JP3313767B2 - Shock reduction device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reducing a shock of an automatic transmission mounted on a vehicle, and more specifically, a forward drive driven by an engine output from a reverse drive state in which the vehicle travels by inertia. TECHNICAL FIELD The present invention relates to a device for reducing a one-way clutch engagement shock that occurs when shifting to a state.

[0002]

2. Description of the Related Art Generally, automatic transmissions mounted on vehicles are
The torque converter and the speed change mechanism are combined, and the power transmission path by the speed change mechanism is switched by selective engagement of a plurality of friction elements, so that the speed is automatically changed according to the operation state. In some types of automatic transmissions, it may be necessary to simultaneously perform the releasing operation and the engaging operation of a plurality of friction elements when switching the power transmission path. In this case, if the timing at which the other friction element is engaged is too early with respect to the release operation of one friction element, a so-called double lock state occurs, causing a large shock, and conversely, the timing at which the other friction element is engaged. If the speed is too slow, the vehicle temporarily enters a neutral state, and particularly in a normal driving state in which power is input to the input side of the transmission mechanism, which causes an idling of the engine rotation.
Therefore, in order to avoid the complexity of the control due to the overlapping operation of the friction elements, it is customary to use a one-way clutch as much as possible to replace the friction elements.

[0003]

In this type of automatic transmission, a one-way clutch is provided in a reverse driving state in which a driving force is input to the output side of a transmission mechanism, such as the first and second speeds of a D range. In some cases, the speed at which the vehicle idles is set. For example, when the accelerator pedal is depressed to compensate for acceleration or a decrease in vehicle speed during traveling in the reverse drive state at such a shift speed, a shock occurs when the one-way clutch in the idling state is locked. Shock is particularly noticeable at low speeds where the reduction ratio is large.

According to the present invention, a one-way clutch forming a power transmission path of a speed change mechanism locks when power is input from an input side of the speed change mechanism, and idles when power is input from an output side of the mechanism. The above-mentioned problem is solved in the automatic transmission in which the gear stage to be set is set, and the one-way clutch is locked when the driving state of the transmission mechanism shifts from the reverse driving state to the normal driving state during traveling at the above-mentioned gear stage. The purpose of the present invention is to reduce the shock generated by the operation.

[0005]

That is, the invention of claim 1 of the present application (hereinafter referred to as a first invention) is a power transmission system for a transmission mechanism.
A one-way clutch that forms a transmission path is provided.
Power from the input side of the transmission mechanism
Locks when input, power is output from the output side of the mechanism
Automatic gear shifting with a gear position that idles when input
One-way clutch in the power transmission path
Rotation speed difference detection means for detecting a rotation speed difference before and after
The driving state of the transmission mechanism is not
Engine output from the reverse drive state driven by the inertia of the vehicle
The above-mentioned difference in the number of rotations
Rotational speed difference detected by the detection means decreases to the set value
Engine output to reduce engine output when
Means for the automatic transmission
It relates to a reduction device.

The invention of claim 2 of the present application (hereinafter referred to as “second
The invention forms a power transmission path for a transmission mechanism.
One-way clutch is provided.
Locks when power is input from the input side of the transmission mechanism.
And idle when power is input from the output side of the mechanism.
Power transmission in automatic transmissions
Detect the difference in rotational speed before and after the one-way clutch
Output speed difference detecting means, and
And the driving state of the transmission mechanism is driven by the inertia of the vehicle.
Forward drive state driven by engine output from reverse drive state
Detected by the rotation speed difference detection means
When the difference in the number of revolutions
Engine output reduction means to reduce power and reverse drive status
One-way class when the transition to
The larger the difference between the rotation speeds before and after the
And a setting value changing means for changing the setting value.
The present invention relates to a shock reduction device for a dynamic transmission.

