Hybrid forklift cooling system and control method

Abstract

The application provides a hybrid forklift cooling system and a hybrid forklift cooling control method, relates to the technical field of forklifts, and a multi-in-one cooler assembly is integrally arranged with an engine cooling module, an engine intercooling module, a hydraulic oil cooling module, a motor electric control cooling module and an electronic fan; an engine cooling subsystem is connected with the engine and the engine cooling module, so that the circulating flow of cooling liquid is realized to achieve cooling; an engine intercooling subsystem is connected with the engine and the engine intercooling module, so that the pressurized gas entering the engine is cooled; a hydraulic oil cooling subsystem is connected with a hydraulic driving device and the hydraulic oil cooling module, so that the circulating flow of hydraulic oil is realized to achieve cooling; and a motor electric control cooling subsystem is connected with a motor electric control assembly and the motor electric control cooling module, so that the circulating flow of cooling liquid is realized to achieve cooling. The application integrates various cooling modules in one place, and realizes heat dissipation by transferring heat through the fan, so that the heat is integrated in one place, and the integration degree of the hybrid forklift heat dissipation and cooling is improved.

Description

Technical Field

[0001] This invention relates to the field of forklift technology, and more particularly to a hybrid forklift cooling system and control method. Background Technology

[0002] The country is vigorously developing the new energy vehicle industry and promoting and popularizing new energy vehicles to achieve carbon emission reduction. Developing new energy vehicles is an inevitable trend and will also drive the transformation of non-road machinery towards new energy sources. Non-road machinery cannot completely replace fuel-powered vehicles in the short term. For forklifts, a hybrid model can serve as a transitional vehicle, meeting the needs of pure electric drive, hybrid drive, pure engine operation, or hydraulically driven working modes.

[0003] Since hybrid forklifts combine the three-electric system of pure electric forklifts with the engine system of traditional fuel forklifts, a suitable cooling system is needed to ensure that all these operating components work at the appropriate temperature.

[0004] The main problems with heat dissipation in hybrid forklifts are as follows: the engine radiator unit and the three-electric system (battery, motor, and electronic control system) radiators are distributed, resulting in a complex overall layout and intricate piping. This distributed design requires individual control of each radiator unit, leading to low integration and cumbersome control. Poor heat dissipation from heat-generating components significantly increases energy loss.

[0005] For those skilled in the art, improving the integration of heat dissipation and cooling in hybrid forklifts is a technical problem that needs to be solved. Summary of the Invention

[0006] This invention provides a hybrid forklift cooling system that transfers heat generated from various parts of the forklift to a multi-functional cooler assembly for centralized outward heat dissipation. By integrating the heat dissipation points into one location, the system improves the integration of heat dissipation and cooling in the hybrid forklift. The specific solution is as follows:

[0007] A hybrid forklift cooling system includes: an engine cooling subsystem, an engine intercooler subsystem, a hydraulic oil cooling subsystem, a motor and electronic control cooling subsystem, and an all-in-one cooler assembly;

[0008] The all-in-one cooler assembly includes an integrated engine cooling module, an engine intercooler module, a hydraulic oil cooling module, a motor control cooling module, and an electric fan; the engine cooling module, the engine intercooler module, the hydraulic oil cooling module, and the motor control cooling module are respectively cooled by air via the electric fan;

[0009] The engine cooling subsystem is used to connect the engine and the engine cooling module, so that the coolant circulates to achieve cooling.

[0010] The engine intercooling subsystem is used to connect the engine and the engine intercooling module to cool the pressurized gas entering the engine.

[0011] The hydraulic oil cooling subsystem is used to connect the hydraulic drive device and the hydraulic oil cooling module, so that the hydraulic oil circulates and achieves cooling.

[0012] The motor control cooling subsystem is used to connect the motor control components and the motor control cooling module to achieve cooling through coolant circulation.

[0013] Optionally, at least two electronic fans are provided and controlled independently of each other;

[0014] The engine cooling module, the engine intercooler module, the hydraulic oil cooling module, and the motor control cooling module are divided into at least two groups, and each group corresponds to at least one of the electric fans;

[0015] The electronic fan is used to independently adjust its heat dissipation power according to the group it is dissipating heat.

[0016] Optionally, the engine cooling subsystem includes a first expansion tank and the engine cooling module;

[0017] The engine cooling module includes a first water chamber, an engine radiator, and a second water chamber. A pressure cover is provided on the first water chamber, and a first degassing connector is provided on the pressure cover. A second degassing connector and a first water pipe are provided on the first water chamber. A second water pipe and a drain outlet are provided on the second water chamber.

[0018] The first degassing connector is connected to the connector on the first expansion tank via a water pipe; the second degassing connector is connected to the engine degassing connector via a water pipe; the first water pipe is connected to the engine water inlet via a water pipe, and the second water pipe is connected to the engine water outlet; the height of the second water pipe is higher than the height of the first water pipe, thereby creating a pressure difference.

[0019] Optionally, the engine intercooling subsystem includes the engine intercooling module;

[0020] The engine intercooling module includes a first chamber, an intercooler, and a second chamber. The first chamber is provided with an intake pipe, and the second chamber is provided with an exhaust pipe.

[0021] The intake manifold is connected to the boost outlet of the engine via an intake hose, and the exhaust manifold is connected to the engine intake via an intake hose.

[0022] Optionally, the hydraulic oil cooling subsystem includes the hydraulic oil cooling module;

[0023] The hydraulic oil cooling module includes a third water chamber, a hydraulic oil radiator, and a fourth water chamber;

[0024] The third water chamber is equipped with a first hydraulic oil pipe joint, and the fourth water chamber is equipped with a second hydraulic oil pipe joint.

