JPS63270252A - Control method for automatic speed changer of synchronized meshing type - Google Patents

Abstract

PURPOSE:To prevent speed change shock and blowup of engine by determining the target degree of opening of a throttle valve for obtainment of the desired output torque from predetermined relationship at the power sinking stage, and by putting the actual degree of opening of the throttle valve identical to the target degree of opening of the throttle valve. CONSTITUTION:The relationship between the degree of opening of the throttle valve and the revolving speed in the condition the actual output torque of the engine 10 is zero is studied through utilization of the fact that no significant change will occur in the amount of change of the engine revolving speed when the output torque of an engine 10 is zero at the time of disengagement of an electromagnetic clutch 12, and thereupon a modification shall be made on a throttle close map. Therefore, the target degree of opening of the throttle valve to nullify the output torque of the engine 10 precisely is obtained regardless of individual difference of engine, change of the engine output torque due to warmed-up condition, and the change in the engine output due to atmospheric pressure. This prevents speed change shock and blowing-up of the engine caused by the output torque becoming negative before the electromagnetic clutch 12 is disengaged.

Description

Detailed Description of the Invention Technical Field The present invention relates to a control method for a synchronous mesh type transmission, and more particularly to a technique for alleviating shocks and engine revs that occur when switching gears in a synchronous mesh type geared transmission. It is something.

Conventional technology One type of control device for automatic transmissions for vehicles is a type of control that automatically switches to a desired gear by driving the shift member of a synchronized mesh transmission with multiple gears using a hydraulic actuator. There is a device. For example, there is a control device described in Japanese Patent Laid-Open No. 59-81230.

In such a control device, a gear to be shifted is determined based on the actual vehicle speed and accelerator pedal operation LL from a previously stored shift diagram, and a shift member is driven so as to obtain this gear. That is, the throttle valve opening degree is reduced in the output reduction process to reduce the output torque of the engine, and the automatic clutch is released and the shift member is driven in the clutch release process to cut off the power transmission path. Power transmission is restarted by engaging the automatic clutch during the transmission process.

By the way, in the above output reduction step, in order to reduce the engine output torque, the throttle valve opening degree was operated to the fully closed position, so the lower speed gear such as the first gear or the second gear When the engine speed is relatively high, such as when shifting up from a gear to a higher gear such as a third gear or a fourth gear, the throttle valve opening simply changes to the fully closed position. If this happens, the engine output torque becomes negative, causing a deceleration shock.

On the other hand, in the output reduction step, the target throttle valve opening is determined based on the actual rotational speed and the desired engine output torque (for example, ON-m) from the relationship indicating the engine output characteristics determined in advance. A control method has been devised in which the actual throttle valve opening is controlled so as to match the target throttle valve opening. for example,
This is the case in Japanese Patent Application No. 61-261366, which was previously filed by the present applicant. According to this, in the output reduction process, the throttle valve opening is reduced so that the engine rotates with zero output torque, so deceleration shock caused by negative engine output torque is eliminated. be done.

Problems to be Solved by the Invention However, in actual engines, there are variations in individual output characteristics, variations in the warm-up state of the engine, and changes in output characteristics caused by atmospheric pressure. Even if the target throttle valve opening in the output reduction process is determined using a certain relationship that indicates the engine output characteristics, it may be related to individual engine variations, or even the same engine may have variations in its warm-up state or atmospheric pressure. Since the output state changes in relation to the state, it is difficult to accurately set the output torque of the engine to the desired value. For this reason, when the gear stage of the synchronous mesh transmission is automatically changed, the engine output torque does not reach the desired value, that is, zero, when the throttle valve opening is reduced in the output reduction step, so the output torque If the output torque fluctuates toward the negative side, an impactful deceleration due to engine braking, that is, a shift shock occurs.On the other hand, if the output torque fluctuates toward the positive side, the engine revs up during the clutch release process, impairing drivability.

Means for Solving the Problems The present invention has been made against the background of the above circumstances.
The purpose of this is to improve drivability by preventing the above-mentioned shift shock and engine revving.

In order to achieve such an object, the gist of the present invention is to provide a method for changing the gear stage of a synchronous mesh type stepped transmission.
An output reduction step in which the throttle valve opening degree is reduced to reduce the engine output, and a clutch release step in which the automatic clutch is released to switch the gear stage are sequentially executed, and in the output reduction step, the engine output is reduced by reducing the engine output. This is a control method for a synchronized mesh automatic transmission in which a target throttle valve opening for obtaining a desired output torque value is determined based on the relationship between the two and the actual throttle valve opening is made to match the target throttle valve opening. (al) a detection step of detecting the actual engine rotational speed in the clutch release step; and (b) a step of detecting the actual engine rotational speed after the automatic clutch is released so that the range of change in the actual engine rotational speed is maintained within a predetermined range. and a correction step of correcting the relationship.

Operation and Effects of the Invention By doing this, when changing the gear stage of the same JTLL meshing type stepped transmission, the range of change in the actual engine rotational speed after the automatic clutch release in the clutch release process can be maintained within a predetermined range. Since the relationship for determining the target throttle valve opening is corrected, variations in the output characteristics of individual engines and changes in the output characteristics related to engine warm-up conditions and atmospheric pressure conditions are taken into account. In addition, the relationship is updated to an optimal relationship for setting the output torque to a desired value, for example, . Therefore, in the subsequent output reduction step, the output torque of the engine can be accurately set to the desired value, and shift shock and engine revving in the clutch release step are eliminated, resulting in suitable drivability.

Here, the correction step preferably corrects the relationship such that when the engine rotation speed in the clutch release step exceeds a predetermined change range, the target throttle valve opening becomes smaller, and the engine rotation speed in the clutch release step is below a predetermined variation range, the above relationship is corrected so that the target throttle valve opening becomes larger.

EXAMPLE Hereinafter, one application example of the present invention will be explained in detail with reference to 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 particle 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, as shown in FIG. Then, the torque is controlled by the excitation current supplied from the control device 16, 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. and a shift rod 18 to which a shift fork (not shown) is attached for shifting to the second gear.
, a shift rod 20 to which a shift fork 19 for shifting to the third and fourth gears is attached, and a shift fork (not shown) for shifting to the fifth and reverse gears is attached. Shift rods 22 and those shift rods 18.20.22
A shift device is provided for selectively driving the shift position from the neutral position to the shift position. The shift device includes a 3-position hydraulic cylinder 26 for shifting that drives the shift select lever 24 in the rotational direction and drives any of the shift rods 18, 20, 22 in the axial direction, and a 3-position hydraulic cylinder 26 that rotates the shift select lever 24. and a 3-position switching hydraulic cylinder 28 that engages the lower end of the shift select lever 24 with any of the shift rods 18, 20, and 22 by positioning it at three positions in the direction of the rotation axis. We are prepared. The 3-position hydraulic cylinder 26 for shift 1 is operated by a combination of the operation of a pair of solenoid valves 30 and 32.
The three-position switching hydraulic cylinder 28 is also controlled to three positions by a combination of the operations of a pair of solenoid valves 34 and 36. That is, the solenoid valves 30, 32, 34 and 3
6, the hydraulic pressure supplied from the hydraulic pump 37 to the hydraulic circuit 38 is selectively supplied to the 3-position hydraulic cylinder 26 for shifting and the 3-position hydraulic cylinder 28 for switching. 36 are both on, the switching three-position hydraulic cylinder 28 engages the shift select lever 24 with the shift rod 20 for switching between the third gear and the fourth gear, but when the solenoid valve 36 is on, If present and the solenoid valve 34 is off, the 3-position switching hydraulic cylinder 28 engages the shift select lever 24 with the shift rod 18 for switching between the first gear stage and the second gear stage; 36
is off and the solenoid valve 34 is on, the three-position switching hydraulic cylinder 28 moves the shift select lever 24 to the fifth position.
It is engaged with a shift rod 22 for switching between a speed gear and a reverse gear.

