JP2019065889A - Control device of transmission - Google Patents

Abstract

To provide a control device of a transmission which can suppress the generation of a belt slide caused by inertia torque.SOLUTION: In gear change control, command values of primary pressure and secondary pressure corresponding to a value of belt input torque which is inputted to a belt-type stepless gear change mechanism are set. Since hydraulic pressure imparted to a sheave of the stepless gear change mechanism is controlled on the basis of the command values, belt grip pressure corresponding to the value of the belt input torque can be obtained. A time change rate of a turbine rotation number is acquired, and inertia torque which can be inputted to the stepless gear change mechanism is calculated from the time change rate. Then, a correction for raising the value of the belt input torque which is used for setting the command values is performed in response to the calculated inertia torque.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a control device for a transmission capable of branching and transmitting power (torque) into two paths between an input shaft and an output shaft.

  As a transmission mounted on a vehicle such as an automobile, there is a continuously variable transmission mechanism for continuously changing the power of the engine, a gear mechanism for transmitting the power of the engine without passing through the continuously variable transmission mechanism, and a continuously variable transmission mechanism It has been proposed to have a planetary gear mechanism for combining the power from the gear and the power from the gear mechanism. In this transmission, the power from the engine can be divided into the continuously variable transmission mechanism and the gear mechanism, and each divided power can be synthesized by the planetary gear mechanism and transmitted to the wheels.

JP, 2004-176890, A

  The applicant has also proposed a transmission capable of dividing and transmitting the power of the drive source into two paths as a power split continuously variable transmission.

  The power split type continuously variable transmission according to the proposal includes a continuously variable transmission mechanism, a parallel shaft gear mechanism and a planetary gear mechanism. The continuously variable transmission mechanism has the same configuration as a known belt-type continuously variable transmission (CVT), that is, a configuration in which a belt is wound around a primary pulley and a secondary pulley. The power of the engine input to the input shaft is transmitted to the primary shaft of the continuously variable transmission mechanism. The secondary shaft of the continuously variable transmission mechanism is connected to the sun gear of the planetary gear mechanism. The parallel shaft gear mechanism includes a split drive gear to which the power of the input shaft is transmitted / interrupted, and a split driven gear which forms a gear train with the split drive gear and which rotates integrally with a carrier of the planetary gear mechanism. An output shaft is connected to the ring gear of the planetary gear mechanism. The rotation of the output shaft is transmitted to the differential gear and transmitted from the differential gear to the left and right drive wheels.

  In this power split type continuously variable transmission, a belt mode and a split mode are provided as power transmission modes during forward traveling.

  In the belt mode, the first clutch that switches power transmission / reception between the input shaft and the split drive gear is released, the split drive gear is free (rotation), and the carrier of the planetary gear mechanism is free. It is turned. In addition, a second clutch that couples / disconnects the sun gear and the ring gear of the planetary gear mechanism is engaged to couple the sun gear and the ring gear. Therefore, the sun gear and the ring gear rotate integrally and the output shaft rotates integrally with the ring gear by the power output from the continuously variable transmission mechanism. Therefore, in the belt mode, the larger the transmission ratio (belt transmission ratio) of the continuously variable transmission mechanism, the proportional to the belt transmission ratio, and the transmission ratio of the entire power split type continuously variable transmission (rotation speed of input shaft / The unit gear ratio, which is the rotation speed of the output shaft, increases.

  In the split mode, the second clutch is released to release the coupling between the sun gear and the ring gear of the planetary gear mechanism. Also, the first clutch is engaged to transmit power from the input shaft to the split drive gear. The power is shifted from a split drive gear through a split driven gear at a constant split transmission ratio (split point) and input to the carrier of the planetary gear mechanism. The sun gear rotates at a rotational speed corresponding to the belt transmission ratio. Therefore, in the split mode, the unit gear ratio becomes smaller as the belt gear ratio is larger, and a gear ratio smaller than the split gear ratio can be realized.

  When the unit gear ratio is changed over the split gear ratio, the change of the unit gear ratio involves switching between the belt mode and the split mode. This mode switching is achieved by switching the engagement of the first clutch and the second clutch. In a state in which the belt gear ratio and the split gear ratio deviate from each other, differential rotation occurs between the sun gear and the carrier, so that switching between engagement of the first clutch and the second clutch can be performed with the belt gear ratio being a split gear If it is performed at the time of shifting to a gear ratio substantially matching the ratio (at or near the synchronization point), it is possible to prevent the occurrence of a shift shock due to differential rotation.