[0007]

[0008] Japanese Patent Publication No. 2-20817 discloses that
Although a configuration for reducing the engine output is shown as a countermeasure for a shock in an automatic transmission, this is performed for the purpose of alleviating a shock at the time of shifting gears. The problem to be solved is completely different from that of the present invention which aims at the reduction of the amount.

[0009]

According to the present invention, the following effects can be obtained.

That is, in any of the first and second aspects of the present invention, when the idle one-way clutch is locked, the engine output is reduced, so that the shock at that time is greatly reduced. become.

[0011] Since so as to detect the rotational speed difference between the front and rear of the one-way clutch in the dynamic force transmission path, so that the transition from the reverse drive state to the forward drive state is determined reliably, not The shock can be appropriately reduced without lowering the engine output as necessary.

In particular, according to the second aspect, the set value for starting the reduction of the engine output increases as the difference between the rotational speeds before and after the one-way clutch at the time when the transition from the reverse driving state to the normal driving state starts is increased. Since the direction is changed, when the one-way clutch is locked, the engine output is surely reduced, and the shock can be surely reduced.

[0013]

As shown in FIG. 1, in a vehicle 1 to which the present invention is applied, left and right front wheels 2a and 2b are used as driving wheels, and an output torque of an engine 3 is transmitted from an automatic transmission 4 to a differential gear. 5 and the front wheels 2a, 2 via the left and right drive shafts 6a, 6b.
b. The engine 3 is provided with spark plugs 7... 7 for each cylinder.

On the other hand, as shown in FIG. 2, the automatic transmission has a torque converter 20 connected to the output shaft 8 of the engine, a transmission mechanism 30 to which the output torque (turbine torque) is input, and A plurality of friction elements 41 to 41 such as clutches and brakes for switching the power transmission path of the mechanism 30
46, one-way clutches 51 and 52, and a hydraulic control unit 60 for selectively changing the gear ratio (gear) of the transmission mechanism 30 by selectively supplying line pressure to the friction elements 41 to 46. Each range of D, S , L, and R as a driving range, 1st to 4th speed in D range,
The first to third speeds in the S range and the first and second speeds in the L range are obtained.

The torque converter 20 includes a pump 2 fixed in a case 21 connected to the engine output shaft 8.
2 and the pump 22
A turbine 23 driven between the pump 22 and the turbine 23 by a hydraulic fluid, and a stator 25 supported by the transmission case 9 via the one-way clutch 24 to increase the torque. A lock-up clutch 26 is provided between the case 21 and the turbine 23 and directly connects the engine output shaft 8 and the turbine 23 via the case 21. The rotation of the turbine 23 is output to the transmission mechanism 30 via the turbine shaft 27. Here, a pump shaft 10 penetrating through the inside of the turbine shaft 27 is connected to the engine output shaft 8, and the oil pump 11 provided at the rear end of the transmission is driven by the shaft 10.

On the other hand, the transmission mechanism 30 is constituted by a Ravigneaux type planetary gear device,
A small-diameter small sun gear 31 loosely fitted thereon, and a turbine shaft 27
A large-diameter large sun gear 32 loosely fitted thereon, a plurality of short pinion gears 33 meshed with the small sun gear 31, and a short half of the short pinion gear 33
A long pinion gear 34, the latter half of which meshes with the large sun gear 32, a carrier 35 rotatably supporting the long pinion gear 34 and the short pinion gear 33, and a ring gear 36 meshed with the long pinion gear 34. It is configured.

A forward clutch 41 and a first one-way clutch 51 are provided in series between the turbine shaft 27 and the small sun gear 31, and a coast clutch 42 is provided in parallel with the clutches 41 and 51. A 3-4 clutch 43 is interposed between the turbine shaft 27 and the carrier 35, and the turbine shaft 27 and the large sun gear 3
2, a reverse clutch 44 is interposed. Further, between the large sun gear 32 and the reverse clutch 44, a 2-4 brake 45 which is a band brake for fixing the large sun gear 32 is provided, and between the carrier 35 and the transmission case 9 is provided. , A second one-way clutch 52 for receiving the reaction force of the carrier 35
And a low reverse brake 46 for fixing the carrier 35
And are provided in parallel. And the ring gear 3
6 is connected to the output gear 12, and rotation is transmitted from the output gear 12 to the left and right front wheels 2 a and 2 b via the differential device 5.

