JP2900667B2 - Slip lock-up control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip lock-up control device which is applied to a vehicle equipped with a power transmission mechanism such as an automatic transmission having a lock-up clutch and maintains the lock-up clutch in a half-clutch state.

[0002]

2. Description of the Related Art Conventionally, as a slip lock-up control device, for example, a device described in "Nissan Full Range Automatic Transmission Maintenance Manual-RE4R01A Type" is known.

The above-mentioned conventional source discloses hardware for electrically controlling a lock-up state by controlling a clutch oil pressure of a lock-up clutch built in a torque converter by a duty valve. Slip lock-up control has been proposed in which the slip rotation speed of the up clutch is controlled to a predetermined value to realize a half-clutch state.

The purpose of performing the slip lock-up control is as follows.

[0005] When the lock-up clutch is completely engaged, there is no loss due to slippage of the torque converter, so that there is a great effect in improving fuel efficiency. On the other hand, fluctuations in the output torque of the engine are directly transmitted, which adversely affects drivability. In particular, in a region where the engine speed is low, the torque fluctuation frequency of the engine becomes low, which may cause a phenomenon that is extremely uncomfortable for the driver. Therefore, in such an operating region, the lock-up clutch is not completely engaged, but is controlled to be in a half-clutch state, so as to achieve both improvement in fuel efficiency and prevention of deterioration in drivability.

[0006]

However, in the above-mentioned conventional lock-up control device, since the average value of the slip rotation speed is controlled to a target value (for example, 70 rpm), a lock-up clutch is used. When the rotation fluctuation width of the engine rotation speed, which is the input rotation speed, is small, as shown by the thin line characteristics in FIG. 10, the slip lock-up state is ensured, but the rotation fluctuation width of the engine rotation speed is large. In this case, as shown by the bold line characteristic in FIG. 10, a complete lock-up state occurs in which the engine speed and the torque converter output speed (output speed of the lock-up clutch) partially become the same. In the lock-up region, the engine torque vibration is directly transmitted to the automatic transmission, and the significance of performing the slip lock-up control is lost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems. In a slip lock-up control device for a lock-up clutch provided in a power transmission mechanism, a slip lock by a half-clutch is always used during slip lock-up control. Ensuring the up state is a common issue.

[0008]

In order to solve the above-mentioned common problem, in the slip lock-up control device according to the first aspect of the present invention, the minimum value of the input rotational speed is set to the target slip value in the output rotational speed detection value.
Means for controlling the engagement force of the lock-up clutch so as to match the value obtained by adding the lock amount α .

That is, as shown in the claim correspondence diagram of FIG. 1A, a power transmission mechanism b having a lock-up clutch a, and a lock-up clutch input speed detection for detecting the input speed of the lock-up clutch a. means c, a lock-up clutch output rotational speed detecting means d for detecting an output rotation speed of the lockup clutch a, the lock
The engagement detected by the up clutch input rotation speed detection means
Stores the minimum value data of force rotation speed,
An input rotational speed minimum value calculating means e for outputting the average value data as the minimum value, the input rotational speed minimum value output speed test
And a slip lock-up control means f for controlling the engagement force of the lock-up clutch a so as to match a value obtained by adding the target slip amount α to the output value .

In order to solve the above-mentioned common problem, in the slip lock-up control device according to the second aspect, the calculated value of the torque fluctuation width based on the actual detection of the output torque is determined by the vehicle speed or the slot.
The control means controls the engagement force of the lock-up clutch so as to match the target value of the torque fluctuation width according to the operating conditions such as the opening degree of the clutch.

That is, as shown in the claim correspondence diagram of FIG. 1B, a power transmission mechanism b having a lock-up clutch a, output torque detecting means g for detecting an output torque of the power transmission mechanism b, the output torque detecting means g
Monitor the detected output, find its maximum and minimum,
The average value of the local maximum data and the average
A torque fluctuation width calculating means h for outputting a difference between the average values as a torque fluctuation width of the output torque, and a target value of the torque fluctuation width as a vehicle speed.
And a torque fluctuation width target value setting means j which is set in accordance with operating conditions i such as a throttle opening and a throttle opening degree, and the engagement force of the lock-up clutch a such that the torque fluctuation width calculation value matches the torque fluctuation width target value. And a slip lock-up control means k for controlling

[0012]

The operation of the first aspect of the present invention will be described.