[0025] Optionally, the motor electronic control cooling subsystem includes the motor electronic control cooling module, an electronic water pump, a second expansion tank, a vehicle power supply dual-function device, a drive motor electronic control dual-function device, and a generator motor controller;

[0026] The motor control cooling module includes a fifth water chamber, a motor control radiator, and a sixth water chamber;

[0027] The fifth water chamber is equipped with a third water pipe connector, the upper side of the sixth water chamber is equipped with a third degassing connector, and the front has a fourth water pipe connector and a fifth water pipe connector; the diameter of the fifth water pipe connector is larger than the diameter of the fourth water pipe connector; the fourth water pipe connector and the fifth water pipe connector are connected as one unit.

[0028] The vehicle power supply dual-function device includes a DC-DC converter and a high-voltage power distribution unit;

[0029] The third degassing connector is connected to the gas storage connector of the second expansion tank via a degassing hose.

[0030] The fourth water pipe connector is connected to the water pipe connector of the second expansion tank via an inlet hose. The fifth water pipe connector is connected to the inlet connector of the electronic water pump via a water pipe. The outlet connector of the electronic water pump is connected to the inlet connector of the vehicle power supply unit via an outlet hose. The outlet connector of the vehicle power supply unit is connected to the inlet connector of the drive motor control unit via an outlet hose. The outlet connector of the drive motor control unit is connected to the inlet connector of the generator motor controller via an outlet hose. The outlet connector of the generator motor controller is connected to the third water pipe connector via an outlet hose.

[0031] Optionally, the all-in-one cooler assembly, after cooling, satisfies the following:

[0032] The engine inlet water temperature after passing through the engine cooling subsystem is ≤105℃;

[0033] The engine intake air temperature after passing through the engine intercooler subsystem is ≤60℃;

[0034] The temperature of the hydraulic oil after passing through the hydraulic oil cooling subsystem is ≤105℃;

[0035] The coolant temperature at the inlet of the vehicle power supply combo device is between -40℃ and 80℃. It should be used with reduced power when the temperature is above 65℃, and the coolant flow rate should be ≥6L / min.

[0036] The inlet temperature of the integrated drive motor and electronic control device is ≤65℃, and the inlet flow rate is 8L / min~12L / min;

[0037] The operating temperature range of the generator motor controller is -40℃ to 65℃.

[0038] Optionally, the all-in-one cooler assembly is located at the rear of the forklift, in front of the forklift counterweight.

[0039] Optionally, it also includes a controller assembly, which includes a power supply, a key start switch, a first relay, a fuse FU, a vehicle control unit (VCU), a second relay, an emergency stop switch, a DC-DC converter, a power battery, a drive motor controller, an on-board power supply unit, an engine ECU, a generator motor controller, an electric fan, and an electric water pump.

[0040] The present invention also provides a cooling control method for a hybrid forklift, applied to the hybrid forklift cooling system described in any of the above claims, comprising:

[0041] When the engine is not running, the hybrid forklift is driven by pure electric power, with the hydraulic oil cooling subsystem and the motor control cooling subsystem operating.

[0042] When the emergency stop switch is closed, the key start switch is in the ON state, and the first relay is closed; the key switch signal wakes up the vehicle controller (VCU) and the power battery; the vehicle controller (VCU) controls the second relay to turn on the electronic water pump; the vehicle controller (VCU) obtains the temperature signals of the drive motor controller, the vehicle power supply unit, the drive motor control unit, and the generator motor controller through CAN communication.

[0043] If -40℃≤ temperature of the vehicle power supply unit ≤ 40℃, or -40℃≤ temperature of the drive motor controller ≤ 50℃, or -40℃≤ temperature of the generator motor controller ≤ 50℃, the fan PWM speed control duty cycle is 10%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the temperature of the vehicle power supply unit ≤ 40℃, the temperature of the drive motor controller, and the temperature of the generator motor controller.

[0044] If 40℃ < vehicle power supply unit temperature ≤ 80℃, or 50℃ < drive motor controller temperature ≤ 65℃, or 50℃ < generator motor controller temperature ≤ 65℃, the fan PWM speed control duty cycle is 90%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the vehicle power supply unit temperature, drive motor controller temperature, and generator motor controller temperature.

[0045] If the temperature of the vehicle power supply unit is >80℃, or the temperature of the drive motor controller is >65℃, or the temperature of the generator motor controller is >65℃, a high water temperature warning will be sent.

[0046] The intermediate PWM speed control duty cycle changes linearly with the temperature curve, which allows the electric fan speed to change in real time with the temperature, avoiding the electric fan from running at high speed all the time and reducing fan noise.

[0047] When the engine is running, it directly drives the hydraulic drive unit, or the engine works with a generator motor to power the range extender; the engine cooling subsystem, engine intercooler subsystem, hydraulic oil cooling subsystem and motor control cooling subsystem operate normally.

[0048] When the key start switch is in the ON state, the first relay is closed, and the vehicle controller (VCU) controls the second relay to turn on the electronic water pump. The vehicle controller (VCU) obtains the temperature signals of the drive motor controller, the vehicle power supply unit, the drive motor control unit, and the generator motor controller through CAN communication, and obtains the engine water temperature signal and the engine intercooler intake air temperature signal through the engine ECU.

[0049] If -40℃≤Vehicle power supply combined temperature≤40℃, or -40℃≤Drive motor controller temperature≤50℃, or -40℃≤Generator motor controller temperature≤50℃, or Engine coolant temperature≤85℃, or Intercooler intake temperature≤53℃, the fan PWM speed control duty cycle is 10%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the vehicle power supply combined temperature, drive motor controller temperature, and generator motor controller temperature.

[0050] If 40℃ < vehicle power supply unit temperature ≤ 80℃, or 50℃ < drive motor controller temperature ≤ 65℃, or 50℃ < generator motor controller temperature ≤ 65℃, or 85℃ < engine coolant temperature ≤ 105℃, or 53℃ < intercooler intake temperature ≤ 60℃, the fan PWM speed control duty cycle is 90%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the vehicle power supply unit temperature and the generator motor controller temperature.

