JP3013625B2 - Transmission control device for continuously variable transmission - Google Patents

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 continuously variable transmission that changes the winding diameter ratio of a belt wound around a pair of pulleys by a hydraulic actuator to perform a continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, a drive belt is wound between a primary pulley and a secondary pulley, and a belt-driven stepless speed change is performed by changing the winding diameter ratio of the belts wound on both pulleys to perform stepless speed change. Machines are known. When such a continuously variable transmission is subjected to shift control, for example, a target primary pulley rotation speed corresponding to the throttle opening is set by a map having characteristics as shown in FIG. 6, or according to a separately set target torque. Set the target primary pulley rotation speed. Then, the control means of the continuously variable transmission adjusts the actual primary pulley rotational speed to the target primary pulley rotational speed.

[0003]

When the target primary pulley rotation speed Npo of such a continuously variable transmission is set in accordance with the throttle opening, the set value here is determined based on the standard weight of the vehicle on a flat road. It is often calculated as running. For example, when the vehicle travels on an uphill curved road, even if the target primary pulley rotation speed Npo equivalent to the throttle opening is simply calculated and the gear ratio equivalent to the same value is achieved, the traveling resistance is larger than that on a flat road. As a result, the acceleration of the vehicle cannot be increased properly, and insufficient acceleration is likely to occur. Further, the operation of returning the accelerator for deceleration when entering the uphill corner and turning on the accelerator for acceleration when exiting the corner is repeated. For this reason, even when the accelerator is sufficiently turned on when exiting a corner on a hill, recovery of the output is delayed, and it tends to take time to increase the vehicle speed, resulting in a problem that the driving feeling such as acceleration response is lowered.

On the other hand, if no acceleration is requested on a downhill, the accelerator is turned off. At this time, however, the target primary pulley rotation speed is set low, and the rotation speed is set high enough to obtain the engine braking effect. The number could not be maintained, causing a problem with the engine braking. An object of the present invention is to provide a shift control device for a continuously variable transmission that can improve the driving feeling when traveling on a curved road.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention is directed to a system in which an input-side primary pulley connected to an engine and an output-side secondary pulley connected to a drive shaft are bridged. In a transmission control device for a continuously variable transmission for a vehicle, which changes a gear ratio by changing a winding diameter ratio of an endless belt, a target primary pulley for detecting a target primary pulley rotation speed corresponding to the throttle opening of the engine and the vehicle speed. a rotation speed detecting means, the heavy from driving information of the vehicle
Weight gradient resistance detecting means for detecting the quantity gradient resistance;
Road bend degree detection that detects the road bend degree from both driving information
Means, target primary pulley rotation speed lower limit setting means for setting a lower limit of the target primary pulley rotation speed according to the weight gradient and the road bending degree, and a lower limit of the target primary pulley rotation speed for the target primary pulley rotation speed. Target primary pulley rotation speed clipping means for performing a clipping process with a value, and speed ratio control means for controlling a speed ratio so that the actual primary pulley rotation speed becomes the clipped target primary pulley rotation speed. I do.

[0006]

[Function] Weight gradient and road bending according to vehicle volume and road surface resistance
The target primary pulley rotation speed lower limit value is set according to the degree , the target primary pulley rotation speed is clipped at the same lower limit value, and the deviation between the clipped target primary pulley rotation speed and the actual primary pulley rotation speed is obtained. Since the gear ratio is controlled so that deviations disappear, weight gradients and road bending
The target primary pulley rotation speed is greatly clipped according to the degree .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A transmission control apparatus for a continuously variable transmission shown in FIG. 1 includes a continuously variable transmission (C) on a power transmission system P connected to an engine 7 of a vehicle.
VT) 20. Here, various devices such as an injector 1 for injecting fuel into the engine 7 and a spark plug 2 for igniting an air-fuel mixture are controlled by a DBWECU 3 as electronic control means of the engine.
The BWECU 3 is connected to a CVT ECU 21 which is an electronic control unit of the continuously variable transmission 20. Note that both ECUs
A communication line is connected between the terminals 3 and 21 so that signals can be always exchanged between them. The DBWECU 3 is connected to an actuator 11 for driving the throttle valve 9 as an intake air amount operation unit that is driven independently of the operation of the accelerator pedal 10.