[0013] Slip lock the up control when, at the input speed minimum value calculating means e, lock-up clutch a minima de input speed input rotational speed detected by the lock-up clutch input rotational speed detecting means c for detecting of the
Data and store the average of the minimum value data
It is output as the minimum value of the force rotation speed . Then, in the slip lock-up control means f, the minimum value of the input rotation speed matches the value obtained by adding the target slip amount α to the output rotation speed detection value from the lock-up clutch output rotation speed detection means d. The engagement force of the lock-up clutch a is controlled.

Accordingly, the minimum value of the input rotation speed of the lock-up clutch a is controlled so as to maintain a value higher than the output rotation speed of the lock-up clutch a. Regardless, during the slip lock-up control, a complete lock-up state in which the input rotation speed and the output rotation speed of the lock-up clutch a coincide with each other is prevented.

The operation of the second aspect will be described.

At the time of the slip lock-up control, the target value of the torque fluctuation width is set in the torque fluctuation width target value setting means j according to the operating conditions i such as the vehicle speed and the throttle opening . On the other hand, in the torque fluctuation width calculating means h, the output detected by the output torque detecting means g for detecting the output torque of the power transmission mechanism b is monitored, and its maximum value and minimum value are monitored.
Is calculated, and the average and local minimum data of the local maximum data
Out the difference between the average value of over motor as the torque fluctuation width of the output torque
Is forced. Then, the slip lock-up control means k controls the engagement force of the lock-up clutch a so that the calculated value of the torque fluctuation width matches the torque fluctuation width target value.

Therefore, even if the input rotation speed of the lock-up clutch a fluctuates, feedback control is performed so that the fluctuation range of the output torque of the lock-up clutch a matches the target value. This means that a complete lock-up state of the lock-up clutch a in which the input rotational speed fluctuation directly changes the output torque during slip lock-up is prevented.

[0018]

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

(First Embodiment) First, the configuration will be described.

FIG. 2 is an overall system diagram showing a slip lock-up control device according to a first embodiment corresponding to the first embodiment of the present invention. An automatic transmission 3 (equivalent to a power transmission mechanism) and an input rotation sensor 5 (lock-up clutch input) which is provided at a position of an input shaft 4 of the lock-up clutch 2 and detects an input rotation speed (= engine rotation speed). A rotation speed detecting means) and an output rotation sensor 7 (lockup clutch output rotation speed detecting means) which is provided at the position of the output shaft 6 of the lock-up clutch 2 and detects an output rotation speed (transmission input rotation speed). Engine control which inputs signals from both sensors 5 and 7 and outputs a control command to hydraulic actuator 8 after performing predetermined arithmetic processing. And it includes a knit 9.

The automatic transmission 3 includes a torque converter 1
0 and a transmission 11, and the lock-up clutch 2 is built in the torque converter 10.

The engine control unit 9 has a minimum value calculator 9a for calculating a minimum value of the input rotation speed.
(Corresponding to an input rotation speed minimum value calculating means) and a lock-up clutch for controlling the engagement capacity of the lock-up clutch 2 so that the input rotation speed minimum value becomes a predetermined target value higher than the output rotation speed detection value. The control unit 9b (corresponding to slip lock-up control means) is incorporated as a control program.

Next, the operation will be described.

FIG. 3 is a flowchart showing the flow of the minimum value calculation processing operation performed by the minimum value calculation section 9a of the engine control unit 9. Each step will be described below. This flowchart is executed at regular intervals (for example, 10 msec).

First, an outline is described. An engine speed is read, its minimum value is obtained, then the average of the past several minimum values (10 times in the flow chart) is calculated, and the calculated value is defined as a “minimum value”. Output.

More specifically, at step 30, an engine rotation signal is read from the input rotation sensor 2, and at step 31
It is determined whether or not FLAG-U = 1. Here, FLAG-U is a FLAG indicating whether or not the engine speed up to the previous time was in an increasing state. If it is “1”, it is in an increasing state, and if it is “0”, it is in a decreasing state. It represents that it was.

If YES in step 31, step 3
Then, it is determined whether or not the current engine speed is equal to or higher than the previous engine speed. If YES, that is, if the increasing state continues, FLAG-U = 1 is maintained, and if NO, If the process proceeds to step 33, the FLAG-U
Is rewritten to “0”.

If NO in step 31, step 34
It is determined whether or not the current engine speed is equal to or lower than the previous engine speed. If YES, that is, if the decreasing state is continued, FLAG-U is kept at 0, and
If NO, the process proceeds to step 35, where FLAG-U is rewritten to "1". Further, the process proceeds to step 36, where the engine speed has been changed from a decrease to an increase. Value data ”.

Finally, in step 37, the average of the last 10 "minimum value data" is output as the "minimum value".

FIG. 4 is a flowchart showing the flow of the clutch capacity control processing operation performed by the lock-up clutch control section 9b of the engine control unit 9. Each step will be described below.

In step 40, the "minimum value" obtained in the process of FIG. 3 and the output rotation signal from the output rotation sensor 7 are read. In step 41, the minimum value of the engine speed and the output speed are set to a predetermined value α ( the target slip of claim 1).
The magnitude is compared with a value obtained by adding a value corresponding to the pumping amount, for example, 30 rpm. When the minimum value <(output rotation speed + α), the engagement force of the lock-up clutch 2 is in an excessively strong state, so the process proceeds to step 42, and a command to reduce the engagement capacity of the lock-up clutch 2 is output. , Minimum value ≧
(Output speed + α), the lock-up clutch 2
Since the engagement force of the lock-up clutch 2 is too weak, the process proceeds to step 43, and a command to increase the engagement capacity of the lock-up clutch 2 is output.

(C) Slip lock-up control operation When slip lock-up control is performed based on a slip lock-up request during traveling, the "minimum value" of the input rotation speed of the lock-up clutch 2 is output from the lock-up clutch 2. The input speed of the lock-up clutch 2 is controlled during the slip lock-up control regardless of the magnitude of the fluctuation range of the input speed of the lock-up clutch 2 regardless of the magnitude of the fluctuation range of the input speed of the lock-up clutch 2. This prevents a complete lock-up state in which the rotational speed and the output rotational speed match.

Next, the effects will be described.

(1) The engagement force of the lock-up clutch 2 is controlled so that the "minimum value" of the input rotation speed becomes a predetermined target value (output rotation speed + α) higher than the output rotation speed by a predetermined value α. Therefore, the slip lock-up state by the half-clutch can always be ensured during the slip lock-up control regardless of the rotation fluctuation of the engine 1. As a result, the original purpose of the slip lock-up control, which achieves both improvement in fuel efficiency and prevention of deterioration in drivability, is always realized.

(2) Since the input information is obtained from the input rotation sensor 5 corresponding to the engine rotation sensor and the output rotation sensor 7 corresponding to the turbine rotation sensor, the control system for the engine 1 and the automatic transmission 3 is normally used. By simply diverting these sensors 5 and 7 used and adding a control program to them, the system of the first embodiment can be introduced with cost advantages.

(Second Embodiment) First, the configuration will be described.

FIG. 5 is an overall system diagram showing a slip lock-up control device according to a second embodiment corresponding to the second embodiment of the present invention. Transmission 3 (corresponding to a power transmission mechanism) and a torque sensor 13 provided at a position of a transmission output shaft 12 and detecting transmission output torque.
(Corresponding to output torque detecting means), an engine speed sensor 14 for detecting engine speed (corresponding to means for detecting operating conditions), and a throttle opening sensor 15 for detecting throttle opening (for detecting operating conditions). Means) and
An engine control unit 16 is provided which receives signals from the sensors 13, 14, 15 and outputs control commands to the hydraulic actuator 8 after performing predetermined arithmetic processing.

The automatic transmission 3 includes a torque converter 1
0 and a transmission 11, and the lock-up clutch 2 is built in the torque converter 10.

The engine control unit 16 includes a torque fluctuation calculator 16a (corresponding to a torque fluctuation calculator) for calculating the torque fluctuation of the output torque from the torque sensor 13, and a target value of the torque fluctuation. Target torque variation width determining unit 16b (corresponding to a torque variation target value setting means) determined according to the rotation speed and the throttle opening.
And a lock-up clutch control section 16c (corresponding to a slip lock-up control means) for controlling the engagement capacity of the lock-up clutch 2 so that the torque fluctuation width calculation value matches the torque fluctuation width target value. ing.

Next, the operation will be described.

FIG. 6 is a flowchart showing the flow of the torque fluctuation width target value determination processing operation performed by the target torque fluctuation width determination section 16b of the engine control unit 16. FIG. Will be described.

In step 60, the engine speed from the engine speed sensor 14 and the throttle opening sensor 1
The throttle opening from 5 is read.

In step 61, the target value of the torque fluctuation width is retrieved from the actually measured values of the engine speed and the throttle opening and the torque fluctuation width target value map shown in FIG. Here, the torque fluctuation target value map shows that when the throttle opening is constant, a torque fluctuation target value that increases with an increase in the engine speed is obtained. It is set such that a torque fluctuation width target value that decreases with an increase in the opening is obtained.

FIG. 8 is a flowchart showing the flow of the torque fluctuation width calculation processing performed by the torque fluctuation width calculation section 16a of the engine control unit 16. Each step will be described below. This flowchart is executed at regular intervals (for example, 10 msec).

First, an overview will be given. The output from the torque sensor 13 is monitored, the maximum value and the minimum value thereof are obtained, and the average value of the maximum values and the average value of the minimum values in recent several times (10 times in the flowchart) are obtained. Is calculated, and the difference is output as “torque fluctuation width”.

Specifically, at step 80, a signal from the torque sensor 13 is read, and at step 81, the FLAG
It is determined whether -U = 1. Where FLAG
-U is a FLAG indicating whether or not the output of the torque sensor 13 has been increasing up to the previous time. "1" indicates that the output was in the increasing state, and "0" indicates that it was not. ing.

If YES in step 81, the process proceeds to step 82, where it is determined whether or not the current torque is equal to or greater than the previous torque. If YES, that is, if the increasing state continues, FLAG- If U = 1, and if NO in step 81, that is, if the transition is from increase to decrease, the process proceeds to step 83, where FLAG-U is set to "0".
And the routine proceeds to step 84, where the previous torque is stored as the latest "maximum value data".

If NO in step 81, the process proceeds to step 85, in which it is determined whether the current torque is equal to or less than the previous torque. If YES, that is, if the decreasing state is continued, FLAG- If U is kept at 0 and NO in step 85, that is, if the transition is from decrease to increase, the process proceeds to step 86, where FLAG-U is rewritten to “1”, and the process proceeds to step 87, where The torque is stored as the latest “minimum value data”.

Finally, in step 88, a value obtained by subtracting the average value of the past 10 "minimum value data" from the average value of the past 10 "maximum value data" is output as "torque fluctuation width".

(C) Clutch capacity control operation FIG. 9 is a flowchart showing the flow of the clutch capacity control processing operation performed by the lock-up clutch control section 16c of the engine control unit 16. Each step will be described below.

In step 90, it is determined whether the torque fluctuation width <the torque fluctuation target value based on the “torque fluctuation target value” obtained in the processing of FIG. 7 and the “torque fluctuation width” obtained in the processing of FIG. Is determined. If YES, the torque fluctuation is excessively suppressed, and the engagement force of the lock-up clutch 2 is in an excessively weak state. Therefore, the process proceeds to step 91, and a command to increase the engagement capacity of the lock-up clutch 2 is output. .

On the other hand, if “NO” in the step 90, the process proceeds to a step 92, in which it is determined whether or not the torque fluctuation width> the torque fluctuation target value. If YES, the torque fluctuation is excessively permitted, and the engagement force of the lock-up clutch 2 is in an excessively strong state.
A command to reduce the engagement capacity of the lock-up clutch 2 is output. It should be noted that torque fluctuation width = torque fluctuation target value,
If both NO in step 90 and step 92,
The engagement force of the lock-up clutch 2 at that time is maintained.

(D) Slip lock-up control operation When the slip lock-up control is performed based on a slip lock-up request during traveling, even if the input speed (engine speed) of the lock-up clutch 2 fluctuates, the lock is locked. Feedback control is performed so that the fluctuation range of the output torque of the up clutch 2 matches the torque fluctuation target value.
This means that a complete lock-up state of the lock-up clutch 2 in which a change in engine speed directly changes in output torque during slip lock-up is prevented.

Next, the effects will be described.

(1) The apparatus for controlling the engagement force of the lock-up clutch 2 so that the torque fluctuation width based on the actual output torque detection coincides with the torque fluctuation width target value corresponding to the operating condition. Regardless of the rotation fluctuation, the slip lockup state by the half clutch can always be ensured during the slip lockup control. As a result, the original purpose of the slip lock-up control, which achieves both improvement in fuel efficiency and prevention of deterioration in drivability, is always realized.

(2) Since the output torque information is used as input information and the feedback control is directly performed on the lock-up clutch 2 so as to suppress the fluctuation range of the output torque, the output torque which affects the drivability is obtained. Fluctuations are systematically suppressed over the entire engine speed range,
In particular, a large improvement in drivability can be obtained in a region where the torque fluctuation frequency of the engine 1 is low and the engine speed is low, accompanied by a phenomenon that is extremely unpleasant for the driver.

Although the embodiments have been described with reference to the drawings, the specific configuration is not limited to the embodiments, and any changes or additions without departing from the gist of the present invention are included in the present invention. It is.

For example, in the embodiment, an example in which the present invention is applied to an automatic transmission having a lock-up clutch in a torque converter has been described. However, the present invention can also be applied to a continuously variable transmission having a lock-up clutch in a fluid coupling.

In the second embodiment, a so-called dead zone is not set. However, various auxiliary control contents may be added, for example, by setting a dead zone to improve control stability.

[0060]

As described above, according to the first aspect of the present invention, in the slip lock-up control device for the lock-up clutch provided in the power transmission mechanism, the minimum value of the input rotation speed is set to the output rotation speed. Set the target slip to the detected value.
Since the slip lock-up control means for controlling the engagement force of the lock-up clutch is provided so as to match the value obtained by adding the lock amount α , the slip lock-up state by the half-clutch can always be ensured during the slip lock-up control. The effect is obtained.

According to the second aspect of the present invention,
In the slip lock-up control device for the lock-up clutch provided in the power transmission mechanism, the calculated value of the torque fluctuation width based on the actual detection of the output torque indicates the vehicle speed and the throttle opening.
Slip lock-up control means that controls the engagement force of the lock-up clutch so that it matches the target value of the torque fluctuation width according to the operating conditions such as the degree Can be obtained.

[Brief description of the drawings]

FIG. 1 (A) is a claim correspondence diagram showing a slip lock-up control device according to claim 1, and FIG. 1 (B).
FIG. 3 is a claim correspondence diagram showing a slip lock-up control device according to claim 2.

FIG. 2 is an overall system diagram showing a slip lock-up control device according to a first embodiment.

FIG. 3 is a flowchart illustrating a flow of a minimum value calculation processing operation performed by an engine control unit of the first embodiment device.

FIG. 4 is a flowchart showing a flow of a clutch capacity control processing operation performed by an engine control unit of the first embodiment device.

FIG. 5 is an overall system diagram showing a slip lock-up control device according to a second embodiment.

FIG. 6 is a flowchart showing a flow of a torque fluctuation target value determination processing operation performed by an engine control unit of the second embodiment device.

FIG. 7 is a diagram showing a torque fluctuation target value map preset in an engine control unit of the second embodiment device.

FIG. 8 is a flowchart illustrating a flow of a torque fluctuation width calculation processing operation performed by an engine control unit of the device of the second embodiment.

FIG. 9 is a flowchart showing a flow of a clutch capacity control processing operation performed by an engine control unit of the second embodiment device.

FIG. 10 is a time chart showing input rotation and output rotation of a torque converter during conventional slip lock-up control.

[Explanation of symbols]

 a Lock-up clutch b Power transmission mechanism c Lock-up clutch input rotation speed detection means d Lock-up clutch output rotation speed detection means e Input rotation speed minimum value calculation means f Slip lock-up control means g Output torque detection means h Torque fluctuation width calculation Means i Operating conditions j Torque fluctuation width target value setting means k Slip lockup control means

Claims (2)

(57) [Claims] 1. A power transmission mechanism having a lock-up clutch, a lock-up clutch input speed detecting means for detecting an input speed of the lock-up clutch, and a lock-up clutch for detecting an output speed of the lock-up clutch. Output speed detecting means, and the lock-up clutch input speed detecting means.
The minimum value data of the input rotation speed is stored and the past
Several times and input speed minimum value computing means for outputting an average minimum value data as the minimum value of the target slit to the input speed minimum value output rotational speed detection value
And a slip lock-up control means for controlling the engagement force of the lock-up clutch so as to match a value obtained by adding the lock amount α . 2. A power transmission mechanism having a lock-up clutch, output torque detection means for detecting an output torque of the power transmission mechanism, and monitoring an output detected by the output torque detection means.
The maximum value and the minimum value are obtained, and the maximum value
Torque fluctuation calculating means for outputting the difference between the average value of the motor data and the average of the minimum value data as the torque fluctuation width of the output torque, and the target value of the torque fluctuation width according to operating conditions such as vehicle speed and throttle opening. A torque fluctuation width target value setting means to be set; and a slip lock-up control means for controlling an engagement force of the lock-up clutch such that the torque fluctuation width calculation value matches the torque fluctuation width target value. A slip lock-up control device, characterized in that: