阅读说明：本技术 一种混凝土搅拌车及其控制方法 (Concrete mixer truck and control method thereof ) 是由 孟宪波 孙强 史信秋 张强 吴邦彦 于 2021-09-14 设计创作，主要内容包括：本发明涉及车辆技术领域,公开了一种混凝土搅拌车及其控制方法,该混凝土搅拌车包括发动机、发动机转速检测组件、变量液压泵、传动组件、液压马达、罐体、控制单元、马达转速检测组件和罐体转速预设单元；控制单元用于根据罐体转速预设单元设置的目标转速以及发动机的转速信息确定变量液压泵的开度信息,根据变量液压泵的开度信息控制变量液压泵的排量,以调整液压马达的转速；并根据马达转速检测组件检测的实际转速与目标转速的差值信息生成变量液压泵开度修正数据,控制变量液压泵根据修正数据调整开度,以对液压马达的转速进行修正。该混凝土搅拌车及其控制方法改善了混凝土搅拌车罐体的转速受发动机转速影响较大的问题。(The invention relates to the technical field of vehicles and discloses a concrete mixer truck and a control method thereof, wherein the concrete mixer truck comprises an engine, an engine rotating speed detection assembly, a variable hydraulic pump, a transmission assembly, a hydraulic motor, a tank body, a control unit, a motor rotating speed detection assembly and a tank body rotating speed preset unit; the control unit is used for determining the opening information of the variable hydraulic pump according to the target rotating speed set by the tank rotating speed presetting unit and the rotating speed information of the engine, and controlling the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor; and generating variable hydraulic pump opening correction data according to difference information between the actual rotating speed and the target rotating speed detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor. The concrete mixer truck and the control method thereof solve the problem that the rotating speed of the tank body of the concrete mixer truck is greatly influenced by the rotating speed of the engine.)

1. A concrete mixer truck, comprising: the device comprises an engine, an engine rotating speed detection assembly, a variable hydraulic pump, a transmission assembly, a hydraulic motor, a tank body, a control unit, a motor rotating speed detection assembly and a tank body rotating speed presetting unit; wherein:

the engine rotating speed detection component is used for detecting rotating speed information of the engine;

the variable hydraulic pump is in transmission connection with the engine through the transmission assembly, and the variable hydraulic pump is connected with the hydraulic motor through a pipeline; the hydraulic motor is used for driving the tank body to rotate;

the motor rotating speed detection assembly is used for detecting rotating speed information of the hydraulic motor;

the tank body rotating speed presetting unit is in signal connection with the control unit and is used for setting a target rotating speed of the tank body;

the control unit is in signal connection with the engine rotating speed detection assembly, the motor rotating speed detection assembly, the variable hydraulic pump and the tank rotating speed presetting unit, and is used for determining the opening information of the variable hydraulic pump according to the target rotating speed set by the tank rotating speed presetting unit and the rotating speed information of the engine, and controlling the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor; and generating opening correction data of the variable hydraulic pump according to difference information between the actual rotating speed detected by the motor rotating speed detection assembly and the target rotating speed, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor.

2. The concrete mixer vehicle of claim 1, wherein the engine is in signal communication with the control unit, the control unit further configured to: and after receiving the unloading instruction of the tank body rotating speed presetting unit, controlling the rotating speed of the engine to be in an oil consumption economic area.

3. The concrete mixer truck of claim 2, wherein the engine speed for the economic region of fuel consumption is 1200-1400 rpm.

4. The concrete mixer truck of claim 1, wherein the transmission assembly includes a gear assembly including an input shaft coupled to the crankshaft of the engine and two output shafts, one of which is coupled to the variable displacement hydraulic pump for driving the variable displacement hydraulic pump and the other of which is coupled to a gearbox for transmitting power to the gearbox.

5. The concrete mixer truck according to claim 4, comprising a flywheel housing covering one side of the engine, wherein the flywheel housing and the engine together define a containing cavity for containing the gear assembly, and the gear assembly is disposed in the containing cavity.

6. Concrete mixer truck according to any one of claims 1-5, characterised in that the control unit is arranged on the engine.

7. Concrete mixer truck according to any one of claims 1-5, characterized in that the control unit comprises a first pin, which is connected to the variable displacement hydraulic pump by a first wire harness.

8. The concrete mixer truck according to any one of claims 1-5, wherein the control unit includes a second pin connected to the motor speed detection assembly via a second wire harness.

9. A control method of a concrete mixer truck, characterized by comprising a control unit which:

receiving target rotating speed information and rotating speed information of an engine sent by a tank rotating speed presetting unit;

determining opening information of a variable hydraulic pump;

controlling the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor;

and generating opening correction data of the variable hydraulic pump according to difference information between the actual rotating speed information and the target rotating speed information detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor.

10. The control method according to claim 9, wherein the control unit:

receiving a discharging instruction of a tank rotating speed presetting unit;

and controlling the rotating speed of the engine to be in an oil consumption economic area.

Technical Field

The invention relates to the technical field of vehicles, in particular to a concrete mixer truck and a control method thereof.

Background

The concrete mixing truck is a special truck for conveying concrete for construction.

Due to the special properties of concrete, it needs to be continuously stirred during transportation, which requires that the tank of the concrete mixer truck carrying the concrete is always in a rotating state during transportation. However, the rotating speed of the tank body of the existing concrete mixer truck is greatly influenced by the rotating speed of the engine, and the rotating speed of the tank body is suddenly changed when the chassis is accelerated and decelerated. This not only affects the quality of the concrete, but also, due to the effect of the rotational inertia of the concrete, can cause extreme instability of the vehicle and the risk of rollover.

Disclosure of Invention

The invention provides a concrete mixer truck and a control method thereof, which are used for solving the problem that the rotating speed of a tank body of the concrete mixer truck is greatly influenced by the rotating speed of an engine.

In order to achieve the purpose, the invention provides the following technical scheme:

a concrete mixer truck comprising: the device comprises an engine, an engine rotating speed detection assembly, a variable hydraulic pump, a transmission assembly, a hydraulic motor, a tank body, a control unit, a motor rotating speed detection assembly and a tank body rotating speed presetting unit; wherein:

the engine rotating speed detection component is used for detecting rotating speed information of the engine;

the variable hydraulic pump is in transmission connection with the engine through the transmission assembly, and the variable hydraulic pump is connected with the hydraulic motor through a pipeline; the hydraulic motor is used for driving the tank body to rotate;

the motor rotating speed detection assembly is used for detecting rotating speed information of the hydraulic motor;

the tank body rotating speed presetting unit is in signal connection with the control unit and is used for setting a target rotating speed of the tank body;

the control unit is in signal connection with the engine rotating speed detection assembly, the motor rotating speed detection assembly, the variable hydraulic pump and the tank rotating speed presetting unit, and is used for determining the opening information of the variable hydraulic pump according to the target rotating speed set by the tank rotating speed presetting unit and the rotating speed information of the engine, and controlling the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor; and generating opening correction data of the variable hydraulic pump according to difference information between the actual rotating speed detected by the motor rotating speed detection assembly and the target rotating speed, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor.

According to the concrete mixer truck provided by the invention, the variable hydraulic pump is in transmission connection with the engine through the transmission assembly, and the variable hydraulic pump is connected with the hydraulic motor through a pipeline; the hydraulic motor is used for driving the tank body to rotate, the engine rotating speed detection assembly is used for detecting rotating speed information of the engine, and the motor rotating speed detection assembly is used for detecting rotating speed information of the hydraulic motor; the tank body rotating speed presetting unit is in signal connection with the control unit and is used for setting the target rotating speed of the tank body; the control unit is in signal connection with the engine rotating speed detection assembly, the motor rotating speed detection assembly, the variable hydraulic pump and the tank rotating speed presetting unit, can determine the opening information of the variable hydraulic pump according to the target rotating speed set by the tank rotating speed presetting unit and the rotating speed information of the engine, and controls the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor; and generating variable hydraulic pump opening correction data according to difference information between the actual rotating speed and the target rotating speed detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor, so that the rotating speed of the hydraulic motor (namely the rotating speed of the tank body) is kept at the target rotating speed as far as possible, the constant-speed rotation is realized, and the influence of the rotating speed of the engine on the rotating speed of the tank body is reduced.

Optionally, the engine is in signal connection with the control unit, and the control unit is further configured to: and after receiving the unloading instruction of the tank body rotating speed presetting unit, controlling the rotating speed of the engine to be in an oil consumption economic area.

Optionally, the engine speed corresponding to the oil consumption economic area is 1200 to 1400 rpm.

Optionally, the transmission assembly includes a gear assembly including an input shaft and two output shafts, the input shaft is connected to the crankshaft of the engine, one of the two output shafts is connected to the variable displacement hydraulic pump for driving the variable displacement hydraulic pump, and the other output shaft is connected to the transmission case for transmitting power to the transmission case.

Optionally the concrete mixer truck is located including the cover the flywheel housing of engine one side, the flywheel housing with the engine encloses jointly and establishes out and is used for holding the chamber that holds of gear assembly, the gear assembly set up in hold in the chamber.

Optionally, the control unit is provided on the engine.

Optionally, the control unit comprises a first pin connected to the variable displacement hydraulic pump by a first harness.

Optionally, the control unit includes a second pin, and the second pin is connected to the motor rotation speed detection assembly through a second wire harness.

The embodiment also provides a control method of the concrete mixer truck, which comprises a control unit, wherein the control unit:

receiving target rotating speed information and rotating speed information of an engine sent by a tank rotating speed presetting unit;

determining opening information of a variable hydraulic pump;

controlling the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor;

and generating opening correction data of the variable hydraulic pump according to difference information between the actual rotating speed information and the target rotating speed information detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor.

Optionally, the control unit:

receiving a discharging instruction of a tank rotating speed presetting unit;

and controlling the rotating speed of the engine to be in an oil consumption economic area.

The invention provides a control method of a concrete mixer truck, which comprises a control unit, wherein the control unit receives target rotating speed information sent by a tank rotating speed presetting unit and rotating speed information of an engine; determining opening information of a variable hydraulic pump; controlling the discharge capacity of the variable hydraulic pump according to the opening information of the variable hydraulic pump so as to adjust the rotating speed of the hydraulic motor; and generating opening correction data of the variable hydraulic pump according to difference information between the actual rotating speed information and the target rotating speed information detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor. Therefore, the rotating speed of the hydraulic motor (namely the rotating speed of the tank body) can be kept at the target rotating speed as much as possible, the constant-speed rotation is realized, and the influence of the rotating speed of the engine on the rotating speed of the tank body is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a concrete mixer truck according to an embodiment of the present invention.

Icon: 1-an engine; 2-variable hydraulic pump; 3-a hydraulic motor; 4-tank body; 5-a control unit; 6-tank rotating speed presetting unit; 7-flywheel housing; 8-a gearbox.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the present embodiment provides a concrete mixer truck including: the device comprises an engine 1, an engine rotating speed detection assembly, a variable hydraulic pump 2, a transmission assembly, a hydraulic motor 3, a tank body 4, a control unit 5, a motor rotating speed detection assembly and a tank body rotating speed presetting unit 6; wherein:

the engine rotating speed detection component is used for detecting rotating speed information of the engine 1;

the variable hydraulic pump 2 is in transmission connection with the engine 1 through a transmission assembly, and the variable hydraulic pump 2 is connected with the hydraulic motor 3 through a pipeline; the hydraulic motor 3 is used for driving the tank 4 to rotate;

the motor rotating speed detection assembly is used for detecting rotating speed information of the hydraulic motor 3;

the tank rotating speed presetting unit 6 is in signal connection with the control unit 5 and is used for setting the target rotating speed of the tank 4;

the control unit 5 is in signal connection with the engine rotating speed detection assembly, the motor rotating speed detection assembly, the variable hydraulic pump 2 and the tank rotating speed presetting unit 6, and is used for determining the opening information of the variable hydraulic pump 2 according to the target rotating speed set by the tank rotating speed presetting unit 6 and the rotating speed information of the engine 1, and controlling the discharge capacity of the variable hydraulic pump 2 according to the opening information of the variable hydraulic pump 2 so as to adjust the rotating speed of the hydraulic motor 3; and generating opening correction data of the variable hydraulic pump 2 according to the difference information between the actual rotating speed and the target rotating speed detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump 2 to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor 3.

In the concrete mixer truck provided by the embodiment, the variable hydraulic pump 2 is in transmission connection with the engine 1 through the transmission assembly, and the variable hydraulic pump 2 is connected with the hydraulic motor 3 through a pipeline; the hydraulic motor 3 is used for driving the tank 4 to rotate, the engine rotating speed detection assembly is used for detecting rotating speed information of the engine 1, and the motor rotating speed detection assembly is used for detecting rotating speed information of the hydraulic motor 3; the tank rotating speed presetting unit 6 is in signal connection with the control unit 5 and is used for setting the target rotating speed of the tank 4; the control unit 5 is in signal connection with the engine rotating speed detection assembly, the motor rotating speed detection assembly, the variable hydraulic pump 2 and the tank rotating speed presetting unit 6, can determine the opening information of the variable hydraulic pump 2 according to the target rotating speed set by the tank rotating speed presetting unit 6 and the rotating speed information of the engine 1, and controls the discharge capacity of the variable hydraulic pump 2 according to the opening information of the variable hydraulic pump 2 so as to adjust the rotating speed of the hydraulic motor 3; and generating opening correction data of the variable hydraulic pump 2 according to difference information between the actual rotating speed and the target rotating speed detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump 2 to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor 3, so that the rotating speed of the hydraulic motor 3 (namely the rotating speed of the tank 4) is kept at the target rotating speed as far as possible, the constant-speed rotation is realized, and the influence of the rotating speed of the engine 1 on the rotating speed of the tank is reduced.

The variable displacement hydraulic pump 2, i.e. a hydraulic pump whose pump displacement can be adjusted. For example, the variable displacement hydraulic pump 2 may be an electrically controlled proportional variable displacement pump, and the opening of the pump may be controlled by an electrically controlled proportional valve on the pump body, so as to implement variable displacement operation.

The control unit 5 may be a motor Electronic Control Unit (ECU), i.e., a control module is integrated into the ECU of the engine 1, and the control module is integrated into the ECU of the engine 1, so that the manufacturing cost can be reduced.

The tank rotating speed presetting unit 6 may be provided in a vehicle cab so as to receive an operation instruction from a driver. After the tank body rotating speed presetting unit 6 receives an operation instruction, the operation instruction is transmitted to the control unit 5 through an electric signal, and the control unit 5 decomposes the operation instruction according to the instruction, so that related hydraulic elements are regulated and controlled.

The working principle of the concrete mixer truck according to the present embodiment will be further explained.

In the process of transporting concrete, a tank body 4 of a concrete mixer truck needs to be in a stable rotating state, an operator can select a desired tank body rotating speed (namely a target rotating speed) through a tank body rotating speed presetting unit 6, a control unit 5 obtains the target rotating speed set by the tank body rotating speed presetting unit 6 and obtains rotating speed information of an engine 1 fed back by an engine rotating speed detection assembly in real time, opening information of a variable hydraulic pump 2 is determined through a preset calculation relation between the opening of the variable hydraulic pump 2 and the rotating speed of the engine 1, and the displacement of the variable hydraulic pump 2 is controlled according to the opening information of the variable hydraulic pump 2 so as to adjust the rotating speed of a hydraulic motor 3; when the hydraulic motor 3 rotates, the control unit 5 receives actual rotating speed information detected by the motor rotating speed detection assembly in real time, generates opening correction data of the variable hydraulic pump 2 according to difference information between the actual rotating speed of the hydraulic motor 3 and a target rotating speed, controls the variable hydraulic pump 2 to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor 3, corrects power loss caused by hydraulic elements, and the correction precision can reach 0.1 rpm/min.

The preset calculation relationship of the opening degree of the variable displacement hydraulic pump 2 and the rotation speed of the engine 1 may be as follows, wherein:

n represents a target rotation speed of the tank body;

n₀representing engine speed;

i represents the transmission ratio of the tank reducer;

i₀representing the transmission ratio of the power take-off end of the engine;

v_Motorrepresents the maximum displacement of the hydraulic motor;

v_{pump and method of operating the same}Representing the maximum displacement of the variable displacement hydraulic pump;

η represents the overall hydraulic system efficiency (this value is related to the variable hydraulic pump and motor volumetric efficiency, the length of the line, etc., and is usually an empirical value);

k represents the opening degree of the variable hydraulic pump;

i、i₀、v_Motor、v_{pump and method of operating the same}And η are known parameters.

When the speed of a vehicle needs to be accelerated in the transportation process, a driver steps on an accelerator pedal, the rotating speed of the engine 1 rises, the control unit 5 can immediately capture the rotating speed information of the engine 1 fed back by the engine rotating speed detection assembly, so that the rotating speed of the hydraulic motor 3 is ensured to be stable by regulating and controlling the displacement of the variable hydraulic pump 2, and the short-time sharp rise of the rotating speed of the hydraulic motor 3 caused by the increase of the displacement of the variable hydraulic pump 2 due to the increase of the rotating speed of the engine 1 is avoided.

Specifically, after capturing the rotation speed information of the engine 1 fed back by the engine rotation speed detection assembly, the control unit 5 determines the opening information of the variable displacement hydraulic pump 2 by combining the target rotation speed of the tank 4, and controls the displacement of the variable displacement hydraulic pump 2 according to the opening information of the variable displacement hydraulic pump 2 to adjust the rotation speed of the hydraulic motor 3; and generating opening correction data of the variable hydraulic pump 2 according to the difference information between the actual rotating speed and the target rotating speed detected by the motor rotating speed detection assembly, and controlling the variable hydraulic pump 2 to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor 3.

In an alternative implementation, the engine 1 is in signal connection with a control unit 5, and the control unit 5 is further configured to: and after receiving the unloading instruction of the tank rotating speed presetting unit 6, controlling the rotating speed of the engine 1 to be in an oil consumption economic area.

When the concrete mixer truck needs to be unloaded, the concrete mixer truck is in a stop state, and after an operator sends an unloading instruction (for example, presses an unloading button) through the tank body rotating speed presetting unit 6, the control unit 5 receives the instruction and controls the engine 1 to immediately increase the rotating speed to the oil consumption economic area; subsequently, the displacement of the variable displacement hydraulic pump 2 is adjusted in conjunction with the correspondence between the rotational speed of the engine 1 and the displacement of the variable displacement hydraulic pump 2. Therefore, when the operator needs to accelerate the discharging speed, the operator only needs to select the required rotating speed of the discharging tank on the tank rotating speed presetting unit 6, and at the moment, the rotating speed of the engine 1 does not respond at first, but the displacement of the variable hydraulic pump 2 is preferentially increased, so that the rotating speed of the hydraulic motor 3 is increased, and the rotating speed of the engine 1 is always in an oil consumption economic area. Therefore, the oil consumption of the engine 1 is lower while the unloading speed is increased, the exhaust temperature of the engine 1 is increased, and the DPF regeneration is facilitated.

Illustratively, the rotation speed of the engine 1 corresponding to the fuel consumption economic area can be 1200 rpm to 1400 rpm.

When the transmission assembly is specifically arranged, in order to make the structure more compact, the transmission assembly may exemplarily include a gear assembly including an input shaft and two output shafts, the input shaft is connected with the crankshaft of the engine 1, one of the two output shafts is connected with the variable displacement hydraulic pump 2 for driving the variable displacement hydraulic pump 2, and the other output shaft is connected with the gearbox 8 for transmitting power to the gearbox 8.

In an optional implementation mode, the concrete mixer truck comprises a flywheel housing 7 arranged on one side of the engine 1, the flywheel housing 7 and the engine 1 jointly enclose a containing cavity for containing a gear assembly, and the gear assembly is arranged in the containing cavity.

In order to make the structure more centralized, in an alternative implementation, the control unit 5 is provided on the engine 1.

The control unit 5 is in signal connection with the variable displacement hydraulic pump 2, and in an optional implementation mode, the control unit 5 comprises a first pin, and the first pin is connected with the variable displacement hydraulic pump 2 through a first wire harness.

Illustratively, a first stitch of the control unit 5 is connected with an electrically controlled proportional valve of the variable displacement pump by a first wiring harness.

The motor speed detection assembly is in signal connection with the control unit 5, and in an optional implementation mode, the control unit 5 comprises a second pin, and the second pin is connected with the motor speed detection assembly through a second wire harness.

In conclusion, in the concrete mixer truck provided by the embodiment, the tank 4 can be rotated at a constant speed in the concrete conveying process. When speeding up or braking, the condition that the rotating speed of the tank body suddenly changes because of the sudden speed change of the engine 1 can not occur, and the transportation stability can be ensured. Simultaneously, the concrete mixer truck that this embodiment provided couples the discharge capacity of 1 rotational speed of engine and variable hydraulic pump 2 in real time, still catches the real-time rotational speed of hydraulic motor 3, revises, can guarantee higher accuracy, further guarantees the stability of jar body 4 pivoted. During unloading operation, the rotating speed of the engine 1 is always in an oil consumption economic area, so that the oil consumption of the engine 1 is lower, the exhaust temperature of the engine 1 is increased, the regeneration of the DPF is facilitated, and the operation environment is optimal.

The control method for the concrete mixer truck provided by the embodiment comprises a control unit 5, wherein the control unit 5 executes the following steps:

step S1, receiving the target rotational speed information and the rotational speed information of the engine 1 sent by the tank rotational speed presetting unit 6;

step S2, determining opening degree information of the variable displacement hydraulic pump 2;

step S3, controlling the displacement of the variable displacement hydraulic pump 2 according to the opening information of the variable displacement hydraulic pump 2 to adjust the rotation speed of the hydraulic motor 3;

in step S4, opening correction data of the variable displacement hydraulic pump 2 is generated based on the difference information between the actual rotational speed information and the target rotational speed information detected by the motor rotational speed detection unit, and the variable displacement hydraulic pump 2 is controlled to adjust the opening based on the correction data to correct the rotational speed of the hydraulic motor 3.

The control method for the concrete mixer truck provided by the embodiment comprises a control unit 5, wherein the control unit 5 receives target rotating speed information sent by a tank rotating speed presetting unit 6 and rotating speed information of an engine 1; determining opening information of the variable hydraulic pump 2; controlling the displacement of the variable displacement hydraulic pump 2 according to the opening information of the variable displacement hydraulic pump 2 to adjust the rotating speed of the hydraulic motor 3; and generating opening correction data of the variable displacement hydraulic pump 2 according to difference information between the actual rotating speed information and the target rotating speed information detected by the motor rotating speed detection assembly, and controlling the variable displacement hydraulic pump 2 to adjust the opening according to the correction data so as to correct the rotating speed of the hydraulic motor 3. Therefore, the rotational speed of the hydraulic motor 3 (i.e., the rotational speed of the tank 4) can be maintained at the target rotational speed as much as possible, constant-speed rotation can be achieved, and the influence of the rotational speed of the engine 1 on the rotational speed of the tank can be reduced.

In an alternative implementation, the control unit 5 further performs the following steps:

step S5, receiving a discharging instruction of the tank rotating speed presetting unit 6;

and step S6, controlling the rotating speed of the engine 1 to be in the fuel consumption economic area.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.