JPH08178043A - Transmission control device - Google Patents

Abstract

PURPOSE: To decelerate responsiveness as the target change gear ratio is approached during response control and realize the control having no overshoot by calculating the target change gear ratio to be set next from a specific equation with a change gear map when the target change gear ratio is set based on the vehicle speed and accelerator depression quantity. CONSTITUTION: The target change gear ratio is read from a speed change map storing the target change gear ratio corresponding to the vehicle speed and accelerator depression quantity, and it is written in a memory. When a clutch 12 is connected, the oil pressure corresponding to the target change gear ratio written in the memory is outputted to a transmission 11 for a speed change. The previous target change gear ratio is written in the map in the second time and subsequently after the clutch 12 is engaged. The target change gear ratio to be set in the (n)th time from the speed change map is selected and set from the equation Rn=(rn+A.Rn-1)/(1+A), where Rn and Rn-1 are the target change gear ratios in the (n)th and (n-1)th times, rn is the target change gear ratio in the (n)th time selected from the speed change map, and A is a time constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of a continuously variable transmission of a vehicle such as an automobile, and more particularly to a transmission control device.

[0002]

2. Description of the Related Art As a conventional continuously variable transmission of this type,
There is a technique disclosed in Japanese Patent Laid-Open No. 4-203670.

This type of continuously variable transmission is equipped with a shift control valve into which the pressure generated by the rotational force of the input pulley is introduced, and the piston in the shift control valve is introduced by the introduction of the pressure while the vehicle is running. Is activated,
When the line pressure is guided to the input side movable pulley and the position of the movable pulley is set appropriately to create the desired gear ratio, and the vehicle stops and the pulley stops rotating, the piston of the shift control valve springs. The force returns to the original position, the pressure introduced to the input side movable pulley is discharged, and the input side movable pulley is returned to the N (neutral) range.

[0004]

However, in the above-mentioned prior art continuously variable transmission, the target gear ratio is determined by the accelerator depression amount and the vehicle speed. Therefore, if a kickdown due to a sudden depression of the accelerator occurs while driving, the actual gear ratio cannot follow the rapid lowdown of the target gear ratio, and as a result, the actual gear ratio momentarily overshoots and the engine speed also increases. Similarly, there is a possibility that the driver will feel a sense of discomfort after being blown up.

In view of this, the present invention is directed to a transmission control device in which the actual gear ratio does not overshoot and the engine is blown up even if a kickdown or the like occurs due to an abrupt depression of the accelerator during driving, which does not give the driver a feeling of strangeness. Is the challenge.

[0006]

In order to solve the above technical problems, a transmission control device according to a first aspect of the present invention stores a target gear ratio when setting the target gear ratio according to a vehicle speed and an accelerator depression amount. Next from the changed gear map (nth time)
The target gear ratio set to Rn = (rn + A.Rn-1) / (1 + A) where Rn: nth target gear ratio Rn-1: n-1th target gear ratio rn: selected from the gear map The target gear ratio A for the n-th time is calculated as A: time constant, and the target gear ratio Rn for the n-th time is set.

[0007]

According to the first aspect of the present invention, when the target gear ratio is set according to the vehicle speed and the accelerator depression amount, the target gear ratio to be set next (nth time) from the gear shift map storing the target gear ratio is Rn = (rn + A Rn-1) / (1 + A) is calculated, and the target variable speed is increased by providing a filter characteristic so as to exponentially follow the target gear ratio Rn.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a transmission control device according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a switching valve and a shift valve in the transmission control device according to the embodiment of the present invention.

In FIG. 1, a continuously variable transmission 1 including a transmission 11 and a clutch 12 shown in the figure is arranged between an engine (not shown) and wheels (not shown). As shown in the figure, the transmission 11 of the continuously variable transmission 1 accelerates or decelerates the rotation of the engine side and transmits the rotation to the wheel side, and the effective diameter connected to the engine side is variable. It is composed of an input side movable pulley 11a, an output side movable pulley 11b which is connected to the wheel side and whose effective diameter is variable, and a transmission belt 11c wound around the input side movable pulley 11a and the output side movable pulley 11b. . Clutch 12
Is for disconnecting or connecting the transmission from the engine to the wheels on the engine side of the transmission 11, and is composed of a vehicle forward clutch 12a and a vehicle reverse clutch 12b.

