JP3195404B2 - Automatic transmission tie-up determination device and control device thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tie-up judging device for an automatic transmission for executing a clutch-to-clutch shift operation relating to two friction engagement devices and a control device therefor.

[0002]

2. Description of the Related Art When performing a specific shift of an automatic transmission, it is often necessary to simultaneously engage and disengage two frictional engagement devices (including a clutch in a broad sense; a brake) ( So-called clutch-to-clutch shifting).
In this case, if the engagement and disengagement of the friction engagement devices are not properly synchronized, the output shaft torque drops or the engine blows up.

For this reason, conventionally, when such control is performed, generally, a one-way clutch having a function substantially equivalent to the function of one friction engagement device is provided to prevent such a problem from occurring. Was considered.

However, the method of synchronizing the respective friction engagement devices by using the one-way clutch as described above increases the cost due to the provision of the one-way clutch,
In addition, problems such as an increase in weight and occupation of a storage space occur.

In view of these points, in recent years, with the improvement of various sensor technologies and the improvement of electronic control technology of hydraulic control devices, it has been proposed to directly execute "clutch-to-clutch shift" without using a one-way clutch. Attempts to reinvigorate again.

[0006] However, the clutch-to-clutch shift needs to be optimized in a so-called torque phase region in which the rotation speed of the rotary member is generally not changed yet. Even with recent electronically controlled automatic transmissions that include an electric actuator and can control the above-mentioned change mode by a computer, it is difficult to recognize that the mode is inappropriate, so that the correction cannot be performed well. is the current situation.

In JP-A-2-37128,
In view of such a current situation, the engine rotation speed during the shift operation is monitored, and when the engine rotation speed is increased (when the engine rotation speed is increased), each friction engagement device is in an underlap state. (The engagement is relatively delayed with respect to the release), while the friction engagement devices are in the overlap state when the engine rotation speed is reduced (with respect to the release). A state in which the engagement is relatively premature: the state is hereinafter referred to as a tie-up state) is disclosed.

[0008]

However, in such a judging method, although the engine blowing can be detected relatively easily, the tie-up judgment is not made.
The problem that only a very long (or strong) tie-up can be determined, that is, the accuracy of the determination is extremely poor, and thus a sufficiently effective hydraulic pressure correction control cannot be executed still remains.

As described above, if the engagement side is relatively early with respect to the disengagement side of the friction engagement device (when a tie-up occurs), the output shaft torque drops sharply, and a strong shift shock occurs. In some cases, an extremely large load torque is applied to each member of the automatic transmission, which may cause a decrease in durability.

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and tie-up in a clutch-to-clutch shift is determined early and accurately, and as a result, effective hydraulic pressure correction control is executed. Accordingly, it is an object of the present invention to reduce shift shock and prevent an excessive load torque from being applied to each member of the automatic transmission, thereby further improving durability.

[0011]

SUMMARY OF THE INVENTION As shown in FIG. 1A, the present invention relates to a tie-up determination device for an automatic transmission that executes a clutch-to-clutch shift according to two friction engagement devices. Means for detecting the acceleration of the rotating member, means for detecting the engine blowing from the relationship between the gear ratio and the rotating speed of the rotating member, and wherein the amount of decrease in the acceleration of the rotating member is equal to or more than a predetermined value and the engine blowing is not detected. This problem has been solved by providing means for determining that a tie-up has occurred at times.

It is to be noted that the automatic transmission has means for detecting an output shaft rotation speed, and means for detecting an input shaft rotation speed.
It is even better if the detection of the engine blowing is made by comparing the input shaft rotation speed with the product of the gear ratio and the output shaft rotation speed.

Further, a hydraulic control device for controlling the bearing torque of the two friction engagement devices is provided, and when the tie-up determination device determines that tie-up has occurred, each of the frictional engagement devices is controlled. The hydraulic pressure may be corrected so that the overlapping of the receiving torques of the combined devices is reduced (claim 3).

