JP2004092522A - Engine output control device for variable speed system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accelerate with good responsiveness to stepping of an accelerator while causing no belt slip of a continuously variable transmission unit even when suddenly stepping on the accelerator. <P>SOLUTION: This engine output control device is provided with a variable speed means 40 for inputting driving force from an engine and changing the speed to output the driving force to driving wheels; a torque capacity computing means 61b for computing torque transmittable by the variable speed means, from the state of the variable speed means; an accelerator sudden stepping determining means 61f for determining whether the accelerator pedal is suddenly stepped on; and an engine output limiting means 60 for limiting the output of the engine when determining the sudden stepping of the accelerator pedal by the accelerator sudden stepping determining means and when the engine torque inputted to the variable speed means exceeds the transmittable torque computed by the torque capacity computing means. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine output control device of a vehicular transmission system suitably used for a power transmission system for transmitting a driving force of an engine of an automobile or the like to driving wheels.
[0002]
[Prior art]
2. Description of the Related Art As a transmission mounted on an automobile or the like, for example, a belt-type CVT (Continuously Variable Transmission) is conventionally known. The belt-type CVT includes a primary pulley for inputting the driving force of the engine, a secondary pulley for outputting the driving force to the driving wheels, a primary pulley and a secondary pulley. And a V-belt for transmission to the vehicle. Pulley groove widths of the primary pulley and the secondary pulley are variable by hydraulic pressure. At the time of shifting, by supplying or discharging hydraulic pressure to the primary pulley and the secondary pulley, the pulley groove width is adjusted, and the ratio (pulley ratio) of the contact radius (effective radius) of the V belt to the primary pulley and the secondary pulley is changed. The ratio of the number of revolutions between the input and output (speed change ratio) is adjusted.
[0003]
In this belt type CVT, it is important not to cause belt slippage in order to prevent a decrease in the durability of the belt. Therefore, the hydraulic pressure supplied to the primary pulley and the secondary pulley is increased as appropriate to increase the force with which the primary pulley and the secondary pulley clamp the V-belt, thereby increasing the torque capacity (the maximum torque that can be transmitted without the CVT slipping the belt). This prevents belt slippage.
[0004]
[Problems to be solved by the invention]
When the accelerator is suddenly depressed during traveling, it is necessary to increase the output of the engine and increase the torque capacity of the CVT in order to prevent belt slippage.
[0005]
However, as described above, the torque capacity of the CVT is increased by increasing the hydraulic pressure supplied to the primary pulley and the secondary pulley, so that the responsiveness is lower than the engine output.
[0006]
For this reason, conventionally, when the accelerator pedal is suddenly depressed, the engine output is limited so that a predetermined fixed time (at least a time sufficient to increase the torque capacity) does not exceed the minimum torque capacity that can be assumed. After a certain period of time, the engine output was increased.
[0007]
However, in this case, the torque responsiveness when the accelerator is depressed is deteriorated, and the acceleration performance is reduced.
[0008]
The present invention has been made in view of such a conventional problem. Even when the accelerator is suddenly depressed, the belt of the CVT unit does not slip and the accelerator is not depressed. It is an object of the present invention to provide a vehicle engine output control device capable of responsively accelerating.
[0009]
[Means for Solving the Problems]
The present invention solves the above problem by the following means. Note that, for easy understanding, reference numerals corresponding to the embodiments of the present invention are given, but the present invention is not limited thereto.
[0010]
According to a first aspect of the present invention, there is provided a speed changing means (40) for inputting a driving force from an engine, shifting the driving force and outputting the changed driving force to driving wheels, and a state in which the torque transmittable by the speed changing means is transmitted. A torque capacity calculating means (61b) calculated from the above, an accelerator rapid depression determining means (61f) for determining whether or not the accelerator pedal is suddenly depressed, and a sudden depression of the accelerator pedal are determined by the accelerator rapid depression determining means. And engine output limiting means (60) for limiting the output of the engine when the engine torque input to the transmission means exceeds the transmittable torque calculated by the torque capacity calculating means. I do.
[0011]
In a second aspect based on the first aspect, the transmission means (40) includes an input-side primary pulley (41) whose groove width changes according to oil pressure, and an output whose groove width changes according to oil pressure. Belt-type continuously variable transmission means comprising: a secondary pulley (42); a belt (43) wound around the primary pulley and the secondary pulley; and a pulley contact radius that varies according to the groove width. It is characterized by the following.
[0012]
In a third aspect based on the first or second aspect, the engine output limiting means (60) calculates an engine torque input to the speed change means based on an engine speed and an accelerator opening. It is characterized by.
[0013]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the accelerator rapid-depression determining means (61f) is configured to determine whether an amount of change in engine torque input to the speed change means is equal to or greater than a predetermined value. , It is determined that the accelerator pedal is suddenly depressed.
[0014]
[Action / Effect]
According to the first aspect, the output of the engine is limited when the accelerator pedal is rapidly depressed and the engine torque input to the speed change means exceeds the transmittable torque of the speed change means. The engine output can be appropriately adjusted even when the driver is stepping on the vehicle.
[0015]
In particular, according to the second aspect of the present invention, the belt-type continuously variable transmission means does not cause belt slippage, and can accelerate with good responsiveness to depression of the accelerator pedal.
[0016]
According to the third aspect, the engine torque input to the speed change means is calculated based on the engine speed and the accelerator opening, so that the engine torque can be easily calculated.
[0017]
According to the fourth aspect, when the amount of change in the engine torque input to the speed change means is equal to or greater than the predetermined value, it is determined that the accelerator pedal has been suddenly depressed, so that the determination can be made easily.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings and the like.
[0019]
FIG. 1 is a schematic configuration diagram showing an embodiment of an engine output control device of a vehicle transmission system according to the present invention.
[0020]
The vehicular transmission system 1 includes a hydraulic pump 10, a torque converter (hereinafter, abbreviated as "torque converter") 20, a forward / backward switching unit 30, and a CVT transmission unit 40, and is controlled by a control unit 60. The vehicle transmission system 1 receives a driving force from the engine 70, changes the driving force, and outputs the driving force to the driving wheels 80.
[0021]
The hydraulic pump 10 is driven by the engine 70 to pump oil. The pressure-fed oil is pressure-adjusted and sent to the forward / backward switching unit 30 and the CVT transmission unit 40, and is used for forward / backward switching and gear shifting.
[0022]
The torque converter 20 is provided between the engine 70 and the forward / backward switching unit 30, and transmits the driving force of the engine 70 by the flow of oil inside. The torque converter 20 has a lock-up mechanism for eliminating a rotation difference between the pump impeller and the turbine liner.
[0023]
The forward / backward switching unit 30 includes a planetary gear 31 that switches a power transmission path between the engine side and the CVT transmission unit side, a forward clutch plate 32, and a reverse clutch plate 33. The forward clutch plate 32 is connected to the forward clutch piston, and is fastened to the planetary gear 31 by the hydraulic pressure (forward clutch pressure) supplied to the forward clutch piston chamber 32a when the vehicle advances. The reverse clutch plate 33 is connected to the reverse clutch piston, and is fastened to the planetary gear 31 by the force of the hydraulic pressure (reverse clutch pressure) supplied to the reverse clutch piston chamber 33a when the vehicle reverses. Further, in the neutral position (neutral or parking), no hydraulic pressure is supplied, and both the forward clutch plate 32 and the reverse clutch plate 33 are released. When the forward clutch plate 32 is fastened to the planetary gear 31, forward rotation is output, and when the reverse clutch plate 33 is fastened to the planetary gear 31, reverse rotation is output.
[0024]
The forward clutch plate 32 and the reverse clutch plate 33 are exclusively engaged. When the vehicle is moving forward (range signal = D range), the forward clutch pressure is supplied to fasten the forward clutch plate 32 and the reverse clutch pressure is drained. And the reverse clutch plate 33 is released. On the other hand, when reversing (range signal = R range), the forward clutch pressure is connected to the drain, the forward clutch plate 32 is released, the reverse clutch pressure is supplied, and the reverse clutch plate 33 is engaged. At the neutral position (range signal = N range), the forward clutch pressure and the reverse clutch pressure are connected to the drain, and both the forward clutch plate 32 and the reverse clutch plate 33 are released.
[0025]
The CVT transmission unit 40 includes a primary pulley 41, a secondary pulley 42, and a V-belt 43.
[0026]
The primary pulley 41 is a pulley on the input shaft side for inputting the driving force of the engine 70. The primary pulley 41 has a fixed conical plate 41a that rotates integrally with the input shaft 41c, a V-shaped pulley groove disposed opposite to the fixed conical plate 41a, and a hydraulic pressure acting on the primary pulley (hereinafter, referred to as the primary pulley 41). And a movable conical plate 41b that can be displaced in the axial direction by “primary pressure”. The rotation speed (input rotation) of the primary pulley 41 is detected by a primary pulley rotation speed sensor 51.
[0027]
Secondary pulley 42 transmits the driving force transmitted by V-belt 43 to driving wheels 80 via idler gears and differential gears. The secondary pulley 42 has a fixed conical plate 42a that rotates integrally with the output shaft 42c, a V-shaped pulley groove disposed opposite to the fixed conical plate 42a, and a hydraulic pressure acting on the secondary pulley (hereinafter, referred to as a secondary pulley 42). A movable conical plate 42b that can be displaced in the axial direction according to “secondary pressure”). The pressure receiving area of the secondary pulley and the pressure receiving area of the primary pulley are equal or almost equal. The rotation (output rotation) speed of the secondary pulley 42 is detected by a secondary pulley rotation speed sensor 52. The vehicle speed is calculated from the rotation speed of the secondary pulley 42.
[0028]
V-belt 43 is wound around primary pulley 41 and secondary pulley 42, and transmits the driving force input to primary pulley 41 to secondary pulley 42.
[0029]
FIG. 2 is a block diagram showing the configuration of the control unit of the engine output control device of the vehicle transmission system according to the present invention.
[0030]
In the present invention, when the control unit 60 detects a sudden depression of the accelerator pedal, the control unit 60 suppresses the output of the engine to prevent the belt slippage of the CVT unit, and minimizes the output suppression. This is intended to perform acceleration with good responsiveness to depression of the accelerator.
[0031]
Hereinafter, the control unit 60, which is particularly important in the present invention, will be described in detail.
[0032]
The control unit 60 has an ATCU 61 and an ECM 62.
[0033]
The ATCU 61 includes a lock-up (hereinafter, abbreviated as “L / U”) area determination unit 61a, a torque capacity calculation unit 61b, an input torque calculation unit 61c, a torque limit determination unit 61d, and a torque limit value calculation unit 61e. , An accelerator sudden depression determination section 61f, a torque limit start / end condition determination section 61g, and a torque limit value output section 61h.
[0034]
The L / U area determination unit 61a receives a primary pulley rotation signal (input rotation signal) and a secondary pulley rotation signal (output rotation signal) from the primary pulley rotation speed sensor 51 and the secondary pulley rotation speed sensor 52, respectively. Further, the L / U region determination unit 61a receives an engine rotation signal from the engine 70. The L / U area determination unit 61a determines whether the lock-up clutch is in the ON state (lock-up area) based on the input signals, and does not limit the torque if the lock-up clutch is not in the lock-up area. The reason for this is that the response of the engine torque entering the CVT transmission section 40 is delayed unless it is in the lockup region, so that it is not necessary to limit the torque.
[0035]
The torque capacity calculation unit 61b outputs a primary pulley rotation signal (input rotation signal), a secondary pulley rotation signal (output rotation signal), and an actual hydraulic signal from the primary pulley rotation speed sensor 51, the secondary pulley rotation speed sensor 52, and the hydraulic pressure sensor 53. input. Then, the torque capacity calculation unit 61b calculates the gear ratio from the input rotation signal and the output rotation signal, and calculates the torque capacity based on the relationship with the actual oil pressure.
[0036]
The input torque calculation unit 61c inputs a target engine torque from the ECM 62 and sets it as the input torque.
[0037]
The torque limit determination unit 61d compares the torque capacity calculated by the torque capacity calculation unit 61b with the input torque calculated by the input torque calculation unit 61c to determine whether it is necessary to limit the input torque. That is, when the input torque exceeds the torque capacity, it is necessary to limit the input torque, and when the input torque does not exceed the torque capacity, it is determined that it is not necessary to limit the input torque.
[0038]
The torque limit value calculator 61e calculates a torque limit value. Specifically, the torque capacity is set to a torque limit value.
[0039]
The accelerator sudden depression determining unit 61f determines whether or not the accelerator pedal is suddenly depressed in the lock-up region. Specifically, if the change amount of the input torque is equal to or larger than a predetermined set value (for example, 40 Nm / 10 msec), it is determined that the accelerator pedal is suddenly depressed. Further, it is determined whether or not to limit the torque based on whether or not the vehicle is suddenly depressed and the input torque exceeds the torque capacity.
[0040]
The torque limit start / end condition determination unit 61g determines a condition for starting or ending the torque limit. Specifically, when it is determined that the accelerator is quickly depressed by the accelerator rapid-depression determining unit 61f, and the input torque exceeds the torque capacity, it is necessary to limit the torque. In that case, the flag is set to 1, Otherwise, the flag is set to 0.
[0041]
The torque limit value output unit 61h outputs the torque limit value as a request value to the torque down amount calculation unit 62b based on the flag of the torque limit start / end condition determination unit 61g. Specifically, when the flag is 1, a signal (that is, torque capacity) of the torque limit value calculation unit 61e is output as a torque limit value. When the flag is 0, it is not necessary to limit the torque. In this case, the limit request value is output as the Max value. The reason for this is that the torque reduction on the engine side is performed when “engine torque> restricted request value”.
[0042]
The ECM 62 includes an engine torque calculation unit 62a, a torque reduction amount calculation unit 62b, and an electronically controlled throttle (hereinafter abbreviated as “electric slot”) control unit 62c.
[0043]
The engine torque calculation unit 62a receives an engine fuel injection amount signal, an engine rotation signal, and an accelerator opening (TV0) signal, and calculates a torque output from the engine based on these signals. The calculation result of the engine torque is output to the torque reduction amount calculation unit 62b and the input torque calculation unit 61c of the ATCU 61.
[0044]
The torque down amount calculation unit 62b calculates the torque down amount based on the torque limit value signal input from the torque limit value output unit 61h of the ATCU 61 and the engine torque signal input from the engine torque calculation unit 62a, and outputs the torque down signal. Output to the braking / throttle opening control unit 62c.
[0045]
The electronically controlled throttle opening control unit 62c controls the electronically controlled throttle opening in order to realize the torque reduction amount input from the torque reduction amount calculation unit 62b.
[0046]
FIG. 3 is a flowchart illustrating the processing of the control unit of the engine output control device of the vehicle transmission system according to the present invention.
[0047]
In step S1, it is determined whether or not the area is a lock-up (L / U) area. If it is in the lock-up area, the process proceeds to step S2, and if it is not in the lock-up area, the process proceeds to step S8.
[0048]
In step S2, a torque capacity is calculated from the gear ratio and the actual oil pressure.
[0049]
In step S3, the input torque is calculated.
[0050]
In step S4, it is determined whether the accelerator is suddenly depressed based on whether or not the amount of change in the input torque is equal to or greater than a set value. If there is a sudden depression of the accelerator, the process proceeds to step S5, and if there is no sudden depression of the accelerator, the process proceeds to step S8.
[0051]
In step S5, it is determined whether or not the input torque is larger than the torque capacity. If the input torque is larger, the process proceeds to step S6, and if not, the process proceeds to step S7.
[0052]
In step S6, the input torque is limited so as to be equal to or less than the torque capacity.
[0053]
In step S7, the torque limitation ends.
[0054]
In step S8, no torque limitation is performed.
[0055]
The above processing is continuously performed at regular intervals (for example, every 10 msec) during traveling.
[0056]
FIG. 4 is a time chart showing the relationship between the accelerator opening and the torque limit request value. The solid line in FIG. 4A is the accelerator opening. 4 (B) and 4 (C), the thick solid lines indicate the required torque limit value, the thin solid lines indicate the torque capacity, and the broken lines indicate the input torque from the engine when there is no torque limit. FIG. 4B shows a conventional case, and FIG. 4C shows the present embodiment.
[0057]
As shown in FIG. 4 (B), conventionally, the minimum value of the assumed torque request value is used as the torque limit request value, and a certain time after the accelerator is rapidly depressed is always based on the torque limit request value. Therefore, depending on the running state, the engine torque is excessively limited, and the torque responsiveness at the time when the accelerator is depressed is poor, and the acceleration performance may be reduced.
[0058]
However, in the present embodiment, as shown in FIG. 4C, the torque capacity calculated based on the gear ratio and the actual oil pressure is used as the torque limit request value. Therefore, the torque limit request value can be made appropriate in accordance with the running state, and the time for applying such a torque limit is minimized. This makes it possible to obtain acceleration with good responsiveness to stepping on the vehicle.
[0059]
Without being limited to the embodiments described above, various modifications and changes can be made within the scope of the technical idea, and it is apparent that they are equivalent to the present invention. For example, in the above-described embodiment, the accelerator sudden depression determination value is set to 40 Nm / 10 msec, but this reference value may be appropriately changed according to the system.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an engine output control device of a vehicle transmission system according to the present invention.
FIG. 2 is a block diagram showing a configuration of a control unit of the engine output control device of the vehicle transmission system according to the present invention.
FIG. 3 is a flowchart illustrating a process of a control unit of the engine output control device of the vehicle transmission system according to the present invention.
FIG. 4 is a time chart showing a relationship between an accelerator opening and a torque limit request value.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle transmission system 10 Hydraulic pump 20 Torque converter 30 Forward / backward switching unit 40 CVT transmission unit 41 Primary pulley 42 Secondary pulley 43 V belt 60 Control unit 61 ATCU
61a Lock-up (L / U) region determination unit 61b Torque capacity calculation unit 61c Input torque calculation unit 61d Torque limit determination unit 61e Torque limit value calculation unit 61f Accelerator sudden step determination unit 61g Torque limit start / end condition determination unit 61h Torque limit Value output unit 62 ECM
62a Engine torque calculation unit 62b Torque reduction amount calculation unit 62c Electric throttle (electric slot) opening degree control unit 70 Engine 80 Drive wheels

Claims (4)

Transmission means for inputting a driving force from the engine, shifting the driving force and outputting to the driving wheels,
Torque capacity calculating means for calculating the torque that can be transmitted by the transmission means from actual hydraulic pressure,
Accelerator rapid depression determining means for determining whether or not the accelerator pedal is rapidly depressed;
Limiting the output of the engine when the sudden depression of the accelerator pedal is determined by the accelerator rapid depression determining means and the engine torque input to the transmission means exceeds the transmittable torque calculated by the torque capacity calculating means. Output control device for a vehicular transmission system, comprising: The shifting means,
An input-side primary pulley whose groove width changes according to the oil pressure,
An output-side secondary pulley whose groove width changes according to the oil pressure,
2. The vehicle according to claim 1, wherein the vehicle is a belt-type continuously variable transmission unit including a belt wound around the primary pulley and the secondary pulley, the belt having a pulley contact radius that changes according to the groove width. 3. Output control device for transmission system for automobiles. 3. The vehicle transmission system according to claim 1, wherein the engine output restriction unit calculates an engine torque input to the transmission unit based on an engine speed and an accelerator opening. 4. Engine output control device. 3. The accelerator suddenly determining unit determines that the accelerator pedal has been suddenly depressed when a change amount of an engine torque input to the transmission unit is equal to or greater than a predetermined value. 4. The engine output control device for a vehicle transmission system according to any one of claims 3 to 3.

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