JP2000046162A - Initialization device for speed change control device for continuously variable transmission - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent inconvenience due to erroneous detection due to a failure of a vehicle speed sensor or the like. SOLUTION: A command value Asstep corresponding to a target gear ratio is provided.
The shift control valve 5 is operated by actuating the step motor 4 and the shift control pressure output from the shift control valve 5 in response to the operation. The controller 61 of the control device is based on both output signals of a vehicle speed sensor 63 for detecting a vehicle speed of a vehicle equipped with the continuously variable transmission and an input rotation sensor 64 for detecting an input rotational speed of the continuously variable transmission. Stop detection means for detecting that the vehicle is stopped, and when the stop detection means detects that the vehicle is stopped, the motor 4
Motor operating means for once operating to a mechanical operation limit position in one direction and then returning to the reference position in the other direction, and said motor initializing operation means at the end of the initializing operation of the motor 4 by the motor initializing operation means. It functions as a stationary motor command value initializing means for initializing a command value to the motor 4 as the reference position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an initialization device for a shift control device for a continuously variable transmission such as a V-belt type or a toroidal type.

[0002]

2. Description of the Related Art Usually, a shift control device of a continuously variable transmission such as a V-belt type or a toroidal type calculates a suitable target gear ratio adapted to an operation state, and uses a gear ratio command corresponding thereto to execute a step motor or servo. By operating a motor such as a motor,
The speed change control valve is configured to be operated at a stroke position corresponding to the target speed change ratio, whereby the speed change control valve generates and outputs a speed change control pressure corresponding to the target speed change ratio, and the continuously variable transmission operates The speed is continuously changed toward the target speed ratio in response to the speed control pressure.

In some cases, the command value to the motor deviates from the actual motor operating position. In such a case, it is difficult to perform accurate shift control. For this reason, in a transmission control device of a continuously variable transmission, it is customary to perform initialization (initialization) so that a motor command value corresponds to an actual motor operation position. Conventionally, there has been known the one disclosed by the present applicant in Japanese Patent Application Laid-Open No. 8-178063.

[0004] This initialization device operates a motor equipped with a continuously variable transmission controlled by a shift control valve operated by a motor if the vehicle is stopped when the power is turned on and the vehicle is stopped. Is operated once in a predetermined direction to the mechanical operation limit position, and then returned to the reference position in the other direction to perform initialization.If the vehicle is running when the vehicle is powered on, the vehicle speed and The current position of the motor is estimated from the actual speed ratio calculated from the input rotation speed of the continuously variable transmission and the motor command value is used as the estimated current position to perform initialization. This eliminates the need for an initialization switch that detects that the operating position of the motor has reached the reference position.

[0005]

However, in the above-mentioned conventional initialization apparatus, it is determined whether or not the vehicle is stopped based only on the output of the vehicle speed sensor. It is determined that the vehicle is stopped and the motor is temporarily operated to the mechanical operation limit position.
On the other hand, even if the vehicle is running, if the vehicle speed sensor itself fails, or if the wiring from the vehicle speed sensor is poorly contacted or disconnected, the output of the vehicle speed sensor may be lost.

However, while the vehicle is running, the initialization device erroneously recognizes that the output of the vehicle speed sensor is lost and the vehicle is stopped due to the above-described factors, and the motor is once operated to the mechanical operation limit position and then returned immediately. However, in the case of a normal transmission control device and a continuously variable transmission in which the transmission ratio is hydraulically controlled by the transmission, the responsiveness is not so high, so that the change in the actual transmission ratio may cause a great discomfort to the driver. Since the operating position of the motor is returned to the proper position, some uncomfortable feeling is required to some extent.However, when the response of the continuously variable transmission in which the transmission ratio is hydraulically controlled by the transmission control device is improved, As described above, when the motor is once operated to the mechanical operation limit position while the vehicle is running and then returned immediately, the actual change in the gear ratio is not changed until the motor operation position returns to the proper position. There is a possibility that give a large sense of discomfort to the person, it is inconvenient as it is.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an initialization apparatus that advantageously solves the above-mentioned problems, and a shift control apparatus for a continuously variable transmission according to the present invention. The initialization device operates a shift control valve by operating a motor according to a command value corresponding to a target gear ratio, and shifts a continuously variable transmission by a shift control pressure output from the shift control valve in accordance with the operation. A speed control device that detects a vehicle speed of a vehicle equipped with the continuously variable transmission, and an input rotation sensor that detects an input rotation speed of the continuously variable transmission. When the stop detection means detects that the vehicle is stopped, the motor is once operated to a mechanical operation limit position in one direction and then returned to a reference position in the other direction. Motor initialization operation means, and a motor-stop-time motor-command-value initialization means for initializing a command value to the motor as the reference position at the end of the motor initialization operation by the motor initialization operation means. It is characterized by:

In the initialization apparatus, the stop detecting means includes a vehicle speed sensor for detecting a vehicle speed of a vehicle equipped with a continuously variable transmission and an input rotation sensor for detecting an input rotational speed of the continuously variable transmission. When the vehicle is stopped based on both output signals, the motor initialization operation means controls the motor that operates the shift control valve that outputs the shift control pressure for shifting the continuously variable transmission to a one-way mechanical operation limit. After the motor is once operated to the position, the motor is returned to the reference position in the other direction, and at the end of the initialization operation of the motor, the motor command value initialization means at the time of stopping initializes the command value to the motor as the reference position. .

Therefore, according to the initialization apparatus of the present invention,
The motor command value can be matched well with the motor operation position, and an initialization switch for detecting that the operation position of the motor operating the shift control valve has reached the reference position can be eliminated, and Since the stop detecting means is a dual system that detects a stop based on the output signals of both the vehicle speed sensor and the input rotation sensor, it is compared with a single system that detects the stop using only the output signal of the vehicle speed sensor. The possibility of erroneous detection due to sensor failure is extremely low.
Even when the responsiveness of the gearshift control device and the continuously variable transmission whose gear ratio is hydraulically controlled by the gearshift control device is enhanced, the driver is erroneously detected as stopping while traveling and the motor is initialized, thereby causing a great discomfort to the driver. The inconvenience of giving can be effectively prevented.

In addition, an initialization apparatus for a transmission control device according to the present invention is characterized in that, in addition to the aforementioned means, an actual transmission ratio calculation for calculating an actual transmission ratio from a vehicle speed of the vehicle and an input rotation speed of the continuously variable transmission. Means, motor operating position estimating means for estimating the operating position of the motor from the actual gear ratio calculated by the actual gear ratio calculating means, and a command to the motor when the vehicle is not stopped by the stop detecting means. A running motor command value initializing means for initializing a value as a motor operating position estimated by the motor operating position estimating means. Can be performed, so that the number of times of initialization is increased by that amount, and the motor command value can always be matched with the motor operation position.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a configuration of a speed change control device having an embodiment of an initialization device of the present invention, together with a cross section perpendicular to an axis of a toroidal type continuously variable transmission including the speed change control device. FIG. 2 is a sectional view showing an axial section of the continuously variable transmission.

First, a toroidal transmission unit which is a main part of the continuously variable transmission will be described. The toroidal transmission unit has an input shaft 20 to which rotation from an engine (not shown) is transmitted. As shown in FIG. 2, the end remote from the engine is rotatably supported in the transmission case 21 via a bearing 22, and the center portion is provided in the intermediate wall 23 of the transmission case 21 with the bearing 24 and It is rotatably supported via a hollow output shaft 25.
On the input shaft 20, input / output cone disks 1 and 2 are rotatably supported, respectively, and these input / output cone disks are arranged such that the toroidal curved surfaces 1a and 2a face each other. A pair of power rollers 3 disposed on both sides of the input shaft 20 with the input shaft 20 interposed between the opposed toroid curved surfaces of the input and output cone disks 1 and 2. The following configuration is employed to sandwich the pressure between the two.

That is, a loading nut 26 is screwed into an end portion of the input shaft 20 supported by the bearing 22, and the loading nut 26 prevents the cam disk 27 from being detached and rotationally engaged with the input shaft 20. A loading cam 28 is interposed between the input cone disk 1 and the end surface of the input cone disk 1 remote from the toroidal curved surface 1a, and the rotation from the input shaft 20 to the cam disk 27 is transmitted to the input cone disk 1 via this loading cam. It has become so. Here, the rotation of the input cone disk 1 is transmitted to the output cone disk 2 via the rotation of both power rollers 3,
During this transmission, the loading cam 28 generates a thrust proportional to the transmission torque to squeeze the power roller 3 between the input and output cone disks 1 and 2, and between the input and output cone disks 1 and 2 via the power roller 3. Make power transmission possible.

The output cone disk 2 is wedge-fitted to an output shaft 25, and an output gear 29 is fitted on the output shaft 25 so as to rotate integrally therewith. The output shaft 25 is further rotatably supported in an end cover 31 of the transmission case 21 via a radial / thrust bearing 30, and the input shaft 20 is separately provided in the end cover 31 via a radial / thrust bearing 32. It is rotatably supported. Here, the radial and thrust bearings 30 and 32 are abutted with each other via a spacer 33 so that they cannot approach each other, and the corresponding output gear 29 and the corresponding input shaft so that they cannot be displaced relative to each other. 20 is abutted in the axial direction. Therefore, the input / output cone discs 1 and 2 are loaded by the loading cam 28.
The thrust acting between the two here becomes an internal force sandwiching the spacer 33, and does not act on the transmission case 21.

As shown in FIG. 1, each power roller 3 is rotatably supported by a trunnion 41. Each of the trunnions 41 is rotatably and swingably connected to both ends of an upper link 43 by a spherical joint 42 at its upper end. The lower end is connected to both ends of a lower link 45 by a spherical joint 44 so as to be rotatable and swingable. The upper link 43 and the lower link 45 are supported by the transmission case 21 at the central portion thereof so as to be vertically swingable by spherical joints 46 and 47 so that the two trunnions 41 can be vertically moved synchronously in opposite directions. ing.

A shift control device for shifting gears by vertically moving the two trunnions 41 in synchronization with each other in the opposite direction will be described below with reference to FIG. Each trunnion 4
1 is provided with pistons 6 for individually moving these in the vertical direction, and on both sides of both pistons 6,
Upper chambers 51, 52 and lower chambers 53, 54 are defined respectively, and a shift control valve 5 is provided to control the strokes of both pistons 6 in opposite directions. Here, the shift control valve 5 includes a spool-type inner valve body 5a and a sleeve-type outer valve body 5b that are slidably fitted to each other,
The outer valve body 5b is slidably fitted to the valve outer housing 5c.

The transmission control valve 5 has an input port 5d connected to a pressure source 55, one communication port 5e connected to the piston chambers 51 and 54, and the other communication port 5f connected to the piston chambers 52 and 53, respectively. Have been. The inner valve element 5a cooperates with the cam surface of the precess cam 7 fixed to the lower end of the one trunnion 41 via a bell crank type shift lever 8, and the outer valve element 5b functions as a step motor as a shift actuator. 4 is driven and engaged in a rack and pinion type.

An operation command for the shift control valve 5 is given as a stroke to the outer valve body 5b via a rack and pinion from an actuator (step motor) 4 that responds to an actuator drive position command Asstep (step position command). According to this operation command, when the outer valve body 5b of the shift control valve 5 is displaced from the neutral position to the position of FIG. 1 relative to the inner valve body 5a and the shift control valve 5 opens, the pressure source 5
Fluid pressure from 5 while (line pressure P _L) is supplied to the chamber 52 and 53, other chambers 51 and 54 is drained, and the relative outer valve body 5b of the shift control valve 5 with respect to the inner valve body 5a When the shift control valve 5 is opened by being displaced from the neutral position in the opposite direction to the above, the fluid pressure from the pressure source 55 is supplied to the chambers 51 and 54, while the other chambers 52 and 53 are drained. By
In the figure, both trunnions 41 are fluid pressure through the piston 6,
Displaced in opposite directions in corresponding vertical directions.

[0019] Both power roller 3 by the displacement of both trunnions 41, will be the rotation axis O ₁ is offset (offset amount y) from the position shown intersecting the rotation axis O ₂ of the input and output cone discs 1 and 2 The power roller 3 is moved by the offset so that the input / output cone disks 1, 2
With the swing component force from, it is tilted (tilt angle φ) around the swing axis O ₃ that is orthogonal to its own rotation axis O _1, and the continuously variable transmission can be performed.

During this shift, the precess cam 7 connected to the lower end of the one trunnion 41 shifts the above-described vertical movement (offset amount y) and tilt angle φ of the trunnion 41 and the power roller 3 via the speed change link 8. Control valve 5
Is mechanically fed back to the inner valve body 5a as shown by x. When the speed ratio command value corresponding to the actuator drive position command Asstep to the step motor 4 is achieved by the above-described stepless speed change, the mechanical feedback via the precess cam 7 is applied to the inner valve of the speed change control valve 5. Body 5
and the a is returned to a relatively initial neutral position with respect to the outer valve member 5b, at the same time, is both power rollers 3, the rotation axis O ₁ intersects the rotation axis O ₂ of the input and output cone discs 1 and 2 By returning to the illustrated position, the state where the speed ratio command value has been achieved is maintained.

Since the purpose of the control is to make the power roller tilt angle φ a value corresponding to the gear ratio command value, the precess cam 7 basically has to feed back only the power roller tilt angle φ. However, the reason why the power roller offset amount y is also fed back here is to provide a damping effect for preventing the shift control from becoming oscillating, thereby avoiding the hunting phenomenon of the shift control.

An actuator drive position command Asstep to the step motor 4 is determined by the controller 61. As a result, as shown in FIG. 1, a signal from a throttle opening sensor 62 for detecting an engine throttle opening TVO, a signal from a vehicle speed sensor 63 for detecting a vehicle speed VSP, and a rotation speed N of the input cone disk 1 are provided to the controller 61 as shown in FIG. _i signal from an input rotation sensor 64 for detecting (or may be the engine speed N _e), the signal from the output rotation sensor 65 that detects the rotational speed N _o of the output cone disc 2, for detecting a transmission working oil temperature TMP A signal from an oil temperature sensor 66 and a line pressure P _L from the hydraulic pressure source 55 are detected (normally, the line pressure P _L is detected from an internal signal of the controller 61 because the line pressure P _L is controlled by the controller 61). signal, and a signal from an engine speed sensor 68 for detecting an engine speed N _e is inputted.

The controller 61 uses the shift map selected based on various conditions such as the transmission operating oil temperature TMP based on the various input information described above, and attains an arrival input based on the engine throttle opening TVO and the vehicle speed VSP. The rotational speed is calculated, and the ultimate speed ratio is calculated by calculation based on the attained input rotational speed and the transmission output rotational speed (output cone disk rotational speed) _No. Then, the controller 61 performs the above-described reaching with a shift response determined by a selected range (a normal forward travel range, a forward sports travel range, etc.), an engine throttle opening TVO, a vehicle speed VSP, a time constant determined based on an accelerator pedal operation speed, and the like. A transient target gear ratio for realizing the gear ratio is calculated.

Further, the controller 61 calculates an actual transmission ratio based on the transmission input rotation speed (input cone disk rotation speed) _Ni and the transmission output rotation speed (output cone disk rotation speed) _No. and thereby calculating a difference in a transmission ratio deviation between the target speed ratio, and calculates a feedback gain based on the transmission input rotational speed N _i and the vehicle speed VSP and the transmission hydraulic oil temperature TMP and the line pressure P _L, which PID based on speed ratio deviation, feedback gain, etc.
(Proportional Integral Derivative) Calculates a feedback correction amount for control, corrects the target gear ratio with the feedback correction amount, and sets a target of the step motor (actuator) 4 for realizing the corrected target gear ratio. The number of steps (actuator target drive position) is determined by a map search, and is output as an actuator drive position command Asstep (shift command value) to the step motor 4.

As a result, the step motor 4 operates in the direction and position corresponding to the drive position command Asstep to operate the transmission control valve 5 via the rack and pinion, and to operate the toroidal type continuously variable transmission as described above. You can change the speed. The process for obtaining the actuator drive position command Asstep (shift command value) is a normal process, and has no direct relation to the present invention, so that further description is omitted.

The controller 61 executes the processing shown in FIG. 3 so as to function also as the initialization device of this embodiment. This processing is executed every time the power of the controller 61 is turned on. First, in step S1, the initialization of the step motor (S / M) 4 is started, and in the next step S2, the vehicle speed sensor is started. The current vehicle speed VSP obtained from the signal from the motor 63 is higher than a predetermined step motor initialization reference vehicle speed SMIVSP (SMI
It is determined whether or not VSP ≦ VSP, and the vehicle speed VSP is lower than the step motor initialization reference vehicle speed SMIVSP (SM
If the IVSP> VSP), in the next step S3, the step motor input cone disk rotational speed N _i input is the rotational speed of the input rotation sensor of the present time determined by the signal from 64 the continuously variable transmission is predetermined initialization reference rotation speed SMIREV more (SMIREV ≦ N _i) indicating whether or not the judges is, the input cone disk rotational speed N _i is the step motor initialization reference rotation speed less than SMIREV (SMI
If the REV> N _i), it is determined that the vehicle since the vehicle speed VSP and input cone disk rotational speed N _i are both less than the reference value is at a stop, in step S4, following the ordinary initializing process Execute Therefore, steps S2 and S3 correspond to a vehicle stop detection unit.

This normal initialization process is the same as the steps 33 to 46 in FIG. 2 in the prior art disclosed in the prior art document (Japanese Patent Laid-Open No. 8-178063). A mechanical operation in a direction in which a drive signal is sent to cause the step motor 4 to stroke the outer valve body 5b of the transmission control valve 5 in a direction for shifting the toroidal transmission unit to the lowest speed ratio (maximum speed ratio during traveling). Once the actuator is operated to the limit position, the drive signal is sent to the step motor for a short time after reaching the operation limit position to completely step out of the step motor 4, and then the drive signal in the opposite direction to the above is sent to the step motor 4. Send step motor 4
Is returned to the reference position corresponding to the lowest speed ratio in the opposite direction to the above, and when the reference position is reached, the drive position command Astep is set to 0 corresponding to the lowest speed ratio. I do. Therefore, the normal initialization processing in step S4 corresponds to the motor initialization operation means and the motor command value initialization means for stopping the vehicle.

On the other hand, in step S2, the vehicle speed VSP
Is equal to or higher than the step motor initialization reference vehicle speed SMIVSP (S
(MIVSP ≦ VSP) and the above step S3
In the input cone disk rotational speed N _i is the step motor initialization reference rotation speed SMIREV more (SMIREV ≦ N _i)
In such a case, the process proceeds from these steps to step S5, and the following high vehicle speed initialization processing is executed.

This high vehicle speed initialization process is the same as that in steps 53 to 55 in FIG. 2 in the above-mentioned prior art. First, the current vehicle speed VSP (from the output rotation sensor 65) obtained from the signal from the vehicle speed sensor 63 is first obtained. the actual speed from the input cone disk rotational speed N _i of current determined by the signal current of the toroidal transmission unit from the rotational speed N _o may be used) and the input rotation sensor 64 of the output cone discs 2 obtained by the signal The ratio is calculated, the stroke position of the outer valve body 5b of the shift control valve 5 is estimated from the actual gear ratio, and the drive position command Asstep is initialized to correspond to the stroke position. Therefore, the high vehicle speed initialization process in step S5 corresponds to the actual speed ratio calculating means, the motor operating position estimating means, and the running motor command value initializing means.

Thus, according to the initialization apparatus of this embodiment, the drive position command Astep, which is the motor command value, can be made to well match the operation position of the step motor 4 and the operation position of the motor that operates the shift control valve. Since the switch for initialization that detects that the vehicle has reached the reference position can be dispensed with, and because it is a dual system that detects when the vehicle is stopped based on the output signals of both the vehicle speed sensor and the input rotation sensor Since the possibility of erroneous detection due to a sensor failure or the like is extremely low as compared with the case of a single system that detects a stop with an output signal of only a vehicle speed sensor, the gear ratio is hydraulically controlled by the gearshift control device as described above. Even if it is applied to a toroidal type continuously variable transmission that performs gear shifting with high responsiveness, it is erroneously detected that the vehicle is stopped during running, and the motor is initialized to perform a large operation. It is possible to effectively prevent the inconvenience that gives the sum feeling. Further, even when a signal indicating that the vehicle is running is output due to a failure of the vehicle speed sensor or the like while the vehicle is stopped, the inconvenience due to erroneous detection can be effectively prevented by the dual system.

Further, according to the initialization apparatus of this embodiment,
The shift control device can be initialized even when the power is turned on or off by the driver operating an ignition key or the like while the vehicle is running. Therefore, the number of initializations increases accordingly, and the drive position, which is the motor command value, is increased. The command Asstep can always be made to correspond to the operation position of the step motor 4 well.

Although the present invention has been described with reference to the illustrated examples, the present invention is not limited to the above-described examples. For example, in the above-described embodiment, the present invention is applied to a shift control device for a toroidal type continuously variable transmission. The present invention can be applied to a belt-type continuously variable transmission and the like, and can provide the above-described effects. In the above-described embodiment, the present invention is applied to the rotary operation type step motor. However, the present invention can be applied to a linear operation type (linear type) step motor and a normal servo motor having a pulse encoder.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a transmission control device having an embodiment of an initialization device of the present invention, along with a cross section perpendicular to an axis of a toroidal-type continuously variable transmission including the transmission control device. .

FIG. 2 is a sectional view showing an axial section of the continuously variable transmission.

FIG. 3 is a flowchart illustrating an initialization process performed by a controller of the shift control device as the initialization device of the embodiment.

[Explanation of symbols]

 Reference Signs List 1 input cone disc 2 output cone disc 3 power roller 4 step motor (shift actuator) 5 shift control valve 6 piston 7 precess cam 8 shift link 20 input shaft 28 loading cam 41 trunnion 43 upper link 45 lower link 61 controller 62 throttle opening sensor 63 Vehicle speed sensor 64 Input rotation sensor 65 Output rotation sensor 66 Oil temperature sensor 67 Line pressure sensor 68 Engine rotation sensor

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasushi Narita 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Yusuke Minagawa 2 Takaracho, Kanagawa-ku, Yokohama-shi Kanagawa Prefecture 72) Inventor Mitsuru Watanabe F-term (reference) 3J051 AA04 BA05 BD02 BE07 CA03 CA05 CB03 DA06 EA06 FA01 3J052 AA04 AA07 AA08 DA06 FB31 GC23 GC43 GC44 GC46 GD11 HA11 LA01

Claims (2)

[Claims] 1. A speed control valve is operated by operating a motor according to a command value corresponding to a target speed ratio, and a continuously variable transmission is shifted by a speed control pressure output by the speed control valve in accordance with the operation. In the shift control device, a vehicle stop is detected based on output signals of both a vehicle speed sensor that detects a vehicle speed of a vehicle equipped with the continuously variable transmission and an input rotation sensor that detects an input rotation speed of the continuously variable transmission. When the vehicle stop is detected by the vehicle stop detecting means,
Motor initialization operation means for operating the motor once to a mechanical operation limit position in one direction and then returning the motor to a reference position in the other direction, and at the end of the motor initialization operation by the motor initialization operation means, And a stop motor command value initializing means for initializing a command value to the motor as the reference position. A shift control device for a continuously variable transmission, comprising: 2. An actual speed ratio calculating means for calculating an actual speed ratio from a vehicle speed of the vehicle and an input rotation speed of the continuously variable transmission; and an actual speed ratio calculated by the actual speed ratio calculating means. Motor operating position estimating means for estimating an operating position; and running for initializing a command value to the motor as a motor operating position estimated by the motor operating position estimating means when the vehicle is not detected by the stop detecting means when the vehicle is stopped. 2. The apparatus according to claim 1, further comprising: an hour motor command value initializing unit.