JPH10176750A - Transmission controller for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bodily sense a running feeling similar to a manual transmission by setting an acceleration side upper limit rotational number and a reduction side upper limit rotational number for the upper and lower parts of a first rotational number for regulating an output for preventing excessive rotation and switching these upper limit rotational numbers according to the acceleration/deceleration intention of a driver. SOLUTION: During traveling of a vehicle, in a transmission controller 2, the acceleration/deceleration state of the vehicle is determined if a manual mode is selected, and an objective input shaft rotational number map value is calculated from the transmission map of the manual mode. Then, the objective input shaft rotational number map value is compared with an acceleration side upper limit rotational number or a reduction side upper limit rotational number and, if it exceeds the upper limit rotational number, an alarm flag is set to 1. Then, after the actual objective input shaft rotational number of the previous control time is stored in the previous value, whether a current state is transmitting or normal is determined and, if a transmitting state is determined, a primary delay actual objective input rotational number is calculated, a step motor 61 is caused to follow-up the objective input shaft rotational number and then a transmission ratio is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a vehicle having a continuously variable transmission, and more particularly to a shift control device for a continuously variable transmission having a manual mode.

[0002]

2. Description of the Related Art Continuously variable transmissions used in vehicles include:
Conventionally, there are a belt type and a toroidal type. In these continuously variable transmission shift control devices, in addition to an automatic shift mode in which a target gear ratio is determined according to a vehicle speed VSP and a throttle opening TVO (or an accelerator opening), As with the conventional manual transmission, there has been known one having a manual mode in which an arbitrary gear can be set. For example, there is Japanese Patent Application No. 8-4810 proposed by the present applicant.

[0003] This is a manual mode in which the speed ratio of a continuously variable transmission is set to an arbitrary gear by operating a shift lever to an upshift or downshift position. The driver can select a desired gear ratio regardless of the degree TVO.

In such a manual mode of the continuously variable transmission, for example, as shown in FIG. 22, a manual mode shift stage SP has a six-stage configuration of first to sixth speeds, and each shift stage SP corresponds to each shift stage SP. The gear ratios i (1) to i (6) are set in advance,
The gear ratio i (n) is switched according to the operation of the shift lever, and the gear ratio i (n) determined manually corresponds to the gear position of the conventional manual transmission.

In such a manual mode, if the driver continues to depress the accelerator pedal at the speed ratio set by the driver, the speed may exceed the permissible speed of the engine. In order to prevent such an engine overrev (overspeed), the gear ratio is automatically changed so that the engine speed or the input speed of the continuously variable transmission does not exceed the preset upper limit _Nelim. doing.

Now, for example, if the first speed (SP = 1) in the drawing is selected and acceleration is continued, if the engine speed or the input shaft speed exceeds the upper limit speed Ne _lim , the speed of the continuously variable transmission is reduced. The gear ratio is automatically and continuously changed to the Hi side to reduce the engine speed to prevent over-rev. In addition, the upper limit rotational speed Ne set on the continuously variable transmission side.
_As shown in FIG. 22, _lim is set to a value smaller than the fuel cut rotation speed Nfc executed by the engine control controller to prevent the engine from overrunning.

[0007]

However, in the conventional shift control device for a continuously variable transmission, if the upper limit rotational speed Ne _lim is to be exceeded, the Hi side is set regardless of the shift speed SP set by the driver. To automatically change the gear ratio to the first gear (SP = 1) because the engine speed is prevented from exceeding the fuel cut speed Nfc.
When the target input shaft rotation speed reaches Ne _lim exceeding the vehicle speed VSP (1), the gear ratio is continuously changed to the Hi side, and the set value of the gear stage SP is set to the first gear (SP =
Since it is automatically upshifted from 1) to 2nd speed (SP = 2), next, when the driver performs an upshift operation,
Upshift from 2nd gear to 3rd gear (SP = 3)
In some cases, the driver may erroneously recognize that the upshift is from the first speed to the second speed, and may not be able to grasp the current gear position.

Accordingly, the present invention has been made in view of the above problems, and prevents the driver from erroneously recognizing the shift position even when the vehicle is driven near the upper limit rotational speed in the manual mode. Aim.

[0009]

According to a first aspect of the present invention, as shown in FIG. 23, an engine connected to a continuously variable transmission 10 includes:
Excessive rotation preventing means 103 for regulating the output when the engine speed exceeds a first rotation speed so as not to exceed an allowable rotation speed.
And a first target gear ratio setting means 100 for setting a target gear ratio of the continuously variable transmission 10 in accordance with a driving state of the vehicle, and a speed change command means 108 operated by a driver. A second target gear ratio setting means 101 for setting a target gear ratio of the step transmission 10 to one of a plurality of predetermined gear positions; and the first target gear ratio setting means 10
A shift mode switching means 102 for selectively switching between 0 and the second target gear ratio setting means 101; a shift control means 104 for changing the gear ratio of the continuously variable transmission 10 based on the output of the shift mode switching means 102; In the speed change control device for a continuously variable transmission provided with: a speed change mode switching means 102 selects a second target speed ratio setting means 101, an acceleration / deceleration intention detecting means 105 for detecting a driver's acceleration / deceleration intention
And setting the acceleration-side upper limit rotation speed of the second target speed ratio setting unit to be higher than the first rotation speed, and setting the deceleration side upper limit rotation speed of the second target speed ratio setting unit to be higher than the first rotation speed. The upper limit rotational speed setting means 106 for setting a smaller value also selects the acceleration upper limit rotational speed when the acceleration / deceleration intention detecting means 106 detects the driver's intention to accelerate. And an upper limit rotation speed switching means 107 for selecting the upper limit rotation speed on the deceleration side when the intention of deceleration is detected, and the shift control means 104 controls the gear ratio so as not to exceed the selected upper limit rotation speed.

