CN109372981B - Vehicle gear shifting control system, driving gear shifting control method and loader - Google Patents
Vehicle gear shifting control system, driving gear shifting control method and loader Download PDFInfo
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- CN109372981B CN109372981B CN201811543291.3A CN201811543291A CN109372981B CN 109372981 B CN109372981 B CN 109372981B CN 201811543291 A CN201811543291 A CN 201811543291A CN 109372981 B CN109372981 B CN 109372981B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/02—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used
- F16H61/0262—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used the signals being hydraulic
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Abstract
The invention relates to the field of vehicle gear shifting, and discloses a vehicle gear shifting control system, a driving gear shifting control method and a loader. When the gear of the gearbox is adjusted, the clutch which needs to be adjusted from a disconnection state to a connection state is firstly adjusted when the gear of the gearbox is adjusted, and the clutch is connected when the displacement of a motor which drives the clutch to rotate and connect is not equal to zero; and then the clutch which needs to be adjusted from the connection state to the disconnection state is disconnected after the displacement of a motor driving the clutch to rotate is equal to zero, so that no power interruption is caused in the gear shifting process, the speed of the vehicle is not impacted when the clutch is disconnected, and the stable change of the speed of the whole vehicle is ensured.
Description
Technical Field
The invention relates to the field of vehicle gear shifting, in particular to a vehicle gear shifting control system, a driving gear shifting control method and a loader.
Background
The gear shifting control systems of the existing loader are mainly three, namely a hydraulic torque converter transmission mechanism, a mechanical transmission mechanism and a hydrostatic driving mechanism.
The gear shifting efficiency of the driving gear shifting control by adopting the hydraulic torque converter transmission mechanism and the mechanical transmission mechanism is low, and the reliability is poor, so that the driving gear shifting control is mostly carried out by adopting a hydrostatic driving mechanism in the prior art. However, most of the existing hydrostatic driving mechanisms work by matching a clutch with a two-gear gearbox, parking and gear shifting cannot be realized, power interruption in the gear shifting process cannot be guaranteed, and the two-gear gearbox cannot meet the requirements of large and medium-sized hydrostatic loaders on torque and speed.
Disclosure of Invention
The invention aims to provide a vehicle gear shifting control system, a driving gear shifting control method and a loader, which can solve the problem that the conventional vehicle hydraulic driving mechanism cannot realize driving gear shifting.
In order to achieve the purpose, the invention adopts the following technical scheme:
a vehicle shift control system comprising a variable displacement pump, a plurality of motors driven by said variable displacement pump and a multi-speed transmission, said transmission comprising a plurality of clutches, at least one clutch being connected to each motor driven by said variable displacement pump, at most one of said at least one clutches connected to the same said motor being engaged.
Further, the plurality of motors includes a first motor and a second motor, and the plurality of clutches includes a first clutch, a second clutch, and a third clutch; the first motor is selectively connected with the input end of the first clutch or the input end of the third clutch, and the second motor is connected with the input end of the second clutch.
Furthermore, the first motor is in transmission connection with a first gear, the input end and the output end of the third clutch are in transmission connection with the first gear and a second gear respectively, and the second gear is in transmission connection with a third gear;
the input end and the output end of the first clutch are in transmission connection with a fourth gear and the third gear respectively, and the fourth gear is in transmission connection with the first gear.
Furthermore, the third gear is connected with a fifth gear which is coaxial with the third gear, the input end and the output end of the second clutch are respectively in transmission connection with the second motor and the sixth gear, and the sixth gear is in transmission connection with the fifth gear.
In order to achieve the above object, the present invention further provides a driving gear shift control method, which is applied to the vehicle gear shift control system, and comprises the following steps: when the gear of the gearbox is adjusted, a clutch which needs to be adjusted from a disconnection state to a connection state is firstly adjusted, and the clutch is connected when the displacement of a motor which drives the clutch to be rotationally connected is not equal to zero; and then the clutch which needs to be adjusted from the engaging state to the disengaging state is disengaged after the displacement of a motor which drives the clutch to rotate is equal to zero.
Further, the displacement of the variable displacement pump, the displacement of the plurality of motors, and the vehicle speed satisfy the formula:
wherein q ispmpRepresenting the displacement of the variable displacement pump, v representing the vehicle speed, η being a known fixed value, n representing the number of motors, qmotiRepresents the displacement of the ith motor; gamma rayiRepresenting the transmission ratio between the output of the i-th motor and the output of the gearbox when the gearbox is operating in the current gear.
Further, the plurality of motors includes a first motor and a second motor, and the plurality of clutches includes a first clutch, a second clutch, and a third clutch; the first motor is selectively connected with the input end of the first clutch or the input end of the third clutch, and the second motor is connected with the input end of the second clutch;
after the vehicle is started, the gearbox automatically adjusts a first gear, when the gearbox works at the first gear, the first clutch and the second clutch are connected, and the third clutch is disconnected; when the gearbox works in two gears, the second clutch is connected, and the first clutch and the third clutch are disconnected; when the gearbox works in third gear, the third clutch is engaged, and the first clutch and the second clutch are disconnected.
