Power distribution transmission system and control method thereof

Abstract

The invention discloses a power distribution transmission system and a control method thereof.The transmission system comprises an engine, a torque converter, a gearbox and a hydraulic pump providing power for a working device, the torque converter comprises a pump wheel and a turbine, the engine is connected with the pump wheel, the pump wheel and the turbine are connected through a hydraulic transmission system, and the turbine is connected with the gearbox; the hydraulic pumps are connected with the oil cylinder through a hydraulic system, the measuring device is used for measuring the transmission ratio between the pump wheel and the turbine, at least one hydraulic pump is a controllable variable hydraulic pump capable of adjusting the displacement, and the controller is used for controlling the displacement of the hydraulic pumps according to the transmission ratio between the pump wheel and the turbine and load information of the hydraulic system. According to the working condition requirements, the displacement of the variable hydraulic pump is controlled under different working conditions, so that the power consumption of the hydraulic pump is reduced, the whole operation process of the machine is monitored, the power is redistributed, the oil consumption is reduced, the power requirement of the whole machine is reduced, and finally the same whole machine performance is met through low displacement and power of a diesel engine.

Description

Technical Field

[0001] The present invention relates to a transmission system and a control method thereof, in particular to a power distribution transmission system and a control method thereof, belonging to the technical field of loaders. Background Art

[0002] At present, wheel loaders use a hydraulic system with a hydraulic torque converter as the main component, a hydraulic transmission and a gear pump. The hydraulic transmission system generates the traction required for the operation, and the hydraulic system generates the digging and lifting force of the working device and realizes the steering function. The performance of the loader is mainly reflected in the large traction, digging and lifting force. Generally, when selecting the power of the diesel engine, the hydraulic power superposition of the hydraulic transmission and the gear pump is combined as the basis for selecting the power of the diesel engine. However, when the loader is digging, the digging force will cause a significant decrease in traction, affecting the digging efficiency. But the engine power cannot be too large, otherwise the economy will be poor and the fuel consumption will increase significantly. Summary of the invention

[0003] The technical problem to be solved by the present invention is: how to reasonably allocate the power to the hydraulic transmission to generate the whole machine traction force and the hydraulic system to generate the digging force and action lifting force, so as to reduce the diesel engine selection cost and the whole vehicle fuel consumption.

[0004] In order to solve the above technical problems, the technical solution of the present invention is to provide a power distribution transmission system, including an engine, a torque converter, a gearbox, and a hydraulic pump that provides power to a working device, the torque converter includes a pump wheel and a turbine, the engine is connected to the pump wheel, the pump wheel and the turbine are connected through a hydraulic transmission system, the turbine is connected to the gearbox, and the hydraulic pump is connected to the cylinder through the hydraulic system. It is characterized in that it also includes a measuring device for measuring the transmission ratio between the pump wheel and the turbine, at least one hydraulic pump is a controllable variable hydraulic pump that can adjust the displacement, and also includes a controller that controls the displacement of the hydraulic pump according to the transmission ratio between the pump wheel and the turbine and the load information of the hydraulic system.

[0005] Preferably, the measuring device is a pump wheel speed sensor and a turbine speed sensor for measuring the rotation speeds of the pump wheel and the turbine; or the measuring device is a torque sensor.

[0006] Preferably, the pump wheel speed sensor is arranged on the engine or the pump wheel; the turbine speed sensor is arranged on the turbine or the gearbox.

[0007] Preferably, the oil cylinder or hydraulic system is provided with a hydraulic sensor, and the hydraulic pump is provided with a proportional solenoid valve for controlling the hydraulic opening; the controller is connected to the torque converter, the hydraulic sensor and the proportional solenoid valve; the hydraulic system load information includes the pressure of the hydraulic load feedback measured by the hydraulic sensor and the flow calculated by the current on the proportional solenoid valve.

[0008] Preferably, the proportional solenoid valve is connected to a controller via a signal, and the controller controls the opening of the proportional solenoid valve to adjust the displacement of the hydraulic pump.

[0009] Preferably, the torque sensor is arranged on the engine, the gearbox or the torque converter.

[0010] Preferably, the oil cylinder or hydraulic system is provided with a hydraulic sensor, and the hydraulic pump is provided with a proportional solenoid valve for controlling the hydraulic opening; the controller is connected to the torque sensor, the hydraulic sensor and the proportional solenoid valve; the hydraulic system load information includes the pressure of the hydraulic load feedback measured by the hydraulic sensor and the flow calculated by the current on the proportional solenoid valve.

[0011] A control method for a power distribution transmission system, characterized in that the controller collects pump and turbine speed signals through a measuring device, and compares the transmission ratio between the turbine speed and the pump wheel speed. The larger the transmission ratio between the turbine speed and the pump wheel speed, the smaller the travel load, and the smaller the transmission ratio between the turbine speed and the pump wheel speed, the larger the travel load; and based on the pump and turbine speed signals, it is determined whether the transmission ratio is greater than a calibration value. If it is greater than the calibration value, the hydraulic pump is not adjusted; if it is less than the calibration value, it is continued to determine whether the working device is working. If the working device is not working, the hydraulic pump is not adjusted; if the working device is working, the displacement of the hydraulic pump is adjusted to adjust the power of the hydraulic pump.

[0012] Preferably, the displacement of the hydraulic pump is adjusted according to the following formula:

[0013] The pressure of hydraulic load feedback × flow rate ÷ 600 is calculated to obtain the power consumed by the hydraulic system, that is, the power of the hydraulic pump. Then, the current is obtained through the formula between power and current. Finally, the proportional solenoid valve is adjusted to the obtained current value to obtain the displacement of the hydraulic pump.

[0014] Through the transmission system of the present invention, the digging force during excavation is controlled to reduce the impact on traction. The hydraulic pump adopts a variable pump to make it controllable. Strength is required but not speed during excavation. During excavation, the hydraulic system pressure is increased to increase the digging force, reduce the power of the pump wheel, and reduce the impact on traction. However, when not excavating, the hydraulic power should be large to increase the lifting force of the working device and improve the lifting efficiency. When the hydraulic power is large and when it is small depends on the power required for the walking traction. A torque converter, a pump wheel speed sensor and a turbine speed sensor (or a torque sensor) are installed on the transmission to determine the size of the required traction. However, since the structure and principle of the torque sensor are relatively complex, the best solution is to reverse the size of the transmission torque by measuring the transmission ratio of the torque converter, thereby solving the problem of monitoring the power required for the transmission. Among them, the driving force of the whole vehicle (i.e., the turbine speed) is the traction, and the digging force is related to the traction and the hydraulic system pressure (i.e., the displacement of the hydraulic pump); but the lifting force is only related to the hydraulic system pressure (i.e., the displacement of the hydraulic pump).

[0015] The hydraulic pump in the traditional structure is a fixed displacement pump, which cannot adjust the power output according to the working condition requirements, resulting in power waste, high displacement and power selection, and high fuel consumption. The transmission system provided by the present invention changes the hydraulic pump into a variable displacement pump.

[0016] The transmission system provided by the present invention can collect the pump wheel, turbine speed information and workload information through the controller according to the working condition requirements, so as to control the variable hydraulic pump displacement under different working conditions, thereby reducing the power consumption of the hydraulic pump, monitoring and power redistribution of the entire operation process of the machine, removing excess surplus power, reducing useless losses, reducing fuel consumption, and reducing the power demand of the whole machine, and finally achieving lower diesel engine displacement and power to meet the same whole machine performance; greatly reducing the diesel engine selection cost and vehicle fuel consumption, and the use of the controller makes the bucket and the boom move in a coordinated manner during compound movements (the gear pump quantitative system in the prior art cannot perform compound movements), thereby improving working efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A transmission principle diagram of a power distribution transmission system;

[0018] Figure 2 The present invention is a flow chart of the working principle of a power distribution transmission system;

[0019] Figure 3 A schematic diagram of the composition of a power distribution transmission system. DETAILED DESCRIPTION

[0020] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0021] Example 1

[0022] The present invention provides a power distribution transmission system, which is an improvement on the traditional transmission system, and reduces the power demand of the whole machine, and finally achieves lower diesel engine displacement and power to meet the same whole machine performance, which greatly reduces the diesel engine selection cost and the fuel consumption of the whole vehicle. The use of the controller makes the bucket and the boom move in a coordinated manner during the compound action, thereby improving the working efficiency.

[0023] like Figure 1-Figure 3 As shown, the present invention includes an engine 4, a torque converter, a gearbox, one or more hydraulic pumps 2 for providing power to a working device, a controller 3, and a measuring device. The torque converter includes a pump wheel 7 and a turbine 1. The engine 4 is connected to the pump wheel 7. The pump wheel 7 and the turbine 1 are connected through a hydraulic transmission system. The turbine 1 is connected to the gearbox. The hydraulic pump 2 is connected to the oil cylinder through a hydraulic system. The measuring device is used to measure the transmission ratio between the pump wheel 7 and the turbine 1. At least one hydraulic pump 2 is a controllable variable hydraulic pump (i.e., one hydraulic pump 2 is a controllable variable hydraulic pump, and the remaining hydraulic pumps 2 can be fixed displacement pumps; or the hydraulic pumps 2 are all controllable variable hydraulic pumps), which can adjust the displacement according to the working conditions to achieve power consumption reduction; the controller 3 has a built-in control program, which can be used to control the displacement of the hydraulic pump 2. The hydraulic pump 2 is connected to the hydraulic system of the working device (i.e., for example, a bucket, a boom or other machine used on the vehicle), and the action of the working device is controlled by the hydraulic system. A hydraulic sensor for measuring the hydraulic load feedback pressure is provided in the hydraulic system.

