JP3677802B2 - Hydraulic control device for automatic transmission - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a hydraulic control device for an automatic transmission, and more particularly to a device for detecting deterioration of hydraulic oil charged in a torque converter.
[0002]
[Prior art]
Conventionally, as a device for detecting deterioration of hydraulic oil of a torque converter, there is a device disclosed in Japanese Patent Laid-Open No. 4-224363.
The torque converter of the apparatus described in the above publication is a turbine that transmits torque between an impeller connected to a crankshaft of an internal combustion engine (engine) and an impeller via hydraulic oil, and is connected to an output shaft. And a direct coupling mechanism that directly couples the turbine and the impeller or controls the slip amount therebetween.
[0003]
When minute slip control is performed by this direct coupling mechanism, when hunting or vibration occurs, it is determined that the hydraulic oil has deteriorated.
[0004]
[Problems to be solved by the invention]
However, the apparatus described in the above publication cannot detect the deterioration of the hydraulic oil unless a direct coupling mechanism is provided, and further requires a means for detecting vibration or hunting, which complicates the configuration.
An object of the present invention is to provide a device that can detect deterioration of hydraulic oil even in an automatic transmission that has a simple configuration and does not include a direct coupling mechanism.
[0005]
[Means for Solving the Problems]
Accordingly, in the first aspect of the present invention, as illustrated in FIG. 8, a torque converter provided between the internal combustion engine and the gear transmission, and an initial input / output of the torque converter for each driving state of the vehicle. an initial rotational speed storage means for storing the rotational speed difference or output rotational speed ratio, a rotation speed detecting means for detecting an actual output rotational speed difference or output rotational speed ratio of the torque converter, the rotational speed detecting means The input / output rotational speed difference or the input / output rotational speed ratio detected by the control unit and the input / output rotational speed difference or the input / output rotational speed ratio detected by the rotational speed detecting means are stored in the initial rotational speed storage means. There is provided a hydraulic control device for an automatic transmission, comprising a deterioration detecting means for detecting deterioration of hydraulic oil of a torque converter based on a difference in input / output rotational speed or an input / output rotational speed ratio .
[0006]
According to a second aspect of the present invention, the deterioration detecting means is stored in the initial rotational speed storage means of the operating state when the input / output rotational speed difference detected by the rotational speed detecting means and the input / output rotational speed are detected. 2. The hydraulic control device for an automatic transmission according to claim 1, further comprising means for detecting deterioration of hydraulic oil of the torque converter based on the difference between the input and output rotational speeds.
[0007]
According to a third aspect of the present invention, the torque converter includes a lockup clutch that directly connects or slips the input shaft and the output shaft, and when the deterioration of the hydraulic oil is detected by the deterioration detecting means, the slip control of the lockup clutch is performed. 3. A hydraulic control device for an automatic transmission according to claim 1, further comprising target slip amount correction means for correcting the target slip amount at the time.
[0008]
The automatic transmission according to any one of claims 1 to 3, further comprising warning means for giving a warning when the deterioration of the hydraulic oil is detected by the deterioration detecting means. A hydraulic control device for a machine is provided.
[0009]
[Action]
By adopting the above configuration, in claim 1, the torque converter is provided between the internal combustion engine and the gear transmission, and the initial rotational speed storage means is the initial input / output of the torque converter for each driving state of the vehicle. The number of revolutions is stored.
The rotational speed detection means detects the actual input / output rotational speed of the torque converter, the deterioration detection means detects the input / output rotational speed detected by the rotational speed detection means, and the input / output rotational speed is detected by the rotational speed detection means. The deterioration of the hydraulic fluid of the torque converter is detected based on the input / output rotational speed stored in the initial rotational speed storage means of the operating state at that time.
[0010]
According to a second aspect of the present invention, the deterioration detecting means is stored in the initial rotational speed storage means of the operating state when the input / output rotational speed difference detected by the rotational speed detecting means and the input / output rotational speed are detected. The deterioration of the hydraulic oil of the torque converter is detected based on the difference between the input and output rotational speeds.
According to a third aspect of the present invention, the torque converter includes a lockup clutch that directly connects or slips the input shaft and the output shaft, and the target slip amount correcting means locks when the deterioration of the hydraulic oil is detected by the deterioration detecting means. Correct the target slip amount during up clutch slip control.
