JP3744406B2 - Control device for continuously variable transmission for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In a continuously variable transmission to which power from an engine whose number of cycles is changed is input, the present invention is as possible as possible to reduce loss of transmitted power while preventing slippage of the power transmission member. The present invention relates to a control device for a continuously variable transmission for a vehicle having a small clamping pressure.
[0002]
[Prior art]
There is known a vehicle in which the number of operation cycles of the engine can be changed according to the required output of the vehicle or the operating state of the engine. For example, this is a vehicle equipped with an engine control device described in Japanese Patent Laid-Open No. 10-103092. According to this, since the engine is changed from the 4-cycle operation to the 2-cycle operation by switching the operation timing of the electromagnetic intake valve and the exhaust valve provided in the engine, the engine output can be easily improved. And can be controlled to suppress fluctuations in the engine output when the operation cycle is changed.
[0003]
[Problems to be solved by the invention]
By the way, in a vehicle, when the power from the engine that can change the number of operation cycles as described above is input to the continuously variable transmission, the torque included in the output torque as the number of engine operation cycles increases. For example, in a belt-type continuously variable transmission, there is a possibility that the belt slips due to the torque vibration.
[0004]
On the other hand, it is conceivable to eliminate the belt slip by uniformly increasing the belt clamping pressure of the belt type continuously variable transmission to a value at which no slip occurs even at the maximum peak value of the torque vibration. Specifically, the belt clamping pressure is unnecessarily increased, resulting in an increase in power loss and a reduction in vehicle fuel consumption.
[0005]
The present invention has been made against the background of the above circumstances, and its object is to provide a power transmission member in a continuously variable transmission for a vehicle in which power is input from an engine capable of changing an operation cycle. It is an object of the present invention to provide a control device that performs control with as little pinching pressure as possible while preventing slippage.
[0006]
[First Means for Solving the Problems]
  The gist of the first invention for achieving this object is to control the clamping pressure on the power transmission member of the continuously variable transmission to which power from the engine capable of changing the operation cycle is input. A control device for a continuously variable transmission for a vehicle, comprising: a clamping pressure control means for changing a clamping pressure with respect to the power transmission member according to an engine operating cycle.Thus, the clamping pressure control means changes the clamping pressure on the power transmission member to a smaller value as the number of operating cycles of the engine decreases.There is.
[0007]
[Effect of the first invention]
In this way, the clamping pressure control means changes the clamping pressure with respect to the power transmission member of the continuously variable transmission according to the operating cycle of the engine, so that it is as small as possible while preventing the power transmission member from slipping. The clamping pressure is used. For example, the clamping pressure on the power transmission member is relatively lowered during low cycle (2 cycle) operation, and the clamping pressure on the power transmission member is relatively increased during high cycle (4 cycle) operation. Depending on the number of cycles, the holding force is made as small as possible while preventing the power transmission member from slipping. Thereby, the fuel consumption of the vehicle is improved.
[0008]
[Other aspects of the first invention]
Here, preferably, the clamping pressure control means changes the clamping pressure on the power transmission member to a smaller value as the number of operating cycles of the engine decreases. In this manner, the pinching pressure on the power transmission member is changed to a smaller value as the number of engine operation cycles decreases, and therefore the power loss of the continuously variable transmission further increases in a state where the number of engine operation cycles decreases. Reduced.
[0009]
[Second means for solving the problem]
The gist of the second invention for achieving the above object is to control the clamping pressure on the power transmission member of the continuously variable transmission to which power from the engine capable of changing the operation cycle is input. A control device for a continuously variable transmission for a vehicle, comprising: (a) torque vibration reducing means for reducing vibration of torque input from the engine to the continuously variable transmission; and (b) torque by the torque vibration reducing means. And a clamping pressure control means for reducing a clamping pressure on the power transmission member of the continuously variable transmission as the amount of vibration reduction increases.
[0010]
[Effect of the second invention]
In this way, the torque vibration reducing means for reducing the vibration of the torque input from the engine to the continuously variable transmission is provided, and as the amount of torque vibration reduction by the torque vibration reducing means increases, the clamping pressure control means Since the clamping pressure with respect to the power transmission member of the continuously variable transmission is reduced, the clamping force with respect to the power transmission member and the continuously variable transmission caused by the same depending on the magnitude of the torque vibration while preventing the power transmission member from slipping. Power loss is reduced as much as possible.
[0011]
Here, preferably, the torque vibration reducing means has an anti-phase with respect to the vibration of the torque input from the engine to the continuously variable transmission to the electric motor connected to the input shaft of the continuously variable transmission. Torque vibration is generated. In this way, the torque vibration input to the continuously variable transmission is preferably reduced by canceling out the torque vibration in the opposite phase to that generated from the electric motor.
[0012]
Preferably, the clamping pressure on the power transmission member of the continuously variable transmission is changed based on at least one of input torque vibration and hydraulic oil temperature of the continuously variable transmission. In this way, by changing to an appropriate value corresponding to at least one of the input torque vibration of the continuously variable transmission and the hydraulic oil temperature, the clamping pressure on the power transmission member and the slippage of the power transmission member are prevented. Due to this, the power loss of the continuously variable transmission is reduced as much as possible.
