavity one, and the other air inlet hole is arranged on the turntable of cavity two. Shell A is arranged with air outlet holes on the side opposite to the fan of the radiator module to form an air duct in cavity one to ensure the normal operation of the radiator module; shell B is arranged with air outlet holes on the side opposite to the fan of the condenser assembly to form an air duct in cavity two to ensure the normal operation of the condenser assembly.

9. The small-tonnage electric excavator according to claim 1, characterized in that: Three groups of electronic water pumps are arranged near the interfaces of the battery pack, the radiator module and the PTC heater B, namely, electronic water pump A, electronic water pump B and electronic water pump C.

10. A small tonnage electric excavator according to claim 9, characterized in that: Air conditioning system refrigeration mode refrigerant circuit: compressor, condenser assembly, electronic expansion valve, evaporator box and heat exchanger, compressor; Air conditioning system heating mode water circuit: electronic water pump C, PTC heater B, evaporator box, electronic water pump C; Battery thermal management system cooling (heating) water circuit: electronic water pump A, battery, heat exchanger / PTC heater A, electronic water pump A; Water circuit of the electrical cooling system: electronic water pump B, electric motor, four-in-one controller, on-board charger, radiator module, electronic water pump B; Hydraulic cooling system oil circuit: hydraulic oil tank, hydraulic components, radiator module, hydraulic oil tank.

11. A small tonnage electric excavator according to claim 10, characterized in that: The air conditioning system and the battery thermal management system use refrigerant pipeline integration, and the solenoid valve can adjust the refrigerant distribution ratio according to the temperature sensors in the battery and the cab; The radiator module is an air-cooled radiator, which includes: a cooling core, a temperature sensor, and a fan. When the coolant flows through the cooling core, the fan takes away excess heat. The temperature sensor is installed at the outlet of the cooling core to detect the temperature of the coolant in real time, adjust the fan speed of the air-cooled radiator according to the temperature, adjust the heat dissipation power, and keep the coolant within a certain temperature range.

12. The small-tonnage electric excavator according to claim 1, characterized in that: The front end of the cab is hinged to the turntable, making it a flippable cab.

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