JPH04136563A - Gear shifting control device for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce gear shifting shock and also liquidate idle running feeling of a vehicle, etc., by setting the set delay time of a delay means that retards the engagement of friction elements based on the rotation speed on the side of input detected by means of a rotation speed detecting means. CONSTITUTION:Respective gear shifting controls are performed by a controller that possesses a CPU, etc., inside. A delay means that corrects a gear shifting means so as to delay the engagement of a coast clutch 17 that administers the response of engine brake by the action of a first one-way clutch 16 only during the set delay time until actual turbine rotation speed falls below the set rotation speed when gear shifting is performed to a shifting stage that shifts to third speed on which engine brake acts due to lowering of engine load is constructed. Further, a delay time setting means that determins a set rotation value wherein extra rotation speed is added on estimated rotation speed after shifted based on actual turbine rotation speed at the starting time of shifting, and sets the set delay time of the delay means so as to delay the engagement of the coast clutch 17 until the actual turbine rotation speed falls below this set rotation value is constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a shift control device for an automatic transmission, and particularly to measures to reduce shift shock.

(Prior Art) Conventionally, automatic transmissions have a gear position where engine braking is effective due to the action of a one-way clutch, and when automatically shifting to this gear position, the friction element to be released is red and firmly engaged. If the friction element to be engaged is engaged prematurely, the one-way clutch will not be able to reverse the rotation, resulting in a problem that an internal lock will almost occur.

Therefore, as disclosed in Japanese Patent Publication No. 6B-63778, the present applicant has proposed that by delaying the engagement of the friction element that controls the action of the one-way clutch for a set period of time, the internal lock can be effectively prevented and the shift shock We are proposing a system that enables smooth gear shifting with less friction.

(Problem to be Solved by the Invention) However, although the above proposal can effectively prevent internal locking in most cases, internal locking may occur in rare cases depending on the driving conditions, giving a gear shift shock to the driver, or On the other hand, the engagement of the friction elements may be too slow, giving a feeling that the vehicle is running idly.

The present invention has been made in view of the above, and its purpose is to provide a delay time for delaying the engagement of friction elements that should be engaged when shifting to a gear position where an internal lock occurs due to the action of a one-way clutch. By making appropriate changes accordingly, the engagement timing of the friction element is always appropriate regardless of the driving condition, effectively reducing or eliminating shift shock caused by internal locking, and eliminating the feeling of idle running of the vehicle. There is a particular thing.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a switching means for switching gears by controlling engagement and release of a plurality of friction elements provided in a transmission gear mechanism, and a reduction in engine load. and a delay means for correcting the switching means so as to delay the engagement of the friction element to be engaged by a set delay time when shifting to a gear position where engine braking is applied.
rotational speed detection means for detecting the input side rotational speed of the transmission during the shift; and delay time setting means for setting the set delay time of the delay means based on the input side rotational speed detected by the rotational speed detection means. The configuration includes the following.

(Function) With the above configuration, in the present invention, when changing gears to a gear position where engine braking is applied, when this gear shift is decelerating due to a decrease in engine load, the driver can strongly avoid the gear shift shock caused by the internal lock. Easy to feel. However, during such a shift, the engagement of the friction element begins only when the input speed of the transmission becomes appropriate for each shift, so the internal lock always ensures prevention regardless of the operating state. As a result, shift shock is effectively reduced and eliminated, and there is no delay in engagement of the friction elements, preventing the vehicle from feeling like it is running idly and allowing appropriate engine braking to be applied.

(Effects of the Invention) As explained above, according to the shift control device for an automatic transmission of the present invention, when shifting to a gear position where engine braking is effective, the engagement timing of the friction element to be engaged is adjusted to the operating condition. Since it can be done properly, it is possible to reliably prevent internal locking regardless of the operating condition and effectively reduce shift shock, and also prevent the friction element from being engaged too late.
This eliminates the feeling that the vehicle is running idle for the driver.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows an automatic transmission Z with 4 forward gears and 1 reverse gear.
is an engine output shaft; 2 is a torque converter comprising a pump 2a connected to the engine output shaft 1, a stator 2b, and a turbine 2c; It is provided so that it can be fixed to the case 4 via a one-way clutch 3 to prevent it from rotating. Further, 5 is a speed change gear mechanism connected to a converter output shaft 2d connected to the turbine 2c of the torque converter 2.