In a second aspect based on the first aspect, the acceleration / deceleration intention detecting means detects a driver's intention to decelerate when the accelerator pedal is released, and in other cases, The intention to decelerate is detected.

In a third aspect based on the first aspect, the second target speed ratio setting means sets the target speed ratio on the deceleration side to the Hi side in comparison with the target speed ratio on the acceleration side. .

In a fourth aspect based on the first aspect, the second target speed ratio setting means includes a time constant setting means for changing an actual speed ratio toward the target speed ratio, This time constant setting means sets the time constant imparting rotation speed to Low.
The lower the gear position, the smaller the setting.

[0015] In a fifth aspect based on the first aspect, the second target speed ratio setting means sets the input shaft speed of the continuously variable transmission to an acceleration-side upper speed limit or a deceleration-side upper speed limit. A warning device is provided for warning that the vehicle has reached the upper limit of the gear position set by the driver when the vehicle speed has reached.

[0014]

According to the first invention, therefore, the second target gear ratio setting means is set by the gear mode switching means.
The gear ratio of the continuously variable transmission is set to the gear position set by the driver, and the engine control means controls the output in order to prevent overspeed according to the driver's intention to accelerate or decelerate. The upper limit rotation speed on the acceleration side and the upper limit rotation speed on the deceleration side are set in, and these upper limit rotation speeds are switched according to the driver's intention of acceleration / deceleration.
By limiting the output beyond the number of revolutions, the acceleration also sharply decreases, and the driver, like a conventional manual transmission,
By experiencing the acceleration peaking when the engine continues to accelerate beyond the permissible engine speed, it is possible to reliably recognize that the upper limit engine speed of the set shift speed is approaching, and further accelerate the engine. In such a case, the speed ratio can be continuously shifted to the Hi side to prevent overspeed, while on the deceleration side, during a downshift or the like, the input shaft speed is higher than the first speed at which the output is regulated. Therefore, if the re-acceleration is performed while the shift position is fixed, the acceleration exceeds the first rotation speed again and the acceleration is reduced due to the sudden decrease in the engine output due to the output regulation, as in the case of the above-described acceleration. Suddenly
The driver can feel that the upper limit rotational speed in the shift stage after the downshift is approaching by experiencing the acceleration peaking, and can enjoy the same driving feeling as a conventional manual transmission. As a result, it is possible to always recognize the shift position while preventing the engine from over-rotating, thereby greatly improving the operability of the continuously variable transmission having the manual mode as compared with the conventional example. It becomes possible.

According to a second aspect of the present invention, a driver's intention to accelerate or decelerate is detected based on an operation state of an accelerator pedal.
Acceleration / deceleration intention can be detected easily and quickly.

In the third invention, the speed ratio on the acceleration side is slightly different from the speed ratio on the deceleration side, and the speed ratio on the acceleration side is set to the low side. Since the speed ratio on the acceleration side is set slightly low on the same gear SP, the acceleration can be performed quickly, and the continuously variable speed with the manual mode can always be recognized while the shift position is recognized. It is possible to further improve the operability of the machine.

According to a fourth aspect of the present invention, the set rotation speed of the time constant for changing the actual speed ratio toward the target speed ratio is Low.
The lower the speed, the slower the speed at which the engine speed rises at the low speed, so that the vehicle can behave in a manner that suppresses an excessive decrease in acceleration due to the output regulation control. In addition to stabilizing and improving the operability, the overshoot of the input shaft speed is reliably prevented, the engine overspeed prevention control can be performed accurately, and the operability of the continuously variable transmission equipped with the manual mode is improved. It is possible to further improve the control accuracy.

According to a fifth aspect of the present invention, when the rotation speed of the input shaft of the continuously variable transmission reaches the upper limit rotation speed on the acceleration side or the upper limit rotation speed on the deceleration side, the warning means sets the upper limit of the gear position set by the driver. In order to warn that the rotation speed has been reached, the driver can easily and reliably recognize the lower limit of the engine output when the rotation speed exceeds the first rotation speed and the warning from the warning means to recognize the upper limit of the current gear position. As a result, the operability and drivability of the continuously variable transmission having the manual mode can be improved as compared with the conventional example.

[0019]

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

FIG. 1 shows an example in which the present invention is applied to a continuously variable transmission 1 employing a double cavity type continuously variable transmission 10 as a continuously variable transmission, in which a torque converter 12 and a forward / reverse switching device 40 are provided. The driving force of the engine is input to the continuously variable transmission 10 via the transmission.

In the continuously variable transmission 1, a step motor 61 responsive to a command value of the shift control controller 2 includes:
The gear ratio of the continuously variable transmission 10 is controlled via the hydraulic control device 4.

An example is shown in which the continuously variable transmission 10 is constituted by a half-toroidal type first toroidal transmission section 18 and a second toroidal transmission section 20 and of a double cavity type having two sets of input / output disks. As shown in FIG. 2, the power roller 18c sandwiched between the input disk and the output disk of the first toroidal transmission unit 18 is supported by an offset rotary shaft 50b.
The trunnion shaft 50a, which is driven up and down in the figure and is rotatable around the axis, is driven in the axial direction by a hydraulic cylinder 50. Although the power roller 18c of the first toroidal transmission unit 18 has been described with reference to FIG. 2, the power roller of the second toroidal transmission unit 20 has the same configuration.

