JP3402209B2 - Initialization device for speed change control device for continuously variable transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A speed change control device for a continuously variable transmission such as a V-belt type or a toroidal type usually calculates a suitable target gear ratio adapted to an operating condition, and outputs a step motor or servo by a gear ratio command corresponding thereto. Operate a motor such as a motor,
It is configured to operate the speed change control valve to a stroke position corresponding to the target speed change ratio, and the operation causes the speed change control valve to generate and output a speed change control pressure corresponding to the target speed change ratio. , In response to the shift control pressure, the speed is continuously changed toward the target gear ratio.

By the way, the command value to the motor may deviate from the actual motor operating position, and in such a case, accurate shift control is difficult to achieve. For this reason, in a shift control device for a continuously variable transmission, it is common practice to perform initialization (initialization) to make the motor command value correspond to the actual motor operating position. Conventionally, the one disclosed by the applicant of the present application in Japanese Patent Application Laid-Open No. 8-178063 is known.

This initialization device is a motor for operating a shift control valve if the vehicle is stopped at the time of power-on of a vehicle equipped with a continuously variable transmission whose shift is controlled by a shift control valve operated by a motor. Is first operated in one 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 power is turned on, Initialization is performed by estimating the current position of the motor from the actual speed ratio calculated from the input rotation speed of the continuously variable transmission and setting the motor command value as the estimated current position. It is possible to eliminate the need for an initialization switch for detecting that the operating position of the motor has reached the reference position.

[0005]

However, in the above-mentioned conventional initialization device, whether or not the vehicle is stopped is determined based on only the output of the vehicle speed sensor, and if there is no output of the vehicle speed sensor. It is judged that it is stopped and the motor is initialized to the mechanical 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 broken, the output of the vehicle speed sensor may be lost.

However, the initialization device erroneously recognizes that the output of the vehicle speed sensor is lost and the vehicle is stopped due to the above factors while the vehicle is running, and the motor is once operated to the mechanical operation limit position and then immediately returned. Even if the normal gear change control device and the continuously variable transmission in which the gear ratio is hydraulically controlled by the normal gear change control device are not so responsive, the change in the actual gear ratio may cause a big discomfort to the driver. Since the operating position of the motor is returned to the proper position, a slight discomfort may be alleviated to some extent.However, when the responsiveness of the speed change control device and the continuously variable transmission in which the gear ratio is hydraulically controlled by the speed change control device is enhanced, As described above, when the motor is once operated to the mechanical limit position while the vehicle is running and then immediately returned, the actual change of the gear ratio may occur until the operating position of the motor is returned 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 device that advantageously solves the above problems, and a shift control device for a continuously variable transmission according to the present invention. The initialization device operates the shift control valve by operating the motor according to the command value corresponding to the target gear ratio, and shifts the continuously variable transmission by the shift control pressure output by the shift control valve in response to the operation. In the shift control device, the output signals of both the vehicle speed sensor that detects the vehicle speed of the vehicle equipped with the continuously variable transmission and the input rotation sensor that detects the input rotation speed of the continuously variable transmission indicate that the vehicle is stopped. When the signal is a signal, the vehicle stop detection means determines that the vehicle is stopped, and when the vehicle stop detection means determines that the vehicle is stopped, the motor is temporarily operated to a mechanical operation limit position in one direction, and then the other direction. What Motor initialization operation means for returning to the quasi-position, and motor command value initialization means during vehicle stop for initializing the 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 including and.

In this initialization device, the vehicle stop detection means includes a vehicle speed sensor for detecting the vehicle speed of a vehicle equipped with the continuously variable transmission and an input rotation sensor for detecting the input rotation speed of the continuously variable transmission. When both output signals are signals indicating that the vehicle is stopped, it is determined that the vehicle is stopped, and when the vehicle stop detection unit determines that the vehicle is stopped, the motor initialization operation unit shifts the continuously variable transmission. The motor that operates the speed change control valve that outputs the speed change control pressure is operated once to a mechanical operation limit position in one direction, then returned to the reference position in the other direction, and stopped at the end of the initialization operation of that motor. The hour motor command value initialization means initializes the command value to the motor as the reference position.

Therefore, according to the initialization device of the present invention,
The motor command value can be matched well with the motor operating position, and the initialization switch for detecting that the operating position of the motor for operating the shift control valve has become the reference position can be eliminated, and further, Since the vehicle stop detection means is a dual system that determines that the vehicle is stopped based on the output signals of both the vehicle speed sensor and the input rotation sensor, in the case of a single system that detects the vehicle stop by the output signal of only the vehicle speed sensor Since the possibility of erroneous detection due to sensor failure etc. is extremely low compared to the above, even if the responsiveness of the gear shift control device and the continuously variable transmission whose hydraulic gear ratio is hydraulically controlled by the gear shift control device is increased, It is possible to effectively prevent the inconvenience of falsely detecting and performing the initialization operation of the motor to give a great discomfort to the driver.

In addition to the above-mentioned means, the initialization device of the speed change control device of the present invention calculates the actual speed ratio from the vehicle speed of the vehicle and the input rotational speed of the continuously variable transmission. Means, a motor operating position estimating means for estimating the operating position of the motor from the actual speed ratio calculated by the actual speed ratio calculating means, and a command to the motor during traveling when the vehicle is not judged to be stopped by the vehicle stop detecting means. The motor operating position estimating means may further include a running motor command value initializing means for initializing the value as a motor operating position estimated by the motor operating position estimating means. Since the initialization can be performed, the number of initializations is increased accordingly, and the motor command value can always be matched well with the motor operating position.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings by way of examples. FIG. 1 shows a structure of a shift control device having an embodiment of the initialization device of the present invention together with a cross section in a direction perpendicular to an axis of a toroidal type continuously variable transmission including the shift control device. FIG. 2 and FIG. 2 are sectional views showing the axial section of the continuously variable transmission.

First, the toroidal transmission unit which is the main part of the continuously variable transmission will be described. The toroidal transmission unit includes an input shaft 20 to which rotation from an engine (not shown) is transmitted. As clearly shown in FIG. 2, an end portion far from the engine is rotatably supported in the transmission case 21 via a bearing 22, and a central portion is provided in the intermediate wall 23 of the transmission case 21 with a bearing 24 and It is rotatably supported via a hollow output shaft 25.
Input / output cone disks 1 and 2 are rotatably supported on the input shaft 20, and the input / output cone disks are arranged so that the toroidal curved surfaces 1a and 2a face each other. Between the opposing toroidal curved surfaces of the input / output cone discs 1 and 2, there are interposed a pair of power rollers 3 arranged on both sides of the input shaft 20 with the input shaft 20 interposed therebetween. The following configuration is adopted for pinching between the two.

That is, a loading nut 26 is screwed onto the end of the input shaft 20 supported by the bearing 22, and the cam nut 27 is retained by the loading nut 26 and is rotationally engaged on the input shaft 20. , A loading cam 28 is interposed between the input cone disc 1 and the end face far from the toroidal curved surface 1a, and the rotation from the input shaft 20 to the cam disc 27 is transmitted to the input cone disc 1 via this loading cam. It has become so. Here, the rotation of the input cone disc 1 is transmitted to the output cone disc 2 through the rotation of both power rollers 3,
During the transmission, the loading cam 28 generates thrust that is proportional to the transmission torque to clamp the power roller 3 between the input / output cone discs 1 and 2, and the thrust between the input / output cone discs 1 and 2 via the power roller 3 is increased. Enable power transmission.

The output cone disk 2 is wedged on the output shaft 25, and an output gear 29 is fitted on the output shaft 25 so as to rotate integrally. 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 / thrust bearings 30 and 32 are butted against each other via the spacer 33 so that they cannot come close to each other, and the output gear 29 and the input shaft corresponding to the output gear 29 and the input shaft are so arranged that they cannot be displaced relative to each other. It is abutted against 20 in the axial direction. Therefore, the loading cam 28 allows the input / output cone disks 1,
The thrust acting between the two acts as an internal force that sandwiches the spacer 33 here, 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, and the upper end of each trunnion 41 is rotatably and oscillated at both ends of an upper link 43 by a spherical joint 42. The lower end of the lower link 45 is movably and rotatably and swingably connected to both ends of the lower link 45 by a spherical joint 44. The upper link 43 and the lower link 45 are supported by the spherical joints 46 and 47 in the center of the transmission case 21 so as to be vertically swingable so that both trunnions 41 can be vertically moved in synchronization with each other in opposite directions. ing.

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

In the shift control valve 5, the input port 5d is connected to the pressure source 55, one communication port 5e is connected to the piston chambers 51 and 54, and the other communication port 5f is connected to the piston chambers 52 and 53, respectively. Has been done. The inner valve body 5a cooperates with the cam surface of the recess cam 7 fixed to the lower end of the one trunnion 41 via the bell crank type speed change lever 8, and the outer valve body 5b operates as a step motor as a speed change actuator. 4, drivingly engaged in a rack and pinion type.

The operation command of the shift control valve 5 is given as a stroke from the actuator (step motor) 4 that responds to the actuator drive position command Asstep (step position command) to the outer valve body 5b via the rack and pinion. By this operation command, the outer valve body 5b of the shift control valve 5 is displaced relative to the inner valve body 5a from the neutral position to, for example, the position shown in FIG.
The fluid pressure (line pressure P _L ) from 5 is supplied to the chambers 52 and 53, while the other chambers 51 and 54 are drained, and the outer valve body 5b of the shift control valve 5 is opposed to the inner valve body 5a. When the speed change control valve 5 is opened by being displaced in the opposite direction from the neutral position, 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. Due to
Both trunnions 41 are fluid pressures through the piston 6 in the figure,
It is displaced in the opposite direction to the corresponding vertical direction.

[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 offset causes the power roller 3 to move to the input / output cone disks 1 and 2.
The tilt component (tilt angle φ) about the swing axis O ₃ orthogonal to the own rotation axis O ₁ can be performed by the swing component force from the stepless speed change.

During such shifting, the precess cam 7 coupled to the lower end of 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 shift link 8. Control valve 5
Feedback is mechanically provided to the inner valve body 5a as indicated by x. When the gear ratio command value corresponding to the actuator drive position command Asstep to the step motor 4 is achieved by the continuously variable gear shift, mechanical feedback via the precess cam 7 causes the internal valve of the gear shift control valve 5 to operate. Body 5
a and return to the initial neutral position relative to the outer valve body 5b, and at the same time, the rotation axes O _{1 of} both power rollers 3 intersect the rotation axes O ₂ of the input / output cone disks 1 and ₂ . By returning to the illustrated position, the achievement state of the above gear ratio command value is maintained.

Since the purpose of control is to set the power roller tilt angle φ to a value corresponding to the gear ratio command value, the precess cam 7 basically needs 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 prevent the shift control from hunting by providing a damping effect that prevents the shift control from becoming oscillatory.

The actuator drive position command Asstep to the step motor 4 is determined by the controller 61. Therefore, as shown in FIG. 1, the controller 61 outputs a signal from the throttle opening sensor 62 that detects the engine throttle opening TVO, a signal from the vehicle speed sensor 63 that detects the vehicle speed VSP, and the rotation speed N of the input cone disc 1. A signal from an input rotation sensor 64 that detects _i (the engine speed N _e may be used), a signal from an output rotation sensor 65 that detects the rotation speed N _o of the output cone disc 2, and a transmission operating oil temperature TMP. From a line pressure sensor 67 that detects the signal from the oil temperature sensor 66 and the line pressure P _L from the hydraulic pressure source 55 (normally, the line pressure P _L is controlled by the controller 61 and therefore detected from an internal signal of the controller 61). And a signal from an engine rotation sensor 68 that detects the engine speed N _e .

Based on the above various input information, the controller 61 uses the shift map selected based on various conditions such as the transmission operating oil temperature TMP and the like, and the arrival input based on the engine throttle opening TVO and the vehicle speed VSP. The number of revolutions is calculated, and the ultimate speed ratio is calculated based on the reached input number of revolutions and the transmission output number of revolutions (output cone disc number of revolutions) _No. Then, the controller 61 reaches the above with a shift response determined by a time range determined based on a selected range (forward normal traveling range, forward sports traveling range, etc.), engine throttle opening TVO, vehicle speed VSP, accelerator pedal operation speed, etc. A transitional target gear ratio is calculated for realizing the gear ratio.

Further, the controller 61 calculates an actual speed ratio based on the transmission input speed (input cone disk speed) N _i and the transmission output speed (output cone disk speed) N _o , and the actual speed ratio is calculated. And a gear ratio deviation that is a deviation between the target gear ratio and the target gear ratio are calculated, and a feedback gain is calculated based on the transmission input rotation speed N _i , the vehicle speed VSP, the transmission hydraulic oil temperature TMP, and the line pressure P _L. PID based on gear ratio deviation, feedback gain, etc.
A target of the step motor (actuator) 4 for calculating a feedback correction amount for (proportional, integral, and derivative) control, correcting the target gear ratio with the feedback correction amount, and realizing the corrected target gear ratio. The number of steps (actuator target drive position) is obtained 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 shift control valve 5 via the rack and pinion, and the toroidal type continuously variable transmission is operated as described above. You can shift gears. The process for obtaining the actuator drive position command Asstep (shift command value) is a normal process and is not directly related to the present invention, and therefore further description is omitted.

By the way, the controller 61 executes the processing shown in FIG. 3 so as to function also as the initialization device of this embodiment. This process is executed each time the power of the controller 61 is turned on. First, in step S1, initialization (initialization) of the step motor (S / M) 4 is started, and in the next step S2, the vehicle speed sensor is detected. The current vehicle speed VSP obtained from the signal from 63 is equal to or higher than the predetermined step motor initialization reference vehicle speed SMIVSP (SMI
It is determined whether or not VSP ≦ VSP, and the vehicle speed VSP is less than the step motor initialization reference vehicle speed SMIVSP (SM
(IVSP> VSP), in the next step S3, a step motor having a predetermined input cone disk rotation speed N _i, which is the input rotation speed of the continuously variable transmission at the present time obtained from the signal from the input rotation sensor 64, is determined. It is determined whether or not the initialization reference rotation speed SMIREV is equal to or higher than (SMIREV ≦ N _i ), and the input cone disk rotation speed N _i is less than the step motor initialization reference rotation speed SMIREV (SMIREV.
REV> N _i ), the vehicle speed VSP and the input cone disc rotation speed N _i are both below the reference value, so it is determined that the vehicle is stopped, and in step S4, the following normal initialization processing is performed. To execute. Therefore, steps S2 and S3 correspond to the vehicle stop detection means.

This normal initialization process is the same as 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 which the step motor 4 is sent a drive signal to cause the outer valve element 5b of the shift control valve 5 to stroke in the direction in which the toroidal transmission unit is shifted toward the lowest speed gear ratio (maximum gear ratio during traveling). After operating once to the limit position and sending a drive signal to the step motor 4 for a short time even after reaching the operation limit position to completely step out the step motor 4, a drive signal in the opposite direction to the above is applied to the step motor 4. Send step motor 4
Is reversely operated to the reference position corresponding to the lowest speed gear ratio, and when the reference position is reached, the drive position command Asstep is initialized to 0 corresponding to the lowest speed gear ratio. I do. Therefore, the normal initializing process in step S4 corresponds to the motor initializing operation means and the motor command value initializing means at vehicle stop.

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

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

Thus, according to the initialization device of this embodiment, the drive position command Asstep, which is a motor command value, can be matched well with the operating position of the step motor 4, and at the same time, the operating position of the motor for operating the shift control valve. It is possible to eliminate the need for an initialization switch that detects when the vehicle has reached the reference position, and because it is a dual system that detects that 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 sensor failure etc. is extremely low compared to the case of a single system that detects that the vehicle is stopped with the output signal of only the vehicle speed sensor, the gear ratio is hydraulically controlled by the gear shift control device as described above. Even if it is applied to a toroidal type continuously variable transmission that shifts with high responsiveness, it is falsely detected that the vehicle is stopped while running and the motor initialization operation is performed 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 double system can effectively prevent the inconvenience caused by the erroneous detection.

Further, according to the initialization device of this embodiment,
Even if the power supply is connected or disconnected by the driver's operation of the ignition key while the vehicle is running, the gear change control device can be initialized, so the number of initializations increases accordingly and the drive position that is the motor command value is increased. The command Asstep can always be matched well with the operating position of the step motor 4.

Although the present invention has been described above based on the illustrated example, the present invention is not limited to the above example. For example, in the above embodiment, the present invention is applied to a shift control device for a toroidal type continuously variable transmission. It can also be applied to a belt type continuously variable transmission and the like, and can bring about the above-described effects. Further, in the above embodiment, the invention is applied to the rotary operation type step motor, but it is also applicable to a linear operation type (linear type) step motor and a normal servo motor having a pulse encoder.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a shift control device having an embodiment of an initialization device of the present invention together with a cross section of a toroidal type continuously variable transmission including the shift control device in a direction perpendicular to an axis line thereof. .

FIG. 2 is a cross-sectional view showing a cross section in the axial direction of the continuously variable transmission.

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

[Explanation of symbols]

1 input cone disc 2 output cone disc 3 power rollers 4-step motor (shift actuator) 5 shift control valve 6 pistons 7 Precessum 8 speed change 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

─────────────────────────────────────────────────── ─── Continuation of front page (72) Yusuke Minagawa, 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor, Mitsuru Watanabe 2 Takara-cho, Kanagawa, Yokohama, Nissan Nissan Motor Co., Ltd. (56) References JP-A-8-178063 (JP, A) JP-A-4-151068 (JP, A) JP-A-60-11753 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48 F16H 15/38

Claims (2)

(57) [Claims] 1. A shift control valve is operated by operating a motor according to a command value corresponding to a target gear ratio, and the continuously variable transmission is shifted by a shift control pressure output by the shift control valve according to the operation. In the shift control device, both output signals of 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 are signals indicating that the vehicle is stopped. And
And stop detecting means determines that the vehicle is stopped when that, when the vehicle is determined to parked by the stop detection means,
Motor initialization operation means for temporarily operating the motor to a mechanical operation limit position in one direction and then returning the operation to the reference position in the other direction; and at the end of the initialization operation of the motor by the motor initialization operation means. An initialization device of a shift control device for a continuously variable transmission, comprising: a motor stop command value initialization means for initializing a command value to the motor as the reference position. 2. An actual speed ratio calculating means for calculating an actual speed ratio from a vehicle speed of the vehicle and an input rotational speed of the continuously variable transmission, and an actual speed ratio of the motor based on an actual speed ratio calculated by the actual speed ratio calculating means. Motor operating position estimating means for estimating an operating position, and traveling for initializing a command value to the motor as a motor operating position estimated by the motor operating position estimating means during traveling when the vehicle is not judged to be stopped by the vehicle stop detecting means The initialization device for a shift control device for a continuously variable transmission according to claim 1, further comprising: an hour motor command value initialization means.