JPS63266265A - Controller for continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent overrun by carrying out speed change control of a continuously variable transmission and mode control of an auxiliary transmission through a judging means based on a differential signal between rotation under L-shift and a limit rotation fed from a rotation comparing means and a signal fed from a target torque ratio setting means. CONSTITUTION:A continuously variable transmission 12 carries out speed change with large torque ratio width through continuously variable speed change of a belt type continuously variable transmission 30 and low/high speed mode switching control of an auxiliary transmission 20. A setting means 113 sets a target torque ratio corresponding to running condition, and a judging means 115 carries out low/high mode switching control of the auxiliary transmission through a switching means 110 based on a difference between a limit rotation of a setting means 104 fed from a rotation comparing means 124 and rotation under L-shift fed from a calculating means 118 and a mode fed from a detecting means 112 thus carrying out continuously variable speed change control by means of the continuously variable transmission 30 through an operating means 100. Consequently, speed change operation can be made quickly without causing overrun.

Description

[Detailed Description of the Invention] (a) Industrial Applicability The present invention relates to a control device for a continuously variable transmission, particularly a continuously variable transmission for automobiles, and specifically relates to a control device for a continuously variable transmission for a vehicle.
The present invention relates to a control device used in a continuously variable transmission, which is a combination of a continuously variable transmission such as a type, and an auxiliary transmission for expanding the torque ratio range, such as a planetary gear device.

(b) Conventional technology Recently, due to the demand for improved fuel consumption, etc., belt-type continuously variable transmissions (FI) have been used as automobile transmissions.
Continuously variable transmissions incorporating T) are attracting attention.

In general, the continuously variable transmission is composed of a belt type continuously variable transmission, a fluid coupling (or electromagnetic powder clutch), a forward/reverse switching device, a reduction gear device, and a differential gear device. Due to limitations such as space and the minimum radius of curvature of the belt, a step-change transmission cannot have a large torque ratio range, and the range of torque ratio provided only by the step-change transmission does not meet various demands for automobiles such as fuel efficiency and shift performance. is not sufficient to respond to

Therefore, as shown in Japanese Patent Application Laid-Open No. 61-103049, an auxiliary transmission consisting of a Lavigny 4 type planetary gear unit is connected in series to a belt-type continuously variable transmission (CVT), and the auxiliary transmission is connected to a low speed gear. A continuously variable transmission has been devised in which the torque ratio range is expanded by switching between high-speed and high-speed gears.

When changing gears, the continuously variable transmission stops the shifting operation of the belt-type continuously variable transmission while the auxiliary transmission is changing, or when the auxiliary transmission is in the opposite direction to the shifting direction of the auxiliary transmission. When the gear is shifted toward an upshift, the continuously variable transmission is shifted toward a downshift, and when the auxiliary transmission is shifted toward a downshift, the continuously variable transmission is shifted toward an upshift. The configuration is configured to change gears and thereby suppress changes in the gear ratio, so that an upshift of the continuously variable transmission continues during an upshift of the auxiliary transmission, or a continuously variable transmission continues to shift during a downshift of the auxiliary transmission. By continuing to downshift, the amount of change in the gear ratio of the entire power transmission device increases, thereby preventing problems that would be disadvantageous in terms of driving sensation.

←→ Problems to be Solved by the Invention By the way, the limit rotation speed of a belt-type continuously variable transmission is determined by various conditions such as the input shaft, output shaft ζ, and durability of the bearings. In a stepped transmission, even if the target input rotation speed is not very high, when a shift from a high gear to a low gear is performed, such as during a kickdown, the upshift of the continuously variable transmission (CVT) is performed by the auxiliary transmission. Since this occurs later than the switching to low speed mode, there is a risk that the input shaft or output shaft of the continuously variable transmission may temporarily rotate beyond its limit rotation speed (overrun). There is a risk of damaging the continuously variable transmission.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems by suppressing the rotation speeds of the input shaft and output shaft of the continuously variable transmission to below their limit rotation speeds.

(b) Means for solving the problem The present invention has been made in view of the above circumstances, and is
As shown in the figure, the continuously variable transmission 12 to be controlled is a continuously variable transmission 30 capable of continuously variable control of the torque ratio.
and an auxiliary transmission device 20 that is combined with the continuously variable transmission device 30 and can switch the shift controllable range between a low speed mode in which the torque ratio is relatively high and a high speed mode in which the torque ratio is relatively low; The continuously variable transmission 30 is variable #J
The sister continuously variable transmission operation means 100 and the auxiliary transmission device 2
mode switching means 110 that operates by switching between 0 and 0.

Further, torque ratio detection means 111 detects the torque ratio of the continuously variable transmission 30, and mode detection means 112 detects whether the auxiliary transmission 20 is in the low speed mode or the high speed mode.
, and target torque ratio setting means 113 for setting a target torque ratio determined based on the driving situation. Further, rotation speed calculation means 11 calculates the rotation speed of the continuously variable transmission 30 when the mode switching means 110 switches to the low speed mode L.
8, a limit rotation speed setting means 104 for setting the limit rotation speed of the continuously variable transmission 30, the rotation speed calculated by the rotation speed calculation means 118, and the limit rotation speed set by the limit rotation speed setting means 104. and, based on signals from the mode detection means 112, the target torque ratio setting means 111, and the rotation speed comparison means 124, the speed is stepless even when switched to the low speed mode L. Gearbox! ! The present invention is characterized in that a determining means 115 is provided which issues a signal to the mode switching means 110 only when it is determined that the rotational speed of the engine 30 does not exceed the limit rotational speed.

(E) Effect Based on the above configuration, the output torque of the engine is transmitted to the wheels via the continuously variable transmission 12, and the automobile runs at an appropriate speed. Continuous torque ratio control of the continuously variable transmission 30 and auxiliary transmission W20
With switching control between low speed mode L and high speed mode H, the sixth
As shown in the figure, the torque ratio should be controlled within a relatively large range.

In addition, the transmission 12 receives signals from various driving situation sensors such as throttle opening, input shaft rotational speed, and vehicle speed, and adjusts the transmission 12 so that predetermined speed change characteristics such as maximum power characteristics or best fuel efficiency characteristics are achieved.
The overall target torque ratio a" is the target torque ratio detection means 11
It is set in 3. When the current torque ratio a of the continuously variable transmission 12 is in the high speed mode H and is shifted down to the low speed mode L as shown in FIG.
Even during the switching, the continuously variable transmission 30 performs an upshift and attempts to change gears as shown by arrow A. However, if the shifting of the continuously variable transmission is delayed by the switching of the auxiliary transmission, arrows B and C A change in the torque ratio occurs as shown by . In this case, the torque ratio of the continuously variable transmission increases rapidly from aH to aL, and a high rotational speed is applied to the continuously variable transmission [30].

In other words, even if the target torque ratio a1 is not so high, it may become a high torque ratio during the shift process.

At this time, for example, when depressing the accelerator for sudden acceleration, so-called kickdown, first the rotation speed N of the input shaft and output shaft of the continuously variable transmission 30 is set to low speed mode L.
1nL and NoutL are calculated by the rotational speed calculation means 118, and the limit rotational speeds Ninmax and Noutwax of the input shaft and output shaft in the continuously variable transmission 30, which are set in advance by the limit rotational speed setting means 104, and the above calculations. The rotational speed N inL and NoutL are compared by the rotational speed comparing means 124 . As a result, the rotation speed N in
L, N outL is the limit rotation speed N in mad-,
When N outIIIaχ is exceeded, the mode switching means 110 is not activated, the high speed mode H is maintained, and only the continuously variable transmission 30 downshifts, even if switching to the low speed mode would normally be performed. .

Then, the rotation speed N1nL, NoutL is the limit rotation speed N
When inmaX and N out wax are no longer exceeded, the judgment means 115 issues an H-, L change signal to the mode switching means 110 based on the signal from the rotation speed comparison means 124, and the mode switching means 110 operates to change the auxiliary gear. Bag M20 is switched from high speed mode H to low speed mode L, and a rapid downshift is performed.

(f) Example Hereinafter, embodiments embodying the present invention will be described.

First, the continuously variable transmission according to the present invention (for details, please refer to the patent application filed in 1986-
205614) according to the schematic diagram shown in FIG. 2, the continuously variable transmission 12 includes a single planetary gear M20 constituting an auxiliary transmission, a belt type continuously variable transmission 30, a transfer device 80. Reduction gear device 71
and a differential gear device 72, a fluid coupling 13 having a lock-up clutch CL, and a forward/reverse switching transmission device 90 consisting of a dual planetary gear device. The single planetary gear device 20 includes a first element 20R (or 2OS) connected to the output section 30a of the continuously variable transmission 30, and a continuously variable transmission 12.
The third element 203 (or 20R) is connected to the input shaft 60 of the continuously variable transmission 12 via a transfer device 80. Also, a mode switching means 110 for switching the planetary gear device 20 between a high speed mode (■) and a low speed mode (L).
is a locking means consisting of a low one-way clutch F and a low lower l-& reverse brake B1, and a high clutch C.
2, and is connected via a transfer device 80 to a third element 20S (or 20R) that serves as a reaction force support member when the locking hand @F, B1 is used as a deceleration mechanism in low speed mode L. , and the high clutch C2 is connected to the input shaft 6.
0 and the third key T: 203 (or 20R).

Specifically, the ring gear 20 of the planetary gear device 20
R is interlocked with the output part 30a of the continuously variable transmission 30, the carrier 20C is interlocked with the output member 70, and the sun gear 203 is connected to the row one-way clutch F and the low coast and reverse brake Bl via the transfer device [80].
It is linked to the high clutch C2 as well as to the high clutch C2.

In addition, the dual planetary gear device 90 has a sun gear 903 connected to the input shaft 60, a carrier 90C connected to the input part 30b of the continuously variable transmission fi30, and connected to the input shaft 60 via the forward clutch C1. Ring gear 90R is connected to reverse brake B2.

Based on the above configuration, each clutch, brake, and one-way clutch in the present continuously variable transmission 12 operate as shown in FIG. 3 at each position. Note that * indicates that the lock-up clutch CL can operate as appropriate.

To explain in detail, in low speed mode L in D range,
In addition to the forward clutch C1 being connected, the row one-way clutch F is activated. In this state, the rotation of the engine crankshaft is transmitted to the input shaft 60 via the lock-up clutch CL or the fluid coupling 13, and is further transmitted directly to the sun gear 90S of the dual planetary gear device 90 and to the carrier via the forward clutch C1. 9
It is transmitted to 0C. Therefore, the dual planetary gear device 90 rotates integrally with the input shaft 60, transmits the forward rotation to the input section 30b of the belt type continuously variable transmission W30, and further changes the speed appropriately by the continuously variable transmission bag M30. is the output section 30a
From the ring gear 2O of the single planetary gear device 20
transmitted to R.

On the other hand, in this state, the sun gear 203, which is a reaction force support element that receives a reaction force, is stopped by the row one-way clutch F via the transfer device 80, and therefore the rotation of the ring gear 2OR is taken out from the carrier 20G as a decelerated rotation. , is further transmitted to the axle shaft 73 via the reduction gear device 71 and the differential WIhMI vehicle device 72.

Furthermore, in high-speed mode H in the D range, the high clutch C2 is connected in addition to the forward clutch C1. In this state, similarly to the above, the forward rotation that has been appropriately shifted by the continuously variable transmission 30 is taken out from the output section 30a and input to the ring gear 20R of the single planetary gear group M20. Meanwhile, at the same time, the rotation of the input shaft 60 is transmitted to the sun gear 203 of the single planetary gear group M20 via the high clutch C2 and the transfer device jl180,
As a result, the ring gear 2 in the planetary gear device 20
Torques from the OR and sun gear 20S are combined and output from the carrier 20G. At this time, since the rotation against the reaction force is transmitted to the sun gear 203 via the transfer device 80, a predetermined plus torque is transmitted via the transfer device 80 without causing torque circulation. Then, the combined torque from the carrier 20C is transmitted to the axle shaft 73 via the reduction gear device 71 and the differential gear device 72.

In addition, in the operation in the D range, it becomes free when reverse torque is applied (during engine braking) based on the one-way clutch F, but in the S range, in addition to the low one-way clutch F, the low coast and reverse brake B1
operates and transmits power even when reverse torque is applied.

Furthermore, in the R range, the reverse brake B2 operates together with the low coast and reverse brake B1. In this state, since the ring gear 90R is fixed by the dual planetary gear device 90, the rotation of the input shaft 60 is reversely rotated from the carrier 90C and input to the belt type continuously variable transmission device 30. On the other hand, the sun gear 205 of the single planetary gear device 20 is fixed based on the operation of the low coast and reverse flake B1, so that the reverse rotation from the continuously variable transmission device 30 is decelerated by the planetary gear device 20 and taken out to the output member 70. Ru.

Further, in the P range and the N range, the low coast and reverse brake B1 is operated.

Next, the above-mentioned continuously variable transmission will be explained in detail with reference to FIG. The input shaft 30b of the continuously variable transmission bag [30 is coaxially and rotatably supported to constitute a first shaft, and the output shaft 30a and gear shaft 70a of the continuously variable transmission 30 are coaxially and rotatably supported. It is supported and constitutes a second shaft. Furthermore, a lock-up clutch CLJ2 is installed on the first shaft! In addition, a mode switching means 110 consisting of a high clutch C2, a low coast and reverse brake B1, and a row one-way clutch F is also provided, and a dual planetary gear device 90 is also provided.
, a forward/reverse switching device consisting of a forward clutch C1 and a reverse brake B2 is provided, and a hydraulic pump 1
7 are arranged. On the other hand, a single planetary gear device 20 is disposed on the second shaft.

To further explain the first shaft portion, the input shaft 60 has one end engaged with the lock-up clutch CL and the output member of the fluid coupling 13 (ζ and the other end engaged with the sun gear 903 of the dual planetary gear device 19Q). A sleeve portion l5a fixed to the case 15 is disposed above the input shaft Cζ6°.A sprocket 81 is connected to the sleeve portion 15a via a one-way clutch F. A sleeve shaft 41 connected to the input shaft 60 is rotatably supported.Furthermore, a flange portion 41a rising from the sleeve shaft 41 has a forward clutch C1 on one side. is installed together with its hydraulic actuator 42, and a high clutch C2 is installed together with its hydraulic actuator 43 on the other side.

The driven side of the high clutch C2 is connected to the boss portion of the sprocket 81, and the boss portion is connected to the case 1.
The low coast and reverse brake B1 is connected to the low coast and reverse brake B1, which is disposed at the hydraulic actuator 45 at the same time.

On the other hand, the driven side of the forward clutch C1 is connected to the carrier 90G of the dual planetary gear device 90,
Also, the ring gear 90 of the dual planetary gear device 90
R is engaged with a reverse brake B2 arranged in the case 15 together with the hydraulic actuator 46.

Note that the carriers 90C mesh with each other and the sun gear 903
Pinion 90P1 and ring gear 90R meshing with
The pinion 90P2 is in mesh with the pinion 90P2.

Further, the continuously variable transmission 30 is disclosed in Japanese Patent Application No. 60-298794.
As described in detail in No. (unpublished), it consists of a primary pulley 31, a secondary pulley 32, and a belt 33 wound around both pulleys, and both pulleys each have a fixed sheave 31a.

32a and movable sheaves 31b and 32b.

Furthermore, the primary pulley 31 has a fixed sheave 31a between a thrust force holding member 34a, which is supported by a bearing and is connected to the input shaft 30b so as to rotate together with the input shaft 30b via a plurality of disc springs 38. A pressure regulating cam mechanism 34 that applies an axial force corresponding to the transmitted torque is disposed, and the movable sheave 31b is slidably supported by the boss portion 31c of the fixed sheave 31a via a ball spline. At the same time, a ball screw device 35 is disposed on the back thereof. The ball screw device 35 has its bolt portion 35
a is connected to the case 15 in a non-rotatable manner and to the input shaft 30b via a thrust bearing in an axially immovable manner, and its nut portion 35b moves integrally with the movable sheave 31b in the axial direction via a thrust bearing. are connected like this. On the other hand, the secondary pulley 32 has a fixed sheave 32a that is rotatably supported by the case 15 together with the output shaft 30a, and a movable sheave 32b that is slidably supported by the output shaft 30a via a ball spline. ing. Further, a ball screw device 36 is disposed on the back surface of the movable sheave 32b, and the bolt portion 36
a is connected non-rotatably to the case 15 and immovably axially to a flange 30d fixed to the output shaft 30a via a thrust bearing, and its nut portion 36b is connected to the movable sheave 32b in the axial direction via a thrust bearing. They are linked together so that they move together. An operating shaft 37 is rotatably supported between the primary pulley 31 and the secondary pulley 32.

Note that since FIG. 4 is a developed view, the operating shaft 37 is drawn upward, but in reality, the operating shaft 37 is located at an intermediate portion between the input shaft 30b and the output shaft 3Qa when viewed from the front. A circular gear 37a, a non-circular gear 37b1, and a worm wheel 37c are fixed to the operation shaft 37, and the wheel 37c is connected to an electric motor 100 (see FIGS. 1 and 7) constituting a continuously variable speed operation means. ) is engaged with the worm 37d. In addition, the circular gear 37
a is in mesh with a wide circular gear 35c fixed to the nut part 35b on the primary pulley 31 side, and a non-circular gear 37b is in mesh with the nut part 3 on the secondary pulley 32 side.
It meshes with a wide non-circular gear 36c fixed to the gear 6b.

Moreover, the single planetary gear device 20 is a gear shaft that constitutes a second shaft. The ring gear 2OR is connected to the output shaft 30a of the belt-type continuously variable transmission 1130 adjacent to the 7-lunge 30d. Also,
A sprocket 82 is rotatably supported integrally with the sun gear 203 on the gear shaft 70a.
A carrier 20C rotatably supporting the pinion 20P is fixed to the pinion 20P.

On the other hand, a silent chain 8 is connected between the sprocket 82 integrated with the sun gear 203 on the second shaft and the sprocket 81 supported by the row one-way clutch F.
3 is wound around, and these sprockets and chains constitute a transfer device 80.

Further, the gear shaft 70a integrally constitutes a gear 71a to constitute an output member 70, and the gear 71a meshes with a gear 71C fixed to an intermediate shaft 71b. Further, a small gear 71d is formed on the intermediate shaft 71b, and the gear 71d meshes with a ring gear 72a fixed to the differential gear device 72 to constitute the speed reduction device 71.

Further, a left and right hand axle shaft 73 extends from the differential gear device 72 .

Next, the operation of the continuously variable transmission 12 will be explained.

The rotation of the engine crankshaft is controlled by the lock-up clutch CL.
Alternatively, it is transmitted to the input shaft 60 via the fluid coupling 13, further transmitted to the sun gear 903 of the dual planetary gear device 90, and further transmitted to the sleeve shaft 41. In the D range and S range, the forward clutch C1 is connected and the reverse brake B2 is released, so the sun gear 903 and carrier 90C of the dual planetary gear system N90 rotate as one, and the ring gear 90R also rotates as one, resulting in forward rotation. Belt type continuously variable transmission! ! 30 input shaft 30b.

The rotation of the input shaft 30b is transmitted to the pressure regulating cam mechanism 34 via the thrust force holding member 34m, and further transmitted to the movable sheave 31b via the fixed sheave 31a of the primary pulley 31 and the ball spline. On this occasion,
In the pressure regulating cam mechanism 34, an axial force corresponding to the input torque acting on the input shaft 30b acts on the back surface of the sheave 31a via the disc spring 38, while the other slope 31b is connected to a ball screw in accordance with a predetermined gear ratio. There is a state ζζ in which the device 35 is fixed in its longitudinal direction, and therefore an equivalent reaction force acts on the back surface of the sheave 31b via the thrust bearing, thereby
The primary pulley 31 clamps the belt 33 with a clamping force corresponding to the input torque.

Further, the rotation of the belt 33 is transmitted to the secondary pulley 32, and further transmitted to the output shaft 30a. Further, during the belt transmission, as will be described later, the motor is controlled based on signals from various sensors such as throttle opening and vehicle speed, and the operating shaft 37 is rotated via the worm 37d and the worm wheel 37c. Then, the circular gear 37a
and 35c, the nut portion 35b of the ball screw device 35 on the primary pulley 31 side rotates, and the nut portion 36b of the ball screw device M36 on the secondary pulley 32 side rotates via the non-circular gears 37b and 36c. As a result, the bolt portion 35a which is prevented from rotating on the case 15,
The nut portions 35b, 36b rotate relative to the ball screw device [35, 36], which move the movable sheaves 31b, 32b via thrust bearings to set the primary pulley 31 and the secondary pulley 32 to a predetermined effective diameter. Then, the set torque ratio can be obtained. At this time, since both ball screw devices j move linearly, there is a difference between the original movement amount of the movable sheave defined by the belt 33, but the secondary pulley 32 side has a non-circular gear 3? b, 36c, the movable sheave is moved by an amount matching its original movement. Also, both sheaves 31a, 31
The belt clamping pressure from b, 32m, and 32b acts on the primary pulley 31 side to pull the input shaft 30b through the thrust bearing, and does not act on the case 15, and similarly, on the secondary pulley 32 side, the belt clamping pressure is not applied to the output shaft 30b. It does not act on the case 15 to pull the shaft 30m.

Furthermore, the rotation of the output shaft 30a of the belt type continuously variable transmission 30 is controlled by the ring gear 2OR of the single planetary gear device 20.
further transmitted to the gear shaft 70a via the carrier 20G.
transmitted to.

In the case of low speed mode L in the D range, the row one-way clutch F is in an operating state as shown in FIG.
The sun gear 203 is stopped from rotating by a row one-way clutch F via a transfer device so, and the single planetary gear device 20 constitutes a speed reduction mechanism.

Therefore, the rotation of the output shaft 30a of the belt-type continuously variable transmission 30 is simply reduced by the single planetary gear W20, and the gears 71a, 71c1, the intermediate shaft 71b1, the gear 7
1d and a mount gear 72a.
The speed is further reduced through the differential gear device 72, and then transmitted to the left and right front axle shafts 73 through the differential gear device 72.

Furthermore, as will be described later, when the high clutch C2 is connected in response to a signal from IIJ Sonobe and switched to high speed mode H, the rotation of the input shaft 6'O is transmitted to the belt type continuously variable transmission M30, and the rotation of the input shaft 6'O is transmitted to the belt type continuously variable transmission M30. Shaft 41 and high clutch C
2 to the sprocket 81, and further transmitted to the sun gear 20S of the single planetary gear device 20 via the silent chain 83 and sprocket 82. At this time, since the sprocket 81 at the input end of the transfer device 80 receives the reaction force from the sun gear 203 of the single planetary gear device through the row one-way clutch F, it is possible to prevent shift retrieval due to the clutch change and to shift the clutch C2. connection (this starts rotation smoothly and transmits torque to the sun gear 203. As a result, the torque continuously variable by the belt type continuously variable transmission 30 and the torque via the transfer device 80 are transferred to the single planetary gear W20. The combined torque is transmitted from the carrier 20C to the gear shaft 70a.

Furthermore, similarly to the low speed mode L described above, the left and right front axle shafts 7 are
3.

In addition, in the low speed mode L in the S range, negative torque from the engine, brakes, etc. is also applied, so o -)-
Nido and reverse brake B1 are engaged and sprocket 8
1 is prevented from rotating in both forward and reverse directions. Further, the high speed mode H in the S range is similar to the high speed mode in the D range.

On the other hand, in the R range, the forward clutch C1 is released and the reverse brake B2 is engaged. Therefore,
The rotation of the input shaft 60 transmitted to the sun gear 903 of the dual planetary gear device 90 is transmitted as reverse rotation from the carrier 90C to the input shaft 30b of the belt type continuously variable transmission 30 when the ring gear 90R stops. At this time, the reaction torque acts on the sprocket 81 as reverse rotation from the sun gear 203 of the single planetary gear device 20 via the transfer device 80, so it is a low course!・&
Reverse brake B1 is activated to stop the sprocket 81.

In addition, in the torque transmission of the above-mentioned continuously variable transmission 12, the fifth
As shown in the figure, in the low speed mode, the entire transmission torque is transmitted via the belt type continuously variable transmission 30, but in the high speed mode H, the belt type m-stage transmission 30it is used.
g! The torque passing through the transfer device 80 and the torque passing through the transfer device 80 are shared at a predetermined ratio according to the torque ratio.

Furthermore, as shown in FIG. 6, a belt type continuously variable transmission 30 is provided.
The torque ratio of the continuously variable transmission 12 to the torque ratio of is curved in the low speed mode, and curved in the high speed mode. It becomes as shown in f$H. Therefore, the step ratio (low speed torque ratio/high speed torque ratio) when stepping from low speed mode L to high speed mode H (or vice versa) is as shown by curve S.

Next, the control device for the continuously variable transmission 12 will be explained with reference to FIG.

This control device (system) U includes a shift control section U1, an engine brake control section U2, and a lock-up clutch control section U.
3. It is equipped with a line pressure control section U4 and a shift range control section U6.

The transmission control unit U includes a target torque ratio setting means 113, a limit rotation speed setting means 104 for setting the limit rotation speed of the continuously variable transmission 30, and a current torque ratio a with a target torque ratio a1 having a predetermined width I. and planetary gear device 20
Low speed and high speed mode L.

In addition to determining the switching of H, the continuously variable speed operation means 100
Judgment means 115 for emitting a signal, continuous variable transmission device 300 Å power shaft 3 for switching from high speed mode H to low speed mode L
0b, a rotation speed calculation means 118 that calculates the rotation speed of the output shaft 30a, and a comparison between the rotation speed calculated by the rotation speed calculation means 118 and the limit rotation speed set in the limit rotation speed setting means lO4, and It has a rotation speed comparison means 124 that issues a signal to the determination means 115. Also, shift # sister part U1
In addition, signals from the primary pulley rotation speed N in sensor 111a and the secondary pulley rotation speed N out sensor 111b that constitute the torque ratio detection means, the throttle opening θ sensor 1z2, the vehicle speed V sensor 123, and the auxiliary gear shift A mode sensor (mode detection means) 112 that detects low speed and high speed modes L and H of the planetary gear device 20 that constitutes the device, and a shift range sensor 125 that detects each range of rP, R, N, D, and S. , and signals calculated and determined based on the signals from these sensors are output to the drive circuit 120 of the electric motor 100 and the L-H shift solenoid drive circuit 121. The motor drive circuit 120 also includes a PWM oscillator that emits a predetermined signal based on signals from the speed change control section U and the engine brake control section U2, a drive circuit that amplifies the signal from the oscillator to a predetermined level, and a drive circuit that amplifies the signal from the oscillator to a predetermined level. It consists of a bridge circuit that supplies signals to the motor 100.

Target torque ratio setting means 11 of the shift control section U1
3 is S based on the primary pulley rotation speed N1n (=engine rotation speed) corresponding to the throttle opening θ and the vehicle speed V.
The target torque ratio is calculated and set so as to perform the maximum power control in the range and to perform the best fuel efficiency control in the D range. Note that the target torque ratio setting means 113 controls intake pipe negative pressure, secondary pulley rotation speed No.
It may be set in response to signals from other driving situation sensors such as ut or output gear rotation speed, and is not limited to maximum power control and best fuel economy control, but also for maximum torque #ft1lJI in the middle of the pond. Of course it's a good thing. The target torque ratio 1 set by the target torque ratio setting means 113 has a predetermined width! A dead zone is set, and the target torque ratio a1 is compared from time to time with the current torque ratio a of the continuously variable transmission 12 based on the vehicle speed V etc. in the judgment means 115, and the torque ratio a is determined from the dead zone width l. A predetermined speed change signal is output at the off-line portion (shaded portion) tζ.

On the other hand, the engine brake control unit U2 receives signals from each sensor as shown in the figure, and controls the motor drive time @12.
0 and L-H shift solenoid drive circuit 121, and when an engine brake state, that is, a state where the throttle opening is zero or near zero is detected in the S range, a comparison different from the target torque ratio for maximum power control is performed. It sets a high target torque ratio and applies effective engine braking.

In addition, the lock-up control unit U3 receives signals from each sensor as shown and outputs them to the lock-up solenoid drive circuit 126, thereby engaging and releasing the lock-up clutch CL provided in the fluid coupling 13.
II! do.

Furthermore, the line pressure control unit U4 receives signals from each sensor as shown in the figure and outputs them to the shift control solenoid drive circuit 127, thereby generating a line pressure corresponding to the throttle opening, and also To reduce the shift sink that occurs when the forward clutch 01 or reverse brake B2 engages when shifting from the D range (or S range) and from the N range to the R range (N→D(S), N-R shift). is detected,
Reduce line pressure, then gradually increase to normal position.

In addition, the shift change control unit U6 receives the signals from each sensor and controls the shift range change motor drive times $1.
29, and the stepping motor is driven and controlled to change the shift position of the manual valve 132 according to the set position of the shift lever installed in the driver's seat.

And each solenoid and motor drive @path 121.12
Reference numerals 9, 126, and 127 operate predetermined valves of the hydraulic control device W1130 to operate the high clutch C2 and the four-coast & reverse brake Bl that constitute the mode switching means 110.
, as well as forward clutch C1 and reverse brake B
2. Lock-up clutch CL and fluid coupling (F/C)
13.

As shown in FIG. 8, the hydraulic control device 130 includes a manual valve 132 (shift control solenoid drive circuit) operated by a minion valve 131 connected to a stepping motor driven by a shift range change motor m drive circuit 129. A regulator valve 135 is actuated by a linear solenoid 133 driven by a lock-up solenoid drive circuit 127; a lock-up control valve 137 is actuated by a solenoid valve 136 driven by a lock-up solenoid drive device 126; It has a four-high shift valve 140 operated by a driven solenoid 139, an accumulator 141, and a low-high shift timing valve 142. The regulator valve 135 includes a port 1-b to which pressure oil from the hydraulic pump 17 is supplied, a line pressure port II, and a lubricating oil port L.
It has u.

In addition, the manual valve 132 is configured such that line pressure is supplied to the first and second line pressure ranges j, l, and R, and line pressure is supplied to the ranges S and D. line pressure is supplied in the baud)-e, S, N, R, and P ranges)f, N.

Equipped with a port g to which line pressure is supplied in the R and P ranges, and a port e is connected to the forward clutch hydraulic servo C1.
and port e of the low/high shift valve 140, port f is connected to port f2 of the low/high shift valve 140, port g is connected to Mug2 of the lock-up control valve 137 and oil chamber g3 of the low/high shift valve 140.
, and port r is reverse brake hydraulic servo B2
are connected to each other.

The lock-up control valve 137 has a line pressure port 14, a port h that communicates with the fluid coupling (F/C) 13, and a port i that communicates with the lock-up clutch hydraulic servo CL. The hydraulic pressure controlled by the valve 136 acts, and the stage room g
2 is provided with a spring that urges the spool upward, and line pressure acts on ranges other than the D and S ranges.

Therefore, when the solenoid valve 136 is turned on, the performance chamber j is drained and the spool is moved upward, and the port I
Line pressure from port 14 is sent to fluid coupling 13, and when solenoid valve 136 is turned off in D and S ranges, the spool moves downward against the spring, and line pressure from port 14 is applied to the lock-up clutch. It is sent to the hydraulic servo OL, which engages the clutch, and further N, R,
In the P range, line pressure acts on the performance chamber g2,
The spool never moves downward.

In addition, the low/high shift valve 140 is connected to the port e2.
The port has ports k and m outside f2, and the port communicates with the high clutch hydraulic servo C2 via an orifice 143 with a check valve, and the port m communicates with an orifice 145 and a low/high shift timing valve 142.
Low coast and reverse brake through hydraulic servo B
It is connected to 1. Furthermore, the low/high shift valve 1
In 40, hydraulic pressure controlled by a solenoid valve 139 is applied to the stage chamber n, and a spring that biases the spool upward is arranged in the stage chamber g3. Line pressure is working. In addition, the accumulator valve 141 has a spring 141a.
The accumulator chamber 141c constituted by the piston communicates with the stage chamber q of the high clutch hydraulic servo C2 and the low/high shift timing valve 142, In addition, line pressure is acting on the back pressure chamber 141d.

Therefore, when the solenoid valve 139 is in the on state,
The stage room n is drained and the spool is in the upper position;
Port f, which is supplied with line pressure in each of the S, N, R, and P ranges (i.e., other than the D range), communicates with port m, and port e2, which is supplied with line pressure in the S and D ranges. is blocked. In this state, line pressure is supplied to the low coast and reverse brake hydraulic servo B1, the brake B1 is engaged and the high clutch C2 is released, and the vehicle is in a low speed mode. Further, when the solenoid valve 139 is turned off, the spool moves downward, communicates the port e2 with the port k, closes the port f2, and drains the port m. In this state, line pressure is supplied to the accumulator chamber 141C and to the high clutch hydraulic servo C2, and the line pressure acts on the upper oil chamber q of the low/high shift timing valve 142 to move the spool downward. , drain the hydraulic pressure of the brake hydraulic servo B1. Therefore, high clutch C2
is engaged and the low coast and reverse brake B1 is released, resulting in a high speed mode state.

Note that in each of the N, R, and P ranges, that is, except for the D and S ranges, line pressure acts on the lower oil chamber g3 of the low/high shift valve 140, and even if the solenoid valve 139 is turned off, the spool will not move downward. The high clutch C2 will not be engaged when the high clutch C2 is moved to . Furthermore, in the D range, even if the solenoid valve 139 is in the on state, line pressure is not supplied to the port f2, so the low coast and reverse brake B1 does not operate.

Next, the operation of the continuously variable transmission control device υ will be explained along the flow.

FIG. 9 is a diagram showing the main flow, and shows the shift lever
Input the position code, throttle opening θ, primary pulley rotation speed N in, secondary pulley rotation speed N out, and vehicle speed V to perform D range control, S range control, N range control, R range control, P range division. Each control of the section is set, and each solenoid 136, 13 is set corresponding to each control.
9 and motor 100.

FIG. 10 is a flowchart showing D range control, in which a signal indicating whether the mode is in low speed mode L or high speed mode H is input from the mode sensor 112 (31), and the throttle opening degree θ is adjusted based on the best fuel economy curve. A target rotation speed N1 of the primary pulley is set (S2). Furthermore, the primary pulley rotation speed N in and the secondary pulley rotation speed Nou
t to the torque ratio T of the continuously variable transmission 30 (= N in
/Nout) is calculated (33), and in step S4, the torque ratio aL of the low speed mode L and the torque ratio aH of the high speed mode H at the torque ratio T are calculated. That is, if the ratio of the number of teeth between the sun gear 203 and the ring gear 20R of the planetary gear device 20 (2OS/2OR) is λ, and the ratio of the number of teeth between the output sprocket 82 and the input sprocket 81 in the transfer device 80 (81/82) is 1, It is calculated by a=T×(1+λ). Furthermore, an allowable deviation width l is set for the target rotational speed to obtain the target rotational speed width N''wax, N'
Set win (SS). Then, in step S6, the upper limit a''wax and the lower limit a of the target torque ratio a1 are determined.
” win is calculated. That is, a'may== (N"maxXC)/Va"m1n
== (N"+m1nX C) / V, and C is a constant (60 x πXD / i dX 1000) determined by the tire diameter D and final reduction ratio 1d.

Note that step 32. SS, 36 corresponds to the target torque ratio setting means 113.

Furthermore, in step S7, it is determined whether the gear device 20 is currently in the low speed mode L or the high speed mode H. If the current mode is low speed mode L, determine whether or not to perform an L-H change using the method shown in Figure 12, Figure 16, or Figure 19, which will be described later. When in mode H, Figures 14 and 17 will be described later.
It is determined whether or not to perform an H→L change using the method shown in the figure or FIG. 20 (311). Also, L in step S8→
In H judgment, if it is decided to perform L-H change,
An L-H change signal is issued to the L-H shift solenoid drive circuit 121 (SS). On the other hand, L-H in step S8
If it is determined in step 311 that the L-4H change is not to be performed, and if it is determined in step 311 that the HL change is not to be performed, the continuously variable transmission (CVT) is )30 gear change determinations are made (310). Note that steps 87 to 312 above are
It corresponds to the determining means 115.

FIG. 11 is a flow showing S range control, and the 10th
The flow shown in the figure is the same except for the engine brake control part, and the same parts are given the same reference numerals and the explanation will be omitted. However, in step S2, unlike the case of D range control, the target @ rotation speed N1 of the primary pulley corresponding to the throttle opening θ is set based on, for example, the maximum power curve.

Step 513 is a step for determining whether to use normal speed change control @U or engine brake control U2. If the throttle opening θ is zero or near zero (660 m1n), the flow goes to engine brake control (314); otherwise, Flows to normal speed change control.

Next, mode switching is performed by the determining means 115 shown in FIGS. 1 and 7, that is, step S8. in FIGS. 10 and 11. The S11 portion will be explained.

First, in accordance with FIGS. 12 to 15, the determining means 11
5 is a low speed mode L and a high speed mode H of the auxiliary transmission 20.
If the target torque ratio a'' is in a region where both can achieve the same torque ratio and a region where only high-speed mode H can achieve, the high-speed mode H operates preferentially, and only the low-speed mode L An embodiment will be described in which a signal is sent to the mode switching means so that the low speed mode L is activated when the target torque ratio a'' is within the achievable range.

FIG. 12 shows the judgment at the time of upshifting, that is, step S8.
is a diagram showing the contents, first, the torque ratio aL in the low speed mode L calculated in step S4 is stored (SS,
). Then, the limit rotation speed N out mx of the secondary pulley 32 set by the limit rotation speed setting means 104 is compared with the current rotation speed N out of the secondary pulley,
The rotation speed N out is the limit rotation speed N out IIIL
If it exceeds X, immediately switch to high speed mode H and reduce the rotation speed of the secondary pulley (38□). Also, the rotation speed N out of the secondary pulley is the limit rotation speed N o
If it is within 11111, as shown in FIG. 13, the maximum torque ratio aH in high speed mode
1aX), the target torque ratio upper limit a'
If wax is higher than torque ratio aHmax, mode switching is not performed and low speed mode L is maintained. On the other hand, when the target torque ratio upper limit a''wax is lower than the torque ratio aH111, the actual torque ratio a is further compared with the target torque ratio upper limit a''lIaχ. In other words, in the case of an upshift, the mode is immediately switched to the high speed mode H, and in the case of a downshift, the mode is not switched and the low speed mode L is maintained. When the continuously variable transmission 30 is in the L position during a downshift,
-H switching is prevented from occurring and deterioration of feeling is prevented.

FIG. 14 shows the judgment at the time of downshifting, that is, step 31.
1. First, the rotation speed N1nL of the primary pulley 31 when the low speed mode L is set is calculated by the rotation speed calculation means 118. That is, from the torque ratio aL (see S4) when the low speed mode L is selected, the vehicle speed v1, and the constant C determined by the tire diameter and final reduction ratio shown earlier, a
, X V / C, rotation speed N1nL using the formula
is calculated (S11.).

Similarly, from the torque ratio aL1 vehicle speed V and the torque ratio T of the continuously variable transmission, aLX V / CX T, that is,
The rotation speed N out L of the secondary pulley 32 when the low speed mode L is set is calculated using the formula N1nL/T (S 112). Then, the rotation speed N1nL of the primary pulley 31 and the limit rotation speed Ni of the primary pulley 31 preset by the limit rotation speed setting means 104 are determined.
If the rotational speed N1nL exceeds the limit rotational speed N1nIlax compared to nmax (S113), the mode is not switched and the high speed mode H is maintained. Note that aH is set as the actual torque ratio a in step 5116 because aH is used as the current torque ratio in the CVT shift determination in step 810 that follows. Also, the rotation speed N1nL of the primary boolean is the limit rotation speed Ni
If nmax is not exceeded, the rotation speed N out L of the secondary pulley 32 and the limit rotation speed N ou of the secondary pulley preset by the limit rotation speed setting means 104
Compare with t wax 5l14), rotation speed N out
If L exceeds the limit rotational speed N out + maχ,
No mode switching is performed and high speed mode H is maintained. If the rotational speed N Out L does not exceed the limit number 4, as shown in FIG. 15, the target torque ratio lower limit a
” Maximum torque ratio aHm in l1In and high speed mode H
5115), if the target torque ratio lower limit a1 is higher than the high speed mode maximum torque ratio aH'wax, the mode is switched to the low speed mode L and a downshift is performed. In addition, the target torque ratio lower limit a ”win is the torque ratio a
If it is lower than Hmaχ, mode switching is not performed and the high speed mode HGiI is maintained.

Further, switching from the low speed mode L to the high speed mode H,
Also, when switching from high speed mode H to low speed mode L, the target torque ratio 1 is between the upper limit a ” ahaχ and the lower @ a
There is a predetermined hysteresis between the maximum torque ratio aHIIlaχ and the high speed mode maximum torque ratio aHIIlaχ, which prevents frequent mode switching.

Then, step 38. Other embodiments of the S11 portion will be described based on FIGS. 16 to 20.

In this embodiment, the determining means 115 performs the switching by a combination of mode switching and variable operation of the continuously variable transmission in a region where the low speed mode L and the high speed mode H can achieve the same torque ratio, and the continuously variable transmission. This is to compare and determine which one can perform a faster shift operation with respect to the target torque ratio, with the case where the shift operation is performed only by variable operation of the transmission device. That is, the torque ratio of the continuously variable transmission 12 is set to a, and the target torque ratio setting means 11
Let the target torque ratio that can be set in step 3 be al, and the torque ratio of the continuously variable transmission in the other mode corresponding to the current torque ratio T of the continuously variable transmission 130 is aLl. is the torque ratio of the low speed mode L to the torque ratio T of the continuously variable transmission 30, then 1a”-al ≧ 1ao-al (
1) Switch the auxiliary transmission 20 when the relationship is satisfied.

FIG. 16 shows the judgment at the time of upshifting, that is, step S8.
is a diagram showing the contents of the target torque ratio, and the lower limits a,' s of the target torque ratio are
Compare in with the torque ratio aH (see 34) of high-speed mode H corresponding to the actual torque ratio T. S S, ), a
If there is a relationship such as "wins a H," an L-H shift is sent to the solenoid drive circuit 121, and the low speed mode L is switched to the high speed mode H (see 39).

On the other hand, if the above-mentioned 31 sets n≦aH does not hold, the above-mentioned mode switching is not performed. Incidentally, in step S87, aL is stored as the actual torque ratio a, but this is determined by IIL in the CVT shift determination in step 310 that follows.
This is because it should be used as the current torque ratio. The same applies to step S8.1, which will be described later.

FIG. 17 shows the judgment at the time of downshifting, that is, step 31.
1, the upper limit a″ma of the target torque ratio
Compare χ with the torque ratio aL in low speed mode L (see 34) corresponding to the actual torque ratio T in 311. ), a″II
If the relationship Iaχ≧aL does not hold, the mode is not switched. In addition, in step 5118, the actual!・Luc ratio a
This is because aH is used as the current torque ratio in the CVT shift determination in the next step SIO. Also, step 311, which will be described later. The same applies to s.

On the other hand, if the above relationship is a″maχ≧aL, first, the rotation speed N1nL of the primary pulley 31 and the rotation speed N o of the secondary pulley 32 when the low speed mode L is set.
ut L in step S11. , where DT is the tire diameter and id is the final reduction ratio, it is calculated as follows. Then, the calculated rotation speed N1nL of the primary pulley 31 is determined by the limit rotation speed setting means 104.
(NinL≧N in
(wax) (311, 0), and if it exceeds, do not switch the mode. Also, it is determined whether the rotation speed N out L of the secondary pulley 32 when the low speed mode is set is more round than the limit rotation speed N out +aaχ of the secondary pulley 32 preset by the limit rotation speed setting means 104 ( N out L≧N out may ) is determined (Sl"Il), and if it exceeds, the mode is not switched. As a result, the continuously variable transmission 30
prevent damage. If neither of them exceeds the limit rotation speed, a signal is sent to the L-H shift solenoid drive circuit 121 to downshift from high speed mode H to low speed mode L.

Next, as shown in FIGS. 18 to 20, step 38
, 311 will be explained.

In the other embodiments described above, the torque ratio is determined based on the rotation speed of the primary pulley 31 and the secondary pulley 32 of the continuously variable bag M30 based on the sensors l1la and 111b. The positions of the movable sheaves 31b and 32b of the pulley 32 are detected, and the torque ratio is determined from the detected positions.

The target primary pulley is determined from the torque ratio T of the continuously variable transmission when achieving the target torque ratio a″ in low speed mode L and the torque ratio TH of the continuously variable transmission when achieving the target torque ratio a″ in high speed mode 11. 31 (or secondary pulley 32
) of movable sheave 31b (or 32b) @SL, S
, respectively. And the low speed and high speed mode L
, H, the target movable sheave positions SL and SN are compared with the current movable sheave position S, and I sLs l < I "H" I
...At the time of (2), if the current high speed mode is H, the mode is switched from H to L, and if the current is the low speed mode L, the speed is changed only by the variable faJ control of the continuously variable transmission 30. (See Figure 18 (la)).

Also, l5L-8l > l5H-31...(3
), if the current mode is high-speed mode H, the gear is changed only by variable control of the continuously variable transmission 30, and if the current mode is low-speed mode, the mode is switched to L-+H (18th mode).
Figure (see bl).

Furthermore, l5L-sl = l5H-3t...
- In case (4), speed change control is performed only by the continuously variable transmission.

Note that the method based on the sheave position described above changes the sheave position from S to S when mode switching time and shift time are taken into consideration.
Time DU to move to L and time D to release clutch C2
When the relationship with C satisfies a predetermined relationship, for example, the relationship Du×Do, it is preferable to switch from high speed mode H to low speed mode L.

Next, a specific example based on the above method will be explained with reference to FIGS. 19 and 20.

FIG. 19 shows the judgment at the time of upshifting, that is, the above-mentioned first
38. This is a diagram showing a different content from Figure 6, in which the current position S of the movable sheave is input. ), and the target sheave position 8S Lwin and SNmax are calculated from the upper and lower limit target torque ratios a ” wax and a ” win (S 89
).

And l5-3L@inl ≧ l S, mx
-S8.0 to judge whether there is a relationship such as S8.0
), if there is such a relationship, from low speed mode L to high speed mode H
, and if there is no such relationship, no mode switching occurs and the target torque ratio a1 is set only by the continuously variable transmission 30.
The gear is shifted to.

FIG. 20 shows the judgment at the time of downshifting, that is, the first
This is a diagram showing the same contents as Figure 7, and first, step S1.
1. ,, S 11. , in step S8. .

38, the lower limit target sheave position 5Lsin and the upper limit target sheave position SHpengχ of the current sheave position [8 are set, and further in step 311.4, Is-3l5-3L ≦ l SH+ux -S l
Determine whether there is a relationship. If the above relationship does not exist, mode switching is not performed and the continuously variable transmission 3
Only 0 is downshifted to the target torque ratio a1,
Further, when the above relationship exists, the high speed mode H is switched to the low speed mode L. At this time, as described above, if the primary pulley rotational speed limit Ninmax and the secondary pulley rotational speed limit N out mx are exceeded, the mode is not switched (311, 7°S 11.).

Note that in the above flow, step S11. .

8112.811. ．． 311.6 constitutes the rotation speed calculation means 118 during -L shift, and step 5113
．． 5l14. Sll! . , S 11. ,, S 11
, 7°51118 constitute the rotational speed comparison means 124.

Next, determination means 1 and 5 related to continuously variable transmission (CVT)
That is, step 810 in FIGS. 1O and 11 will be explained along with FIG. 21.

First, when the input rotation speed is low, the current vehicle speed V is set to an extremely low vehicle speed (V
), the gear shift operation is inhibited (S15). If the vehicle speed is not extremely low and the actual torque ratio a is larger than the target torque ratio a1 by 1 (S16), the continuously variable transmission 30
If the actual torque ratio is smaller than the target torque ratio a'' (318), the continuously variable transmission 30 will shift down (319), and in other cases, the continuously variable transmission fi30 will shift up. Shift does not work (S20)
. In this embodiment, in order to prevent deterioration of feeling due to frequent shifting operations of the continuously variable transmission 30, the target torque ratio a' has an upper limit a ``wax'' and a lower limit a ``wi''.
It has a predetermined width of n. In addition, if the gear shift operation of the continuously variable transmission M30 is performed immediately after issuing the mode switching signal, even if the mode switching is not completed, step S4 (specifically, step S8., 81
16.38□, Sl 1,, S 8. ,, S 11
, 5), the torque ratios aL and aH in low speed mode L or high speed mode H with the mode switching completed (clutch C2 engagement or disengagement completed) have been read.
In the shift determination of the continuously variable transmission 30, the torque ratio aL in the low-speed mode L or the torque ratio aH in the high-speed mode H after the mode switching is completed, determines whether to upshift or downshift now. It is determined whether the state should be maintained. Therefore, as the torque ratio a,
By using the torque ratio aL or a8 after mode switching, even if the mode is being switched, the continuously variable transmission M3
In the case of 0, the speed change can be controlled in advance for the state after mode switching, and the target torque ratio a1 can be quickly approached. Also, the actual torque ratio T is the lower limit of the torque ratio (T win
) and the upper limit (T wax ), and if the limit is exceeded, the continuously variable transmission stops shifting (321, 322
).

Next, control in the R range will be explained with reference to FIG.

First, as in step 15 above, to prevent gear shifting at extremely low vehicle speeds (323), and the rotational speed N of the primary pulley.
The upper limit of rotation speed N wa is set to prevent in from increasing excessively.
x is suppressed (824), and if x is exceeded, the continuously variable transmission is upshifted (325).

Also, calculate the torque ratio T of the continuously variable transmission 526),
The torque ratio T is compared with the torque ratio upper limit T vahx of the continuously variable transmission, which is mainly determined by the belt rotation speed (S27).
, if it is small, the continuously variable transmission will downshift (328)
, and otherwise stop (329).

Note that in the N range and P range, all solenoid drive circuits and motor drive circuits are stopped.

(g) As described in detail, according to the present invention, the rotation speed calculation means 1
a rotation speed comparing means 124 that compares the rotation speed when switching to the low speed mode L calculated in step 18 with the limit rotation speed set by the limit rotation speed setting means 104; and a mode detection means 1.
12 and the signal from the target torque ratio setting means 113, only when it is determined that the rotational speed of the continuously variable transmission 30 will not exceed the limit rotational speed even if it is switched to the low speed mode L, the signal from the determination means 115 is sent. Since the configuration is configured to switch to low speed mode L at
By accurately switching modes, the input shaft 30b of the continuously variable transmission 30.

Overrun in which the output shaft 30a rotates beyond the limit rotation speed can be reliably prevented, and damage to the continuously variable transmission 130 can be prevented.

Further, the continuously variable transmission 30 includes primary and secondary pulleys 31 . each having two sheaves whose effective diameters can be changed.
32 and a belt 33 wound around both pulleys 31 and 32, the belt-type continuously variable transmission 30 suppresses the rotation speed within the limit rotation of the bearing on which a large thrust load is applied, and achieves continuously variable speed. Damage to the mounting [30] can be reliably prevented.

In addition, torque ratio detection means 111 and mode detection means 112
and receiving a signal from the target torque ratio setting means 113,
Whether the determining means 115 performs this by a combination of mode switching of the auxiliary transmission 20 and variable operation of the continuously variable transmission W130;
When determining whether to perform the variable operation only by the variable operation of the continuously variable transmission 30, it is possible to completely automatically operate the entire continuously variable transmission 12, although the shift range is expanded by combining it with the auxiliary transmission 20. This can greatly simplify the operation.

Furthermore, the determination means 115 determines whether the mode switching is performed by a combination of mode switching and continuously variable speed, or whether it is performed by only continuously variable speed.
Comparing and determining which one can perform a faster shift operation with respect to the target torque ratio allows the shift operation to be performed more efficiently and quickly.Especially, when kicking down by depressing the accelerator pedal, switching to low speed mode L It becomes possible to shift faster than the shift operation speed of the continuously variable transmission 30, improves responsiveness, and can respond without delay even when a large downshift is required, such as during kickdown.

Further, the determining means 115 determines whether the low speed mode L and the high speed mode H
If both are in a region where an equal torque ratio can be achieved, high-speed mode H is determined to operate preferentially.
It is possible to perform gear shifting operations with high transmission efficiency, and it is possible to further improve fuel efficiency.

Further, the continuously variable speed operation means 100 is composed of an electric motor,
When the movable sheave is operated by converting the rotation based on the electric motor into thrust force by the screw device 35, 36, the electric signal from the control unit U is not converted into hydraulic pressure.
It can be directly transmitted to the operating means 100 for control, and the structure of the control device U can be simplified, and the continuously variable transmission device 3 can be controlled.
0 responsiveness can be improved.

Furthermore, a planetary gear device 20 is used as an auxiliary transmission device, and the gear device functions as a reduction mechanism to achieve low speed mode L.
When the gear device functions as a split drive mechanism to set the high speed mode H, the share of the transmission torque acting on the continuously variable transmission 30 in the high speed mode H decreases, reducing the frictional force with the belt etc. A small axial force for holding the belt is sufficient, high transmission efficiency can be obtained, and the clamping force acting on the belt can be reduced to improve durability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the functions of the present invention. FIG. 2 is a schematic diagram showing a continuously variable transmission to which the present invention can be applied, FIG. 3 is a diagram showing the operation of each element in each position, and FIG. 4 is a diagram showing the continuously variable transmission. FIG. Furthermore, Fig. 5 is a diagram showing the relationship between the torque ratio and the transmission torque sharing ratio, and Fig. 6 is a diagram showing the relationship between the torque ratio and the transmission torque sharing ratio, and Fig. 6 is the belt!・Step ratio and continuously variable transmission for the torque ratio!・It is a diagram showing the relationship between the torque ratio. FIG. 7 is a diagram showing a # pushing device for a continuously variable transmission according to the present invention, and FIG. 8 is a diagram showing its hydraulic control device. Furthermore, Fig. 9 shows the main flow, Fig. 10 shows the D range flow, and the 1st
Figure 1 shows the S range flow. FIG. 12 is a flowchart showing the determination at the time of upshift showing the content of mode switching, and FIG. 13 is a diagram showing each torque ratio in that state. Further, FIG. 14 is a flowchart showing the determination at the time of downshifting, and FIG. 15 is a diagram showing each torque ratio in that state. Further, FIG. 16 is a flowchart showing the determination at the time of upshifting in another embodiment, and FIG. 17 is a flowchart showing the determination at the time of downshifting. Furthermore, FIG. 18 (al, (bl
19 is a diagram showing judgment at the time of shifting in another embodiment;
20 and 20 are diagrams showing a flow embodying the embodiment. FIG. 21 is a flowchart showing the contents of the continuously variable transmission determination means, and FIG. 22 is a flowchart showing R range fullJ control. 12...Continuously variable transmission, 20...Auxiliary transmission (
single planetary gear device), 20C...second element (carrier), 20R/first element (
Ring gear), 20S...Third element (sun gear), 30...(Bell! type) continuously variable transmission,
30a... Output part (shaft), 30b... Input part (shaft)
, 31...Primary boot 9, 32...Secondary pulley, 33...Belt, 70...
Output member, 100... stepless, variable speed operation means (electric motor), 104... limit rotation speed setting means,
110. C2, B1...mode switching means,
111...torque ratio detection means, 112...mode detection means, 113...target torque ratio setting means,
115... Judgment means, 118... Rotation speed calculation means, 124... Rotation speed comparison means, 130.
...Hydraulic control device, Bl, F...Locking means,
Bl...Low coast and reverse brake, B
2... Reverse brake, C1... Forward clutch, C2... High clutch, CL...
・Lock-up clutch, F--row one-way clutch, H...high-speed mode, L-1,
Low speed mode, U...Continuously variable transmission control device, U
,...(speed change) control section.

Claims (6)

[Claims] (1) A continuously variable transmission capable of continuously variable control of the torque ratio, and in combination with the continuously variable transmission, a shift controllable range,
an auxiliary transmission capable of switching between a low speed mode in a relatively high torque ratio region and a high speed mode in a relatively low torque ratio region; a continuously variable transmission operation means for variably controlling the continuously variable transmission; and the auxiliary transmission. A continuously variable transmission comprising: mode switching means for switching and operating the continuously variable transmission; torque ratio detection means for detecting a torque ratio of the continuously variable transmission; a mode detection means for detecting whether the transmission is in a low speed mode; a target torque ratio setting means for setting a target torque ratio determined based on the driving situation; limit rotation speed setting means for setting a limit rotation speed of the continuously variable transmission; the rotation speed calculated by the rotation speed calculation means; and the limit rotation speed set by the limit rotation speed setting means. a rotation speed comparison means for comparing the rotation speed of the continuously variable transmission, based on signals from the mode detection means, the target torque ratio setting means, and the rotation speed comparison means, so that the rotation speed of the continuously variable transmission remains at its limit rotation speed even when switched to the low speed mode. A control device for a continuously variable transmission, comprising: determining means that issues a signal to the mode switching means only when it is determined that the mode switching means does not exceed. (2) The scope of the claim that the continuously variable transmission is a belt-type continuously variable transmission comprising primary and secondary pulleys each having two sheaves whose effective diameters can be changed, and a belt wound around these pulleys. 2. The control device for a continuously variable transmission according to item 1. (3) The determining means determines whether the mode is in a range where the low speed mode and the high speed mode can achieve equal torque ratios based on the signals from the torque ratio detecting means, the mode detecting means, and the target torque ratio setting means. Comparing and determining which one can perform a faster shift operation with respect to the target torque ratio between a combination of switching and variable operation of the continuously variable transmission and a case where only the variable operation of the continuously variable transmission is used. The control device for a continuously variable transmission according to claim 1, wherein a signal is issued to the continuously variable transmission operation means and the mode switching means based on the determination. (4) The determining means determines, based on signals from the mode detecting means and the target torque ratio setting means, a region in which the low speed mode and the high speed mode can achieve the same torque ratio, and a region in which only the high speed mode can achieve the same torque ratio. If the target torque ratio is in a region that can be achieved only by the low speed mode, the high speed mode is activated with priority, and when the target torque ratio is in a region that can only be achieved by the low speed mode, the low speed mode is activated. A signal is issued to the mode switching means, and a signal is sent to the continuously variable speed operating means to achieve the target torque ratio in the selected mode based on the signals from the torque ratio detection means and the target torque ratio setting means. A control device for a continuously variable transmission according to claim 1. (5) the continuously variable speed operation means comprises an electric motor;
3. The control device for a continuously variable transmission according to claim 2, wherein rotation based on the electric motor is converted into thrust force by a screw device to operate the movable sheave of the continuously variable transmission. (6) The auxiliary transmission device includes a first element connected to the output part of the continuously variable transmission, a second element connected to the output member of the continuously variable transmission, and an input member of the continuously variable transmission. a planetary gear device having a third element connected thereto; and the mode switching means comprising a locking means and a clutch, and connecting the locking means to the third element; and the input member, the locking means operates to cause the planetary gear device to function as a speed reduction mechanism and enter the low speed mode, and the engagement of the clutch causes the planetary gear device to operate in the low speed mode. The control device for a continuously variable transmission according to claim 1, which functions as a split drive mechanism to achieve the high speed mode.