Further, when both the solenoid valves 30 and 32 are on, the 3-position shift hydraulic cylinder 26 is positioned in a neutral state, but when the solenoid valve 30 is on and the solenoid valve 32 is off, the 3-position shift hydraulic cylinder 26 is positioned in a neutral state. If the cylinder 26 moves any one of the shift rondos to the 1st speed, 3rd speed, or 5th speed side, and conversely, when the solenoid valve 30 is off and the solenoid valve 32 is on, the 3-position hydraulic cylinder 26 for shift moves one of the shift ronds to 2nd gear, 4th gear, or the reverse side. Figure 6 shows
It shows the relationship between the movement locus of the upper end of the shift select lever 24 and the gear stage established thereby. □ The vehicle is equipped with various sensors for detecting driving parameters, and signals from these sensors are supplied to the control device 16. For example, an accelerator sensor 42 provided on an accelerator pedal 40 sends a voltage signal ■3cc representing the amount of accelerator operation to the control device 40.
6.

Engine rotation speed sensor 44 provided in engine 10
From there, a signal t0 representing the engine rotation period is sent to the control device 1.
6. An input shaft rotation sensor 50 and an output shaft rotation sensor 52 provided in the vicinity of the input shaft 46 and output shaft 48 of the stepped transmission 14 output a signal t representing the rotation period of the input shaft 46.

and a signal representing the rotation period of the output shaft 48. . .

is output to the control device 16. Furthermore, the stepped transmission 14
Shift position detection switch 54°56.58 provided in
．． From 60, signals N, 4 to N581 are sent to the control device 16.
Output to. A pair of shift position detection switches 54.5
Operation of the 3-position hydraulic cylinder 26 for shifting by the combination of signals from 6? ) J position is detected, and the operating position of the three-position switching hydraulic cylinder 28 is detected by a combination of signals from a pair of shift position detection switches 58 and 60. These shift position detection switches 5
4°56.58.60 is the same as that described in Japanese Patent Application No. 41977/1987 previously filed by the present applicant.

The throttle valve 80 is provided with a throttle sensor 84 for detecting its actual opening, and the output signal V of the throttle sensor 84 or the control device 16
supplied to

The control device 16 includes a CPU 66, a ROM 68, and a RAM 70.
, an input interface 72, a clutch drive circuit 74, a throttle drive circuit 76, a solenoid valve drive circuit 78, etc., and the CPU 66 is an R
Using the memory function of AM70, the input signal is processed according to the program stored in advance in ROM68, and the solenoid valve 3
0, 32, 34, and 36 from the electromagnetic valve drive circuit 78, and the electromagnetic clutch 1.
An excitation current for controlling the clutch drive circuit 74 is outputted from the clutch drive circuit 74. Further, the throttle drive circuit 76 outputs a drive signal to a throttle actuator 82 that drives a throttle valve 80 provided in the intake pipe of the engine 10. Note that the RAM 70 is provided with a memory (not shown), and information stored therein is held.

The operation of the control device configured as described above will be explained below.

When an ignition key (not shown) is operated to start the engine 10 and the control device 16 is powered on, various initialization subroutines are executed. The throttle closing map creation routine shown in FIG. 7 is one of them.

In step SSI of FIG. 7, it is determined whether the throttle close map is already stored in the RAM 70. If it is determined that the no-load engine rotation speed map has been stored, this no-load engine rotation speed map creation routine is terminated, but if it is determined that it is not stored, the following step SS2 is executed and the map is stored in the ROM 68 in advance. The relationship between the output torque of the engine 10 and the throttle valve opening and engine rotational speed is read out.

This relationship is a typical output characteristic determined from the specifications of the engine 10, and FIG. 8 shows an example of this relationship.

In step SS3, the eighth
From the relationship in the figure, the no-load throttle valve opening at which the engine 10 achieves the desired output torque, that is, no-load (output torque is ON・m), is determined for each engine rotational speed, for example, as shown in FIG. Additionally, a throttle closing map is created which is the relationship between the throttle valve opening and the engine rotation speed for rotating the engine IO with no load (zero output torque). Then, in step SS4, the throttle closure map obtained as described above is stored in the RAM 70. The throttle close map at this time becomes a basic map and is subject to updating by a learning routine to be described later.

When the execution of the initialization process including the above-mentioned throttle close map creation routine is completed, the main routine shown in FIG. 10 is executed. First, in step SI, an input signal t is received from each sensor. ,tl,,tout,vacc
%vt,, N5w1 to N,...4 are read. Next, in step S2, the following equation (1
), (2), (3), (4), (5), (6), the actual engine rotation speed N8, input shaft rotation speed N8
．． , output shaft rotational speed N6LIL, vehicle speed SPD, accelerator operation EIAC, and throttle valve opening θ are calculated, respectively.

Netpm=(1/1o)X60sec -・1t
lN,,,=(1/11fi)X60sec -・
12) Not+t = (1/1otrt) x
60sec ・-・(3) SPD km/h -N
,,L・γ4,.

4πr ・6(l mt,, 4/1000 ・・(4
) However, r is the radius of the wheel, T6. , is the transmission ratio of the differential gear device.

Aec=(acc−cLoss)/(vm, x
Vc(os,)'100 (5) However, veto□ and V□8 are output signals from the accelerator sensor 42 when the accelerator pedal 40 is not operated and when the accelerator pedal 40 is fully operated.

θ%=(■Evct0■)/(vl″ax−vcto
sa )・100 (6) However, vCLOsll and V′″1″X are output signals from the throttle sensor 84 when the throttle valve 80 is fully closed and fully open.

In the subsequent step S3, the gear stage detection routine is executed, so that the shift position detection switches 54, 5
The current gear T is detected based on the signals N, 84 to N5t-1 from 6, 58 and 60.

In the subsequent step S4, it is determined whether the content of the shift sequence flag F'chg indicating that a shift operation is being executed is "0". If it is not "0", the steps from step 88 described below are executed in order to preferentially execute the shift control, but if it is "0", the shift operation has been completed, so the target gear stage determination routine is executed in step S5. By executing this, the target gear stage γ8 for the next shift is determined.

That is, a shift diagram corresponding to the actual gear position γ is selected from among multiple types of shift diagrams stored in advance in the ROM 68, and interpolation calculations are performed from the shift diagram based on the actual throttle valve opening. Rear gear shift point vehicle speed 5PDup and downshift shift point vehicle speed SPD,
, , are calculated. When the actual vehicle speed SPD becomes equal to or higher than the upshift shift point vehicle speed SPD, p, 1 is added to the target gear stage T11, but the actual vehicle speed SPD becomes the downshift shift point vehicle speed 5PDa. 8, or less, 1 is subtracted from the target gear stage T8. Figure 11(a),
fb), (cl is an example of a shift diagram used in the target gear determination routine, (al is an example of a shift diagram selected while driving in the first gear, and (b) is an example of a shift diagram used in the target gear determination routine. Shift diagram selected while driving in high gear (C1 is the fifth
FIG. 4 is a shift diagram that is selected while the vehicle is running in a high gear. In the figure, the solid line is for determining the vehicle speed at the shift point during shift amplifier, and the broken line is for determining the vehicle speed at the shift point during downshift.

Once the target gear stage is determined as described above, in step S6, it is determined whether the target gear stage indicated by the contents of the register γ and the actual gear stage indicated by the contents of the register γ match. Ru. - If it fails, steps S10 and subsequent steps are executed since no shift operation is required; however, if they do not match, steps S87 and below are executed since a shift operation is required. That is, the shift sequence flag F is set prior to the shift operation by executing the step and knob S7.
The contents of chg are first set to "1", and then in step S8, the gear shift operation routine shown in FIG. 12 is executed to change the gear position of the stepped transmission 14 to the target gear position indicated by the contents of the register T11. A series of gear shifting operations are performed to switch to .

In FIG. 12, first, the content of the shift sequence flag FC119 is determined in step SHI. If the content of the shift sequence flag Fchg is "1", a series of steps SH2 to SH7 are performed to reduce the output of the engine 10 before the electromagnetic clutch 12 is released.
is executed. The content of the shift sequence flag Fchg being "1" indicates that the engine output reduction step is being executed. In step SH2, the ninth
The target throttle valve opening θ at the actual engine speed N from the throttle closing map shown in the figure. , f are determined. This target throttle valve opening θ. f is a value for setting the output torque of the engine 10 to zero, for example, at the actual engine rotational speed Nll.

In the throttle closing map shown in FIG. 9, each data point is updated every time a gear shift operation is performed by a learning routine to be described later.

In this step S H2, the target throttle valve opening degree θ of the engine 10 is determined. 1. When * is determined, step SH
3, the actual throttle valve opening θ of the engine 10 is the target throttle valve opening θ in the output reduction step. ,f''
It is determined whether the value is the same as or not.

The actual throttle valve opening θ is the target throttle valve opening θ. If the value is the same as ff', the purpose of the output reduction process has been achieved, and steps SH8 and subsequent steps, which will be described later, constituting the clutch release process are executed, but if they are not the same, steps SH4 and subsequent steps are executed.

In step SH4, the actual throttle valve opening θ is set as the target throttle valve opening θ obtained as described above. ff
8, the control 1v on the throttle actuator 82 is sequentially determined according to the following control equation (7).

In step SH5, the control Hvc for the electromagnetic clutch 12 is maintained at the previous control N V cl (n-11), and in step SH6, the control Hvc for each electromagnetic valve 30, 32, 34, 36 for shifting is maintained.
The contents of ffi V - hr rt are zero, that is, a state in which no drive signal is output to any solenoid valve. Then, in step SH7, the shift sequence flag F
The content of ch9 is set to "1". While the above series of steps are repeated, when the control ffi V th for the throttle actuator 82 is changed and the throttle valve opening θ is made to match the target throttle valve opening θoff8, the output reduction step is ended, A clutch release process starting from step SH8 is started to switch gears while interrupting power transmission.

In step SH8, it is determined whether the actual gear stage stored in the register γ and the target gear stage stored in the register T* match, and if they match, the gear stage switching operation is completed. Therefore, steps 5H12 and subsequent steps described below are executed, but since they do not initially match, the electromagnetic clutch 12 is released in step SH9 to avoid gear change failure due to engine inertia. Wholesale Ivch is set to zero. Then, by executing the gear switching routine in step 5HIO, the hydraulic cylinder 26 or the hydraulic cylinders 26 and 28 is operated, and the actual gear of the stepped transmission 14 is automatically switched to the target gear. It will be done. When the execution of the gear change routine in step S Hlo is completed in this way, the content of the shift sequence flag F ch9 is set to "2" in step S HII.

When the gear stage switching is completed by executing the above steps, it is determined in step S H8 that the target gear stage and the actual gear stage have failed, so retransmission is performed to retransmit the power of the engine 10. Step 5H12 and subsequent steps for executing the process are executed.

In step 5H12, the actual throttle valve opening θ
(%) is smaller than the accelerator operation amount Acc (%). This step 5H12 is for determining the end of the retransmission process.

Since it is initially small, step 5H13 is executed and the control amount for the electromagnetic clutch 12 is set to ■. , are sequentially increased by a predetermined constant increase value ΔVC1 (−ΔTcL). In the following step S) (14, for example, the target throttle valve opening degree θ for retransmission is determined based on the control 1v for the electromagnetic clutch 12 and the actual engine rotational speed N from the engine torque map shown in FIG. Calculated.

That is, the throttle valve opening θ is determined to obtain an output torque similar to the transmission torque Tc of the electromagnetic clutch 12. As a result, the throttle valve opening degree θ is successively increased. Then, in step 5H15, the throttle actuator 82 is controlled to the target throttle valve opening degree θ. J and actual throttle valve opening θ
The value θ to match. It is assumed that r. In the following step SHI3, control "lk" for each solenoid valve 30, 32, 34, 36 for shift is performed.
The content of t is zero, that is, a state in which no drive signal is output to any solenoid valve. Then, in step 5H17, 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 voltage for the throttle actuator 82 is successively changed so that the throttle valve opening θ becomes the target throttle valve opening θ each time. 2 will be followed.

By repeating the above series of steps, when it is determined in step 5H12 that the throttle valve opening θ and the accelerator operation amount AcC match, the shift sequence flag F is set in step 5H18. The content of 9 is set to "0".

When the shift operation routine is completed as described above, the first shift operation routine is completed.
In step S9 of FIG.
etc. are driven. As a result, the gear position of the stepped transmission 14 is switched to the target gear position.

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 Sll, control g v is performed for the electromagnetic clutch 12 so that the;h+I control Rv cL maximizes the transmission torque. cLmax. However, if the determination in step 310 is affirmed, in step S12 the control amount VC is
L is changed sequentially.

V, , = (N, -Ni□)XK (8) where K is a constant.

Then, in step S13, the control iV for the throttle actuator 82 is changed to the actual accelerator operation IJ.
After it is determined that it corresponds to A c c, the control '+'ff ffi is output in the above-mentioned step S9.

FIG. 13 shows the throttle valve opening, the transmission torque of the electromagnetic clutch 12, and the engine rotation speed that are changed during the above-mentioned speed change operation.

By the way, the target throttle valve opening degree θ in the output reduction process of the speed change operation. The throttle closing map shown in FIG. 9 used to determine ff* is corrected by the learning routine shown in FIG. 1.

This learning routine is executed every time there is a shift request. This shift request is made, for example, when the determination in step S6 in FIG. 10 is negative, or when the shift operation routine shown in FIG. 12 is executed. First, in step SG1, a change value ΔR in the engine rotation speed (rotation speed of the input shaft 46) after the clutch is released is detected. This engine rotational speed change value ΔR is, for example, the engine rotational speed at or just before the time when the electromagnetic clutch 12 starts disengaging in FIG. It is determined by determining the rotational speed and the difference between them. Alternatively, it is calculated by determining the difference between the engine rotation speed immediately before the electromagnetic clutch 12 is released by executing step SH9 and the engine rotation speed after a predetermined period of time has passed. Since the engine rotation speed for producing the rotation difference is detected at known time intervals, ΔR is also the rate of change (change rate) of the engine rotation speed after the electromagnetic clutch 12 is released.

Then, in step SG2, it is determined whether the engine speed change value ΔR is below a predetermined range, and in step SG3, it is determined whether the engine speed change value ΔR is above a predetermined range. Ru. This predetermined range is a reference range for determining whether or not the rotational speed of the engine 10 is changing at a substantially constant value, and the upper and lower limits of the range are relatively small, for example, about ten or more rpm. Each value is used. If the judgments in steps SG2 and SG3 are both negative, the rotational speed of the engine 10 remains at a substantially constant value and is within the reference range between the upper limit value and the lower limit value. No. 10 is considered to be operating in a state where the output torque is zero, and the data of the throttle closing map is not updated.

However, if the determination in step SG2 is affirmative, the power transmission path is cut off and the engine 1
Since the rotational speed of the engine 10 has decreased due to the loss of the driving force from the drive wheels, the data update routine of step SG4 is executed to update the data stored in the RAM 70 in FIG. In the throttle closing map shown in , the throttle valve opening degree at the engine speed immediately before the electromagnetic clutch 12 is released is updated to a value increased by a predetermined amount. Further, if the determination in step SG3 is affirmative, the rotational speed of the engine 10 is increased due to the late disconnection of the power transmission path, which cuts off the driving force that the engine 10 has been applying to the drive wheels. Therefore, the data update routine of step SG5 is executed to change the throttle valve opening by a predetermined amount at the engine rotational speed immediately before the electromagnetic clutch 12 is released from the throttle closing map shown in FIG. 9 stored in the RAM 70. Update to a decreased value.

Although a predetermined constant value may be used as the increase/decrease value of the throttle valve opening in the throttle closing map, for example, it may be determined based on the amount of change ΔR of the engine rotation speed from the relationship shown in FIG. Good too. In this case, for example, if the judgment in step SG3 is affirmative and the change in engine rotational speed at that time ■ΔR is the value shown in a in FIG. is the value shown in b, so as shown in Figure 15,
The previous data point θ is increased by increasing the throttle valve opening corresponding to the engine speed C immediately before the release of the electromagnetic clutch 12 by b.

-1 to new data point θ. Update to.

In addition, when updating the data points in the throttle closing map, not only the data points indicating the throttle valve opening corresponding to the engine speed C immediately before the electromagnetic clutch 12 is released, but also other data points are updated. The data points in the closed map may be updated together so that the curves connecting the data points become smooth. FIG. 16 is a diagram showing an example, where the previous data point θ
C-2-'+ θe-1-'+ θc-1. θ,.

, -1, new data point θc- from G0゜2-1
2, θc-1, G0, θ. , 1. It has been updated to G0゜2. In this example, the data point θ corresponds to the engine rotational speed C immediately before the electromagnetic clutch 12 is released. A total of 5 data points, including 2 adjacent points on both sides of -1, are updated, and the amount of correction is the data point θ
, the further away it is from use, the smaller it becomes. For example, if the correction amount for data point θ-1 is b, data points θC-1-1 and θ. . , -1 correction amount is b/
2. The amount of correction for data points θc-2-' and θc+2-1 is set to b/4.

In addition, regarding the output characteristics of the engine 10, the output torque is usually determined by various conditions such as individual differences between engines, warm-up state, and atmospheric pressure, but the output torque value relative to the rotation speed is relatively comparative. Since the target is not engraved, the first
As shown in FIG. 7, the modification 1b determined at the data point θ −1 corresponding to the engine rotational speed C immediately before the release of the electromagnetic clutch 12 may be applied to all data points to update the entire data point.

As described above, according to this application example, the target throttle valve opening degree θ for output reduction is set in the output reduction process in switching gears of the stepped transmission 14. 11' is corrected by the learning routine shown in FIG. 1, which is executed every time a shift request is made. That is, by utilizing the fact that when the output torque of the engine 10 is zero when the electromagnetic clutch 12 is released, there is almost no change in the amount of change ΔR of the engine rotation speed, the actual output torque of the engine 10 in the zero state is calculated. By learning the relationship between rotational speed and throttle valve opening, the throttle closing map is corrected. Therefore, regardless of individual differences in the engine 10, changes in the output torque of the engine 10 due to warm-up conditions, changes in the output torque of the engine 10 due to atmospheric pressure, etc., the target throttle valve opening is set to accurately bring the output torque of the engine 10 to zero. degree θ. 2. Since I can be obtained, the electromagnetic clutch 12
The deceleration shock caused by the output torque becoming negative before the electromagnetic clutch 12 is released, and the revving of the engine 10 caused by the output torque still being positive even after the electromagnetic clutch 12 is released are preferably eliminated.

Therefore, the unpleasant shock that occurs when the stepped transmission 14 is automatically shifted while the vehicle is running is eliminated, and the decrease in fuel efficiency due to engine 10 revving is eliminated.

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 embodiment, the target throttle valve opening degree θ is set in the output reduction step. 118 is determined from the relationship shown in FIG. 9, and is the target throttle valve opening θ. ff
' is controlled to match the actual throttle valve opening θ, but the drive signal supplied to the throttle actuator 82 can be used as a parameter in place of the throttle valve opening θ, and if a diesel engine is installed. In the vehicle where the throttle actuator 82
The rotation angle of the control I roll lever of the fuel injection pump rotationally driven by can be used as a control parameter in place of the throttle valve opening θ. The throttle valve opening degree described in the claims of this specification may be replaced with an equivalent parameter such as the above,
They should be interpreted as words representing mutually equivalent parameters.

Further, although the magnetic particle type electromagnetic clutch 12 is used in the application example described above, other types of automatic clutches capable of engagement control such as a hydraulic clutch may 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 the drawing]

FIG. 1 is a flowchart showing the operation of the learning routine for updating the throttle closure map of FIG. Second
The figure shows the shift control system of a stepped automatic transmission to which the present invention is applied.
FIG. 4 is a block diagram showing the 4'B device. FIG. 3 is a diagram showing the characteristics of the electromagnetic clutch shown in FIG. 2. 4 and 5 are diagrams showing a hydraulic drive device for switching gears of the stepped transmission shown in FIG. 2, and are sectional views of essential parts as seen from cross sections at right angles to each other. Figure 6 is similar to Figures 4 and 5.
It is a figure which shows the relationship between the locus of the end part of the shift select lever of a figure, and a shift position. FIG. 7 is a flowchart illustrating a part of the initial processing in the control device of FIG. 2. FIG. 8 is a diagram showing the output torque characteristics of the engine shown in FIG. 2. FIG. 9 is a diagram showing a throttle closing valve 77 used in the control device of FIG. 2. Figure 10 shows the second
3 is a flowchart illustrating the operation of the control device shown in the figure. FIG. 11 is a diagram showing the shift diagrams stored in advance in the control device of FIG. A shift diagram selected in the first gear stage, and (C) a shift diagram selected in the fifth gear stage. FIG. 12 is a flowchart illustrating the speed change operation routine of FIG. 10. FIG. 13 is a time chart showing changes in throttle valve opening, electromagnetic clutch transmission torque, and engine rotation speed that occur in connection with the automatic gear shift operation in the device shown in FIG. FIG. 14 is a diagram used in the flowchart of FIG. 1, and is a diagram showing the relationship between the amount of change in engine rotational speed and correction (2). FIG. 15 is a diagram illustrating updating of data points in the flowchart of FIG. 1. 1st
6 and 17 are diagrams corresponding to FIG. 15 in other application examples of the present invention. 10: Engine 12: Magnetic powder electromagnetic clutch (automatic clutch) 14: Stepped transmission (automatic transmission) Applicant: Toyota Motor Corporation No. 1vlJ Figure 3 Figure 6 Power filter, ee (A)
tshi'> Toih Figure 5 Figure 8 Figure 0: Slo, YF Le A Kaisho Figure 9 Figure 13Figure 15

Claims (1)

[Scope of Claims] 1) When changing the gear stage of a synchronous mesh type stepped transmission, an output reduction step of reducing the throttle valve opening to reduce the engine output, and releasing an automatic clutch to change the gear stage. The clutch release process for switching the
In the output reduction step, a target throttle valve opening for obtaining a desired output torque value is determined from a predetermined relationship, and the actual throttle valve opening is made to match the target throttle valve opening. A control method for a synchronized mesh automatic transmission, comprising: a detection step of detecting the actual engine rotation speed in the clutch release step; and a step of detecting the actual engine rotation speed after the automatic clutch is released within a predetermined range. A method for controlling a synchronous mesh automatic transmission, comprising: a correction step of correcting the relationship so that the relationship is maintained within (2) In the correction step, the relationship is corrected so that the target throttle valve opening becomes smaller when the engine rotation speed in the clutch release step exceeds the predetermined change range, and the engine rotation speed in the clutch release step is The method of controlling a synchronized mesh automatic transmission according to claim 1, wherein the relationship is corrected so that the target throttle valve opening becomes larger when the speed is below the predetermined change range.