The transmission ratio is continuously changed by changing the inclination angle (displacement around the trunnion shaft 50a) of the power roller 18c according to the vertical displacement of the trunnion shaft 50a.

The shift control controller 2 reads the throttle opening TVO (or the accelerator pedal opening ACS) in response to the driver's operation of an accelerator pedal (not shown) and the engine speed Ne from the engine control controller 3. The input shaft rotation speed Nt detected by the input shaft rotation sensor 6 of the continuously variable transmission 10, the output shaft rotation speed No detected by the output shaft rotation sensor 7, and the shift lever 5 as shift command means and shift mode switching means. The shift position Pos set by the driver is read from the select switch 5A, and, as described later, a shift map set in advance based on one of the automatic shift mode and the manual mode selected by the driver. To determine the actual target input shaft rotation speed RREV according to the operation state, and drive the speed ratio changing means. Step motor 61 as an actuator (see FIGS. 1 and 2) target gear ratio RTO and PI to
Control amount AS according to feedback control amount by control or the like
The drive amount of the step motor 61 (the number of steps FSTP) and the speed ratio (the actual target speed ratio RRT)
The relationship O) is uniquely determined as shown in FIG.

On the other hand, the engine control controller 3 controls the fuel injection amount in accordance with the operating state,
When the engine speed Ne is going to exceed a predetermined speed Nfc, control is performed to prevent overspeed by fuel cut. The fuel cut for preventing overspeed is performed as shown in FIG. 4 or the fuel cut rotation speed Nfc as the first rotation speed shown in the shift map of FIG. 19, and the allowable rotation speed of the engine is set to a value larger than the fuel cut rotation speed.

Here, the continuously variable transmission 1 has a manual mode in addition to the automatic transmission mode, and the select switch 5A of the shift lever 5 is configured, for example, as shown in FIG. A manual mode changeover switch 13 (shift mode changeover means), an up switch 8 and a down switch 9 in addition to the conventional shift position such as a D range. Each time the signal passes through the switch 13, the mode is switched from the D range to the manual mode or vice versa.

In the manual mode, the up switch 8 or the down switch 9 is operated by operating the shift lever 5.
Is turned ON, for example, the gear SP is sequentially switched between the first gear to the seventh gear based on the shift map of FIG.
A target input shaft rotation speed RREV0 (or a target gear ratio) corresponding to the gear position SP is set.

On the other hand, in the automatic transmission mode, although not shown, the vehicle speed V is set using the throttle opening TVO and the like as parameters.
A target input shaft speed RREV0 (or a target gear ratio) corresponding to the SP is set. Note that “P”, “R”,
“N” indicates a shift position of parking, reverse, and neutral, respectively.

In response to the manual mode, a warning display section 11 is provided at a position visible to the driver to notify that the selected gear SP has exceeded a predetermined upper limit rotational speed by lighting or blinking. Is provided as shown in FIG.
The warning display unit 11 is driven based on a warning signal Fsp from the transmission control controller 2.

The transmission ratio changing means of the continuously variable transmission 10 is, as shown in FIG. 2, a trunnion shaft 50a axially supporting a power roller 18c of the continuously variable transmission 10 of a toroidal type. A hydraulic cylinder 50 driven to
A control valve 60 that supplies pressure oil to the hydraulic cylinder 50 while feeding back the actual gear ratio in accordance with the drive of the step motor 61 and the displacement of the trunnion shaft 50a is mainly configured. The spool 63 is driven in response to a command from the hydraulic cylinder 50 and the oil chambers 5 above and below the piston 50P of the hydraulic cylinder 50
Supply and discharge hydraulic pressure to 0H and 50L.

The axial displacement of the trunnion shaft 50a and the displacement around the shaft (= the tilt angle of the power roller 18c) in accordance with the hydraulic pressure are relative to the spool 63 via a follower mechanism 67 including a link. Moving sleeve 64
And the hydraulic pressure to the hydraulic cylinder 50 is
The drive amount of the step motor 61 according to the target speed ratio RTO and the tilt angle of the power roller 18c, that is, the actual speed ratio RTO, are adjusted, and this speed ratio is adjusted as shown in FIG. Is uniquely determined in accordance with the driving amount of.

Next, the shift map in the manual mode set in the shift control controller 2 shows an example in which the number of shift steps is seven as shown in FIG. 4, and each shift step SP (n) Is set to a predetermined gear ratio i (n). Here, n = 1 to 7.

Each gear SP (n) has an acceleration side (Dri)
ve side) and the deceleration side (Coast side)
The upper limit rotation speed Nc is set above and below the fuel cut rotation speed Nfc at which the engine controller 3 performs the overspeed prevention control, and the upper limit rotation speed Nd on the acceleration side is set to the rotation speed ΔNx from the fuel cut rotation speed Nfc. While the upper limit rotational speed Nc on the deceleration side is set smaller than the fuel cut rotational speed Nfc by the rotational speed ΔNx,
Nx is preset to, for example, 1000 rpm. In the drawings, VSP (1d) to (5d) denote the vehicle speed VSP reaching the upper limit rotation speed Nd on the acceleration side of each shift speed, VS.
P (1c) to (6c) indicate the vehicle speeds VSP reaching the upper limit rotational speed Nc on the deceleration side of each shift speed, respectively.

