JP3266320B2 - Control 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 a control device for an automatic transmission, and more particularly to a control device for a non-forward range such as an N range or an R range.
The present invention relates to a control device for an automatic transmission that switches to a start stage through a predetermined high speed stage when a shift operation to a forward range such as a range is performed.

[0002]

2. Description of the Related Art Generally, an automatic transmission mounted on an automobile combines a torque converter, a speed change mechanism, and a plurality of friction elements for switching a power transmission path of the speed change mechanism.
By selectively engaging these friction elements automatically in accordance with the driving state or in response to switching of the range by manual operation of the driver, the gear is switched to a predetermined gear position. In these types of automatic transmissions, the engagement or release operations of the friction elements are controlled by the supply and discharge of hydraulic pressure.

In this type of automatic transmission, there is a problem that an unpleasant shock called a so-called ND shock occurs, for example, when operating from the N range to the D range at the time of starting. That is, during this ND operation, the predetermined frictional element is engaged from the neutral state in which all the frictional elements are released, and the gear is switched to the first gear. At this time, the output torque of the engine is changed. Is increased at a large ratio corresponding to the speed reduction ratio of the first speed and transmitted to the wheels, and this causes the occupant to feel discomfort as a shock.

In order to solve this problem, for example,
As disclosed in Japanese Unexamined Patent Publication No. 93527, it has been considered that when selecting from the N range to the D range, switching to the first speed is performed via the high speed gear for a predetermined time. In other words, since the output torque of the transmission is relatively small in the high-speed stage where the reduction ratio is small, the shock when this torque is transmitted to the wheel side is reduced.

[0005]

However, the following problems may occur in the automatic transmission in which the vehicle is passed through the high speed stage when starting as described above.

That is, in this type of automatic transmission, the engagement or disengagement operation of the friction element is controlled by the hydraulic pressure. Therefore, at low temperatures, the shift speed is increased by the increase in the viscosity of the hydraulic oil. Therefore, the time required for switching to the position becomes longer, and the startability may be deteriorated.

[0007]

[0008] The same problem as described above also occurs when the forward range such as the D range is directly selected from the R range.

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problem in an automatic transmission in which a non-forward range such as an N range is switched to a forward range via a high-speed stage when a forward range such as a D range is selected. Therefore, it is an object of the present invention to achieve both select shock reduction and startability.

[0010]

[0011]

[0012]

Means for Solving the Problems That is, the claims of the present application
1 of the invention (hereinafter, referred to as first invention) control system for an automatic transmission according to, upon a select operation from the non-forward range to the forward range, a predetermined time before setting the gear stage to the starting stage, high speed stage In an automatic transmission provided with start control means for setting the temperature, a temperature detection means for detecting the temperature of the power unit, and a high speed stage by the start control means when the temperature detected by the detection means is lower than a predetermined value. A high-speed gear setting operation prohibiting means for prohibiting the setting operation is provided.

The invention of claim 2 of the present application (hereinafter referred to as the second invention )
The control device for an automatic transmission according to the present invention is provided with start control means for setting a high speed stage for a predetermined time before setting a shift stage to a start stage during a select operation from a non-forward range to a forward range. And a high-speed gear setting time changer for changing the high-speed gear setting time by the start control means to a shorter direction as the temperature detected by the detection means decreases. Means is provided.

[0014]

[0015]

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

[0016] First, according to the first invention, when a select from a non-forward range, such as the N range to the forward range such as D range, the automatic transmission was switched to the start gear by way of the high speed stage, the low temperature will be more in the setting of the high-speed gear is prohibited, deterioration of starting performance due to the increase in the viscosity of the hydraulic oil is prevented at the time.

According to the second aspect of the present invention , the time required for setting the high-speed gear is gradually reduced with a decrease in the oil temperature, so that a good starting performance can be obtained while appropriately preventing a select shock. Will be done.

[0018]

[0019]

Embodiments of the present invention will be described below.

First, the mechanical structure of the automatic transmission according to this embodiment will be described with reference to FIG.
Is a torque converter 20 as a main component,
Transmission mechanism 30 driven by the output of converter 20
And a plurality of friction elements 41 to 46 such as clutches and brakes for switching the power transmission path of the mechanism 30 and the one-way clutches 51 and 52, and the D, S, L, and R ranges as a travel range. And 1 in the D range
4th speed, 1st to 3rd speed in the S range, and 1st to 2nd speed in the L range.

The torque converter 20 includes a pump 2 fixed in a case 21 connected to the engine output shaft 1.
2 and the pump 22
A turbine 23 driven between the pump 22 and the turbine 23, and a stator 25 supported by the transmission case 11 via the one-way clutch 24 to perform a torque increasing action; Case 21 above
And a lock-up clutch 26 that is provided between the engine 23 and the turbine 23 and directly connects the engine output shaft 1 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,
The pump shaft 12 penetrating through the inside of the turbine shaft 27 is connected to the engine output shaft 1.
Thereby, the oil pump 13 provided at the rear end of the transmission is driven.

On the other hand, the transmission mechanism 30 is composed of 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 interposed between the turbine shaft 27 and the small sun gear 31, and a coast clutch 42 is interposed 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 11 is provided. The second one-way clutch 5 for receiving the reaction force of the carrier 35
2 and a low reverse brake 4 for fixing the carrier 35
6 are provided in parallel. The ring gear 36 is connected to the output gear 14, and rotation is transmitted from the output gear 14 to left and right wheels (not shown) via a differential device.

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.

[0025]

[Table 1] Further, a controller 60 for performing various controls on the automatic transmission is provided. The controller 60 stores a signal from a vehicle speed sensor 61 for detecting a vehicle speed of the vehicle and a throttle opening as a representative characteristic of engine output. A signal from a throttle opening sensor 62 to be detected, a signal from a shift position sensor 63 to detect a position (range) of a shift lever provided in the automatic transmission 10,
A signal from a turbine speed sensor 64 that detects the turbine speed of the torque converter 20 and a signal from an oil temperature sensor 65 that detects the oil temperature of the working oil of the automatic transmission are input. . Then, for each range selected by a shift lever (not shown), the controller 60 stores the actual vehicle speed and the throttle opening in a map set in advance according to the vehicle speed of the vehicle and the throttle opening of the engine. The first to third solenoid valves 71 to 73 for speed change are selected in accordance with the operating state at that time, and the speed is selected so as to obtain the speed.
To output a control signal.

The controller 60 changes the speed of the automatic transmission 10 to a high speed (for example, 3
The control at the time of starting to set the starting stage (for example, the first speed) is performed via the first speed. The control at the time of starting is performed as follows according to, for example, the flowchart of FIG.

That is, the controller 60 executes step S
After reading various signals in step 1, flag S2 in step S2.
It is determined whether or not F is set to 1. This hula
F Is normally cleared to 0.

If the value of the flag F is not 1, the controller 60 proceeds to step S3 to determine whether or not the range has been operated from the N range to the D range. If the determination is YES, the controller 60 proceeds to step S4. It is determined whether or not the oil temperature t is lower than a predetermined reference value t ₀ . When the controller 60 determines that the oil temperature t is not lower than the reference value t ₀ , the process proceeds to step S5, and determines whether the throttle opening θ is larger than a predetermined reference value θ ₀ . That is, it is determined whether or not the accelerator pedal is depressed greatly.

[0029] The controller 60, when it is determined that the throttle opening theta is not greater than the reference value theta ₀ is the first to third gear as gear position proceeds to step S6 is set to the third speed Solenoid valves 71-73
And outputs a control signal to the flag F in step S7.
Is set to 1. Next, in step S8, it is determined whether or not the set time by the timer has elapsed since the ND selection operation. If the set time has not elapsed, the process proceeds to step S8.
When the set time has elapsed, the first, third, and third shift solenoids are set so as to execute the loop processing of steps S1, S2, and S8, and when the set time has elapsed, exit from the loop processing and proceed to step S9. The control signal is output to the valves 71 to 73, and the flag F is cleared to 0 in step S10.

On the other hand, the controller 60 executes the above step S
If it is determined in Step 4 that the oil temperature t is lower than the reference value t ₀ , or if it is determined in Step S 5 that the throttle opening θ is larger than the predetermined reference value θ ₀ , Step S
Steps S9 to S8 are skipped, and the control signal is output to the first to third shift solenoid valves 71 to 73 so as to immediately set the shift speed to the first speed.

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

That is, for example, when the oil temperature t is higher than the reference value t ₀ , as shown in FIG. 4, when the range is selected from the N range to the D range, the speed is once set to the third speed. Then, the state of the third speed is maintained until the set time T ₀ elapses, and then the state is switched to the first speed. As a result, immediately after the selection from the N range to the D range, the torque transmitted to the wheels via the automatic transmission 20 is reduced, and the shock is reduced.

On the other hand, when the oil temperature t is lower than the reference value t ₀ , as shown in FIG. 5, when the range is selected from the N range to the D range, the shift speed is immediately set to the first speed. Therefore, although a slight shock occurs immediately after the selection, an extreme deterioration of the startability is avoided.

Further, even when the throttle opening θ is larger than the reference value θ ₀ , when the range is selected from the N range to the D range, the gear is immediately set to the first speed. In this case, a slight shock is generated immediately after the selection, but a good start acceleration can be obtained.

Note that, instead of step S8 in the flowchart of FIG. 3, the first speed may be switched when the turbine speed detected by the turbine speed sensor 64 falls below a predetermined value.

Next, starting control according to a second embodiment of the present invention will be described with reference to the flowchart of FIG.

That is, the controller 60 executes step T
After reading various signals in step 1, it is determined in step T2 whether the flag F is set to 1.

If the value of the flag F is not 1, the controller 60 proceeds to step T3 to determine whether or not the range has been operated from the N range to the D range. If the determination is YES, the controller 60 proceeds to step T4. It is determined whether or not the throttle opening θ is larger than a predetermined reference value θ ₀ .

