Multi-gear AMT valve block assembly for tractor gearbox

Abstract

The utility model provides a multi-gear AMT (Automated Mechanical Transmission) valve block assembly for a tractor gearbox, which is used for solving the problems that the processing difficulty of a shell of a power gear shifting auxiliary box is greatly increased due to the fact that an oil duct is directly arranged on the power gear shifting auxiliary box and an electromagnetic valve and a gear shifting control mechanism are arranged on the power gear shifting auxiliary box of the existing tractor; and therefore, the machining precision is reduced. According to the multi-gear AMT valve block assembly for the tractor gearbox, the displacement of the gear shifting piston and the displacement of the gear selecting piston in the gear shifting oil cylinder and the displacement of the gear selecting piston in the gear selecting oil cylinder are controlled through the proportional electromagnetic valves respectively, hydraulic control is more accurate, response is rapid, operation is easy, the gear shifting success rate is effectively increased, and gear shifting is more stable and reliable; meanwhile, a pressure switch and a position sensor are combined to monitor the gear shifting state, the monitoring precision is improved, and successful completion of gear selecting and shifting actions is further guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to tractor gearbox especially for tractor gearbox's multi -stop AMT valve block assembly. BACKGROUND

[0002] The gearbox is the core component of the tractor, and its performance has an important influence on the power performance, operation efficiency and economy of the tractor. At present, the traditional tractor usually adopts meshing sleeve shifting or synchronizer shifting gearbox, which realizes the shifting function through complex mechanical transmission, and the driver's operation is cumbersome. The power shift gearbox controls the combination and disconnection of multiple wet clutches and synchronizers through a hydraulic control system, and realizes the shifting function through different clutch and synchronizer combinations. Compared with the traditional gearbox, the power shift gearbox simplifies the shifting operation, has simple overall arrangement, compact structure, easy operation and high transmission efficiency, greatly improves the overall operation efficiency of the vehicle and reduces the labor intensity of the driver.

[0003] The power shift gearbox usually consists of a power shift main gearbox, a power shift auxiliary gearbox, a wet brake rear axle and a PTO. Among them, the design of the power shift auxiliary gearbox selection shift valve block assembly is related to the shifting quality, durability and safety of the gearbox, and is the key to the design of the power shift gearbox. Although Chinese patent CN216555309U discloses a harvesting machinery electro-hydraulic control shift gearbox, it belongs to the field of harvesting machinery, and the shift adopts a three-position four-way reversing valve. The three-position four-way reversing valve takes into account two oil cylinders, which cannot maintain pressure when reversing in the middle position, and thus the selection shift door has only two, which cannot realize multi-position shifting. Chinese patent CN213512025U discloses an automatic transmission electro-hydraulic control valve, but it is a selection shift valve block structure of the power shift main gearbox and does not involve the power shift auxiliary gearbox selection shift valve block. At present, the power shift auxiliary gearbox of the tractor does not separately set the valve block, and it usually directly sets the oil channel on the power shift auxiliary gearbox and installs the electromagnetic valve and the shift operating mechanism, but this way is affected by the material and preparation process of the power shift auxiliary gearbox, greatly increasing the machining difficulty of the power shift auxiliary gearbox shell, and thus reducing its machining precision. UTILITY MODEL CONTENTS

[0004] The utility model aims at solving the technical problem that the existing tractor power shift auxiliary gearbox directly sets the oil channel on the power shift auxiliary gearbox and installs the electromagnetic valve and the shift operating mechanism, greatly increasing the machining difficulty of the power shift auxiliary gearbox shell, and thus reducing its machining precision, and provides a multi-stop AMT valve block assembly for tractor gearbox.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the utility model is as follows:

[0006] A kind of multi-gear AMT valve block assembly for tractor gearbox, for realizing five-gear, six-gear control, it is special in that, including valve block, gear shift operating mechanism, gear control mechanism and gear state monitoring mechanism;

[0007] The gear shift operating mechanism includes two gear shift oil cylinders, two gear selection oil cylinders and gear shift knob arranged in the valve block;

[0008] The gear shift pistons in the two gear shift oil cylinders are coaxially fixed by gear shift shaft, and the gear selection pistons in the two gear selection oil cylinders are coaxially fixed by gear selection shaft;The gear shift shaft is located above the gear selection shaft, and is arranged vertically;

[0009] The upper end of the gear shift shaft is provided with a clamping groove along the movement direction of the gear selection piston;

[0010] The middle part of the gear shift knob is fixed in the middle part of the gear selection shaft, the upper end is embedded in the clamping groove of the gear shift shaft, and can slide along the direction of the clamping groove, and the lower end is used for cooperating with the gear shift yoke of the tractor gearbox;

[0011] The gear control mechanism includes four proportional solenoid valves arranged on the valve block;

[0012] The side wall of the valve block is provided with a total oil inlet communicated with the external oil tank, and the total oil inlet is communicated with the oil inlets of the four proportional solenoid valves through four oil paths;The oil outlets of two proportional solenoid valves are respectively communicated with the piston cavities of the corresponding gear shift oil cylinders through oil paths, and the oil outlets of the other two proportional solenoid valves are respectively communicated with the piston cavities of the corresponding gear selection oil cylinders through oil paths;The oil return ports of the four proportional solenoid valves are respectively communicated with the external oil tank through corresponding oil paths;

[0013] The gear state monitoring mechanism includes four pressure sensors, a position sensor and a pressure switch;

[0014] The four pressure sensors are respectively arranged on the oil paths between the four proportional solenoid valves and the corresponding piston cavities, for monitoring the gear state;

[0015] The position sensor is used for monitoring the displacement of the gear shift piston;

[0016] An arc-shaped groove is formed in the side wall of the gear shift knob corresponding to the movement direction of the gear shift piston;The pressure switch is installed on the valve block, and the pressure contact is embedded in the arc-shaped groove of the gear shift knob, for monitoring the movement state of the gear selection piston.

[0017] Further, it further includes two-position four-way electromagnetic reversing valve, first reversing valve pressure sensor and second reversing valve pressure sensor;

[0018] The side wall of the valve block is further provided with a first pressure oil port and a second pressure oil port communicated with other mechanisms of the external gearbox.

[0019] The oil inlet of the two-position four-way electromagnetic reversing valve is communicated with the total oil inlet through a corresponding oil path, and the two oil outlets are respectively communicated with the first pressure oil port and the second pressure oil port through corresponding oil paths;

[0020] The first reversing valve pressure sensor is installed on the oil path between the two-position four-way electromagnetic reversing valve and the first pressure oil port, and the second reversing valve pressure sensor is installed on the oil path between the two-position four-way electromagnetic reversing valve and the second pressure oil port, for monitoring the pressure state of the corresponding oil path respectively;

[0021] The oil return port of the two-position four-way electromagnetic reversing valve is communicated with the external oil tank through a corresponding oil path.

[0022] Further, the position sensor comprises a Hall sensor arranged on the valve block and a magnetic steel arranged on the shift shaft.

[0023] Further, the middle part of the shift knob is fixed in the middle part of the selected shift shaft through a snap ring.

[0024] In addition, the utility model also provides another kind of multi-gear AMT valve block assembly for tractor gearbox, for realizing three-gear, four-gear control, and its special feature is that it comprises a valve block, a shift control mechanism, a gear control mechanism and a gear state monitoring mechanism.

[0025] The shift control mechanism comprises two shift oil cylinders, a selected shift oil cylinder and a shift knob arranged in the valve block.

[0026] The shift pistons in the two shift oil cylinders are coaxially connected through the shift shaft, the selected shift piston in the selected shift oil cylinder is provided with a selected shift shaft at one end and a compression spring between the other end and the inner wall of the selected shift oil cylinder piston cavity; the shift shaft is located above the selected shift shaft and is arranged perpendicularly.

[0027] A clamping groove is formed in the shift shaft above the selected shift piston in the movement direction of the selected shift piston.

[0028] The middle part of the shift knob is fixed in the middle part of the selected shift shaft, the upper end of the shift knob is embedded in the clamping groove of the shift shaft and can slide in the direction of the clamping groove, and the lower end of the shift knob is used for cooperating with the shift yoke of the tractor gearbox.

[0029] The gear control mechanism comprises three proportional electromagnetic valves arranged on the valve block.

[0030] The side wall of the valve block is provided with a total oil inlet communicated with an external oil tank, and the total oil inlet is communicated with the oil inlets of the three proportional electromagnetic valves through three oil paths; the oil outlets of two proportional electromagnetic valves are respectively communicated with the piston cavities of the corresponding gear shift oil cylinders through oil paths, and the oil outlet of the other proportional electromagnetic valve is communicated with the piston cavity of the selected gear cylinder through an oil path; the oil return ports of the three proportional electromagnetic valves are respectively communicated with the external oil tank through corresponding oil paths;

[0031] The gear position state monitoring mechanism comprises three pressure sensors, a position sensor and a pressure switch.

[0032] The three pressure sensors are respectively arranged on the oil paths between the three proportional electromagnetic valves and the corresponding piston cavities, and are used for monitoring the gear position state.

[0033] The position sensor is used for monitoring the displacement of the gear shift piston.

[0034] An arc-shaped groove is formed in the side wall of the gear shift knob corresponding to the movement direction of the gear shift piston; the pressure switch is installed on the valve block, and the pressure contact of the pressure switch is embedded in the arc-shaped groove of the gear shift knob, and is used for monitoring the movement state of the selected gear piston.

[0035] Further, the gear position state monitoring mechanism further comprises a two-position four-way electromagnetic reversing valve, a first reversing valve pressure sensor and a second reversing valve pressure sensor.

[0036] The side wall of the valve block is further provided with a first pressure oil port and a second pressure oil port communicated with other mechanisms of an external gearbox.

[0037] The oil inlet of the two-position four-way electromagnetic reversing valve is communicated with the total oil inlet through a corresponding oil path, and the two oil outlets of the two-position four-way electromagnetic reversing valve are respectively communicated with the first pressure oil port and the second pressure oil port through corresponding oil paths.

[0038] The first reversing valve pressure sensor is installed on the oil path between the two-position four-way electromagnetic reversing valve and the first pressure oil port, and the second reversing valve pressure sensor is installed on the oil path between the two-position four-way electromagnetic reversing valve and the second pressure oil port, and is used for monitoring the pressure state of the corresponding oil path.

[0039] The oil return port of the two-position four-way electromagnetic reversing valve is communicated with the external oil tank through a corresponding oil path.

[0040] Further, the position sensor comprises a Hall sensor arranged on the valve block and a magnetic steel arranged on the gear shift shaft.

[0041] Further, the middle part of the gear shift knob is fixed in the middle part of the selected gear shaft through a snap ring.

[0042] The beneficial effects of the utility model compared with prior art are:

[0043] 1. The multi-gear AMT valve block assembly for the tractor gearbox provided by the utility model realizes the bidirectional displacement of the gear shifting piston and the gear selecting piston in the gear shifting cylinder and the gear selecting cylinder by adopting proportional electromagnetic valves respectively when five-gear and six-gear controls are realized, the hydraulic control is more accurate, the response is quick, the operation is simple, the gear shifting success rate is effectively improved, the gear shifting is more stable and reliable, the gear shifting state is monitored by adopting the combination of the pressure switch and the position sensor, the monitoring precision is improved, and the successful completion of the gear selecting and gear shifting actions is further ensured.

[0044] 2. The multi-gear AMT valve block assembly for the tractor gearbox provided by the utility model integrates the gear shifting control mechanism, the pressure switch, the position sensor, the pressure sensor and the electromagnetic valve on the valve block, the structure is compact, the disassembly and assembly are convenient, and the space can be effectively saved; meanwhile, the structure reduces the oil way and the valve hole arrangement of the power gear shifting auxiliary gearbox shell assembled therewith, reduces the machining difficulty of the power gear shifting auxiliary gearbox shell, and ensures the machining precision.

[0045] 3. Another multi-gear AMT valve block assembly for the tractor gearbox provided by the utility model realizes the bidirectional displacement of the gear shifting piston in the gear shifting cylinder by adopting a proportional electromagnetic valve when three-gear and four-gear controls are realized, the bidirectional displacement of the gear selecting piston in the gear selecting cylinder is controlled by adopting the proportional electromagnetic valve and the compression spring in cooperation, the control is more accurate, the response is quick, the operation is simple, the gear shifting success rate is effectively improved, the gear shifting is more stable and reliable, the gear shifting state is monitored by adopting the combination of the pressure switch and the position sensor, the monitoring precision is improved, and the successful completion of the gear selecting and gear shifting actions is further ensured. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is a top view of the multi-gear AMT valve block assembly for the tractor gearbox of the utility model embodiment one;

[0047] Figure 2 It is a bottom view of the multi-gear AMT valve block assembly for the tractor gearbox of the utility model embodiment one;

[0048] Figure 3 It is a structural schematic view of the gear shifting control mechanism in the utility model embodiment one;

[0049] Figure 4 It is a hydraulic principle schematic view of the utility model embodiment one;

[0050] Figure 5 It is a gear position schematic view of the utility model embodiment one for realizing five-gear control;

[0051] Figure 6 It is a hydraulic principle schematic view of the utility model embodiment two;

[0052] Figure 7 The gear position diagram for implementing four-gear control of the second embodiment of the utility model.

[0053] Specific reference signs are as follows:

[0054] 0-valve block, 1-first reversing valve pressure sensor, 2-first pressure oil port, 3-second reversing valve pressure sensor, 4-second pressure oil port, 5-two-position four-way electromagnetic reversing valve, 6-total oil inlet, 7-first gear shifting proportional electromagnetic valve, 8-second gear shifting proportional electromagnetic valve, 9-first gear selecting proportional electromagnetic valve, 10-second gear selecting proportional electromagnetic valve, 11-oil tank, 12-first gear shifting pressure sensor, 13-second gear shifting pressure sensor, 14-gear shifting oil cylinder, 15-gear selecting oil cylinder, 16-first gear selecting pressure sensor, 17-second gear selecting pressure sensor, 18-position sensor, 19-gear shifting knob, 191-arc-shaped groove, 20-clamp ring, 21-pressure switch, 211-pressure contact, 22-gear shifting piston, 23-gear selecting piston, 24-gear shifting shaft, 25-gear selecting shaft. DETAILED DESCRIPTION

[0055] In order to make the advantages and characteristics of the utility model clearer, the utility model will be further described in detail below in combination with the drawings and specific embodiments.

[0056] Embodiment one

[0057] A multi-gear AMT valve block assembly for a tractor gearbox is used to implement five-gear and six-gear control, and comprises a valve block 0, a gear shifting control mechanism, a gear position state monitoring mechanism and a gear position control mechanism.

[0058] As shown in Figure 1 , Figure 2 , the gear shifting control mechanism comprises two gear shifting oil cylinders 14, two gear selecting oil cylinders 15 and a gear shifting knob 19 arranged in the valve block 0. The two gear shifting oil cylinders 14 are respectively provided with gear shifting pistons 22, and the two gear selecting oil cylinders 15 are respectively provided with gear selecting pistons 23. The space in the two gear shifting oil cylinders 14 containing the gear shifting pistons 22 forms a corresponding gear shifting piston cavity, and the space in the two gear selecting oil cylinders 15 containing the gear selecting pistons 23 forms a corresponding gear shifting piston cavity. The two gear shifting pistons 22 are coaxially fixedly connected through a gear shifting shaft 24, the two gear selecting pistons 23 are coaxially fixedly connected through a gear selecting shaft 25, the gear shifting shaft 24 is located above the gear selecting shaft 25, and the gear shifting shaft 24 and the gear selecting shaft 25 are arranged perpendicularly to each other.

[0059] As shown in Figure 3As shown, the upper end of the shift shaft 24 has a slot along the direction of movement of the select piston 23. The middle portion of the shift knob 19 is secured to the middle portion of the select shaft 25 via a retaining ring 20, with its upper end embedded in the slot of the shift shaft 24. The displacement direction of the shift piston 22 is defined as the X-axis, and the displacement direction of the select piston 23 is defined as the Y-axis. When the shift piston 22 moves along the X-axis, it drives the select piston 23 to rotate along the Y-axis via the shift knob 19, achieving gear shifting. Simultaneously, the shift knob 19 can slide along the slot, allowing it to follow the Y-axis displacement of the select piston 23. The lower end of the shift knob 19 is used to cooperate with the transmission's shift fork to shift gears.

