AMT gearbox capable of shifting without power interruption and control method thereof

Abstract

The invention discloses an AMT gearbox capable of shifting gears without power interruption. The AMT gearbox comprises a driving motor, a gear shifting mechanism and a gear shifting mechanism, one end of the input shaft is connected with the output end of the driving motor; the friction plate type clutch is arranged at the other end of the input shaft; the first-gear driving gear is fixedly arranged on the input shaft in a sleeving manner; the second-gear driving gear is hollowly sleeved on the input shaft; an output shaft; the first-gear driven gear is hollowly sleeved on the output shaft and is meshed with the first-gear driving gear; the second-gear driven gear is fixedly arranged on the output shaft in a sleeving manner and is meshed with the second-gear driving gear; an outer ring of the one-way overrunning clutch is fixedly connected with the first-gear driven gear, and an inner ring of the one-way overrunning clutch fixedly sleeves the output shaft; the jaw clutch is axially arranged on the output shaft in a sliding and sleeving manner and can be connected with the first-gear driven gear in an embedded manner; a half shaft; the differential mechanism is fixedly arranged on the half shaft in a sleeving mode and connected with the output shaft through a reduction gear. The invention further discloses a control method of the AMT gearbox capable of shifting gears without power interruption.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gearboxes, and particularly relates to an AMT gearbox with power interruption-free shifting and a control method thereof. BACKGROUND

[0002] With the increasingly severe global energy crisis and environmental problems, pure electric vehicles have become an important direction for the transformation of the automobile industry. As the core component of electric vehicles, the efficiency of the electric drive system directly affects the power and economy of the vehicle. Most electric vehicles on the market currently use fixed-ratio reducers, which are simple in structure, but it is difficult to keep the drive motor running efficiently under all operating conditions, especially when driving at high or low speeds. Energy utilization efficiency is significantly reduced, which restricts the vehicle's range and power performance.

[0003] To solve this problem, the two-gear automatic transmission (such as power interruption-free AMT, I-AMT) scheme has gradually attracted attention. This structure can make the drive motor always work in the high-efficiency interval by switching the gear ratio, reducing the power consumption by 5% to 10%, and reducing the demand for motor power and the cost of the vehicle. However, the friction plate clutch in the I-AMT will shift during long-term use due to factors such as friction plate wear and diaphragm spring fatigue, resulting in power interruption, jerk, or misalignment during shifting, which seriously affects the driving experience and the service life of the gearbox.

[0004] In the prior art, the self-learning of AMT focuses on static position calibration, lacks real-time adaptive compensation mechanism for dynamic wear, and the learning strategy does not fully consider the characteristics of power interruption-free shifting, making it difficult to accurately capture the shift amount of the clutch key working point. Therefore, developing a clutch position self-learning technology suitable for electric vehicle power interruption-free AMT to realize dynamic identification and compensation of the slip point and full engagement point has become a key to improving the performance of the gearbox. SUMMARY

[0005] The purpose of the present application is to provide an AMT gearbox with power interruption-free shifting, which can ensure power interruption-free shifting during shifting and improve driving smoothness.

[0006] The purpose of the present application is to provide a control method for an AMT gearbox with power interruption-free shifting, which can dynamically compensate for the position shift caused by clutch wear, ensure shifting accuracy, and prolong the service life of the clutch.

[0007] The technical scheme provided by the present application is as follows:

[0008] An AMT gearbox with power interruption-free shifting comprises:

[0009] drive motor;

[0010] input shaft, one end of which is connected to the output end of the drive motor;

[0011] friction plate clutch, which is arranged at the other end of the input shaft;

[0012] one-gear driving gear, which is fixedly sleeved on the input shaft;

[0013] two-gear driving gear, which is loosely sleeved on the input shaft;

[0014] output shaft, which is arranged in parallel to the input shaft;

[0015] one-gear driven gear, which is loosely sleeved on the output shaft and is engaged with the one-gear driving gear;

[0016] two-gear driven gear, which is fixedly sleeved on the output shaft and is engaged with the two-gear driving gear;

[0017] one-way overrunning clutch, the outer ring of which is fixedly connected with the one-gear driven gear, and the inner ring of which is fixedly sleeved on the output shaft;

[0018] jaw clutch, which is axially slidably sleeved on the output shaft and can be engaged with the one-gear driven gear;

[0019] half shaft, both ends of which are connected with wheels;

[0020] differential, which is fixedly sleeved on the half shaft and is connected with the output shaft through a reduction gear.

[0021] Preferably, the friction plate clutch comprises a driving part and a driven part, and the driving part of the friction plate clutch is fixedly connected with the other end of the input shaft.

[0022] Preferably, the application further comprises:

[0023] loosely sleeved shaft, which is loosely sleeved on the input shaft; one end of the loosely sleeved shaft is fixedly connected with the two-gear driving gear, and the other end is fixedly connected with the driven part of the friction plate clutch.

[0024] Preferably, the reduction gear comprises:

[0025] main reduction gear, which is fixedly sleeved on the output shaft;

[0026] secondary reduction gear, which is loosely sleeved on the half shaft and is engaged with the main reduction gear; the secondary reduction gear is fixedly connected with the differential.

[0027] Preferably, a plurality of tooth grooves are evenly distributed on the first gear driven gear; the dog clutch is provided with teeth corresponding to the positions of the tooth grooves; the first gear driven gear is connected with the dog clutch through the tooth grooves and the teeth; the number of the tooth grooves and the teeth is 6.

[0028] Preferably, further comprising:

[0029] The clutch actuator comprises:

[0030] The direct current motor is connected with the friction plate clutch through a worm-gear-linkage transmission mechanism and a yoke, and is used to drive the friction plate clutch to combine or separate;

[0031] An angle sensor is arranged on the worm-gear-linkage transmission mechanism, and is used to monitor the position of the friction plate clutch.

[0032] Preferably, a gearbox control unit comprises: a clutch actuator controller which controls the clutch actuator; the gearbox control unit receives the signal of the angle sensor and outputs a PWM control instruction to the clutch actuator.

[0033] A control method of an AMT gearbox with power interruption shifting comprises:

[0034] When the gearbox is in the first gear, the dog clutch is separated from the first gear driven gear, the friction plate clutch is in a separated state, and the one-way overrunning clutch is in a combined state; power is transmitted from the driving motor to the first gear driving gear, and then transmitted to the half shaft through the first gear driven gear, the one-way overrunning clutch, the output shaft, the reduction gear and the differential, to drive the wheels to run;

[0035] When the gearbox is in the second gear, the dog clutch is separated from the first gear driven gear, the friction plate clutch is in a combined state, and the one-way overrunning clutch is in an overrunning state; power is transmitted from the driving motor to the friction plate clutch, and then transmitted to the half shaft through the idle shaft, the second gear driving gear, the second gear driven gear, the output shaft, the reduction gear and the differential, to drive the wheels to run;

[0036] When the gearbox is in the reverse gear, the dog clutch is combined with the first gear driven gear, the friction plate clutch is in a separated state, and the one-way overrunning clutch is in an overrunning state; power is transmitted from the driving motor to the first gear driving gear, and then transmitted to the half shaft through the first gear driven gear, the dog clutch, the output shaft, the reduction gear and the differential, to drive the wheels to run.

[0037] Preferably, it further comprises: updating the starting point and the ending point of the friction plate clutch combination in the shifting process through the clutch self-learning algorithm, ensuring that the gearbox has no power interruption in the shifting process, and the clutch self-learning comprises:

[0038] Step one: after the vehicle is powered on, the gearbox control unit initializes and reads the historical self-learning results of the friction plate clutch; the clutch actuator controls the friction plate clutch to be in a separated state;

[0039] Step two: the gearbox control unit determines whether the clutch self-learning condition and the shifting trigger condition are met through the state parameters of the vehicle and the driver's operation instructions;

[0040] Step three: when the vehicle is detected to be in reverse gear, the slip point self-learning of the friction plate clutch is started, and after the learning is completed, the learning results of the slip point self-learning are recorded, and the gearbox enters the reverse gear; when the gearbox is detected to be in gear one to gear two, the complete combination point self-learning of the friction plate clutch is started, and after the learning is completed, the learning results of the complete combination point self-learning are recorded, and the gearbox still operates in gear two;

[0041] Step four: according to the learning results of the slip point self-learning and the complete combination point self-learning, the parameters in the clutch actuator controller and the control of the friction plate clutch are adjusted to compensate for the errors caused by wear.

[0042] Preferably, the PWM control instruction output by the clutch actuator controller to the clutch actuator is:

[0043] x1=y m

[0044]

[0045] In the formula, x1, x2, and x3 are state variables of the clutch actuator controller; is the derivative of the state variable x2; is the derivative of the state variable x3; y m is the expected angle of the short rocker arm of the clutch actuator; is the expected angular velocity of the short rocker arm of the clutch actuator; Z1 is the number of worm heads; Z2 is the number of turbine teeth; μ is the transmission efficiency of the turbine worm-rod transmission mechanism; K m1 is the torque constant of the DC motor; K e is the back electromotive force constant of the DC motor; J1 is the rotational inertia of the short rocker arm; J3 is the rotational inertia of the long rocker arm; f(x1) is the rotational angle of the long rocker arm; F[ bXΔf(x1) is the force of the shift fork acting on the top rod; Δf(x1) is the rotation angle difference of the long swing arm; m is the output PWM duty ratio of the clutch actuator DC motor; u is the input voltage of the DC motor; v r The pressure drop of the armature circuit resistance; L is the total inductance of the armature circuit.

[0046] The beneficial effects of the present application are:

[0047] The AMT gearbox without power interruption shifting provided by the application can ensure no power interruption during shifting process through the cooperation of the friction plate clutch, one-way overrunning clutch and interlocking clutch, and improve driving smoothness.

[0048] The control method of the AMT gearbox without power interruption shifting provided by the application designs a clutch actuator controller, which can dynamically compensate the position deviation caused by clutch wear, ensure shifting accuracy and prolong clutch life. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The structure schematic diagram of the AMT gearbox without power interruption shifting.

[0050] Figure 2 The power transmission schematic diagram of the first gear of the AMT gearbox without power interruption shifting.

[0051] Figure 3 The power transmission schematic diagram of the second gear of the AMT gearbox without power interruption shifting.

[0052] Figure 4 The power transmission schematic diagram of the reverse gear of the AMT gearbox without power interruption shifting.

[0053] Figure 5 The structure schematic diagram of the friction plate clutch and clutch actuator.

[0054] Figure 6 The cross-sectional schematic diagram of the clutch actuator.

[0055] Figure 7 The structure diagram of the connecting relationship of the connecting rod.

[0056] Figure 8 The cross-sectional schematic diagram of the friction plate clutch.

[0057] Figure 9 The TCU control flowchart.

[0058] Figure 10 The sliding point self-learning flowchart.

[0059] Figure 11 The complete binding point self-learning flowchart of the invention.

[0060] Figure 12 The clutch actuator controller control chart of the invention.

[0061] Figure 13 The torque and speed diagram of the AMT gearbox upshift of the invention without power interruption.

[0062] Figure 14 The torque and speed diagram of the AMT gearbox downshift of the invention without power interruption.

[0063] Figure: drive motor 110, input shaft 120, output shaft 130, half shaft 140, empty shaft 150, first gear driving gear 210, first gear driven gear 220, second gear driving gear 310, second gear driven gear 320, main reduction gear 410, from reduction gear 420, differential 430, one-way overrunning clutch 510, jaw clutch 610, friction plate clutch 710, clutch outer hub 711, upper pressure plate 712, lower pressure plate 713, pressure plate 714, diaphragm spring 715, steel sheet 716, friction plate 717, thrust bearing 718, separating bearing 719, DC motor 720, fan turbine 731, worm 732, center gear 733, sensor reduction gear 734, short rocker arm 735, pull rod 736, long rocker arm 737, clutch rocker arm 738, yoke 739, jacking rod 741, jacking rod sleeve 742. DETAILED DESCRIPTION

[0064] The invention will be further described in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0065] As Figure 1As shown, the application provides a power-off interrupt gear shifting AMT gearbox, which comprises: a driving motor 110; an input shaft 120, one end of which is connected with the output end of the driving motor 110 through a spline; a friction plate clutch 710, which comprises a driving part and a driven part, the driving part is fixedly connected with the other end of the input shaft 120; in this embodiment, the friction plate clutch 710 is a normally closed wet clutch; a first gear driving gear 210, which is fixedly sleeved on the input shaft 120; a second gear driving gear 310, which is loosely sleeved on the input shaft 120; a loose sleeve shaft 150, which is loosely sleeved on the input shaft 120; one end of the loose sleeve shaft 150 is fixedly connected with the second gear driving gear 310, and the other end is fixedly connected with the driven part of the friction plate clutch 710; an output shaft 130, which is arranged parallel to the input shaft 120; a first gear driven gear 220, which is loosely sleeved on the output shaft 130 and engaged with the first gear driving gear 210; a plurality of tooth grooves are uniformly distributed on the first gear driven gear 220; a second gear driven gear 320, which is fixedly sleeved on the output shaft 130 and engaged with the second gear driving gear 310; a one-way overrunning clutch 510, the outer ring of which is fixedly connected with the first gear driven gear 220, and the inner ring is fixedly connected and fixedly sleeved on the output shaft 130 through a flat key; a jaw clutch 610, which is sleeved on the output shaft 130 through a rectangular spline, the jaw clutch 610 can rotate with the output shaft 130 or axially slide on the output shaft 130; the jaw clutch 610 is provided with teeth corresponding to the positions of the tooth grooves, the first gear driven gear 220 is engaged and connected with the jaw clutch 610 through the cooperation of the tooth grooves and the teeth; in this embodiment, the number of the tooth grooves and the teeth is 6; a half shaft 140, both ends of which are connected with wheels; a reduction gear comprises: a main reduction gear 410, which is fixedly sleeved on the output shaft 130; a slave reduction gear 420, which is loosely sleeved on the half shaft 140 and engaged with the main reduction gear 410; a differential 430, which is fixedly sleeved on the half shaft 140 and fixedly connected with the slave reduction gear 420; the differential 430 is connected with the output shaft 130 through the reduction gear.

[0066] As Figure 2As shown in the figure, the power transmission of the one gear of the AMT gearbox with power interruption shifting of the application is: when the gearbox is in the first gear, the jaw clutch 610 is separated from the first driven gear 220, the friction plate clutch 710 is in the separated state, and the one-way overrunning clutch 510 is in the combined state; the power is transmitted from the driving motor 110 to the first driven gear 210 through the input shaft 120, and then transmitted to the half shaft 140 through the first driven gear 220, the one-way overrunning clutch 510, the output shaft 130, the reduction gear and the differential 430, driving the wheels to run.

[0067] As shown in the figure, Figure 3 As shown in the figure, the power transmission of the one gear of the AMT gearbox with power interruption shifting of the application is: when the gearbox is in the first gear, the jaw clutch 610 is separated from the first driven gear 220, the friction plate clutch 710 is in the separated state, and the one-way overrunning clutch 510 is in the combined state; the power is transmitted from the driving motor 110 to the first driven gear 210 through the input shaft 120, and then transmitted to the half shaft 140 through the first driven gear 220, the one-way overrunning clutch 510, the output shaft 130, the reduction gear and the differential 430, driving the wheels to run.

[0068] As shown in the figure, Figure 4 As shown in the figure, the power transmission of the one gear of the AMT gearbox with power interruption shifting of the application is: when the gearbox is in the first gear, the jaw clutch 610 is separated from the first driven gear 220, the friction plate clutch 710 is in the separated state, and the one-way overrunning clutch 510 is in the combined state; the power is transmitted from the driving motor 110 to the first driven gear 210 through the input shaft 120, and then transmitted to the half shaft 140 through the first driven gear 220, the one-way overrunning clutch 510, the output shaft 130, the reduction gear and the differential 430, driving the wheels to run.

[0069] As shown in the figure, Figures 5-7As shown, the present application provides a power-off interrupt gear shifting AMT gearbox, further comprising: a clutch actuator for controlling the engagement and disengagement of the friction plate clutch 710; the clutch actuator comprises: a DC motor 720 responsible for driving the friction plate clutch 710 to engage or disengage, achieving precise semi-linkage control through the instructions of the gearbox control unit; a yoke 739; a top rod 741, one end of which is in contact with the yoke 739; a top rod sleeve 742, which is arranged in the friction plate clutch 710 and connected with the other end of the top rod 741; a worm-gear-linkage transmission mechanism for connecting the DC motor 720 and the friction plate clutch 710; the worm-gear-linkage transmission mechanism comprises: a worm 732 connected with the output end of the DC motor 720; a sector turbine 731 cooperatively driven with the worm 732; a center gear 733 synchronously rotating with the sector turbine 731; the number of teeth of the center gear 733 is less than that of the sector turbine 731; a sensor reduction gear 734 meshing with the center gear 733; a short rocker arm 735, one end of which is connected with the center gear 733 and the other end of which is connected with the sector turbine 731, the angle of the short rocker arm 735 being changed through the rotation of the sector turbine 731; a pull rod 736, a long rocker arm 737, and a clutch rocker arm 738, which are sequentially arranged between the short rocker arm 735 and the yoke 739; an angle sensor arranged on the sensor reduction gear 734 for monitoring the position of the friction plate clutch 710, so as to determine whether the friction plate clutch 710 is completely engaged or disengaged.

[0070] The armature circuit voltage balance equation and the torque balance equation of the DC motor 720 are respectively:

[0071]

[0072] In the formula, e is the induced electromotive force of the DC motor, V; K e is the back electromotive force constant of the DC motor, V / rad / s; θ is the rotation angle of the DC motor, rad; u is the input voltage of the DC motor, V; v r is the voltage drop of the armature circuit resistance, V; L is the total inductance of the armature circuit, H; i is the armature circuit current, A; K m1 is the torque constant of the DC motor, N·m / A; T m1 is the output torque of the DC motor, N·m; T f is the torque of the friction loss of the DC motor, N·m; J d is the moment of inertia of the DC motor, Kg·㎡.

[0073] The conversion formula of the output torque of the DC motor 720 to the worm-gear output torque is:

[0074]

[0075] Where T′ m1 is the output torque of the worm gear, N·m; μ is the transmission efficiency of the worm gear-connecting rod transmission mechanism; Z1 is the number of worm gear heads; Z2 is the number of worm teeth.

[0076] The angular relationship between the connecting rods is as follows:

[0077] l3·sinθ3=l1·cosθ1+l2·sinθ2

[0078] l4=l2·cosθ2+l3·cosθ3-l1·sinθ1

[0079] Wherein, l1 is the length of the short rocker arm, mm; l2 is the length of the pull rod, mm; l3 is the length of the long rocker arm, mm; l4 is the straight-line distance, mm; θ1 is the rotation angle of the short rocker arm; θ2 is the rotation angle of the pull rod; θ3 is the rotation angle of the long rocker arm.

[0080] When the clutch actuator is working, the torque is transmitted by the DC motor 720 to the turbine and the worm 732, driving the short rocker arm 735 on the turbine to rotate around a fixed point. The short rocker arm 735 pulls the pull rod 736 to move approximately horizontally, thereby driving the long rocker arm 737 to swing. Since the shift fork shaft is fixed to the gearbox housing and can only rotate axially, and the shift fork shaft is fixedly connected to the long rocker arm 737 and the shift fork 739 respectively, the swing of the long rocker arm 737 will drive the shift fork shaft and the shift fork 739 to rotate, and the rotation angle of the shift fork 739 is exactly the same as that of the long rocker arm 737. In the actual control process of the friction plate clutch 710, the displacement of the friction plate clutch 710 is small, and the engagement and disengagement of the friction plate clutch 710 are achieved within a range of several millimeters. Therefore, the small-angle rotation of the shift fork 739 can be approximately regarded as a linear motion:

[0081] w b =l b ×tanθ3≈l b ×Δθ3=l b ×[f(θ1)-f(θ′1)]

[0082] f(θ1)=θ3

[0083] Where w b is the displacement distance of the shift fork, mm; l b is the length of the shift fork, mm; Δθ3 is the rotation angle of the long rocker arm during the clutch movement, rad; θ′1 is the final rotation angle of the short rocker arm.

[0084] Because the pull rod 736 has small mass, its moment of inertia can be ignored, and the moment balance equation of the turbine output torque to the top rod 741 is:

[0085]

[0086] In the formula, J1 is the moment of inertia of the short rocker arm; J3 is the moment of inertia of the long rocker arm; F(w b ) is the force of the shift fork acting on the top rod.

[0087] As shown in Figure 8 , the friction plate clutch 710 is composed of a clutch outer hub 711, an upper pressure plate 712, a lower pressure plate 713, a pressure plate 714, a diaphragm spring 715, a steel sheet 716, a friction plate 717, a thrust bearing 718, a separation bearing 719, and bolts, wherein the clutch outer hub 711 is fixedly connected with the loose sleeve shaft 150, the thrust bearing 718 is arranged between the clutch outer hub 711 and the upper pressure plate 712, so that the upper pressure plate 712 is fixed on the input shaft 120, a plurality of friction plates 717 and steel sheets 716 are arranged between the upper pressure plate 712 and the lower pressure plate 713, the pressure plate 714 is connected with the lower pressure plate 713 through bolts, and the diaphragm spring 715 is in a pre-tightening state, the friction plate 717 is compressed, and the friction plate clutch 710 can transmit power. When the friction plate clutch 710 is to be separated, the clutch actuator transmits force to the pressure plate 714 through the separation bearing 719, because the pressure plate 714 is fixedly connected with the lower pressure plate 713 and the upper pressure plate 712 is fixed on a shaft and cannot move axially, under the action of the thrust of the thrust bearing 718, the pressure plate 714 and the lower pressure plate 713 move rightward together, compress the diaphragm spring 715 to be elastically deformed, the distance between the upper pressure plate 712 and the lower pressure plate 713 increases, the friction plate 717 and the steel sheet 716 are no longer compressed, and the friction plate clutch 710 cannot transmit power.

[0088] As shown in Figure 9 , the power-free interrupt gear shifting AMT gearbox provided by the application further comprises a motor encoder arranged on the driving motor 110 and used for collecting the pulse number of the driving motor 110, a rotating speed sensor arranged on the output shaft 130 and used for collecting the rotating speed of the output shaft 130, and a gearbox control unit (TCU) comprising a clutch actuator controller, an output signal of which controls the clutch actuator, thereby controlling the combination or separation of the friction plate clutch 710, and the gearbox control unit receives the signals of the angle sensor, the motor encoder, and the rotating speed sensor and outputs a PWM control instruction to the clutch actuator.

[0089] The control method of the power-off interrupt shifting AMT gearbox provided by the application further comprises: updating the starting point and the ending point of the friction plate clutch 710 combination in the shifting process through the clutch self-learning algorithm to ensure that the gearbox has no power interruption during the shifting process; Step one: after the vehicle is powered on, the gearbox control unit is initialized and the historical self-learning result of the friction plate clutch 710 is read; the clutch actuator controls the friction plate clutch 710 to be in a separated state; Step two: the gearbox control unit determines whether the clutch self-learning condition and the shifting trigger condition are met through the state parameters of the vehicle and the driver's operation instruction; Step three: when it is detected that the vehicle is in the reverse gear, the sliding friction point self-learning of the friction plate clutch 710 is started, and after the learning is completed, the learning result of the sliding friction point self-learning is recorded, and the gearbox enters the reverse gear; when it is detected that the gearbox is shifted from the first gear to the second gear, the complete combination point self-learning of the friction plate clutch 710 is started, and after the learning is completed, the learning result of the complete combination point self-learning is recorded, and the gearbox still runs in the second gear; Step four: according to the learning result of the sliding friction point self-learning and the complete combination point self-learning, the parameters in the clutch actuator controller and the control of the friction plate clutch 710 are adjusted to compensate for the error caused by wear.

[0090] As shown in Figure 10 , the gearbox control unit detects that the vehicle is in the reverse gear, and the friction plate clutch 710 enters the clutch sliding friction point self-learning, and the process is as follows:

[0091] Step one: the clutch actuator controls the friction plate clutch 710 to combine a certain displacement, so that the combination degree of the friction plate clutch 710 at this time is greater than the sliding friction point; the driving motor 110 outputs the torque of the reverse 30% throttle opening for 0.1s; wherein, the actual torque output by the driving motor 110 according to the throttle opening is:

[0092] T m2 = Acc * T(n m2 )

[0093] In the formula, T m2 is the output torque of the driving motor; Acc is the throttle opening, n m2 is the driving motor speed; T(n m2 ) is the motor output torque corresponding to the motor speed n m2 on the external characteristic curve, which is obtained according to the driving motor model;

[0094] The linear displacement of the shift fork 739 is detected as the displacement of the clutch actuator controlling the combination of the friction plate clutch 710.

[0095] Step two, the motor encoder detects the pulse change of the drive motor 110, if no change, it means the friction plate clutch 710 has been combined.

[0096] Step three, the drive motor 110 outputs the torque of 20% ~ 25% of the throttle opening, and maintains for a maximum of 2s; At this time, there are two power transmission paths with different transmission ratios between the drive motor 110 and the outer circle of the one-way overrunning clutch 510, and they interfere with each other, so the drive motor 110 will be locked. At this time, the TCU will clear the motor pulse count received by the motor encoder and restart counting.

[0097] Step four, the clutch actuator controls the slow separation of the friction plate clutch 710, and the motor encoder continues to detect the number of pulses and the pulse increase speed of the drive motor 110.

[0098] Step five, if the number of pulses increases from 2 to 10 continuously within 2s, and the time for each increase of 2 pulses is less than 0.3s, the clutch slip point self-learning is successful, and the angle of the short rocker arm 735 of the friction plate clutch 710 when the number of pulses of the drive motor 110 is 2 is recorded as the slip point self-learning result; otherwise, the clutch slip point self-learning fails, and no self-learning result is recorded this time.

[0099] Step six, after the clutch slip point self-learning is successful or fails, exit the slip point self-learning, clear the torque of the DC motor 720, stop the movement of the friction plate clutch 710, and enter the reverse process.

[0100] Among them, there are three conditions for the end of clutch slip point self-learning, any one of which meets the clutch slip point self-learning end: one is that the clutch slip point self-learning is successful when the above pulse change condition is met; two is that the pulse number change does not meet the rule, and the time for the pulse number to decrease or increase by two pulses is more than 0.3s, then the clutch slip point self-learning fails, and the self-learning is exited when the pulse number increases to 20 as the friction plate clutch 710 separates, three is the time limit, whether the learning is successful or not, if the clutch slip point self-learning time exceeds two seconds, the clutch slip point self-learning is also exited. When the self-learning module is exited, the torque output by the drive motor 110 is cleared, the friction clutch stops moving, and the transmission enters the reverse process. When the clutch slip point self-learning is completed, the drive motor 110 will continue to rotate due to inertia, but since it is reversed, it cannot transmit power to the wheels through the one-way overrunning clutch 510, and the drive motor 110 will only idle slightly without changing the stationary state of the vehicle in N gear. Since the entire clutch slip point self-learning time is usually around 1.5s, it has little effect on responding to the driver's reverse gear instruction during actual driving, and it is within the acceptable range.

[0101] As shown in Figure 11 the friction plate clutch 710 enters the clutch fully engaged point self-learning after entering the second gear state 0.3s after the gearbox second gear upshift is completed, and the process is as follows:

[0102] Step one, record the initial position of the clutch actuator on the axis of the input shaft 120 and the initial angle of the short rocker arm 735 detected by the angle sensor, i.e. the second gear position.

[0103] Step two, the DC motor 720 outputs an initial PWM duty cycle that is very small and slowly and uniformly increases the torque, which is transmitted through the worm gear-link transmission mechanism, and the fork 739 starts to approach the top rod 741, and the actual position of the clutch actuator on the axis of the input shaft 120 and the actual angle of the short rocker arm 735 are detected in real time; in this embodiment, the DC motor 720 outputs a torque with an initial PWM duty cycle of 3% and an increase of 1% every 10 milliseconds.

[0104] Step three, when the difference between the actual position of the clutch actuator and the initial position reaches 0.3-0.9mm, the PWM is no longer increased; the torque of the DC motor 720 is maintained at the same size at this time and continues to act for a short time t, and since the resistance of the idle stroke is significantly smaller than the resistance of the friction plate clutch 710 separation, the torque of the DC motor 720 at this time will make the fork 739 and the top rod 741 close but cannot push the friction plate clutch 710 to separate, and the torque output is 0 after ts.

[0105] Step four, the motor PWM is cleared, and the actual angle of the short rocker arm 735 at this time is recorded as the learning result of the clutch fully engaged point self-learning.

[0106] Step five, exit the clutch fully engaged point self-learning, and the transmission continues to drive in the second gear state.

[0107] As shown in Figure 12 the clutch actuator controller is a PID controller, and the actual angle, angular velocity of the short rocker arm 735 and the real-time current of the DC motor 720 are used as state variables to obtain the system state equation:

[0108]

[0109] In the formula, x1, x2, x3 are state variables of the clutch actuator controller; is the derivative of state variable x2; is the derivative of state variable x3;

[0110] The short rocker arm is actually taken as the system output y, and the expected output is set as y m The PWM control instruction output by the clutch actuator controller to the clutch actuator is:

[0111] x1=y m

[0112]

[0113] In the formula, y m is the expected angle of the short rocker arm of the clutch actuator; is the expected angular velocity of the short rocker arm of the clutch actuator; f(x1) is the rotation angle of the long rocker arm; F[l b xΔf(x1)] is the force of the shift fork acting on the top rod; Δf(x1) is the rotation angle difference of the long rocker arm; m is the output PWM duty ratio of the clutch actuator DC motor;

[0114] The clutch actuator controller outputs a control signal to the clutch actuator, and the clutch actuator controls the short rocker arm 735 of the friction plate clutch 710 to rotate by a corresponding angle according to the control signal, realizes the combination or separation of the friction plate clutch 710, can dynamically compensate the position deviation caused by clutch wear, ensures the gear shifting precision, and prolongs the service life of the clutch.

[0115] As shown in Figures 13-14 , each module in Simscape is used to build a transmission and a vehicle model, each module is connected according to the transmission structure and the power transmission route, in this embodiment, the driving motor 110 is a 4KW three-phase alternating current asynchronous motor with a rated speed of 2500rpm, the DC motor 720 is an 80W DC brush motor, and the no-power interruption upshift simulation and the no-power interruption downshift simulation are performed.

[0116] As shown in Figure 13As shown, when the transmission is in the first gear state, the jaw clutch 610 is separated from the first driven gear 220 and rotates with the output shaft 130, the clutch actuator controls the friction clutch to be in the separated state; torque is transmitted from the driving motor 110 to the output shaft 130 through the first driving gear, the first driven gear 220 and the one-way overrunning clutch 510. When the speed sensor detects that the vehicle speed and the throttle opening degree meet the upshift condition, the clutch actuator controls the friction clutch 710 to start to be engaged, and at t1, the torque phase is entered, the speed of the hollow shaft gradually increases, and since the second gear has a smaller gear ratio, the speed of the output shaft 130 and the one-way overrunning clutch 510 connected to the output shaft 130 also increases, and since the speed of the inner and outer rings of the one-way overrunning clutch 510 is smaller and smaller, the torque transmitted by the one-way overrunning clutch 510 is smaller and smaller, and the torque transmitted by the friction clutch 710 is larger and larger, until the speed of the inner ring of the one-way overrunning clutch 510 exceeds that of the outer ring, at which time the rollers in the one-way overrunning clutch 510 are in a free state, and the one-way overrunning clutch 510 cannot transmit torque, and all the torque is transmitted by the friction clutch 710, and at t2, the upshift process enters the inertia phase, the friction clutch 710 continues to be engaged, the slip difference between the driving part and the driven part of the friction clutch 710 gradually decreases, the speed of the output shaft 130 and the inner ring of the one-way overrunning clutch 510 gradually increases, until the friction clutch 710 is completely engaged, and at t3, the speed sensor detects that the speed of the output shaft 130 is stable, which means that the transmission has completed the conversion from the first gear to the second gear, and Figure 13 It can be seen that the torque output by the output shaft 130 to the wheels is always not zero, which means that there is no power interruption during the upshift process.

[0117] As Figure 14As shown, when the transmission is in the second gear state, the jaw clutch 610 is separated from the first driven gear 220 and rotates with the output shaft 130, the clutch actuator controls the friction clutch to be in the engaged state; the one-way overrunning clutch 510 rotates clockwise and the inner ring rotates faster than the outer ring, no torque is transmitted, and all torque is transmitted by the friction clutch 710. When the speed sensor detects that the vehicle speed drops to the downshift speed, the clutch actuator controls the friction clutch 710 to start to separate, enters the inertia phase at t1, the friction clutch 710 starts to slip, the inner ring speed of the one-way overrunning clutch 510 gradually decreases but is always greater than the outer ring speed, the load of the drive motor 110 decreases, so the speed increases, until the inner ring speed of the one-way overrunning clutch 510 is equal to the outer ring speed, enters the torque phase at t2, the friction clutch 710 continues to separate, the slip difference between the driving part and the driven part of the friction clutch 710 gradually increases, the transmitted torque gradually decreases, the speed difference between the inner and outer rings of the one-way overrunning clutch 510 gradually increases, the transmitted torque gradually increases, at t3 the friction clutch 710 is completely separated, the transmission enters the first gear, and the downshift conversion is completed, and the output shaft 130 outputs torque to the wheels. Figure 14 It can be seen that the output shaft 130 outputs torque to the wheels all the time, which indicates that there is no power interruption during the downshift process.

[0118] The application provides an AMT gearbox without power interruption during gear shifting, wherein the gearbox is connected through a friction plate clutch, a one-way overrunning clutch and a jaw clutch, the power transmission path is seamlessly connected during gear shifting between the first gear and the second gear, the power interruption during gear shifting is avoided, and the driving smoothness is improved; during gear upshift, the friction plate clutch is gradually combined to transmit power, the one-way overrunning clutch automatically enters the overrunning state with the increase of the output shaft speed, and no power is transmitted, so that the power is continuously output; during gear downshift, the friction plate clutch is gradually separated, and the one-way overrunning clutch is automatically combined with the decrease of the output shaft speed to replace the power transmission. The simulation results show that the output shaft torque is always zero during gear upshift and gear downshift, the power interruption problem during gear shifting of the traditional AMT is completely solved, the jerk is avoided, and the driving comfort is improved; the parallel shaft layout of the input shaft, the output shaft and the half shaft is adopted, the gear meshing and the clutch combination are used to realize the functions of the first gear, the second gear and the reverse gear, and no additional reverse gear set is needed; the reverse gear is combined with the driven gear of the first gear through the jaw clutch, the power is reversely transmitted through the overrunning state of the one-way overrunning clutch, the structure is simplified, and the volume and the weight of the gearbox are reduced; the friction plate clutch adopts the normally closed wet type design, is matched with the turbine worm-rod transmission mechanism, has the characteristics of high efficient power transmission and precise control, the wet structure has good heat dissipation, reduces the friction plate wear, and prolongs the service life; the rigid connection of the gear and the clutch reduces the energy loss during power transmission; the power interruption feature avoids the power waste during gear shifting, the driving motor always works in the high efficient interval, and the driving motor is helpful to improve the cruising range of the electric vehicle.

[0119] The application provides a control method of an AMT gearbox with power interruption shifting, a clutch actuator controller is designed, which can dynamically compensate the position deviation caused by clutch wear, ensure the shifting accuracy, and prolong the service life of the clutch; when the gear is engaged or disengaged, the critical position of the friction plate clutch at which the power starts to be transmitted is determined by detecting the pulse change of the driving motor, and the sliding point deviation caused by wear is compensated; after the first gear is shifted to the second gear, the fully engaged position is determined by controlling the displacement change of the clutch actuator, so that the insufficient or over-tight engagement caused by wear is avoided; the self-learning result of the clutch is updated to the gearbox control unit (TCU) in real time, the control parameters are dynamically adjusted, and the defect that the traditional AMT static calibration cannot adapt to wear is solved; the TCU receives multi-source signals such as angle sensors, motor encoders and speed sensors, outputs PWM instructions through a PID controller, accurately controls the engagement or disengagement degree of the friction plate clutch, has fast response speed and small control error; the control logic covers all working conditions, and the stable operation of the system is ensured; the engagement or disengagement of the friction plate clutch is realized through linear control of the worm-turbine-linkage mechanism, rigid impact is avoided, and the wear of the friction plate is reduced; the self-learning algorithm of the clutch compensates the wear error in real time, avoids the slipping or sticking caused by the deviation of the engagement point, prolongs the service life of the clutch, reduces the maintenance frequency, the power transmission path of the first gear, the second gear and the reverse gear is clear, the state switching of the toothed clutch and the one-way overrunning clutch is realized, reliable switching of different gears is realized, and the requirements of vehicle starting, acceleration and reversing in multiple scenes are met; the control method responds quickly to the operation instruction of the driver, can automatically trigger the gear shifting according to the vehicle speed, load and other parameters, and takes into account the power and economy.

[0120] Although the embodiments of the application have been disclosed as above, they are not limited to the application listed in the specification and the embodiments, and can be fully applied to various fields suitable for the application, and additional modifications can be easily realized by those skilled in the art, therefore, the application is not limited to specific details and the figures shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. An AMT transmission with no power interruption shifting, characterized in that: include: Drive motor; an input shaft, one end of which is connected to the output end of the drive motor; a friction plate clutch, which is arranged at the other end of the input shaft; A first gear driving gear, which is fixedly sleeved on the input shaft; A second gear driving gear is loosely mounted on the input shaft; an output shaft disposed parallel to the input shaft; a first-gear driven gear, which is loosely mounted on the output shaft and meshes with the first-gear driving gear; A second-gear driven gear, which is fixedly sleeved on the output shaft and meshes with the second-gear driving gear; A one-way overrunning clutch, the outer ring of which is fixedly connected to the first gear driven gear, and the inner ring of which is fixedly sleeved on the output shaft; a dog clutch, which is axially slidably sleeved on the output shaft and can be engaged with the first gear driven gear; Axle shafts, whose ends are connected to the wheels; The differential is fixedly sleeved on the half shaft and connected to the output shaft through a reduction gear.

2. The AMT transmission with no power interruption shifting according to claim 1, characterized in that: The friction plate clutch includes an active part and a passive part. The active part of the friction plate clutch is fixedly connected to the other end of the input shaft.

3. The AMT transmission with no power interruption shifting according to claim 2, characterized in that: Also includes: An idler shaft is loosely sleeved on the input shaft; one end of the idler shaft is fixedly connected to the second-gear driving gear, and the other end is fixedly connected to the driven part of the friction plate clutch.

4. The AMT transmission with no power interruption shifting according to claim 1, characterized in that: The reduction gear comprises: A main reduction gear, which is fixedly sleeved on the output shaft; A slave reduction gear is loosely mounted on the half shaft and meshes with the main reduction gear; the slave reduction gear is fixedly connected to the differential.

5. The AMT transmission with no power interruption shifting according to claim 1, characterized in that: A plurality of tooth grooves are evenly distributed on the first-gear driven gear; the tooth clutch is provided with teeth at positions corresponding to the tooth grooves, and the first-gear driven gear is engaged and connected with the tooth clutch through the tooth grooves and the teeth; the number of the tooth grooves and the number of the teeth are both 6.

6. The AMT transmission with no power interruption shifting according to claim 1, characterized in that: Also includes: A clutch actuator, comprising: a DC motor connected to the friction plate clutch via a worm gear-connecting rod transmission mechanism and a shift fork, and used to drive the friction plate clutch to engage or disengage; An angle sensor is provided on the worm gear-connecting rod transmission mechanism and is used for monitoring the position of the friction plate clutch.

7. The AMT transmission with no power interruption shifting according to claim 6, characterized in that: The transmission control unit includes a clutch actuator controller for controlling the clutch actuator; the transmission control unit receives a signal from the angle sensor and outputs a PWM control instruction to the clutch actuator.

8. A control method for an AMT transmission with no power interruption shifting, for controlling the AMT transmission with no power interruption shifting according to any one of claims 1 to 7, characterized in that: include: When the gearbox is in first gear, the dog clutch is disengaged from the first gear driven gear, the friction plate clutch is in a disengaged state, and the one-way overrunning clutch is in an engaged state; power is transmitted from the drive motor to the first gear driving gear, and then transmitted to the half-shaft via the first gear driven gear, the one-way overrunning clutch, the output shaft, the reduction gear and the differential, thereby driving the wheels; When the transmission is in second gear, the dog clutch is disengaged from the first gear driven gear, the friction plate clutch is in an engaged state, and the one-way overrunning clutch is in an overrunning state; power is transmitted from the drive motor to the friction plate clutch, and then transmitted to the half-shafts via the idler shaft, the second gear driving gear, the second gear driven gear, the output shaft, the reduction gear and the differential, thereby driving the wheels; When the gearbox is in reverse gear, the dog clutch is engaged with the first gear driven gear, the friction plate clutch is in a disengaged state, and the one-way overrunning clutch is in an overrunning state; power is transmitted from the drive motor to the first gear driving gear, and then transmitted to the half-shaft via the first gear driven gear, the dog clutch, the output shaft, the reduction gear and the differential, thereby driving the wheels to move.

9. The control method of the AMT transmission with no power interruption shifting according to claim 8, characterized in that: Also includes: The clutch self-learning algorithm updates the starting and ending points of the friction plate clutch engagement during the shifting process to ensure that there is no power interruption during the gearshifting process. The clutch self-learning algorithm includes: Step 1: After the vehicle is powered on, the transmission control unit is initialized and reads the historical self-learning results of the friction plate clutch; The clutch actuator controls the friction plate clutch to be in a disengaged state; Step 2: The transmission control unit determines whether the clutch self-learning conditions and the shift triggering conditions are met based on the vehicle's state parameters and the driver's operation instructions; Step 3: When it is detected that the vehicle is engaged in reverse gear, the self-learning of the slip point of the friction plate clutch is started. After the learning is completed, the learning result of the slip point self-learning is recorded, and the gearbox enters reverse gear; when it is detected that the gearbox has completed the shift from first gear to second gear, the self-learning of the full engagement point of the friction plate clutch is started. After the learning is completed, the learning result of the full engagement point self-learning is recorded, and the gearbox still operates in second gear; Step 4: According to the learning results of the sliding point self-learning and the complete engagement point self-learning, adjust the parameters in the clutch actuator controller and the control of the friction plate clutch to compensate for the error caused by wear.

10. The control method of the AMT transmission with no power interruption shifting according to claim 9, characterized in that: The PWM control instruction output by the clutch actuator controller to the clutch actuator is: x1=y m Where x1, x2, and x3 are the state variables of the clutch actuator controller; is the derivative of the state variable x2; is the derivative of the state variable x3; y m is the desired angle of the short rocker arm of the clutch actuator; is the expected angular velocity of the short rocker arm of the clutch actuator; Z1 is the number of worm heads; Z2 is the number of turbine teeth; μ is the transmission efficiency of the worm-connecting rod transmission mechanism; K m1 is the torque constant of the DC motor; K e is the DC motor back electromotive force constant; J1 is the moment of inertia of the short rocker arm; J3 is the moment of inertia of the long rocker arm; f(x1) is the rotation angle of the long rocker arm; F[l b ×Δf(x1)] is the force of the shift fork on the push rod; Δf(x1) is the rotation angle difference of the long rocker arm; m is the PWM duty cycle of the clutch actuator DC motor output; u is the DC motor input voltage; v r is the voltage drop of the armature circuit resistance; L is the total inductance of the armature circuit.

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