That is, on the acceleration side, the first speed (SP = 1)
Is selected and the accelerator pedal is continuously depressed, the vehicle speed VSP = VSP (1d) is reached at a predetermined speed ratio i (1), and the input shaft rotation speed (the input shaft rotation speed when the torque converter 12 is locked up). = Engine speed Ne) becomes the acceleration-side upper limit speed Nd, and thereafter, the gear ratio is set to continuously shift from i (1) to the Hi side so that the input shaft speed does not exceed the upper limit value Nd. Is done.

On the other hand, on the deceleration side, even if a downshift from the second speed to the first speed is performed at a speed equal to or higher than the vehicle speed VSP (1c), the gear ratio i is set so that the target input shaft speed does not exceed the deceleration side upper limit Nc. After setting to Hi side than (1), vehicle speed VSP
Becomes smaller than VSP (1c), the gear ratio is fixed to the predetermined value i (1) of the first speed.

The shift control controller 2 having such a manual mode uses the vehicle speed VSP, the throttle opening TVO, and the shift position Pos from the select switch 5A as parameters as shown in the control conceptual diagrams of FIGS. A shift determining unit 70 for determining an actual target input shaft rotation speed RREV according to the driving state of the vehicle and the driver's request;
For example, a feedback control unit based on PI control is performed in accordance with the deviation, and the transmission control unit 80 drives the step motor 61 in accordance with the target gear ratio RTO and the feedback control amount.

As shown in FIG. 6, when the automatic shift mode is set, the speed determining unit 70 determines the target input shaft speed map value RREV0 based on the vehicle speed VSP and the throttle opening TVO. In the manual mode, the gear position determining unit 7 is based on the shift position Pos.
1 determines the shift speed SP (n),
Is the target input shaft rotation speed map value RREV from the map of FIG.
Calculate 0.

Then, the target rotational speed change amount determining section 73 obtains an actual target input shaft rotational speed RREV with a first-order delay as described later from the target input shaft rotational speed map value RREV0.

Here, an example of the control performed by the transmission control controller 2 is shown in the flowcharts of FIGS.
The details will be described below with reference to the control conceptual diagrams of FIGS. Each flowchart is executed at predetermined time intervals, for example, 1
This is executed every 0 msec.

First, FIG. 7 is a flowchart of a signal measurement process for detecting a driving state of a vehicle and an operation state of a driver.
In step S1, while reading the throttle opening TVO and the engine speed Ne from the engine controller 3 as the operating state of the engine, while reading the input shaft speed Nt and the output shaft speed No from the continuously variable transmission 10,
To detect the driver's driving intention, select switch 5
The shift position Pos from A is read.

In step S2, each value indicating the driving state of the vehicle is calculated. First, the vehicle speed VSP is obtained by multiplying the output shaft speed No by the conversion constant A.
The actual gear ratio RTO is calculated from the ratio between the input shaft speed Nt and the output shaft speed No.

Next, the flow chart of FIG. 8 shows an outline of the shift control performed based on the operating state obtained in steps S1 and S2.

In step S3, as will be described later, a target input shaft rotation speed map value RREV is set in accordance with the driving state of the vehicle.
0, the target gear ratio map value RTO0 is calculated,
A shift determining unit for determining an actual target input shaft rotation speed RREV with a first-order delay, the shift determining unit 7 shown in the control conceptual diagram of FIG.
It corresponds to 0.

In step S4, based on the actual target input shaft rotation speed RREV obtained in step S3,
It calculates the control amount ASTP of the step motor 61, and corresponds to the shift control unit 80 in FIG.

As shown in the flow chart of FIG. 9, the shift control unit obtains the control position FSTP of the step motor 61 in accordance with the target speed ratio RTO in step S5, and then executes PI (proportional integration) control in step S6. A feedback control amount FBSTP of the motor 61 is calculated, and in step S7, a control amount ASTP corresponding to a response characteristic of the step motor 61 and the like is obtained.

Then, in step S8 in FIG. 10, the control amount ASTP obtained in step S8 is instructed to the step motor 61 to drive the gear ratio changing means.
In step S9, a warning signal Fsp is output to the warning display unit 11.

Next, the shift judging section shown in the step S3 of FIG. 8 and the control conceptual diagrams of FIGS. 5 and 6 is constituted by a subroutine of FIGS. 11 and 12, and will be described in detail below.

First, in step S10, it is determined whether or not the shift position Pos from the select switch 5A has been switched from the D range to the manual mode. If the manual mode has been selected, the process proceeds to step S11. If it remains in the D range, the process proceeds to step S14.

In the case of the manual mode, step S
After determining the gear stage SP in accordance with the shift position Pos in step 11, the acceleration / deceleration state M of the vehicle is determined in step S12.

The acceleration / deceleration of the vehicle is determined, for example, according to the estimated value of the running resistance and the throttle opening TVO, etc., according to the driver's request for acceleration or deceleration M = D
live (acceleration side) or M = Coast (deceleration side).

By using the estimated running resistance value in the above determination, the acceleration can be accelerated if the throttle opening TVO is equal to or larger than a predetermined value even when the vehicle acceleration temporarily becomes negative (deceleration), such as during a steep slope. The request can be determined, and the driver's intention can be accurately determined.

The calculation of the running resistance estimation value is performed by a model matching method or the like as in Japanese Patent Application No. 7-309293 proposed by the present applicant.

Next, in step S13, a target input shaft rotation speed map value RREV0 corresponding to the vehicle speed VSP is calculated from the shift map in the manual mode shown in FIG. 4 using the shift speed SP and the acceleration / deceleration state M as parameters.