[0013]
Preferably, the clamping pressure control means includes a basic clamping pressure determining means for determining a basic clamping pressure based on a transmission ratio of the continuously variable transmission and input torque related information, and the basic clamping pressure determining means. And a clamping pressure correcting means for correcting the determined basic clamping pressure based on at least one of the input torque vibration and the hydraulic oil temperature of the continuously variable transmission. According to this configuration, the basic clamping pressure determined by the basic clamping pressure determination unit is corrected by the clamping pressure correction unit based on at least one of the input torque vibration of the continuously variable transmission and the hydraulic oil temperature. While preventing the transmission member from slipping, the clamping pressure on the power transmission member and the power loss of the continuously variable transmission resulting therefrom are reduced as much as possible. In addition, there is an advantage that the basic clamping pressure is ensured even if the correction fails due to some reason such as sensor abnormality.
[0014]
Preferably, the continuously variable transmission includes a stepped transmission and a continuously variable transmission, and the power of the engine is input to the continuously variable transmission through the stepped transmission. The clamping pressure correcting means corrects the basic clamping pressure based on the gear ratio of the stepped transmission unit and / or the gear ratio of the continuously variable transmission unit. In this way, the torque vibration input to the continuously variable transmission changes according to the gear ratio of the stepped transmission, and the ease of slipping changes according to the gear ratio within the continuously variable transmission. The basic clamping pressure is corrected based on the transmission ratio of the stepped transmission unit and / or the transmission ratio of the continuously variable transmission unit, thereby preventing the slippage of the power transmission member and the clamping pressure with respect to the power transmission member The power loss of the continuously variable transmission is reduced as much as possible.
[0015]
Preferably, a torque vibration reduction impossibility determining means for determining whether or not torque vibration reduction by the torque vibration reduction means cannot be obtained is provided, and the pinching pressure correction means of the pinching pressure control means includes: If it is determined by the torque vibration reduction impossibility determination means that the torque vibration reduction by the torque vibration reduction means cannot be obtained, it is determined in advance so that the power transmission member does not slip even when the torque vibration is not reduced. The basic clamping pressure is corrected by the corrected amount. By doing so, the clamping pressure is controlled so that the power transmission member does not slip even when the torque vibration reduction means cannot reduce the torque vibration.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 1 is a skeleton diagram illustrating a configuration of a power transmission device for a hybrid vehicle to which an engine control device according to an embodiment of the present invention is applied. In the figure, the output of the engine 10 as a power source is sequentially input to a continuously variable transmission 17 including a sub-transmission unit 14 and a continuously variable transmission unit 16 via a vibration damping device (damper) 12, and a differential gear device. It is transmitted to a pair of drive wheels (for example, front wheels) 22 via 18 and axle 20. A motor generator MG2 that functions as a second power source and a generator is connected to the input shaft of the auxiliary transmission 14.
[0018]
In order to reduce fuel consumption, the engine 10 preferably performs lean combustion in which the air-fuel ratio A / F is higher than the stoichiometric air-fuel ratio at light load by in-cylinder fuel injection. It consists of a lean burn engine. The engine 10 includes a pair of left and right banks each composed of, for example, three cylinders, and the pair of banks can be operated independently or simultaneously, and the number of operating cylinders can be changed. Yes. The intake pipe of the engine 10 is provided with a supercharger as necessary and a throttle valve operated by a throttle actuator. This throttle valve is basically an operation amount of an accelerator pedal (not shown), that is, an accelerator opening θ_ACCThrottle opening θ of a size corresponding to_THHowever, in order to adjust the output of the engine 10, the opening is controlled according to various vehicle conditions such as during a shift transition.
[0019]
The engine 10 is connected to a motor generator MG1 that functions as an electric motor, a generator, and the like for starting the engine 10, driving auxiliary equipment, and collecting rotational energy.
[0020]
The engine 10 is configured so that the number of operation cycles can be changed. For example, as shown in FIG. 2, a variable valve mechanism 28 including electromagnetic actuators 24 and 26 that open and close the intake valve 20 and the exhaust valve 22 of each cylinder, and a rotation sensor 32 that detects the rotation angle of the crankshaft 30. And a valve drive control device 34 for controlling the operation timing (timing) of the intake valve 20 and the exhaust valve 22 according to the signal. The valve drive control device 34 not only changes the operation timing to the optimal time according to the engine load, but also realizes an open / close timing and a two-cycle operation that realize a four-cycle operation according to an operation cycle switching command such as an acceleration operation. It controls so that it becomes the opening and closing time to do. For example, as shown in FIG. 3, the electromagnetic actuators 24 and 26 are connected to the intake valve 20 or the exhaust valve 22 and are made of a magnetic material supported so as to be movable in the axial direction of the intake valve 20 or the exhaust valve 22. A disk-shaped movable member 36, a pair of electromagnets 38 and 40 provided at positions sandwiching the movable member 36 to selectively attract the movable member 36, and the movable member 36 are urged toward the neutral position. A pair of springs 42 and 44 is provided.
[0021]
The auxiliary transmission unit 14 of the continuously variable transmission 17 has a gear ratio (gear ratio) γ._A[= Engine speed (input shaft speed) / speed of input shaft 56 (output shaft speed)] is 1 and the gear ratio is 1 / ρ.₁The two forward gears with the low speed gear and the gear ratio is -1 / ρ₂And the gear ratio is -1 / ρ₁This is a stepped transmission having a Ravigneaux type planetary gear device having two reverse gears and a low speed side gear. The auxiliary transmission unit 14 includes a first input shaft 50 connected to the engine 10 via the first clutch C1, and a second input shaft 52 connected to the engine 10 via the first clutch C1 and the second clutch C2. A first sun gear S1 and a second sun gear S2 provided on the first input shaft 50 and the second input shaft 52, and a carrier K selectively connected to the non-rotating housing 54 via the brake B1. A ring gear R connected to the output shaft of the sub-transmission unit 14, that is, the input shaft 56 of the continuously variable transmission unit 16, is rotatably supported by the carrier K, and has a large shaft length meshing with the first sun gear S1 and the ring gear R. The planetary gear P1 and the second planetary gear having a short axial length that is rotatably supported by the carrier K and meshes with the second sun gear S2 and the first planetary gear P1. And a car P2. The motor generator MG2 is coupled to the second input shaft 52.
[0022]
FIG. 4 shows the operation of shift levers such as P, R, N, D, 2, L, etc., which are well-known shift gears obtained by combining the engagement operations of the friction engagement devices in the auxiliary transmission unit 14. It is an engagement table | surface shown for every position (shift position). In FIG. 4, ◯ indicates engagement, × indicates release, and Δ indicates slip engagement. In the auxiliary transmission unit 14, at the D lever position of the shift lever, for example, the first clutch C1 and the second clutch C2 are engaged and the brake B is released, so that the gear ratio γ_AIs established, and the first gear C1 and the second clutch C2 are released and the brake B is engaged, for example, so that the gear ratio γ_AIs "1 / ρ₁”Is established. Further, at the R range position of the shift lever, for example, the first clutch C1 and the brake B are engaged and the second clutch C2 is released, whereby the speed ratio γ_AIs "-1 / ρ₂Is established, and for example, the first clutch C1 and the brake B are released and the second clutch C2 is engaged._AIs "-1 / ρ₁”Is established. The clutches C1 and C2 and the brake B are all hydraulic friction engagement devices that are engaged by a hydraulic actuator.
[0023]
When the vehicle is traveling backward by motor driving, the rotation of the motor generator MG2 is reversed and input to the second sun gear S2. While the vehicle is stopped, basically, the creep force is ensured by the motor generator MG2 in both forward and reverse. For this reason, even when the remaining charge of the secondary battery 68 is insufficient, the electric power generated from the motor generator MG2 is supplied to the secondary battery 68 for charging by starting the engine 10, so that it is not during a failure. The motor generator MG2 is always capable of starting the motor. In forward travel, motor start travel is performed while securing a creep torque by motor generator MG2. Further, the engine 10 is started by the motor generator MG1, and when the synchronous rotation is reached, the clutch C1 is engaged, and the engine 10 performs the second (2nd) traveling. The engine 10 can also start, and at low speed, the vehicle speed V is gradually increased while slipping the clutch C1. When the speed is relatively high, the clutch C1 is completely engaged. In reverse travel, the motor generator MG2 is driven reversely to ensure the creep force, and the engine 10 is further started when torque is required. At low speed, the clutch C1 is slipped in the same manner as described above. Thus, the auxiliary transmission unit 14 is characterized in that all functions are achieved with a small number of rotating elements. When the drive source is switched from the motor generator MG2 to the engine 10 during reverse travel, the brake B1 remains unchanged, and there is no need to switch the operation of the friction engagement device.
[0024]
Returning to FIG. 1, the continuously variable transmission 16 of the continuously variable transmission 17 includes an input-side variable pulley 60 having a variable effective diameter provided on the input shaft 56 and a variable effective diameter provided on the output shaft 62. This is a belt-type continuously variable transmission including an output-side variable pulley 64 and a transmission belt 66 wound around the input-side variable pulley 60 and the output-side variable pulley 64. The transmission belt 66 functions as a power transmission member that transmits power by friction while being pressed between the pair of input-side variable pulley 60 and output-side variable pulley 64. The input-side variable pulley 60 includes a fixed rotating body 60a fixed to the input shaft 56 and a movable rotating body 60b provided on the input shaft 56 so as to be movable in the axial direction and not rotatable about the axis. A clamping pressure is applied by the input side hydraulic cylinder. The output-side variable pulley 64 also includes a fixed rotating body 64a fixed to the output shaft 62, and a movable rotating body 64b provided on the output shaft 62 so as to be movable in the axial direction and not rotatable about the shaft. The clamping pressure is applied by the output side hydraulic cylinder that does not. Generally, the input side hydraulic cylinder has a gear ratio γ of the continuously variable transmission 16._CVT(= Rotational speed N of the input shaft 56_IN/ Rotation speed N of output shaft 62_OUT), And the output hydraulic cylinder is used to optimally control the tension of the transmission belt 66.
[0025]
The vehicle is provided with a secondary battery 68 such as a rechargeable lead-acid battery and a fuel cell 70 that generates power based on a fuel such as hydrogen. The secondary battery 68 and / or the fuel cell 70 can be selectively used as a power source for the motor generator MG1 and / or the motor generator MG2 by the switching device 72.
[0026]
FIG. 5 illustrates a signal input to the electronic control device 80 and a signal output from the electronic control device 80. For example, the electronic control unit 80 includes an accelerator opening θ that is an operation amount of an accelerator pedal._ACC, The rotational speed N of the output shaft 62 of the continuously variable transmission 16._OUTVehicle speed signal corresponding to the engine speed N_E, A supercharging pressure P in the intake pipe 50_a, A signal representing the air-fuel ratio A / F, and the operation position S of the shift lever SH_HA signal representing, etc. is supplied from a sensor (not shown). Further, the electronic control unit 80 receives an injection signal for controlling the amount of fuel injected from the fuel injection valve into the cylinder of the engine 10, and the gear ratio γ of the automatic transmission 16._CVTA shift command signal for controlling a shift solenoid that drives a shift valve in the hydraulic control circuit 78, a tension command signal for controlling the tension of the transmission belt 66 of the continuously variable transmission 16, and the number of cycles of the engine 10. A signal or the like is output.
[0027]
The electronic control unit 80 includes a so-called microcomputer including a CPU, a ROM, a RAM, an input / output interface, and the like, and performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. By doing so, the gear ratio γ of the continuously variable transmission 16_CVTShift control for automatically switching to the optimum value, tension control for controlling the tension of the transmission belt 66 of the continuously variable transmission 16 to the optimum value, supercharging pressure control, air-fuel ratio control, cylinder selection switching control, operation cycle switching control And so on. For example, in the shift control described above, the accelerator opening θ can be calculated from a well-known relationship (shift diagram) stored in advance._ACC(%) And the target speed ratio γ based on the vehicle speed V_CVT ^*To determine the actual gear ratio γ_CVTIs the target gear ratio γ_CVT ^*The input side hydraulic cylinder is operated so as to coincide with. In the above tension control, the actual throttle valve opening θ is determined from the relationship stored in advance._TH, Engine speed N_E, And the gear ratio γ of the auxiliary transmission 14_AThe basic clamping pressure is calculated based on the actual hydraulic oil temperature T_OILThe basic clamping pressure is corrected based on the torque vibration width or the number of engine 10 cycles, and the output side hydraulic cylinder is operated to clamp the transmission belt 66 with the corrected clamping pressure and control the tension. Further, in the cylinder selection switching control, the number of operating cylinders is reduced or the operation of the cylinders whose operation of the valve mechanism is determined to be abnormal is stopped when the vehicle is lightly loaded to improve fuel efficiency. In the operation cycle switching control, the number of operation cycles of the engine 10 is determined based on the actual vehicle speed V and the accelerator opening θ from a map (relation) stored in advance, and the variable valve mechanism is set so as to be the number of operation cycles. The operation timing of 28 is controlled.
[0028]
FIG. 6 is a functional block diagram illustrating the main part of the control function of the electronic control unit 80. In FIG. 6, the gear ratio calculation means 84 is a gear ratio γ of the continuously variable transmission unit 16._CVT(= N_IN/ N_OUT) Is the input shaft rotational speed N of the continuously variable transmission 16._INAnd output shaft rotation speed N_OUTCalculate based on The engine output torque estimating means 86 has a throttle opening θ_TH, Engine speed N_EOutput torque T of engine 10 based on_EIs calculated (estimated). For example, the actual throttle opening θ_THAnd engine speed N_EBased on the engine output torque T_EIs calculated. When the sub-transmission unit 14 is not provided, it also functions as input torque estimation means for the continuously variable transmission unit 16. The input torque T of the continuously variable transmission unit 16_INIs the engine output torque T_EThe gear ratio γ of the auxiliary transmission unit 14_AIt is calculated by multiplying. The oil temperature detecting means 88 is a temperature of hydraulic oil used in the continuously variable transmission 17, that is, a temperature T of hydraulic oil in the hydraulic control circuit 78._OILIs detected. The operation cycle number determination means 92 is based on a signal for instructing the actual operation cycle number of the engine 10, for example, whether it is a 4-cycle operation or a 2-cycle operation, and a cycle number output from the electronic control unit 80. judge. Torque vibration reducing means 92 outputs torque vibration having substantially the same amplitude and opposite phase as that of torque vibration output from engine 10 or having substantially the same amplitude as torque vibration output from engine 10. The torque vibration input from the engine 10 to the continuously variable transmission 16 is attenuated by causing the motor generator MG2 to generate load torque having the same phase. The torque vibration output from the engine 10 increases as the number of cycles increases, the engine load increases, and the engine speed N increases._EThere is a property that becomes larger as the value decreases. The torque vibration detecting unit 94 detects the torque vibration input to the continuously variable transmission 17, that is, the torque vibration attenuated by the torque vibration reducing unit 92, the torque detected by a torque sensor (not shown), and the continuously variable transmission 17. Is detected based on the input shaft rotational acceleration, the anti-phase torque vibration generated from the motor generator MG2, the in-phase load torque, or the like.
[0029]
  The clamping pressure control means 96 is an input torque vibration of the continuously variable transmission 17, preferably an input torque vibration of the continuously variable transmission section 16 input after the torque vibration is attenuated by the torque vibration reducing means 92, or related thereto. The variable pulleys 60, 64 with respect to the transmission belt (power transmission member) 66 of the continuously variable transmission 16 are set to be as small as possible within a range in which the transmission belt 66 does not slip, based on the torque vibration related parameters. Is changed, that is, the tension of the transmission belt 66 is changed. For example, the clamping pressure with respect to the transmission belt 66 is set to a small value within a range in which the transmission belt 66 does not slip at the maximum peak value of the input torque vibration of the continuously variable transmission unit 16. The magnitude (vibration width) of the input torque vibration input to the continuously variable transmission unit 16 isengineRotational speed N_EAs the torque vibration attenuation amount by the motor generator MG2 becomes smaller,Number of operating cycles,Throttle opening θ_TH, The gear ratio γ of the auxiliary transmission 14_AThe larger the is, the greater the change in relation to it._TH, Accelerator engine 10 operation cycle, engine speed N_E, Torque vibration attenuation amount by motor generator MG2, gear ratio γ of auxiliary transmission 14_AAnd the like correspond to the torque vibration related parameters. Therefore, the clamping pressure control means 96 is provided with the engine 10 determined by the operation cycle number determination means 90.engineRotational speed N_EAs the torque vibration attenuation amount by the motor generator MG2 becomes smaller,Number of operating cycles,Throttle opening θ_THThe larger the is, the speed ratio γ of the auxiliary transmission unit 14_AAs the value increases, the clamping pressure on the transmission belt 66 is changed to a larger value.
[0030]
In the continuously variable transmission 16, slipping is likely to occur when the viscosity of the hydraulic oil interposed between the transmission belt 66 and the variable pulleys 60 and 64 that sandwich the transmission belt 66 increases. The hydraulic oil temperature T detected by the oil temperature detecting means 88_OILThe hydraulic oil temperature T_OILThe pinching pressure on the transmission belt 66 is changed so that the pinching pressure increases as the lower the value.
[0031]
The clamping pressure control means 96 is preferably configured so that the transmission gear ratio γ of the actual continuously variable transmission unit 16 is determined from a previously stored relationship._CVTAnd input torque T of continuously variable transmission 16_IN(= T_E× γ_A7), for example, the basic clamping pressure determining means 98 for determining the basic clamping pressure shown in FIG. 7, and the basic clamping pressure determined by the basic clamping pressure determining means 98 is the input torque vibration of the continuously variable transmission 16 or its Related parameters and hydraulic oil temperature T_OILAnd a clamping pressure correcting means 100 for correcting based on at least one of the above. The clamping pressure correction means 100 does not execute the basic clamping pressure increase correction when the number of operating cycles of the engine 10 is small, for example, 2 cycles, but when the number of operating cycles is large (large), for example, 4 cycles, From the relationship stored in advance as shown in FIG. 8, FIG. 9, FIG. 10, or FIG. 11, the actual torque vibration width or the parameter related to torque vibration and the hydraulic oil temperature T_OILThe correction amount (rate), that is, the increase amount (rate) is determined based on the above, and the basic clamping pressure is determined using the correction amount so as to be a value between the basic clamping pressure and the maximum corrected clamping pressure in FIG. Correct (correct). This basic clamping pressure is the engagement pressure P of the output side hydraulic cylinder that applies thrust to the movable rotating body 64b of the output side variable pulley 64._OUTIt corresponds to.
[0032]
8 and 9, the transmission gear ratio γ of the auxiliary transmission unit 14_AAnd gear ratio γ of continuously variable transmission 16_CVTAnd the total gear ratio γ (= γ_A× γ_CVT) Is used as a parameter. In the continuously variable transmission 16 according to the present embodiment, as described above, the input side hydraulic cylinder uses the transmission ratio γ._CVTTherefore, in FIG. 8 and FIG. 9, the increase amount (rate) of the clamping pressure correction is increased as the speed ratio γ is reduced (high gear). In the continuously variable transmission 16, the transmission ratio γ_CVTIn FIG. 8 and FIG. 9, the clamping pressure correction increase amount (rate) is set to increase as the speed ratio γ increases (low gear). Further, the gear ratio γ of the auxiliary transmission unit 14_AFor any hydraulic cylinder, the gear ratio γ_CVTIs controlled, the gear ratio γ_AThe larger the value (low gear), the larger the clamping pressure correction increase amount (rate).
[0033]
The torque vibration reduction impossibility determination means 102 is in a state where the torque vibration reduction operation using the motor generator MG2 by the torque vibration reduction means 92 cannot be obtained, for example, a failure of the motor generator MG2, a secondary battery as a power source of the motor generator MG2, or 72, it is determined whether or not the motor generator MG2 cannot be operated to reduce torque vibration due to a failure of the fuel cell 70 or insufficient charge remaining. The clamping pressure correction means 100 of the clamping pressure control means 96 determines that the torque vibration reduction impossibility determination means 102 is in a state where the torque vibration reduction operation using the motor generator MG2 by the torque vibration reduction means 92 cannot be obtained. In such a case, the basic clamping pressure is corrected by adding a predetermined correction amount, for example, a maximum correction amount, to the basic clamping pressure so that the transmission belt 66 does not slip even when torque vibration is not reduced.
[0034]
FIG. 12 is a flowchart for explaining a main part of the control operation by the electronic control unit 80, that is, a holding pressure control routine of the continuously variable transmission 17, which is repeatedly executed at an extremely short cycle of about several milliseconds to several tens of milliseconds. In FIG. 12, in step (hereinafter, step is omitted) S1 corresponding to the operation cycle number determination means 90, it is determined whether or not the operation cycle of the engine 10 is four. If the determination at S1 is negative, the torque oscillation is a small operating cycle, and therefore, at S2 corresponding to the clamping pressure control means 96, for example, the basic belt clamping pressure shown in FIG. Pressure P of the output hydraulic cylinder to obtain_OUTIs output. However, when the determination of S1 is negative, that is, when the number of operating cycles of the engine 10 is four, the torque T output from the engine 10_E, That is, the fluctuation of the torque input to the continuously variable transmission 16 is large.
[0035]
In S3, it is determined whether or not the remaining amount of charge of the fuel cell 70 is sufficient. If the determination in S3 is negative, it is determined in S4 whether or not the remaining charge of the secondary battery 68 is sufficient. In the present embodiment, these S3 and S4 correspond to the torque reduction impossibility determining means 102 that determines whether or not the torque reduction operation by the motor generator MG2 cannot be obtained. When the determinations at S3 and S4 are both negative, the torque reduction operation by the motor generator MG2 cannot be obtained. Therefore, the torque reduction operation is obtained at S5 corresponding to the clamping pressure control means 96. In order to obtain the maximum correction belt clamping pressure, a maximum correction belt clamping pressure obtained by adding a preset maximum correction amount to the basic clamping pressure so that the transmission belt 66 does not slip even in the absence of the transmission belt 66 is determined. Engagement pressure P of the output side hydraulic cylinder_OUTIs output.
[0036]
However, if either of the above determinations in S3 and S4 is affirmed, in S6 corresponding to the torque vibration detecting means 94, the input to the continuously variable transmission 17 after the torque vibration is removed by the motor generator MG2. The torque vibration amount thus calculated is calculated based on the drive current of motor generator MG2, for example. Next, in S7 corresponding to the clamping pressure correcting means 100, the clamping pressure is as small as possible within a range in which the transmission belt 66 does not slip even in the presence of torque vibration input to the continuously variable transmission 16. For example, the torque vibration width or the torque vibration related parameter and the hydraulic oil temperature T input to the actual continuously variable transmission unit 16 from any of the previously stored relationships shown in FIGS. 8 to 11._OILThe correction amount (rate), that is, the increase amount (rate) is determined based on the above, and the basic clamping pressure is corrected (corrected) using the correction amount, and the corrected basic clamping pressure is obtained. Engagement pressure P of the output side hydraulic cylinder that applies thrust to the movable rotating body 64b of the side variable pulley 64_OUTIs regulated.
[0037]
  As described above, according to the present embodiment, the clamping pressure for the transmission belt (power transmission member) 66 of the continuously variable transmission 16 is changed by the clamping pressure control means 96 (S7) according to the operation cycle of the engine 10. Therefore, the holding pressure is made as small as possible while preventing the transmission belt 66 from slipping. For example, during low-cycle (two-cycle) operation, the clamping pressure against the power transmission member is relativelyLowIn the high cycle (4 cycles) operation, the clamping pressure on the power transmission member is relatively increased, so that the power transmission member is prevented from slipping according to the number of cycles during each operation, and the clamping force is as small as possible. Pressure. Thereby, the fuel consumption of the vehicle is improved.
[0038]
Further, according to this embodiment, the clamping pressure control means 96 changes the clamping pressure on the transmission belt 66 to a smaller value as the number of operating cycles of the engine 10 decreases. Since the pinching pressure against the transmission belt 66 is changed to a smaller value as the number decreases, the power loss of the continuously variable transmission is further reduced when the number of operation cycles of the engine 10 is reduced.
[0039]
Further, according to the present embodiment, the torque vibration reducing means 92 for reducing the vibration of the torque input from the engine 10 to the continuously variable transmission 17 is provided, and the torque vibration reduction amount by the torque vibration reducing means 92 becomes larger. The clamping pressure control means 96 reduces the clamping pressure of the continuously variable transmission unit 16 with respect to the transmission belt 66. Therefore, the clamping pressure with respect to the transmission belt 66 and the slippage of the transmission belt 66 according to the magnitude of torque vibration are prevented. As a result, the power loss of the continuously variable transmission 17, that is, the continuously variable transmission 16 is reduced as much as possible.
[0040]
Further, according to the present embodiment, the torque vibration reducing means 96 is input from the engine 10 to the continuously variable transmission unit 16 to the motor generator (electric motor) MG2 connected to the input shaft 56 of the continuously variable transmission unit 16. Therefore, the torque vibration input to the continuously variable transmission unit 16 is preferably reduced by canceling out the torque vibration of the opposite phase. The
[0041]
Further, according to this embodiment, the clamping pressure of the continuously variable transmission unit 16 against the transmission belt 66 is such that the input torque vibration of the continuously variable transmission unit 16 and the hydraulic oil temperature T_OILTherefore, the input torque vibration of the continuously variable transmission unit 16 and the hydraulic oil temperature T are changed._OILBy changing to an appropriate value according to the above, while preventing the transmission belt 66 from slipping, the clamping pressure on the transmission belt 66 and the power loss of the continuously variable transmission unit 16 resulting therefrom are reduced as much as possible.
[0042]
Further, according to the present embodiment, the clamping pressure control means 96 is provided with the gear ratio γ of the continuously variable transmission unit 16._CVTAnd input torque T_INBasic clamping pressure determining means 98 for determining the basic clamping pressure based on (input torque related information), and the basic clamping pressure determined by the basic clamping pressure determining means 98 are used as input torque vibration and hydraulic oil of the continuously variable transmission unit 16. Temperature T_OILTherefore, the basic clamping pressure determined by the basic clamping pressure determining means 98 is determined by the clamping pressure correcting means 100 so that the input torque vibration and the operation of the continuously variable transmission 16 are operated. Oil temperature T_OILTherefore, the slipping force of the continuously variable transmission unit 16 and the power loss of the continuously variable transmission unit 16 resulting therefrom are reduced as much as possible while preventing the continuously variable transmission unit 16 from slipping. In addition, there is an advantage that the basic clamping pressure is ensured and the vehicle can travel even if the correction is in a failed state due to some reason such as sensor abnormality.
[0043]
Further, according to this embodiment, the power of the engine 10 is input to the continuously variable transmission unit 16 via the auxiliary transmission unit (stepped transmission) 14, and the clamping pressure correcting means 100 is The basic clamping pressure is corrected based on the gear ratio of the step transmission unit 16. The torque input to the continuously variable transmission unit 16 is the gear ratio γ of the auxiliary transmission unit 14._AChange in accordance with the transmission ratio γ of the auxiliary transmission unit 14._ABy correcting the basic clamping pressure based on the above, the clamping pressure on the transmission belt 66 and the power loss of the continuously variable transmission unit 16 resulting therefrom are reduced as much as possible while preventing the transmission belt 66 from slipping.
[0044]
In addition, according to the present embodiment, the torque vibration reduction impossibility determining means 102 (S3, S4) for determining whether or not the torque vibration reduction by the torque vibration reducing means 92 cannot be obtained is provided. If the torque vibration reduction impossibility determination means 102 determines that the torque vibration reduction means 92 cannot reduce the torque vibration, the clamping pressure correction means 100 of the control means 96 has no torque vibration reduction. However, the basic clamping pressure is corrected by a predetermined correction amount so that the power transmission member does not slide. By doing so, the clamping pressure is controlled so that the power transmission member does not slip even when the torque vibration reduction means cannot reduce the torque vibration.
[0045]
As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.
[0046]
For example, the above-described continuously variable transmission unit 16 is a so-called belt-type continuously variable transmission in which a transmission belt 66 functioning as a power transmission member is wound around a pair of variable pulleys 60 and 64 whose effective diameter is variable. A pair of cones rotated around a common axis and a plurality of rollers capable of rotating around the axis intersecting the axis are sandwiched between the pair of cones, and the rotation center of the roller and the axis It may be a so-called traction type continuously variable transmission or the like in which the gear ratio is variable by changing the crossing angle with the. In this traction type continuously variable transmission, a roller sandwiched between a pair of cones functions as a power transmission member.
[0047]
In the above-described embodiment, the torque vibration reducing means 92 for reducing the torque vibration by the motor generator MG2 is provided. However, the motor generator MG2 and the torque vibration reducing means 92 are not necessarily provided.
[0048]
Further, in the above-described embodiment, the auxiliary transmission unit 14 having the forward / reverse switching and the forward two-speed shifting function is provided between the engine 10 and the continuously variable transmission unit 16. May be provided on the output side, and the sub-transmission unit 14 does not necessarily have to have a forward shifting function of two steps.
[0049]
In the above-described embodiment, the basic clamping pressure determining means 98 is the input torque T_INAnd gear ratio γ_AThe basic clamping pressure was determined based on the_THAnd engine speed N_EInput torque related parameters and gear ratio γ_ABased on the above, the basic clamping pressure may be determined.
[0050]
In the above-described embodiment, when the number of operating cycles of the engine 10 is two, the basic clamping pressure is used. When the number of operating cycles of the engine 10 is four, any one of FIGS. The clamping pressure correction increase amount (rate) is obtained from the relationship, and the basic clamping pressure is corrected to increase, thereby increasing the clamping pressure on the transmission belt 66. From the relationship including the number of engine cycles as a parameter, A clamping pressure increase correction value may be obtained.
[0051]
Further, in the vehicle of the above-described embodiment, the electromagnetic variable valve mechanism 28 in which the intake valve 20 and the exhaust valve 22 are driven and controlled by the electromagnetic actuators 24 and 26 is provided. Further, a variable valve mechanism or the like of a type in which a pulse motor or a servo motor that rotationally drives a cam for raising and lowering (lifting) the exhaust valve 22 and speed-controlling the output shaft of the pulse motor or the servo motor may be used.
[0052]
In addition, although not illustrated one by one, the present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.
[Brief description of the drawings]
FIG. 1 is a skeleton diagram illustrating a configuration of a vehicle power transmission device including a continuously variable transmission whose clamping pressure is controlled by a control device for a continuously variable transmission for a vehicle according to an embodiment of the present invention.
2 is a diagram for explaining a variable valve mechanism provided in each cylinder of the engine of FIG. 1. FIG.
3 is a diagram for explaining a configuration of an electromagnetic actuator provided in the variable valve mechanism of FIG. 2 to open and close an intake valve or an exhaust valve.
4 is a diagram for explaining a travel mode or a gear stage obtained by a combination of an operation position of a shift lever and an operation of a friction engagement device in the auxiliary transmission of FIG. 1;
5 is a diagram for explaining input / output signals of an electronic control device provided in the vehicle of the embodiment of FIG. 1; FIG.
6 is a functional block diagram illustrating a main part of a control function of the electronic control device of FIG.
7 is a diagram illustrating a basic clamping pressure calculated by a basic clamping pressure determination unit and a clamping pressure correction increase amount calculated by a clamping pressure correction unit in the clamping pressure control unit of FIG. 6; FIG.
FIG. 8 is a diagram showing an example of a relationship used for determining an increase in clamping pressure correction in the clamping pressure control unit, that is, the clamping pressure correction unit in FIG. 6;
9 is a diagram showing another example of the relationship used for determining the amount of increase in the clamping pressure correction in the clamping pressure control means, that is, the clamping pressure correction means in FIG. 6. FIG.
10 is a diagram showing another example of the relationship used for determining the amount of increase in the clamping pressure correction in the clamping pressure control means, that is, the clamping pressure correction means in FIG. 6. FIG.
11 is a diagram showing another example of the relationship used for determining the amount of increase in the clamping pressure correction in the clamping pressure control means, that is, the clamping pressure correction means in FIG. 6. FIG.
12 is a flowchart illustrating a main part of a control operation of the electronic control device of FIG.
[Explanation of symbols]
10: Engine
14: Sub-transmission unit
16: continuously variable transmission
17: Continuously variable transmission
90: Electronic control device (engine control device)
92: Torque vibration reducing means
96: clamping pressure control means
98: Basic clamping pressure determining means
100: clamping pressure correction means
102: Torque vibration reduction impossibility determination means

Claims (7)

A control device for a continuously variable transmission for a vehicle for controlling a clamping pressure with respect to a power transmission member of a continuously variable transmission to which power from an engine capable of changing an operation cycle is input,
The clamping force control means for changing the clamping pressure on the power transmitting member in accordance with the operating cycle of the engine, seen including,
The clamping force control means, the control device of Der Ru vehicle continuously variable transmission which changes to a smaller value squeezing force to said power transmitting member as the number of operating cycles of the engine is reduced. A control device for a continuously variable transmission for a vehicle for controlling a clamping pressure with respect to a power transmission member of a continuously variable transmission to which power from an engine capable of changing an operation cycle is input,
Torque vibration reducing means for reducing vibration of torque input from the engine to the continuously variable transmission;
A control device for a continuously variable transmission for a vehicle, comprising: a clamping pressure control means for reducing a clamping pressure with respect to a power transmission member of the continuously variable transmission as the amount of torque vibration reduction by the torque vibration reducing means increases. . The torque vibration reducing means causes the electric motor connected to the input shaft of the continuously variable transmission to generate a torque vibration having a phase opposite to that of the torque input from the engine to the continuously variable transmission. The control device for a continuously variable transmission for a vehicle according to claim 2 . The clamping force with respect to the power transmission member of the continuously variable transmission, continuously variable machine input torque vibration and Mu either for a vehicle according to claim 1 to 3 is intended to be changed on the basis of at least one of the hydraulic oil temperature Control device for step transmission. The clamping pressure control means includes a basic clamping pressure determining means for determining a basic clamping pressure based on a gear ratio of the continuously variable transmission and input torque related information, and a basic clamping pressure determined by the basic clamping pressure determining means. the continuously variable transmission input torque vibration and hydraulic oil temperature either control device for a continuously variable transmission for a vehicle in which of claims 1 to 4 which comprises a clamping pressure correcting means for correcting, based on at least one of. The continuously variable transmission includes a stepped transmission unit and a continuously variable transmission unit, and the power of the engine is input to the continuously variable transmission unit via the stepped transmission unit, and the clamping pressure correcting means 6. The control device for a continuously variable transmission for a vehicle according to claim 5 , wherein the basic clamping pressure is corrected based on a gear ratio of the stepped transmission unit and / or a gear ratio of the continuously variable transmission unit. Torque vibration reduction impossibility determining means for determining whether or not torque vibration reduction by the torque vibration reduction means cannot be obtained is provided, and the clamping pressure correction means of the clamping pressure control means determines that the torque vibration cannot be reduced. If it is determined by the means that the torque vibration cannot be reduced by the torque vibration reducing means, the basic correction amount is set at a predetermined correction amount so that the power transmission member does not slip even when the torque vibration is not reduced. The control device for a continuously variable transmission for a vehicle according to claim 6 , wherein the clamping pressure is corrected.

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