JPH02238139A - Control method of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent the connecting shock by changing rapidly the actual rotation speed toward the object rotation speed until the synchronous time reaches to a specific value, when the gear stage is shifted, and after that, changing the rotation speed gently, and reconnecting an automatic clutch when the both rotation speeds are coincided. CONSTITUTION:When a synchronous gearing type multistage transmission 14 is controlled to shift by a control device 16 which inputs the output signals of various sensors to detect operation parameters, the object engine rotation speed when an object gear stage is achieved is computed as well as computing the differential value of the engine rotation speed at first. And, depending on the above differential value, the object rotation speed, and the actual rotation speed, the synchronous time until the actual rotation speed reaches to the object rotation speed is computed successively. And it is decided whether the synchronous time is reduced to a specific value or not, and when the decision is NO, the opening of a throttle valve 80 is controlled to change the actual rotation speed rapidly toward the object rotation speed. When the decision is YES, it is controlled to change the actual rotation speed gently.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a control method for an automatic transmission for a vehicle.

Prior Art When automatically switching a synchronous mesh type stepped transmission having multiple gears to a target gear, the throttle valve is closed to reduce the engine output, and then the automatic clutch is opened to reduce the engine power. Control of an automatic transmission for a vehicle in which the gear position of the stepped transmission is changed while transmission is temporarily interrupted, and then the automatic clutch is re-engaged to re-transmit power from the engine. A method is being considered. For example, patent application No. 63-2383 filed earlier by the present applicant.
This is what is described in No. 44.

Problems to be Solved by the Invention However, there are still problems to be solved in this method of controlling an automatic transmission for a vehicle.

In other words, the retransmission of power from the engine is usually carried out by so-called half-clutch control in which the automatic clutch is gradually re-engaged while opening the throttle valve, which makes it difficult to obtain sufficient durability of the automatic clutch and also causes so-called judder. There are cases.

On the other hand, at the same time as the gear shift operation starts,
The opening of the throttle valve is controlled to obtain an engine rotation speed that is synchronized with the rotation speed of the input shaft of the stepped transmission when the target gear is established, and after the gear change operation is completed, the actual engine It has been considered to wait until the rotation speed is synchronized with the rotation speed of the input shaft of the stepped transmission before re-engaging the automatic clutch, but this method reduces the engagement shock when the automatic clutch re-engages. Although it is possible to solve the problems associated with the above-mentioned half-shift control, it takes a relatively long time for the rotational speed of the engine to synchronize with the rotational speed of the input shaft of the stepped transmission, making it difficult to perform quick gear changes. .

The present invention has been made against the background of the above-mentioned circumstances, and its purpose is to reduce the engagement shock when re-engaging an automatic clutch without performing half-clutch control, and to quickly shift gears. An object of the present invention is to provide a method for controlling an automatic transmission for a vehicle.

Means for Solving the Problems In order to achieve the above object, the present invention provides that when automatically switching a synchronous mesh type stepped transmission having a plurality of gears to a target gear, the throttle valve is closed and the engine is turned off. After reducing the output, the automatic clutch is released to temporarily interrupt power transmission from the engine, while the gears of the stepped transmission are changed, and the engine rotational speed and the stepped transmission are changed. A method for controlling an automatic transmission for a vehicle in which the automatic clutch is re-engaged after synchronization with the rotational speed of an input shaft to retransmit engine power, the method comprising: (a) a differential value of the rotational speed of the engine; an engine rotation speed differential value and a target engine rotation speed calculation step of calculating a target engine rotation speed that is the same value as the rotation speed of the input shaft of the stepped transmission when the target gear stage is established; , (b) The actual engine rotation speed is calculated based on the engine rotation speed differential value, the target engine rotation speed and the engine rotation speed differential value calculated by the target engine rotation speed calculation step, and the actual engine rotation speed. A synchronization time calculation step of sequentially calculating the synchronization time until (Cl) reaches the target engine rotation speed, and determining whether or not the synchronization time calculated by the synchronization time calculation step has decreased to a predetermined value. a determining step; (d) in the determining step, if it is determined that the synchronization time has not decreased to the predetermined value, the actual engine rotation speed quickly moves toward the target engine rotation speed; The opening degree of the throttle valve is controlled so that the opening degree of the throttle valve changes, and when it is determined that the synchronization time has decreased to a predetermined value, the actual engine rotation speed changes more gradually than before. The present invention is characterized in that it includes a throttle valve opening degree control step of controlling the opening degree of the throttle valve.

In the method for controlling a vehicle automatic transmission configured as described above, the differential value of the engine rotational speed is calculated in the engine rotational speed differential value and target engine rotational speed calculation step, and the differential value of the engine rotational speed is calculated and the target gear position is determined. A target engine rotation speed, which is the same value as the rotation speed of the human power shaft of the stepped transmission, is calculated, and a synchronization time is calculated based on the differential value of these engine rotation speeds, the target engine rotation speed, and the actual engine rotation speed. In the calculation process, the synchronization time until the actual engine rotation speed reaches the target engine rotation speed is calculated one after another. Then, a determination step determines whether or not the synchronization time has decreased to a predetermined value, and if it is determined that the synchronization time has not decreased to the predetermined value, the actual engine rotation speed is set to the target engine speed. The opening degree of the throttle valve is controlled by the control process so that the opening degree of the throttle valve quickly changes toward the rotation speed, and when it is determined that the synchronization time has decreased to a predetermined value, the actual engine rotation speed is The opening degree of the throttle valve is controlled by a control process so that it changes gradually.

Effects of the Invention As a result, until the synchronization time reaches a predetermined value, the opening degree of the throttle valve is controlled so that the actual engine speed quickly changes toward the target engine speed, and After the synchronization time reaches a predetermined value, the opening degree of the throttle valve is controlled so that the actual engine speed changes more gradually toward the target engine speed, and then the actual engine speed changes. Since the automatic clutch will be re-engaged when the engine speed reaches the target engine speed and synchronized with the rotation speed of the manual shaft of the stepped transmission, the automatic clutch will re-engage without performing half clutch control. This makes it possible to suitably reduce the locking shock when the gears are engaged, and also to quickly shift gears.

EXAMPLE Hereinafter, an application example of the present invention will be explained in detail based on the drawings.

In FIG. 2, power from a vehicle engine 10 is transmitted to drive wheels via a magnetic particle electromagnetic clutch 12, a stepped transmission 14, and a differential gear (not shown). The magnetic powder electromagnetic clutch 12 functions as an automatic clutch in this application example, and is inserted between the crankshaft 15 and the input shaft 46 of the stepped transmission 14, and is controlled by the control device l.
The engagement is controlled by the excitation current supplied from 6, and a torque corresponding to the excitation current is transmitted. The crankshaft 15 and the input shaft 46 of the stepped transmission 14 correspond to the input shaft and output shaft of the magnetic particle type electromagnetic clutch 12.

The stepped transmission 14 is a synchronized mesh transmission with five forward speeds and one reverse speed, which is well known as a manual transmission. The solenoid valve 30 is configured similarly to that described.
, 32, 34, and 36, the hydraulic pressure supplied from the hydraulic pump 37 to the hydraulic circuit 38 is applied to a 3-position hydraulic cylinder for shift and a 3-position hydraulic cylinder for select (not shown).
Based on the selective supply to the position hydraulic cylinder, the first gear, the second gear, the third gear, the fourth gear, etc. The fifth gear or reverse gear is established.

The vehicle is equipped with various sensors for detecting driving parameters, and signals from these sensors are supplied to the control device 16. That is, the accelerator sensor 42 provided on the accelerator pedal 40 outputs a voltage signal v see representing the amount of accelerator operation to the control device 16.

Engine rotation speed sensor 44 provided in engine 10
t. is a signal representing the engine rotation period. is control device 1
6. An input shaft rotation sensor 50 and an output shaft rotation sensor 52 provided near the input shaft 46 and output shaft 48 of the stepped transmission 14 output a signal Lin representing the rotation period of the input shaft 46 and a signal Lin representing the rotation period of the output shaft 48. A signal t representing uL is output to the control device 16. Shift position detection switches 54, 56 provided in the stepped transmission 14,
From 58 and 60, the signal N. 84 to N. , 1 are output to the control device 16, and the operating positions of the 3-position hydraulic cylinder for shift and the 3-position hydraulic cylinder for select are detected by a combination of these signals.

These shift position detection switches 54, 56, 58, 60
is Utility Model Application No. 62-153449, which was previously filed by the present applicant.
It is the same as that described in the No. Furthermore, a signal indicating the opening degree of the throttle valve 80 is sent from a throttle sensor 84 provided in the intake pipe of the engine IO. il
It is output to the device 16.

The control device 16 includes a CPU 6, a ROM 68, and a RAM 7.
0, input interface 72, clutch drive circuit 74,
It is a so-called microcomputer equipped with a throttle drive circuit 76, a solenoid valve drive circuit 78, etc., and processes input signals according to a program stored in advance in the ROM 68 while utilizing the storage function of the RAM 70, and processes the solenoid valves 30, 32,
34 and 36 from the electromagnetic valve drive circuit 78, an excitation current for controlling the electromagnetic clutch 12 is output from the clutch drive circuit 74, and a drive signal for driving the throttle valve 80. The signal is sent from the throttle drive circuit 76 to the throttle actuator 8.
Output to 2. The output terminal configuration of the solenoid valve drive circuit 78 and the terminal configuration of the input terminal of the input interface 72 corresponding to the shift position detection switches 54, 56, 58, and 60 are described in the above-mentioned Japanese Patent Laid-Open No. 116942/1983. Same as described.

Hereinafter, the operation of this application example will be explained according to the flowchart shown in FIG.

First, in step Sl, the input signal 1 from each sensor is
,,1,,,j OIIL , Vice % Vths
Nsw1 to N. , 4 are read. Next, in step S2, the actual engine rotation speed N is determined from the above signal according to the following equations (1) to (6). , input shaft rotation speed N
, , output shaft rotational speed N. uL, vehicle speed SPD, accelerator operation amount ACC, and throttle valve opening θ are calculated.