Further, as shown in FIG. 1B, the present invention relates to a tie-up judging device for an automatic transmission for executing a clutch-to-clutch shift of two friction engagement devices. , Means for detecting engine blowing from the relationship between the gear ratio and the rotation speed of the rotating member, means for determining when the torque phase starts and when the inertia phase opens, and when the torque phase starts and when the inertia phase opens. Means for determining that a tie-up has occurred when the difference between the accelerations of the rotating members is equal to or more than a predetermined value and engine blowing is not detected. 4).

[0015] In this case as well, there are provided means for detecting the output shaft rotation speed of the automatic transmission and means for detecting the input shaft rotation speed, and the detection of the engine blowing is performed based on the input shaft rotation speed and the gear ratio. It is preferable to make the comparison with the product of the output shaft rotation speed and the output shaft rotation speed (claim 5).

Further, a hydraulic control device for controlling the bearing torque of the two friction engagement devices is provided, and when the tie-up determination device determines that a tie-up has occurred, each of the frictional engagement devices is controlled. The hydraulic pressure may be corrected so that the overlap of the receiving torques of the combined devices is reduced (claim 6).

[0017]

According to the present invention, at the time of tie-up or underlap, the output shaft torque falls as a result, and this can be detected early as a change in the acceleration of the rotating member (change rate (differential value) of the rotating speed of the rotating member). In the torque phase, the relationship between the rotational speeds of the rotary members is defined by the gear ratio (since the rotational speed has not yet changed for shifting), and the detection of the underlap (engine blowing) itself is relatively difficult. Focusing on the easiness, the occurrence of a tie-up is determined by comprehensively combining them.

That is, in the clutch-to-clutch shift, the acceleration of the rotating member decreases both when the engine blows and when the tie-up occurs. Therefore, when the reduction amount of the acceleration of the rotating member is equal to or more than the predetermined value and the engine blowing is not detected, it can be determined that the tie-up has occurred. Engine blowing can be determined relatively early and accurately using conventional methods.
According to the present invention, as a result, both engine blowing and tie-up can be determined early and accurately.

Further, in order to more accurately execute the determination of the tie-up, the present invention further provides that the difference between the acceleration of the rotating member at the start of the torque phase and the opening of the inertia phase is equal to or greater than a predetermined value, and the engine blows. It is proposed to determine that a tie-up has occurred when not detected.

As a result, a more reliable tie-up determination can be performed than the above-described determination.
It is not only a condition that the amount of decrease is equal to or more than a predetermined value, but also a condition that a difference in acceleration of the rotating member between the start of the torque phase and the opening of the inertia phase is equal to or more than the predetermined value. Resistance). When only the absolute value of acceleration is used as a reference, for example, a difference may occur between an uphill and a downhill.

It should be noted that, regardless of which determination method is used to determine tie-up, the determination of engine blowing may be made by comparing the input shaft rotation speed with the product of the gear ratio and the output shaft rotation speed.

Further, when it is determined that a tie-up has occurred in this way, if the hydraulic pressure is corrected so that the overlapping of the torques of the friction engagement devices is reduced, the tie-up determination can be made quickly and promptly. As a result, better shifting characteristics can be obtained.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, a specific example of an automatic transmission to which the present invention is applied is shown by a skeleton in FIG. The automatic transmission 2 includes a torque converter 111, an auxiliary transmission unit 112, and a main transmission unit 113.

The torque converter 111 has a lock-up clutch 124. The lock-up clutch 124 is provided between a front cover 127 integrated with the pump impeller 126 and a member (hub) 129 integrally mounted with the turbine runner 128.

The crankshaft (not shown) of the engine 1 is connected to a front cover 127. The input shaft 130 connected to the turbine runner 128 is connected to the overdrive planetary gear mechanism 13
And one carrier 132.

In the planetary gear mechanism 131, a clutch C0 and a one-way clutch F0 are provided between the carrier 132 and the sun gear 133. The one-way clutch F0 is engaged when the sun gear 133 rotates forward relative to the carrier 132 (rotation in the rotation direction of the input shaft 130).