The speed change gear mechanism 5 is provided with a Ravigneau type planetary gear mechanism 7 inside, and the planetary gear mechanism 7 includes a small diameter sun gear 8 and a large diameter sun gear 9 arranged in the front and rear, and the small diameter sun gear 8.
The long pinion gear 11 meshes with the large diameter sun gear 9 and the short pinion gear 10, and the ring gear 12 meshes with the long pinion gear 11. Above small diameter sun gear 8
is connected to the forward clutch 15 disposed behind it and the converter output shaft 2 connected in series to the clutch 15.
The output shaft 2d of the torque converter 2 is connected to the output shaft 2d of the torque converter 2 through a first one-way clutch 16 that prevents reverse driving of the torque converter 2. A coast clutch 17 is connected in parallel to a path connecting the forward clutch 15 and the first one-way clutch 16 in series. Also,
The large-diameter sun gear 9 is arranged diagonally behind the 2-4
It is connected to the output shaft 2d of the torque converter 2 via a brake 18 and a reverse clutch 19 arranged behind the 2-4 brake 18. The long pinion gear 11 also includes a roll reverse brake 21 that fixes the long pinion gear 11 via its rear carrier 20, and a second one-way clutch that allows the long pinion gear 11 to rotate in the same direction as the engine output shaft 1. 22 are connected in parallel, and the front carrier 23 is connected to the output shaft 2d of the torque converter 2 via a 3-4 clutch 24. moreover,
The ring gear 12 is connected to an output gear 25 disposed in front of the ring gear 12. In the figure, 27 is a lock-up clutch that directly connects the engine output shaft 1 and the converter output shaft 2d, and 28 is an oil pump driven by the engine output shaft 1 via an intermediate shaft 29.

Table 1 shows the operating states of each clutch and brake at each gear in the above configuration.

Here, in Table 1 above, the D position is from 1st speed to 4th speed.
The S position indicates automatic shifting between 1st and 3rd speeds, and the L position indicates automatic shifting between 1st and 2nd speeds.

Next, a hydraulic circuit for supplying and discharging hydraulic oil to each friction element such as the 2-4 brake 18 will be described with reference to FIG. Here, among the above friction elements, 2-4 brake 1
The servo mechanism 45 as a hydraulic actuator in No. 8 is composed of a servo piston having an apply chamber 45a and a release chamber 45b.
4 brake 18 is engaged, and the apply chamber 45a is
The 2-4 brake 18 is released when release pressure is applied to the release chamber 45b, regardless of whether or not the engagement pressure is applied to the release chamber 45b. Further, the other friction elements are constituted by ordinary hydraulic pistons, and the friction elements are engaged when hydraulic oil is supplied.

In other words, the internal configuration of the servo mechanism 45 is as follows: A piston 45C connected to the 2-4 brake 18 via a rod 18a.
A hydraulic release chamber 45b and an apply chamber 45a are divided vertically in the figure by the piston 45c, and the piston 45C is compressed into the release chamber 45b and the apply chamber 4 is
It has a spring 45d that biases toward the 5a side. The piston 45c is formed so that its pressure receiving area is larger in the release chamber 45b and smaller in the apply chamber 45a, and due to the difference in pressure receiving area, the tightening pressure (line pressure) in the apply chamber 45H is reduced. Regardless of whether it is activated or not, if release pressure (line pressure) acts on the release chamber 45b, the release pressure moves the piston 45c downward in the figure and operates the 2-4 brake 18 to the release side. It is structured as follows. When the 2-4 brake 18 is requested to be engaged, the engagement pressure is introduced into the apply chamber 45a and the release pressure is discharged from the release chamber 45b.
c is moved upward in the figure to engage the 2-4 brake 18.

Next, the hydraulic circuit 60 shown in FIG. 2 is equipped with a pressure regulator that adjusts the pressure of the hydraulic oil discharged from the oil pump 28 shown in FIG. 1 to the main line 100 to a predetermined line pressure.
A regulator valve 61 is provided. Further, in the vicinity of the pressure regulator valve 61, there is a throttle valve 62 that generates a throttle pressure according to the throttle valve opening of the engine, a throttle modulator valve 63 that adjusts this throttle pressure, and a backup valve 93. is provided.

The hydraulic circuit 60 also includes a manual valve 64 that selectively sends the line pressure generated by the pressure regulator valve 61 to each hydraulic line according to the selected range, and a manual valve 64 that operates according to the gear position to reduce the line pressure. Shift valves 71, 72, and 73 of 1-2, 2-3, and 3-4 are provided to selectively supply the friction elements to each of the friction elements.

The manual valve 64 has an input port f into which line pressure is introduced from the main line 100, and first to fifth output ports a to e, and by movement of the spool 64a, the input port f is in the D range. So let's move on to the first part. The second output ports a and b are connected to the first output port in the S range. Second. The third output ports a, b, and c are connected to the first output port in the L range. Third. Fourth output boat a, C.

d, and in the R range, to the fifth output port e. And each output port a
-e includes the first to fifth output lines 101 to 10, respectively.
5 is connected.

In addition, the above 1-2.2-3.3-4 shift valve 71,
72 and 73 are spools 71a, respectively.

72a and 73a are biased to the right side in the drawing by springs, and a control boat 71 is installed on the right side of these spools.
72b, 73b. And 1-
A first control line 106 branched from the main line 100 is connected to the control boat 71b of the second shift valve 71.
2-3. A second output line branched from the first output line 101 is connected to the control boats 72b and 73b of the 3-4 shift valves 72 and 73. Third control lines 107, 108 are connected respectively, and these control lines 106.1
1.07 and 108 respectively. A second and third solenoid valve 76, 77, 78 is provided. When these solenoid valves 76 to 78 are OFF, control pressure is introduced into the control boats 71b to 73b of the shift valves, and the spools 71a to 73a are positioned on the left side in the drawing, and when ON, the control pressure is introduced into the control boats 71b to 73b of the shift valves. Port 71b~7
3b is drained, and the spools 71a to 73
a is positioned on the right side.

Here, these solenoid valves 76 to 78 are turned on according to the gear stage to be set depending on the vehicle speed of the vehicle and the throttle/sottle valve opening of the engine.

Although the solenoid valves 76 to 78 are controlled to be OFF, each of the solenoid valves 76 to 78 is controlled to be ON at each gear stage in the driving range.
The OFF combination patterns are set as shown in Table 1 above.

On the other hand, each output capo in the manual valve 64)
1st to 5th output lines 101 to 101 connected to a-e
105, a first output line 101 that communicates with the main line 100 in each of the D, S, and L forward ranges is led to the forward clutch 15 via a one-way orifice 80. Therefore, as described above, the forward clutch 15 is always engaged in the S and L ranges. still,
The first output line 101 is provided with an N-D accumulator 81 for buffering when the forward clutch is engaged.

Further, a line 111 is branched from this first output line 101 and led to the 1-2 shift valve 71, and this branch line 111 is connected to the spool 71a when the first solenoid valve 76 is turned on. When it moves to the right side, it is communicated with the servo apply line 112 that reaches the apply chamber 45a of the servo mechanism 45 via the one-way orifice 82. Therefore, the first
2. When the solenoid valve 76 is ON, that is, in the D range. At the 3rd and 4th speeds, the 2nd and 3rd speeds of the S range, and the 2nd speeds of the L range, the fastening pressure is introduced into the apply chamber 45a. In addition, the above servo apply line 112 also has
A 1-2 accumulator 83 is provided as a buffer when the servo mechanism 45 (2-4 brake) is engaged.

Further, the second output line 102, which communicates with the main line 100 in the D and S ranges, is led to a 2-3 shift valve 72. When the second solenoid valve 77 is OFF and the spool 72a is located on the left side, the line 102 is communicated with the 3-4 clutch line 113 that reaches the actuator 43g of the 3-4 clutch 24 through the one-way orifice 84. Therefore, when the second solenoid valve 77 is OFF in the D and S ranges, that is, the 3-4 clutch 24 is engaged in the 3rd and 4th speeds of the D range and the 3rd speed of the S range. The 3-4 clutch line 113 is provided with a bypass valve 85 and a 2-3 timing valve 86 in parallel with the one-way orifice 84 to adjust the engagement timing of the 3-4 clutch 24. , said 3-4 clutch line] 13
A 2-3 accumulator 87 is also provided for buffering when the 3-4 clutch is engaged.

Further, a line 114 branched from the 3-4 clutch line 113 and a line 115 branched from the first output line 101 are led to the 3-4 shift valve 73. Then, when the third solenoid valve 78 is OFF and the spool 73a is located on the left side, a line 114 branched from the 3-4 clutch line 113 passes through the one-way orifice 88 to the release chamber 4 of the servo mechanism 45.
5b, a line 115 branched from the first output line 101, or a coast clutch line 117 extending to the coast clutch 17 via a one-way orifice 89. Therefore, in the D and S ranges, the second. When both the third solenoid valves 77 and 78 are OFF, that is, in the 3rd speed of the D range and the 3rd speed of the S range, the release chamber 45 of the servo mechanism 45
When the release pressure is introduced to b and the 2-4 brake 18 is released, and the third solenoid valve 78 is OFF in the S and L ranges, that is, the 3rd speed of the D range, the 3rd speed of the S range, and the L The coast clutch 17 is engaged in 2nd gear of the range, 2nd and 3rd gears when the hold switch is operated in the S range, and 1st and 2nd gears when the hold switch is operated in the L range.

Here, between the 3-4 clutch line 113 and the line 114 branched from the line 113, a 3-4 clutch pressure and a release chamber of the servo mechanism 45 are connected via respective branch lines 118 and 119. A 3-2 timing valve 90 and a 3-2 capacity valve 91 are provided for adjusting the discharge timing of release pressure to 45b. Additionally, the coast clutch line 117 includes a bypass line 1 that bypasses the one-way orifice 89.
20 is provided, and 3- for opening and closing the line 120.
A 4-capacity valve 92 is provided. This valve 92 is activated when the 3-4 clutch pressure is generated and when the manual valve 64 is selected to the S range or L range and the third output line 103 is switched to the main line 1.
00, the bypass line 120 is opened to adjust the discharge timing of the coast clutch pressure.

Further, the fourth output line 104, which is connected to the main line 100 in the L range by the manual valve 64, is connected to the 1-2
It is guided to a shift valve 71. And the line 1
22 is a one-way orifice 9 when the first solenoid valve 76 is OFF and the spool 71a is located on the left side.
5 and a shuttle valve 96 to a low and reverse brake line 123 leading to the low and reverse brake 21 . Therefore, when the first solenoid valve 76 is OFF in the L range, that is, in the first gear of the L range, the low and reverse brake 21 is engaged.

Further, a fifth output line 105 that communicates with the main line 100 in the R range communicates with the low and reverse brake line 123 via the one-way orifice 97 and the shuttle valve 96, and also communicates with the fifth output line 105.
A reverse clutch line 124 is branched from 05 to the reverse clutch 19 via a one-way orifice 98. Therefore, in the R range, the low & reverse brake 21 and reverse clutch 19 are always engaged. Furthermore, the reverse clutch line 124 is also equipped with an N-R accumulator 99 for buffering when the reverse clutch is engaged.
is provided. Further, a line 125 branched from the fifth output line 105 is led to the pressure increasing side of the regulator valve 61, and the line pressure is increased in the R range.

In addition to the above configuration, this hydraulic circuit 60 includes a lock-up clutch 2 in the torque converter 2 shown in FIG.
A lock-up valve 201 is provided for operating the valve 7. This valve 201 is connected to a torque converter line 202 from the pressure regulator valve 61.
The main line 100 is connected as a control line 203 to the control port 201b at one end. When the lock-up solenoid valve 204 provided in the control line 203 is turned on, the control pressure in the control boat 201b is drained and the spool 201a is positioned on the right side, so that the torque converter line 202 is turned on. It communicates with a line 205 leading into the torque converter 2, thereby increasing the internal pressure of the torque converter 2 and engaging the lock-up clutch 27. Also, the solenoid valve 204 is OFF.
When the control pressure is introduced into the control boat 201b and the spool 201a moves to the left, the torque converter line 202 communicates with the lockup release line 206, and lockup release pressure is introduced into the torque converter 2. , the lock-up clutch 27 is configured to be released.

Each of the above-mentioned speed change controls is performed by a controller 150 shown in FIG. 2 which includes a CPU, etc., and the speed change gear mechanism 5
It constitutes a switching means 153 that controls the engagement and release of a plurality of friction elements provided for switching the gear stage.

As shown in the figure, the controller 150 includes an opening sensor 151 that detects the throttle valve opening of the engine, and an opening sensor 151 that detects the input side rotation speed of the automatic transmission Z based on the rotation speed of the turbine 2c of the torque converter 2. A rotation speed sensor 152 as rotation speed detection means is connected.

Next, the speed change control during 2->3 speed change (applying and releasing the 2-4 brake 18 and releasing and engaging the 3-4 clutch 24) will be explained based on the control flow shown in FIG.

After starting, it is determined in step S1 whether the throttle valve opening θ is less than a small set value (for example, 1/32 opening value), and in a state where the engine load is reduced when θ<1/32, the throttle valve opening θ is determined in step S2. The control pattern for the solenoid valves 76 to 78 is selected at the first intermediate position in Table N2 below. As a result, the apply chamber 45 of the servo mechanism 45 as shown in FIG.
At the same time, the engagement pressure acting on the clutch a is released, and the engagement pressure is supplied to the 3-4 clutch 24, and the third speed starts to be established.

After that, in order to engage the coast clutch 17 after a set time in order to set the third gear to a gear position where engine braking is effective, first, in step S3, the actual turbine rotation speed TREVO at the start of the shift is read, and in step S4, after the shift is completed, the coast clutch 17 is engaged. The predicted turbine rotation speed TREVI is calculated. and,
In step S5, as shown in FIG.
From the map data stored in the ROM of 50, the rotation speed TRE is somewhat higher than the predicted rotation speed TREVI after the above shift
VB is read out in correspondence with the actual turbine rotation speed TREVO.

Here, the map data of FIG. 4 is set such that the higher the actual turbine rotational speed TREVO is, the higher the additional rotational speed TREVB is. This is because the higher the actual turbine rotational speed TREVO at the start of gearshifting, the larger the range of change in the turbine rotational speed during gearshifting, so the engagement timing of coast clutch 17 is made constant between each gearshift. Then, in step S6, the predicted rotational speed TREVI after the shift is
Additional rotation speed Tl? Add EVB WL, rotation speed TR
Let EVA (-TREVI+TREVB) be the fastening start rotation speed.

After that, in step S7, the actual turbine rotation speed T is again determined.
l? EV is read, and in step S8, this turbine rotation speed TREV is repeatedly compared with the above-mentioned engagement start rotation speed TREVA, and when TREV (TREV^) is reached,
In step S9, the control pattern for the solenoid valves 76 to 78 is selected to the second intermediate position in Table 2 above. As a result, a fastening pressure is applied to the release chamber 45b of the servo mechanism 45, and as shown in FIG.
7 is tightened, thereby locking the first one-way clutch 16 and ensuring the effectiveness of the engine brake.

After that, select the third speed in Table 2 above, and then select the first speed.
By turning on the solenoid valve 76, a fastening pressure is supplied to the apply chamber 45a of the servo mechanism 45 in advance, and the process ends.

On the other hand, in step S1, when the engine load is increased such that θ≧1/32, the solenoid valves 76 to 78 are controlled at each step S in step S10 in order to uniformly delay the engagement of the coast clutch 17 by the set time T. After selecting the pattern at the first intermediate position in Table 2 above, the pattern is selected at the second intermediate position in step Sl+.

Therefore, in the control flow of FIG. 3 above, step S
1. S2. Through S7 to S9, the throttle valve opening θ becomes θ
< 1/32 When the engine load is reduced to 1/32, when shifting to the third gear where the engine brake is applied, the coast clutch 17 (third gear) which controls the effectiveness of the engine brake is activated by the action of the first one-way clutch 16 The engagement of the friction element (which should be engaged at high speed) is delayed by taking the first intermediate position in Table 2 for the set delay time to until the actual turbine rotation speed TREV becomes less than the set rotation speed TREVA. A delay means 155 is configured to correct the switching means 153.

In addition, in steps 83 to S6 of the same control flow, the set rotational speed TREVA is calculated by adding the additional rotational speed TREVB obtained from FIG. Find the set rotational value Tl when the actual turbine rotational speed TREV is 2? A delay time setting means 156 is configured to set the set delay time to of the delay means 155 so as to delay the engagement of the coast clutch 17 until it becomes less than EV^.

Therefore, in the above embodiment, when shifting from 2 to 3, as shown in FIG.
This delay time to is determined by adding the additional rotation speed TREVB found from Fig. 4 to the actual turbine rotation speed TREV, which is the set rotation speed according to the operating condition, that is, the expected turbine rotation speed TREVI after shifting. Set rotation speed TR
Since this is an appropriate time until EVA is reached, the longitudinal acceleration G and the turbine rotation speed of the vehicle change smoothly, as shown in the figure. Therefore, as in the conventional case, coast clutch 1
7 is engaged very quickly as shown in Fig. 7 (a), it reliably prevents internal locking, eliminates the temporary decrease in longitudinal acceleration G and the temporary decrease in turbine rotation speed, and improves speed change. The shock can be effectively reduced, and the thrust shock (sudden increase in longitudinal acceleration G) in the case shown in FIG.
It also prevents the situation where the coast clutch 17 is slow to engage, as shown in Fig. 2(C), where the engine brake is not effective and the engine runs idle before engagement, and the retraction shock (abrupt longitudinal acceleration G) at the time of engagement. (lowering) can be prevented.

Further, FIG. 6 shows another embodiment, and in the above embodiment, 2-
Instead of being applied to the 3rd gear shift, this is applied to the 3-4 gear shift (coast clutch 17 engagement->release control, and 2-4 brake 18 release-engagement control).

In other words, as shown in Table 3, solenoid valves 76-
In addition to the third and fourth speeds, an intermediate position is added to the control pattern of No. 78, and when shifting from the third speed to the fourth speed, the set delay time to (TREVdR
2-4, which controls the effectiveness of engine braking by the action of the second one-way clutch 22. The engaged state of the brake 18 (
The state in which the fastening pressure is applied to the apply chamber 45a of the servo mechanism 45 is forcibly released, and when the delay time to has elapsed, the fastening pressure is applied to the apply chamber 45a again. 4 brake 18 is re-engaged.

Therefore, in this embodiment as well, the releasing operation of the coast clutch 17 and the engaging operation of the 2-4 brake 18 are performed appropriately between the two, and it is possible to reliably prevent internal locking due to simultaneous engagement of both. , 2-4 It is possible to effectively reduce the feeling of idle running of the vehicle and the pull-in shock caused by the delay in the engagement operation of the brake 18.

[Brief explanation of the drawing]

Figures 1 to 6 show embodiments of the present invention, with Figure 1 being a skeleton diagram of an automatic transmission, Figure 2 being a hydraulic circuit diagram, and Figure 3 being a hydraulic circuit diagram.
The figure is a flowchart diagram showing control during 2-3 gear shifting.
The figures are diagrams showing the characteristics of the additional rotation speed with respect to the actual turbine rotation speed, FIG. 5 is an explanatory diagram of operation, and FIG. 6 is an explanatory diagram of operation showing another embodiment. FIG. 7 is an explanatory diagram of the operation of a conventional example. 5... Speed change gear mechanism, 17... Coast clutch,
18...2-4 brake, 24...3-4 clutch, 152... rotation speed sensor (rotation speed detection means), 15
3...Switching means, 155...Delaying means, 156...
- Delay time setting means.

Claims (2)

[Claims] (1) A switching means that controls the engagement and release of a plurality of friction elements provided in a transmission gear mechanism to switch gears, and a friction element that is to be engaged when shifting to a gear where engine braking is applied due to a decrease in engine load. a delay means for correcting the switching means so as to delay the engagement by a set delay time; a rotation speed detection means for detecting the rotation speed on the input side of the transmission during the gear change; A shift control device for an automatic transmission, comprising: delay time setting means for setting a set delay time of the delay means based on the rotational speed. (2) The delay time setting means sets the set delay time to be a period until the input side rotational speed of the transmission reaches a rotational speed that has a predetermined relationship with the input side rotational speed at the end of shifting. A speed change control device for an automatic transmission according to claim (1).