Na rpm = (1/tQ) x60sec
-... (1) Nin = (1/tt, 1)X6
0sec...121Nout = (1/
taut) x5 0sec...(3) SPD
km/h = N out ·γ,. ,・2r
cr ・60 ai++ ・1/1000 ・・(
41 However, r is the radius of the wheel, and rdtr is the speed ratio of the differential gear device.

A ((%=(v1cc −νctos*)/(V
maX V cL. 3. )×100 ・ ・ ・(
5) However, VCLOI6 and Vllll are the accelerator sensor 42 when the accelerator pedal 40 is not operated and when the accelerator pedal 40 is fully operated.
This is the output signal from .

θ%= (v,, ,close)/(va+
heat x-vctos@)×100 (6) where vcl0- and vmax are output signals from the throttle sensor 84 when the throttle valve 80 is fully closed and fully open.

Next, a gear position determination routine in step S3 is executed. This gear stage determination routine is described in the above-mentioned Japanese Patent Application Laid-Open No. 63-1169.
This is similar to that described in Japanese Patent No. 42, and the signals N. from shift position detection switches 54, 56, 58, and 60 ，
, 4 to N. , 1, and a value indicating the current gear is stored in a register T.

In the following step S4, it is determined whether the content of the shift sequence flag Fch* indicating that a shift operation is being executed is "0". If it is not rOJ, steps 38 and below will be executed in order to preferentially execute the shift control, but if it is "0", the shift operation has been completed, so the target gear shown in FIG. 4 is set in step S5. By executing the speed determination routine, the target gear speed for the next shift is determined. That is, in steps SMI to SMI2, based on the numerical value indicating the actual gear in the register γ, a shift diagram corresponding to the actual gear is selected from a plurality of types of shift diagrams stored in advance in the ROM 6B. is selected, and in step SM13, the upshift shift point vehicle speed SPD. , and downshift shift point vehicle speed SPD. . Wow is calculated. The method of calculating this shift point vehicle speed is the same as the method described in the above-mentioned Japanese Patent Application Laid-Open No. 63-116942, and is calculated by interpolation based on the actual throttle valve opening from the data map forming the shift diagram. Calculated by calculation. Then, in step SMI4, the actual vehicle speed SPD is changed to the upshift shift point vehicle speed SP0.
If the value is 9 or more, the contents of the register γ" that stores the numerical value indicating the target gear stage are changed to "γ+1" in step SM15.
'' and the content of the upshift flag Fup is set to "1" in step SM16, but in step SMI7 the actual vehicle speed SPD is set to the downshift shift point vehicle speed spoa. ■If below, step S
In M1B, the contents of register γ" are set to "r-1", and in step SM19, the contents of upshift flag F-- up are set to "0". That is,
The contents of the register γ" are one gear higher than the current gear, or one gear lower than the current gear, and if it is high, the upshift flag F up indicates that an upshift is being performed. If the upshift flag F0 is low, the upshift flag F0 is set to "0" to indicate a downshift.

Returning to FIG. 3, when the target gear is determined as described above, in step S6, the target gear indicated by the contents of register γ4 matches the actual gear indicated by the contents of register T. It is determined whether or not. If they match, no shift operation is required and steps SIO and subsequent steps are executed; however, if they do not match, a shift operation is required and steps SIO and subsequent steps are executed. That is, step S
7 is executed, the contents of the shift sequence flag Fchs are first set to "1" prior to the shift operation, and in step S8, the shift operation routine shown in FIG. Transmission 14
A series of gear change operations are performed to switch the gear to the target gear indicated by the contents of register γ8.

In FIG. 1, first, the contents of the shift sequence flag Fcbg are determined in step SHI. When the content of the shift sequence flag Feh9 is rlJ, a series of steps SH2 to SH are performed to start the power cutoff operation.
IO is executed. This shift sequence flag Fck
The content of g being "1" indicates that the output reduction step of the engine 10 is being executed. Step S
At H2, the output torque T. and engine rotational speed N. From the relationship between N. and throttle valve opening θ (engine torque map), the actual engine rotation speed N. Then, the actual output torque T of the engine 10 is calculated based on the actual throttle valve opening θ. This output torque T. The calculation method is the same as the method described in the above-mentioned Japanese Patent Application Laid-Open No. 116942/1983.

When the actual output torque T1 of the engine 10 is determined in step SH2, the absolute value T,l of the output torque of the engine 10 is determined in advance as the target output torque T at the time of power cutoff. It is determined whether the value is greater than 11*.

This target output torque T. tt'' is a sufficiently small value and is set to zero or a value close to zero. If the absolute value IT01 of the output torque is not larger than the target output torque T0, the purpose of the output reduction step cannot be achieved. Therefore, the power transmission interruption process from step SHII is executed,
If it is larger, the flowchart shown in FIG. 5 is executed in step SH4, and the amount of decrease ΔTll+I+1 of the output torque of the engine 10 for each period in the n speed is calculated according to the following equation (7).

