JPH0577660A - Speed change control device for automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To smoothly conduct clutch-to-clutch speed change by enhancing accuracy in detecting engine torque (input torque to an automatic transmission). CONSTITUTION:In a system which directly or indirectly detects engine torque and conducts clutch-to-clutch speed change based on the detected engine torque, in order to prevent the output torque of an automatic transmission from being fluctuated due to the load fluctuation of engine accessories (air conditioner, power steering, etc.), it is prohibited that load for the accessories is fluctuated while clutch-to-clutch speed change is under operation. As a result, clutch-to- clutch speed change can be smoothly conducted in a stable condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and more particularly, to a shift control device for a vehicle automatic transmission which may perform clutch-to-clutch shift.

[0002]

2. Description of the Related Art In order to achieve a specific shift of an automatic transmission, it is often necessary to simultaneously engage and disengage two friction engagement devices (so-called clutch-to-clutch shift). In this case, unless the engagement and disengagement of the friction engagement devices are properly synchronized, the gear train of the automatic transmission is momentarily in a rigid state or in a neutral state and the output shaft torque is reduced. There is a possibility of a sudden descent or engine upstroke.

Therefore, in the case of performing such control conventionally, 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, in the method of synchronizing the friction engagement devices by using the one-way clutch in this way, the cost is increased, the weight is increased, and the accommodation space is increased because the one-way clutch is attached. There is a problem such as occupying.

In view of such a point, in recent years, as a technique for satisfactorily achieving such "clutch-to-clutch shift" without using a one-way clutch, it is responsive to the hydraulic pressure of one friction engagement device. There is known one in which a sequence valve for determining the supply / discharge timing of the working oil pressure to the other friction engagement device is introduced into the operation hydraulic circuit of the other friction engagement device (Japanese Patent Laid-Open No. 64-64- 653
54). In this technique, when executing the clutch-to-clutch shift, the operating hydraulic pressure is controlled depending on the engine load (torque).

By the way, it is the actual situation that the direct detection of the actual value of the engine load (torque) is difficult with the current technology because of the cost, the mountability of the sensor, the accuracy, and the like. It is detected by the accelerator opening (or throttle opening). Therefore, the detection accuracy is low (it does not always correspond well to the actual engine torque).
There was a problem.

In view of such a point, as is well known in the field of recent engine control technology, Q / N (engine 1
It has also been proposed to (more accurately) detect engine torque using intake air quantity per revolution.

[0008]

However, even if the engine torque is well detected by this Q / N, the load condition of various auxiliary machines of the engine (for example, a compressor for an air conditioner, an alternator, etc.) If there is a change, there is a problem that the value cannot be said to be accurate information in reality.

That is, the purpose of detecting "engine torque" when performing clutch-to-clutch shift is not to detect "engine torque itself", but more specifically, "input of automatic transmission". Its true purpose is to detect "torque". Therefore, even if the engine torque is the same, the torque that enters the input shaft of the automatic transmission changes when the load of various auxiliary machines fluctuates, so the engine torque estimated simply by the accelerator opening and Q / N is calculated. When the control of the automatic transmission is executed based on the above, there is a problem that this is different from the actual input torque value in the automatic transmission.

The problem that the input torque of the automatic transmission fluctuates due to the load fluctuations of the various auxiliary machines is that the engine torque is indirectly detected by detecting means such as accelerator opening, throttle opening, or intake pipe negative pressure. The problem is the same whether it is detected directly or directly, that is, no matter how accurately the engine torque itself is detected.

The present invention has been made in view of such a conventional problem, and in the case of a shift requiring extremely delicate control such as a clutch-to-clutch shift, this shift is executed. In order to solve the above-mentioned problems, it is prohibited to change the load condition of various auxiliary machines during the period of time, thereby eliminating the fluctuation of the input torque to the automatic transmission and executing a good clutch-to-clutch shift. is there.

[0012]

SUMMARY OF THE INVENTION As shown in FIG. 1, the present invention provides a shift control device for an automatic transmission for a vehicle, which may perform clutch-to-clutch shift depending on engine torque. A means for detecting the engine torque, a means for executing the clutch-to-clutch shift based on the detected engine torque, a means for controlling a load state of an auxiliary machine of the engine, and a means for executing the clutch-to-clutch shift. And a means for prohibiting a change in the load state of the engine accessory, thereby solving the above problem.

[0013]

According to the present invention, when executing the clutch-to-clutch shift depending on the engine torque (originally, the input torque of the automatic transmission), the engine torque is basically detected as in the conventional method, but more accurate. In order to execute the clutch-to-clutch shift, it is prohibited to change the load states of various auxiliary machines of the engine while the clutch-to-clutch shift is executed.

As a result, while the clutch-to-clutch shift is being executed, the input torque of the automatic transmission is changed at least by changing the load state of the auxiliary machine, and as a result, the clutch-to-clutch shift is changed as usual. It becomes possible to prevent the shift shock from increasing due to the impossibility of execution.

In carrying out the present invention, it is more preferable to detect how much the load of the auxiliary machine is at the present time and correct the detected engine torque value. By doing this, not only does torque fluctuation disappear during shifting, but
The value itself (accuracy) of the input torque of the automatic transmission can be favorably maintained.

In this way, when the load of the auxiliary machine at the present time is detected and the engine torque (indirectly detected) is corrected based on this load value, the clutch-to-clutch shift is being executed in real time. Then, a method of detecting the load variation of the auxiliary machine and sequentially reflecting it in the calculation of the input torque of the automatic transmission can be considered. However, it detects this in real time for a load that changes during a shift,
Further, it is extremely difficult to interlock the hydraulic control device with this detected value and perform correction control of the engagement state of the friction engagement device in relation to responsiveness.

According to the present invention, while the clutch-to-clutch shift is being executed, the variation of the auxiliary machine is prohibited, so that the load (value) at the start of the clutch-to-clutch shift can be simply corrected. Since it is sufficient and there is no fluctuation during the shift, it is possible to execute a very stable shift.

[0018]

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

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

The engine 1 is controlled by the engine control computer 7 and the injection valve 19 of the engine 1 is used.
The fuel injection amount and the ignition timing of the distributor 20 are controlled, and an engine output corresponding to the accelerator opening (operation amount) of the accelerator pedal 22 and the engine rotation speed is obtained.

That is, the intake pipe 24 of the engine 1 has a main throttle valve 26 that opens and closes in conjunction with the movement of the accelerator pedal 22, and a motor driven by a command from the engine control computer 7 regardless of the accelerator pedal 22. A sub-throttle valve 30 that opens and closes in conjunction with the movement of 28 is arranged in series. Since the main throttle valve 26 is directly connected to the accelerator pedal, the accelerator operation amount and the engine output directly correspond to each other, but the sub-throttle valve 30 can freely set its opening, so that the whole throttle valve 26 can be set as a whole. The throttle opening having the intended characteristics can be obtained. Specifically, since it is in series, it is governed by the smaller opening of the two. The sub-throttle valve 30 is for arbitrarily controlling the engine torque for other purposes.
It is not directly related to the present invention.

In the engine control computer 7, the engine speed by the engine speed sensor 9, the intake air amount by the intake air amount sensor 10, the intake air temperature by the intake air temperature sensor 11, 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 ON signal by the brake switch 15, and the like are input. Q / N is obtained from the intake air amount Q and the engine speed N.

The engine control computer 7 determines the fuel injection amount and ignition timing based on these signals. The determination of the fuel injection amount will be described later in detail.

On the other hand, the automatic transmission control computer 8 includes the accelerator opening sensor 12 and the vehicle speed sensor 1.
3, the engine water 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 travel selection pattern such as fuel economy-oriented travel or power performance-oriented travel, and an air conditioner on / off signal from the auxiliary machine sensor 18 are input. As a result, the solenoid valves S1 to S4 and the SLN, SLT, SLU are controlled, and the engagement state of each friction engagement device is selectively changed as a result of the change of the oil passage in the hydraulic control device 3, thereby reducing the vehicle speed. And a gear stage corresponding to the accelerator opening degree can be smoothly obtained.

A specific example of the above-described automatic transmission 2 is shown in a skeleton diagram in FIG. The automatic transmission 2 includes a torque converter 111, an auxiliary transmission unit 112, and a main transmission unit 113.

The torque converter 111 has a lockup clutch 124. The lockup clutch 124 is provided between a front cover 127 that is integrated with the pump impeller 126 and a member (hub) 129 to which a turbine runner 128 is integrally attached.

The crankshaft (not shown) of the engine 1 is connected to the front cover 127. The input shaft 130 connected to the turbine runner 128 includes an overdrive planetary gear mechanism 13 that constitutes the auxiliary transmission unit 112.
It is connected to one carrier 132.

A clutch C0 and a one-way clutch F0 are provided between the carrier 132 and the sun gear 133 in the planetary gear mechanism 131. The one-way clutch F0 is adapted to be engaged when the sun gear 133 rotates forward relative to the carrier 132 (rotates in the rotational direction of the input shaft 130).

On the other hand, a brake B0 for selectively stopping the rotation of the sun gear 133 is provided. Further, a ring gear 134 which is an output element of the auxiliary transmission section 112 is connected to an intermediate shaft 135 which is an input element of the main transmission section 113.

The sub-transmission unit 112 has the planetary gear mechanism 1 when the clutch C0 or the one-way clutch F0 is engaged.
Since the whole 31 rotates integrally, the intermediate shaft 135
Rotates at the same speed as the input shaft 130. Further, in the state where the brake B0 is engaged and the rotation of the sun gear 133 is stopped, the ring gear 134 is accelerated with respect to the input shaft 130 to rotate normally. That is, the subtransmission unit 112 can set switching between high and low.

The main transmission unit 113 has three sets of planetary gear mechanisms 140, 150, 160, and these gear mechanisms 140, 150, 160 are connected as follows.

That is, the sun gear 141 of the first planetary gear mechanism 140 and the sun gear 151 of the second planetary gear mechanism 150 are integrally connected to each other, and the ring gear 143 of the first planetary gear mechanism 140 and the second planetary gear mechanism 150 are connected. Carrier 1
52 and the carrier 162 of the third planetary gear mechanism 160 are connected together. Further, the output shaft 170 is connected to the carrier 162 of the third planetary gear mechanism 160. Further, the ring gear 153 of the second planetary gear mechanism 150 is connected to the sun gear 161 of the third planetary gear mechanism 160.

In the gear train of the main transmission unit 113, it is possible to set one reverse gear and four forward gears, and a clutch and a brake therefor are provided as follows.

That is, the ring gear 153 of the second planetary gear mechanism 150 and the sun gear 161 of the third planetary gear mechanism 160.
A clutch C1 is provided between the intermediate shaft 135 and the intermediate shaft 135, and a clutch C2 is provided between the sun gear 141 of the first planetary gear mechanism 140 and the sun gear 151 of the second planetary gear mechanism 150 and the intermediate shaft 135.

A brake B1 for stopping the rotation of the sun gears 141 and 151 of the first planetary gear mechanism 140 and the second planetary gear mechanism 150 is arranged. Also, these sun gear 1
A one-way clutch F1 and a brake B2 are arranged in series between 41 and 151 and the casing 171.
The one-way clutch F1 is adapted to be engaged when the sun gears 141 and 151 try to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 135).

The carrier 142 of the first planetary gear mechanism 140
A brake B3 is provided between the casing and the casing 171. In addition, the ring gear 16 of the third planetary gear mechanism 160
A brake B4 and a one-way clutch F2 as elements for stopping the rotation of No. 3 are arranged in parallel with each other between the casing 171. The one-way clutch F2 is adapted to be engaged when the ring gear 163 tries to rotate in the reverse direction.

In the automatic transmission 2 described above, the auxiliary transmission unit 112
Can perform high / low two-stage switching, and the main transmission unit 113 can perform four-speed shifting on the forward side, so that it is possible to perform a reverse one-speed shift and a forward eight-speed shift as a whole. it can. An engagement operation table of each clutch and brake for setting these shift speeds is shown in FIG. In FIG. 4, a circle indicates an engaged state, a circle indicates an engaged state during engine braking, and a blank indicates a released state.

However, in this embodiment, only the first, second, third, fourth and fifth speeds are actually used. As is apparent from this figure, the second speed-the third
The shift between the gears is a clutch-to-clutch shift in which the brakes B2 and B3 must be engaged and released at the same time.

In this embodiment, the input torque Tin to the automatic transmission is detected by correcting the auxiliary machine load or the like from the detected engine torque actually obtained from Q / N (described later), and this is detected from the second speed stage. It is adapted to be used during power-on upshift to the third speed stage (upshift performed when power is transmitted from the engine side to the wheel side). Specifically, a 2-3 timing valve (not shown) controls the drain pressure of the brake B3 to the minimum required pressure in accordance with the increase of the engagement pressure of the brake B2. The relational expression at this time is shown below.

TB3 = A × Tin−B × TB2 (1) Tin ... Input torque of automatic transmission TB2 ... Transmission torque of brake B2 TB3 ... Transmission torque of brake B3 A, B ... Constant

Here, the input torque T of the automatic transmission is
Since in can be detected with high accuracy according to the present invention, control based on this equation (1) can be executed with high accuracy.
Thus, the clutch-to-clutch shift from the second speed stage to the third speed stage can be favorably executed.

In the present invention, how to accurately reflect the input torque that is accurately detected is reflected in the clutch-to-clutch shift is not limited to this.

Next, referring to FIG. 5, there is shown a control flow for inhibiting the load variation of the auxiliary machine during the clutch-to-clutch shift from the second speed stage to the third speed stage.

First, in step 210, various signals,
For example, signals such as the throttle opening θ, the vehicle speed V, the select position of the pattern select switch, the shift range, and the air conditioner on / off state are acquired.

In step 220, it is judged whether or not the clutch-to-clutch shift from the second speed stage to the third speed stage should occur. In this embodiment, the present invention is applied only during the clutch-to-clutch shift from the second speed stage to the third speed stage.
The process proceeds to step 230 only when the determination of "S" is made.

At step 230, it is judged if an air conditioner on / off switching signal is generated. When the air conditioner switching signal is not generated, that is, when the on state or the off state is continued as it is, steps 240 and 25.
It bypasses 0 and proceeds to 260 as it is.

However, if it is determined in step 230 that the air conditioner is turned on or off, the process proceeds to step 240, the flag F1 is set to 1, and the switching signal is held and switched in step 250. The previous state continues.

In step 260, it is determined whether or not gear shifting is in progress. If gear shifting is not completed, step 230
The steps from ~ 260 are repeated. Eventually, when the shift is completed, the routine proceeds to step 270, where it is determined whether or not the flag F1 is 1, and if it is not 1, the routine directly returns, but if it is 1, it is requested to switch the air conditioning during the shift. However, since it means that this has not been executed, the actual switching is performed in step 280.

By executing this control flow, the clutch-to-clutch shift from the second speed stage to the third speed stage will be executed at least with the air-conditioning state unchanged. Can be executed.

Next, from the Q / N (corresponding to the engine torque) detected using FIG. 6, the input torque Tin of the automatic transmission is set.
The control flow for obtaining is shown.

First, in step 310, various signals are read.

At step 320, it is judged if the clutch-to-clutch shift from the second speed stage to the third speed stage is executed. If it is determined that this shift is to be executed, the routine proceeds to step 330, where the engine torque TeY is obtained from Q / N.

As shown in FIG. 7, the engine torque TeY predicted by Q / N is the agitation loss Tlos of the engine.
And the engine torque T actually output from the engine
It is the sum of eX. Here, since the stirring loss Tlos can be almost ignored, TeX is effectively estimated by Q / N.

As is apparent from FIG. 7, the TeX actually output from this engine is partially consumed as the torque Th for driving the auxiliary machine, and the rest is input as Tin into the automatic transmission. Come on. Therefore, in step 340, the air conditioner is turned on and off (Th) as a representative of the auxiliary equipment.
Is detected, and the input torque Tin to the automatic transmission is calculated by TeX-Th based on this state (Th) (step 350).

More specifically, in this correction,
Considering the torque amplification by the torque converter, the input torque can be calculated with higher accuracy.

In step 360, the clutch-to-clutch shift from the second speed stage to the third speed stage is executed based on the obtained input torque Tin.

In this embodiment, in order to eliminate the influence of the load of the auxiliary machine, the load state of the auxiliary machine is forcibly changed to either the ON state or the OFF state, and then the clutch-to-clutch shift is executed. The clutch-to-clutch shift without load fluctuations is performed without compromising the durability of the auxiliary machine (reasonably) because the configuration is such that the actual speed up to that point is maintained. You can

In this embodiment, the engine torque T
Although Q / N is used as the means for detecting e, the present invention is also applicable to the case where the engine torque is detected by other detecting means, for example, the accelerator opening, the throttle opening or the intake pipe negative pressure. The effect of is obtained.

Further, in this embodiment, only the ON / OFF of the air conditioning, which has the most influence as the load of the auxiliary equipment, is taken into consideration. However, when the present invention is carried out, other load states, Needless to say, it is even better if the power steering on / off state, power window on / off state, front / rear wiper on / off state, and other states are taken into consideration.

[0060]

As described above, according to the present invention, the engine torque (input torque of the automatic transmission) can be detected with high accuracy. Therefore, the clutch-to-clutch shift operation performed based on this can be performed. It is possible to carry out according to predetermined conditions, and it is possible to obtain an excellent effect that it is possible to prevent an increase in shift shock.

[Brief description of drawings]

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

FIG. 2 is a schematic block diagram showing an embodiment of the present invention.

FIG. 3 is a skeleton diagram showing a gear train of the apparatus according to the embodiment.

FIG. 4 is a diagram showing an operating state of each friction engagement device of the gear train.

FIG. 5 is a flow chart showing a control flow for maintaining the load of an auxiliary machine unchanged.

FIG. 6 is a flowchart showing a control flow for calculating an input torque of the automatic transmission.

FIG. 7 is a block diagram showing a relationship between engine torque and input torque of the automatic transmission.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Automatic transmission, 7 ... Engine control computer, 8 ... Automatic transmission control computer, brakes B2, B3 ... Clutch-to-clutch shift brake between second speed and third speed, 9 ... Engine speed sensor, 11 ... Intake air amount sensor, 18 ... Auxiliary equipment sensor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Hojo, 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor, Hiroki Matsuoka, 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. ( 72) Inventor Masahiro Hayabuchi 10 Takane, Fujii-cho, Anjo City, Aichi Prefecture, Aisin A / Daburi Co., Ltd.

Claims (1)

[Claims] 1. A shift control device for a vehicular automatic transmission that may perform clutch-to-clutch shift depending on engine torque, and means for detecting the engine torque, and the clutch based on the detected engine torque. A means for executing a two-clutch shift, a means for controlling a load state of an engine accessory, and a means for inhibiting a change in a load state of an engine accessory when executing the clutch two-clutch shift. A shift control device for an automatic transmission for a vehicle characterized by the above.