JPH086798B2 - Control method of automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] In the present invention, a plurality of counter shafts are discontinuously connected to an input shaft via a hydraulic clutch for switching the counter shafts, and are fitted on the respective counter shafts. The transmission gear can be intermittently connected to each counter shaft by a synchromesh type clutch for gear selection,
The present invention relates to a shift control method for an automatic transmission in which each of the hydraulic clutches is connected to a hydraulic pressure switching valve.

[Prior Art] First, an outline of an automatic transmission will be described. In FIG. 1, an input shaft 2 of an automatic transmission 1 is a lockup clutch.
The output shaft 5 of the automatic transmission 1 is arranged in a straight line with the input shaft 2. For example, two first and second counter shafts 6 and 7 are arranged in parallel with the input shaft 2 and the output shaft 5. The first counter shaft 6 includes, in order from the torque converter 3 side, a gear 8 for taking in the counter shaft power, a speed change gear 9 for the fifth speed, a speed change gear 10 for the third speed, and a speed change gear 10 for the first speed. The speed change gear 11 and the reverse speed change gear 12 are rotatably fitted, and the gear 8 always meshes with the gear 25 of the input shaft 2 to change the fifth speed change gear 9, the third speed change gear 10, and the third speed change gear 10. Speed change gear for 1st speed
Reference numeral 11 always meshes with the gears 27, 28, 29 of the output shaft 5, respectively, and the reverse transmission gear 12 always meshes with the gear 31 of the output shaft 5 via the reverse rotation intermediate gear 30.

A torque converter side end of the first counter shaft 6 is provided with a gear 8 and a first hydraulic clutch 13 for switching the counter shaft, which continues power transmission of the first counter shaft 6. Fifth
A first cyclomesh type clutch 14 for gear selection is arranged between the speed change gear 9 and the third speed change gear 10, and the clutch 14 is used for the fifth speed change gear 9. And the first
The state in which the counter shaft 6 is connected and the shift gear 10 for the third speed
The first counter shaft 6 and the first counter shaft 6 can be switched between a connected state and a neutral state in which both of these connections are released. A second synchromesh type clutch 15 for gear selection is disposed between the first speed transmission gear 11 and the reverse speed transmission gear 12, and the clutch 15 includes the first speed transmission gear 11 and the first speed transmission gear 11. The state in which the counter shaft is connected, and the reverse transmission gear 12 and the first
It is freely switchable between a state in which the counter shaft 6 is connected and a neutral state in which both of these connections are released.

The second counter shaft 7 has a counter shaft power intake gear 18, a sixth speed gear change gear 19, a fourth speed gear change gear 20, and a second gear speed change gear in order from the Turkish converter 3 side. Speed change gear
21 is rotatably fitted. Gear 18 is the gear of input shaft 2
The transmission gear 19 for the sixth speed, the transmission gear 20 for the fourth speed, and the transmission gear 21 for the second speed are constantly meshed with gears 26, 28, 29 of output shaft 5, respectively. A torque converter side end of the second counter shaft 7 is provided with a gear 18 and a second hydraulic clutch 22 for switching the counter shaft, which continues power transmission of the second counter shaft 7. A gear selection third synchromesh clutch 23 is arranged between the sixth speed gears 19 and 19 and the fourth speed gear 20.
The clutch 23 connects the transmission gear 19 for the sixth speed and the second counter shaft 7 together, connects the transmission gear 20 for the fourth speed with the second counter shaft 7 and connects them together. It can be switched to the neutral state where it is released. A gear selection fourth synchromesh clutch 24 is arranged opposite to the second speed transmission gear 21, and the clutch 24 connects the second speed transmission gear 11 and the second counter shaft 7 to each other. It is possible to switch between this and the state of releasing the connection.
As the prior art, there is JP-A 64-21254.

[Problems to be Solved by the Invention] In the automatic transmission 1 of FIG. 1, for example, when traveling at the second speed, the first hydraulic clutch 13 for switching the counter shaft is in the released state and the second hydraulic clutch 22 is in the connected state. And the second
The transmission gear 21 for high speed is the 24th synchromesh clutch 24
Is connected to the second counter shaft 7 via. The other synchromesh clutches 14, 15, 23 are in the neutral state. That is, the rotation torque of the input shaft 2 is transmitted through the gears 26, 18, the second hydraulic clutch 22, the second counter shaft 7, the fourth synchromesh clutch 24, the second speed transmission gear 21 and the gear 29 to the output shaft 5. The first counter shaft 6 is not involved in power transmission.

In this state, the relationship between the rotational speeds of the shafts is as follows.

Nc2 = N2 = Ng2 = N0 × io2 = N−1 × e × io2 N3 = N2 × i12 where Nc2 is the second hydraulic clutch 22 for switching the counter shaft.
Rotation speed, N2 is the rotation speed of the second counter shaft 7, Ng2 is the second
The rotation speed of the transmission gear 21 for high speed, N0 is the rotation speed of the input shaft 2, i0
2 is the gear ratio between the gear 26 of the input shaft 2 and the gear 18 of the second counter shaft 7, N-1 is the number of revolutions of the torque converter 3 on the input section 4 side, e is the gear ratio in the torque converter 3, and i12 is the The gear ratio between the second speed transmission gear 21 and the gear 29 of the output shaft 5 (second
It is a gear ratio between the second counter shaft 7 and the output shaft 5 during high speed travel.

The shift from the 2nd speed to the next speed is usually a downshift to the 1st speed or an upshift to the 3rd speed.
As described above, the first counter shaft 6 does not participate in power transmission during idling and is idling, so during gear shift,
By the second synchromesh clutch 15 or the first synchromesh clutch 14, the difference in rotation speed between the rotation speed Ng1 of the first speed transmission gear 11 and the shaft rotation speed N1 of the first counter shaft 6 ΔN = Ng1-N1, Alternatively, the rotational speed difference between the rotational speed Ng3 of the third speed transmission gear 10 and the rotational speed N1 of the first counter shaft 6 ΔN = Ng3-N1
Must be synchronized.

However, the rotation speed N1 of the first counter shaft 6 during idling is the first
It varies depending on the friction torque of each part on the counter shaft 6, the accompanying torque of the first hydraulic clutch 13, and the like, and the rotation speed of the first hydraulic clutch 13 is not fixed. N1 = Nc1− △ X when shifting up, N1 ＝ Nc1 ＋ △ when shifting down
X is the direction in which the synchro load is reduced, but it may be reversed, and the synchro load during shift is not stable, and the shift operation performance becomes unstable.

[Means for Solving the Problems] In order to solve the above problems, the present invention includes an input shaft, an output shaft, and a plurality of counter shafts, each counter shaft being input via a counter shaft switching hydraulic clutch. The counter shafts are continuously connected, and the shift gears for the respective shift stages, which mesh with the gears of the output shaft, are fitted on the respective counter shafts.
These transmission gears can be intermittently connected to each counter shaft by a synchromesh clutch for gear selection, and each hydraulic clutch is connected to a hydraulic switching valve and the input section always rotates at a constant gear ratio with respect to the input shaft. In the automatic transmission, the open / close cycle of each switching valve can be adjusted by controlling the duty ratio by the control device, and the rotation speed of the counter shaft in the idling state and the rotation speed of the corresponding hydraulic clutch input section or input shaft can be rotated. The number of rotations is detected and the control unit compares the two rotation speeds.The duty ratio of the open / close cycle of the switching valve is controlled so that the counter shaft in the idle state synchronizes with the rotation speed of the corresponding hydraulic clutch. Guide hydraulic pressure to the clutch.

[Operation] During operation at a certain gear, the counter shaft connected to the counter shaft switching hydraulic clutch is used for torque transmission, and the counter shaft released from the counter shaft switching hydraulic clutch is It is spinning. The input part of the hydraulic clutch on the release side rotates at a constant gear ratio with the input shaft.

During the above operation, the rotational speed of the idling counter shaft and, for example, the input shaft is detected by the rotational speed detection mechanism, the rotational speed difference is subcutaneously calculated by the control device, and the idling counter shaft is released from the hydraulic clutch. The duty ratio of the opening / closing cycle of the switching valve is controlled so as to rotate synchronously, and low hydraulic pressure is supplied to the hydraulic clutch that is not involved in power transmission.

By synchronizing the idling counter shaft and the corresponding hydraulic clutch, the rotational speed difference between the transmission gear and the counter shaft in the synchromesh clutch on the idling counter shaft is set to a constant value.

Therefore, at the time of shifting to the next shift stage, the speed change gear of the next stage is connected to the counter shaft which is idling, but the rotational speed difference to be synchronized by the synchromesh clutch corresponding to the shift gear, that is, the change gear of the next stage. Since the difference in the number of revolutions of the counter shaft is constant, the synchro load is also constant, and the shifting operation is always stable.