When the controller 60 determines that the throttle opening θ is not larger than the reference value θ ₀ , it proceeds to step T5 and uses the timer time map shown in FIG. Timer time T corresponding to
Set ₀ . In this map, the timer time T ₀ is a fixed time T ₁ in a region where the oil temperature t is higher than a predetermined reference value t ₀ , and the map is in a region where the oil temperature t is lower than the reference value t _0. As the temperature decreases, the timer time T ₀
Is set to decrease.

Further, the controller 60 outputs a control signal to the first to third solenoid valves 71 to 73 so that the third speed is set to the third speed in step T6, and sets the flag F to 1 in step T7. Set to. Next, in step T8, it is determined whether or not the set time has elapsed since the ND selection operation. If the set time has not elapsed, the loop processing of steps T1, T2, and T8 is executed, and the set time is set. When the elapsed time, the process exits from the loop processing and proceeds to step T9, in which the first to third speed-changing solenoid valves 7 are set so that the shift speed is set to the first speed.
1 to 73, and outputs a control signal to step T10.
Clears the flag F to 0.

On the other hand, the controller 60 executes the above-described step T
When it is determined that the throttle opening theta is larger than the predetermined reference value theta ₀ in 4 shifts to step T9 skips steps T5 to T8, first the first through to set immediately first speed shift stage 3 speed solenoid valve 7
Control signals are output to 1 to 73.

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

[0043] That is, for example, when the oil temperature t is higher than the reference value t _0, once a select from N range to D range, the shift stage is set once the third speed. And this 3
Speed state, as shown by the solid line in FIG. 8 after being held until the elapse of the set time T _1, is switched to the first speed.

As a result, immediately after the range is selected from the N range to the D range, the torque transmitted to the wheels via the automatic transmission 20 becomes small, as in the above embodiment, and the shock is reduced. Become.

On the other hand, when the oil temperature t is at less than the reference value t ₀ is the select from N range to the D range,
The gear will be set to 3rd gear once,
At this time, the state of the third gear is indicated by a chain line in FIG.
Will be held until the shortened set time T ₂ elapses than at high temperatures. Since this time is changed so as to be shorter as the oil temperature t decreases, a good startability can be obtained while appropriately preventing the select shock.

It should be noted that the above-described control may be performed even when the range is selected from the R range to the D range.
The above-described control may be performed when a forward range other than the D range is selected from the range and the R range.

In the above embodiment, the temperature of the hydraulic oil of the automatic transmission is directly detected. However, the temperature of the hydraulic oil is determined by the temperature of the cooling water of the engine constituting the power unit with the automatic transmission. You may make it detect. Further, the engine output may be detected by other appropriate means instead of the throttle opening.

[0048]

As described above, according to the present invention, when a non-forward range such as the N range is selected from the forward range such as the D range, the automatic transmission is switched to the start stage via the high speed stage. At low temperatures, the time required to set the shift stage to the high speed stage is shortened, or the setting to the high speed stage is prohibited by restricting the setting to the high speed stage. Deterioration of startability due to an increase in viscosity is avoided.

In particular, according to the second aspect of the present invention , the time required for setting the high-speed gear is gradually reduced as the temperature decreases, so that a good starting performance can be obtained while appropriately preventing a select shock. Will be.

[0050]

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of an automatic transmission.

FIG. 2 is a control system diagram of the automatic transmission.

FIG. 3 is a flowchart showing a first embodiment of start control.

FIG. 4 is a time chart showing an operation at a high oil temperature.

FIG. 5 is a time chart showing an operation at a low oil temperature.

FIG. 6 is a flowchart illustrating a second embodiment of start control.

FIG. 7 is an explanatory diagram of a map used in the control.

FIG. 8 is a time chart showing an operation by the control.

[Explanation of symbols]

 Reference Signs List 10 automatic transmission 60 controller 62 throttle opening sensor 63 shift position sensor 65 oil temperature sensor 71 first solenoid valve for shifting 72 second solenoid valve for shifting 73 third solenoid valve for shifting

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Mitsuru Hayase 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-2-209662 (JP, A) Shokai Sho59 −92249 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] 1. A control device for an automatic transmission provided with start control means for setting a high speed stage for a predetermined time before setting a shift stage to a start stage during a select operation from a non-forward range to a forward range. Temperature detecting means for detecting the temperature of the power unit, and high-speed gear setting operation inhibiting means for inhibiting the setting operation of the high-speed gear by the starting control means when the temperature detected by the detecting means is lower than a predetermined value. And a control device for the automatic transmission. 2. A control device for an automatic transmission, comprising: start control means for setting a high speed stage for a predetermined time before setting a shift stage to a start stage during a select operation from a non-forward range to a forward range. Temperature detecting means for detecting the temperature of the power unit, and high-speed gear setting time changing means for changing the high-speed gear setting time by the start control means to a shorter direction as the temperature detected by the detecting means is lower. A control device for an automatic transmission, which is provided.