The engine 7 has a Karman vortex airflow sensor 6 for detecting the flow rate of intake air from the air cleaner element 5 in the air cleaner body 4. In addition to the airflow sensor 6, an engine speed sensor 24 for outputting information on the engine speed Ne, and a throttle opening sensor 1 for outputting information on the throttle opening Th of the throttle valve 9
2. Operation information detecting means such as an accelerator sensor 13 for outputting accelerator opening θa information of the accelerator pedal 10 and a water temperature sensor 39 for outputting water temperature WT information are provided. These data are measured and input to the DBWECU 3. This is a well-known configuration.

The throttle valve 9 is not an accelerator pedal 10 depressed by the driver, but an actuator (in this embodiment,
It is opened and closed by a step motor 11. In the present embodiment, a so-called DBW (drive-by-wire) system in which the actuator 11 is controlled by the DBWECU 3 is employed. However, a normal accelerator pedal and a throttle valve connected by a link or the like may be used. Absent. The crankshaft of the engine 7 has a fluid coupling 8 and a planetary gear type forward / reverse switching device 15.
Is connected to the continuously variable transmission 20 of FIG.

Here, the continuously variable transmission 20 is a primary shaft 2 integrally connected to the output shaft of the forward / reverse switching unit 15.
2 and a secondary pulley 28 having a secondary shaft 29 for outputting a rotational force to the speed reducer 30. A steel belt 27 is stretched over the primary pulley 26 and the secondary pulley 28. The secondary shaft 29 is configured to transmit torque to the drive wheels 32 of the drive shaft 31 via a speed reducer 30 and a differential (not shown). Both the pulleys 26 and 28 are configured to be divided into two, and the movable side pulley members 261 and 281 are provided.
Are inserted into the fixed pulley members 262 and 282 so that they cannot be rotated relative to each other and can be moved toward and away from each other. This movable pulley material 26
A primary cylinder 33 and a secondary cylinder 34 are formed between the first and second pulley members 262 and 282 as hydraulic actuators for operating the relative distance between the two pulleys.

A pair of rotation sensors s1 and s2 for detecting the rotational speeds Np and Ns of the primary pulley 26 and the secondary pulley 28 are mounted as means for detecting the actual speed ratio in (= Np / Ns). In this case, the movable pulley 261 is brought closer to the fixed pulley 262 of the primary pulley 26 to increase the winding diameter of the primary pulley, and the movable pulley 281 is separated from the fixed pulley 282 of the secondary pulley 28 and the winding diameter is increased. To reduce the actual speed ratio in (the primary rotational speed Np
/ Secondary rotation speed Ns), that is, a low gear ratio (high gear), and conversely, a high gear ratio (low gear).
Is achieved. Here, the continuously variable transmission 20
Will be described with reference to FIG.

The oil pump 37 is driven by a fluid coupling 8 connected to the engine 7, and the oil pump 3
The hydraulic pressure discharged from 7 is regulated by a regulator valve 40 to an appropriate pressure, so-called line pressure. The duty of this regulator valve 40 is controlled by a first electromagnetic control valve 41 driven by the CVT ECU 21 at a duty ratio set in accordance with the driving state of the vehicle. The line pressure regulated by the regulator valve 40 is supplied into the secondary cylinder 34 (see FIG. 5) of the secondary pulley 28, and is also introduced into the speed ratio control valve 35. The speed ratio control valve 35 is duty-controlled by a second electromagnetic control valve 42 driven by the CVT ECU 21 at a duty ratio set in accordance with the driving state of the vehicle, and the primary cylinder of the primary pulley 26 is driven to a desired speed ratio. 33 (see FIG. 5).