  However, when a kick down is required due to the accelerator pedal being quickly and largely depressed in split mode, the belt gear ratio is shifted to the split gear ratio and then the engagement between the first clutch and the second clutch is switched. The gear change response is bad. Therefore, when kick-down is required, the transmission torque capacity of the first clutch is reduced and the first clutch is slipped to cause the rotation (rotation of the sun gear) output from the continuously variable transmission mechanism to blow up. The second clutch is engaged when the differential rotation between the rotation and the rotation of the output shaft (the rotation of the ring gear) disappears.

  However, there is a large differential rotation between the sun gear and the ring gear due to variations in the indicated pressure and the actual pressure of the hydraulic pressure for engaging the second clutch, and the variations in the clutch clearance of the second clutch and the time taken to close it. The second clutch may be engaged in a state in which In this case, there is a concern that the belt may slip as a large inertia torque is input to the belt.

  An object of the present invention is to provide a control device for a transmission that can suppress the occurrence of belt slippage due to inertia torque.

  In order to achieve the above object, a control device of a transmission according to the present invention is a belt for continuously shifting power on a power transmission path from an input shaft to which power is input to an output shaft to which power is output. Control device for use in a transmission provided with a continuously variable transmission mechanism of the formula, wherein command value setting means for setting a command value for obtaining a belt clamping pressure corresponding to the value of input torque inputted to the continuously variable transmission mechanism According to the inertia torque calculation means for calculating the inertia torque which can be inputted to the continuously variable transmission mechanism from the time rate of change of the rotational speed inputted to the continuously variable transmission mechanism, and the inertia torque calculated by the inertia torque calculation means, And correction means for increasing the value of the input torque used for setting the command value by the command value setting means.

  According to this configuration, the command value for obtaining the belt clamping pressure corresponding to the value of the input torque input to the continuously variable transmission mechanism is set. By controlling the hydraulic pressure applied to the sheave of the continuously variable transmission mechanism based on the command value, a belt clamping pressure corresponding to the value of the input torque can be obtained. As a result, when a much larger inertia torque is not input to the continuously variable transmission mechanism, it is possible to suppress the occurrence of belt slippage by an appropriate belt clamping pressure.

  On the other hand, the time change rate of the rotation speed input to the continuously variable transmission mechanism is acquired, and the inertia change that can be input to the continuously variable transmission mechanism is calculated from the time change rate. Then, in accordance with the calculated inertia torque, correction is performed to increase the value of the input torque used for setting the command value. As a result, the belt clamping pressure is raised, so that the occurrence of belt slippage can be suppressed even if a large inertia torque is input to the continuously variable transmission mechanism.

  The correction means may raise the value of the input torque used for setting of the command value by the command value setting means when the inertia torque calculated by the inertia torque calculation means exceeds the predetermined value.

  Thus, when the inertia torque calculated from the time rate of change of the rotational speed input to the continuously variable transmission mechanism is equal to or less than the predetermined value, the value of the input torque used for setting the command value can not be increased. Therefore, it is possible to suppress a decrease in torque transmission efficiency of the continuously variable transmission mechanism due to the belt clamping pressure being unnecessarily large.

  The transmission is a power transmission mode for transmitting power between the input shaft and the output shaft, a first mode in which no differential rotation occurs between the secondary shaft of the continuously variable transmission mechanism and the output shaft, and the secondary shaft And the output shaft may have a second mode in which differential rotation occurs.

  In the case where the power transmission mode is switched from the second mode to the first mode with the power transmission mode being the second mode and a large differential rotation occurring between the secondary shaft and the output shaft, the continuously variable transmission There is a concern that the belt may slip when a large inerter shuttle is input. In such a case, it is possible to suppress the occurrence of belt slippage by performing correction that raises the value of the input torque used for setting the command value.

  According to the present invention, it is possible to suppress the occurrence of belt slippage due to the inertia torque.

It is a skeleton diagram showing composition of a drive system of vehicles. It is a figure which shows the state of each engagement element with which a transmission is equipped. It is an alignment chart which shows the relationship of the rotation speed (rotation speed) of the sun gear of the planetary gear mechanism with which a transmission is equipped, a carrier, and a ring gear. FIG. 5 is a view showing a relationship between a transmission ratio (belt transmission ratio) of the continuously variable transmission mechanism provided in the transmission and a transmission ratio (unit transmission ratio) of the entire power split type continuously variable transmission. It is a figure showing composition of a control system concerning one embodiment of the present invention. It is a figure which shows the time change of the turbine rotation speed at the time of mode switching from a split mode to a belt mode, and the belt input torque used for the setting of a primary thrust and a secondary thrust.

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

<Drive system of vehicle>
FIG. 1 is a skeleton diagram showing a configuration of a drive system of a vehicle 1.

  The vehicle 1 is an automobile having an engine 2 as a drive source.

  The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air to the combustion chamber of the engine 2, an injector (fuel injection device) for injecting fuel to intake air, and an ignition plug for generating an electric discharge in the combustion chamber. It is done. The engine 2 is additionally provided with a starter for starting it. The power of the engine 2 is transmitted to the differential gear 5 through the torque converter 3 and the transmission 4 and transmitted to the left and right drive wheels 7L, 7R from the differential gear 5 through the left and right drive shafts 6L, 6R. .

  The engine 2 is provided with an E / G output shaft 11. The E / G output shaft 11 is rotated by the power generated by the engine 2.

  The torque converter 3 includes a pump impeller 21, a turbine runner 22 and a lockup clutch (lockup mechanism) 23. The E / G output shaft 11 is connected to the pump impeller 21, and the pump impeller 21 is integrally rotatably provided around the same rotation axis as the E / G output shaft 11. The turbine runner 22 is rotatably provided about the same rotation axis as the pump impeller 21. The lockup clutch 23 is provided to connect / disconnect the pump impeller 21 and the turbine runner 22 directly. When the lockup clutch 23 is engaged, the pump impeller 21 and the turbine runner 22 are directly connected, and when the lockup clutch 23 is released, the pump impeller 21 and the turbine runner 22 are separated.

  When the E / G output shaft 11 is rotated in a state where the lockup clutch 23 is released, the pump impeller 21 is rotated. When the pump impeller 21 rotates, a flow of oil from the pump impeller 21 toward the turbine runner 22 is generated. The flow of oil is received by the turbine runner 22 and the turbine runner 22 rotates. At this time, an amplification action of the torque converter 3 occurs, and a power larger than the power (torque) of the E / G output shaft 11 is generated in the turbine runner 22.

  In the state where the lockup clutch 23 is engaged, when the E / G output shaft 11 is rotated, the E / G output shaft 11, the pump impeller 21 and the turbine runner 22 integrally rotate.

  The transmission 4 is provided with an input shaft 31 and an output shaft 32, and is a so-called power split type (torque that is configured to be able to split the power input to the input shaft 31 into two paths and transmit it to the output shaft 32. It is a split type) transmission. The transmission 4 includes a continuously variable transmission mechanism 33, a front reduction gear mechanism 34, a planetary gear mechanism 35, and a split transmission mechanism 36 in order to configure two power transmission paths.

  The input shaft 31 is connected to the turbine runner 22 of the torque converter 3 and provided integrally rotatably around the same rotation axis as the turbine runner 22.

  The output shaft 32 is provided in parallel with the input shaft 31. An output gear 37 is supported by the output shaft 32 so as not to be relatively rotatable. The output gear 37 meshes with the differential gear 5 (the ring gear of the differential gear 5).

  The continuously variable transmission mechanism 33 has a configuration similar to that of a well-known belt-type continuously variable transmission (CVT). Specifically, the continuously variable transmission mechanism 33 includes a primary shaft 41, a secondary shaft 42 provided parallel to the primary shaft 41, a primary pulley 43 supported relative non-rotatably to the primary shaft 41, and a secondary shaft 42. , And a belt 45 wound around the primary pulley 43 and the secondary pulley 44. As shown in FIG.

  The primary pulley 43 is disposed opposite to the fixed sheave 51 fixed to the primary shaft 41 and the fixed sheave 51 with the belt 45 interposed therebetween, and is a movable sheave supported by the primary shaft 41 so as to be movable in the axial direction and relatively nonrotatably. And (primary sheave) 52. A cylinder 53 fixed to the primary shaft 41 is provided on the opposite side of the movable sheave 52 with respect to the fixed sheave 51, and an oil pressure chamber 54 is formed between the movable sheave 52 and the cylinder 53.

