JP3087869B2 - Transmission control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, a gear shift mechanism and a plurality of friction engagement devices have been provided, and the engagement of the friction engagement devices has been selectively switched by the operation of a hydraulic control device. A shift control device for an automatic transmission configured to achieve the above is already widely known.

In this type of device, a shift valve is switched (a shift is commanded), and hydraulic pressure is supplied to a servo mechanism of a predetermined friction engagement device. Then, the engagement of the friction engagement device is achieved by the servo mechanism, and a desired shift speed is established.

On the other hand, there is known an automatic transmission in which an automatic shift mode for automatically setting a shift stage and a manual shift mode for manually setting a shift stage can be appropriately selected by a driver's judgment (Japanese Patent Laid-Open Publication No. HEI 9 (1994) -209605). 2-8545 gazette,
No. 125174).

[0005]

In an automatic transmission in which the automatic transmission mode and the manual transmission mode can be selected as described above, the shift feeling is improved particularly in the manual transmission mode, and the responsiveness is improved particularly. Shifting is required to be performed, but conventionally, such measures have not been sufficiently taken.

The present invention has been made in view of such a conventional problem, and aims to improve shift feeling (especially, shift response) particularly when a manual shift mode is selected. It is an object of the present invention to provide a shift control device for an automatic transmission, which can perform the following.

[0007]

As shown in FIG. 1, the present invention relates to a shift control device for an automatic transmission which shifts by controlling the supply and discharge of an engagement pressure to a friction engagement device. Means for increasing the engagement pressure supplied to the friction engagement device to a value higher than a steady pressure in response to execution of a shift, means for detecting the start of engagement of the friction engagement device (start of an inertia phase), Means for stopping the pressure increase of the engagement pressure by the pressure increasing means in response to detection of the start of engagement of the engagement device; The provision of the above has solved the above-mentioned problem.

[0008]

In the automatic transmission, when the control shift valve is switched in response to the occurrence of a shift determination (when a shift is commanded), hydraulic pressure is supplied to a predetermined friction engagement device. There is a time delay from when the shift command is issued until the friction material of the friction engagement device actually starts engaging and the rotation speed of the rotating member changes. That is, after the lapse of the delay time, a so-called inertia phase (a period in which the rotation speed of the rotating member changes due to the shift) starts. Therefore, if the period from the shift command to the start of the inertia phase is shortened, the shift response is improved.

In order to improve the response of the friction engagement device, basically, the engagement pressure supplied to the friction engagement device should be increased. However, simply increasing the pressure, especially in relation to the start timing of the inertia phase, cannot sufficiently improve the shift response if the period for increasing the pressure is too short.
If it is too long, the shift shock becomes large due to excessive engagement pressure. This is because if the pressure is kept increased even after the inertia phase is entered, the friction engagement device is engaged at a stretch.

In the speed change control device of the present invention, the engagement pressure is intentionally increased from the steady pressure by the pressure increasing means with the execution of the speed change, and the increase is stopped when the start of the inertia phase is detected. As a result, a boosting period in which there is no excess or deficiency is set, and improvement in shift response and prevention of increase in shift shock are simultaneously achieved. Further, for example, even when the start of the inertia phase cannot be detected due to a failure in the sensor system, compensation for preventing the pressure increase time of the engagement pressure from exceeding a predetermined time is compensated, thereby preventing the shift shock from increasing.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing a basic configuration of one embodiment of the present invention. E is an engine, A is an automatic transmission, and C is a hydraulic control device of the automatic transmission.

The automatic transmission A includes an automatic shift mode for automatically setting a shift speed in accordance with a traveling state and a manual shift mode for setting a shift speed based on a manual operation (here, "direct shift mode"; And "DM") can be selected by operating the shift lever.

The opening of the throttle valve 10 of the engine E is adjusted by an actuator 11, and the actuator 11 is provided with an engine electronic control unit (E-ECU) 12.
Is controlled by

The engine electronic control unit 12 has a central processing element (CPU), a storage element (ROM, RAM), and an input / output interface as main elements, and is provided with a sensor 14 for detecting a depression amount of an accelerator pedal 13. , A vehicle speed signal, a brake signal from a side brake switch or a foot brake switch, an engine water temperature signal, and the like. And
The throttle valve 10 is set to a predetermined opening by operating the actuator 11 in accordance with the operation amount of the accelerator pedal 13, and the fuel injection amount by the fuel injection device 15 is controlled to an amount suitable for the throttle opening.

In the automatic transmission A, a solenoid valve (not shown) of the hydraulic control device C is controlled by an electronic control unit (A-ECU) 16 for the automatic transmission, and a manual valve (FIG. (Not shown) to achieve a predetermined gear position.

As shown in FIG. 2, the shift device 17 includes a parking range (P), a reverse range (R), a neutral range (N), a drive range (D), a three range (3), and a two range (2). , L range (L) and a direct mode range (DM) for manual gear shifting can be switched and selected by a shift lever (described later).

When the direct shift mode (DM) range is selected, an operation signal is sent to the electronic control unit 16 for the automatic transmission by a switch provided on the shift lever, thereby manually changing the first gear to the fourth gear. Any gear up to the gear can be set.

Briefly describing this point, as shown in FIG. 4, a plus (+) switch 18 for shifting the gear position in the up direction is provided above the shift lever 18.
A is provided in front of a lower portion of the shift lever 18 for shifting the gear position in the down direction.
A switch 18B is provided. When these switches are pressed while the shift lever 18 is positioned in the direct shift mode (DM), the transmission performs an upshift (+) or a downshift (-) one by one with respect to the current gear. . This operation is configured so as to be effective only in the direct shift mode (DM).

The electronic control unit 16 for the automatic transmission shown in FIG.
Are central processing elements (CPU) and storage elements (ROM, R
AM) and an input / output interface as main elements. According to a shift position signal input from the shift device 17, the selected mode is an automatic shift mode or a manual shift mode (direct shift mode).
In the direct shift mode selection state, the plus switch 18A or the minus switch 1
The gear position is determined according to the signal from the gear 8B, and a gear change command signal corresponding to the gear position is output to the hydraulic control device C.

The electronic control unit 16 for the automatic transmission includes:
Signals such as a turbine rotation signal Nc0 of the torque converter, a vehicle speed V, a throttle opening θ, a brake signal, an engine water temperature, and a pattern select signal are input.

Next, the mechanical structure of the automatic transmission A will be described with reference to the skeleton diagram of FIG.

This automatic transmission A has a torque converter 21 having a lock-up clutch 20 and a second transmission section (overdrive mechanism) having a set of planetary gear mechanisms.
30 and a first transmission section (underdrive mechanism section) 40 for setting a plurality of forward speeds and reverse speeds by two sets of planetary gear mechanisms.

The second transmission section 30 performs two-stage switching between high and low. The carrier 31 of the planetary gear mechanism is connected to the turbine runner 22 of the torque converter 21. A clutch C0 and a one-way clutch F0 are provided between the carrier 31 and the sun gear 32 so as to be in a parallel relationship with each other. Further, a brake B0 is provided between the sun gear 32 and the housing HU.

The sun gears 41 and 42 of each planetary gear mechanism of the first transmission section 40 are provided on a common sun gear shaft 43, and the ring gear 44 of the planetary gear mechanism on the left side (front side) of the transmission section 40 in the drawing. A first clutch C1 is provided between the first transmission C1 and the ring gear 33 in the second transmission section 30.

The sun gear shaft 43 and the second transmission 30
A second clutch C2 is provided between the second clutch C2 and the ring gear 33. In the first transmission section 40, the carrier 45 of the planetary gear mechanism on the left side in the figure and the ring gear 46 of the planetary gear mechanism on the right side (rear side) are integrally connected. or,
The output shaft 4 is connected to the carrier 45 and the ring gear 46.
7 are connected.

The brake B1 which is a band brake
Are provided to stop the rotation of the sun gear shaft 43. Specifically, the brake B1 is provided on the outer peripheral side of the clutch drum of the clutch C2. A one-way clutch F1 is provided between the sun gear shaft 43 and the housing HU.
And the brake B2 are arranged in series. Further, a one-way clutch F2 and a brake B3 are arranged in parallel between the carrier 48 and the housing HU in the rear planetary arrangement mechanism.

In this embodiment, means for increasing the line pressure of the hydraulic control device C is provided as means for increasing the engagement pressure. FIG. 8 shows the outline.

In FIG. 8, reference numeral 302 denotes a pump,
4 is a primary regulator valve, and SLT is a linear solenoid valve. The primary regulator valve 304 generally uses a throttle oil pressure adjusted according to the accelerator opening as a pilot pressure to a port 308.
The input pressure is adjusted to adjust the source pressure discharged from the pump 302 to the line hydraulic pressure PL. However, in this example,
A linear solenoid valve SLT is provided to increase the line hydraulic pressure PL only during the period from the shift determination to the start of the inertia phase. The linear solenoid valve SLT is provided by the electronic control unit 12 for the engine and the electronic control unit 16 for the automatic transmission. A hydraulic pressure P _slt that controls and reflects the throttle opening and can execute the pressure increase is generated, and the line pressure PL is adjusted using the hydraulic pressure P _slt as a pilot pressure.

FIG. 5 shows the essential parts of the hydraulic control device C in detail.

In the figure, reference numeral 74 denotes a manual valve. The manual valve 74 is connected to the shift device 17.
Equipped with a spool 72 that is moved in conjunction with the movement of
It is connected to a line pressure oil passage 76 that guides the line pressure PL regulated by the primary regulator valve 304 described above. That is, in the 3, D, or DM range, the spool 72 is positioned at the illustrated D position, so that the forward port pressure having the same magnitude as the line pressure PL is output from the D port 78. In the S (2) range, the spool 72
Is positioned at the S position, the line pressure PL is output from the D port 78 and the S port 80, and L (1)
In the range, the D port 78, the S port 80, and the L port 8 are positioned by positioning the spool 72 at the L position.
2 outputs a line pressure PL.

The line pressure PL output from the D port 78 is supplied to the clutch C1 and to the first solenoid valve (solenoid) 62 and the third solenoid valve 66 via orifices 84 and 88, respectively. . The line pressure PL in the line pressure oil passage 76 is also supplied to the second solenoid valve 64 via the orifice 86. First to third solenoid valves 6
Reference numerals 2, 64, and 66 denote on-off valves, respectively, which release the downstream sides of the orifices 84, 86, and 88 to an atmospheric pressure when in an energized state.
4, 86 and 88, the signal pressures Ps1, Ps
2. Generate Ps3.

The line pressure PL output from the S port 80 is supplied to a supply port 92 of the O / D lock valve 90. The O / D lock valve 90 has a spool 98 selectively positioned at a non-lock position where the supply port 92 communicates with the output port 94, a lock position where the output port communicates with the drain port 96, and the spool 98. 10 for urging the spring toward the lock position
0, and an oil chamber 102 to which the signal pressure Ps1 is guided to position the spool 98 at the unlocked position. O /
When the shift device 17 is operated in the S range or the L range and the first solenoid valve 62 is in the non-excited state, the D lock valve 90 activates the coast brake cutoff valve 1.
The hydraulic pressure for preferentially locating the 04 in the non-cut position is output from the output port 94.

Coast brake cutoff valve 104
Is for operating the engine brake at the first speed and the second speed in the direct shift mode, and has an input port 106 connected to the D port 78 of the manual valve 74 and a drain port 118, The output port 1 connected to a first D port 162 of a 2-3 shift valve 148 to be described later is connected to one of the input port 106 and the drain port 118 by the spool 110.
08 is selectively communicated. Reference numeral 112 denotes a spring that urges the spool 110 in the valve opening direction. Reference numeral 114 denotes an oil chamber that accommodates the spring 112 and receives a hydraulic pressure from the output port 94.
116 is a signal pressure Ps3 for positioning the spool 110 at the cut position against the urging force of the spring 112.
It is an oil chamber to accept.

With this configuration, when the signal pressure Ps3 is generated, the spool 110 is positioned at the cut position. However, when the oil pressure from the output port 94 is acting on the oil chamber 114, the spool 110 has priority. At the non-cut position.

The 1-2 shift valve 120 is a valve which is switched by the second solenoid valve 64 when shifting from the first speed to the second speed, and accommodates a spool 122 and a spring 124 for urging the spool 122. An oil chamber 126 and an oil chamber 128 for receiving a signal pressure Ps2 for moving the spool 122 against the spring 124 are provided.

The 1-2 shift valve 120 has a second coast port 130 and a first brake port 133 selectively communicated with one of the second coast port 130 and the drain port 132. The first brake port 133 is connected to the brake B1 via a second coast modulator valve 134. Also, the 1-2 shift valve 120 includes:
A D port 136 communicating with the D port 78 of the manual valve 74 is provided. A brake B2 is connected to a second brake port 140 selectively communicated with one of the D port 136 and the other drain port 138. Have been. Further, a third drain selectively connected to one of the other drain port 142 and the low coast port 144 is provided.
The brake port 146 is connected to the brake B3.

The 2-3 shift valve 148 is a valve that is switched when the first solenoid valve 62 shifts from the second speed to the third speed, and includes a spool 150 and a spring 152 that biases the spool 150. An oil chamber 156 is provided for receiving the signal pressure Ps1 in order to move the spool 150 against the spring 152. The 2-3 shift valve 148 includes a manual valve 7
The L range pressure output from the fourth L port 82 is supplied to the oil chamber 154. The 2-3 shift valve 148 is provided with a first drain port 158, a brake port 160, and a first D port 162, and the brake port 160 is connected to the 1-2 shift valve 1
20 is connected to the second coast port 130 and the brake port 160 is connected to the first drain port 15.
8 and one of the first D ports 162.

The 2-3 shift valve 148 is provided with a hold output port 164, an input port 166, a clutch port 168, and a second drain port 170 in this order. When the first drain port 158 and the brake port 160 are in communication, the first D port 162
And the hold output port 164, the input port 166 and the clutch port 168 communicate with each other, and the brake port 1
When the port 60 communicates with the first D port 162, the hold output port 164 and the input port 166, and the clutch port 168 and the second drain port 170 communicate with each other.

Further, the 2-3 shift valve 148 is provided with a brake port 172 and a second D port 174, and the clutch port 168 is connected to the input port 166.
The second drain port 170 communicates with the brake port 172 and, conversely, the clutch port 1
When 68 is in communication with the second drain port 170, the brake port 172 and the second D port 174 are in communication. And the clutch port 1
68 is connected to the clutch C <b> 2 and the oil chamber 126 of the 1-2 shift valve 120. Also, brake port 17
2 is a low coast port 144 of the 1-2 shift valve 120 via a low coast modulator valve 176.
It is connected to the.

The 3-4 shift valve 180 is a valve that is switched by the second solenoid valve 64 at the time of shifting from the third speed to the fourth speed so as to execute the shift of the second shift unit 30. An oil chamber 186 containing a spool 182, a spring 184 for urging the spool 182,
Signal pressure P to move the spool 182 against
and an oil chamber 188 for receiving s2.

The oil chamber 186 is connected to the hold output port 164 of the 2-3 shift valve 148.
In the 3-4 shift valve 180, when the signal pressure Ps2 is supplied, the input port 190 connected to the line pressure oil passage 76 communicates with the brake port 192 connected to the brake B0, and the signal pressure Ps2 Is not supplied, the input port 190 communicates with the clutch port 194 connected to the clutch C0.

The hydraulic control device C configured as described above
As shown in the operation table of FIG. 6, the first solenoid valve 62, the second solenoid valve 64, the third
Depending on the combination of the operations of the solenoid valve 66, each friction engagement device is engaged or released to realize a predetermined gear position. In FIG. 6, a circle indicates an excited state or an engaged state.
Crosses indicate a non-excited state or a released state, respectively.

When a shift command for the first speed or the second speed in the case where a direct shift mode described later is set, the third solenoid valve 66 is excited and the coast brake cutoff valve 104 is turned on. The spool 110 is shown in FIG.
, The forward range pressure output from the D port 78 of the manual valve 74 changes to the first D port 162 of the 2-3 shift valve 148.
And the second D port 174. Therefore, the first
When establishing the first speed or the second speed, the first solenoid valve 6
2 is set to the excited state, the spool 150 of the 2-3 shift valve 148 is actuated according to the biasing force of the spring 152.
The first D port 1 is positioned at the position shown on the right side of FIG.
62 communicates with the brake port 160 and the second D port 1
74 communicates with the brake port 172. Therefore, the forward range pressure is supplied to the second coast port 130 and the low coast port 144 of the 1-2 shift valve 120 which communicate with the brake port 160 and the brake port 172, respectively.

In the first shift stage, the signal pressure Ps2 is supplied to the oil chamber 128 of the 1-2 shift valve 120, and the low coast port 144 is connected to the third brake port 14.
6, since the brake B3 is engaged by the supply of the forward range pressure, the rotation of the carrier 48 is prevented, and the engine brake operates even in the first speed. The 1-2 shift valve 120 is connected to the second shift valve 120.
At the speed stage, the signal pressure Ps2 is not supplied to the oil chamber 128, the second coast port 130 communicates with the first brake port 133, and the brake B1 is engaged by the supply of the forward range pressure. The rotation of the sun gears 41 and 42 in the first transmission section 40 is prevented, and the engine brake operates even in the second speed.

As described above, in this automatic transmission A,
The shift in the automatic shift mode and the shift in the manual shift mode can be performed. Switching between the modes and selection of the shift speed in the manual shift mode are performed by the shift device 17 described above.
Done by Then, the direct shift mode (D
In M), by operating the switch 18A or 18B of the shift lever 18, the shift speed can be set to any one of the first to fourth speeds.

In the automatic transmission A, when there is a shift determination, the electronic control unit 16 for the automatic transmission is controlled by the hydraulic control unit C at approximately the same time as in the manual shift mode and after a predetermined time in the automatic shift mode. 1st to 3rd solenoid valves S1, S
2. A gear shift command signal is output to S3, whereby the engagement hydraulic pressure is supplied / discharged to / from the friction engagement devices (various clutches and brakes), and an appropriate gear position is achieved.

Further, in the automatic transmission A, as described above, the electronic control unit 16 for the automatic transmission has the throttle opening degree,
Depending on other conditions described below, the solenoid valve SL
By operating T, the primary regulator valve 304 is operated to adjust the line pressure, thereby realizing smooth and responsive shift characteristics.

Next, with reference to the flowchart of FIG. 7, a description will be given of the content of the engagement pressure boosting control for improving the speed change characteristics by adjusting the line pressure.

When this control is started, first, initialization processing (initialization processing of various timers and flags described later) is performed in step 502, and input processing of various sensor signals and the like is performed in step 504. Next, at step 506, it is determined whether or not the shift position is in the direct shift mode (DM). If the mode is not the direct shift mode, the subsequent processing is passed and the process proceeds to the return step.

In the case of the direct shift mode, it is determined in step 508 whether or not an upshift has been determined. If no upshift has been determined, the process proceeds to a return step.

If the shift mode is the direct shift mode and an upshift is determined, the flow proceeds to step 510 and subsequent steps to increase the engagement pressure (line pressure).

In other cases, for example, in the auto mode, the boost control is not executed. The reason is that it is not particularly necessary to increase the responsiveness of the shift determination in a normal auto mode shift, but the durability of the friction material of the solenoid valve and the friction engagement device is impaired due to repeated application of high oil pressure. This is because they may be

When the process proceeds to step 510, the line pressure is increased from the steady pressure in step 510.
As a result, the engagement pressure supplied to the friction engagement device increases, the flow rate increases, and the period until the start of the inertia phase is shortened. That is, the shift response is improved.

It should be noted that the line pressure may be increased simultaneously with the occurrence of the shift determination (shift command) as shown in this flow, or may be performed after a predetermined short time has elapsed.

After step 510, the process proceeds to step 512, where it is determined whether the flag F1 is "0". This flag F1 is a flag indicating whether or not the current process is the first process after the line pressure is increased. If the flag F1 is "0", it indicates the first process after the line pressure is increased. This indicates that the processing is the second or later processing after the line pressure is increased.

If the determination in step 510 is YES,
In step 514, the timer T21 is set to "0" and started. The timer T21 serves as a fail-safe (back-up) for the boost control and a backup for the torque-down control.

After the timer starts in step 514, the flag F1 is set to "1" in step 516. Then, the process proceeds to step 518.

In step 518, it is determined whether or not the inertia phase has started. This determination is made by detecting that the rotation speed Nco of the rotating member in the automatic transmission, for example, the turbine shaft, has begun to decrease as the engagement of the friction engagement device starts. More specifically, whether or not the turbine rotation speed Nco has become smaller than a rotation speed obtained by subtracting a constant ΔN (about 50 rpm) from a value obtained by multiplying the output shaft rotation speed No by the gear ratio i before shifting (Nco <No) × i-Δ
N).

Until the start of the inertia phase is confirmed,
After the determination in step 520, the process returns to step 510 to continue increasing the line pressure. Then, when the start of the inertia phase is confirmed, the process proceeds to step 522 to stop the line pressure increase control, return the line pressure to the original steady value,
Subsequent shifting is performed. If the high line pressure is maintained, the shift shock becomes too large. However, since the line pressure is returned to the original steady value simultaneously with the start of the inertia phase, the shift shock is prevented from increasing. Here, the torque reduction is executed together with the detection of the start of the inertia phase (step 524).

If the start of the inertia phase is not easily confirmed for some reason, that is, the timer T21
Is larger than the predetermined value α, the process forcibly proceeds to step 522 to stop the control of increasing the line pressure. Then, after step 522, the process proceeds to step 524 to start control such as torque down control.
Proceed to the return step.

The value of the predetermined value α is changed according to the type of shift and the throttle opening. It may be changed depending on the vehicle speed. When the timer T21 is not shared with the torque down control, it may be set independently.

As is apparent from the above description, according to the shift control device of the above embodiment, the line pressure supplied to the friction engagement device is increased for an appropriate period during an upshift in the direct shift mode. . Therefore, the shift response is improved without increasing the shift shock.

In the above-described embodiment, the line pressure is increased in order to increase the engagement pressure. However, more directly (for example, although not shown in FIG. The engagement pressure itself may be increased (by increasing the discharge pressure of an accumulator disposed in the oil passage to the oil passage).

In the above embodiment, the engagement pressure is increased at the time of the upshift. However, the engagement pressure may be increased at the time of the downshift.

[0066]

As described above, according to the shift control apparatus for an automatic transmission according to the present invention, shift responsiveness can be improved while suppressing shift shock, and the shift feeling is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention.

FIG. 2 is a block diagram showing one embodiment of the present invention.

FIG. 3 is a skeleton diagram of the automatic transmission A in the embodiment.

FIG. 4 is a perspective view of a shift lever used in the embodiment.

FIG. 5 is a hydraulic system diagram of a hydraulic control device of the automatic transmission according to the embodiment.

FIG. 6 is an operation table of the automatic transmission according to the embodiment.

FIG. 7 is a flowchart showing an example of a control routine of the embodiment.

FIG. 8 is a main part hydraulic system diagram showing a line hydraulic pressure adjusting circuit of the embodiment.

[Explanation of symbols]

 16: Electronic control device for automatic transmission 17: Shift device 304: Primary regulator valve A: Automatic transmission C: Hydraulic control device SLT: Linear solenoid valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takayuki Okada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Takeshi Takeshi 10 Takane Fujii Town, Anjo City, Aichi Prefecture Aisin AW Inside (72) Inventor Masashi Hattori 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (56) References JP-A-59-219549 (JP, A) JP-A-2-46360 (JP, A) JP-A-4-107359 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 61/00-61/12

Claims (1)

(57) [Claims] 1. A shift control device for an automatic transmission which performs a shift by controlling a supply and discharge of an engagement pressure to and from a friction engagement device. Means for increasing the pressure from a steady pressure, means for detecting the start of engagement of the friction engagement device, and means for stopping the increase of the engagement pressure by the pressure increasing means upon detection of the start of engagement of the friction engagement device. A shift control device for an automatic transmission, comprising: a means for compensating a time for increasing the engagement pressure by the pressure increasing means so as not to exceed a predetermined time.