[0011]
Furthermore, in claim 4, the warning means issues a warning when the deterioration of the hydraulic oil is detected by the deterioration detection means.
[0012]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an automatic transmission according to a first embodiment using the present invention. However, with respect to the torque converter 3, only the upper half sectional view is shown, and the lower half is omitted.
[0013]
The output rotation of the internal combustion engine (engine) 1 is input to the torque converter 3 via the input shaft 2. A front cover 4 and an impeller 5 of the torque converter 3 are connected to the input shaft 2. The turbine 6 is rotatably accommodated in the front cover 4 and is fixed to the output shaft 7. The torque converter 3 transmits torque between the impeller 5 and the turbine 6 via hydraulic oil when a lockup clutch 8 of a direct coupling mechanism described later is opened. The output shaft of the torque converter 3 is connected to the gear transmission 12.
[0014]
The lockup clutch 8 is fixed to the output shaft and rotates integrally with the turbine 6. A space 9 is defined between the lockup clutch 8 and the front cover 4, and the space 9 communicates with a port 10 of the torque converter 3. When hydraulic oil is supplied to the space 9 via the port 10, hydraulic pressure is applied to the lockup clutch 8 in a direction to separate it from the front cover 4. Further, the torque converter 3 has another port 11, and when hydraulic oil is supplied from this port, the hydraulic pressure is operated in a direction in which the lockup clutch is pressed against the front cover 4.
[0015]
The hydraulic fluid supplied to the torque converter 3 via the ports 10 and 11 is controlled by the hydraulic control device 13. The hydraulic control device 13 is controlled by an electronic control unit (ECU) 14. FIG. 2 is a block diagram showing processing executed by the ECU 14. Hereinafter, a description will be given with reference to FIG.
First, signals from various sensors are input to the ECU 14. As these sensors, in the present embodiment, the input rotation speed sensor 15 for detecting an input rotational speed N _p of the torque converter 3, the output rotational speed sensor 16 for detecting an output rotation speed N _T of the torque converter 3, detects the vehicle speed V A vehicle speed sensor, a throttle opening sensor for detecting the throttle opening θ, an oil temperature sensor for detecting the hydraulic oil temperature T, and a transmission rotation speed sensor for detecting the output rotation speed N ₀ of the transmission gear.
[0016]
The driving condition detection unit 141 reads the driving state of the vehicle from the signal input to the ECU 14 and determines whether the driving state of the vehicle has changed. The subsequent torque converter input / output rotation difference calculation unit 142 calculates the input / output rotation speed difference of the torque converter from the input and output of the output rotation speed sensor when the driving state of the vehicle is stable. Further, the torque converter input / output rotation speed map search unit searches the map for the initial value of the torque converter input / output rotation speed difference corresponding to the operation state at this time.
[0017]
The deterioration determination unit 144 determines the degree of deterioration of the hydraulic oil based on the actual value calculated by the torque converter input / output rotation speed difference calculation unit 142 and the initial value searched by the torque converter input / output rotation speed map search unit. To do. Then, the processing command unit 145 outputs a signal to light the warning lamp 17 based on the result determined by the deterioration determination unit, for example.
[0018]
Next, the process executed by the ECU 14 will be described based on the flowchart shown in FIG. This flowchart is executed every predetermined time.
Further, in this flowchart, the priority is set lower than other controls necessary for vehicle travel such as over-shift control.
When this processing is started, first, at step 100, the value of the counter C is cleared. The counter C is a counter for counting that the same operating condition continues for a predetermined period. In the following step 200, the operation conditions input from various sensors are read. In this embodiment, the transmission gear position obtained from the input rotational speed N _p , the output rotational speed N _T , the vehicle speed V, the throttle opening θ, the hydraulic oil temperature T, and the transmission gear rotational speed of the torque converter 3 is read as operating conditions.
[0019]
In step 300, it is determined whether each operating condition read in step 200 is larger than the maximum value read in the previous time or smaller than the minimum value. If an affirmative determination is made, the process proceeds to step 400, and the value is set. Update the maximum value or the minimum value, and proceed to Step 500. If a negative determination is made in step 300, the process proceeds to step 500 as it is.