The line pressure is controlled by the modulator valve 43.
The hydraulic pressure regulated by the valve is transmitted to the gear ratio control valve 35, the first electromagnetic control valve 41, and the second electromagnetic control valve 4.
2 and acts as a pilot pressure for these. The other detection signal from DBWECU3 the CVTECU21, are configured to the lateral acceleration G _Y than both the rotational speed Np, Ns and lateral acceleration sensor 44 of the primary pulley 26 and secondary pulley 28 is input. CV
The main part of the TECU 7 is constituted by a microcomputer, and a built-in storage circuit has a target primary pulley rotation speed detection map shown in FIG. 6, a target primary pulley rotation speed correction amount setting map shown in FIG. Rotation speed lower limit setting map, hysteresis processing map for weight gradient resistance in FIG. 9, hysteresis processing map for bending degree in FIG. 10, CVT control processing routine in FIG. 12, target primary pulley rotation speed correction in FIG. An amount setting routine, a bending degree detection routine in FIG. 14, and other control programs are stored and processed. FIG. 3 shows a configuration block diagram of the present invention.

Here, the traveling road surface information detecting means A1 is
Includes quantity gradient detecting means a1 and road bending degree detecting means a2
And the weight gradient detecting means a1 is the traveling road surface information.
The weight gradient resistance Rw is detected, and the road bending degree detecting means a2
The degree of curvature Wd (Jw) of the road is detected . The target primary pulley rotation speed detection means A2 is configured to output a target primary pulley rotation speed N according to the throttle opening Th of the engine and the vehicle speed V.
Po is detected. Target primary pulley rotation speed lower limit value setting means A3 sets the target primary pulley rotational speed limit value N _PL depending on the travel road surface information. Target primary pulley speed clipping means A4 is clipping the target primary pulley speed Npo at the target primary pulley rotation speed lower limit value N _PL. The deviation rotation speed calculating means A5 calculates a deviation rotation speed E1 between the clipped target primary pulley rotation speed Npo and the actual rotation speed Np of the primary pulley. The duty ratio setting means A6 sets the duty rate according to the deviation E1, and the shift control means A7 drives the second electromagnetic control valve 42 as the pulley operating means at the same duty rate. The second electromagnetic control valve 42 controls the hydraulic actuator 33 by duty-controlling the speed ratio control valve 35. Here, the deviation rotation speed calculation means A5, the duty ratio setting means A6, and the speed change control means A7 constitute a speed ratio control means.

The transmission control apparatus for the continuously variable transmission according to the present embodiment will now be described with reference to an engine output control routine shown in FIG. 11, a CVT control routine shown in FIG. 12, a routine for setting a target primary pulley rotational speed correction amount shown in FIG. The description will be made with reference to the bending degree detection routine of FIG. 14 and the functional block diagram of FIG. In this embodiment, the engine 7 is started by operating an ignition key (not shown), and the control in the DBWECU 3 and the CVT ECU 21 shown in FIGS. 1 and 2 is also started. When the control is started, the DBWECU 3 executes a well-known main routine (not shown). Here, the initial setting and detection data of each sensor are fetched, and the detection data is fetched in a predetermined area determined for each data. Well-known controls such as a well-known fuel supply control process, an ignition timing control process, and an engine output control process are executed. Here, an example of the engine output control process will be described.

As shown in FIG. 11, in the engine output control process, the detection data of the sensor, here, the throttle opening T
h, accelerator opening θa, engine speed Ne, water temperature WT
Etc. is taken into a predetermined area. Step r2
First, an intake air amount A / N is calculated from the accelerator opening θa and the engine speed Ne using an intake air amount calculation map and a required torque calculation map (not shown), and the required torque To is calculated from the calculated intake air amount A / N and the engine speed Ne. I do. Step r
In steps 3 and r4, the water temperature information WT is taken in, a friction loss torque T _WT of the sliding portion is calculated from a predetermined map (see mp1 in FIG. 2), and the friction loss torque T _WT is added to the required torque To to obtain a target torque. T1 is determined, and the process proceeds to step r5.
Here, the intake air amount A / N according to the target torque T1 and the engine speed Ne is obtained from an intake air amount calculation map (not shown), and the target throttle opening Th is not shown from the intake air amount A / N and the engine speed Ne. It is calculated using a throttle opening calculation map.

In step r6, the target throttle opening Th
And the actual opening degree θn to calculate a deviation Δθ, calculate an output Pun that can eliminate the deviation Δθ, and calculate the output Pu.
By driving the pulse motor 11 at n, the opening of the throttle valve 9 is adjusted, and the engine generates the target torque T1. On the other hand,
The CVT ECU 21 performs CVT control in accordance with the control programs shown in FIGS. Here we make the initial settings,
The rotational speeds Np and Ns of the primary pulley 26 and the secondary pulley 28, the handle angle δ, the throttle opening Th from the DBWECU 3, and the detection data of each sensor,
The engine speed Ne and others are taken in and stored in a predetermined area.

In step s3, the vehicle speed V is calculated from the primary pulley rotation speed Np and the reduction ratio ε, and the acceleration α (= dV / dt) obtained by differentiating the vehicle speed V is calculated, and the primary pulley rotation speed Np and the secondary pulley rotation speed are calculated. Ns
Thus, the actual gear ratio in (= Np / Ns) is calculated.
In step s4, a target primary pulley rotation speed Npo corresponding to the throttle opening Th and the vehicle speed V is detected by a target primary pulley rotation speed detection map mp2 (see FIGS. 2 and 6). Thereafter, the process of setting the degree of bending Jw in step s5 is executed as shown in FIG. That is, in step p1, the degree of bending Jw is detected. The bending degree Jw is an integral value of the product of the absolute value of the steering wheel angle δ and the calculated lateral gravitational acceleration Gr (hereinafter simply referred to as lateral Gr), as shown in the equation (7). It has been demanded. Note that the calculated lateral Gr is calculated by equation (8),
The same value increases as the vehicle speed V and the steering wheel angle δ increase.

Jw = 1 / T × ∫ | δ | × | Gr | dt (7) Gr = (δ / (ρ × 57.3)) / (I × (A + 1 /
V ² ) × 9.8) (8) where T is unit time [sec], V is vehicle speed [m / sec], δ is steering wheel angle [deg], ρ is steering wheel equivalent gear ratio, I Is a wheelbase [m], and A is a stability factor which is an index of sensitivity indicating how the lateral Gr increases when the steering wheel is turned further. The larger the stability factor A is, the larger the value of the stability G becomes.
This is a characteristic value representing a state where r does not increase so much. After this,
When reaching p2 from step p1, the calculated degree of bending J
The w is subjected to a hysteresis processing along the bending degree hysteresis processing map mp7 as shown in FIGS. 2 and 10, the corrected bending degree Wd is calculated, and the routine returns. Here, the vehicle speed V
In addition, the minute change amount of the bending degree Jw corresponding to the fine fluctuation of the steering wheel angle δ is absorbed in the range of the set width ΔJw, and the correction bending degree Wd can be prevented from finely changing.

Thereafter, the target primary pulley rotational speed correction amount CN from step s5 to step s6 of the CVT control process is performed.
The setting process of p is executed as shown in FIG. That is, the weight gradient resistance Rw is detected in step q1. The weight gradient resistance Rw is obtained by subtracting the aerodynamic resistance R1, the acceleration resistance R2, the rolling resistance R3, the cornering resistance R4, and the resistance R5 due to the speed change from the engine driving force Te, as shown in the following equation (6). Set as a value. Here, the engine driving force (drive torque) Te is a product of the output torque and the speed ratio (the total speed ratio of the forward / reverse switching unit, the continuously variable transmission, and the speed reducer), and the output torque is the torque of the fluid coupling 8. The ratio is obtained by multiplying the actual engine torque (a value obtained by subtracting pump loss and other loss torque from the engine torque).

Here, the aerodynamic resistance R1 is given by equation (1), the acceleration resistance R2 is given by equation (2), and the rolling resistance R3 is given by equation (3).
The cornering resistance R4 is given by the following equation (4).
5 is calculated by the equation (5). Aerodynamic drag R1 = 1/2 × ρ × S × C D × V 2 [Kgf] ..... (1) where, [rho is 0.1229 in air density [Kgf · sec
² / m ⁴ ], and S is the total projected area of the vehicle, here 1.9.
3 [m ^2], C _D value here is 0.395, V, upon the vehicle speed, and R1 = 0.049V ² [Kgf].

The acceleration resistance R2 = [M + 1 / R × (I E × i 2 + I M + 2 × I T) ] ×
α [Kgf] (2) where M is the vehicle weight [K
gf], R is the wheel radius [m], the moment of inertia of I _E is engine [Kgf · m · sec ^2], I _M is the moment of inertia of the CVT and the drive shaft [Kgf · m · s
ec ^2], I _T is the moment of inertia per one wheel of the drive wheel 32 [Kgf · m · sec ^2], alpha is the longitudinal acceleration of the vehicle [m / sec ^2], the speed ratio i is Np / Ns, the equation Is obtained from the equation of motion of the vehicle. For example, I _E =
_{0.016, I M + 2 × I} T = 0.16, if you set R = 0.28, acceleration resistance R2 = [M + 7.4255 × i
² + 2.0408)] × α [Kgf]. Rolling resistance R3 = Ro [Kgf] (3) Here, Ro (= μr × M) is a rolling resistance at the time of free rolling and is about 0.013 × M.

Cornering resistance R4 = C _F ² / C _P = (0.6M / 2 × Gr) ² / C _P f ×
2+ (0.4M / 2 × Gr) 2 / C P r × 2 [Kgf] &
(4) where C _F is the cornering force [Kgf] and C _P
Represents cornering power [Kgf / rad]. In addition, the front / rear weight distribution of the vehicle is 6: 4, and C _P f = 70 [Kg
f / deg] = 4010 [Kgf / rad], C _P r =
90 [Kgf / deg] = 15160 [Kgf / ra]
d] and Gr as the lateral acceleration [g], R4 = 6.
0389 × 1/10 ⁵ × M ² × Gr ² [Kgf]. Resistance due to shifting R5 = di / dt × _IE × Ne × 1 / R [Kgf] (5) Here, di / dt indicates a shifting speed.

Such values are sequentially calculated based on the equations (1) to (5), and are used in the equation (6) for calculating the weight gradient resistance Rw. Rw = Te-R1-R2-R3-R4-R5 [Kgf] (6) After calculating such a weight gradient resistance Rw, step q1 in the process of setting the target primary pulley rotation number correction amount CNp.
Reaches q2.

At step q2, the weight gradient resistance Rw obtained at step q1 is taken as an input value, and this value is subjected to hysteresis processing based on a hysteresis processing map mp5 for weight gradient resistance, that is, the weight gradient resistance Rw that changes sequentially.
Is subjected to absorption processing of a deviation of a predetermined fluctuation range ± Δh, is calculated as a corrected weight gradient resistance Rw, and is stored in a predetermined area. When step q3 is reached,
Here, the target primary pulley rotational speed correction amount CNp according to the throttle opening Th and the corrected weight gradient resistance Rw after the hysteresis processing is calculated based on the target primary pulley rotational speed correction amount calculation map mp3 in FIG.

In the target primary pulley rotational speed correction amount setting map, the throttle opening Th having a large driving margin is set.
In the middle range, the correction amount CNp is set to be sufficiently large in the large range of the throttle opening Th with a small drive margin so that the correction amount CNp is sufficiently large.
Is set to be small, and when the weight gradient resistance Rw is large and the throttle opening is in the middle range, the correction amount CNp is set to be large. Therefore, especially in the middle range of the throttle opening Th, Improves responsiveness. CV
When the process reaches step s7 from step s6 of the T control process, the corrected weight gradient resistance Rw obtained in step q2 and the corrected bending degree Wd obtained in step p2 are fetched, and the target primary pulley rotation speed lower limit corresponding to these values is obtained. N _PL is set in the target primary pulley rotation speed lower limit setting map mp4 as shown in FIG.

Here, the weight gradient resistance Rw tends to increase its positive value when traveling on an uphill or in accordance with an increase in the weight of the vehicle body, and on the downhill, increase its negative value. In the target primary pulley rotation speed lower limit value setting map mp4, the target primary pulley rotation speed lower limit value N _PL increases as the absolute value | Rw | increases.
It is set larger, in particular, (in this case N _PL0) predetermined level the lower limit N _PL even zero weight grade resistance Rw is held in. In addition to this characteristic, comprising the map mp4, large correction tortuosity Wd, a larger set characterizing the lower limit N _PL The closer to zero the weight grade resistance Rw. As a result, the target primary pulley rotation speed Npo is increased by a predetermined amount even when the throttle opening is reduced when traveling on a curved road, the engine brake is applied when traveling on a curved road, and the acceleration response when exiting a curved road is improved. Can be achieved.

Furthermore Step s8 target primary pulley rotation speed Npo obtained in step s4, it is determined whether or not lower than the set lower limit value N _PL, only if below the lower limit of the target primary pulley speed Npo at step s9 N
_The clip is set on the _PL , and the process proceeds to step s10. By this clipping process, the target primary pulley rotation speed Npo is prevented from excessively decreasing, and even if the accelerator opening is zero, the target primary pulley rotation speed is raised to secure acceleration responsiveness and engine braking performance. ,
The target primary pulley rotation speed Pno is further increased in accordance with the increase in the absolute value of the weight gradient resistance Rw, thereby improving the driving feeling. In step s10, step s
A corrected target primary pulley rotation speed Npc is obtained by adding the target primary pulley rotation speed Npo determined in step 4 or s9 and the target primary pulley rotation speed correction amount CNp obtained in step s6.

Further, in steps s11 to s13, a deviation E1 (= Npc-Np) between the corrected target primary pulley rotational speed Npc and the actual primary pulley rotational speed Npn is calculated. Then, in step s12, a duty ratio corresponding to the deviation E1 is calculated. decide. Then, in step s13, the second electromagnetic control valve 42 is driven at the duty ratio set in step s12, and the process returns to the main routine. That is, the second electromagnetic control valve 42 in which the speed ratio control valve 35 is driven at the duty ratio set in step s12
In response to the control pressure from, the amount of oil supplied to the primary cylinder 33 is controlled, and as a result, the gear ratio is changed so that the actual primary pulley rotational speed approaches the corrected target primary pulley rotational speed.

As a result of such CVT control processing, the continuously variable transmission 20 changes the actual primary pulley rotation speed N
p is adjusted to the corrected target primary pulley rotation speed Npc, and then the speed is continuously shifted from the high gear to the lower gear ratio to achieve a gear ratio that balances the vehicle speed and the engine speed. The ratio (target speed ratio) is maintained. Therefore, even if the throttle opening decreases when the vehicle enters a curved road, the corrected bending degree W
The target primary pulley rotation speed Np increases as d increases.
By raising o, it is possible to secure the engine braking force at the time of traveling on a curved road and to improve the acceleration responsiveness at the time of exiting a curved road. These effects are particularly remarkable when traveling on an uphill or downhill.

Here, even if the calculated value of the weight gradient resistance Rw fluctuates finely due to a calculation error including sensor noise, a swell of a road, a level difference, or the like, the corrected weight gradient resistance Rw varies by a hysteresis process. Since the calculation is performed by absorbing the deviation of ± Δh, it is possible to prevent the target primary pulley rotation speed Npo from fluctuating due to these effects, and the driving feeling is improved. In the above-described process, the weight gradient resistance Rw becomes the engine driving force Te as shown in the equation (6).
More aerodynamic resistance R1, acceleration resistance R2, and rolling resistance R3
And a value obtained by subtracting the cornering resistance R4 and the resistance R5 due to shifting, but some of these may be eliminated for simplification of the configuration. Further, the lateral G _Y has been calculated by the equation (8), but may be detected using only the lateral G _Y sensor 44 in some cases.