Table 1 summarizes the relationship between the operating state of the friction elements 41 to 46 such as the clutches and brakes and the one-way clutches 51 and 52 and the shift speed.

[0019]

[Table 1] Further, a control unit (hereinafter, referred to as an ECU) 70 for integrally controlling the engine 3 and the automatic transmission is provided. The ECU 70 is provided with a signal from a vehicle speed sensor 71 for detecting the vehicle speed of the vehicle, A signal from a throttle sensor 72 for detecting the opening, an engine rotation sensor 73 for detecting the engine speed
, A signal from a turbine rotation sensor 74 for detecting the turbine speed, and a signal from a shift position sensor 75 for detecting the shift position of the select lever 13 selected by the driver. , A shift control by a shift solenoid valve 61... 61 provided in a hydraulic control unit 60 and a line pressure control by a duty solenoid valve 62 similarly provided in the hydraulic control unit 60. In addition, ignition control for the ignition plugs 7... 7 is performed.

In the above configuration, for example, the D range 2
As can be seen from Table 1 above, the coast clutch 42 for engine braking is not engaged, and therefore power is input from the output gear side of the transmission mechanism 30 as in the case of inertial running with the accelerator pedal released. In the reverse driving state, the first one-way clutch 51 parallel to the coast clutch 42 idles. In this case, for example, if the accelerator pedal is depressed in order to compensate for acceleration or a decrease in vehicle speed, a large shock is generated when the first one-way clutch 51 in the idling state is locked.

Therefore, in this embodiment, in order to reduce the shock when the first and second one-way clutches 51 and 52 are locked, control is performed to reduce the output torque of the engine 3 by the ignition control. This shock reduction control is specifically described in FIG.
According to the main routine shown in the flowchart in FIG.

[0022] That is, ECU 70 is on the read various signals in Step S1, and sets the torque reduction start determination value N _S by performing a predetermined torque reduction start determination value setting process in step S2, the torque in step S3 the value of the flag F indicating that the down-start determination value N _S is set determines whether 1.

The ECU70 time it is determined that the value of the flag F is set to 1, that is, when it is determined that the torque reduction start determination value N _S is set, whether during the shift proceeds to step S4 by determining, first, the rotational speed of the downstream side of the second one-way clutch 51 (hereinafter, referred to as the wheel-side rotation speed) N ₀ and the upstream side in the power transmission path in step S5 when it is determined not during a shift , That is, the turbine rotational speed _NT, and a rotational speed difference (hereinafter, referred to as a rotational speed difference) △ N between them is calculated.

That is, the ECU 70 calculates the rotational speed difference ΔN by applying the vehicle speed V, the gear ratio G, the conversion coefficient K, and the turbine rotational speed _NT to the following equation.

[0025] △ N = K × G × V -N T ...... And what ECU70 equals willing the rotational speed difference △ N is torque reduction start determination value _{N S} to step S6, whether it is smaller than Is determined, the predetermined torque down control is executed to reduce the output torque of the engine 3.

On the other hand, when the ECU 70 determines in step S4 that the gear is being shifted, it sets 0 to the flag F in step S8 and returns.

The torque-down start determination value setting process includes:
This is performed as follows according to a subroutine whose flowchart is shown in FIG.

That is, the ECU 70 checks the gear position in step S21, and determines whether or not the gear position is a gear position for engine braking. When the ECU 70 determines that the gear position is not the gear position for engine braking, the ECU 70 checks the throttle opening in steps S22 and S23, and when it is determined that the throttle opening is the last fully closed state and is not the present fully closed state, That is, when it is determined that the driving state of the transmission mechanism 30 is the moment when the transition from the reverse driving state to the normal driving state has started, the rotation speed difference ΔN is calculated from the vehicle speed V, the turbine rotation speed _{NT, and the} like at that time. Together with FIG.
As shown in the figure, the map of the torque decrease start determination value in which the rotational speed difference is set as a parameter in advance is stored in the map of the rotational speed difference
By collating the N, after setting the corresponding torque reduction start determination value N _S, the process returns to the main routine sets the flag F to 1 (step S24~S2
6). Here, the map, the torque-down start determination value N _S as the rotational speed difference △ N is increased is set to increase.

When the gear is an engine brake gear, the flag F is set to 0 in step S27 and the program returns to the main routine.

On the other hand, the torque down control is executed as follows according to a subroutine whose flowchart is shown in FIG.

[0031] That is, ECU 70, along with calculating a change rate .delta.N _T of the turbine rotational speed N _T in step S71, the turbine rotational speed determined by the torque-down start determination value N _S and the throttle opening θ and the step S71 in step S72 a rate of change .delta.N _T, FIG. 7 (a), (b) , by fitting to the retard time map of the ignition timing shown (c), the set retarding time T _R corresponding. Here, the map, the torque-down start determination value N _S, as the throttle opening θ and the turbine speed change rate .delta.N _T increases, the retard time T _R corresponds to it is set so that each larger I have.

Further, ECU 70 is a torque reduction start determination value N _S and the throttle opening θ and the turbine speed change rate .delta.N _T in step S73, FIG. 8 (a), (b) , (c)
The corresponding retard amount _RE is set by applying the retard amount map shown in FIG. Here, the map, in this case, as the torque reduction start determination value N _S, the throttle opening θ and the turbine speed change rate .delta.N _T increases, increases each retard amount R _E and correspondingly It is set as follows.

[0033] Then, ECU 70 by outputting the ignition control signal in accordance with a manner retard time T _R and the retard amount R _E obtained as above to the ignition plug 7 ... 7, reducing the output torque of the engine 3 Let it.

[0034] Incidentally, when setting the retard time T _R and the retard amount R _E, may be adding the gear ratio G.

According to the above configuration, the following operation can be obtained.

That is, suppose that the accelerator pedal is depressed during the inertial running of the vehicle at the second speed in the D range, for example, to compensate for a decrease in vehicle speed. In this case, as shown in FIG. 9, when the throttle opening θ is the value of the rotational speed difference △ N is a △ N ₁ at time t ₁ has changed from the fully closed state, the map of FIG. 5 N _S1 so that the torque reduction start determination value N _S having a value is set (see FIG. 4, step S22 to S25).

Then, as shown by the broken line in the figure, the turbine rotational speed _NT increases, and the rotational speed difference ΔN between the turbine rotational speed N ₀ and the wheel rotational speed N ₀ decreases, and the torque-down start determination value N _S
At time t ₂ when matched with, with only the ignition timing retardation amount R _E1 is set in accordance with the torque reduction start determination value N _S is retarded, the torque-down start determination value that state in a similar manner N _S This is maintained until the delay time T _R1 set according to the time elapses.

Therefore, the first one-way clutch 51
Is locked, the output torque is reduced, and the shock when the one-way clutch 51 is locked is reduced.

On the other hand, as shown by the dashed line in the figure, the value of the rotational speed difference ΔN at time t ₁ when the turbine rotational speed _NT is low and the throttle opening θ changes from the fully closed state is {N ₂ (> △).
When was N _1), this time from the map of FIG. 5 N _S2
Torque reduction start determination value N _S having a value of (> N _S1) is to be set.

[0040] Thus, it becomes possible to the rotational speed difference △ N is coincident with a relatively early point t ₃ the torque reduction start determination value N _S, so that the timing of the ignition timing is retarded is accelerated with it .

Thus, the turbine speed N _TI.e.
Even if the engine speed increases at an accelerated rate,
Ignition timing is retarded at an appropriate timing according to
As a result, the first one-way clutch 51 locks.
The shock at the time of starting is surely prevented.

In this embodiment, the torque is reduced by controlling the ignition timing. However, the torque may be reduced by another method such as fuel injection control.

[0043]

As described above, according to the present invention, the one-way clutch forming the power transmission path of the transmission mechanism locks when power is input from the input side of the transmission mechanism, and locks from the output side of the mechanism. When the one-way clutch is locked during traveling at the above-described speed in an automatic transmission in which the speed is set to idle when power is input, the engine output is reduced. Shock is greatly reduced.

Then, as in the embodiment, by detecting the difference between the rotational speeds of the one-way clutch before and after in the power transmission path, the shift from the reverse driving state to the normal driving state is reliably determined. The above-mentioned shock can be appropriately reduced without unnecessarily lowering the engine output.

Further, as the rotational speed difference before and after the one-way clutch at the time when the drive state of the transmission mechanism shifts from the reverse drive state to the forward drive state is increased, the set value for starting the reduction of the engine output is increased. When the one-way clutch is locked, the engine output is surely reduced, and the shock can be reliably reduced.

[Brief description of the drawings]

FIG. 1 is a control system diagram of an engine and an automatic transmission.

FIG. 2 is a skeleton diagram of an automatic transmission.

FIG. 3 is a flowchart illustrating a main routine of shock reduction control performed by an ECU.

FIG. 4 is a flowchart illustrating a process of setting a torque-down start determination value used in the control.

FIG. 5 is an explanatory diagram of a map used for setting a torque-down start determination value.

FIG. 6 is a flowchart showing a torque down control.

FIG. 7 is an explanatory diagram of a map used for setting a delay time.

FIG. 8 is an explanatory diagram of a map used for setting a retard amount.

FIG. 9 is a time chart showing the operation of the embodiment.

[Explanation of symbols]

 Reference Signs List 3 engine 4 automatic transmission 7 spark plug 51 first one-way clutch 70 ECU 71 vehicle speed sensor 72 throttle sensor 74 turbine speed sensor

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazuo Sasaki 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-64-85844 (JP, A) JP-A-3 -32939 (JP, A) JP-A-61-119432 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 29/00-29/06 B60K 41/00-41/28

Claims (2)

(57) [Claims] 1. A one-way clutch that forms a power transmission path of a transmission mechanism is provided. The one-way clutch locks when power is input from an input side of the transmission mechanism, and receives power from an output side of the mechanism. Power transmission in an automatic transmission in which the speed at which
Detect the difference in rotational speed before and after the one-way clutch
The rotational speed difference detecting means is provided, and when the drive state of the transmission mechanism shifts from a reverse drive state driven by inertia of the vehicle to a forward drive state driven by engine output during traveling at the shift speed. , Detected by the rotational speed difference detecting means
An engine output reducing means for reducing the engine output when the difference in the number of revolutions decreases to a set value . 2. A one-way clutch, which forms a power transmission path of a speed change mechanism, is locked when power is input from an input side of the speed change mechanism, and power is input from an output side of the mechanism. And a speed difference detecting means for detecting a speed difference before and after the one-way clutch in a power transmission path, and the speed change mechanism during traveling at the speed. When the driving state of the vehicle shifts from the reverse driving state driven by the inertia of the vehicle to the normal driving state driven by the engine output, the rotation speed difference detected by the rotation speed difference detecting means has decreased to a set value. and engine output reduction means for reducing the engine output at the time, or the reverse drive state
One-way class when the transition to
The larger the difference between the rotation speeds before and after the
A shock reduction device for an automatic transmission, comprising a set value changing means for changing the value .