[0051] If the temperature of the vehicle power supply unit is >80℃, or the temperature of the drive motor controller is >65℃, or the temperature of the generator motor controller is >65℃, or the engine coolant temperature is >105℃, or the intercooler intake temperature is >60℃, an overheat warning will be issued.

[0052] The intermediate PWM speed control duty cycle changes linearly with the temperature curve, allowing the electric fan speed to change in real time with the temperature, avoiding the electric fan from running at high speed all the time and reducing fan noise.

[0053] This invention provides a hybrid forklift cooling system. The multi-functional cooler assembly integrates an engine cooling module, an engine intercooler module, a hydraulic oil cooling module, a motor and electronic control cooling module, and an electric fan. The engine cooling subsystem connects the engine and the engine cooling module, enabling coolant circulation for cooling. The engine intercooler subsystem connects the engine and the engine intercooler module, cooling the pressurized gas entering the engine. The hydraulic oil cooling subsystem connects the hydraulic drive unit and the hydraulic oil cooling module, enabling hydraulic oil circulation for cooling. The motor and electronic control cooling subsystem connects the motor and electronic control components and the motor and electronic control cooling module, enabling coolant circulation for cooling. This invention integrates all cooling modules into one location and uses a fan to transfer heat for dissipation, thus consolidating the heat dissipation points in one place and improving the overall integration of cooling in the hybrid forklift. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of the structure of the hybrid forklift cooling system provided by the present invention;

[0056] Figure 2 This is a schematic diagram of the electronic control system for the hybrid forklift cooling system provided by the present invention;

[0057] Figure 3 A front view of a specific embodiment of an all-in-one cooler assembly;

[0058] Figure 4 Right side view of one specific embodiment of the all-in-one cooler assembly;

[0059] Figure 5 This is a left-side view of one specific embodiment of the all-in-one cooler assembly.

[0060] The image includes:

[0061] Engine cooling subsystem 1, first expansion tank 11, engine intercooler subsystem 2, hydraulic oil cooling subsystem 3, motor and electronic control cooling subsystem 4, electronic water pump 41, second expansion tank 42, vehicle power supply dual-function device 43, DC-DC converter 431, drive motor and electronic control dual-function device 44, drive motor controller 441, generator motor controller 45.

[0062] All-in-one cooler assembly 5, engine cooling module 51, first water chamber 511, pressure cap 5111, first degassing pipe 5112, second degassing pipe 5113, first water pipe 5114, engine radiator 512, second water chamber 513, second water pipe 5131, drain port 5132, engine intercooler module 52, first air chamber 521, intake pipe 5211, intercooler 522, second air chamber 523, exhaust pipe 5231 Hydraulic oil cooling module 53, third water chamber 531, first hydraulic oil pipe joint 5311, hydraulic oil radiator 532, fourth water chamber 533, second hydraulic oil pipe joint 5331, motor and electronic control cooling module 54, fifth water chamber 541, third water pipe joint 5411, motor and electronic control radiator 542, sixth water chamber 543, third degassing pipe 5431, fourth water pipe joint 5432, fifth water pipe joint 5433, electric fan 55;

[0063] Engine 6, engine venting pipe 61, engine water inlet 62, engine water outlet 63, booster exhaust port 64, engine air inlet 65, clutch 66;

[0064] Controller assembly 7, power supply 7.1, key start switch 7.2, first relay 7.3, fuse FU 7.4, vehicle control unit (VCU) 7.5, second relay 7.6, emergency stop switch 7.7, power battery 7.8, engine ECU 7.9;

[0065] 8. Hydraulic drive unit; 9. Generator motor. Detailed Implementation

[0066] The core of this invention is to provide a hybrid forklift cooling system that transfers the heat generated by various parts of the forklift to a multi-functional cooler assembly for centralized outward heat dissipation, integrating the heat dissipation points in one place, thereby improving the integration of heat dissipation and cooling in the hybrid forklift.

[0067] To enable those skilled in the art to better understand the technical solution of the present invention, the hybrid forklift cooling system and hybrid forklift cooling control method provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0068] Combination Figure 1 As shown in the diagram, solid lines represent water pipe lines, and dashed lines represent electrical lines. It should be noted that a certain component may belong to different units. For example, the engine cooling module 51 is part of the all-in-one cooler assembly 5, but it is also a structure of the engine cooling subsystem 1.

[0069] This invention provides a hybrid forklift cooling system, comprising: an engine cooling subsystem 1, an engine intercooler subsystem 2, a hydraulic oil cooling subsystem 3, a motor and electronic control cooling subsystem 4, and a multi-functional cooler assembly 5. The engine cooling subsystem 1 cools the engine 6 using coolant; the engine intercooler subsystem 2 cools the high-temperature intake air from the turbocharged engine, bringing the air entering the engine 6 to a suitable temperature; the hydraulic oil cooling subsystem 3 cools the hydraulic oil; and the motor and electronic control cooling subsystem 4 cools the coolant flowing through the motor, electronic control, and other electrical components. The engine cooling subsystem 1, engine intercooler subsystem 2, hydraulic oil cooling subsystem 3, and motor and electronic control cooling subsystem 4 collectively transfer heat to the multi-functional cooler assembly 5, which then dissipates the heat to the outside.

[0070] Combination Figure 3 , Figure 4 , Figure 5 As shown, the all-in-one cooler assembly 5 includes an integrated engine cooling module 51, an engine intercooler module 52, a hydraulic oil cooling module 53, a motor and electronic control cooling module 54, and an electric fan 55; (See attached image) Figure 3 The layout shown is such that the engine cooling module 51, engine intercooler module 52, hydraulic oil cooling module 53, and motor control cooling module 54 are arranged from top to bottom. Alternatively, they can be arranged horizontally, and the order of the four modules can be changed.