On the other hand, a brake B0 for selectively stopping the rotation of the sun gear 133 is provided. Further, a ring gear 134 which is an output element of the auxiliary transmission section 112 is connected to an intermediate shaft 135 which is an input element of the main transmission section 113.

When the clutch C0 or the one-way clutch F0 is engaged, the auxiliary transmission portion 112
Since the whole of the shaft 31 rotates integrally, the intermediate shaft 135 is rotated.
Rotate at the same speed as the input shaft 130. When the brake B0 is engaged and the rotation of the sun gear 133 is stopped, the ring gear 134 is rotated forward with the speed increased with respect to the input shaft 130. That is, the subtransmission unit 112 can set high-low two-stage switching.

The main transmission section 113 has three sets of planetary gear mechanisms 140, 150 and 160, and these gear mechanisms 140, 150 and 160 are connected as follows.

That is, the sun gear 141 of the first planetary gear mechanism 140 and the sun gear 151 of the second planetary gear mechanism 150 are integrally connected to each other, and the ring gear 143 of the first planetary gear mechanism 140 and the sun gear 151 of the second planetary gear mechanism 150 are connected together. Carrier 1
52 and the carrier 162 of the third planetary gear mechanism 160 are connected. The output shaft 170 is connected to the carrier 162 of the third planetary gear mechanism 160. Further, a ring gear 153 of the second planetary gear mechanism 150 is connected to a sun gear 161 of the third planetary gear mechanism 160.

In the gear train of the main transmission portion 113, one reverse speed and four forward speeds can be set, and a clutch and a brake for that purpose are provided as follows.

That is, the ring gear 153 of the second planetary gear mechanism 150 and the sun gear 161 of the third planetary gear mechanism 160
A clutch C1 is provided between the intermediate shaft 135 and the sun gear 141 of the first planetary gear mechanism 140 and a sun gear 151 of the second planetary gear mechanism 150.

A brake B1 for stopping rotation of the sun gears 141 and 151 of the first planetary gear mechanism 140 and the second planetary gear mechanism 150 is provided. In addition, these sun gears 1
A one-way clutch F1 and a brake B2 are arranged in series between 41, 151 and the casing 171.
The one-way clutch F1 is engaged when the sun gears 141 and 151 try to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 135).

Carrier 142 of first planetary gear mechanism 140
A brake B3 is provided between the motor and the casing 171. Also, the ring gear 16 of the third planetary gear mechanism 160
The brake B4 and the one-way clutch F2 are arranged in parallel between the casing 171 and the brake B4 as elements for stopping the rotation of the motor 3. The one-way clutch F2 is adapted to be engaged when the ring gear 163 attempts to rotate in the reverse direction.

In the automatic transmission 2 described above, the auxiliary transmission portion 112
Can perform high-low two-stage switching, and the main transmission unit 113 can perform four-stage shifting on the forward side, so that a total of one reverse stage and eight forward stages can be performed. it can. FIG. 3 shows an engagement operation table of each clutch and brake for setting these shift speeds. In FIG. 3, a circle indicates an engaged state, a black circle indicates an engaged state during engine braking, and a blank indicates a released state.

However, in this embodiment, only the first, second, third, fourth and fifth gears are actually used.

As can be seen from this figure, the shift between the second speed and the third speed is a clutch-to-clutch shift of the brake B2 and the brake B3.

