JPH08169262A - Control device for automatic transmission - Google Patents

Abstract

PURPOSE: To lower engine torque on pertinent timing for reducing a gear change shock by issuing an instruction about the start of controlling the gear change process of an automatic transmission, when the execution of engine torque drop control is detected. CONSTITUTION: A gear change control computer 14 makes judgement about the execution of a gear change, and prior to the start of a gear change control process, sends a flag and a torque reduction amount to an engine control computer 5 via a communication line 18, requesting the start of a torque reduction process. Then, the computer 5, upon receipt of a signal for the flag and the amount, executes a torque reduction control process after a communication delay and an execution delay, and transmits a flag showing the execution of the control to the computer 14 via the line 18. The computer 14, upon receipt of a signal for the flag, drives gear gear change solenoids 15a and 15b, and a line pressure control solenoid 16, thereby starting a gear change control process. As a result, the gear change process can be controlled in the condition where engine torque is certainly lowered.

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, and more particularly to a device for changing the torque generated by an engine in order to reduce a shift shock during a shifting process.

[0002]

2. Description of the Related Art Conventionally, in an automatic transmission, various friction elements (clutch, brake, etc.) of a speed change gear mechanism are selectively hydraulically operated by line pressure to select a predetermined shift speed, and the friction element to be operated is changed. By doing so, gear shifting to another gear is performed.

At this time, a shock (shift shock) occurs due to a change in drive torque due to a shift. That is, during the shifting process, the inertia of the rotary member of the automatic transmission gives a temporary peak to the driving torque, and this peak appears as a shifting shock. Therefore, in order to reduce the shift shock, it is sufficient to suppress the occurrence of the temporary peak of the drive torque.

As a means for that purpose, conventionally, by adjusting the hydraulic pressure applied to various friction elements to generate an appropriate slip, the rotational energy of the transmission is dissipated as frictional heat to suppress fluctuations in drive torque. Is taken.
Furthermore, in recent years, with the increase in the output of the engine, the balance between the durability of the friction element and the shift shock becomes severe, and a method of reducing the shift shock by reducing the engine torque itself is adopted. It has become.

That is, in the conventional method of slowly engaging the friction element to suppress the shift shock, the durability of the friction element occurs in a high-power engine, so that the engine output is temporarily reduced during the shifting process. Therefore, the burden on the friction element is reduced.

[0006] Therefore, a product is already available that connects the engine control computer and the transmission control computer by communication to perform cooperative control. The control content of this cooperative control is such that a torque down request signal is first generated from the transmission control computer to the engine control computer at the start of gear shifting. Then, the engine control computer that has received the request for torque reduction executes torque reduction by means such as fuel cut and ignition retard at appropriate timing, and communicates the execution to the transmission control computer. .

In addition to this, in order to reduce shift shock, an output shaft torque sensor is used to detect a decrease in torque at the start of shift, and the line pressure of the transmission is controlled according to the result. There is also a method (JP-A-4-29).
666).

[0008]

However, in the conventional control technique using the above-mentioned communication, the engine control computer executes the torque down control in accordance with its operating state (after receiving the torque down request communication). Therefore, the timing of torque reduction may not always be synchronized with the timing at which the transmission control computer starts the shift control. As a result, there is a problem that a large shift shock occurs particularly when the timing of torque reduction is delayed.

Although a method of using the above-described Tokuru sensor may be considered in order to align the timing of torque reduction, an expensive torque sensor is required, which is not always preferable. The present invention has been made to solve the above problems, and in a high-power engine that performs cooperative control by communication without using an expensive torque sensor, reduces the torque at a suitable timing to prevent a shift shock. An object of the present invention is to provide a control device for an automatic transmission that can be reduced.

[0010]

Means for Solving the Problems The first aspect of the present invention is shown in FIG.
As illustrated in, during the shifting process of the hydraulic automatic transmission,
In an automatic transmission control device for changing a torque generated by an engine to reduce a shift shock, an engine torque control means for controlling an output torque of the engine, a shift operation of the automatic transmission and a hydraulic control associated therewith. And a torque reduction instruction means for instructing the engine torque control means to perform engine torque reduction control according to the shift request of the transmission control means, and the engine torque according to the instruction of the torque reduction instruction means. A torque reduction control detection unit that detects that the control unit executes the engine torque reduction control, and the transmission control when the execution of the engine torque reduction control is detected by the torque reduction control detection unit. A torque drop notification signal for notifying the engine torque drop is output to the automatic change means. And control instruction means for instructing the control of the speed change process of the machine, a control device for an automatic transmission characterized by comprising the the gist.

The invention according to claim 2 is characterized in that the control of the shift process of the automatic transmission is shift control by switching the hydraulic pressure by using the torque decrease notification signal as a trigger. The gist is the control device of the automatic transmission.

According to a third aspect of the present invention, the control of the shift process of the automatic transmission is a control of the transient hydraulic pressure during the shift period triggered by the torque decrease notification signal. The gist is the automatic transmission control device.

According to a fourth aspect of the present invention, the torque reduction control detecting means detects the torque reduction by the change of the ignition retard execution signal or the ignition timing signal of the engine to the retard side. The gist is the control device for an automatic transmission according to any one of Items 1 to 3.

According to a fifth aspect of the present invention, the torque reduction control detecting means detects the torque reduction based on a fuel cut execution signal of the engine or a decrease in fuel injection amount. The gist is the control device for the automatic transmission described above.

According to a sixth aspect of the present invention, the torque reduction control detecting means detects a torque reduction due to a reduction in the input shaft speed of the automatic transmission.
The gist is the control device for an automatic transmission according to any one of items 1 to 3.

[0016]

According to the invention of claim 1, the torque reduction instruction means instructs the engine torque control means to perform engine torque reduction control in accordance with the shift request of the transmission control means, and the torque reduction control detection means causes the engine torque control means to operate. It is detected that the engine torque reduction control has been executed.
Then, when the execution of the engine torque reduction control is detected, the control instruction means outputs a torque reduction notification signal for notifying the reduction of the engine torque to the transmission control means to notify the transmission process of the automatic transmission. Instruct control.

That is, according to the present invention, the control of the shift process such as the shift control is started only when the actual torque reduction is detected by the torque down control of the engine. Therefore, the engine control and the transmission control are performed. No need for delicate timing adjustments between. Further, since the control of the shift process in the state where the engine torque is reliably reduced can be executed, it is possible to reduce the shift shock while compensating the durability of the friction element. Further, the detection of the decrease of the engine torque in this control uses the execution command value of the control computer and the like, and therefore an expensive torque sensor is not required.

According to the second aspect of the present invention, since the shift control by switching the hydraulic pressure is performed by using the torque decrease notification signal as a trigger, the shift shock can be reduced and the shift control can be suitably performed. In the invention of claim 3, the transient oil pressure is controlled during the shift period by using the torque decrease notification signal as a trigger. Therefore, the shift shock can be more precisely reduced and the shift control can be preferably performed. It is possible to

According to the invention of claim 4, the ignition retard execution signal or the ignition timing signal of the engine is changed to the retard side.
It is possible to detect a torque decrease. According to the fifth aspect of the invention, it is possible to detect the torque reduction by the fuel cut execution signal of the engine or the decrease of the fuel injection amount.

According to the sixth aspect of the invention, it is possible to detect the decrease in torque by the decrease in the input shaft speed of the automatic transmission.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 2 shows the overall configuration of an automatic transmission control system incorporating a control device for performing cooperative control according to Embodiment 1.

As shown in FIG. 2, an engine 1 mounted on a vehicle and electronically controlled is connected to drive wheels 4 via an automatic transmission 2 and a differential gear 3. The engine 1 includes an engine control computer 5,
The engine control computer 5 includes an engine rotation sensor 6 for detecting an engine speed, a vehicle speed sensor 7 for detecting a vehicle speed (output shaft speed of the automatic transmission 2), and a throttle sensor for detecting a throttle opening of the engine 1. 8 and each signal of the intake air amount sensor 9 for detecting the intake air amount.

The engine control computer 5 determines the fuel injection amount based on these input information, issues a command to the engine 1, and supplies an ignition signal (not shown) to the engine 1. Then, in response to this command, a fuel supply device and an ignition device (not shown) are activated, fuel is supplied and burned in accordance with the rotation of the engine 1, and the engine 1 is driven and controlled.

The automatic transmission 2 is the torque converter 1
0 and a speed change gear mechanism 11 are provided, and the power supplied from the engine 1 is transmitted to the input shaft 12 of the speed change gear mechanism 11 via the engine output shaft 1a (see FIG. 3) and the torque converter 10. Then, the transmission input rotation to the input shaft 12 is accelerated and decelerated according to the selected speed of the speed change gear mechanism 11 to the output shaft 13 or reaches the drive wheels 4 from the output shaft 13 via the differential gear 3. You can drive a car.

Since the automatic transmission 2 is a known one as shown in FIG. 3, its detailed description will be omitted.
The transmission gear mechanism 11 includes various clutches (R / R) that determine a power transmission path (gear stage) from the input shaft 12 to the output shaft 13.
C, H / C, LO / C, OR / C, F / C, FO / C)
It incorporates various friction elements such as brakes and brakes (B / B, LR / B).

As shown in FIG. 2, the speed change gear mechanism 11 is connected to a control valve 15 which is driven based on a command from a speed change control computer 14, and an appropriate hydraulic pressure is supplied from the control valve 15. Gear shifting is realized by operating the hydraulic pressure on various friction elements.

The control valve 15 is provided with two shift control solenoids 15 for switching the path for supplying hydraulic pressure for each shift stage in response to a command from the shift control computer 14.
A line pressure control solenoid 16 for controlling the magnitude of hydraulic pressure is arranged. Although the two shift control solenoids 15a and 15b are used in the present embodiment, the number of shift control solenoids may be increased depending on the number of shift stages and the internal configuration of the control valve 15. Further, a solenoid may be added to adjust the timing for the rapid filling and discharging of the hydraulic oil during the shift transition. Further, as the line pressure control solenoid 16,
In the present embodiment, the duty solenoid will be described below, but other means such as a linear solenoid may be used as long as the mechanism can change the hydraulic pressure.

Although not shown, the shift control computer 14 is composed of a microcomputer including a CPU, a ROM, a RAM and an I / O device, and measures the rotation speed of the input shaft 12 in addition to the vehicle speed sensor 7 and the throttle sensor 8. Each signal of the input shaft rotation sensor 17 is input.

Further, the engine control computer 5 and the shift control computer 14 are connected by a communication line 18 so that control information and commands can be bidirectionally communicated. The communication line 18 is a LAN (Local Area N).
a multi-communication mechanism such as etwork), or wiring for connecting the input / output ports of the control computers 5 and 14 for each required communication.

Next, the shift control by the shift control computer 14 will be described with reference to the graph of FIG. The shift control computer 14 uses the signals from the vehicle speed sensor 7 and the throttle sensor 8 to change the current driving state to a shift diagram (predetermined according to the throttle opening and the vehicle speed) as shown in FIG. The gear position is determined by determining which gear region it is in. It should be noted that in the shift diagram, in order to prevent chattering when determining the shift speed, the n-th speed (n = 1,
2, 3) to n + 1-th speed shift (upshift) and m-th speed (m = 2, 3, 4) to m-1th speed shift (downshift), in the case of upshift, a solid line, In the case of downshift, different judgment lines are used as shown by the dotted lines.

Then, according to the determination result obtained on the basis of FIG. 4, the two shift control solenoids 15a and 15b are turned off.
N / OFF (on / off) is selected and executed as shown in Table 1 below, for example.

[0032]

[Table 1]

In this way, the shift control solenoids 15a, 15b
By controlling the ON / OFF of the control valve and driving the control valve 15, the hydraulic pressure that can be applied to various friction elements inside the speed change gear mechanism 11 changes, and the necessary clutches and brakes are activated, and The gear position is maintained or the gear shift is achieved as shown.

The shift control computer 14 is also provided.
Also controls the line pressure control solenoid 16 as described below. In the normal case where the gear position does not change, the hydraulic pressure (line pressure) given by the map for the throttle opening as shown in FIG. 5 is generated. Specifically, first, the required line pressure is obtained from the map of FIG. 5 according to the signal from the throttle sensor 8, and then this line pressure is converted into a duty value according to the map of FIG. 6 for line pressure control. The solenoid 16 is driven with the duty value to realize the target line pressure. In this case, combining FIG. 5 and FIG. 6,
It goes without saying that the duty value may be directly obtained from the throttle opening.

On the other hand, if there is a request to change the gear position as a result of the gear shift determination performed based on FIG. 4, the gear shift control solenoids 15a and 15b are turned ON / OFF and the gear shift shock is alleviated. In order to control the line pressure. The method will be described by taking an upshift as an example. Starting from a predetermined initial hydraulic pressure Pi depending on the gear position, the throttle opening, the torque generated by the engine 1 or the magnitude of the torque generated in the input shaft 12,
The line pressure is feedback-controlled so that a change in the rotational speed of the input shaft 12 that is set so that the change in the torque of the output shaft 13 has a predetermined shape can be obtained.

The state of the control operation at that time is shown in FIG.
Note that FIG. 7 shows the operation of shifting from the first speed to the second speed. As shown in FIG. 7, first, along with the shift command, the shift control solenoid 15a is kept ON, and the other shift control solenoids 15b are changed from OFF to ON. At the same time, the line pressure is set to the initial value Pi. After that, since the actual rotation speed of the input shaft 12 starts to decrease from the target value at point A, the hydraulic pressure is reduced so that the gradient matches the target value (line pressure feedback control). And further B
After reaching the point, the rotation speed of the input shaft 12 started to increase,
Gear shifting ends. The feedback control is also ended in accordance with the timing, and a predetermined time T0 (for example, 0.25 to
Keep the line pressure low for 0.5 seconds). afterwards,
Return to the original reference oil pressure (initial value) Pi. The line pressure is kept at a low value during this T0 time in order to mitigate the shock caused by the sudden change in the torque at the end of the shift.

The above is the gear shift control in a general operating state. In this embodiment, as will be described later, gear shift shock is further reduced, and wear of the friction element is increased especially when the throttle opening with a large engine output is high. In order to improve the durability and absorb the shift shock well, the engine output torque is controlled to be reduced during the shift transition.

Then, the whole procedure of the torque down control by the cooperation of the engine control computer 5 and the shift control computer 14 will be described with reference to the time chart of FIG. As shown in FIG. 8, first, at the time point a, the shift control computer 14 is set to the above-mentioned FIG.
Execution of the shift is determined based on the shift diagram shown in FIG. At this time, prior to the shift operation, the communication line 18 transmits a flag requesting the start of torque down and the amount of torque down (as one command code) to the engine control computer 5. The amount of torque down (that is, the command code) increases as the output of the engine at the start of gear shift increases, and an example thereof is shown in Table 2 below.

[0039]

[Table 2]

In the engine control computer 5 that has received the communication, after the delay time (communication delay) related to the communication process and the delay time (execution delay) due to the control timing deviation, the ignition timing is instructed according to the torque down instruction. The torque-down control is executed by controlling the retardation of the fuel injection amount, decreasing the fuel injection amount, or cutting the fuel injection. Further, the engine control computer 5 has a flag indicating the execution of this torque down control or an RA indicating the execution state.
The M value is transmitted to the shift control computer 14 via the communication line 18.

On the other hand, in the shift control computer 14,
At the time point b (FIG. 8) after the communication delay time has elapsed after the execution of the torque reduction, this torque reduction execution signal is received from the engine control computer 5, and the above-described shift control, that is, the shift control solenoid. The drive control of the solenoids 15a and 15b and the line pressure control solenoid 16 is started.

As described above, in this embodiment, the shift control computer 14 drives the shift control solenoids 15a and 15b after detecting the start of execution of the torque down control by the engine control computer 5 to shift gears. Start control. Therefore, complicated timing adjustment between the two,
The remarkable effect that the shift control can be realized in the state where the engine torque is surely reduced without requiring the delicate adaptation or the timing learning control for performing the expected shift start control.

Further, there is an advantage that appropriate shift control can be realized by communication between the computers 5 and 14 without using an expensive torque sensor. In this embodiment, torque reduction is performed when the number of rotations of the transmission input shaft 12 becomes Nt0 × k (k is a constant determined by engine performance and the like) from the value Nt0 at the time point a when the shift is determined. The request has been canceled. This is a measure for preventing the execution of the torque down control of the engine from continuing after the shift process is completed. That is, simply at time point c (Fig. 1
If the torque down request is released at the time when the gear shift is completed (as shown in 1), the torque down processing and sufficient acceleration are performed until the gear shift ends and acceleration at a new gear stage is required due to the delay as described above. Torque cannot be obtained, causing an unpleasant shock. Therefore, the torque down request is released before the shift process is completed, and when the shift process is completed, sufficient acceleration torque can be generated in the engine.

As a method of detecting a decrease in engine torque, there is a method of actually detecting a decrease in the number of revolutions of the transmission input shaft 12 in addition to the method by communication from the engine control computer 5 described above. . That is, in the state before shifting, the input shaft 12 is rotated by the output torque of the engine 1 according to the operating state. When the torque reduction control as described above is executed there, the torque for maintaining the acceleration of the vehicle is lost, and the rotation of the input shaft 12 starts to decrease. Therefore, the shift control computer 14 issues a shift request to the engine control computer 5 and then, even though the throttle opening does not change, the input shaft 12 does not change.
Execution of the torque down control can be detected by detecting that the increase in the rotation speed (acceleration state) of 1 has started to become dull. It should be noted that when the acceleration state starts to slow down, the number of revolutions has not yet started to decrease, so the driver does not feel a sense of discomfort such as deceleration of the vehicle.

Next, the engine 1 and the automatic transmission 2 described above
The control that realizes the cooperative control of 1 will be described in more detail with reference to the flowchart. 9 is a flowchart of the control executed by the shift control computer 14, and FIG. 10 is a flowchart of the control executed by the engine control computer 5.

First, the control executed by the shift control computer 14 will be described with reference to FIG. In step 210, the throttle opening required for gear shift determination,
The vehicle speed and the rotation speed Nt of the input shaft 12 are read.

Next, the routine proceeds to step 220, where it is judged whether or not there is a shift according to the shift diagram shown in the map of FIG. That is, when the line connecting the relational position of the vehicle speed-throttle opening in the previous calculation and the relational position in the current calculation crosses the solid or dotted shift line, it is determined that there is a shift.

If it is determined that there is a gear shift, the routine proceeds to step 230, where it is determined whether or not the engine is in a high output region where torque reduction is required. That is, Table 2 above
As shown in, it is determined whether the throttle opening is 25% or more. Then, when the throttle opening is 25% or more, it is determined that the torque down control is necessary, and the routine proceeds to step 240.

In step 240, according to Table 2 above,
A command value for torque down control according to the throttle opening is calculated, and the result is obtained from the command code values (1 to 3) shown in Table 2. In the following step 250, a torque down request is issued to the engine controlling computer 5 through the communication line 18. That is, the command value code obtained in step 240 is used as the engine control computer 14
Send to.

In the following step 260, execution of torque reduction is detected. This step 260 is repeatedly executed until the execution of torque reduction is detected. The following methods I) and II) are available as methods for detecting this torque reduction execution. I) First, the simplest method is to receive an execution flag from the engine control computer 5.

That is, it is a method in which the execution of torque reduction is detected and judged by receiving a predetermined flag or execution code from the engine control computer 5. In this case, it may be decided to receive the coded code, or the ignition timing data may be received regularly to retard the ignition timing that occurs within a predetermined time from the ignition retard request. Change (in the case of ignition retard control), periodically receive the fuel injection time, and detect the shortening of the fuel injection time that occurred within a predetermined time from the fuel cut request (fuel cut time). In case of control).

II) Another method is to detect a change in the number of revolutions of the input shaft 12. That is, after outputting the torque down request from the shift control computer 14,
A predetermined time of the rotation speed of the input shaft 12 (for example, 32 msec to 15 msec)
Change in input shaft rotation speed at a certain value during 0 msec △
nt (n) is determined, and when this variation Δnt (n) satisfies the following equations (1) to (3), it is determined that torque reduction has been executed.

Δnt (n−1) = nt (n−1) −nt (n−2) (1) Δnt (n) = nt (n) −nt (n−1) (2) Δ nt (n−1) −Δnt (n) ≧ Δ0 (3) This means the following.

That is, since the control is performed when the throttle opening has a certain value, the vehicle is in an accelerating state and the change amount Δnt (n) has a positive value. Therefore, the decrease in that value in the predetermined time is detected by the above equation (3). That is, the expression (3) indicates that the engine torque has decreased due to the execution of the torque reduction, and the acceleration state of the vehicle has become dull. It should be noted that in equation (3) above, Δ0
The value of is in the range of about 0 to 50 rpm and is appropriately selected depending on the performance of the input shaft rotation sensor 17, the engine output performance of the vehicle, and the like.

Next, when the execution of the torque down control is detected in the judgment of step 260, step 270
Proceed to. Also, when it is determined in the determination of step 230 that the torque down control is unnecessary (command value code 0), the process proceeds to step 270.

In step 270, according to Table 1 above,
A shift control solenoid 15a for each determined shift speed,
Turn b on / off. In the following step 280, the line pressure at the initial stage of gear shifting is set, the duty value is obtained according to the characteristic diagram of FIG. 6, and the set initial line pressure is obtained.
The line pressure control solenoid 16 is duty-driven.

At the following step 290, feedback control of the line pressure is performed so that the rotation speed of the input shaft 12 changes in a predetermined manner. That is, as shown in FIG. 7, when the actual rotation speed of the input shaft 12 starts to decrease away from the target value,
Control is performed to reduce the hydraulic pressure so that the gradient matches the target value. It should be noted that this feedback control is repeatedly executed until it is determined in the shift determination in step 300 below that the shift is terminated.

In the case of the upshift just described, in the determination of the end of step 300, the direction of the change of the input shaft rotation speed is opposite, that is, the rotation speed which has decreased due to the progress of the shift increases again. It suffices to detect the turning point. Alternatively, it is necessary to detect when the difference between the value obtained by multiplying the vehicle speed by the reciprocal of the gear ratio of the gear in which the speed change gear mechanism 11 is in progress and the input shaft rotation speed is below a predetermined value (for example, 50 rpm). You may judge by.

Further, returning to the previous step, if it is not judged in the step 220 that the gear shift is started, the routine proceeds to steps 310 to 330 to shift the solenoid 15 for gear shift control.
ON / OFF of a and b keep the current state,
Based on FIGS. 5 and 6, the line pressure and the duty value corresponding thereto are calculated, and the line pressure control solenoid 16 is driven to the duty value.

The control process described above is repeatedly executed while the shift control computer 14 is powered on in preparation for the next shift. Also, at that time, step 260
The determination process of or 300 is repeated at a cycle of 16 msec or 25 msec, for example. Next, the control executed by the engine control computer 5 will be described with reference to FIG. 10A is a flowchart of the control executed in the main routine, and FIG. 10B is a flowchart of the control executed in the interrupt routine synchronized with the rotation of the engine 1.

First, the processing shown in FIG. 10A will be described. In step 410, the intake air amount and the engine speed are read based on the signals from the respective sensors. In the following step 420, as a value proportional to the intake air amount,
A fuel injection amount, that is, an energization time to an injector (not shown) is calculated.

In the following step 430, the ignition timing is obtained as a function of the engine speed. This is an operation for obtaining the rotation angle (advance amount) of the engine crankshaft corresponding to the flame propagation time determined by the size of the cylinder.
Then, the above-described operations of steps 420 and 430 are repeatedly executed in time for each fuel injection and ignition.

Next, the processing shown in FIG. 10B will be described. The interrupt process synchronized with the engine rotation is activated every 120 degrees of the engine crankshaft rotation angle (in the case of a 6-cylinder engine). First, step 51
At 0, the injection cylinder is determined. For example, considering an inline 6-cylinder engine, from the front side of the engine 1, # 1, # 2- #
6, the injection is performed in the order of # 1, # 5, # 3, # 6, # 2, and # 4. In this order, the cylinder number immediately before the start of the suction process is selected from the current rotational position of the crankshaft.

In the following step 520, the process shown in FIG.
The injector energization start timing is determined so that the injector energization time obtained in the main routine of (3) is completed by a predetermined crank angle position. In the following step 530, the presence or absence of a request for fuel cut control is confirmed by the state of the command code. The command code is determined by the shift control computer 14 in step 240 of FIG. 9 and transmitted to the engine control computer 5 in step 250.

If it is determined in step 530 that the command code is 3, the process proceeds to step 540. This request requires fuel cut for all cylinders,
The current fuel injection amount, that is, the injector energization time is set to zero. After that, the process proceeds to step 560.

If it is determined in step 530 that the command code is 2, the process proceeds to step 550.
Here, since it is necessary to cut the fuel in half the number of cylinders (three cylinders in this embodiment), for example, when the current fuel injection cylinders are # 1, # 2, and # 3, the fuel injection amount, That is, the injector energization time is set to zero, while the fuel injection cylinder
In the case of 4, # 5 and # 6, the values obtained in the main routine of FIG. After that, the process proceeds to step 560.

Further, when the command code is 0 or 1 in the determination of step 530, the process proceeds to step 560. In step 560, the energization of the injector of the determined cylinder is started. After the set energization time has elapsed, energization is terminated by the I / O timer function of the microcomputer. Then, it proceeds to step 570.

In step 570, the cylinder to be ignited is determined from the rotational position of the engine crankshaft. In the following step 580, the presence or absence of the ignition retard request is determined by the command value code. When the command value code is 1 (request for ignition retardation), the process proceeds to step 590. When the command value code is other than 1 (0, 2, 3), the process proceeds to step 600.

At step 590, the ignition timing obtained in the main routine of FIG. 10A is changed to the retard side by θddeg. Further, in step 600, a timer incorporated in the microcomputer for starting and ending energization of an igniter (not shown) is started so that ignition is executed at the set ignition timing. With this timer, energization ON / OFF of the igniter, that is, ignition is executed.

With the above, the processing of the interrupt routine is completed. Therefore, as shown in FIGS. 9 and 10, the engine control computer 5 and the shift control computer 14 are shown.
The control can realize the cooperative control of the engine 1 and the automatic transmission 2, and thereby reduce the above-mentioned shift shock. (Second Embodiment) Next, a second embodiment will be described.

Since the device configuration of this embodiment is the same as that of the first embodiment, the different operation will be described with reference to the time chart of FIG. The device number is
The same numbers as in Example 1 above are used. Unlike the first embodiment, the present embodiment operates the shift control solenoids 15a and 15b prior to transmitting the torque down command code and the torque down execution flag.
1 has a slow hydraulic response, and the shift control solenoids 15a and 15b
This is suitable when it takes time to start the shift phenomenon after the oil passage is switched by.

As shown in FIG. 11, first, at the time point a,
The shift control computer 14 determines the execution of the shift based on the shift diagram shown in FIG. At this time, as shown in FIG.
As described above, the friction elements are switched by the shift control solenoids 15a and 15b, and the line pressure is also the shift initial hydraulic pressure P.
Set to i. Then, after a predetermined time tT (≧ 0 sec) determined from the characteristic of the hydraulic response elapses, a flag requesting the engine control computer 5 to start torque reduction and a torque reduction amount (one command (As a code) to the engine control computer 5.

In the engine control computer 5, after a time delay of communication delay and execution delay, the torque is controlled by retarding the ignition timing or by reducing the fuel injection amount or cutting the fuel injection in accordance with the torque down instruction. Run down The engine control computer 5 transmits the flag indicating this execution or the RAM value indicating the execution state to the shift control computer 14 through the communication line 18.

The shift control computer 14 receives the torque down execution signal from the engine control computer 5 at a time point b (FIG. 11) after the communication delay time has elapsed after the torque down was executed, and the transmission 14 Input shaft 1
Feedback control for adjusting the rotation speed of 2 to a predetermined gradient is started. The execution period of the feedback control is indicated by the control execution flag shown at the bottom of FIG.

That is, after the start of the torque down control by the engine control computer 5 is detected, the line pressure is feedback-controlled to adjust the rotational speed of the transmission input shaft 12 to control the torque down control. The shift shock can be controlled appropriately.

This control will be briefly described below with reference to FIG. First, as a result of the shift determination, the shift control solenoids 15a and 15b are immediately operated to switch the friction element. Then, with the switching of the friction element, the rotation speed of the input shaft 12 starts to decrease according to the first gradient.
After that, when torque down control is executed by communication between the two computers 5 and 14, the rotation speed of the input shaft 12 decreases according to a steeper second gradient due to the effect of this torque down control. Then, during the engine-transmission coordinated control, a target value for the change in the number of revolutions of the input shaft 12 is set so as to follow the second gradient, and feedback control of the line pressure toward the target value is performed to cause a shift shock. Reduce.

In the present embodiment, the feedback control of the line pressure described above is performed at the time when the rotation speed of the input shaft 12 is decreased by the first gradient, similarly to the normal control (shown in FIG. 7). When started, it is necessary to perform processing such as changing the target value at the time when the point of change to the second gradient is detected, and vibration of hydraulic pressure occurs due to response delay of the control system, which causes a shift shock. There is.

This state is shown in FIG. 12, in which the feedback control of the line pressure for making the rotation speed of the input shaft 12 follow the target value is started at the point, and the rotation speed gradient is set to the second value as the torque reduction is executed at the point. Changes to. Therefore, even if there is a slight delay in the detection of the torque down control execution and the target value is changed at a point, the line pressure and the change in the rotation speed of the input shaft 12 cause vibrations due to the response delay of the feedback control system. However, this is a shift shock.

Therefore, in the present embodiment, as shown in FIG. 11, by starting the feedback control of the line pressure after the torque down control is executed, inadvertent hydraulic pressure control is prevented and shift shock is generated. Is preventing. It should be noted that the execution of the torque down control by the engine control computer 5 may be performed by detecting the point at which the change in the rotation speed of the transmission input shaft 12 changes from the first gradient to the second gradient. Needless to say.

As described above, in this embodiment, the shift control computer 14 is the engine control computer 5.
After the start of torque down control by the engine is detected, hydraulic control during the gear shift period (line pressure feedback control)
To start. Therefore, complicated timing adjustments between the two computers 5 and 14 and delicate adaptation for performing expected shift start control and timing learning control are not required, and the shift control can be performed reliably with the engine torque reduced. It has a remarkable effect that it can be realized.

Needless to say, the present invention is not limited to the above-mentioned embodiments, and can be carried out in various modes without departing from the gist of the present invention. For example, in each of the above-described embodiments, the engine control computer 5 and the transmission control computer 14 are separate bodies and are connected by a bidirectional communication line 18, but the engine control and the transmission control are controlled. May be processed by one computer. In that case, the information exchanged by the communication line 18 is the data of the RAM allocated to the predetermined address in the computer by the programs of the engine control and the transmission control which are repeatedly executed at appropriate intervals. , It is replaced by the process of rewriting to the latest value or reading and using.

[0082]

As described in detail above, according to the first aspect of the invention, the engine torque control means is instructed to perform the engine torque reduction control according to the shift request of the transmission control means, and the engine torque control means reduces the engine torque. When the execution of the control is detected, the torque reduction notification signal is output to the transmission control means to instruct the control of the shift process of the automatic transmission.

That is, according to the present invention, prior to the control of the shift process such as the shift control, the torque down control of the engine is started, the execution of the torque down control is detected, and then the hydraulic control for the shift is performed. Even in the control at the time of gear shift in the driving condition that is the output, there is a remarkable effect that it is possible to realize suitable control without gear shift shock while compensating the wear durability of the friction element. Further, since the detection of the torque down can be realized by using the calculated value of the control computer or the like, there is an advantage that the expensive torque sensor is not required and the cost can be realized.

According to the second aspect of the present invention, the shift shock is reduced and the shift control can be suitably performed by performing the shift control by switching the hydraulic pressure using the torque decrease notification signal as a trigger. According to the third aspect of the present invention, the transient oil pressure is controlled during the shift period by using the torque decrease notification signal as a trigger. Therefore, the shift shock can be reduced more precisely than in the second aspect, and the control during the shift is preferably performed. It can be carried out.

According to the invention of claim 4, the ignition retard execution signal or the ignition timing signal of the engine is changed to the retard side,
A decrease in torque can be detected. According to the fifth aspect of the invention, the decrease in torque can be detected by the fuel cut execution signal of the engine or the decrease in the fuel injection amount. According to the invention of claim 6, the decrease in torque can be detected by the decrease in the input shaft rotation speed of the automatic transmission.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the configuration of the invention of claim 1.

FIG. 2 is a schematic configuration diagram showing an overall configuration of an automatic transmission control system incorporating the control device of the first embodiment.

FIG. 3 is a schematic configuration diagram showing a configuration of an automatic transmission.

FIG. 4 is a graph showing shift lines for upshift and downshift.

FIG. 5 is a map for obtaining a line pressure from a throttle opening.

FIG. 6 is a map for obtaining a duty value from line pressure.

FIG. 7 is a timing chart showing a normal shift state.

FIG. 8 is a timing chart showing a gear shift state according to the first embodiment.

FIG. 9 is a flowchart showing a control process of the shift control computer according to the first embodiment.

FIG. 10 shows a control process of an engine control computer according to a second embodiment, (a) is a flowchart showing a main routine thereof, and (b) is a flowchart showing an interrupt routine thereof.

FIG. 11 is a timing chart showing a gear shift state according to the second embodiment.

FIG. 12 is a timing chart showing an unfavorable shift state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Automatic transmission 5 ... Engine control computer 6 ... Engine rotation sensor 7 ... Vehicle speed sensor 8 ... Throttle sensor 10 ... Torque converter 11 ... Shift gear mechanism 12 ... Input shaft 13 ... Output shaft 14 ... Shift control computer 15 ... Control valves 15a, 15b ... Shift control solenoid 16 ... Line pressure control solenoid

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideki Masamura, 1-1, Showa-cho, Kariya city, Aichi Prefecture, Nihon Denso Co., Ltd. (72) Inventor, Kayo Obayashi, 1-1, Showa-cho, Kariya city, Aichi prefecture Sozo Co., Ltd.

Claims (6)

[Claims] 1. A control device for an automatic transmission, wherein torque generated by the engine is changed to reduce a shift shock during a shifting process of the hydraulic automatic transmission, the engine controlling output torque of the engine. Torque control means, transmission control means for performing shift operation of the automatic transmission and accompanying hydraulic control, and torque for instructing the engine torque control means to perform engine torque reduction control in accordance with a shift request of the transmission control means. Reduction instruction means, torque reduction control detection means for detecting that the engine torque reduction control is executed by the engine torque control means according to the instruction of the torque reduction instruction means, and the engine torque control means for detecting the engine torque by the torque reduction control detection means. Is detected, the transmission control means is caused to reduce the engine torque. And outputs the torque reduction notification signal for notifying the control device of the automatic transmission, characterized in that and a control instruction means for instructing the control of the speed change process of the automatic transmission. 2. The control of the automatic transmission according to claim 1, wherein the control of the shift process of the automatic transmission is shift control by switching the hydraulic pressure by using the torque decrease notification signal as a trigger. apparatus. 3. The automatic transmission according to claim 1, wherein the control of the shift process of the automatic transmission is a control of the transient hydraulic pressure during the shift period triggered by the torque decrease notification signal. Control device. 4. The torque reduction control detecting means detects the torque reduction by changing the ignition retard execution signal or the ignition timing signal of the engine to the retard side. A control device for an automatic transmission according to any one of the above. 5. The automatic shift according to claim 1, wherein the torque reduction control detection means detects a torque reduction based on a fuel cut execution signal of the engine or a decrease in fuel injection amount. Machine control device. 6. The automatic transmission according to claim 1, wherein the torque reduction control detecting means detects a torque reduction due to a reduction in an input shaft rotation speed of the automatic transmission. Control device.