JPH0796779A - Control unit of automatic transmission - Google Patents

Abstract

PURPOSE:To provide an automatic transmission control unit that can prevent a clutch slip effectively in the case where a shift from N range to D range or R range by a racing select or in the case where an accelerator is operated immediately after shifting from the N range to the D range or R range, respectively. CONSTITUTION:At a power plant equipped with an engine CE and an automatic transmission AT, a shift from an N range to a D range or R range is carried out, the output torque this engine CE is lowered, and thereby a supply of torque from the engine side to the automatic transmission side is reduced to some extent, Accordingly, at the time of racing selection or the like, a slip or seizure in the clutch to be clamped by shifting is prevented from occurring, so that durability in the clutch is well enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission.

[0002]

2. Description of the Related Art Generally, a torque converter and a speed change gear mechanism are arranged in series in an automatic transmission for an automobile, and the torque converter changes the torque of an engine output shaft and transmits the torque to a turbine shaft. Is configured to further change the torque of the turbine shaft and transmit the torque to the drive wheels. Here, the speed change gear mechanism is usually a planetary gear mechanism including a plurality of gears such as a sun gear, a ring gear, and a pinion gear, and the speed change gear mechanism includes a clutch for turning on / off torque transmission to a predetermined gear, Alternatively, various hydraulic friction engagement elements such as a brake for fixing (brake on) and releasing (brake off) a predetermined gear are provided. A hydraulic mechanism that supplies and discharges operating hydraulic pressure (operating oil) to and from each of these friction engagement elements is provided, and the on / off pattern of each friction engagement element is switched by this hydraulic mechanism so that gear shifting is performed. Has become.

In such an automatic transmission, the line pressure or operating hydraulic pressure of the hydraulic mechanism must be an appropriate pressure according to the amount of power transmission in each friction engagement element, and if the line pressure is too high, power loss will occur. On the other hand, if the line pressure is too low, slippage occurs in the frictional fastening element, causing abnormal wear or abnormal heat generation in the friction plate. Therefore, in the conventional automatic transmission, the line pressure is controlled by the control unit according to the operating state (for example, throttle opening, turbine speed).

[0004]

However, in such a conventional automatic transmission, when the racing selection is made, that is, when the engine speed is increased in the N range and the engine is shifted to the D range or the R range, the throttle opening is so large. Since the line pressure or the operating hydraulic pressure is relatively low, the power or torque applied to the clutch engaged by the shift is large, so that the time required for the engagement is long, and therefore the slip between the plates is large. However, there is a problem in that the durability of the clutch is deteriorated due to the occurrence of seizure on the clutch.

Specifically, when shifting from the N range to the D range, the forward clutch is engaged and the first speed is set, so that the durability of the forward clutch is reduced. Further, since the reverse clutch is engaged when shifting from the N range to the R range, the durability of the reverse clutch is reduced.

Further, even when the accelerator is depressed immediately after shifting from the N range to the D range or the R range, a large power or torque is applied to the forward clutch or the reverse clutch even though the line pressure or the hydraulic pressure is low. Since it is added, there is a problem that its durability is reduced.

Therefore, when shifting from the N range to the D range, an automatic transmission is proposed in which the speed change gear mechanism is set to the 1st speed via the 3rd speed to enhance the durability of the forward clutch. (See, for example, Japanese Patent Publication No. 3-69018). This is because, in the third gear, the three clutches of the forward clutch, the coast clutch and the 3-4 clutch are engaged in the third speed, so that the torque applied to each clutch from the engine side is reduced.

However, for example, Japanese Patent Publication No. 3-690
The automatic transmission disclosed in Japanese Patent No. 18 has a problem in that the durability of the reverse clutch cannot be increased because the third speed cannot be passed when shifting from the N range to the R range. Further, even when shifting from the N range to the D range, since considerable torque is still applied to each clutch, there is a problem that the durability cannot be sufficiently enhanced.

The present invention has been made in order to solve the above-mentioned conventional problems.
Automatic shift that can effectively prevent deterioration of durability of each clutch when the range is shifted to the D range or the R range, or when the accelerator is depressed immediately after shifting from the N range to the D range or the R range An object is to provide a control device for a machine.

