JP6641914B2 - Control device for automatic transmission for vehicles - Google Patents

Description

  The present invention relates to a control device for a vehicle automatic transmission.

  2. Description of the Related Art Conventionally, when a target range requested by a driver is determined according to a lever operation of a shift lever, a control device for a vehicular automatic transmission forms a target range by hydraulic control and shifts to a corresponding shift speed. In this case, the automatic transmission generally includes a manual valve that is linked to lever operation. For example, in a P (parking) range or an N (neutral) range, the hydraulic control is forcibly disabled to provide a fail-safe function. Has been realized. Assuming a configuration having such a manual valve, the target range is regarded as the D (drive) range when the lever is operated from the current range, and the D range is regarded as the D range before the target range is determined. It has been proposed to perform hydraulic control (for example, Patent Document 1). This process performs a fail-safe operation for a failure of the lever position detecting device that detects the lever position. This assumed D range hydraulic control prevents the D range from being erroneously formed by the action of the manual valve even when the shift lever position is determined to be outside the D range.

JP 2005-240992 A

  By the way, in recent years, shift-by-wire, which implements hydraulic control for forming a target range by electronic control, has been provided, and may be mounted on a manual valveless vehicle without a manual valve. When the shift lever position detection device fails in such a configuration in which the D-range assumed hydraulic control is performed in a manual valveless vehicle, the D range is directly formed by the D-range assumed hydraulic control, so that the target range is not the D range. Even in this case, there is a possibility that the D range may be erroneously formed. For this reason, in a manual valveless vehicle, it is necessary to perform hydraulic control for forming the target range after the target range is determined.

  However, in the manual valve-less vehicle, since the hydraulic control for forming the target range is started after the target range is determined, when performing the hydraulic control assuming the D range, the vehicle has a more manual valve than the configuration including the manual valve. The start timing by the hydraulic control for forming the D range will be delayed. For this reason, even if the lever is operated to the D range, for example, the time required until the vehicle can actually start is increased, so that the driver feels poor responsiveness.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a structure in which a shift to a target range requested by a driver is performed by shift-by-wire without using a manual valve that is interlocked with a lever operation on a shift lever. It is an object of the present invention to provide a control device for an automatic transmission for a vehicle, which can prevent a shift delay from occurring.

  According to the first aspect of the present invention, when the shift lever (1) is operated from the home position, the control unit (4) regards the target range as a specific range and sends the specific range from the hydraulic pressure supply unit (8). The hydraulic pressure of the hydraulic oil supplied to the specific range forming friction engagement element (10) corresponding to the specified range is set to the standby output hydraulic pressure immediately before the specific range forming friction engagement element (10) is engaged. Execute the hydraulic control preparation. Then, when the lever is operated to the specific range, the target range determining unit (3) determines the target range to the specific range, so that the hydraulic supply unit (8) sends the specific range forming friction engagement element (10). A specific range engagement hydraulic control for increasing the hydraulic pressure of the supplied hydraulic oil from the standby output hydraulic pressure is executed. Accordingly, when the target range is determined to be the specific range, the friction engagement element (10) for forming the specific range is immediately engaged, so that a shift delay occurs when the shift lever is operated to the specific range. Can be prevented.

FIG. 1 is a block diagram schematically showing an overall configuration according to a first embodiment. Block diagram showing a schematic configuration of a hydraulic control circuit Block diagram showing a schematic configuration of an automatic transmission control circuit Flow chart showing shift hydraulic pressure control processing Time chart showing preparation for D range hydraulic control Time chart showing hydraulic control preparation standby state Time chart showing the state of change from D range hydraulic control preparation to R range hydraulic control preparation 9 is a flowchart illustrating a hydraulic pressure control process during shift according to the second embodiment. FIG. 9 is a block diagram illustrating a schematic configuration of an automatic transmission control circuit according to a third embodiment. Flow chart showing the output oil pressure value learning process during the oil pressure control preparation standby state Flowchart showing an output hydraulic pressure value learning process during a hydraulic control preparation standby state according to the fourth embodiment. Flowchart showing a rotation fluctuation monitoring process during preparation for hydraulic control in a fifth embodiment.

