Dual-power cooperative work forklift integrated power system and control method thereof

Abstract

The invention discloses a dual-power cooperative work forklift integrated power system and a control method thereof, and particularly relates to the technical field of forklifts.The dual-power cooperative work forklift integrated power system comprises a walking power system, an operation power system, a mode switching controller and a coupling mechanism; the vehicle control unit is in signal connection with the walking power system, the operation power system and the mode switching controller, and the walking power system is connected with the operation power system through a coupling mechanism. And the mode switching controller is in signal connection with the coupling mechanism. Switching of two working states is realized by constructing coupling of the walking power system and the working power system: 1, the walking power system and the working power system work independently; and secondly, the walking driving motor and the hydraulic oil pump motor cooperatively drive the forklift to walk, loads are shared by the walking driving motor and the hydraulic oil pump motor, the torque requirement for the walking driving motor under the full-load climbing working condition of the forklift is lowered, and the power performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of forklifts. More specifically, the present invention relates to an integrated power system for a forklift with dual-power collaborative work and a control method therefor. Background Art

[0002] Commonly known electric forklifts include two sets of power systems: one is a walking power system for driving the vehicle to travel and transport goods electrically; the other is an operation power system for driving the forklift device and meeting the operation requirements of lifting and stacking goods. Taking a typical four-wheel counterbalanced electric forklift as an example, the vehicle includes a vehicle drive system composed of a motor, a reducer, and a drive axle to realize the traveling and transfer of the forklift; and another electric drive hydraulic operation system composed of components such as a motor, a hydraulic pump, and a hydraulic cylinder to realize operations such as goods lifting and stacking. At present, the two power systems of the electric forklift, namely the walking and operation power systems, mainly adopt the method of independent work and independent layout and installation.

[0003] Among them, Chinese Patent Application No. 201910394602.2 discloses an integrated power system for an electric forklift drive and hydraulic system and a control method therefor. This solution integrates two independent hydraulic systems with a walking drive system; improving the integration degree of the power system and facilitating the installation of the whole vehicle.

[0004] However, in actual use, in the above solution: due to the independence of the hydraulic system and the walking drive system, coupled operation cannot be achieved, that is, when one power system is working, the other power system is often idle, and the two systems cannot achieve collaborative work, resulting in high overall cost, low power density, and low efficiency.

[0005] Therefore, the present invention proposes an integrated power system for a forklift with dual-power collaborative work and a control method therefor as a further improvement to improve the overall efficiency of the electric forklift. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides an integrated power system for a forklift with dual-power collaborative work and a control method therefor to solve the problems proposed in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solution: An integrated power system for a forklift with dual-power collaborative work includes a vehicle controller, and further includes: a walking power system, an operation power system, a mode switching controller, and a coupling mechanism;

[0008] The vehicle controller is respectively signal-connected to the walking power system, the operation power system, and the mode switching controller,

[0009] The walking power system is connected to the operation power system through a coupling mechanism;

[0010] The mode switching controller is signal - connected to the coupling mechanism.

[0011] Furthermore, the traveling power system includes: a traveling motor controller, a traveling drive motor, a traveling transmission mechanism, and a drive axle;

[0012] The vehicle controller is signal - connected to the traveling drive motor through the traveling motor controller, and the traveling drive motor is transmission - connected to the drive axle through the traveling transmission mechanism;

[0013] The traveling transmission mechanism includes: a traveling input shaft gear, a first transmission gear, a second transmission gear, a first transmission shaft, a traveling power output gear, and a differential;

[0014] The output shaft of the traveling drive motor is fixedly connected to the traveling input shaft gear, the traveling input shaft gear is meshed with the first transmission gear, the first transmission gear and the second transmission gear are respectively fixedly sleeved at both ends of the first transmission shaft, and the second transmission gear is transmission - connected to the traveling power output gear through a coupling transmission mechanism;

[0015] The differential is fixedly installed at the center of the traveling power output gear, and the differential is fixedly connected to the drive axle.

[0016] Furthermore, the operation power system includes: a hydraulic oil pump motor controller, a hydraulic oil pump motor, a hydraulic transmission mechanism, and a hydraulic oil pump;

[0017] The vehicle controller is signal - connected to the hydraulic oil pump motor through the hydraulic oil pump motor controller, and the hydraulic oil pump motor is transmission - connected to the hydraulic oil pump through the hydraulic transmission mechanism;

[0018] The hydraulic transmission mechanism includes: a first input shaft gear, a hydraulic power output gear, and a hydraulic power output shaft;

[0019] The output shaft of the hydraulic oil pump motor is fixedly connected to the first input shaft gear, the first input shaft gear is meshed with the hydraulic power output gear, and the hydraulic power output gear is fixedly connected to the drive shaft of the hydraulic oil pump through the hydraulic power output shaft.

[0020] Furthermore, the coupling mechanism includes: a clutch and a coupling gear;

[0021] The clutch and the coupling gear for controlling the connection between the coupling gear and the hydraulic power output shaft are both installed on the hydraulic power output shaft, and the coupling gear is meshed with the second transmission gear;

[0022] The mode switching controller is signal - connected to the clutch.

[0023] Further, the coupling transmission mechanism includes: a third transmission gear, a fourth transmission gear, and a second transmission shaft;

[0024] The second transmission gear is meshed and connected with the third transmission gear. The third transmission gear and the fourth transmission gear are respectively fixedly sleeved at both ends of the second transmission shaft, and the fourth transmission gear is meshed and connected with the traveling power output gear.

[0025] Further, the drive axle includes: a left half shaft and a right half shaft;

[0026] The differential is respectively connected with the left half shaft and the right half shaft, and both the left half shaft and the right half shaft are connected with the wheel hub for driving the vehicle to travel.

[0027] A control method for a forklift integrated power system includes the above-mentioned forklift integrated power system with dual power working together. The specific steps of the control method are as follows:

[0028] S1: Corresponding the pedal opening to the desired speed of the vehicle, and establishing a corresponding speed closed-loop control mechanism;

[0029] S2: Disconnecting the clutch, and controlling the vehicle to travel by the traveling drive motor;

[0030] S3: Real-time detection: the difference D between the desired vehicle speed and the actual vehicle speed in the speed closed-loop control mechanism in S1;

[0031] S4: Based on the difference between the desired vehicle speed and the actual vehicle speed in S3, setting a critical value R for the traveling drive motor and the hydraulic oil pump motor to jointly drive the vehicle to travel;

[0032] S5: Judging the magnitudes of D and R: if D ≤ R, then enter S6; if D > R, then enter S7;

[0033] S6: The clutch is in the disconnected state, and the traveling drive motor independently drives the vehicle to travel; then return to S3;

[0034] S7: The clutch is in the closed state, and the traveling drive motor and the hydraulic oil pump motor jointly drive the vehicle to travel; then return to S3.

[0035] Further, in S4, when there is a load or during climbing, when the output power and output torque of the traveling drive motor cannot meet the power and torque required for vehicle driving, the critical value R is set.

[0036] Further, in S6, the output power and output torque of the traveling drive motor meet the power and torque required for vehicle driving.

[0037] Further, in S7, the output power and output torque of the traveling drive motor and the hydraulic oil pump motor jointly driving the vehicle to travel meet the power and torque required for vehicle driving.

[0038] Technical effects and advantages of the present invention:

[0039] 1. Compared with the prior art, by constructing the coupling of the traveling power system and the operating power system, the free switching between the independent operation and the collaborative operation of the two power systems can be realized: on the one hand, the traveling power system can independently perform vehicle traveling and cargo transportation, while the operating power system can independently perform operations such as lifting and stacking of goods; on the other hand, the traveling drive motor of the traveling power system and the hydraulic oil pump motor of the operating power system jointly drive the vehicle to travel, sharing the load of the traveling power system between the traveling drive motor and the hydraulic oil pump motor, reducing the torque requirement for the traveling drive motor under the condition of the forklift climbing with full load, increasing the working speed, avoiding harsh working conditions such as the motor outputting at low speed and high torque, and thus greatly improving the power performance and energy efficiency of the vehicle, and realizing a significant improvement in the overall energy efficiency of the integrated power system of the forklift.

[0040] 2. Compared with the prior art, by setting the coupling of the traveling power system and the operating power system, integrating the design of the traveling power system and the operating power system, the common use of multiple components in the coupling mechanism can greatly reduce the material cost of the system, reduce the overall volume, and increase the power density; by using the coupling design of the traveling power system and the operating power system, transferring the surplus power of the operating power system to the traveling power system, the specifications of the traveling drive motor and its related electronic control and heat dissipation components can be reduced, and thus the overall cost of the power system can be reduced. Description of the drawings

[0041] Figure 1 is the system block diagram of the present invention.

[0042] Figure 2 is the structural schematic diagram of the traveling transmission mechanism, the hydraulic transmission mechanism and the coupling mechanism of the present invention.

[0043] Figure 3 is the flow schematic diagram of the control method of the present invention.

[0044] Reference numerals are:

[0045] 1. Vehicle controller;

[0046] 2. Traveling power system;

[0047] 21. Traveling motor controller;

[0048] 22. Traveling drive motor;

[0049] 23. Traveling transmission mechanism;

[0050] 231. Traveling input shaft gear; 232. First transmission gear; 233. Second transmission gear;

[0051] 234. First transmission shaft; 235. Traveling power output gear; 236. Differential;

[0052] 24. Driving axle; 241. Left half shaft; 242. Right half shaft;

[0053] 25. Coupling transmission mechanism;

[0054] 251. Third transmission gear; 252. Fourth transmission gear; 253. Second transmission shaft;

[0055] 3. Operating power system;

[0056] 31. Hydraulic oil pump motor controller; 32. Hydraulic oil pump motor;

[0057] 33. Hydraulic transmission mechanism;

[0058] 331. First input shaft gear; 332. Hydraulic power output gear; 333. Hydraulic power output shaft;

[0059] 34. Hydraulic oil pump;

[0060] 4. Mode switching controller;

[0061] 5. Coupling mechanism; 51. Clutch; 52. Coupling gear. Specific embodiments

[0062] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0063] As shown in the attached Figure 1 and attached Figure 2 A forklift integrated power system with dual-power collaborative work, including a vehicle controller 1, further including: a traveling power system 2, an operating power system 3, a mode switching controller 4, and a coupling mechanism 5;

[0064] The vehicle controller 1 is respectively connected to the traveling power system 2, the operating power system 3, and the mode switching controller 4 by signals,

[0065] The traveling power system 2 is connected to the operating power system 3 through the coupling mechanism 5;

[0066] The mode switching controller 4 is connected to the coupling mechanism 5 by signals;

[0067] Among them, the vehicle controller 1 realizes the free switching between the independent operation and collaborative operation of the two power systems according to the working state and working conditions of the traveling power system 2.

[0068] In a preferred embodiment, as shown in the appendix Figure 2 The traveling power system 2 includes: a traveling motor controller 21, a traveling drive motor 22, a traveling transmission mechanism 23, and a drive axle 24;

[0069] The vehicle controller 1 is signal-connected to the traveling drive motor 22 through the traveling motor controller 21, and the traveling drive motor 22 is drivingly connected to the drive axle 24 through the traveling transmission mechanism 23;

[0070] Among them, the vehicle controller 1 and the traveling motor controller 21 control the power output of the traveling drive motor 22 according to the driver's instructions, and drive the wheels to rotate through the coupling mechanism 5 and the drive axle 24 to realize vehicle traveling and cargo transportation.

[0071] The traveling transmission mechanism 23 includes: a traveling input shaft gear 231, a first transmission gear 232, a second transmission gear 233, a first transmission shaft 234, a traveling power output gear 235, and a differential 236;

[0072] The output shaft of the traveling drive motor 22 is fixedly connected to the traveling input shaft gear 231, the traveling input shaft gear 231 is meshingly connected to the first transmission gear 232, the first transmission gear 232 and the second transmission gear 233 are respectively fixedly sleeved at both ends of the first transmission shaft 234, and the second transmission gear 233 is drivingly connected to the traveling power output gear 235 through the coupling transmission mechanism 25;

[0073] The differential 236 is fixedly installed at the center of the traveling power output gear 235, and the differential 236 is fixedly connected to the drive axle 24;

[0074] Among them, the traveling drive motor 22 transmits power to the second transmission gear 233 through the traveling input shaft gear 231, the first transmission gear 232, and the first transmission shaft 234 to rotate, the second transmission gear 233 drives the traveling power output gear 235 to rotate through the coupling transmission mechanism 25, and the differential 236 installed at the center of the traveling power output gear 235 is connected to the drive axle 24 to drive the vehicle to travel.

[0075] In a preferred embodiment, as shown in the appendix Figure 2 The working power system 3 includes: a hydraulic oil pump motor controller 31, a hydraulic oil pump motor 32, a hydraulic transmission mechanism 33, and a hydraulic oil pump 34;

[0076] The vehicle controller 1 is signal - connected to the hydraulic oil pump motor controller 31, and the hydraulic oil pump motor 32 is drivingly connected to the hydraulic oil pump 34 through a hydraulic transmission mechanism 33;

[0077] Among them, the vehicle controller 1 and the hydraulic oil pump motor controller 31 control the motor torque and speed output of the hydraulic oil pump 34 according to the driver's instructions, drive the hydraulic oil pump 34 to work, provide power for the operation power system 3, and realize operation operations such as lifting and stacking of goods.

[0078] The hydraulic transmission mechanism 33 includes: a first input shaft gear 331, a hydraulic power output gear 332, and a hydraulic power output shaft 333;

[0079] The output shaft of the hydraulic oil pump motor 32 is fixedly connected to the first input shaft gear 331, the first input shaft gear 331 is meshingly connected to the hydraulic power output gear 332, and the hydraulic power output gear 332 is fixedly connected to the drive shaft of the hydraulic oil pump 34 through the hydraulic power output shaft 333;

[0080] Among them, the hydraulic oil pump motor 32 drives the hydraulic power output shaft 333 to rotate through the first input shaft gear 331 and the hydraulic power output gear 332, and then drives the hydraulic oil pump 34 to rotate, realizing the operation of the operation power system 3;

[0081] In a preferred embodiment, as shown in the appendix Figure 2 The coupling mechanism 5 includes: a clutch 51 and a coupling gear 52;

[0082] The clutch 51 and the coupling gear 52 for controlling the connection between the coupling gear 52 and the hydraulic power output shaft 333 are both installed on the hydraulic power output shaft 333, and the coupling gear 52 is meshingly connected to the second transmission gear 233;

[0083] The mode - switching controller 4 is signal - connected to the clutch 51;

[0084] Among them, according to the open and closed states of the clutch 51, the independent work and coordinated work of the two power systems of the traveling power system 2 and the operation power system 3 can be freely switched:

[0085] Specifically: under the condition that the clutch 51 is open, the coupling gear 52 is disconnected from the hydraulic power output shaft 333, and the coupling gear 52 can rotate freely on the hydraulic power output shaft 333; therefore, the hydraulic oil pump motor 32 drives the hydraulic oil pump 34 to meet the forklift operation requirements; while the traveling drive motor 22 can drive the vehicle to travel, realizing the independent work of the operation power system 3 and the traveling power system 2;

[0086] When the clutch 51 is closed, the coupling gear 52 is fixedly connected to the hydraulic power output shaft 333, so that the coupling gear 52 rotates synchronously with the hydraulic power output shaft 333; the power of the hydraulic oil pump motor 32 is transmitted to the second transmission gear 233 by using the meshing connection between the coupling gear 52 and the second transmission gear 233; the traveling drive motor 22 also transmits the power to the second transmission gear 233 to rotate. Since the second transmission gear 233 drives the traveling power output gear 235 to rotate through the coupling transmission mechanism 25, that is, to drive the vehicle to travel, the coupling between the operation power system 3 and the traveling power system 2 is realized;

[0087] Among them, it is known that the integrated power system of a forklift not only needs to meet the power requirements for the vehicle's own travel, but also needs to meet the power requirements for cargo transportation. The power requirement is small when driving on flat ground with no load, and the power requirement is large under working conditions such as climbing with full load, that is, the driving wheels require a large driving torque; in order to meet the torque requirements of the traveling power system 2 of the forklift, traditionally, a high-power motor, a large reduction ratio reducer, etc. are usually used to meet the requirements of the traveling power system 2; thus, the high-power motor leads to a significant increase in the costs of the motor and the electronic control, and the large reduction ratio reducer leads to a high rotational speed of the motor input shaft, large vibration, and poor NVH level;

[0088] Therefore, the present invention proposes an integrated power system for a forklift with dual-power collaborative work, which can freely switch the working state according to the demand of the traveling power system 2 of the forklift for the driving force;

[0089] When in working conditions such as the vehicle running without load and traveling on flat ground, the output power and output torque of the traveling drive motor 22 meet the power requirements for the vehicle to travel, and the coupling mechanism 5 controls the clutch 51 to disengage, and the traveling power system 2 and the operation power system 3 are in independent working conditions.

[0090] When the output power and output torque of the traveling drive motor 22 do not meet the power requirements of the vehicle under working conditions such as when the vehicle is fully loaded and climbing a slope, the traveling power system 2 needs to output extremely large torque and power. At this time, the coupling mechanism 5 controls the clutch 51 to close, and the traveling power system 2 is coupled with the working power system 3. The traveling drive motor 22 and the hydraulic oil pump motor 32 jointly drive the vehicle to travel, sharing the load of the traveling power system 2 between the traveling drive motor 22 and the hydraulic oil pump motor 32, thereby greatly improving the power performance and energy efficiency of the vehicle. Therefore, under the condition that the torque output of the traveling drive motor 22 in the traveling power system 2 remains unchanged, the reduction ratio of the reducer in the traveling power system 2 can be reduced. When the reduction ratio of the reducer is reduced, the rotational speeds of the traveling motor and the input shaft of the reducer during the high-speed driving of the forklift can be reduced, thereby reducing the noise of the traveling power system 2 and improving the NVH level of the forklift; reducing its torque output; and sharing the power demand under harsh working conditions between the traveling drive motor 22 and the hydraulic oil pump motor 32. Therefore, the heat generation of the traveling motor under the condition of full load climbing can be greatly reduced, and the thermal stability of the power system can be improved.

[0091] Therefore, the dual-power collaborative work of the present invention can improve power performance, energy consumption economy, and maximum climbing ability.

[0092] In a preferred embodiment, as shown in the appendix Figure 2 The coupling transmission mechanism 25 includes: a third transmission gear 251, a fourth transmission gear 252, and a second transmission shaft 253;

[0093] The second transmission gear 233 is meshed and connected with the third transmission gear 251. The third transmission gear 251 and the fourth transmission gear 252 are respectively fixedly sleeved at both ends of the second transmission shaft 253. The fourth transmission gear 252 is meshed and connected with the traveling power output gear 235.

[0094] In a preferred embodiment, as shown in the appendix Figure 2 The drive axle 24 includes: a left half shaft 241 and a right half shaft 242;

[0095] The differential 236 is respectively connected with the left half shaft 241 and the right half shaft 242. The left half shaft 241 and the right half shaft 242 are both connected with the wheels used to drive the vehicle to travel.

[0096] Among them, the differential 236 installed at the center of the traveling power output gear 235 is connected with the left half shaft 241 and the right half shaft 242 of the drive axle 24; the left half shaft 241 and the right half shaft 242 are connected with the drive wheels to drive the vehicle to travel.

[0097] Among them, the drive axle 24 is composed of components such as the left half shaft 241, the right half shaft 242, the wheels, and the housing; the components are fixed through connecting pieces such as bolts to form an integral body.

[0098] As shown in the appendix Figure 3 A control method for a forklift integrated power system includes a forklift integrated power system with dual power working together. The steps of the specific control method are as follows:

[0099] S1: Correlate the pedal opening with the desired speed of the vehicle and establish a corresponding speed closed-loop control mechanism;

[0100] In the vehicle control unit 1, a functional relationship between the throttle pedal opening and the desired speed of the vehicle is established. Taking a linear relationship as an example:

[0101] v = (V / U)*u,

[0102] The voltage range of the throttle pedal signal is 0 - U, where U is the maximum voltage of the throttle pedal;

[0103] The vehicle driving speed range is 0 - V, where V is the maximum vehicle speed;

[0104] The desired speed of the vehicle at the current moment is v;

[0105] The voltage of the throttle pedal signal at the current moment is u;

[0106] The vehicle control unit 1 obtains the desired vehicle speed v at the current moment according to the throttle pedal opening signal at the current moment (i.e., the current voltage u of the throttle pedal), calculates and obtains the target speed r of the driving motor 22. The vehicle control unit 1 sends the target speed r signal of the driving motor 22 to the driving motor controller 21, and the driving motor controller 21 realizes the closed-loop control of the vehicle driving speed through its internal PID control algorithm.

[0107] Among them, since the driver controls the driving speed of the forklift through the driving throttle pedal, the opening value of the pedal is corresponding to the desired driving speed of the vehicle, and then a closed-loop control mechanism for the vehicle driving speed is established.

[0108] S2: Disconnect the clutch 51 and control the vehicle to move by the driving motor 22;

[0109] Among them, in S2, when the vehicle is in the initial condition, the clutch 51 in the coupling mechanism 5 is in the disconnected state, the driving power system 2 and the operating power system 3 operate independently of each other, and the vehicle is driven by the driving motor 22.

[0110] S3: Real-time detection: the difference D between the desired vehicle speed and the actual vehicle speed in the speed closed-loop control mechanism in S1;

[0111] S4: Based on the difference between the desired vehicle speed and the actual vehicle speed in S3, set the critical value R for the driving motor 22 and the hydraulic oil pump motor 32 to jointly drive the vehicle to move;

[0112] S5: Determine the magnitude relationship between D and R: If D ≤ R, proceed to S6; if D > R, proceed to S7;

[0113] S6: The clutch 51 is in the disengaged state, and the traveling drive motor 22 independently drives the vehicle to travel; then return to S3;

[0114] S7: The clutch 51 is in the engaged state, and the traveling drive motor 22 and the hydraulic oil pump motor 32 cooperate to drive the vehicle to travel; then return to S3.

[0115] Among them, when the clutch 51 is engaged, at this time, the first input shaft gear 331, the hydraulic power output gear 332, the coupling gear 52, the second transmission gear 233, the third transmission gear 251, the fourth transmission gear 252, and the traveling power output gear 235 form a transmission system:

[0116] A definite proportional relationship is established between the vehicle traveling speed v and the rotational speed of the hydraulic oil pump motor 32. (The proportional value is calculated based on the transmission ratio of the transmission system and the tire radius)

[0117] The vehicle controller 1 calculates the target rotational speed of the hydraulic oil pump motor 32 according to the desired vehicle speed, sends the target rotational speed of the hydraulic oil pump motor 32 to the hydraulic oil pump motor controller 31, and the hydraulic oil pump motor controller 31 performs closed-loop control on the rotational speed of the oil pump motor according to the target rotational speed and the PID control algorithm, so as to realize the cooperative driving of the vehicle by the hydraulic oil pump motor 32 and the traveling drive motor 22.

[0118] In a preferred embodiment, as shown in the appendix Figure 3 In S4, when there is a load or climbing, when the output power and output torque of the traveling drive motor 22 cannot meet the power and torque required for vehicle travel, a critical value R is set.

[0119] Among them, under conditions such as full-load climbing that require high power and torque output, when the output torque and output power of the traveling drive motor 22 cannot meet the torque and power requirements for travel, the difference D value between the actual vehicle speed and the desired vehicle speed corresponding to the pedal will increase; therefore, the critical value R is set as the threshold for engaging the clutch 51.

[0120] In a preferred embodiment, as shown in the appendix Figure 3 In S6, the output power and output torque of the traveling drive motor 22 meet the power and torque required for vehicle travel.

[0121] Among them, under the working conditions where the output power and output torque of the traveling drive motor 22 meet the power demand for vehicle travel, the actual traveling speed of the vehicle is relatively close to the vehicle speed corresponding to the opening of the drive pedal, that is, there is a small range of fluctuations, so the difference D value is small;

[0122] In a preferred embodiment, as shown in the appendix Figure 3 In S7, the output power and output torque of the traveling drive motor 22 and the hydraulic oil pump motor 32 jointly driving the vehicle to travel meet the power and torque required for vehicle driving; so that the vehicle controller 1 controls the dual power to work together, that is, controls the traveling power system 2 and the working power system 3 to jointly output power and output torque, and further enables the traveling drive motor 22 and the hydraulic oil pump motor 32 to jointly drive the vehicle to travel, improving the climbing, towing ability and the overall machine efficiency.

[0123] Among them, according to the actual on-site situation: under the driving working conditions of the forklift, operation or minor operation is usually not allowed, and at this time, the load of the hydraulic oil pump motor 32 is small; therefore, in the present invention, by coupling the traveling power system 2 of the forklift with the working power system 3, the surplus power and torque of the hydraulic oil pump motor 32 in the working power system 3 can be transmitted to the power and torque output by the traveling drive motor 22 in the traveling power system 2, thereby greatly improving the dynamic performance of the traveling power system 2.

[0124] It should be noted that the control method proposed in the present invention is only the simplest implementable control logic, and the control methods aiming at improving energy consumption economy, maximum traveling speed, etc. realized based on the structure and principle of the present invention also fall within the protection scope of the present invention.

[0125] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0126] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A forklift integrated power system with dual-power collaborative work, comprising a vehicle controller (1), characterized in that: It also includes: a traveling power system (2), a working power system (3), a mode switching controller (4), and a coupling mechanism (5); the vehicle controller (1) is respectively in signal connection with the traveling power system (2), the working power system (3), and the mode switching controller (4), the traveling power system (2) is connected to the working power system (3) through the coupling mechanism (5); the mode switching controller (4) is in signal connection with the coupling mechanism (5).

2. The integrated power system of a forklift with dual power working in coordination according to claim 1, characterized in that: The traveling power system (2) includes: a traveling motor controller (21), a traveling drive motor (22), a traveling transmission mechanism (23), and a drive axle (24); the vehicle controller (1) is in signal connection with the traveling drive motor (22) through the traveling motor controller (21), and the traveling drive motor (22) is in transmission connection with the drive axle (24) through the traveling transmission mechanism (23); the traveling transmission mechanism (23) includes: a traveling input shaft gear (231), a first transmission gear (232), a second transmission gear (233), a first transmission shaft (234), a traveling power output gear (235), and a differential (236); the output shaft of the traveling drive motor (22) is fixedly connected to the traveling input shaft gear (231), the traveling input shaft gear (231) is meshed and connected to the first transmission gear (232), the first transmission gear (232) and the second transmission gear (233) are respectively fixedly sleeved at both ends of the first transmission shaft (234), and the second transmission gear (233) is in transmission connection with the traveling power output gear (235) through a coupling transmission mechanism (25); the differential (236) is fixedly installed at the center of the traveling power output gear (235), and the differential (236) is fixedly connected to the drive axle (24).

3. The integrated power system of a forklift with dual-power collaborative operation according to claim 1, characterized in that: The working power system (3) includes: a hydraulic oil pump motor controller (31), a hydraulic oil pump motor (32), a hydraulic transmission mechanism (33), and a hydraulic oil pump (34); the vehicle controller (1) is in signal connection with the hydraulic oil pump motor (32) through the hydraulic oil pump motor controller (31), and the hydraulic oil pump motor (32) is in transmission connection with the hydraulic oil pump (34) through the hydraulic transmission mechanism (33); the hydraulic transmission mechanism (33) includes: a first input shaft gear (331), a hydraulic power output gear (332), and a hydraulic power output shaft (333); the output shaft of the hydraulic oil pump motor (32) is fixedly connected to the first input shaft gear (331), the first input shaft gear (331) is meshed and connected to the hydraulic power output gear (332), and the hydraulic power output gear (332) is fixedly connected to the drive shaft of the hydraulic oil pump (34) through the hydraulic power output shaft (333).

4. A forklift integrated power system with dual power working in coordination according to claim 2 or 3, characterized in that: The coupling mechanism (5) includes: a clutch (51) and a coupling gear (52); Both the clutch (51) and the coupling gear (52) for controlling the connection between the coupling gear (52) and the hydraulic power output shaft (333) are mounted on the hydraulic power output shaft (333), and the coupling gear (52) is meshed and connected with the second transmission gear (233). The mode switching controller (4) is signal-connected to the clutch (51).

5. The integrated power system of a forklift with dual power working in coordination according to claim 2, wherein: The coupling transmission mechanism (25) includes: a third transmission gear (251), a fourth transmission gear (252), and a second transmission shaft (253). The second transmission gear (233) is meshed and connected with the third transmission gear (251). The third transmission gear (251) and the fourth transmission gear (252) are respectively fixedly sleeved at both ends of the second transmission shaft (253), and the fourth transmission gear (252) is meshed and connected with the vehicle driving power output gear (235).

6. The integrated power system of a forklift with dual-power collaborative operation according to claim 2, wherein: The drive axle (24) includes: a left half shaft (241) and a right half shaft (242). The differential (236) is respectively connected to the left half shaft (241) and the right half shaft (242), and both the left half shaft (241) and the right half shaft (242) are connected to the wheels for driving the vehicle to travel.

7. A control method for a forklift integrated power system, comprising a forklift integrated power system for dual-power collaborative work according to any one of claims 1-6, characterized in that: The steps of the specific control method are as follows: S1: Corresponding the pedal opening to the desired speed of the vehicle and establishing a corresponding speed closed-loop control mechanism. S2: Disconnecting the clutch (51) and controlling the vehicle to travel by the traveling drive motor (22). S3: Detecting in real time the difference D between the vehicle speed in the speed closed-loop control mechanism in S1 and the actual vehicle speed. S4: Based on the difference between the vehicle speed and the actual vehicle speed in S3, setting a critical value R for the traveling drive motor (22) and the hydraulic oil pump motor (32) to jointly drive the vehicle to travel. S5: Judging the magnitudes of D and R: If D ≤ R, then enter S6; if D > R, then enter S7. S6: The clutch (51) is in the disconnected state, and the traveling drive motor (22) independently drives the vehicle to travel; then return to S3. S7: The clutch (51) is in the closed state, and the traveling drive motor (22) and the hydraulic oil pump motor (32) jointly drive the vehicle to travel; then return to S3.

8. A control method for an integrated power system of a forklift according to claim 7, characterized in that: In S4, when there is a load or climbing, when the output power and output torque of the traveling drive motor (22) cannot meet the power and torque required for vehicle driving, the critical value R is set.

9. The control method of an integrated power system for a forklift according to claim 7, characterized in that: In S6, the output power and output torque of the traveling drive motor (22) meet the power and torque required for vehicle driving.

10. A control method for an integrated power system of a forklift according to claim 7, characterized in that: In S7, the output power and output torque of the traveling drive motor (22) and the hydraulic oil pump motor (32) jointly driving the vehicle to travel meet the power and torque required for vehicle driving.

Images