[0071] The engine cooling module 51, engine intercooler module 52, hydraulic oil cooling module 53, and motor / electronic control cooling module 54 are cooled independently. Each of these modules is cooled by air via an electric fan 55. Heat is transferred to each module, and the rotation of the electric fan 55 generates airflow to cool them.

[0072] Specifically, the engine cooling subsystem 1 is used to connect the engine 6 and the engine cooling module 51, so that the coolant can circulate and achieve cooling. When the coolant flows through the engine 6, the heat of the engine 6 is transferred to the coolant. When the coolant passes through the engine cooling module 51, it dissipates heat and then re-enters the engine 6 to form a cycle after the coolant is cooled down.

[0073] The engine intercooling subsystem 2 is used to connect the engine 6 and the engine intercooling module 52, so as to cool the pressurized gas entering the engine 6. The engine 6 is equipped with a turbine, which pressurizes the air entering the engine 6, and at the same time causes the air temperature to rise. The pressurized air passes through the engine intercooling subsystem 2, which cools the air before it enters the engine 6.

[0074] The hydraulic oil cooling subsystem 3 is used to connect the hydraulic drive unit 8 and the hydraulic oil cooling module 53, so that the hydraulic oil can circulate and be cooled. The hybrid forklift can walk or lift by hydraulic drive, and the high temperature hydraulic oil is cooled by the hydraulic oil cooling subsystem 3.

[0075] The motor control cooling subsystem 4 is used to connect the motor control components and the motor control cooling module 54 so that the coolant can circulate and achieve cooling. The motor control components include several components for driving or control. For components with large heat generation, coolant is also required to cool them down. After absorbing heat, the coolant passes through the motor control cooling subsystem 4 for cooling.

[0076] Traditional hybrid forklifts use a dispersed arrangement of engine radiator units and three-electric system radiators, resulting in a complex overall layout and intricate piping. This invention, however, centrally transfers heat to a multi-functional cooler assembly 5, integrating multiple radiator units into one unit, simplifying the overall vehicle layout and achieving optimization and convenience.

[0077] Based on the above scheme, the present invention provides at least two electronic fans 55, which are independently controlled, and each electronic fan 55 independently controls its working state. The engine cooling module 51, engine intercooler module 52, hydraulic oil cooling module 53, and motor control cooling module 54 are divided into at least two groups, and each group corresponds to at least one electronic fan 55; the electronic fan 55 is used to independently adjust its heat dissipation power according to the group it is cooling.

[0078] Combination Figure 3 As shown, the engine cooling module 51 and the engine intercooler module 52 correspond to the two upper electric fans 55, which form a group and can be adjusted synchronously; the hydraulic oil cooling module 53 and the motor control cooling module 54 correspond to the two lower electric fans 55, which form a group and can be adjusted synchronously.

[0079] The quantity, distribution location, size, model, and other parameters of the electronic fans 55 can be set according to specific needs. Each electronic fan 55 can be a fan of the same specification or a fan of different specifications.

[0080] Furthermore, the engine cooling subsystem 1 includes a first expansion tank 11 and an engine cooling module 51, as well as corresponding pipelines; wherein the engine cooling module 51 includes a first water chamber 511, an engine radiator 512 and a second water chamber 513, the first water chamber 511 and the second water chamber 513 are respectively located at both ends of the engine radiator 512 and are interconnected.

[0081] A pressure cover 5111 is provided on the first water chamber 511, and a first degassing pipe 5112 is provided on the pressure cover 5111; a second degassing pipe 5113 and a first water pipe 5114 are provided on the first water chamber 511.

[0082] The second water chamber 513 has a second water pipe 5131 and a water outlet 5132.

[0083] The first degassing pipe 5112 is connected to the first expansion tank 11 via a water pipe. It is mainly used to remove gas from the engine cooling module 51 to prevent air from affecting the heat dissipation effect. The first expansion tank 11 mainly serves to exhaust gas and replenish water.

[0084] The second air bleeder 5113 is connected to the engine air bleeder 61 via a water pipe and is mainly used to remove air from the engine.

[0085] The first water pipe 5114 is connected to the engine water inlet 62 via a water pipe, and the second water pipe 5131 is connected to the engine water outlet 63. The height of the second water pipe 5131 is higher than that of the first water pipe 5114, thereby creating a pressure difference, which helps the coolant flow and achieves better heat dissipation.

[0086] When the engine cooling subsystem 1 is working, the coolant flows from the engine water outlet 63 through the engine cooling module 51, and then flows into the engine 6 through the engine water inlet 62, forming a cooling cycle that continuously cools the engine 6 and ensures that the engine 6 works normally.

[0087] Furthermore, the engine intercooling subsystem 2 includes an engine intercooling module 52 and corresponding piping and other structures; the engine intercooling module 52 includes a first air chamber 521, an intercooler 522 and a second air chamber 523, the first air chamber 521 and the second air chamber 523 are located at both ends of the intercooler 522 and are interconnected.

[0088] The first air chamber 521 is provided with an intake pipe 5211, and the second air chamber 523 is provided with an exhaust pipe 5231; the intake pipe 5211 is connected to the boost outlet 64 of the engine 6 through an intake hose, and the exhaust pipe 5231 is connected to the engine intake 65 through an intake hose.

[0089] When the engine intercooling subsystem 2 is working, the pressurized high-temperature air flows through the intake pipe 5211 and the engine intercooling module 52. The cooled air enters the engine cylinder through the intake port 65 to assist combustion and do work. This not only reduces the intake temperature of the engine 6 and ensures that the engine 6 operates at the optimal operating temperature, but also increases the intake volume and alleviates the thermal load of the engine 6.

[0090] Furthermore, the hydraulic oil cooling subsystem 3 includes a hydraulic oil cooling module 53 and corresponding piping structures; the hydraulic oil cooling module 53 includes a third water chamber 531, a hydraulic oil radiator 532, and a fourth water chamber 533; the third water chamber 531 is equipped with a first hydraulic oil pipe connector 5311, and the fourth water chamber 533 is equipped with a second hydraulic oil pipe connector 5331. To facilitate the installation of hydraulic oil pipes, the first hydraulic oil pipe connector 5311 and the second hydraulic oil pipe connector 5331 are required to be installed on the rear side of the hydraulic oil cooling module 53, that is, on the side opposite to the electric fan 55.

