JPS61175360A - Memorization of piston stroke position of automatic transmission - Google Patents

Abstract

PURPOSE:To accord the rotary element stop timing with the piston transfer completion timing independently of the direction of torque by setting the piston transfer completion position as standard and controlling the piston transfer completion position on fastening with the rotary element on the basis of the standard value. CONSTITUTION:The stroke completion position of a piston 50 is represented by the partial pressure ratio (k), and the stroke completion position of the piston 50 is controlled, having the value of the partial pressure ratio at the stroke completion position of the piston 50 on speed change as standard value. Therefore, the value (k) as the max. value is memorized, and the stroke completion position of the piston 50 is controlled on the basis of the value (k), and then the reduction of the value (k) below a normal value according to the direction of the torque applied onto a kick-down drum 34 is prevented. Therefore, the rotary element stop timing and the piston transfer completion timing accord with each other without delaying the speed-change starting timing independently from the direction of the torque applied onto the rotary elements.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to the movement of a piston that operates a band brake that fixes rotating elements in an automatic transmission that automatically changes gears depending on the driving condition of a vehicle. (stroke) position storage method.

<Prior art> As one of the automatic transmissions for vehicles, hydraulic pressure is supplied to frictional engagement elements such as clutches and brakes, and when a rotational element such as an arbitrary rotating drum or gear is selected, the transmission ratio is changed ( It is known that automatic gear shifting (shifting) is performed according to the vehicle's driving condition, and pressure oil is supplied to these frictional retention elements in order to protect various devices and equipment and maintain a comfortable ride. Tatami passing is performed gradually according to predetermined characteristics consisting of the initial oil pressure supplied after the transmission of the shift start signal.

The general structure of such a conventional automatic transmission for a vehicle is shown in FIG. 2, as shown in FIG.
The crankshaft 12 is connected to the bond 1 of the Torqueon part 13.
4, the torque converter 13 has a 4-wheel drive unit 14, a turbine 15, a stator 16, and a one-way clutch 17, and the stator 16 is connected to the case 18 via the one-way clutch 17. The stator 16 is connected to the crankshaft 12 by the one-way clutch 17.
The structure allows rotation in the same direction as , but does not allow rotation in the opposite direction. The torque transmitted to the turbine 15 is transmitted by an input shaft 19 to a forward drive 4 disposed at the rear thereof.
The signal is transmitted to a gear transmission that achieves one reverse gear.

The gear transmission includes three sets of clutches 20, 21, 22, two sets of brakes 23, 24, and one one-way clutch 2.
5 and a set of Lavieyo type play gear mechanism 26. This Ravigno type play gear mechanism 26 rotatably supports a ring ear 27, a longion gear 28, a short pinion gear 29, a front sun gear 30, a rear sun gear 31, and the pinion gear 28.29t, and is rotatably fitted to the input shaft 19. The ring ear 27 is connected to the output shaft 33, the front sun gear 30 is connected to the input shaft 19 via the kickdown drum 34 and the front clutch 20, and the rear sun gear 31 is connected to the input shaft 19 via the kickdown drum 34 and the front clutch 20. The carrier 32 is connected to the input shaft 19 via the clutch 21t, and the low reverse brake 24 and one-way clutch 2 are arranged in parallel with each other.
5 to the case 18, and is connected to the input shaft 19 via a 4-speed clutch 22t disposed at the rear end of the gear transmission. In addition, the kickdown "Lam 34 is in case 18 due to 23 during the kickdown play.
The torque passing through the luck gear mechanism 26 is transferred to the output ear 35 fixed to the output shaft 33.
The signal is then transmitted to the drive shaft side of the drive wheel (not shown).

Each of the above-mentioned clutches 20 to 22 and brakes 23 and 24, which are frictional engagement elements, is each constructed of a hydraulic device equipped with a retaining piston device or a serging device. It is operated via a hydraulic control device by the pressure oil generated in a connected oil pump (not shown), and the detailed operation of its constituent elements is explained in 4I 1975.
This is the standard disclosed in Publication No. 8-46258 and the like.

First, shifting from first speed to second speed will be explained based on the hydraulic circuit shown in FIG. 3.

For example, in a 1st gear position other than the 1st gear fixed range, the front clutch 20 and 4th gear clutch 22 are disengaged, and the kickdown brake 23 and low reverse brake 24 are released. Further, the rear clutch 21 is connected and the one-way clutch 25 is functioning. In this case, upshifting to the second speed is achieved only by connecting the kickdown brake 23, and the one-way clutch 25 is rendered inoperative.

A 1-2 shift valve 37 is connected to the engagement side hydraulic chamber 36m of the kick-down servo 36 that controls the operation of the kick-down brake 23 via an oil passage 3B. The speed change control valve 39 and the shift control valve 40 are connected via oil passages 41 and 42, respectively. The kickdown drum 34 is wrapped with a 7-gun latch 23&, and the kickdown drum 34 is fixed integrally with the case side of the transmission by tightening the 11'' dodger 231&n.9.

The pair of electromagnetic valves 43 and 44 that control the operation of the shift control valve 4G in the first gear position both open the oil passages 45 and 46, so that the spool 4 at the center of the shift control valve 40
7 is displaced to the left in FIG. 3 to connect the oil passage 42t to the drain oil/-)
The spool 48 of No. 7 has been displaced to the left end in FIG. 3 and is in good condition. As a result, the oil passage 38 is drained from the 1-2 shift valve 3γ.
-) Pressure provided in the withdrawal side hydraulic chamber 36b of the kickdown circuit 36 in communication with ,
The kickdown brake 23 has been released from the kickdown drum 34. Further, of the two oil passages 51 and 52 connected to the speed change control valve 39, the duty rate of the solenoid valve 54 attached to one oil passage 51 and subjected to duty control by the electronic control device 53 is set to 100%. Therefore, the spool 55 of the speed change control valve 39 is displaced to the left in FIG. ) Connected to EX.

When upshifting from this state to 2nd speed, the electronic control device 53 operates one of the solenoid valves 43 to block the oil passage 45') due to vehicle running conditions.
is displaced to the right in FIG. −2 is fed to the shift valve 37. Therefore, 1-2 shift valve 3
The spool 48 of No. 7 is displaced to the right end in FIG.
．． 41 communicate with each other via the 1-2 shift valve 37. on the other hand,
Since the duty rate of the electromagnetic valve 54 is decreased (by the electronic control device 53), line pressure acts on the oil passage 51, 52, and due to the difference in pressure receiving area of the spool 55 of the speed change control valve 39, the spool 55 changes as shown in FIG. , is displaced to the right, and the oil passages 41 and 52 communicate with each other via the speed change control valve 39. As a result, the line pressure from the oil passage 52 is supplied to the locking side hydraulic chamber 36m of the kickdown circuit 36 through the oil passage 41.38, displacing the piston 5° to the left in Fig. 3, and kicking. down brake 23
is actuated, and the kickdown drum 34 is tightened and fixed to the RS-C1/DOB V2 kg 23 m.

Next, the shift from 3rd gear to 2nd gear will be explained based on FIG.

Front clutch 20 for downshifting from 3rd gear to 2nd gear
This is achieved by releasing the brake and connecting the kickdown brake 23. Although the front clutch 2° is omitted in the diagram,
It has a structure that engages with hydraulic pressure and returns with a spring when the hydraulic pressure is released, and connects the output shaft of the torque converter 13 (input shaft of the transmission) and the kickdown brake 2.
It is provided between the drum 34 of No. 3 and serves as a trap to connect and separate the two. The engagement side of the front clutch 20 and the disengagement side hydraulic chamber 36b of the kick-closing circulator 36 are connected by an oil passage 60], and a 2-3 speed shift valve 61 is connected to the oil passage 60 by an oil passage 62. The 2nd-3rd speed shift valve 61 is connected to the oil passage 38 by an oil passage 63, and is controlled by oil pressure from a shift control valve (not shown) so that the oil passages 62 and 63 are communicated or blocked. 64 is an oil drain passage, and 65 is an orifice provided in the oil drain passage 64.

If you look at the transition from 3rd gear to 2nd gear with the above structure,
In the third speed state, the oil pressure controlled by the shift control valve 39 is 1
- 2nd speed shift valve 37t - Kick finish unser M36
It enters the maintenance side hydraulic chamber 36m, and the oil passage 63
The oil is supplied to the disengagement side hydraulic chamber 36b1 of the first pull-down circuit 36 through the third-speed shift valve 61 to the engagement side of the front clutch 2o. When a shift signal to the second speed is issued, in the second-to-third speed shift valve 61, the oil passages 62 and 63 are shut off, and the oil passage 62 and the oil drain passage 64 are communicated with each other. Therefore, the hydraulic pressure in the disengagement side hydraulic chamber 36b of the kickdown circuit 36 and the front clutch 2° is discharged, and the piston 50t is displaced to the left in FIG. 3 to operate the kickdown brake 23.
The kickdown drum 34 is tightened and fixed to the brake band 23&, and the front clutch 20 is disengaged to achieve second speed.

As mentioned above, when shifting from 1st gear to 2nd gear, from 3rd gear to 2nd gear
In both cases, the piston 5
0 to operate the kickdown brake 23,
The kickdown drum 34 is fixed by tightening the 7'ca side. Also, although a detailed explanation has been omitted, the kickdown drum 34 also operates when shifting to 4th gear. It is fixed by the brake 23a.

When fixing the kickdown drum 34, the kickdown drum 34 is fixed in synchronization with the disengagement of related clutches so that large torque fluctuations do not occur.

That is, as shown in FIG. 3, the piston sensor 6 detects the stroke completion position of the piston 50 when shifting from 3rd speed to 2nd speed.
6, and this detected position is expressed as a partial pressure ratio that determines the starting position of reducing the hydraulic pressure to the engagement side hydraulic chamber 36m of the kickdown drum 36, and - the binding kickdown drum 3 is detected.
The supply pressure to the piston 50 is controlled in accordance with the following formula so that the rotation stop timing and the stroke completion timing of the spindle stone 50 coincide with each other.

Duty rate corrected with one-time feedback Note that α is a constant.

In the above equation, k is stored as the output value of the piston sensor 66 at the piston 500 stroke completion position in the 2nd and 4th gears that stop the rotation of the kickdown drum 34, and each time the rotation of the kickdown drum 34 is reached (1st gear → 2nd speed, 3rd speed → 2nd speed,
Feedback control is performed by replacing the value with the latest value at each end of the shift from 3rd gear to 4th gear.

<Problems to be Solved by the Invention> However, even if the kickdown drum 34 is tightened in the same manner, the direction of the torque applied to the kickdown drum 34 is reversed during acceleration and during non-braking, and therefore, the band The torque of pressing the brake 23a also differs. (When the band brake 23a is pressed, torque is applied in the self-locking direction during 2nd speed acceleration and 4th speed engine braking, and in the opposite direction during 2nd speed engine braking and 4th speed acceleration.

) / When the torque of the kund brake 23a is different, the piston 500 stroke completion position is different, and the value of k2 will fluctuate.
) formula, the corrected duty rate becomes inaccurate, and 3
Kickdown drum 3 during shift control from speed to second speed
It becomes impossible to make the 40 rotation stop timing coincide with the piston 500 stroke completion timing.

Also, when shifting from 1st to 2nd speed and from 3rd to 4th speed, which is controlled using k, when the Nokun F brake 23m is pressed, the torque is applied in the anti-self-binding direction, so that F)kAX is less than the normal value. In this case, as shown by the rutted lines in Figure 5, the period from when the shift command is issued to when the shift starts, by lowering the command oil pressure and reducing the moving speed of the piston 50, is long from Δt to Δta.
The time to start shifting is also delayed accordingly.

The present invention has been made in view of the above-mentioned circumstances, and is a piston for an automatic transmission capable of matching the rotational element stop timing and the piston movement completion timing without delaying the shift start timing regardless of the direction of the torque applied to the rotational element. The purpose of the present invention is to provide a safe location storage method.

Means for Solving the Problems〉 The method of the present invention for achieving the above object includes a rotating element,
a band brake that can fix the rotating element; a piston that can be moved by hydraulic pressure to tighten the band brake when fixing the rotating element; and a hydraulic drive that supplies oil to the piston to move the core stone. and a piston movement position detection device for detecting the movement position of the piston, the hydraulic pressure supplied from the hydraulic drive source to the piston and the magnitude of the torque applied to the rotating element are within a predetermined range. A piston stroke position memory for an automatic transmission characterized in that the piston movement completion position at the time of the rotational element engagement is set as a reference value, and the piston movement completion position at the time of the rotational element engagement is controlled based on the reference value. It lies in the method.

<Example> An embodiment of the piston stroke position storage method according to the present invention will be described with reference to FIG. 1, which is a flowchart thereof, and FIGS. 3 and 4.5, which show the hydraulic circuit of the transmission described above. explain.

If the stroke completion position of the male stone 50 is expressed as a partial pressure ratio, this value is the kickdown drum 34.
When the torque is applied in the self-binding direction, the torque is larger when it is applied in the anti-self-binding direction, and even when the torque is applied in the same self-binding direction, the 4th gear engine is faster when accelerating in 2nd gear. Since the torque applied to the kickdown drum 34 is large during braking, the value of is also large.

Based on the above, in this embodiment, the time t within a predetermined range is defined as the time of shifting from 1st gear to 2nd gear, and at this time,
The value is taken as the basic value of the piston 500 stroke completion position. Note that the time within the predetermined range is not necessarily limited to the time of shifting from 1st to 2nd speed. explain.

After connecting the power cord, reset the striped flag and determine whether the ignition switch is on. When the ignition switch is ON, it is determined whether or not the flag k is set, and if the flag k is not set, the first shift from 1st gear to 2nd gear after connecting the When changing gears, set timer 'i S&C. If 5 seconds time up is judged, piston 500
Detect the partial pressure ratio applied to the shift start position, and calculate the partial pressure ratio 4 for the first shift from 1st to 2nd speed after connecting the battery as + 35.86 (to). Then, the calculated value of 9 is stored, and the value of and is set to 7 lags. Next, it is determined whether a shift command has been issued, and if a shift command has been issued, it is determined whether the shift command is for shifting from 1st speed to 2nd speed. When it is determined that the shift is from 1st speed to 2nd speed, the throttle opening θtt is detected, and it is determined whether or not this throttle opening θt is 50- or more. When it is determined that the throttle opening degree θt is 50% or more, it is determined whether the shift from 1st to 2nd gear has been completed (whether the supply pressure to the kickdownser M36 has reached the maximum), and the shift is completed. If it is determined that the process has ended, the timer t-0 is set to one value τ.

When a time-up of 0.1 seconds is determined, the partial pressure ratio kit- at the position of the piston 50 at that time is detected and replaced as the value of this waste tk*, and the value of is stored in the replacement field.

This is remembered in nine! The stroke completion position of the piston 50 is controlled by using the value of the partial pressure ratio at the stroke completion position of the piston 50 to be applied during shifting from 3rd speed to 2nd speed, from 3rd speed to 4th speed, and from 1st speed to 2nd speed. Then open the throttle [5G
% or more and the partial pressure ratio at every 500 stroke positions of the piston every 0.1 seconds after shifting from 1st to 2nd speed (point A) is replaced as the latest value to control the stroke completion position of the piston 50. do.

Therefore, instead of storing the maximum value of - in the method described above and controlling the piston 500 stroke completion position based on this value, the value of is determined by the direction of the torque applied to the kickdown drum 34. If the value is below the normal value, there will be no sharpness, and the section where the stroke speed of the piston 5.0 is reduced when shifting from 1st to 2nd gear and from 3rd to 4th gear is long and last? There is no longer a delay in the shift start timing when shifting from 3rd to 4th gear. Also, when shifting from 3rd to 2nd gear, By using the value memorized by the method described above, the negative value will remain constant regardless of the pressing torque of the band brake 23m. This makes it possible to always match them.

<Effects of the Invention> By controlling the piston stroke completion position using the piston stroke position storage method of the automatic transmission of the present invention,
Regardless of the direction of the torque applied to the rotating element, the rotating element stop timing and the piston movement completion timing can be made to coincide without delaying the shift start timing.

[Brief explanation of the drawing]

FIG. 1 is a flowchart according to an embodiment of the present invention, and FIG.
The figure is a mechanical conceptual diagram showing the structure of an automatic transmission, Figure 3 is a configuration diagram of an example of the hydraulic system of the transmission that is the object of control of the present invention, Figure 4 is an explanatory diagram of the piston sensor, and Figure 5 (a ) (
b) (C) is a diagram showing changes in electrical command oil pressure, male stone sensor output, and output shaft torque with respect to time, taking as an example a shift from 1st speed to 2nd speed. In the drawing, 20 is the front clutch, 23 is the kickdown brake, 23 is the front and rear end field, 34 is the kickdown drum, 36 is the kickdowner, 37 is the 1st-2nd speed shift valve, and 39 is the transmission. 50 is a piston, 61 is a 2-3 speed shift valve, and 66 is a piston sensor. Patent Applicant Mitsubishi Motors Corporation Representative Patent Attorney Shibu Mitsuishi (and 1 other person) Figure 1 Procedural Amendment (Method) June 9, 1985

Claims (1)

[Claims] A rotating element, a band brake capable of fixing the rotating element, a piston capable of moving by hydraulic pressure to engage the band brake when fixing the rotating element, and supplying oil to the piston in order to move the piston. and a piston movement position detection device that detects the movement position of the piston, the hydraulic pressure supplied from the hydraulic drive source to the piston and the magnitude of the torque applied to the rotating element are within a predetermined range. The piston stroke of an automatic transmission characterized in that the piston movement completion position when the rotating element is engaged is set as a reference value, and the piston movement completion position when the rotating element is engaged is controlled based on the reference value. Location memory method.