Further, during the process that the gearbox works in the first gear, when the displacement of the variable pump is smaller than the maximum displacement of the variable pump, the first motor and the second motor work at the corresponding maximum displacement, and during the process that the vehicle accelerates, the displacement of the variable pump is increased at a first preset speed; during deceleration of the vehicle, the displacement of the variable displacement pump is reduced at a first preset rate;
when the displacement of the variable displacement pump is equal to the maximum displacement thereof, the displacement of the first motor and the displacement of the second motor are respectively reduced at a second preset speed and a third preset speed during the acceleration of the vehicle; during deceleration of the vehicle, the displacement of the first motor and the displacement of the second motor are increased at a second preset rate and a third preset rate, respectively.
Further, in the process that the gearbox works at the first gear, when the variable displacement pump works at the maximum displacement and is in the acceleration process, if the displacement of the first motor and the displacement of the second motor are respectively reduced to a first preset displacement and a second preset displacement, the displacement of the first motor is adjusted to be zero, the second motor works at the maximum displacement, and the variable displacement pump works at the displacement calculated according to the formula; and the first clutch is disconnected after the displacement volume of the first motor becomes zero.
Further, in the engineering that the gearbox works at the second gear, when the displacement of the variable pump is smaller than the maximum displacement and in the acceleration process, the displacement of the first motor is zero, and the second motor works at the maximum displacement; during vehicle acceleration, the displacement of the variable displacement pump is increased at a fourth preset rate; during deceleration of the vehicle, the displacement of the variable displacement pump is reduced at a fourth preset rate;
when the displacement of the variable displacement pump is equal to the maximum displacement, the displacement of the first motor is zero; during vehicle acceleration, the displacement of the second motor is reduced at a fifth preset rate; during deceleration of the vehicle, the displacement of the second motor is increased at a fifth predetermined rate.
Further, when the transmission operates at the second gear and the vehicle is in the process of decelerating, when the displacement of the first motor is zero and the second motor operates at the maximum displacement, if the displacement of the variable displacement pump is reduced to the sixth preset displacement, the first clutch is engaged, then the displacement of the first motor and the displacement of the second motor are respectively adjusted to the first preset displacement and the second preset displacement, and the variable displacement pump operates at the displacement calculated according to the formula.
Further, when the transmission operates at the second gear and the vehicle is accelerating, when the variable displacement pump operates at the maximum displacement, if the displacement of the second motor is reduced to a third preset displacement, the third clutch is engaged, then the displacement of the second motor is adjusted to zero, the displacement of the first motor is adjusted to the maximum displacement, and the variable displacement pump operates at the displacement calculated according to the formula; and the second clutch is disengaged after the displacement of the second motor is adjusted to zero.
Further, in the process that the gearbox works in the third gear, when the displacement of the variable pump is smaller than the maximum displacement of the variable pump, the displacement of the second motor is zero, the first motor works at the maximum displacement of the variable pump, and in the process that the vehicle accelerates, the displacement of the variable pump is increased at a sixth preset speed; during deceleration of the vehicle, the displacement of the variable displacement pump is reduced at a sixth preset rate;
when the displacement of the variable displacement pump is equal to the maximum displacement, the displacement of the second motor is zero; during the acceleration of the vehicle, the displacement of the first motor is reduced at a seventh preset speed, and when the displacement of the first motor reaches a fourth preset displacement, the vehicle speed reaches the maximum; during deceleration of the vehicle, the displacement of the first motor is increased at a seventh preset rate.
Further, when the gearbox works in a third gear and the vehicle is in a deceleration process, when the displacement of the second motor is zero and the first motor works at the maximum displacement, if the displacement of the variable pump is reduced to a fifth preset displacement, the second clutch is engaged, then the displacement of the second motor is adjusted to a third preset displacement, meanwhile, the displacement of the first motor is adjusted to be zero, and the variable pump works at the displacement calculated according to the formula; and disconnecting the third clutch after the displacement of the first motor is zero.
Further, the displacement of the variable displacement pump is adjusted by adjusting the control current of the variable displacement pump, and the displacement of each motor is respectively adjusted by adjusting the control current of each motor.
The invention further provides a loader which comprises the vehicle gear shifting control system.
The invention has the beneficial effects that: the invention adopts two variable pumps, two motors and a three-gear transmission to carry out gear shifting work; when the gear of the gearbox is adjusted, a clutch which needs to be adjusted from a disconnection state to a connection state is firstly engaged when the displacement of a motor which drives the clutch to rotate and connect is not equal to zero; and then the clutch which needs to be adjusted from the connection state to the disconnection state is disconnected after the displacement of a motor driving the clutch to rotate is equal to zero, so that no power interruption is caused in the whole gear shifting process, the speed of the whole vehicle is not impacted when the clutch is disconnected, the stable change of the speed of the whole vehicle is ensured, and the automatic gear shifting is realized in the driving process.
Drawings
FIG. 1 is a schematic diagram of a vehicle shift control system according to the present invention;
FIG. 2 is a graph of displacement versus vehicle speed for the variable displacement pump and two motors of the present invention;
FIG. 3 is a flow chart of a method for controlling a shift of an upshift drive with the vehicle shift control system of the present invention;
FIG. 4 is a flow chart of a method for gear shifting control of a downshifting vehicle using the gear shifting control system of the present invention.
In the figure:
1. a variable displacement pump; 2. a first motor; 3. a second motor; 4. a first clutch; 5. a second clutch; 6. a third clutch; 7. a first gear; 8. a second gear; 9. a third gear; 10. a fourth gear; 11. a fifth gear; 12. and a sixth gear.
Detailed Description
The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.
As shown in fig. 1, the present embodiment provides a vehicle gear shifting control system, which is mainly applied to a hydrostatic loader, and ensures that the speed of the entire vehicle changes steadily and no power interruption occurs during the gear shifting process by coordinating and controlling the clutch of the transmission, the variable displacement pump 1 and the displacement of the two motors.
Referring to fig. 1, the vehicle shift control system includes a variable pump 4, a plurality of motors driven by the variable pump 1, and a multi-speed transmission including a plurality of clutches, at least one clutch being connected to each motor driven by the variable pump 1, at most one clutch connected to the same motor being in an engaged state. In the embodiment, two motors are provided, namely a first motor 2 and a second motor 3; the plurality of clutches includes a first clutch 4, a second clutch 5, and a third clutch 6; the first motor 2 is selectively connected to the input of the first clutch 4 or to the input of the third clutch 6, and the second motor 3 is connected to the input of the second clutch 5.
Specifically, the first motor 2 is connected with a first gear 7, the input end and the output end of the third clutch 6 are respectively connected with the first gear 7 and a second gear 8, and the second gear 8 is in transmission connection with a third gear 9; the input and output of the first clutch 4 are connected to a fourth gear 10 and a third gear 9, respectively, the fourth gear 10 meshing with the first gear 7. The third gear 9 is connected with a fifth gear 11 which is coaxial with the third gear, the input end and the output end of the second clutch 5 are respectively connected with the second motor 3 and a sixth gear 12, and the sixth gear 12 is in transmission connection with the fifth gear 11.
In the embodiment, the gearbox is provided with three gears, the change of the mechanical transmission ratio is realized by controlling the on-off of three clutches, when the gearbox works at a first gear, the first clutch 4 and the second clutch 5 are connected, the third clutch 6 is disconnected, the first motor 2 and the second motor 3 work simultaneously, and the mechanical transmission ratio is maximum at the moment; when the gearbox works in the first gear, the second clutch 5 is connected, the first clutch 4 and the third clutch 6 are disconnected, the first motor 2 does not work, only the second motor 3 works, and compared with the gearbox which works in the second gear, the mechanical transmission ratio is reduced; when the gearbox works in a third gear, the first clutch 4 and the second clutch 5 do not work, the third clutch 6 is connected, the second motor 3 does not work, only the first motor 2 works, the mechanical transmission ratio is minimum in the process, and the corresponding vehicle speed is maximum.
The embodiment also provides a driving gear-shifting control method, which is characterized in that by adopting the vehicle gear-shifting control system, when the gear of the gearbox is adjusted, the clutch which needs to be adjusted from a disconnection state to a connection state is firstly adjusted when the gear of the gearbox is adjusted, and the clutch is connected when the displacement of a motor which drives the clutch to be rotationally connected is not equal to zero; and then the clutch which needs to be adjusted from the connection state to the disconnection state is disconnected after the displacement of a motor driving the clutch to rotate is equal to zero, so that no power interruption is caused in the whole gear shifting process, the speed of the whole vehicle is not impacted when the clutch is disconnected, the stable change of the speed of the whole vehicle is ensured, and the automatic gear shifting is realized in the driving process.
Wherein, the discharge capacity and the speed of a plurality of motors of variable pump satisfy following formula:
wherein q ispmpRepresenting the displacement of the variable displacement pump, v representing the vehicle speed, η being a known fixed value, n representing the number of motors, qmotiRepresents the displacement of the ith motor; gamma rayiRepresenting the transmission ratio between the output of the i-th motor and the output of the gearbox when the gearbox is operating in the current gear.
The present embodiment specifically describes the driving shift control method with a vehicle shift system including two motors and three clutches. Referring to the relationship between the displacement of the variable displacement pump 1 and the two motors and the vehicle speed shown in fig. 2, the speed range of the whole vehicle is divided into eight stages.
As can be seen from the above equation (1), the displacement volume of the variable displacement pump 1, the displacement volumes of the first motor 2 and the second motor 3, and the vehicle speed satisfy the following equations:
qpmp＝v×η×(qmot1×γ1+qmot2×γ2) (2)
wherein q ispmpRepresenting the displacement of the variable pump, v representing the vehicle speed, η being a known constant value, η being related to the radius of the wheels, rear axle ratio, etc., each vehicle having a defined η, qmot1、qmot2Respectively representing the displacement volumes of the first motor 2 and the second motor 3; gamma ray1Representing the transmission ratio, gamma, between the output of the first motor 2 and the output of the gearbox when the gearbox is operating in the current gear2Which represents the transmission ratio between the output of the second motor 3 and the output of the gearbox when the gearbox is operating in the current gear.
The vehicle speed is adjusted by adjusting the displacement of the variable displacement pump 1 or the displacement of the two motors, and the vehicle speed is increased from the lowest to the highest, which is taken as an example, and the driving gear shift control method is described in detail with reference to the flow charts of the up-speed driving gear shift control method shown in fig. 2 and 3.
And S10, automatically adjusting the gearbox to be in the first gear after the vehicle is started.
S11, the first motor 2 and the second motor 3 are all operated at respective maximum displacements, the displacement of the variable displacement pump 1 being increased at a first preset rate.
In order to meet the rotation demand, the displacement of the variable displacement pump 1 cannot be zero, and the initial displacement of the variable displacement pump 1 is a preset minimum displacement in the present embodiment. The maximum displacement of the first motor 2 and the maximum displacement of the second motor 3 may be equal or unequal, and in this embodiment, the maximum displacement of the first motor 2 and the maximum displacement of the second motor 3 are equal.
The first preset speed is determined according to the gear shifting efficiency required by the hydraulic loader, the gear shifting efficiency is influenced by first gear shifting time, the first gear shifting time refers to the shortest time consumed when the gearbox automatically enters the first gear after being started and then directly enters the second gear by increasing the accelerator, the first gear shifting time is generally determined, and the displacement of the variable displacement pump 1 is required to be increased to the maximum displacement within the first gear shifting time.
As can be seen from the above equation (2), when the transmission operates in first gear, since the first motor 2 and the second motor 3 both operate at the respective maximum displacement in step S11, the displacement of the variable displacement pump 1 is proportional to the vehicle speed, that is, the vehicle speed increases as the displacement of the variable displacement pump 1 increases.
S12, after the displacement of the variable displacement pump 1 reaches its maximum displacement, the variable displacement pump 1 operates at its maximum displacement, and the displacement of the first motor 2 and the displacement of the second motor 3 are reduced at the second preset rate and the third preset rate, respectively.
In this embodiment, the second preset rate and the third preset rate are equal. As is known from the above description, when the transmission is operated in the first gear, since the variable displacement pump 1 is operated at the maximum displacement after the displacement of the variable displacement pump 1 reaches the maximum displacement thereof in step S12, the vehicle speed is inversely proportional to the displacement of the first motor 2 and the displacement of the second motor 3, and the vehicle speed gradually increases as the displacement of the first motor 2 and the displacement of the second motor 3 decrease.
S13, adjusting the displacement volume of the first motor 2 to zero when the displacement volume of the first motor 2 and the displacement volume of the second motor 3 are reduced to a first preset displacement volume and a second preset displacement volume, respectively, the second motor 3 is operated at the maximum displacement volume, the variable displacement pump 1 is operated at the displacement volume calculated according to the above formula (2), and the first clutch 4 is disengaged after the displacement volume of the first motor 2 becomes zero.
The first preset displacement and the second preset displacement are equal, the minimum displacement of the two motors is set for ensuring that the requirement of the whole vehicle on the speed torque is met, once the displacement of the two motors is smaller than the minimum displacement, the efficiency of the hydraulic system can be rapidly reduced, and then the requirement of the whole vehicle on the speed torque can not be met.
In the present embodiment, the maximum displacement of the first motor 2 is equal to the maximum displacement of the second motor 3, and if the maximum displacements of the first motor 2 and the second motor 3 are not equal to each other, it is required to reduce the displacements of the first motor 2 and the second motor 3 from the corresponding maximum displacements to the first preset displacement and the second preset displacement, respectively, within a predetermined time, and accordingly, the second preset rate and the third preset rate are different. The prescribed time is determined according to a demand for shift efficiency, and the first preset rate and the third preset rate are determined according to the prescribed time.
The gear shifting condition for adjusting the gear box from the first gear to the second gear is as follows: the variable displacement pump 1 operates at its maximum displacement, and the displacement of the first motor 2 and the displacement of the second motor 3 are reduced to a first preset displacement and a second preset displacement, respectively; the condition for completing the adjustment of the gearbox from the first gear to the second gear is as follows: each clutch has been adjusted to its respective engaged state when the transmission is operating in two gears.
The vehicle speed is considered to be constant during the period from the time when the shift condition for adjusting the transmission from first gear to second gear is satisfied to the time when the shift is completed, and the displacement of the variable displacement pump 1 is reduced by adjusting the displacements of the first motor 2 and the second motor 3.
Step S13 is a gear shift process for shifting the transmission from first gear to second gear, and it takes time to adjust the displacement of the first motor 2 to zero and the displacement of the second motor 3 to its maximum displacement, but this time is very short, usually about 500 milliseconds, and in the process of adjusting the displacements of the two motors, the variable displacement pump 1 operates at the displacement calculated according to the above formula (2) under the condition that the vehicle speed is not changed.
The engagement state of the three clutches when the gearbox operates in the second gear is compared with the engagement state of the three clutches when the gearbox operates in the first gear, and when the gearbox is switched from the first gear to the second gear, the first clutch 4 is only required to be disconnected. Therefore, in the process of switching the first gear operation of the gearbox to the second gear operation, after the displacement of the first motor 2 is adjusted to zero, the first clutch 4 is disconnected, so that no vehicle speed impact can be ensured in the process of disconnecting the first clutch 4, and the second clutch 5 is always in an engaged state in the gear shifting process, so that no power interruption occurs.
S14, the first motor 2 is kept at zero displacement, the second motor 3 is kept operating at its maximum displacement, and the displacement of the variable displacement pump 1 is increased at a fourth preset rate.
During operation of the gearbox in second gear, the first motor 2 is held at zero displacement in step S14, so γ1When the second motor 3 operates at the maximum displacement, the displacement of the variable pump 1 is proportional to the vehicle speed, and the vehicle speed gradually increases as the displacement of the variable pump 1 increases.
S15, after the displacement of the variable displacement pump 1 reaches its maximum displacement, the variable displacement pump 1 operates at its maximum displacement, the first motor 2 continues to maintain zero displacement, and the displacement of the second motor 3 decreases at a fifth preset rate.
During operation of the transmission in two gears, the variable displacement pump 1 is operated at its maximum displacement in step S15, the first motor 2 continues to maintain zero displacement, and as the displacement of the second motor 3 gradually decreases, the displacement of the second motor 3 is inversely proportional to the vehicle speed, and the vehicle speed gradually increases, as can be seen from the above equation (2).
The fourth preset speed and the fifth preset speed are determined according to the requirement on the gear shifting speed, in particular to the shortest time spent by the gearbox to enter the second gear to meet the gear shifting condition of shifting to the third gear.
S16, when the displacement of the second motor 3 is reduced to a third preset displacement, the third clutch 6 is engaged, the displacement of the second motor 3 is adjusted to zero, the displacement of the first motor 2 is adjusted to the maximum displacement, and the variable displacement pump 1 operates at the displacement calculated according to the formula (2); and the second clutch 5 is disconnected again after the displacement of the second motor 3 is adjusted to zero.
Compared with the three-clutch engagement state during the two-gear operation of the gearbox, the engagement state of the three clutches during the three-gear operation of the gearbox requires that the third clutch 6 is disengaged, the second clutch 5 is engaged, and the first clutch 4 is kept in the disengaged state, so that the second clutch 5 is engaged in advance before the third clutch 6 is not disengaged in order to avoid the power interruption during the gear shifting process. And after the displacement of the second motor 3 is adjusted to zero, the third clutch 6 is disconnected, so that the speed impact of the whole vehicle can be avoided.
The gear shifting condition for adjusting the gearbox from the second gear to the third gear is as follows: the variable displacement pump 1 operates at its maximum displacement, and the displacement of the first motor 2 is zero and the displacement of the second motor 3 is reduced to a third preset displacement; the condition for completing the adjustment of the gearbox from the second gear to the third gear is as follows: each clutch has been adjusted to the corresponding engaged state when the gearbox is operating in third gear.
In the process from the time when the shift condition for adjusting the transmission from second gear to third gear is satisfied to the time when the shift is completed, the vehicle speed is considered to be constant, and the displacement of the variable displacement pump 1 is reduced by adjusting the displacements of the first motor 2 and the second motor 3.
Step S16 is a gear shift process for shifting the transmission from second gear to third gear, it also takes time to adjust the displacement of the second motor 3 to zero and the displacement of the first motor 2 to its maximum displacement, but this time is very short, usually about 500 milliseconds, and in the process of adjusting the displacements of the two motors, the variable displacement pump 1 operates at the displacement calculated according to the above formula (2) under the condition that the vehicle speed is not changed.
S17, the second motor 3 keeps maintaining zero displacement, the first motor 2 keeps operating at its maximum displacement, and the displacement of the variable displacement pump 1 increases at a sixth preset rate.
During operation of the gearbox in third gear, the second motor 3 is held at zero displacement in step S17, so γ2When the first motor 2 is operated at the maximum displacement, the displacement of the variable pump 1 is proportional to the vehicle speed, and as the displacement of the variable pump 1 increases,the vehicle speed gradually increases.
S18, after the displacement of the variable displacement pump 1 reaches its maximum displacement, the variable displacement pump 1 operates at its maximum displacement, the second motor 3 continues to maintain zero displacement, and the displacement of the first motor 2 decreases at a seventh preset rate; when the displacement volume of the first motor 2 reaches the fourth preset displacement volume, the vehicle speed reaches the maximum.
During operation of the transmission in third gear, the variable displacement pump 1 is operated at its maximum displacement in step S18, the second motor 3 continues to maintain zero displacement, and as the displacement of the first motor 2 is gradually reduced, the displacement of the first motor 2 is inversely proportional to the vehicle speed, and the vehicle speed is gradually increased, as can be seen from the above equation (2).
In order to guarantee the requirement of the whole vehicle on the speed torque, the displacement of the first motor 2 is required to be not smaller than the fourth preset displacement in the process, so that the vehicle speed is maximized when the displacement of the first motor 2 reaches the fourth preset displacement, and the opening degree of the corresponding accelerator pedal is maximized at the moment.
The sixth preset speed and the seventh preset speed are determined according to the requirement for the gear shifting speed, in particular according to the shortest time spent by the gearbox to enter the third gear until the maximum speed is reached.
In this embodiment, the displacement of the variable displacement pump 1 is adjusted by adjusting the control current of the variable displacement pump 1, and the displacement of the two motors is adjusted by adjusting the control current of the two motors, respectively. The control current of the variable pump 1 and the control current of the two motors are related to the opening degree of an accelerator pedal, wherein the opening degree of the variable pump 1 is in direct proportion to the accelerator pedal, and the control current of the two motors is possibly in direct proportion to or in inverse proportion to the opening degree of the accelerator pedal, and is determined according to the type of the selected motor.
The driving shift control method during the vehicle speed reduction process is substantially the same as the driving shift control method during the vehicle speed increase process, and the following description will be given in detail by taking the example of switching from the highest vehicle speed in the third gear to the lowest speed in the first gear, and by referring to the flowcharts of the speed reduction driving shift control method shown in fig. 2 and 4.
S20, the variable displacement pump 1 is operated at its maximum displacement, the second motor 3 is kept at zero displacement, and the displacement of the first motor 2 is increased by the fourth preset displacement at a seventh preset rate.
S21, after the displacement of the first motor 2 reaches its maximum displacement, the first motor 2 continues to operate at its maximum displacement, the second motor 3 maintains a zero displacement, and the displacement of the variable displacement pump 1 decreases at a sixth preset rate.
S22, when the displacement of the variable displacement pump 1 is reduced to a fifth preset displacement, the second clutch 5 is engaged, the displacement of the second motor 3 is adjusted to a third preset displacement, and the displacement of the first motor 2 is adjusted to be zero, and the variable displacement pump 1 operates at the displacement calculated according to the formula (2); and the third clutch 6 is disengaged after the displacement volume of the first motor 2 is zero.
The fifth preset displacement is the displacement of the variable displacement pump 1 corresponding to the moment the gearbox is just adjusted from the second gear to the third gear in the speed-up process. By the adjustment of step S22, the displacement of the variable displacement pump 1 reaches its maximum displacement at the moment when the transmission is just switched from third gear to second gear.
S23, the variable displacement pump 1 is operated at its maximum displacement, the first motor 2 is kept at zero displacement, and the displacement of the second motor 3 is increased at a fifth preset rate.
The displacement of the variable displacement pump 1 is instantaneously increased to the maximum displacement during the shifting of the transmission from the third gear operation to the second gear operation, that is, during the adjustment of the displacements of the first motor 2 and the second motor 3 in step S22.
S24, after the displacement of the second motor 3 reaches its maximum displacement, the first motor 2 maintains zero displacement, the second motor 3 operates at its maximum displacement, and the displacement of the variable displacement pump 1 decreases at a fourth preset rate.
And S25, after the displacement of the variable pump 1 is reduced to the sixth preset displacement, firstly engaging a clutch which needs to be engaged when the gearbox works in the first gear, firstly engaging the first clutch 4, then respectively adjusting the displacement of the first motor 2 and the displacement of the second motor 3 to the first preset displacement and the second preset displacement, and enabling the variable pump 1 to work according to the displacement calculated by the formula (2).
The sixth preset displacement is the displacement of the variable displacement pump 1 corresponding to the case where the gearbox is just adjusted from the first gear to the second gear in the speed-up process. By the adjustment of step S25, the displacement of the variable displacement pump 1 reaches its maximum displacement at the moment when the transmission is just switched from second gear to first gear.
S26, the variable displacement pump 1 is operated at its maximum displacement, and the displacement of the first motor 2 and the displacement of the second motor 3 are increased at the second preset rate and the third preset rate, respectively.
And S27, when the displacement of the first motor 2 and the displacement of the second motor 3 are adjusted to the corresponding maximum displacement, the vehicle speed is lowest.
The invention also provides a loader which comprises the vehicle gear shifting control system and adopts the driving gear shifting control method to carry out gear shifting control, so that automatic gear shifting in the driving process can be realized, speed impact and speed interruption are avoided, and the stable change of the speed of the whole vehicle is ensured.
The motor referred to in this embodiment remains at zero displacement, i.e. it is not operating.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (10)
1. A driving gear shift control method, characterized in that a vehicle gear shift control system comprises a variable pump (1), a plurality of motors driven by the variable pump (1) and a multi-speed transmission, the transmission comprising a plurality of clutches, at least one clutch being connected to each motor driven by the variable pump (1), at most one of the at least one clutches connected to the same motor being in an engaged state;
the method for applying the vehicle gear-shifting control system comprises the following steps: when the gear of the gearbox is adjusted, a clutch which needs to be adjusted from a disconnection state to a connection state is firstly adjusted, and the clutch is connected when the displacement of a motor which drives the clutch to be rotationally connected is not equal to zero; then the clutch which needs to be adjusted from the connection state to the disconnection state is disconnected after the displacement of a motor which drives the clutch to rotate is equal to zero;
the displacement of the variable displacement pump (1), the displacements of the plurality of motors, and the vehicle speed satisfy the formula:
wherein q ispmpRepresenting the displacement of the variable displacement pump, v representing the vehicle speed, η being a known fixed value, n representing the number of motors, qmotiRepresents the displacement of the ith motor; gamma rayiRepresenting the transmission ratio between the output end of the ith motor and the output end of the gearbox when the gearbox works at the current gear;
the plurality of motors includes a first motor (2) and a second motor (3), and the plurality of clutches includes a first clutch (4), a second clutch (5), and a third clutch (6); the first motor (2) is selectively connected with the input end of the first clutch (4) or the input end of the third clutch (6), and the second motor (3) is connected with the input end of the second clutch (5);
after the vehicle is started, the first gear of the gearbox is automatically adjusted, when the gearbox works at the first gear, the first clutch (4) and the second clutch (5) are connected, and the third clutch (6) is disconnected; when the gearbox works in two gears, the second clutch (5) is connected, and the first clutch (4) and the third clutch (6) are disconnected; when the gearbox works in a third gear, the third clutch (6) is engaged, and the first clutch (4) and the second clutch (5) are disconnected;
in the process that the gearbox works in a first gear, when the displacement of the variable displacement pump (1) is smaller than the maximum displacement of the variable displacement pump, the first motor (2) and the second motor (3) work at the corresponding maximum displacement, and in the process of vehicle acceleration, the displacement of the variable displacement pump (1) is increased at a first preset speed; during deceleration of the vehicle, the displacement of the variable displacement pump (1) is reduced at a first preset rate;
when the displacement of the variable displacement pump (1) is equal to the maximum displacement thereof, the displacement of the first motor (2) and the displacement of the second motor (3) are reduced at a second preset rate and a third preset rate, respectively, during acceleration of the vehicle; during deceleration of the vehicle, the displacement of the first motor (2) and the displacement of the second motor (3) are increased at a second preset rate and a third preset rate, respectively;
in the process that the gearbox works at a first gear, when the variable pump (1) works at the maximum displacement and is in an acceleration process, if the displacement of the first motor (2) and the displacement of the second motor (3) are respectively reduced to a first preset displacement and a second preset displacement, the displacement of the first motor (2) is adjusted to be zero, the second motor (3) works at the maximum displacement, and the variable pump (1) works at the displacement calculated according to the formula; and the first clutch (4) is disconnected after the displacement volume of the first motor (2) becomes zero.
2. A service shift control method as claimed in claim 1, wherein in a transmission operating in two gears, when the displacement of the variable displacement pump (1) is less than its maximum displacement and during acceleration, the displacement of the first motor (2) is zero and the second motor (3) is operating at maximum displacement; during vehicle acceleration, the displacement of the variable displacement pump (1) is increased at a fourth preset rate; during deceleration of the vehicle, the displacement of the variable displacement pump (1) is reduced at a fourth preset rate;
when the displacement of the variable displacement pump (1) is equal to the maximum displacement, the displacement of the first motor (2) is zero; during vehicle acceleration, the displacement of the second motor (3) is reduced at a fifth preset rate; during deceleration of the vehicle, the displacement of the second motor (3) is increased at a fifth preset rate.
3. A method as claimed in claim 1, wherein the transmission is operating in two gear and the vehicle is decelerating, and wherein when the displacement of the first motor (2) is zero and the second motor (3) is operating at its maximum displacement, the first clutch (4) is engaged if the displacement of the variable displacement pump (1) is reduced to a sixth predetermined displacement, and the displacement of the first motor (2) and the displacement of the second motor (3) are adjusted to first and second predetermined displacements respectively, the variable displacement pump (1) operating at the displacement calculated according to said formula.
4. A method of gear shift according to claim 3, characterized in that the gearbox is operated in two gear and the vehicle is under acceleration, while the variable displacement pump (1) is operating at its maximum displacement, if the displacement of the second motor (3) is reduced to a third preset displacement, the third clutch (6) is engaged, then the displacement of the second motor (3) is adjusted to zero and the displacement of the first motor (2) is adjusted to maximum displacement, the variable displacement pump (1) operating at a displacement calculated according to said formula; and the second clutch (5) is disconnected after the displacement of the second motor (3) is adjusted to zero.
5. A service shift control method as claimed in claim 4, wherein during operation of the gearbox in third gear, when the displacement of the variable displacement pump (1) is less than its maximum displacement, the displacement of the second motor (3) is zero, the first motor (2) is operated at its maximum displacement, and during vehicle acceleration, the displacement of the variable displacement pump (1) is increased at a sixth predetermined rate; during deceleration of the vehicle, the displacement of the variable displacement pump (1) is reduced at a sixth preset rate;
when the displacement of the variable displacement pump (1) is equal to the maximum displacement, the displacement of the second motor (3) is zero; during vehicle acceleration, the displacement of the first motor (2) is reduced at a seventh preset rate, and when the displacement of the first motor (2) reaches a fourth preset displacement, the vehicle speed reaches the maximum; during deceleration of the vehicle, the displacement of the first motor (2) is increased at a seventh preset rate.
6. A method of gear shift control according to claim 5, characterized in that, during deceleration of the vehicle and operation of the gearbox in third gear, when the displacement of the second motor (3) is zero and the first motor (2) is operating at its maximum displacement, if the displacement of the variable displacement pump (1) is reduced to a fifth predetermined displacement, the second clutch (5) is engaged first, and then the displacement of the second motor (3) is adjusted to a third predetermined displacement, while the displacement of the first motor (2) is adjusted to zero, the variable displacement pump (1) operating at a displacement calculated according to said formula; and the third clutch (6) is disengaged after the displacement of the first motor (2) is zero.
7. A service shift control method according to claim 1, characterized in that the displacement of the variable displacement pump (1) is adjusted by adjusting the control current of the variable displacement pump (1), and the displacement of each motor is adjusted separately by adjusting the control current of each motor.
8. A driving gear shift control method according to claim 1, characterized in that the first motor (2) is in driving connection with a first gear (7), the input and output of the third clutch (6) are in driving connection with the first gear (7) and a second gear (8), respectively, the second gear (8) is in driving connection with a third gear (9);
the input end and the output end of the first clutch (4) are in transmission connection with a fourth gear (10) and the third gear (9) respectively, and the fourth gear (10) is in transmission connection with the first gear (7).
9. A driving gear shift control method according to claim 8, characterized in that the third gear (9) is connected with a fifth gear (11) arranged coaxially therewith, the input and output of the second clutch (5) are in driving connection with the second motor (3) and a sixth gear (12), respectively, the sixth gear (12) is in driving connection with the fifth gear (11).
10. A loader characterized in that a running gear shift control method according to any one of claims 1 to 9 is employed.
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| CN201811543291.3A CN109372981B (en) | 2018-12-17 | 2018-12-17 | Vehicle gear shifting control system, driving gear shifting control method and loader |
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| CN201811543291.3A CN109372981B (en) | 2018-12-17 | 2018-12-17 | Vehicle gear shifting control system, driving gear shifting control method and loader |
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| CN110239341A (en) * | 2019-06-27 | 2019-09-17 | 山推工程机械股份有限公司 | A kind of transmission system and engineering truck |
| CN110985629B (en) * | 2019-12-26 | 2023-02-17 | 广西柳工机械股份有限公司 | Hydrostatic drive transmission system, speed change control method and loader |
| CN112664650B (en) * | 2021-01-05 | 2023-01-06 | 潍柴动力股份有限公司 | Gear shifting control method and system for hydrostatic automatic AT gearbox |
| CN112982538B (en) * | 2021-02-24 | 2022-06-21 | 索特传动设备有限公司 | Control method and device of wheel loader, wheel loader and storage medium |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2646599B2 (en) * | 1987-07-31 | 1997-08-27 | 株式会社島津製作所 | Continuously variable transmission |
| DE4307616C2 (en) * | 1993-03-08 | 1996-06-27 | Mannesmann Ag | Hydrostatic-mechanical transmission |
| JP3786390B2 (en) * | 1998-02-20 | 2006-06-14 | 株式会社小松製作所 | Driving device for multiple hydraulic motors |
| WO2007010743A1 (en) * | 2005-07-22 | 2007-01-25 | Komatsu Ltd. | Device and method for continuously variable transmission of traveling vehicle |
| JP5171053B2 (en) * | 2007-02-09 | 2013-03-27 | 日立建機株式会社 | Clutch control device for hydraulic drive vehicle |
| DE102013216850B4 (en) * | 2013-08-23 | 2015-03-05 | Danfoss Power Solutions Gmbh & Co. Ohg | ON / OFF DOME METHOD |
| CN103758976A (en) * | 2014-01-08 | 2014-04-30 | 湖南三一路面机械有限公司 | Power transmission system and grader |
| DE102015209356B3 (en) * | 2015-05-21 | 2016-08-25 | Danfoss Power Solutions Gmbh & Co. Ohg | LOAD-RELATED CONTROL OF HYDRAULIC MOTORS |
| DE102016207228A1 (en) * | 2016-04-28 | 2017-11-02 | Robert Bosch Gmbh | Transmission combination, travel drive and method for controlling the gearbox combination |
| CN106122423B (en) * | 2016-08-12 | 2018-06-08 | 燕山大学 | Hydromechanical Stepless Transmission power changes a section control method |
| DE102017211232A1 (en) * | 2017-07-03 | 2019-01-03 | Robert Bosch Gmbh | Travel drive and method for driving a traction drive |
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