A dual clutch commercial vehicle transmission and a shift control method thereof

Abstract

The application discloses a double-clutch commercial vehicle gearbox, comprising a wet clutch, a gearbox, a synchronizer, a planetary gear mechanism and an output flange, which cooperate to complete the gear shifting of the gearbox, so that the gear shifting is more rapid, power loss is small, gear shifting jerk is obviously improved, and the service life of the gearbox is greatly prolonged. The application also discloses a gear shifting control method of the double-clutch commercial vehicle gearbox, a sensor module detects a current gear position, determines a target gear position, calculates a clutch target torque based on logical rules according to engine target speed, accelerator pedal opening degree, vehicle weight and road slope and the like information, converts the clutch target torque into the pressure of each working oil cavity during the switching of the double clutch, keeps the clutch expected target torque unchanged, makes the clutch switching process as smooth as possible, so that the power loss is small, the gear shifting jerk is improved, and meanwhile, a gear selection and shifting module controls the action of each gear shifting sliding sleeve, so that the position of the shift fork shaft is moved to a target value, and the gear shifting action is completed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle gearbox, more particularly, the present application relates to a double clutch commercial vehicle gearbox and a shift control method thereof. BACKGROUND

[0002] Automatic gearbox is favored by major manufacturers due to its high transmission efficiency, excellent driving experience, and high reliability. In foreign countries, the popularity of heavy commercial vehicle automatic gearbox is already quite high, and the domestic use environment has become mature, and the domestic heavy commercial vehicle automatic gearbox has entered a rapid development stage. The existing heavy commercial vehicle automatic transmission mainly includes hydraulic automatic transmission AT, mechanical automatic transmission AMT, double clutch automatic transmission DCT and several others.

[0003] The traditional hydraulic automatic transmission AT has low transmission efficiency and complex structure in the shift process, which not only increases the manufacturing cost, but also increases the maintenance cost.

[0004] The mechanical automatic transmission AMT is used more and more widely in commercial vehicles due to its simple structure, low manufacturing cost, high mechanical transmission efficiency, good fuel economy, small power loss and convenient maintenance, but the traditional commercial vehicle AMT gearbox adopts a dry clutch connected to the engine at the front end. Since the heavy commercial vehicle gearbox often has more than ten gears, the shift is completed by multiple synchronizers and slide sleeves, and in the shift process, not only the shift jerk is strong, but also the shift time is long, the driving comfort is poor, the dry clutch wears greatly, is easy to overheat, the transmission is unstable, and damage is easy to occur, resulting in increased cost.

[0005] The shift of the double clutch automatic transmission DCT is operated between two sets of actuators, the shift speed is faster, and the power loss caused in the shift process is smaller, thereby having the advantages of fast shift, uninterrupted power, low fuel consumption and excellent comfort, but compared with the AMT developed based on the traditional MT, the development and production cost is higher, the development period is longer, and at present only a small number of gearbox manufacturers and heavy commercial vehicle models use DCT transmission, and the domestic application and development of DCT for commercial vehicles are still in the initial stage. Moreover, the DCT transmission is equivalent to an AMT with two sets of actuators, and the volume and weight increase, but due to the limitation of the vehicle space, the volume and weight of the gearbox are limited, so the existing double clutch gearbox abroad generally integrates and reduces the clutch structure, and the torque that can be withstood is limited, which is difficult to meet the needs of high-torque multi-gear heavy commercial vehicles. SUMMARY

[0006] The purpose of the present application is to design and develop a double clutch commercial vehicle gearbox, which combines a wet double clutch with multiple shift slide sleeves to complete the gear switching of the gearbox, thereby improving the smoothness and service life.

[0007] The application also designs and develops a shift control method of the double-clutch commercial vehicle gearbox, which switches gears according to the clutch expected target torque of the target gear, realizes faster gear shifting, and combines with the clutch intermediate pressure control to make the gear shifting smoother.

[0008] The technical scheme provided by the application is:

[0009] A double-clutch commercial vehicle gearbox comprises:

[0010] A wet clutch comprises a first clutch and a second clutch, and a power input shaft is selectively connected with the first clutch or the second clutch;

[0011] A gearbox is connected with the output end of the wet clutch and is used for outputting power of different gears, and the gearbox comprises:

[0012] A housing;

[0013] A first auxiliary input shaft is connected with the output end of the first clutch;

[0014] A first auxiliary input shaft input gear is fixed on the first auxiliary input shaft;

[0015] A second auxiliary input shaft is connected with the output end of the second clutch, and the second auxiliary input shaft is sleeved on the outside of the first auxiliary input shaft;

[0016] A second auxiliary input shaft input gear is fixed on the second auxiliary input shaft;

[0017] At least one intermediate shaft is fixed in the housing and is arranged in parallel with the first auxiliary input shaft and the second auxiliary input shaft, and intermediate shaft K1 gears, intermediate shaft K2 gears, intermediate shaft 2-gear gears, intermediate shaft 1-gear gears and intermediate shaft reverse gears are vertically fixed on the at least one intermediate shaft at intervals,

[0018] An output shaft is rotatably arranged in the housing, and output shaft 2-gear gears, output shaft 1-gear gears and output shaft reverse gears are sleeved on the output shaft at intervals;

[0019] A first main gear shift sleeve is axially movably sleeved on the output shaft, and the first main gear shift sleeve is selectively engaged with the output shaft 2-gear gears;

[0020] A second main gear shift sleeve is axially movably sleeved on the output shaft, and the second main gear shift sleeve is selectively engaged with the output shaft 1-gear gears or the output shaft reverse gears;

[0021] A synchronizer is arranged in the housing, and the synchronizer comprises a low-gear cone hub, a low-high-gear sleeve and a high-gear cone hub;

[0022] A planetary gear mechanism is arranged in the housing, and the planetary gear mechanism comprises a ring gear, a planet carrier and a sun gear;

[0023] An output flange is fixed on the planet carrier for power output;

[0024] The intermediate shaft K1 gear is in mesh with the second auxiliary input shaft input gear, the intermediate shaft K2 gear is in mesh with the first auxiliary input shaft input gear, the intermediate shaft 2-gear gear is in mesh with the output shaft 2-gear gear, the intermediate shaft 1-gear gear is in mesh with the output shaft 1-gear gear, the intermediate shaft reverse gear is in mesh with the output shaft reverse gear, the low-high-gear sleeve is arranged in the ring gear and is axially movable, the low-high-gear sleeve is selectively in mesh with the low-gear cone hub or the high-gear cone hub, the low-gear cone hub is rotatably fixed in the housing, the high-gear cone hub is fixed on the planet carrier, and the output shaft is fixedly connected with the sun gear.

[0025] Preferably, the first clutch comprises:

[0026] A first outer piece support is fixedly connected with the power input shaft, and an accommodating cavity is formed inside the first outer piece support;

[0027] A plurality of first steel pieces are arranged on the inner side of the first outer piece support in a spaced and slidable manner;

[0028] A first inner piece support is arranged in the accommodating cavity, and the first inner piece support is connected with the first auxiliary input shaft;

[0029] A plurality of first friction pieces are arranged on the outer side of the first inner piece support in a spaced and slidable manner, and the plurality of first friction pieces are arranged in a parallel and spaced manner in sequence with the plurality of first steel pieces.

[0030] Preferably, the second clutch comprises:

[0031] A second outer piece support is arranged in the accommodating cavity, and the end of the second outer piece support is coaxially connected with the end of the first outer piece support;

[0032] A plurality of second steel pieces are arranged on the inner side of the second outer piece support in a spaced and slidable manner;

[0033] A second inner piece support is arranged in the accommodating cavity, and the second inner piece support is connected with the second auxiliary input shaft;

[0034] A plurality of second friction plates are arranged in parallel and spaced apart on the outside of the second inner plate support, and the plurality of second friction plates are arranged in parallel and spaced apart in sequence with the plurality of second steel plates;

[0035] A second piston is arranged between the second outer plate support and the second inner plate support, and one end of the second piston selectively pushes the plurality of second steel plates;

[0036] A coil spring is sleeved on the outside of the second secondary input shaft, and the coil spring is supported between the second piston and the second inner plate support.

[0037] Preferably, the first clutch further comprises:

[0038] A first piston is arranged between the second outer plate support and the first outer plate support, and the first piston selectively pushes the plurality of first steel plates;

[0039] A butterfly spring is sleeved on the outside of the second outer plate support, and the butterfly spring is supported between the first piston and the second outer plate support.

[0040] Preferably, the first clutch further comprises:

[0041] A first oil inlet pipe is arranged between the first piston and the first outer plate support, and the oil in the first oil inlet pipe can push the first piston to move axially;

[0042] A first oil passage valve is arranged at the oil inlet of the first oil inlet pipe;

[0043] A second oil inlet pipe is arranged between the second piston and the second outer plate support, and the oil in the second oil inlet pipe can push the second piston to move axially;

[0044] A second oil passage valve is arranged at the oil inlet of the second oil inlet pipe.

[0045] Preferably, the first clutch further comprises:

[0046] A gear ring fixing plate is fixed inside the housing;

[0047] A spacer plate is arranged vertically inside the housing;

[0048] An idler fixing plate is arranged in parallel with the spacer plate inside the housing;

[0049] A reverse idler is rotatably arranged between the idler fixing plate and the spacer plate, and the reverse idler is in meshing engagement with the reverse gear of the intermediate shaft;

[0050] The low-gear cone hub is rotatably arranged on the ring gear fixing plate, the at least one intermediate shaft is rotatably arranged between the housing and the spacer plate, and the output shaft is rotatably arranged on the spacer plate.

[0051] Preferably, further comprising:

[0052] A driving oil pump connected with the first and second oil inlet pipes;

[0053] A selection and shifting module connected with the first, second and high-low gear sliding sleeves, for driving the first, second and / or high-low gear sliding sleeves to move along the output shaft;

[0054] Two pressure sensors arranged in the first and second oil inlet pipes respectively;

[0055] A plurality of position sensors arranged in the housing, and the plurality of position sensors correspond to the first, second and high-low gear shifting fork shafts respectively;

[0056] A rotation speed sensor arranged in the housing, and the rotation speed sensor corresponds to the power input end of the planet carrier;

[0057] A pedal opening sensor arranged at the position of the vehicle's internal pedal, and the pedal opening sensor corresponds to the vehicle's accelerator pedal;

[0058] A vehicle weight sensor arranged on the chassis of the vehicle, for monitoring the weight of the vehicle;

[0059] A road slope sensor arranged at the front end of the vehicle, for monitoring the slope of the road on which the vehicle travels;

[0060] An electronic control unit connected with the driving oil pump, the selection and shifting module, the two pressure sensors, the plurality of position sensors, the rotation speed sensor, the pedal opening sensor, the vehicle weight sensor, the road slope sensor, the first and second oil path valves, for collecting and processing signals.

[0061] Preferably, the selection and shifting module comprises:

[0062] A shifting driving device fixed in the housing, for outputting shifting power;

[0063] A selection driving device fixed in the housing, and the selection driving device is connected with the shifting driving device, for outputting selection power;

[0064] An execution device connected with the selection driving device, for driving the first, second and / or high-low gear shifting fork shafts to move.

[0065] A shift control method of a double clutch commercial vehicle gearbox, using the double clutch commercial vehicle gearbox, comprising the following steps:

[0066] Step one, collecting the current gear, determining the target gear;

[0067] Step two, determining the clutch expected target torque of the target gear:

[0068] T c =T c1 ·λ1+T c2 ·λ2;

[0069] In the formula, T c1 is the first target torque of the clutch, T c2 is the second target torque of the clutch, λ1 is the first weight coefficient, and λ2 is the second weight coefficient;

[0070] Step three, switching the clutch, so that the target clutch transmits the torque to reach the clutch expected target torque of the target gear, and the target clutch oil cavity pressure reaches the target pressure point, while the shift module drives the first main gear sleeve, the second main gear sleeve and / or the high-low gear sleeve to move, and the shift is completed;

[0071] Wherein, the target pressure point satisfies:

[0072]

[0073] In the formula, P i is the target pressure point of the i-th clutch, T j is the torque transmitted by the i-th clutch, μ is the friction coefficient, N is the number of friction surfaces, R is the effective friction radius, F Sj_max is the maximum elastic force of the return spring, S j is the piston area of the i-th clutch hydraulic cylinder, i=1,2, j=A,B, and i=1, j=A, i=2, j=B.

[0074] Preferably, in the process of switching the clutch, the oil way valve opening of the target clutch is controlled by PI control, and the oil way valve opening of the original clutch is controlled by PD control.

[0075] The beneficial effects of the present application are:

[0076] The double clutch commercial vehicle gearbox designed and developed by the present application adopts wet type double clutch and shift sleeve to complete the gear shifting of the gearbox, the shift is more rapid, the power loss is small, the shift jerk is obviously improved, and the wet type double clutch is adopted, the service life is long, the clutch friction plate is in the oil liquid at multiple positions, and is not easy to overheat, which greatly prolongs the service life of the gearbox.

[0077] The application discloses a shift control method of a double clutch commercial vehicle gearbox. BRIEF DESCRIPTION OF DRAWINGS

[0078] Figure 1 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0079] Figure 2 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0080] Figure 3 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0081] Figure 4 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0082] Figure 5 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0083] Figure 6 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0084] Figure 7 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0085] Figure 8 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0086] Figure 9 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0087] Figure 10 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0088] Figure 11 The application discloses a shift control method of a double clutch commercial vehicle gearbox.

[0089] Figure 12 The application discloses a shift control method of a double clutch commercial vehicle gearbox. DETAILED DESCRIPTION

[0090] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0091] like Figure 1 As shown, the present invention provides a dual-clutch commercial vehicle transmission comprising: a power input shaft 100, a wet clutch 200, a transmission, a synchronizer, a planetary gear mechanism, and an output flange 1700. The wet clutch 200 includes a first clutch and a second clutch. The transmission includes: a housing 300, a first auxiliary input shaft 110, a second auxiliary input shaft 120, at least one intermediate shaft 130, an idler intermediate shaft 140, an output shaft 150, a coupling 160, a spacer plate 301, an idler fixing plate 302, a first auxiliary input shaft input gear 3100, a second auxiliary input shaft input gear 3200, and an output flange 1700. The system includes: intermediate shaft K1 gear 331, intermediate shaft K2 gear 332, intermediate shaft 2nd gear 333, intermediate shaft 1st gear 334, intermediate shaft reverse gear 335, reverse idler gear 340, output shaft 2nd gear 35151, output shaft 1st gear 352, output shaft reverse gear 353, first main gear sleeve 361, and second main gear sleeve 362. The planetary gear mechanism includes: sun gear 410, planet gear 420, planet carrier 430, gear ring 440, and gear ring support 450. The synchronizer includes: high and low gear sleeves 460, gear ring fixing plate 470, low gear cone hub 480, and high gear cone hub 490.

[0092] In this embodiment, there are two intermediate shafts, which are symmetrically arranged on both sides of the first secondary input shaft 110.

[0093] The housing 300 is internally provided with a partition plate 301, which divides the housing 300 into two parts. The first part is a gearbox, and the second part is a synchronizer and a planetary gear mechanism. The gearbox is connected to the planetary gear mechanism. The idler gear fixing plate 302 is fixed in the first part, and the gear ring fixing plate 470 is fixed in the second part. Both the idler gear fixing plate 302 and the gear ring fixing plate 470 are arranged parallel to and spaced apart from each other from the partition plate 301.

[0094] An idler wheel intermediate shaft 140 is rotatably disposed between the idler wheel fixing plate 302 and the spacer plate 301, and the reverse idler wheel 340 is fixed on the idler wheel intermediate shaft 140.

[0095] The first sub input shaft 110 is connected with the power input shaft 100 through a first clutch, the second sub input shaft 120 is connected with the power input shaft 100 through a second clutch, the first sub input shaft 110 and the second sub input shaft 120 are coaxially arranged, the second sub input shaft 120 is sleeved on the first sub input shaft 110, the first sub input shaft 110 and the second sub input shaft 120 can rotate relative to each other, the first sub input shaft 110 is a solid shaft, the second sub input shaft 120 is a hollow shaft, the optical axis of the first sub input shaft 110 passes through the shaft center of the second sub input shaft 120, and the second sub input shaft 120 can rotate and extend into the housing 300.

[0096] The first sub input shaft 110 is connected with the power input shaft 100 through a first clutch, the second sub input shaft 120 is connected with the power input shaft 100 through a second clutch, the first sub input shaft 110 and the second sub input shaft 120 are coaxially arranged, the second sub input shaft 120 is sleeved on the first sub input shaft 110, the first sub input shaft 110 and the second sub input shaft 120 can rotate relative to each other, the first sub input shaft 110 is a solid shaft, the second sub input shaft 120 is a hollow shaft, the optical axis of the first sub input shaft 110 passes through the shaft center of the second sub input shaft 120, and the second sub input shaft 120 can rotate and extend into the housing 300.

[0097] The second sub input shaft input gear 3200 is always meshed with the intermediate shaft K1 gear 331, the first sub input shaft input gear 3100 is always meshed with the intermediate shaft K2 gear 332, the intermediate shaft 2 gear 333 is always meshed with the output shaft 2 gear 35151, the intermediate shaft 1 gear 334 is always meshed with the output shaft 1 gear 352, the reverse idler 340 is always meshed with the intermediate shaft reverse gear 335 and the output shaft reverse gear 353, the first main gear sleeve 361 can be selectively meshed with the output shaft 2 gear 35151, and the second main gear sleeve 362 can be selectively meshed with the output shaft 1 gear 352 or the output shaft reverse gear 353.

[0098] The outer spline of the gear ring bracket 450 is fixedly engaged with the inner teeth of the gear ring 440, the inner spline of the gear ring bracket 450 is gapingly engaged with the outer spline of the high-low gear sleeve 460, the outer spline of the high-low gear sleeve 460 is axially movable on the inner spline of the gear ring bracket 450, the inner spline of the high-low gear sleeve 460 is gapingly engaged with the outer spline of the low gear cone hub 480 or the outer spline of the high gear cone hub 490, the high-low gear sleeve 460 is axially movable on the outer spline of the low gear cone hub 480 and the outer spline of the high gear cone hub 490, the inner spline of the high-low gear sleeve 460 is switched between the engagement with the outer spline of the low gear cone hub 480 and the outer spline of the high gear cone hub 490, the inner spline of the low gear cone hub 480 is fixedly engaged with the spline of the gear ring fixed plate 470, the inner spline of the high gear cone hub 490 is fixedly engaged with the outer spline of the planet carrier 430, the sun gear 410 is connected with one end of the output shaft 150 through the coupling 160, and the output flange 1700 is fixedly connected with the planet carrier 430.

[0099] When the high-low gear sleeve 460 moves left, the inner spline of the high-low gear sleeve 460 is engaged with the outer spline of the low gear cone hub 480, the gear ring 440 is fixed through the gear ring bracket 450, the high-low gear sleeve 460, the low gear cone hub 480 and the gear ring fixed plate 470, the gear ring 440 is fixed, power is input by the sun gear 410, and the planet carrier 430 outputs; when the high-low gear sleeve 460 moves right, the inner spline of the high-low gear sleeve 460 is engaged with the outer spline of the high gear cone hub 490, the gear ring 440 is fixed through the gear ring bracket 450, the high-low gear sleeve 460 and the high gear cone hub 490 and the planet carrier 430, the gear ring 440 is integrated with the planet carrier 430, power is input by the sun gear 410, and the planet carrier 430 outputs.

[0100] As shown in Figure 2 , the first clutch includes a first outer piece support 211, a plurality of first steel sheets 213, a first inner piece support 212, a plurality of first friction sheets 214, a first piston 215, a butterfly spring 216, a first oil inlet pipeline 217 and a first oil way valve (not shown in the figure), as shown in Figure 3 , the second clutch includes a second outer piece support 221, a plurality of second steel sheets 223, a second inner piece support 222, a plurality of second friction sheets 224, a second piston 225, a spiral spring 226, a second oil inlet pipeline 227 and a second oil way valve (not shown in the figure).

[0101] The power input shaft 100 is fixed on the outside of the first outer sheet support 211 and forms a containing cavity inside; a plurality of first steel sheets 213 are connected with the first outer sheet support 211 through spline connection, the spline connection adopts clearance fit, the plurality of first steel sheets 213 can move axially inside the first outer sheet support 211 through spline; the first inner sheet support 212 is arranged in the containing cavity, and the first inner sheet support 212 is fixedly connected with the first auxiliary input shaft 110, a plurality of first friction plates 214 are connected with the first inner sheet support 212 through spline connection, the spline connection adopts clearance fit, the plurality of first friction plates 214 can move axially outside the first inner sheet support 212 through spline, and the plurality of first friction plates 214 and the plurality of first steel sheets 213 are arranged in parallel and spaced apart in turn; the second outer sheet support 221 is arranged in the containing cavity, and the end of the second outer sheet support 221 is coaxially connected with the end of the first outer sheet support 211; the second inner sheet support 222 is arranged in the containing cavity, and the second inner sheet support 222 is connected with the second auxiliary input shaft 120; a plurality of second friction plates 224 are connected with the second inner sheet support 222 through spline connection, the spline connection adopts clearance fit, and the plurality of second friction plates 224 can move axially outside the second inner sheet support 222 through spline; a plurality of second steel sheets 223 are connected with the second outer sheet support 221 through spline connection, the spline connection adopts clearance fit, and the plurality of second steel sheets 223 can move axially inside the second outer sheet support 221 through spline, and the plurality of second friction plates 224 and the plurality of second steel sheets 223 are arranged in parallel and spaced apart in turn; the second outer sheet support 221 is also fixed with the power input shaft 100; the first piston 215 is arranged between the second outer sheet support 221 and the first outer sheet support 211, and the first piston 215 can selectively push the plurality of first steel sheets 213; the disc spring 216 is sleeved outside the second outer sheet support 221, and the disc spring 216 is supported between the first piston 215 and the second outer sheet support 221; the second piston 225 is arranged between the second outer sheet support 221 and the second inner sheet support 222, and one end of the second piston 225 can selectively push the plurality of second steel sheets 223; the spiral spring 226 is sleeved outside the second auxiliary input shaft 120, and the spiral spring 226 is supported between the second piston 225 and the second inner sheet support 222; the first oil inlet pipe 217 is arranged between the first piston 215 and the first outer sheet support 211, and the oil in the first oil inlet pipe 217 can push the first piston 215 to move axially; the first oil way valve is arranged at the oil inlet of the first oil inlet pipe 217; the second oil inlet pipe 227 is arranged between the second piston 225 and the second outer sheet support 221, and the oil in the second oil inlet pipe 227 can push the second piston 225 to move axially; the second oil way valve is arranged at the oil inlet of the second oil inlet pipe 227.

[0102] When the first clutch works, the plurality of first friction plates 214 and the plurality of first steel sheets 213 are pressed by the first piston 215, and power from the power input shaft 100 is transmitted to the first sub input shaft 110 through the first clutch by friction transmission; when the second clutch works, the plurality of second friction plates 224 and the plurality of second steel sheets 223 are pressed by the second piston 225, and power from the power input shaft 100 is transmitted to the second sub input shaft 120 through the second clutch by friction transmission.

[0103] The application also includes: the driving oil pump 510 is connected with the first oil inlet pipeline 217 and the second oil inlet pipeline 227, like Figure 4 、 Figure 5As shown, the selecting and shifting module 520 comprises a shifting driving device, a selecting driving device and an executing device, wherein the shifting driving device comprises a shifting motor 521, a screw rod 522 and a screw nut 523, the shifting motor 521 is fixed inside the shell 300, one end of the screw rod 522 is connected with the output end of the shifting motor 521, the other end is rotatably fixed inside the shell 300 (as preferred, the other end of the screw rod 522 is rotatably fixed on the spacer plate 301, the idler fixed plate 302 or the gear ring fixed plate 470 through a bearing), and the screw nut 523 is rotatably arranged on the screw rod 522 for converting rotation into linear motion; the selecting driving device comprises a selecting motor 524, a speed reduction gear 525, a sliding platform 527a and a spline shaft 526, the selecting motor 524 is fixed inside the shell 300, the speed reduction gear 525 is fixed on the output end of the selecting motor 524, one end of the spline shaft 526 is fixed on the speed reduction gear 525, and the other end is rotatably arranged inside the shell 300 (as preferred, the other end of the spline shaft 526 is rotatably fixed on the spacer plate 301, the idler fixed plate 302 or the gear ring fixed plate 470 through a bearing), the sliding platform 527a is sleeved outside the spline shaft 526 and can move axially on the spline shaft 526, and the sliding platform 527a is fixedly connected with the screw nut; the executing device comprises a selecting shift finger 527b, a shifting shift block 528, a first shift fork shaft 529a, a second shift fork shaft 529b and a high-low shift fork shaft 529c, the selecting shift finger 527b is fixedly connected with the sliding platform 527a through a selecting platform, the shifting shift block 528 is provided with three shift block grooves, and the three shift block grooves correspond to the first shift fork shaft 529a, the second shift fork shaft 529b and the high-low shift fork shaft 529c, the first shift fork shaft 529a, the second shift fork shaft 529b and the high-low shift fork shaft 529c are respectively and one-to-one provided with a first shift fork, a second shift fork and a high-low shift fork, the first shift fork is clamped on the first main shift sleeve 361, the second shift fork is clamped on the second main shift sleeve 362, and the high-low shift fork is clamped on the high-low shift sleeve 460, for driving the first main shift sleeve 361, the second main shift sleeve 362 and / or the high-low shift sleeve 460 to move along the output shaft.

[0104] The shifting process of the selecting and shifting module 520 is as follows: the shifting motor 521 drives the screw rod 522 to rotate through the key groove to transmit driving force, the screw rod 522 has a screw rod nut 523 capable of performing cyclic reciprocating motion, a plurality of steel balls are in contact with the screw rod 522, when the screw rod 522 rotates, the steel balls between the screw rod nut 523 and the screw rod 522 roll in the sliding groove on the screw rod 522 to push the cyclic reciprocating motion of the screw rod nut 523, the screw rod nut 523 drives the sliding platform 527a to move axially, the sliding platform 527a drives the shifting block 528, the shifting fork shaft (the first shifting fork shaft 529a, the second shifting fork shaft 529b or the high-low gear shifting fork shaft 529c) and the shifting fork (the first shifting fork, the second shifting fork or the high-low gear shifting fork) to move axially together, thereby realizing the shifting action.

[0105] The selecting process of the selecting and shifting module 520 is as follows: when the selecting motor 524 rotates, the driving reduction gear 525 is driven to rotate the spline shaft 526, the sliding platform 527a rotates together with the spline shaft 526, the sliding platform 527a drives the selecting shift finger 527b to rotate, thereby realizing that the selecting shift finger 527b can be switched between three block grooves, and completing the selecting action.

[0106] The sensor module 530 includes: two pressure sensors, three position sensors, a rotating speed sensor, a pedal opening degree sensor, a vehicle weight sensor and a road slope sensor, the two pressure sensors are arranged in the first oil inlet pipeline 217 and the second oil inlet pipeline 227 respectively, and are used to detect the internal pressure of the wet clutch 2; the three position sensors are arranged in the housing 300, and correspond to the first shifting fork shaft 529a, the second shifting fork shaft 529b and the high-low gear shifting fork shaft 529c respectively, and are used to detect the position of the shifting fork shaft, and together with the selecting and shifting module 520 to ensure that the shifting action is in place; the rotating speed sensor is arranged in the housing 300, and corresponds to the outer spline of the input end of the planet carrier 430, and is used to detect the rotating speed of each shaft; the pedal opening degree sensor is arranged at the position of the foot pedal inside the vehicle, and is arranged relative to the accelerator pedal of the vehicle, and is used to monitor the opening degree of the accelerator pedal; the vehicle weight sensor is arranged on the chassis of the vehicle, and is used to monitor the weight of the vehicle; the road slope sensor is arranged at the front end of the vehicle, and is used to monitor the slope of the road on which the vehicle travels. The sensor module 530 transmits signals to the electronic control unit 500 through a data line, the electronic control unit (TCU) 500 is connected with the driving oil pump 510, the selecting and shifting module 520, the sensor module 530, the first oil way valve and the second oil way valve, processes and analyzes the signals collected by the sensor module 530, thereby generating signals for controlling the action of the selecting and shifting module 520.

[0107] The gear positions and actuator working table of the dual-clutch commercial vehicle transmission described in this invention are shown in Table 1. In the table, "×" indicates disengagement, "√" indicates engagement, "←" indicates left shift, "∣" indicates center position, and "→" indicates right shift.

[0108] Table 1 Gear Positions and Actuator Component Worksheet

[0109]

[0110]

[0111] Specifically, let's take 4th and 5th gears as examples to explain their working principle and shifting process:

[0112] like Figure 6 As shown, the power transmission route for 4th gear is as follows:

[0113] The power is transmitted to the intermediate shaft 130 via the first input shaft input gear 310 and the intermediate shaft K2 gear 332. The intermediate shaft 2nd gear 333 rotates synchronously with the intermediate shaft 130. The power is transmitted to the output shaft 2nd gear 351 via the intermediate shaft 2nd gear 333. The first main gear sleeve 361 moves to the right and connects with the output shaft 2nd gear 351. The second main gear sleeve 362 is in the middle position. The power is transmitted to the output shaft 150 via the output shaft 2nd gear 351 and the first main gear sleeve 361. The power is transmitted to the sun gear 410 via the coupling 160. The high and low gear sleeve 460 moves to the left and connects the gear ring 440 with the gear ring fixing plate 470. The power is transmitted to the output flange 170 via the planetary gear 420 and the planet carrier 430.

[0114] like Figure 7 As shown, the power transmission route for 5th gear is as follows:

[0115] The power is transmitted to the intermediate shaft 130 via the second input shaft input gear 320 and the intermediate shaft K1 gear 331. The intermediate shaft first gear 334 rotates synchronously with the intermediate shaft 130. The power is transmitted to the output shaft first gear 352 via the intermediate shaft first gear 334. The second main gear sleeve 362 moves to the left and connects with the output shaft first gear 352. The first main gear sleeve 361 is in the middle position. The power is transmitted to the output shaft 150 via the output shaft first gear 352 and the second main gear sleeve 362. The power is transmitted to the sun gear 410 via the coupling 160. The high and low gear sleeve 460 moves to the right and connects the gear ring 440 with the planet carrier 430. The power is transmitted to the output flange 170 via the planet gear 420 and the planet carrier 430.

[0116] The process of shifting from 4th to 5th gear is as follows:

[0117] TCU 500 controls the driving oil pump 510 to stop supplying high-pressure oil to the first clutch, the first piston 215 returns to the original position under the action of the elastic force of the disc spring 216, the first clutch stops working, TCU 500 controls the driving oil pump 510 to supply high-pressure oil to the second clutch, and the second piston 225 pushes the plurality of second steel sheets 223 and the plurality of second friction sheets 224 to be pressed tightly, and the second clutch enters the working state. In this process, the oil pressure in the first clutch gradually decreases, the torque gradually decreases, the plurality of first steel sheets 213 and the plurality of first friction sheets 214 gradually loosen, the power is gradually cut off, the oil pressure of the second clutch gradually increases, the plurality of second steel sheets 223 and the plurality of second friction sheets 224 gradually press tightly, and the torque gradually increases.

[0118] In the switching process of the first clutch and the second clutch, TCU 6 controls the shift module 7 to make the first main shift sleeve 361 retreat to the neutral position, and the second main shift sleeve 362 moves left to synchronize the rotation speed of the output shaft 1 gear 352 and the output shaft 150. At the same time, TCU 6 controls the shift module 7 to make the high-low shift sleeve 460 move right to synchronize the rotation speed of the gear ring 440 and the planetary carrier 430.

[0119] After the 4th gear is upgraded to the 5th gear, the wet clutch 2 is switched from the first clutch to the second clutch, so that the power transmission of the input shaft 1 is switched from the input shaft B33 to the input shaft B33, and the power is transmitted to the intermediate shaft 130 through the second secondary input shaft input gear 320 and the intermediate shaft K1 gear 331, and then transmitted to the output shaft 150 through the intermediate shaft 1 gear 334, the output shaft 1 gear 352, and the second main shift sleeve 362, and the power is transmitted to the sun gear 410 through the coupling 160, and finally transmitted to the output flange 170 through the planetary gear 420 and the planetary carrier 430.

[0120] The double-clutch commercial vehicle gearbox designed and developed by the application adopts a wet double-clutch and a shift sleeve to complete the gear switching of the gearbox, so that the gear shifting is faster, the power loss is small, and the gear shifting jerk is obviously improved. Moreover, the wet double-clutch is adopted, the service life is long, the clutch friction sheets are mostly in the oil, and overheating is not easy, so that the service life of the gearbox is greatly prolonged.

[0121] The application also provides a gear shifting control method of the double-clutch commercial vehicle gearbox.

[0122] As shown in Figure 8 The sensor module detects the current gear and sends the current gear information to the TCU, the TCU makes a gear decision to give a target gear, the gearbox performs a gear shifting action, and the gear shifting process starts.

[0123] As shown in Figure 9 First, the engine target speed ω e, specifically as shown in Table 2, the clutch first target torque T c1 :

[0124]

[0125] wherein K P is a torque proportional gain, and has a value range of 8-26; K I is a torque integral coefficient, and has a value range of 15-34; K D is a torque differential coefficient, and has a value range of 41-55; e(k) is the current engine speed deviation, Σe(k) is the cumulative sum of the current and previous speed deviations, e(k-1) is the previous engine speed deviation; T is a sampling period, generally 50ms or 100ms; and k is a sampling serial number, generally 1, 2, 3,..., k.

[0126] The current engine speed deviation satisfies:

[0127] e(k) = ω e (k) - ω a (k) ;

[0128] wherein ω e (k) is the engine target speed, and ω a (k) is the engine actual speed.

[0129] Table 2 Engine target speed (rmp) at target gear switching

[0130]

[0131] As shown in Table 3, the engine target torque T e is obtained by looking up the accelerator pedal opening degree, the engine target speed ω e , and the engine target torque T c2 is obtained by multiplying the engine target torque by a gain coefficient obtained by looking up the current vehicle weight and the road slope, as shown in Table 4.

[0132] Table 3 Relationship table between engine target torque (Nm) and accelerator pedal opening degree (%) and engine target speed (rmp)

[0133]

[0134]

[0135] Table 4 Relationship table between gain coefficient and current vehicle weight (t) and road slope (°)

[0136]

[0137] The clutch expected target torque satisfies:

[0138] T c = T c1 · λ1+ T c2 · λ2;

[0139] In the formula, λ1 is a first weight coefficient, λ2 is a second weight coefficient, and λ1 is in a range of 0.9-1.1, and λ2 is determined by a road slope percentage and a vehicle weight coefficient:

[0140]

[0141] In the formula, δ is the road slope percentage, and θ is the vehicle weight coefficient.

[0142] The vehicle weight coefficient satisfies:

[0143]

[0144] In the formula, G s is a current weight of the vehicle, and G max is a full load weight of the vehicle.

[0145] When the clutch needs to be switched during the shifting process, the original clutch oil cavity pressure needs to be reduced, and the target clutch oil cavity pressure needs to be increased, the original clutch is controlled to approach a sliding wear state to eliminate the target clutch air gap; when the original clutch reaches the sliding wear state, the target clutch air gap elimination is completed, the original clutch oil cavity pressure is continuously reduced, and the target clutch oil cavity pressure is continuously increased; when the original clutch oil cavity pressure is 0, the target clutch oil cavity pressure is continuously increased to synchronize the engine and the target clutch speed; when the engine and the target clutch speed synchronization is completed, the target clutch oil cavity pressure is increased to the target pressure point, and the clutch switching is completed.

[0146] In the embodiment, it is determined by test that when the original clutch oil cavity pressure is reduced to below 8 bar, the original clutch reaches the sliding wear state.

[0147] When the clutch is switched, the target clutch torque needs to reach the clutch expected target torque, and when the first clutch is switched to the second clutch, the following needs to be satisfied:

[0148] T B = T c ;

[0149] In the formula, T B is the torque transmitted by the second clutch.

[0150] The target pressure point of the second clutch is:

[0151]

[0152] Where, μ is the friction coefficient, and generally takes the value of 0.3-0.4, N is the number of friction surface, R is the effective friction radius, F SB_max is the maximum spring force of the return spring (coil spring), S B is the second clutch hydraulic cylinder piston area, the number of friction surface and the second clutch hydraulic cylinder piston area are known parameters;

[0153] In this embodiment, N = 2, R = 430 mm.

[0154] When switching from the second clutch to the first clutch, it needs to meet:

[0155] T A = T c ;

[0156] Where, T A is the torque transmitted by the first clutch;

[0157] The target pressure point of the first clutch is:

[0158]

[0159] Where, F SA_max is the maximum spring force of the return spring (coil spring), S A is the first clutch hydraulic cylinder piston area;

[0160] The torque transmitted by the first clutch and the second clutch is respectively:

[0161] T A = μNR(S A P A -F SA );

[0162] T B = μNR(S B P B -F SB );

[0163] Where, T A is the torque transmitted by the first clutch, T B is the torque transmitted by the second clutch, μ is the friction coefficient, N is the number of friction surface, R is the effective friction radius, S A is the first clutch hydraulic cylinder piston area, P A is the first clutch working oil pressure, F SA is the first clutch return spring force, S B is the second clutch hydraulic cylinder piston area, P BFor the second clutch working oil pressure, F SB For the second clutch return spring force;

[0164] In the clutch slip process, the oil valve opening of the target clutch is controlled by PI, and based on this, the oil valve opening of the original clutch is controlled by PD, for example, when switching from the first clutch to the second clutch, the second clutch pressure difference is:

[0165] E B = P2 - P B ;

[0166] In the formula, E B is the second clutch pressure difference;

[0167] The second oil valve opening α B (%) is obtained by PI control, and the second clutch working oil pressure P B is detected by the sensor module;

[0168] Wherein, the second oil valve opening α B satisfies:

[0169] α B = K PB E B (k) + TK IB ∑E B (k);

[0170] In the formula, K PB is the second opening proportional gain, with a value range of 4-12; K IB is the opening integral coefficient, with a value range of 8-13; E B (k) is the second clutch pressure difference at this sampling, and ∑E B (k) is the cumulative sum of the current and previous second clutch pressure differences;

[0171] The second clutch pressure difference E B is taken as the target pressure of the first clutch, and the first clutch pressure difference is:

[0172] E A = E B -P A ;

[0173] In the formula, E A is the first clutch pressure difference;

[0174] The first oil valve opening α A (%) is obtained by PD control, and the actual working oil pressure P A of the first clutch is detected by the sensor module;

[0175] Wherein, the first oil valve opening αA satisfy:

[0176]

[0177] In the formula, K PA K represents the first opening proportional gain, with a value ranging from 5 to 11. DA E is the differential coefficient of the opening, ranging from 10 to 15; A (k) represents the first clutch pressure difference during this sampling, E A (k-1) is the first clutch pressure difference during the last sampling;

[0178] Meanwhile, during the wet dual-clutch switching process, the TCU controls the shift module to perform shifting, that is, by driving three sliding sleeves through the shift fork shaft, the shifting is achieved by combining the gearbox, synchronizer and planetary gear mechanism.

[0179] In this embodiment, the relationship between the position values ​​of each shift fork shaft and the position of each sliding sleeve is shown in Table 5.

[0180] Table 5. Relationship between the position values ​​of each shift fork shaft and the position of each sliding sleeve.

[0181]

[0182] Taking shifting from 4th to 5th gear as an example, such as Figure 10 As shown, firstly, the pressure in the first clutch oil chamber is reduced to control the first clutch towards a slipping state, while simultaneously increasing the pressure in the second clutch oil chamber to eliminate the second clutch's free travel. At this time, as... Figure 11 As shown, the opening degree of the second oil circuit valve is obtained through PI control, and the opening degree of the first oil circuit valve is obtained through PD control. When the first clutch reaches the slipping state, the free travel of the second clutch is eliminated, the oil chamber pressure of the first clutch continues to decrease, and the oil chamber pressure of the second clutch continues to increase. When the oil chamber pressure of the first clutch is 0, the oil chamber pressure of the second clutch continues to increase to synchronize the engine speed with the second clutch speed. When the engine speed and the second clutch speed are synchronized, the working chamber pressure of the second clutch is increased to the target pressure point, the clutch switching is completed, and the gear shift is completed.

[0183] The target position value of the first shift fork shaft is 0, the target position value of the second shift fork shaft is 21, and the target position value of the high / low gear shift fork shaft is -27. The shift module starts to execute the shift strategy. The first master gear slide sleeve 361 returns to the center position, the second master gear slide sleeve 362 moves to the left, and the high / low gear slide sleeve 460 moves to the right. The sensor module detects the positions of the first shift fork shaft, the second shift fork shaft, and the high / low gear shift fork shaft, and returns the position information to the TCU. The TCU determines whether the position matches the target position based on the position information.

[0184] like Figure 12The figure shows the torque change curve of the engine and the first clutch and the second clutch when the gear is raised from 4 to 5, in which the solid line T e1 A1 B1 The figure shows the torque change curve of the engine and the first clutch and the second clutch when the gear is raised from 4 to 5, in which the solid line T e2 A2 B2 The figure shows the torque change curve of the engine and the first clutch and the second clutch when the gear is raised from 4 to 5, in which the solid line T e2 A2 B2 By comparison, it can be seen that the control method of the present application can make the engine and the clutch transmission torque fluctuation smaller, and the torque transmission more stable, so as to improve the gear jerk and improve the driving comfort.

[0185] The gear shifting control method of the double clutch commercial vehicle transmission designed and developed by the present application detects the current gear position by a sensor module, and sends the current gear position information to a TCU, the TCU makes a gear position decision to give a target gear position, calculates the clutch target torque based on the engine target speed, the accelerator pedal opening degree, the vehicle weight and the road slope information based on the logic rules, and converts the clutch target torque into the working oil cavity pressure during the double clutch switching, when the working oil cavity pressure rises, the working oil cavity pressure of the other working oil cavity decreases, and the clutch target torque is maintained unchanged, so as to make the clutch switching process as stable as possible, so as to make the power loss small, improve the gear jerk, and control the gear shifting sleeve action by the gear shifting module, so as to move the yoke shaft position to the target value, and finally complete the gear shifting action.

[0186] Although the embodiments of the present application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, and can be fully applied to various fields suitable for the present application, and other modifications can be easily realized by those skilled in the art, therefore the present application is not limited to the specific details and the embodiments shown and described herein, and the general concept defined by the claims and the equivalent scope.

Claims

1. A dual-clutch commercial vehicle transmission, characterized in that, include: A wet clutch, comprising a first clutch and a second clutch, wherein the power input shaft is selectively connected to either the first clutch or the second clutch; A gearbox, connected to the output end of the wet clutch, for outputting power in different gears, the gearbox comprising: case; The first input shaft is connected to the output end of the first clutch; The first input shaft input gear is fixed on the first input shaft; The second auxiliary input shaft is connected to the output end of the second clutch, and the second auxiliary input shaft is loosely fitted outside the first auxiliary input shaft; The second input shaft input gear is fixed on the second input shaft; At least one intermediate shaft is fixed inside the housing and is arranged parallel to the first auxiliary input shaft and the second auxiliary input shaft. At least one intermediate shaft is vertically fixed with intermediate shaft K1 gear, intermediate shaft K2 gear, intermediate shaft 2nd gear, intermediate shaft 1st gear and intermediate shaft reverse gear at intervals. The output shaft is rotatably disposed within the housing, and the output shaft is fitted with a second gear, a first gear, and a reverse gear at intervals. The first main gear sleeve is axially movable and sleeved on the output shaft, and the first main gear sleeve can mesh with the second gear of the output shaft. The second main gear sleeve is axially movable and sleeved on the output shaft, and the second main gear sleeve can mesh with the first gear or the reverse gear of the output shaft. A synchronizer is disposed within the housing, and the synchronizer includes a low-gear cone hub, a high-low gear sliding sleeve, and a high-gear cone hub; A planetary gear mechanism is disposed within the housing, and the planetary gear mechanism includes a ring gear, planet gears, a planet carrier, and a sun gear; Output flange, which is fixed on the planetary carrier, is used for power output; The intermediate shaft K1 gear meshes with the second auxiliary input shaft input gear, the intermediate shaft K2 gear meshes with the first auxiliary input shaft input gear, the intermediate shaft 2nd gear meshes with the output shaft 2nd gear, the intermediate shaft 1st gear meshes with the output shaft 1st gear, the intermediate shaft reverse gear meshes with the output shaft reverse gear, the high and low gear sliding sleeves are axially movable and are disposed within the gear ring, and the high and low gear sliding sleeves can selectively mesh with the low gear cone hub or the high gear cone hub, the low gear cone hub is rotatably fixed in the housing, the high gear cone hub is fixed on the planet carrier, and the output shaft is fixedly connected to the sun gear; The first clutch includes: The first outer support plate is fixedly connected to the power input shaft and has an internal receiving cavity; Multiple first steel plates are slidably arranged at intervals on the inner side of the first outer plate support; A first inner sheet support is disposed in the receiving cavity, and the first inner sheet support is connected to the first auxiliary input shaft; A plurality of first friction plates are slidably disposed on the outer side of the first inner plate support, and the plurality of first friction plates and the plurality of first steel plates are arranged in parallel and spaced apart in sequence. The second clutch includes: The second outer support is disposed in the receiving cavity, and the end of the second outer support is coaxially connected to the end of the first outer support. Multiple second steel plates are slidably arranged at intervals on the inner side of the second outer plate support; The second inner plate support is disposed in the receiving cavity and is connected to the second auxiliary input shaft; Multiple second friction plates are slidably disposed on the outside of the second inner plate support, and the multiple second friction plates and the multiple second steel plates are arranged in parallel and spaced apart in sequence; A second piston is disposed between the second outer sheet support and the second inner sheet support, and one end of the second piston is capable of pushing the plurality of second steel sheets; A helical spring is sleeved on the outside of the second auxiliary input shaft, and the helical spring is supported between the second piston and the second inner plate support. The first clutch also includes: A first piston is disposed between the second outer plate support and the first outer plate support, and the first piston is capable of pushing the plurality of first steel plates; A butterfly spring is sleeved on the outside of the second outer plate support, and the butterfly spring is supported between the first piston and the second outer plate support.

2. The dual-clutch commercial vehicle transmission as described in claim 1, characterized in that, Also includes: A first oil inlet pipe is disposed between the first piston and the first outer plate support, and the oil in the first oil inlet pipe can push the first piston to move axially. The first oil circuit valve is located at the oil inlet of the first oil inlet pipe; The second oil inlet pipe is disposed between the second piston and the second outer plate support, and the oil in the second oil inlet pipe can push the second piston to move axially. The second oil circuit valve is located at the oil inlet of the second oil inlet pipe.

3. The dual-clutch commercial vehicle transmission as described in claim 2, characterized in that, Also includes: A gear ring fixing plate is fixed inside the housing; A partition plate, which is vertically disposed inside the housing; An idler wheel fixing plate is disposed inside the housing, parallel to the spacer plate; A reverse idler gear is rotatably disposed between the idler gear fixing plate and the spacer plate, and the reverse idler gear meshes with the reverse gear of the intermediate shaft; The low-gear cone hub is rotatably mounted on the gear ring fixing plate, the at least one intermediate shaft is rotatably mounted between the housing and the spacer plate, and the output shaft is rotatably mounted on the spacer plate.

4. The dual-clutch commercial vehicle transmission as described in claim 3, characterized in that, Also includes: Drive an oil pump, which is connected to the first oil inlet pipe and the second oil inlet pipe; A gear shifting module is connected to the first main gear slide, the second main gear slide, and the high and low gear slide, and is used to drive the first main gear slide, the second main gear slide, and / or the high and low gear slide to move along the output shaft; Two pressure sensors are installed in the first oil inlet pipe and the second oil inlet pipe, respectively; Multiple position sensors are disposed within the housing, and the multiple position sensors are respectively disposed corresponding to the first shift fork shaft, the second shift fork shaft, and the high and low gear shift fork shaft; A speed sensor is disposed inside the housing and is disposed corresponding to the power input end of the planetary carrier; A pedal opening sensor is installed inside the vehicle at the foot pedal position, and the pedal opening sensor is positioned relative to the vehicle's accelerator pedal. A vehicle weight sensor is installed on the chassis of a vehicle to monitor the vehicle's weight. A road slope sensor, which is installed at the front of the vehicle, is used to monitor the slope of the road on which the vehicle travels; The electronic control unit is connected to the drive oil pump, gear shifting module, two pressure sensors, multiple position sensors, speed sensor, pedal opening sensor, vehicle weight sensor, road slope sensor, first oil circuit valve and second oil circuit valve, and is used for signal collection and processing.

5. The dual-clutch commercial vehicle transmission as described in claim 4, characterized in that, The gear selection module includes: A gear shift drive device, which is fixed inside the housing, is used to output gear shifting power; A gear selection drive device is fixed inside the housing and is connected to the gear shift drive device for outputting gear selection power. An actuator, which is connected to the gear selection drive device, is used to drive the first shift fork shaft, the second shift fork shaft and / or the high and low gear shift fork shaft to move.

6. A shift control method for a dual-clutch commercial vehicle transmission, using the dual-clutch commercial vehicle transmission as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Collect the current gear position and determine the target gear position; Step 2: Determine the expected target torque of the clutch in the target gear: T c =T c1 ·λ1+T c2 ·λ2; In the formula, T c1 T is the first target torque for the clutch. c2 λ1 is the second target torque of the clutch, λ2 is the first weighting coefficient, and λ2 is the second weighting coefficient. Step 3: Switch the clutch so that the torque transmitted by the target clutch reaches the expected target torque of the clutch in the target gear, and the oil chamber pressure of the target clutch reaches the target pressure point. At the same time, the gear shifting module drives the first master gear slide sleeve, the second master gear slide sleeve and / or the high and low gear slide sleeves to move, and the gear shift is completed. The target pressure point satisfies the following: In the formula, P i T is the target pressure point of the i-th clutch. j Let μ be the torque transmitted by the i-th clutch, N be the friction coefficient, R be the number of friction surfaces, and F be the effective friction radius. Sj_max S is the maximum elastic force of the return spring. j Let be the piston area of ​​the i-th clutch hydraulic cylinder, i = 1, 2, j = A, B, and when i = 1, j = A, and when i = 2, j = B.

7. The shift control method for a dual-clutch commercial vehicle transmission as described in claim 6, characterized in that, The second weighting coefficient satisfies: In the formula, δ is the percentage of road slope, and θ is the vehicle weight coefficient; The vehicle weight coefficient satisfies: In the formula, G s G represents the current weight of the vehicle. max This refers to the vehicle's full load weight.

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