JP2006183780A - Control device for continuously variable transmission with infinite gear ratio, control method for continuously variable transmission with infinite gear ratio - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a continuously variable transmission with an infinite gear ratio capable of avoiding an overheating state of a motor or the like and reliably maintaining a hill hold function for a long time.
SOLUTION: A target motor output torque value of a motor that gives input torque to an infinitely variable gear ratio is calculated based on an accelerator depression amount and a vehicle speed (S3), and the target motor output torque value is determined as an infinite gear ratio. When it is higher than the input torque value of the unit input shaft of the large continuously variable transmission (S5), the input torque value is changed to the target motor output torque value (S6), and the total shift of the infinitely variable transmission continuously variable transmission is made. The ratio is held at the geared neutral point, and the rotation speed of the unit output shaft is held at zero.
[Selection] FIG.

Description

  The present invention relates to a control device for an infinitely variable gear ratio continuously variable transmission and a control method for an infinitely variable gear ratio continuously variable transmission, and more particularly to a technique for realizing a hill hold function for stopping a vehicle on a gradient or the like.

  Conventionally, for example, as a technique for realizing a hill hold function for holding a vehicle in a stopped state on a slope while suppressing local heat generation such as a drive motor and an inverter for generating a running torque of an electric vehicle, A technique described in Patent Document 1 below is known. In Patent Document 1, in order to realize the hill hold function, it is determined that the stall state in which the change in the speed of the vehicle according to the rotation speed of the drive motor is equal to or less than a predetermined value is continuously generated by the drive motor. In some cases, lowering the target value of the output torque of the motor or maintaining the target value prevents excessive heat generation from the drive motor and the inverter.

Conventionally, as described in Patent Document 2 below, a combination of an engine that is a driving force source and a continuously variable transmission with an infinite gear ratio makes the shock and discomfort when operating the select lever when the vehicle stops. Techniques for preventing this are known.
JP 2001-320802 A JP 2001-82595 A

  However, in order to realize the hill hold function, the torque is continuously output without rotating the motor. Therefore, a predetermined torque value is continuously applied to the motor even for a predetermined time. There is a possibility of overheating. On the other hand, if the target torque of the motor is reduced too much in order to avoid overheating of the motor, there is a problem that the hill hold function cannot be realized because the vehicle moves backward or forward due to the gradient.

  On the other hand, in order to realize the hill hold function with a gasoline engine, even if the engine torque is set appropriately, excessive fuel is supplied and air is discharged into the engine to prevent the engine from stopping. There is a problem that it is very difficult to detect the gradient and appropriately control the engine.

  Therefore, the present invention has been proposed in view of the above-described circumstances, and it is possible to avoid an overheating state of a motor or the like, and to maintain a hill hold function reliably for a long time. It is an object of the present invention to provide a control device for a step transmission and a control method for a continuously variable transmission with an infinite gear ratio.

  According to the present invention, a unit input shaft connected to a motor is connected to a toroidal continuously variable transmission mechanism and a constant transmission mechanism capable of continuously changing a transmission gear ratio, and the continuously variable transmission mechanism and the constant transmission mechanism. An infinitely variable gear ratio transmission in which the output shaft of the mechanism is connected to the unit output shaft via a planetary gear mechanism, a power circulation mode clutch and a direct connection mode clutch, a shift position detecting means for detecting a shift position, and the motor Input torque detecting means for detecting the input torque acting on the unit input shaft in accordance with the output torque of the vehicle, accelerator depression amount detecting means for detecting the accelerator depression amount, vehicle speed detecting means for detecting the vehicle speed, and the continuously variable An actuator for changing a speed ratio of the speed change mechanism; and the actuator based on the shift position, the amount of depression of the accelerator, and the vehicle speed. The gear ratio control means for changing the total gear ratio of the infinitely variable gear ratio by controlling the gear ratio, the target motor output torque value of the motor is calculated, and the target motor output torque is set to the target motor output torque. Motor driving means for driving the motor.

  In the present invention, the target motor output torque value is calculated by the motor drive means based on the depression amount detected by the accelerator depression amount detection means and the vehicle speed detected by the vehicle speed detection means, and the target motor output When the torque value is higher than the input torque detected by the input torque detecting means, the input torque value is changed to the target motor output torque value, and the gear ratio control means is used to change the infinite gear ratio continuously variable transmission. The above-mentioned problem is solved by maintaining the total gear ratio at the geared neutral point.

  According to the present invention, the output torque is generated from the unit output shaft so as to keep the total transmission ratio of the infinitely variable transmission continuously variable transmission at the geared neutral point, and the hill hold function is realized in a state where the motor is rotated. As a result, an overheating state of the motor or the like can be avoided and the hill hold function can be reliably maintained for a long time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Configuration of infinitely variable transmission continuously variable transmission]
1 to 3 show a schematic configuration of an infinitely variable gear ratio continuously variable transmission whose operation is controlled by a control device for an infinitely variable gear ratio continuously variable transmission according to the present invention. The step transmission is configured using a so-called half-toroidal continuously variable transmission mechanism 2.

  As shown in FIGS. 1 to 3, the infinitely variable transmission continuously variable transmission (IVT) is an IVT input shaft 1 (unit input shaft) connected to a shaft that transmits the torque of a motor that generates driving torque of the vehicle. In addition, a continuously variable transmission mechanism 2 capable of continuously changing a gear ratio and a constant transmission mechanism 3 (reduction gear) composed of a gear 3a and a gear 3b are connected in parallel to output the continuously variable transmission. The shaft 4 and the constant transmission mechanism output shaft 3c are coaxially arranged on the IVT output shaft 6 (unit output shaft) side, and the continuously variable transmission output shaft 4 and the constant transmission mechanism output shaft 3c are connected by the planetary gear mechanism 5. Concatenated.

  Here, the motor is, for example, a multiphase AC motor, and generates torque by switching an interphase current. A hydraulic pump 110 (to be described later) is connected to a shaft that transmits the torque of the motor. The hydraulic pump 110 is rotated by a driving force of a motor and operates with a hydraulic circuit described later.

  The continuously variable transmission mechanism output shaft 4 transmits driving force to and from the output sprocket 2a of the continuously variable transmission mechanism 2 via the sprocket 4a and the chain 40. One end of the continuously variable transmission output shaft 4 is connected to the sun gear 5a of the planetary gear mechanism 5, and the other end is selectively fastened to the IVT output shaft 6 that is the output shaft of the infinitely variable gear ratio continuously variable transmission. A direct connection mode clutch 10 is provided.

  On the other hand, the constant speed change mechanism output shaft 3c is connected to the carrier 5b of the planetary gear mechanism 5 through the power circulation mode clutch 9, and the ring gear 5c meshing with the pinion of the carrier 5b is connected to the IVT output shaft 6. The

  A transmission output gear 7 is provided on the IVT output shaft 6, and the transmission output gear 7 meshes with the final gear 12 of the differential gear 8 and is connected to the differential gear 8 with a predetermined total reduction ratio, The driving force is transmitted to 11b.

  As shown in FIG. 1, the continuously variable transmission mechanism 2 is a toroidal continuously variable transmission mechanism having a double cavity that holds and presses the power rollers 20 and 20 with two sets of an input disk 21 and an output disk 22, respectively. The roller 20 is rotatably supported by a trunnion 23 (see FIG. 4) described later. By changing the tilt angle of the power roller 20 by the trunnion 23 in accordance with the number of steps (rotation angle = drive position) of a step motor 36 (actuator) described later, the gear ratio of the continuously variable transmission mechanism 2, The total gear ratio of the continuously variable transmission with an infinite gear ratio can be changed steplessly.

  The relationship between the transmission ratio of the continuously variable transmission mechanism 2 and the reciprocal (1 / IVT ratio) of the total transmission ratio of the infinitely variable transmission continuously variable transmission is as shown in FIG. Here, the IVT ratio is the speed ratio between the IVT input shaft 1 and the IVT output shaft 6, that is, the total gear ratio of the continuously variable transmission with an infinite gear ratio.

  As shown in FIG. 6, in the power circulation mode in which the power circulation mode clutch 9 is engaged and the direct connection mode clutch 10 is released, the speed change is made according to the difference in the gear ratio between the continuously variable transmission mechanism 2 and the constant transmission mechanism 3. The ratio can be continuously changed including infinite (geared neutral point GNP in the figure) on both the forward side and the backward side. Further, in the direct coupling mode in which the power circulation mode clutch 9 is released and the direct coupling mode clutch 10 is engaged, the shift control according to the gear ratio of the continuously variable transmission mechanism 2 can be performed. Here, at the geared neutral point GNP, the total transmission ratio of the infinitely variable transmission continuously variable transmission is 0, and the rotational speed of the IVT output shaft 6 is also 0.

  As shown in FIG. 1, the toroidal-type continuously variable transmission mechanism 2 is composed of a double-cavity half-toroidal type that sandwiches and presses the power rollers 20 and 20 with two sets of input disks 21 and output disks 22, The output sprocket 2a interposed between the pair of output disks 22 is a continuously variable transmission output shaft on the IVT output shaft 6 side arranged in parallel with the IVT input shaft 1 and the CVT input shaft 1b via the chain 40. 4 is connected to the sprocket 4a.

  As shown in FIG. 2, the IVT input shaft 1 and the CVT input shaft 1b are coaxially arranged and coupled in the rotational direction via the loading cam 13, and the IVT input shaft 1 is connected to the motor. The CVT input shaft 1b is coupled to the two sets of input disks 21 and 21 and is coupled to the shaft, and the loading cam 13 according to the input torque from the IVT input shaft 1 is formed. The power rollers 20 and 20 are sandwiched and pressed between the input and output disks by the axial pressing force generated.

  Here, the transmission mechanism and mechanical feedback mechanism of the toroidal-type continuously variable transmission mechanism 2 will be described.

  As shown in FIG. 4, the power rollers 20 and 20 that are sandwiched between the input / output disks 21 and 22 and are disposed at opposing positions are supported by trunnions 23 and 23 so that the base ends can swing freely. Are pivotally supported by pivot shafts 24 and 24 having predetermined offsets. A bearing (not shown) such as a needle bearing is interposed between the proximal end side of the pivot shaft 24 and the trunnion 23.

  In FIG. 4, a trunnion 23 that supports the base end side of the power roller 20 so as to freely swing is coupled to the hydraulic cylinder 30 at the lower portion, and is supported so as to be displaceable in the axial direction and rotatable about the axis. In addition, at one lower end of the plurality of trunnions 23, an inclination angle to a shift control valve 46, which will be described later, that is, an actual transmission ratio (actual CVT ratio) of the continuously variable transmission mechanism 2 and an axial displacement of the trunnion 23 is obtained. A precess cam 35 for synthesizing and feeding back is provided.

  The hydraulic cylinder 30 includes upper and lower oil chambers 30A and 30B defined by a piston 31, and as shown in FIG. 4, the hydraulic cylinders 30 and 30 of the trunnion 23 arranged opposite to each other are arranged in the oil chambers 30A and 30B. The arrangement is set to be reversed with respect to each other. The trunnions 23 are driven by the hydraulic cylinders 30 in opposite directions in the vertical direction in the drawing. The trunnions 23 are connected via a swingable link (not shown) on the top and bottom of the pivot shaft 24, and the trunnions 23 are displaced in opposite directions.

  For this reason, when the hydraulic pressure of each oil chamber 30A in each hydraulic cylinder 30 is increased and simultaneously the hydraulic pressure of each oil chamber 30B is decreased, the trunnion 23 on the right side in the figure rises, while The trunnion 23 descends and the power roller 20 tilts (displaces around the axis of the trunnion 23) toward the Lo side (transmission ratio = larger side), and the gear shift is performed. At this time, the pivot shaft 24 swings around the axis 24c according to the axial displacement of the trunnion 23 so that the rotation shaft 20c of the power roller 20 and the rotation shaft 1c of the input / output disk coincide with each other. While maintaining the tilted state, the rotating shaft 20c can be made to coincide with the rotating shaft 1c of the input / output disk to transmit the driving force.

  On the other hand, when the oil pressure in the oil chamber 30A is decreased and the oil pressure in the oil chamber 30B is increased at the same time, the reverse operation is performed, and the trunnion 23 on the right side in the figure is lowered, while the trunnion 23 on the left side in the figure is raised Then, the power roller 20 is tilted to the Hi side (transmission ratio = small side) to perform the speed change. As shown in FIG. 4, the recess cam 35 is provided with a cam groove or a cam surface having a predetermined inclination in the circumferential direction, and one end of a feedback link 38 swingable in the cam groove or the cam surface is provided. Make sliding contact.

  For example, the feedback link 38 is formed in an L shape and is supported so as to be swingable about a swing shaft 39. The feedback link 38 is in sliding contact with the cam groove or the cam surface at one end, and the speed change link at the other end. The rotation amount of the trunnion 23, that is, the tilt angle and the axial displacement amount are combined and transmitted to one end of the transmission link 37.

  As shown in the hydraulic circuit of FIG. 5, the speed change link 37 is connected to the end of the spool 46S of the shift control valve 46 at the center, and at the opposite end connected to the feedback link 38 is connected to the step motor 36. It is connected. The shift link 37 displaces the spool 46S of the shift control valve 46 in the axial direction by driving the step motor 36, and displaces the shift control valve 46 in the axial direction in accordance with the rotation of the trunnion 23 and the axial displacement.

  On the other hand, the power circulation mode clutch 9 and the direct connection mode clutch 10 for switching between the direct connection mode and the power circulation mode are coaxially arranged on the IVT output shaft 6 with the planetary gear mechanism 5 interposed therebetween, as shown in FIG. .

  The power circulation mode clutch 9 is engaged when the clutch pressure (control pressure) Pprc supplied to the oil chamber 9a faces the return spring 9b and presses the piston, and the clutch capacity is increased according to the increase in the clutch pressure Pprc. From the released state to the fastened state.

  Similarly, the direct coupling mode clutch 10 is engaged when the clutch pressure Pdc supplied to the oil chamber 10a opposes the return spring 10b and presses the piston, and the clutch capacity increases as the clutch pressure Pdc increases. From the released state to the fastened state.

  The power circulation mode clutch 9 and the direct coupling mode clutch 10 are both released when the inhibitor switch 84 (see FIG. 3) that responds to the operation of the shift select lever is in the neutral position N or the parking position P. One of the clutches is engaged when the vehicle is in the forward position D, and the power circulation mode clutch 9 is engaged at the reverse position R. When the vehicle starts, as shown in FIG. Shifting is started from the neutral point GNP.

  As shown in FIG. 3, the shift control of the infinitely variable transmission continuously variable transmission is performed by a shift control controller 80 mainly composed of a microcomputer, and the rotational speed Ni (IVT input shaft 1 or CVT input shaft 1b) = From the first rotational speed sensor 81 that detects the motor rotational speed Ne) and from the second rotational speed sensor 82 of the continuously variable transmission that detects the rotational speed No of the continuously variable transmission output shaft 4 or the output sprocket 2a. , The output from the vehicle speed sensor 83 that detects the vehicle speed VSP from the rotation speed of the IVT output shaft 6 and the like, the depression amount APS of the accelerator pedal detected by the accelerator opening sensor 85, and the operation of a shift select lever (not shown) The shift position POS from the inhibitor switch 84 that responds to the brake pedal, the brake pedal depression amount BRK detected by the brake opening sensor 86, etc. Which is input.

  Since the IVT input shaft 1 and the CVT input shaft 1b are directly connected to the motor, the input shaft rotational speed Ni and the motor rotational speed Ne of the continuously variable transmission mechanism 2 are equivalent. Further, as described above, the detected value POS (shift position POS) of the inhibitor switch 84 is set to the D range for the forward position, the R range for the reverse position, the N range for the neutral position, and the P range for the parking position.

  The shift control controller 80 inputs the detection values of the sensors 81 to 86 as the driving state of the vehicle, and drives the solenoids 91 and 92 by duty control according to the driving state, thereby driving the power circulation mode clutch 9 and the direct connection mode clutch. The signal pressure is controlled so as to selectively fasten 10 and the power circulation mode and the direct coupling mode are switched.

  Then, the step motor 36 is adjusted so that the IVT ratio (speed ratio between the IVT input shaft 1 and the IVT output shaft 6 = total gear ratio) according to the driving state of the vehicle such as the shift position by the shift select lever, the accelerator depression amount, and the vehicle speed. The gear ratio (CVT ratio) of the continuously variable transmission mechanism 2 is controlled by driving the (actuator). Thereby, the transmission control controller 80 functions as a transmission ratio control means.

  Further, the speed change controller 80 calculates a target motor output torque value that is a target value of the motor output torque connected to the IVT input shaft 1, and drives the motor so as to obtain the target motor output torque. Function as. As will be described later, the shift control controller 80 calculates a target motor output torque value based on the accelerator depression amount and the vehicle speed in order to realize the hill hold function of the vehicle with the minimum motor output torque. When the output torque value is higher than the input torque acting on the IVT input shaft 1, the input torque value is changed to the target motor output torque value.

`` Configuration of hydraulic control ''
Next, the hydraulic control device in the infinitely variable transmission continuously variable transmission will be described in detail with reference to FIG. First, the hydraulic control device is operated by the output torque of the motor, and the pressure of the hydraulic oil supplied from the hydraulic pump 110 that drives the continuously variable transmission mechanism 2 is controlled by the signal pressure of the PL solenoid 90. The pressure is adjusted to a predetermined pressure and supplied to the line pressure circuit 101 as the line pressure PL. Here, the hydraulic pressure generated by the hydraulic pump 110 is increased or decreased according to the output torque of the motor, and has a value corresponding to the input torque to the IVT input shaft 1.

  The line pressure circuit 101 is connected to a shift control valve 46 that controls the flow rate and supply direction of hydraulic oil to the hydraulic cylinder 30 that drives the trunnion 23. As described above, the transmission control is performed via the transmission link 37. The spool 46S is displaced according to the displacement of the step motor 36 or the feedback link 38 controlled by the controller 80, and the line pressure PL corresponding to the displacement amount of the spool 46S is set to one of the two oil chambers 30A, 30B of the hydraulic cylinder 30. Supply to one side.

  Further, the line pressure circuit 101 is provided with a solenoid 92 for controlling the power circulation mode clutch 9 and a solenoid 91 for controlling the direct coupling mode clutch 10. These solenoids 91 and 92 are duty-controlled by the shift control controller 80. The

  In response to the signal pressure from the solenoid 92 driven by the duty control, the control valve 94 regulates the line pressure PL from the manual valve 60 and supplies it as the clutch pressure Pprc to the power circulation mode clutch 9 for engagement and disengagement. As the signal pressure increases, the clutch pressure Pprc also increases, the power circulation mode clutch 9 is engaged from the disengaged state, and the torque transmission capacity increases according to the clutch pressure Pprc, while from the solenoid 92 When the signal pressure decreases, the clutch pressure Pprc also decreases, and the oil chamber 9a (see FIG. 2) of the power circulation mode clutch 9 is connected to the drain side and released.

  Similarly, the control valve 93 regulates the line pressure PL from the manual valve 60 according to the signal pressure from the solenoid 91, supplies it to the direct coupling mode clutch 10 as the clutch pressure Pdc, and engages and disengages the solenoid valve. When the signal pressure from 91 increases, the clutch pressure Pdc also increases and is engaged from the released state, and the torque transmission capacity increases according to the clutch pressure Pdc. On the other hand, when the signal pressure decreases, the clutch pressure Pdc also decreases. The valve 93 connects and releases the oil chamber 10a (see FIG. 2) of the direct connection mode clutch 10 to the drain side.

  Thus, by duty control of the solenoids 92 and 91 by the speed change controller 80, one of the power circulation mode clutch 9 and the direct coupling mode clutch 10 is engaged, and the power circulation mode and the direct coupling mode are selectively switched. At the same time, the transmission torque can be controlled according to the duty ratio of the solenoids 91 and 92.

  Here, the shift control valve 46 includes a supply port 46P that communicates with the line pressure circuit 101, a Lo-side port 46L that communicates with the oil chamber 30A of the hydraulic cylinder 30, and a Hi-side port that communicates with the oil chamber 30B of the hydraulic cylinder 30. 46H and two drain ports 46D, 46D are provided across the supply port 46P, and one of the supply port 46P to the Lo side port 46L or the Hi side port 46H according to the axial displacement of the spool 46S. The line pressure PL is regulated and supplied, while the other port communicates with the drain port 46D.

  On the other hand, when the spool 46S is in the neutral position, the supply port 46P, the drain port 46D, the Lo side port 46L, and the Hi side port 46H are sealed.

  When the spool 46S is displaced from the neutral position upward in the figure, the supply port 46P and the Lo-side port 46L communicate with each other, while the Hi-side port 46H communicates with the drain port 46D, and the opening amount of the supply port 46P and the supply port 46P A flow rate corresponding to the differential pressure (pressure difference) of the Lo side port 46L is supplied to the Lo side port 46L.

  Conversely, when the spool 46S is displaced from the neutral position downward in the figure, the supply port 46P and the Hi-side port 46H communicate with each other, while the Lo-side port 46L communicates with the drain port 46D, and the opening amount of the supply port 46P and the supply port A flow rate corresponding to the differential pressure (pressure difference) between 46P and the Hi side port 46H is supplied to the Hi side port 46H.

  Thus, the differential pressure is determined according to the balance between the flow rate flowing from the supply port 46P to one of the oil chambers 30A or 30B of the hydraulic cylinder 30 and the flow rate flowing from the other of the oil chambers 30A or 30B to the drain port 46D.

  If the target CVT ratio tic changes to the Lo side, the shift controller 80 decreases the step number Step in the step motor 36 and the one end of the shift link 37 is directed upward in FIG. 5 in accordance with the target CVT ratio tic. To displace.

  At this time, if the inclination angle of the power roller 20 is in a steady state, the recess cam 35 is stopped, so the spool 46S is also displaced upward, and the supply port 46P and the Lo side port 46L communicate with each other, while the Hi side port 46H. Communicates with the drain port 46D, and the hydraulic pressure in the oil chamber 30A increases according to the flow rate supplied from the supply port 46P through the Lo-side port 46L.

  On the other hand, the hydraulic pressure in the oil chamber 30B is discharged from the drain port 46D, the right trunnion 23 shown in FIG. 4 rises, and the power roller 20 tilts toward the Lo side of the CVT ratio as the trunnion 23 rises. Change gears.

  As described above, the pivot shaft 24 swings in accordance with the amount of axial displacement of the trunnion 23, whereby the rotating shaft 20c of the power roller 20 is held on the same plane as the rotating shaft 1c of the input / output disk. The

  By driving the hydraulic cylinder 30, the trunnion 23 is displaced in the axial direction and around the axis, and the displacement of the trunnion 23 is transmitted to the transmission link 37 via the feedback link 38 and responds to the tilting of the power roller 20 toward the Lo side. In FIG. 5, the feedback link 38 displaces the left end portion of the speed change link 37 downward.

  Accordingly, the spool 46S that has been displaced upward is displaced downward toward the neutral position, and when the tilt angle of the power roller 20 matches the target CVT ratio tic, the spool 46S is driven by the recess cam 35 and again. Returning to the neutral position, the drive of the hydraulic cylinder 30 is stopped.

  Thus, when shifting to the Lo side (transmission ratio = larger side) of the CVT ratio, first, the spool 46S is driven by the step motor 36, whereby hydraulic oil is supplied from the line pressure circuit 101 to the oil chamber 30A. On the other hand, the pressure oil in the oil chamber 30B is discharged to the tank, and the trunnion 23 is displaced, whereby the tilt angle of the power roller 20 is directed to the Lo side.

  Next, since the tilt angle of the power roller 20 and the axial displacement of the trunnion 23 are fed back to the shift control valve 46 via the recess cam 35, the feedback link 38 and the speed change link 37, the spool 46S gradually returns to the neutral position. Thus, the target CVT ratio tic commanded by the step motor 36 and the actual CVT ratio according to the tilt angle of the power roller 20 can be matched.

  The relationship between the target CVT ratio tic and the step number Step of the step motor 36 is determined by the shift controller 80 based on a preset map as shown in FIG. The target CVT ratio tic can be matched with the actual CVT ratio by controlling the number of steps.

  On the other hand, when the target CVT ratio tic changes to the Hi side, the step motor 36 and the like are driven in the opposite direction to the above, and the power roller 20 tilts to the Hi side.

  Further, the shift control controller 80 releases the power circulation mode clutch 9 to release the connection between the motor side and the drive wheel side while the vehicle having the N range or P range selected by the shift select lever is stopped, The gear ratio of the continuously variable transmission mechanism 2 is adjusted so as to maintain the geared neutral point GNP. Note that the power circulation mode clutch remains engaged while the vehicle is stopped with the D range selected.

  When starting the vehicle, the shift control controller 80 controls the solenoid 92 based on the shift position POS corresponding to the shift select lever, the actual CVT ratio, and the motor rotation speed Ne to gradually engage the power circulation mode clutch 9. However, the step motor 36 is controlled so that the IVT ratio becomes a target value corresponding to the operating state.

[Torque flow of infinitely variable transmission continuously variable transmission]
The driving force input to the continuously variable transmission mechanism 2 employed in such an infinitely variable gear ratio continuously variable transmission, that is, the input torque from the motor, is transmitted from the input disk 21 to the output disk 22 in the direct connection mode. The However, in the power circulation mode, since the 1 / IVT ratio is switched between forward and reverse at the geared neutral point GNP, the input torque to the continuously variable transmission mechanism 2 is transferred from the input disk 21 to the output disk 22 at the reverse time. If the direction of the input torque is transmitted and the direction is a positive direction, the torque is transmitted from the output disk 22 to the input disk 21 at the time of forward movement, and the direction of the input torque is a negative direction.

  In the power circulation mode, as shown in FIGS. 8 and 9, the difference in the output shaft rotational speed between the continuously variable transmission output shaft 4 input to the planetary gear mechanism 5 and the output shaft 3 c of the constant transmission mechanism 3, that is, The IVT output shaft 6 is coupled according to the difference between the rotational speed of the sun gear 5a coupled to the continuously variable transmission output shaft 4 and the revolution speed of the pinion of the carrier 5b coupled to the output shaft 3c of the constant transmission mechanism 3. The rotation direction of the ring gear 5c is determined.

  Now, when the planetary gear mechanism 5 is viewed from the right side (stepless transmission output gear 7 side) in the figure in FIG. 8, it becomes as shown in FIG. 9, and the speed and direction of each rotating element in the figure are indicated by solid arrows. The torque transmission direction is indicated by a broken line, and the forward, reverse, and geared neutral points are shown in FIGS. 9A, 9B, and 9C, respectively.

"Operation of the planetary gear mechanism 5 when moving forward"
9A, when the revolution speed of the pinion of the carrier 5b is larger than the rotational speed of the sun gear 5a, that is, the CVT ratio of the continuously variable transmission mechanism 2 is as shown in FIG. When the pinion of the carrier 5b rotates counterclockwise in the figure when the geared neutral point GNP shown in FIG. 2 is on the larger side (Lo side), the ring gear 5c rotates counterclockwise in the figure and the final gear 12 Rotates in the forward direction.

  At this time, since the torque transmitted to the pinion of the carrier 5b is transmitted to the ring gear 5c and the sun gear 5a, the input torque to the continuously variable transmission mechanism 2 is transmitted via the chain 40 as shown by the solid line in FIG. Are input from the output disk 22 side and are in the negative direction. Incidentally, the torque transmitted from the output disk 22 to the input disk 21 is transmitted from the CVT input shaft 1b and the IVT input shaft 1 to the constant speed change mechanism 3, and the driving force circulates.

"Operation of planetary gear mechanism 5 in reverse"
9B, when the rotational speed of the sun gear 5a is sufficiently larger than the revolution speed of the pinion of the carrier 5b, that is, the CVT ratio of the continuously variable transmission mechanism 2 is as shown in FIG. When the pinion of the carrier 5b rotates in the clockwise direction in the figure when the geared neutral point GNP shown in FIG. 6 is on the smaller side (Hi side), the ring gear 5c also rotates in the clockwise direction in the figure, and the final gear 12 Rotates in the reverse direction.

  At this time, since the torque transmitted to the sun gear 5a is transmitted to the carrier 5b and the ring gear 5c, the input torque to the continuously variable transmission mechanism 2 is changed from the input disk 21 to the output disk as shown by the broken line in FIG. The torque transmitted in the forward direction to 22 and transmitted to the carrier 5b via the sun gear 5a circulates again from the CVT input shaft 1b to the input disk 21 via the constant speed change mechanism 3.

"Operation of planetary gear mechanism 5 at geared neutral point"
On the other hand, as shown in FIG. 9C, when the rotational speed of the sun gear 5a and the revolution speed of the pinion of the carrier 5b become values corresponding to the gear ratio between the sun gear 5a and the ring gear 5c, the pinion of the carrier 5b is The ring gear 5c stops and the torque from the motor only circulates from the sun gear 5a to the carrier 5b, and the operation of the continuously variable transmission mechanism 2 is continued while the final gear 12 is stopped. At this time, the IVT ratio becomes infinite.

[Hill hold function of continuously variable transmission with infinite gear ratio]
Next, it will be described that the hill hold function for reliably stopping the vehicle on the slope can be realized by the infinitely variable transmission ratio continuously variable transmission configured as described above.

  The hill hold function of the infinitely variable gear ratio continuously variable transmission is achieved by operating the infinitely variable gear ratio infinitely variable transmission under the control of the speed control controller 80, which is a control device for the infinitely variable speed ratio continuously variable transmission. Realize the function. The control process for realizing the hill hold function is performed by storing map data as shown in FIGS. 10 and 11 in advance by the shift controller 80 and executing the process shown in the flowchart of FIG. .

  In the following, a case will be described in which a driver generates braking force by operating a brake pedal or a side brake and releases these brakes in a state where the vehicle is stopped on an uphill road. Further, the D range is selected by the shift select lever, and the speed change controller 80 sets the continuously variable transmission with infinite gear ratio to the power circulation mode with the power circulation mode clutch 9 engaged.

  First, in step S <b> 1, the speed change controller 80 reads the accelerator pedal depression amount APS detected by the accelerator opening sensor 85, and the vehicle speed corresponding to the rotational speed of the IVT output shaft 6 detected by the vehicle speed sensor 83. Read VSP.

  Next, in step S2, the speed change controller 80 calculates the target motor rotation speed Ntgt from the vehicle speed VSP read in step S1 with reference to the map data shown in FIG. In the map data shown in FIG. 10, the target motor speed Ntgt is set to a constant value of N1 when the vehicle speed VSP is in the range of V1 from 0 to the highest transmission ratio of the infinitely variable transmission continuously variable transmission. This is data for setting the target motor rotational speed Ntgt higher as VSP becomes higher than V1, and is stored in advance in a memory (not shown) of the shift control controller 80.

  Next, in step S3, the speed change controller 80 calculates a target motor output torque Ttgt from the vehicle speed VSP and the accelerator pedal depression amount APS read in step S1, with reference to the map data shown in FIG. In the map data shown in FIG. 11, when the vehicle speed VSP is in the range of 0 to V1, the target motor output torque Ttgt is set to a higher value as the accelerator pedal depression amount APS is larger, and the vehicle speed VSP is higher than V1. The target motor output torque Ttgt increases as the target motor output torque Ttgt increases, but the data decreases the target motor output torque Ttgt as the vehicle speed VSP increases, and is stored in a memory (not shown) of the speed change controller 80 in advance. Has been.

  Next, the speed change controller 80 obtains an actual motor output torque Treal which is an input torque acting on the IVT input shaft 1 in step S4. At this time, the shift controller 80 may obtain the actual motor output torque Treal from the current value and the rotational speed supplied to the motor by a motor controller (not shown), may read the detection value of the actual torque sensor, and Is a hydraulic pump 110 that drives the trunnion 23 that holds the power roller 20 of the continuously variable transmission mechanism 2 and detects the pump pressure of the hydraulic pump 110 that is driven by the output torque of the motor to estimate the actual motor output torque Treal. You may do it.

  Next, in step S5, the shift controller 80 compares the target motor output torque Ttgt obtained in step S3 with the actual motor output torque Treal obtained in step S4, and the target motor output torque Ttgt is determined as the actual motor output torque. If it is not smaller than Treal, the process is terminated, and if the target motor output torque Ttgt is smaller than the actual motor output torque Treal, the process proceeds to step S6.

  Next, in step S6, the speed change controller 80 sets the target motor output torque Ttgt obtained in step S4 to the actual motor output torque Treal. Thus, when the target motor output torque Ttgt is higher than the input torque acting on the IVT input shaft 1, the current actual motor output torque Treal is set to the target motor output torque Ttgt.

  Here, when the vehicle is stopped, the vehicle speed VSP is 0 and the target motor speed Ntgt is set to N1, but the shift control controller 80 indicates that the brake is released by the brake pedal depression amount BRK. When the vehicle is moved back due to the vehicle weight and the gradient, the required torque output from the infinitely variable gear ratio continuously variable transmission for maintaining the vehicle stop state changes according to the gradient.

  Further, when the vehicle moves backward due to a gradient, the 1 / IVT ratio of the infinitely variable transmission ratio continuously variable transmission will change from the geared neutral point GNP in the power circulation mode to the reverse side as described in FIG. And On the other hand, the speed change controller 80 controls the CVT ratio of the continuously variable transmission mechanism 2 by controlling the number of steps of the step motor 36, and determines the total speed ratio of the infinitely variable speed ratio continuously variable transmission. Feedback control to the neutral point GNP. That is, by changing the tilt angle of the power roller 20 by the trunnion 23, the CVT ratio of the continuously variable transmission mechanism 2 is increased, whereby the total gear ratio of the infinitely variable gear ratio is set to the geared neutral point. Control to return to GNP and hold.

  Thus, when feedback control is performed so that the total transmission ratio of the infinitely variable transmission continuously variable transmission is zero, the torque passing through the continuously variable transmission mechanism 2 increases, and the hydraulic pressure that holds the power roller 20 increases. As a result, the load on the motor increases. At this time, since the target motor speed Ntgt is controlled to a value corresponding to the vehicle speed VSP in step S2, the motor output torque is increased while maintaining the motor speed at the target motor speed Ntgt. Prevent retreat.

[Effect of the embodiment]
As described above in detail, according to the infinitely variable transmission continuously variable transmission to which the present invention is applied, the shift controller 80 calculates the target motor output torque Ttgt based on the accelerator depression amount and the vehicle speed, and When the motor output torque Ttgt is higher than the input torque acting on the IVT input shaft 1, the input torque value is changed to the target motor output torque Ttgt, and the total gear ratio of the infinite gear ratio continuously variable transmission is set to the geared neutral point. The output torque of an infinitely variable gear ratio continuously variable transmission can be generated while rotating the motor, for example, avoiding an overheating state of the motor due to the current flowing only in a specific phase of the motor. The hill hold function can be reliably maintained over a long period of time.

  Further, according to this infinitely variable gear ratio continuously variable transmission, the pump of the hydraulic pump 110 that is driven by the motor to generate the hydraulic pressure that drives the continuously variable transmission mechanism 2 from the input torque that acts on the IVT input shaft 1. Since it is detected from the pressure, the torque currently acting on the IVT input shaft 1 can be accurately obtained.

  Further, for the change in axle torque that travels due to the gradient, the output torque necessary for the continuously variable transmission with an infinite gear ratio can be accurately obtained using the mechanical feedback mechanism of the continuously variable transmission mechanism 2. it can. Thereby, the hill hold function can be realized with a minimum motor output torque.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

FIG. 1 is a diagram illustrating a schematic configuration of a continuously variable transmission having an infinite gear ratio according to an embodiment of the present invention. It is principal part sectional drawing of a gear ratio infinitely variable continuously variable transmission. It is a control block diagram of a continuously variable transmission with an infinite gear ratio. It is a schematic sectional drawing of a toroidal type continuously variable transmission. It is a circuit diagram of a hydraulic control device. It is a figure which shows the relationship between the transmission ratio of a continuously variable transmission mechanism, and the reciprocal number of the transmission ratio of an infinitely variable transmission ratio continuously variable transmission. It is a conceptual diagram of an infinitely variable gear ratio continuously variable transmission and shows torque transmission according to the traveling direction. It is a map which shows the relationship between the step number of a step motor, and CVT ratio. Similarly, it is a conceptual diagram showing the operation of the planetary gear mechanism in the power circulation mode, in which (A) shows the forward time, (B) shows the reverse time, and (C) shows the geared neutral point GNP. It is a figure which shows the relationship between a vehicle speed and target motor rotation speed. It is a figure which shows the relationship between a vehicle speed and a target motor output torque. It is a flowchart which shows the process sequence for implement | achieving a hill hold function using an infinitely variable gear ratio continuously variable transmission.

Explanation of symbols

1 IVT input shaft 2 continuously variable transmission mechanism 3 constant transmission mechanism 4 continuously variable transmission mechanism output shaft 5 planetary gear mechanism 6 IVT output shaft 7 continuously variable transmission output gear 8 differential gear 9 power circulation mode clutch 10 direct connection mode clutch 12 final Gear 13 Loading cam 20 Power roller 21 Input disk 22 Output disk 23 Trunnion 24 Pivot shaft 30 Hydraulic cylinder 31 Piston 35 Precess cam 36 Step motor 37 Shift link 38 Feedback link 39 Swing shaft 40 Chain 46 Shift control valve 60 Manual valve 80 Shift control Controller 81 First rotation speed sensor 82 Second rotation speed sensor 83 Vehicle speed sensor 84 Inhibitor switch 85 Accelerator opening sensor 86 Brake opening sensor 90 PL solenoid 9 1 Solenoid 92 Solenoid 93, 94 Control valve 100 Pressure regulator 101 Line pressure circuit 110 Hydraulic pump

Claims (5)

A toroidal continuously variable transmission mechanism and a constant transmission mechanism capable of continuously changing a gear ratio are connected to a unit input shaft connected to a motor, respectively, and an output shaft of the continuously variable transmission mechanism and the constant transmission mechanism Is connected to the unit output shaft through a planetary gear mechanism, a power circulation mode clutch and a direct connection mode clutch, a shift ratio infinitely variable transmission, a shift position detecting means for detecting a shift position, and an output torque of the motor In response, input torque detection means for detecting input torque acting on the unit input shaft, accelerator depression amount detection means for detecting accelerator depression amount, vehicle speed detection means for detecting vehicle speed, and shifting of the continuously variable transmission mechanism An actuator that changes the ratio, and the actuator is controlled based on the shift position, the amount of depression of the accelerator, and the vehicle speed. The gear ratio control means for changing the total gear ratio of the infinitely variable gear ratio continuously variable transmission, the target motor output torque value of the motor is calculated, and the motor is driven to obtain the target motor output torque. Motor driving means for causing
The motor driving means calculates a target motor output torque value based on a depression amount detected by the accelerator depression amount detection means and a vehicle speed detected by the vehicle speed detection means, and the target motor output torque value is calculated as the input torque. When the input torque is higher than the input torque detected by the detection means, the input torque value is changed to the target motor output torque value,
The gear ratio control means holds the total gear ratio of the infinitely variable gear ratio continuously variable transmission at a geared neutral point.   2. The infinite gear ratio infinitely variable transmission according to claim 1, wherein the input torque detecting means detects the input torque from a pump pressure of a hydraulic pump that generates a hydraulic pressure for driving the continuously variable transmission mechanism. Machine control device.   The gear ratio infinitely variable continuously variable transmission according to claim 2, wherein the hydraulic pump is driven by the motor, and the input torque detecting means converts the pump pressure of the hydraulic pump into an input torque of the motor. Machine control device. A toroidal continuously variable transmission mechanism and a constant transmission mechanism capable of continuously changing a gear ratio are connected to a unit input shaft connected to a motor, respectively, and an output shaft of the continuously variable transmission mechanism and the constant transmission mechanism Is connected to the unit output shaft through a planetary gear mechanism, a power circulation mode clutch and a direct connection mode clutch, a shift ratio infinitely variable transmission, a shift position detecting means for detecting a shift position, and an output torque of the motor In response, input torque detection means for detecting input torque acting on the unit input shaft, accelerator depression amount detection means for detecting accelerator depression amount, vehicle speed detection means for detecting vehicle speed, and shifting of the continuously variable transmission mechanism An actuator that changes the ratio, and the actuator is controlled based on the shift position, the amount of depression of the accelerator, and the vehicle speed. Said method of controlling a gear ratio transmission ratio and a transmission ratio control means for changing the overall gear ratio of the infinitely variable transmission infinitely variable transmission by,
When the target motor output torque value of the motor is calculated and the motor is driven to obtain the target motor output torque, the depression amount detected by the accelerator depression amount detection unit and the vehicle speed detection unit are detected. Calculate the target motor output torque value based on the vehicle speed,
When the target motor output torque value is higher than the input torque detected by the input torque detection means, the input torque value is changed to the target motor output torque value, and the gear ratio infinitely variable continuously variable transmission is A control method for an infinitely variable gear ratio continuously variable transmission, characterized in that the total gear ratio is maintained at a geared neutral point.   5. The continuously variable transmission with an infinite gear ratio according to claim 4, wherein a pump pressure of a hydraulic pump that generates hydraulic pressure for driving the continuously variable transmission mechanism is detected and the input torque is obtained from the pump pressure. Control method.