[0024] In this embodiment, the measuring device is a pump wheel speed sensor 5 and a turbine speed sensor 6 for measuring the speed of the pump wheel 7 and the turbine 1. The pump wheel speed sensor 5 is arranged on the engine 4 or the pump wheel 7; the turbine speed sensor 6 is arranged on the turbine 1 or the gearbox. A hydraulic sensor is arranged on the oil cylinder or the hydraulic system, and a proportional solenoid valve for controlling the hydraulic opening is arranged on the hydraulic pump 2; wherein each proportional solenoid valve can obtain the flow size by current conversion (existing technology).

[0025] Among them, the speed of the turbine 1 reflects the speed of the whole vehicle and the amount of power allocated by the engine 4 required for driving; the speed of the pump wheel 7 reflects the real-time power used by the engine 4 (diesel engine); the displacement of the hydraulic pump 2 reflects the power allocated by the engine 4 to the working device.

[0026] The controller 3 is connected to the torque converter, the hydraulic sensor and the proportional solenoid valve; the load information of the hydraulic system includes the pressure of the hydraulic load feedback measured by the hydraulic sensor and the flow calculated by the current on the proportional solenoid valve. The proportional solenoid valve is connected to the controller 3 through a signal, and the controller 3 controls the opening of the proportional solenoid valve to adjust the displacement of the hydraulic pump 2. The proportional solenoid valve controls the current size, thereby controlling the opening of the proportional solenoid valve, and thus controlling the displacement of the hydraulic pump 2.

[0027] The transmission system of the present invention can collect the speed information of the pump wheel 7 and the turbine 1 and the work load information (obtained through the hydraulic sensor and the proportional solenoid valve) through the controller 3 according to the working condition requirements. When the controller 3 collects the speed signals of the pump wheel 7 and the turbine 1 through the pump wheel speed sensor 5 and the turbine speed sensor 6, the greater the transmission ratio between the turbine 1 speed and the pump wheel 7 speed, the smaller the travel load, and the smaller the transmission ratio between the turbine 1 speed and the pump wheel 7 speed, the greater the travel load. According to the speed signals of the pump wheel 7 and the turbine 1, it is judged whether the transmission ratio (i.e., the torque converter ratio) is greater than the calibration value. If it is greater than the calibration value, the hydraulic pump 2 is not adjusted, that is, the power of the hydraulic pump 2 remains unchanged; if it is less than the calibration value, it continues to judge whether the working device is working. If the working device is not working (the pressure of the hydraulic load feedback can be used to judge whether the working device is working; when the pressure is very small or 0, it is in a non-working state), the hydraulic pump 2 is not adjusted; if the working device is working, the displacement of the hydraulic pump 2 is adjusted, thereby adjusting the power of the hydraulic pump 2. For example, setting the speed transmission ratio to less than 0.5 (i.e., the calibration value) to determine the traction working condition requires a large load working condition. The calibration value is the value obtained when the traction force and the digging force are balanced, which is obtained through repeated tests.

[0028] According to the load of the hydraulic system, adjust the displacement of hydraulic pump 2. The formula is as follows:

[0029] The pressure (bar) of hydraulic load feedback × flow rate (L / min) ÷ 600 is calculated to obtain the power consumed by the hydraulic system, that is, the power of hydraulic pump 2. Then, the current is obtained through the formula between power and current. Finally, the proportional solenoid valve is adjusted to the obtained current value to obtain the displacement of hydraulic pump 2. The opening of the proportional solenoid valve is adjusted by the controller 3.

[0030] This enables monitoring of the entire operation process of the machine and power redistribution, removes excess power, reduces useless losses, reduces fuel consumption, reduces the power demand of the entire machine, and ultimately achieves the use of lower diesel engine displacement and power to meet the same overall machine performance.

[0031] In the present invention, the torque converter can also be connected to the pump wheel speed sensor 5 and the turbine speed sensor 6 to be replaced by a torque sensor. However, since the present invention only requires the transmission ratio between the turbine 1 speed and the pump wheel 7 speed, it is not necessary to accurately obtain the specific torques. Therefore, the torque converter is used in this embodiment.

[0032] Example 2

[0033] In this embodiment, the measuring device is a torque sensor. The torque sensor is arranged on the engine 4 or the gearbox or the torque converter. The oil cylinder or the hydraulic system is provided with a hydraulic sensor, and the hydraulic pump 2 is provided with a proportional solenoid valve for controlling the hydraulic opening; the controller 3 is connected with the torque sensor, the hydraulic sensor and the proportional solenoid valve; the load information of the hydraulic system includes the pressure of the hydraulic load feedback measured by the hydraulic sensor and the flow calculated by the current on the proportional solenoid valve.

[0034] The rest is the same as Example 1.

Claims

1. A power distribution transmission system, comprising an engine (4), a torque converter, a gearbox, and a hydraulic pump (2) for providing power to a working device, wherein the torque converter comprises a pump wheel (7) and a turbine (1), the engine (4) is connected to the pump wheel (7), the pump wheel (7) and the turbine (1) are connected via a hydraulic transmission system, the turbine (1) is connected to the gearbox, and the hydraulic pump (2) is connected to an oil cylinder via a hydraulic system, characterized in that: The invention also includes a measuring device for measuring the transmission ratio between the pump wheel (7) and the turbine (1), at least one hydraulic pump (2) is a controllable variable hydraulic pump capable of adjusting the displacement, and a controller (3) for controlling the displacement of the hydraulic pump (2) according to the transmission ratio between the pump wheel (7) and the turbine (1) and the load information of the hydraulic system.

2. A power distribution transmission system as claimed in claim 1, characterized in that: The measuring device is a pump wheel speed sensor (5) and a turbine speed sensor (6) for measuring the rotation speed of the pump wheel (7) and the turbine (1); or the measuring device is a torque sensor.

3. A power distribution transmission system as claimed in claim 2, characterized in that: The pump wheel speed sensor (5) is arranged on the engine (4) or the pump wheel (7); the turbine speed sensor (6) is arranged on the turbine (1) or the gearbox.

4. A power distribution transmission system as claimed in claim 2, characterized in that: The oil cylinder or hydraulic system is provided with a hydraulic sensor, and the hydraulic pump (2) is provided with a proportional solenoid valve for controlling the hydraulic opening; the controller (3) is connected to the torque converter, the hydraulic sensor and the proportional solenoid valve; the load information of the hydraulic system includes the pressure of the hydraulic load feedback measured by the hydraulic sensor and the flow calculated by the current on the proportional solenoid valve.

5. A power distribution transmission system as claimed in claim 4, characterized in that: The proportional solenoid valve is connected to a controller (3) via a signal, and the controller (3) controls the opening of the proportional solenoid valve, thereby adjusting the displacement of the hydraulic pump (2).

6. A power distribution transmission system as claimed in claim 2, characterized in that: The torque sensor is arranged on the engine (4) or the gearbox or the torque converter.

7. A power distribution transmission system as claimed in claim 2, characterized in that: The oil cylinder or hydraulic system is provided with a hydraulic sensor, and the hydraulic pump (2) is provided with a proportional solenoid valve for controlling the hydraulic opening; the controller (3) is connected to the torque sensor, the hydraulic sensor and the proportional solenoid valve; the load information of the hydraulic system includes the pressure of the hydraulic load feedback measured by the hydraulic sensor and the flow calculated by the current on the proportional solenoid valve.

8. A control method for a power distribution transmission system according to any one of claims 1 to 7, characterized in that: The controller (3) collects the speed signals of the pump wheel (7) and the turbine (1) through the measuring device, and compares the transmission ratio between the turbine (1) speed and the pump wheel (7) speed. The larger the transmission ratio between the turbine (1) speed and the pump wheel (7) speed, the smaller the travel load, and the smaller the transmission ratio between the turbine (1) speed and the pump wheel (7) speed, the larger the travel load. The controller (3) determines whether the transmission ratio is greater than a calibration value based on the speed signals of the pump wheel (7) and the turbine (1). If the transmission ratio is greater than the calibration value, the hydraulic pump (2) is not adjusted. If the transmission ratio is less than the calibration value, the controller continues to determine whether the working device is working. If the working device is not working, the hydraulic pump (2) is not adjusted. If the working device is working, the displacement of the hydraulic pump (2) is adjusted, thereby adjusting the power of the hydraulic pump (2).

9. A control method for a power distribution transmission system as claimed in claim 8, characterized in that: The displacement of the hydraulic pump (2) is adjusted according to the following formula: The pressure (bar) of the hydraulic load feedback × the flow rate (L / min) ÷ 600 is calculated to obtain the power consumed by the hydraulic system, that is, the power of the hydraulic pump (2). Then, the magnitude of the current is obtained through the formula between power and current. Finally, the proportional solenoid valve is adjusted to the obtained current value to obtain the displacement of the hydraulic pump (2).

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