However, r is the radius of the wheel, m is the vehicle mass, 1 is the calculation period, and T0. 《7. is the gear ratio of the n-speed stage, T is the gear ratio of the differential gear device, and J0 is the reference acceleration change rate of the vehicle.

The reference acceleration change rate J0 is set so that the engine 10 can suitably reduce both the sluggishness and deceleration shock when the output of the engine 10 decreases during automatic gear shifting while the vehicle is running.
The output torque of the engine 10 is set to a value determined experimentally in advance in relation to the output reduction time, and the output torque of the engine 10 is sequentially reduced according to the current gear while maintaining the reference acceleration change rate J0. It has become.

Next, in step SH5, the actual output torque T. The following formula (
8), the target output torque T for each cycle of the engine 10. ” is calculated.

T. ” = T. −ΔTa(1 ・ ・ ・
(8) In step SH6, a target throttle valve opening θ0 is determined from the engine torque map based on the actual engine rotational speed N8 and the target output torque T0 for each cycle. degree θ0
The method for determining the target throttle valve opening degree θ is described in the above-mentioned Japanese Unexamined Patent Publication No. 116942/1983. ,,′ is the same as the method used to find .

In step SH7, in order to make the actual throttle valve opening θ match the target throttle valve opening θ1 obtained as described above, the control amount for the throttle actuator 82 obtains the target throttle valve opening θ. The value θ4 is assumed to be θ4.

In step SH8, in preparation for the next cycle, the current control amount ■d for the electromagnetic clutch l2 is updated as the previous control amount VCL (Fl-11), and
In step SH9, each solenoid valve 30, 32 for shifting
, 34, 36, the content of the control amount Vthift is zero,
In other words, no drive signal is output to any of the solenoid valves. Then, in step SHIQ, the content of the shift sequence flag F chs is set to "1". While the above series of steps are repeated, the step SH
3, the absolute value of the output torque of the engine 10 IT. 1
is the target engine torque T when the power is cut off. When it becomes less than ff', the output reduction step is terminated, and a power transmission interruption step starting from step SHll is started for switching gears while interrupting power transmission.

In step SHII, it is determined whether the actual gear stored in the register T and the target gear stored in the register T0 match, and if they match, the gear switching is completed. Therefore, step S described below
H20 and below are executed, but if they do not match, the control amount ■. is made zero and the electromagnetic clutch 12 is released. Then, in step SHl3, the target engine rotational speed N%, which is the same value as the input shaft rotational speed V4n of the stepped transmission 14 when the target gear to be shifted is established, is calculated from the following equation (9) to determine the actual Output shaft rotational speed N out and target gear speed ratio γ,, LA. Calculated based on 9.

N a ” ”' T rmti. “XNOuL
・ ・ ・(9) In the following step SH14,
The above target engine rotation speed N% is the idle rotation speed N of the engine 10! , , it is determined whether or not it is larger than .

If this judgment is affirmative, the throttle control routine of step SH15 is executed, but if this judgment is negative, step SH16 is executed and the target engine rotational speed N. i'' and actual engine speed N
．． In other words, the target throttle valve opening degree θ7 for power transmission interruption is set to match the output torque of the engine 10 to approximately zero. ' is calculated from the engine torque map by the same method as in step SH6, and
Step SH17 is executed, and the control amount Vth for the throttle actuator 82 is the target throttle valve opening degree θ7. 'The value θ7. *, the gear change routine of step SH18 is executed. Note that if the determination in step SH14 is negative, that is, the target engine rotation speed N0 is equal to the idle rotation speed N. ，
For example, when the vehicle is traveling on a relatively steep uphill road in 1st gear, the vehicle speed increases and an upshift operation to 2nd gear is performed, and the gear change operation is in progress. The vehicle speed decreases and N. ”<N.d. However, normally step SH14 is followed by step SH1.
5 will be executed.

The throttle control routine described above is executed, for example, as shown in FIG. First, in STI, the actual engine rotation speed N0 is the target engine rotation speed N. 9 and synchronizes with the input shaft rotational speed N in of the stepped transmission 14 (synchronization time) ttyrtc is calculated by the following formula (I
Calculated according to Q).

The above dN. /dt is the engine rotation speed N. The differential value of engine rotation speed N. This shows the rate of change of .DELTA.L, and is determined every .DELTA.L time using the interrupt routine shown in FIG. 7, for example. In this interrupt routine, step SWl is first executed, and the current engine rotation speed No. (++) is changed to the previous engine rotation speed No. (n-).
l), the engine rotational speed N.l) at time Δt is obtained. The amount of change ΔN0 is calculated. Next, step SW2 is executed and ΔN. /Δt is calculated, and the value is the differential value dN. of the engine rotational speed N0.
After being stored in the RAM 70 as the variable name /dt, step SW3 is executed and the current E? Jin rotation speed No.
(n) is stored in the RAM 70 as the variable name of the previous engine rotational speed Noin-11.

Returning to FIG. 6, in step ST2, it is determined whether the content of the upshift flag F_up is "1". If this determination is affirmative and it is determined that it is an upshift, step ST3 is executed,
It is determined whether the synchronization time tsync calculated in step STI is smaller than a predetermined constant value.

If the judgment in step ST3 is negative, that is, if the synchronization time is still a constant value and has not decreased to Speed N. In order to quickly reduce the amount of control for the throttle actuator 82, the control amount t is set to zero. However, if the judgment in step ST3 is affirmative, that is, if the synchronization time t is reduced to a constant value, , by executing step ST6 similar to step SH16, the target engine rotational speed N. j″ and the actual engine rotational speed N.
The target throttle valve opening θno'' for making the output torque of the engine 10 substantially zero by matching the above, /+{after being calculated from the engine torque map, step ST7
is executed, and control I is set to a value θ7.9 to obtain the target throttle valve opening θ7.1. The above constant value also means that the actual engine rotation speed N0 is the target engine rotation speed N. When re-engaging the electromagnetic clutch 12 after reaching *, it is desirable to set it to the shortest time that can suitably reduce the locking shock.

If the determination in step ST2 is negative and it is determined that it is a downshift, step ST5 is executed and the synchronization time t syfi calculated in step STI is
It is determined whether c is smaller than a predetermined constant value t2. If the determination in step ST5 is negative, that is, if the synchronization time tsync has not yet decreased to the constant value t, step ST8 is executed, and the throttle is adjusted to quickly increase the engine rotational speed N0. The control amount for the actuator 82 is set to V1+1+. This control amount Vthl is preferably set to a value that allows the maximum allowable rotational speed of the engine 0 to be obtained in a no-load state, that is, a value that allows the throttle valve 80 to be fully opened. On the other hand, if the determination in step ST5 is affirmative, that is, the synchronization time t sya. has decreased to a constant value t2, the above step ST6
and ST7 are executed, and the target engine rotation speed N
% and actual engine speed N. Target throttle valve opening θ7. ′ is calculated, and
The control itVLh uses the value θ7. to obtain the target throttle valve opening θ7r. It is said to be *. The constant value t2 is the actual engine rotation speed N.Similar to the constant value t, described above. When re-engaging the electromagnetic clutch 12 after reaching the target engine rotational speed N%, it is desirable to set the time to the shortest time that can suitably reduce the engagement shock. In addition, in the power transmission interruption step, the synchronization time t sy
nt: and constant values t+, t. Due to the magnitude of z, the judgments in steps ST3 and ST5 are not affirmed and steps ST6 and ST7 are true? It may not be possible.

When the throttle control routine of step SH15 is thus completed, the gear change routine of step SH1B is executed. This gear switching routine is similar to that described in the above-mentioned Japanese Patent Application Laid-Open No. 63-116942, and in order to switch the current gear to the target gear, an appropriate one of the solenoid valves 30, 32, 34, and 36 is selected. The control amount V S h i■ for the solenoid valve is determined.

Continuing <<In step SH19, the content of the shift sequence flag Fchq is set to "2". When the gear change is completed by executing the above series of steps, it is determined in the step SHII that the target gear and the actual gear match, so in order to retransmit the power of the engine 10, Step SH20 and subsequent steps are executed.

In step SH20, the step SH13
Similarly, when the target gear is established, the stepped transmission 14
A target engine rotational speed N%, which is the same value as the input shaft rotational speed N i fi, is calculated. Next step SH2
1, the target engine rotation speed N % is equal to the idle rotation speed N i d as in step SH14.
It is determined whether or not it is larger than l. If this determination is affirmative, step SH22 is executed, but if this determination is negative, step SH29 is executed. In this case, as described above, the target engine rotation speed N
% is rarely smaller than the idle rotational speed N i d L , normally steps SH22 and subsequent steps are executed following step SH21.

In step SH29, the throttle valve opening θ (%
) is smaller than the accelerator operation amount AeC (%). This step SH29 is for determining whether or not the retransmission of power from the engine 10 has been completed when the target engine rotational speed N% is smaller than the idle rotational speed N.sub.2. Initially, the throttle valve opening θ is smaller than the accelerator operation amount Acc, so step S
H30 is executed, and the current transmission torque T ct to the electromagnetic clutch 12 is determined according to control equation (11) shown below.

T el =T cL (++- 11 +Δ'rc
t・--00? In formula 01), ΔT c
t is determined based on the accelerator operation amount Ace from a predetermined relationship.

In the following step SH31, the electromagnetic clutch l2
Control amount for ■. , is set as the value Te1 for obtaining the current transmission torque T■ determined in step SH30, and in step SH32, the control amount ■ for the electromagnetic clutch l2 is determined from the engine torque map.
. and actual engine speed N. Target throttle valve opening θ for power retransmission based on . n1. is calculated by the same method as in step SH6. That is, the output torque T. of the engine 10 is The throttle valve opening degree θ is determined so as to match the transmission torque TcL of the electromagnetic clutch 12. Then, in step SH33,
The control amount VLh for the throttle actuator 82 is the target throttle valve opening θ. , the value θ to obtain 0.