[0060] like Figure 4 As shown, the gear control mechanism includes a first gear shift ratio solenoid valve 7, a second gear shift ratio solenoid valve 8, a first gear selection ratio solenoid valve 9, and a second gear selection ratio solenoid valve 10. A total oil inlet 6 connected to an external oil tank 11 is provided on the side wall of the valve block 0. The total oil inlet 6 is connected to the oil inlets of the first gear shift ratio solenoid valve 7, the second gear shift ratio solenoid valve 8, the first gear selection ratio solenoid valve 9, and the second gear selection ratio solenoid valve 10 through four oil circuits; the oil outlets of the first gear shift ratio solenoid valve 7 and the second gear shift ratio solenoid valve 8 are used to communicate with the two gear shift piston chambers respectively, and the oil outlets of the first gear selection ratio solenoid valve 9 and the second gear selection ratio solenoid valve 10 are used to communicate with the two gear selection piston chambers respectively, that is, the oil outlet of the first gear shift ratio solenoid valve 7 is connected to one gear shift ratio solenoid valve through one oil circuit. The oil outlet of the second shift proportional solenoid valve 8 is connected to another shift piston chamber via an oil circuit, the oil outlet of the first gear selection proportional solenoid valve 9 is connected to one gear selection piston chamber via an oil circuit, and the oil outlet of the second gear selection proportional solenoid valve 10 is connected to another gear selection piston chamber via an oil circuit. This is used to control the hydraulic pressure in the corresponding oil circuits through the first shift proportional solenoid valve 7 and the second shift proportional solenoid valve 8 to push the shift piston 22 to generate displacement, and to control the hydraulic pressure in the corresponding oil circuits through the first gear selection proportional solenoid valve 9 and the second gear selection proportional solenoid valve 10 to push the gear selection piston 23 to generate displacement. The oil return ports of the first shift proportional solenoid valve 7, the second shift proportional solenoid valve 8, the first gear selection proportional solenoid valve 9, and the second gear selection proportional solenoid valve 10 are respectively connected to the external oil tank 11 through corresponding oil circuits, so that the oil in the hydraulic system can flow back to the external oil tank 11.

[0061] In addition, the embodiment is provided with two-position four-way electromagnetic reversing valve 5, first reversing valve pressure sensor 1 and second reversing valve pressure sensor 3. The side wall of valve block 0 is further provided with first pressure oil port 2 and second pressure oil port 4 which are communicated with other mechanisms of external gearbox, the oil inlet of two-position four-way electromagnetic reversing valve 5 is communicated with total oil inlet 6 through corresponding oil path, and the two oil outlets are respectively communicated with first pressure oil port 2 and second pressure oil port 3 through corresponding oil path. First reversing valve pressure sensor 1 is installed on the oil path between two-position four-way electromagnetic reversing valve 5 and first pressure oil port 2, and second reversing valve pressure sensor 3 is installed on the oil path between two-position four-way electromagnetic reversing valve 5 and second pressure oil port 4, for monitoring the pressure state of the corresponding oil path respectively. The oil return port of two-position four-way electromagnetic reversing valve 5 is communicated with external oil tank 11 through corresponding oil path.

[0062] Gear state monitoring mechanism includes first gear shifting pressure sensor 12, second gear shifting pressure sensor 13, first gear selection pressure sensor 16, second gear selection pressure sensor 17, position sensor 18 and pressure switch 21. First gear shifting pressure sensor 12 is installed on the oil path between first gear shifting proportional electromagnetic valve 7 and corresponding gear shifting piston cavity, second gear shifting pressure sensor 13 is installed on the oil path between second gear shifting proportional electromagnetic valve 8 and corresponding gear shifting piston cavity, first gear selection pressure sensor 16 is installed on the oil path between first gear selection proportional electromagnetic valve 9 and corresponding gear selection piston cavity, and second gear selection pressure sensor 17 is installed on the oil path between second gear selection proportional electromagnetic valve 10 and corresponding gear selection piston cavity, for monitoring the pressure of the corresponding oil path through first gear shifting pressure sensor 12, second gear shifting pressure sensor 13, first gear selection pressure sensor 16 and second gear selection pressure sensor 17 respectively, and then realizing the monitoring of gear state.

[0063] Position sensor 18 is used for monitoring the displacement of gear shifting piston 22, and in the embodiment, position sensor 18 includes Hall sensor arranged on valve block 0 and magnetic steel arranged on gear shifting shaft 24, when magnetic steel follows gear shifting shaft 24 to produce displacement in X axis direction, Hall sensor determines the position of gear shifting piston 22 according to the change of received magnetic field.

[0064] The side wall of the shift knob 19 corresponding to the movement direction of the shift piston 22 is provided with an arc-shaped slot 191, and the pressure switch 21 is installed on the valve block 0, with the pressure contact 211 embedded in the arc-shaped slot 191 of the shift knob 19. When the shift piston 23 is displaced in the Y-axis direction, the shift knob 19 is also synchronously displaced in the Y-axis direction. At this time, the pressure contact 211 of the pressure switch 21 will be in contact with one side of the arc-shaped slot 191 of the shift knob 19, so that the pressure switch 21 completes the monitoring of the movement state of the shift piston 23. When the state of the pressure switch 21 is 0-1-0, it indicates that the pressure switch 21 is triggered, wherein 0 indicates that the switch is off, 1 indicates that the switch is on, and 0-1-0 indicates that the pressure switch 21 is triggered and the final state is off.

[0065] As shown in Figure 5 , a gear position diagram for realizing five-gear control in the embodiment is shown. The position of the shift piston 23 after being displaced in the negative direction of the Y-axis is recorded as the gate 1 position, the position of the shift piston 23 when no displacement occurs is recorded as the gate 2 position, and the position of the shift piston 23 after being displaced in the positive direction of the Y-axis is recorded as the gate 3 position. At the same time, the position of the shift piston 22 after being displaced in the positive direction of the X-axis is recorded as the low gear position, the position of the shift piston 22 when no displacement occurs is recorded as the neutral gear position, and the position of the shift piston 22 after being displaced in the negative direction of the X-axis is recorded as the high gear position.

[0066] When the shift piston 23 is displaced to the gate 1 position and the shift piston 22 is displaced to the low gear position, the gear position state is synchronizer 1 gear; when the shift piston 23 is displaced to the gate 1 position and the shift piston 22 is displaced to the high gear position, the gear position state is synchronizer 2 gear; when the shift piston 23 is displaced to the gate 2 position and the shift piston 22 is displaced to the low gear position, the gear position state is synchronizer 3 gear; when the shift piston 23 is displaced to the gate 2 position and the shift piston 22 is displaced to the high gear position, the gear position state is synchronizer 4 gear; when the shift piston 23 is displaced to the gate 3 position and the shift piston 22 is displaced to the low gear position, the gear position state is synchronizer 5 gear; in addition, as long as the shift piston 22 is displaced to the neutral gear position, the gear position state is synchronizer neutral gear. The specific steps of gear engagement are as follows:

[0067] (1) Synchronizer neutral gear: the first shift proportional solenoid valve 7 and the second shift proportional solenoid valve 8 are respectively applied with control current, and a pressure difference is formed on the outside of the two shift oil cylinders 14, which pushes the shift piston 22 to move to the neutral gear position. If the monitoring values of the first shift pressure sensor 12 and the second shift pressure sensor 13 are respectively consistent with the corresponding neutral gear pressure target values, and the monitoring value of the position sensor 18 is consistent with the corresponding neutral gear position target value, it indicates that the gear position state is neutral gear.

[0068] (2) Synchronizer 1st gear: First, a control current is applied to the second gear selection proportional solenoid valve 10, and pressure is generated inside the gear selection cylinder 15 connected to the oil outlet of the second gear selection proportional solenoid valve 10, pushing the gear selection piston 23 to the door 1 position. If the monitoring value of the second gear selection pressure sensor 17 is consistent with its corresponding door 1 pressure target value, the pressure switch 21 is triggered, indicating that the gear selection state is door 1. Then, a control current is applied to the second shift proportional solenoid valve 8, and pressure is generated inside the shift cylinder 14 connected to the oil outlet of the second shift proportional solenoid valve 8, pushing the shift piston 22 to the low gear position. At this time, the shift head 19 rotates around the Y axis, pushing the shift fork in the tractor gearbox to move, completing the gear shift. If the monitoring value of the second shift pressure sensor 13 is consistent with its corresponding low gear pressure target value, and the monitoring value of the position sensor 18 is consistent with its corresponding low gear position target value, it indicates that the gear state is synchronizer 1st gear.

[0069] (3) Synchronizer 2nd gear: First, a control current is applied to the second gear selection proportional solenoid valve 10, and pressure is generated inside the gear selection cylinder 15 connected to the oil outlet of the second gear selection proportional solenoid valve 10, pushing the gear selection piston 23 to the door 1 position. If the monitoring value of the second gear selection pressure sensor 17 is consistent with its door 1 pressure target value, the pressure switch 21 is triggered, indicating that the gear selection state is door 1. Then, a control current is applied to the first shift proportional solenoid valve 7, and pressure is generated inside the shift cylinder 14 connected to the oil outlet of the first shift proportional solenoid valve 7, pushing the shift piston 22 to the high gear position. At this time, the shift knob 19 rotates around the Y axis, pushing the shift fork in the tractor gearbox to move, completing the gear shift. If the monitoring value of the first shift pressure sensor 12 is consistent with its corresponding high gear pressure target value, and the monitoring value of the position sensor 18 is consistent with its corresponding high gear position target value, it indicates that the gear state is synchronizer 2nd gear.

[0070] (4) Synchronizer 3rd gear: First, control current is applied to the first gear selection proportional solenoid valve 9 and the second gear selection proportional solenoid valve 10 respectively. A pressure difference will be formed on the outside of the two gear selection cylinders 15, pushing the gear selection piston 23 to the door 2 position. If the monitoring values ​​of the first gear selection pressure sensor 16 and the second gear selection pressure sensor 17 are consistent with their corresponding pressure target values, the pressure switch 21 will not be triggered, indicating that the gear selection state is door 2. Then, control current is applied to the second shift proportional solenoid valve 8. Pressure is generated inside the shift cylinder 14 connected to the oil outlet of the second shift proportional solenoid valve 8, pushing the shift piston 22 to the low gear position. At this time, the shift head 19 rotates around the Y axis, pushing the shift fork in the tractor gearbox to move, completing the gear shift. If the monitoring value of the second shift pressure sensor 13 is consistent with its corresponding low gear pressure target value, and the monitoring value of the position sensor 18 is consistent with its corresponding low gear position target value, it indicates that the gear state is synchronizer 3rd gear.

[0071] (5) Synchronizer 4: First, the first and second selection proportional solenoid valves 9 and 10 are respectively applied with control current, and the outside of the two selection oil cylinders 15 will form a pressure difference, pushing the selection piston 23 to move to the door 2 position. If the monitoring value of the first selection pressure sensor 16 and the second selection pressure sensor 17 is consistent with the corresponding pressure target value, the pressure switch 21 will not be triggered, indicating that the selection position is door 2. Then the first shift proportional solenoid valve 7 is applied with control current, and the inside of the shift oil cylinder 14 connected with the oil outlet of the first shift proportional solenoid valve 7 forms pressure, pushing the shift piston 22 to move to the high gear position, at this time the shift knob 19 rotates around the Y axis, pushing the shift fork in the tractor gearbox to move, completing the gear shifting. If the monitoring value of the first shift pressure sensor 12 is consistent with the corresponding high gear pressure target value, and the monitoring value of the position sensor 18 is consistent with the corresponding high gear position target value, it indicates that the gear position is synchronizer 4.

[0072] (6) Synchronizer 5: First, the first selection proportional solenoid valve 9 is applied with control current, and the inside of the selection oil cylinder 15 connected with the oil outlet of the first selection proportional solenoid valve 9 forms pressure, pushing the selection piston 23 to move to the door 3 position. If the monitoring value of the first selection pressure sensor 16 is consistent with the corresponding pressure target value, the pressure switch 21 is triggered, indicating that the selection position is door 3. Then the second shift proportional solenoid valve 8 is applied with control current, and the inside of the shift oil cylinder 14 connected with the oil outlet of the second shift proportional solenoid valve 8 forms pressure, pushing the shift piston 22 to move to the low gear position, at this time the shift knob 19 rotates around the Y axis, pushing the shift fork in the tractor gearbox to move, completing the gear shifting. If the monitoring value of the second shift pressure sensor 13 is consistent with the corresponding low gear pressure target value, and the monitoring value of the position sensor 18 is consistent with the corresponding low gear position target value, it indicates that the gear position is synchronizer 5.

[0073] The embodiment of the multi-gear AMT valve block assembly for tractor gearbox is used to realize six-gear control, and the selection piston 23 is displaced to the door 3 position, and the shift piston 22 is displaced to the high gear position, and the gear position is synchronizer 6.

[0074] Embodiment two

[0075] As Figure 6As shown, this embodiment shows a multi-speed AMT valve block assembly for a tractor transmission, used to control third and fourth gears. This embodiment differs from the first embodiment in that it has only one gear select cylinder 15. Accordingly, it has only the first gear select proportional solenoid valve 9 and the first gear select pressure sensor 16, but no second gear select proportional solenoid valve 10 and second gear select pressure sensor 17, for controlling third and fourth gears. In this embodiment, a gear select shaft 25 is attached to one end of the gear select piston 23 within the gear select cylinder 15, and a compression spring is interposed between the other end of the gear select piston 23 and the inner wall of the gear select piston cavity. The remaining structure of this embodiment is identical to that of the first embodiment.

[0076] Since a shift select piston 23 has only one oil inlet circuit, the pressure oil entering the shift select cylinder 15 can only push the shift select piston 23 to move in the positive direction of the Y axis. Therefore, the present invention pushes the shift select piston 23 to move in the negative direction of the Y axis by the spring force of the compression spring arranged between the shift select piston 23 and the inner wall of the shift select piston cavity.

[0077] like Figure 7 As shown, this is a schematic diagram of the gear positions for realizing four-gear control in this embodiment. The position of the gear selector piston 23 after negative displacement along the Y-axis is recorded as the door 1 position, and the position of the gear selector piston 23 after positive displacement along the Y-axis is recorded as the door 2 position. At the same time, the position of the shift piston 22 after positive displacement along the X-axis is recorded as the low-gear position, the position of the shift piston 22 when it is not displaced is recorded as the neutral position, and the position of the shift piston 22 after negative displacement along the X-axis is recorded as the high-gear position.

[0078] When there is no pressure oil in the selector cylinder 15, the selector piston 23 is displaced to the door 1 position under the spring force of the compression spring. If the shift piston 22 is displaced to the low gear position at this time, the gear state is synchronizer 1 gear; when the selector piston 23 is displaced to the door 1 position and the shift piston 22 is displaced to the high gear position, the gear state is synchronizer 2 gear; when pressure oil is introduced into the selector cylinder 15, the selector piston 23 is pushed to the door 2 position. If the shift piston 22 is displaced to the low gear position at this time, the gear state is synchronizer 3 gear; when the selector piston 23 is displaced to the door 2 position and the shift cylinder piston 22 is displaced to the high gear position, the gear state is synchronizer 4 gear; in addition, as long as the shift piston 22 is displaced to the neutral position, the gear state is synchronizer neutral. The specific steps for shifting gears are as follows:

[0079] (1) Synchronizer Neutral: Control current is applied to the first and second shift ratio solenoid valves 7 and 8, respectively. This creates a pressure differential on the outsides of the two shift cylinders 14, pushing the shift piston 22 to the neutral position. If the monitoring values ​​of the first and second shift pressure sensors 12 and 13 are consistent with their corresponding neutral pressure target values, and the monitoring value of the position sensor 18 is consistent with its corresponding neutral position target value, the gear position is in neutral.

[0080] (2) Synchronizer 1 : No control current is applied to the first gear selection proportional solenoid valve 9, and the gear selection piston 23 moves to the gate 1 position under the spring force of the compression spring. If the monitoring value of the first gear selection pressure sensor 16 is 0, the pressure switch is triggered, indicating that the gear selection position is gate 1. Then, a control current is applied to the second gear shifting proportional solenoid valve 8, and pressure is formed inside the gear shifting cylinder 14 connected to the oil outlet of the second gear shifting proportional solenoid valve 8, pushing the gear shifting piston 22 to move to the low gear position. At this time, the gear shifting knob 19 rotates around the Y axis, pushing the gear shifting yoke in the tractor gearbox to move, and the gear shifting is completed. If the monitoring value of the second gear shifting pressure sensor 13 is consistent with the low gear pressure target value corresponding thereto, and the monitoring value of the position sensor 18 is consistent with the low gear position target value corresponding thereto, it indicates that the gear position is synchronizer 1.