(1st Embodiment)
A first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a plurality of lever positions are set on a shift lever 1 operated by a driver, and a position detecting device 2 for detecting the lever position is provided. “Lever position information” indicating the current lever position is output from the position detection device 2 to a shift-by-wire (SBW) ECU 3 (corresponding to a target range determination unit). As the lever positions, at least M (home), N (neutral), D (drive), and R (rear) are set. A non-contact state exists as a state other than the lever position. A non-contact state is a state in which sliding contacts that slide in response to lever operation are located between fixed contacts corresponding to each lever position, and do not belong to any lever position. is there. The shift lever 1 has an automatic return mechanism that automatically moves and returns to the M position when not operated.

  The SBWECU 3 determines the target range requested by the driver using the “lever position information” input from the position detection device 2. The target range of the present embodiment is the N-D-R range. In this case, the M position is not the target range because the M position is a neutral position where the automatic return is performed. The SBWECU 3 notifies the electronically controlled shift (hereinafter, ECT) ECU 4 (corresponding to a control unit) of “lever position information” and “target range”.

  The ECT ECU 4 uses the “lever position information” and the “target range” input from the SBWECU 3 to determine a gear position at which the rotation of the prime mover 6 is shifted by instructing the automatic transmission 5 to perform hydraulic control. The automatic transmission 5 has a built-in torque converter 7, and the input shaft of the torque converter 7 rotates according to the rotation of the prime mover 6. The torque converter 7 automatically shifts the rotation of the prime mover 6 so as to have a reduction ratio determined by the rotation difference between the input shaft and the output shaft.

  A hydraulic pump 8 (corresponding to a hydraulic supply unit) is connected to an output shaft of the torque converter 7. The hydraulic pump 8 supplies hydraulic oil pumped from an oil pan (not shown) to the hydraulic control circuit 9.

  A plurality of planetary gear mechanisms (not shown) are arranged in a straight line on the automatic transmission 5, and the rotation of the output shaft of the torque converter 7 is output to the drive wheels of the vehicle via the planetary gear mechanisms. In order to output the rotation of the prime mover 6 to the driving wheels of the vehicle via the planetary gear mechanism in this way, to stop the rotation of the clutch and the predetermined element for connecting the predetermined elements constituting the planetary gear mechanism. The hydraulic oil is supplied from the hydraulic control circuit 9 to these clutches and brakes. Hereinafter, the clutch and the brake are collectively referred to as a friction engagement element 10.

  The hydraulic control circuit 9 supplies hydraulic oil to a predetermined friction engagement element 10 in response to a command from the ECT ECU 4 or stops supply of hydraulic oil supplied to the predetermined friction engagement element 10. By doing so, the gear is switched to the gear corresponding to the target range. The shift speed corresponding to the target range is neutral in the N range, first speed in the D range, and reverse speed in the R range. For example, when the snow mode is set, the speed corresponding to the D range is the second speed.

The hydraulic control circuit 9 includes a line pressure control circuit 11, an automatic transmission control circuit 12, and a lock-up control circuit 13, as shown in FIG.
The line pressure control circuit 11 controls the hydraulic pressure of the hydraulic oil supplied from the hydraulic pump 8 to be constant.

  The automatic transmission control circuit 12 includes a plurality of hydraulic control valves 14 as shown in FIG. 3, and turns on a predetermined hydraulic control valve 14 in response to a command from the ECT ECU 4 to thereby set a predetermined friction engagement element 10. The supply of the hydraulic oil to the predetermined frictional engagement element 10 is stopped by supplying hydraulic oil to the engine or by turning off a predetermined hydraulic control valve 14. The hydraulic control valve 14 is, for example, a linear solenoid valve, and is capable of controlling the supply amount of hydraulic oil supplied to the friction engagement element 10 according to position control on the linear solenoid.

The lock-up control circuit 13 controls a supply amount of hydraulic oil supplied to a lock-up clutch for engaging an input shaft and an output shaft of the torque converter 7.
In the present embodiment, the hydraulic control circuit 9 is not provided with a manual valve that forcibly invalidates the hydraulic control by mechanically moving in conjunction with the operation of the shift lever 1. This is because, when a configuration in which a manual valve is provided is employed, it is necessary to mechanically connect the manual valve and the shift lever 1, and there is a restriction on the arrangement of the shift lever 1.

Next, among the operations of the ECT ECU 4, the shift hydraulic control related to the present invention will be described.
As shown in FIG. 4, the ECT ECU 4 refers to the “lever position information” output from the shift lever 1 device, and determines whether the lever has deviated from the M position, that is, whether the lever is operated from the M position (S101). When the driver starts operating the shift lever 1 from the M position (see FIG. 5), since the "lever position information" is no longer at the M position (S101: YES), it is determined whether the N range has been determined as the target range. A determination is made (S102). In this case, if the N range is determined as the target range (S102: YES), it is determined whether a predetermined delay time (see FIG. 5) for preventing temporary erroneous detection due to noise has been counted (S103). Until the delay time has elapsed (S103: NO), steps S101 to S103 are repeatedly executed to monitor whether the lever position has reached the M position or whether the N range has been determined as the target range.

  When the driver has returned the shift lever 1 from the N range to the M position (S101: NO), the control ends. On the other hand, if the driver operates the shift lever 1 to a lever other than the N range to determine the target range before the delay time elapses (S102: NO), the sweep control for forming the target range is executed. (S113).

  Specifically, when the D range is determined as the target range before the delay time has elapsed, the automatic shift control circuit 12 is instructed to shift to the first speed. If the R range is determined as the target range before the delay time has elapsed, the automatic shift control circuit 12 is instructed to shift to the reverse speed.

  Here, the sweep control for forming the target range is performed in two stages. That is, as the first stage, the D-range hydraulic pressure control preparation for executing the hydraulic pressure of the hydraulic oil supplied to the friction engagement element 10 as the standby output hydraulic pressure immediately before the friction engagement element 10 is engaged is executed, and As a step, D range engagement oil pressure control for bringing the friction engagement element 10 into an engaged state by increasing the oil pressure from the standby output oil pressure is executed. In this case, the first stage D range hydraulic control preparation and the second stage D range engagement hydraulic control are continuously executed. The reason why the sweep control of the D range is performed in two stages is to reduce the shift shock caused by bringing the friction engagement element 10 into the engaged state at once.

If the predetermined delay time has elapsed while the shift lever 1 has not returned to the M position and the target range has been determined to be the N range (S103: YES), the D range hydraulic pressure control preparation is executed (S104). In the preparation of the D range hydraulic control, the target range is regarded as the D range (corresponding to the specific range), and the frictional engagement element 10 (the specific range forming friction engagement After performing D-range hydraulic control preparation (corresponding to specific range hydraulic control preparation) which is the first stage of the sweep control described above, the D range engagement hydraulic pressure which is the second stage of the sweep control is performed. A standby state is maintained in which the output hydraulic pressure during standby immediately before the rotation of the friction engagement element 10 fluctuates without continuously performing the control. The reason why the target range is regarded as the D range is that there is a higher possibility that the shift to the D range is made than the shift from the N range to the R range.
Thereafter, while maintaining the standby state for the preparation of the D range hydraulic control, it is confirmed that the lever position is other than the M position (S105: YES), and whether the target range is the D range (S106) or the R range (S107). To monitor.

When the driver returns the shift lever 1 from the N range to the M position (S105: NO), the D range hydraulic pressure control preparation is canceled (S111), and this control ends.
If the driver operates the shift lever 1 from the N range to the D range to determine the target range as the D range (S106: YES), it is determined whether the preparation for the D range hydraulic control is completed (S108). This determination is made based on whether or not a predetermined period of time has elapsed in preparation for the D range hydraulic pressure control. If the preparation of the D range hydraulic control is not completed (S108: NO), the preparation of the D range hydraulic control is continued (S109), and the D range engagement hydraulic control (corresponding to the specific range engagement hydraulic control) is executed. (S110). On the other hand, when the preparation for the D range hydraulic control is completed (S108: YES), the D range engagement hydraulic control is immediately executed (S110).

  As described above, when the shift lever 1 is smoothly operated from the N range to the D range, as shown in FIG. 5, the preparation of the D range hydraulic control is executed before the determination of the target range. The hydraulic control completion timing at which the engagement of the friction engagement element 10 is completed to form the D range is advanced, and the responsiveness to lever operation can be improved.

  On the other hand, when steps S104 to S107 are repeated because the lever operation time from the N range to the D range is long, that is, when the non-contact state continues, as shown in FIG. In this state, the friction engagement element 10 can be engaged immediately after the target range is determined, and the hydraulic control completion timing can be earlier than in the prior art.

In the flowchart of FIG. 4, when the target range is determined to be the R range in preparation for the D range hydraulic control (S107: YES), the D range hydraulic control preparation being executed is canceled (S112), and the determination is performed. The sweep control for forming the target range is executed (S113). In the sweep control in this case, the above-described first-stage preparation of the D- range hydraulic control and the second-stage D- range engagement hydraulic control are continuously executed. When the lever operation is performed from the N range to the R range in this manner, as shown in FIG. 7, after the target range is determined to be the R range, the D range hydraulic control preparation is performed without forming the D range. The responsiveness is equivalent to that of a conventional manual valve-less vehicle because it is released and the R-range hydraulic control preparation is immediately executed.

  According to such an embodiment, when the shift lever 1 is operated from the home position, the ECT ECU 4 assumes that the target range is the D range and executes the D range oil pressure control preparation, whereby the friction engagement element 10 When the target output range is determined to be the D range according to the lever operation, the D range engagement hydraulic control for increasing the hydraulic pressure from the standby output hydraulic pressure to the standby output hydraulic pressure is performed. Is determined to be in the D range, the friction engagement element 10 is immediately engaged, and it is possible to prevent a shift delay from occurring when the lever is operated in the D range.

(2nd Embodiment)
The second embodiment of the present invention will be described with reference to FIG. 8, and the same steps as those in the first embodiment will be denoted by the same step numbers, and description thereof will be omitted. The present embodiment is characterized in that the time limit is set during the standby for the preparation of the D range hydraulic pressure control described in the first embodiment.
As in the first embodiment, when the standby state for the preparation of the D range hydraulic pressure control, that is, the undetermined state of the target range, continues, the hydraulic pressure of the hydraulic oil supplied to the friction engagement element 10 needs to be maintained. This leads to deterioration of power consumption for driving.

Under such circumstances, in the present embodiment, the time limit is provided during the standby time for the preparation of the D range hydraulic pressure control.
As shown in FIG. 8, when the DECT-range hydraulic control preparation is executed (S104), and when the execution of the D-range hydraulic control preparation is not more than a predetermined time (S201: YES), the shift lever 1 moves to the home position. The operation of confirming that the position does not become the M position (S105: YES) and that the target range is not fixed (S106: NO, S107: NO) is repeatedly executed, and the execution time exceeds a predetermined time. In this case (S201: NO), the preparation for the D range hydraulic pressure control is canceled (S202), and this control ends.

  According to such an embodiment, when the standby state of the preparation of the D-range hydraulic control is continued for the predetermined time, the preparation of the D-range hydraulic control is canceled, so that the power consumption for driving the hydraulic control valve 14 is deteriorated. Can be prevented.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS. The present embodiment is characterized in that a value of an output hydraulic pressure during standby (hereinafter, an output hydraulic pressure value during standby) during standby for preparation for D-range hydraulic pressure control is learned.

  While the standby output hydraulic pressure value needs to be set to a hydraulic pressure value that does not cause rotational fluctuations in the friction engagement element 10, the hydraulic pressure value that causes rotational fluctuations in the friction engagement element 10 depends on the oil temperature state and friction engagement state. The value varies due to wear of the element 10 or the like. For this reason, in a state where the output hydraulic pressure value during standby is fixed, the difference from the appropriate hydraulic pressure value may increase. In such a case, the supply time of the hydraulic pressure until the friction engagement element 10 is engaged becomes long. Therefore, the responsiveness at the time of shifting is deteriorated.

  Under such circumstances, in the present embodiment, the oil pressure value immediately before affecting the rotation of the friction engagement element 10 is accurately detected, and the response during gear shifting is ensured by appropriately reflecting the oil pressure value during standby to the output oil pressure value. I did it. In this case, since it is necessary to detect a hydraulic pressure value that affects the rotation of the friction engagement element 10, as shown in FIG. 9, a hydraulic pressure sensor 15 that measures the hydraulic pressure value of the hydraulic control valve 14 (corresponding to a hydraulic pressure detection unit) And the output oil pressure value learning process is executed during the D range formation oil pressure control.

  That is, the ECT ECU 4 (corresponding to the rotation detecting unit) sets the initial value as the standby output oil pressure value after detecting that the target range is determined to be the D range (S301: YES), as shown in FIG. (S302), the rotation fluctuation of the friction engagement element 10 is monitored (S303: NO). At this time, the hydraulic pressure for the hydraulic oil supplied to the friction engagement element 10 is reduced as shown in FIG. Ascending, the friction engagement element 10 is finally engaged. Then, since rotation fluctuation of the friction engagement element 10 occurs (S303: YES), the oil pressure value at that time is acquired by the oil pressure sensor 15 (S304). Then, a value obtained by subtracting a predetermined amount that is a small difference for avoiding engagement from the obtained hydraulic pressure value is learned as a new standby output hydraulic pressure value (S305).

  According to such an embodiment, when the rotation of the friction engagement element 10 fluctuates during the execution of the hydraulic control for forming the D range, a new standby output oil pressure value is learned. Is always appropriate, and responsiveness during shifting can be ensured.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that the above-described standby output oil pressure value is learned without using an oil pressure sensor.
After detecting that the target range is determined to be the D range as shown in FIG. 11 (S401: YES), the ECT ECU 4 initializes the rotation fluctuation time (S402), and then there is no rotation fluctuation of the friction engagement element 10. (S403: YES), the rotation fluctuation time is counted up (S404). Then, when the hydraulic pressure of the hydraulic oil supplied to the friction engagement element 10 increases and the friction engagement element 10 rotates and fluctuates (S403: NO), the correction is performed based on the hydraulic pressure increase amount for the time until the rotation fluctuation occurs. An output oil pressure value is calculated (S405). That is, since the output hydraulic pressure value for correction = the rotation fluctuation time × the hydraulic pressure increase amount per unit time−the predetermined amount, the output hydraulic pressure value for correction is obtained from this equation. Next, the hydraulic pressure value obtained by adding the calculated hydraulic pressure increase amount to the currently set standby hydraulic pressure value and subtracting a predetermined amount is learned as a new standby output hydraulic pressure value (S406).
According to such an embodiment, an appropriate standby output hydraulic pressure value can be learned and set without using a hydraulic pressure sensor.
(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIG. The present embodiment is characterized in that abnormal engagement of the friction engagement element 10 is avoided.
Since the output hydraulic pressure value during standby changes as described above, it is assumed that the friction engagement element 10 is engaged and rotates carelessly even during standby for preparation for D range hydraulic pressure control.

In order to cope with such a situation, the rotation fluctuation monitoring process is executed for the purpose of avoiding the situation where the formation of the D range is executed during the standby for the preparation of the D range hydraulic pressure control.
That is, as shown in FIG. 12, the ECT ECU 4 constantly monitors the rotation fluctuation of the friction engagement element 10 (S502: NO) in the standby state for the preparation of the D range hydraulic pressure control (S502: NO), and the rotation fluctuation starts to occur. If (S502: YES), the current standby output hydraulic pressure value is reduced by a predetermined amount (S503).

According to such an embodiment, even if a problem occurs in which the friction engagement element 10 rotates during the standby for the preparation of the D range hydraulic pressure control, the current standby output hydraulic pressure value is reduced by the predetermined amount. Thus, the situation where the rotation of the friction engagement element 10 continues can be avoided.
In this embodiment, the clutch is assumed as the friction engagement element 10 in FIG. 12, but when the brake is to be applied, the friction engagement element 10 that has been rotating during the standby for the preparation of the D range hydraulic control is stopped. Will be detected.

(Other embodiments)
The present invention is not limited to the above embodiment, and may be modified or expanded as follows, or each modification may be combined with the above embodiment.
As the shift lever, a shift lever having a configuration in which the P, R, N, and D ranges are linearly arranged as in the related art may be applied. Of course, even in such a configuration, the manual valve is not provided, and the P range corresponds to the home position.

The automatic transmission may be a CVT (Continuously Variable Transmission) or a DCT (Dual Clutch Transmission).
Although the D range is employed as the specific range, an R range may be employed.

In the drawings, 1 is a shift lever, 3 is a SBWECU (target range determining unit), 4 is an ECT ECU (control unit), 8 is a hydraulic pump (hydraulic supply unit), and 10 is a friction engagement element.

Claims (6)

A control device for an automatic transmission for a vehicle that shifts to a target range requested by a driver by shift-by-wire without using a manual valve that mechanically moves in conjunction with a lever operation on a shift lever (1),
Target range determination unit to determine the goals range in response to the end of the lever operation to the shift lever by a user and (3),
A hydraulic pressure supply unit (8) for supplying hydraulic oil to the friction engagement element (10),
When the shift lever is operated from the home position, the target range is regarded as the specific range, and the hydraulic pressure of the hydraulic oil supplied from the hydraulic pressure supply unit to the specific range forming friction engagement element is changed to the specific range. When the specific range hydraulic pressure control preparation for setting the output hydraulic pressure during standby immediately before the friction engagement element is brought into the engaged state is performed, and the target range determination unit determines the specific range as the target range, the hydraulic pressure supply unit A control unit (4) for executing a specific range engagement hydraulic pressure control for increasing a hydraulic pressure of hydraulic oil supplied to the specific range forming friction engagement element from the standby output hydraulic pressure;
A control device for an automatic transmission for a vehicle, comprising: Wherein, if the state in which the target range decision unit during the execution of the specific range hydraulic control preparation can not determine the target range continues for a predetermined time, to claim 1 to end the execution of the specific range hydraulic control preparation A control device for an automatic transmission for a vehicle according to the above. A rotation detector (4) for detecting a rotation state of the specific range forming friction engagement element;
A hydraulic pressure detection unit (15) that detects a hydraulic pressure of hydraulic oil supplied from the hydraulic pressure supply unit to the specific range forming friction engagement element,
The control unit, when the rotation detection unit detects that the specific range forming friction engagement element has rotated during execution of the specific range engagement hydraulic control, the hydraulic pressure value detected by the hydraulic pressure detection unit 3. The control device for an automatic transmission for a vehicle according to claim 1, wherein the control unit acquires the output hydraulic pressure during standby when executing the preparation for the specific range hydraulic pressure control based on the hydraulic pressure value. 4. A rotation detector (4) for detecting a rotation state of the specific range forming friction engagement element,
The control unit is configured to determine a hydraulic pressure value of hydraulic oil supplied to the specific range forming friction engagement element based on a time until the rotation detection unit detects that the specific range forming friction engagement element rotates. The control device for an automatic transmission for a vehicle according to claim 1 or 2, wherein the standby output oil pressure at the time of executing the preparation for the specific range oil pressure control is determined based on the obtained oil pressure value. A rotation detector (4) for detecting a rotation state of the specific range forming friction engagement element,
5. The control unit reduces the standby output hydraulic pressure when the rotation detection unit detects rotation of the specific range forming friction engagement element when performing the specific range hydraulic control preparation. 6. The control device for a vehicle automatic transmission according to any one of claims 1 to 4.   The control device for a vehicle automatic transmission according to any one of claims 1 to 5, wherein the specific range is a D (drive) range.

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