In step S15, the above-mentioned step S13
The target input shaft rotation speed map value RREV0 obtained in the above is compared with the acceleration-side upper limit rotation speed Nd or the deceleration-side upper limit rotation speed Nc according to the acceleration / deceleration state M, and the upper limit rotation speed according to the current acceleration / deceleration state M is obtained. In the above case, the process proceeds to step S16,
While the warning flag Fsp is set to 1, if not, the process proceeds to step S17, where the warning flag Fsp is reset to 0, and the process proceeds to the target rotation speed change amount determination unit in step S18.

On the other hand, if it is determined in step S10 that the automatic transmission mode has been set, the process proceeds to step S14, where the throttle opening TVO is set to a target input shaft rotation speed map value RR based on a parameter and vehicle speed VSP from a shift map (not shown).
After obtaining EV0, the process proceeds to the target rotation speed change amount determination unit in step S18.

The target rotational speed change amount determining section in step S18 is constituted by a subroutine of steps S20 to S24 in FIG.

First, in step S20, the actual target input shaft speed RREV during the previous control is stored in the previous value RREVold, and in step S21, it is determined whether the current shift is in progress (shift transient state) or in a steady state. If the shift is in progress, the process proceeds to step S22, in which the fixed value K1 is substituted for the first-order time constant Kr.
2, the primary input delay time constant Kr, the target input shaft speed map value RREV0, and the previous value actual target input shaft speed R
From REVold, a first-order actual target input shaft rotation speed RREV is calculated based on the following equation.

RREV = (RREV0 + RREVold × Kr) / (Kr + 1) (1) Therefore, the relationship between the target input shaft speed map value RREV0 and the actual target input shaft speed RREV is as shown in FIG. The actual target input shaft rotation speed RREV gradually increases toward the map value RREV0 by the first-order lag time constant Kr set according to the opening degree TVO, and the step motor 6
1 is made to follow the target input shaft rotation speed map value RREV0.

On the other hand, if it is determined in step S21 that the vehicle is in the steady state, the process proceeds to step S23.
The target input shaft speed map value RREV0 is substituted for the actual target input shaft speed RREV, and the process is terminated.

In this way, when the actual target input shaft speed RREV is obtained from the first-order lag time constant Kr and the shift determining section is finished, the shift control section shown in step S4 of FIG.
That is, the processing of steps S5 to S7 in FIG. 9 is performed.

The shift control amount calculating section in step S5 and the feedback control amount calculating section in step S6 comprise a subroutine of steps S30 to S36 in FIG. 13. Steps S30 and S31 are executed by the shift control amount calculating section. Subsequent steps S32 to S36 show the feedback control amount calculation unit.

First, in step S30, the actual target gear ratio RRTO is determined from the ratio of the temporarily delayed actual target input shaft rotation speed RREV calculated by the above equation (1) to the output shaft rotation speed No of the continuously variable transmission 10. .

Next, in step S31, the control step number FSTP, which is the drive amount of the step motor 61, is calculated from the map shown in FIG. The map of FIG. 15 is set in advance according to the characteristics of the step motor 61 and the like.

In the subsequent feedback control amount calculation, first, in step S32, the actual target input shaft rotation speed RR
The difference Nerr between the EV and the input shaft rotation speed Nt is obtained, and in step S33, the integrated value of the rotation speed difference Nerr is calculated as the rotation speed difference integrated value Ni.

In step S34, the proportional difference FBp of the feedback control amount is calculated by multiplying the rotational speed difference Nerr by a predetermined proportional gain kp. Note that the proportional gain k
p is determined from a predetermined map or function (not shown) according to the actual speed ratio RTO and the vehicle speed VSP.

In step S35, the above-mentioned step S33
Is multiplied by a predetermined integral gain ki to calculate the integral FBi of the feedback control amount. Note that the integral gain ki is determined by the actual speed ratio RTO and the vehicle speed VS.
It is determined from a predetermined map or function (not shown) corresponding to P.

Thus, in step S36, the proportional component F
From the sum of Bp and the integral FBi, the feedback control amount FB
STP (the number of steps) is obtained.

Next, the step motor controller shown in step S7 of FIG. 9 is configured as a subroutine shown in FIG.

First, in step S40, the number of control steps FSTP obtained in step S31 of the shift control unit is determined.
And step S36 of the feedback control amount calculation unit
Is obtained as the target step number DSRSTP.

In steps S42 to S47, the control amount AS is determined according to the response speed of the step motor 61 from the target step number DSRSTP and the current control amount ASTP.
When the calculation of TP is performed and the target control amount DSRSTP is larger than the current control amount ASTP, the control amount ASTP is increased by a preset control amount DSTP to the target value DSRSTP. Note that DSTP indicates the number of steps per unit time, and is set in advance according to the speed characteristics of the step motor 61.

That is, in FIG. 17, the control amount ASTP actually output to the step motor 61 is equal to the target control amount D.
The step motor 61 is driven so that the spool 63 of the control valve 60 has a predetermined speed ratio by increasing or decreasing the predetermined control amount DSTP until SRSTP is reached.

The control amount ASTP obtained from the flowcharts of FIGS. 7 to 14 is output from the transmission control controller 2 to the step motor 61 in step S8 of the signal output section shown in FIG. The continuously variable transmission 10 is set to the actual target gear ratio RRTO by tilting at a speed corresponding to the first-order lag constant Kr, and the warning flag Fsp is output to the warning display unit 11 in step S9, and the gear position in the manual mode is set. When the input shaft rotation speed becomes equal to or higher than the upper limit rotation speed Nd or Nc in SP, a warning display unit 11 is provided.
Flashes or flashes, and the gear ratio i corresponding to the shift speed SP
Notify the driver that the limit that can maintain (n) has been reached.

With the continuously variable transmission 1 as described above, for example, the shift lever 5 is operated to set the manual mode 1
It is assumed that the speed is set to (SP = 1) and the accelerator is depressed to accelerate. In the following description, it is assumed that the torque converter 12 is in the lockup state, and the engine speed Ne = the input shaft speed Nt.

Now, the input shaft rotation speed Nt is lower than the deceleration-side upper limit rotation speed Nc, and the vehicle accelerates in accordance with the speed ratio i (1) of the first speed by increasing the throttle opening TVO. In steps S12 and S13 of step S11, it is determined that an acceleration request has been made, the acceleration / deceleration state M = Drive, and the upper limit rotation speed is set to the acceleration-side upper limit rotation speed Nd.

The input shaft rotation speed according to the increase of the vehicle speed VSP =
When the engine rotation speed Ne exceeds the deceleration-side upper limit rotation speed Nc and reaches the fuel cut rotation speed Nfc, the engine control controller 3 starts the engine overspeed prevention control by the fuel cut.

For this reason, the acceleration suddenly decreases due to the sudden decrease in the engine output, so that the driver feels the acceleration peaking when the engine continues to accelerate beyond the permissible engine speed, similarly to the conventional manual transmission. By doing so, it is possible to recognize that the upper limit rotational speed Nd in the first speed has approached, and to operate the shift lever 5 in FIG. 3 toward the upshift switch 8 to shift up to the second speed (SP = 2). Can be.

When the vehicle continues to accelerate further beyond the fuel cut rotation speed Nfc, the vehicle speed V in FIG.
SP increases to VSP (1d) in the figure and the input shaft speed N
Since t reaches the acceleration-side upper limit rotation speed Nd, the transmission control controller 2 sets the target input shaft rotation speed RREV = Nd.
The gear ratio is continuously shifted to the Hi side to prevent overspeed. At this time, since the warning flag Fsp is set to 1 from steps S13 and S15 in FIG. 11, the warning display unit 11 is turned on or blinks to indicate that the manual mode gear ratio i (1) has been released. Can warn others.

On the other hand, the deceleration side will be described. For example, the second speed (SP = 2) in the manual mode is set.
At point A in FIG. 4, when the accelerator pedal is released (throttle opening TVO = 0) and the downshift switch 9 is turned on by operating the shift lever 5, the speed is reduced from steps S11 and S12 in FIG. The downshift is determined, and the acceleration / deceleration state M = Coast, and the upper limit rotation speed is set to the reduction upper limit rotation speed Nc.

Therefore, the target input shaft speed RREV0
Becomes the upper limit speed Nc on the deceleration side shown by the dotted line in FIG. 4, and from steps S13 and S15 in FIG.
Since the warning flag Fsp is set to 1, the warning display section 11 is turned on or blinks to warn the driver that the downshift to the gear ratio i (1) in the manual mode has been restricted. is there.

When the vehicle speed VSP decreases to VSP (1c) in the figure due to this downshift, step S13 is performed.
As a result, the gear ratio is fixed to the value i (n) of the first speed, and at the same time, the warning flag is reset from steps S15 and S17, and the warning display section 11 is turned off. Setting value for requesting (SP = 1)
Can be recognized.

At the time of this downshift, the upper limit rotational speed Nc on the deceleration side is always restricted by a predetermined value ΔNx smaller than the fuel cut rotational speed Nfc. Therefore, if re-acceleration is performed with the shift position fixed, As in the case of the above acceleration, the fuel cut speed Nfc is exceeded again. Therefore, the engine control controller 3 performs the fuel cut, and the acceleration rapidly decreases due to the sudden decrease in the engine output. It is possible to recognize that the upper limit rotational speed Nd in the first speed after the shift is approaching, and it is possible to enjoy a driving feeling similar to that of the conventional manual transmission, and it is possible to always recognize the shift position. As a result, the operability of the continuously variable transmission having the manual mode can be greatly improved as compared with the conventional example.

FIGS. 18 and 19 show a second embodiment.
The acceleration / deceleration determination of the first embodiment is based on the throttle opening TV
This is performed only by O.

FIG. 18 is a flowchart of the first embodiment in which step S12 shown in the flowchart of FIG. 11 is deleted.
Step S13 for calculating the target input shaft rotation speed map value RREV0 is changed to step S13A. In this step S13A, a shift map shown in FIG. 19 is used instead of the shift map shown in FIG. 4 of the first embodiment. The gear ratio in the manual mode is set based on the vehicle speed VSP, the gear stage SP, and the throttle opening TVO.

In the shift map of FIG. 19, the solid line
The map is set when VO ≠ 0, that is, when the accelerator pedal is depressed, and the broken line in the figure is set when TVO = 0, that is, when the accelerator pedal is released to perform engine braking or coasting. If the solid line map is the acceleration side and the broken line map is the deceleration side, the speed ratio i (n) of the acceleration side map is slightly larger than the speed ratio i (n) ′ of the deceleration side map. (Lo
The values are set on the (w-side), and the others are the same as in the first embodiment.

The upper limit rotation speed Nd on the acceleration side (Drive side)
And the upper limit rotation speed Nc on the deceleration side (Coast side) is set above and below the fuel cut rotation speed Nfc at which the engine controller 3 performs the overspeed prevention control, as in the first embodiment. The upper limit rotation speed Nd is set to be higher than the fuel cut rotation speed Nfc by the rotation speed ΔNx, while the upper limit rotation speed Nc on the deceleration side is set to be lower than the fuel cut rotation speed Nfc by the rotation speed ΔNx;
Nx is preset to, for example, 1000 rpm. In the drawings, VSP (1d) to (5d) denote the vehicle speed VSP reaching the upper limit rotation speed Nd on the acceleration side of each shift speed, VS.
P (1c) to (6c) indicate the vehicle speeds VSP reaching the upper limit rotational speed Nc on the deceleration side of each shift speed, respectively.

That is, on the acceleration side, the first speed (SP = 1)
Select and hold down the accelerator pedal (TVO 0)
The vehicle speed VSP = VSP at a predetermined speed ratio i (1).
(1d) and the input shaft speed (torque converter 1
In the lockup of 2, the input shaft rotation speed = engine rotation speed Ne) becomes the acceleration-side upper limit rotation speed Nd, and thereafter, the gear ratio i is set so that the input shaft rotation speed does not exceed the upper limit value Nd.
It is set so as to continuously shift to Hi side from (1).

On the other hand, the deceleration side is the same as the prior art except that the speed ratio i (n) 'on the Hi side is set as compared with the same speed position on the acceleration side, and the accelerator pedal is released (TVO). =
0) Even if a downshift from the second speed to the first speed is performed at the vehicle speed VSP (1c) or higher, the target input shaft rotation speed remains at the deceleration-side upper limit Nc.
Is set higher than the predetermined value i (1) ′ of the first speed, and the vehicle speed VSP is set to VSP (1c).
At this point, the speed ratio is fixed to a predetermined speed ratio i (1) ′ on the deceleration side of the first speed.

The determination of the acceleration side and the deceleration side is made only in accordance with the throttle opening TVO, so that the acceleration / deceleration intention can be easily and promptly determined. And the speed ratio on the acceleration side is L
When the vehicle is accelerated after downshifting because it is set to the ow side, the speed ratio on the acceleration side is set slightly to the low side even though the gear stage is the same, so acceleration can be performed quickly. Thus, in addition to the functions and effects of the first embodiment, the operability of the continuously variable transmission having the manual mode can be further improved.

FIGS. 20 and 21 show a third embodiment, in which the number of revolutions to which the first-order lag constant Kr is applied is set to be smaller as the shift speed SP becomes lower. It is.

FIG. 20 is a flow chart of the first embodiment shown in FIG. 12, in which the step S22 of giving the first-order lag constant Kr is replaced with the input shaft rotation speed Nn corresponding to the shift speed SP.
(N = 1 to 7) is changed to the step S22A for changing the first-order lag time constant Kr, and the rest is the same as the first embodiment. The value set to the constant Kr by the shift speed SP and the input shaft speed Nn is set to a fixed value K1 similar to that in the first embodiment, a value corresponding to the shift speed SP, or the like.

Then, in step S13 shown in FIG. 11 of the first embodiment, the target input shaft speed RREV
The shift map in manual mode for setting 0 is
The upper limit rotational speed Nd on the acceleration side is set to be larger than the fuel cut rotational speed Nfc by a predetermined value ΔNx in the same manner as described above. The deceleration side is the same as in the first or second embodiment, and is not shown.

In the shift map shown in FIG. 21, the first-order lag, ie, the rotational speed Nn at which the first-order lag constant Kr is provided when the gear stage SP = 1, is N1 in the figure.
ＮN7 (N7 corresponding to the seventh speed is not shown), and these first-order lag constant imparting rotation speeds Nn are set in a relationship of N1 <N2 <N3 <N4 <N5 <N6 <N7.

At the time of acceleration or the like, the lower the speed ratio, the higher the speed at which the engine speed Ne rises. Therefore, when the speed at which the first-order lag constant Kr is applied is the same at all the speed stages SP, the first speed to the first speed or the lower speed ratio. When the acceleration is performed at the low-speed gear SP such as the second speed, the decrease in the acceleration when the fuel cut speed Nfc is exceeded is excessively large and the drivability is impaired, or when the acceleration exceeds the acceleration-side upper limit speed Nd. Overshoot of the target input shaft speed may occur.

For this reason, by setting the first-order lag constant-providing rotational speed Nn to be smaller at the lower gear stage SP where the gear ratio is larger, the actual target input shaft rotational speed RREV is reduced as shown by the broken line in FIG. Engine speed Ne at the gear ratio
= The rising speed of the input shaft rotation speed Nt can be gently changed, and the excessive decrease in acceleration due to fuel cut as described above is suppressed to stabilize the behavior of the vehicle and improve drivability. The overshoot of the rotation speed Nt is reliably prevented, and the engine overspeed prevention control can be accurately performed. The operability of the continuously variable transmission having the manual mode is further improved, and the control accuracy is improved. be able to.

In the above embodiment, the case where the toroidal type is employed as the continuously variable transmission has been described.
Although not shown, the same operation and effect as described above can be obtained when the V-belt type is adopted.

Also, an example is shown in which the warning display section 11 is employed as a warning means for notifying the driver that the current gear stage SP cannot be maintained. However, although not shown, this is a means for generating a warning by voice or the like. You may.

Further, steps S32 to S3 in FIG.
The feedback control amount calculation of No. 6 was performed from the difference Nerr between the actual target value RREV of the input shaft speed and the current value Nt,
Although not shown, the same operation and effect can be obtained by performing the operation based on the difference between the actual gear ratio and the target gear ratio, the difference between the target value of the tilt angle of the power roller 18c, and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram of a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of gear ratio changing means of the toroidal continuously variable transmission.

FIG. 3 is a schematic diagram of a shift gate provided with a manual mode.

