JPH0260844A - Method for controlling on-vehicle automatic transmission - Google Patents

Abstract

PURPOSE:To prevent engine stall by accelerating at least one out of the closing speed of a throttle valve, the opening speed of the throttle valve and the engaging speed of an automatic clutch depending on the inclination of roads when each step of gear shifting of a synchronously intermeshing type stepped transmission is switched. CONSTITUTION:When a control device 16 shifts a synchronously intermeshing type stepped transmission 14, the output of an engine 10 is lowered with a throttle valve 80 closed, then plural steps of gear shifting are automatically switched with an automatic clutch 12 released. After switch-over has been made, the throttle valve 80 is opened so as to engage the automatic clutch 12 so that power is transmitted again. In this case, at least one out of the closing speed of the throttle valve 80 at the time of lowering engine output, the opening speed of the throttle valve at the time of transmitting power again and the engaging speed of the automatic clutch is much more accelerated as the inclination of roads detected by an inclination sensor 62 becomes greater. This constitution can thereby effectively prevent an reduction in speed and engine stall at the time of automatic shifting.

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.

Conventional technology After closing the throttle valve and reducing the engine power,
While the automatic clutch is released to temporarily interrupt the power transmission of the engine, the plurality of gears of the synchronous mesh type geared transmission are automatically changed, and the throttle valve is closed after the gears are changed. A method of controlling an automatic transmission for a vehicle has been considered in which the automatic transmission is opened and the automatic clutch is engaged to transmit power from the engine again. For example, there is a method for controlling an automatic transmission for a vehicle described in Japanese Patent Application Laid-open No. 116942/1987, which was previously filed by the present applicant. In this control method, a target throttle is set to obtain an appropriate engine output torque or rotational speed in at least one of an engine output reduction step, a power transmission interruption step, and a power retransmission step based on a predetermined relationship. The valve opening degree is determined, and the actual throttle valve opening degree in the at least one step is controlled so as to become the target throttle valve opening degree, so that during automatic shifting of the synchronized mesh type stepped transmission. The occurrence of shift shock caused by at least one of the output reduction step, the power transmission interruption step, and the power retransmission step is eliminated, and drivability is improved.

Problems to be Solved by the Invention However, there are still problems to be solved in the conventional automatic transmission control method.

That is, the speed at which the throttle valve is closed to the target throttle valve opening when reducing engine output, the speed at which the throttle valve is opened to the target throttle valve opening when retransmitting engine power, and the automatic clutch is engaged. The speeds are typically kept relatively low in order to reduce shift shock. For this reason, automatic gear shifting takes a relatively long time, and especially when driving uphill, the vehicle may be decelerated relatively significantly during gear shifting, impairing smooth running or causing engine stall. be.

The present invention has been made against the background of the above-mentioned circumstances, and its purpose is to shorten the shift time when traveling uphill, thereby effectively preventing deceleration and engine stall during automatic gear shifting. 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 a method for controlling an automatic transmission for a vehicle as described above, which comprises: (a) a gradient detection step of detecting a road gradient; (b) at least one of the speed at which the throttle valve is closed when reducing the output of the engine, and the speed at which the throttle valve is opened and the speed at which the automatic clutch is engaged when the power of the engine is retransmitted; The present invention is characterized in that it includes a control step of controlling the speed to be increased as the road gradient detected in the gradient detection step increases.

By doing this, the road gradient is detected in the gradient detection process, and the speed at which the throttle valve is closed when reducing the engine output, the opening speed and automatic speed when the engine power is retransmitted is determined. At least one of the speed at which the clutch is engaged and the speed at which the clutch is engaged is controlled in the control process so that the speed becomes faster as the road gradient becomes larger.

Effects of the Invention As a result, the time required for automatic gear shifting can be suitably shortened as the road gradient increases, so when driving on an uphill road,
It is possible to effectively prevent the vehicle from being relatively largely decelerated during gear shifting, thereby impairing smooth running and causing engine stall.

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 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. The engagement is controlled by an excitation current supplied from the control device 16, and a torque corresponding to the excitation current is transmitted. The crankshaft 15 and the stepped transmission 14
The input shaft 46 corresponds 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 third gear and the second gear, and a shift rod 20 to which a shift fork 19 for shifting to the third gear and the fourth gear is attached. , a shift rod 22 to which a shift fork (not shown) is attached for shifting to the fifth gear and reverse gear, and for selectively driving the shift rods 18, 20, 22 from the neutral position to the shift position. Equipped with a shift device.

The shift device includes a three-position hydraulic cylinder 26 for shifting that drives the shift select lever 24 in the rotational direction and drives any one of the shift rods 18, 20, 22 in the axial direction.
The shift select lever 24 is rotatably supported, and the lower end of the shift select lever 24 is engaged with any of the shift rods 18, 20, and 22 by positioning it at three positions in the direction of the rotation axis. Select 3
position hydraulic cylinder 28. The 3-position hydraulic cylinder 26 for shift is controlled to 3 positions by a combination of the operation of a pair of solenoid valves 30 and 32, and the 3-position hydraulic cylinder 28 for selection is also controlled by a combination of the operation of a pair of solenoid valves 34 and 36. It is designed to be controlled in three positions depending on the combination of. That is, by the combination of the operations of the solenoid valves 30, 32, 34, 36,
The hydraulic pressure supplied from the hydraulic pump 37 to the hydraulic circuit 38 is applied to the 3-position hydraulic cylinder 26 for shift and the 3-position hydraulic cylinder 26 for select.
The position hydraulic cylinder 28 is selectively supplied with, for example:
When both the electromagnetic valves 34 and 36 are on, the 3-position hydraulic cylinder 28 for selection is activated by the shift select lever 24.
is engaged with the shift rod 20 for switching between the third gear and the fourth gear, but when the solenoid valve 34 is on and the solenoid valve 36 is off, the 3-position hydraulic cylinder 28 for selection is shifted. When the select lever 24 is engaged with the shift rod X8 for switching between the first gear and the second gear, and on the other hand, when the solenoid valve 34 is off and the solenoid valve 36 is on, the select 3-position hydraulic pressure is activated. The second cylinder engages the shift select lever 24 with the shift rod 22 for switching between the fifth gear and the 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. The cylinder 26 is the shift rod 1
8, 20, or 22 to the 1st speed, 3rd speed, or 5th speed side, and conversely, if the solenoid valve 30 is off and the solenoid valve 3
2 is on, the three-position hydraulic cylinder 26 for shifting moves any one of the shift rods 18, 20, 22 to the second speed, fourth speed, or reverse side. FIG. 6 shows the relationship between the locus of movement 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. That is, a voltage signal v3c representing the amount of accelerator operation is output from the accelerator sensor 42 provided on the accelerator pedal 40. is control device 1
6.

Engine rotation speed sensor 44 provided in engine 10
A signal tt+ representing the engine rotation period is outputted to the control device 16. A signal t representing the rotation period of the input shaft 46 is output from 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.

A signal t0° representing the rotation period of the output shaft 48 is output to the control device 16. Shift position detection switches 54, 56, 58, and 60 provided in the stepped transmission 14 output signals Ns, 4 to N, , 1 to the control device 16. The operating position of the 3-position hydraulic cylinder 26 for shifting is detected by the combination of signals from the pair of shift position detection switches 54 and 56, and the pair of shift position detection switches 54 and 56
The operating position of the 3-position hydraulic cylinder for selection on the 2nd day is detected by the combination of signals from 8.60. These shift position detection switches 54.56.5
8.60 is the Utility Model Application No. 62-15, which the present applicant previously applied for.
This is the same as that described in No. 3449. Furthermore, a signal Vth representing the opening degree of the throttle valve 80 is sent from a throttle sensor 84 provided in the intake pipe of the engine 10.
However, the inclination angle sensor 62 outputs a signal Vα representing the road slope.

, are output to the control device 16, respectively.

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, and the like. Processing the input signal, 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.

FIG. 7 shows an example of the configuration of the output terminals of the electromagnetic valve drive circuit 78, which consists of four bits, bits 0 to 3. 0
Pinto, bit 1, pinto 2, and bit 3 correspond to solenoid valves 30, 32, 34, and 36, respectively. Similarly, FIG. 8 shows an example of a partial configuration of an input terminal of an input interface 72 consisting of four bits, bits 0 to 3. 0th bit, 1st bit,
The 2nd and 3rd bits are shift position detection switches.
4.56.58.60, respectively.

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

First, in step S1, the input signal t from each sensor is
,,,ji,,,'out % vacc % Vth
s N5w1 to N584 and Vαc1 are read.

Next, in step S2, the following equation (1) is calculated from the above signal.
Actual engine speed N according to (8). , input shaft rotational speed N in, output shaft rotational speed Nout, vehicle speed SPD, accelerator operation amount A cc, throttle valve opening θ
, road surface inclination angle αc1 are calculated.

NN11rp = (1/lo) X60sec
...(1)N,, = (1,/LH,)
X60sec ・ ・ 12) No, t −(
1/l,,,,t)X60sec ・ ・ ・(3)
SPD km/h = N, t・γdif,
2πr・60. ,．． 4. , ・1/1000 ・ ・(
4) However, r is the radius of the wheel, γ61. This is the gear ratio of the differential gear.

AcC=(ν1ce−ν.,.sa)/(v mix
vctosa)40・(5) However, VCLO5@ and vffiaX 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, h-veLQse)/(shi'aX-vc
Losa ), 10 However, vclos@ and vffi
IX is an output signal from the throttle sensor 84 when the throttle valve 80 is fully closed and fully opened.

α,=KcL−(vα,,−V, ) −・−(7
) However, α5 is the road surface inclination angle, Kct is the sensor gain constant, and ■. is the reference potential at a tilt angle of O°.

FIG. 10 is a diagram showing an example of the relationship of equation (7) above.

Since the road surface inclination angle α5 includes an acceleration component of the vehicle, it is corrected to the road surface inclination angle α according to the following equation (8).

α, = α-tan −' (Dspd/g) ・
...(8) However, D5□ is the differential value of the vehicle speed SPD, and g is the gravitational acceleration.

In the subsequent step S3, the gear position determination routine shown in FIG. 11 is executed to detect the current gear position based on the signals N584 to N581 from the shift position detection switches 54, 56, 58, 6o. . Since the signals N, . That is, when none of the signals N384 to N, , 1 is supplied, the binary number B becomes zero, so the stepped transmission 14 is determined to be in the neutral state, and the signals Ns, , 2 and N5 .
.

4 is supplied, the binary number B becomes 5, so it is determined that the first gear is selected, and when the signals N, 2, and N13 are supplied, the binary number B becomes 6, so the second gear is determined. If it is determined that the gear is in the third gear and only the signals N, , 44 are supplied, the binary number B becomes 1, so it is determined that the gear is in the third gear, and the signals N,
, 3 is supplied, the binary number B becomes 2, so it is determined that the fourth gear is present, and signals N581 and N584 are supplied.
If the signal N, 81 and N, , 3 are supplied, the binary number B becomes 10, so the 5th gear is determined. The current gear position is determined and a value indicating the current gear position is stored in the register T.

In the subsequent step S4, it is determined whether the contents of the shift sequence flag Fch9 indicating that a shift operation is being executed is "0". If it is 'OJ', the gear shifting operation has been completed, so the target shown in FIG. By executing the gear position determination routine, the target gear position for the next shift is determined. That is, steps SMI to 5M1
2, based on the numerical value indicating the actual gear in the register T, a shift diagram corresponding to the actual gear is selected from among a plurality of types of shift diagrams stored in advance in the ROM6B. , in step 5M13, the upshift shift point vehicle speed SPD,p and the downshift shift point vehicle speed SPD, are calculated by interpolation based on the actual throttle valve opening from the shift diagram. , , are calculated. Then, in step 5M14, the actual vehicle speed SP
When D becomes equal to or higher than the upshift shift point vehicle speed 5PDup, the contents of the register T8 that stores the numerical value indicating the target gear are set to γ+1 in step 5M15, but in step 5M16 the actual vehicle speed SPD becomes the downshift shift point vehicle speed. SPD,. -Step SM if below]
, 7, the contents of register T* are set to γ-1. In other words, the contents of the register T* are set to a gear stage that is one stage higher than the current gear stage or a gear stage that is one stage lower than the current gear stage. FIGS. 13(a), 13(b), and 13(C) respectively show examples of the speed change diagrams selected in step SM2.3M4.5Ml0. In the figure, the solid line is for determining the vehicle speed at the shift point during upshifting, and the broken line is for determining the vehicle speed at the shift point at downshifting. Furthermore, in step 5M13, if the shift diagram is shown in FIG. 14, the shift point vehicle speed is calculated from the data map that constitutes the diagram based on the actual accelerator operation amount Acc and the X on the map.
Comparison is made sequentially with the axis data, and when the X-axis data becomes less than ACC, it is set as X2, and the previous X-axis data where Acc<X-axis data is set as Xl, then the following equation (9) is performed.

Returning to FIG. 9, when the target gear is determined as described above, in step S6, the target gear indicated by the contents of register T8 matches the actual gear indicated by the contents of register γ. It is determined whether or not. If they match, there is no need for a gear shift operation, and steps Sll and subsequent steps are executed; however, if they do not match, a gear shift operation is required, and steps from step 87 are executed. That is, step S
7 is executed, the contents of the shift sequence flag FCh9 are first set to "1" prior to the shift operation, and then in step S8, the road surface inclination angle α calculated in step S2 is set. , the shift speed correction coefficient α is determined from a predetermined relationship shown in FIG. 15, for example. The shift speed correction coefficient α is set to 1 when the road surface inclination angle α, 1 is 0°, and is gradually increased as the absolute value of the road surface inclination angle α becomes larger.

Next, in step S9, the speed change operation routine shown in FIG. 1 is executed to perform a series of speed change operations for switching the gear position of the stepped transmission 14 to the target gear position indicated by the contents of the register γ8. .

In FIG. 1, first, in step SHI, the contents of the shift sequence flag Fchg are determined. If the content of the shift sequence flag F ch9 is "1", a series of steps SH2 to S are performed to start the power cutoff operation.
H8 is executed. This shift sequence flag F ch
The content of 9 being "1" indicates that the output reduction step of the engine 10 is being executed. Step S
At H2, the actual output torque T of the engine 10 is calculated based on the actual engine speed N and the actual throttle valve opening θ from the engine characteristics determined in advance and stored in the ROM 68. The above engine characteristics are, for example, the relationship between output torque T9, engine rotational speed N, and throttle valve opening θ as shown in FIG.
engine torque map). The above output torque T. The calculation of is performed as follows. First, the engine rotational speed N8 is converted into an X-axis coordinate and the throttle valve opening θ is converted into a Y-axis coordinate. This conversion can be done, for example, by engine speed N8
For this, set "0" as the initial value for the coordinate Compare sequentially. A pair of X-axis data sandwiching the engine rotation speed N is held, and when <X-axis data, the engine rotation speed N is held. A pair of X-axis data obtained in this way are indicated by Xl and X2 in FIG. 17. 17th
As shown in Y and Y2 in the figure, a pair of Y-axis data for the throttle valve opening degree θ is obtained in the same manner. Next, output torque data a specified by the intersection point of coordinates Y and X, and output torque data b specified by the intersection point X of coordinates Y and X2 are extracted from the engine characteristic diagram in FIG. The engine output torque e indicated at the intersection with the engine rotational speed N is calculated based on, for example, the following equation.

Similarly, output torque data C specified by the intersection of coordinates Y2 and X and output torque data d specified by the intersection X of coordinates Y2 and X2 are extracted from the engine characteristic diagram in FIG. Rotational speed N. The engine output torque f shown at the intersection with is calculated based on, for example, the following equation (11).

Then, output torque T corresponding to the actual throttle valve opening θ and engine rotational speed N8 is obtained from e and f obtained as described above. is calculated according to the following equation 02).

When the actual output torque T of the engine 10 is determined in step SH2 in this way, step SH3
, the absolute value 1T of the output torque of the engine 10, and the target output torque T at the time of power cutoff, where l is preset. It is determined whether the value is larger than f. If it is not larger than that, the purpose of the output reduction process has been achieved, and the power transmission interruption process in step SH9 and below is executed, but if it is larger, the actual engine rotational speed is determined from the engine torque map shown in FIG. 16 in step SH4. N. and the target output torque T. Target throttle valve opening θ based on ff.

ff* is determined. This target throttle valve opening θ. 7
．． * indicates the output torque TQ of the engine 10 as T above. 7.
It is a small value to make it, as shown in Figure 18,
First, the engine rotation speed N is calculated using the same method as the equation (9) above.
. Find the X-coordinate of , and find the Y-axis coordinate Y corresponding to the throttle valve opening θ. Output torque T specified by the intersection of and engine rotational speed N8. is obtained by the same method as the above equation 02), and is calculated according to the following equations 03), θ4), and 05). That is, the coordinate Y. engine output torque T. and target output torque T. f, and T.

KuT. When f, the next Y axis, in other words, the engine output torque T1 indicated by the intersection of the coordinate Y1 and the engine rotational speed N8 is calculated, and T1 and T are calculated again. Compare with ff. In this way, sequential comparisons are made, and T.

When ≧Totr, the engine output torque at coordinate Y-1) is T-1. and T. , Yo and Y-1,
The target throttle valve opening degree θ.tr. is calculated from the throttle valve opening degrees θ7 and θ(n-11) corresponding to the target output torque T.ff.

+θ(n-11 . . . 03) In step SH5, the actual throttle valve opening θ is set as the target throttle valve opening θ obtained as described above. ff
’X, the throttle actuator 82
The control 1v for is determined according to the control formula 〇〇 shown below.

・ ・ ・(Ibl In the above formula 00, Δθ is determined based on the accelerator operation 1jlA, c from the predetermined relationship shown in FIG. 19, for example. This predetermined relationship is suitable for driving on flat roads. The value obtained by multiplying Δθ obtained from this relationship by α by the speed change correction coefficient according to the road surface slope is subtracted from the previous control amount ■th (,, -11).

In step SH6, the current control 1v0 for the electromagnetic clutch 12 is updated as the previous control amount Vcl(.-1,) in preparation for the next cycle, and in step SH7, each electromagnetic valve 30, 32, . 3
4. The content of the control amount (1) and 8 for 36 is zero, that is, a state in which no drive signal is output to any solenoid valve. Then, in step SH8, the content of the shift sequence flag Fchq is set to "1". While the above series of steps are repeated, the throttle actuator 8
2, the control 1V is decreased and the throttle valve opening θ becomes the target throttle valve opening θ. Matched with rr8. In such a state, in step SH3, the absolute value IT,l of the output torque of the engine 10 becomes the target engine torque T07. It is determined that the following is true, so
The output reduction step is ended, and a power transmission interruption step starting from step SH9 is started for switching gears while interrupting power transmission.

In step SH9, it is determined whether the actual gear stored in the register γ matches the target gear stored in the register γ", and if they match, the gear switching operation is completed. Therefore, steps 5T (16 and below) to be described later are executed, but if no failure has occurred, the control amount ■ is set to zero in step 5H10, and the electromagnetic clutch 12 is released. Then, step 5H1
1, the engine rotational speed N% when the target gear to be shifted is established is the actual output shaft rotational speed N from the following equation θ'7). ut and target gear gear ratio T41
．． . Calculated based on 8. The gear ratio of this target gear is γ1□5. ' is shown in FIG. 20, for example.

Na” = T rlti.”XNout
-.-07) In the following step 5H12, the engine rotation speed N when the target gear is established. Target throttle valve opening degree θ for power transmission interruption to match * with the actual engine rotational speed N, that is, to make the output torque of the engine 10 substantially zero. 8 is calculated. Then, in step S H13, the control amount (I) for the throttle actuator 82 is set to the values θ, Q'' for obtaining the target throttle valve openings θ, I. Next, the gear change routine of step S H14 is executed. be done.

The gear stage switching routine is executed as shown in FIG. 21, for example. First, in step SGI, the data indicating the target gear stage stored in the register γ1 is transferred to the second
By processing using the signal processing routine shown in Figure 2, numerical values that can be easily handled as drive signals,
Converts to a number that can be output as a binary number with the same bit array. That is, in order to convert the data into data having the same arrangement as the input terminals of the input ink face 72 shown in FIG. Shift side data T*5 for activating the select hydraulic cylinder 28, and select side data T”s+ for operating the select hydraulic cylinder 28.
is converted into For example, if the target gear is the first gear, the shift side data T8. If mine is "1" and the select side data 7'st is "4", and the target gear is the second gear, the shift side data T'sb is "2" and the select side data r'sL is "4". ”, and if the target gear is the third gear, the shift [• side data T” sh is “1” and the select side data T89. is set to "0",
If the target gear is the 4th gear, shift side data T0
is "2" and the select side data T0.1 is "0", and if the target gear is the 5th gear, the shift side data T"sh is "1" and the select side data T'sr is " 8
”, and if the target gear is the 6th (reverse) gear, the shift side data T80 is “2” and the select side data γ
*1 is set as "8".

In step SG2 of FIG. 21, the contents of the register γ are converted into shift-side data γsk and select-side data γ5 by a processing routine not shown, just as described above. These shift side data γsh and select I/side data γ5. are shift position detection switches 54, 56, 58.
The signal Ns supplied from 60 to input interface 72
, 4 to Ns, 1, the lower 2 bits and the upper 2 bits (including the lower 2 bits of "0" as a numerical value) may be used.

In step SG3, select side data T19. based on the target gear stage. and select side data γ based on the actual gear stage.
At step SG4, it is determined whether shift-side data T* based on the target gear and shift-side data rsh based on the actual gear match. If the determinations in steps SG3 and SG4 are both affirmative, there is no need to change gears, so step SG5 is executed and the contents of the control amounts (2) and (ift) are set to zero. However, step S
If the determination in step G3 is affirmative but the determination in step SG4 is negative, step 306 is executed and the contents of the control It V S k i f L are set as shift-side data T* based on the target gear.

As a result, the three-position hydraulic cylinder 26 for shifting is driven in step S9, which will be described later, and the target gear stage is established. Further, if the determination in step SG3 is negative, it is necessary to use a shift rod different from the one currently engaged with the shift select lever 24, so in step SG7 the shift side data γsh based on the actual gear position is is zero, that is, 3 for shift
It is determined whether the position hydraulic cylinder 26 is in the neutral position. If the judgment in step SG7 is affirmative, the contents of the control variables ■, Select side data based on target gear stage 7” sL
It is said that However, if the determination in step SG7 is negative, the content of the control ffi V 5hift is set to "3" in step SG9 in order to operate the three-position shift hydraulic cylinder 26 to the neutral position. This control amount■. Since the content "3" of ifL is "11" in binary, the solenoid valve drive circuit 78 is set to 0 in step S9.
Drive signals are output from the number bit and the number 1 bit to the electromagnetic valves 30 and 32, respectively. When the three-position hydraulic cylinder 26 for shifting is operated to the neutral position in this way, steps SG8 and S9 of the next cycle
The shift rod is selected, and the target gear is established in steps SG6 and S9 of the next cycle.

When the execution of the gear change routine in step 5H14 in FIG. 1 is completed in this manner, the content of the shift sequence flag Fchg is set to "2" in step SH15. When the gear shift is completed by executing the above series of steps, it is determined in step SH9 that the target gear matches the actual gear, so that the power of the engine 10 can be transmitted again. Step 5HI6 and subsequent steps are executed.

In step 5H16, throttle valve opening θ (%)
It is determined whether or not is smaller than the accelerator operation 11Acc (%). This step 5H16 is for determining whether the retransmission of power from the engine 10 has been completed. Since it is initially small, the current control amount vet for the electromagnetic clutch 12 is determined in step SH17 according to control formula 08) shown below.

V cl −V ct +n−11+Δ■cL×α−
--08) In the above equation 08), Δ■o is, for example, based on the predetermined relationship shown in FIG.
It is determined based on Acc. This predetermined relationship is suitable for driving on flat roads, and the previous control 3qv, , is calculated by multiplying the shift speed correction coefficient corresponding to the road surface slope by α. I-,,
Increased by more.

In the following step S I (1B, for example, the 16th
From the engine torque map shown in the figure, the electromagnetic clutch 1
The target throttle valve opening degree θ for power retransmission is based on the control amount VcL and the actual engine rotational speed N8 for 2.

2 is calculated by the same method as in step SH4. That is, the throttle valve opening degree θ for making the output torque T of the engine 10 match the transmission torque TcL of the electromagnetic clutch 12 is determined. Then, in step 5H19, the control fflVLh for the throttle actuator 82 is set to a value θ for obtaining the target throttle valve opening degree θ0,,'. 2. This value θ
. ,.

is the control 4fl AV obtained in step 5H17
Since it is calculated based on c +, Ste. Tsubu S
This value θ in H19. Control 1v potato control amount ■ set to n'. , it will be increased according to the road surface gradient. In the following step SH20, the control ML V s for each electromagnetic valve 30, 32, 34, 36
The content of h i t t is zero, that is, a state in which no drive signal is output to any solenoid valve. Then, in step SH21, the content of the shift sequence flag F ch9 is set to ``3''. In the process of repeating the above series of steps, the control 1v, .
is the target throttle valve opening θ in each case. − is made to follow.

By repeating the above series of steps, if it is determined in step S H16 that the throttle valve opening θ and the accelerator operation amount Acc match, the shift sequence flag F ch9 is set in step S H22.
The content of is set to "0".

When the gear shift operation routine is completed as described above, the ninth shift operation routine is completed.
■ In step SIO in the figure. 4. ■I, VShif
Each control value such as t is output to the electromagnetic clutch 12, throttle actuator 82, and electromagnetic valve 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 judgment in step S11 is negative, it is necessary to maintain the electromagnetic clutch 12 in the engaged state, so in step S12, the control amount 1vc for the electromagnetic clutch 12 is set to the control amount ■ to maximize the transmission torque TCL. cL″a″. However, step Sll
If the judgment in step S13 is affirmative, the control amount ■ゎ is determined according to the control equation shown in the following equation θ9).

is changed sequentially.

V-1= (N-N1dt)
・ ・ -Q9) However, K is a constant. Then, after the control amount V tH for the throttle actuator 82 is made to correspond to the actual accelerator operation i1 Acc in step S14, the control value is output in the above-mentioned step SIO. Ru.

As described above, according to the present application example, in the output reduction step in switching gears of the stepped transmission 14, the output torque T9 of the engine 10 is set to a predetermined small target engine torque T o f f . Target throttle valve opening θ for output reduction. While ff* is calculated,
The actual throttle valve opening θ is the target throttle valve opening θ. 11'', the output torque T8 of the engine 10 never becomes negative. Therefore, when the throttle valve opening θ is decreased at the start of automatic gear shift operation, the electromagnetic clutch 12 is not engaged. This prevents deceleration shock from occurring even if there is some residual overlap.

In addition, in the power transmission interruption process in changing the gear of the gear transmission 14, the input shaft rotation speed N in when the engine rotation speed N8 is established as the target gear
The target throttle valve opening θn2 for power interruption to achieve the same rotational speed is determined, and the actual throttle valve opening θ is controlled to the target throttle valve opening θ,8. , the difference in rotational speed at the time of reappointment is reduced, and the coupling shock of the electromagnetic clutch 12 is eliminated.

In addition, in the re-engaging process (power re-transmission process) in switching gears of the stepped transmission 14, the electromagnetic clutch 12
The target throttle valve opening degree θ for re-engagement is such that the output torque T of the engine 10 becomes equal to the transmission torque T ct as the transmission torque T ct increases. ,,' are determined, and the actual throttle valve opening θ is controlled to the target throttle valve opening θon*, so that the throttle valve opening θ and the transmission torque T of the electromagnetic clutch 12 are
In the process of increasing ct, the throttle valve opening θ does not become excessively large or excessively small relative to the transmission torque Tel of the electromagnetic clutch 12.

Therefore, the occurrence of engagement shock due to premature engagement due to engine 10 revving caused by excessive increase in throttle valve opening θ or excessive increase in transmission torque T c of electromagnetic clutch 12 is avoided. Preferably prevented.

Furthermore, according to this application example, step S of the output reduction process
At H5, change the actual throttle valve opening θ to the target throttle.
Torque valve opening θ. , f'', the amount of decrease in the control amount (I) for the throttle actuator 82 to match with the speed change speed correction coefficient α increases as the road surface inclination angle αct increases, that is, the road surface inclination angle α.

, is controlled so that the speed at which the throttle valve 80 is closed becomes faster as
The amount of increase in cL is the road surface slope angle α6. In other words, the road surface inclination angle α increases as the angle increases. .

The larger the target throttle valve opening θ, the faster the speed at which the electromagnetic clutch 12 is engaged is controlled. −
Similarly to the control amount VeL, the control amounts V and h for the throttle actuator 82 to obtain the road surface inclination angle α
. is controlled so that it becomes larger as , that is, as the road surface inclination angle α becomes larger, the speed at which the throttle valve 80 is opened becomes faster. As a result, the road surface slope angle α. As , becomes larger, the time required for automatic gear shifting is suitably shortened, so especially when driving uphill, the vehicle is decelerated relatively significantly during gear shifting, which impairs smooth running or causes engine stall. This effectively prevents this from happening.

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-mentioned application example, the target throttle valve opening θ is obtained in each of the output reduction step, power transmission interruption step, and power retransmission step when changing gears of the stepped transmission 14. , f θI θoz, but the drivability is improved to some extent even when the above control is executed in any one step.

Furthermore, in the above application example, the speed at which the throttle valve 80 is closed in the output reduction step, the speed at which the electromagnetic clutch 12 is engaged in the power retransmission step, and the speed at which the throttle valve 80 is opened in the power retransmission step are determined by the road surface inclination angle. α. , are controlled to become faster as
At least one of the speed at which the throttle valve 80 is engaged and the speed at which the throttle valve 80 is opened corresponds to the road surface inclination angle α. Even if the speed is controlled to increase as This will be prevented to some extent from occurring.

In the above-mentioned application example, the shift speed correction coefficient α is the road surface inclination angle α0. It is set to increase gradually as the absolute value of increases, but when αct≦0, α is set to 1 as described above2, and only when αC1>0, α is gradually increased as αC5 becomes larger. Even if the vehicle is configured in this manner, the above-mentioned effects can be obtained during the gear change while traveling on the uphill road.

Furthermore, in step SH2 of the application example described above, the actual output torque T of the engine 10 is calculated based on the actual engine rotational speed N8 and the throttle valve opening θ from a predetermined relationship. The output torque of the engine 10 may be detected by providing the following.

Furthermore, although the magnetic particle type electromagnetic clutch 12 is used in the application example described above, other types of automatic clutches that can control engagement, 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 the drawing]

FIG. 1 is a diagram illustrating a gear shift operation routine which is a main part of the flowchart of FIG. 9. FIG. 2 is a block diagram showing a shift control device for a stepped automatic transmission to which the present invention is applicable. 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. FIG. 6 is a diagram showing the relationship between the locus of the end of the shift select lever in FIGS. 4 and 5 and the shift position. 7th
8 and 8 are diagrams respectively illustrating the terminal configuration of the electromagnetic valve drive circuit of FIG. 2 and the terminal configuration of a part of the input interface. FIG. 9 is a flowchart for explaining the operation of the shift control device of FIG. 2. FIG. 10 is a diagram showing a predetermined relationship between the output value of the inclination angle sensor and the road surface inclination angle α5. Figures 11 and 12
Each figure is a diagram showing the routines executed in the flowchart of FIG. 9. Figure 13 (a), (b),
(C) is a diagram showing the shift diagrams stored in advance in the ROM in FIG. (C) is the diagram selected in the fifth gear. FIG. 14 is a diagram illustrating the calculation for determining the shift point vehicle speed in the flowchart of FIG. 1. FIG. 15 is a diagram showing a predetermined relationship between the road surface inclination angle α and the speed change correction coefficient. FIG. 16 is a diagram showing an example of engine output characteristics. FIG. 17 is a diagram illustrating a method for calculating engine output torque. FIG. 18 is a diagram illustrating a method for calculating the target throttle valve opening. FIG. 19 is a diagram showing a predetermined relationship between the accelerator operation amount and Δθ in step SH5 of the gear shift operation routine. FIG. 20 is a chart showing the speed ratio of each gear of the stepped transmission. FIG. 21 is a diagram showing a routine executed in the flowchart of FIG. 1. FIG. 22 is a diagram showing a routine executed in the flowchart of FIG. 21. FIG. 23 shows the accelerator operation amount and Δ■ at step 5H17 of the gear shift operation routine. , is a diagram showing a predetermined relationship between . 10: Engine 12: Magnetic powder electromagnetic clutch (automatic clutch) 14: Stepped transmission 80: Throttle valve Figure 3 Figure 7 Figure 8 Figure 6 Figure 5 Figure 10 Figure 15 Route 6 Mui 1 Stilt angle &cL Fig. 13 U Slot 1 Valve opening cylinder 14 Fig. km/h Y-axis Fig. 19 Fig. 20 Hagi 3 Fig. U]

Claims (1)

[Claims] After the throttle valve is closed to reduce the engine output, the automatic clutch is released to temporarily interrupt the power transmission of the engine, and the synchronized mesh stepped transmission is A method for controlling an automatic transmission for a vehicle, wherein the gear stage is automatically changed, and after the gear stage is changed, the throttle valve is opened and the automatic clutch is engaged to transmit power from the engine again. a slope detection step of detecting a road slope, a speed at which the throttle valve is closed when reducing the output of the engine, a speed at which the throttle valve is opened when power from the engine is retransmitted, and a speed at which the automatic clutch is adjusted. A control method for an automatic transmission for a vehicle, comprising a control step of controlling at least one of the engagement speed and the engagement speed to be increased as the road gradient detected in the gradient detection step increases.