[0020]
In step 500, the counter value is incremented by one. Then, in step 600, it is determined whether or not the value of the counter C is larger than the predetermined value A. When the value is equal to or smaller than the predetermined value A, the process returns to step 200 again, and the processing from step 200 to step 500 is repeated. If it is determined in step 600 that the value of the counter C is greater than the predetermined value A, the process proceeds to step 700.
[0021]
In step 700, it is determined whether or not the difference between the maximum value and the minimum value of each sensor input is less than a predetermined value B, and whether or not the gear position has changed. If a negative determination is made here, all of the operating conditions read in step 200 are cleared, and the process returns to step 100. If an affirmative determination is made, the process proceeds to step 800 to start processing for detecting deterioration of hydraulic oil.
[0022]
First, in step 800, from the three-dimensional map of the vehicle speed V, the throttle opening θ, and the hydraulic oil temperature T shown in FIG. 4, the initial value N _PT of the input / output rotational speed difference of the torque converter corresponding to the operating condition read this time. Read in. Next, in step 900, the current input / output rotational speed difference NR _PT of the torque converter is calculated from the following equation using the value read in step 300.
[0023]
[Expression 1]
NR _PT = {(MAX _NP + MIN _NP )-(MAX _NT + MIN _NT )} / 2
Here, MAX _NP is the maximum value of the input speed of the torque converter, MIN _NP is the minimum value of the input speed of the torque converter, MAX _NT is the maximum value of the output speed of the torque converter, and MIN _NT is the output speed of the torque converter. The minimum number.
[0024]
Then, in step 1000, it is determined by the following formula whether the working hydraulic pressure has deteriorated.
[0025]
[Expression 2]
abs (N _PT −NR _PT )> D
Here, abs (N _PT −NR _PT ) is an absolute value of a difference between the initial value N _PT and the current value NR _PT . Here, if an affirmative determination is made, it is determined that the hydraulic oil has deteriorated, the process proceeds to step 1100, and the deterioration of the hydraulic oil is reported by a warning light. When a negative determination is made, the process proceeds to step 1200.
[0026]
That is, in the present invention, the deterioration is detected by utilizing the fact that the input / output relationship of the torque converter changes because the viscosity changes when the hydraulic oil of the torque converter deteriorates.
Next, an embodiment in which the shift of the target slip amount of the lockup clutch accompanying the deterioration of the hydraulic oil is corrected using the hydraulic oil deterioration detection result of the present invention will be described as a second embodiment with reference to FIG. Steps that perform the same processing as in FIG. 3 are assigned the same step numbers as in FIG. 3, and descriptions thereof are omitted.
[0027]
When this process is executed, the same process as in FIG. 3 is executed from step 100 to step 1000. When an affirmative determination is made at step 1000, that is, when it is determined that the hydraulic oil has deteriorated, the routine proceeds to step 2000, where the slip initial target control value shown in FIG. 6 is rewritten.
In this embodiment, a value obtained by subtracting the correction value ΔD _SL from the initial target control value D _SL is newly set as the target control value D _SL . Further, as shown in FIG. 7, in this embodiment, since the off time of the duty signal is given as the control value, the lock-up clutch is shown in FIG. 1 by subtracting the correction value ΔD _SL when the hydraulic oil deteriorates. It is corrected in the direction to be pressed against the front cover. This is because when the hydraulic oil is deteriorated, the viscosity of the oil is lowered, so that the lockup clutch is easily slipped.
[0028]
As described above, by adopting the configuration of the second embodiment, it is possible to easily control the lockup clutch to the target slip amount even when the hydraulic oil is deteriorated.
In each of the above embodiments, the throttle opening is used to detect the operating condition. However, the present invention is not limited to this, and other signals that can estimate the engine torque may be used.
[0029]
Further, in each of the above embodiments, the deterioration determination is determined using the predetermined value D as a threshold value. However, a plurality of threshold values are provided so that the deterioration degree is detected and displayed at each stage. Good. At this time, the correction value ΔD _SL in the second embodiment may be set to a value that increases as the degree of deterioration increases, for example, according to the degree of deterioration.
In the present embodiment, the warning lamp is turned on when the deterioration of the hydraulic oil is detected, but other warnings may be made by voice or the like.