111. In the following step SH34, the control amount Vthi for each electromagnetic valve 30, 32, 34, 36 is
The content of ft is zero, that is, a state in which no drive signal is output to any solenoid valve. Then, in step SH35, the content of the shift sequence flag Fchg is "3".
It is said that In the process in which the above series of steps are repeated, the control amount V for the throttle actuator 82 is sequentially increased so that the throttle valve opening θ reaches the target throttle valve opening θ each time. It is made to follow Il+'.

While the above series of steps are repeated, if it is determined that the throttle valve opening θ and the accelerator stroke amount Ace have failed in step SH29, step SH
At step 36, the contents of the shift sequence flag Fch9 are set to "0".

In the step SH22, the step SH2
Similarly to 9, it is determined whether the throttle valve opening degree θ (%) is smaller than the accelerator operation amount Acc (%). If it is determined that the throttle valve opening degree θ is smaller than the accelerator operation amount Acc, step SH24 is executed and the actual engine rotation? degree N0 and the input shaft rotational speed N! f
It is determined whether the difference with i is smaller than a predetermined constant value N. This constant value N, is the actual engine rotational speed N. This is a small value that serves as a reference for determining whether or not the input shaft rotational speed N in and ing. Initially, they are not synchronized, so by executing step SH25, the control amount ■
．． is set to zero, the electromagnetic clutch 12 is maintained in the open state, and then step SH26 is executed.

In step SH26, a throttle control routine shown in FIG. 6 similar to step SH15 is executed. That is, first in step ST1, the actual engine rotational speed N. A synchronization time t8y■ until reaching the target engine rotational speed N% and synchronizing with the input shaft rotational speed Nin is calculated. If it is determined in step ST2 that it is an upshift, step ST3
is executed, and the synchronization time t*ync becomes the constant value t,
Smaller than? It is decided whether or not. If this determination is negative, step ST4 is executed to fully open the throttle valve 80 and set the engine rotational speed N. In order to quickly reduce the amount of control for the throttle actuator 82, the control amount is set to zero, but if it is affirmed,
Engine rotation speed N. Step ST6 is executed to reduce the target engine rotation speed N. more slowly than before. ” and the actual engine rotational speed N. Target throttle valve opening degree θ.1 for power retransmission
2" is calculated, and step ST'7 is executed to set the control amount ■ to the target throttle valve opening θ.
Value θ to obtain t'. 7■ It is said that

If it is determined in step ST2 that it is a downshift, step ST5 is executed, and it is determined whether the synchronization time tiync is smaller than the constant value t2. If this determination is negative, step ST8 is executed to fully open the throttle valve 80 and set the engine rotational speed N. In order to quickly increase the control amount VLh, The control amount ■ is set to 1, but if affirmed, the engine rotation speed N. In order to increase more slowly than before, steps ST6 and ST7 are performed.
is executed and the target engine rotation speed N. The target throttle valve opening degree θ.nt9 is calculated to match the actual engine rotational speed N.'' with the actual engine rotational speed N., and the control amount is the value θ to obtain the target throttle valve opening degree θ.729.

It is said to be 7■9. In the power retransmission step, the synchronization time t IFFIC and the constant value LI+j! The above step ST3. There are cases where the determination in ST5 is not denied and steps ST4 and ST8 are not executed.

When the throttle control routine of step SH26 ends in this way, steps SH34 and SH3
5 is executed, the content of the control amount Vshift for each electromagnetic valve 30, 32, 34, 36 is set to zero, and
The contents of the shift sequence flag Fck* are set to "3".

While the above series of steps are executed, the actual engine rotation speed N. is the input shaft rotation speed N! If the judgment in step SH24 is affirmative in synchronization with fi, step S
H27 is executed to determine the current transmission torque TcL to the electromagnetic clutch 12 in the same manner as step SH30, and step SH2B is executed to determine the control amount for the electromagnetic clutch 12 in order to re-engage the electromagnetic clutch 12 at once. After VCt is controlled to 1vct'''1κ to maximize the transmission torque Tct, the steps SH3 and subsequent steps are executed.
In H32, in order to sequentially change the throttle valve opening θ, step SH2 is determined from the engine torque map.
The current transmission torque TC determined in step 7 [and the target throttle valve opening θ based on the actual engine rotational speed N0]. 7,. will be determined.

On the other hand, if it is determined in step SH22 that the throttle valve opening degree θ (%) is larger than the accelerator operation amount Acc (%), step SH23 similar to step SH24 is executed. This step SH2
In 3, the actual en? If it is determined that the input shaft rotational speed N0 is synchronized with the input shaft rotational speed Vrn of the stepped transmission l4, step SH36 is executed and the shift sequence flag Fchg is cleared, but the synchronization is still not performed. If it is determined that the
Following Step 4, steps SH25 and subsequent steps are executed.

In the process in which the above-mentioned speed change operation routine is repeatedly executed, step S9 in FIG. 3 is executed one after another. In this step S9, each control value such as VcL, I, Vshi, etc. determined sequentially in the shift operation routine is outputted to control the electromagnetic clutch 12 and the throttle actuator 82.
, solenoid valves 30, 32, 34, 36, etc. are driven. As a result, the gear of the stepped transmission 14 is switched to the target gear.