[0091] When the hydraulic oil cooling subsystem 3 is working, the hydraulic oil in the hydraulic system flows through the second hydraulic oil pipe joint 5331 into the hydraulic oil cooling module 53. After being cooled, it flows back to the hydraulic oil tank through the first hydraulic oil pipe joint 5311, forming a cooling cycle process of the hydraulic oil and reducing the working temperature of the hydraulic oil.

[0092] Furthermore, the motor and electronic control cooling subsystem 4 includes a motor and electronic control cooling module 54, an electronic water pump 41, a second expansion tank 42, a vehicle power supply integrated device 43, a drive motor and electronic control integrated device 44, and a generator motor controller 45. The motor and electronic control cooling module 54 includes a fifth water chamber 541, a motor and electronic control radiator 542, and a sixth water chamber 543; the fifth water chamber 541 and the sixth water chamber 543 are respectively located at both ends of the motor and electronic control radiator 542 and are interconnected.

[0093] The fifth water chamber 541 is equipped with a third water pipe connector 5411, and the sixth water chamber 543 is equipped with a third degassing pipe connector 5431 on the upper side. The front has a fourth water pipe connector 5432 and a fifth water pipe connector 5433. The diameter of the fifth water pipe connector 5433 is larger than that of the fourth water pipe connector 5432. For the convenience of the pipeline route, the fourth water pipe connector 5432 and the fifth water pipe connector 5433 are connected as one unit.

[0094] The vehicle power supply dual-function device 43 includes a DC-DC converter 431 and a high-voltage power distribution unit.

[0095] The third degassing pipe 5431 is connected to the air storage pipe of the second expansion tank 42 via a degassing hose. It is mainly used to remove air from the motor control cooling module 54 to prevent air from affecting the heat dissipation effect. The second expansion tank 42 can also play the role of venting and replenishing water.

[0096] The fourth water pipe connector 5432 is connected to the water pipe connector of the second expansion tank 42 via an inlet hose; the fifth water pipe connector 5433 is connected to the inlet connector of the electronic water pump 41 via a water pipe. The outlet connector of the electronic water pump 41 is connected to the inlet connector of the vehicle power supply dual-function device 43 via an outlet hose; the outlet connector of the vehicle power supply dual-function device 43 is connected to the inlet connector of the drive motor control dual-function device 44 via an outlet hose; the outlet connector of the drive motor control dual-function device 44 is connected to the inlet connector of the generator motor controller 45 via an outlet hose; and the outlet connector of the generator motor controller 45 is connected to the third water pipe connector 5411 via an outlet hose.

[0097] When the motor-electric control cooling subsystem 4 is working, the coolant passes through the motor-electric control cooling module 54, then sequentially through the electronic water pump 41, the vehicle power supply integrated device 43, the drive motor electric control integrated device 44, and the generator motor controller 45, before flowing back to the motor-electric control cooling module 54, forming a series cooling circulation system. This system sequentially cools the heat-generating components in the system, ensuring they operate normally at a suitable temperature. When the coolant in this cooling system is insufficient, coolant can be added through the filler port of the second expansion tank 42.

[0098] The normal operation of the hybrid forklift cooling system requires setting appropriate control strategies based on the engine 6 water temperature, the temperature of the on-board power supply device 43, the temperature of the drive motor control device 44, and the temperature of the generator motor controller 45.

[0099] The engine inlet water temperature after passing through engine cooling subsystem 1 is ≤105℃, and the engine intake air temperature after passing through engine intercooler subsystem 2 is ≤60℃. The hydraulic oil temperature after passing through hydraulic oil cooling subsystem 3 is ≤105℃, and under normal circumstances it will be less than 110℃, which is sufficient for the normal operation of the hydraulic system and does not need to be a key consideration in the design.

[0100] The vehicle power supply dual-function device 43 has a coolant temperature between -40℃ and 80℃ at the inlet. It reduces power when the temperature is above 65℃ and has a coolant flow rate of ≥6L / min.

[0101] The drive motor and electronic control integrated device has an inlet water temperature of ≤65℃ and an inlet water flow rate of 8L / min~12L / min.

[0102] The operating temperature range of the generator motor controller 45 is -40℃ to 65℃.

[0103] The all-in-one cooler assembly 5 of the present invention is located at the rear of the forklift, in front of the forklift counterweight. The pipeline concentrates heat to the rear of the forklift, reducing the impact on the driver's comfort.

[0104] Combination Figure 2 As shown, the hybrid forklift cooling system of the present invention also includes a controller assembly 7, which includes a power supply 7.1, a key start switch 7.2, a first relay 7.3, a fuse FU 7.4, a vehicle control unit (VCU) 7.5, a second relay 7.6, an emergency stop switch 7.7, a DC-DC converter 431, a power battery 7.8, a drive motor controller 441, an on-board power supply combo device 43, an engine ECU 7.9, a generator motor controller 45, an electric fan 55, and an electric water pump 41. The DC-DC converter 431 mainly converts the high voltage of the power battery 7.8 to a low voltage to charge the power supply 7.1. The key start switch 7.2 controls whether the circuit connected to the second relay 7.6 is on or off through the first relay 7.3.

[0105] The DC-DC converter 431, power battery 7.8, drive motor controller 441, vehicle power supply combo device 43, engine ECU 7.9, vehicle controller VCU 7.5, electric fan 55 and electric water pump 41 are connected to the positive terminal of power supply 7.1 at one end and the negative terminal of power supply 7.1 at the other end.

[0106] The power battery 7.8, drive motor controller 441, vehicle power supply combo device 43, and engine ECU 7.9 communicate with each other via CAN and the vehicle controller VCU 7.5.

[0107] The power supply to the electronic water pump 41 is turned on by the vehicle controller VCU 7.5 through the electronic water pump power control signal to control the second relay 7.6. The electronic water pump 41 can precisely control the flow rate according to the cooling device's demand for coolant.

[0108] The fuse FU7.4 serves to protect the circuit; it disconnects when the current in the circuit exceeds a specified value.

[0109] The emergency stop switch 7.7 is closed when the vehicle is working normally and opened when not in operation.

[0110] The electric fan 55 is controlled by the vehicle controller VCU7.5 using PWM control, adjusting the fan speed based on the coolant temperature. PWM, or Pulse Width Modulation, modulates the width of a series of pulses to create the desired waveform (including shape and amplitude), digitally encoding the analog signal level. In other words, it adjusts the signal and energy levels by changing the duty cycle. The duty cycle refers to the percentage of time the signal is at a high level within a given period.

[0111] This invention also provides a cooling control method for a hybrid forklift, applied to the aforementioned hybrid forklift cooling system, to ensure that each heat-generating component can operate under optimal working conditions, specifically including the following:

[0112] When engine 6 is not working, the hybrid forklift is driven by pure electricity, and the hydraulic oil cooling subsystem 3 and the motor control cooling subsystem 4 are working.

[0113] Emergency stop switch 7.7 is closed, key start switch 7.2 is in the ON state, and first relay 7.3 is closed; key switch signal wakes up vehicle controller VCU 7.5 and power battery 7.8; vehicle controller VCU 7.5 controls second relay 7.6 to turn on electronic water pump 41; vehicle controller VCU 7.5 obtains temperature signals from drive motor controller 441, vehicle power supply dual device 43, drive motor electronic control dual device 44, and generator motor controller 45 via CAN communication.

[0114] If -40℃≤Temperature of the vehicle power supply 2-in-1 device 43≤40℃, or -40℃≤Temperature of the drive motor controller 441≤50℃, or -40℃≤Temperature of the generator motor controller 45≤50℃, the fan PWM speed control duty cycle is 10%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the temperatures of the vehicle power supply 2-in-1 device 43, the drive motor controller 441, and the generator motor controller 45.

[0115] If 40℃ < vehicle power supply dual-function device 43 temperature ≤ 80℃, or 50℃ < drive motor controller 441 temperature ≤ 65℃, or 50℃ < generator motor controller 45 temperature ≤ 65℃, the fan PWM speed regulation duty cycle is 90%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the vehicle power supply dual-function device 43 temperature, drive motor controller 441 temperature, and generator motor controller 45 temperature.

[0116] If the temperature of the vehicle power supply unit 43 is greater than 80°C, or the temperature of the drive motor controller 441 is greater than 65°C, or the temperature of the generator motor controller 45 is greater than 65°C, a high water temperature warning will be sent.

[0117] The intermediate PWM speed control duty cycle changes linearly with the temperature curve, allowing the speed of the electronic fan 55 to change in real time with the temperature, thus preventing the electronic fan 55 from running at high speed continuously and reducing fan noise.

[0118] When engine 6 is operating, engine 6 directly drives hydraulic drive unit 8, or engine 6, in conjunction with generator motor 9, acts as a range extender. A clutch 66 for power disconnection is provided between engine 6 and generator motor 9. Engine cooling subsystem 1, engine intercooler subsystem 2, hydraulic oil cooling subsystem 3, and motor control cooling subsystem 4 operate normally. Generator motor 9 can operate in either generator or electric motor mode. Hydraulic drive unit 8 can be driven by engine 6 alone, generator motor 9 alone, or a combination of engine 6 and generator motor 9. During driving, a range extender structure is used, with the drive motor driving the transmission mechanism. Power can be supplied by the power battery 7.8 alone, by engine 6 and generator motor 9 acting as a range extender directly, or by the battery and range extender simultaneously.

[0119] When the key start switch 7.2 is in the ON state, the first relay 7.3 is closed, and the vehicle controller VCU 7.5 controls the second relay 7.6 to turn on the electronic water pump 41. The vehicle controller VCU 7.5 obtains the temperature signals of the drive motor controller 441, the vehicle power supply dual device 43, the drive motor electronic control dual device 44, and the generator motor controller 45 through CAN communication, and obtains the engine water temperature signal and the engine intercooler intake air temperature signal through the engine ECU 7.9.

[0120] If the temperature of the vehicle power supply duo-function device 43 is -40℃ ≤ 40℃, or the temperature of the drive motor controller 441 is -40℃ ≤ 50℃, or the temperature of the generator motor controller 45 is -40℃ ≤ 50℃, or the engine coolant temperature is ≤ 85℃, or the intercooler intake temperature is ≤ 53℃, the fan PWM speed control duty cycle is 10%. The PWM duty cycle is taken as the highest value of the duty cycle corresponding to the temperatures of the vehicle power supply duo-function device 43, the drive motor controller 441, and the generator motor controller 45.

[0121] If 40℃ < vehicle power supply dual-function device 43 temperature ≤ 80℃, or 50℃ < drive motor controller 441 temperature ≤ 65℃, or 50℃ < generator motor controller 45 temperature ≤ 65℃, or 85℃ < engine coolant temperature ≤ 105℃, or 53℃ < intercooler intake temperature ≤ 60℃, the fan PWM speed control duty cycle is 90%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the vehicle power supply dual-function device 43 temperature, drive motor controller 441 temperature, and generator motor controller 45 temperature.

[0122] If the temperature of the vehicle power supply unit 43 is greater than 80°C, or the temperature of the drive motor controller 441 is greater than 65°C, or the temperature of the generator motor controller 45 is greater than 65°C, or the engine coolant temperature is greater than 105°C, or the intercooler intake temperature is greater than 60°C, an overheat warning will be issued.

[0123] The intermediate PWM speed control duty cycle changes linearly with the temperature curve, allowing the speed of the electronic fan 55 to change in real time with the temperature, thus preventing the electronic fan 55 from running at high speed continuously and reducing fan noise.

[0124] Poor heat dissipation of heat-generating components significantly increases energy loss. The cooling system structure designed in this invention allows each heat-generating component to operate under optimal working conditions, enabling them to achieve their peak performance in hybrid mode and thus reducing fuel consumption. Traditional distributed radiator unit designs require individual control of each unit, resulting in low integration and cumbersome control. This invention's control method monitors the temperature of heat-generating components in real time and uses appropriate power for cooling.

[0125] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hybrid forklift cooling system, characterized in that, include: Engine cooling subsystem (1), engine intercooling subsystem (2), hydraulic oil cooling subsystem (3), motor and electronic control cooling subsystem (4) and multi-in-one cooler assembly (5); The all-in-one cooler assembly (5) includes an integrated engine cooling module (51), an engine intercooler module (52), a hydraulic oil cooling module (53), a motor control cooling module (54), and an electric fan (55); the engine cooling module (51), the engine intercooler module (52), the hydraulic oil cooling module (53), and the motor control cooling module (54) are respectively cooled by air via the electric fan (55); The engine cooling subsystem (1) is used to connect the engine (6) and the engine cooling module (51) to achieve cooling by circulating the coolant. The engine intercooling subsystem (2) is used to connect the engine (6) and the engine intercooling module (52) to cool the pressurized gas entering the engine (6); The hydraulic oil cooling subsystem (3) is used to connect the hydraulic drive device (8) and the hydraulic oil cooling module (53) to achieve cooling by circulating the hydraulic oil. The motor control cooling subsystem (4) is used to connect the motor control components and the motor control cooling module (54) so ​​that the coolant can circulate and achieve cooling. At least two electronic fans (55) are provided and are controlled independently of each other; The engine cooling module (51), the engine intercooler module (52), the hydraulic oil cooling module (53), and the motor control cooling module (54) are divided into at least two groups, and each group corresponds to at least one of the electronic fans (55). The electronic fan (55) is used to independently adjust the heat dissipation power according to the group it is dissipating heat; The motor control cooling subsystem (4) includes the motor control cooling module (54), electronic water pump (41), second expansion tank (42), vehicle power supply dual device (43), drive motor control dual device (44) and generator motor controller (45). The motor control cooling module (54) includes a fifth water chamber (541), a motor control radiator (542), and a sixth water chamber (543). The fifth water chamber (541) is equipped with a third water pipe connector (5411), and the sixth water chamber (543) is equipped with a third degassing connector (5431) on its upper side. The front has a fourth water pipe connector (5432) and a fifth water pipe connector (5433). The diameter of the fifth water pipe connector (5433) is larger than that of the fourth water pipe connector (5432). The fourth water pipe connector (5432) and the fifth water pipe connector (5433) are connected as one unit. The vehicle power supply dual-function device (43) includes a DC-DC converter (431) and a high-voltage power distribution unit; The third degassing connector (5431) is connected to the gas storage connector of the second expansion tank (42) via a degassing hose; The fourth water pipe connector (5432) is connected to the water pipe connector of the second expansion tank (42) via a water inlet hose. The fifth water pipe connector (5433) is connected to the water inlet connector of the electronic water pump (41) via a water pipe. The water outlet connector of the electronic water pump (41) is connected to the water inlet connector of the vehicle power supply dual-function device (43) via a water outlet hose. The water outlet connector of the vehicle power supply dual-function device (43) is connected to the water inlet connector of the drive motor control dual-function device (44) via a water outlet hose. The water outlet connector of the drive motor control dual-function device (44) is connected to the water inlet connector of the generator motor controller (45) via a water outlet hose. The water outlet connector of the generator motor controller (45) is connected to the third water pipe connector (5411) via a water outlet hose.

2. The hybrid forklift cooling system according to claim 1, characterized in that, The engine cooling subsystem (1) includes a first expansion tank (11) and the engine cooling module (51). The engine cooling module (51) includes a first water chamber (511), an engine radiator (512), and a second water chamber (513). A pressure cover (5111) is provided on the first water chamber (511), and a first degassing connector (5112) is provided on the pressure cover (5111). A second degassing connector (5113) and a first water pipe (5114) are provided on the first water chamber (511). A second water pipe (5131) and a drain outlet (5132) are provided on the second water chamber (513). The first degassing connector (5112) is connected to the connector on the first expansion tank (11) via a water pipe; the second degassing connector (5113) is connected to the engine degassing connector (61) via a water pipe; the first water pipe (5114) is connected to the engine water inlet (62) via a water pipe, and the second water pipe (5131) is connected to the engine water outlet (63); the height of the second water pipe (5131) is higher than the height of the first water pipe (5114), thereby forming a pressure difference.

3. The hybrid forklift cooling system according to claim 1, characterized in that, The engine intercooling subsystem (2) includes the engine intercooling module (52). The engine intercooling module (52) includes a first air chamber (521), an intercooler (522), and a second air chamber (523). The first air chamber (521) is provided with an intake pipe (5211), and the second air chamber (523) is provided with an exhaust pipe (5231). The intake pipe (5211) is connected to the boost outlet (64) of the engine (6) via an intake hose, and the outlet pipe (5231) is connected to the engine intake (65) via an intake hose.

4. The hybrid forklift cooling system according to claim 1, characterized in that, The hydraulic oil cooling subsystem (3) includes the hydraulic oil cooling module (53); The hydraulic oil cooling module (53) includes a third water chamber (531), a hydraulic oil radiator (532), and a fourth water chamber (533). The third water chamber (531) is provided with a first hydraulic oil pipe joint (5311), and the fourth water chamber (533) is provided with a second hydraulic oil pipe joint (5331).

5. The hybrid forklift cooling system according to claim 1, characterized in that, The all-in-one cooler assembly (5) satisfies the following after cooling: The engine inlet water temperature after passing through the engine cooling subsystem (1) is ≤105℃; The engine intake air temperature after passing through the engine intercooler subsystem (2) is ≤60℃; The temperature of the hydraulic oil after passing through the hydraulic oil cooling subsystem (3) is ≤105℃; The vehicle power supply dual-function device (43) has a coolant temperature at the inlet of water in the range of -40℃ to 80℃. It is used with reduced power above 65℃ and the coolant flow rate is ≥6L / min. Drive motor and electronic control combined device (44) Inlet water temperature ≤65℃, inlet water flow rate 8L / min~12L / min; The operating temperature range of the generator motor controller (45) is -40℃ to 65℃.

6. The hybrid forklift cooling system according to claim 1, characterized in that, The all-in-one cooler assembly (5) is located at the rear of the forklift, in front of the forklift counterweight.

7. The hybrid forklift cooling system according to any one of claims 1 to 6, characterized in that, It also includes a controller assembly (7), which includes a power supply (7.1), a key start switch (7.2), a first relay (7.3), a fuse FU (7.4), a vehicle control unit (VCU) (7.5), a second relay (7.6), an emergency stop switch (7.7), a DC-DC converter (431), a power battery (7.8), a drive motor controller (441), an on-board power supply unit (43), an engine ECU (7.9), a generator motor controller (45), an electric fan (55), and an electric water pump (41).

8. A cooling control method for a hybrid forklift, applied to the hybrid forklift cooling system according to any one of claims 1 to 7, characterized in that, include: When the engine (6) is not working, the hybrid forklift is driven by pure electricity, and the hydraulic oil cooling subsystem (3) and the motor control cooling subsystem (4) are working; The emergency stop switch (7.7) is closed, the key start switch (7.2) is in the on state, and the first relay (7.3) is closed; the key switch signal wakes up the vehicle controller VCU (7.5) and the power battery (7.8); the vehicle controller VCU (7.5) controls the second relay (7.6) to turn on the electronic water pump (41); the vehicle controller VCU (7.5) obtains the temperature signals of the drive motor controller (441), the vehicle power supply dual-function device (43), the drive motor electronic control dual-function device (44), and the generator motor controller (45) through CAN communication; If -40℃≤ temperature of the vehicle power supply combination device (43)≤40℃, or -40℃≤ temperature of the drive motor controller (441)≤50℃, or -40℃≤ temperature of the generator motor controller (45)≤50℃, the fan PWM speed regulation duty cycle is 10%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the temperature of the vehicle power supply combination device (43), the temperature of the drive motor controller (441), and the temperature of the generator motor controller (45); If 40℃ < the temperature of the vehicle power supply combination device (43) ≤ 80℃, or 50℃ < the temperature of the drive motor controller (441) ≤ 65℃, or 50℃ < the temperature of the generator motor controller (45) ≤ 65℃, the fan PWM speed regulation duty cycle is 90%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the temperature of the vehicle power supply combination device (43), the temperature of the drive motor controller (441), and the temperature of the generator motor controller (45); If the temperature of the vehicle power supply combination device (43) is >80°C, or the temperature of the drive motor controller (441) is >65°C, or the temperature of the generator motor controller (45) is >65°C, a water temperature overheating warning will be sent. The intermediate PWM speed regulation duty cycle changes linearly with the temperature curve, so that the speed of the electronic fan (55) can change with the temperature in real time, avoiding the electronic fan (55) from always being in a high-speed rotation state and reducing fan noise; When the engine (6) is working, it directly drives the hydraulic drive device (8), or the engine (6) works with the generator motor (9) to supply power to the range extender; the engine cooling subsystem (1), the engine intercooling subsystem (2), the hydraulic oil cooling subsystem (3) and the motor electronic control cooling subsystem (4) are working normally; When the key start switch (7.2) is in the ON state, the first relay (7.3) is closed, and the vehicle controller VCU (7.5) controls the second relay (7.6) to turn on the electronic water pump (41). The vehicle controller VCU (7.5) obtains the temperature signals of the drive motor controller (441), the vehicle power supply dual device (43), the drive motor electronic control dual device (44), and the generator motor controller (45) through CAN communication, and obtains the engine water temperature signal and the engine intercooler intake air temperature signal through the engine ECU (7.9). If -40℃≤ temperature of vehicle power supply dual-function device (43)≤40℃ or -40℃≤ temperature of drive motor controller (441)≤50℃ or -40℃≤ temperature of generator motor controller (45)≤50℃ or engine water temperature≤85℃ or intercooler intake temperature≤53℃, the fan PWM speed regulation duty cycle is 10%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the temperature of vehicle power supply dual-function device (43), temperature of drive motor controller (441), and temperature of generator motor controller (45); If 40℃ < vehicle power supply dual-function device (43) temperature ≤ 80℃, or 50℃ < drive motor controller (441) temperature ≤ 65℃, or 50℃ < generator motor controller (45) temperature ≤ 65℃, or 85℃ < engine water temperature ≤ 105℃, or 53℃ < intercooler intake temperature ≤ 60℃, the fan PWM speed regulation duty cycle is 90%; the PWM duty cycle is taken as the highest value of the duty cycle corresponding to the vehicle power supply dual-function device (43) temperature, drive motor controller (441) temperature, and generator motor controller (45) temperature; If the temperature of the vehicle power supply combination device (43) is >80℃, or the temperature of the drive motor controller (441) is >65℃, or the temperature of the generator motor controller (45) is >65℃, or the engine water temperature is >105℃, or the intercooler intake temperature is >60℃, an overheat warning will be issued. The intermediate PWM speed control duty cycle changes linearly with the temperature curve, so that the speed of the electronic fan (55) can change with the temperature in real time, avoiding the electronic fan (55) from always being in a high-speed rotation state and reducing fan noise.

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