[0030]
In each of the above embodiments, the deterioration of the hydraulic oil is detected from the difference between the initial input / output rotational speed difference of the torque converter and the current input / output rotational speed difference of the torque converter. The ratio between the initial torque converter input / output rotational speed difference and the current torque converter input / output rotational speed difference, or the initial torque converter input / output rotational speed ratio and the current torque converter input / output rotational speed ratio. The deterioration of the hydraulic oil may be detected from the difference between the two.
[0031]
In addition, the initial value of the input / output rotation speed of the torque converter may be a preset value, or a preset value may be set for a predetermined period after the battery is connected to the vehicle (for example, several trips, within a predetermined time). Etc.) may be corrected with actual data detected.
Furthermore, in this embodiment, the warning light is turned on once the deterioration is detected or the target slip amount is corrected. However, these deteriorations are not detected until a predetermined number of times are detected in order to prevent erroneous detection. You may make it perform control.
[0032]
By determining the deterioration of the hydraulic oil in this way, it is possible to inform the user of the vehicle of the replacement timing of the hydraulic oil. Further, when the period in which the deterioration of the hydraulic oil is detected is extremely short, it may be determined that there is an abnormality in the automatic transmission.
[0033]
【The invention's effect】
As described above, in the first or second aspect of the invention, the automatic input / output speed of the torque converter is detected by detecting the initial input / output rotational speed and the current input / output rotational speed. Even in a transmission, it is possible to easily detect deterioration of hydraulic oil.
[0034]
In the invention according to claim 3, the target slip control of the lockup clutch can be satisfactorily detected even when the hydraulic oil is deteriorated.
Furthermore, in the invention described in claim 4, it is possible to notify the operating vehicle replacement time and the like by notifying the driver vehicle or the like by the warning means of the deterioration of the operating oil.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an automatic transmission used in a first embodiment of the present invention.
FIG. 2 is a block diagram of the electronic control unit of the first embodiment.
FIG. 3 is a flowchart executed by the electronic control unit in the first embodiment.
FIG. 4 is a three-dimensional map for obtaining an initial value of an input / output rotation speed difference in the first embodiment.
FIG. 5 is a flowchart executed by the electronic control unit in the second embodiment.
FIG. 6 is a map for obtaining a target slip amount in the second embodiment.
FIG. 7 is an explanatory diagram for explaining a control signal when executing slip control in the second embodiment.
FIG. 8 is a block diagram showing components of the present invention.
[Explanation of symbols]
1 Internal combustion engine
2 Input shaft 3 Torque converter 7 Output shaft 8 Lock-up clutch 12 Gear transmission 13 Hydraulic control device 14 Electronic control unit (ECU)
15 Input speed sensor 16 Output speed sensor 17 Warning light

Claims (4)

A torque converter provided between the internal combustion engine and the gear transmission;
Initial rotational speed storage means for storing an initial input / output rotational speed of the torque converter for each driving state of the vehicle;
A rotational speed detection means for detecting an actual input / output rotational speed difference or input / output rotational speed ratio of the torque converter;
The input / output rotational speed difference or the input / output rotational speed ratio detected by the rotational speed detecting means and the initial rotational speed storage means of the operating state when the input / output rotational speed is detected by the rotational speed detecting means are stored. A hydraulic pressure control apparatus for an automatic transmission, comprising: a deterioration detecting means for detecting deterioration of hydraulic oil of the torque converter based on the input / output rotational speed difference or the input / output rotational speed ratio .   The deterioration detecting means is the input / output rotation stored in the initial rotational speed storage means in the operating state when the input / output rotational speed difference detected by the rotational speed detecting means and the input / output rotational speed is detected. 2. The hydraulic control device for an automatic transmission according to claim 1, further comprising means for detecting deterioration of hydraulic oil of the torque converter based on a difference in number. The torque converter includes a lockup clutch that directly controls or slip-controls an input shaft and an output shaft,
3. A target slip amount correcting means for correcting a target slip amount at the time of slip control of the lock-up clutch when the deterioration of the hydraulic oil is detected by the deterioration detecting means. The automatic transmission hydraulic control device described.   The hydraulic control device for an automatic transmission according to any one of claims 1 to 3, further comprising warning means for giving a warning when the deterioration of the hydraulic oil is detected by the deterioration detection means.

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