JPH09242574A - Control device for automatic transmission - Google Patents

Abstract

(57) An object of the present invention is to prevent a shock caused by changing an output characteristic of a driving force source during a gear shift in an automatic transmission. A control device for an automatic transmission of a vehicle, which changes an output characteristic of a driving force source with respect to an accelerator operation amount according to a gear ratio, wherein the output characteristic is changed in accordance with a gear shift before completion of the gear shift. It is configured to terminate. The change of the output characteristics is finished during the inertia phase in the upshift, and finished in the predetermined period before the completion of the downshift in the case of the downshift.

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 an automatic transmission connected to a driving force source such as an engine capable of changing an output characteristic with respect to an accelerator opening degree, and more particularly to changing the output characteristic of the driving force source. The present invention relates to a control device for an automatic transmission in a vehicle that changes according to a ratio.

[0002]

2. Description of the Related Art Recently, with the development of electronic control technology, the output of a driving force source such as an engine in a vehicle has been electrically controlled. For example, in a vehicle equipped with an engine, the amount of accelerator pedal operation (accelerator opening)
Is electrically detected, and the throttle opening is controlled according to the detection result to improve drivability such as obtaining various traveling characteristics. An example thereof is described in JP-A-61-126336.

The conventional device described in this publication is configured such that the opening characteristic of the throttle valve with respect to the accelerator operation amount can be changed for each shift stage, and a large output is required at the low shift stage. The change of the throttle opening degree with respect to the change of the accelerator operation amount is set to be larger than that at the high speed stage. That is, in the case of a downshift, the opening characteristic is changed together with the downshift so that the opening of the throttle valve increases, and conversely, in the case of an upshift, the opening of the throttle valve becomes relatively small. The opening characteristic is configured to be changed together with the upshift.

[0004]

Therefore, in the above-described conventional device, the opening of the throttle valve, that is, the opening characteristic with respect to the accelerator opening is changed in accordance with the shift, so that when the shift is executed, the throttle opening is performed. The throttle opening may change due to a change in the degree characteristic. For example, if a downshift is determined and executed based on a change in vehicle speed or throttle opening, the output torque increases with an increase in the gear ratio, and the throttle valve is opened by changing the throttle opening characteristic to output the engine output. Will increase. As a result, the change in the driving force is caused by the dual factors of the change of the throttle opening characteristic of the engine and the change of the gear ratio of the automatic transmission. It may become complicated and the shift shock may worsen.

Incidentally, the situation is the same in the case of the upshift as well, and in the case of the upshift, the output torque is reduced due to the reduction of the gear ratio in the automatic transmission and the throttle opening characteristic is changed. The driving force may be significantly reduced due to the double factor of the decrease in engine output, which may exacerbate the shift shock.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to improve a shift shock caused by a change in an output characteristic of a driving force source accompanying a shift. This object is achieved by ending the change of the output characteristic of the driving force source before the completion of the shift.

[0007]

In order to achieve the above-mentioned object, the invention of claim 1 is an automatic transmission of a vehicle in which an output characteristic of a driving force source with respect to an accelerator operation amount is made different according to a gear ratio. In the machine control device, the change of the output characteristic due to the gear shift is configured to be finished before the gear shift is completed.

The invention of claim 2 is characterized in that the control for changing the output characteristic of the driving force source is configured to be terminated during the inertia phase in the case of an upshift. .

Further, the invention of claim 3 is characterized in that the control for changing the output characteristic of the driving force source is finished in the case of a downshift from the time when the shift is completed to a predetermined time before. It is what

Therefore, according to the present invention, the change of the driving force due to the change of the output characteristic of the driving force source occurs during the change of the output torque due to the change of the gear ratio in the automatic transmission. A change in the output torque due to the change in the ratio and a change in the output torque due to the change in the output characteristic of the driving force source are prevented from occurring continuously or in superposition.

In particular, according to the second aspect of the invention, the change in the output characteristic of the driving force source occurs in the inertia phase during upshifting in the automatic transmission. Therefore, the torque change due to the change in the output characteristic is caused by the torque change in the inertia phase. Becomes a mixed state, and it is possible to suppress a sudden change in the output torque at the end of the shift.