[0010]

In order to achieve the above object, as shown in the configuration of FIG. 1, the first invention is provided with a clutch b which is disengaged by the hydraulic pressure supplied and discharged by the hydraulic control mechanism a. In the control device of the automatic transmission c, which is adapted to switch the shift characteristics in response to the disengagement of the clutch b, when engaging the clutch b, the hydraulic pressure supplied to the clutch b is increased. Provided is a control device for an automatic transmission, which is provided with a power supply restricting means e for restricting power supply from an engine d to a clutch b.

A second aspect of the present invention is the automatic transmission control device according to the first aspect, wherein at least the automatic transmission c is
A neutral range for stopping the transmission of power input from the engine d to the wheel side, and a traveling range for transmitting the power to the wheel side, and the power supply restricting means e,
Provided is a control device for an automatic transmission, characterized in that when switching from the neutral range to the travel range, the output torque of the engine d is regulated according to the accelerator depression amount immediately after switching.

A third aspect of the present invention is the control device for an automatic transmission according to the second aspect, in which the power supply restricting means e changes the engine speed according to the clutch capacity when switching from the neutral range to the travel range. Provided is a control device for an automatic transmission, which is characterized in that it is lowered.

In a fourth aspect of the invention, in the control device for an automatic transmission according to the second aspect, when the power supply restricting means e switches from the neutral range to the travel range, the output of the engine d is output for a predetermined time after the switching. There is provided a control device for an automatic transmission, characterized in that the predetermined time is set according to the oil temperature while reducing the torque.

A fifth aspect of the present invention is the control device for an automatic transmission according to any one of the second to fourth aspects, wherein the power supply regulating means e changes from the neutral range to the travel range when the engine water temperature is low. There is provided a control device for an automatic transmission, characterized in that the output torque of the engine d is not regulated at the time of switching.

[0015]

EXAMPLES Examples of the present invention will be specifically described below.
As shown in FIG. 2, the power plant for an automobile includes a four-cylinder engine CE that produces torque, and an automatic transmission AT that changes the output torque of the engine CE. And in each cylinder of the engine CE,
The air-fuel mixture is supplied from the independent intake passage 1 into the combustion chamber 2, and the air-fuel mixture is ignited and burned by the ignition plug 3 after being compressed by a piston (not shown). It is designed to be discharged to the outside via. Here, facing each independent intake passage 1,
A fuel injection valve 5 that injects fuel into the intake air is provided. Further, each of the independent intake passages 1 is gathered on the upstream side into one common intake passage 6, and a throttle valve 7 which is opened / closed in conjunction with an accelerator pedal (not shown) is provided in the common intake passage 6. ing.

As shown in FIG. 3, the automatic transmission AT is provided with a torque converter T and a speed change gear mechanism G. The torque converter T changes the torque of the engine output shaft 8 and transmits it to the turbine shaft 9. The speed change gear mechanism G further changes the torque of the turbine shaft 9 and, when the reverse gear is selected, reverses the rotation and outputs the output gear 10 to the drive wheels. The turbine shaft 9 is formed in a pipe shape, and a pump shaft 11 connected to the engine output shaft 8 is disposed in the hollow portion of the turbine shaft 9.
2 is rotationally driven.

The torque converter T has an engine output shaft 8
A pump 13p that rotates integrally with the turbine 13t, a turbine 13t that rotates integrally with the turbine shaft 9 and is driven to rotate by hydraulic fluid discharged from the pump 13p, and a turbine 1
It is composed of a stator 13s that rectifies the hydraulic oil that flows back from the 3t to the pump 13p in a direction that promotes the rotation of the pump 13p, and changes the torque of the engine output shaft 8 at a gear ratio that corresponds to the rotational difference between the pump 13p and the turbine 13t. It is designed to shift gears. Here, the stator 13s is connected to the fixed portion via a stator one-way clutch W ₁ . A lockup clutch 14 that directly connects the engine output shaft 8 and the turbine shaft 9 in a predetermined operating region is provided in order to reduce power loss and improve fuel efficiency.

The speed change gear mechanism G is an ordinary planetary gear system, and the speed change gear mechanism G has a relatively small diameter small sun gear 1 loosely fitted in the turbine shaft 9.
5, a large sun gear 16 with a relatively large diameter that is loosely fitted to the turbine shaft 9 behind the small sun gear 15 (on the left side in FIG. 3), and a plurality of short pinion gears 17 that mesh with the small sun gear 15 (only one is shown) The front part (right side in FIG. 3) meshes with the short pinion gear 17, the rear part meshes with the large sun gear 16, the long pinion gear 18, the ring gear 19 meshing with the long pinion gear 18, the short pinion gear 17 and the long pinion gear 18 are rotatable. A carrier 20 for supporting (rotating) is provided. In the speed change gear mechanism G, the small sun gear 15, the large sun gear 16 or the carrier 20 serves as a torque input section in accordance with the gear position,
The ring gear 19 serves as a torque output portion at any gear.
The ring gear 19 is connected to the output gear 10.

A plurality of clutches and brakes are provided in order to switch the torque transmission path (power transmission path) in the speed change gear mechanism G, that is, to change the speed ratio or the rotation direction. Specifically, a forward clutch 21 and a first one-way clutch W ₂ are provided in series between the turbine shaft 9 and the small sun gear 15, and the coast 21 is parallel to both clutches 21 and W ₂ . The clutch 23 is provided. Then, between the turbine shaft 9 and the carrier 20, 3-
A four-clutch 24 is provided, and a reverse clutch 25 is provided between the turbine shaft 9 and the large sun gear 16. Further, between the large sun gear 16 and the reverse clutch 25, the large sun gear 1 is provided at a predetermined speed.
A 2-4 brake 26 is provided for fixing 6 which consists of a band brake actuated by a servo piston. Further, a low reverse brake 27 that fixes the carrier 20 at a predetermined speed and a second one-way clutch W ₃ that receives the reaction force of the carrier 20 are provided in parallel between the carrier 20 and the fixed portion. There is.
In the following, these clutches and brakes will be collectively referred to as "friction engagement elements" as appropriate.

Then, each clutch 21, 23, 24, 25
By changing the on / off patterns of the brakes 26, 27, various ranges or gears as shown in Table 1 can be obtained. Hereinafter, with reference to Table 1, a torque transmission path in each range or shift stage and its shift characteristics will be described. In addition, ON / OFF of each friction engagement element can be switched by the hydraulic control mechanism FS controlled by the control unit C (see FIG. 2).

[0021]

[Table 1]

(1) P range ... All friction engagement elements are turned off. In this case, the torque of the turbine shaft 9 is not transmitted to the output gear 10. (2) R range ... The reverse clutch 25 and the low reverse brake 27 are turned on, and the other friction engagement elements are turned off. The first and second one-way clutches W ₂ and W ₃ have no particular effect. The torque of the turbine shaft 9 is input to the large sun gear 16 via the reverse clutch 25, and the large sun gear 16, the long pinion gear 18, and the ring gear 19 function as a fixed gear train that meshes in this order. In this case, the torque input to the large sun gear 16 is shifted at a speed reduction ratio determined by the number of teeth of the large sun gear 16 and the number of teeth of the ring gear 19, and is output from the output gear 10. In this R range, the ring gear 19 (output gear 10) rotates in the opposite direction to the large sun gear 16 (turbine shaft 9), and the drive wheels are driven in the reverse direction. (3) N range ... Same as in the P range.

(4) First speed in D range ... Forward clutch 2
1 is turned on and the other frictional fastening elements are turned off. First,
The second one-way clutches W ₂ and W ₃ are normally locked, but idle during coasting. The torque of the turbine shaft 9 is input to the small sun gear 15 via the forward clutch 21 and the first one-way clutch W _2, and the small sun gear 15, the short pinion gear 17, the long pinion gear 18, and the ring gear 19 are
It functions as a fixed gear train that meshes in this order. In this case, the torque input to the small sun gear 15 is shifted at a speed reduction ratio determined by the number of teeth of the small sun gear 15 and the number of teeth of the ring gear 19, and is output from the output gear 10. The ring gear 19 (output gear 10) rotates in the same direction as the small sun gear 15 (turbine shaft 9), and the drive wheels are driven in the forward direction. At the first speed in the D range, engine braking cannot be obtained due to the action of the first one-way clutch W ₂ .

(5) D range 2nd speed ... forward clutch 2
The 1 and 2-4 brakes 26 are turned on and the other friction engagement elements are turned off. The first one-way clutch W ₂ is normally locked, but idling during coasting
The one-way clutch W ₃ always idles. Since the large sun gear 16 is fixed, the long pinion gear 18
It revolves around the large sun gear 16 while rotating. Therefore, basically, torque is transmitted through the same route as in the case of the first speed in the D range, but the rotation of the ring gear 19 increases by the amount of revolution of the long pinion gear 18, and the reduction ratio is smaller than that in the first speed in the D range. Become. At the second speed in the D range, engine braking cannot be obtained due to the action of the first one-way clutch W ₂ .

(6) D range 3rd speed ... forward clutch 2
1, the coast clutch 23, and the 3-4 clutch 24 are turned on, and the other friction engagement elements are turned off. The first one-way clutch W ₂ has no particular effect, and the second one-way clutch W ₃ always idles. Small sun gear 1
5 and the carrier 20 are locked to each other via the coast clutch 23, the turbine shaft 9 and the 3-4 clutch 24, so that the speed change gear mechanism G is directly connected. Therefore, the torque of the turbine shaft 9 is output from the output gear 10 without being shifted. Since the vehicle is in the direct connection state, it is natural that the engine brake can be obtained.

(7) 4th speed in D range ... Forward clutch 2
The 1 and 3-4 clutch 24 and the 2-4 brake 26 are turned on, and the other friction engagement elements are turned off. The first and second one-way clutches W ₂ and W ₃ always idle. The torque of the turbine shaft 9 is input to the carrier 20 via the 3-4 clutch 24, and the torque of the carrier 20 is sequentially transmitted to the output gear 10 via the long pinion gear 18 and the ring gear 19. Since the large sun gear 16 is fixed by the 2-4 brake 26, the long pinion gear 18 revolves around the large sun gear 16 while rotating on its axis. Therefore, the rotation speed of the ring gear 19 is higher than the rotation speed of the carrier 20 (turbine shaft rotation speed) by the amount of rotation of the long pinion gear 18, and the transmission gear mechanism G is in the overdrive (acceleration) state.

(8) 2nd range 1st speed ... Same as in the D range 1st speed. (9) Second range, second speed ... The forward clutch 21, the coast clutch 23, and the 2-4 brake 26 are turned on, and the other friction engagement elements are turned off. 1st one-way clutch W
₂ has no particular effect, and the second one-way clutch W ₃ idles. In this case, the torque transmission path and the speed change characteristic are basically the same as those in the D range second speed,
Since the first one-way clutch W ₂ does not function, engine braking is obtained.

(10) Second range, third speed ... Same as in the D range, third speed. (11) 1st range 1st speed ... The forward clutch 21, the coast clutch 23, and the low reverse brake 27 are turned on, and the other friction engagement elements are turned off. The first and second one-way clutches W ₂ and W ₃ have no particular effect. In this case, the torque transmission path and the shift characteristics are basically D
Similar to the case of the first speed range, but engine braking can be obtained because the first and second one-way clutches W ₂ and W ₃ do not function. (12) 1st range 2nd speed ... Same as 2nd range 2nd speed.

Again, as shown in FIG. 2, the automatic transmission AT
Is provided with a hydraulic control mechanism FS for turning on and off each friction engagement element of the speed change gear mechanism G. Although not shown in detail, the hydraulic control mechanism FS is
A line pressure control unit that controls the line pressure (source pressure) of S, a torque converter control unit that controls the supply of hydraulic pressure to the torque converter T and the lockup clutch 14, and a number of hydraulic pressures that supply or release hydraulic pressure to each unit. A network of hydraulic passages consisting of passages, a manual valve that shifts according to the select operation of the select lever, and switches the supply route of operating hydraulic pressure,
A plurality of shift valves that are shifted according to the position of the manual valve and the operating state of the vehicle (for example, vehicle speed and throttle opening), and a plurality of accumulators that buffer the supply or release of hydraulic pressure to predetermined friction engagement elements. , A plurality of timing valves for adjusting the timing of supply or release of hydraulic pressure to a predetermined frictional engagement element, multiple orifices for adjusting the flow resistance of a predetermined portion of the hydraulic passage network, a one-way valve, etc. .

Then, the selected range (P, R, N,
(D, 2,1 range) and the operating state of the vehicle, the hydraulic pressure control mechanism FS controls the hydraulic pressure applied to each friction engagement element to switch the shift speed of the speed change gear mechanism G. ing. Here, 2-4 brake 26
Is a servo piston type band brake equipped with an apply port and a release port, and is turned on (brake actuated) when hydraulic pressure is applied only to the apply port, and when hydraulic pressure is applied to both ports. Alternatively, both are turned off (brake released) when the hydraulic pressure is released. All the other friction engagement elements are turned on (fastened) when the hydraulic pressure is applied, and turned off (released) when the hydraulic pressure is released.

The hydraulic control mechanism FS is controlled by a control unit C composed of a microcomputer. Specifically, the hydraulic control mechanism FS includes three on / off solenoid valves 31, 32, 33 for controlling the shift valve and two solenoid valves 34 for controlling the lockup clutch 14 of the torque converter T. , 35 and a duty solenoid valve 36 for controlling the line pressure. These solenoid valves 31 to 36 are provided in the control unit C.
Is controlled by. That is, the control unit C includes the on / off solenoid valve 3
1 to 33, the gear stage of the transmission gear mechanism G is switched according to the selected range and the operating state, the line pressure is controlled via the duty solenoid valve 36 according to the operating state, and the solenoid valve 34, The lock-up control of the torque converter T is performed via 35.

The control unit C is a comprehensive control device for the engine CE and the automatic transmission AT including the "power supply regulation means" described in the claims, and is detected by the throttle sensor 41. Throttle opening, engine water temperature detected by water temperature sensor 42, engine rotation speed detected by rotation speed sensor 43, turbine rotation speed detected by turbine sensor 44, ATF oil temperature detected by oil temperature sensor 45,
In addition to the above-mentioned controls, various controls of the engine CE and the automatic transmission AT are performed using the range signal or the like output from the inhibitor 46 as control information.

However, general control of the engine or the automatic transmission by the control unit is well known, and since such general control is not the gist of the present invention, the description thereof will be omitted. Then, according to the gist of the present invention, from the N range to the traveling range
Only the torque down control at the time of shifting to (D range, R range) will be described. That is, the engine CE
In the power train including the automatic transmission AT and the automatic transmission AT, when shifting from the N range to the D range or the R range, basically, until the hydraulic pressure supplied to the corresponding clutch is sufficiently increased, Side to the automatic transmission side to suppress the supply of power or torque (torque down), reduce the power or torque input to the clutch engaged at the time of the shift to prevent slippage of the clutch. Torque down control is performed to improve durability.

The control method of the torque down control will be described below with reference to the flow chart shown in FIG. 4 and with reference to FIGS. 2 to 3 as appropriate, taking the case of shifting from the N range to the D range as an example. When the control is started, first in step # 1, the range signal SIG (t) and the throttle opening t
vo (t), engine engine speed Ne (t), ATF oil temperature tem
Various information such as p (t) is read as control information.

Next, in step # 2, the range signal SIG
It is determined whether (t) is in the D range. Where S
If it is determined that IG (t) is not in the D range (N
O), since it is not necessary to reduce the torque, all the following steps (steps # 3 to # 8) are skipped and the process returns to step # 1. On the other hand, if it is determined in step # 2 that the range signal SIG (t) is in the D range (YE
S), and in step # 3, the previous range signal SIG (t
-Δt) is in the N range. Here, when it is determined that SIG (t-Δt) is in the N range (YES), it means that the shift from the N range to the D range has been performed this time.

In this way, when the N range is shifted to the D range, basically, the forward clutch 2
In order to prevent the deterioration of durability of No. 1, the output torque of the engine CE is decreased. In this embodiment, the output torque or the rotational speed of the engine CE is reduced by stopping the fuel injection from all or part of the fuel injection valve 5. The output torque or the rotation speed of the engine CE may be reduced by retarding the ignition timing of the spark plug 3 via the ignition device 30.

In the present embodiment, when the N range is shifted to the D range and the torque reduction is started,
The torque down is canceled when a predetermined time (hereinafter, referred to as torque down time) has elapsed.
Here, the torque down time is the throttle opening tvo (t),
It is set according to the engine speed Ne (t) and the ATF oil temperature temp (t). That is, as the throttle opening is larger or the engine speed is higher, the output torque of the engine CE immediately before the shift is larger, so that the torque down time is made longer and the torque input to the automatic transmission is made stronger. I try to suppress it. Further, when the ATF oil temperature is low, the viscosity is high and therefore the hydraulic pressure or the supply of hydraulic oil to the forward clutch 21 is delayed, so the torque down time is lengthened and the torque input to the automatic transmission side is more strongly suppressed. I am trying.

Specifically, in step # 4, the timer is set to
Throttle opening tvo (t), engine speed Ne (t) and oil temperature te
The torque down time set according to mp (t) is set as an initial value. This timer is a timer for determining whether or not the torque down time has elapsed after shifting from the N range to the D range and starting the torque down. The torque down time (initial value) is
Since the throttle opening, engine speed and oil temperature are mapped as parameters and stored in the memory of the control unit C, in step # 4, the initial value (torque down time) must be read from the map. become.

On the other hand, in step # 3, the previous range signal S
If it is determined that IG (t-Δt) is not in N range,
(NO), which means that the shift has already been made to the D range before the last time and the D range state is currently being continued.
Therefore, in order to continue counting by the timer, the count value tA of the timer is decremented by Δt in step # 5. Note that Δt is the time required to execute this torque down control routine once.

After step # 4 or step # 5 is executed, the count value of the timer is counted in step # 6.
It is determined whether tA is less than 0, that is, whether the torque down time has elapsed. Where tA ≧ 0
If it is determined to be (NO), the torque down time has not yet elapsed after shifting to the D range, so the torque down request signal is set in step # 7 to continue the torque down. Return to # 1. On the other hand, if it is determined in step # 6 that tA <0 (YES), the torque down time has already elapsed, so the torque down request signal is reset and the torque down is released in step # 8. Then, the procedure returns to step # 1.

FIG. 5 shows the range signal (G ₁ ) and the torque down request signal when the N range is shifted to the D range at time t ₁ when the torque down control is performed.
The change characteristics of (G ₂ ) and the output torque (G ₃ ) of the engine CE with time are shown. In FIG. 5, the torque down is released at time t ₂ . Therefore, the torque down time in this case is (t ₂ −t ₁ ).

In this way, when the N range is shifted to the D range, the output torque of the engine CE is suppressed according to the operating state, so that the torque input to the transmission side (clutch) becomes small and the line Even if the pressure does not rise sufficiently, the forward clutch 21 does not slip or seize, and its durability is effectively enhanced.

In the flow chart shown in FIG. 4, N
Although the shift from the range to the D range is taken as an example, the same torque down control is performed in the shift from the N range to the R range to prevent the reverse clutch 25 from slipping or seizing. And its durability is effectively increased.

Although not shown in the flow chart of FIG. 4, it is preferable to add the following control to the torque down control. That is, in the flowchart shown in FIG. 4, when the N range is shifted to the D range, torque reduction is always performed. However, when the accelerator depression amount is equal to or greater than a predetermined value, or the throttle opening increasing speed is increased. It is preferable to perform the torque reduction only when is greater than or equal to a predetermined value. In other words, the torque reduction is canceled when the accelerator depression amount or the increasing rate of the throttle opening is small. When the amount of accelerator pedal depression or the rate of increase in throttle opening is small,
Since the power or torque input from the engine side to the automatic transmission side is originally small, the forward clutch 21
This is because slippage is unlikely to occur. Further, by doing so, the acceleration performance after shifting to the D range (R range) can be enhanced.

Further, when the engine water temperature detected by the water temperature sensor 42 is low, that is, when the engine is cold, the output torque of the engine CE should not be suppressed even if the N range is shifted to the D range (R range), that is, the torque is controlled. It is preferable to stop the down control. Kashi,
This is because misfire or engine stall may occur if the torque reduction control is performed when the engine is cold.
Therefore, by doing so, it is possible to reliably prevent misfire or engine stall when the engine is cold.

[0046]

According to the first aspect of the invention, since the power supply from the engine to the clutch is restricted until the hydraulic pressure supplied to the clutch rises, the predetermined clutch is engaged from the N range. When the gear is shifted to the D range or the R range, the power or torque input to the clutch becomes small, and the clutch slippage occurs even when the operating hydraulic pressure (line pressure) of the clutch is not sufficiently increased. Alternatively, seizure does not occur and the durability of the clutch is enhanced.

According to the second invention, basically, the same action and effect as those of the first invention can be obtained. Furthermore, when shifting from the N range to the driving range (D range, R range),
Since the output torque of the engine is regulated according to the accelerator depression amount, the durability of the clutch that is engaged during the shift can be more effectively enhanced.

According to the third invention, basically, the same operation and effect as those of the second invention can be obtained. Furthermore, when shifting from the N range to the driving range (D range, R range),
Since the engine speed is reduced according to the clutch capacity, the power or torque input to the clutch that is engaged by the shift is effectively reduced, and the durability of the clutch is even more effectively enhanced.

According to the fourth invention, basically, the same operation and effect as those of the second invention can be obtained. Furthermore, when shifting from the N range to the driving range (D range, R range),
Since the torque down time of the engine is set according to the oil temperature, the accuracy of the torque down control can be improved by lengthening the torque down time when the oil temperature is low and therefore the hydraulic pressure transmission is poor. The durability of the engaged clutch can be improved even more effectively.

According to the fifth invention, basically the same action and effect as any one of the second to fourth inventions can be obtained. Furthermore, when the engine water temperature is low, that is, when the engine is cold, the N range to the driving range (D range, R range)
Even if it is shifted to the range), the engine output is not regulated, so misfire or engine stall is prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of first to fifth inventions corresponding to claims 1 to 5.

FIG. 2 is a system configuration diagram of a power plant including a control device according to the present invention.

3 is a skeleton diagram showing a power transmission structure of the automatic transmission of the power plant shown in FIG.

FIG. 4 is a flowchart showing a control method of torque down control.

FIG. 5 is a diagram showing a change characteristic with respect to time of a range signal, a torque-down request signal, and an engine torque when shifting from the N range to the D range.

[Explanation of symbols]

 AT ... Automatic transmission CE ... Engine FS ... Hydraulic control mechanism C ... Control unit G ... Shift gear mechanism 21 ... Forward clutch 23 ... Coast clutch 24 ... 3-4 clutch 25 ... Reverse clutch 42 ... Water temperature sensor 45 ... Oil temperature sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Shinozuka 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (5)

[Claims] 1. A control device for an automatic transmission, comprising: a clutch that is disengaged by hydraulic pressure supplied and discharged by a hydraulic control mechanism, and that switches gear shift characteristics in response to disengagement of the clutch. A control device for an automatic transmission, characterized in that, when the clutch is engaged, a power supply restricting means is provided for restricting power supply from the engine to the clutch until the hydraulic pressure supplied to the clutch rises. 2. The automatic transmission control device according to claim 1, wherein the automatic transmission stops at least the transmission of power input from the engine to the wheel side, and the power is transmitted to the wheel side. And a driving range that is transmitted to the driving range, and the power supply regulation means regulates the output torque of the engine according to the accelerator depression amount immediately after switching when switching from the neutral range to the traveling range. A control device for an automatic transmission characterized by: 3. The control device for an automatic transmission according to claim 2, wherein the power supply restriction means reduces the engine speed according to the clutch capacity when switching from the neutral range to the travel range. A control device for an automatic transmission that is characterized by: 4. The control device for an automatic transmission according to claim 2, wherein the power supply restricting means reduces the output torque of the engine for a predetermined time after switching when switching from the neutral range to the travel range. A control device for an automatic transmission, wherein the predetermined time is set according to an oil temperature. 5. The automatic transmission control device according to any one of claims 2 to 4, wherein the power supply restriction means switches from the neutral range to the travel range when the engine water temperature is low. A control device for an automatic transmission, characterized in that the output torque of the engine is not regulated.