FIG. 4 is a shift map in a manual mode, and shows a shift stage SP.
The relationship between the vehicle speed VSP and the target input shaft rotation speed is shown by using

FIG. 5 is a block diagram showing an outline of a shift control.

FIG. 6 is a block diagram showing an outline of a shift determining unit.

FIG. 7 is a flowchart illustrating an example of control performed by a shift control controller, illustrating a signal measurement process.

FIG. 8 is a flowchart showing an example of control, and
The outline of the VT control process will be described.

FIG. 9 is a flowchart showing an example of control, and shows an outline of a shift control unit.

FIG. 10 is a flowchart showing an example of the same control.
4 shows a signal output process.

FIG. 11 is a flowchart showing details of a shift determination unit similarly performed in CVT control processing.

FIG. 12 is a flowchart showing details of a target rotation speed change amount determination unit which also constitutes a shift determination unit.

FIG. 13 is a flowchart showing details of a shift control amount calculation unit and an FB control calculation unit which are also performed by the shift control unit.

FIG. 14 is a flowchart showing details of a step motor control unit.

FIG. 15 is a map showing a relationship between an actual target gear ratio RRTO and a control position FSTP of a step motor.

FIG. 16 is a graph illustrating a relationship between a time constant Kr, an actual target input shaft rotation speed RREV, and a target rotation speed map value RREV0 over time.

FIG. 17 is a graph showing a relationship between a target step number DSRSTP and an actual output step number ASTP.

FIG. 18 is a flowchart illustrating a shift determining unit according to the second embodiment.

FIG. 19 is also a shift map in the manual mode,
The relationship between the vehicle speed VSP and the target input shaft rotation speed is shown using the gear stage SP as a parameter. The solid line in the figure indicates the acceleration side, and the broken line in the figure indicates the deceleration side.

FIG. 20 shows a third embodiment, and is a flowchart of a target rotation speed change amount determination unit.

FIG. 21 is a shift map in the manual mode,
The vehicle speed VSP and the target input shaft rotation speed are shown by using the shift speed SP as a parameter, and the broken line in the figure shows the actual target rotation speed RREV.

FIG. 22 is a shift map in a manual mode according to a conventional example.
7 shows the relationship between the vehicle speed VSP and the target input shaft rotation speed using the gear SP as a parameter.

FIG. 23 is a diagram corresponding to claims corresponding to the first to fifth inventions.

[Explanation of symbols]

 Reference Signs List 1 continuously variable transmission 2 shift control controller 3 engine control controller 5 shift lever 5A select switch 6 input shaft rotation sensor 7 output shaft rotation sensor 8 up switch 9 down switch 10 continuously variable transmission 13 manual mode changeover switch 18c power roller 70 speed change Judgment unit 71 Shift stage determination unit 72 Revolution speed calculation unit 73 Target rotation speed change amount determination unit 80 Shift control unit 100 First target gear ratio setting unit 101 Second target gear ratio setting unit 102 Gear mode switching unit 103 Overspeed prevention unit 104 shift control means 105 acceleration / deceleration intention detection means 106 upper limit rotation speed setting means 107 upper limit rotation speed switching means 108 shift command means

Claims (5)

[Claims] 1. An engine connected to a continuously variable transmission; an overspeed preventing means for regulating output when the engine exceeds a first speed so as not to exceed an allowable speed; First target gear ratio setting means for setting a target gear ratio of the continuously variable transmission according to a state; and a target gear ratio of the continuously variable transmission based on a signal from a gear shift command means operated by a driver. Second target gear ratio setting means for setting one of a plurality of gear positions set in advance; gear mode switching means for selectively switching between the first target gear ratio setting means and the second target gear ratio setting means; A shift control unit for changing a speed ratio of the continuously variable transmission based on an output of the shift mode switching unit, wherein the shift mode switching unit sets a second target speed ratio. When you choose the means Acceleration / deceleration intention detecting means for detecting acceleration / deceleration intention of the driver; and setting the acceleration-side upper limit rotation speed of the second target speed ratio setting means to be higher than the first rotation speed. An upper limit rotation speed setting unit that sets a deceleration side upper limit rotation speed of the setting unit to be smaller than the first rotation speed; and the acceleration side upper limit rotation speed when the acceleration / deceleration intention detection unit detects a driver's acceleration intention. And an upper limit rotation speed switching unit that selects the deceleration-side upper limit rotation speed when the acceleration / deceleration intention detection unit detects a driver's deceleration intention. A speed change control device for a continuously variable transmission, wherein the speed change ratio is controlled so as not to exceed the range. 2. The acceleration / deceleration intention detecting means detects a driver's intention to decelerate when the accelerator pedal is released, and detects the driver's intention to decelerate in other cases. The shift control device for a continuously variable transmission according to claim 1. 3. The continuously variable transmission according to claim 1, wherein the second target gear ratio setting means sets the target gear ratio on the deceleration side to a higher gear than the target gear ratio on the acceleration side. Transmission control device for transmission. 4. The second target gear ratio setting means includes a time constant setting means for changing an actual gear ratio toward the target gear ratio, and the time constant setting means sets the time constant imparting rotation speed to Low. The shift control device for a continuously variable transmission according to claim 1, wherein the smaller the speed, the smaller the speed is set. 5. The second target gear ratio setting means, wherein when the input shaft rotation speed of the continuously variable transmission reaches the acceleration-side upper limit rotation speed or the deceleration-side upper limit rotation speed, a gear position set by the driver is set. The shift control device for a continuously variable transmission according to claim 1, further comprising a warning unit that warns that the rotation speed has reached an upper limit.