[0032]

As described above, the transmission control apparatus for a continuously variable transmission according to the present invention provides a target primary pulley rotation of a continuously variable transmission.
For number control, the target
By setting the lower limit of the rotation speed of the pulley,
Even if throttle opening is zero, target prime rotation
The number can be raised a predetermined amount, the target primary pulley rotation speed of preventing excessive reduction, can be ensured handed acceleration response and engine brakes during uphill entering or during downhill engine brake to the bending line, Improved driving feeling
I do .

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a shift control device for a continuously variable transmission as one embodiment of the present invention.

FIG. 2 is a functional block diagram of an electronic control unit in the apparatus of FIG.

FIG. 3 is a configuration block diagram of the present invention.

FIG. 4 is a hydraulic circuit diagram in the apparatus of FIG.

FIG. 5 is a sectional view of a main part of a continuously variable transmission used by the apparatus of FIG. 1;

FIG. 6 is a characteristic diagram of a target primary pulley rotation speed detection map adopted by the electronic control device in the device of FIG. 1;

FIG. 7 is a characteristic diagram of a target primary pulley rotation speed correction amount setting map adopted by the electronic control device in the device of FIG. 1;

FIG. 8 is a characteristic diagram of a target primary pulley rotation speed lower limit setting map employed by the electronic control unit in the apparatus of FIG. 1;

FIG. 9 is a characteristic diagram of a hysteresis processing map for a weight gradient resistance adopted by an electronic control device in the device of FIG. 1;

FIG. 10 is a characteristic diagram of a hysteresis processing map for a degree of bending employed by the electronic control device in the device of FIG. 1;

FIG. 11 is a flowchart of an engine output control routine employed by the electronic control unit in the apparatus of FIG.

FIG. 12 shows a CV adopted by the electronic control unit in the apparatus shown in FIG.
It is a flowchart of a T control processing routine.

FIG. 13 is a flowchart of a routine for setting a target primary pulley rotation speed correction amount adopted by the electronic control unit in the apparatus of FIG. 1;

FIG. 14 is a flowchart of a bending degree calculation routine adopted by the electronic control unit in the apparatus of FIG. 1;

[Explanation of symbols]

Reference Signs List 1 engine 3 DBWECU 7 CVT ECU 12 throttle opening sensor 13 accelerator sensor 20 continuously variable transmission 21 CVT ECU 23 electromagnetic control valve 24 engine speed sensor 26 primary pulley 27 drive belt 28 secondary pulley 33 primary cylinder 34 secondary cylinder 39 lateral acceleration sensor 35 transmission ratio control valve in the actual speed ratio s1 rotation sensor s2 rotation sensor Pc shift control hydraulic N _PL lower limit Rw weight grade resistance Jw tortuosity Wd correction tortuosity

────────────────────────────────────────────────── (5) References JP-A-3-121349 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61 / 16-61/24 F16H 63/40-63/48 F16H 9/00

Claims (1)

(57) [Claims] 1. A gear ratio is changed by changing a winding diameter ratio of an endless belt stretched between an input-side primary pulley connected to an engine and an output-side secondary pulley connected to a drive shaft. In the shift control device for a continuously variable transmission for a vehicle, target primary pulley rotation speed detecting means for detecting a target primary pulley rotation speed corresponding to the throttle opening degree and the vehicle speed of the engine; and a weight gradient resistance from the driving information of the vehicle. Weight gradient to detect
Road resistance detecting means for detecting a road bending degree from driving information of the vehicle;
Degree detection means, target primary pulley rotation speed lower limit value setting means for setting a lower limit value of the target primary pulley rotation speed according to the weight gradient and the road bending degree , and the target primary pulley rotation speed as the target primary pulley rotation speed. Target primary pulley rotation speed clipping means for clipping at the lower limit of the number, and speed ratio control means for controlling the speed ratio so that the actual primary pulley rotation speed becomes the clipped target primary pulley rotation speed. A shift control device for a continuously variable transmission, comprising: