Electrically driven bulldozer control device, control method, and bulldozer

Abstract

This invention discloses an electric bulldozer control device, control method, and bulldozer. The control device includes a hydraulic system and a control system. The hydraulic system includes a hydraulic pump and an electrically controlled multi-way directional valve. The input end of the hydraulic pump is connected to a hydraulic oil tank, and the output end of the hydraulic pump is connected to the inlet of the electrically controlled multi-way directional valve. The return port of the electrically controlled multi-way directional valve is connected to the hydraulic oil tank. Multiple actuator cylinders are connected to the working port of the electrically controlled multi-way directional valve. The control system includes a controller and a motor. The motor is connected to the hydraulic pump, and the controller is connected to the control handle and the motor signal. This application can achieve zero power loss in the hydraulic system when the system is not in motion. When the system is in motion, the control signal directly acts on the power source motor, fundamentally controlling the power output of the hydraulic system, reducing power loss caused by inactive actuators, throttling of the multi-way valve, or load feedback, and improving the response speed of the hydraulic system.

Description

Technical Field

[0001] This invention relates to the field of electric bulldozer technology, specifically to an electric bulldozer control device, control method, and bulldozer. Background Technology

[0002] To reduce the proportion of fossil fuel consumption, low energy consumption and clean exhaust emissions in construction machinery are inevitable trends, leading to the emergence of electric bulldozers.

[0003] Traditional bulldozer hydraulic systems are either gear pumps paired with open-center multi-way valves or variable displacement piston pumps paired with closed-center load-sensitive multi-way valves. Regardless of the type of hydraulic system, the cylinder movement speed is controlled by adjusting the opening size of the multi-way valve core, rather than by controlling the power output of the hydraulic system from the power source, thus causing a certain amount of power loss. Summary of the Invention

[0004] The purpose of this invention is to provide an electric drive bulldozer control device, control method, and bulldozer to solve the problem of power loss caused by controlling the cylinder action speed by controlling the opening size of the valve core of the road valve in the prior art.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention discloses an electric drive bulldozer control device, comprising:

[0007] The hydraulic system includes a hydraulic pump and an electrically controlled multi-way directional valve. The input end of the hydraulic pump is connected to a hydraulic oil tank, the output end of the hydraulic pump is connected to the oil inlet of the electrically controlled multi-way directional valve, the return port of the electrically controlled multi-way directional valve is connected to the hydraulic oil tank, and multiple actuator cylinders are connected to the working port of the electrically controlled multi-way directional valve.

[0008] The control system includes a controller and a motor, the motor being connected to the hydraulic pump, and the controller being connected to the control handle and the motor signal.

[0009] The controller is configured to send a control command after receiving a control signal from the control handle. The control command is used to control the motor to rotate so that the hydraulic pump connected to the motor can draw oil; and to control the operation of the electronically controlled multi-way directional valve so that the working port of the electronically controlled multi-way directional valve is connected to the corresponding actuator cylinder so that the hydraulic oil drawn by the hydraulic pump can be delivered to the corresponding actuator cylinder.

[0010] Furthermore, the controller includes a first controller and a second controller connected to the control handle;

[0011] The first controller is signal-connected to the electrically controlled multiple-way directional valve to control the operation of the electrically controlled multiple-way directional valve;

[0012] The second controller is connected to the motor signal to control the rotation of the motor.

[0013] Furthermore, the second controller is also configured to control the speed of the motor based on the relationship between the power required to perform the cylinder action and the rated output power of the motor.

[0014] Furthermore, the hydraulic pump and the motor are rigidly connected.

[0015] Furthermore, the oil flow rate of each section of the electronically controlled multi-way directional valve is matched with the speed of the actuator cylinder connected to it.

[0016] In a second aspect, the present invention discloses a control method for an electrically driven bulldozer, employing the control device described in any one of the first aspects, the control method comprising:

[0017] Receive control signals sent by the control handle;

[0018] According to the control signal, a control command is sent to control the motor to rotate, so that the hydraulic pump connected to the motor can draw oil;

[0019] According to the control signal, a control command is sent to control the operation of the electronically controlled multi-way directional valve, so that the working port of the electronically controlled multi-way directional valve is connected to the corresponding actuator cylinder, so as to deliver the hydraulic oil drawn by the hydraulic pump to the corresponding actuator cylinder.

[0020] Furthermore, according to the control signal, a control command is sent to control the operation of the electrically controlled multi-way directional valve, so that the working port of the electrically controlled multi-way directional valve is connected to the corresponding actuator cylinder, including:

[0021] The second controller sends control commands to control the motor to rotate according to the control signal, so that the hydraulic pump connected to the motor can draw oil.

[0022] The first controller sends a control command according to the control signal to control the operation of the electronically controlled multi-way directional valve, so that the working port of the electronically controlled multi-way directional valve is connected to the corresponding actuator cylinder, so as to deliver the hydraulic oil drawn by the hydraulic pump to the corresponding actuator cylinder.

[0023] Furthermore, the first controller sends control instructions according to the control signal as follows: after receiving the control signal from the control handle, the first controller immediately sends the corresponding control instructions to the electronically controlled multi-way reversing valve.

[0024] The second controller sends control commands according to the control signal as follows: After receiving the control signal sent by the control handle, the second controller sends the corresponding control command to the motor after a preset delay.

[0025] Control methods also include:

[0026] After the second controller interrupts receiving the control signal from the control handle, it immediately sends a corresponding stop control command to the motor;

[0027] After the first controller interrupts receiving the control signal from the control handle, it sends a corresponding stop control command to the electronically controlled multi-way directional valve after a preset delay.

[0028] Furthermore, it also includes:

[0029] Determine the relationship between the power required to perform the hydraulic cylinder action and the rated output power of the motor;

[0030] When the power required to perform the hydraulic cylinder action is less than the rated output power of the motor, the second controller controls the speed of the motor according to the control command.

[0031] When the power required to perform the hydraulic cylinder action exceeds the rated output power of the motor, the second controller limits the motor speed based on the feedback signal from the motor.

[0032] Thirdly, the present invention discloses an electric bulldozer, including the electric bulldozer control device described in any one of the first aspects.

[0033] According to the above technical solution, the embodiments of the present invention have at least the following effects:

[0034] The control device designed in this application controls the motor rotation and connects the working port of the electronically controlled multi-way directional valve to the corresponding actuator cylinder only after receiving a control signal. By controlling the power source motor, the power output of the hydraulic system is fundamentally controlled, solving the power loss caused by controlling the opening size of the multi-way valve core to control the cylinder action speed, reducing the power loss caused by multi-way valve throttling or load feedback, and improving the response speed of the hydraulic system. When no signal is received, the motor does not drive the hydraulic pump to draw oil, reducing the power loss caused by the actuator not moving, and improving the response speed of the hydraulic system. Attached Figure Description

[0035] Figure 1 This is a connection block diagram of the control device according to a specific embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the signal timing for the "after-on, first-off" control method of the present invention.

[0037] The components include: 1. Control handle; 2. First controller; 3. Second controller; 4. Motor; 5. Hydraulic oil tank; 6. Hydraulic pump; 7. Electrically controlled multi-way directional valve; 8. Actuating cylinder. Detailed Implementation

[0038] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0039] It should be noted that in the description of this invention, the terms "front," "rear," "left," "right," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "front," "rear," "left," "right," "upper," and "lower" used in the description of this invention refer to the directions shown in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0040] The purpose of this application is to fundamentally control the power output of the hydraulic system, reduce power loss caused by non-action of actuators, throttling of multi-way valves, or load feedback, and improve the response speed of the hydraulic system. Example

[0041] A control device for an electrically driven bulldozer includes a hydraulic system and a control system. The hydraulic system includes a hydraulic pump 6 and an electrically controlled multi-way directional valve 7. The input end of the hydraulic pump 6 is connected to a hydraulic oil tank 5, and the output end of the hydraulic pump 6 is connected to the oil inlet of the electrically controlled multi-way directional valve 7. The return oil port of the electrically controlled multi-way directional valve 7 is connected to the hydraulic oil tank 5. Multiple actuator cylinders 8 are connected to the working oil port of the electrically controlled multi-way directional valve 7. The control system includes a controller and a motor 4. The motor 4 is connected to the hydraulic pump 6, and the controller is signal-connected to the control handle 1 and the motor 4. The controller is configured to send a control command after receiving a control signal from the control handle 1. The control command is used to control the rotation of the motor 4 so that the hydraulic pump 6 connected to the motor 4 draws oil; and to control the operation of the electrically controlled multi-way directional valve 7 so that the working oil port of the electrically controlled multi-way directional valve 7 connects to the corresponding actuator cylinder 8, so as to deliver the hydraulic oil drawn by the hydraulic pump 6 to the corresponding actuator cylinder 8.

[0042] The control device designed in this application controls the motor rotation and connects the working port of the electronically controlled multi-way directional valve to the corresponding actuator cylinder only after receiving a control signal. By controlling the power source motor, the power output of the hydraulic system is fundamentally controlled, solving the power loss caused by controlling the opening size of the multi-way valve core to control the cylinder action speed, reducing the power loss caused by multi-way valve throttling or load feedback, and improving the response speed of the hydraulic system. When no signal is received, the motor does not drive the hydraulic pump to draw oil, reducing the power loss caused by the actuator not moving, and improving the response speed of the hydraulic system.

[0043] In this application, the electrically controlled multi-way directional valve 7 serves to switch on and off. The flow rate of the electrically controlled multi-way valve is controlled according to the rotation speed of the motor 4, that is, it is related to the magnitude of the action request signal output by the operating handle 1. When the operation of the operating handle 1 is larger, the rotation speed of the motor 4 is faster, and the flow rate entering the electrically controlled multi-way directional valve 7 is also larger. The electrically controlled multi-way directional valve 7 controls the flow rate to the corresponding actuator cylinder 8 according to the control signal of the operating handle to perform the required action.

[0044] In some further embodiments, the controller includes a first controller 2 and a second controller 3. The first controller 2 serves as the central hub for the overall machine's operational logic and data interaction, with its input terminal connected to the control handle 1 and its output terminal connected to the electronically controlled multi-way directional valve 7. The second controller 2 serves as the central hub for controlling the speed and power of the motor 4, with its input terminal connected to the control handle 1 and its output terminal connected to the motor 4.

[0045] The first controller 2 and the second controller 3 control the electronically controlled multi-way directional valve 7 and the motor 4 respectively according to the output signal of the operating handle 1; wherein, the control of the motor 4 can be the control of its speed and power, and further, the control of its speed is the main focus, while the control of its power is secondary.

[0046] Furthermore, to maximize the output power of the motor, the hydraulic pump 6 is rigidly connected to the motor 4.

[0047] Furthermore, to improve operational comfort and predictability, the oil flow rate of each section of the electrically controlled multi-way directional valve 7 is matched with the speed of each actuator cylinder 8. Specifically, based on the hydraulic oil required for the actuator's operation, the piston diameter of the connected actuator cylinder 8 is designed to vary. The larger the piston diameter, the more hydraulic oil is required. Correspondingly, the dimensions of each section of the electrically controlled multi-way directional valve 7 are designed according to the piston diameter to achieve the goal of matching the oil flow rate of each section of the electrically controlled multi-way directional valve 7 with the speed of each actuator cylinder 8.

[0048] In some embodiments, the second controller is further configured to control the speed of the motor 4 based on the relationship between the power required to actuate the hydraulic cylinder 8 and the rated output power of the motor 4. That is, when the power required to actuate the hydraulic cylinder 8 is less than the rated output power of the motor 4, the second controller 3 controls the speed of the motor 4 according to the control command; when the power required to actuate the hydraulic cylinder 8 is greater than the rated output power of the motor 4, the second controller 3 limits the speed of the motor 4 according to the feedback signal of the motor 4.

[0049] In summary, the working principle of the electric bulldozer control device of the present invention is as follows:

[0050] When the control handle 1 does not output an action request signal, the first controller 2 and the second controller 3 do not send signals to the electronically controlled multi-way reversing valve 7 and the motor 4, and the motor 4 rotates at zero speed.

[0051] The control handle 1 outputs an action request signal to the first controller 2 and the second controller 3. After receiving the signal, the first controller 2 outputs a signal corresponding to the action request to the electronically controlled multi-way directional valve 7. After receiving the signal, the second controller 3 outputs a signal corresponding to the action request to the motor 4 (a control strategy of "open first, close later" can be further adopted, where the first controller 2 immediately outputs a signal corresponding to the action request to the electronically controlled multi-way directional valve 7 after receiving the signal, and the second controller 3 outputs a signal corresponding to the action request to the motor 4 after a 50ms delay). Under the control of the second controller 3, the output speed of the motor 4 is related to the magnitude of the action request signal output by the control handle 1. When the output power of the motor 4 exceeds its rated output power, the motor 4 feeds back a signal to the second controller 3, and the second controller 3 adjusts the output signal to reduce the speed of the motor 4.

[0052] When the motor 4 starts to rotate, the motor 4 drives the hydraulic pump 6 to rotate. The hydraulic pump 6 draws oil from the hydraulic oil tank 5 and outputs high-pressure oil into the electronically controlled multi-way directional valve 7. The electronically controlled multi-way directional valve 7 distributes the oil to each action cylinder 8 according to the signal input by the first controller 2, thereby realizing the action of the machine.

[0053] This application enables zero power loss in the hydraulic system when the system is inactive, and when the system is activated, the control signal acts directly on the power source motor, fundamentally controlling the power output of the hydraulic system, reducing power loss caused by inactive actuators, throttling of multi-way valves, or load feedback, and improving the response speed of the hydraulic system. Example

[0054] Based on the control device provided in Embodiment 1, this embodiment also provides a control method. The method is implemented based on the control device of Embodiment 1 and includes the following steps: receiving a control signal sent by the control handle 1; sending a control command according to the control signal to control the motor 4 to rotate so that the hydraulic pump 6 connected to the motor 4 draws oil; sending a control command according to the control signal to control the electric multi-way directional valve 7 to operate so that the working port of the electric multi-way directional valve 7 is connected to the corresponding actuator cylinder 8 so as to deliver the hydraulic oil drawn by the hydraulic pump 6 to the corresponding actuator cylinder 8.

[0055] Furthermore, the second controller 3 sends a control command according to the control signal to control the motor 4 to rotate, so that the hydraulic pump 6 connected to the motor 4 can draw oil; the first controller 2 sends a control command according to the control signal to control the electric multi-way directional valve 7 to operate, so that the working port of the electric multi-way directional valve 7 is connected to the corresponding actuator cylinder 8, so as to deliver the hydraulic oil drawn by the hydraulic pump 6 to the corresponding actuator cylinder 8.

[0056] To maximize the utilization of the power output from the power source and avoid system voltage buildup, this invention proposes a "last-on, first-off" control method for the power source motor. This method is as follows: After receiving the control signal from the operating handle 1, the first controller 2 immediately sends a corresponding control command to the electronically controlled multi-way directional valve 7; after receiving the control signal from the operating handle 1, the second controller 3 sends a corresponding control command to the motor 4 after a preset delay; after the second controller 3 stops receiving the control signal from the operating handle 1, it immediately sends a corresponding stop control command to the motor 4; after the first controller 2 stops receiving the control signal from the operating handle 1, it sends a corresponding stop control command to the electronically controlled multi-way directional valve 7 after a preset delay.

[0057] like Figure 2 The diagram illustrates the relationship between the control handle, motor, and electrically controlled multi-way directional valve and time. The "last-open, first-close" control method can be specifically represented as follows: When the control handle 1 begins to output a signal (at time t1), the first controller 2 immediately responds, sending a corresponding signal to the electrically controlled multi-way directional valve 7 at time t1. The second controller 3, with a delay of approximately 50ms, sends a corresponding signal to the motor 4 at time t2. When the control handle 1 stops outputting a signal (at time t3), the second controller 3 immediately responds, sending a corresponding signal to the motor 4 at time t3. The first controller 2, with a delay of approximately 50ms, sends a corresponding signal to the electrically controlled multi-way directional valve 7 at time t4. The delay time can be appropriately increased or decreased, ranging from 20-70ms.

[0058] In some further embodiments, the second controller can also control the speed of the motor 4 based on the relationship between the power required to actuate the hydraulic cylinder 8 and the rated output power of the motor 4. Specifically, to avoid overloading the motor 4, when the power required to actuate each hydraulic cylinder 8 is less than the rated output power of the motor 4, the second controller 3 controls the speed of the motor 4 based on the handle output signal 1; when the power required to actuate each hydraulic cylinder 8 is greater than the rated output power of the motor 4, the second controller 3 limits the speed of the motor 4 based on the feedback signal from the motor 4. Example

[0059] This embodiment discloses an electrically driven bulldozer. The bulldozer in this embodiment adopts the control device in Embodiment 1. The bulldozer can also adopt the control method provided in Embodiment 2.

[0060] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. An electrically driven bulldozer control method characterized by, An electrically driven bulldozer control device is adopted, which comprises: a hydraulic system comprising a hydraulic pump (6) and an electrically controlled multi-way reversing valve (7), an input end of the hydraulic pump (6) being connected with a hydraulic oil tank (5), an output end of the hydraulic pump (6) being connected with an oil inlet of the electrically controlled multi-way reversing valve (7), an oil return of the electrically controlled multi-way reversing valve (7) being connected with the hydraulic oil tank (5), and a plurality of execution oil cylinders (8) being connected with working oil inlets of the electrically controlled multi-way reversing valve (7); a control system comprising a controller and a motor, the motor (4) being connected with the hydraulic pump (6), and the controller being signal connected with a control handle (1) and the motor (4); the controller is configured to send a control instruction after receiving a control signal sent by the control handle (1), the control instruction being used to control the motor (4) to rotate so as to make the hydraulic pump (6) connected with the motor (4) to suck oil, and to control the electrically controlled multi-way reversing valve (7) to act so as to make the working oil inlets of the electrically controlled multi-way reversing valve (7) to be communicated with corresponding execution oil cylinders (8) to deliver the hydraulic oil sucked by the hydraulic pump (6) to the corresponding execution oil cylinders (8); the control method comprises: receiving a control signal sent by the control handle (1); sending a control instruction according to the control signal to control the motor (4) to rotate so as to make the hydraulic pump (6) connected with the motor (4) to suck oil; sending a control instruction according to the control signal to control the electrically controlled multi-way reversing valve (7) to act so as to make the working oil inlets of the electrically controlled multi-way reversing valve (7) to be communicated with corresponding execution oil cylinders (8) to deliver the hydraulic oil sucked by the hydraulic pump (6) to the corresponding execution oil cylinders (8); sending a control instruction according to the control signal to control the electrically controlled multi-way reversing valve (7) to act so as to make the working oil inlets of the electrically controlled multi-way reversing valve (7) to be communicated with corresponding execution oil cylinders (8) comprises: the second controller (3) sends a control instruction according to the control signal to control the motor (4) to rotate so as to make the hydraulic pump (6) connected with the motor (4) to suck oil; the first controller (2) sends a control instruction according to the control signal to control the electrically controlled multi-way reversing valve (7) to act so as to make the working oil inlets of the electrically controlled multi-way reversing valve (7) to be communicated with corresponding execution oil cylinders (8) to deliver the hydraulic oil sucked by the hydraulic pump (6) to the corresponding execution oil cylinders (8); the control instruction sent by the first controller (2) according to the control signal is that the first controller (2) sends corresponding control instructions to the electrically controlled multi-way reversing valve (7) immediately after receiving the control signal of the control handle (1); the control instruction sent by the second controller (3) according to the control signal is that the second controller (3) sends corresponding control instructions to the motor (4) after delaying a preset time after receiving the control signal sent by the control handle (1); the control method further comprises: the second controller (3) sends a stop control instruction to the motor (4) immediately after interrupting the reception of the control signal of the control handle (1); The first controller (2) sends a corresponding stop control instruction to the electric control multi-way reversing valve (7) after receiving the control signal of the operating handle (1) and delaying for a preset time.

2. The electrically driven bulldozer control method of claim 1, wherein, Further comprising: judging the relationship between the power required for the action of the execution cylinder (8) and the rated output power of the motor (4); when the power required for the action of the execution cylinder (8) is less than the rated output power of the motor (4), the second controller (3) controls the rotating speed of the motor (4) according to the control instruction; when the power required for the action of the execution cylinder (8) is greater than the rated output power of the motor (4), the second controller (3) limits the rotating speed of the motor (4) according to the feedback signal of the motor (4).

3. The electrically driven bulldozer control method of claim 1, wherein, The controller comprises a first controller (2) and a second controller (3) connected with the operating handle (1); the first controller (2) and the electric control multi-way reversing valve (7) are signal connected to control the action of the electric control multi-way reversing valve (7); the second controller (3) and the motor (4) are signal connected to control the rotation of the motor (4).

4. The electrically driven bulldozer control method of claim 3, wherein, The second controller is further configured to control the rotating speed of the motor (4) according to the relationship between the power required for the action of the execution cylinder (8) and the rated output power of the motor (4).

5. The electrically driven bulldozer control method of claim 1, wherein, The hydraulic pump (6) and the motor (4) are rigidly connected.

6. The electrically driven bulldozer control method of claim 1, wherein, The oil flow of each connection of the electric control multi-way reversing valve (7) matches the speed of the execution cylinder (8) connected therewith.

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