JP3279224B2 - Transmission control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a transmission mounted on a vehicle. For example, the present invention relates to a control device for a transmission mounted on a vehicle. In addition to the continuously variable transmission mechanism that variably controls the gear ratio by adjusting the width, a coaxial starting clutch is provided between the engine and the toroidal-type continuously variable transmission mechanism or general planetary gear type stepped transmission mechanism. It is suitable for things.

[0002]

2. Description of the Related Art For example, a control device for a belt-type continuously variable transmission is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-200 proposed by the present applicant.
No. 461 is disclosed. As disclosed in this prior art, in controlling the gear ratio variably by adjusting the groove width of the pulley, the working fluid pressure is supplied to two cones constituting the pulley in order to prevent the belt from slipping. ,
The thrust, that is, the pressing force, holds the belt between the two cones. Further, in this conventional technique, a torque converter, a forward / reverse switching mechanism, and the like are provided between the engine and the continuously variable transmission mechanism. Among them, the torque converter is a conventional one, but the forward / reverse switching mechanism is provided with a starting clutch such as a forward clutch or a reverse brake, which are engaged or disengaged by the supplied working fluid pressure. I do. Incidentally, the working fluid pressure supplied to these starting clutches is referred to as clutch pressure, and the working fluid pressurized by the pump is regulated by a clutch engagement control pressure regulating valve including, for example, a duty valve. In this case, the clutch pressure can be controlled by a duty ratio control signal to the duty valve. Further, in this conventional technique, for example, a working fluid supplied to a cylinder chamber of a pulley is pressed against the outside of the cylinder chamber by a centrifugal force generated by rotation of the pulley, thereby increasing the working fluid pressure in the cylinder chamber. That is, the invention relates to centrifugal pressure. More specifically, a fluid pressure obtained by subtracting the centrifugal pressure from the working fluid pressure supplied to the belt is treated as a fluid pressure to be controlled.

[0003]

Incidentally, the above-mentioned centrifugal pressure is actually also generated in a starting clutch such as the aforementioned forward clutch. Specifically, such a centrifugal pressure is proportional to the square of the rotation speed of the starting clutch, but in the case of a normal starting clutch, the viscosity of the working fluid is within a set range, that is, the working fluid When the temperature is a normal use environment, for example, a centrifugal pressure that is generated in the piston fluid chamber of the forward clutch is not a problem. However, when the viscosity of the working fluid is extremely high, that is, when the temperature of the working fluid is extremely low, the centrifugal pressure increases, and even if the actually supplied working fluid pressure is low, the start clutch is engaged. The situation is similar. That is, in a transmission in which the piston fluid chamber of the starting clutch is disposed on a shaft that rotates together with the engine, the transmission should not be performed when the temperature of the working fluid is low and the input rotation speed to the starting clutch is large. At that time, that is, even when the non-traveling range is selected, the output of the engine is transmitted.

[0004] The present invention has been developed in view of these problems, and it is an object of the present invention to provide a transmission control device that can prevent transmission of engine output when transmission should not be performed. Things.

[0005]

In order to solve the above-mentioned problems, a control apparatus for a transmission according to a first aspect of the present invention comprises:
Even if the non-travel range is selected, a piston fluid chamber of the starting clutch in the transmission is provided on the shaft that rotates together with the internal combustion engine, and the working fluid pressure to the starting clutch is regulated by the clutch engagement control pressure regulating valve. In the control device for a transmission, the working fluid temperature detecting means for detecting the temperature of the working fluid, the input speed detecting means for detecting the input speed to the starting clutch, and the input speed Based on the input rotation speed detected by the detection means, the transmission torque of the starting clutch generated when at least the temperature of the working fluid detected by the working fluid temperature detection means is equal to or lower than a predetermined low temperature predetermined value. , A non-running range detecting unit for detecting that the selected shift range is a non-running range, and a non-running range detected by the non-running range detecting unit. It is detected that a range and create
Due to the centrifugal pressure of the dynamic fluid, the output of the internal combustion engine
And the input rotation speed transmitted to the drive system is detected by the transmission torque detecting means when the temperature of the working fluid detected by the working fluid temperature detecting means is equal to or lower than a predetermined low temperature predetermined value. When the transmission torque of the starting clutch is equal to or greater than a predetermined value, input speed reducing means for reducing at least the input speed to the starting clutch is provided.

The starting clutch used here is, for example, a forward clutch mechanism, and the internal combustion engine is generally called an engine. In addition, the shift range of the automatic transmission generally set is the conventional P, R, N, D, 2, L (1).
In general, in a traveling range such as the R and D ranges, the starting clutch such as the clutch mechanism is originally engaged, and the engine output is to be transmitted.
Further, in the P range of the non-traveling range, an individual parking brake is applied and the engine output cannot be transmitted mechanically. Therefore, the N range is the non-running range state where the engine output should not be transmitted.

In the transmission control apparatus according to a second aspect of the present invention, the predetermined value of the transmission torque of the starting clutch is set to a value that causes the vehicle to generate a predetermined longitudinal acceleration. It is characterized by the following.

[0008] In the transmission control apparatus according to a third aspect of the present invention, the input speed reducing means includes an output reducing means for reducing the output of the internal combustion engine. Is what you do.

According to a fourth aspect of the present invention, in the transmission control apparatus, the piston fluid chamber of the starting clutch in the transmission is provided on the shaft that rotates together with the internal combustion engine even when the non-traveling range is selected. A control device for a transmission, wherein the working fluid pressure to the starting clutch is regulated by a clutch engagement control pressure regulating valve, wherein the working fluid temperature detecting means for detecting a temperature of the working fluid; Input rotation speed detection means for detecting the input rotation speed to the clutch, non-travel range detection means for detecting that the selected shift range is a non-travel range, and non-travel range detection means. Is detected and the centrifugal pressure of the working fluid
Internal combustion engine output from the starting clutch to the drive train
When the input rotation speed is transmitted, and the temperature of the working fluid detected by the working fluid temperature detecting means is equal to or lower than a predetermined low temperature predetermined value, the starting clutch detected by the transmitting torque detecting means. When the transmission torque is equal to or greater than a predetermined value, the motor further comprises an input rotation speed reducing means for reducing at least the input rotation speed to the starting clutch.

In the transmission control apparatus according to a fifth aspect of the present invention, the predetermined value of the transmission torque of the starting clutch is set to a value that causes the vehicle to generate a predetermined longitudinal acceleration. It is characterized by the following.

In the transmission control apparatus according to a sixth aspect of the present invention, the input speed reducing means includes an output reducing means for reducing the output of the internal combustion engine. Is what you do.

[0012]

According to the transmission control apparatus of the present invention, the non-traveling range in which the output of the engine (internal combustion engine) should not be transmitted is detected, and the operation at that time is performed. When the fluid temperature is equal to or lower than a predetermined low temperature value and the input rotation speed to the starting clutch is
Is the output of the engine due to the centrifugal pressure of the body a starting clutch?
When the transmission torque of the starting clutch detected from the input rotation speed is equal to or more than a predetermined value set in advance, at least the starting clutch is transmitted. , The centrifugal pressure of the working fluid generated in the piston fluid chamber can be reduced to prevent transmission of the engine output by the starting clutch.

Further, according to the transmission control apparatus of the second aspect of the present invention, the predetermined value of the transmission torque of the starting clutch is set to a value that causes the vehicle to generate a predetermined longitudinal acceleration. Thus, it is possible to prevent the vehicle from starting due to transmission of the engine output by the starting clutch.

According to the transmission control apparatus of the present invention, the starting clutch can be reduced by reducing the output of the internal combustion engine when reducing the input rotation speed to the starting clutch. And the transmitted engine output itself can be effectively reduced.

According to the transmission control apparatus of the present invention, the non-traveling range in which the output of the engine (internal combustion engine) should not be transmitted is detected, and the temperature of the working fluid at that time is detected. When the input rotation speed to the starting clutch is lower than the predetermined low temperature predetermined value and the working fluid
Engine output from the starting clutch
When the input rotation speed is transmitted to the drive system and is equal to or more than a predetermined value that generates a transmission torque of the starting clutch set in advance, by reducing at least the input rotation speed to the starting clutch, By reducing the centrifugal pressure of the working fluid generated in the piston fluid chamber, transmission of the engine output by the starting clutch can be prevented.

Further, according to the transmission control apparatus of the present invention, the predetermined value of the transmission torque of the starting clutch is set to a value that causes the vehicle to generate a predetermined longitudinal acceleration. Thus, it is possible to prevent the vehicle from starting due to transmission of the engine output by the starting clutch.

Further, according to the transmission control apparatus of the present invention, the starting clutch can be reduced by reducing the output of the internal combustion engine when reducing the input rotation speed to the starting clutch. And the transmitted engine output itself can be effectively reduced.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a transmission control apparatus according to an embodiment of the present invention.

FIG. 1 is a schematic diagram showing a continuously variable transmission and a control device therefor according to an embodiment of the present invention. First, the power transmission mechanism of this continuously variable transmission is described in Japanese Patent Application Laid-Open No. Hei 7-317895, previously proposed by the present applicant, except that the fluid coupling is changed to a torque converter. For the sake of equality, equivalent components will be briefly described with the same reference numerals. It should be noted that reference numeral 10 in FIG.
Is an engine, 12 is a torque converter, 15 is a forward / reverse switching mechanism, 29 is a V-belt type continuously variable transmission mechanism, 56 is a differential gear, and 66 and 68 are left and right drive shafts for front wheels.

A throttle valve 19 that opens and closes in accordance with the amount of depression of an accelerator pedal by a driver is provided in the intake pipe 11 of the engine 10. The throttle valve 19 is provided with a throttle opening sensor 303 for detecting its opening (hereinafter also referred to as throttle opening) TVO. Further, the output shaft 10a of the engine 10, the rotational speed (hereinafter, referred to as engine speed) the engine speed sensor 301 for detecting the N _E is attached. The engine control unit 200 controls, for example, the fuel injection amount, its timing, ignition timing, and the like according to the engine load and the vehicle speed, so that the rotation state of the engine 10 is controlled to an optimal state according to the running state of the vehicle. You. The engine control unit 200 includes a transmission control unit 300 described later.
When a fuel cut request signal is sent from the engine, the supply of fuel to a preset cylinder is cut off, the engine output itself is reduced, and at the same time the rotational speed is reduced. Also, the throttle opening sensor 303
The detection signal of the throttle opening TVO detected by the above indicates that the throttle opening TVO is large and the depression amount of the accelerator pedal is large. Further, the engine speed sensor 301 may be configured to detect an engine speed from an ignition ignition pulse of the engine.

The torque converter 12 connected to the output shaft 10a of the engine 10 has an existing lock-up mechanism. The left side of the illustrated lock-up facing is the apply-side fluid chamber 12a, and the opposite side thereof. ,
That is, the space between the lock-up facing and the torque converter cover becomes the release-side fluid chamber 12b, and the apply-side fluid chamber 1b
When the working fluid pressure to the release side fluid chamber 12b increases, the lock-up state occurs. Note that the output shaft of the torque converter 12
That is, the turbine output shaft 13 has an input rotation speed sensor 30 for detecting an input rotation speed (hereinafter simply referred to as input rotation speed) N _Pri from the forward / reverse switching mechanism 15 to the continuously variable transmission mechanism 29.
5 are attached. The forward / reverse switching mechanism 15 described later may control the so-called creep running force or the like when the accelerator pedal is not depressed, for example, by variably adjusting the engagement force of the forward clutch 40.
During normal traveling, the forward clutch 40 is completely engaged, so that the rotation speed of the turbine output shaft 13 is controlled by the input speed to the forward clutch 40 and the input speed N _Pri to the continuously variable transmission mechanism. Used as The working fluid supplied to the release-side fluid chamber 12b is drained through the apply-side fluid chamber 12a, and the drain of the working fluid supplied to the apply-side fluid chamber 12a is discharged from the release-side fluid chamber 12b. It is diverted to other cooling and lubrication systems. Therefore, the lock-up / unlock-up switching control is performed by switching the supply direction of the working fluid to the lock-up mechanism, not by switching the fluid path itself.

The forward / reverse switching mechanism 15 includes a planetary gear mechanism 17, a forward clutch 40, and a reverse brake 50. Among them, the planetary gear mechanism 17
Is configured to have a multi-stage pinion row, and a pinion carrier that supports these pinion rows is
Is connected to the drive pulley 16 of the continuously variable transmission mechanism 29, and a sun gear is connected to the turbine rotating shaft 13. The pinion carrier is provided with a forward clutch 4.
0 enables fastening to the turbine rotating shaft 13;
The ring gear of the planetary gear mechanism 17 can be fastened to the stationary part by the reverse brake 50. Therefore, when the forward clutch 40 is engaged by the working fluid pressure to the fluid chamber 40a, the drive shaft 14 is connected via the pinion carrier.
And the turbine output shaft 13 rotate at the same speed in the same direction. When the reverse brake 50 is engaged by the working fluid pressure to the fluid chamber 50a, the drive shaft 14 rotates at a constant speed in the opposite direction to the turbine output shaft 13 via a multi-stage pinion row. Here, the piston fluid chamber 40 of the forward clutch 40
a is the engine 1 via the torque converter 12
It will be on an axis that rotates with zero.

The drive pulley 16 constituting the continuously variable transmission mechanism 29 has a fixed cone 18 which rotates integrally with the drive shaft 14 and a V-shaped pulley groove which is disposed to face the same and has a V-shaped pulley groove. And a movable movable cone 22. The movable cone 22 of the drive pulley 16 is formed with a cylinder chamber 20 to which a working fluid pressure is supplied to sandwich the belt 24 between the movable cone 22 and the fixed cone 18. Further, a driven pulley 26 around which the belt 24 is wound in a pair with the driving pulley 16 has a fixed cone 30 which rotates integrally with a driven shaft 28 and a V-shaped pulley groove which is disposed opposite to the fixed cone 30. A cylinder formed with a movable cone 34 which is movable in the axial direction, and to which the working fluid pressure is supplied in order to clamp the belt 24 between the movable cone 34 and the fixed cone 30. A chamber 32 is formed.

The belt-type continuously variable transmission mechanism 29 uses a pinion 108a meshing with the rack 182 to
08, and the rack 182 and the movable cone 22 of the movable pulley 16 are connected by a lever 178.
The rotation of the step motor 108 is controlled by a drive signal DS _{/ M} from a transmission control unit 300 described later, thereby moving the movable cone 22 of the drive pulley 16 and the movable cone 34 of the driven pulley 26 in the axial direction. By changing the radius of the contact position with the belt 24, the rotation ratio between the driving pulley 16 and the driven pulley 26, that is, the gear ratio (pulley ratio) can be changed. In the pulley ratio contact position radius change control, for example, as described above, in the present embodiment, the movable cone 22 of the drive pulley 16 is moved to change the groove width thereof, and thereby the movable cone 34 of the driven pulley 26 is changed.
Are automatically moved to change the groove width. This is because the belt 24 is a push-type belt that mainly transmits a driving force in the pressing direction as described above. The push-type belt is configured by arranging well-known elements (thin plates) in the longitudinal direction or the winding direction of the belt.

The drive gear 46 fixed to the driven shaft 28 meshes with the idler gear 48 on the idler shaft 52, and the pinion gear 54 provided on the idler shaft 52 meshes with the final gear 44, Front and left and right drive shafts 66 and 68 are connected to the gear 44 via a differential 56. A vehicle speed sensor 302 for detecting the vehicle speed V _SP is attached to the final output shaft.

Next, a fluid pressure control device for the continuously variable transmission will be described. In the fluid pressure control device, the working fluid in the reservoir 130 is sufficiently boosted by the pump 101 rotated by the rotational driving force of the engine 10 and supplied to the actuator unit 100. The configuration inside the actuator unit 100 is the same as that described in Japanese Patent Application Laid-Open No. Hei 7-317895 proposed earlier by the present applicant.
The detailed illustration and description are omitted, and only the description of the valve configuration required in the present embodiment will be given. The fluid pressure control device is provided with a working fluid temperature sensor 306 that detects the temperature TMP of the working fluid in the reservoir 130.

The reference numeral 104 in FIG.
03 is operated directly by the mainly brake pressure P _BRK to the cylinder chamber 50a of the reverse brake 50 and the clutch pressure P _CL to the cylinder chamber 40a of the forward clutch 40
This is a manual valve for controlling the switching between. The select lever 103 detects the selected shift position and outputs a shift range signal S _RANGE corresponding to the detected shift position.
Is provided. By the way, this shift range signal S _RANGE is set to P, R, N, D, 2, according to the shift position of the actual vehicle.
The signal is equivalent to L.

Reference numeral 106 denotes a gear that is operated in accordance with the relative displacement between the step motor 108 and the movable cone 22 of the driving pulley 16, that is, the behavior of the lever 178, and mainly the state of gear shifting, that is, the required gear ratio. The driving pulley 106 depends on the relative relationship with the groove width of the driving pulley 16.
This is a shift control valve that controls the working fluid pressure (line pressure) P _{L (Pri)} to the side.

Reference numeral 128 denotes a lock-up which is driven by a drive signal D _{L / U} from a transmission control unit 300, which will be described later, and which mainly controls lock-up / unlock-up by the lock-up mechanism of the torque converter 12. This is a control duty valve. By the way, the lock-up control duty valve 128
Acts to lock up the torque converter 12 with a control signal with a large duty ratio and unlock with a control signal with a small duty ratio. Also, reference numeral 1
Reference numeral 29 denotes a clutch engagement control duty valve which is driven by a drive signal _DCL from a transmission control unit 300 described later and mainly controls the engagement force of the forward clutch 40 or the reverse brake 50. The clutch engagement control duty valve 129 acts to engage the forward clutch 40 or the reverse brake 50 with a control signal having a large duty ratio, and release the engagement with a control signal having a small duty ratio. The clutch engagement control duty valve 129 supplies an appropriate working fluid pressure as a clutch pressure to the forward clutch 40 in accordance with a calculation process of FIG.
In the N range, since the output of the engine must not be transmitted to the continuously variable transmission mechanism 29, the working fluid pressure is not supplied, that is, the clutch pressure is set to 0 (MPa).

Reference numeral 120 denotes a transmission controller to be described later.
Drive signal D from troll unit 30_PLDriven by
In order to clamp the belt 24 as described above,
The working fluid pressure applied to the driven pulley 26 and the drive pulley 16
Below, this fluid pressure is also referred to as line pressure) P_LControl
And a line pressure control duty valve 120. In addition,
In the cited publication, this duty valve 120 is
It is a duty valve for fire. This is this due
The output pressure from the tee valve 120
The pilot pressure of a pilot pressure regulating valve called a fire valve
And as a result, the pressure modifier valve
Output pressure acts as the pilot pressure of the line pressure regulating valve
And a line formed upstream of the line pressure regulating valve
Pressure P_LThis is for adjusting the pressure. However, this explanation
As is clear from FIG.
Controlling the duty ratio, indirectly,
P _LCan be controlled. This also
In the present embodiment, as shown in FIG.
To the line pressure control duty valve 120
Control signal or drive signal duty ratio D / T_PLincrease of
(Target) line pressure P_{L (OR)}Increases linearly
Shall be. By the way, the pressure modifier
When the output pressure from the valve is increased, the original clutch pressure and
At the same time, increase the lockup pressure of the LUC converter
(Different slopes and intercepts)
You.

The transmission control unit 300
A microcomputer 310 as control means for outputting a control signal for controlling the continuously variable transmission mechanism 29 and the actuator unit 100 by executing, for example, an arithmetic process shown in FIG. The control circuit 310 includes drive circuits 311 to 314 that convert the control signal output from the drive signal to an actual actuator, that is, drive signals suitable for the step motor 108 and the duty valves 120, 128, and 129.

Among them, the microcomputer 31
0 denotes an input interface circuit 310a having, for example, an A / D conversion function, an arithmetic processing device 310b such as a microprocessor, and a storage device 310c such as a ROM and a RAM.
And an output interface circuit 310d having a D / A conversion function, for example. The microcomputer 310 obtains the rotation angle, that is, the position of the step motor 108 which controls the actual gear ratio by performing the arithmetic processing described in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 7-317895, and the position is achieved. Pulse control signal S
And outputs the _{S / M,} determine the optimum line pressure P _L to pinch the belt 24, calculates a duty ratio D / T _PL of the line pressure control duty valve 120 required to achieve it, and it outputs the line pressure control signal S _PL corresponding to the line pressure control duty ratio D / T _PL, or optimal fluid pressure to lock up / lockup control of the lockup mechanism of the torque converter 12 (hereinafter , Which is also simply referred to as torque converter pressure) P _{T / C} is determined, and a lock-up control duty valve 1 necessary to achieve the P _{T / C} is obtained.
28 of calculating the duty ratio D _/ T L / _U, and outputs the lock-up control signal S _{L / U} in accordance with the lock-up control duty ratio D _/ T L / _U, for example not depressed the accelerator pedal Working fluid pressure (hereinafter also referred to simply as clutch pressure) P that is optimal for creep running of the vehicle in the state
_CL is obtained, a duty ratio D / T _CL of the clutch engagement control duty valve 129 required to achieve the _CL is calculated, and a clutch engagement control signal S _CL corresponding to the clutch pressure control duty ratio D / T _CL is calculated. Output.

The drive circuit 311 converts the pulse control signal S _{S / M} into a drive signal D _{S / M} suitable for the step motor 108, and the drive circuit 312 outputs the line pressure control signal S _PL
To the drive signal D _PL suitable for the line pressure control duty valve 120, and the drive circuit 313 outputs the lock-up control signal S
_{L / U} is used as the drive signal D _{L / U} suitable for the lock-up control duty valve 128, and the drive circuit 314 uses the clutch engagement control signal S _CL as the clutch engagement control duty valve 129.
Are converted into drive signals _DCL suitable for the output, and output.

For example, the form of the control signal or the pulse control signal corresponding to the duty ratio already satisfies the desired duty ratio and the number of pulses, and the driving circuits 311 to 31
Reference numeral 4 merely performs electrical processing such as amplifying the signal, but does not process the signal itself.

The engine control unit 200 also has its own microcomputer, which communicates with the microcomputer 310 of the transmission control unit 300 so that the engine and the transmission can be controlled according to the vehicle running state. It is configured to control to an optimum state. In the present embodiment, the supply of fuel to the preset cylinder is cut off for a predetermined time in response to the fuel cut request signal from the transmission control unit 300 as described above.

Next, a schematic configuration of the entire shift control of the present embodiment will be described in accordance with a general flow calculation process shown in FIG.
This calculation process is basically a simple summary of the shift control described in JP-A-7-317895 in a state where the D range is selected and there is no request from the engine control unit side. Yes, the details will be referred to the gazette, and only the outline of the general flow will be described here. This calculation process is executed as a timer interrupt process at every predetermined sampling time (for example, 10 msec) ΔT. Note that, in the subsequent arithmetic processing, any step for communication is not particularly provided, but a necessary program or map or necessary data in the arithmetic processing device 310b is read from the storage device 310c as needed.
Conversely, the data calculated by the arithmetic processing unit 310b is updated and stored in the storage device 310c as needed.

In this calculation process, first, in step S1,
The vehicle speed V from the vehicle speed sensor 302 _SP,Engine RPM
Engine speed N from sensor 301_E, Input rotation speed
Input speed N from sensor 305_Pri, Throttle opening
Throttle opening TVO from the sensor 303 and the inhibitor
Range signal S from the data switch 304_RANGERead
Put in.

[0038] and then proceeds to step S2, according to each individual arithmetic process, the vehicle speed V _SP, and calculates the current transmission ratio C _P from the input rotation speed N _Pri. Specifically, the output speed N _Sec of the continuously variable transmission mechanism 29 is obtained by dividing the vehicle speed V _SP proportional to the final output shaft rotation speed by the so-called final reduction ratio n from the continuously variable transmission mechanism 29 to the final output shaft. Is obtained, the current gear ratio C _P can be obtained by calculating the ratio of the input rotation speed N _Pri to this.

Next, the process proceeds to step S3, where the throttle opening TV is set in accordance with individual calculation processing such as control map search.
Of O, it calculates the engine torque T _E from the engine speed N _E. Specifically, as shown in FIG. 4, for example, the throttle opening TVO is used as a parameter and the engine speed N _E
Calculating a current engine torque T _E from the output characteristic diagram of the engine torque T _E corresponding to.

Next, the process proceeds to step S4, where individual computations are performed.
According to the processing, the line pressure P_LControl. concrete
To convert the control map shown in Fig. 5 to a torque converter.
Is calculated, and this torque ratio t is calculated by the engine.
Torque T_EAnd input torque T_PriIs calculated, then
From the control map as shown in FIG._PriPassing
And current gear ratio C_PReference line pressure P according to_L0Calculate
You. Here, from the viewpoint of belt durability, the line pressure P_LIs small
The belt 24 is preferable, but the torque to be transmitted to the belt 24 is
To prevent the belt from slipping.
And the torque is the gear ratio C
_PAnd / or the input torque T_PriIs large
As it is large, increase the belt clamping force by that much
This reference line pressure P_L0Need to be larger. Change
The reference line pressure P_L0From the output rotational speed N_SecTo
Proportional centrifugal pressure P_L1Target line to control the reduced value of
Pressure P _L0RAnd the corresponding line pressure control signal S_PLCreate
Output.

Next, the flow shifts to step S5, where lock-up control is performed in accordance with individual arithmetic processing. In particular,
For example, a lock-up vehicle speed V _ON and an unlock-up vehicle speed V _OFF according to the vehicle speed V _SP and the throttle opening TVO are set from a control map as shown in FIG. 7, and in principle, if the vehicle speed V _SP is higher than the lock-up vehicle speed V _ON lockup and creating outputs the control signal S _{L / U} so that lockup if lockup vehicle speed V _OFF below, especially when transition to the lock-up side, and the engine speed N _E at that time When the difference between the input rotation speed N _Pri and the turbine output shaft rotation speed is large, the duty ratio D / T _{L / U} is increased with a relatively large gain corresponding to the difference value, and the difference value between the two. Becomes smaller, that is, when the lock-up tends to occur, the duty ratio D / T is changed by a relatively small predetermined value.
Increase _{L / U} to mitigate shock during full lock-up transition.

Next, the process proceeds to step S6, and the attained speed ratio _CD is calculated according to individual calculation processing such as control map search. The goal transmission ratio C _D achieves the current engine speed N _E and a vehicle speed V _SP and the throttle opening TVO, the most ideal speed ratio of the continuously variable transmission mechanism 29, in particular 8 as shown in, if set speed ratio C, 3 person coincide perfectly, while satisfying the vehicle speed V _SP and the engine speed N _E at that time, the amount of depression of the accelerator pedal by the driver, i.e. the throttle opening Acceleration corresponding to TVO can be obtained. Here, for example, FIG. 8 reaches the gear ratio C _D
Assuming that the control map is used to set the speed, a straight line having a constant slope passing through the origin becomes a certain speed change ratio. Large, that is, the maximum gear ratio C
On the other hand, the straight line which is _Lo and has the smallest inclination may be considered to have the smallest reduction ratio of the entire vehicle, that is, the D range minimum speed ratio _CDHi .

Next, the routine proceeds to step S7, where the target gear ratio C _R is calculated according to the individual calculation processing. Specifically, in principle the goal transmission ratio C _D is greater if the downshift direction from the current transmission ratio C _P, if smaller upshift direction, for example, the fastest shift speed dC current transmission ratio C _{P R} / the gear ratio after dt or smallest time constant τ predetermined sampling time and shift with ΔT set as the target speed ratio C _R. However, when the throttle opening TVO changes from the state close to the fully open state to the closing direction, that is, when the accelerator pedal is released, the shift speed dC _R / dt is slightly reduced or the time constant τ is slightly increased. Therefore, when the accelerator pedal is released, the speed of change of the throttle opening in the closing direction is fast and the amount of change of the throttle opening in the closing direction is large, so that the speed change rate dC _R / dt is further reduced or the time constant τ is reduced. The speed ratios are further increased, and the target speed ratios _CR are set respectively.

Next, the processing shifts to step S8, where individual calculations are performed.
The clutch engagement control is performed according to the processing. In particular,
Vehicle speed V in principle_SPIs greater than the creep control threshold.
Fasten latch 40, vehicle speed V_SPIs below the creep control threshold
And the throttle opening TVO is a fully closed threshold value for creep control.
If so, the control signal S is issued to cancel the fastening._CLCreate and output
But the vehicle speed V_SPIs less than the creep control threshold and the slot
If the opening TVO is less than the fully closed threshold,
Engine rotation speed N_EAnd input rotation speed N_Pri, That is, the turbine
The gain is inversely proportional to the difference between the
Tee ratio D / T _CLBy setting the
Engage clutch when vehicle is easy to creep due to sound
Reduce the force and engage the clutch when creeping is difficult
I try to strengthen my strength.

Next, the flow shifts to step S9, where the gear ratio control is performed in accordance with the individual arithmetic processing, and then the program returns to the main program. Specifically, the set target gear ratio C
_{For R} , the total number of pulses and the number of pulses are set to the unit time value for shifting at the shift speed dC _R / dt or time constant τ at that time, and the pulse control signal S _{S / M} satisfying both of them is set. And then returns to the main program.

Next, a description will be given, with reference to the flowchart of FIG. 9, of the arithmetic processing in which the timer interrupt processing is individually performed at the same sampling time ΔT in parallel with the arithmetic processing of FIG. In this calculation process, first, in step S11, the shift range signal S _RANGE , the working fluid temperature TMP, and the input rotation speed N _Pri are read.

[0047] and then proceeds to step S12, the read filled-in shift range signal S _RANGE is N-range, i.e. it is determined whether the non-driving range, the shift range signal S _RANGE is in N range If there is, step S
Then, the process returns to the main program. In step 13, it is determined whether or not the read working fluid temperature TMP is equal to or lower than a predetermined value TMP ₀ set at a low temperature of, for example, about −10 ° C., and the working fluid temperature TMP is set to a predetermined value. Value TMP ₀
If so, the process proceeds to step S14; otherwise, the process directly returns to the main program.

[0048] At step S14, according to each individual arithmetic process to calculate the transmission torque (capacity) T _TR due to centrifugal pressure generated in the forward clutch 40 is starting clutch. Specifically, before reaching step S14, in step S13, the working fluid temperature TMP is set to the predetermined low temperature value TMP _0.
Since it is known that the viscosity of the working fluid is accordingly high, as shown in FIG. 10, for example, as shown in FIG. 10, the rotational speed of the forward clutch 40, which is the starting clutch, depends on the viscosity of the working fluid. That is, the transmission torque (capacity) T _TR is calculated from the centrifugal pressure proportional to the square of the input rotation speed N _Pri . In other words, the transmission torque (capacity) T _TR is such that the working fluid having a low viscosity at a high temperature is pressed to the outside by rotating at a high speed in the fluid chamber 40a of the forward clutch 40, and is equal to the square value of the rotation speed. When the piston is pressed by the corresponding fluid pressure, that is, centrifugal pressure, the forward clutch 4
0 is the transmittable torque (strictly speaking, its capacity). In the characteristic diagram shown in FIG. 10, the transmission torque _TTR is not generated unless the input rotation speed N _Pri is increased to a certain degree or more because of the so-called play of the forward clutch 40.

Next, the process proceeds to step S15, where it is determined whether the calculated transmission torque (capacity) T _TR is equal to or greater than a predetermined value T _TR0 , and the transmission torque (capacity) T _{TR is determined.} Is greater than or equal to the predetermined value T _TR0 , the step S
The process proceeds to step 16; otherwise, the process returns to the main program. Here, the output of the engine is transmitted by the forward clutch 40, the driving force corresponding to the transmission ratio C _P of the continuously variable transmission mechanism 29 at that time and its transmission torque T _TR, one to the vehicle predetermined longitudinal acceleration G _X is generated (acts). In this case, the gear ratio C _P are selected by the continuously variable transmission mechanism 29 Since N-range the maximum speed ratio C
_{Hi is} constant, so the transmission torque T _TR and the longitudinal acceleration G _X
Has a linear relationship as shown in FIG. Therefore,
For example, if the upper limit of the transmission torque T _TR when the upper limit value of the longitudinal acceleration G _X without discomfort even when acting on the vehicle and a predetermined value G _X0 in the N range and the predetermined value T _TR0, such longitudinal Only when the acceleration G _X (G _X0 ) is likely to occur, the program shifts to the next step S16.

In step S16, a fuel cut request signal is output to the engine control unit 200 in accordance with the individual arithmetic processing, and the process returns to the main plum.

Next, the operation of the present embodiment will be described.
However, the outline of the shift control is described in the above-mentioned Japanese Patent Application Laid-Open No. 7-317895.
It is omitted here because it is the same as that described in the gazette
In particular, the fuel cut request system accompanying the arithmetic processing of FIG.
The operation of the control will be described in detail. In this calculation process,
The selected shift range is the N range,
Transmission to the drive train, including the continuously variable transmission.
In the non-running range and the working fluid temperature TMP
For example, a low temperature predetermined value TMP of about −10 ° C.₀Is the following,
Moreover, the input rotation speed N_PriTransmission torque T calculated from_TRBut,
Predetermined longitudinal acceleration predetermined value G_X0Drive the vehicle
Predetermined value T_TR0When it is over, the engine control
Request signal to the fuel cell unit 200
Is output. Thereby, the output of the engine is reduced.
As the rotation speed decreases,
Input speed N to switch 40_PriBy reducing
Transmission torque T of forward clutch 40_TRMake the car smaller
Longitudinal acceleration G acting on both _XSmaller.

As described above, the low-temperature working fluid has a high viscosity. When the high-viscosity working fluid is rotated at a high speed in the fluid chamber 40a of the forward clutch 40, the working fluid is centrifugally acted on by the centrifugal force. The fluid pressure is increased by being pressed outward. The increase in the fluid pressure is the centrifugal pressure, and the centrifugal pressure acts on the piston, thereby engaging the forward clutch 40. If the forward clutch 40 is engaged in this manner, the output of the engine is transmitted to the drive system after the continuously variable transmission mechanism even in the N range and the supplied working fluid pressure is zero, As a result, the driving force acts on the driving wheels, and the vehicle is accelerated. Of course, the fluid chamber 40a of the forward clutch 40 has a sufficient volume, and a return spring (not shown) also generates a sufficient reaction force.
Such a problem does not occur when the temperature of the working fluid is in the normal use range, but may occur when the temperature of the working fluid is extremely low, which can be said to be extraordinary.

In the case where the working fluid temperature is low and a predetermined acceleration is generated in the vehicle due to the centrifugal pressure in the forward clutch 40, the transmitted engine output is reduced. At the same time, by reducing the rotation speed, the input rotation speed N of the forward clutch 40 is reduced.
_Pri is reduced, thereby reducing the centrifugal pressure and releasing the engagement of the forward clutch 40, thereby reducing the acceleration generated in the vehicle.

As described above, this embodiment is an embodiment of the transmission control device according to claims 1 to 3 of the present invention. The forward clutch 40 corresponds to a starting clutch of the present invention. Similarly, the clutch engagement control duty valve 129 constitutes a clutch engagement control pressure regulating valve,
The working fluid temperature sensor 306 and step S11 of the calculation processing in FIG. 9 constitute a working fluid temperature detection means, and the input rotation speed sensor 305 and step S11 of the calculation processing in FIG. 9 constitute an input rotation number detection means. Step S14 of the calculation processing of FIG. 9 constitutes the transmission torque detecting means, steps S11 and S12 of the inhibitor switch 304 and the calculation processing of FIG. 9 constitute the non-traveling range detection means, and steps S12 and S12 of the calculation processing of FIG. S13, step S15, and step S16 constitute output reduction means and input rotation speed reduction means.

Next, a second embodiment of the transmission control device of the present invention will be described with reference to FIG. The main configuration of the vehicle in this embodiment is the same as that in FIG. 1 of the first embodiment. The main control of the continuously variable transmission is the same as the general flow shown in FIG. 3 of the first embodiment,
Further, various control maps used for the same are the same as those shown in FIGS. 4 to 8 of the first embodiment. on the other hand,
Instead of the arithmetic processing of FIG. 9 performed in parallel with the general flow of FIG. 3, the arithmetic processing shown in the flowchart of FIG. 12 is executed. However, the calculation processing of FIG.
Is similar to the arithmetic processing described above, and some of the steps are equivalent. Therefore, the same reference numerals are given to the same steps, and the detailed description thereof will be omitted. Then, when listing the differences between the arithmetic processing of FIG. 9 and the arithmetic processing of FIG. 12, step S14 is deleted and step S15 is changed to step S15 ′.

More specifically, in step S15 ', when the read input rotational speed N _Pri is _{equal to} or more than the input rotational speed predetermined value N _Pri0 that generates the above-described predetermined value T _TR0 of the transmission torque (capacity). Then, the flow shifts to step S16 to output a fuel cut request signal.

The acceleration G _X set in advance as described above
(G _X0 ) to be transmitted (generated) to the vehicle
_{Since TR} (T _TR0 ) is proportional to the square value of the input rotation speed P _Pri , the input rotation speed N _Pri (N _Pri0 ) corresponding to the predetermined value T _TR0 of the transmission torque is also uniquely determined. Accordingly, the input rotation speed N _Pri is set to a predetermined value N _Pri0 of the input rotation speed for generating the predetermined acceleration value G _X0 , and the fuel cut is performed when the read input rotation speed N _Pri is _{equal to} or more than the predetermined value N _Pri0. In the present embodiment for outputting the request signal, similarly to the first embodiment, when the working fluid temperature is low and the predetermined acceleration is generated in the vehicle due to the centrifugal pressure in the forward clutch 40, _Reduces the input engine speed N _Pri of the forward clutch 40 by lowering the output of the transmitted engine and lowering the rotation speed thereof, thereby reducing the centrifugal pressure and engaging the forward clutch 40. And the acceleration generated in the vehicle can be reduced.

As described above, this embodiment is an embodiment of the transmission control device according to claims 4 to 6 of the present invention, and the forward clutch 40 corresponds to a starting clutch of the present invention. Similarly, the clutch engagement control duty valve 129 constitutes a clutch engagement control pressure regulating valve,
The working fluid temperature sensor 306 and step S11 of the calculation processing in FIG. 12 constitute the working fluid temperature detection means, and the input rotation speed sensor 305 and step S11 of the calculation processing in FIG.
Constitutes the input rotational speed detecting means, and the inhibitor switch 3
Steps S11 and S12 of the arithmetic processing of FIG. 04 and FIG. 12 constitute the non-traveling range detecting means, and steps S12, S13, and S of the arithmetic processing of FIG.
15 'and step S16 constitute output reduction means and input rotation speed reduction means.

In the above-described embodiment, only the transmission using the belt-type continuously variable transmission mechanism has been described in detail. However, the transmission mechanism itself may be anything, such as a toroidal type continuously variable transmission mechanism or a general planetary gear type stepped transmission. A transmission mechanism or the like can also be used. In other words, it is important that the piston fluid chamber of the starting clutch between the drive system and the engine after these transmission mechanisms is on the shaft that rotates with the engine.

Further, in the above-described embodiment, only those in which each control unit is constructed by a microcomputer are described in detail. However, the present invention is not limited to this, and may be configured by combining electronic circuits such as arithmetic circuits. Needless to say.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a continuously variable transmission and a control device thereof.

FIG. 2 is a control map for setting a duty ratio from a target line pressure to a line pressure control duty valve.

FIG. 3 is a flowchart illustrating an example of a calculation process executed by the transmission control unit of FIG. 1;

FIG. 4 is a control map for setting an engine torque from an engine speed using a throttle opening as a parameter.

FIG. 5 is a control map for setting a torque ratio from a torque converter input / output speed ratio.

FIG. 6 is a control map for setting a reference line pressure from a gear ratio using an input torque as a parameter.

FIG. 7 is a control map for setting a lockup vehicle speed and an unlockup vehicle speed from a vehicle speed and a throttle opening.

FIG. 8 is a control map for setting a gear ratio from a vehicle speed using a throttle opening as a parameter.

FIG. 9 is a flowchart showing a first embodiment of a calculation process performed by the transmission control device of the present invention.

FIG. 10 is an explanatory diagram showing a correlation between an input rotation speed to a starting clutch and a transmission torque.

FIG. 11 is an explanatory diagram showing a correlation between a transmission torque and a longitudinal acceleration generated in a vehicle.

FIG. 12 is a flowchart showing a second embodiment of the arithmetic processing performed by the transmission control device of the present invention.

[Explanation of symbols]

 10 is an engine 12 is a torque converter 16 is a drive pulley 19 is a throttle valve 20 is a cylinder chamber 24 is a belt 26 is a driven pulley 29 is a continuously variable transmission mechanism 32 is a cylinder chamber 108 is a step motor 120 is a line pressure control duty valve 128 Lock-up control duty valve 129 is a clutch engagement control pressure switching valve 200 is an engine control unit 300 is a transmission control unit 301 is an engine speed sensor 302 is a vehicle speed sensor 303 is a throttle opening sensor 304 is an inhibitor switch 305 is an input rotation Number sensor 306 is working fluid temperature sensor 310 is microcomputer

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-3-107667 (JP, A) JP-A-1-1155741 (JP, A) JP-A-2-159420 (JP, A) JP-A-8-108 200461 (JP, A) JP-A-7-317895 (JP, A) JP-A-5-1587 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 48/00-48 / 12 B60K 41/02 F02D 29/00

Claims (6)

(57) [Claims] 1. A piston fluid chamber for a starting clutch in a transmission provided on a shaft which rotates together with an internal combustion engine even when a non-traveling range is selected, and a working fluid pressure applied to the starting clutch for controlling clutch engagement. In a control device for a transmission configured to regulate the pressure by a pressure regulating valve, a working fluid temperature detecting means for detecting a temperature of the working fluid, and an input speed detecting means for detecting an input speed to the starting clutch. Based on the input rotation speed detected by the input rotation speed detection means, at least when the temperature of the working fluid detected by the working fluid temperature detection means is equal to or lower than a predetermined low temperature predetermined value. Transmission torque detection means for detecting the transmission torque of the clutch for use, non-traveling range detection means for detecting that the selected shift range is a non-traveling range,
The non-traveling range detecting means detects the non-traveling range and outputs the output of the internal combustion engine by the centrifugal pressure of the working fluid.
Input from the starting clutch to the drive train.
The transmission torque of the starting clutch detected by the transmission torque detecting means when the temperature of the working fluid detected by the working fluid temperature detecting means is equal to or lower than a predetermined low temperature predetermined value is preset. A transmission control device comprising at least an input rotation speed reducing means for reducing the input rotation speed to the starting clutch when the predetermined value is equal to or more than the predetermined value. 2. The transmission control device according to claim 1, wherein the predetermined value of the transmission torque of the starting clutch is set to a value that causes a vehicle to generate a predetermined longitudinal acceleration. 3. The transmission control device according to claim 1, wherein the input rotation speed reduction unit includes an output reduction unit that reduces an output of the internal combustion engine. 4. A piston fluid chamber for a starting clutch in a transmission provided on a shaft which rotates together with an internal combustion engine even when a non-traveling range is selected, and a working fluid pressure applied to the starting clutch is used for clutch engagement control. In a control device for a transmission configured to regulate the pressure by a pressure regulating valve, a working fluid temperature detecting means for detecting a temperature of the working fluid, and an input speed detecting means for detecting an input speed to the starting clutch. Non-traveling range detecting means for detecting that the selected shift range is the non-traveling range, and the non-traveling range detecting means detecting the non-traveling range and the centrifugal pressure of the working fluid.
Internal combustion engine output from the starting clutch to the drive train
When the input rotation speed is transmitted, and the temperature of the working fluid detected by the working fluid temperature detecting means is equal to or lower than a predetermined low temperature predetermined value, the starting clutch detected by the transmitting torque detecting means. A control device for a transmission, comprising: input speed reduction means for reducing at least the input speed to the starting clutch when the transmission torque is equal to or more than a predetermined value set in advance. 5. The transmission control device according to claim 4, wherein the predetermined value of the transmission torque of the starting clutch is set to a value that causes the vehicle to generate a predetermined longitudinal acceleration. 6. The control device for a transmission according to claim 4, wherein said input rotation speed reducing means includes an output reducing means for reducing an output of said internal combustion engine.