A mechanical transmission system applied to a bulldozer and its working method

Abstract

The present invention provides a mechanical transmission system applied to a bulldozer and its working method, which includes a main clutch, a gearbox, a shift control solenoid valve, a direction control solenoid valve, a shift operating device, a main clutch operating device, a main clutch operating position sensor, and a controller. The shift operating device performs shifting or direction-changing operations on the gearbox and transmits the state signal of the shift operating device to the controller; the main clutch operating device disconnects or connects the power transmission of the main clutch; the main clutch operating position sensor monitors the position of the main clutch operating device and transmits the state to the controller; the controller receives the state of the main clutch being disconnected or connected; receives the state signal sent by the shift operating device, and controls the gearbox to automatically enter the state indicated by the shift operating device; when the engine speed drops to a set value, the controller adjusts the gearbox to the neutral state, making the operation of the mechanical transmission system simple and effectively avoiding engine stalling when the operating load changes greatly.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission systems, and particularly to a mechanical transmission system applied to a bulldozer and its working method. Background Art

[0002] The mechanical transmission form of current bulldozers on the market is as follows: The engine outputs power, and the power is transmitted to the gearbox through the engagement and disengagement of the main clutch. After being speed-changed and torque-increased by the gearbox, it is transmitted to the central transmission. After the central transmission reduces speed and increases torque again, it is transmitted to the final drive to drive the crawler, enabling the machine to move and operate; in this mechanical transmission system, the main clutch is a normally open type, and the gearbox is a mechanical shift fork type shift / reverse gearbox. The main clutch and the shift / reverse control are of a mechanical link structure. The main clutch control is linked with the shift control. When the main clutch control handle is operated to be in the disengaged state, the gearbox control handle can be operated for shifting / reversing; when the main clutch control handle is operated to be in the engaged state, the main clutch control link mechanism locks the shift / reverse control of the gearbox, and shifting / reversing cannot be performed; this transmission system has complex operations, large operating forces, high requirements for the operating skills of the driver, and poor overall controllability. At the same time, when the operating load changes greatly, the power cannot be disconnected in time, resulting in engine stalling. After the engine stalls, since the transmission system is still in the engaged state, it is difficult to start the engine. Summary of the Invention

[0003] A mechanical transmission system applied to a bulldozer and its working method disclosed by the present invention solve the problems that the mechanical transmission system of current bulldozers has complex operations and poor controllability; and when the operating load changes greatly, the power cannot be disconnected in time, resulting in engine stalling, making the operation of the mechanical transmission system simple and effectively avoiding engine stalling when the operating load changes greatly.

[0004] To achieve the above object, the technical solution of the present invention is specifically implemented as follows:

[0005] On one hand, the present invention discloses a mechanical transmission system applied to a bulldozer, which includes a main clutch, a gearbox, a shift control solenoid valve, a direction control solenoid valve, a shift operating device, a main clutch operating device, a main clutch operating position sensor and a controller. Among them, the input end of the main clutch is connected to the output end of the engine to transmit or cut off the power output by the engine; the gearbox is connected to the main clutch through a universal joint to change the torque, speed and movement direction of the bulldozer under different working conditions when the engine speed and torque remain unchanged; the shift control solenoid valve is used to realize the speed change of the gearbox; the direction control solenoid valve is used to realize the change of the movement direction of the gearbox; the shift operating device is used to shift gears or change the direction of the gearbox and transmit the state signal of the shift operating device to the controller; the main clutch operating device is used to disconnect or connect the power transmission of the main clutch; the main clutch operating position sensor is used to monitor the position of the main clutch operating device in real time and transmit the state of the main clutch being disconnected or connected to the controller; the controller is used to receive the state of the main clutch being disconnected or connected sent by the main clutch operating position sensor; and is used to receive the state signal sent by the shift operating device and control the gearbox to automatically enter the state indicated by the shift operating device; when the engine speed drops to a set value, the controller automatically adjusts the gearbox to the neutral state.

[0006] Further, a mechanical transmission system applied to a bulldozer further includes a safety solenoid valve, which is used to make the transmission system in a state without control oil when the bulldozer stops working, ensuring the safety of the bulldozer.

[0007] Further, the shift operating device is a joystick.

[0008] Further, the main clutch operating device is a foot pedal.

[0009] Further, the main clutch is a normally closed main clutch.

[0010] Further, the gearbox is an electro-hydraulic hybrid control gearbox or an electronically controlled gearbox.

[0011] On the other hand, the present invention discloses a working method of a mechanical transmission system applied to a bulldozer, including the following steps:

[0012] Under normal conditions, the main clutch operating device (6) is in the initial position, the gearbox (2) is in the neutral state, and the safety solenoid valve (10) is in the power-off state. At this time, when operating the shift operating device (5) or the main clutch operating device (6), the gearbox (2) cannot achieve power output and the bulldozer cannot move.

[0013] When work is required, turn on the safety solenoid valve (10), operate the main clutch control device (6) so that the main clutch (1) is in the disengaged state. The main clutch control position sensor (7) monitors the disengaged state of the main clutch (1) and transmits it to the controller (8); then operate the transmission control device (5) and transmit the state finally indicated by the transmission control device (5) to the controller (8). The controller (8) controls the transmission (2) to automatically enter the state finally indicated by the transmission control device (5). Finally, operate the main clutch control device (6) to return it to the initial state, the transmission system is turned on, and the power is transmitted normally, and the bulldozer enters the working state;

[0014] When in the working state and still need to adjust the transmission (2), operate the main clutch control device (6) so that the main clutch (1) is in the disengaged state. The main clutch control position sensor (7) monitors the disengaged state of the main clutch (1) and transmits it to the controller (8); then operate the transmission control device (5) and transmit the state finally indicated by the transmission control device (5) to the controller (8). The controller (8) controls the transmission (2) to automatically enter the state finally indicated by the transmission control device (5). Finally, operate the main clutch control device (6) to return it to the initial state;

[0015] When steering is required in the working state, operate the transmission control device (5) to the left or right to achieve the steering of the bulldozer in the working state;

[0016] When in the working state, when the load changes violently and the controller (8) detects that the engine speed drops to the preset value, the controller (8) outputs a control signal to automatically adjust the transmission (2) to the neutral state to prevent the engine from stalling;

[0017] When stopping work, turn off the safety solenoid valve (10) to make the transmission system in a state without control oil to ensure the safety of the bulldozer.

[0018] Beneficial technical effects:

[0019] The present invention discloses a mechanical transmission system and a working method thereof for a bulldozer, including a main clutch, a gearbox, a speed change control solenoid valve, a direction change control solenoid valve, a speed change operating device, a main clutch operating device, a main clutch operating position sensor, and a controller. Among them, the input end of the main clutch is connected to the output end of the engine to transmit or cut off the power output by the engine; the gearbox is connected to the main clutch through a universal joint to change the torque, speed, and movement direction of the bulldozer under the condition that the engine speed and torque remain unchanged; the speed change control solenoid valve is used to realize the speed change of the gearbox; the direction change control solenoid valve is used to realize the change of the movement direction of the gearbox; the speed change operating device is used to shift gears or change the direction of the gearbox and transmit the state signal of the speed change operating device to the controller; the main clutch operating device is used to disconnect or connect the power transmission of the main clutch; the main clutch operating position sensor is used to monitor the position of the main clutch operating device in real time and transmit the state of the main clutch being disconnected or connected to the controller; the controller is used to receive the state of the main clutch being disconnected or connected sent by the main clutch operating position sensor; and is used to receive the state signal sent by the speed change operating device and control the gearbox to automatically enter the state indicated by the speed change operating device; when the engine speed drops to a set value, the controller automatically adjusts the gearbox to the neutral state, solving the problems that the operation of the mechanical transmission system of the current bulldozer is complex and the handling feeling is poor; and when the operation load changes greatly, the power cannot be disconnected in time, resulting in the engine stalling, making the operation of the mechanical transmission system simple and effectively avoiding the engine stalling when the operation load changes greatly. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the description of the embodiments will be briefly introduced below.

[0021] Figure 1 It is a system structure diagram of a mechanical transmission system for a bulldozer according to the present invention.

[0022] Among them, 1 - main clutch, 2 - gearbox, 3 - speed change control solenoid valve, 4 - direction change control solenoid valve, 5 - speed change operating device, 6 - main clutch operating device, 7 - main clutch operating position sensor, 8 - controller, 9 - universal joint, 10 - safety solenoid valve. Detailed Embodiments

[0023] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0024] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] On the one hand, the present invention discloses a mechanical transmission system applied to a bulldozer. Refer to Figure 1 , specifically, the mechanical transmission system applied to a bulldozer includes a main clutch 1, a gearbox 2, a speed control solenoid valve 3, a direction control solenoid valve 4, a speed shifting device 5, a main clutch operating device 6, a main clutch operating position sensor 7, and a controller 8. Among them, the input end of the main clutch 1 is connected to the output end of the engine, that is, the input end of the main clutch 1 is connected to the engine flywheel and fixed on the transfer case by bolts to transmit or cut off the power output by the engine. Preferably, the main clutch 1 is a normally closed main clutch; the gearbox 2 is installed on the frame, and the gearbox 2 is connected to the main clutch 1 through a universal joint 9 to change the torque, speed, and movement direction of the bulldozer under different working conditions while the engine speed and torque remain unchanged. When there is a deviation in the coaxiality between the input of the gearbox 2 and the output of the main clutch 1, it is compensated by the universal joint 9. Preferably, the gearbox 2 is an electro-hydraulic hybrid control gearbox or an electronically controlled gearbox; the speed control solenoid valve 3 is used to achieve the speed change of the gearbox 2, and the speed control solenoid valve 3 is installed on a separate valve block or a speed change valve body; the direction control solenoid valve 4 is used to achieve the change of the movement direction of the gearbox 2, and the direction control solenoid valve 4 is installed on a separate valve block or a speed change valve body; the speed shifting device 5 is used to shift gears or change the direction of the gearbox 2 and transmit the state signal of the speed shifting device 5 to the controller 8. Preferably, the speed shifting device 5 is a control handle installed on the floor frame control box; the main clutch operating device 6 is used to disconnect or connect the power transmission of the main clutch 1. Preferably, the main clutch operating device 6 is a foot pedal installed on the left side of the front pedal of the floor frame through a bracket; the main clutch operating position sensor 7 is used to monitor the position of the main clutch operating device 6 in real time and transmit the disconnected or connected state of the main clutch 1 to the controller 8, and is installed on the main clutch operating device 6; the controller 8 is integrated in the whole machine instrument and installed on the instrument bracket, used to receive the disconnected or connected state of the main clutch 1 sent by the main clutch operating position sensor 7; used to receive the state signal sent by the speed shifting device 5 and control the gearbox 2 to automatically enter the state indicated by the speed shifting device 5; when the engine speed drops to a set value, the controller 8 automatically adjusts the gearbox 2 to the neutral state, realizing the electronic control of the mechanical transmission system of the bulldozer, making the operation of the mechanical transmission system simple and effectively avoiding the engine stalling when the operating load changes greatly.

[0026] As a preferred embodiment of the present invention, the mechanical transmission system applied to a bulldozer disclosed by the present invention further includes a safety solenoid valve 10, which is used to make the transmission system in a state without control oil when the bulldozer stops working, ensuring the safety of the bulldozer.

[0027] The working process of the mechanical transmission system applied to a bulldozer disclosed by the present invention is as follows:

[0028] Since the main clutch 1 of the present invention adopts a normally closed main clutch, under normal conditions, the main clutch 1 is in the engaged state. The power output by the engine drives the universal joint 9 through the main clutch 1, thereby driving the gearbox 2. The gearbox is in the neutral position and there is no power output. The gearshift control handle 5 is in the neutral state, the main clutch control pedal 6 is in the starting position, and the safety solenoid valve 10 is in the power-off and disconnected state. At this time, operating the gearshift control handle 5, the main clutch control pedal 6, and the gearbox 2 cannot achieve power output, and the bulldozer has no movement. When the safety solenoid valve is energized and connected, step on the main clutch control pedal 6. The main clutch control position sensor 7 monitors the position signal of the main clutch control pedal (since it is a normally closed main clutch, when stepped on, the main clutch is in the disconnected state), and transmits the state of the main clutch control pedal (disconnected state) to the controller 8. Then operate the gearshift control handle 5 and transmit the state of the gearshift control handle 5 at this time to the controller 8. After calculation by the controller 8, the gearbox 2 automatically enters the state indicated by the gearshift control handle 5. Release the main clutch control pedal 6, and the entire transmission system is connected, and the power is transmitted normally, and the bulldozer enters the working state. If steering is required, just swing the gearshift control handle 5 to the left or right. If the gearbox 2 needs to be operated again, step on the main clutch control pedal 6 again, then operate the gearshift control handle 5, and then release the main clutch control pedal. During the operation of the bulldozer, when the load changes violently and the controller 8 detects that the engine speed drops to a preset value, the controller 8 directly outputs a control signal to automatically adjust the gearbox 2 to the neutral state to prevent the engine from stalling. When the bulldozer stops operating, disconnect the safety solenoid valve 10 to make the transmission system in a state without control oil to ensure the safety of the bulldozer.

[0029] On the other hand, the present invention discloses a working method of a mechanical transmission system applied to a bulldozer, which specifically includes the following steps:

[0030] Under normal conditions, the main clutch control device 6 is in the initial position, the gearbox 2 is in the neutral state, and the safety solenoid valve 10 is in the power-off state. At this time, operating the gearshift control device 5 or the main clutch control device 6, the gearbox 2 cannot achieve power output, and the bulldozer cannot move.

[0031] When work is required, turn on the safety solenoid valve 10, operate the main clutch control device 6 to make the main clutch 1 in the disengaged state. The main clutch control position sensor 7 monitors the disengaged state of the main clutch 1 and transmits it to the controller 8. Then operate the transmission control device 5 and transmit the state finally indicated by the transmission control device 5 to the controller 8. The controller 8 controls the transmission 2 to automatically enter the state finally indicated by the transmission control device 5. Finally, operate the main clutch control device 6 to return it to the initial state, the transmission system is turned on, power is transmitted normally, and the bulldozer enters the working state;

[0032] When in the working state and still need to adjust the transmission 2, operate the main clutch control device 6 to make the main clutch 1 in the disengaged state. The main clutch control position sensor 7 monitors the disengaged state of the main clutch 1 and transmits it to the controller 8. Then operate the transmission control device 5 and transmit the state finally indicated by the transmission control device 5 to the controller 8. The controller 8 controls the transmission 2 to automatically enter the state finally indicated by the transmission control device 5. Finally, operate the main clutch control device 6 to return it to the initial state;

[0033] When steering is required in the working state, operate the transmission control device 5 to the left or right to achieve the steering of the bulldozer in the working state;

[0034] When in the working state, when the load changes violently and the controller 8 detects that the engine speed drops to the preset value, the controller 8 outputs a control signal to automatically adjust the transmission 2 to the neutral state to prevent the engine from stalling;

[0035] When stopping work, turn off the safety solenoid valve 10 to make the transmission system in a state without control oil to ensure the safety of the bulldozer.

[0036] A mechanical transmission system and its working method applied to a bulldozer disclosed by the present invention make the operation of the transmission system simple, greatly reduce the operation intensity of the driver, and can effectively prevent the engine from stalling.

[0037] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0038] The above embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A mechanical transmission system applied to a bulldozer, characterized in that, Including: A main clutch (1), the input end of the main clutch (1) is connected to the output end of the engine, and is used to transmit or cut off the power output by the engine; A transmission (2), the transmission (2) is connected to the main clutch (1) through a universal joint (9), and is used to change the torque, speed and movement direction of the bulldozer under different working conditions when the engine speed and torque remain unchanged; A speed change control solenoid valve (3), which is used to realize the speed change of the transmission (2); A direction change control solenoid valve (4), which is used to realize the change of the movement direction of the transmission (2); A speed change operating device (5), which is used to shift gears or change directions for the transmission (2), and transmit the status signal of the speed change operating device (5) to the controller (8); A main clutch operating device (6), which is used to disconnect or connect the power transmission of the main clutch (1); A main clutch operating position sensor (7), which is used to monitor the position of the main clutch operating device (6) in real time, and transmit the disconnected or connected state of the main clutch (1) to the controller (8); A controller (8), which is used to receive the disconnected or connected state of the main clutch (1) sent by the main clutch operating position sensor (7); used to receive the status signal sent by the speed change operating device (5), and control the transmission (2) to automatically enter the state indicated by the speed change operating device (5); when the engine speed drops to a set value, the controller (8) automatically adjusts the transmission (2) to the neutral state.

2. The mechanical transmission system for a bulldozer according to claim 1, wherein It further includes a safety solenoid valve (10), which is used to make the drive system in a state without control oil when the bulldozer stops working, ensuring the safety of the bulldozer.

3. A mechanical transmission system applied to a bulldozer according to claim 1, characterized in that, The speed change operating device (5) is an operating handle.

4. A mechanical transmission system applied to a bulldozer according to claim 1, characterized in that, The main clutch operating device (6) is a foot pedal.

5. A mechanical transmission system applied to a bulldozer according to claim 1, characterized in that, The main clutch (1) is a normally closed main clutch.

6. A mechanical transmission system applied to a bulldozer according to claim 1, characterized in that, The transmission (2) is a transmission with electro-hydraulic hybrid control or an electronically controlled transmission.

7. A working method of a mechanical transmission system applied to a bulldozer according to any one of claims 1-6, characterized in that, Including the following steps: Under normal conditions, the main clutch operating device (6) is in the initial position, the transmission (2) is in the neutral state, and the safety solenoid valve (10) is in the power-off state. At this time, when operating the speed change operating device (5) or the main clutch operating device (6), the transmission (2) cannot achieve power output, and the bulldozer cannot move; When work is required, turn on the safety solenoid valve (10), operate the main clutch operating device (6) to make the main clutch (1) in the disconnected state. The main clutch operating position sensor (7) monitors the disconnected state of the main clutch (1) and transmits it to the controller (8); then operate the speed change operating device (5) and transmit the state finally indicated by the speed change operating device (5) to the controller (8). The controller (8) controls the transmission (2) to automatically enter the state finally indicated by the speed change operating device (5). Finally, operate the main clutch operating device (6) to return it to the initial state, the drive system is connected, the power is transmitted normally, and the bulldozer enters the working state; When in the working state and still needing to adjust the transmission (2), operate the main clutch operating device (6) so that the main clutch (1) is in the disengaged state. The main clutch operating position sensor (7) monitors the disengaged state of the main clutch (1) and transmits it to the controller (8); then operate the transmission operating device (5) and transmit the state finally indicated by the transmission operating device (5) to the controller (8). The controller (8) controls the transmission (2) to automatically enter the state finally indicated by the transmission operating device (5), and finally operate the main clutch operating device (6) to return it to the initial state; When steering is required in the working state, operate the transmission operating device (5) to the left or right to achieve the steering of the bulldozer in the working state; When in the working state, when the load changes violently and the controller (8) detects that the engine speed drops to the preset value, the controller (8) outputs a control signal to automatically adjust the transmission (2) to the neutral state to prevent the engine from stalling; When stopping work, disconnect the safety solenoid valve (10) to make the drive system in a state without control oil to ensure the safety of the bulldozer.

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