[Embodiment] The basic structure of the automatic transmission of FIG. 1 to which the present invention is applied has already been described in the section of the prior art, and will be omitted.

FIG. 3 shows a hydraulic piping diagram of the automatic transmission shown in FIG. 1, in which the first hydraulic clutch 13 and the second hydraulic clutch 22 are connected to the two-position electromagnetic switching valves 31, 32, respectively, and the torque converter 3 The lockup clutch 3a is connected to a two-position electromagnetic switching valve 33, which is connected to a hydraulic supply pump 37 via a pressure regulating valve 36. Reference numerals 41, 42, 43, and 44 are actuators for switching the first, second, third, and fourth synchromesh clutches 14, 15, 23, and 24 (FIG. 1), respectively, and detailed description thereof will be omitted. It is connected to the hydraulic pump 37 via a series of switching valve devices 47.

In FIG. 2, a hydraulic clutch for switching each counter shaft
The electromagnetic switching valves 31 and 32 of 13, 22 are electromagnetically connected to the opening / closing control device 50, and the pulse command signal of the control device 50 controls the duty ratio of the energization of the solenoids of the electromagnetic switching valves 31 and 32. The opening / closing cycle of the electromagnetic switching valves 31, 32 can be adjusted to freely adjust the desired hydraulic pressure supply amount.

Rotational speed detection mechanisms 35, 36, 38 are connected to the respective counter shafts 6, 7 and the input shaft 2, and the rotational speeds of the respective shafts are detected and input to the control device 50, respectively.

The control device 50, among the rotational speed values detected by the rotational speed detection mechanisms 35, 36, 38, the rotational speed of the counter shaft in the idling state,
Calculate the difference in the number of rotations of the input shaft. The control device 50 stores in advance the difference between the rotational speeds of the hydraulic clutches (on the input side) 13, 22 and the rotational speed of the input shaft 2 as a reference value. In order to match the detected rotational speed difference with the reference value, the duty ratio of the opening / closing cycle of the corresponding switching valve is controlled to supply a low hydraulic pressure to the hydraulic clutch, and the counter shaft in the idling state is applied to the corresponding hydraulic clutch. Sync to.

 Next, a specific control example will be described.

For example, while operating at the second speed, the second hydraulic clutch 22 of FIG.
, The first hydraulic clutch 13 is disengaged, the second speed transmission gear 21 is connected to the second counter shaft 7 via the fourth synchromesh clutch 24, and the second counter shaft 7 is involved in power transmission. are doing. Other synchromesh clutch 1
4,15,23 are neutral.

The rotation speed N1 of the first counter shaft 6 is as follows, assuming that the control relating to the present application is not working.

N1 = N0 × i01 × Mfc1 / (Mfc1 ± Mfj) where N0 is the rotation speed of the input shaft 2 and i01 is the gear 2 of the input shaft 2.
5 and the gear ratio of the first counter shaft 6 gear 18, Mfc1 is the accompanying torque of the first hydraulic clutch 13, and Mfj is the first counter shaft 6
Friction resistance torque of the above transmission gears 8, 9, 10, 11, 12 and synchromesh clutches 14, 15, where (+) acts in the deceleration direction and (-) acts in the acceleration direction. Show.

Note that Mfj = Mf1 + Mf3 + Mf5 + MFR, and Mf1, Mf3, Mf5,
MFR is the friction resistance torque of each transmission gear 9, 10, 11, 12.

The relative speeds to be synchronized during the shift are from the second speed to the first
ΔN = Ng1-N1 when downshifting to speed, ΔN = Ng3-N1 when upshifting from second speed to third speed.

Considering a downshift from the second speed to the first speed, for example, the rotational speed difference ΔN between the first speed transmission gear 11 and the first counter shaft that should be synchronized during the shift is ΔN = Ng1-N1 = N3 x 1 / i12-N0 x i01 x Mfc1 / (Mfc1 ± ΣMfj). However, since the rotation speed N3 of the output shaft 5 is N3 = N0 × i01 × i12, ΔN = N0 × i02−N0 × i01 × Mfc1 / (Mfc1 ± ΣMij) ΔN = N0 × {i02−i01 × Mfc1 / (Mfc1 ± ΣMfj)}. The hydraulic pressure of the first hydraulic clutch 13 is controlled at a low duty ratio so that the value of the unstable term is set to 1 in the above expression, that is, the first hydraulic clutch 13 and the first counter shaft 6 in the idling state are synchronized. As a result, ΔN = N0 (i02-i01).

That is, the rotational speed difference ΔN between the idling first counter shaft 6 and the first speed transmission gear 11 is always kept constant, and the second synchromesh type is used when shifting to the first speed. The synchro load of the clutch 15 is stable, and stable shout operation can always be performed.

Further, during the operation at the first speed, the first counter shaft 6 is involved in the power transmission, and the second counter shaft 7 is idle without being involved in the power transmission. In this case, the rotational speed of the second counter shaft 7 during idling is compared with the rotational speed of the input shaft 2, and the open / close cycle of the switching valve 32 of the second hydraulic clutch 22 is controlled by the duty ratio, so that the low hydraulic pressure is controlled to the second hydraulic pressure. It is supplied to the hydraulic clutch 22 and the second counter shaft 7 is synchronized with the rotation speed of the input portion of the second hydraulic clutch 22.

Therefore, when shifting up from the first speed, the difference in rotational speed between the second transmission gear 21 and the second counter shaft 7 at the next stage to be connected is kept constant, so that the fourth synchromesh clutch 24 The synchro load of is stable.

The synchro load is stable in the shift operations of the other shift stages, as in the above case.

[Other Embodiments] In the above embodiment, the rotational speed of the input shaft is input to the control device as the rotational speed for calculating the rotational speed difference with the counter shaft. A rotation speed detection mechanism is provided for each input part) to directly detect the rotation speed of the hydraulic clutch, and the opening / closing of the hydraulic clutch is controlled by a low duty ratio so that the counter shaft in the idling state is synchronized with the rotation speed of the corresponding hydraulic clutch. You may do it.

[Effects of the Invention] As described above, the present invention includes a plurality of counter shafts that are discontinuously connected to the input shaft via the counter shaft switching hydraulic clutches, and each shift speed fitted to each counter shaft. Each transmission gear can be intermittently connected to each counter shaft by a synchromesh clutch for gear selection,
In the automatic transmission in which each of the hydraulic clutches described above always rotates at a constant gear ratio with respect to the input shaft and is connected to each hydraulic switching valve: The opening / closing cycle of each switching valve is adjustable by the duty ratio control by the control device. , The rotation speed of the counter shaft in the idling state and the rotation speed of the corresponding hydraulic clutch input section or input shaft are detected by the rotation number detecting mechanism, and both rotational speeds are compared and calculated by the control device, and the counter shaft in the idling state is detected. Since the duty ratio of the open / close cycle of the switching valve is controlled so that the hydraulic pressure is guided to the hydraulic clutch so that it synchronizes with the corresponding rotational speed of the hydraulic clutch, the rotational speed difference of the synchromesh clutch at the time of shift shifting is controlled. Can always be controlled to a predetermined value, and the synchro load can be kept constant.

 Therefore, the shift operation is always stable.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing an example of an automatic transmission to which the control method according to the present invention is applied, FIG. 2 is a piping and wiring diagram showing a control device and the like for implementing the control method according to the present invention, and FIG. 2 is an example of a hydraulic control circuit diagram of the automatic transmission of FIG. 1 ... Automatic transmission, 2 ... Input shaft, 3 ... Torque converter, 5 ... Output shaft, 6,7 ... Counter shaft, 9,10,11,12,19,20,21 .. , 13,22 …… First and second hydraulic clutches for switching counter shafts, 14, 15, 23, 24
...... Synchromesh clutch, 31,32 …… Switching valve, 3
5,36,38 …… Rotation speed detection mechanism, 50 …… Control device

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F16H 3/093 8609-3J

Claims (1)

[Claims] 1. An input shaft, an output shaft, and a plurality of counter shafts, each counter shaft being discontinuously connected to the input shaft via a counter shaft switching hydraulic clutch, and on each counter shaft, The transmission gears for the respective shift speeds, which mesh with the gears of the output shaft, are fitted together, and the transmission gears can be intermittently connected to the counter shafts by a synchromesh type clutch for gear selection. In the automatic transmission in which the input section always rotates at a constant gear ratio with respect to the input shaft, the open / close cycle of each switching valve can be adjusted by the duty ratio control by the control device to rotate the counter shaft in the idling state. The number of revolutions and the corresponding number of revolutions of the hydraulic clutch input section or input shaft are detected by the revolution number detection mechanism, and both revolution numbers are compared and calculated by the control device to determine the idling state. As counter shaft is synchronized with the rotational speed of the corresponding hydraulic clutch, a control method for an automatic transmission, characterized in that for guiding the oil pressure to the hydraulic clutch by controlling the duty ratio of the switching cycle of the switching valve.