JP3075791B2 - Lockup 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 lock-up control device for an automatic transmission having a torque converter with a lock-up mechanism.

[0002]

2. Description of the Related Art In recent years, in order to improve fuel efficiency, torque converters having a lock-up mechanism for directly connecting input and output shafts are becoming mainstream. By the way, some of the devices provided with this lock-up mechanism control the engagement of the lock-up mechanism based on a preset control pattern in order to further improve the fuel efficiency. As a control device of a torque converter provided with such a lock-up mechanism, for example, Japanese Patent Laid-Open No. 2-25
There are those described in JP-A-6963 and JP-A-60-241572.

In the former case, the lock-up control pattern is changed from a basic lock-up pattern to an acceleration and deceleration lock-up pattern depending on the load change state, and the lock-up engagement state is completely changed. There is disclosed a technique of performing control by dividing the state into a state to be performed and a slip state. Further, in the latter, in order to reduce a shift shock, a technique is disclosed in which the state of the torque converter area is maintained from the start of the shift until the gear position change is actually completed, and the lock-up mechanism is not engaged. . With these controls,
In each case, the lockup timing is managed using the vehicle speed and the throttle opening as parameters.

[0004]

However, in such a conventional technique, since the lock-up timing is managed using the vehicle speed and the throttle opening as parameters, the lock-up is performed at various torque ratios. There is a problem that a shock of time occurs. In addition, since the lock-up is performed at various torque ratios, the lock-up may occur when the rotation speeds of the input shaft and the output shaft are significantly different, and the amount of wear of the lock-up clutch increases. is there. This problem is particularly important because slip lock-up control, which is employed to eliminate vibration and muffled sound caused by lock-up, is performed.

The present invention has been made in view of such a conventional problem. By controlling the torque ratio at the time of lock-up, the shock at the time of lock-up can be reduced and the wear of the lock-up clutch can be reduced. An object of the present invention is to provide a torque converter control device capable of reducing the amount, and an automatic transmission type vehicle including the same.

[0006]

According to a first aspect of the present invention, there is provided a torque converter control device for obtaining a torque ratio correlation value directly or indirectly representing a torque ratio of a torque converter. A gear ratio detecting means for detecting a gear ratio of the transmission, and a lock-up point.
Storage means for torque ratio correlation value is stored for each type speed ratio of the transmission a predetermined Te, the torque ratio correlation value
Whether the torque ratio correlation value acquired by the acquisition unit is equal to or greater than the torque ratio correlation value corresponding to the detected gear ratio among the torque ratio correlation values stored as lock-up points in the storage unit. Determining means for determining whether or not the torque ratio correlation value acquired by the torque ratio correlation value acquiring means is a lock-up point in the storage means.
And an instructing means for instructing the lock-up mechanism to lock up when the determining means determines that the torque ratio correlation value is equal to or more than the torque ratio correlation value stored as a torque value. Things.

Here, the lock-up control device for the automatic transmission is provided with a means for detecting an input-side rotational speed of the torque converter, and the input-side rotational speed detected by the determination means is stored in the memory. Of the input-side rotational speeds stored in the means, it is determined whether or not the input-side rotational speed corresponding to the detected gear ratio is equal to or more than, and the detected input-side rotational speed is stored in the storage unit. Preferably, the configuration is such that when it is determined that the value is equal to or greater than the stored value, the instruction means can instruct the lock-up mechanism to perform lock-up.

The storage means stores the input-side rotational speed at which the lock-up is released for each of the various speed ratios of the transmission, and the input-side rotational speed detected by the determining means is stored in the storage means. It is determined whether the input-side rotational speed related to the lock-up release stored in the storage means is equal to or less than the input-side rotational speed corresponding to the detected gear ratio. When it is determined that the lock-up mechanism is instructed, the lock-up mechanism may be instructed to be released by the instructing means.

Preferably, the torque ratio correlation value stored in the storage means is equal to or greater than a value at which the efficiency of the torque converter indicates a maximum value. Further, the torque ratio correlation value stored in the storage means may be set to increase as the speed ratio of the transmission decreases.

As the torque ratio correlation value, specifically, a rotation speed ratio or a rotation speed difference between an input side rotation speed and an output side rotation speed of the torque converter is mentioned. In this case, the torque ratio correlation value obtaining means includes a rotation speed means for directly or indirectly detecting an input side rotation speed and an output side rotation speed of the torque converter, and the input side rotation speed and the output side speed. Therefore, it is necessary to have a calculation means for calculating the rotation speed ratio or the rotation speed difference between the two. Further, the lock-up control device of the automatic transmission can be applied to a device in which the lock-up mechanism includes a slip lock-up unit. In that case, the instruction unit locks up from a non-lock-up state. Before instructing to do so, it is necessary to instruct to perform slip lockup.

Further, the automatic transmission may be an automatic stepped transmission or an automatic continuously variable transmission. When the present invention is provided to an automatic stepped transmission, the torque ratio correlation value and the like are stored for each gear ratio of each gear, and when the present invention is applied to an automatic continuously variable transmission, a transmission is used. For each of a plurality of preset gear ratios from the upper gear ratio to the lower gear ratio, the torque ratio correlation value or the like is stored, or the relationship between the gear ratio and the torque ratio or the like is represented by a function or the like. It is preferable to store it.

[0012]

The torque ratio correlation value directly or indirectly representing the torque ratio of the torque converter is obtained by the torque ratio correlation value obtaining means, and the gear ratio of the transmission is detected by the gear ratio detecting means. The determining unit determines that the acquired torque ratio correlation value is one of the torque ratio correlation values stored in the storage unit.
It is determined whether or not it is equal to or greater than a torque ratio correlation value corresponding to the detected gear ratio. When it is determined that the obtained torque ratio correlation value is equal to or greater than the torque ratio correlation value stored in the storage unit, the instruction unit instructs the lock-up mechanism to lock up,
It becomes a lock-up state.

As described above, since the lockup point at which the lockup state changes from the non-lockup state to the lockup state is managed by the torque ratio correlation value determined for each speed ratio, the torque ratio during lockup can be reduced. Therefore, the amount of wear of the lock-up shock and the lock-up clutch can be reduced. In particular, when the torque ratio correlation value for locking up is set to a value at which the efficiency of the torque converter indicates the maximum value, the effect of reducing the lock-up shock is large.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a lockup control device for an automatic transmission according to the present invention will be described below with reference to FIGS. FIG. 1 shows an example of an automobile to which an embodiment of the present invention is applied. In FIG. 1, an engine 10 includes a driven part 16 such as a driving wheel of the automobile via a torque converter 12, an automatic stepped transmission 14, and the like. It is connected. The torque converter 12 is a three-element one-stage torque converter with a lock-up clutch, and includes a pump impeller 18 directly connected to the engine output shaft 11 and a turbine impeller 20 directly connected to the driven shaft 13. It includes a direction clutch 22, a stator 24 connected to the direction clutch 22, and a lock-up mechanism 26.

The basic operation of the torque converter 12 will be briefly described below. When the engine 10 is driven, the pump impeller 1 directly connected to the output shaft 11
8 rotates, and the oil filled therein moves toward the turbine impeller 20. And the pump impeller 18
The oil pumped from the tank impinges on the turbine impeller 20, and the impact force rotates the turbine impeller 20. The oil hitting the turbine impeller 20 then travels to the stator 24, and the reaction force generated when the oil flows out further rotates the turbine impeller 20. In this series of operations, the stator 24 is attached to the turbine impeller 20.
From the oil to the pump impeller 18 and change the oil flow.

The lock-up mechanism 26 includes a shaft 1 on the driven side.
3 and a front cover 26 directly connected to the engine output shaft 11 and engaged with the lock-up clutch 26a during lock-up.
b and a drive mechanism for driving the lock-up clutch 26a. The drive mechanism of the lock-up clutch 26a will be described later. Torque converter 12
A shaft 13 on the driven side between the motor and the transmission 14 has a turbine sensor 28 for detecting the rotational speed of the turbine impeller 20.
Is arranged. A vehicle speed sensor 30 is disposed on the output side shaft 15 of the transmission 14.

The control unit 32 includes, as shown in FIG.
A central processing unit (hereinafter abbreviated as CPU) 50; a read-only memory (hereinafter abbreviated as ROM) 52 for storing a control program and various data; a read / write memory (hereinafter abbreviated as RAM) 54; It comprises a port 56 and an output port 58. CPU50, ROM5
2, RAM 54, input port and output port 58,
They are connected by a bus 58. The input port 56 receives signals 34 from the turbine sensor 28, the vehicle speed sensor 30, the throttle opening sensor 60, the air amount sensor 62, the engine speed sensor 64, and the shift state sensor 65. In the control unit 32, the CPU 50 calculates a shift schedule, a lock-up schedule, and the like according to a program or the like stored in the ROM 52 based on information about the engine 10 and the transmission 14 obtained from these sensors, and based on the calculation results. It outputs shift control signals 36 and 38 and a lock-up control signal 40. The shift control signals 36 and 38 output from the output port 58 are output to shift control valves 66 and 68 provided in the transmission 14 to control the gear ratio. Further, the lock-up control signal 40 is output to a duty solenoid 70 provided in the transmission 14 to perform lock-up control. The drive mechanism of the lock-up clutch 26a includes a duty solenoid 70, a lock-up control valve 72 driven by the duty solenoid 70, and a hydraulic mechanism (shown in the figure) that operates the lock-up clutch 26 under hydraulic control of the control valve 72. And not). This drive mechanism
All are provided in the transmission 14. In FIG. 1, the lock-up control signal 40 indicates that the lock-up clutch 26a
Is output to the duty solenoid 70 provided in the transmission 14 as described above in order to make it easier to understand the nature of the signal 40. .

In the present embodiment, the torque ratio correlation value acquiring means includes an engine speed sensor 64, a turbine sensor 28, and a ROM 5 in which various programs are stored.
2 and a CPU 50 for calculating a rotation speed ratio or a rotation speed difference according to a program stored in the ROM 52. Further, the judgment means is the ROM 52
And a CPU 50, and the instruction means is a ROM 5.
2. It comprises a CPU 50 and an output port 58.

FIG. 3 shows the characteristics of the torque converter 12. Note that this characteristic corresponds to the torque converter 1 of this embodiment.
It is not a characteristic peculiar to 2, but a general characteristic of a three-element one-stage torque converter. In the figure, the horizontal axis represents the ratio between the rotation speed Nt of the turbine impeller 20 and the rotation speed Np of the pump impeller 18, that is, the rotation speed ratio e (= Nt / N).
p), the vertical axis represents the torque ratio t (= T _t / T _p , T _t : output torque, T _p : input torque) and efficiency η (= t ·
e). The torque ratio t becomes maximum at the stall point where the rotation speed ratio e = 0, and decreases as the rotation speed ratio e increases, and the torque ratio t becomes 1 at a certain rotation speed ratio e = a. Such a point where the torque ratio t becomes 1 is generally called a clutch point. When the rotational speed ratio e ≧ a is equal to or higher than the clutch point, the stator 24 idles in the same direction as the engine rotation by the one-way clutch 22 and loses its function as a torque converter (torque does not increase or decrease), and functions as a clutch. Therefore, this range is called a fluid coupling range, and a range of the rotational speed ratio e <a below the clutch point is called a torque converter range. In general, the characteristic curve of the efficiency η is a parabolic curve having a local maximum value within the torque converter range, and a curve increasing with the rotation speed ratio e in the coupling range. is there.

In the present embodiment, the control is performed so as to lock up within the range of the rotational speed ratio e equal to or more than the rotational speed ratio e = b at the maximum value of the efficiency characteristic curve.
The lockup shock and the wear of the lockup clutch 26a are reduced. That is, when the rotation speed ratio e = b at this maximum value is less than the torque ratio t, the torque ratio t is large, and the rotation speed difference between the input-side pump impeller 18 and the output-side turbine impeller 20 (hereinafter referred to as the rotation difference).
Since ΔN is large, if the lock-up is performed in this range, the lock-up shock is large and the amount of wear of the lock-up clutch 26a increases. On the other hand, even if the lock-up is performed in the range where the rotation speed ratio e = b or more at the maximum value, the torque ratio t and the rotation difference ΔN are small, so that the lock-up shock is small and the lock-up clutch 2
6a has a small wear amount.

FIGS. 4 and 5 show lock-up timing characteristics of the torque converter 12 with respect to various parameters. In the figure, the horizontal axis is the vehicle speed V, the vertical axis is the rotation speed ratio e, the engine speed Ne, and the rotation difference ΔN, and the speed of the select range D (D ₄ > D ₃ > D ₂ > D ₁ ) is a parameter. And FIG. 4 illustrates a lockup area and a non-lockup area, and FIG. 5 illustrates a lockup area, a slip lockup area, and a non-lockup area. In FIG.
Regarding the rotational speed ratio e, as described above, at any speed ratio, the value of the boundary value (lockup point) dividing the lockup region and the non-lockup region is set to the rotational speed ratio at the maximum value of the efficiency characteristic curve. The rotation speed ratio e is equal to or more than e = b. Further, the rotational speed ratio e of the lock-up point is increased as the speed becomes lower. In particular, the lock-up point of the lowest speed stage D ₁ is the rotational speed ratio e> a more than clutch point. This is because the torque applied to the drive wheels and the like increases as the speed decreases, and the lock-up shock tends to increase. Therefore, in order to suppress this, the torque ratio t is reduced (rotation speed ratio e
Because it locks up where it is).

As for the engine speed Ne, the engine speed Ne at the lock-up point is increased as the speed increases. This is to eliminate the vibration and muffled sound generated when the lockup is performed at a low speed at a high speed. Regarding the rotation difference ΔN, the rotation difference ΔN at the lock-up point is reduced as the speed becomes lower. This is because the rotational difference ΔN
This is because the lock-up shock is reduced by locking up in a small state. The rotation difference ΔN
Is related to a constant correlation with the rotation speed ratio e, that is, the rotation difference ΔN at which the rotation speed ratio e increases becomes smaller. Therefore, basically, one of the lock-up points can be managed. . In FIG. 5, the boundary value between the lockup region and the slip lockup region, and the boundary value between the lockup region and the slip lockup region are set in the same manner as the boundary values in FIG.

Next, the operation procedure of the control unit 32 will be described with reference to the flowcharts shown in FIGS. First, in the ROM 52 of the control unit 32, FIG.
The case where the lock-up timing characteristics for the rotation speed ratio e and the engine speed Ne are stored will be described with reference to FIGS. FIG. 6 shows a flowchart of the rotation speed ratio calculation. In step 101, the air amount QA, throttle opening θ, engine speed Ne, turbine speed Nt, etc. are read from the various sensors 62, 60,.
t and the rotational speed ratio e (= N
t / Ne = _nt / _np ) is calculated. In step 108, the basic fuel injection time TP is calculated, and in step 11
If 0, the gear position, that is, the gear ratio D, is obtained from the shift control valves 66 and 68. Next, the process proceeds to step 112 in FIG.

FIG. 8 shows a flowchart of lock-up control based on the rotation speed ratio. 6 and 8 is set to, for example, 10 ms. In step 112, it is checked whether or not the shift is in progress. This is determined based on a signal from the shift state sensor 65. If the shift is in progress, the routine proceeds to step 140, where a lock-up release signal is output to the duty solenoid 70. If the lockup is being performed, the lockup is released, and if the lockup is not performed, this state is maintained. If the shift is not being performed, the routine proceeds to step 114. In step 114, the current value θNEW of the throttle opening θ and the previous value θOLD
Is calculated and compared with a certain value C1 in step 116. C1 is, for example, a fixed value or a value determined by a load. Here, the change state of the throttle opening is checked to determine whether rapid acceleration or rapid deceleration is being performed. Throttle opening change Δ
If θ is equal to or less than C1, the process proceeds to step 118, and if θ exceeds C1, the process proceeds to step 132. In step 118, the difference ΔTP between the current value TPNEW of the basic fuel injection time TP and the previous value TPOLD is calculated, and in step 120, it is compared with a certain value C2. C2 is, for example, a fixed value or a value determined by a load. Here, the change state of the basic fuel injection time is checked, and if the change amount ΔTP is equal to or less than C2, that is, if the change in the basic fuel injection time TP is small, the process proceeds to step 122, and if the change is large, the process ends.

In step 122, it is checked whether or not the engine speed Ne to be locked up is in accordance with the gear ratio acquired in step 110. If it is not less than the engine speed Ne to be locked up, the routine proceeds to step 124, and if not, the routine proceeds to step 138. In step 124, the state of the lock-up clutch 26a is checked. If it is already in the ON state, the state is maintained.
Proceed to step 128. In step 128, it is checked whether or not the rotation speed ratio e should be locked up according to the speed ratio acquired in step 110. If the rotation speed ratio e is equal to or higher than the rotation speed ratio e to be locked up, step 1
At 30, the lock-up control is turned on. If the rotation speed ratio e to be locked up is not satisfied, the process ends.

In step 132, the difference Δθ between the current value θNEW of the throttle opening θ and the previous value θOLD is calculated. If the difference Δθ is larger than zero in step 134, it is determined that the gear is in an upshift state, and the routine proceeds to step 136. . If it is zero or negative in step 134, the previously set lock-up control state is maintained. If Δθ is equal to or greater than the value C3, it is determined that the vehicle is accelerating, and the routine proceeds to step 114, where lockup is released.
If Δθ is smaller than a certain value C3, the previously set lock-up control state is maintained. C3 is, for example, a fixed value or a value determined by a load. Step 13
At 8, it is checked whether or not the engine speed is the lock-up release engine speed. If the engine speed is equal to or lower than the lockup release engine speed, the routine proceeds to step 140, where a lockup release signal is output to the duty solenoid 70.

As described above, in this embodiment, the rotational speed ratio is obtained by calculation, the torque ratio of the torque converter is obtained indirectly, and the lock-up timing is set based on this value. Shock and wear of the lock-up clutch 26a can be reduced. In particular, in consideration of the fact that the lock-up shock becomes larger at the lower gear, the lock-up is performed at a lower torque ratio at the lower gear, so that the effect of reducing the lock-up shock when the lower gear is used is great.
Lockup should not be performed during sudden acceleration or sudden deceleration. This is because there is a very high possibility that the gear ratio changes during that time, and the torque amplifying action of the torque converter 12 should be used during that time. Therefore, in the present embodiment, this is checked using two variables of the throttle opening change amount Δθ and the basic fuel injection time change amount ΔTP. That is, it is early checked from the throttle opening change amount Δθ whether or not to enter a rapid acceleration state, and it is determined whether or not lock-up is to be performed in principle. It is checked whether or not the lockup is to be finally performed with the basic fuel injection time change amount ΔTP that changes. In this embodiment,
Throttle opening change Δθ and basic fuel injection time change Δ
Although it is determined whether the vehicle is undergoing rapid acceleration or sudden deceleration using TP, if it represents the amount of change in engine load instead of the amount of change in basic fuel injection time ΔTP, for example, the amount of change in engine speed May be used.

The above is the case where the turbine sensor 28 is provided. However, the present invention can be applied even when the turbine sensor 28 is not provided. This case will be described with reference to FIG. FIG. 6 shows the turbine sensor 2
9 shows a rotational speed ratio calculation flowchart when there is no 8;
In step 100, the vehicle speed V, the air amount QA, the throttle opening θ, the engine speed Ne, and the like are read. In step 102, the rotational speed ratio e is calculated from the vehicle speed V and the engine rotational speed Ne by the following equation.

[0029]

(Equation 1)

Here, i: the total reduction ratio V: the vehicle speed r: the effective radius of the tire of the driving wheel (m) Ne: the engine speed (r / min) After the rotation speed ratio e has been obtained, the description has been given above. Steps 108 and 110 are performed in the same manner as the processing, and then the process proceeds to step 112 in FIG.

Next, the operation when the lock-up timing characteristic for the engine speed Ne and the rotation difference ΔN of FIG. 4 is stored in the ROM 52 of the control unit 32 will be described with reference to FIGS. 9 and 10. . FIG. 9 shows a calculation flowchart of the rotation difference ΔN between the engine rotation speed Ne and the turbine rotation speed Np. Step 1
In step 04, the air amount QA, the throttle opening θ, the engine speed Ne, the turbine speed Nt, and the like are read. In step 105, the rotation difference ΔN, which is the difference between the engine speed Ne and the turbine speed Nt, is calculated. Do. Step 10
8 calculates the basic fuel injection time TP, and proceeds to step 11
A value of 0 determines the gear position from the shift control valves A and B. Next, the process proceeds to step 112 in FIG.

FIG. 10 shows a flowchart of lockup control based on the rotation difference ΔN. 9 and 10 is set to, for example, 10 ms. In this flowchart, the processing contents of the steps (even numbers) having the same numbers as the steps of the flowchart of the lockup control based on the rotation speed ratio e shown in FIG. 8 are the same.
Therefore, only step 129 having different processing contents will be described. In step 129, it is checked whether or not the rotation difference ΔN to be locked up according to the gear ratio. If the rotation difference ΔN is equal to or smaller than the rotation difference to be locked up, the lock-up control is turned on in step 130. If it is larger than the rotation difference ΔN to be locked up, the process ends. Even in this case, the same effects as those in the case where the flows shown in FIGS. 6 to 8 are implemented can be obtained. Although the lockup timing is basically controlled by the torque ratio t of the torque converter 12 according to the present invention, a rotation speed ratio or a rotation difference correlated with the torque ratio t is used instead of the torque ratio t. It was just a substitute.

In the flow charts shown in FIGS. 8 and 10, the conditions for turning on the lock-up are the throttle opening, the basic fuel injection time, the engine speed and the rotational speed ratio (or rotational difference). However, vehicle speed information may be used instead of the engine speed. Further, as the condition for releasing the lock-up, the change amount of the throttle opening, the engine speed, and the like are used during gear shifting, but vehicle speed information may be used instead of the engine speed. Also, since the change in the throttle opening is the rate of change of the load applied to the vehicle,
Instead of the throttle opening change amount, the suction negative pressure change amount may be used. When the slip lock-up control is performed, the slip lock-up may be performed when the lock-up is turned on or when the lock-up is released in the flowcharts shown in FIGS. In this embodiment, a stepped type automatic transmission is used,
The present invention is not limited to this, and there is no problem if the present invention is applied to a stepless type. Further, in the present embodiment, the case where the torque converter 12 is connected to the engine 10 has been described. However, the present invention may be applied to a case where the torque converter 12 is connected to a motor that has recently started to be used.

[0034]

According to the present invention, since the torque ratio at the time of lock-up can be managed for each of various speed ratios, the amount of lock-up shock and wear of the lock-up clutch can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an entire drive system including an automobile engine and an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a block circuit diagram of a control unit.

FIG. 3 is a graph showing characteristics of a torque converter.

FIG. 4 is a graph showing lock-up timing characteristics of a torque converter with respect to various parameters.

FIG. 5 is a graph showing lock-up timing characteristics of a torque converter with respect to various parameters.

FIG. 6 is a flowchart of a rotation speed ratio calculation when a turbine sensor is provided.

FIG. 7 is a flowchart of a rotation speed ratio calculation when there is no turbine sensor.

FIG. 8 is a flowchart of lockup control based on a rotation speed ratio.

FIG. 9 is a flowchart of a calculation of a rotation difference between an engine speed and a turbine speed.

FIG. 10 is a flowchart of lockup control based on a rotation difference.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Engine, 12 ... Torque converter, 14 ... Automatic stepped transmission, 18 ... Pump impeller, 20 ... Turbine impeller, 24 ... Stator, 26 ... Lockup mechanism, 26a
... lock-up clutch, 28 ... turbine sensor, 30
... Vehicle speed sensor, 32 ... Control unit, 50 ... CPU, 5
2 ROM, 54 RAM, 60 throttle opening sensor, 62 air amount sensor, 64 engine speed sensor, 65 gear shift state sensor.

Claims (8)

(57) [Claims] 1. A lock-up control device for an automatic transmission having a torque converter with a lock-up mechanism, wherein a torque ratio correlation value for directly or indirectly representing a torque ratio of the torque converter is obtained. Obtaining means; speed ratio detecting means for detecting the speed ratio of the transmission; storage means for storing a torque ratio correlation value predetermined as a lockup point for each speed ratio of the transmission; The torque ratio correlation value acquired by the correlation value acquisition unit is equal to or greater than the torque ratio correlation value corresponding to the detected gear ratio among the torque ratio correlation values stored as lock-up points in the storage unit. Determining means for determining whether or not the torque ratio correlation value is obtained by the torque ratio correlation value obtaining means; Instructing means for instructing the lock-up mechanism to lock up when the determining means determines that the torque ratio correlation value is equal to or more than the torque ratio correlation value stored as an up point. Automatic transmission lock-up control device. 2. A lock-up control device for an automatic transmission having a torque converter with a lock-up mechanism, wherein a torque ratio correlation value for directly or indirectly representing a torque ratio of the torque converter is obtained. Acquisition means; means for detecting an input-side rotational speed of the torque converter; speed ratio detection means for detecting a speed ratio of a transmission; and a torque predetermined as a lockup point for each speed ratio of the transmission. A storage unit in which a predetermined input-side rotational speed is stored as a ratio correlation value and a lockup point, and the torque ratio correlation value acquired by the torque ratio correlation value acquisition unit is a lockup point in the storage unit. Of the stored torque ratio correlation values, it is equal to or greater than the torque ratio correlation value corresponding to the detected gear ratio With judges whether, it was detected the input side rotational speed,
Judging means for judging whether or not the input-side rotational speed stored as a lock-up point in the storage means is equal to or higher than the input-side rotational speed corresponding to the detected gear ratio; and the torque ratio correlation value. When the determination unit determines that the torque ratio correlation value acquired by the acquisition unit and the detected input-side rotation side are greater than or equal to a value stored as a lock-up point in the storage unit, the lock-up mechanism A lock-up control device for an automatic transmission, the lock-up control device comprising: 3. The storage means stores an input-side rotational speed as a lock-up release point for each of various speed ratios of the transmission, and the determining means stores the detected input-side rotational speed. Determining whether the input-side rotational speed stored as a lock-up release point in the storage unit is equal to or lower than an input-side rotational speed corresponding to the detected gear ratio; and When the determination unit determines that the rotation speed is equal to or lower than the input-side rotation speed stored as the lock-up release point in the storage unit, it instructs the lock-up mechanism to release the lock-up. The lockup control device for an automatic transmission according to claim 2. 4. The torque ratio correlation value stored as a lock-up point in the storage means is equal to or greater than a value at which the efficiency of the torque converter indicates a maximum value. A lock-up control device for an automatic transmission according to any of the preceding claims. 5. The system according to claim 1, wherein said torque ratio correlation value stored as a lock-up point in said storage means is set to increase as the speed ratio of said transmission decreases. 5. The lock-up control device for an automatic transmission according to claim 3 or 4. 6. A shift state detecting means for detecting whether or not the automatic transmission is shifting, wherein the instruction means locks the lock-up mechanism when the automatic transmission is shifting. 6. The lock-up control device for an automatic transmission according to claim 1, wherein the lock-up release instruction is issued prior to the up-up instruction. 7. A throttle opening detecting means for detecting a throttle opening, and a calculating means for calculating a change amount between the detected throttle opening and a throttle opening detected a predetermined time before, wherein the determination is made. Means for judging whether or not the amount of change in the throttle opening is equal to or less than a preset value; and the instructing means further comprises: for example, the amount of change in the throttle opening is equal to or less than a preset value. When it is determined that the lock-up mechanism is locked, the lock-up mechanism is instructed to lock up.
7. The lock-up control device for an automatic transmission according to 5 or 6. 8. The torque ratio correlation value is a rotation speed ratio or a rotation speed difference between an input-side rotation speed and an output-side rotation speed of the torque converter. A rotation speed detecting means for directly or indirectly detecting an input side rotation speed and an output side rotation speed, and a calculation for calculating a rotation speed ratio or a rotation speed difference between the two based on the input side rotation speed and the output side speed. claim, characterized in that it is composed and means 3, 4, 5, 6 or 7
A lock-up control device for an automatic transmission according to any of the preceding claims.