The engagement and disengagement of each clutch and brake are executed by driving an electromagnetic valve or a linear solenoid in the hydraulic control device 20 based on a command from the computer 30. The computer 30 receives signals from various sensor groups 40, for example, a vehicle speed signal (a signal of an output shaft rotation speed N0) from a vehicle speed sensor 41, a throttle opening signal (an accelerator opening signal) from a throttle sensor 42, and a pattern select switch. A basic signal such as a pattern select signal from the driver 43 (a selection signal for power-oriented driving, fuel-efficient driving, etc., selected by the driver), a shift position signal from a shift position switch 44, and a foot brake signal from a brake switch 45. In addition, a rotation speed signal of the clutch C0 from the C0 sensor 46 is input. Since the rotational speed of the clutch C0 is the same as the turbine rotational speed Nt (the input shaft rotational speed of the automatic transmission) Nt at the time of shifting between the second speed stage and the third speed stage, the rotational speed of the clutch C0 is detected. The turbine rotation speed Nt can be grasped.

Since various methods are conventionally known for the hydraulic control itself when shifting the brakes B2 and B3, a detailed description thereof will be omitted here. However, basically, the brakes B2 and B3 are basically The back pressure of the accumulator provided in the oil passage may be controlled by an accumulator control valve and a linear solenoid for controlling the same. Since the control on the release side is performed to reduce the hydraulic pressure, the drain amount of the hydraulic circuit may be controlled by a linear solenoid.

Next, FIG. 4 shows a control flow executed by the computer 30.

In this embodiment, from the second gear to the third gear
The present invention is applied at the time of upshifting to a gear.

As is apparent from FIG. 3, the upshift from the second speed to the third speed is a clutch-to-clutch shift by releasing the brake B3 and engaging the brake B2. In this embodiment, the engagement of the brake B2 is executed at a predetermined speed, so that the tie-up,
Alternatively, when it is determined that the engine is blowing, the brake B3
The tie-up or engine blowing is eliminated by controlling the release hydraulic pressure of the engine. Brake B
The release hydraulic pressure of No. 3 increases when the duty ratio Dsln of a linear solenoid (not shown) increases, and decreases when the duty ratio Dsln decreases.

First, in step 201, it is determined whether an upshift from the second speed to the third speed occurs. This determination is made by determining from the map of the throttle opening and the vehicle speed whether or not the current running state has crossed the upshift point from the second gear to the third gear. When there is no upshift determination from the second speed to the third speed, the control is reset as it is, and the control according to the present invention is not particularly executed.

In step 202, a shift output is output based on this shift determination. More specifically, the circuit is configured such that a shift valve (not shown) is switched by an electromagnetic valve driven by a command from the computer 30, and the brake B3 is basically released and the brake B2 is engaged. . Thus, the movement of the oil is started. In this embodiment, the movement of the oil, that is, the decrease of the hydraulic pressure of the brake B3 and the brake B2
This is to appropriately control the relative transient characteristic of the increase in the hydraulic pressure.

That is, in step 203, first, the differential value of the output shaft rotation speed N0 (the acceleration of the output shaft rotation) dN
0 is calculated. In step 204, the current differential value d
It is determined whether or not N0 (i) is smaller than a value obtained by subtracting a predetermined value ΔdN0 from the previous differential value dN0 (i-1). This determination is for determining the start of the torque phase or the engine blowing. In either case, the differential value of the output shaft rotation speed drops, so that this equation holds.

In step 205, the turbine rotation speed (= rotation speed of the clutch C0) Nt is changed to the output shaft rotation speed N
It is determined whether the gear ratio on the low gear side, that is, the gear ratio il of the second speed stage in this case, is greater than a value obtained by adding a predetermined value ΔN1 to 0. With this determination, it can be confirmed whether or not engine blowing has occurred.

That is, in the case of an upshift from the second speed to the third speed, the turbine rotational speed Nt is changed from N0 × il to N0.
× ih (ih is a high gear side, that is, a gear ratio of the third speed). Therefore, the turbine rotation speed Nt becomes N0
Xil plus a predetermined value ΔN1 would not be possible if the gearshift had proceeded normally,
Accordingly, when this is true, it can be determined that the engine is being blown due to the release of the brake B3 progressing relatively faster than the engagement of the brake B2.

If it is determined in step 205 that the engine has blown, the process proceeds to step 214, where the duty ratio Dslu of the linear solenoid is corrected to a value increased by ΔDslu, and the tie-up direction, that is, the release of the brake B3 is delayed. Oil pressure is corrected in the direction in which the engine blows, thereby suppressing engine blowing.

On the other hand, if no engine blowing is detected in step 205, the routine proceeds to step 206, where the differential value dN0 (i) of the output shaft rotational speed N0, that is, the differential value when the torque phase starts, Is stored as dN0 A1.

In step 207, the output shaft rotation speed N
The calculation of the derivative dN0 of 0 is continued. Step 2
In step 08, the occurrence of engine blowing is continuously checked. If the engine blowing is detected, the routine immediately proceeds to step 214, where the hydraulic pressure is corrected in the tie-up direction.

In step 209, the differential value dN0 (k) of the current output shaft rotation speed N0 is changed to the previous value dN0 (k).
It is determined whether the value is larger than a value obtained by adding a predetermined value dN0 to -1). Thus, the start of the inertia phase can be detected. This is because, when the torque phase is switched to the inertia phase, the differential value dN0 of the output shaft rotation speed N0 is inverted (falling down → rising).

Steps 207 to 209 are repeated until the inertia phase is detected.
If the engine blowing is detected in step 8,
Go to 4.

When the inertia phase is detected, the flow proceeds to step 210, where the differential value immediately before the inertia phase is determined to be started, that is, the differential value dN0 (k-1) at the start of the inertia phase. Is recorded as dN0 A2, and in step 211, the differential value dN at the start of the torque phase
0 Differential value when inertia phase is open from A1 dN0 A2
Is calculated.

In step 212, it is determined whether or not dN0A is larger than a predetermined value dN0AS. When it is determined that the tie-up has occurred, it is determined that a tie-up has occurred. In step 213, the duty ratio D of the linear solenoid
The hydraulic pressure is corrected so that slu is reduced by ΔDslu. As a result, the tie-up is eliminated.

In this embodiment, the start of the torque phase (or the decrease in the differential value due to the engine blowing) is detected early in step 204 by the slight decrease in the differential value dN0 of the output shaft rotational speed N0. Regarding the specific determination of the tie-up, the difference between the differential value at the start of the torque phase and the differential value at the start of the inertia phase is equal to or more than a predetermined value, and furthermore, it is determined that the engine has not blown during that time. However, when tie-up is determined by a simpler flow, ΔdN in step 204
By setting the value of 0 to a larger and more appropriate value, it is possible to check the amount of decrease in the differential value of the output shaft rotational speed, and to multiply this by the fact that the engine has not been blown up. It is also possible to configure so as to detect a tie-up by matching.

In the above embodiment, the occurrence of engine blowing is determined whether the turbine rotation speed Nt is greater than the output shaft rotation speed N0 multiplied by the low gear side gear ratio il plus a predetermined value ΔN1. Although it is determined based on the above, the engine blowing is detected early and surely. However, there are several other methods for detecting the engine blowing itself, and therefore, it is not always necessary to use this method. Good.

Next, FIG. 5 shows a shift transient characteristic when this control flow is executed.

The broken line in the figure shows the characteristics when tie-up occurs in the conventional control, and the solid line shows the characteristics when correction is made when tie-up is detected in the above control flow.

The differential value (acceleration of rotation of the output shaft) dN0 of the output shaft rotation speed N0 shows a characteristic substantially similar to the output shaft torque T0. In the case of the broken line, the difference dN0 AdN0 AS between the torque phase and the differential value at the start of the inertia phase increases,
(Because engine blowing cannot be confirmed at that time), tie-up can be determined. In this case, the duty ratio Dslu of the linear solenoid for controlling the engagement pressure of the brake B3 is corrected in the direction of decreasing the hydraulic pressure of the brake B3, so that good shift characteristics (solid line) can be obtained. Things.

In this embodiment, since the engine blowing is always corrected, the circuit B tends to release the brake B3 quickly, that is, the circuit is apt to cause the engine blowing. When the shift is advanced while appropriately correcting, it is not necessary to increase the correction amount when the tie-up is determined.

Needless to say, the present invention can be applied to real-time feedback control. However, based on this feedback correction mode, when the initial setting of the release pressure of the brake B3 in the next gear shift is developed, The shift characteristics can be converged in a better direction.

[0063]

As described above, according to the present invention, tie-up (and engine blowing) can be determined early and reliably, so that the clutch-to-clutch shift can be more appropriately controlled. Is obtained.

[Brief description of the drawings]

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

FIG. 2 is a block diagram schematically showing an automatic transmission for a vehicle to which the present invention is applied;

FIG. 3 is a diagram showing an operation state of each friction engagement device of the automatic transmission.

FIG. 4 is a flowchart showing a control flow executed in a computer for controlling the automatic transmission.

FIG. 5 is a diagram showing shift transient characteristics when the control flow is executed.

[Explanation of symbols]

 B2: brake, B3: brake, Nt: turbine rotation speed (input shaft rotation speed), 20: hydraulic control device, 30: computer, 40: various sensor units.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kunihiro Iwazuki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Automobile Co., Ltd. (72) Inventor Mamoru Niimi 10 Takane Fujii Town, Anjo City, Aichi Prefecture Aisin Ai・ Within AW Co., Ltd. (72) Inventor Masahiko Ando 10th Takane, Fujii-machi, Anjo, Aichi Prefecture Inside AW Co., Ltd.・ Inside of WWW. (56) References JP-A-3-186651 (JP, A) JP-A-2-256959 (JP, A) JP-A-3-84260 (JP, A) JP-A-3-79857 ( JP, A) JP-A-5-231511 (JP, A) JP-A-5-87228 (JP, A) JP-A-2-37128 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , (DB name) F16H 59 / 00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (6)

(57) [Claims] 1. A tie-up determination device for an automatic transmission for executing clutch-to-clutch shifting according to two friction engagement devices, comprising: means for detecting acceleration of a rotating member; Means for detecting engine blowing from the relationship, and means for determining that tie-up has occurred when the amount of decrease in acceleration of the rotating member is equal to or greater than a predetermined value and engine blowing is not detected. Automatic transmission tie-up determination device. 2. An automatic transmission according to claim 1, further comprising: means for detecting an output shaft rotation speed of the automatic transmission; and means for detecting an input shaft rotation speed. A tie-up determination device for an automatic transmission, wherein the tie-up determination is performed by comparing the product of the ratio and the output shaft rotation speed. 3. A hydraulic control device for controlling a bearing torque of the two frictional engagement devices, wherein each of the frictional engagement devices is determined when the tie-up determination device determines that a tie-up has occurred. A tie-up control device for an automatic transmission, wherein the hydraulic pressure is corrected so that the overlapping of the receiving torques of the combined devices is reduced. 4. A tie-up judging device for an automatic transmission which executes clutch-to-clutch shifting according to two frictional engagement devices, comprising: means for detecting acceleration of a rotating member; Means for detecting the engine blowing from the relationship, means for detecting the start of the torque phase and the opening of the inertia phase, the difference between the acceleration of the rotating member at the start of the torque phase and the opening of the inertia phase being equal to or greater than a predetermined value, and Means for determining that tie-up has occurred when is not detected, the tie-up determination device for an automatic transmission, comprising: 5. The automatic transmission according to claim 4, further comprising: means for detecting an output shaft rotation speed of the automatic transmission; and means for detecting an input shaft rotation speed. A tie-up determination device for an automatic transmission, wherein the tie-up determination is performed by comparing the product of the ratio and the output shaft rotation speed. 6. A hydraulic control device for controlling a bearing torque of the two frictional engagement devices, wherein each of the frictional engagement devices is determined when a tie-up is determined by the tie-up determination device according to claim 4. A tie-up control device for an automatic transmission, wherein the hydraulic pressure is corrected so that the overlapping of the receiving torques of the combined devices is reduced.