Walking power system for engineering machinery, engineering machinery and walking control method

Abstract

The invention relates to the field of power systems, and discloses a walking power system for engineering machinery, the engineering machinery and a walking control method.The walking power system comprises a chassis, a first engine, a motor and a power battery, the chassis comprises a first drive axle and a second drive axle, and the first engine is in transmission connection with the first drive axle; the motor is in transmission connection with the second drive axle. The power battery is connected with the motor to drive the motor. According to the walking power system for the engineering machine and the engineering machine, dual-power output can be achieved, the driving force of the engineering machine is effectively improved, and therefore the loading capacity, the climbing capacity, the transition capacity and the like are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of power systems, and specifically relates to a walking power system for engineering machinery, engineering machinery, and a walking control method. Background Art

[0002] At present, the travel power system of construction machinery usually adopts hydraulic drive, mechanical drive or a combination of the two. For example, existing large-tonnage cranes are equipped with multiple mechanical drive axles and multiple hydraulic drive axles, which provide the vehicle with strong torque and response speed, and effectively prevent part of the drive axle from being suspended in the air, resulting in insufficient climbing ability of the vehicle and insufficient friction coefficient of the road surface causing the drive wheel to slip. However, whether it is hydraulic drive or mechanical drive, it relies on the engine to generate source power, which is transmitted to the drive axle through the transmission and transmission system. Therefore, under the condition of insufficient engine power, even if the mechanical drive is combined with the hydraulic drive, it still cannot solve the problems of climbing and transition difficulties caused by insufficient power. Summary of the invention

[0003] In response to at least one of the above-mentioned defects or shortcomings of the prior art, the present application provides a walking power system, engineering machinery and walking control method for engineering machinery, which can achieve dual power output and effectively improve the driving force of the engineering machinery, thereby improving the load-bearing capacity, climbing ability and transfer ability, etc.

[0004] In order to achieve the above-mentioned purpose, the present application provides, on one hand, a walking power system for an engineering machine, comprising:

[0005] A chassis including a first drive axle and a second drive axle;

[0006] A first engine, drivingly connected to the first drive axle;

[0007] an electric motor, drivingly connected to the second drive axle;

[0008] A power battery is connected to the electric motor to drive the electric motor.

[0009] In some embodiments, the travel power system further includes a hydraulic pump and a hydraulic motor, the electric motor, the hydraulic pump, the hydraulic motor and the second drive axle are sequentially transmission-connected, and the electric motor, the hydraulic pump and the hydraulic motor are all arranged on the chassis.

[0010] In some embodiments, the travel power system further includes a speed reducer transmission-connected between the electric motor and the second drive axle.

[0011] In some embodiments, under the condition that the driving force of the first engine is less than a preset critical driving force and the vehicle speed of the engineering machine is less than a preset critical speed, the first engine drives the first drive axle and the power battery drives the second drive axle.

[0012] In some embodiments, the travel power system further includes a first generator connected between the first engine and the power battery.

[0013] In some embodiments, under the condition that the driving force of the first engine is less than a preset critical driving force and the vehicle speed of the engineering machine is not less than a preset critical speed, the first engine drives the first generator to charge the power battery.

[0014] In some embodiments, under a condition where the driving force of the first engine is not less than a preset critical driving force, the first engine drives the first generator to charge the power battery.

[0015] In some embodiments, the walking power system further includes a second engine and a second generator, and the second engine, the second generator and the power battery are connected in sequence.

[0016] In some embodiments, under the conditions where the driving force of the first engine is less than a preset critical driving force, the speed of the engineering machinery is less than a preset critical speed, and the power of the power battery is lower than a preset critical power, the second engine drives the second generator to charge the power battery.

[0017] In some embodiments, under the conditions that the driving force of the first engine is less than a preset critical driving force, the speed of the engineering machinery is less than a preset critical speed, and the power level of the power battery is not less than a preset critical power level, the power battery drives the second drive axle.

[0018] In some embodiments, the travel power system also includes a superstructure supported on the chassis, the second engine and the second generator are both arranged on the superstructure, and the first engine, the power battery and the electric motor are all arranged on the chassis.

[0019] A second aspect of the present application provides an engineering machine, comprising the above-mentioned traveling power system for the engineering machine.

[0020] A third aspect of the present application provides a walking control method for an engineering machine, wherein the walking control method is executed based on the above-mentioned walking power system for the engineering machine.

[0021] In some embodiments, the walking control method includes:

[0022] detecting the driving force of the first engine and the speed of the engineering machine;

[0023] determining whether the driving force is not less than a preset critical driving force and whether the vehicle speed is not less than a preset critical speed;

[0024] When it is determined that the driving force is less than the preset critical driving force and the vehicle speed is less than the preset critical speed, the first engine is controlled to drive the first drive axle and the power battery is controlled to drive the second drive axle.

[0025] In some embodiments, the travel power system further includes a first generator connected between the first engine and the power battery.

[0026] In some embodiments, the walking control method includes:

[0027] detecting the driving force of the first engine and the speed of the engineering machine;

[0028] determining whether the driving force is not less than a preset critical driving force and whether the vehicle speed is not less than a preset critical speed;

[0029] When it is determined that the driving force is less than the preset critical driving force and the vehicle speed is not less than the preset critical speed, the first engine is controlled to drive the first generator to charge the power battery.

[0030] In some embodiments, the walking control method includes:

[0031] detecting a driving force of the first engine;

[0032] determining whether the driving force is not less than a preset critical driving force;

[0033] When it is determined that the driving force is not less than the preset critical driving force, the first engine is controlled to drive the first generator to charge the power battery.

[0034] In some embodiments, the walking power system further includes a second engine and a second generator, and the second engine, the second generator and the power battery are connected in sequence.

[0035] In some embodiments, the walking control method includes:

[0036] detecting the driving force of the first engine, the speed of the engineering machine, and the power level of the power battery;

[0037] determining whether the driving force is not less than a preset critical driving force, whether the vehicle speed is not less than a preset critical speed, and whether the power is less than a preset critical power;

[0038] When it is determined that the driving force is less than the preset critical driving force, the vehicle speed is less than the preset critical speed, and the power is lower than the preset critical power, controlling the second engine to drive the second generator to charge the power battery;

[0039] When it is determined that the driving force is less than the preset critical driving force, the vehicle speed is less than the preset critical speed, and the electric quantity is not less than the preset critical electric quantity, the power battery is controlled to drive the second drive axle.

[0040] It can be seen from the above technical scheme that the travel power system for engineering machinery of the present invention is provided with a first drive axle and a second drive axle which are independent of each other. When the driving force of the first engine is insufficient, power is supplied to the electric motor through the power battery, so that the electric motor can drive the second drive axle to output driving force, thereby supplementing sufficient driving force for the engineering machinery, effectively solving the problems of low load-bearing capacity, insufficient climbing ability, easy slipping, etc. of the engineering machinery, so that it can adapt to various working environments and road conditions.

[0041] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0043] Figure 1 This is a schematic diagram of a first walking power system for engineering machinery in a specific implementation manner of the present application;

[0044] Figure 2 This is a schematic diagram of a second traveling power system for engineering machinery in a specific embodiment of the present application;

[0045] Figure 3 This is a schematic diagram of a third traveling power system for engineering machinery in a specific implementation manner of the present application;

[0046] Figure 4 This is a schematic diagram of a fourth traveling power system for engineering machinery in a specific implementation manner of the present application;

[0047] Figure 5 It is a schematic diagram of a control method for a walking power system of an engineering machine in a specific implementation manner of the present application;

[0048] Figure 6It is a schematic diagram of another control method for a traveling power system of an engineering machine in a specific implementation manner of the present application.

[0049] Description of Reference Numerals

[0050] 1 First drive axle 2 Second drive axle

[0051] 3 First engine 4 Electric motor

[0052] 5 Power battery 6 Hydraulic pump

[0053] 7 Hydraulic motor 8 Reducer

[0054] 9 First generator 10 Second engine

[0055] 11 Second generator 12 Clutch

[0056] 13 Gearbox 14 Drive shaft DETAILED DESCRIPTION

[0057] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0058] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with exemplary embodiments.

[0059] like Figures 1 to 4 As shown, the first exemplary embodiment of the present application provides a walking power system for engineering machinery, which mainly includes a chassis, a first engine 3, an electric motor 4 and a power battery 5. Among them, the chassis includes a first drive axle 1 and a second drive axle 2, and the first engine 3 is connected to the first drive axle 1 in a transmission manner. Taking the figure as an example, a mechanical drive axle can be selected as the first drive axle 1. The first engine 3 can be connected to the first drive axle 1 by connecting the clutch 12, the gearbox 13 and the transmission shaft 14 in sequence, so that the first engine 3 can drive the first drive axle 1 to output the first driving force. The electric motor 4 is connected to the second drive axle 2 in a transmission manner, and the power battery 5 is connected to the electric motor 4 to drive the electric motor 4 to work, thereby driving the second drive axle 2 to output the second driving force.

[0060] It can be seen that the walking power system for engineering machinery of this exemplary embodiment can output the first driving force and the second driving force simultaneously through the mutually independent first driving axle and the second driving axle, and can also output the first driving force or the second driving force separately. When the driving force of the first engine is insufficient, that is, when the power output of the first engine is insufficient to drive the engineering machinery to walk normally, the power battery is used to supply power to the electric motor, so that the electric motor can drive the second driving axle to output the second driving force, thereby being able to supplement sufficient driving force for the engineering machinery, effectively improving the load-bearing capacity, climbing ability and transfer ability of the engineering machinery, so that it can adapt to various working environments and road conditions. For example, when the road conditions are bumpy or the slope is large, the dual-power drive mode can be manually or automatically turned on to reduce the engine load, and the hybrid power meets the low-carbon requirements.

[0061] It should be noted that, in this exemplary embodiment, there is no limit to the number of the first drive axle 1 and the second drive axle 2. For example, there may be multiple first drive axles 1 and second drive axles 2, wherein the second drive axle 2 may be divided into front drive and rear drive. In actual applications, an appropriate number of first drive axles 1 and second drive axles 2 and their arrangement positions may be selected according to the tonnage requirements of the construction machinery.

[0062] In one embodiment, referring to Figure 1 and Figure 2 The travel power system includes a hydraulic pump 6 and a hydraulic motor 7. The motor 4, the hydraulic pump 6, the hydraulic motor 7 and the second drive axle 2 are sequentially connected in a transmission manner, so that the mechanical energy of the motor 4 is converted into hydraulic energy for driving the second drive axle 2, thereby driving the second drive axle 2 to operate. In this embodiment, the second drive axle 2 is equivalent to a hydraulic drive axle.

[0063] From the content of the background technology part, it can be seen that current heavy-duty engineering machinery (such as large-tonnage cranes) are usually equipped with mechanical drive axles and hydraulic drive axles. The hydraulic drive axle has a larger torque and is suitable for working conditions such as super-large tonnage loads and climbing. There are generally two ways to drive the mechanical drive axle and the hydraulic drive axle. One is to supply power to the mechanical drive axle and the hydraulic drive axle at the same time through the chassis engine, and the other is to set up two engines to drive the mechanical drive axle and the hydraulic drive axle respectively. Compared with the former driving method, the second driving method can effectively solve the problem of insufficient power of a single engine, but in the case of two engines, due to space problems, it is generally necessary to set the two engines respectively on the chassis and the upper vehicle of the engineering machinery, wherein the hydraulic drive axle is driven by the upper vehicle engine, specifically, the upper vehicle engine drives the hydraulic pump located on the upper vehicle to work, and the hydraulic pump is used to transport the hydraulic oil to the hydraulic motor located on the chassis through the center swivel joint, and then the hydraulic motor drives the hydraulic drive axle to output hydraulic driving force.

[0064] However, as the tonnage of construction machinery continues to increase and develops into super-large tonnage construction machinery, such as super-large tonnage cranes, the number of parts on and off the vehicle increases, and the space available for the layout of center swivel joints and high-pressure oil pipes is further compressed. On the contrary, in order to further improve the load capacity of construction machinery, larger center swivel joints and high-pressure oil pipes with larger pipe diameters and bending radii must be configured. This makes the layout and maintenance of hydraulic pipelines extremely difficult, seriously hindering the application and development of hydraulic drive technology in super-large tonnage construction machinery.

[0065] To this end, the walking power system of this exemplary embodiment uses an electric motor 4 to replace the engine set on the vehicle in the prior art, and sets the electric motor 4, hydraulic pump 6 and hydraulic motor 7 on the chassis, and uses the electric motor 4 to drive the hydraulic motor 7, so that the hydraulic driving force can be transmitted in the chassis. From the perspective of the overall structural layout, compared with the prior art, this exemplary embodiment can eliminate the use of a central swivel joint, does not need to occupy the space on the vehicle to arrange the high-pressure oil pipe, and can reduce the layout length of the high-pressure oil pipe, thereby reducing the loss of hydraulic energy along the way.

[0066] Furthermore, in this exemplary embodiment, a high-speed motor can be used as the motor 4, and correspondingly, a high-speed pump can be used as the hydraulic pump 6, wherein the high-speed motor can drive the high-speed pump to reach a rotation speed of 5000-6000r / min. Compared with the prior art using an engine with an average rotation speed of 2000r / min, when the same flow rate of hydraulic oil is required to be output, a smaller displacement high-speed pump can be used (the displacement of the high-speed pump can be reduced to 1 / 3 of the original hydraulic pump), thereby further reducing the weight, volume and cost of the hydraulic pump 6 and saving its installation space on the construction machinery.

[0067] In one embodiment, referring to Figure 3 and Figure 4 , the walking power system also includes a reducer 8 that is transmission-connected between the motor 4 and the second drive axle 2. In other words, the motor 4 and the second drive axle 2 can be connected by mechanical transmission, and the second drive axle 2 is a mechanical drive axle. Transmission by the reducer 8 can improve the torsion resistance of the motor 4 and achieve high torque transmission. Compared with the hydraulic transmission method, the walking power system of this exemplary embodiment can save the layout of the hydraulic system and reduce the preparation cost. Of course, in other embodiments, when multiple second drive axles 2 are provided, some of the second drive axles 2 can be driven by the hydraulic pump 6 and the hydraulic motor 7, and the remaining second drive axles 2 can be driven by the reducer 8. This application does not limit this.

[0068] In one embodiment, under the condition that the driving force of the first engine 3 is less than the preset critical driving force and the speed of the engineering machinery is less than the preset critical speed, the first engine 3 can drive the first drive axle 1 and the power battery 5 can drive the second drive axle 2, so that the first drive axle 1 and the second drive axle 2 can output driving force synchronously, thereby improving the climbing ability of the engineering machinery.

[0069] In one embodiment, referring to Figures 1 to 4 The walking power system also includes a first generator 9 connected between the first engine 3 and the power battery 5. The first engine 3 can drive the first generator 9 to charge the power battery 5, so that the surplus energy output by the first engine 3 can be reasonably utilized to achieve effective energy storage and improve energy efficiency.

[0070] Specifically, under the condition that the driving force of the first engine 3 is less than the preset critical driving force and the speed of the engineering machinery is not less than the preset critical speed, or under the condition that the driving force of the first engine 3 is not less than the preset critical driving force, relying on the first engine 3 to drive the first drive axle 1 is sufficient to drive the engineering machinery to travel normally, and there is no need to additionally discharge the power battery 5 to drive the second drive axle 2. The power output by the first engine 3 has a certain margin. For this reason, the first engine 3 can drive the first generator 9 to charge the power battery 5 to reduce energy consumption.

[0071] In one embodiment, referring to Figure 2 and Figure 4 The walking power system also includes a second engine 10 and a second generator 11. The second engine 10, the second generator 11 and the power battery 5 are connected in sequence, so that the second engine 10 can drive the second generator 11 to charge the power battery 5.

[0072] Specifically, under the condition that the driving force of the first engine 3 is less than the preset critical driving force, the speed of the engineering machine is less than the preset critical speed, and the power of the power battery 5 is less than the preset critical power, the second engine 10 can drive the second generator 11 to charge the power battery 5, and replenish the power of the power battery 5 in time. In addition, the second generator 11 can also be connected to the motor 4. When the second generator 11 charges the power battery 5, if the second generator 11 has surplus power, the second generator 11 can supply power to the motor 4, drive the motor 4 to drive the second drive axle 2, and realize dual power output.

[0073] Of course, under the operating conditions where the driving force of the first engine 3 is less than the preset critical driving force, the speed of the construction machinery is less than the preset critical speed, and the power level of the power battery 5 is not less than the preset critical power level, that is, when the power battery 5 has sufficient power, the power battery 5 can drive the second drive axle 2, and there is no need to start the second engine 10 to charge the power battery 5, thereby reducing energy consumption.

[0074] In addition to charging the power battery 5 by the second engine 10 , the power battery 5 can also be charged by an external power source during the idle period of the construction machinery, thereby reducing the consumption of fossil fuels.

[0075] Furthermore, in this exemplary embodiment, the travel power system further includes an upper vehicle supported on the chassis, the second engine 10 and the second generator 11 are both arranged on the upper vehicle, and the first engine 3, the power battery 5 and the motor 4 are all arranged on the chassis. Although the second generator 11 is far away from the power battery 5, a smaller electrical cable is used to transmit energy, which effectively solves the problem of difficult layout of components and hydraulic oil pipes.

[0076] The second exemplary embodiment of the present application provides an engineering machinery, including the above-mentioned traveling power system for the engineering machinery. Obviously, the engineering machinery of this exemplary embodiment has all the technical effects brought by the above-mentioned traveling power system, so they will not be described in detail here.

[0077] The third exemplary embodiment of the present application provides a walking control method for engineering machinery, and the walking control method is executed based on the above-mentioned walking power system for engineering machinery. Therefore, the various embodiments of the walking control method described below can obviously also obtain the technical effects brought by the above-mentioned corresponding embodiments. Therefore, for each embodiment described below, if there are additional technical effects brought by its method characteristics, only the additional technical effects will be described to avoid repeating the previous content.

[0078] Specifically, the walking control method of this exemplary embodiment includes:

[0079] S0: Detecting the driving force of the first engine 3 and the speed of the construction machine;

[0080] S1: Determine whether the driving force is not less than a preset critical driving force and whether the vehicle speed is not less than a preset critical speed;

[0081] S2: When it is determined that the driving force is less than the preset critical driving force and the vehicle speed is less than the preset critical speed, the first engine 3 is controlled to drive the first drive axle 1 and the power battery 5 is controlled to drive the second drive axle 2 .

[0082] In one embodiment, when the walking power system is provided with a first generator 9, the walking control method of this embodiment includes:

[0083] S0': detecting the driving force of the first engine 3;

[0084] S1': judging whether the driving force is not less than a preset critical driving force;

[0085] S2': when it is determined that the driving force is not less than the preset critical driving force, controlling the first engine 3 to drive the first generator 9 to charge the power battery 5;

[0086] S3': when it is determined that the driving force is less than the preset critical driving force, detecting the speed of the construction machinery;

[0087] S4': Determine whether the vehicle speed is not less than a preset critical speed;

[0088] S5 ′: when it is determined that the vehicle speed is not less than the preset critical speed, the first engine 3 is controlled to drive the first generator 9 to charge the power battery 5 .

[0089] In one embodiment, when the walking power system is provided with a second engine 10 and a second generator 11, the walking control method of this embodiment includes:

[0090] S0”: detecting the driving force of the first engine 3, the speed of the construction machinery and the power level of the power battery 5;

[0091] S1”: Determine whether the driving force is not less than a preset critical driving force, whether the preset critical speed is not less than the vehicle speed, and whether the power is less than a preset critical power;

[0092] S2”: when it is determined that the driving force is less than the preset critical driving force, the vehicle speed is less than the preset critical speed, and the power is less than the preset critical power, the second engine 10 is controlled to drive the second generator 11 to charge the power battery 5;

[0093] S3”: when it is determined that the driving force is less than the preset critical driving force, the vehicle speed is less than the preset critical speed, and the power level is not less than the preset critical power level, the power battery 5 is controlled to drive the second drive axle 2 .

[0094] In each of the above-mentioned embodiments, a torque sensor can be used to detect the driving force of the first engine 3, a speed sensor can be used to detect the speed of the engineering machinery, and a voltage sensor can be used to detect the power of the power battery 5. Among them, the torque sensor can be set on the output shaft of the first engine 3 or the transmission shaft of the first drive axle 1 to measure the driving force of the first engine 3 in real time. The speed sensor is set on the output shaft or transmission shaft of the first drive axle 1, and the speed of the engineering machinery is measured in real time using the photoelectric or Hall effect principle. The voltage sensor is set in the power battery 5. Since there is a curve corresponding relationship between the battery voltage and the power, the voltage sensor can convert the voltage of the power battery 5 into the power of the power battery 5 after detecting it.

[0095] In addition, the above-mentioned walking power system includes a processor for receiving and comparing data information. Specifically, the processor can receive data information from the torque sensor and the speed sensor respectively, and is preset with the above-mentioned preset critical driving force, preset critical speed and preset critical power. The driving force, vehicle speed and power received in real time are compared with the preset critical driving force, preset critical speed and preset critical power respectively, so as to judge whether the driving force of the first engine 3 is not less than the preset critical driving force, whether the preset critical speed of the engineering machinery is not less than the vehicle speed, and whether the power of the power battery 5 is lower than the preset critical power. After obtaining the judgment result, the processor can control the corresponding actuator to perform the corresponding work.

[0096] The following combined Figure 5 and Figure 6 The specific embodiment shown illustrates the walking control method described above.

[0097] First, the power control method of single-engine construction machinery is explained. Figure 5 As shown, after the first engine 3 is started, the first engine 3 drives the first drive axle 1 to run, thereby driving the engineering machinery to start walking. During the walking period, the real-time driving force of the first engine 3 is detected to determine whether it is not less than the preset critical driving force. If it is determined that the real-time driving force is not less than the preset critical driving force, the first drive axle 1 continues to be used to drive the engineering machinery to walk normally, and at the same time, the first engine 3 is controlled to drive the first generator 9 to charge the power battery 5. If it is determined that the real-time driving force is less than the preset critical driving force, the real-time vehicle speed of the engineering machinery is then detected to determine whether the real-time vehicle speed is less than the preset critical speed. If it is determined that the real-time vehicle speed is not less than the preset critical speed, the first drive axle 1 continues to be used to drive the engineering machinery to walk normally, and at the same time, the first engine 3 is controlled to drive the first generator 9 to charge the power battery 5. If it is determined that the real-time vehicle speed is less than the preset critical speed, the power battery 5 is controlled to supply power to the motor 4, so that the motor 4 drives the second drive axle 2 to run, thereby realizing dual power output, until the real-time vehicle speed is not less than the preset critical speed.

[0098] Next, a power control method for a dual-engine construction machine (i.e., a first engine 3 and a second engine 10) is described. Figure 6As shown, after the first engine 3 is started, the first engine 3 drives the first drive axle 1 to run, thereby driving the engineering machine to start walking. During the walking, the real-time driving force of the first engine 3 is detected to determine whether it is not less than the preset critical driving force. If it is determined that the real-time driving force is not less than the preset critical driving force, the first drive axle 1 continues to be used to drive the engineering machine to walk normally, and at the same time, the first engine 3 is controlled to drive the first generator 9 to charge the power battery 5. If it is determined that the real-time driving force is less than the preset critical driving force, the real-time vehicle speed of the engineering machine is then detected to determine whether the real-time vehicle speed is less than the preset critical speed. If it is determined that the real-time vehicle speed is not less than the preset critical speed, the first drive axle 1 continues to be used to drive the engineering machine to walk normally. Move, and at the same time control the first engine 3 to drive the first generator 9 to charge the power battery 5. If it is determined that the real-time vehicle speed is less than the preset critical speed, then detect the real-time power of the motor 4 to determine whether the real-time power is not less than the preset critical power. If it is determined that the real-time power is not less than the preset critical power, control the power battery 5 to supply power to the motor 4, so that the motor 4 drives the second drive axle 2 to operate, and realize dual power output. If it is determined that the real-time power is lower than the preset critical power, control the second engine 10 to start, and drive the second generator 11 to charge the power battery 5. After the power battery 5 is replenished with sufficient electric energy, control the power battery 5 to supply power to the motor 4, so that the motor 4 drives the second drive axle 2 to operate.

[0099] In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0100] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0101] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0102] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A walking power system for engineering machinery, characterized in that: include: A chassis comprising a first drive axle (1) and a second drive axle (2); A first engine (3) drivingly connected to the first drive axle (1); An electric motor (4) drivingly connected to the second drive bridge (2); A power battery (5) is connected to the electric motor (4) so ​​as to be able to drive the electric motor (4).

2. The traveling power system for engineering machinery according to claim 1, characterized in that: The walking power system also includes a hydraulic pump (6) and a hydraulic motor (7); the electric motor (4), the hydraulic pump (6), the hydraulic motor (7) and the second drive axle (2) are sequentially connected in a transmission manner; and the electric motor (4), the hydraulic pump (6) and the hydraulic motor (7) are all arranged on the chassis.

3. The traveling power system for engineering machinery according to claim 1, characterized in that: The walking power system also includes a speed reducer (8) which is transmission-connected between the electric motor (4) and the second drive axle (2).

4. The traveling power system for engineering machinery according to claim 1, characterized in that: Under the operating condition that the driving force of the first engine (3) is less than a preset critical driving force and the speed of the engineering machinery is less than a preset critical speed, the first engine (3) drives the first drive axle (1) and the power battery (5) drives the second drive axle (2).