[0081] (3) Synchronizer 2 : No control current is applied to the first gear selection proportional solenoid valve 9, and the gear selection piston 23 moves to the gate 1 position under the spring force of the compression spring. If the monitoring value of the first gear selection pressure sensor 16 is 0, the pressure switch is triggered, indicating that the gear selection position is gate 1. Then, a control current is applied to the first gear shifting proportional solenoid valve 7, and pressure is formed inside the gear shifting cylinder 14 connected to the oil outlet of the first gear shifting proportional solenoid valve 7, pushing the gear shifting piston 22 to move to the high gear position. At this time, the gear shifting knob 19 rotates around the Y axis, pushing the gear shifting yoke in the tractor gearbox to move, and the gear shifting is completed. If the monitoring value of the first gear shifting pressure sensor 12 is consistent with the high gear pressure target value corresponding thereto, and the monitoring value of the position sensor 18 is consistent with the high gear position target value corresponding thereto, it indicates that the gear position is synchronizer 2.

[0082] (4) Synchronizer 3 : A control current is first applied to the first gear selection proportional solenoid valve 9, and pressure oil is introduced into the gear selection cylinder 15, pushing the gear selection piston 23 to move to the gate 2 position. If the monitoring value of the first gear selection pressure sensor 16 is consistent with the target value, the pressure switch is triggered, indicating that the gear selection position is gate 2. Then, a control current is applied to the second gear shifting proportional solenoid valve 8, and pressure is formed inside the gear shifting cylinder 14 connected to the oil outlet of the second gear shifting proportional solenoid valve 8, pushing the gear shifting piston 22 to move to the low gear position. At this time, the gear shifting knob 19 rotates around the Y axis, pushing the gear shifting yoke in the tractor gearbox to move, and the gear shifting is completed. If the monitoring value of the second gear shifting pressure sensor 13 is consistent with the low gear pressure target value corresponding thereto, and the monitoring value of the position sensor 18 is consistent with the low gear position target value corresponding thereto, it indicates that the gear position is synchronizer 3.

[0083] (5) Synchronizer 4th gear: first, the first gear selector proportional solenoid valve 9 is applied to the control current, the inside of the gear selector cylinder 15 is connected to the pressure oil, the gear selector piston 23 is pushed to move to the door 2 position. If the first gear selector pressure sensor 16 monitoring value is consistent with the target value, the pressure switch is triggered, indicating that the gear selection position is door 2. Then the first gear shift proportional solenoid valve 7 is applied to the control current, and the gear shift proportional solenoid valve 7 is connected to the oil outlet. The inside of the gear shift cylinder 14 forms a pressure, and the gear shift piston 22 is pushed to move to the high gear position. At this time, the gear shift knob 19 rotates around the Y axis, and the gear shift yoke in the tractor gearbox is pushed to move, and the gear shift is completed. If the monitoring value of the first gear shift pressure sensor 12 is consistent with the high gear pressure target value corresponding to the first gear shift pressure sensor 12, and the monitoring value of the position sensor 18 is consistent with the high gear position target value corresponding to the position sensor 18, it is indicated that the gear position is synchronizer 4th gear.

[0084] The above is only used to illustrate the technical scheme of the utility model, not to limit it. For ordinary professional technicians in the art, the specific technical scheme recorded in the above embodiment can be modified, or some technical features can be replaced. These modifications or replacements do not change the essence of the corresponding technical scheme out of the scope of the technical scheme protected by the utility model.

Claims

1. A multi-speed AMT valve block assembly for a tractor transmission, used to achieve fifth and sixth gear control, characterized by: It includes a valve block (0), a gear shift operating mechanism, a gear position control mechanism, and a gear position state monitoring mechanism; The shift operating mechanism comprises two shift oil cylinders (14), two gear selection oil cylinders (15) and a shift dial head (19) arranged in a valve block (0); The shift pistons (22) in the two shift oil cylinders (14) are coaxially fixedly connected via a shift shaft (24), and the shift selection pistons (23) in the two shift selection oil cylinders (15) are coaxially fixedly connected via a shift selection shaft (25); the shift shaft (24) is located above the shift selection shaft (25) and is arranged perpendicular to each other; The upper end of the shift shaft (24) is provided with a slot along the movement direction of the shift selection piston (23); The middle part of the shift head (19) is fixed to the middle part of the gear selection shaft (25), the upper end of which is embedded in the slot of the shift shaft (24) and can slide along the slot direction, and the lower end of which is used to cooperate with the shift fork of the tractor gearbox; The gear control mechanism comprises four proportional solenoid valves arranged on a valve block (0); A main oil inlet (6) communicating with an external oil tank (11) is provided on the side wall of the valve block (0). The main oil inlet (6) is communicated with the oil inlets of four proportional solenoid valves through four oil circuits. The oil outlets of two proportional solenoid valves are communicated with the piston chambers of corresponding shift oil cylinders (14) through oil circuits, and the oil outlets of the other two proportional solenoid valves are communicated with the piston chambers of corresponding shift oil cylinders (15) through oil circuits. The oil return ports of the four proportional solenoid valves are communicated with the external oil tank (11) through corresponding oil circuits. The gear state monitoring mechanism includes four pressure sensors, a position sensor (18) and a pressure switch (21); The four pressure sensors are respectively arranged in the oil circuits between the four proportional solenoid valves and the corresponding piston chambers to monitor the gear status; The position sensor (18) is used to monitor the displacement of the shift piston (22); An arcuate groove (191) is provided on a side wall of the shift head (19) corresponding to the movement direction of the shift piston (22); the pressure switch (21) is mounted on the valve block (0), and its pressure contact (211) is embedded in the arcuate groove (191) of the shift head (19) for monitoring the movement state of the shift piston (23).

2. The multi-speed AMT valve block assembly for a tractor transmission according to claim 1, characterized in that: It also includes a two-position four-way electromagnetic reversing valve (5), a first reversing valve pressure sensor (1), and a second reversing valve pressure sensor (3); The side wall of the valve block (0) is also provided with a first pressure oil port (2) and a second pressure oil port (4) which are communicated with other mechanisms of the external gearbox; The oil inlet of the two-position four-way electromagnetic reversing valve (5) is connected to the main oil inlet (6) through a corresponding oil circuit, and the two oil outlets thereof are respectively connected to the first pressure oil port (2) and the second pressure oil port (4) through corresponding oil circuits; The first reversing valve pressure sensor (1) is installed on the oil circuit between the two-position four-way electromagnetic reversing valve (5) and the first pressure oil port (2), and the second reversing valve pressure sensor (3) is installed on the oil circuit between the two-position four-way electromagnetic reversing valve (5) and the second pressure oil port (4), for respectively monitoring the pressure states of the corresponding oil circuits; The oil return port of the two-position four-way electromagnetic reversing valve (5) is connected to the external oil tank (11) through a corresponding oil circuit.

3. The multi-speed AMT valve block assembly for a tractor transmission according to claim 2, characterized in that: The position sensor (18) includes a Hall sensor arranged on the valve block (0) and a magnet arranged on the shift shaft (24).

4. The multi-speed AMT valve block assembly for a tractor transmission according to claim 3, characterized in that: The middle part of the shift dial head (19) is fixed to the middle part of the shift selection shaft (25) through a clamping ring (20).

5. A multi-speed AMT valve block assembly for a tractor transmission, used to achieve third and fourth gear control, characterized by: It includes a valve block (0), a gear shift operating mechanism, a gear position control mechanism, and a gear position state monitoring mechanism; The shift operating mechanism comprises two shift oil cylinders (14), a gear selection oil cylinder (15) and a shift dial head (19) arranged in a valve block (0); The shift pistons (22) in the two shift oil cylinders (14) are coaxially fixedly connected via a shift shaft (24); one end of the shift piston (23) in the shift selection oil cylinder (15) is provided with a shift shaft (25), and a compression spring is provided between the other end and the inner wall of the piston cavity of the shift selection oil cylinder (15); the shift shaft (24) is located above the shift shaft (25) and is arranged perpendicular to each other; The upper end of the shift shaft (24) is provided with a slot along the movement direction of the shift selection piston (23); The middle part of the shift head (19) is fixed to the middle part of the gear selection shaft (25), the upper end of which is embedded in the slot of the shift shaft (24) and can slide along the slot direction, and the lower end of which is used to cooperate with the shift fork of the tractor gearbox; The gear control mechanism comprises three proportional solenoid valves arranged on a valve block (0); A main oil inlet (6) communicating with an external oil tank (11) is provided on the side wall of the valve block (0). The main oil inlet (6) is communicated with the oil inlets of three proportional solenoid valves through three oil circuits. The oil outlets of two proportional solenoid valves are communicated with the piston chambers of corresponding shift oil cylinders (14) through oil circuits, and the oil outlet of another proportional solenoid valve is communicated with the piston chamber of a shift oil cylinder (15) through an oil circuit. The oil return ports of the three proportional solenoid valves are communicated with the external oil tank (11) through corresponding oil circuits. The gear state monitoring mechanism includes three pressure sensors, a position sensor (18) and a pressure switch (21); The three pressure sensors are respectively arranged in the oil circuits between the three proportional solenoid valves and the corresponding piston chambers to monitor the gear status; The position sensor (18) is used to monitor the displacement of the shift piston (22); An arcuate groove (191) is provided on a side wall of the shift head (19) corresponding to the movement direction of the shift piston (22); the pressure switch (21) is mounted on the valve block (0), and its pressure contact (211) is embedded in the arcuate groove (191) of the shift head (19) for monitoring the movement state of the shift piston (23).

6. The multi-speed AMT valve block assembly for a tractor transmission according to claim 5, characterized in that: It also includes a two-position four-way electromagnetic reversing valve (5), a first reversing valve pressure sensor (1), and a second reversing valve pressure sensor (3); The side wall of the valve block (0) is also provided with a first pressure oil port (2) and a second pressure oil port (4) which are communicated with other mechanisms of the external gearbox; The oil inlet of the two-position four-way electromagnetic reversing valve (5) is connected to the main oil inlet (6) through a corresponding oil circuit, and the two oil outlets thereof are respectively connected to the first pressure oil port (2) and the second pressure oil port (4) through corresponding oil circuits; The first reversing valve pressure sensor (1) is installed on the oil circuit between the two-position four-way electromagnetic reversing valve (5) and the first pressure oil port (2), and the second reversing valve pressure sensor (3) is installed on the oil circuit between the two-position four-way electromagnetic reversing valve (5) and the second pressure oil port (4), for respectively monitoring the pressure states of the corresponding oil circuits; The oil return port of the two-position four-way electromagnetic reversing valve (5) is connected to the external oil tank (11) through a corresponding oil circuit.

7. The multi-speed AMT valve block assembly for a tractor transmission according to claim 6, characterized in that: The position sensor (18) includes a Hall sensor arranged on the valve block (0) and a magnet arranged on the shift shaft (24).

8. The multi-speed AMT valve block assembly for a tractor transmission according to claim 7, characterized in that: The middle part of the shift dial head (19) is fixed to the middle part of the shift selection shaft (25) through a clamping ring (20).

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