  Secondary pulley 44 is disposed opposite to fixed sheave 55 fixed to secondary shaft 42 and fixed sheave 55 with belt 45 interposed therebetween, and movable sheave supported on secondary shaft 42 so as to be movable in the axial direction and relatively non-rotatable. And (secondary sheave) 56. A cylinder 57 fixed to the secondary shaft 42 is provided on the opposite side of the movable sheave 56 with respect to the fixed sheave 55, and a hydraulic chamber 58 is formed between the movable sheave 56 and the cylinder 57. The positional relationship between the fixed sheave 55 and the movable sheave 56 in the rotational axis direction is reverse to the positional relationship between the fixed sheave 51 of the primary pulley 43 and the movable sheave 52.

  In the continuously variable transmission mechanism 33, the hydraulic pressure supplied to the hydraulic chambers 54, 58 of the primary pulley 43 and the secondary pulley 44 is controlled, and the groove widths of the primary pulley 43 and the secondary pulley 44 are changed. The pulley ratio between the pulley 43 and the secondary pulley 44 is continuously changed steplessly.

  Specifically, when the pulley ratio is reduced, the oil pressure supplied to the oil pressure chamber 54 of the primary pulley 43 is increased. As a result, the movable sheave 52 of the primary pulley 43 moves toward the fixed sheave 51, and the distance (groove width) between the fixed sheave 51 and the movable sheave 52 decreases. Along with this, the winding diameter of the belt 45 with respect to the primary pulley 43 increases, and the distance (groove width) between the fixed sheave 55 and the movable sheave 56 of the secondary pulley 44 increases. As a result, the pulley ratio between the primary pulley 43 and the secondary pulley 44 decreases.

  When the pulley ratio is increased, the oil pressure supplied to the oil pressure chamber 54 of the primary pulley 43 is lowered. As a result, the thrust ratio, which is the ratio of the thrust (primary thrust) of primary pulley 43 to the thrust (secondary thrust) of secondary pulley 44, decreases, and the distance between fixed sheave 55 and movable sheave 56 of secondary pulley 44 decreases. The distance between the fixed sheave 51 of the primary pulley 43 and the movable sheave 52 is increased. As a result, the pulley ratio between the primary pulley 43 and the secondary pulley 44 is increased.

  On the other hand, the thrust of the primary pulley 43 and the secondary pulley 44 needs to be large enough to prevent slippage (belt slippage) between the primary pulley 43 and the secondary pulley 44 and the belt 45. Therefore, the hydraulic pressure supplied to the hydraulic chamber 54 of the primary pulley 43 and the hydraulic chamber 58 of the secondary pulley 44 is controlled so as to obtain a necessary and sufficient clamping pressure without causing belt slippage.

  The front reduction gear mechanism 34 reverses and decelerates the power input to the input shaft 31 and transmits the power to the primary shaft 41. Specifically, the front reduction gear mechanism 34 has a larger diameter and a larger number of teeth than the input shaft gear 61 and the input shaft gear 61 supported by the input shaft 31 so as not to allow relative rotation, and spline fitting on the primary shaft 41 , And a primary shaft gear 62 meshed with the input shaft gear 61 so as not to be relatively rotatable.

  The planetary gear mechanism 35 includes a sun gear 71, a carrier 72 and a ring gear 73. The sun gear 71 is non-rotatably supported by the secondary shaft 42 by spline fitting. The carrier 72 is rotatably fitted around the output shaft 32. The carrier 72 rotatably supports a plurality of pinion gears 74. The plurality of pinion gears 74 are disposed on the circumference and mesh with the sun gear 71. The ring gear 73 has an annular shape that collectively surrounds a plurality of pinion gears 74, and meshes with each pinion gear 74 from the outer side in the rotational radial direction of the secondary shaft 42. Further, an output shaft 32 is connected to the ring gear 73, and the ring gear 73 is integrally rotatably provided around the same rotation axis as the output shaft 32.

  The split transmission mechanism 36 is a parallel shaft gear mechanism including a split drive gear 81 and a split driven gear 82 meshing with the split drive gear 81.

  The split drive gear 81 is fitted on the input shaft 31 so as to be capable of relative rotation.

  The split driven gear 82 is integrally rotatably provided about the same rotation axis as the carrier 72 of the planetary gear mechanism 35. The split driven gear 82 is formed to have a smaller diameter than the split drive gear 81 and has a smaller number of teeth than the split drive gear 81.

  The transmission 4 further includes clutches C1 and C2 and a brake B1.

  The clutch C1 is switched between an engaged state in which the input shaft 31 and the split drive gear 81 are directly coupled (jointly rotatably coupled) and a released state in which the direct coupling is released.

  The clutch C2 is switched between an engaged state in which the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are directly coupled (coupled integrally rotatably) and a released state in which the direct coupling is released.

  The brake B1 is switched between an engagement state in which the carrier 72 of the planetary gear mechanism 35 is braked and a release state in which the rotation of the carrier 72 is permitted.

<Power transmission mode>
FIG. 2 is a diagram showing the states of the clutches C1 and C2 and the brake B1 when the vehicle 1 is moving forward and backward. FIG. 3 is a collinear diagram showing the relationship between the rotational speeds (rotational speeds) of the sun gear 71, the carrier 72 and the ring gear 73 of the planetary gear mechanism 35. As shown in FIG. FIG. 4 shows a belt transmission ratio, which is the transmission ratio by the continuously variable transmission mechanism 33, and a unit transmission ratio, which is the transmission ratio of the entire transmission 4, that is, a unit that is the rotational speed ratio between the input shaft 31 and the output shaft 32. It is a figure which shows the relationship with a gear ratio.

  In FIG. 2, "o" indicates that the clutches C1 and C2 and the brake B1 are in the engaged state. "X" indicates that the clutches C1 and C2 and the brake B1 are in the released state.

  The transmission 4 has a belt mode and a split mode as a power transmission mode when the vehicle 1 moves forward. The belt mode and the split mode are switched by switching between a state in which the clutch C1 is engaged and a state in which the clutch C2 is engaged (recombination of the clutches C1 and C2).

  In the belt mode, as shown in FIG. 2, the clutch C1 and the brake B1 are released and the clutch C2 is engaged. As a result, the split drive gear 81 is separated from the input shaft 31, the carrier 72 of the planetary gear mechanism 35 becomes free (free rotation state), and the sun gear 71 and ring gear 73 of the planetary gear mechanism 35 are directly coupled.

  The power input to the input shaft 31 is reversed and decelerated by the front reduction gear mechanism 34, transmitted to the primary shaft 41 of the continuously variable transmission mechanism 33, and causes the primary shaft 41 and the primary pulley 43 to rotate. The rotation of the primary pulley 43 is transmitted to the secondary pulley 44 via the belt 45 and causes the secondary pulley 44 and the secondary shaft 42 to rotate. Since the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are directly connected, the sun gear 71, the ring gear 73 and the output shaft 32 rotate integrally with the secondary shaft 42. Therefore, in the belt mode, as shown in FIGS. 3 and 4, the unit gear ratio is equal to the belt gear ratio (the pulley ratio of primary pulley 43 and secondary pulley 44 of continuously variable transmission mechanism 33) to the front reduction ratio (input shaft It corresponds to the value obtained by multiplying the rotation speed of 31 / the rotation speed of the primary shaft 41).

  In the split mode, as shown in FIG. 2, the clutch C1 is engaged, and the clutch C2 and the brake B1 are released. As a result, the input shaft 31 and the split drive gear 81 are coupled, and the rotation of the input shaft 31 can be transmitted to the carrier 72 of the planetary gear mechanism 35 via the split drive gear 81 and the split driven gear 82. The 35 sun gear 71 and the ring gear 73 are separated.

  The power input to the input shaft 31 is accelerated from the split drive gear 81 via the split driven gear 82 to the carrier 72 of the planetary gear mechanism 35 and transmitted. The power transmitted to the carrier 72 is divided and transmitted from the carrier 72 to the sun gear 71 and the ring gear 73. The power of the sun gear 71 is transmitted to the primary shaft gear 62 via the secondary shaft 42, the secondary pulley 44, the belt 45, the primary pulley 43 and the primary shaft 41, and transmitted from the primary shaft gear 62 to the input shaft gear 61. Therefore, in the belt mode, the input shaft gear 61 becomes a drive gear and the primary shaft gear 62 becomes a driven gear, while in the split mode, the primary shaft gear 62 becomes a drive gear and the input shaft gear 61 becomes a driven gear. .

  Since the gear ratio (split speed ratio) between split drive gear 81 and split driven gear 82 is constant and unchanged (fixed), in split mode, if the power input to input shaft 31 is constant, planetary gear mechanism 35 The rotation of the carrier 72 is maintained at a constant speed. Therefore, when the belt gear ratio is increased, the rotational speed of the sun gear 71 of the planetary gear mechanism 35 is reduced, so the rotational speed of the ring gear 73 (output shaft 32) of the planetary gear mechanism 35 is shown as shown by a broken line in FIG. Go up. As a result, in the split mode, as shown in FIG. 4, the unit gear ratio of the transmission 4 decreases as the belt gear ratio of the continuously variable transmission mechanism 33 increases.

  The rotation of the output shaft 32 in the belt mode and the split mode is transmitted to the differential gear 5 via the output gear 37. Thus, the drive shafts 6L, 6R and the drive wheels 7L, 7R of the vehicle 1 rotate in the forward direction.

  In the reverse mode when the vehicle 1 is in reverse, as shown in FIG. 2, the clutches C1 and C2 are released and the brake B1 is engaged. As a result, the split drive gear 81 is separated from the input shaft 31, the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are separated, and the carrier 72 of the planetary gear mechanism 35 is braked.

  The power input to the input shaft 31 is reversed and decelerated by the front reduction gear mechanism 34, transmitted to the primary shaft 41 of the continuously variable transmission mechanism 33, and transmitted from the primary shaft 41 to the primary pulley 43, the belt 45 and the secondary pulley 44. The sun gear 71 of the planetary gear mechanism 35 is rotated integrally with the secondary shaft 42 and transmitted to the secondary shaft 42. Since the carrier 72 of the planetary gear mechanism 35 is braked, when the sun gear 71 rotates, the ring gear 73 of the planetary gear mechanism 35 rotates in the opposite direction to the sun gear 71. The rotation direction of the ring gear 73 is opposite to the rotation direction of the ring gear 73 at the time of forward movement (belt mode and split mode). Then, the output shaft 32 rotates integrally with the ring gear 73. The rotation of the output shaft 32 is transmitted to the differential gear 5 via the output gear 37. Thus, the drive shafts 6L and 6R and the drive wheels 7L and 7R of the vehicle 1 rotate in the reverse direction.

<Control system of vehicle>
FIG. 5 is a block diagram showing a configuration of a control system of the vehicle 1.

  The vehicle 1 is provided with an ECU (Electronic Control Unit) having a configuration including a microcomputer (micro controller unit). The microcomputer incorporates, for example, a CPU, a ROM and a RAM, and a data flash (flash memory). Although only one ECU 101 for controlling the transmission 4 is shown in FIG. 5, the vehicle 1 is equipped with a plurality of ECUs having the same configuration as the ECU 101 in order to control each part. . The plurality of ECUs including the ECU 101 are connected so as to enable two-way communication by a CAN (Controller Area Network) communication protocol.

  Various sensors necessary for control are connected to the ECU 101. As an example, the ECU 101 receives a pulse signal synchronized with the rotation of the primary shaft 41 and a turbine rotation sensor 111 that outputs a pulse signal synchronized with the rotation of the turbine runner 22 (see FIG. 1) of the torque converter 3 as a detection signal. A primary rotation sensor 112 outputting as a detection signal, a secondary rotation sensor 113 outputting a pulse signal synchronized with the rotation of the secondary shaft 42 as a detection signal, a primary sheave pressure of the transmission 4 (an oil pressure acting on the primary sheave 52), The output rotation sensor 114 outputs a pulse signal synchronized with the rotation of the output shaft 32 as a detection signal, and the two hydraulic pressure sensors 115 output detection signals according to the secondary sheave pressure (the hydraulic pressure acting on the secondary sheave 56). Is connected.

  In the ECU 101, the turbine rotation speed (rotation speed of the turbine runner 22), the primary rotation, from the detection signals of the turbine rotation sensor 111, the primary rotation sensor 112, the secondary rotation sensor 113, the output rotation sensor 114 and the two oil pressure sensors 115. The number (rotation speed of the primary shaft 41), the secondary rotation speed (rotation speed of the secondary shaft 42), the output rotation speed (rotation speed of the output shaft 32), the primary sheave pressure and the secondary sheave pressure are acquired. Further, in the ECU 101, information is acquired from other ECUs. Then, based on information acquired from various sensors by the ECU 101, information input from other ECUs, etc., for each part of the unit including the torque converter 3 and the transmission 4 for transmission control of the transmission 4 and the like. Various valves included in a hydraulic circuit for supplying hydraulic pressure are controlled.

<Speed change control>
The unit gear ratio of the transmission 4 is changed by the control of the belt gear ratio by the ECU 101. In the control of the unit gear ratio, first, a target rotation number corresponding to the accelerator opening degree and the vehicle speed is set based on the shift diagram. The shift map is a map that defines the relationship between the accelerator opening degree and the vehicle speed and the target rotational speed, and is stored in, for example, the ROM of the ECU 101. Information on the accelerator opening and the vehicle speed is transmitted from, for example, an engine ECU that controls the engine 2 to the ECU 101. When the target rotational speed is set, the rotational speed input to the input shaft 31, that is, a target gear ratio for matching the turbine rotational speed to the target rotational speed is determined, and the target belt gear ratio according to the target gear ratio is set. Ru.

  Next, on the basis of the target belt speed ratio and the belt input torque input to the continuously variable transmission mechanism 33, a primary thrust capable of obtaining a belt clamping pressure necessary for preventing belt slippage in the continuously variable transmission mechanism 33 and Secondary thrust is set. The belt input torque is obtained by multiplying the input torque input to the input shaft 31 by the front reduction ratio by the front reduction gear mechanism 34 and the torque sharing ratio, which is the ratio of the torque that the continuously variable transmission mechanism 33 shares to the input torque. Calculated by The input torque is calculated by multiplying the engine torque by the torque ratio of the torque converter 3. The engine torque is estimated, for example, by the engine ECU from the accelerator opening degree and the engine rotational speed, and is transmitted from the engine ECU to the ECU 101. The torque ratio is a torque amplification factor corresponding to the speed ratio of the torque converter 3, and the speed ratio is a division value obtained by dividing the turbine speed by the engine speed. The torque sharing ratio can be determined from the gear ratio of the split transmission mechanism 36, the belt transmission ratio, and the like.

  Thereafter, from the primary thrust and the secondary thrust, command values of the primary pressure which is the hydraulic pressure that gives the primary thrust to the movable sheave 52 of the primary pulley 43 and the secondary pressure that is the hydraulic pressure that gives the secondary thrust to the movable sheave 56 of the secondary pulley 44 are set. The hydraulic pressure supplied to the hydraulic chamber 54 of the primary pulley 43 and the hydraulic chamber 58 of the secondary pulley 44 is controlled so that the deviation between the target belt speed ratio and the actual belt speed ratio approaches zero based on each command value. Be done. The actual belt gear ratio can be obtained by dividing the primary rotation number by the secondary rotation number.

<Mode switching control>
When the unit gear ratio is changed over the split gear ratio, the change of the unit gear ratio is accompanied by switching between the belt mode and the split mode (hereinafter simply referred to as "mode switching"). Mode switching is achieved by switching the engagement of the clutches C1 and C2. That is, by controlling the hydraulic pressure supplied to the clutches C1 and C2, the released clutch C1 (engagement side) is engaged, and the engaged clutch C2 (release side) is released, so that the belt mode is started. Switch to split mode. Conversely, when the clutch C1 in the engaged state (release side) is released and the clutch C2 in the released state (engagement side) is engaged, the split mode is switched to the belt mode.

  FIG. 6 is a diagram showing the time change of the turbine rotational speed at the time of mode switching from the split mode to the belt mode, and the belt input torque used to set the primary thrust and the secondary thrust.

  When the unit gear ratio deviates from the split gear ratio, the rotational speed difference between the secondary rotational speed and the output rotational speed, that is, the differential rotation between the secondary shaft 42 (sun gear 71) and the output shaft 32 (ring gear 73) It is happening.

  Therefore, in the normal mode switching, the engagement of the clutches C1 and C2 is switched after the unit gear ratio is shifted to the split gear ratio.

  However, while the vehicle 1 is traveling in the split mode, when the accelerator pedal is quickly and largely depressed by the driver's acceleration request and the target gear ratio of the unit gear ratio is set to a value larger than the split gear ratio, The ECU 101 determines that a kick-down is requested (time T1), and switches the engagement of the clutches C1 and C2 while the unit gear ratio does not match the split gear ratio.

  At this time, the oil pressure supplied to the clutch C1 is reduced by the ECU 101 so that the transfer torque capacity of the clutch C1 on the release side falls below the input torque. When the transfer torque capacity of the clutch C1 falls below the input torque, the clutch C1 is in the half clutch state, slippage occurs in the clutch C1, and the turbine rotational speed is increased. As the turbine speed increases, the primary speed and the secondary speed of the continuously variable transmission mechanism 33 increase. As a result, the difference in rotational speed between the secondary rotational speed and the output rotational speed is reduced. When the rotation speed difference between the secondary rotation speed and the output rotation speed decreases to a predetermined value, the ECU 101 causes the oil pressure (instruction pressure) supplied to the clutch C2 to reach the full opening pressure (the oil pressure at which the clutch C2 can be fully engaged) at once. It is raised (time T3).

  At the start of this control, a target rotation change rate, which is a target value of the time change rate due to the increase of the turbine rotation speed, is set, and used to set the primary thrust and the secondary thrust according to the inertia rotation according to the target rotation change rate. The belt input torque value is increased. That is, the addition value of the inertia torque corresponding to the target rotation change rate is added to the value of the belt input torque calculated by the above-described method. As a result, command values of the primary thrust and the secondary thrust become large, and a belt clamping pressure capable of suppressing the occurrence of belt slippage can be obtained.

  In addition, when the blow-up of the turbine rotational speed occurs due to the half clutch of the clutch C1, the ECU 101 causes the inner shaft of the output shaft 32 to be generated by complete engagement of the clutch C2 from the time change rate of the turbine rotational speed. An inertia torque that can be input to the continuously variable transmission mechanism 33 is calculated. When the inertia torque exceeds a predetermined value (time T2), the value obtained by adding the addition value of the inertia torque corresponding to the target rotation change rate to the value of the belt input torque calculated by the above-described method is the inertia. An addition value corresponding to the torque is further added. As a result, the command values of the primary thrust and the secondary thrust are further raised, and a clamping pressure capable of suppressing the occurrence of belt slippage is obtained.

<Function effect>
As described above, in the shift control, each command value of the primary pressure and the secondary pressure according to the value of the belt input torque input to the continuously variable transmission mechanism 33 is set. By controlling the hydraulic pressure applied to the movable sheaves 52 and 56 of the continuously variable transmission mechanism 33 based on the command value, a belt clamping pressure corresponding to the value of the belt input torque can be obtained. As a result, when a much larger inertia torque is not input to the continuously variable transmission mechanism 33, the belt slippage can be suppressed by an appropriate belt clamping pressure.

  On the other hand, the time rate of change of the turbine rotational speed is acquired, and an inertia torque that can be input to the continuously variable transmission mechanism 33 is calculated from the time rate of change. Then, if the calculated inertia torque exceeds a predetermined value, a correction is performed to raise the value of the belt input torque used for setting the command value. As a result, the belt clamping pressure is raised, so that even if a large inertia torque is input to the continuously variable transmission mechanism 33, the occurrence of belt slippage can be suppressed.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  The control to add the addition value according to the inertia torque to the value of the belt input torque when the inertia torque that can be input to the continuously variable transmission mechanism 33 exceeds a predetermined value is when switching the engagement of the clutches C1 and C2. However, the present invention is not limited thereto, and may be performed, for example, when the vehicle 1 passes over a protrusion such as a speed bump if there is a concern about the occurrence of belt slippage due to the inertia torque. When the vehicle 1 rides over the protrusion, the wheels float up from the road surface, and after the number of rotations of the output shaft rises, the number of rotations of the output shaft may decrease sharply due to the wheels landing. When the number of revolutions of the output shaft decreases rapidly, an inertia torque may be generated on the output shaft, which may cause belt slippage due to the inertia torque.

  In the above-described embodiment, the configuration is described in which the power is transmitted by branching to the first path via the continuously variable transmission mechanism 33 and the second path via the split transmission mechanism 36. However, the split transmission mechanism 36 Not limited to the parallel shaft gear mechanism including the drive gear 81 and the split driven gear 82, a mechanism other than a gear mechanism such as a belt mechanism may be used. When a belt mechanism is adopted, the belt mechanism may have a fixed gear ratio or may have a variable gear ratio.

  Moreover, although the power split type transmission was taken up as the transmission 4, this invention is widely applicable to a belt type continuously variable transmission.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

4: Transmission 31: Input shaft 32: Output shaft 33: Continuously variable transmission mechanism 101: ECU (control device, command value setting means, inertia torque calculation means, correction means)

Claims (1)

A control device for use in a transmission provided with a belt-type continuously variable transmission mechanism for continuously changing power on a power transmission path extending from an input shaft to which power is input to an output shaft for outputting power,
Command value setting means for setting a command value for obtaining the belt clamping pressure according to the value of the input torque input to the continuously variable transmission mechanism;
Inner inertia shuttle calculation means for calculating inner inertia torque that can be input to the continuously variable transmission mechanism from the time change rate of the rotational speed inputted to the continuously variable transmission mechanism;
A control unit comprising: correction means for raising the value of input torque used for setting of the command value by the command value setting means in accordance with the inertia torque calculated by the inertia torque calculation means.

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