JPH0633817B2 - Shift control method for automatic transmission - Google Patents

Description

Detailed Description of the Invention a. Object of the Invention (Industrial field of use) The present invention relates to an automatic transmission adapted to switch a power transmission path to perform automatic shifting by operating control of a hydraulically operated clutch.

(Prior Art) An automatic transmission is configured to automatically change gears in accordance with a traveling state to obtain desired traveling characteristics. For this reason, it is often the case that there is a shift map in which a shift-up line and a shift-down line are set for each shift from the relationship between the vehicle speed and the engine output, and the shift control is performed by observing the running state on the shift map. It is being appreciated. An example of such shift control is, for example, Japanese Patent Laid-Open No. 61-189354.
Some are disclosed in Japanese Patent Publication.

In performing such shift control, it is required to reduce shock during shifting as much as possible, and various measures have been taken conventionally.

For example, during power-on shift-down (a state in which the accelerator pedal is depressed to perform a shift-down, which corresponds to kick-down), or power-off shift-up (returning the accelerator pedal from being depressed while driving). As for the shift control in the case of performing the shift-up by), when the shift command is issued, first, the engagement of the preceding-stage clutch (the clutch that has been engaged until then) is released, and then The control is performed such that the rear-stage clutch (the clutch that is newly engaged by shifting) is engaged when the input rotation and the output rotation are synchronized. If such control is performed, there is no exchange of inertial energy between the input side and the output side when the rear clutch is engaged, so that there is an advantage that smooth gear shifting is performed.

(Problems to be Solved by the Invention) However, in the conventional control, the detection of the synchronization point of the input / output rotation of the latter-stage clutch is performed using a timer, or based on the relationship between the vehicle speed and the engine rotation. Therefore, there is a problem that the detection accuracy is low due to the influence of the oil temperature, the variation due to the individual difference, the influence of the slip of the torque converter, the fluid coupling and the like.
If the detection of the synchronization point is deviated, for example, the engagement timing of the rear-stage clutch becomes early to cause a shift shock, or the engagement timing of the rear-stage clutch is delayed, which causes an uncomfortable feeling due to engine upstroke or delay in shift. There is a problem.

Further, in the conventional control, even if the synchronization point of the input / output rotation of the rear-stage clutch is detected, the engagement command of the rear-stage clutch is issued, and the working hydraulic pressure is supplied to the rear-stage clutch,
After the piston is moved by the ineffective stroke by this hydraulic pressure, the engagement of the clutch is started for the first time, so that there is a problem that there is a delay in the start of engagement of the clutch. For this purpose, it suffices to issue an engagement command slightly earlier than the synchronization time point, but the invalid stroke has a large variation due to individual differences, and it is difficult to accurately detect the synchronization time point before synchronization. There's a problem.

The present invention, in view of the above problems, in the case of power-on shift-down or power-off shift-up,
(EN) Provided is a shift control method capable of accurately detecting a synchronization point of input / output rotations in a rear clutch, and engaging this clutch without time delay when this detection is performed. To aim.

B. Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, in the shift control method of the present invention, the input / output rotation is detected by detecting the rotation of the input side rotating member and the output side rotating member of the hydraulically actuated clutch. Number ratio (=
Output rotation speed / input rotation speed) is detected, and the input / output rotation synchronization is detected by detecting that the input / output rotation speed ratio of the hydraulically operated clutch for the rear stage (the clutch for the rear stage) has become approximately 1.0 during shifting. When either the power-on shift-down or the power-off shift-up is performed, the operating hydraulic pressure supplied to the rear clutch is changed from the start of the shift to the input / output rotation. The pressure is kept slightly lower than the engagement start hydraulic pressure until the synchronization is determined, and the operating hydraulic pressure is raised to a predetermined engagement pressure when the input / output rotation synchronization is determined.

(Operation) When the shift control of the automatic transmission is performed by the above method, when a power-on shift-down or a power-off shift-up is performed, for example, when a shift command is issued based on a shift map, the preceding hydraulic operation is performed. The oil pressure supplied to the clutch is reduced, and the engagement of the front-stage clutch is released.At this time, the input / output rotation of the rear-stage clutch is detected, and the input / output rotation of the rear-stage clutch is synchronized. At the same time (when they match), the hydraulic pressure supplied to the latter-stage clutch is raised to a predetermined engagement pressure and this clutch is engaged. In this case, since the input / output rotational speed ratio of the latter-stage clutch is directly detected by detecting the rotations of the input-side rotating member and the output-side rotating member, the synchronization point can be accurately detected. Further, since the input / output rotation of the rear-stage clutch is detected from the time the shift command is issued, the hydraulic pressure supplied to the rear-stage clutch is slightly lower than the engagement start hydraulic pressure. By this hydraulic pressure, the piston of the second-stage clutch is moved by an invalid stroke, and is held at the position immediately before the clutch is engaged.
Therefore, when the synchronization of the input / output rotation is detected and the hydraulic pressure supplied to the latter-stage clutch is increased, the engagement of the latter-stage clutch is immediately started, and with the detection of the above-mentioned synchronization, the latter-stage clutch is accurately and without time delay. Are engaged.

(Examples) Specific examples will be described below with reference to the drawings.

First, referring to FIG. 1, the structure of an automatic transmission that is shift-controlled using the method of the present invention will be described. In this transmission AT, the engine output transmitted from the output shaft 1 of the engine via the torque converter 2 is changed in speed by a transmission mechanism 10 having a gear train forming a plurality of power transmission paths, and the output shaft 6 is output. Is output to. Specifically, the output of the torque converter 2 is output to the input shaft 3, and five sets of gear trains are arranged in parallel with each other between the input shaft 3 and the counter shaft 4 arranged in parallel therewith. The transmission is transmitted to the counter shaft 4 by any one of the gears, and is further output to the output shaft 6 via the output gear trains 5a and 5b arranged between the counter shaft 4 and the output shaft 6.

The five sets of gear trains arranged between the input shaft 3 and the counter shaft 4 are the first speed gear trains 11a and 11b, the second speed gear trains 12a and 12b, and the second speed gear train 13a. 13b,
Fourth speed gear train 14a, 14b and reverse gear train 15
a, 15b and 15c, each gear train is provided with hydraulically operated clutches 11c, 12c, 13c, 14c and 15d for transmitting power by the gear train. A one-way clutch 11d is provided in the first speed gear 11b. Therefore, by selectively operating these hydraulically actuated clutches, it is possible to select power transmission by any one of the above-mentioned five gear trains and perform gear shifting.

The operation control of the above-mentioned five sets of hydraulically operated clutches 11c to 15d is performed from the hydraulic control valve 20 to the hydraulic line 21.
It is performed by the hydraulic pressure supplied and discharged through a to 21e.

The operation of the hydraulic control valve 20 is performed by the operation of the manual valve 25 connected to the shift lever 45 operated by the driver through the wire 45a, the operation of the two solenoid valves 22 and 23, and the operation of the linear solenoid valve 56. It

The solenoid valves 22 and 23 are connected to the signal lines 31a and 3
The linear solenoid valve 56 is turned on / off by an operation signal sent from the controller 30 via 1b.
Is operated by a signal sent from the controller 30 via the signal line 31c. A rotation signal from a first rotation sensor 35, which detects the input side rotation speed of the hydraulic clutch based on the rotation of the reverse gear 15c, is sent to the controller 30 via a signal line 35a, and the output gear 5b rotates. A rotation signal from the second rotation sensor 32 that detects the output rotation speed of the hydraulically operated clutch based on the
A throttle opening degree signal from a throttle opening degree sensor 33 for detecting the opening degree is sent through a line 33a. The throttle 41 is connected to a throttle pedal 43 via a wire 42, and the throttle pedal depression amount can be detected by detecting the throttle opening.

The shift control in the transmission configured as described above will be described.

The shift control is performed according to the shift range set by the manual valve 25 in the hydraulic control valve 20 according to the operation of the shift lever 45. The shift range includes, for example, P, R, N, D, S, and 2 ranges. In the P range and the N range, all hydraulically actuated clutches 11c to 15d are disengaged and the transmission is in a neutral state. In the R range, the reverse hydraulically actuated clutch 15d is engaged to set the reverse gear, and in the D range, the S range and the 2 range, the shift is performed based on the shift map.

As shown in FIG. 5, this shift map shows a shift up line L _U and a shift down line L _U as shown in the graph in which the vertical axis represents the throttle opening θ _TH and the horizontal axis represents the vehicle speed V. _{When the} running state defined by the engine throttle opening (accelerator pedal depression amount) and the vehicle speed crosses the shift-up line L _U to the right, the shift-up is performed, and the shift-down is performed after the shift-up. When the line L _D is crossed to the left, a downshift is performed. In FIG. 5, only one shift-up line and one shift-down line are shown, but in reality, a plurality of shift lines are set according to the number.

Here, the power-on shift-down, depressing the accelerator pedal during running, across the up side region downshift line L _D (right region) from the down-side region (left region) as shown by the arrow B Says when downshifting is done. On the other hand, power-off / shift-up means a case where the accelerator pedal is released during traveling and the shift-up line L _U is crossed from the down region to the up region as shown by an arrow A in the figure to perform shift up. .

When a shift-up line or a shift-down line in the shift map is crossed, the solenoid valves 22 and 23 are transmitted from the controller 30 via the signal lines 31a and 31b.
An actuation signal is output to the hydraulic control valve 20 and the hydraulic actuation clutch 11c is actuated accordingly.
The hydraulic pressure is supplied to and discharged from up to 15d, and upshift or downshift is performed.

The hydraulic control valve 20 will be described with reference to FIG.

In the control valve 20, the hydraulic oil in the oil tank 7 supplied from the pump 8 is guided to the regulator valve 50 via the line 101, and the regulator valve 5 is supplied.
By 0, the pressure is adjusted to a predetermined line pressure. This line pressure is guided to the manual valve 25 via the line 110, and the line pressure is changed by the operation of the manual valve 25 and the various valves in the control valve 20. 13c, 1
4c and 15d are selectively supplied according to the traveling conditions, and the operation control of each clutch is performed.

First, various valves in the control valve 20 will be described. The check valve 52 is disposed on the downstream side of the regulator valve 50, and prevents the hydraulic pressure of the lubricating oil sent to the lubricating portion of the transmission through the line 102 from exceeding a predetermined pressure. The modulator valve 54 reduces the line pressure sent via the line 103 to create a modulator pressure of a predetermined pressure, and the working oil of the modulator pressure is supplied via the line 104 to the torque converter 2.
To a lock-up clutch control circuit (not shown) for controlling the lock-up clutch of
05 via the first and second solenoid valves 22, 2
3 is sent to control the shift valve operation.

The manual valve 25 is operated in conjunction with a shift lever 45 operated by the driver, and is operated by the P, R, N, D,
It is located in one of the 6 positions S and 2, and the line pressure from the line 110 is applied to the line 25a depending on each position.
~ 25g selectively feed.

1-2 shift valve 60, 2-3 shift valve 62, 3
-4 shift valve 64 has manual valve 25 of D,
In either of the S and 2 positions, the operation is controlled by the action of the modulated pressure supplied through the lines 106a to 106f according to the ON / OFF operation of the first and second solenoid valves 22 and 23. Clutch 11c, 12c, 13c, 14c for 1st speed to 4th speed
It is a valve that controls the supply and discharge of line pressure to and from.

The lines 106a and 106b are connected to the first solenoid valve 22.
To the line 10 through the orifice 22a.
Therefore, when the power supply to the first solenoid valve 22 is off, the port to the drain side is closed and the hydraulic oil having the modulated pressure from the line 105 is supplied to the lines 106a and 106b. Then, when the energization is on, the port to the drain side is opened and the pressure in the lines 106a and 106b becomes substantially zero. The lines 106c to 106f are connected to the second solenoid valve 23.
And the line 10 through the orifice 23a.
5, when the power supply to the second solenoid valve 23 is off, the port to the drain side is closed and the hydraulic oil having the modulated pressure from the line 105 is supplied to the lines 106c to 106f. When the power is on, the port to the drain side is opened and the line 106
The pressures of c to 106f become almost zero.

Here, the line 106a is connected to the right end of the 1-2 shift valve 60, and the line 106b is connected to the 2-3 shift valve 62.
Is connected to the right end of the 1-2 shift valve 60, the line 106e is connected to the right end of the 3-4 shift valve 64, and the line 106f is connected to the left end of the 2-3 shift valve 62. The line 106e,
106f is a manual valve 25 and a line 106d
To the second solenoid valve 23. For this reason, if the conduction ON / OFF of the first and second solenoid valves 22 and 23 is controlled to control the supply and discharge of the modulated pressure from the line 105 to the lines 106a to 106f, 1-2 and 2 are obtained. -3, 3-4 shift valves 60, 62,
It is possible to control the operation of the hydraulic pressure control device 64, and thereby the line pressure supplied from the line 110 via the manual valve 25 is controlled by the hydraulically operated clutches 11c, 12c, 13c ,.
14c can be selectively supplied to perform desired gear shifting.

The control valve 20 has first to fourth orifice control valves 70, 72, 74, 76, which release the hydraulic pressure in the hydraulic chamber of the preceding clutch during gear shifting.
It is performed at the same timing as the hydraulic pressure rise in the hydraulic chamber of the latter-stage clutch. First orifice control valve 70
Controls the hydraulic pressure release timing of the third speed clutch during the shift from the third speed to the second speed, and the second orifice control valve 72 controls the hydraulic pressure of the second speed clutch during the shift from the second speed to the third speed or from the second speed to the fourth speed. The release timing is controlled, the hydraulic pressure release timing of the fourth speed clutch is controlled by the third orifice control valve 74 when shifting from the fourth speed to the third speed or the fourth speed to the second speed, and the fourth orifice control valve 76 controls the third speed from the third speed. The hydraulic pressure release timing of the third speed clutch at the time of shifting to the fourth speed is controlled.

Furthermore, each hydraulically actuated clutch 11c, 12c, 13c,
The accumulators 81, 82, 83, 84 having pressure receiving chambers communicating with the hydraulic chambers of 14c are provided. The pressure receiving chambers of these accumulators and the piston members 81a, 82 are provided.
Lines 121, 122, 123, and 124 are connected to the back pressure chambers facing each other via a, 83a, and 84a. These lines 121, 122, 123, and 124 are line 1
It is connected to the linear solenoid valve 56 via 20a, 120b and 120.

The linear solenoid valve 56 is a linear solenoid 56.
a, and the operating force can be controlled by controlling the energizing current to the linear solenoid 56a to control the magnitude of the hydraulic pressure supplied to the line 120.
Therefore, by controlling the current supplied to the linear solenoid 56a, it is possible to control the hydraulic pressure in the back pressure chamber of each of the accumulators 81 to 84, and as a result, the hydraulic pressure chamber of the engagement clutch (post-stage clutch) at the time of gear shifting. The hydraulic pressure can be controlled freely.

In the hydraulic controller valve 20 configured as described above, each valve is appropriately operated by the operation of the manual valve 25 by the operation of the shift lever 45 and the on / off operation of the solenoid valves 22 and 23, and each hydraulically operated clutch 11c. , 12c, 13c, 14c is selectively controlled to supply the line pressure, and automatic gear shifting is performed.

In the control valve 20 configured as described above, the manual valve 2 operated by operating the shift lever 45
5 and ON / O of solenoid valves 22 and 23
The above-mentioned valves are operated by the FF operation, and the line pressure is selectively supplied to each of the clutches 11c to 15d.
Although automatic gear shifting is performed, its operation is well known in the art, and therefore its description is omitted.

In the transmission having the above structure, the shift control in the case where the power-on shift down or the power off shift up is performed will be described with reference to the flowchart of FIG. 3 and the graphs of FIGS. 4A and 4B. To do.

In this control, first, in step S1, the traveling state on the shift map is searched, and in step S2, it is determined whether or not the power-on / downshift state is present, that is, the change in the state shown by the arrow B in FIG. A determination is made as to whether it has occurred. When a power-on shift-down state changes the shift command, as shown in FIG. 4A to the current gear position (front) target gear from S _o (subsequent) S _a (time t _1). During the fixed time delay T _1D (step S3), the shift solenoid valve 2
It is to 2,23 outputs a signal _{S o} to maintain the current gear position (step S4), and and the linear solenoid 5 in the meantime
The output current to 6a is set to the maximum value I (max) (step S5), and the supply line pressure to the current shift stage clutch (previous stage clutch) is maintained at the maximum and the clutch is kept in the engaged state. deep.

When this time T _1D has elapsed (time t ₂ ), step S6
And the input / output rotation speed ratio e _CLa (= output rotation speed / input rotation speed) of the target gear shift clutch (rear clutch) is
Threshold value e set as a value slightly larger than 1.0
_It is determined whether it is smaller than _CLIED . The input / output rotation speed is obtained by converting the detection values of the first and second rotation sensors 35 and 32 using the gear ratio from the detected gears 15c and 15d to the rear clutch. When the current gear shift clutch is engaged, the input / output speed ratio of this clutch is 1.0, and the input rotation of the target gear shift clutch that is downshifted is smaller than the output rotation. The input / output rotational speed ratio e _CLa of the clutch is considerably larger than 1.0 (see FIG. 4A). At this time, the _routine proceeds to step S7, where the shift solenoids 22 and 23 are shifted.
Target gear position from the current shift speed (downshift) signal S _a is outputted, simultaneously to the (time t ₂₎ output current to a predetermined low value I (LOWD) to the linear solenoid 56a to.

When the signal S _a is outputted to the shift solenoid 22, 23 hydraulic control valve 20 is operated, the engagement of the clutch is released the oil pressure supplied to the current speed-shifting clutch is released. At the same time, the low back pressure generated in the linear solenoid valve 56 corresponding to the low current value I (LOWD) is supplied to the back pressure chamber of the accumulator connected to the target gear shift clutch. At this time, since the accelerator pedal is depressed, the engine speed Ne increases accordingly as shown in FIG. 4A. The engine speed slightly increases at time t ₁ , but this is because the engine output increases at the time when the accelerator pedal is depressed (at the time of power-on). This is because the slip of the converter becomes large. Therefore, it is not preferable to convert the input rotation of the clutch from the engine rotation to obtain an error. However, in this example, since the input rotation is detected by converting the rotation of the gear 15c mechanically connected to the input side of the clutch to the gear ratio up to this clutch, accurate rotation detection can be performed. it can.

When the engine speed increases as described above, the input speed of the target gear shift clutch increases, and the input / output speed ratio e _CLa gradually _approaches 1.0. When the input / output rotation speed ratio e _CLa becomes smaller than the threshold value e _CLIED which is set slightly larger than 1.0 in consideration of the error, the process proceeds from step S6 to step S9, and the linear solenoid 56
The maximum current I (max) is applied to a, the hydraulic pressure supplied to the back pressure chamber of the accumulator connected to the target gear shift clutch is rapidly increased, and the hydraulic pressure of the hydraulic chamber of this target gear shift clutch is rapidly increased. The clutch is engaged and the shift is completed (time t ₃ ).

Note that the current value I (LOWD) to the linear solenoid 56a between the time t ₂ to time t _3, the more pressure-regulated hydraulic linear solenoid valve 56 having the linear solenoid 56a is acting as an accumulator back pressure The hydraulic chamber pressure of the target shift speed clutch obtained in this way is set to a value that is slightly lower than the engagement start pressure of the target shift speed clutch. Therefore, in the target gear shift clutch, during the period from time t ₂ to time t ₃ , the piston receives a pressure slightly lower than the engagement start pressure and resists the return spring force for the amount of the invalid stroke. has a state just before the engagement by moving the apply side, when the output current to the linear solenoid 56a is increased is the line pressure increased to I (max) at time t _3,
The target gear shift clutch is engaged with almost no time delay, and a smooth downshift is performed.

At this point, the power-on downshift is completed, so
The command signal S _a to the shift command and shifting solenoid valve by replacing the S _o (step S10), and the gear position after the shifting grasped as the current gear position, performs subsequent shift control.

On the other hand, if it is determined in step S2 that the power-on / shift-down state is not established, the process proceeds to step S11 to determine whether or not power-off / shift-up is performed, that is, a change in the state indicated by arrow A in FIG. Is determined. If a power-off upshift condition changes the shift command, as shown in Figure 4B to the current gear position (front) target gear from S _o (subsequent) S _a (time t _1). During the fixed time delay T _1U (step S12), the shift solenoid valve 2
It is to 2,23 outputs a signal S _o to maintain the current gear position (step S13), and and the output current to Sonia solenoid 56a in the meantime in the maximum value I (max) (Step S14) for the current gear stage The clutch (previous stage clutch) is maintained in the engaged state.

When this time T _1U elapses (time t ₂ ), step S1
In step 5, it is determined whether or not the input / output speed ratio e _CLa of the target gear shift clutch (rear clutch) is larger than a threshold value e _CLIEU set as a value slightly smaller than 1.0. When the current gear shift clutch is engaged, the input / output rotation speed ratio of this clutch is 1.0, and the input rotation of the target gear shift clutch that is upshifted is greater than the output rotation. Clutch input / output speed ratio e
_CLa is considerably smaller than 1.0 (see Figure 4B), this time, the signal _{S a} to shift to the target gear shift solenoid valves 22 and 23 are outputted proceeds to step S16, to simultaneously linear solenoid 56a Output current is set to a predetermined low value I (LOWU) (time t ₂ ).

As a result, the engagement of the current gear shift clutch is released,
The hydraulic pressure in the hydraulic chamber of the target shift stage clutch becomes a low line pressure corresponding to the low current value I (LOWU). At this time, the accelerator pedal is returned, so that the engine speed Ne decreases as shown in FIG. 4B. The engine speed slightly decreases at time t ₁ , but this is the same as the above case because the slip of the torque converter reverses due to the decrease in the engine output accompanying the return of the accelerator pedal. is there.

When the engine speed decreases as described above, the input speed of the target gear shift clutch decreases, and the input / output speed ratio e _CLa gradually _approaches 1.0. When the input / output rotation speed ratio e _CLe becomes larger than the threshold value e _CLIEU which is set to be slightly larger than 1.0 in consideration of the error, the process proceeds from step S15 to step S18, and the maximum current I to the linear solenoid 56a is increased. (max) is flowed, the back pressure of the accumulator connected to the target gear shift clutch increases, the clutch gear hydraulic chamber pressure for this target gear shift abruptly increases, and this target gear shift clutch is engaged to shift gears. Complete (time t ₃ ).

Also in this case, the current value I to the linear solenoid 56a between the time t ₂ to time t ₃ (LOWU)
Indicates that the hydraulic chamber pressure of the target shift speed clutch generated corresponding to the back pressure regulated by the linear solenoid valve 56 having the linear solenoid 56a is slightly smaller than the engagement start pressure of the target shift speed clutch. It is set to such a value that the pressure becomes lower. Therefore, in the clutch target gear, the piston is in the state immediately before the engagement moved by the engagement side invalid stroke against the return spring force, to the linear solenoid 56a at time t ₃ When the output current is increased to I (max) and the line pressure rises, the target gear shift clutch is engaged with almost no time delay, and a smooth shift amplifier is performed.

This way, the power-off upshift is completed, a command signal S _a to the shift command and shifting solenoid valve by replacing the S _o (step S19), grasps the shift stage after the gear shift as the current gear position , And subsequent shift control is performed.

If it is determined in step S11 that neither power off nor shift up is performed, this flow is ended as it is.

In the automatic transmission described above, an example is shown in which the line pressure control in the control valve 20 is performed by the linear solenoid valve 56 having the linear solenoid 56a. However, the shift control of the present invention has such a configuration. The present invention is not limited to the transmission, but the case of a transmission having another configuration will be described with reference to FIG.

FIG. 6 shows a different example of the hydraulic control valve used in the automatic transmission, and the same parts of the hydraulic control valve 20 of FIG. 2 are designated by the same reference numerals.

Also in this hydraulic control valve 20 ', the hydraulic oil in the oil tank 7 supplied from the pump 8 is supplied to the line 1
It is led to the regulator valve 50 via 01, and the regulator valve 50 regulates the pressure to a predetermined line pressure.
This line pressure is guided to the manual valve 25 via the line 110, and the line pressure travels to the hydraulically operated clutches 11c, 12c, 13c, 14c, 15d as the manual valve 25 and other valves operate. It is selectively supplied according to the conditions, and the operation control of each clutch is performed.

This control valve 20 'is also a 1-2 shift valve 65, a 2-3 shift valve 62, a 3-4 shift valve 6
4 (the 1-2 shift valve 65 is the second
Although the structure is slightly different from the one shown in the figure, its operation and role are the same.)
The operation is controlled by the action of the modulated pressure supplied through the lines 106a to 106f according to the OFF operation,
Each hydraulically actuated clutch 11c, 12c, 13c, 14c is selectively actuated to shift gears.

Further, the first to third orifice control valves 7
The first orifice control valve 75 controls the hydraulic pressure release timing of the third speed clutch during the shift from the third speed to the second speed and the shift from the third speed to the fourth speed. Orifice control valve 76
Is used to control the hydraulic pressure release timing of the second speed clutch at the time of shifting from the second speed to the third speed or from the second speed to the fourth speed, and at the time of shifting from the fourth speed to the third speed or from the fourth speed to the second speed by the third orifice control valve 77. The hydraulic pressure release timing of the fourth speed clutch is controlled.

In the present hydraulic control valve, unlike the valeb 20 shown in FIG. 2, the hydraulic operating clutches 11c, 12c,
It does not have an accumulator having a pressure receiving chamber that communicates with the hydraulic chambers 13c, 14c, 15d, and therefore does not have a linear solenoid valve that controls the accumulator back pressure. However, a pressure control valve 58 for controlling the line pressure supplied to each clutch 11c, 12c, 13c, 14c according to the operation of the manual valve 25 and the shift valves 65, 62, 64 from the line 110 is provided.

The pressure control valve 58 also has a linear solenoid 58a, and the line pressure can be directly controlled by controlling the current supplied to the sonia solenoid 58a. In addition, the 2nd-4th clutch 12c-
14c includes clutch pressure switches 90, 92, 9
4 is connected and the movement of the spool of the switches 90, 92 and 94 can be detected by the electric switches 91, 93 and 95 to detect the start of operation of each of the clutches 12c to 14c.

For this reason, in the transmission having the control valve 20 'of this example, by controlling the value of the current supplied to the linear solenoid 58a of the pressure control valve 58, the operating hydraulic pressure of the rear-stage clutch at the time of shifting can be controlled. Therefore, the power-on shift-down control or the power-off shift-up control shown in FIGS. 3, 4A, and 4B can be performed in the same manner as above.

In the above, an example in which the control of the operating hydraulic pressure of the rear clutch at the time of gear shift is performed by the valve having the linear solenoid has been shown, but the present invention is not limited to this, and the hydraulic control is performed by, for example, a duty ratio controlled solenoid valve. It can also be used for things that do.

C. EFFECTS OF THE INVENTION As described above, according to the method of the present invention, when a gear shift command is issued when power-on shift-down or power-off shift-up is performed, the hydraulic pressure supplied to the hydraulic clutch for the preceding stage is supplied. Is decreased, the engagement of the front-stage clutch is released, and the input / output rotation of the rear-stage clutch is detected. It is determined that the input / output rotation of the rear-stage clutch is approximately 1.0 and the input / output rotation is synchronized. At this time, the hydraulic pressure supplied to the latter-stage clutch is increased to a predetermined engagement pressure so that this clutch is engaged.At this time, the input / output speed ratio of the latter-stage clutch is set to the input side rotation member and Since the rotation is directly detected by detecting the rotation of the output-side rotating member, the synchronization point can be accurately detected, and the clutch for the subsequent stage can be detected from the time when the shift command is issued. Until the input / output rotation synchronization of the switch is detected, the hydraulic pressure supplied to the rear-stage clutch is kept slightly lower than the engagement start hydraulic pressure. When the clutch is moved and held at the position immediately before the clutch is engaged, and therefore the synchronization of the input / output rotation is detected and the hydraulic pressure supplied to the clutch for the latter stage is increased, the engagement of the latter stage clutch immediately starts. ,
With the detection of the synchronization, it is possible to accurately engage the rear clutch without a time delay.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an automatic transmission controlled by the method of the present invention, FIG. 2 is a circuit diagram showing a hydraulic control valve for performing shift control of the transmission, and FIG. 3 is a control diagram according to the present invention. A flow chart shown in FIGS. 4A and 4B is a graph showing changes in signals, input / output speed ratio, engine speed, etc. when the control shown in the above flow chart is performed, and FIG. 5 is a shift map used for shift control. FIG. 6 is a circuit diagram showing another example of the hydraulic control valve. 20 ... hydraulic control valve 22,23 ... shift solenoid valve 25 ... manual valve 32,25 ... rotation sensor

Front Page Continuation (72) Inventor Yoshihisa Iwaki Chuo 1-4-1 Wako-shi, Saitama Inside of Honda R & D Co., Ltd. (56) References JP-A-63-106452 (JP, A)

Claims (1)

[Claims] 1. A gear train forming a plurality of power transmission paths,
In an automatic transmission including a plurality of hydraulically operated clutches that are operated by receiving hydraulic pressure and select the power transmission path by the gear train, rotation of an input side rotating member and an output side rotating member of the hydraulically operated clutch. And the input / output speed ratio is detected, and when the input / output speed ratio of the hydraulically actuated clutch for the latter stage of gear shifting has become approximately 1.0 during a gear shift, this hydraulic actuated clutch is detected. When the input / output rotation synchronization is not determined and either one of the power-on shift-down and the power-off shift-up is performed, the operating hydraulic pressure to the hydraulically actuated clutch for the latter stage of the shift is changed from the start of the shift. Until the input / output rotation synchronization of the hydraulic operating clutch for the rear stage is determined, the pressure is kept slightly lower than the engagement start hydraulic pressure, and when the input / output rotation synchronization is determined, a predetermined engagement is performed. Shift control method of an automatic transmission, characterized in that to perform the gear shift control is increased to pressure.