JP6090255B2 - Control device and control method for automatic transmission - Google Patents

Description

  The present invention relates to control of an automatic transmission mounted on a vehicle, and belongs to the field of vehicle shift control technology.

  A stepped automatic transmission mounted on a vehicle such as an automobile generally includes a plurality of planetary gear sets (planetary gear mechanisms) and a plurality of hydraulic frictional engagement elements such as clutches and brakes, and these are controlled by a hydraulic circuit. By selectively fastening these frictional engagement elements, the power transmission path passing through each planetary gear set is switched, so that a plurality of forward shift speeds and typically one reverse speed speed can be realized.

  A hydraulic circuit of this type of automatic transmission is provided with a switching valve for switching a hydraulic pressure supply path as disclosed in, for example, Japanese Patent Application Laid-Open No. H10-228707, and frictional engagement that is fastened by switching control of the switching valve. The element is switched.

JP-A-6-058401

  In the hydraulic control mechanism of the automatic transmission, the switching valve includes a low-speed friction engagement element that is engaged at a predetermined low transmission ratio and a high-speed friction that is engaged at a predetermined high transmission ratio that is smaller than the low transmission ratio. In some cases, it is provided to selectively supply hydraulic pressure to the fastening element.

  However, when shifting up from the predetermined intermediate gear ratio, which is greater than the predetermined high gear ratio, and is realized when the low-speed and high-speed friction engagement elements are not fastened, to the predetermined high gear ratio. If the switching valve has an abnormality in the switching operation due to an abnormality in the valve stick or the hydraulic control valve that operates the switching valve, the predetermined low A shift down to a gear ratio may be realized. At this time, for example, when the accelerator pedal is depressed for acceleration, the engine may overspeed due to an erroneous shift down.

  Also, in order to avoid such an erroneous downshifting, is the switching valve normally switched to a position where hydraulic pressure can be supplied to the high-speed friction engagement element before the upshift command is issued? It is conceivable to make a diagnosis in advance, but before the upshift command is issued, even if the switching valve is normally switched, another hydraulic control valve such as a solenoid valve may be used to connect the high-speed friction engagement element. The hydraulic pressure supply is regulated. Accordingly, since it is not possible to detect the hydraulic pressure supply to the high-speed friction engagement element at the time before the upshift command is issued, it is technically necessary to diagnose whether the switching valve is operating normally. It is difficult to.

  Furthermore, even if such an abnormality diagnosis is technically possible, if the upshift from the predetermined low gear ratio to the predetermined high gear ratio is performed quickly, the time for abnormality diagnosis cannot be secured. Therefore, the operation failure of the switching valve may not be detected before the upshift command to the high gear ratio. Therefore, even in such a case, an erroneous downshift is realized due to the malfunction of the switching valve, and the engine may overspeed.

  Therefore, the present invention suppresses engine over-rotation in a vehicle equipped with an automatic transmission when an abnormality occurs in the hydraulic control mechanism that causes an erroneous downshift in response to the upshift command. Is an issue.

  In order to solve the above-mentioned problems, a control device and a control method for an automatic transmission according to the present invention are configured as follows.

First, the invention according to claim 1 of the present application is
A first friction engagement element that is engaged at a first transmission ratio;
A second frictional engagement element that is engaged at a second transmission ratio that is smaller than the first transmission ratio;
And a hydraulic control mechanism that is selectively switched between a first state in which hydraulic pressure can be supplied to the first frictional engagement element and a second state in which hydraulic pressure can be supplied to the second frictional engagement element. A transmission control device,
Confirmation means for confirming that the hydraulic control mechanism is in the second state;
As a vehicle speed condition when shifting up from the third gear ratio, which is larger than the second gear ratio, and the first and second friction engagement elements are released to the second gear ratio, A predetermined normal condition is used when the confirmation unit confirms the second state, and when the confirmation unit does not confirm the second state, the normal condition is satisfied. And a shift condition setting means for setting a shift-up condition to the second gear ratio so that the low vehicle speed side condition set on the low vehicle speed side is used.

The invention according to claim 2 is the invention according to claim 1,
The shift condition setting means sets the normal condition so that the vehicle speed condition is higher when the acceleration request amount for the vehicle is larger than the predetermined amount than when it is less than the predetermined amount, and the acceleration request The low vehicle speed side condition is set so that the vehicle speed is lower than the normal condition when the amount is greater than the predetermined amount, and the vehicle speed is the same as the normal condition when the requested acceleration amount is equal to or less than the predetermined amount. Is set.

Further, the invention according to claim 3 is the invention according to claim 1 or 2,
The speed change condition setting means sets the vehicle speed condition when the hydraulic control mechanism is switched from the second state to the first state in a state where the confirmation means confirms the second state. The normal condition is changed to the low vehicle speed side condition.

Furthermore, the invention according to claim 4 is the invention according to any one of claims 1 to 3,
The hydraulic control mechanism includes a switching valve that is switched to selectively supply hydraulic pressure to the first friction engagement element and the second friction engagement element.

The invention according to claim 5 is the invention according to claim 4,
The hydraulic control mechanism includes a hydraulic control valve provided between the switching valve and a hydraulic source,
The hydraulic control valve opens the hydraulic pressure supplied from the hydraulic pressure source to the switching valve side at the first gear ratio and the second gear ratio, and from the hydraulic power source at the third gear ratio. The hydraulic pressure supply to the switching valve is shut off.

Furthermore, the invention according to claim 6 provides
A first friction engagement element that is engaged at a first transmission ratio;
A second frictional engagement element that is engaged at a second transmission ratio that is smaller than the first transmission ratio;
And a hydraulic control mechanism that is selectively switched between a first state in which hydraulic pressure can be supplied to the first frictional engagement element and a second state in which hydraulic pressure can be supplied to the second frictional engagement element. A transmission control method comprising:
A confirmation step for confirming whether or not the hydraulic control mechanism is in the second state;
As a vehicle speed condition when shifting up from the third gear ratio, which is larger than the second gear ratio, and the first and second friction engagement elements are released to the second gear ratio, When it is confirmed that the second state is confirmed in the confirmation step, a predetermined normal condition is used. When it is not confirmed that the second state is confirmed in the confirmation step, the normal condition is satisfied. And a shift condition setting step for setting a shift-up condition to the second gear ratio so that the low vehicle speed side condition set on the low vehicle speed side is used.

  First, according to the control device for an automatic transmission according to the first aspect of the present invention, for example, it is confirmed that the hydraulic control mechanism is capable of supplying hydraulic pressure to the second frictional engagement element during acceleration of the vehicle. If there is a possibility that the hydraulic control mechanism is abnormal, an up-shift command from the third gear ratio to the second gear ratio is issued at a relatively low vehicle speed earlier than usual. Therefore, even if the downshift to the first gear ratio is realized in response to the upshift command to the second gear ratio due to an abnormality in the hydraulic control mechanism, the increase in the engine speed can be kept relatively low. , Engine overspeed can be suppressed.

  Further, the engine overspeed can be suppressed by changing the shift-up condition as described above without performing special abnormality diagnosis control for determining whether or not the hydraulic control mechanism is abnormal. Therefore, even when the speed-up from the first gear ratio to the second gear ratio is quickly performed to such an extent that the time for abnormality diagnosis control cannot be secured, it is possible to reliably suppress the engine overspeed.

  According to the second aspect of the present invention, when the requested acceleration amount for the vehicle is larger than the predetermined amount, a shift-up command from the third gear ratio to the second gear ratio is issued when the low vehicle speed condition is satisfied. Thus, even if an erroneous shift down as described above is realized, it is possible to suppress over-rotation of the engine. On the other hand, when the requested acceleration amount for the vehicle is equal to or less than the predetermined amount, it is difficult for the engine to overspeed even if an erroneous downshift is realized. Therefore, the shift to the second gear ratio is performed based on normal conditions. Up and normal shift control can be performed.

  Furthermore, according to the third aspect of the present invention, even if it is once confirmed that the hydraulic control mechanism has been switched from the first state to the second state, the hydraulic control mechanism is then changed to the first state. When it becomes unknown whether or not the switching to the next second state is normally performed by returning, the vehicle speed condition when the shift-up from the third gear ratio to the second gear ratio is performed is By returning to the low vehicle speed side condition from the normal condition, the upshift to the next second gear ratio is performed at a relatively low vehicle speed. Therefore, even if the downshift to the first gear ratio is erroneously realized due to an abnormality in which the hydraulic control mechanism cannot be switched to the second state at the time of this upshifting, it is possible to suppress engine overspeed.

  According to a fourth aspect of the present invention, in the switching operation of the switching valve that is switched to selectively supply the hydraulic pressure to the first friction engagement element and the second friction engagement element, In addition, when an abnormality occurs due to a failure of a hydraulic control valve that controls the switching valve or the like, it is possible to suppress over-rotation of the engine when an erroneous downshift is realized.

  Further, according to the invention described in claim 5, since the hydraulic pressure is not supplied to any of the first and second friction engagement elements at the third gear ratio, even if the operation of the switching valve is abnormal, Although it is difficult to detect this abnormality at the third gear ratio, as described above, until it is confirmed that the switching to the second state has been normally performed, Since an upshift command to a two gear ratio is issued, even if an erroneous downshift is realized with respect to the upshift command, engine overspeed can be suppressed. Therefore, it is not necessary to diagnose in advance whether or not the switching valve is malfunctioning by any method at the third gear ratio. For this reason, even when the speed change from the first speed ratio to the second speed ratio is performed quickly to such an extent that a time for such diagnosis cannot be secured, it is possible to reliably suppress the engine overspeed.

  Further, according to the control method for the automatic transmission according to the sixth aspect of the present invention, for example, it is confirmed that the hydraulic control mechanism is capable of supplying hydraulic pressure to the second frictional engagement element during acceleration of the vehicle. If there is a possibility that the hydraulic control mechanism is abnormal, an up-shift command from the third gear ratio to the second gear ratio is issued at a relatively low vehicle speed earlier than usual. Therefore, even if the downshift to the first gear ratio is realized in response to the upshift command to the second gear ratio due to an abnormality in the hydraulic control mechanism, the increase in the engine speed can be kept relatively low. , Engine overspeed can be suppressed.

  Further, the engine overspeed can be suppressed by changing the shift-up condition as described above without performing special abnormality diagnosis control for determining whether or not the hydraulic control mechanism is abnormal. Therefore, even when the speed-up from the first gear ratio to the second gear ratio is quickly performed to such an extent that the time for abnormality diagnosis control cannot be secured, it is possible to reliably suppress the engine overspeed.

1 is a skeleton diagram of an automatic transmission according to an embodiment of the present invention. It is a fastening table | surface which shows the relationship between the fastening combination of the friction fastening element of the automatic transmission, and a gear stage. It is a control system figure of the automatic transmission. It is a circuit diagram which shows the hydraulic circuit of the automatic transmission. It is a circuit diagram which shows the hydraulic circuit in the 1st speed state. It is a circuit diagram which shows the same hydraulic circuit in a 4th speed state. It is a circuit diagram which shows the same hydraulic circuit in a 3rd speed state. It is a shift diagram which shows an example of 3-4 speed upshift conditions. It is a shift diagram which shows the modification of 3-4 speed upshift conditions. It is a flowchart which shows an example of control operation of switching confirmation control. It is a flowchart which shows the control action of the shift condition setting control which concerns on 1st Example. It is a time chart which shows an example of a time-dependent change of each element in case the same transmission condition setting control is performed. It is a flowchart which shows the control action of the shift condition setting control which concerns on 2nd Example. It is a time chart which shows an example of a time-dependent change of each element in case the same transmission condition setting control is performed. It is a circuit diagram which shows the hydraulic circuit which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below.

[Configuration of automatic transmission]
As shown in FIG. 1, an automatic transmission 1 according to an embodiment of the present invention has an input shaft 4 connected to an engine output shaft 2 via a torque converter 3.

  The torque converter 3 includes a case 3a connected to the engine output shaft 2, a pump 3b fixed in the case 3a, and a turbine that is disposed opposite to the pump 3b and driven by the pump 3b via hydraulic oil. 3c, a stator 3e interposed between the pump 3b and the turbine 3c, and supported by the transmission case 5 via the one-way clutch 3d to increase the torque, and between the case 3a and the turbine 3c. And a lockup clutch 3f that directly connects the engine output shaft 2 and the turbine 3c via the case 3a. The rotation of the turbine 3 c is transmitted to the automatic transmission 1 via the input shaft 4.

  A mechanical oil pump 6 driven by the engine via the torque converter 3 is disposed between the automatic transmission 1 and the torque converter 3, and the oil pump 6 automatically Hydraulic pressure is supplied to a hydraulic circuit 100 (see FIG. 4), which will be described later, used for controlling the transmission 1 and the torque converter 3.

  First, second, and third planetary gear sets (hereinafter referred to as “first, second, and third gear sets”) 10 are provided on the input shaft 4 of the automatic transmission 1 from the drive source side (torque converter 3 side). , 20, 30 are arranged.

  On the input shaft 4, the power from the input shaft 4 is selectively transmitted to the gear set 10, 20, 30 side as a frictional engagement element for switching the power transmission path constituted by the gear sets 10, 20, 30. A low clutch 40 and a high clutch 50 are disposed. Furthermore, on the input shaft 4, LR (low reverse) brakes 60, 26 brakes 70, and R35 brakes 80 for fixing predetermined rotating elements of the respective gear sets 10, 20, 30 are arranged in this order from the drive source side. Has been placed.

  Of the first to third gear sets 10, 20, 30, the first gear set 10 and the second gear set 20 are single pinion type planetary gear sets, and are engaged with the sun gears 11, 21 and these sun gears 11, 21. The plurality of pinions 12 and 22, the carriers 13 and 23 that respectively support the pinions 12 and 22, and the ring gears 14 and 24 that mesh with the pinions 12 and 22.

  The third gear set 30 is a double pinion type planetary gear set, and includes a sun gear 31, a plurality of first pinions 32a meshed with the sun gear 31, a second pinion 32b meshed with the first pinion 32a, and these The carrier 33 supports the pinions 32a and 32b, and the ring gear 34 meshed with the second pinion 32b.

  The input shaft 4 is directly connected to the sun gear 31 of the third gear set 30. The sun gear 11 of the first gear set 10 and the sun gear 21 of the second gear set 20 are coupled to each other and connected to the output member 41 of the low clutch 40. The output member 51 of the high clutch 50 is connected to the carrier 23 of the second gear set 20.

  Further, the ring gear 14 of the first gear set 10 and the carrier 23 of the second gear set 20 are coupled to each other and connected to the transmission case 5 via the LR brake 60 so as to be connectable and detachable. The ring gear 24 of the second gear set 20 and the ring gear 34 of the third gear set 30 are coupled to each other, and are connected to the transmission case 5 via a 26 brake 70 so as to be connected and disconnected. The carrier 33 of the third gear set 30 is connected to the transmission case 5 via an R35 brake 80 so as to be connectable and detachable. The carrier 13 of the first gear set 10 is connected to an output gear 7 that outputs the output of the automatic transmission 1 to the drive wheels (not shown).

  With the above configuration, the automatic transmission 1 has a fastening table shown in FIG. 2 according to the combination of the engagement states of the friction engagement elements (the low clutch 40, the high clutch 50, the LR brake 60, the 26 brake 70, and the R35 brake 80). As shown in FIG. 1, 1st to 6th speed in the D range and a reverse speed in the R range are formed.

[Automatic transmission control system]
As shown in FIG. 3, the automatic transmission 1 is a hydraulic circuit for selectively supplying a line pressure for engagement to the friction engagement elements 40, 50, 60, 70, and 80 to realize the above-described shift stage. 100.

  The hydraulic circuit 100 includes first, second, third, fourth, and fifth solenoid valves (hereinafter, “solenoid valve” is referred to as “SV”) 101, 102, 103, 104, and 105 for shift control. In addition, for example, a plurality of SVs 106 are provided. The first SV 101 is an on / off solenoid valve capable of controlling only opening and closing, and the second to fifth SVs 102 to 105 are linear solenoid valves capable of controlling the opening degree. Further, the hydraulic circuit 100 is provided with a hydraulic switch 222 that detects the engaged / released state of the high clutch 50.

  The SVs 101 to 106 of the hydraulic circuit 100 are controlled by the control device 200. The control device 200 includes an ECU (Engine Control Unit) 201 mounted on the engine and a TCM (Transmission Control Module) 202 mounted on the automatic transmission 1, and the ECU 201 and the TCM 202 perform, for example, CAN communication. Are electrically connected to each other.

  The ECU 201 receives signals from an accelerator sensor 210 that detects an accelerator pedal depression amount (accelerator opening) as an acceleration request amount for the vehicle, an engine speed sensor 211 that detects an engine speed, and the like. Based on the input signal, various controls relating to the operation of the engine, such as control of engine output torque, are performed.

  The TCM 202 includes a signal from the vehicle speed sensor 212 that detects the speed of the vehicle, a signal from the range sensor 213 that detects the range of the automatic transmission 1 selected by the driver, and the rotation of the turbine 3 c of the torque converter 3. A signal from the turbine rotational speed sensor 214 for detecting the number and a signal from the hydraulic switch 222 provided in the hydraulic circuit 100 are input. In addition, a signal from the accelerator sensor 210 and a signal from the engine speed sensor 211 are input to the TCM 202 via the ECU 201.

  Based on these input signals, the TCM 202 outputs a signal to each of the SVs 101 to 106 of the hydraulic circuit 100. Accordingly, the opening / closing or opening degree of each of the SVs 101 to 106 is controlled according to the selected range and the running state of the vehicle, and the hydraulic pressure supply to each frictional engagement element 40, 50, 60, 70, 80 is controlled. Thus, the shift control of the automatic transmission 1 is performed. Further, the TCM 202 outputs various command signals relating to the operation of the engine, such as an engine output torque, to the ECU 201 according to the state of the shift control.

[Hydraulic circuit]
The configuration of the hydraulic circuit 100 will be described with reference to FIG.

  In addition to the SVs 101 to 106 and the hydraulic switch 222, the hydraulic circuit 100 is operated by a regulator valve 108 that adjusts the discharge pressure of the oil pump 6 to a line pressure and supplies the line pressure to the main line 120, and a driver's range selection operation. Manual valve 110, predetermined hydraulic circuit 112 provided with various valves including the other SV 106, first switching valve 114 controlled by first SV 101, and second switching valve controlled by first switching valve 114 116 and a third switching valve 118 controlled by the third SV 103. Although not shown, the hydraulic circuit 100 is also provided with circuits for supplying hydraulic oil to the torque converter 3 and for controlling the lock-up clutch 3f.

  The line pressure of the main line 120 is output to the D range line 121 when the manual valve 110 is in the D range operating position, and is output to the R range line 122 when the manual valve 110 is in the R range operating position. .

  In the first switching valve 114, the spool 141 is moved to the left side by stopping the hydraulic pressure supply from the predetermined hydraulic circuit 112 to the control port A1 via the line 123 by the on / off control of the first SV 101 provided on the line 123. The spool 141 is switched to the second state where the spool 141 is moved to the right side by supplying hydraulic pressure from the predetermined hydraulic circuit 112 to the control port A1. In the first state of the first switching valve 114, the line pressure input to the input port B1 is output from the output port C1 to the line 124. In the second state of the first switching valve 114, the hydraulic pressure of the D range line 121 input to the input port B2 in the D range selected state is output from the output port C2 to the line 129.

  The second switching valve 116 has a first state in which the spool 142 is moved to the right side by supplying hydraulic pressure from the line 124 to the control port D1 by the switching control of the first switching valve 114 by the first SV 101, and from the line 124. When the hydraulic pressure supply to the control port D1 is stopped, the spool 142 is switched between the second state where the spool 142 is moved to the left side.

  In the first state of the second switching valve 116, the hydraulic pressure of the line 125 branched from the line 124 is input from the input port E2 and temporarily output from the output port F1 to the line 126. When the hydraulic pressure of the line 126 is input to the input port E3 by the control of the second SV 102 provided on the line 126, the hydraulic pressure is output from the output port F2 to the line 127 and supplied to the LR brake 60. The

  In the second state of the second switching valve 116, the hydraulic pressure input from the predetermined hydraulic circuit 112 to the input port E1 is once output from the output port F1 to the line 126, and the hydraulic pressure in the line 126 is controlled by the second SV102 to the input port E3. , The hydraulic pressure is output from the output port F3 to the line 128 and supplied to the high clutch 50.

  The third switching valve 118 includes a first control port G1 to which the hydraulic pressure is supplied from the predetermined hydraulic circuit 112 via the line 130, and a second control port G2 to which the hydraulic pressure of the line 131 branched from the line 130 is supplied. I have. A third SV 103 is provided on the line 131, and the hydraulic pressure of the line 131 is adjusted by controlling the opening degree of the third SV 103. The third switching valve 118 reduces the hydraulic pressure input from the line 131 to the second control port G2 by reducing the opening degree of the third SV 103, and the first state where the spool 143 is moved to the left side, By increasing the opening degree of 3SV 103 and increasing the hydraulic pressure of the line 131 input to the second control port G2, the spool 143 is switched to the second state brought to the right.

  When the hydraulic pressure is supplied from the first switching valve 114 to the input port H2 via the line 129 in the first state of the third switching valve 118, the hydraulic pressure is output from the output port I2 to the line 134, and It can be supplied to the R35 brake 80 by the control of the fourth SV 104 provided on the line 134.

  Further, in the first state of the third switching valve 118, when the line 131 is closed by the third SV 103, the hydraulic pressure of the line 132 branched from the line 131 is not input to the input port H1, so the line from the output port I1 is The hydraulic pressure is not supplied to the low clutch 40 via 133. On the other hand, even in the first state of the third switching valve 118, by controlling the opening degree of the third SV 103, the hydraulic pressure in the line 131 is reduced to such an extent that the spool 143 is moved to the left side, and a somewhat high pressure is applied. In this case, the hydraulic pressure of the line 132 is input from the input port H1 and output from the output port I1, so that the hydraulic pressure can be supplied to the low clutch 40 via the line 133. it can.

  In the second state of the third switching valve 118, the hydraulic pressure of the D range line 121 is input to the two input ports H3 and H4, and the hydraulic pressure input to the input port H3 is output from the output port I1 and is output to the low clutch 40. The hydraulic pressure input to the input port H4 is output from the output port I2, and can be supplied to the R35 brake 80 by the control of the fourth SV104.

  A hydraulic switch 222 is provided on a line 128 directly connected to the high clutch 50, and the engagement / release state of the high clutch 50 can be detected by the hydraulic switch 222.

  As described above, the engagement and release control of the LR brake 60 and the high clutch 50 is directly performed by the switching control of the second switching valve 116 or the opening degree control of the second SV 102. The control is performed by switching control of the first switching valve 114 by the first SV101. The engagement and disengagement control of the low clutch 40 is performed by switching the third switching valve 118 by the third SV 103 or controlling the opening degree of the third SV 103 when the third switching valve 118 is in the first state. Thus, the engagement and release control of the R35 brake 80 is performed by the switching control of the third switching valve 118 by the third SV 103 and the opening degree control of the fourth SV 104. Further, the engagement and release control of the 26 brake 70 is directly performed by controlling the opening degree of the fifth SV 105 provided on the line 136 connecting the predetermined hydraulic circuit 112 and the 26 brake 70.

  By performing the engagement and release control of the respective frictional engagement elements 40, 50, 60, 70, and 80 in this way, the shift control is performed so that each shift stage is realized according to the engagement table of FIG.

  FIG. 5 shows a hydraulic pressure supply state of the hydraulic circuit 100 at the first speed. In the first speed state, the first SV 101 is closed, and the first switching valve 114 is in the first state in which the spool 141 is moved to the left side. As a result, the second switching valve 116 enters the first state in which the spool 142 is moved to the right side, and the high clutch 50 is released. Further, in the first speed state, the LR brake 60 is engaged by releasing the hydraulic pressure supply to the input port E3 of the second switching valve 116 by the second SV102. Further, in the first speed state, by increasing the opening degree of the third SV 103, the third switching valve 118 is in the second state in which the spool 143 is moved to the right side, and the low clutch 40 is engaged. In the first speed state, the fourth SV 104 is closed, and the R35 brake 80 is thereby released.

  FIG. 6 shows a hydraulic pressure supply state of the hydraulic circuit 100 at the fourth speed. In the fourth speed state, when the first SV 101 is opened, the first switching valve 114 is in the second state in which the spool 141 is moved to the right side. As a result, the second switching valve 116 enters the second state in which the spool 142 is moved to the left side, and the LR brake 60 is released. Further, in the fourth speed state, the high clutch 50 is engaged by releasing the hydraulic pressure supply to the input port E3 of the second switching valve 116 by the second SV102. Further, in the fourth speed state, the third switching valve 118 is in the second state brought to the right as in the first speed state, and the low clutch 40 is engaged. Further, as in the first speed state, the R35 brake 80 is in a released state.

  Comparing the first speed state shown in FIG. 5 and the fourth speed state shown in FIG. 6, the state of the third switching valve 118 for engaging the low clutch 40 is the same, and either the LR brake 60 or the high clutch 50 is used. The states of the first switching valve 114 and the second switching valve 116 for selectively fastening these are different.

  The second switching valve 116 is directly connected to both the LR brake 60 and the high clutch 50, and selectively connects the line 127 connected to the LR brake 60 and the line 128 connected to the high clutch 50 to the oil pump 6 side. It is configured. That is, the second switching valve 116 is also used as a valve that directly controls the engaged / released state of both the frictional engagement elements 50, 60.

  When the D range is selected, the LR brake 60 is engaged only at the first speed, and is released at the second speed or higher. On the other hand, the high clutch 50 is engaged at the 4th to 6th speeds and is released at the 1st to 3rd speeds. Therefore, in the second to third speeds, neither the high clutch 50 nor the LR brake 60 is engaged. Therefore, the LR brake 60 is engaged to shift down to the first speed, or the high clutch is used to shift up to the fourth speed. The switching control of the second switching valve 116 for the purpose of fastening 50 can be performed in advance with a time margin at the second to third speeds. Therefore, even when the second switching valve 116 is also used for the fastening / release control of both the frictional engagement elements 50, 60, the fastening / release control can be performed without any trouble.

  FIG. 7 shows a hydraulic pressure supply state in which the second switching valve 116 is switched to the second state in order to shift up to the fourth speed in the third speed state. As shown in FIG. 7, in the third speed state, the hydraulic pressure supply to the input port E3 of the second switching valve 116 is blocked by the second SV 102 provided between the second switching valve 116 and the oil pump 6.

  When the upshift from the third speed to the fourth speed is performed, the R35 brake 80 is released by closing the fourth SV 104, and the second SV 102 is opened to be introduced from the line 126 to the input port E3 of the second switching valve 116. The high clutch 50 is engaged by outputting the hydraulic pressure from the output port F3 to the line 128.

  However, at this time, a valve stick that is fixed in a state where the spool 141 of the first switching valve 114 is moved toward the left side or fixed in a state where the spool 142 of the second switching valve 116 is moved toward the right side, or When the second switching valve 116 is fixed in the first state due to an abnormality such as a failure of the first SV 101, the hydraulic pressure introduced to the input port E3 of the second switching valve 116 is the output port F2. Will be output to line 127. Then, although the upshift command to the fourth speed is issued, the LR brake 60 is engaged instead of the high clutch 50, so that the downshift to the first speed is erroneously realized. If such a downshift from the third speed to the first speed is executed in the acceleration state where the accelerator pedal is depressed, the engine may overspeed. In order to suppress such over-rotation of the engine, the TCM 202 performs the following shift condition setting control.

[Shift condition setting control]
In the shift control, a so-called shift diagram using the vehicle speed and the accelerator opening as parameters is used as a shift condition (shift-up condition and shift-down condition) of each shift pattern, and the vehicle speed detected by the vehicle speed sensor 212 and the accelerator When the accelerator opening detected by the sensor 210 satisfies the shift condition, a shift up or down is performed.

  Predetermined normal conditions are set as the shift conditions for each shift pattern. Although the shift control is basically performed based on these normal conditions, a shift condition different from the normal conditions is used depending on the driving state. The TCM 202 performs shift condition setting control for appropriately setting the shift condition according to the driving state in order to always perform shift control using the optimal shift condition.

  In the present embodiment, the conditions for shifting up from the 3rd speed to the 4th speed (hereinafter referred to as “3-4 speed shift up condition”) are set to the normal condition and the lower vehicle speed side than the normal condition. Low vehicle speed side conditions are used. The third speed in the present embodiment corresponds to the “third speed ratio” in the claims, and the fourth speed in the present embodiment corresponds to the “second speed ratio” in the claims.

  In the shift condition setting control, the normal condition is basically set as the 3-4 speed shift up condition, and the shift down to the 1st speed is realized in response to the shift up command to the 4th speed as described above. A low vehicle speed condition is set in a possible driving state. Specifically, when it is confirmed that the second switching valve 116 is switched from the first state to the second state, the normal condition is used, and the second switching valve 116 is moved to the second state. When it is not confirmed that the vehicle has been switched, the low vehicle speed side condition is used. The first speed in this embodiment corresponds to the “first speed ratio” in the claims.

  Whether or not the second switching valve 116 has been switched to the second state is determined by the switching confirmation control described later. This switching confirmation control is always repeatedly executed during forward traveling of the vehicle, and shift condition setting control is performed in accordance with the presence or absence of confirmation determination by the switching confirmation control.

  As the normal condition, for example, a condition defined by a solid line indicated by reference numeral 300 in FIG. 8 is set. The normal condition 300 is set such that the vehicle speed condition is higher when the accelerator opening is larger than the predetermined opening Y1 than when the accelerator opening is lower than the predetermined opening Y1.

  As the low vehicle speed side condition, for example, a condition defined by a broken line indicated by reference numeral 310 in FIG. 8 is set. The low vehicle speed side condition 310 is such that when the accelerator opening is larger than the predetermined opening Y1, the normal condition 300 is set so that the vehicle speed is lower than the normal condition 300 and when the accelerator opening is equal to or less than the predetermined opening Y1. It is set to be the same vehicle speed as.

  By setting the low vehicle speed side condition 310 in this way, when the vehicle is accelerating with the accelerator opening larger than the predetermined opening Y1, the second switching valve 116 is switched to the second state. Is not confirmed, i.e., when there is a possibility that the downshift to the first speed may be realized due to the malfunction of the second switching valve 116 when the next upshift command to the fourth speed is issued. A shift up command to the fourth speed is issued at a relatively low vehicle speed earlier than usual. Therefore, even if the second switching valve 116 is erroneously shifted down to the first speed due to a malfunction of the second switching valve 116, the increase in the engine speed can be suppressed to a relatively low level and the engine overspeed can be suppressed.

  On the other hand, when the accelerator opening is equal to or less than the predetermined opening Y1, the normal shift control using the normal condition 300 is performed in an operating state in which the engine is unlikely to over-rotate.

  However, the configuration of the low vehicle speed side condition is not limited to the condition 310 shown in FIG. 8. For example, the low vehicle speed side condition defined by the broken line indicated by reference numeral 312 in FIG. 9 may be used. The low vehicle speed condition 312 shown in FIG. 9 is uniformly set to the low vehicle speed side than the normal condition 300 regardless of the accelerator opening.

  When such a low vehicle speed side condition 312 is set, an upshift command to the fourth speed is issued at a relatively low vehicle speed earlier than usual regardless of the accelerator opening. Therefore, if the second changeover valve 116 is erroneously shifted down to the first speed due to a malfunction, the increase in the engine speed can be suppressed to a relatively low value regardless of the operating state at this time.

[Switching confirmation control]
An example of the control operation of the switching confirmation control performed by the TCM 202 will be described with reference to the flowchart shown in FIG.

  The control operation shown in FIG. 10 is always repeatedly executed while the shift control during forward traveling of the vehicle is being performed.

  First, in step S1, it is determined whether or not a command to turn on the first SV 101 is issued in order to switch the first switching valve 114 and the second switching valve 116 from the first state to the second state in the shift control. Is done.

  If it is determined in step S1 that the first SV 101 has been turned on, the output signal of the hydraulic switch 222 for the high clutch 50 is read in step S2, and the hydraulic switch 222 is turned on / off in step S3. Based on this, it is determined whether or not the high clutch 50 is in the engaged state.

  As shown in the engagement table of FIG. 2, the high clutch 50 is in the engaged state at the 4th to 6th speed, so in step S3, when any of the 4th to 6th speeds is realized, It is determined that the high clutch 50 is in the engaged state.

  When it is determined in step S3 that the high clutch 50 is in the engaged state, confirmation determination is performed in which it is determined in step S4 that the second switching valve 116 has been confirmed to be in the second state.

  On the other hand, if it is determined in step S3 that the high clutch 50 is not in the engaged state, even if the second switching valve 116 is in the second state, this cannot be confirmed, so the confirmation determination in step S4 is not executed.

  After the confirmation determination in step S4 is executed, in step S5, a command to turn off the first SV 101 to return the first switching valve 114 and the second switching valve 116 from the second state to the first state, respectively. It is determined whether it has been delivered.

  The determination in step S5 is repeatedly executed until an off command for the first SV 101 is issued, during which the confirmation determination made in step S4 is maintained.

  If it is determined in step S5 that the first SV 101 off command has been issued, the confirmation determination in step S4 is canceled in step S6.

  In the switching confirmation control described above, even if the confirmation determination in step S4 is executed by confirming that the second switching valve 116 has been normally switched to the second state, the second switching valve 116 is subsequently executed. When a command is issued to return the first state to the first state, the confirmation determination is canceled because the next switching to the second state is not always performed normally (step S6). Thereby, when the confirmation determination by the switching confirmation control is valid, the second switching valve 116 is always in the second state.

  However, the switching confirmation control is not limited to the control operation illustrated in FIG. 10, and may be configured by another control operation capable of confirming that the second switching valve 116 is in the second state. For example, in the control operation shown in FIG. 10, the determination is made for the first time when the high clutch 50 is engaged by shifting up to the fourth speed, but the second switching valve 116 is in the second speed or the second speed when the second clutch 116 is in the second speed. When switching to the state, if it can be diagnosed by some method before shifting up to the fourth speed whether the second switching valve 116 has been switched to the second state or not, a confirmation determination is made based on the diagnosis result. May be executed.

[Control action of shift condition setting control]
Hereinafter, the first embodiment and the second embodiment will be described as specific examples of the control operation of the shift condition setting control.

[First embodiment]
The control operation of the shift condition setting control according to the first embodiment will be described with reference to the flowchart shown in FIG. 11 and the time chart shown in FIG.

  The control operation shown in FIG. 11 is always executed repeatedly while the shift control during forward traveling of the vehicle is performed. Further, since all the determination processes in the control operation shown in FIG. 11 are executed based on the processing contents in the shift control or the switching confirmation control performed by the TCM 202 itself, in the control operation shown in FIG. An input signal to the TCM 202 is not used.

  In the control operation shown in FIG. 11, first, in step S11, the 3-4 speed upshift condition is set to the normal condition, and thereafter, basically, the shift control is performed based on the normal condition.

  In the next step S12, it is determined whether or not an on command for the first SV 101 for switching the first switching valve 114 and the second switching valve 116 from the first state to the second state is issued in the shift control. Is done. The determination in step S12 is made based on the state of shift control performed by the TCM 202 itself.

  Note that the first SV 101 on command is issued in advance before the upshift command to the fourth speed is issued during acceleration traveling, and specifically, for example, a predetermined time has elapsed since the upshift command to the third speed was issued. It is issued at the timing.

  If the result of determination in step S12 is that an on command for the first SV 101 has not been issued, shift control based on normal conditions is continued.

  On the other hand, if the first SV 101 on command is issued as a result of the determination in step S12, the first SV 101 is turned on in the next step S13. At this time, when the failure of the first SV 101 or the abnormality such as the valve stick of the first switching valve 114 or the second switching valve 116 has not occurred, the first switching valve 114 and the second switching valve 116 are respectively The state is normally switched to the second state.

  In subsequent step S14, it is determined whether or not the confirmation determination (step S4 in FIG. 10) by the above-described switching confirmation control (see FIG. 10) has been made. The determination in step S14 is made based on the status of switching confirmation control performed by the TCM 202 itself.

  As described above, the confirmation determination is executed, for example, when a shift up to the fourth speed is realized. However, when diagnosing whether or not the second switching valve 116 is in the second state by any method in the second speed or the third speed state, it is determined that the second switching valve 116 is in the second state by this diagnosis. When this is done, confirmation determination by switching confirmation control is executed.

  If the confirmation determination is not made as a result of the determination in step S14, the 3-4 speed upshift condition is changed from the normal condition to the low vehicle speed condition in step S19, and the first switching is performed in the shift control in step S20. It is determined whether or not an OFF command for the first SV 101 for returning the valve 114 and the second switching valve 116 from the second state to the first state is issued. The determination in step S20 is made based on the state of shift control performed by the TCM 202 itself.

  A series of control operations from step S14 through step S19 to step S20 is repeatedly performed until a confirmation determination is made by switching confirmation control or an OFF command for the first SV 101 is issued. While this series of control operations is being performed, there is a possibility that downshifting to the first speed may be realized due to a malfunction of the second switching valve 116 when an upshifting command to the fourth speed is issued. However, since the low vehicle speed side condition is set as the 3-4 speed shift up condition, even if the second switching valve 116 malfunctions, the downshift is realized at a relatively low vehicle speed. Engine overspeed can be suppressed.

  As a result of the determination in step S20, when a command to turn off the first SV 101 is issued, the first switching valve 114 and the second switching valve 116 are returned to the first state by turning off the first SV 101 in step S21. Alternatively, when a malfunction that is originally fixed in the first state has occurred, the first state is maintained. In the subsequent step S22, the 3-4 speed upshift condition is returned to the normal condition, and thereby, the shift control based on the normal condition is performed until the next ON command (step S13) of the first SV 101 is issued.

  On the other hand, when the confirmation determination is made as a result of the determination in step S14, since the second switching valve 116 is operating normally, the shift up to the fourth speed can be normally realized. Normal conditions are used as the 3-4 speed up conditions.

  In the subsequent step S16, as in step S20, it is determined whether or not an off command for the first SV 101 has been issued. The determination in step S16 is repeated until the first SV 101 off command is issued, but the 3-4 speed upshift condition is maintained at the normal condition during that time.

  As a result of the determination in step S16, when a command to turn off the first SV 101 is issued, the first switching valve 114 and the second switching valve 116 are respectively returned to the first state by turning off the first SV 101 in step S17. . In the subsequent step S18, the 3-4 speed upshift condition is continuously maintained at the normal condition.

  As described above, according to the first embodiment, only after a command for switching the second switching valve 116 to the second state is issued until a confirmation determination for confirming this switching is issued, 3-4 The low vehicle speed condition is used as the speed shift up condition, and the normal condition is basically used during the other periods. Therefore, basically, the normal shift control based on the normal condition is performed, and the low vehicle speed side condition is used when necessary, so that the erroneous shift down to the first speed due to the malfunction of the second switching valve 116 is assumed. Even if is realized, it is possible to suppress over-rotation of the engine due to this downshift.

  In the case where the confirmation determination by the switching confirmation control is not made despite the shift up command to the fourth speed being issued, the high clutch 50 cannot be engaged due to the malfunction of the second switching valve 116, and the high clutch 50 Therefore, in the subsequent shift control, limp home control that performs forward traveling only at the 1st to 3rd speeds is executed.

  FIG. 12 is a time chart showing an example of a change over time of each element when the shift control is performed while performing the switching confirmation control shown in FIG. 10 and the shift condition setting control shown in FIG.

  At time t0 shown in FIG. 12, the automatic transmission 1 is in the third speed state, and the 3-4 speed upshift condition is set to the normal condition. When a first SV 101 on command is issued to switch the first switching valve 114 and the second switching valve 116 from the first state to the second state at a predetermined timing t1 in the third speed state, a 3-4 speed shift is performed. The up condition is switched from the normal condition to the low vehicle speed condition.

  At this time, if the second switching valve 116 is normally switched to the second state, the high clutch 50 is engaged at the time t2 by the subsequent upshift command to the fourth speed, thereby realizing the fourth speed. At the same time, when the engaged state of the high clutch 50 is detected, a confirmation determination is made by the switching confirmation control, and the 3-4 speed upshift condition is returned to the normal condition.

  On the other hand, when the malfunction of the second switching valve 116 occurs due to the valve stick or the like, the high clutch 50 is engaged as indicated by the symbol a after time t2 after the upshift command to the fourth speed is issued. Therefore, the confirmation determination by the switching confirmation control is not performed as indicated by the symbol b. In this case, as indicated by reference symbol c, the 3rd to 4th speed upshifts are made after time t2 until time t6 when the first SV 101 off command for returning the second switching valve 116 to the first state is issued. The low vehicle speed side condition is used as the condition.

  As described above, when the malfunction of the second switching valve 116 occurs, the low vehicle speed side condition is used even after the time t2, so after the downshift command to the third speed is once issued at the time t3, The timing t4 at which the upshift command to the fourth speed is issued is earlier than the timing t5 of the upshift command when the normal condition is used. Therefore, even if the downshift to the first speed is erroneously realized due to the malfunction of the second switching valve 116, since the downshift is realized at a relatively low vehicle speed, the engine overspeed Can be suppressed.

  In addition, the engine overspeed can be suppressed by changing the 3-4 speed upshift conditions as described above without performing special abnormality diagnosis control for determining whether or not the second switching valve 116 is malfunctioning. Even when the upshift command to the 4th speed is issued as quickly as the time for abnormality diagnosis control cannot be secured in the 2nd speed or 3rd speed state, the overspeed of the engine can be reliably suppressed.

  Further, in the case where the shift control shown in FIG. 12 is performed, when the second switching valve 116 operates normally, except for the period from time t1 to time t2, The shift control can be performed.

[Second Embodiment]
The control operation of the shift condition setting control according to the second embodiment will be described with reference to the flowchart shown in FIG. 13 and the time chart shown in FIG.

  The control operation shown in FIG. 13 is always repeatedly executed while the shift control during forward traveling of the vehicle is performed. Further, since all determination processes in the control operation shown in FIG. 13 are executed based on the processing contents in the above-described shift control or switching confirmation control performed by the TCM 202 itself, in the control operation shown in FIG. An input signal to the TCM 202 is not used.

  In the control operation shown in FIG. 13, first, in step S31, the 3-4 speed upshift condition is set to the low vehicle speed side condition, and thereafter, the first switching valve 114 and the second switching valve 116 are changed from the first state to the first state. The low vehicle speed side condition is maintained until the first SV 101 on command for switching to the state 2 is issued and the confirmation determination by the switching confirmation control is made.

  In the next step S32, it is determined whether or not an ON command for the first SV 101 is issued in the shift control. As a result of the determination in step S32, when the first SV 101 on command is issued, the first SV 101 is turned on in the next step S33.

  In subsequent step S34, it is determined whether or not the confirmation determination (step S4 in FIG. 10) by the above-described switching confirmation control (see FIG. 10) has been made.

  As a result of the determination in step S34, if the confirmation determination is not made, in step S39, the 3-4 speed shift up condition is maintained at the low vehicle speed side condition. In step S40, in the shift control, the first switching valve 114 and It is determined whether or not an off command for the first SV 101 for returning the second switching valve 116 from the second state to the first state has been issued.

  A series of control operations from step S34 through step S39 to step S40 is repeated until a confirmation determination is made by the switching confirmation control or an OFF command for the first SV 101 is issued. While this series of control operations is being performed, there is a possibility that downshifting to the first speed may be realized due to a malfunction of the second switching valve 116 when an upshifting command to the fourth speed is issued. However, since the low vehicle speed side condition is set as the 3-4 speed shift up condition, even if the second switching valve 116 malfunctions, the downshift is realized at a relatively low vehicle speed. Engine overspeed can be suppressed.

  As a result of the determination in step S40, when a command to turn off the first SV 101 is issued, the first switching valve 114 and the second switching valve 116 are returned to the first state by turning off the first SV 101 in step S41. Alternatively, when a malfunction that is originally fixed in the first state has occurred, the first state is maintained. In the following step S42, the 3-4 speed upshift condition is maintained at the low vehicle speed side condition. The maintenance of the low vehicle speed side condition is continued until an ON command for the first SV 101 is next issued and a confirmation determination is made by the switching confirmation control.

  On the other hand, if the confirmation determination is made as a result of the determination in step S34, since the second switching valve 116 is operating normally, there is a high possibility that the upshift to the fourth speed is normally realized. Thus, the 3-4 speed shift up condition is changed from the low vehicle speed side condition to the normal condition.

  In the subsequent step S36, as in step S40, it is determined whether or not an off command for the first SV 101 has been issued. The determination in step S36 is repeated until the first SV 101 off command is issued, but the 3-4 speed upshift condition is maintained at the normal condition during that time.

  As a result of the determination in step S36, when a command to turn off the first SV 101 is issued, the first switching valve 114 and the second switching valve 116 are returned to the first state by turning off the first SV 101 in step S37. In the subsequent step S38, the 3-4 speed upshift condition is returned to the low vehicle speed side condition. The maintenance of the low vehicle speed side condition is continued until an ON command for the first SV 101 is next issued and a confirmation determination is made by the switching confirmation control.

  As described above, according to the second embodiment, when a command for switching the second switching valve 116 to the second state is issued and a confirmation determination for confirming this switching is issued, a 3-4 speed shift is performed. Since the normal condition is used as the condition, when the second switching valve 116 is operating normally, the upshift to the fourth speed can be performed based on the normal condition. In addition, when the confirmation determination is not issued, the low vehicle speed side condition is used as the 3-4 speed shift up condition, so that the erroneous shift down to the first speed due to the malfunction of the second switching valve 116 is realized. In addition, it is possible to suppress engine overspeed due to this downshift.

  FIG. 14 is a time chart showing an example of a change over time of each element when the shift control is performed while performing the switching confirmation control shown in FIG. 10 and the shift condition setting control shown in FIG.

  In the control example shown in FIG. 14, at time t10, the automatic transmission 1 is in the third speed state, and the 3-4 speed upshift condition is set to the low vehicle speed side condition. Thereafter, at a predetermined timing t11 in the third speed state, an on-command for the first SV 101 is issued to switch the first switching valve 114 and the second switching valve 116 from the first state to the second state.

  At this time, since the 3-4 speed upshift condition is already set to the low vehicle speed side condition, it is not necessary to change this setting.

  When the second switching valve 116 is normally switched to the second state with respect to the first SV 101 on command at time t11, the high clutch 50 is turned on at time t12 by the subsequent upshift command to the fourth speed. The fourth speed is realized by being engaged, and the confirmation determination by the switching confirmation control is made by detecting the engagement state of the high clutch 50, and the 3-4 speed upshift condition is changed from the low vehicle speed side condition to the normal condition. Changed to

  On the other hand, when the malfunction of the second switching valve 116 occurs due to a valve stick or the like, the high clutch 50 is engaged as indicated by the symbol d after time t12 after the upshift command to the fourth speed is issued. Accordingly, the confirmation determination by the switching confirmation control is not performed as indicated by the symbol e. In this case, as indicated by the symbol f, after time t12, up to time t16 when the first SV 101 off command for returning the second switching valve 116 to the first state is issued, up to 3-4 speed up. The low vehicle speed side condition is used as the condition.

  When the malfunction of the second switching valve 116 has occurred, the low vehicle speed condition is used after time t12. Therefore, after a downshift command to the third speed is issued once at time t13, then the fourth speed is shifted to the fourth speed. The timing t14 at which the upshift command is issued is earlier than the timing t15 of the upshift command when the normal condition is used. Therefore, even if the downshift to the first speed is erroneously realized due to the malfunction of the second switching valve 116, since the downshift is realized at a relatively low vehicle speed, the engine overspeed Can be suppressed.

  In addition, the engine overspeed can be suppressed by changing the 3-4 speed upshift conditions as described above without performing special abnormality diagnosis control for determining whether or not the second switching valve 116 is malfunctioning. Even when the upshift command to the 4th speed is issued as quickly as the time for abnormality diagnosis control cannot be secured in the 2nd speed or 3rd speed state, the overspeed of the engine can be reliably suppressed.

  Furthermore, in the control example shown in FIG. 14, during the period from when the confirmation determination by the switching confirmation control is performed (time t12) to when the first SV 101 off command is issued (time t16), the normal condition is based on the normal condition. Shift control can be performed.

  Furthermore, in the control example shown in FIG. 14, even when the confirmation determination by the switching confirmation control is once made, the second switching valve 116 is then returned to the first state to switch to the next second state. When it is in a state where it is not known whether or not the vehicle is normally operated (time t16), the 3rd to 4th gear shift-up condition is returned from the normal condition to the low vehicle speed condition, and the shift to the next 4th gear is performed. The up command is issued at a relatively low vehicle speed. Therefore, at the time of this upshift command, even if the downshift to the first speed is realized due to the malfunction of the second switching valve 116, the overspeed of the engine can be suppressed.

[Other Embodiments]
A configuration of a hydraulic circuit 400 of an automatic transmission according to another embodiment of the present invention will be described with reference to FIG.

  The hydraulic circuit 400 is configured in the same manner as the hydraulic circuit 100 of the above-described embodiment except for portions related to the engagement and release of the LR brake 60, and the description of the same components as the hydraulic circuit 100 is omitted. In addition, the same reference numerals are given in FIG.

  In the embodiment shown in FIG. 15, a double-acting actuator (not shown) having a fastening piston and a clearance adjustment piston is used as the hydraulic actuator of the LR brake 60, and the hydraulic circuit 400 includes the clearance adjustment piston together with the clearance adjustment piston. A clearance chamber 62 for supplying hydraulic pressure to stroke the fastening piston to a fastening preparation position where a small clearance state is set, and a hydraulic pressure supply for fastening the LR brake 60 by operating the fastening piston in the fastening preparation position are made. A fastening chamber 61 is provided.

  The fastening chamber 61 is directly connected to the output port F2 of the second switching valve 116 via the line 410, and the clearance chamber 62 is connected to the line 124 connected to the output port C1 of the first switching valve 114 via the line 420. It is connected.

  Line pressure is supplied to the clearance chamber 62 via the line 124 and the line 420 from the output port C1 of the first switching valve 114 in the first state in which the spool 141 is located on the left side when the first SV 101 is turned off. The Thereby, the said fastening piston strokes to a fastening preparation position with the said clearance adjustment piston, and is hold | maintained in this fastening preparation position.

  As described above, when the first switching valve 114 is in the first state, the second switching valve 116 is in the first state in which the spool 142 is positioned on the right side. Therefore, when the fastening piston is in the fastening preparation position, the second switching valve 116 is in the first state, and when the second SV 102 is opened in this state, the input port E3 of the second switching valve 116 from the line 126 is opened. The line pressure is input to the fastening chamber 61 from the output port F2 of the second switching valve 116 via the line 410. Thereby, the said fastening piston presses a friction board and the LR brake 60 is fastened.

  As described above, the clearance adjustment is performed by supplying the hydraulic pressure to the clearance chamber 62 first, and then the fastening hydraulic pressure is supplied to the fastening chamber 61, whereby the LR brake 60 can be fastened in a small clearance state. Therefore, it is possible to perform fastening control with high precision and excellent responsiveness with respect to the LR brake 60 having a large capacity.

  On the other hand, in the released state of the LR brake 60, the fastening piston and the clearance adjusting piston can be retracted to a position where a large clearance state is obtained, thereby suppressing rotational resistance due to the viscosity of the lubricating oil.

  Other configurations in the hydraulic circuit 400 are the same as those in the hydraulic circuit 100 in the above-described embodiment, and the same shift control as in the above-described embodiment is performed in the forward shift speed of the second speed or higher.

  Therefore, also in the embodiment shown in FIG. 15, the 3-4 speed upshift condition is appropriately set according to the presence / absence of the confirmation determination in the switching confirmation control according to the shift condition setting control. Therefore, if a malfunction of the second switching valve 116 occurs, an upshift command from the 3rd speed to the 4th speed is issued early at a relatively low vehicle speed, so that an erroneous downshift to the 1st speed may occur. Even if it is realized, engine overspeed can be suppressed.

  While the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, the configuration in which the 3-4 speed shift-up condition is changed to the low vehicle speed side has been described. The same applies to the conditions.

  As described above, according to the present invention, in a vehicle equipped with an automatic transmission, when an abnormality occurs in the hydraulic control mechanism such that an erroneous downshift is realized in response to the upshift command, an engine overload occurs. Since rotation can be suppressed, the automatic transmission having a hydraulic control mechanism and a vehicle equipped with the automatic transmission may be suitably used in the manufacturing industry.

DESCRIPTION OF SYMBOLS 1 Automatic transmission 3 Torque converter 3c Turbine 3f Lock-up clutch 4 Input shaft 6 Oil pump (hydraulic power source)
40 Low clutch 50 High clutch (second frictional engagement element)
60 LR brake (first frictional engagement element)
70 26 brake 80 R35 brake 100 Hydraulic circuit (hydraulic control mechanism)
101 1st solenoid valve 102 2nd solenoid valve (hydraulic control valve)
103 3rd solenoid valve 104 4th solenoid valve 105 5th solenoid valve 110 Manual valve 114 1st switching valve 116 2nd switching valve 118 3rd switching valve 200 Control apparatus 201 ECU
202 TCM
222 Hydraulic switch

Claims (6)

A first friction engagement element that is engaged at a first transmission ratio;
A second frictional engagement element that is engaged at a second transmission ratio that is smaller than the first transmission ratio;
And a hydraulic control mechanism that is selectively switched between a first state in which hydraulic pressure can be supplied to the first frictional engagement element and a second state in which hydraulic pressure can be supplied to the second frictional engagement element. A transmission control device,
Confirmation means for confirming that the hydraulic control mechanism is in the second state;
As a vehicle speed condition when shifting up from the third gear ratio, which is larger than the second gear ratio, and the first and second friction engagement elements are released to the second gear ratio, A predetermined normal condition is used when the confirmation unit confirms the second state, and when the confirmation unit does not confirm the second state, the normal condition is satisfied. And a shift condition setting means for setting a shift-up condition to the second gear ratio so that the low vehicle speed side condition set on the low vehicle speed side is used. apparatus.   The shift condition setting means sets the normal condition so that the vehicle speed condition is higher when the acceleration request amount for the vehicle is larger than the predetermined amount than when it is less than the predetermined amount, and the acceleration request The low vehicle speed side condition is set so that the vehicle speed is lower than the normal condition when the amount is greater than the predetermined amount, and the vehicle speed is the same as the normal condition when the requested acceleration amount is equal to or less than the predetermined amount. The control apparatus for an automatic transmission according to claim 1, wherein:   The speed change condition setting means sets the vehicle speed condition when the hydraulic control mechanism is switched from the second state to the first state in a state where the confirmation means confirms the second state. The control device for an automatic transmission according to claim 1 or 2, wherein the normal condition is changed to the low vehicle speed side condition.   4. The hydraulic control mechanism according to claim 1, further comprising a switching valve that is switched to selectively supply hydraulic pressure to the first friction engagement element and the second friction engagement element. The control device for an automatic transmission according to any one of the preceding claims. The hydraulic control mechanism includes a hydraulic control valve provided between the switching valve and a hydraulic source,
The hydraulic control valve opens the hydraulic pressure supplied from the hydraulic pressure source to the switching valve side at the first gear ratio and the second gear ratio, and from the hydraulic power source at the third gear ratio. 5. The automatic transmission control device according to claim 4, wherein the hydraulic pressure supply to the switching valve is shut off. A first friction engagement element that is engaged at a first transmission ratio;
A second frictional engagement element that is engaged at a second transmission ratio that is smaller than the first transmission ratio;
And a hydraulic control mechanism that is selectively switched between a first state in which hydraulic pressure can be supplied to the first frictional engagement element and a second state in which hydraulic pressure can be supplied to the second frictional engagement element. A transmission control method comprising:
A confirmation step for confirming whether or not the hydraulic control mechanism is in the second state;
As a vehicle speed condition when shifting up from the third gear ratio, which is larger than the second gear ratio, and the first and second friction engagement elements are released to the second gear ratio, When it is confirmed that the second state is confirmed in the confirmation step, a predetermined normal condition is used. When it is not confirmed that the second state is confirmed in the confirmation step, the normal condition is satisfied. And a shift condition setting step for setting a shift-up condition to the second gear ratio so that the low vehicle speed side condition set on the low vehicle speed side is used. Method.

Images