JP3202763B2 - Shift control device for automatic transmission for vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a shift control apparatus for automatic transmission.

[0002]

BACKGROUND OF THE INVENTION In order to achieve a particular shift in an automatic transmission, it is often necessary to simultaneously engage and disengage two frictional engagement devices (a so-called clutch-to-clutch shift). In this case, if the synchronization and disengagement of the respective friction engagement devices are not properly synchronized, the gear train of the automatic transmission instantaneously becomes rigid or neutral, and the output shaft torque is reduced. Descents and engine spikes occur.

For this reason, when such control is conventionally performed, a one-way clutch having a function substantially equivalent to the function of one of the friction engagement devices is provided to prevent such a problem from occurring. ing.

However, the method of synchronizing the respective friction engagement devices by using the one-way clutch as described above has problems such as an increase in weight and occupation of a housing space due to the provision of the one-way clutch. .

[0005] In view of the above, in recent years, the following technology has been disclosed as a technology for satisfactorily achieving such a "clutch-to-clutch shift" without using a one-way clutch (SAE). Paper 890529
).

This technique is used to achieve a specific shift.
Release one friction engagement device and release the other friction engagement device.
So-called clutch-to-clutch
When executing the shift control, for example, power offStatus
(Power is transmitted from the wheel side to the driving force source (engine, etc.) side
In the driven state)Executed when runningup
When shifting, first slide the release-side friction engagement device.
With synchronous rotation speed after shifting the engine rotation speed by
And then engage the frictional engagement device on the engagement side.
That is.

[0007]

However, in practice, it is very difficult to perform the engagement on the engagement side when the engine rotation speed is near the synchronized rotation speed after shifting under various operating conditions. It is. Therefore, for example, when the engagement of the friction engagement device on the engagement side is delayed due to the upshift with the power off, a so-called underlap state is established, and the drive system is in a very unstable state.

In such a case, even if the vehicle speed slightly fluctuates or the driver's foot slightly touches the accelerator pedal, the drive system is easily turned off and the power is turned on (power is supplied to the engine side wheels). (The driving state transmitted to the side).

[0009] By this switching, a tapping sound is generated due to a change in the driving direction of the gear in, for example, a differential section, and the driving feeling is also considerably impaired.

[0010] Such a problem is caused by a problem that the underlap state is intentionally generated from the viewpoint of controllability.
In an automatic transmission configured to execute a two-clutch shift, this is inevitably likely to occur.

[0011] Such a problem is not limited to the clutch-to-clutch shift as described above. The shift to engage a specific frictional engagement device after the rotation speed of the engine is reduced to the synchronous rotation speed is not limited. Commonly occurs in

[0012] For example, when the speed is changed from the speed achieved by locking the one-way clutch in the drive range in a power-off state, the engine speed naturally decreases due to the idling of the one-way clutch. It is said that if a gearshift command is issued after waiting for the engine rotation speed to drop to the synchronous rotation speed, a good gearshift with almost no occurrence of inertia torque can be achieved.

This shift is not a so-called "clutch-to-clutch shift" as described above, but an area where the power-on state and the power-off state are easily switched depending on the running state of the vehicle during the shift. It is still a shift that can be done. Therefore, the above-described problem still arises.

The present invention has been made in view of such a conventional problem, and has been made in the case of a power-off clutch-to-clutch shift or from a speed where the one-way clutch idles in a power-off state. In the case of gear shifting, the transmission direction of the power transmission system is always kept constant, and it is possible to prevent the occurrence of a tapping sound in a differential portion or the like or a loss of drive feeling due to the reverse of the transmission direction. It is an object of the present invention to provide a shift control device for an automatic transmission which can solve the above-mentioned problems.

[0015]

The present invention SUMMARY OF], as shown from the gist thereof in FIG. 1, a structure in which power generated by the driving power source is transmitted to the driven parts, a power-off, specific in the frictional engagement device shift control apparatus for a vehicular automatic transmission to perform a shift of the clutch-to-clutch by engaging the, in performing the shift, drive force source which is not driving the dynamic system and the driven Means for limiting the output of the driving force source so that the output of the driving force source does not fall below the output value set as the guard value. The present invention has solved the above problem.

[0016]

According to the present invention, first, the present invention applies all-out variable <br/> speed to detect whether or not the running state to be executed.

This detection is made when the accelerator pedal is released at a speed equal to or higher than a predetermined value, for example, when the vehicle is in a gear position where a clutch-to-clutch gear shift can occur or in a gear position where the one-way clutch idles in a power-off state. What is necessary is just to detect whether it is in such a state.

As a result, when the shift is executed,
(Shifting as it results has been performed) kinematic system drive even running state such that power off (engine or the like) is driven
The output value of the driving force source that does not enter the (power off) state is set as the guard value. This setting may be set, for example, depending on the vehicle speed at that time.

[0019] On top of that, the output of the actual driving force source, to control the driving force source output while not become less said output <br/> force value.

As a result, the drive system is shifted and
Even when the vehicle is in a running state in which the power is turned off as it is when the engine and the engine are connected , the power is always maintained in the power-on state by adjusting the output of the drive source, so that the driving direction is reversed. Thus, there is no possibility that a tapping sound is generated in a differential portion or the like.

[0021] The present invention has the output of the drive power source is a requirement that you do not become less than a predetermined <br/> output values, the predetermined driving force when the accelerator pedal is depressed Output of the driving power source that is greater than the output value of the
It does not hinder .

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is an overall schematic diagram of an integrated control device for an automatic transmission and an engine to which the present invention is applied.

The engine (drive power source) 1 controls the fuel injection amount at its injection valve 19 and the ignition timing at the distributor 20 by an engine control computer 7, and the accelerator pedal 2
2, an engine output corresponding to the accelerator opening (operation amount) and the engine rotation speed can be obtained.

That is, a main throttle valve 26 which opens and closes in conjunction with the movement of an accelerator pedal 22 is provided in an intake pipe 24 of the engine 1, and a well-known drive which is driven by a command from the engine control computer 7 irrespective of the accelerator pedal 22. Idle speed control valve (ISC
V) 30 are arranged in parallel, and the two valves 2
The present invention is realized by the functions of 6 and 30.

The ISCV 30 is a valve for automatically controlling the idling rotational speed according to the warm-up state or the on / off state of the air conditioner.

Since the main throttle valve 26 is directly connected to the accelerator pedal, the accelerator operation amount and the engine output linearly correspond to each other. However, the ISCV 30 is opened to the extent that the idle speed can be freely controlled. Since the degree can be freely set, an equivalent throttle opening (throttle opening obtained by combining the main throttle valve 26 and the ISCV 30) having the characteristics intended in the present invention as a whole can be sufficiently obtained.

In the present invention, the method for controlling the engine output is not limited. For example, a method of controlling the fuel injection amount or a method of providing a sub throttle valve in parallel in addition to the main throttle valve may be used.

The automatic transmission 2 is controlled by an automatic transmission control computer 8 to control the solenoid valves S1 to S1 of the hydraulic control device 3.
S3 is controlled, and as a result of the change of the oil passage in the hydraulic control device 3, the engagement state of each friction engagement device is selectively changed,
The shift speed corresponding to the vehicle speed and the accelerator opening can be obtained.

The engine control computer 7 includes an engine rotation speed detected by an engine rotation sensor 9, an intake air amount detected by an intake air amount sensor 10, and an intake air temperature sensor 1.
1, the accelerator opening by the accelerator opening sensor 12, the vehicle speed by the vehicle speed sensor 13, the engine water temperature by the engine water temperature sensor 14, the brake switch 1
5 are input.

The engine control computer 7 determines the fuel injection amount and the ignition timing based on these signals.

On the other hand, the automatic transmission control computer 8 includes the accelerator opening sensor 12 and the vehicle speed sensor 1.
3. In addition to the signals from the engine coolant temperature sensor 14, the brake switch 15, etc., the position of the shift lever by the shift position sensor 16, the pattern select switch 17
A driving selection pattern such as fuel-conservation-oriented traveling or power-performance-oriented traveling, a signal for permitting a shift to overdrive by the overdrive switch 18 and the like are input, and the vehicle speed,
The electromagnetic valves S1 to S3 are controlled to be ON-OFF so as to obtain a gear position corresponding to the accelerator opening.

FIG. 3 shows a transmission section of the automatic transmission 2. This transmission unit includes a torque converter 120, an overdrive mechanism 140, and an underdrive mechanism 160.

The torque converter 120 is a pump 1
21, a turbine 122, and a stator 123, and includes a lock-up clutch 124.

The overdrive mechanism 140 includes a planetary gear set including a sun gear 143, a planetary pinion 142 meshing with the sun gear 143, a carrier 141 supporting the planetary pinion 142, and a ring gear 144 meshing with the planetary pinion 142. Prepared,
The rotational state of the planetary gear unit is controlled by a clutch C0, a brake B0, and a one-way clutch F0.

The underdrive mechanism 160 includes a common sun gear 161, planetary pinions 164 and 165 meshing with the sun gear 161, and the planetary pinion 1.
Ring gear 1 meshing with carriers 166 and 167 supporting planet 64 and 165 and planetary pinions 164 and 165
62, 163. The planetary gear set includes two sets of clutches C1, C2 and a brake B which determine the rotational state of the planetary gear set and the state of connection with the overdrive mechanism 40.
1, B3 and one-way clutch F2.

Each gear is achieved by engaging the clutches C0, C1, C2 and the brakes B0, B1, B3 as shown in FIG. 4 (indicated by a circle in FIG. 4). At this time, the one-way clutches F0 and F2 are operated (locked) at the time of driving (when power is transmitted from the engine to the wheels) at the position indicated by the mark ◎ in FIG.

The shift from the second speed to the third speed is a so-called "clutch-to-clutch shift" in which the brake B1 is released and the clutch C2 is engaged.
Therefore, in this embodiment, the present invention is applied to the clutch-to-clutch shift from the second speed to the third speed when the power is off.

The control flows of FIGS. 5 and 6 show the flow of the power-off clutch-to-clutch upshift control from the second speed to the third speed.

First, in step 210, various signals are read. Specifically, for example, the accelerator opening θ, the vehicle speed V, the selected position of the pattern select switch 17, and the like are read.

In step 220, it is determined whether or not the current speed is the second speed. If the current gear is not the 2nd gear,
It is determined that the present invention is not applied, and the process is returned as it is.

If it is the second speed, step 230
Then, it is determined whether the accelerator opening θ is equal to or greater than a predetermined value A. When the accelerator opening .theta. Is equal to or less than the predetermined value A and the engine output is controlled to increase or decrease, the control is not executed because the shock is not good, and the control is not executed (returned as it is).

When it is determined that the accelerator opening θ is equal to or greater than the predetermined value A, the routine proceeds to step 240, where it is determined whether or not the rate of change of the accelerator opening θ is equal to or less than a negative predetermined value B including zero. .

As described above, in steps 220 to 240, the current speed is the second speed, the accelerator opening θ is greater than the predetermined value A, and the accelerator opening θ is released at a certain speed or higher. If it is determined that there is, after waiting for the engine rotational speed to decrease to the synchronous rotational speed (by releasing the brake B1), the specific frictional engagement device (clutch C2) is released. It is predicted that "engagement speed" will occur, and the routine proceeds to step 250, where the lower limit value THmin of the opening degree of the ISCV 30 is set.
This setting is a value that ensures a predetermined engine output value at which the drive system is not driven at the vehicle speed.

The lower limit value THmin is, as shown in FIG. 7, specifically, the position of the pattern select switch, that is, the P (power) pattern, the N (normal) pattern, and the E (normal) pattern.
(Economy) Set according to the vehicle speed depending on the pattern.

As a result, the power of the drive system of the vehicle is constantly maintained (drive state). The lower limit THmin of the ISCV may be obtained by calculation from the turbine torque of the torque converter or the like.

Further, feedback control and learning control may be applied to the maintenance of the lower limit to improve the control accuracy.

In step 260, it is determined whether a shift determination has been made. Until the shift is determined, the state of the second speed stage is maintained as it is, so that this control is not particularly executed (returned as it is).

On the other hand, if it is detected that a shift has been determined,
Proceeding to step 270, the timer Tm1 is reset to zero and starts counting. This timer Tm1 is
This is for setting the time during which the control of the ISCV 30 is being executed. Qualitatively, the automatic transmission operates from the second gear to the third gear.
This is for executing the engine output control only during a time when there is a possibility that an underlap state may occur, particularly when executing a power-off clutch-to-clutch shift to a gear.

At step 280, the hydraulic pressure of the automatic transmission is corrected. This is because the actual input torque is generally different from the automatic transmission, although the hydraulic characteristics are set so that a predetermined engagement pressure can be obtained at a predetermined accelerator opening degree. In this case, the engagement pressure is corrected.

This correction may be a correction of the line pressure, or a correction of the engagement pressure by correcting the back pressure of the accumulator.

At step 290, control of ISCV 30 is continued. This control is performed at step 300 by T
It continues until it is recognized that m1 has counted up.
Eventually, if it is determined that the timer Tm1 has reached Tm0, the routine proceeds to step 310, where the lower limit setting control is released, and in step 320, the hydraulic pressure correction control is stopped.

After that, the valve is closed while the ISCV 30 is smoothed. In addition, in step 340, the pressure is returned to a value corresponding to the accelerator opening θ while the oil pressure is moderated.

As shown in FIG. 8, from the second gear to the third gear
In the case of a power-off upshift to the second gear, brake B1
Is released and the clutch C2 is engaged, but in this case, the driving state (driving direction) of the vehicle becomes very unstable, and the power-on state and the power can be easily changed by a slight depression of the accelerator pedal or a change in the vehicle speed. The off state is reversed (see the broken line in FIG. 8).

According to this embodiment, the lower limit value THmin is secured by opening and closing the ISCV 30 so that the equivalent throttle opening does not fall below a predetermined value, that is, the engine output is reduced.
Since the dynamic system is controlled so as not to be driven, the driving direction is always maintained in the direction from the engine side to the wheel side, and a tapping sound is generated in a differential portion or the like,
It is possible to prevent the shift feeling from being impaired due to switching between power-on and power-off.

[0056]

As described above, according to the present invention, the vehicle driving direction can be changed in the case of a clutch-to-clutch shift at the time of power-off or a shift from a speed where the one-way clutch idles at the time of power-off. When the gears are reversed, it is possible to obtain an excellent effect that it is possible to appropriately prevent the occurrence of a tapping sound in the differential portion and the deterioration of the shift feeling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is an overall schematic view of a vehicle automatic transmission and an engine to which an embodiment of the present invention is applied.

FIG. 3 is a skeleton diagram showing a gear train of the automatic transmission.

FIG. 4 is a diagram showing an engagement state of a friction engagement device of the automatic transmission.

FIG. 5 is a flowchart showing a control flow executed by the apparatus of the embodiment.

FIG. 6 is a flowchart showing a continuation of the control flow.

FIG. 7 is a diagram showing an example of setting an ISCV valve opening;

FIG. 8 is a diagram showing shift transient characteristics that qualitatively show the effect of the embodiment of the present invention.

[Explanation of symbols]

B1: disengagement side frictional engagement device, C2: engagement side frictional engagement device, 22: accelerator pedal, 26: main throttle valve, 28: motor, 30: ISCV (idle speed control valve), 12: accelerator opening sensor , 13 ... Vehicle speed sensor.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI F16H 61/04 F16H 61/04 // F16H 63:40 (72) Inventor Kunihiro Iwatsuki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Yasuo Hojo 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hiromichi Kimura 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masahiro Hayabuchi Inside Aisin City, Aki Prefecture, Takane 10 Takane, Aisin AW Co., Ltd. (72) Inventor Masahiko Ando, Aki Prefecture, Aki City, Fujii Town Takane 10, Aisin AW Co., Ltd. No. 10 Takane, Fujii-machi, Anjo-shi, Aichi Prefecture Inside Aisin AW Co., Ltd. (56) References JP-A-2-70934 (JP, A) JP-A-2-3762 (JP, A) −49756 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 41/04 F02D 29/00 -29/02 F02D 45/00 F16H 61/00

Claims (1)

(57) [Claims] 1. A structure in which motive power generated by a driving force source is transmitted to a driven portion, wherein a clutch-to-clutch shift is executed by engaging a specific frictional engagement device when the power is off. In the shift control device for an automatic transmission for a vehicle, an output value of the driving force source that is not driven by a driving system when executing the shift is set as a guard value, and an output of the driving force source is the guard value. Means for controlling the output of the driving force source so as not to be less than or equal to the output value set as (i).