A power shift tractor transmission system control system and its implementation method

Abstract

This application discloses a power shift tractor transmission system control system, including an engine controller connected to a gearbox controller. The gearbox controller is connected to a clutch pedal, a reversing lever, an instrument panel, a gear shift lever, a gearbox speed sensor, a clutch oil pressure sensor, a transmission system temperature sensor, and a proportional valve assembly. The engine controller, instrument panel, and gearbox controller are connected via a CAN bus. All components are mounted on the tractor body 1. It has the following advantages: it can realize high and low power shifting and power reversing functions; the shifting control is controlled by the gearbox controller; and multiple control methods are used for various operating conditions.

Description

Technical Field

[0001] This invention belongs to the field of tractors and relates to a tractor transmission system control method, and more particularly to a power shift tractor transmission system control system and control method. Background Technology

[0002] Currently, most small tractors in China use conventional manual mechanical shifting transmissions, such as sliding gear shifting, meshing sleeve shifting, and synchronizer shifting. These mechanical shifting transmissions require direct operation by the driver, which is labor-intensive. In addition, drivers need to have certain experience and be proficient in controlling the clutch and mechanical gear operation in order to use the tractor effectively.

[0003] In addition, mechanical shift tractors cannot be equipped with automatic driving devices to control the tractor's forward / reverse operation and high / low gear switching.

[0004] The power shift transmission system controls the engagement of the clutches in each gear through the TCU, and the clutch working state can be precisely controlled. The optimal clutch control curve obtained through a large number of tests, as well as the action sequence of different clutches under various operating conditions, can effectively improve work efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a power shift tractor transmission system control system and implementation method to address the above-mentioned shortcomings. This system can realize power high and low gears and power reversal functions. The shift control is controlled by the gearbox controller, and multiple control methods are adopted for various operating conditions.

[0006] To solve the above technical problems, the present invention adopts the following technical solution:

[0007] A power shift tractor transmission system control system includes an engine controller, which is connected to a gearbox controller. The gearbox controller is connected to a clutch pedal, a reversing lever, an instrument, a shift lever, a gearbox speed sensor, a clutch oil supply pressure sensor, a transmission system temperature sensor, and a proportional valve assembly. The engine controller, the instrument, and the gearbox controller are connected via a CAN bus. All of the above components are installed on the tractor body 1.

[0008] The gear shift lever is equipped with a clutch button switch and a high / low gear button switch, which are connected to the transmission controller.

[0009] The proportional valve assembly includes an L-gear valve, an H-gear valve, an F-gear valve, and an R-gear valve. The L-gear valve, H-gear valve, F-gear valve, and R-gear valve are all independently controlled by the transmission controller. The L-gear, H-gear, F-gear, and R-gear correspond to low power gear, high power gear, forward gear, and reverse gear, respectively.

[0010] The transmission system control system also includes a power shift transmission system, which has four independent clutches: L-gear clutch, H-gear clutch, F-gear clutch, and R-gear clutch, corresponding to L-gear, H-gear, F-gear, and R-gear respectively. The valves in the proportional valve assembly control the operation of the clutches corresponding to the gears.

[0011] A method for implementing a power shift tractor transmission system control system, the method being applied to the power shift tractor transmission system control system, including a power reversal control method, a high / low gear switching control method, a shift lever / clutch button control method, and a clutch pedal control method.

[0012] Furthermore, the power commutation control method includes a normal power commutation control method, the specific process of which is as follows:

[0013] When the tractor is operating in L and F gears, and the driver operates the reversing handle to change from F to R gear, the F switch signal in the reversing handle changes from high to low, and then the R switch changes from low to high. At this time, the transmission controller closes the L and F gear valves, and the speed n8 measured by the transmission speed sensor decreases until the speed is zero. When the R switch signal in the reversing handle goes high, the transmission controller drives the L and R gear valves 11.4 to work according to the programmed curve. At this time, the transmission system begins to rotate in the reverse direction, and the speed n8 can be seen to rise in the reverse direction to a stable speed.

[0014] Furthermore, the power commutation control method also includes a rapid power commutation control method, the specific process of which is as follows:

[0015] When the tractor is working in L and F gears, and the driver quickly changes the reversing lever from F to R gear, the transmission controller closes the L and F gear valves. The speed n8 measured by the transmission speed sensor decreases, but not to the appropriate reversing speed range close to 0. When the R switch signal in the reversing lever goes high, the transmission controller determines that the appropriate reversing speed range has not been reached and does not control the valves to work. At this time, the vehicle has no driving force, and the speed n8 continues to decrease.

[0016] Furthermore, the control process of the transmission controller in the power reversing control method is as follows:

[0017] When the speed n8 drops to the allowable reversing speed range, the transmission controller drives the L gear valve and R gear valve 11.4 to work according to the programmed curve. At this time, the transmission system changes from low-speed forward rotation to reverse rotation, and the speed n8 can be seen to rise in the reverse direction to a stable speed.

[0018] The transmission controller receives the states of the F and R switches in the reversing lever, as well as the measured speed n8 from the speed sensor 8, to determine the current H and L gear status. If the initial state is forward F and L gear operation, when the F switch signal in the reversing lever changes from high to low, the transmission controller disconnects the control signals of the F gear valve of the currently operating F gear clutch and the L gear valve of the L gear clutch. When the R switch in the reversing lever changes from low to high, the transmission controller determines whether the speed n8 is within the allowable reversing range. If the condition is met, the transmission controller controls the R and L gear valves according to the set curve, engaging the R and L gear clutches.

[0019] Furthermore, the specific process of the high / low gear switching control method is as follows:

[0020] When the tractor is working in L and F gears, when the driver presses the high / low gear button switch on the gear shift lever, the signal state of the high / low gear button switch changes from low to high. The gearbox controller drives the L gear valve and H gear valve to work according to the programmed curve. At this time, the transmission speed increases and then tends to stabilize. It can be seen that the speed n8 is higher than before the operation.

[0021] Furthermore, the control process of the transmission controller in the high / low gear switching control method is as follows:

[0022] The transmission controller first determines the current working state and gear state. The tractor is in L gear and F gear. When the transmission controller detects that the high and low gear button switch state changes from low to high, the transmission controller controls the H gear valve and L gear valve according to the set curve, engages the H gear clutch and L gear clutch respectively, and then updates the H and L gear states in the transmission controller and stores them in the transmission controller.

[0023] Furthermore, the specific process of the gear shift lever clutch button control method is as follows:

[0024] When the tractor is working in L and F gears, when the driver presses the clutch button switch on the shift lever, the signal state of the clutch button switch changes from low to high. At this time, the gearbox controller closes the L gear valve and F gear valve. At this time, there is no driving force in the transmission system, and the speed n8 can be seen to start to drop.

[0025] At this point, the driver moves the shift lever to change to the appropriate mechanical gear. After completing this, the driver releases the clutch button. The transmission controller then drives the L-gear valve and F-gear valve to work according to the programmed curve. At this point, the transmission speed stops decreasing and then increases, and the speed n8 rises back to the previous speed.

[0026] Furthermore, the control process of the transmission controller in the gear shift lever clutch button control method is as follows:

[0027] The transmission controller first determines the gear status of the current program execution. The tractor is in L gear or F gear. When it detects that the clutch button switch on the shift lever changes from low to high, the transmission controller cuts off the control signals of the F gear valve of the F gear clutch and the L gear valve of the L gear clutch. Until the transmission controller detects that the clutch button switch changes from high to low, the transmission controller controls the F gear valve and L gear valve according to the set curve, and engages the F gear clutch and L gear clutch respectively.

[0028] Furthermore, the specific process of the clutch pedal control method is as follows:

[0029] When the tractor is working in L and F gears, the driver depresses the clutch pedal, and the clutch pedal signal changes from low to high. At this time, the transmission controller closes the L and F gear valves. There is no driving force in the transmission system, and the speed n8 can be seen to start to drop. The driver can move the shift lever to change to a suitable mechanical gear. After that, the driver releases the clutch pedal. At this time, the transmission controller drives the L and F gear valves to work according to the programmed curve. At this time, the transmission speed stops dropping and then rises, and the speed n8 rises back to the previous speed.

[0030] When the tractor is working in L and F gears, the driver presses the clutch pedal. The clutch pedal signal changes from low to high. At this time, the gearbox controller closes the L gear valve and the F gear valve. At this time, there is no driving force in the transmission system. You can see that the speed n8 starts to drop until the speed is zero.

[0031] When the driver slowly releases the clutch pedal, the transmission controller proportionally controls the drive current of the L-gear valve and F-gear valve based on the clutch pedal signal. At this time, the drive torque of the transmission system gradually increases, and the speed n8 also gradually rises.

[0032] When the driver feels the speed is appropriate, he will stabilize the clutch pedal at the current position. At this time, the transmission controller controls the drive current of the L gear valve and F gear valve to keep it stable, so that the clutch transmission maintains a stable speed difference, so that the transmission system can transmit at low speed and the speed n8 is stabilized at the current low speed.

[0033] When the driver no longer needs to operate the clutch in half position, the clutch pedal is fully released. At this time, the clutch pedal signal becomes the lowest. The transmission controller drives the L-gear valve and F-gear valve to work according to the programmed curve. At this time, the transmission speed stops rising and can be seen to rise to the previous speed.

[0034] Furthermore, the control process of the transmission controller in the clutch pedal control method is as follows:

[0035] The transmission controller receives the status of the F and R switches in the reversing lever, as well as the clutch pedal sensor signal, to determine the current H and L gear status of the program. The initial state is F and L gear working state. When the clutch pedal sensor signal is detected to rise from the lowest value, the transmission controller cuts off the control signals of the F gear valve of the F gear clutch and the L gear valve of the L gear clutch, disengaging the corresponding clutch. When the transmission controller detects that the clutch pedal signal drops from high to low and reaches the lowest value, the transmission controller controls the F gear valve and L gear valve according to the set curve, engaging the F gear clutch and L gear clutch respectively.

[0036] If the transmission controller detects that the clutch pedal signal changes from high to low and stays at the middle value, the transmission controller controls the F-gear valve of the F-gear clutch and the L-gear valve of the L-gear clutch according to the percentage of clutch pedal engagement and the corresponding percentage of the set curve. This controls the degree of engagement of the corresponding clutches, allowing the clutches to work in a semi-engaged state until the clutch pedal reaches its maximum value. At this point, the control values ​​of the F-gear valve of the F-gear clutch and the L-gear valve of the L-gear clutch reach their maximum, and the corresponding clutches are fully engaged.

[0037] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0038] 1. During the power reversal process, the high and low gear clutches are also disengaged, and then they are engaged together with the gear clutch after the reversal. When the two clutches participate in the reversal, the speed difference of the transmission system is synchronized, reducing the speed difference on a single clutch and improving the service life of the clutch.

[0039] 2. A transmission speed sensor has been added. When the reversing speed is too high, the reversing operation control will not be activated, which improves safety. At the same time, the clutch will not have excessively large differences in high-speed reversing speed, and the clutch life will be further improved.

[0040] 3. A clutch button has been added to the mechanical shift lever. When pressed, both clutches are completely disengaged, which is more thorough than conventional power reversing which only disengages one clutch. Changing mechanical gears is easier and more convenient, and the shifting speed is faster and less strenuous.

[0041] 4. The high and low power gears are independent of the power reversing mechanism. When the gear speed is not suitable during operation under load, the high and low power gears can be switched to change speed, reducing the need for conventional power reversing tractors to stop and change gears, and further improving work efficiency. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0043] Figure 1 This is a schematic diagram of a power shift tractor transmission system control system according to the present invention;

[0044] Figure 2 This is a diagram of a mechanical shift lever for a power shift tractor transmission system control system according to the present invention;

[0045] Figure 3 This is a schematic diagram of a proportional valve assembly in a power shift tractor transmission system control system according to the present invention;

[0046] Figure 4 This is a schematic diagram of the transmission system of a power shift tractor transmission system control system according to the present invention;

[0047] Figure 5 This is a schematic diagram illustrating the normal power reversal control principle of the power shift tractor transmission system according to the present invention.

[0048] Figure 6 This is a schematic diagram illustrating the principle of the rapid power reversal control of the power shift tractor transmission system according to the present invention.

[0049] Figure 7 This is a schematic diagram illustrating the principle of the power shift tractor transmission system high / low gear switching control of the present invention.

[0050] Figure 8 This is a schematic diagram of the control principle of the reversing handle and clutch button of the power shift tractor transmission system according to the present invention;

[0051] Figure 9 This is a schematic diagram of the clutch pedal control principle of the power shift tractor transmission system according to the present invention;

[0052] Figure 10 This is a schematic diagram illustrating the principle of clutch pedal semi-clutch control in the power shift tractor transmission system of the present invention.

[0053] Figure 11 This is a diagram illustrating the power reversal process of the power shift tractor transmission system of the present invention.

[0054] Figure 12 This is a diagram illustrating the high / low gear switching process of the power shift tractor transmission system of the present invention;

[0055] Figure 13 This is a process diagram illustrating the control of the clutch button on the power shift tractor transmission system according to the present invention.

[0056] Figure 14 This is a process diagram of the foot-operated clutch control of the power shift tractor transmission system according to the present invention;

[0057] Figure 15 This is a transmission route diagram of the power shift transmission system of the present invention;

[0058] Figure 16 This is a diagram showing the positions of each shaft and the meshing of the front gear in the power shift transmission system of the present invention;

[0059] Figure 17 This is a diagram showing the positions of each shaft and the meshing of the intermediate gear in the power shift transmission system of the present invention.

[0060] Figure 18 This diagram shows the positions of each shaft and the meshing of the rear gear in the power shift transmission system of this invention. Detailed Implementation

[0061] Examples, such as Figure 1 As shown, a power shift tractor transmission control system includes an engine controller 2, which is connected to a gearbox controller 6. The gearbox controller 6 is connected to a clutch pedal 3, a reversing lever 4, an instrument panel 5, a gear shift lever 7, a gearbox speed sensor 8, a clutch oil supply pressure sensor 9, a transmission temperature sensor 10, and a proportional valve assembly 11. The engine controller 2, instrument panel 5, and gearbox controller 6 are connected via a CAN bus. All of these components are mounted on the tractor body 1. The engine controller 2 sends relevant data on the engine's operating status (such as engine speed, oil pressure, and water temperature) to the CAN bus. The instrument panel 5 displays relevant parameters (such as engine speed, oil pressure, water temperature, and power shift transmission gear status) for the driver to view and judge. The gearbox controller 6 reads the necessary information (such as engine speed and engine load) from the CAN bus to determine the operating status and execute control actions.

[0062] The gearbox speed sensor 8 is used to measure the speed and direction of rotation on the output shaft of the power shift gearbox and sends the data to the gearbox controller 6.

[0063] The clutch oil supply pressure sensor 9 is used to monitor the hydraulic system pressure, and the transmission system temperature sensor 10 is used to monitor the transmission system operating temperature to ensure that the system operates under normal conditions.

[0064] The different states of the reversing handle 4 can be sent to the transmission controller 6 in three working states: forward (F gear), neutral (N gear), and reverse (R gear), corresponding to the three working states of power reversal.

[0065] like Figures 15 to 18As shown, the transmission system control system also includes a power shift transmission system 12, including an engine input shaft 31. The engine input shaft 31 transmits engine power to the transmission system. The engine input shaft 31 is hinged to the gearbox housing via bearing #1 32 and bearing #2 314. Gear #1 33 is fixed on the engine input shaft 31, and gear #2 35 meshes with gear #1 33.

[0066] The transmission system also includes clutch assembly A, which is hinged to the gearbox housing via bearings 34 and 411. Gear 38 is machined in the middle of clutch assembly A. L-gear clutch 37 and F-gear clutch 39 are installed on both sides of gear 38. Gears 35 and 36 are double gears. L-gear clutch 37 can fix gears 35 and 36 to clutch assembly A to transmit power. Clutch assembly A is also fixed to gear 310 via F-gear clutch 39 to transmit power.

[0067] Gear #36 meshes with gear #521, gear #68 meshes with gear #719, gear #410 meshes with gear #812, and gear #25 meshes with gear #13.

[0068] The transmission system also includes a #2 clutch assembly B, which is hinged to the gearbox housing via a #5 bearing 322 and a #6 bearing 316. A #7 gear 319 is machined in the middle of the #2 clutch assembly B. An H-gear clutch 320 and an R-gear clutch 318 are mounted on both sides of the #7 gear 319. A #5 gear 321 is fixed to the #2 clutch assembly B via the H-gear clutch 320 to transmit power. A #10 gear 317 is also fixed to the #2 clutch assembly B via the R-gear clutch 318 to transmit power.

[0069] The 10# gear 317 meshes with the 8# gear 312.

[0070] The transmission system also includes a gear shift assembly 315, which is located at the rear end of the engine input shaft 31 and is used to realize other gears. It is a conventional mechanical structure and will not be described in detail. The gear shift assembly 315 includes a drive shaft 323, which is hinged to the gearbox housing via a bearing 313. A gear 312 is fixedly installed at the front end of the drive shaft 323. The power of the gear 312 is transmitted to the gear shift assembly 315 through the drive shaft 323 to drive the tractor to move.

[0071] Power transmission path for each gear:

[0072] In forward low gear, engage L gear clutch 37 and F gear clutch 39:

[0073] Engine power → Engine input shaft 31 → Gear 1# 33 → Gear 2# 35 → L gear clutch 37 → Clutch 1# assembly A → F gear clutch 39 → Gear 4# 310 → Gear 8# 312 → Drive shaft 323 → Transmission mechanism assembly 315.

[0074] Forward high gear, H gear clutch 320 and F gear clutch 39 are engaged:

[0075] Engine power → Engine input shaft 31 → Gear 1# 33 → Gear 2# 35 → Gear 3# 36 → Gear 5# 321 → H gear clutch 320 → Clutch 2# assembly B → Gear 7# 319 → Gear 6# 38 → F gear clutch 39 → Gear 4# 310 → Gear 8# 312 → Drive shaft 323 → Transmission mechanism assembly 315.

[0076] Reverse to a lower gear, engage L gear clutch 37 and R gear clutch 318:

[0077] Engine power → Engine input shaft 31 → Gear 1# 33 → Gear 2# 35 → L gear clutch 37 → Clutch 1# assembly A → Gear 6# 38 → Gear 7# 319 → R gear clutch 318 → Gear 10# 317 → Gear 8# 312 → Drive shaft 323 → Transmission mechanism assembly 315.

[0078] Reverse to a higher gear, engage the H gear clutch 320 and the R gear clutch 318:

[0079] Engine power → Engine input shaft 31 → Gear 1# 33 → Gear 2# 35 → Gear 3# 36 → Gear 5# 321 → H gear clutch 320 → Clutch 2# assembly B → R gear clutch 318 → Gear 10# 317 → Gear 8# 312 → Drive shaft 323 → Transmission mechanism assembly 315.

[0080] like Figure 4 As shown, the power shift transmission system 12 has four independent clutches, namely the L-gear clutch, H-gear clutch, F-gear clutch, and R-gear clutch, which correspond to L-gear, H-gear, F-gear, and R-gear respectively. The valve in the proportional valve assembly 11 controls the operation of the clutch of the corresponding gear.

[0081] The power shift transmission system 12 can achieve four gear positions—high and low gear shifting, and power reversing shifting—through a three-axis gear transmission within a limited gearbox space. The power shift transmission system 12 does not have a separate reverse idler gear, reducing the number of gears. The high and low gears, as well as the forward and reverse gears, are all operated independently, reducing the number of clutch operations for each gear position during shifting and improving clutch lifespan.

[0082] The transmission system control system also includes a mechanical stepped gear transmission system 13, which is a conventional mechanical shift transmission system. Different gears (such as 1st gear, 2nd gear, 3rd gear, 4th gear, etc.) are changed by moving the shift lever 7.

[0083] like Figure 2 As shown, the gear shift lever 7 is equipped with a clutch button switch 7.1 and a high / low gear button switch 7.2. When the clutch button switch 7.1 is pressed, a control signal is sent to the transmission controller 6 to initiate the clutch interruption operation. At this time, the driver can quickly move the gear shift lever 7 to the target mechanical gear, and then release the clutch button switch 7.1 to complete the mechanical gear shift operation. When the high / low gear button switch 7.2 is pressed, a control signal is sent to the transmission controller 6 to initiate the power high / low gear shift operation.

[0084] like Figure 3 As shown, the proportional valve assembly 11 includes an L-gear valve 11.1, an H-gear valve 11.2, an F-gear valve 11.3, and an R-gear valve 11.4. The L-gear valve 11.1, H-gear valve 11.2, F-gear valve 11.3, and R-gear valve 11.4 are all independently controlled by the transmission controller 6. The L-gear, H-gear, F-gear, and R-gear correspond to low power gear, high power gear, forward gear, and reverse gear, respectively.

[0085] A method for implementing a power shift tractor transmission system control system includes a power reversal control method, a high / low gear switching control method, a shift lever / clutch button control method, and a clutch pedal control method.

[0086] like Figure 5 As shown, the power commutation control method includes a normal power commutation control method, the specific process of which is as follows:

[0087] When the tractor is operating in L and F gears, and the driver operates the reversing handle 4 from F gear to R gear, the F switch signal in the reversing handle 4 changes from high to low, and then the R switch changes from low to high. At this time, the transmission controller 6 closes the L gear valve 11.1 and the F gear valve 11.3, and the speed n8 measured by the transmission speed sensor 8 decreases until the speed is zero. When the R switch signal in the reversing handle 4 goes high, the transmission controller 6 drives the L gear valve 11.1 and the R gear valve 11.4 to work according to the programmed curve. At this time, the transmission system begins to rotate in the reverse direction, and the speed n8 can be seen to rise in the reverse direction to a stable speed.

[0088] like Figure 6 As shown, the power commutation control method also includes a fast power commutation control method, the specific process of which is as follows:

[0089] When the tractor is working in L and F gears, and the driver quickly changes the reversing lever 4 from F gear to R gear, the transmission controller 6 closes the L gear valve 11.1 and the F gear valve 11.3. The speed n8 measured by the transmission speed sensor 8 decreases, but does not drop to the appropriate reversing speed range close to 0. At this time, the R switch signal in the reversing lever 4 goes high, and the transmission controller 6 determines that the appropriate reversing speed range has not been reached, so it does not control the valves to work. At this time, the vehicle has no driving force, and the speed n8 continues to decrease.

[0090] like Figure 11 As shown, the control process of the gearbox controller 6 in the power reversing control method is as follows:

[0091] When the speed n8 drops to the allowable reversing speed range, the gearbox controller 6 drives the L gear valve 11.1 and R gear valve 11.4 to work according to the programmed curve. At this time, the transmission system changes from low-speed forward rotation to reverse rotation, and the speed n8 can be seen to rise in the reverse direction to a stable speed.

[0092] The transmission controller 6 receives the states of the F and R switches in the reversing handle 4, as well as the measured speed n8 from the speed sensor 8, to determine the current H and L gear status. If the initial state is forward F and L gear operation, when the F switch signal in the reversing handle 4 changes from high to low, the transmission controller cuts off the control signals of the currently operating F gear clutch's F gear valve 11.3 and L gear clutch's L gear valve 11.1. When the R switch in the reversing handle 4 changes from low to high, the transmission controller determines whether the speed n8 is within the allowable reversing range. If the condition is met, the transmission controller controls the R gear valve 11.4 and L gear valve 11.1 according to the set curve, engaging the R and L gear clutches.

[0093] The set curve is obtained by testing curves with different slopes and variations to obtain the clutch valve control curve with the best performance. This curve is then stored in the transmission controller as the clutch valve control curve.

[0094] During the power reversal process, the high and low gear clutches are also disengaged, and then engaged together with the gear clutch after the reversal. When the two clutches participate in the reversal, the speed difference of the transmission system is synchronized, reducing the speed difference on the clutches and improving the service life of the clutches.

[0095] like Figure 7 As shown, the specific process of the high / low gear switching control method is as follows:

[0096] When the tractor is working in L and F gears, when the driver presses the high / low gear button switch 7.2 on the gear shift lever 7, the signal state of the high / low gear button switch 7.2 changes from low to high. The gearbox controller 6 drives the L gear valve 11.1 and H gear valve 11.2 to work according to the programmed curve. At this time, the transmission speed increases and then tends to stabilize. It can be seen that the speed n8 is higher than before the operation.

[0097] like Figure 12 As shown, the control process of the gearbox controller 6 in the high / low gear switching control method is as follows:

[0098] The transmission controller first determines the current working state and gear state. The tractor is in L gear and F gear. When the transmission controller detects that the state of the high / low gear button switch 7.2 changes from low to high, the transmission controller controls the H gear valve and L gear valve according to the set curve, engages the H gear clutch and L gear clutch respectively, and then updates the H and L gear states in the transmission controller and stores them in the transmission controller.

[0099] The setting curve in the above-mentioned high and low gear switching is obtained by testing curves with different slopes and changes to obtain the clutch valve control curve with the best performance. This curve is then stored in the transmission controller as the clutch valve control curve.

[0100] The above-mentioned control method of switching from L gear to H gear increases the speed ratio of the tractor's transmission system, that is, increases the output speed. However, since the two clutches alternately transmit torque, the torque on the output shaft is not interrupted. For the tractor, it is like switching from a low power gear to a high power gear when there is a traction load. The tractor does not need to stop, shift gears and then start again like a mechanically shifted tractor, thus improving work efficiency.

[0101] In addition, the benefits of switching from H gear to L gear are similar: the tractor can shift to a lower gear without stopping under load, and the operation process is not interrupted.

[0102] like Figure 8 As shown, the specific process of the gear shift lever clutch button control method is as follows:

[0103] When the tractor is working in L and F gears, when the driver presses the clutch button switch 7.1 on the shift lever 7, the signal state of the clutch button switch 7.1 changes from low to high. At this time, the gearbox controller 6 closes the L gear valve 11.1 and the F gear valve 11.3. At this time, there is no driving force in the transmission system, and the speed n8 can be seen to start to drop.

[0104] At this time, the driver moves the shift lever 7 to change to the appropriate mechanical gear. After completion, the clutch button switch 7.1 is released. At this time, the transmission controller 6 drives the L gear valve 11.1 and F gear valve 11.3 to work according to the programmed curve. At this time, the transmission speed stops decreasing and then increases, and the speed n8 rises back to the previous speed.

[0105] The shift lever clutch button allows the driver to easily perform mechanical gear shifting operations, simplifying the operation (no longer requiring the clutch pedal to be pressed). When the driver needs to shift to a mechanical gear, the driver only needs to hold the shift lever while pressing the clutch button switch with their finger to disconnect the power. At this time, the driver only needs to move the shift lever to the desired gear and then release it to complete the mechanical gear shift.

[0106] like Figure 13 As shown, the control process of the transmission controller 6 in the gear shift lever clutch button control method is as follows:

[0107] The transmission controller first determines the gear status of the current program execution. The tractor is in L gear or F gear. When it detects that the state of the clutch button switch 7.1 on the shift lever 7 changes from low to high, the transmission controller cuts off the control signals of the F gear valve of the F gear clutch and the L gear valve of the L gear clutch. Until the transmission controller detects that the clutch button switch 7.1 changes from high to low, the transmission controller controls the F gear valve and L gear valve according to the set curve, and engages the F gear clutch and L gear clutch respectively.

[0108] The setting curve in the above-mentioned lever clutch button control process is obtained by testing curves with different slopes and changes to obtain the clutch valve control curve with the best performance. This curve is then stored in the gearbox controller as the clutch valve control curve.

[0109] like Figure 9 and Figure 10 As shown, the specific process of the clutch pedal control method is as follows:

[0110] When the tractor is operating in L and F gears, the driver depresses the clutch pedal 3. The clutch pedal 3 signal changes from low to high. At this time, the gearbox controller 6 closes the L gear valve 11.1 and the F gear valve 11.3. At this time, there is no driving force in the transmission system, and the speed n8 can be seen to start to drop. The driver can move the shift lever 7 to change to a suitable mechanical gear. After that, the driver releases the clutch pedal 3. At this time, the gearbox controller 6 drives the L gear valve 11.1 and the F gear valve 11.3 to work according to the programmed curve. At this time, the speed of the transmission system stops dropping and then rises, and the speed n8 rises back to the previous speed.

[0111] When the tractor is working in L and F gears, the driver presses the clutch pedal 3. The clutch pedal 3 signal changes from low to high. At this time, the gearbox controller 6 closes the L gear valve 11.1 and the F gear valve 11.3. At this time, there is no driving force in the transmission system, and the speed n8 can be seen to start to drop until the speed is zero.

[0112] When the driver slowly releases the clutch pedal 3, the transmission controller 6 proportionally controls the drive current of the L gear valve 11.1 and the F gear valve 11.3 according to the signal from the clutch pedal 3. At this time, the drive torque of the transmission system gradually increases, and the speed n8 also gradually rises.

[0113] When the driver feels the speed is appropriate, he will stabilize the clutch pedal 3 at the current position. At this time, the transmission controller 6 controls the drive current of the L gear valve 11.1 and F gear valve 11.3 to remain stable, so the clutch transmission maintains a stable speed difference, allowing the transmission system to transmit at low speed, and the speed n8 stabilizes at the current low speed.

[0114] When the driver no longer needs to operate the clutch in half position, the clutch pedal 3 is fully released. At this time, the signal of the clutch pedal 3 becomes the lowest. At this time, the transmission controller 6 drives the L gear valve 11.1 and F gear valve 11.3 to work according to the programmed curve. At this time, the transmission speed stops rising and the speed n8 can be seen to rise to the previous speed.

[0115] Due to the usual tractor usage habits, when the tractor needs to move slightly, the driver is used to using the clutch pedal to control the clutch slippage state to drive the vehicle slightly, and to operate the clutch pedal in conjunction with shifting mechanical gears.

[0116] When the driver fully depresses the clutch pedal and then fully releases it after completing the operation, the control method is the same as that of the clutch button on the gear shift lever, which meets the driver's needs for shifting gears by pressing the clutch.

[0117] When the driver depresses the clutch pedal about halfway, the clutch pedal control method performs half-clutch control, and the tractor moves slightly.

[0118] like Figure 14 As shown, the control process of the gearbox controller 6 in the clutch pedal control method is as follows:

[0119] The transmission controller receives the status of the F and R switches in the reversing lever 4, as well as the signal from the clutch pedal 3 sensor, to determine the current H and L gear status of the program. The initial state is F and L gear operation. When the clutch pedal 3 sensor signal is detected to rise from its lowest value, the transmission controller cuts off the control signals of the F gear valve of the F gear clutch and the L gear valve of the L gear clutch, disengaging the corresponding clutch. When the transmission controller detects that the clutch pedal 3 signal has dropped from high to low and reached its lowest value, the transmission controller controls the F gear valve and L gear valve according to the set curve, engaging the F gear clutch and L gear clutch respectively.

[0120] If the transmission controller detects that the signal from clutch pedal 3 changes from high to low and stays at the middle value, the transmission controller controls the F-gear valve of the F-gear clutch and the L-gear valve of the L-gear clutch according to the percentage of clutch pedal engagement and the percentage of the set curve, thereby controlling the degree of engagement of the corresponding clutches, so that the clutches can work in a half-clutch state until the clutch pedal reaches the highest value. At this time, the control values ​​of the F-gear valve of the F-gear clutch and the L-gear valve of the L-gear clutch reach the maximum, and the corresponding clutches are fully engaged.

[0121] The aforementioned setting curve is obtained by testing curves with different slopes and variations to obtain the clutch valve control curve with the best performance. This curve is then stored in the transmission controller as the clutch valve control curve.

[0122] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for implementing a power shift tractor transmission system control system, characterized in that: The power shift tractor transmission system control system includes an engine controller (2), which is connected to a gearbox controller (6). The gearbox controller (6) is connected to a clutch pedal (3), a reversing handle (4), an instrument (5), a shift handle (7), a gearbox speed sensor (8), a clutch oil supply pressure sensor (9), a transmission system temperature sensor (10), and a proportional valve assembly (11). The engine controller (2), the instrument (5), and the gearbox controller (6) are connected via a CAN bus. All of the above components are installed on the tractor body (1). The shift lever (7) is equipped with a clutch button switch (7.1) and a high / low gear button switch (7.2), which are connected to the transmission controller (6). The proportional valve assembly (11) includes an L-gear valve (11.1), an H-gear valve (11.2), an F-gear valve (11.3), and an R-gear valve (11.4). The L-gear valve (11.1), H-gear valve (11.2), F-gear valve (11.3), and R-gear valve (11.4) are all independently controlled by the transmission controller (6). The L-gear, H-gear, F-gear, and R-gear correspond to low power gear, high power gear, forward gear, and reverse gear, respectively. The transmission system control system also includes a power shift transmission system (12), which has four independent clutches: L-gear clutch, H-gear clutch, F-gear clutch, and R-gear clutch, corresponding to L-gear, H-gear, F-gear, and R-gear respectively. The valve in the proportional valve assembly (11) controls the operation of the clutch corresponding to the gear. The implementation method is applied to the transmission system control system of a power shift tractor, including a power reversal control method, a high / low gear switching control method, a shift lever clutch button control method, and a clutch pedal control method. The control process of the transmission controller in the power reversing control method is as follows: When the speed n8 of the gearbox output shaft drops to the allowable reversing speed range, the gearbox controller (6) drives the L gear valve (11.1) and R gear valve (11.4) to work according to the program setting curve. At this time, the transmission system changes from low-speed forward rotation to reverse rotation, and the speed n8 of the gearbox output shaft rises in the reverse direction to a stable speed. The transmission controller (6) receives the status of the F switch and R switch in the reversing handle (4) and the speed n8 of the transmission output shaft measured by the transmission speed sensor (8). It determines the current H gear and L gear status of the program. If the initial status is forward F gear and L gear working status, when the F switch signal status in the reversing handle (4) changes from high to low, the transmission controller cuts off the control signals of the F gear valve (11.3) of the currently working F gear clutch and the L gear valve (11.1) of the L gear clutch. When the R switch in the reversing handle (4) changes from low to high, the transmission controller determines whether the speed n8 of the transmission output shaft is within the allowable reversing range. If the condition is met, the transmission controller controls the R gear valve (11.4) and L gear valve (11.1) according to the set curve, and combines the R gear clutch and L gear clutch. The set curve is obtained by testing curves with different slopes and variations to obtain the clutch valve control curve with the best performance. The set curve is stored in the transmission controller as the clutch valve control curve.

2. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The power commutation control method includes a normal power commutation control method, the specific process of which is as follows: When the tractor is working in L and F gears, when the driver operates the reversing handle (4) to change from F gear to R gear, the F switch signal in the reversing handle (4) changes from high to low, and then the R switch changes from low to high. At this time, the gearbox controller (6) closes the L gear valve (11.1) and the F gear valve (11.3), and the speed n8 measured by the gearbox speed sensor (8) decreases until the speed is zero. When the R switch signal in the reversing handle (4) becomes high, the gearbox controller (6) drives the L gear valve (11.1) and the R gear valve (11.4) to work according to the program setting curve. At this time, the transmission system starts to rotate in the opposite direction, and the speed n8 can be seen to rise in the opposite direction to a stable speed.

3. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The power commutation control method also includes a rapid power commutation control method, the specific process of which is as follows: When the tractor is working in L and F gears, the driver operates the reversing handle (4) to quickly change from F gear to R gear. At this time, the gearbox controller (6) closes the L gear valve (11.1) and the F gear valve (11.3). The speed n8 measured by the gearbox speed sensor (8) decreases, but does not drop to the appropriate reversing speed range close to 0. At this time, after the R switch signal in the reversing handle (4) goes high, the gearbox controller (6) judges that the appropriate reversing speed range has not been reached and does not control the valve to work. At this time, the vehicle has no driving force, and the speed n8 continues to decrease.

4. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The specific process of the high / low gear switching control method is as follows: When the tractor is working in L and F gears, when the driver presses the high / low gear button switch (7.2) on the shift lever (7), the signal state of the high / low gear button switch (7.2) changes from low to high. The gearbox controller (6) drives the L gear valve (11.1) and H gear valve (11.2) to work according to the program setting curve. At this time, the transmission speed increases and then tends to stabilize. The speed n8 of the gearbox output shaft is higher than before the operation.

5. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The control process of the transmission controller in the high / low gear switching control method is as follows: The transmission controller first determines the current working state and gear state. The tractor is in L gear and F gear. When the transmission controller detects that the state of the high and low gear button switch (7.2) changes from low to high, the transmission controller controls the H gear valve and L gear valve according to the set curve, and engages the H gear clutch and L gear clutch respectively. Then, the transmission controller updates the H gear and L gear states in the transmission controller and stores them in the transmission controller.

6. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The specific process of the gear shift lever clutch button control method is as follows: When the tractor is working in L and F gears, when the driver presses the clutch button switch (7.1) on the shift lever (7), the signal state of the clutch button switch (7.1) changes from low to high. At this time, the gearbox controller (6) closes the L gear valve (11.1) and the F gear valve (11.3). At this time, there is no driving force in the transmission system, and the speed n8 of the gearbox output shaft begins to decrease. At this time, the driver moves the shift lever (7) to change to the appropriate mechanical gear. After completion, the clutch button switch (7.1) is released. At this time, the transmission controller (6) drives the L gear valve (11.1) and F gear valve (11.3) to work according to the program setting curve. At this time, the transmission speed stops decreasing and then increases. The speed n8 of the transmission output shaft increases back to the previous speed.

7. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The control process of the transmission controller in the gear shift lever clutch button control method is as follows: The transmission controller first determines the gear status of the current program execution. The tractor is in L gear and F gear. When it detects that the state of the clutch button switch (7.1) on the shift lever (7) changes from low to high, the transmission controller cuts off the control signals of the F gear valve of the F gear clutch and the L gear valve of the L gear clutch. Until the transmission controller detects that the clutch button switch (7.1) changes from high to low, the transmission controller controls the F gear valve and L gear valve according to the set curve, and engages the F gear clutch and L gear clutch respectively.

8. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The specific process of the clutch pedal control method is as follows: When the tractor is working in L and F gears, the driver presses the clutch pedal (3), and the clutch pedal (3) signal changes from low to high. At this time, the gearbox controller (6) closes the L gear valve (11.1) and the F gear valve (11.3). At this time, there is no driving force in the transmission system, and the speed n8 of the gearbox output shaft begins to decrease. The driver moves the shift lever (7) to change to the appropriate mechanical gear. After completion, the driver releases the clutch pedal (3). At this time, the gearbox controller (6) drives the L gear valve (11.1) and the F gear valve (11.3) to work according to the programmed curve. At this time, the speed of the transmission system stops decreasing and then increases. The speed n8 of the gearbox output shaft increases back to the previous speed. When the tractor is working in L and F gears, the driver presses the clutch pedal (3), and the clutch pedal (3) signal changes from low to high. At this time, the gearbox controller (6) closes the L gear valve (11.1) and the F gear valve (11.3). At this time, there is no driving force in the transmission system, and the speed n8 of the gearbox output shaft begins to decrease until the speed is zero. When the driver slowly releases the clutch pedal (3), the transmission controller (6) proportionally controls the drive current of the L gear valve (11.1) and F gear valve (11.3) according to the signal from the clutch pedal (3). At this time, the drive torque of the transmission system gradually increases, and the speed n8 of the transmission output shaft also gradually increases. When the driver feels that the speed is appropriate, he will stabilize the clutch pedal (3) at the current position. At this time, the transmission controller (6) controls the drive current of the L gear valve (11.1) and F gear valve (11.3) to remain stable, so the clutch transmission maintains a stable speed difference state, so that the transmission system can transmit at low speed and the speed n8 of the transmission output shaft remains stable at the current low speed. When the driver no longer needs to operate the clutch, he fully releases the clutch pedal (3). At this time, the signal of the clutch pedal (3) becomes the lowest. At this time, the transmission controller (6) drives the L gear valve (11.1) and F gear valve (11.3) to work according to the program setting curve. At this time, the transmission speed stops rising and the speed n8 of the transmission output shaft rises to the previous speed.

9. The method for implementing a power shift tractor transmission system control system as described in claim 1, characterized in that: The control process of the transmission controller in the clutch pedal control method is as follows: The transmission controller receives the status of the F switch and R switch in the reversing lever (4) and the clutch pedal (3) sensor signal to determine the current H gear and L gear status of the program. The initial status is the F gear and L gear working status. When the clutch pedal (3) sensor signal is detected to increase from the lowest value, the transmission controller cuts off the F gear valve control signal of the F gear clutch and the L gear valve control signal of the L gear clutch, and disconnects the corresponding clutch. When the transmission controller detects that the clutch pedal (3) signal decreases from high to low and reaches the lowest value, the transmission controller controls the F gear valve and L gear valve according to the set curve to engage the F gear clutch and L gear clutch respectively. If the transmission controller monitors the signal of the clutch pedal (3) from high to low and stays at the middle value, the transmission controller controls the F-gear valve of the F-gear clutch and the L-gear valve of the L-gear clutch according to the percentage of clutch pedal engagement and the percentage of the set curve, thereby controlling the engagement degree of the corresponding clutches, so that the clutches work in a half-clutch state until the clutch pedal reaches the highest value, then the control value of the F-gear valve of the corresponding F-gear clutch and the L-gear valve of the L-gear clutch reaches the maximum, and the corresponding clutches are fully engaged.

Images