5. The traveling power system for engineering machinery according to claim 1, characterized in that: The walking power system also includes a first generator (9) connected between the first engine (3) and the power battery (5).

6. The traveling power system for engineering machinery according to claim 5, characterized in that: Under the operating condition that the driving force of the first engine (3) is less than a preset critical driving force and the speed of the engineering machinery is not less than a preset critical speed, the first engine (3) drives the first generator (9) to charge the power battery (5).

7. The traveling power system for engineering machinery according to claim 5, characterized in that: Under the operating condition that the driving force of the first engine (3) is not less than a preset critical driving force, the first engine (3) drives the first generator (9) to charge the power battery (5).

8. The traveling power system for engineering machinery according to claim 1, characterized in that: The walking power system further comprises a second engine (10) and a second generator (11), and the second engine (10), the second generator (11) and the power battery (5) are connected in sequence.

9. The traveling power system for engineering machinery according to claim 8, characterized in that: Under the operating conditions where the driving force of the first engine (3) is less than a preset critical driving force, the speed of the engineering machinery is less than a preset critical speed, and the power level of the power battery (5) is lower than a preset critical power level, the second engine (10) drives the second generator (11) to charge the power battery (5).

10. The traveling power system for engineering machinery according to claim 8, characterized in that: Under the operating conditions that the driving force of the first engine (3) is less than a preset critical driving force, the speed of the engineering machinery is less than a preset critical speed, and the power level of the power battery (5) is not less than a preset critical power level, the power battery (5) drives the second drive axle (2).

11. The traveling power system for engineering machinery according to claim 8, characterized in that: The walking power system also includes an upper vehicle supported on the chassis, the second engine (10) and the second generator (11) are both arranged on the upper vehicle, and the first engine (3), the power battery (5) and the electric motor (4) are all arranged on the chassis.

12. Construction machinery, characterized in that: It comprises a traveling power system for engineering machinery according to any one of claims 1 to 11.

13. A walking control method for engineering machinery, characterized in that: The travel control method is executed based on the travel power system for engineering machinery according to any one of claims 1 to 3.

14. The walking control method for engineering machinery according to claim 13, characterized in that: The walking control method comprises: detecting the driving force of the first engine (3) and the speed of the engineering machine; determining whether the driving force is not less than a preset critical driving force and whether the vehicle speed is not less than a preset critical speed; When it is determined that the driving force is less than the preset critical driving force and the vehicle speed is less than the preset critical speed, the first engine (3) is controlled to drive the first drive axle (1) and the power battery (5) is controlled to drive the second drive axle (2).

15. The walking control method for engineering machinery according to claim 13, characterized in that: The walking power system also includes a first generator (9) connected between the first engine (3) and the power battery (5).

16. The walking control method for engineering machinery according to claim 15, characterized in that: The walking control method comprises: detecting the driving force of the first engine (3) and the speed of the engineering machine; determining whether the driving force is not less than a preset critical driving force and whether the vehicle speed is not less than a preset critical speed; When it is determined that the driving force is less than the preset critical driving force and the vehicle speed is not less than the preset critical speed, the first engine (3) is controlled to drive the first generator (9) to charge the power battery (5).

17. The walking control method for engineering machinery according to claim 15, characterized in that: The walking control method comprises: detecting the driving force of the first engine (3); determining whether the driving force is not less than a preset critical driving force; When it is determined that the driving force is not less than the preset critical driving force, the first engine (3) is controlled to drive the first generator (9) to charge the power battery (5).

18. The walking control method for engineering machinery according to claim 15, characterized in that: The walking power system further comprises a second engine (10) and a second generator (11), and the second engine (10), the second generator (11) and the power battery (5) are connected in sequence.

19. The walking control method for engineering machinery according to claim 18, characterized in that: The walking control method comprises: Detecting the driving force of the first engine (3), the speed of the engineering machine, and the power level of the power battery (5); determining whether the driving force is not less than a preset critical driving force, whether the vehicle speed is not less than a preset critical speed, and whether the power is less than a preset critical power; When it is determined that the driving force is less than the preset critical driving force, the vehicle speed is less than the preset critical speed, and the power is less than the preset critical power, controlling the second engine (10) to drive the second generator (11) to charge the power battery (5); When it is determined that the driving force is less than the preset critical driving force, the vehicle speed is less than the preset critical speed, and the power level is not less than the preset critical power level, the power battery (5) is controlled to drive the second drive axle (2).

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