If it is determined that the current gear and the target gear match in step S6 of FIG. It is determined whether or not the following is true. If the determination in step S10 is negative, it is necessary to maintain the electromagnetic clutch 12 in the engaged state, so in step 311, the control amount ■ for the electromagnetic clutch l2 is determined. is the control amount V eL'■ for maximizing the transmission torque Tct. However, if the determination at step 310 is affirmative, then at step S12, the control value Vct is successively changed according to the control formula shown in (2) below.

vct=(N.-Neat)XK
- ・-02) However, K is a constant and the control amount for the throttle actuator 82 in step 313 is the actual accelerator operation t.
After the control value is determined to correspond to A c c , the control value is output in step S9 described above.

As described above, according to this application example, in the power transmission interruption process and the power retransmission process after the output of the engine 10 is reduced, the actual power transmission is performed within a range that does not cause an engagement shock when the electromagnetic clutch 12 is re-engaged. engine rotational speed N
．． is quickly changed toward the target engine rotational speed N% when the target gear is established. That is,
In the power transmission interruption process and the power retransmission process after the output of the engine 10 is reduced, the target engine rotational speed N. 1 is greater than the idle speed NtaL and is an upshift, the actual engine speed N.1 is greater than the idle speed NtaL and is an upshift. reaches the target engine rotation speed N% and the input shaft rotation speed N
While the synchronization time ts,,,c until synchronization with i Fl does not reach the above-mentioned fixed value t1, the throttle valve 80 is kept fully closed, so that the actual engine rotational speed N. is quickly decreased toward the target engine rotation speed N%, and after the synchronization time t*ync reaches the constant value 11, the throttle valve opening θ is reduced to the target engine rotation speed N%. The target throttle valve opening degree θ7. ,θ
. 10, the actual engine rotation speed N.
is the target engine rotation speed N. ', while the target engine rotational speed N% is reduced to the idle rotational speed N%. ，，? In the case of a downshift, the throttle valve 80 is kept fully open until the synchronization time 7c reaches the constant value N8, so that the actual engine rotation speed N8 becomes the target engine rotation speed. N. *, and after the synchronization time tsync reaches the constant value L2, the throttle valve opening θ reaches the target engine rotational speed N. Target throttle valve opening degree θ7 corresponding to *.

, θ. 1! . As a result, the actual engine rotation speed N0 is increased more gradually toward the target engine rotation speed N0 than before. Then, the actual engine rotation speed N. is the target engine rotation speed N. 1
Since the electromagnetic clutch 12 is re-engaged all at once when the input shaft rotation speed N1 of the stepped transmission 14 reaches the target engine rotation speed N. * is idle rotation speed N
．． In the normal case where it is larger than (2), it is possible to suitably reduce the locking shock when the electromagnetic clutch I2 is re-engaged without performing half-clutch control, and it is also possible to quickly shift gears.

Here, FIG. 8 shows the engine rotation speed N when automatic upshifting is performed. , is a diagram showing an example of changes in the input shaft rotational speed Nin of the stepped transmission 14, the control amount for the throttle actuator 82, and the transmission torque Tct for the electromagnetic clutch 12, (a)
(b) is based on the control method of the present invention, and (b) is based on the conventional control method. Figure 8 (b) according to the conventional method
), the actual engine rotational speed N. The controlled variable ■ is synchronized with the input shaft rotational speed N i n until the target engine rotational speed N.
' Target throttle valve opening θ7.1 and θ corresponding to .

7, the rate at which the engine rotational speed N decreases is relatively slow, whereas in FIG. Retransmission is started and the actual engine rotational speed N.
The controlled variable Vth is set to zero until a predetermined time before synchronization with the input shaft rotational speed N i n , and thereafter the control amount Vth remains at the target engine rotation until the actual engine rotational speed N0 synchronizes with the input shaft rotational speed N i n Speed N. . Target throttle valve opening θ corresponding to . ,,2'. As a result, in FIG. 8(a) according to the method of the present invention, the engine rotational speed N. Figure 8(b) shows that the rate of decrease in
The time required for retransmission of power from the engine 10 and the shift time for upshifting are suitably shortened.

Further, according to this application example, in the throttle control routine, the actual engine rotation speed N. , target engine rotational speed N. when the target gear is established. , and engine rotational speed N. The differential value dN. /d t based on the actual engine speed N. is the target engine rotation speed N. ”
The synchronization time until synchronization with t tyn. is configured to be predictively calculated, so even when the load on engine auxiliary equipment such as the air conditioner, compressor, and alternator fluctuates, synchronization can be achieved while suitably reducing the locking shock when re-engaging the electromagnetic clutch 12. It can save time.

Furthermore, according to this application example, when the target engine rotational speed N% is less than the idle rotational speed 1'Jz41 during gear shifting, power is retransmitted using half-clutch control similar to the conventional method, and the electromagnetic clutch 12 is locked up, so N. ” It is possible to prevent a problem in which the gear shift is not completed when <NidL.

