KR20150029466A - Shift control method of automatic transmission - Google Patents

Abstract

Disclosed is a gear shift control method of an automatic transmission. The gear shift control method capable of controlling a gear to be shifted from a current step realized by the engagement of a first, a second, and a third friction element to a target step realized by the engagement of a fourth, a fifth, and a sixth friction element comprises: a step of shifting the gear to the current step by additionally engaging a surplus friction element among the fourth, the fifth, and the sixth friction element at the end of shifting the gear to the current step; a step of step-releasing one of the surplus friction element and the first, the second, and the third friction element at a start timing of a gear shift according to the target step when shifting the gear from the current step to the target step; and a step of controlling the gear to be shifted to the target step after step-releasing the friction element. According to the present invention, the gear shift control method is capable of reducing control elements in the case of shifting the gear to the target step by additionally engaging the surplus friction element when shifting the gear to the current step, thereby performing a skip-shift.

Description

Technical Field [0001] The present invention relates to a shift control method for an automatic transmission,

The present invention relates to a shift control method for an automatic transmission. More particularly, the present invention relates to a shift control method of an automatic transmission in which a skip shift from a current stage to a target stage in a kickdown skip The present invention relates to a shift control method for an automatic transmission that is capable of performing a skip shift by reducing an amount of a control element during a target speed change.

Generally, a vehicle equipped with an automatic transmission controls an oil pressure in a shift range set according to the running speed of the vehicle and the throttle opening amount, so that the automatic transmission can be operated by automatically shifting the transmission to the target.

Therefore, in a vehicle equipped with an automatic transmission whose operating state is controlled according to the hydraulic pressure, there is no need to operate a clutch pedal for interrupting the power to the engine in order to vary the operating state of the corresponding shift gear, And the engine stall due to the malfunction of the driver during running or the inexperience of running does not occur. Therefore, even in the case of a novice, the operation can be facilitated.

In such an automatic transmission, a torque converter changes the rotational power of the engine, and the solenoid valve is controlled by a control signal applied from a transmission control unit (TCU) according to the driving state of the vehicle A hydraulic circuit is formed so that the corresponding friction element can be operated to execute the automatic shift operation.

Therefore, the automatic transmission outputs the corresponding control signal in accordance with the shift position of the shift lever of the driver, the vehicle speed and the amount of opening of the throttle valve, and the corresponding solenoid valve is driven by the output control signal to effect the valve port conversion of the hydraulic circuit. And controls the operating state of the operating friction element for selecting one of the gear positions of the gear mechanism of the transmission mechanism by the hydraulic pressure supplied from the oil pump. The friction element composed of the clutch and the brake switches the operating state of the planetary gear set according to the selective operation of the friction element, changes to an appropriate speed ratio, and is transmitted to the drive gear.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 2008-0012173 (published on Mar. 11, 2008, entitled "Shift Control Method of Automatic Transmission").

In recent years, the development of high-speed automatic transmission has been progressing to improve fuel efficiency. As a result, the number of clutches for forming a large number of speed change stages is increasing. Four, four, five, And six clutches are required for 10 speeds.

Generally, clutch-to-clutch shifting control is performed by releasing one friction element and engaging another friction element. However, in the case of performing a specific skip shift, there are four control elements that release two friction elements and engage the other two friction elements.

However, in a 10-speed automatic transmission, in the case of a kick down skip shift such as 10 3 shift and 7 2 shift, six control elements are generated, so that a direct skip shift can not be performed, The control is performed by a method in which

Thus, there is a problem in that when the shift is made to the target stage via the intermediate stage, the shift time becomes longer after shifting to the intermediate stage.

That is, there is a problem that the shift time becomes long by performing the 4 → 3 shift after the completion of the 10 → 4 shift, and the shift is performed smoothly by performing the shift to the target stage after performing the shift to the intermediate stage There is a problem that the transmission feeling is reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a control system for a vehicle, The present invention is to provide a shift control method of an automatic transmission that can perform a skip shift by additionally engaging an excessive friction element in shifting to a current stage to reduce a control element in a target speed change.

The shift control method for an automatic transmission according to the present invention is a method for controlling a shift from a current stage realized by fastening of first, second and third friction elements to a target stage implemented by fastening of the fourth, 6. A shift control method for an automatic transmission, comprising: shifting an additional friction element among the fourth, fifth, and sixth friction elements at the end of a shift period when shifting to a current stage; Releasing the excess friction element and any one of the first, second, and third friction elements at the shift start point according to the target stage in shifting from the current stage to the target stage; And performing a shift control to a target stage after the step is released.

In the present invention, the surplus friction element is a friction element having the same rotational speed as any one of the first, second, and third friction elements in the fourth, fifth, and sixth friction elements.

The step releasing step according to the present invention is characterized in that any frictional element among the excess frictional elements and the first, second and third frictional elements having the same rotational speed is released stepwise.

At this time, the surplus friction element is preferentially released stepwise.

The step releasing step according to the present invention is characterized in releasing the step at the point of time of rising to the shift control initial full line pressure.

The shift control method of an automatic transmission according to the present invention is a shift control method for an automatic transmission in which a skip shift from a current stage to a target stage occurs at a gear stage exceeding four control elements during a kick down skip shift, By further tightening the friction element, the control element is reduced during the target speed change, so that the kick down skip shift can be performed, the shift time can be shortened, and the shift feeling can be improved.

1 is a structural diagram of a 10-speed automatic transmission applied to a shift control method of an automatic transmission according to an embodiment of the present invention.
2 is a view showing a table of operating elements of a 10-speed automatic transmission applied to a shift control method of an automatic transmission according to an embodiment of the present invention.
3 is a view showing a lever diagram of a 10-speed range in a shift control method of an automatic transmission according to an embodiment of the present invention.
4 is a view showing a lever diagram of a 7-speed range in a shift control method of an automatic transmission according to an embodiment of the present invention.
5 is a block diagram illustrating a shift control apparatus for an automatic transmission according to an embodiment of the present invention.
6 is a flowchart illustrating a shift control method for an automatic transmission according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a shift hydraulic pressure control according to a shift control method of an automatic transmission according to an embodiment of the present invention. FIG.

Hereinafter, a shift control method for an automatic transmission according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

1 is a structural diagram of a 10-speed automatic transmission applied to a shift control method of an automatic transmission according to an embodiment of the present invention.

As shown in FIG. 1, a 10-speed automatic transmission applied to a shift control method of an automatic transmission according to an embodiment of the present invention includes six (6) planetary gear sets The four clutches C1 to C4 and the two brakes B1 and B2, which are friction elements, are combined and controlled.

That is, the first planetary gear set 1 is a single pinion planetary gear set that includes the first sun gear S1, the first planetary carrier PC1, and the first ring gear R1 as operating members, The second planetary carrier PC2 and the second ring gear R2 as operating members and the third planetary gear set 3 is a single pinion planetary gear set including the second sun gear S2, The third planetary carrier PC3 and the third ring gear R3 as operating members and the fourth planetary gear set 4 includes the double pinion planetary gear set 4 as the single pinion planetary gear set, A fourth planetary carrier S4, a fourth planetary carrier PC4, and a fourth ring gear R4 as operation members.

Further, the automatic transmission includes an input shaft IN for receiving power, an output shaft OUT for outputting power, and a transmission case H.

In this automatic transmission, the first sun gear S1 is variable-stopped by being connected to the transmission case H by placing the first brake B1, and fixedly connected to the second sun gear S2.

The first ring gear R1 is variable stopped by being connected to the transmission case H by placing the second brake B2 and the first planetary carrier PC1 is fixedly connected to the third planetary carrier PC3, The planetary carrier PC3 is fixedly connected to the fourth ring gear R4.

The second planetary carrier PC2 functions as an input element by being fixedly connected to the input shaft IN and the second planetary carrier PC2 also functions as the fourth sun gear S4 and variable .

The second ring gear R2 is variably connected to the fourth planetary gear S4 and rotatably connected to the fourth planetary carrier PC4 by placing the first clutch C1 while being variably connected to the fourth sun gear S4 by the second clutch C2, 4 planetary carrier PC4 is fixedly connected to the third sun gear S3.

Further, the second ring gear R2 is variably connected to the fourth ring gear R4 by placing the fourth clutch C4.

The third ring gear R3 is fixedly connected to the output shaft OUT, thereby functioning as an output element at all times.

FIG. 2 is a view showing a table of operating elements of a 10-speed automatic transmission applied to a shift control method of an automatic transmission according to an embodiment of the present invention, and FIG. 3 is a flowchart illustrating a shift control method of an automatic transmission according to an embodiment of the present invention And FIG. 4 is a view showing a seventh speed lever diagram in the shift control method of an automatic transmission according to an embodiment of the present invention. Referring to FIG.

1, the first clutch C1, the first brake B1, and the second brake B2 are operated in the reverse rotation (R) in the 10-speed automatic transmission configured as shown in FIG. 1, and the neutral (N The first brake B1 and the second brake B2 are operated and the third clutch C3, the first brake B1 and the second brake B2 are actuated in the first speed and in the second speed, The second clutch C2, the first brake B1 and the second brake B2 are operated and the second clutch C2, the third clutch C3 and the second brake B2 in the third speed The fourth clutch C4 and the second brake B2 are operated in the fourth speed and the third clutch C3 and the fourth clutch C4 are engaged in the fifth speed, The second brake B2 is operated and the first clutch C1, the third clutch C3 and the second brake B2 are actuated in the sixth speed, and in the seventh speed, the first clutch C1, (C3), and the fourth clutch (C4) are operated, and further, the second clutch (C2) The first clutch C1 and the third clutch C3 and the first brake B1 are actuated in the eighth state and the third clutch C3 and the fourth clutch C4 in the ninth state, The first clutch C1 and the fourth clutch C4 and the first brake B1 are actuated and the second clutch C2 is further actuated by the excess friction element Respectively.

When the kick-down skip shift occurs from the tenth to the third speed in the operating element table, the first clutch C1 is disengaged, the second clutch C2 is engaged, and the third clutch C3 is engaged The fourth clutch C4 is released, the first brake B1 is disengaged, the second brake B2 is engaged, but the six control elements are operated in this way, The first clutch C1 is released stepwise to the shift start point at the time of shifting to the third speed and the shifting is progressed so that the four control elements 2 One-element, two-element engagement).

3, when the first clutch C1, the fourth clutch C4, and the first brake B1 are actuated, the fourth sun gear S4, the third ring C4, The third planetary carrier PC3, the fourth ring gear R4, the third sun gear S3 and the fourth planetary carrier PC4 become integral with each other, that is, do. At this time, the second ring gear R2 and the fourth sun gear S4 that are variably connected by the second clutch C2 also rotate at the same relative speed, so that even when the second clutch C2 is engaged as an excessive friction element, So that no fluctuation occurs in the gear structure.

Therefore, by further tightening the second clutch C2, which is an excess friction element, in the shift control to the tenth speed, it is possible to reduce the control element in the shift control to the other target stage.

On the other hand, for example, in the case of shifting from the third speed to the fourth speed when the second clutch C2 is shifted from the third speed to the shift start point, the first brake B1 is disengaged , And the second brake B2 can be tightened to simplify the control with the two control elements.

When a kick down skip shift occurs from the seventh gear to the second gear, the first clutch C1, the third clutch C3 and the fourth clutch 4 are disengaged and the second clutch C2, It is possible to control by operating six control elements for engaging the brake B1 and the second brake B2, but by engaging the second clutch C2, which is an excessive friction element in shifting to the seventh speed, , The first clutch C1 is released stepwise to the shift start point, and then the shift is made so that the shift can be performed to the four control elements (two elements corresponding to the two elements).

4, when the first clutch C1, the third clutch C3 and the fourth clutch C1 are operated, the fourth sun gear S4, the third ring C1, The third planetary carrier PC3, the fourth ring gear R4, the third sun gear S3, the fourth planetary carrier PC4, the second sun gear S2, the second planetary carrier PC2, And the second ring gear R2 are integrally formed, that is, the relative speed becomes zero, and the rotation is performed. At this time, the second ring gear R2 and the fourth sun gear S4 that are variably connected by the second clutch C2 also rotate at the same relative speed, so that even when the second clutch C2 is engaged as an excessive friction element, So that no fluctuation occurs in the gear structure.

Therefore, by further tightening the second clutch C2, which is an excess friction element, in the shift control to the seventh speed, it is possible to reduce the control element in the shift control to the other target stage.

5 is a block diagram of a system for performing a shift control method of an automatic transmission according to an embodiment of the present invention.

5, a system for performing a shift control method for an automatic transmission according to an embodiment of the present invention includes a throttle opening sensor 10, a vehicle speed sensor 20, a turbine speed sensor 30, (40), a transmission control unit (50), and a hydraulic control unit (60).

The throttle opening sensor 10 detects an opening degree change of the throttle valve operated by the degree of operation of the accelerator pedal and transmits a signal to the throttle valve control unit 50 to the throttle opening degree sensor 10.

The vehicle speed sensor 20 detects the speed of the vehicle and transmits a signal to the transmission control unit 50.

The turbine speed sensor 30 detects the current turbine speed operating on the input torque of the transmission from the angular displacement of the crankshaft and transmits the signal to the transmission control unit 50.

The hydraulic pressure sensor 40 detects the hydraulic pressure acting on each releasing element and the engaging element and transmits it to the transmission control unit 50.

The transmission control unit 50 may be implemented with one or more processors operating by a set program, and the set program is programmed to perform each step of the shift control method of the automatic transmission according to the embodiment of the present invention.

The transmission control unit 50 receives a throttle opening signal, a vehicle speed signal, a turbine speed signal and a hydraulic pressure signal from the throttle opening sensor 10, the vehicle speed sensor 20, the turbine speed sensor 30 and the hydraulic pressure sensor 40, Receive.

Further, the transmission control unit 50 calculates the current gear ratio based on the vehicle speed and the turbine speed.

The transmission control unit 50 generates and transmits the hydraulic pressure transmission signal corresponding to the above signals to the hydraulic pressure control unit 60. [

Further, the transmission control unit 50 includes a map table 55. [

The map table 55 stores the throttle opening degree corresponding to the vehicle speed at each gear position. Therefore, the transmission control unit 50 calculates a target shift stage corresponding to the throttle opening signal and the vehicle speed signal, and determines whether the shift condition is satisfied.

In the map table 55, release factors and tightening pressures applied to the releasing elements and the engaging elements corresponding to the respective gear positions are stored.

In the map table 55, gear ratios corresponding to the respective gear positions are stored.

The specific values stored in the map table 55 may be set to values desirable to those skilled in the art according to the specifications of the vehicle and / or the engine in which the shift control method of the automatic transmission according to the embodiment of the present invention is implemented.

The hydraulic pressure control unit 60 receives the hydraulic pressure transmission signal from the transmission control unit 50, and controls the hydraulic pressure applied to each release element and the engagement element. The hydraulic control unit (60) includes at least one control valve and a solenoid valve for controlling the hydraulic pressure applied to each release element and the engagement element.

FIG. 6 is a flowchart for explaining a shift control method of an automatic transmission according to an embodiment of the present invention, and FIG. 7 is a diagram illustrating a shift hydraulic pressure control scheme according to a shift control method of an automatic transmission according to an embodiment of the present invention.

As shown in FIG. 6, the shift control method of an automatic transmission according to an embodiment of the present invention includes shifting of the first, second, and third frictional elements, The present invention is applied to a case where there is a shift control to the target stage implemented by the present invention.

That is, the present invention is applied to the case where there are six control elements by performing releasing and fastening of all friction elements when shifting from the current stage to the target stage.

In the operating element table shown in Fig. 2, the present stage satisfying such conditions corresponds to the tenth and seventh terns.

That is, in the case of the tenth gear, it is implemented by engagement of the first clutch C1, the fourth clutch C4, and the first brake B1. The third speed is implemented by engagement of the second clutch C2, the third clutch C3, and the second brake B2.

Therefore, when kick down skip shift occurs from the tenth to the third gear, six control elements must be driven for the shift control.

On the other hand, in the case of the seventh speed, it is implemented by engaging the first clutch C1, the third clutch C3, and the fourth clutch C4. And, the second speed is implemented by engagement of the second clutch C2, the first brake B1, and the second brake B2.

Therefore, when a kick down skip shift occurs from the seventh speed to the second speed, six control elements must be driven for the shift control.

Thus, when the current stage is the 10th speed and the 7th speed, there are cases where the number of control elements exceeds 4 in the case of the third stage or the second single stage.

Therefore, the transmission control unit 50 calculates a target shift stage corresponding to the throttle opening signal and the vehicle speed signal, and determines whether the target stage is set to the tenth or seventh speed, which is the current stage (S10).

At this time, if the current speed is not the tenth or seventh speed, the shift control is performed to the target speed through the general speed change control (S20).

However, when shifting to the present stage, the surplus friction element is additionally tightened at the end of the current one-speed shift (S12).

The surplus friction element further fastens the second clutch C2 with the clutch constituting the constant speed stage, in which the relative speed of the variable linking member is zero and the rotational speed is the same, even when the clutch is not operated.

That is, in the case of the tenth gear, after the first clutch C1, the fourth clutch C4, and the first brake B1 are engaged, the second clutch C2 is further tightened at the end of the shift.

In this way, after the shift control is performed to the current stage, the line pressure control is performed to the present stage (S14).

Then, it is determined whether a shift signal is input (S16).

At this time, if the second clutch C2, which is an excessive friction element, is released according to the target stage at the time of shifting from the present stage to the target stage, the step is released at the shift start point (S18).

That is, as shown in Fig. 7, the step is released at the point of time when the second clutch C2 is raised to the shift-control initial full-line pressure.

Thereafter, release and engagement are performed in accordance with the operating element of the target stage to perform shift control (S20).

In general, the shift control is shifted to the full-line pressure and released and tightened as much as the set amount. When the shift-side oil passage is filled with oil pressure and the shifting to the target stage is completed, the revolution speed of the turbine is changed from the present stage to the target stage, After that, it is raised to the full line pressure and completely tightened, and then the line pressure control is performed to the target stage.

When the second stage clutch C2, which is a surplus friction element, is held at the target stage from above, the first clutch C1 having the same rotation speed at the shift start time is released stepwise.

That is, when the second clutch C2 is engaged when shifting from the present stage to the target stage, the first clutch C1 is released stepwise at the shift start point. However, when the second clutch C2 is disengaged, the second clutch C2 is released stepwise at the shift start point.

When both the first clutch C1 and the second clutch C2 are disengaged, the second clutch C2 is preferentially released in a stepwise manner.

When the 10th to 3rd speed kick down skip shift occurs when the second clutch C2 is additionally engaged, when the first clutch C1 is released stepwise at the shift start time, the third clutch C3 and the second brake Element releasing and two-element engaging four-element control in which the second clutch B2 is engaged and the fourth clutch C4 and the first brake B1 are disengaged.

On the other hand, when the 10th to 4th speed skip shift occurs, the first four-element control is performed. However, when the first clutch C1 is released stepwise at the shift start time by additionally engaging the second clutch C2 during the 10th speed change, It is simplified to a two-element control in which the brake B1 is released and the second brake B2 is engaged.

As described above, according to the shift control method for an automatic transmission according to the present invention, in the case of a current stage in which a skip shift from a current stage to a target stage occurs at a gear stage exceeding four control elements in a kick down skip shift By additionally engaging an excessive friction element in shifting to the current stage, the control element is reduced in the target speed change, so that the kick down skip shift can be performed, the shift time can be shortened, and the shift feeling can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand.

Accordingly, the technical scope of the present invention should be defined by the following claims.

1 to 4: First to fourth planetary gear sets
10: Stroke opening sensor 20: Vehicle speed sensor
30: turbine speed sensor 40: hydraulic sensor
50: Transmission control unit 55: Map table
60: Hydraulic control units S1 to S4: First to fourth ring gears
C1 to C4: First to fourth clutches PC1 to PC4: First to fourth planetary carriers
R1 to R4: first to fourth ring gears B1, B2: first and second ring gears B1,

Claims (5)

A shift control method of an automatic transmission for controlling a shift from a current stage implemented by engagement of first, second, and third friction elements to a target stage implemented by engagement of fourth, fifth, and sixth friction elements,
Further comprising the steps of: (a) shifting an excessive frictional element among the fourth, fifth, and sixth frictional elements by further tightening at the end of shifting when shifting to the current stage;
Releasing a friction element of any one of the excess friction element and the first, second, and third friction elements at a shift start time according to the target stage when shifting from the current stage to the target stage; And
And performing the shift control to the target stage after releasing the step.
2. The automatic transmission according to claim 1, wherein the excess friction element is a friction element having the same rotational speed as any one of the first, second and third friction elements in the fourth, fifth and sixth friction elements Way.
The automatic transmission according to claim 1, wherein said step releasing step frees a friction element of any one of said excess friction element and said first, second and third friction elements, A shift control method.
4. The shift control method for an automatic transmission according to claim 3, wherein said surplus friction element is preferentially released stepwise.
2. The shift control method for an automatic transmission according to claim 1, wherein the step releasing step releases the step at a point of time when it is raised to the shift control initial full-line pressure.

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