According to the third aspect of the invention, in the neutral state up to the synchronous rotation speed in the low speed side after the gear shift, a torque change occurs due to a change in the output characteristic of the driving force source. No change appears in the output torque and therefore the shift shock is good.

[0013]

Next, the present invention will be described more specifically with reference to the drawings. First, an example of an engine (driving force source) E and an automatic transmission A, which are objects of the present invention, will be described. FIG. 4 is an overall control system diagram thereof and an engine to which the automatic transmission A is connected. E is configured to electrically control its output, and an electronic throttle valve 13 driven by a throttle actuator 16 composed of a servomotor is provided in the intake conduit 12. On the other hand, the depression amount of the accelerator pedal 15 for controlling the output of the engine E, that is, the accelerator opening degree is detected by a sensor (not shown), and the detection signal is input to the engine electronic control unit (E-ECU) 17. . The electronic control unit 17 mainly includes a central processing unit (CPU), a storage device (RAM, ROM), and an input / output interface,
The electronic control unit 17 includes, as data for control, engine (E / G) rotation speed N, intake air amount Q, intake air temperature, throttle opening, vehicle speed, engine water temperature, signal from brake switch, and the like. Various signals are input. The opening of the electronic throttle valve 13 is controlled based on these data, and the fuel injection amount and the ignition timing of the engine E are controlled.

In the automatic transmission A, the hydraulic control device 18 controls gear shifting and lockup clutch, line pressure, or engagement pressure of a predetermined friction engagement device. The hydraulic control device 18 is configured to be electrically controlled, has first to third shift solenoid valves S1,..., S3 for performing a shift, and has a first for controlling an engine brake state. 4 solenoid valve S4, linear solenoid valve SLT for controlling line pressure, linear solenoid valve SLN for controlling accumulator back pressure, linear for controlling engagement pressure of a lock-up clutch or a predetermined friction engagement device. A solenoid valve SLU is provided.

An electronic control unit (T-ECU) 19 for an automatic transmission that outputs a signal to these solenoid valves to control gear shift, line pressure, accumulator back pressure, etc.
Is provided. This electronic control unit for automatic transmission 19
Is a central processing unit (CPU) and a storage device (RA
M, ROM) and an input / output interface. The electronic control unit 19 includes throttle opening, vehicle speed, engine coolant temperature, signals from a brake switch, shift position,
A signal from a pattern select switch, a signal from an overdrive switch, a signal from a C0 sensor that detects the rotational speed of a clutch C0 described later, an oil temperature of the automatic transmission,
A signal from a manual shift switch is input.

The electronic control unit 19 for the automatic transmission and the electronic control unit 17 for the engine are connected to each other so that data can be communicated with each other, and the electronic control unit 17 for the engine transfers to the electronic control unit 19 for the automatic transmission. On the other hand, a signal such as the intake air amount per rotation (Q / N) is transmitted, and an instruction signal for each solenoid valve is sent from the automatic transmission electronic control unit 19 to the engine electronic control unit 17. A signal equivalent to, a signal instructing a shift speed, and the like are transmitted.

That is, the electronic control unit 19 for the automatic transmission
Is based on input data and a map stored in advance, and indicates ON / OF of a gear position and a lock-up clutch.
F, or the pressure adjustment level of the line pressure or the engagement pressure is determined, and based on the determination result, an instruction signal is output to a predetermined solenoid valve, and further, the determination of the failure and the control based on the failure are performed. . The engine electronic control unit 17 controls the fuel injection amount, the ignition timing, the opening degree of the electronic throttle valve 13 and the like based on the input data, and also controls the fuel injection amount at the time of shifting in the automatic transmission A. The output torque is temporarily reduced by reducing the ignition timing, changing the ignition timing, or reducing the opening of the electronic throttle valve 13.

FIG. 5 is a diagram showing an example of a gear train of the above-described automatic transmission A, and in the configuration shown here, five forward gears and one reverse gear are set. That is, the automatic transmission A shown here is
, A sub transmission unit 21 and a main transmission unit 22. The torque converter 20 includes a lock-up clutch 23
The lock-up clutch 23 has a front cover 25 integrated with the pump impeller 24.
(Hub) 2 integrally mounted with the turbine runner 26
7 is provided. An engine crankshaft (each not shown) is connected to a front cover 25 and an input shaft 28 to which a turbine runner 26 is connected.
Is connected to the carrier 30 of the overdrive planetary gear mechanism 29 that constitutes the subtransmission portion 21.

The carrier 3 in this planetary gear mechanism 29
A multi-plate clutch C0 and a one-way clutch F0 are provided between the first gear 0 and the sun gear 31. The one-way clutch F0 is engaged when the sun gear 31 rotates forward relative to the carrier 30 (rotation in the rotation direction of the input shaft 28). A multi-disc brake B0 for selectively stopping the rotation of the sun gear 31 is provided.
The ring gear 3 which is an output element of the subtransmission portion 21
2 is connected to an intermediate shaft 33 which is an input element of the main transmission unit 22. Further, an NC0 sensor 34 for detecting the rotation speed of the multi-plate clutch C0, that is, the input rotation speed, is provided.

Therefore, in the auxiliary transmission portion 21, the entire planetary gear mechanism 29 rotates integrally when the multi-plate clutch C0 or the one-way clutch F0 is engaged, so that the intermediate shaft 33 has the same speed as the input shaft 28. At low speed. When the brake B0 is engaged and the rotation of the sun gear 31 is stopped, the speed of the ring gear 32 is increased with respect to the input shaft 28 and the ring gear 32 is rotated forward, so that a high gear is established.

On the other hand, the main transmission section 22 has three sets of planetary gear mechanisms 40, 50, and 60, and their rotating elements are connected as follows. That is, the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 of the second planetary gear mechanism 50 are integrally connected to each other, and the ring gear 43 of the first planetary gear mechanism 40 and the carrier 52 of the second planetary gear mechanism 50 are connected to each other. The three members of the third planetary gear mechanism 60 and the carrier 62 are connected, and the output shaft 65 is connected to the carrier 62. Further, the ring gear 53 of the second planetary gear mechanism 50 is connected to the sun gear 61 of the third planetary gear mechanism 60.

In the gear train of the main transmission unit 22, it is possible to set a reverse gear and four gears on the forward side, and clutches and brakes therefor are provided as follows. First, the clutch will be described. The ring gear 53 of the second planetary gear mechanism 50 and the third gear
A first clutch C1 is provided between the sun gear 61 of the planetary gear mechanism 60 and the intermediate shaft 33, and the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 of the second planetary gear mechanism 50 and the intermediate shaft are connected to each other. A second clutch C2 is provided between the clutch 33 and the second clutch C2.

Next, the brake will be described. The first brake B1 is a band brake, and the sun gears 41, 5 of the first planetary gear mechanism 40 and the second planetary gear mechanism 50.
It is arranged to stop the rotation of 1. A first one-way clutch F1 and a second brake B2, which is a multi-plate brake, are arranged in series between the sun gears 41 and 51 (that is, the common sun gear shaft) and the casing 66. One-way clutch F1 has sun gears 41 and 5
1 is engaged when it is about to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 28). The third brake B3, which is a multi-plate brake, is connected to the first planetary gear mechanism 4
0 and the casing 66. As a brake for stopping the rotation of the ring gear 63 of the third planetary gear mechanism 60, a fourth brake B4, which is a multi-plate brake, and a second one-way clutch F2 are provided.
6 are arranged in parallel. The second one-way clutch F2 is adapted to be engaged when the ring gear 63 is about to rotate in the reverse direction.

In the above-described automatic transmission A, it is possible to set five forward speeds and one reverse speed by engaging and disengaging each clutch and brake as shown in the operation table of FIG. In FIG. 6, the mark ○ indicates the engaged state, the mark 時 に indicates the engaged state at the time of engine braking, the mark △ indicates either engaged or released, and the blank indicates the released state.

The control of the electronic throttle valve 13 will now be described. The electronic throttle valve 13 is controlled by the engine electronic control unit 17 driving the throttle actuator 16 in response to the depression operation of the accelerator pedal 15.
An opening based on other control factors is added to or subtracted from the basic throttle opening TTA corresponding to the depression amount (accelerator opening) VPA of 5. The relationship is shown diagrammatically in FIG. 7, in which the required opening degree TTACC from the cruise control is added to or subtracted from the basic throttle opening degree TTA to set the throttle target opening degree TTANGLE. Further, the throttle opening degree TVECT required based on the gear shift in the automatic transmission A, the throttle opening degree TVEFI required based on the fuel injection control, or the throttle opening degree TVTRC required based on the traction control is set. If so, the minimum value of these openings is set as the throttle target opening TTANGLE. Then, the engine electronic control unit 17 determines that the target throttle opening T
The throttle actuator 16 is driven to achieve TANGLE, and as a result, the current throttle opening θ is obtained.
Further, the characteristic of the basic throttle opening TTA with respect to the accelerator opening VPA is made non-linear, and the characteristic is
It can be changed according to the driving state of the engine E and the gear stage of the automatic transmission A.

Therefore, in the vehicle equipped with the engine E and the automatic transmission A described above, the control characteristic (opening characteristic) of the throttle opening θ with respect to the accelerator opening VPA of the engine E accompanying the shift in the automatic transmission A. Is changed. The control for changing the throttle opening characteristic according to the present invention is executed as follows in order to improve the shift shock.

FIG. 1 is a flow chart for explaining an example of the control. After the processing of the input signal including the reading of data and the judgment of the failure of the sensor and the switches (step 1) is performed, the output of the shift is output. It is determined whether or not is performed (step 2). If a negative determination is made here, the control routine is exited without performing any particular control, and if an affirmative determination is made, it is determined whether the shift is an upshift (step 3).

When the upshift is output,
It is determined whether or not the inertia phase at that shift has started (step 4). This determination can be made by a conventionally known method, for example, by determining that the difference between the value obtained by multiplying the output shaft speed by the gear ratio before shifting and the input speed NC0 has reached a predetermined value. can do. If the inertia phase has not started, it returns. If the inertia phase has started, the timer value CTRT from the start of the inertia phase is the reset timer value TRT set in advance.
It is determined whether or not this is the case (step 5). Here, the value TRT of the return timer is the time from the start of the inertia phase to the end thereof at the latest, and a constant value can be used, or the vehicle speed, the throttle opening and the shift pattern etc. are preset as parameters. You can use map values or variables.

If the answer of Step 5 is negative and the engine is still in the inertia phase, the throttle opening .theta. Has a throttle opening characteristic corresponding to the gear after the shift (in this example, the throttle opening .theta. It is determined whether or not the opening θ is equal to or larger than the opening θ2 in the high characteristic in which the opening θ becomes relatively large (step 6). If the determination in step 6 is negative because the throttle opening θ has not reached the value θ2 in the new opening characteristic, the count value CTRT of the timer is incremented by “1” (step 7),
Further, the throttle opening θ is increased by a predetermined value dθ (step 8). Then return.

The increase width dθ of the throttle opening θ is the throttle opening characteristic (in this example, the throttle opening θ with respect to the accelerator opening VPA) corresponding to the gear position before the shift.
The value obtained by dividing the difference between the value θ1 in the low characteristic) where θ becomes relatively small and the value θ2 in the throttle opening characteristic corresponding to the gear after the gear shift by the return timer value TRT ( (Θ2-θ1) / TRT). That is, the throttle opening θ is gradually increased according to the gradient of the deviation of the throttle opening due to the difference in characteristics.

In this way, the throttle opening θ is gradually increased, and when the value reaches the value θ2 in the opening characteristic corresponding to the gear after the gear shift and a positive determination is made in step 6, Proceeding to step 9, the throttle opening .theta. Is set to the value .theta.2 of the new opening characteristic.

If the timer value CTRT is incremented by "1" to reach the return timer value TRT, and if an affirmative decision is made in step 5, step 9
The throttle opening θ to the new opening characteristic value θ2
Set to.

Changes in the input rotational speed NC0, the output torque TO, the input torque TT, and the throttle opening θ when the above control is executed at the time of power-on upshift are schematically shown in the time chart of FIG. . In FIG. 2, t0
The gear shift starts at the time point, the input rotational speed NCO decreases accordingly, and the inertia phase starts (time point t1). At this point, the output torque TO increases as the return timer starts counting, but the input torque TT increases as the throttle opening θ gradually increases as the throttle opening characteristic changes, so the output torque TO increases. The increasing tendency is larger than that in the case where the throttle opening θ is not increased (shown by the one-dot chain line in FIG. 2).

The input torque TT gradually increases due to the increase of the throttle opening θ due to the change of the throttle opening characteristic described above, and the throttle opening θ becomes the value θ2 of the new characteristic at the time t2 when the reset timer TRT counts up. Become. At time t3 thereafter, the frictional engagement devices involved in the gear shift are almost completely engaged, and the input rotation speed NC0 reaches the synchronous rotation speed at the gear after the gear shift. At the same time, the output torque TO becomes a value corresponding to the gear ratio after the gear shift. Such a change in the output torque To occurs during a normal gear shift, and the gear shift shock does not deteriorate.

On the other hand, when the switching of the throttle opening .theta.
As indicated by the alternate long and short dash line in FIG. 2, since the input torque is smaller than in the above case, the synchronous rotation speed is reached at time t4 earlier than time t3, and then the throttle opening θ is switched. Therefore, the output torque T0 changes with the change of the throttle opening .theta. After the change with the shift, and as a result, the output torque TO decreases and increases in a short time, and the shift shock increases.

On the other hand, in the flow chart of FIG. 1, when the negative determination is made in step 3 because the downshift is output, the estimated time until the input speed NCO reaches the synchronous speed at the shift stage after the shift is made. It is determined whether TCYC is less than or equal to a preset return timer TRT (step 1
0). If a negative determination is made here, it means that the gear shift has not yet proceeded sufficiently, so this control routine is exited. On the other hand, if an affirmative decision is made, it means that the gear shift has progressed to within a predetermined period before the completion of synchronization, and in this case, the throttle opening θ corresponds to the gear after gear shift. It is judged whether or not the value is not more than a value θ2 in a certain throttle opening characteristic (step 11). When a negative determination is made in step 11 because the throttle opening θ is larger than the value θ2 determined by the throttle opening characteristic after gear shifting, the throttle opening θ is decreased by the predetermined value dθ (step 12). Then return.

In this way, the throttle opening θ is gradually decreased, and as a result, the throttle opening θ becomes a value θ2 determined by the throttle opening characteristic after the gear shift, and if an affirmative judgment is made in step 11, the routine proceeds to step 13. At throttle opening θ
To its value θ2. That is, in the case of the downshift, the switching of the throttle opening θ according to the change of the throttle opening characteristic is executed and completed within a predetermined time before the shift is completed.

This will be described with reference to the time chart of FIG. 3. At time t10 when the shift is started, the friction engagement device involved in the shift is controlled to be released, so that the input rotation speed (for example, turbine rotation speed) NT. Begins to increase, and the output torque To decreases. And the expected time t of synchronization
From twelve to the time t11 before the predetermined time TRT, the throttle opening θ is gradually reduced as described above,
The input torque TT gradually decreases. As a result, the input rotation speed NT increases slowly. Further, since the automatic transmission A is in the neutral state, the output torque does not change even if the throttle opening θ is changed. At time t12, the input rotation speed NT reaches the synchronous rotation speed at the gear after the gear shift, and at the same time, the output torque TO increases to a value determined by the gear ratio. Such a change in the output torque To occurs during a normal gear shift, and the gear shift shock does not deteriorate.

On the other hand, if switching is to be performed after the shift due to a change in the control characteristic of the throttle opening θ, the throttle opening θ is not decreased during the shift, as shown by the alternate long and short dash line in FIG. Is advanced earlier, and the synchronization is completed at the time point t13 before the time point t12. After that, since the throttle opening θ is changed according to the change of the throttle opening characteristic, the output torque TO which has once increased to the value determined by the gear ratio after the gear change is accompanied by the change of the throttle opening θ. Decrease. As a result, the output torque TO increases and decreases in a short time, and the shift shock increases.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and an automatic transmission other than the automatic transmission having the gear train shown in FIG. 5 can be used. It can be applied to the target control device. Further, in the above embodiment, the control characteristic is changed so that the throttle opening is increased by the upshift, and the control characteristic is changed so that the throttle opening is decreased by the downshift. The mode of changing the throttle opening characteristic is not limited to that shown in the above embodiment, but can be set appropriately. Further, the present invention may be a vehicle using another power output device such as a motor, in addition to the one using an engine (internal combustion engine) as a driving force source. Therefore, the means for controlling the output may be, for example, a means for controlling the current other than the throttle valve. The automatic transmission targeted by the present invention may be of a type other than those shown in the above embodiments, such as a continuously variable transmission.

[0041]

As described above, according to the present invention,
Changes in output torque due to changes in the output ratio of the driving force source occur during changes in output torque due to changes in the transmission ratio of the automatic transmission. And the change of the output torque due to the change of the output of the driving force source does not occur continuously or in superposition, and as a result, according to the present invention, the throttle opening characteristic is combined with the change of the gear ratio. The changing control can be executed without aggravating the shift shock.

In particular, according to the second aspect of the invention, the change in the output characteristic of the driving force source occurs in the inertia phase at the time of upshift in the automatic transmission. Therefore, the change in the output characteristic is caused by the torque change in the inertia phase. A change in torque is mixed in, a sudden change in output torque at the end of the shift can be suppressed, and a shift shock can be prevented.

Further, in the third aspect of the invention, in the neutral state up to the synchronous rotation speed at the low speed side after the gear shift, a torque change occurs due to the change of the output characteristic of the driving force source. Changes do not appear in the output torque, so gear shift shocks can be prevented.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining control contents executed by a control device of the present invention.

[Fig. 2] Input speed at power-on upshift,
5 is a time chart showing changes in output torque, input torque, and throttle opening.

[Fig. 3] Input speed at power-on downshift,
7 is a time chart showing changes in output torque and input torque.

FIG. 4 is a diagram showing an overall control system according to the present invention.

FIG. 5 is a skeleton diagram showing an example of a gear train of an automatic transmission targeted by the present invention.

FIG. 6 is a diagram showing an engagement operation table of a friction engagement device for setting each shift speed in the automatic transmission.

FIG. 7 is a diagram showing a relationship of determinants of an actual throttle opening.

[Explanation of symbols]

 13 Electronic Throttle Valve 15 Accelerator Pedal 16 Throttle Actuator 17 Electronic Control Device for Engine 18 Hydraulic Control Device 19 Electronic Control Device for Automatic Transmission A Automatic Transmission E Engine

Claims (3)

[Claims] 1. A control device for an automatic transmission of a vehicle, wherein an output characteristic of a driving force source with respect to an accelerator operation amount is changed according to a gear ratio, wherein the change of the output characteristic associated with a gear shift is finished before the completion of the gear shift. A control device for an automatic transmission, which is configured to: 2. In a control device for an automatic transmission that changes an output characteristic of a driving force source with respect to an accelerator operation amount according to a gear ratio, a change of the output characteristic due to an upshift is performed during an inertia phase in the upshift. A control device for an automatic transmission, which is configured to be terminated. 3. A control device for an automatic transmission in which an output characteristic of a driving force source with respect to an accelerator operation amount is changed according to a gear ratio, wherein a change of the output characteristic due to a downshift is performed for a predetermined time after completion of the downshift. A control device for an automatic transmission, characterized in that the control device is configured to be terminated by the time before.