Further, according to this application example, in the output reduction step of the engine 10 prior to changing the gear position of the stepped transmission 14, the output torque T. Decrease amount ΔT07 per cycle
, is calculated based on the reference acceleration change rate J0 of the vehicle, and the output torque T. of the engine 10 is calculated based on the reference acceleration change rate J0 of the vehicle. and the amount of decrease ΔT. . , the target output torque T,11 for each period is based on
and its target output torque T. The target throttle valve opening θ0 to obtain 11 is calculated sequentially, and the actual throttle valve opening θ is controlled to the target throttle valve opening θ". The acceleration rate can be maintained at the reference acceleration change rate J0.As a result, the feeling of stiffness and deceleration shock when the output of the engine 10 decreases are suitably reduced.
Shifting feeling is further improved. In this case, the amount of decrease ΔT. . , are corrected based on the current gear position, so there is an advantage that the amount of decrease in the output torque can be adjusted according to the gear position.

One application example of the present invention has been described above based on the drawings, but
The invention also applies in other aspects.

For example, in the above application example, the predetermined constant value 1,
,1. is used, but instead of that, the synchronization time t
A predetermined value that is changed depending on *ync etc. may be used.

Further, in the above application example, the engine rotation speed N. The differential value dN. /dt is determined by an interrupt routine executed every ΔL time, but it is determined each time the power transmission interruption step and power retransmission step of the gear shift operation routine are executed. There is no problem.

In addition, in the application example described above, in both the power transmission interruption process and the power retransmission process, the throttle is not activated. Although the throttle control routine is configured to be executed, the effects of the present invention can still be obtained to some extent even when the throttle control routine is configured to be executed only in one of the two steps.

Further, in the above application example, when the synchronization time t@Vne is smaller than the constant value t1, the control amount I is set to zero in order to fully close the throttle valve 80, and the synchronization time is also set to zero. ,,. It is said that when the control fV is smaller than the constant value 11, the control value fV is set to the value for fully opening the throttle valve 80. However, it is not necessarily necessary to configure it in this way; (2) The target throttle valve opening degree θ7 for interrupting power transmission.

and target throttle valve opening θ for power retransmission. The value θ, . ．． θ. If the control amount is smaller than 7', and in the latter case, the control amount is equal to the value θ. ，
θ. If it is made larger than 7■', a certain effect of the present invention can be obtained.

Furthermore, although the magnetic particle type electromagnetic clutch l2 is used in the application example described above, other types of automatic clutches capable of engagement control such as a hydraulic clutch may also be used.

It should be noted that the above description is merely an example of application of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a speed change operation routine that is a main part of the flowchart in FIG. 3. FIG. 2 is a block diagram showing a shift control device for a stepped automatic transmission to which the present invention is applied. FIG. 3 is a flowchart for explaining the operation of the shift control device of FIG. 2. FIG. 4 is a diagram showing a routine executed in the flowchart of FIG. 3. 5 and 6 are diagrams showing the routines executed in the flowchart of FIG. 1, respectively. FIG. 7 is a diagram showing an interrupt routine executed at predetermined time intervals in the flowchart of FIG. 3. FIG. 8 is a diagram showing an example of changes in engine rotational speed, input shaft rotational speed, throttle control amount, and clutch control amount during upshifting according to the control method of the present invention, in comparison with the conventional case. be. : Engine: Magnetic powder electromagnetic clutch (automatic clutch): Stepped transmission: Input shaft: Throttle valve

Claims (1)

[Claims] When automatically switching a synchronous mesh type stepped transmission having a plurality of gears to a target gear, the throttle valve is closed to reduce the engine output, and then the automatic clutch is released. While the power transmission of the engine is temporarily interrupted, the gear stage of the stepped transmission is changed, and after the rotational speed of the engine and the rotational speed of the input shaft of the stepped transmission are synchronized, A method for controlling an automatic transmission for a vehicle in which power is retransmitted from the engine by re-engaging an automatic clutch, the method comprising: calculating a differential value of the rotational speed of the engine, and determining when the target gear is established. an engine rotational speed differential value and a target engine rotational speed calculation step of calculating a target engine rotational speed that is the same value as the rotational speed of the input shaft of the stepped transmission; and the engine rotational speed differential value and the target engine rotational speed. Based on the differential value of the engine rotation speed calculated in the calculation step, the target engine rotation speed, and the actual engine rotation speed, the synchronization time until the actual engine rotation speed reaches the target engine rotation speed is calculated sequentially. a step of determining whether or not the synchronization time calculated by the synchronization time calculation step has decreased to a predetermined value; If it is determined that the actual engine rotation speed has not decreased to the predetermined value, the opening degree of the throttle valve is controlled so that the actual engine rotation speed quickly changes toward the target engine rotation speed, and the synchronization time is a throttle valve opening degree control step of controlling the opening degree of the throttle valve so that the actual engine rotational speed changes more gradually than before when it is determined that the actual engine speed has decreased to the predetermined value; A method for controlling an automatic transmission for a vehicle, the method comprising: