JP3750177B2 - Toroidal continuously variable transmission - Google Patents

Description

[0001]
[ TECHNICAL FIELD OF THE INVENTION ]
The present invention includes an input disk and an output disk that are arranged opposite to each other, and a pair of power rollers that steplessly shift the rotation of the input disk in accordance with a change in the tilt angle with respect to both the disks and transmit it to the output disk. The present invention relates to a toroidal type continuously variable transmission including a transmission unit.
[0002]
[Prior art]
As a toroidal continuously variable transmission mounted on an automobile, a double cavity type toroidal continuously variable transmission in which two transmission units are arranged on the same shaft is generally used. A toroidal-type continuously variable transmission generally includes an input shaft to which engine output is input, a pair of input disks that are rotatably supported with respect to the input shafts, and are arranged to face each of the input disks and are input shafts. A pair of output disks supported rotatably with respect to the disk, a tiltable power roller disposed between a pair of opposed input disks and an output disk and transmitting rotation from the input disk to the output disk, and a pair of opposed disks A connecting member for integrally connecting the output disks, a pair of flange portions provided on the input shaft and the input disk, which are arranged between the input disks and act on each of the input disks to press the power roller according to the magnitude of the input torque. It has a pressing means to change the force. By tilting the power roller, the rotation of the input disk is applied to the output disk according to the tilt angle. It is configured to shift to be transmitted to the stage.
[0003]
FIG. 3 shows the toroidal-type continuously variable transmission in a form showing only the engine-side transmission unit of the pair of transmission units. The output of the engine E is transmitted to the input disk 3 of the transmission unit 1 via the input shaft 21 and the loading cam 22, and is transmitted in the order of the power roller 2 and the output disk 23 to be output to the output shaft 24. Shift control of the toroidal-type continuously variable transmission is performed by displacing the trunnion 4 that supports the power roller 2 in the direction of the tilting axis that extends in the direction perpendicular to the drawing sheet. That is, when the trunnion 4 is displaced in the direction of the tilt axis, a tilting force around the tilt axis is generated from the input / output disks 3 and 23 with respect to the power roller 2. When the power roller 2 tilts around the tilting axis, the contact rotation radius ratio r of the input / output disks 3 and 23 with the power roller 2 ₁ / R ₂ Thus, the rotation speed ratio between the input / output shafts 22 and 24, that is, the gear ratio can be changed. The displacement of the trunnion 4 in the tilt axis direction is controlled by hydraulic pressures Pup and Pdown applied to the piston 7 (see FIGS. 1 and 4) supplied to the hydraulic cylinder and fixed to the trunnion 4 in the tilt axis direction. Is done. With respect to the toroidal continuously variable transmission in which the pair of transmission units 1 are arranged on the input / output shafts 22 and 24, one more speed change operation similar to the above is obtained, and a large speed ratio range can be obtained. it can.
[0004]
Various conventional toroidal continuously variable transmissions as described above (Japanese Patent Laid-Open No. 7-151218, JP 7-317867 A For example, a toroidal continuously variable transmission as shown in FIG. 4 is known. In order to simplify the explanation, FIG. 4 shows a configuration in which the shift control for one transmission unit is performed, but in the case of a double cavity type toroidal continuously variable transmission, another hydraulic pressure is used. Since it only needs to be configured so that it can be supplied to the hydraulic cylinder of the transmission unit, the description of the structure of another transmission unit and the supply of hydraulic pressure to the hydraulic cylinder is omitted.
[0005]
In the structure of the transmission unit 1 of the toroidal-type continuously variable transmission shown in FIG. 4, the same components as those shown in FIG. The pair of power rollers 2 in the transmission unit 1 are arranged to face each other so as to be sandwiched between an input disk 3 and an output disk (not shown) arranged to face each other. The power roller 2 is supported via an eccentric shaft 5 that is rotatable with respect to a support member called a trunnion 4. The trunnion 4 is supported so as to be rotatable with respect to a transmission casing (not shown) and movable in the axial direction. That is, the trunnion 4 has the tilting shaft 6, can be moved in the axial direction of the tilting shaft 6, and can also be rotated about the tilting shaft 6. A piston 7 is fixed to the tilt shaft 6 of the trunnion 4, and the piston 7 can slide in a hydraulic cylinder 8 formed in the transmission casing. Cylinder chambers 8 a and 8 b defined by the piston 7 are formed in the hydraulic cylinder 8.
[0006]
The cylinder chambers 8a and 8b of the hydraulic cylinder 8 communicate with the spool valve 10 through pipe lines 9a and 9b. The spool 11 disposed in the spool valve 10 is held in a neutral position by springs 12 disposed at both ends in the axial direction. The spool valve 10 has a Sa port formed at one end, an Sb port formed at the other end, pilot pressure is supplied to the Sa port via the solenoid valve 13a, and pilot pressure is supplied to the Sb port via the solenoid valve 13b. Is supplied. The spool valve 10 is connected to the P port connected to the pilot pressure, the A port connected to the cylinder chamber 8a via the conduit 9a, the B port connected to the cylinder chamber 8b via the conduit 9b, and the drain. T port is provided. The solenoid valves 13a and 13b are configured to operate in accordance with a control signal output from the controller 14.
[0007]
A recess cam 15 is connected to the tip of one tilting shaft 6, one end of a lever 16 pivotally attached at the center is in contact with the recess cam 15, and the other end of the lever 16 is connected to a potentiometer 17. The potentiometer 17 detects the axial displacement and the tilt angle of the tilt shaft 6 of the trunnion 4 as a combined displacement amount, and inputs a detection signal to the controller 14. In addition to the composite displacement amount, the controller 14 receives information for controlling a shift from a shift information detecting device 30 including a vehicle speed sensor, that is, an output shaft rotation sensor 18, an engine rotation sensor 19, an accelerator pedal depression amount 20, and the like. . Shift information signals such as the fuel supply amount corresponding to the vehicle speed, the engine speed, and the accelerator pedal depression amount detected by these sensors are input to the controller 14.
[0008]
In the toroidal-type continuously variable transmission, the trunnion 4 is moved from the neutral position (the position where the rotation center axis of the power roller 2 intersects the rotation center axis of the input disk 3 and the output disk 23) to either one of the tilt shaft 6 When it is displaced in the axial direction, the property that the trunnion 4 tilts around the tilting shaft 6 at a direction and speed according to the direction and the amount of displacement, and the shift is performed by this tilting is utilized. The controller 14 controls the solenoid valve 13a so that the differential pressure between the hydraulic pressures Sa and Sb that displace the trunnion 4 in the tilt axis direction is proportional to the deviation between the target speed ratio and the actual speed ratio (hereinafter referred to as the actual speed ratio). , 13b are controlled.
[0009]
Next, the operation of the toroidal-type continuously variable transmission will be described. First, the controller 14 calculates a target gear ratio based on detection values relating to various shift information detected by the various sensors. That is, the target gear ratio is detected by the above-described various sensors, and the output shaft rotation stored in the controller 14 is stored on the basis of data such as the output shaft rotation speed, engine rotation speed, and throttle opening input to the controller 14. It is determined from a map table corresponding to a combination of the number, engine speed, throttle opening, and the like. Further, the controller 14 calculates an actual gear ratio from the combined displacement amount of the tilt angle of the trunnion 4 and the tilt axis direction detected by the precess cam 15 and the potentiometer 17, and calculates the gear ratio deviation between the target gear ratio and the actual gear ratio. calculate. Since the combined displacement of the potentiometer 17 when the power roller 2 is in the neutral position and the gear ratio is 1, the actual gear ratio is calculated from the tilt angle when the power roller 2 is in the neutral position. Can do. Further, the controller 14 sets the target displacement of the trunnion 4 according to the gear ratio deviation, and adds the control signal according to the neutral position of the spool valve to the solenoid valves 13a and 13b and the control signal according to the gear ratio deviation. Output a signal.
[0010]
Accordingly, hydraulic pressures Sa and Sb are supplied to both ends of the spool valve 10 from the solenoid valves 13a and 13b. The spool valve 10 is displaced to a position where the forces of the hydraulic pressures Sa and Sb supplied from the solenoid valves 13a and 13b and the spring 12 are balanced. At this time, if the relationship between the hydraulic pressures Sa and Sb supplied to the spool valve 10 is Sa> Sb, the spool 11 is shifted to the left in FIG. 4, and the pipe line 9a is connected to the pressure source P via the P port. The pipe 9b communicates with the drain via the T port, so that the pressure Pa in the pipe 9a is larger than the pressure Pb in the pipe 9b (Pa> Pb). As a result, due to the pressure difference between the cylinder chambers 8a and 8b, the piston 7 moves, and in FIG. 4, the left trunnion 4 is displaced upward in the tilt axis direction, and the right trunnion 4 is displaced downward in the tilt axis direction. Along with this displacement, each trunnion 4 tilts about the tilting axis 6, and the power roller 2 starts to tilt in response to the force in the direction of the speed vector from the input disk 3 and output disk 23, and the speed change operation is started. The
[0011]
In the toroidal type continuously variable transmission, the controller 14 performs feedback control so that the actual gear ratio approaches the target gear ratio. That is, as the actual speed ratio approaches the target speed ratio, the target displacement of the trunnion 4 approaches zero, and when the actual speed ratio matches the target speed ratio, the target displacement of the trunnion 4 becomes zero. At this time, the pressure applied to both ends of the spool valve 10 becomes equal (Sa = Sb), the spool 11 of the spool valve 10 returns to the neutral position, the spool valve 10 is closed, and the supply of hydraulic pressure to the hydraulic cylinder 8 is stopped. Thus, the shifting operation is completed.
[0012]
An engine such as a diesel engine has a rotational speed-torque characteristic with a fuel injection amount (throttle opening) as a parameter as shown in FIG. That is, the engine has a property that when the throttle opening is kept constant, the engine value rapidly decreases after the engine torque reaches a certain maximum value when the engine speed increases. Driving the engine at the engine speed that indicates the maximum torque value, in other words, moving the engine to a higher engine torque, increases the efficiency and fuel efficiency.
[0013]
[Problems to be solved by the invention]
With the conventional shift control technology for the toroidal-type continuously variable transmission, predetermined performance may not be obtained depending on the accelerator opening degree, vehicle speed detection accuracy, component variations, and the like. In particular, in an engine having a rotational speed-torque characteristic as shown in FIG. 5, for example, it is ideal to control the operation at point A in the figure when the accelerator depression amount is 40%. It may be driven at point or C point. In particular, at the engine speed higher than the point A, such as the point C, the torque rapidly decreases as the engine speed increases, so that the obtained vehicle performance (acceleration performance, fuel efficiency performance) is significantly deteriorated. In view of such technical circumstances, the toroidal type continuously variable transmission has a problem that it is necessary to avoid the above-described inconvenience that the actual torque value is reduced to a predetermined torque or less.
[0014]
[Means for solving the problems]
An object of the present invention is to solve the above-mentioned problem. In a toroidal-type continuously variable transmission, an actual input torque value is detected to determine whether or not the torque value has decreased to a predetermined torque value or less. It is an object of the present invention to provide a toroidal-type continuously variable transmission that can control the shift of a toroidal transmission unit so that input / output torque is optimally balanced in terms of engine output characteristics when the torque is reduced below a torque value.
[0015]
This invention ,versus An input disk and an output disk arranged in a direction, a pair of power rollers for continuously changing the rotation of the input disk in accordance with a change in tilt angle with respect to the both disks, and transmitting the rotation to the output disk; A pair of trunnions that respectively rotate in a rotatable manner and tilt around a tilting axis from a neutral position, a hydraulic cylinder that displaces the trunnion in the direction of the tilting axis, and a spool are in a neutral position A spool valve that selectively shuts off the cylinder chamber in a state and displaces the cylinder chamber selectively from a hydraulic source and a tank while being displaced from the neutral position; a solenoid valve that controls a spool position of the spool valve; A pressure sensor that detects the hydraulic pressure acting on each of the two cylinder chambers and a gear ratio deviation between the target gear ratio and the actual gear ratio. And controlling the operation of the solenoid valve in response to the control signal, the pressure difference between the two hydraulic pressures detected by the pressure sensor, the actual input torque obtained from the target speed ratio or the actual speed ratio, and at least an accelerator pedal A controller that corrects the target gear ratio based on a torque deviation from a target input torque that is determined based on information including the amount of depression. Have ,
The controller performs control so as to correct the target speed ratio to the speed increasing side according to the torque deviation when the actual input torque is smaller than the target input torque. Toroidal-type continuously variable transmission.
[0016]
Since this toroidal-type continuously variable transmission is configured as described above, the target gear ratio changes when the accelerator depression amount is changed or when a braking operation such as a brake pedal is performed. Since a gear ratio deviation occurs between the ratio and the actual gear ratio, the controller determines that a gear shift is necessary and performs gear shift control. This toroidal-type continuously variable transmission includes information on the pressure difference between the hydraulic pressures acting on both cylinder chambers detected by the pressure sensor, the actual input torque obtained from the target gear ratio or the actual gear ratio, and at least information on the accelerator pedal depression amount. The target gear ratio is corrected based on an input torque deviation from a target input torque calculated based on the information included. In this toroidal continuously variable transmission, the engine speed is high in the engine operating state, but when the actual input torque is small, the target gear ratio is corrected and matched with the corrected target gear ratio. Therefore, the engine speed is adjusted to match the output shaft speed and the engine output torque at that time. Therefore, this toroidal type continuously variable transmission makes it possible to shift to an ideal operating point on the engine characteristic curve, thereby improving the speed change performance and the fuel consumption of the engine.
00 17 ]
This toroidal-type continuously variable transmission has a high engine speed, and when the engine output torque, that is, the actual input torque is smaller than the target input torque, the upshift is performed so that the target gear ratio is increased. In this case, the speed change control is performed so as to follow the corrected target speed ratio by the normal speed ratio control. In this toroidal type continuously variable transmission, when the shift is shifted up, the output shaft rotational speed and the output torque corresponding to the output torque at that time can be reduced, and the engine rotational speed is lowered. Therefore, the engine output torque is increased by the shift control of the toroidal type continuously variable transmission, and it is possible to shift to an ideal operating point on the engine characteristic curve.
00 18 ]
The controller stores the target input torque, the actual input torque, and the amount to be corrected for the target gear ratio in a memory as a previously determined table. The target input torque and the actual input torque are calculated from the detected values of the accelerator pedal depression amount, the pressure difference in the cylinder chamber and the like using the table, and the target input using the calculated both input torques and another table. A gear ratio correction amount is calculated. If an arithmetic expression such as an empirical formula is known instead of the table, the controller may calculate it based on the experimental formula.
00 19 ]
The solenoid valve that controls the spool position of the spool valve may be any one such as a duty valve, a proportional valve, or the like that can electrically control the hydraulic pressure, and may be any type such as a two-way valve or a three-way valve. The solenoid valve only needs to be able to supply hydraulic pressure to both ends of the spool valve. Therefore, one solenoid valve may be connected to each end of the spool valve. Alternatively, one solenoid valve is connected to only one end of the spool valve, and a certain hydraulic pressure is applied to the other end of the spool valve, or a spring is provided to the other end. Also good. In that case, it is necessary to set a large spring force.
00 20 ]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a toroidal type continuously variable transmission according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of a toroidal continuously variable transmission according to the present invention. The toroidal-type continuously variable transmission of the present invention generally has the same configuration as that of the conventional one shown in FIG. 4 except for the configuration related to the controller. Is omitted.
00 21 ]
In FIG. 1, an output shaft rotational speed sensor 18 for detecting the output shaft rotational speed of the toroidal type continuously variable transmission, an engine rotational sensor 19 for detecting the rotational speed of the engine, and an accelerator pedal depression amount sensor 20 for detecting the fuel supply amount. Information necessary for shifting from the sensor is input to the controller 25.
00 22 ]
Based on these pieces of information, the controller 25 uses a table or an arithmetic expression stored in the inside to obtain a target speed ratio e that is optimum for the driving situation. ₀ Is calculated. The controller 25 detects the actual speed ratio calculated from the combined displacement amount of the tilt angle of the trunnion 4 detected by the precess cam 15 and the potentiometer 17 and the tilt axis direction. Target gear ratio e ₀ On the basis that the hydraulic pressures Sa and Sb are supplied from the solenoid valves 13a and 13b to both ends of the spool valve 10 based on the transmission ratio deviation between the actual transmission ratio and the actual transmission ratio, the conventional transmission ratio deviation is controlled to zero. This is the same as the controller 14 of the toroidal type continuously variable transmission.
00 23 ]
Compared with the conventional one shown in FIG. 4, this toroidal type continuously variable transmission supplies the hydraulic pressure supplied to the cylinder chambers 8a, 8b of the hydraulic cylinder 8 for displacing the trunnion 4 in the direction of the tilt axis. The controller 25 to which the detected signal is input is detected by the target speed ratio e. ₀ Is corrected, the spool valve 10 is operated to change the position of the trunnion 4 in the direction of the tilt axis, and the gear ratio is controlled. A pressure sensor 26a for detecting the hydraulic pressure for the cylinder chamber 8a is provided in the pipe line 9a, and a pressure sensor 26b for detecting the hydraulic pressure for the cylinder chamber 8b is provided for the pipe line 9b. The controller 25 receives the detection signals from the pressure sensors 26a and 26b and calculates a pressure difference ΔP between the hydraulic pressure Pup acting on the cylinder chamber 8a and the hydraulic pressure Pdown acting on the cylinder chamber 8b.
00 24 ]
The actual input torque Tin of the toroidal type continuously variable transmission has a characteristic that it is proportional to the pressure difference ΔP under a constant gear ratio. If the actual input torque Tin is constant, the pressure difference ΔP is opposed to a force proportional to the contact rotation radius r1 between the input disk 3 and the power roller 2 (that is, related to the transmission ratio e). Accordingly, the actual input torque Tin is determined by the pressure difference ΔP and the speed ratio e (target speed ratio e ₀ But you can. ) As a function.
00 25 ]
On the other hand, based on at least the accelerator pedal depression amount (throttle opening) θ detected by the accelerator pedal depression amount sensor 20 corresponding to the fuel supply amount, an accelerator is calculated from a table or an arithmetic expression stored in advance in the memory of the controller 25. A target input torque (target input torque Tino) corresponding to the pedal depression amount (throttle opening) θ is calculated. Therefore, the torque deviation ΔTin can be calculated as the difference between the actual input torque Tin and the target input torque Tino.
00 26 ]
When the sign of the torque deviation ΔTin is negative, that is, when it is found that the actual input torque Tin is smaller than the target input torque Tino, the engine speed is increased as shown as point C in FIG. Assuming that the actual input torque Tin, which is also the engine output torque, is small, the target gear ratio is shifted up, that is, the ratio of the input shaft speed to the output shaft speed is reduced. Correct in the direction of. As the gear ratio correction amount Δe, an appropriate correction amount can be obtained experimentally for the torque deviation ΔTin and stored in the memory of the controller 25 in advance. Instead, the correction amount Δe may be obtained by multiplying the torque deviation ΔTin by a proportional constant approximately. If the sign of the torque deviation ΔTin is positive, that is, if it is found that the actual input torque Tin does not fall below the target input torque Tino, the engine is considered to be operating in an optimal state, and the target shift Ratio e ₀ Is not corrected.
00 27 ]
For example, when a toroidal continuously variable transmission is used in a vehicle, the target gear ratio e is obtained when the actual input torque Tin, which is also the engine output torque, is small for a high engine speed. ₀ Is corrected in the upshift direction so that the speed increases, the corrected target speed ratio e is corrected by normal speed ratio control. ₀ Shift control is performed so as to follow. When the shift is shifted up, the input shaft rotational speed corresponding to the output shaft rotational speed at that time can be reduced, and the engine rotational speed is decreased. Therefore, the engine output torque changes in the increasing direction, and it is possible to shift to an ideal operating point on the engine characteristic curve.
00 28 ]
Next, the procedure of the shift control of the toroidal type continuously variable transmission will be described based on the flowchart of FIG. Before the shift operation is started, it is assumed that the trunnion 4 is in a so-called neutral position where the rotation center axis of the power roller 2 and the rotation center axes of the input disk 3 and the output disk 23 intersect. May have an arbitrary shift position.
00 29 ]
In the main routine, gear ratio control is performed according to the deviation between the target input torque and the actual input torque. That is, the engine rotation sensor 19, the accelerator pedal depression amount 20, the vehicle speed sensor, that is, the output shaft rotation sensor 18, and the like in the shift information detector 30 are used to change the engine rotation speed, the accelerator pedal depression amount, the transmission output shaft rotation speed, and the like. Information is detected. Based on the detected gear shift information, the controller 25 calculates an optimum target gear ratio by means such as a table or an arithmetic expression stored therein, and calculates the target gear ratio e. ₀ (Step S1). The actual gear ratio is the target gear ratio e ₀ The control to match is executed in the main routine.
00 30 ]
Based on the accelerator pedal depression amount (throttle opening) θ, the target input torque Tino is selected from, for example, a table [Tino = f1 (θ)] stored in the memory of the controller 25. When the driver tries to accelerate the vehicle, the accelerator pedal is greatly depressed to increase the torque transmitted to the transmission output shaft without changing the gear ratio. At this time, if there is a loss in the target input torque to the toroidal continuously variable transmission, that is, if there is a loss in the power transmission path from the engine to the toroidal continuously variable transmission, the engine output torque including the loss is as follows: A high target input torque Tino is set (step S2). Setting of the target input torque Tino does not need to be based only on the accelerator pedal depression amount θ, but may depend on the accelerator pedal depression speed, or may be determined in advance by a map or the like in general according to the driving situation.
00 31 ]
As a premise for calculating the actual input torque, a pressure difference ΔP between the hydraulic pressures Pup and Pdown acting on the cylinder chambers 8a and 8b of the hydraulic cylinder 8 is calculated to obtain a pressure difference ΔP = Pup−Pdown (step S3).
00 32 ]
The pressure difference ΔP represents the force F in the direction of the tilt axis of the trunnion 4 and is proportional to the actual input torque Tin at a constant gear ratio. On the other hand, the pressure difference ΔP is a contact rotation radius r between the input disk 3 and the power roller 2 at a constant input torque. ₁ It is proportional to (a function of the actual transmission ratio e). Therefore, the actual input torque Tin is a function of the pressure difference ΔP and the actual speed ratio e, that is, Tin = f2 (ΔP, e) (step S4).
00 33 ]
A torque deviation ΔTin is calculated as a difference between the target input torque Tino obtained in step S2 and the actual input torque Tin obtained in step S4 (ΔTin = Tin−Tino) (step S5).
00 34 ]
It is determined whether the torque deviation ΔTin calculated in step S5 is a positive value or a negative value (step S6). If the torque deviation ΔTin is a positive value, the actual input torque Tin is greater than the target input torque Tino, which means that the torque is not insufficient, and the main routine of step S9. Returning to the normal gear ratio control.
00 35 ]
If it is determined in step S6 that the torque deviation ΔTin is a negative value, the actual input torque Tin is smaller than the target input torque Tino and the torque is insufficient, that is, the engine speed is the target. It is assumed that the engine is being operated at a higher speed than In order to reduce the engine speed, the target gear ratio e ₀ Is controlled so as to correct the output shaft rotational speed to the speed increasing side. Target gear ratio e ₀ Is obtained from a table or an arithmetic expression stored in the memory of the controller 25. That is, the correction amount Δe = f3 (ΔTin) (step S7).
00 36 ]
Target speed ratio e before correction ₀ Is corrected by the gear ratio correction amount Δe obtained in step S7 (e ₀ = E + Δe) (step S8). Target speed ratio e corrected in step S8 ₀ Is obtained, the process returns to the main routine (step S9), and the corrected target gear ratio e ₀ A new target gear ratio e ₀ As its target gear ratio e ₀ The actual speed ratio is controlled by performing the same speed change operation as in the prior art so that The engine has a new target gear ratio e ₀ Therefore, the rotational speed is reduced to meet the gear ratio that shifts to meet the above and the small actual input torque.
00 37 ]
【The invention's effect】
Since the toroidal type continuously variable transmission according to the present invention is configured as described above, the detection accuracy of the output shaft speed of the transmission, the amount of depression of the accelerator pedal (that is, the throttle opening), or the engine due to component variations The inaccuracy of the characteristics can be absorbed by the control of the controller, and the engine can be kept in an ideal operating state. For example, even in the case of an engine such as a diesel engine that has a characteristic that the output torque rapidly decreases when operating at a higher speed than the target engine speed, the output shaft speed of the transmission and the throttle When it is detected that the engine speed is higher than the target speed due to the detection accuracy of the opening or the variation in parts and the actual input torque is reduced compared to the target input torque, By correcting the target gear ratio of the toroidal type continuously variable transmission, the engine can be operated at an appropriate speed. Therefore, if this toroidal type continuously variable transmission is used, predetermined performance can be ensured for engine acceleration and fuel consumption.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a toroidal continuously variable transmission according to the present invention.
2 is a flowchart showing a control procedure for obtaining a correction amount of a target gear ratio according to a deviation between an actual input torque and a target input torque in the toroidal type continuously variable transmission of FIG.
FIG. 3 is a diagram showing an outline of a conventional toroidal-type continuously variable transmission.
FIG. 4 is a circuit diagram showing an outline of transmission ratio control of a conventional toroidal-type continuously variable transmission.
FIG. 5 is a graph showing engine speed-torque characteristics.
[Explanation of symbols]
1 Transmission unit
2 Power roller
3 Input disk
4 Trunnion
6 Tilt axis
8 Hydraulic cylinder
8a, 8b Cylinder chamber
10 Spool valve
11 Spool
13a, 13b Solenoid valve
17 Potentiometer
20 Accelerator pedal depression amount sensor
25 controller
26 Pressure sensor

Claims (1)

An input disk and an output disk arranged to face each other, a pair of power rollers for continuously changing the rotation of the input disk in accordance with a change in tilt angle with respect to both disks, and transmitting the rotation to the output disk, and the power roller A pair of trunnions that support the rotation of the trunnion around the tilting axis from the neutral position, two cylinder chambers, a hydraulic cylinder that displaces the trunnion in the direction of the tilting axis, and the spool are in the neutral position A spool valve for selectively communicating each cylinder chamber with a hydraulic pressure source and a tank in a state where the cylinder chamber is shut off and displaced from the neutral position in a state; a solenoid valve for controlling a spool position of the spool valve; A pressure sensor that detects the hydraulic pressure acting on each of the two cylinder chambers, and a gear ratio deviation between the target gear ratio and the actual gear ratio. And controlling the operation of the solenoid valve in response to the control signal, the pressure difference between the two hydraulic pressures detected by the pressure sensor and the actual input torque obtained from the target gear ratio or the actual gear ratio, and at least the accelerator A controller for correcting the target gear ratio based on a torque deviation from a target input torque determined based on information including information on a pedal depression amount;
The controller is a toroidal-type continuously variable control that controls to correct the target gear ratio to the speed increasing side according to the torque deviation when the actual input torque is smaller than the target input torque. transmission.

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