The operation of the transmission 11 is performed by the transmission control valve 21 and the regulator valve 2 connected to the oil pump 5.
The operation of the clutch 12 is controlled by the shift control unit 2 including the oil pump 5 and the reduction valve 4.
It is controlled by the clutch control unit 3 including a clutch control valve 31 and the like which will be described later and are connected via the.

As described above, the continuously variable transmission according to this embodiment has the input side pulley means 11A having the input side movable pulley 11a and the input side fixed pulley 11d and the output side movable pulley 11b.
And an output side pulley means 1 having an output side fixed pulley 11e
1B and a transmission belt 11c for transmitting the driving force of the input side pulley means 11A to the output side pulley means 11B, the hydraulic pressure is introduced to shift the driving force output from the clutch 12, and after shifting And a transmission 11 for transmitting the driving force of the above to the drive wheels.

The regulator valve 22 is operated by a solenoid valve 24 which is pulse width modulated (PWM) controlled by a control circuit 6 which is a microcomputer which controls the transmission control apparatus of the present embodiment as a whole. The line pressure PL of the shift control unit 2 is determined by adjusting the source pressure from the solenoid valve 5 based on the solenoid pressure P2 from the solenoid valve 24. A hydraulic system is connected to operate the output side movable pulley 11b by the line pressure PL.

The shift control valve 21 is operated by a solenoid valve 23 whose pulse width is modulated by the control circuit 6, regulates the control pressure PI based on the solenoid pressure P1 from the solenoid valve 23, and moves the input side movable pulley. The control pressure PI of 11a is determined. A hydraulic system is connected to operate the input side movable pulley 11a by the control pressure PI. The solenoid valve 23 is a normally open type that does not generate the solenoid pressure P1 in the non-energized state, and the shift control valve 21 generates a minimum control pressure PI at a predetermined current value of the solenoid valve 23 or less. The solenoid valve 24 is a normally closed type that generates the maximum solenoid pressure P2 in the non-energized state, and the regulator valve 22 generates the maximum line pressure PL at a predetermined current value of the solenoid valve 24 or less. Therefore, the solenoid valve 23 and the solenoid valve 2
4, the transmission 11 has a minimum effective diameter of the input side movable pulley 11a, and the transmission side movable pulley 11 has a minimum effective diameter.
The effective diameter of b is the maximum and lowest speed.

The reduction valve 4 determines the control pressure PE of the clutch control unit 3 by adjusting the line pressure PL of the shift control unit 2. The clutch control valve 31 of the clutch control unit 3 includes a control circuit 6 Is controlled by the solenoid valve 32 which is pulse width modulated, and the control pressure PC is determined by adjusting the control pressure PE based on the solenoid pressure P3 from the solenoid valve 32. This control pressure PC is used as a clutch hydraulic pressure PFC or a clutch hydraulic pressure PRC, and a hydraulic pressure is applied via a switching valve 7 and a shift valve 8 described later so that the clutch hydraulic pressure PFC or the clutch hydraulic pressure PRC actuates the forward clutch 12a or the reverse clutch 12b. The system is connected.

Further, the solenoid valve 32 is a normally open type which does not generate the solenoid pressure P3 in a non-energized state, and the clutch control valve 31 generates a minimum control pressure PC at a predetermined current value of the solenoid valve 32 or less. Will be made.

The shift lever 9 operated by a vehicle occupant is provided with a shift position signal generating means 10 for detecting the position of the shift lever 9, and the shift lever 9 can be operated by a vehicle occupant. The shift valve 8 is operated.

The control circuit 6 is composed of a microcomputer, and has a built-in memory that stores a shift map for setting a target shift ratio according to the vehicle speed and the accelerator pedal depression amount. Further, the solenoid valve 24, the solenoid valve 23, and the solenoid valve 32 are controlled, and the output from the shift position signal generating means 10 for detecting the position of the shift lever 9 is input. Further, input side pulley means 11 having an input side movable pulley 11a and an input side fixed pulley 11d.
The rotation speed of the shaft A is detected by the input side rotation detector 13, and the output side movable pulley 11b and the output side fixed pulley 11e are detected.
The output side rotation detector 14 detects the number of rotations of the shaft of the output side pulley means 11B having the above, inputs those outputs, and determines the current gear ratio. Further, a signal corresponding to the depression pressure of an accelerator pedal (not shown), that is, an accelerator sensor output is input. Also, the output side pulley means 11B
The vehicle speed is calculated and input from the number of rotations of the shaft.

Next, the configurations of the switching valve and the shift valve of this embodiment will be described.

As shown in FIG. 2, the switching valve 7 is operated by the solenoid valve 32 and is composed of a body 71 and a spool 72. Spool 7
2 is slidably arranged in the body 71, and has a piston portion 72a and a passage 72 having a pressure receiving surface of a predetermined size.
Lands 72d for forming b and 72c are formed. The spool 72 configured in this way is the body 71
A spring 73 disposed between and is constantly biased to one end side (left side in FIG. 2). In the body 71, the solenoid pressure P3 from the solenoid valve 32 is applied to the piston portion 72.
A supply port 71a supplied to act on a, input / output ports 71b, 71c communicating with the passage 72b, and input / output ports 71d, 71e communicating with the passage 72c are formed, and the input port 71b is a clutch. Control valve 3
The control pressure PC from 1 is supplied, and the input port 71d is connected so that the control pressure PE from the reduction valve 4 is supplied.

The shift valve 8 is operated by the operation of a shift lever 9 which can be operated by a vehicle occupant, and is composed of a body 81 and a spool 82 operated by the shift lever 9. The spool 82 is the body 81
It is slidably disposed in the passage 82a and the passage 8
Lands 82b, 82c, 82d for forming 2e are formed. The body 81 is formed with input / output ports 81a, 81b, 81c communicating with the passage 82a. The input port 81a is connected so that the control pressure PC from the control valve 31 is supplied via the switching valve 7, the output port 81b is connected to the reverse clutch 12b, and the output port 81c is connected to the forward clutch 12a. ing. In addition, the output port 81 is provided in the body 81 through the passage 82a.
b, a supply port 81e capable of communicating with the output port 81c is formed through a supply port 81d capable of communicating with b and a passage 82e, and the control pressure PE from the reduction valve 4 passes through the switching valve 7 at the supply ports 81d, 81e. Connected so that it is supplied.

By these lands 82b, 82c, 82d, input / output ports 81a, 81b81c, supply port 81
The mutual relationship between d, 81e and the discharge port 81f formed in the body 81 is determined for each operation range selected by operating the shift lever 9. Further, the output port 71e of the switching valve 7 and the supply port 81 of the shift valve 8 through which the control pressure PE flows.
An orifice 90 is formed between d and 81e.

Next, the operation of the switching valve 7 and the shift valve 8 will be described.

When the engine of the vehicle is started, the solenoid valves 23, 24 and 32 are energized by the control circuit 6 at a predetermined current value to generate solenoid pressures P1, P2 and P3 of a predetermined value, and the regulator valve 22 causes the line pressure to be increased. PL is
A control pressure PE is generated by the reduction valve 4, a control pressure PI is generated by the shift control valve 21, and a control pressure PC is generated by the clutch control valve 31. The line pressure PL generated by the regulator valve 22 is generated on the output side movable pulley 11b, and the control pressure PI generated by the speed change control valve 21 is generated on the input side movable pulley 11a by the clutch control valve 31. The control pressure PC is supplied to the switching valve 7, respectively. Further, the spool 72 of the switching valve 7
Applies the solenoid pressure P3 from the supply port 71a to the piston 7
It is received by 2a and moved to the other end side (right side in FIG. 2) against the urging force of the spring 73, the output port 71c and the passage 72b communicate with each other, and the output port 71d and the passage 72c are blocked. As a result, the control pressure PC supplied to the input port 71b of the switching valve 7 is supplied to the shift valve 8 from the output port 71c via the passage 72b. At this time, the control pressure PE supplied to the input port 71d of the switching valve 7 is not supplied to the shift valve 8.

In this state, when the P range or the N range is selected by operating the shift lever 9, the shift valve 8 is disconnected from the communication between the input port 81a and the output port 81b or the output port 81c via the passage 82a. It As a result, the control pressure PC supplied to the input port 81a of the shift valve 8 is not discharged as the clutch hydraulic pressure PRC or the clutch hydraulic pressure PFC from the output port 81b or the output port 81c, and is not discharged to the reverse clutch 12b and the forward clutch 12a. The clutch hydraulic pressure PRC or clutch PFC is not supplied. Therefore, the engine and the transmission 11, that is,
The wheels are disconnected from each other by a reverse clutch 12b and a forward clutch 12a.

By operating the shift lever 9, D,
When the S or L range is selected, the shift valve 8 has the input port 81a and the output port 81c communicated with each other through the passage 82a. As a result, the control pressure PC supplied to the input port 81a of the shift valve 8 is discharged from the output port 81c as the clutch hydraulic pressure PFC and supplied to the forward clutch 12a, whereby the engine and the transmission 11, that is, the wheels. Is connected based on the clutch hydraulic pressure PFC (control pressure PC) via the forward clutch 12a. Incidentally, the solenoid valve 32 for generating the solenoid pressure P3 which is the source of the control pressure PC is controlled by the signal from the control circuit 6 from the start of the operation of the shift lever 9 to the control pressure PC corresponding to the predetermined D, S and L ranges. As described above, since the pulse width modulation control is performed, the forward clutch 12a operates so as to make the connection between the engine and the wheels smooth with less shock. Then, when the D range is selected, the solenoid valves 23 and 24 are subjected to pulse width modulation control by a signal from the control circuit 6, and the shift control valve 21 and the regulator valve 2 are controlled.
By the operation of 2, the input side movable pulley 11a and the output side movable pulley 11b are operated based on the line PL and the control pressure PI, and the transmission 11 is continuously variable between the lowest speed stage and the highest speed stage. . Further, when the L range is selected, the transmission 11 is shifted by the operation of the shift control valve 21 and the regulator valve 22 so as to be constant at the lowest speed stage, and when the S range is selected. , Shift control valve 2
1 and the operation of the regulator valve 22 cause the transmission 11 to shift at a speed higher than the lowest speed.

Furthermore, when the R range is selected by the operation of the shift lever 9, the shift valve 8 shifts to the input port 8
1a and the output port 81b are communicated with each other via the passage 82a. As a result, the control pressure PC supplied to the input port 81a of the shift valve 8 is discharged from the output port 81b as the clutch hydraulic pressure PRC and supplied to the reverse clutch 12b, whereby the engine and the transmission 11, that is, the wheels. To the clutch hydraulic pressure PR via the reverse clutch 12b.
Connection is made on the basis of C, that is, the control pressure PC set in the R range. The solenoid valve 32 for generating the solenoid pressure P3 which is the source of the control pressure PC is controlled by a signal from the control circuit 6 so that the control pressure PC corresponds to a predetermined R range from the start of the operation of the shift lever 9. Since the pulse width modulation control is performed, the reverse clutch 12b operates so as to smoothly connect the engine and the wheels. Further, in this case, the control valve 21 and the regulator valve 2
By the operation of 2, the transmission 11 is shifted so as to be constant at the lowest speed.

Next, the operation of the transmission control device of this embodiment will be described with reference to FIG.

FIG. 3 is a flow chart showing the control operation of the control circuit 6 in the transmission control device according to the embodiment of the present invention. Note that this flowchart is called during execution of the main program (not shown).

First, when the clutch 12 is engaged, the flag F1 is cleared ("0") by a routine not shown.

When this routine is entered, step S1
At first, it is judged whether the flag F1 to be set is set ("1"), and when it is not set, it means that this routine is entered for the first time. Therefore, only at this time, at step S2, the vehicle speed and the accelerator pedal depression amount are set. The target gear ratio rn corresponding to the vehicle speed and the accelerator pedal depression amount is read from the gear shift map which stores the target gear ratio corresponding to the target gear ratio, and at step S3, the n-th target gear shift (where n is an integer of n ≧ 2) is read. The target gear ratio rn is written in the memory that stores the ratio Rn. Further, in step S4, the flag F1 that is lowered when the clutch 12 is in the engaged state is set, and in step S8, the target gear ratio Rn
The hydraulic pressure corresponding to the memory that stores is output to the transmission 11.

Next, when it is determined in step S1 that the flag F1 which is initially set is set ("1"), this routine is executed from the second time onward from the time when the clutch 12 is engaged, and step S5 Then, the previous target gear ratio Rn is written in the memory for storing the n-1th target gear ratio Rn-1. Further, in step S6, the target gear ratio rn corresponding to the current vehicle speed and accelerator depression amount is read from the shift map which stores the target gear ratio corresponding to the vehicle velocity and accelerator depression amount.

In step S7, when the target gear ratio is set according to the vehicle speed and the accelerator depression amount, the target gear ratio to be set next (nth time) from the gear shift map storing the target gear ratio is selected and set from the following equation. That is, Rn = (rn + A.Rn-1) / (1 + A) where Rn: target speed ratio of nth time Rn-1: target speed ratio of n-1 time rn: target speed change of nth time selected from the speed change map The ratio A is calculated as a time constant, the target speed ratio Rn for the second and subsequent n times is selected, and the hydraulic pressure corresponding to the memory storing the target speed ratio Rn is output to the transmission 11 in step S8.

Therefore, even if the accelerator depression amount is sharp, such as kick down, the initial response is fast and the response is slower as the target gear ratio is approached due to the filter characteristic that approximates an exponential function. Since the actual gear ratio cannot keep up with the rapid lowdown of the target gear ratio, the actual gear ratio overshoots, the engine speed also blows up, and the driver feels uncomfortable. Does not occur. That is, even if a kickdown or the like occurs due to a sudden depression of the accelerator while the vehicle is running, the actual gear ratio does not overshoot and the engine is blown up, so that the driver does not feel uncomfortable.

As described above, the transmission control system according to the present embodiment includes the clutch 12 for transmitting the driving force of the engine, the input side pulley means 11A having the input side movable pulley 11a and the input side fixed pulley 11d, and the output side movable means. Output side pulley means 11 having a pulley 11b and an output side fixed pulley 11e
B, and a transmission belt 11c that transmits the driving force of the input side pulley means 11A to the output side pulley means 11B, the hydraulic pressure is introduced to shift the driving force output from the clutch 12, and after shifting Shift position signal generating means 1 for detecting the positions of the transmission 11 for transmitting the driving force of the vehicle to the drive wheels and the shift lever 9 and generating a shift position signal.
When the target gear ratio is set to 0 and the vehicle speed and the accelerator pedal depression amount, the target gear ratio to be set next (nth time) from the gear shift map storing the target gear ratio is Rn = (rn + A.
Rn-1) / (1 + A) is calculated to set the target gear ratio Rn for the n-th time, which can be the embodiment of claim 1.

Therefore, even if the kickdown is performed,
Since the response characteristics are controlled so that the initial response is fast and the response is slower as the target gear ratio is approached by the filter characteristics that are close to an exponential function, the actual gear ratio can follow a rapid lowdown of the target gear ratio. The actual gear ratio does not overshoot, the engine speed also rises, and the driver does not feel a sense of discomfort.

In the above embodiment, when setting the target gear ratio according to the vehicle speed and the accelerator pedal depression amount, the target gear ratio to be set next (nth time) from the gear shift map storing the target gear ratio is Rn = (rn + A.multidot.A). Rn-1) / (1 + A) is calculated to set the target gear ratio Rn for the nth time. However, in the case of implementing the present invention, the initial response speed is increased by the filter characteristics approximate to an exponential function. Since it suffices if response control can be performed so that the response becomes slower as it approaches the target gear ratio, the clutch 12 that transmits the driving force of the engine,
Input side pulley means 11A having an input side movable pulley 11a and an input side fixed pulley 11d and an output side movable pulley 11
b and an output side pulley means 11B having an output side fixed pulley 11e and a transmission belt 11c for transmitting the driving force of the input side pulley means 11A to the output side pulley means 11B, and introducing the hydraulic pressure to the clutch. The transmission 11 that shifts the driving force output from 12 and transmits the driving force after the shifting to the driving wheels, and a shift map that stores the target transmission ratio when setting the target transmission ratio by the vehicle speed and the accelerator depression amount. Select a predetermined target gear ratio from the
It can be an embodiment in which the response is delayed so as to approach the target gear ratio, and this can be the embodiment of claim 2.

Therefore, as in the former case, the response control is performed so that even if kickdown is performed, the initial response is fast and the response becomes slower as the target gear ratio is approached, by the filter characteristic that approximates an exponential function. Therefore, the actual gear ratio cannot follow the rapid decrease of the target gear ratio, the actual gear ratio overshoots, the engine speed also blows up, and the driver does not feel uncomfortable such as a feeling of idling.

[0039]

As described above, in the transmission control device according to the first aspect of the present invention, when the target gear ratio is set according to the vehicle speed and the accelerator depression amount, the next (nth) gear map is stored from the gear map storing the target gear ratio. The target gear ratio to be set to Rn = (rn
+ ARn-1) / (1 + A) to set the target speed ratio Rn for the n-th time. Therefore, even if kickdown is performed, the initial response can be improved by the filter characteristics approximate to the exponential function. Since the response control is performed so that the response is slower and the response becomes slower as the target gear ratio is approached, the actual gear ratio cannot follow the rapid lowdown of the target gear ratio, the actual gear ratio overshoots, and the engine speed It also has the effect of not blowing up and giving the driver a feeling of strangeness such as a feeling of running.

According to the second aspect of the present invention, when the target gear ratio is set according to the vehicle speed and the accelerator pedal depression amount, a predetermined target gear ratio is selected from a gear map storing the target gear ratio, and the initial responsiveness is set. Since the response is such that the response becomes faster and the response becomes slower as it approaches the target gear ratio, even if kickdown is performed, the initial response is obtained by the filter characteristic approximate to the exponential function, as in the case of the kickdown. Since the response control is performed so that the response speed becomes faster and the response becomes slower as it approaches the target gear ratio, the actual gear ratio cannot follow the rapid lowdown of the target gear ratio and the actual gear ratio overshoots. The number of revolutions is also blown up, and the effect that the driver does not feel uncomfortable like a runaway feeling is achieved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a transmission control device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a switching valve and a shift valve in a transmission control device according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a control operation of a control circuit in the transmission control device according to the embodiment of the present invention.

[Explanation of symbols]

 6 Control circuit 11 Transmission 11a Input side movable pulley 11b Output side movable pulley 11c Conductive belt 11d Input side fixed pulley 11e Output side fixed pulley 11A Input side pulley means 11B Output side pulley means 12 Clutch

Claims (2)

[Claims] 1. A clutch for transmitting a driving force of an engine, an input side pulley means having an input side movable pulley and an input side fixed pulley, an output side pulley means having an output side movable pulley and an output side fixed pulley, and the input. A transmission belt for transmitting the driving force of the side pulley means to the output side pulley means, introducing hydraulic pressure to change the driving force output from the clutch, and transmitting the changed driving force to the driving wheels. In a transmission control device including a transmission, when setting a target gear ratio according to a vehicle speed and an accelerator pedal depression amount, a target gear ratio to be set next (nth time) from a gear shift map storing the target gear ratio is Rn = (Rn + A.Rn-1) / (1 + A) where Rn: n (n is an integer of 2) target speed ratio Rn-1: n-1 target speed ratio rn: nth speed selected from the speed map Target change The ratio A: calculated as the time constant, the transmission control device and sets the n-th target gear ratio Rn. 2. A clutch for transmitting a driving force of an engine, an input side pulley means having an input side movable pulley and an input side fixed pulley, an output side pulley means having an output side movable pulley and an output side fixed pulley, and the input. A transmission belt for transmitting the driving force of the side pulley means to the output side pulley means, introducing hydraulic pressure to shift the driving force output from the clutch, and transmitting the shifted driving force to the driving wheels. In a transmission control device including a transmission, when setting a target gear ratio according to the vehicle speed and the accelerator pedal depression amount, a predetermined target gear ratio is selected from a gear map that stores the target gear ratio to improve the initial response. The transmission control device is characterized in that the response is delayed so as to approach the target gear ratio.