JP4654872B2 - Hydraulic control device for automatic transmission for vehicle - Google Patents

Description

  The present invention relates to a hydraulic control device for an automatic transmission for a vehicle, and in particular, by using a solenoid valve for shifting for controlling the engagement pressure of a plurality of hydraulic friction engagement devices that establish a plurality of gear stages. The present invention relates to a hydraulic control device that performs engagement / release control of a lockup mechanism.

  In an automatic transmission that establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of hydraulic engagement devices, the engagement pressures of the plurality of hydraulic friction engagement devices are individually set. For example, Patent Literature 1 discloses a hydraulic control device that directly and independently controls using a solenoid valve. On the other hand, in Patent Document 2, in a continuously variable transmission having a fluid transmission device with a lockup mechanism, engagement pressure control of a hydraulic friction engagement device of a forward / reverse switching device is performed using a single solenoid valve. And a technique for performing both torque capacity control of the lockup mechanism have been proposed. That is, by switching the output destination of the control hydraulic pressure output from the solenoid valve by a relay valve (switching valve), the engagement pressure control and the solenoid for supplying the engagement pressure corresponding to the output hydraulic pressure of the solenoid valve to the friction engagement device Torque capacity control for supplying a control pressure corresponding to the output hydraulic pressure of the valve to the lockup mechanism can be performed alternatively using a single solenoid valve.

JP 2000-249219 A JP 2001-248725 A

  By the way, applying the technique of Patent Document 2 to the automatic transmission of Patent Document 1, for example, a solenoid valve that controls the engagement pressure of a predetermined hydraulic friction engagement device among a plurality of hydraulic friction engagement devices, It can be considered to be used also as a solenoid valve for controlling the torque capacity of the lockup mechanism. At this time, an oil for torque capacity control in which the hydraulic circuit supplies a control pressure corresponding to the output hydraulic pressure of the solenoid valve to the lockup mechanism due to a failure of the solenoid valve for switching control of the relay valve or a failure of the relay valve itself. There is a possibility that a switching abnormality fixed to the road may occur. When this switching abnormality occurs, if the control hydraulic pressure is output from the solenoid valve in order to engage a predetermined hydraulic friction engagement device, the vehicle is in a vehicle running state that becomes a preset lockup release region. However, the lock-up mechanism may be engaged.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide a fluid transmission device with a lock-up mechanism and selectively engage a plurality of hydraulic friction engagement devices. In a vehicle automatic transmission that establishes a plurality of gear stages having different gear ratios, a solenoid valve that controls the engagement pressure of a predetermined hydraulic friction engagement device is used to control the torque capacity of a lockup mechanism. It is an object of the present invention to provide a hydraulic control device that prevents an unplanned engagement operation of a lock-up mechanism when used in combination.

In order to achieve the above object, the gist of the present invention is that (a) a hydraulic transmission device with a lock-up mechanism is provided, and a gear ratio is obtained by selectively engaging a plurality of hydraulic friction engagement devices. A hydraulic control device for an automatic transmission for a vehicle that establishes a plurality of different gear stages, and (b) a predetermined hydraulic pressure engaged to obtain an engine braking action among the plurality of hydraulic friction engagement devices A single solenoid valve that selectively controls the engagement pressure of the friction engagement device and the torque capacity of the lockup mechanism, and (c) the predetermined hydraulic friction according to the output hydraulic pressure of the solenoid valve A first oil passage for controlling the engagement pressure of the engagement device and a second oil passage for controlling the torque capacity of the lock-up mechanism according to the output hydraulic pressure of the solenoid valve are used for the vehicle automatic. Concerning transmission operation of transmission A relay valve which can be switched without a (d) switching換異normal determining means for the relay valve to determine whether switching abnormality occurs that is fixed to the second oil passage becomes impossible switching, ( e) an engagement prohibiting means for prohibiting the engagement of the predetermined hydraulic friction engagement device when the switching abnormality determining means determines that the switching abnormality has occurred.

  According to this configuration, the predetermined hydraulic pressure according to the output hydraulic pressure of a single solenoid valve that selectively controls the engagement pressure of the predetermined hydraulic friction engagement device and the torque capacity of the lockup mechanism. That switches between a first oil passage for controlling the engagement pressure of the friction engagement device and a second oil passage for controlling the torque capacity of the lock-up mechanism according to the output hydraulic pressure of the solenoid valve When it is determined that the switching abnormality has occurred by the switching abnormality determining means for determining whether or not the valve has become non-switchable and the switching abnormality fixed to the second oil passage has occurred, the engagement prohibiting means determines the predetermined abnormality. Therefore, the solenoid valve for controlling the engagement pressure of the predetermined hydraulic friction engagement device is also used as the solenoid valve for controlling the torque capacity of the lockup mechanism. Even switching abnormality occurs that is fixed to the second oil passage when allowed, engagement operation of the lockup mechanism, not scheduled is prevented.

Here, preferably, the engagement prohibiting unit is a unit that does not output a control pressure for engaging a predetermined hydraulic friction engagement device that is engaged to obtain the engine braking action. Preferably, an operating device is provided that can be switched between a travel position for switching the automatic transmission to a power transmission enabled state and a non-travel position for switching the automatic transmission to a power transmission cut-off state. The abnormality determining means is configured to switch to the first oil passage and output hydraulic pressure from the solenoid valve when the operating device is switched to the non-travel position, and to output the predetermined hydraulic friction engagement device. It is determined whether or not the switching abnormality has occurred based on the detection result of the hydraulic pressure from the solenoid valve for controlling the engagement pressure. In this way, when a switching abnormality that cannot be switched to the first oil path occurs, even if the hydraulic pressure is output from the solenoid valve, the hydraulic pressure for controlling the engagement pressure of the predetermined hydraulic friction engagement device Therefore, the occurrence of switching abnormality can be determined. In addition, since the abnormality determination is performed when the automatic transmission is in the power transmission cut-off state, an unexpected engagement operation of the lockup mechanism is prevented when the operating device is switched to the travel position. In other words, since the abnormality determination is performed before traveling, the engagement operation of the lock-up mechanism that is not scheduled during traveling of the vehicle is prevented.

  Preferably, the automatic transmission is constituted by a planetary gear type multi-stage transmission whose gear stage is switched by selectively connecting rotating elements of a plurality of sets of planetary gear apparatuses by a hydraulic friction engagement device. For example, various automatic transmissions capable of selectively engaging and releasing a plurality of hydraulic friction engagement devices to establish a plurality of gear stages can be employed. The mounting posture of the automatic transmission with respect to the vehicle is a FR (front engine / front drive) FF vehicle in which the transmission axis is in the width direction of the vehicle. Front engine / rear drive) Vertical type such as a vehicle may be used. The automatic transmission only needs to be able to achieve a plurality of gear stages alternatively, for example, various multi-stage automatic transmissions such as 5 forward speeds, 6 forward speeds, 7 forward speeds, and 8 forward speeds. A machine can be used.

  Preferably, as the hydraulic friction engagement device, a multi-plate type, single-plate type clutch or brake engaged by a hydraulic actuator, or a belt type brake is widely used. An oil pump that supplies hydraulic oil for engaging the hydraulic friction engagement device may be driven by a traveling power source to discharge the hydraulic oil, for example, but is arranged separately from the traveling power source. It may be driven by a dedicated electric motor provided.

  Preferably, the hydraulic control circuit including the hydraulic friction engagement device supplies, for example, the output hydraulic pressure of the solenoid valve directly to a hydraulic actuator (hydraulic cylinder) or a lockup mechanism of the hydraulic friction engagement device. Is desirable in terms of responsiveness and control accuracy of hydraulic pressure (engagement pressure and torque capacity), but the control valve is controlled by the output hydraulic pressure, and the hydraulic pressure is adjusted by the control valve to control the hydraulic actuator and lockup mechanism. It can also be configured to supply hydraulic oil to.

  Preferably, one solenoid valve is provided, for example, corresponding to each of a plurality of hydraulic friction engagement devices, but a plurality of solenoid valves that are not simultaneously engaged, engaged, or controlled to be released. When a hydraulic friction engagement device is present, various modes are possible, such as providing a common solenoid valve for them. In addition, the solenoid valve is provided with a feedback oil chamber to which output hydraulic pressure is guided, for example, on one end side of the spool valve element and a spring, and in balance with electromagnetic force by a solenoid provided on the other end side, A linear solenoid valve that regulates the output hydraulic pressure is preferably used, but an ON-OFF solenoid valve that controls the hydraulic pressure by duty control may also be employed.

  Preferably, the relay valve is configured to switch an oil path by moving a valve body such as a spool by a signal oil pressure supplied from, for example, an ON-OFF solenoid valve. In this case, an electromagnetic valve that directly moves a valve body such as a spool may be employed, or a predetermined oil pressure may be introduced as a signal pressure to mechanically switch the oil path.

  Preferably, a torque converter, a fluid coupling, or the like is used as the fluid transmission device.

  In this specification, “supplying hydraulic pressure” means “applying hydraulic pressure” or “supplying hydraulic oil controlled to the hydraulic pressure”.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram illustrating the configuration of a vehicular automatic transmission (hereinafter referred to as an automatic transmission) 10 to which the present invention is applied. FIG. 2 is an operation chart (engagement operation table) for explaining combinations of operations of engagement devices (engagement elements) when a plurality of gear stages (shift stages) of the automatic transmission 10 are established. This automatic transmission 10 includes a first transmission unit 14 mainly composed of a double pinion type first planetary gear unit 12 and a single pinion type in a transmission case 32 as a non-rotating member attached to a vehicle body. The second planetary gear unit 16 and the second transmission unit 20 mainly composed of the double pinion type third planetary gear unit 18 are provided on a common axis C, and the rotation of the input shaft 22 is shifted and output. Output from the shaft 24. The input shaft 22 corresponds to an input rotation member. In this embodiment, the input shaft 22 is a fluid transmission device provided in the automatic transmission 10 between the engine 26 that is a driving power source and the first transmission unit 14. This is the turbine shaft of the torque converter 28. The output shaft 24 corresponds to an output rotating member, and rotationally drives the left and right drive wheels sequentially through, for example, a differential gear device (final reduction gear) (not shown) and a pair of axles. The torque converter 28 is rotationally driven by the engine 26 to transmit the power of the engine 26 to the input shaft 22 via the fluid, and to directly transmit the power of the engine 26 to the input shaft 22 without passing the fluid. As a lock-up clutch 30. The automatic transmission 10 is configured substantially symmetrically with respect to the center line (axial center) C, and the lower half of the axial center C is omitted in the skeleton diagram of FIG.

  The first planetary gear unit 12 includes a sun gear S1, a plurality of pairs of pinion gears P1 that mesh with each other, a carrier CA1 that supports the pinion gears P1 so as to rotate and revolve, and a ring gear R1 that meshes with the sun gears S1 via the pinion gears P1, sun gears S1, Three rotating elements are constituted by the carrier CA1 and the ring gear R1. The carrier CA1 is connected to the input shaft 22 and is driven to rotate. The sun gear S1 is fixed to the transmission case 32 so as not to rotate. The ring gear R <b> 1 functions as an intermediate output member, is rotated at a reduced speed with respect to the input shaft 22, and transmits the rotation to the second transmission unit 20. In the present embodiment, the path for transmitting the rotation of the input shaft 22 to the second transmission unit 20 at the same speed is the first intermediate output path for transmitting the rotation at a predetermined constant gear ratio (= 1.0). The first intermediate output path PA1 includes a first path PA1a that transmits rotation from the input shaft 22 to the second transmission unit 20 without passing through the first planetary gear unit 12, and a first planet from the input shaft 22. There is a second path PA1b that transmits the rotation to the second transmission unit 20 via the carrier CA1 of the gear device 12. Further, the transmission ratio from the input shaft 22 to the second transmission unit 20 via the carrier CA1, the pinion gear P1 disposed on the carrier CA1, and the ring gear R1 is larger than the first intermediate output path PA1 (> 1). .0) is a second intermediate output path PA2 that transmits the rotation of the input shaft 22 with a reduced speed (deceleration).

  The second planetary gear device 16 includes a sun gear S2, a pinion gear P2, a carrier CA2 that supports the pinion gear P2 so as to rotate and revolve, and a ring gear R2 that meshes with the sun gear S2 via the pinion gear P2. The third planetary gear unit 18 meshes with the sun gear S3 via the sun gear S3, a plurality of pairs of pinion gears P2 and P3 that mesh with each other, a carrier CA3 that supports the pinion gears P2 and P3 so that they can rotate and revolve, and pinion gears P2 and P3. A ring gear R3 is provided.

  In the second planetary gear device 16 and the third planetary gear device 18, four rotating elements RM <b> 1 to RM <b> 4 are configured by being partially connected to each other. Specifically, the first rotating element RM1 is configured by the sun gear S2 of the second planetary gear unit 16, and the carrier CA2 of the second planetary gear unit 16 and the carrier CA3 of the third planetary gear unit 16 are integrally connected to each other. The second rotating element RM2 is configured, and the ring gear R2 of the second planetary gear unit 16 and the ring gear R3 of the third planetary gear unit 18 are integrally connected to each other to configure the third rotating element RM3, and the third planetary gear unit. The 18th sun gear S3 constitutes a fourth rotating element RM4. In the second planetary gear device 16 and the third planetary gear device 18, the carriers CA2 and CA3 are configured by a common member, the ring gears R2 and R3 are configured by a common member, and the second planetary gear device 18 The pinion gear P <b> 2 of the planetary gear device 16 is a Ravigneaux type planetary gear train that also serves as the second pinion gear of the third planetary gear device 18.

  The first rotating element RM1 (sun gear S2) is selectively connected to the transmission case 32 via the first brake B1 and stopped rotating, and the first planetary gear unit 12 which is an intermediate output member via the third clutch C3. Ring gear R1 (that is, second intermediate output path PA2) is selectively connected to the carrier CA1 of the first planetary gear device 12 via the fourth clutch C4 (that is, second path PA1b of the first intermediate output path PA1). Is selectively linked to The second rotation element RM2 (carriers CA2 and CA3) is selectively connected to the transmission case 32 via the second brake B2 and stopped, and the input shaft 22 (that is, the first shaft 22) (ie, the first clutch C2). It is selectively connected to the first path PA1a) of the intermediate output path PA1. The third rotation element RM3 (ring gears R2 and R3) is integrally connected to the output shaft 24 to output rotation. The fourth rotation element RM4 (sun gear S3) is connected to the ring gear R1 via the first clutch C1. Between the second rotating element RM2 and the transmission case 32, there is a second one-way clutch F1 that prevents the reverse rotation while allowing the second rotating element RM2 to rotate forward (the same rotational direction as the input shaft 22). It is provided in parallel with the brake B2.

  Returning to FIG. 2, this engagement operation table is a table for explaining the operation states of the clutches C <b> 1 to C <b> 4 and the brakes B <b> 1 and B <b> 2 when each gear stage of the automatic transmission 10 is established. The state, “(◯)” represents the engaged state only during engine braking, and the blank represents the released state. As described above, the automatic transmission 10 includes three sets of planetary gear devices 12, 16, and 18, and a plurality of gears having different gear ratios by selectively engaging the clutches C1 to C4 and the brakes B1 and B2. A multi-stage shift of eight stages, for example, eight forward stages, is achieved. In particular, since the one-way clutch F1 is provided in parallel with the second brake B2, when the first gear (1st) is established, the second brake B2 is engaged during engine braking, while during driving. Be released.

  The gear ratios that differ for each gear stage are appropriately determined by the gear ratios ρ1, ρ2, and ρ3 of the first planetary gear device 12, the second planetary gear device 16, and the third planetary gear device 18. The clutches C1 to C4 and the brakes B1 and B2 (hereinafter simply referred to as the clutch C and the brake B unless otherwise distinguished) are hydraulic friction members that are controlled by a hydraulic actuator such as a multi-plate clutch or a brake. A joint device (hereinafter referred to as an engagement device).

  FIG. 3 is a circuit diagram relating to the linear solenoid valves SL1 to SL5 and SLU for controlling the operation of the hydraulic actuators of the clutch C and the brake B and the lockup clutch 30, and a hydraulic control circuit constituting a part of the hydraulic control device. FIG.

  In FIG. 3, D range pressures (forward range pressure, forward hydraulic pressure) PD output from the hydraulic pressure supply device 46 are respectively applied to the hydraulic actuators (hydraulic cylinders) 34, 36, 42 of the clutches C1, C2 and the brake B1. The pressure is regulated and directly supplied by the linear solenoid valves SL1, SL2, and SL5, and the line hydraulic pressure PL1 output from the hydraulic pressure supply device 46 is supplied to the hydraulic actuators 38 and 40 of the clutches C3 and C4, respectively. The pressure is adjusted by SL4 and supplied directly.

Further, the D range pressure PD or the reverse pressure (reverse hydraulic pressure) PR output from the hydraulic pressure supply device 46 is supplied to the hydraulic actuator 44 of the second brake B2 via the second brake control circuit 90. Yes. The second brake control circuit 90 is supplied with the control pressure P _SLU that is the output hydraulic pressure of the linear solenoid valve SLU that uses the modulator hydraulic pressure PM output from the hydraulic pressure supply device 46 as a source pressure via the switching circuit 100. It has become. Further, when the control pressure P _SLU supplied to the second brake control circuit 90 via the switching circuit 100 becomes equal to or higher than a predetermined pressure for generating the engagement torque of the second brake B2, a predetermined signal, for example, an ON signal A hydraulic switch 48 that outputs SW _ON to the electronic control device 160 (see FIG. 5) is provided on the input side of the second brake control circuit 90.

The hydraulic pressure supply device 46 adjusts the line hydraulic pressure PL1 (first line hydraulic pressure PL1) using the hydraulic pressure generated from a mechanical oil pump 52 (see FIG. 1) rotated and driven by the engine 26 as a primary pressure. Secondary regulator for regulating the line oil pressure PL2 (second line oil pressure PL2, secondary pressure PL2) using the oil pressure discharged from the regulator valve 82 as a source pressure for regulating the line oil pressure PL1 by the regulator valve 82). A linear solenoid valve SLT that supplies a signal pressure P _SLT to the first pressure regulating valve 82 and the second pressure regulating valve 84 in order to regulate the valve (second pressure regulating valve) 84 and the line hydraulic pressures PL1 and PL2 according to the engine load and the like. Modulator pressure PM is adjusted to a constant value using line oil pressure PL1 as the original pressure. The shift lever 72 receives the line hydraulic pressure PL1 that is input by switching the oil path by being mechanically operated in accordance with the operation of the durator valve 86 and the shift lever 72 that is mechanically connected via a cable or a link. A manual valve 88 that outputs as a D range pressure PD when operated to the “D” position or “S” position or as a reverse pressure PR when operated to the “R” position is provided. PL2, modulator hydraulic pressure PM, D range pressure PD, and reverse pressure PR are supplied.

  The linear solenoid valves SL1 to SL5 and SLU have basically the same configuration, and are excited and de-energized independently by the electronic control unit 160, and the hydraulic pressures of the hydraulic actuators 34 to 44 are independently regulated and controlled. The engagement pressures of C1 to C4 and brakes B1 and B2 are controlled. In the automatic transmission 10, for example, as shown in the engagement operation table of FIG. 2, each gear stage is established by engaging a predetermined engagement device. In the shift control of the automatic transmission 10, for example, a so-called clutch-to-clutch shift is performed in which release and engagement of the clutch C and the brake B involved in the shift are controlled simultaneously. For example, as shown in the engagement operation table of FIG. 2, in the downshift from the fifth speed to the fourth speed, the clutch C2 is disengaged and the clutch C4 is engaged, so that the release transient hydraulic pressure of the clutch C2 is suppressed so as to suppress the shift shock. And the engagement transient hydraulic pressure of the clutch C4 are appropriately controlled. Thus, since the engagement devices (clutch C, brake B) of the automatic transmission 10 are respectively controlled by the linear solenoid valves SL1 to SL5, SLU, the responsiveness of the operation of the engagement device is improved. Alternatively, the hydraulic circuit for the engagement / release operation of the engagement device is simplified.

  Further, the linear solenoid valve SLU is configured so that the engagement pressure of the second brake B2 serving as a predetermined hydraulic friction engagement device of the clutch C and the brake B and the torque of the lockup clutch 30 are switched by the oil path switching by the switching circuit 100. This is a single (shared) solenoid valve that selectively controls the capacity. The second brake B2 is a hydraulic friction engagement device that is engaged only at the time of engine braking. For example, the lockup clutch 30 is set so that engine stall does not occur during engine braking (particularly during engine braking during low-speed traveling). Since the lockup is not turned on, it is not necessary to control the engagement pressure of the second brake B2 and the torque capacity of the lockup clutch 30 at the same time. Therefore, a single solenoid valve can be used for these controls. is there.

  FIG. 4 includes schematic diagrams of the second brake control circuit 90 and the switching circuit 100, and the engagement pressure control of the second brake B2 and the torque capacity control of the lockup clutch 30 by the linear solenoid valve SLU switched by the switching circuit 100. It is a figure for demonstrating.

4, the second brake control circuit 90 includes a second brake control valve 92 that outputs the engagement pressure P _B2 of the second brake B2 according to the control pressure P _SLU using the D range pressure PD as a source pressure, A shuttle valve 94 that outputs either the hydraulic pressure P _B2 or the reverse pressure PR supplied from the brake control valve 92 to the second brake B2, and when the control pressure P _SLU is supplied, the engagement pressure P _B2 Is output to the second brake B2, or when the reverse pressure PR is supplied, the reverse pressure PR is output to the second brake B2.

Lockup clutch 30, As is well known, the release-side oil supplied through the hydraulic P _ON and the release oil passage 106 of the engagement-side oil chamber 104 supplied via the engagement oil path 102 This is a hydraulic friction clutch that is frictionally engaged with the front cover 110 by a differential pressure ΔP (= P _ON −P _OFF ) with respect to the hydraulic pressure P _OFF in the chamber 108. The operating condition of the torque converter 28 is, for example, a so-called lockup-off in which the differential pressure ΔP is negative and the lockup clutch 30 is released, and the differential pressure ΔP is zero or more and the lockup clutch 30 is half-engaged. The so-called slip state, and the so-called lock-up on, in which the lock-up clutch 30 is completely engaged by setting the differential pressure ΔP to the maximum value, are roughly classified. Further, in the slip state of the lock-up clutch 30, since the differential pressure ΔP is set to zero, the torque sharing of the lock-up clutch 30 is eliminated, and the torque converter 28 is set to the operating condition equivalent to the lock-up off.

  The switching circuit 100 includes a lockup relay valve 112 for switching the lockup clutch 30 between a disengaged state, that is, a lockup off state, and a slip state including a disengaged state, that is, a disengaged state or a lockup on state. A lock-up control valve that adjusts the differential pressure ΔP when the lock-up clutch 30 is in the engaged state by 112 and switches the operating state of the lock-up clutch 30 from the slip state including the released state to the lock-up on range. 114.

The lock-up relay valve 112 includes a spool valve element 116, a spring 118 that is provided on one shaft end side of the spool valve element 116 and applies a thrust toward the release (OFF) side position of the spool valve element 116, a spool valve Position for engaging (ON) the spool valve element 116 provided on the other shaft end side of the spool valve element 116 and the oil chamber 120 that receives the reverse pressure PR to urge the element 116 to the OFF position. and an oil chamber 122 that receives the control pressure P _SL is output hydraulic pressure of the oN-OFF solenoid valve SL to source pressure modulator pressure PM to urge fart. This ON-OFF solenoid valve SL is excited and de-energized by the electronic control device 160, and functions as a control pressure generating valve that switches the engagement and release states of the lockup clutch 30.

The lock-up control valve 114 includes a spool valve element 124, a spring 126 that applies a thrust F ₁₂₆ that moves the spool valve element 124 toward a slip (SLIP) side position, and a spool valve element 124 that moves toward the SLIP side position. an oil chamber 128 for receiving the hydraulic pressure P _oN in the engagement-side oil chamber 104 of the torque converter 28 in order to energize, the torque converter in order urges the spool valve element 124 to complete engagement (oN) side position 28, an oil chamber 130 for receiving the hydraulic pressure P _OFF in the release side oil chamber 108, and an oil chamber 132 for receiving the control pressure P _SLU to urge the spool valve element 124 toward the ON side position.

  The switching circuit 100 configured as described above switches the operating oil pressure supply state to the engagement side oil chamber 104 and the disengagement side oil chamber 108 to switch the operation state of the lockup clutch 30, or the second brake B2. The hydraulic pressure is supplied to the second brake B2, and the engagement pressure of the second brake B2 is controlled.

First, a case where the lockup clutch 30 is locked up and the control pressure _PSLU can be supplied to the second brake B2 will be described. In the lock-up relay valve 112, the control pressure _{P SL} is the spool 116 by the thrust of the spring 118 is not supplied to the oil chamber 122 is urged to the release (OFF) side position, supplied to the input port 134 line The pressure PL2 is supplied from the release side port 136 through the release oil passage 106 to the release side oil chamber 108. Then, the hydraulic oil discharged to the engagement side port 138 through the engagement oil passage 102 through the engagement side oil chamber 104 is discharged from the discharge port 140 to an oil cooler (COOLER) or a cooler bypass (COOLER BY-PASS). The As a result, the lockup clutch 30 is turned off.

Further, when the lockup relay valve 112 is switched to the release side position, the control pressure _PSLU supplied to the input port 142 can be supplied from the brake side port 144 to the second brake control circuit 90. At this time, when the control pressure _{PSLU that} is equal to or higher than a predetermined pressure for generating the engagement torque of the second brake B2 is output from the linear solenoid valve SLU, the engagement pressure of the second brake B2 is output by the second brake control circuit 90. At the same time, an ON signal SW _ON is output from the hydraulic switch 48 to the electronic control unit 160.

Next, the case where the lock-up clutch 30 is in the slip state including the disengaged state or the lock-up on state and the control pressure _PSLU cannot be supplied to the second brake B2 will be described. In the lock-up relay valve 112, the control pressure when _{P SL} is spool 116 is supplied to the oil chamber 122 is urged into engagement (ON) side position, the supplied line pressure PL2 is engaged to the input port 134 The oil is supplied to the engagement side oil chamber 104 from the combination side port 138 through the engagement oil passage 102. Line pressure PL2 supplied to the engagement-side oil chamber 104 is pressure _{P ON.} At the same time, the release side oil chamber 108 is communicated with the control port 148 of the lockup control valve 114 from the release side port 136 through the bypass port 146 through the release oil passage 106. Then, the hydraulic pressure P _OFF in the release side oil chamber 108 is adjusted by the lockup control valve 114, that is, the differential pressure ΔP is adjusted by the lockup control valve 114, and the operating state of the lockup clutch 30 is slipped or locked. Switchable within the range of up-on.

Specifically, when the spool valve element 116 of the lockup relay valve 112 is biased to the engagement side position, that is, when the lockup clutch 30 is switched to the engagement side state, the lockup control valve In 114, the control pressure _PSLU for urging the spool valve element 124 to the fully engaged (ON) side position is not supplied to the oil chamber 132, and the spool valve element 124 slips by the thrust F _{126 of the} spring 126 ( In the SLIP) side position, the line pressure PL2 supplied to the input port 150 is supplied from the control port 148 via the bypass port 146 and from the release side port 136 through the release oil passage 106 to the release side oil chamber 108. In this state, the differential pressure ΔP is controlled by the control pressure _PSLU to control the slip state (including the released state) of the lockup clutch 30.

Further, when the spool valve element 116 of the lockup relay valve 112 is urged to the engagement side position, the spool valve element 124 is urged to the complete engagement (ON) side position in the lockup control valve 114. When the control pressure P _SLU is supplied to the oil chamber 132, the line pressure PL2 is not supplied from the input port 150 to the release-side oil chamber 108, and the hydraulic oil is discharged from the release-side oil chamber 108 to the control port. Blocked at 148. As a result, since the hydraulic pressure P _OFF is made zero, the differential pressure ΔP is maximized and the lockup clutch 30 is brought into a fully engaged state.

Thus, the lockup relay valve 112 controls the engagement pressure of the second brake B2 as a predetermined engagement device in accordance with the control pressure _PSLU that is the output hydraulic pressure of the linear solenoid valve SLU. An oil passage (hereinafter referred to as a first oil passage), that is, a release side position, and a second oil passage (hereinafter referred to as a second oil passage) for controlling the torque capacity of the lockup clutch 30 according to the control pressure _PSLU. That is, it is a relay valve that switches the position on the engagement side.

  FIG. 5 is a block diagram illustrating a main part of a control system provided in the vehicle for controlling the automatic transmission 10 of FIG. The electronic control unit 160 includes a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM, and signals according to a program stored in the ROM in advance. By performing the process, output control of the engine 26, shift control of the automatic transmission 10, torque capacity control of the lockup clutch 30, and the like are executed, and for engine control and automatic transmission 10 as required. And for hydraulic control of the lock-up clutch 30.

5, an accelerator operation amount sensor 56 for detecting an operation amount Acc of an accelerator pedal 54, the engine rotational speed sensor 58 for detecting the rotational speed N _E of the engine 26, detects the intake air quantity Q of the engine 26 an intake air amount sensor 60, the intake air temperature sensor 62 for detecting the temperature T _a of intake air, a throttle valve opening sensor 64 for detecting an opening theta _TH of the electronic throttle valve, the vehicle speed V (output shaft for a vehicle speed sensor 66 for detecting the corresponding) to the rotational speed N _OUT of 24, coolant temperature sensor 68 for detecting the cooling water temperature T _W of the engine 26, for detecting the presence or absence of the operation of the foot brake is a service brake Lever for detecting which lever position (operation position) P _{SH the} brake switch 70 and the shift lever 72 are located at Position sensor 74, turbine rotation speed sensor 76 for detecting turbine rotation speed N _T (= rotation speed N _IN of input shaft 22), and AT oil temperature T _OIL that is the temperature of hydraulic oil in hydraulic control circuit 50 is detected. AT oil temperature sensor 78 for, such as an acceleration sensor 80 for detecting an acceleration (deceleration) G of the vehicle is provided, and the like these sensors and switches, the accelerator operation amount Acc, the engine rotational speed N _E , Intake air amount Q, intake air temperature T _A , throttle valve opening θ _TH , vehicle speed V, output shaft rotation speed N _OUT , engine coolant temperature T _W , presence / absence of brake operation, lever position P _SH of shift lever 72, turbine rotational speed _N T (= input shaft rotational speed _N iN), AT oil temperature _{T oIL,} the vehicle acceleration (deceleration) G, ON from hydraulic switch 48 Signal representing the like No. _{SW ON} is supplied to the electronic control unit 160.

  Also, the linear solenoid valves SL1 to SL5 and the SLU excitation / de-energization, current control signal, lock-up for controlling the switching of the engagement / release state of the clutch C and the brake B and the transient hydraulic pressure at the engagement / release. The ON / OFF solenoid valve SL excitation / de-energization signal for switching the oil path of the relay valve 112, the torque capacity of the lockup clutch 30 such as the current control signal of the linear solenoid valve SLU for controlling the differential pressure ΔP, etc. Supplied from the control device 160.

  The shift lever 72 is disposed in the vicinity of the driver's seat, for example, and is manually operated to five lever positions “P”, “R”, “N”, “D”, or “S” as shown in FIG. It is like that.

  The “P” position (range) releases the power transmission path in the automatic transmission 10, that is, a neutral state (neutral state) in which the power transmission in the automatic transmission 10 is interrupted, and is mechanically output by the mechanical parking mechanism. This is a parking position (position) for preventing (locking) the rotation of 24, and the “R” position is a reverse travel position (position) for making the rotation direction of the output shaft 24 of the automatic transmission 10 reverse. , “N” position is a neutral position (position) for neutralizing power transmission in the automatic transmission 10, and “D” position is the first to eighth speeds of the automatic transmission 10. The automatic shift mode is established in the shift range (D range) that allows the shift, and all the forward gears from the first gear stage “1st” to the eighth gear stage “8th” are used. The forward travel position (position) for executing the shift control, and the “S” position is the forward travel capable of manual shift by switching a plurality of shift ranges having different gear speeds on the high-speed side or a plurality of different gear stages. Position.

  In this “S” position, the shift range or gear stage is shifted to the up side every time the shift lever 72 is operated, and the shift range or gear stage is shifted to the down side every time the shift lever 72 is operated. A “-” position is provided for this purpose. For example, in the “S” position, any of the “D” range, “7” range,..., “2” range, “L” range is the “+” position or “−” position of the shift lever 72. Changed according to the operation. The “L” range in the “S” position is also an engine brake range for obtaining a further engine brake effect by engaging the second brake B2 at the first gear stage “1st”.

  In each of the shift positions indicated by the “P” to “S” positions, the “P” position and the “N” position are power transmission cut-off positions that disable driving of the vehicle in which the power transmission path in the automatic transmission 10 is cut off. (Position), which is a non-traveling position (position) that is selected when the vehicle is not traveling. The “R” position, the “D” position, and the “S” position are power transmission possible positions (positions) that enable driving of the vehicle to which the power transmission path in the automatic transmission 10 is connected. This is the travel position selected when traveling.

  Thus, the shift lever 72 is an operating device that can be switched between a traveling position for switching the automatic transmission 10 to a power transmission enabled state and a non-traveling position for switching the automatic transmission 10 to a power transmission interrupted state. .

  FIG. 7 is a functional block diagram for explaining a main part of the control function by the electronic control unit 160. In FIG. 7, the shift control means 162 changes the actual vehicle speed V and the accelerator operation amount Acc from the relationship (map, shift diagram) stored in advance with the vehicle speed V and the accelerator operation amount Acc as parameters, for example, as shown in FIG. Based on the shift determination, it is determined whether or not the shift of the automatic transmission 10 should be executed. For example, the shift stage of the automatic transmission 10 to be shifted is determined, and the automatic shift is performed so that the determined shift stage is obtained. The automatic shift control of the machine 10 is executed. At this time, the shift control means 162 engages and / or releases the hydraulic friction engagement device involved in the shift of the automatic transmission 10 so that the shift stage is achieved according to, for example, the engagement table shown in FIG. A command (shift output command, hydraulic command) is output to the hydraulic control circuit 50.

  The hydraulic control circuit 50 operates the linear solenoid valves SL1 to SL5 and SLU in the hydraulic control circuit 50 so that the shift of the automatic transmission 10 is executed in accordance with the command, and the hydraulic friction mechanism involved in the shift. Actuate the hydraulic actuator of the combined device.

In the shift diagram of FIG. 8, a solid line is a shift line for determining an upshift (upshift line), and a broken line is a shift line for determining a downshift (downshift line). Further, the shift line in the shift diagram of FIG. 8 indicates whether or not the actual vehicle speed V crosses the line on the horizontal line indicating the actual accelerator operation amount Acc (%), that is, the value on which the shift on the shift line is to be executed ( It is for determining whether exceeds the shift point vehicle speed) V _S, also will have been previously stored as a series of the values V _S that shift point vehicle speed. Note that the shift line diagram of FIG. 8 illustrates the shift lines in the first gear stage to the sixth gear stage among the first gear stage to the eighth gear stage in which a shift is executed by the automatic transmission 10.

For example, if the shift control means 162 determines that the actual vehicle speed V has crossed the 7th speed → 8th speed upshift line at which the 7th speed → 8th speed upshift should be executed, that is, the shift point vehicle speed _V7-8 is set. If it is determined that the clutch C3 has been exceeded, a command to release the clutch C3 and engage the brake B1 is output to the hydraulic control circuit 50, that is, a command to drain (drain) the engagement hydraulic pressure of the clutch C3 by non-excitation. In addition to outputting to the solenoid valve SL3, a command to supply the engagement hydraulic pressure of the brake B1 by excitation is output to the linear solenoid valve SL5.

  As described above, the shift control means 162 controls the excitation and de-excitation of the linear solenoid valves SL1 to SL5 and SLU, respectively, thereby causing the clutches C1 to C4 and the brake B1 corresponding to the linear solenoid valves SL1 to SL5 and SLU, respectively. , B2 is functionally provided with an engagement capacity control means 164 for switching the engagement / release state of B2 to establish one of the first gear stage “1st” to the eighth gear stage “8th”.

Further, when the engagement capacity control means 164 controls the engagement pressure of the second brake B2 by the linear solenoid valve SLU in order to obtain the engine brake action in the “L” range, the lockup relay valve 112 is the first. It needs to be switched to the oil passage. Therefore, the shift control means 162, as the control pressure _{P SLU} when engine braking is required is supplied to the second brake B2, ON-OFF solenoid valve SL by the control pressure _{P SL} without outputting the lock-up relay valve A relay valve control means 166 for switching 112 to the first oil passage side is functionally provided.

Further, when the electronic control device 160 controls the differential pressure ΔP by the control pressure P _SLU because the torque capacity of the lock-up clutch 30 can be controlled, the lock-up relay valve 112 needs to be switched to the second oil passage. is there. Therefore, the relay valve control unit 166, as the pressure difference ΔP is controlled by the linear solenoid valve SLU, the lock-up relay valve 112 by outputting a control pressure _{P SL} by the ON-OFF solenoid valve SL to the second oil path side Switch.

The electronic control unit 160 has a release (lock-up off) region, a slip control region, and an engagement (lock-up on) region in two-dimensional coordinates having the throttle valve opening θ _TH and the vehicle speed V as parameters, for example, as shown in FIG. Lockup for controlling the switching of the operation state of the lockup clutch 30 based on the actual vehicle running state, for example, the throttle valve opening θ _TH and the vehicle speed V, from a previously stored relationship (map, lockup region diagram) having A clutch control means is functionally provided.

  For example, the electronic control device 160 outputs a control command for the ON-OFF solenoid valve SL to the hydraulic control circuit 50 for switching the lockup clutch 30 to lockup off or switching to slip or lockup on, A control command for the linear solenoid valve SLU is output to the hydraulic control circuit 50 for controlling the differential pressure ΔP.

  As described above, the linear solenoid valve SLU of the present embodiment controls the engagement pressure of the second brake B2 when the engine brake is necessary by switching the oil passage by the lockup relay valve 112, and the lockup clutch 30 This is a single solenoid valve that controls the torque capacity (differential pressure ΔP) of the lockup clutch 30 when the operating state is switched in the slip state or lockup on range.

  By the way, there is a possibility that a switching abnormality in which the switching of the first / second oil passages by the lockup relay valve 112 becomes impossible due to a failure of the lockup relay valve 112 itself or a failure of the ON-OFF solenoid valve SL may occur.

For example, a command to control pressure P _SL is not output a control pressure P _SL by the failure and relay valve control means 166 for spool 116 of the lock-up relay valve 112 despite not being supplied is fixed to the engagement side position Regardless of the fact that the control pressure _PSL is output from the ON-OFF solenoid valve SL, the switching abnormality in which the switching to the first oil passage by the lockup relay valve 112 becomes impossible, that is, the switching circuit 100 is fixed to the second oil passage. Switching abnormality may occur.

When the switching abnormality fixed to the second oil passage has occurred, if the control pressure P _SLU is output from the linear solenoid valve SLU to engage the second brake B2 by the engagement capacity control means 164. For example, the control pressure P _SL is output to the ON-OFF solenoid valve SL by the relay valve control means 166 in the vehicle running state that becomes the lock-up release region preset in the lock-up region diagram as shown in FIG. There is a possibility that the lockup clutch 30 may be engaged even though a command not to be output is output.

In particular, in this embodiment, since the engagement pressure of the second brake B2 that is engaged during engine braking and the torque capacity of the lockup clutch 30 are controlled by the same linear solenoid valve SLU, the switching circuit 100 is the second one. When the switching abnormality fixed to the oil passage has occurred, the control pressure P _SLU is applied from the linear solenoid valve SLU to engage the second brake B2 by the engagement capacity control means 164 in order to apply the engine brake. When output, the relay valve control means 166 sets the lock-up clutch 30 to be in the lock-up on state even though a command not to output the control pressure P _SL to the ON-OFF solenoid valve SL is output. The power transmission path between the drive wheel and the drive wheel is in a directly connected state, that is, in a state where power transmission is possible. There is a possibility that engine stall occurs with a decrease in the vehicle speed V Te.

  Therefore, a switching abnormality in which the lockup relay valve 112 is fixed in the second oil passage is prevented so that an unexpected lockup on the lockup clutch 30 is prevented when a switching abnormality fixed in the second oil passage occurs. When this occurs, the engagement of the second brake B2 is prohibited.

  Specifically, the switching abnormality determination unit 168 determines whether or not the switching abnormality of the lockup relay valve 112 by the relay valve control unit 166 is disabled and the switching abnormality fixed to the second oil passage has occurred.

For example, the switching abnormality determination means 168 is based on the shift position determination means 170 that determines the lever position P _SH of the shift lever 72 based on the signal output of the lever position sensor 74 and the ON signal SW _ON from the hydraulic switch 48. 2 and a hydraulic switching signal determining means 172 determines whether or not the control pressure P _SLU is detected to control the engagement pressure of the second brake B2 is supplied to the brake control circuit 90, the shift position determining means When it is determined by 170 that the shift lever 72 is switched to a non-traveling position (position) such as the “P” position or the “N” position, the lockup relay valve 112 is switched to the first oil passage side. Thus, the relay valve control means 166 controls the solenoid valve SL from the ON-OFF solenoid valve SL. Without output pressure P _SL, and together with outputting the control pressure P _SLU for engaging the second brake B2 from the linear solenoid valve SLU by engaging the capacity control means 164, the second brake by the hydraulic switching signal determining means 172 switching abnormality occurs that is fixed to the second oil passage becomes impossible to switch the lock-up relay valve 112 by relay valve control means 166 based on a detection result of the control pressure P _SLU for controlling the engaging pressure of B2 It is determined whether or not.

That is, when the lockup relay valve 112 is normally switched to the first oil passage by the relay valve control means 166, if the control pressure P _SLU is output from the linear solenoid valve SLU by the engagement capacity control means 164, the hydraulic switch 48 is turned on. since the signal SW _oN is output, when the control pressure P _SLU for controlling the engaging pressure of the second brake B2 is determined to have been detected by the oil pressure switch signal judging unit 172, switching換異normal determination The means 168 determines that the lockup relay valve 112 can be switched to the first oil passage by the relay valve control means 166 and is in a normal state in which the switching abnormality fixed to the second oil passage does not occur.

Further, when a switching abnormality occurs in which the lockup relay valve 112 cannot be switched to the first oil passage by the relay valve control means 166, it is assumed that the control pressure P _SLU is output from the linear solenoid valve SLU by the engagement capacity control means 164. Since the ON signal SW _ON is not output from the hydraulic switch 48, when it is determined by the hydraulic switch signal determination means 172 that the control pressure P _SLU for controlling the engagement pressure of the second brake B2 is not detected. Is a failure (fail) state in which the switching abnormality determining means 168 is unable to switch the lock-up relay valve 112 to the first oil passage by the relay valve control means 166 and the switching abnormality is fixed to the second oil passage. It is determined that

  The switching abnormality determination means 168 also prevents the lockup clutch 30 from being unscheduled during traveling when the shift lever 72 is switched to the traveling position such as the “D” position or the “S” position. When the shift lever 72 is switched to the non-traveling position such as the “P” position or the “N” position, the automatic transmission 10 before traveling is in a power transmission cut-off state, and thus abnormality determination is performed.

  Further, the switching abnormality determination means 168 is configured so that when the shift lever 72 is in the “P” position or the “N” position so that the engine stall does not occur even when the switching abnormality fixed to the second oil passage occurs. Abnormality judgment is performed.

In the engagement prohibiting means 174, the switching abnormality determining means 168 makes it impossible for the relay valve control means 166 to switch the lock-up relay valve 112 to the first oil passage, and a switching abnormality that is fixed to the second oil passage occurs. When it is determined that the second brake B2 is engaged, the engagement of the second brake B2 is prohibited. For example, the engagement prohibiting means 174 sets a prohibition flag F for prohibiting the engagement of the second brake B2 when it is determined by the switching abnormality determining means 168 that a switching abnormality fixed to the second oil passage has occurred. The engagement capacity control means 164 outputs the control pressure P _SLU for controlling the engagement pressure of the second brake B2 from the linear solenoid valve SLU while the prohibition flag F is set by the engagement prohibition means 174. I won't let you.

Specifically, when the automatic transmission 10 is in the power transmission cut-off state, a switching abnormality fixed to the second oil passage is determined by the switching abnormality determining unit 168, and the prohibition flag F is set by the engagement prohibiting unit 174. In the “L” range when the automatic transmission 10 is in a state where power can be transmitted when the shift lever 72 is switched to the travel position such as the “D” position or the “R” position. If the command does not output a control pressure P _SL to the oN-OFF solenoid valve SL to obtain an engine brake effect engages the second brake B2 is output by a relay valve control unit 166, the linear solenoid valve SLU lockup clutch 30 is set to the lock-up on the control pressure P _SLU for engaging the second brake B2 which is output e As Jin stall is prevented from occurring, the engagement capacity control means 164 does not output the control pressure P _SLU for controlling the engaging pressure of the second brake B2 from the linear solenoid valve SLU, first The second brake B2 for obtaining the engine braking action at the gear stage (1st) is not engaged.

Further, the engagement capacity control means 164 controls the ON-OFF solenoid valve SL to control the torque capacity of the lockup clutch 30 even while the prohibition flag F is set by the engagement prohibition means 174. When the command to output the control pressure _PSL is output by the relay valve control means 166, the control pressure P _SLU is output from the linear solenoid valve SLU in order to control the differential pressure ΔP of the lockup clutch 30.

  FIG. 10 is a flowchart for explaining the main part of the control operation of the electronic control unit 160, that is, the control operation for determining the switching abnormality of the lock-up relay valve 112. Is to be executed.

First, in step S1 corresponding to the shift position determination means 170 (hereinafter, step is omitted), the lever position P _SH of the shift lever 72 is set to the “P” position or “N” based on the signal output of the lever position sensor 74. It is determined whether or not the vehicle has been switched to a non-traveling position (position) such as a position.

If the determination at S1 is negative, this routine is terminated. If the determination is affirmative, the lockup relay valve 112 is switched to the first oil passage side at S2 corresponding to the switching abnormality determination means 168. without outputting a control pressure _{P SL} by the relay valve control unit 166 from the ON-OFF solenoid valve SL, and the control pressure _{P SLU} from the linear solenoid valve SLU by the second engaging capacity control means 164 to engage the brake B2 Output.

Next, in S3 corresponding to the hydraulic switch signal determination means 172, whether or not the control pressure P _SLU for controlling the engagement pressure of the second brake B2 is detected based on the ON signal SW _ON from the hydraulic switch 48 is determined. Is determined.

When the ON signal SW _ON is output from the hydraulic switch 48 and the determination in S3 is affirmed, in S5 corresponding to the switching abnormality determination means 168, the first oil passage of the lockup relay valve 112 by the relay valve control means 166 is performed. It is determined that it is in a normal state in which the switching abnormality fixed to the second oil passage does not occur.

When the ON signal SW _ON is not output from the hydraulic switch 48 and the determination in S3 is negative, the first oil passage of the lockup relay valve 112 by the relay valve control unit 166 is performed in S4 corresponding to the switching abnormality determination unit 168. It is determined that it is a failure (fail) state in which the switching abnormality fixed to the second oil passage is made impossible.

Next, in S6 corresponding to the engagement prohibiting means 174, a prohibition flag F for prohibiting the engagement of the second brake B2 is set. While the prohibition flag F is set, the engagement pressure control means 164 does not output the control pressure P _SLU for controlling the engagement pressure of the second brake B2 from the linear solenoid valve SLU.

As described above, according to the present embodiment, the control pressure that is the output hydraulic pressure of the single linear solenoid valve SLU that selectively controls the engagement pressure of the second brake B2 and the torque capacity of the lockup clutch 30. _Switching between the first oil path for controlling the engagement pressure of the second brake B2 according to P _SLU and the second oil path for controlling the torque capacity of the lockup clutch 30 according to the control pressure P _SLU When it is determined that the switching abnormality has occurred by the switching abnormality determining means 168 that determines whether or not a switching abnormality has occurred in which the lockup relay valve 112 cannot be switched and is fixed to the second oil passage, the engagement prohibiting means Since the engagement of the second brake B2 is prohibited by 174, the torque capacity control of the lockup clutch 30 is performed on the solenoid valve that controls the engagement pressure of the second brake B2. Even switching abnormality to be fixed to the second oil passage occurred when is also used as a solenoid valve, lock-up on the lock-up clutch 30 is not expected can be prevented.

  In particular, when it is determined by the switching abnormality determining means 168 that a switching abnormality fixed to the second oil passage has occurred, the engagement prohibiting means 174 prohibits the engagement of the second brake B2 for obtaining the engine braking action. Therefore, the occurrence of engine stall is prevented even when the vehicle speed V decreases because the lockup clutch 30 is not turned on when a switching abnormality fixed to the second oil passage occurs.

Further, according to this embodiment, the switching abnormality determination means 168 causes the relay valve control means 166 to switch the lockup relay valve 112 to the first oil passage side when the shift lever 72 is switched to the non-traveling position. In addition, the control pressure P _SLU is output from the linear solenoid valve SLU by the engagement capacity control means 164, and the detection result of the control pressure P _SLU for controlling the engagement pressure of the second brake B2 by the hydraulic switch signal determination means 172 is obtained. Based on this, it is determined whether or not the lockup relay valve 112 cannot be switched by the relay valve control means 166 and a switching abnormality fixed to the second oil passage has occurred. Therefore, the relay valve control means 166 determines whether or not the lockup relay valve 112 is switched. When a switching abnormality occurs in which 112 cannot be switched to the first oil passage, the engagement capacity control is performed. Since the control pressure P _SLU for controlling the engaging pressure of the second brake B2 by the hydraulic switching signal determining means 172 even to output control pressure P _SLU from the linear solenoid valve SLU is not detected by the means 164, switching abnormality The determination means 168 can determine the occurrence of a switching abnormality in which the lock-up relay valve 112 cannot be switched to the first oil path by the relay valve control means 166 and is fixed to the second oil path.

  In addition, since the abnormality determination is performed by the switching abnormality determination unit 168 when the automatic transmission 10 is in the power transmission cut-off state, when the shift lever 72 is switched to the travel position, an unexpected engagement of the lockup clutch 30 is performed. Movement is prevented. In other words, since the abnormality determination is performed by the switching abnormality determination means 168 before traveling, the engagement operation of the lock-up clutch 30 that is not planned during traveling of the vehicle is prevented.

  Further, since the automatic transmission 10 is in the power transmission cut-off state, even if a switching abnormality fixed to the second oil passage occurs, the abnormality determination is performed by the switching abnormality determination means 168 without causing an engine stall. Is called. As described above, the abnormality determination is performed by the switching abnormality determination unit 168 when the automatic transmission 10 is in the power transmission cut-off state, so that the engine stall is prevented when the shift lever 72 is switched to the travel position. The

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

For example, in the above-described embodiment, when the switching prohibition determining unit 168 determines that the switching abnormality of the lockup relay valve 112 has occurred, the engagement prohibiting unit 174 performs engine braking at the first gear (1st). A prohibition flag F for prohibiting the engagement of the second brake B2 for obtaining the action is set, and the control pressure P _SLU for engaging the second brake B2 is output from the linear solenoid valve SLU by the engagement capacity control means 164. Although not been allowed, it may if control pressure P _SLU for engaging the second brake B2 to obtain the engine braking effect in at least a first gear stage (1st) is output, prohibited by switching換異normal determining means 168 As the flag F, various prohibition flags F other than prohibiting the engagement of the second brake B2 can be applied in the present invention.

  For example, when it is determined by the switching abnormality determining unit 168 that the switching abnormality of the lockup relay valve 112 has occurred, the engagement prohibiting unit 174 is first controlled by the shift control unit 162 when the shift lever 72 is switched to the travel position. A prohibition flag for prohibiting a shift command to the gear stage “1st” may be set. Even if it does in this way, even if the switching abnormality fixed to a 2nd oil path arises, the lockup on of the lockup clutch 30 which is not planned is prevented.

  Further, when it is determined by the switching abnormality determination unit 168 that the switching abnormality of the lockup relay valve 112 has occurred, the engagement prohibiting unit 174 detects the engine brake in the “L” range when the shift lever 72 is switched to the traveling position. A prohibition flag for prohibiting the operation may be set. Even if it does in this way, even if the switching abnormality fixed to a 2nd oil path arises, the lockup on of the lockup clutch 30 which is not planned is prevented.

Further, when it is determined by the switching abnormality determination unit 168 that the switching abnormality of the lockup relay valve 112 has occurred, the engagement prohibiting unit 174 is operated by the engagement capacity control unit 164 when the shift lever 72 is switched to the travel position. an output command of the control pressure P _SLU from the linear solenoid valve SLU may make a prohibition flag to prohibit uniformly. In this case, in addition to the second brake B2, the lockup clutch 30 is not engaged. Even if it does in this way, even if the switching abnormality fixed to a 2nd oil path arises, the lockup on of the lockup clutch 30 which is not planned is prevented.

  In the above-described embodiment, the predetermined hydraulic friction engagement device of the clutch C and the brake B is the second brake B2 that is engaged only during engine braking. However, the predetermined hydraulic friction engagement device is It is not limited to a hydraulic friction engagement device that is engaged only during engine braking.

  For example, a hydraulic friction engagement device that establishes a shift stage of the automatic transmission 10 that does not lock-up the lock-up clutch 30 may be used. That is, since it is not necessary to simultaneously control the engagement pressure of the hydraulic friction engagement device and the torque capacity of the lock-up clutch 30, a single (shared) solenoid valve is used for these controls. Specifically, a traveling state is set in which the lockup clutch 30 is locked up only in the sixth gear to the eighth gear, and the lockup clutch 30 is locked up in the first gear to the fifth gear. If it is set so as not to do so, the first clutch C1 that is at least engaged to establish the first gear to the fifth gear may be a predetermined hydraulic friction engagement device. Even if it does in this way, even if the switching abnormality fixed to a 2nd oil path arises, the lockup on of the lockup clutch 30 which is not planned is prevented.

Further, in the above-described embodiment, the switching abnormality determination means 168 determines whether or not the switching abnormality of the lockup relay valve 112 by the relay valve control means 166 is disabled and the switching abnormality fixed to the second oil passage has occurred. When the shift lever 72 is switched to the non-traveling position, the lockup relay valve 112 is switched to the first oil passage side, the control pressure P _SLU is output from the linear solenoid valve SLU, and the second brake B2 is engaged. Although the determination is made based on the detection result of the control pressure _PSLU for controlling the pressure, other determination methods may be used.

For example, switching換異normal determination unit 168, when a vehicle traveling state in which the lock-up release space that is preset in the lockup region diagram shown in FIG. 9, the turbine speed N _T and the engine speed N You may determine by comparing with _E. Specifically, switching換異normal determination unit 168, when the turbine speed N _T and the engine speed N _E is substantially the same as in the case of lock-up on, or they rotational speed difference (= N _T - If N _E ) is substantially zero as in the case of lock-up on, the switching of the lock-up relay valve 112 to the first oil path by the relay valve control means 166 becomes impossible and is fixed to the second oil path. It is determined that the fault (fail) state has occurred. Even in this case, when it is determined by the switching abnormality determining means 168 that the switching abnormality fixed to the second oil passage has occurred, the engagement prohibiting means 174 prohibits the engagement of the predetermined hydraulic friction engagement device. Therefore, when the solenoid valve for controlling the engagement pressure of the predetermined hydraulic friction engagement device is also used as the solenoid valve for controlling the torque capacity of the lockup clutch 30, the switching abnormality is fixed to the second oil passage. Even if this occurs, the lockup on of the lockup clutch 30 that is not scheduled is prevented.

Further, when a switching abnormality fixed to the second oil passage occurs, the predetermined hydraulic friction engagement device is not engaged and the automatic transmission 10 is in a power transmission cut-off state. The determination means 168 determines the actual turbine rotational speed N _T ^* (= N _OUT × γ) obtained from the output shaft rotational speed N _OUT and the speed ratio γ at the gear stage to be established at that time and the actual during traveling. Determination may be made by comparing with the turbine rotational speed _NT . Specifically, the switching abnormality determination unit 168 determines whether the estimated turbine rotation speed _NT ^* and the actual turbine rotation speed _NT are not within a predetermined determination speed difference that is substantially the same. It is determined that the failure is a failure (fail) state in which the switching control of the lockup relay valve 112 to the first oil passage by the valve control means 166 becomes impossible and the switching abnormality fixed to the second oil passage has occurred. Even in this case, when it is determined by the switching abnormality determining means 168 that the switching abnormality fixed to the second oil passage has occurred, the engagement prohibiting means 174 prohibits the engagement of the predetermined hydraulic friction engagement device. Therefore, when the solenoid valve for controlling the engagement pressure of the predetermined hydraulic friction engagement device is also used as the solenoid valve for controlling the torque capacity of the lockup clutch 30, the switching abnormality is fixed to the second oil passage. Even if this occurs, the lockup on of the lockup clutch 30 that is not scheduled is prevented.

In the above-described embodiment, the invention can be applied even if the second brake control valve 92 provided in the second brake control circuit 90 is not necessarily provided. In this case, the control pressure _PSLU supplied to the second brake control valve 92 is supplied to the brake B2 via the shuttle valve 94 as it is. In this case, the hydraulic switch 48 may be provided between the shuttle valve 94 and the brake B2 so as to detect the control pressure _PSLU output from the shuttle valve 94.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a vehicle automatic transmission to which the present invention is applied. FIG. 2 is an operation chart for explaining a combination of operations of the hydraulic friction engagement device when establishing a plurality of gear stages of the vehicle automatic transmission of FIG. 1. It is a circuit diagram regarding the linear solenoid valve which controls the action | operation of each hydraulic actuator of a clutch and a brake, and a lockup clutch, Comprising: It is a figure which shows the hydraulic control circuit as a hydraulic control apparatus. FIG. 5 is a diagram for explaining engagement pressure control of a second brake and torque capacity control of a lockup clutch by a linear solenoid valve that is switched by the switching circuit, including schematic diagrams of a second brake control circuit and a switching circuit. FIG. 2 is a block diagram illustrating a main part of a control system provided in the vehicle for controlling the automatic transmission of FIG. 1 and the like. It is a figure explaining the operation position of the shift lever of FIG. It is a functional block diagram explaining the principal part of the control function by the electronic controller of FIG. It is a figure which shows an example of the shift map used in the shift control of an automatic transmission. It is a figure explaining an example of the lockup area | region diagram used for control of the lockup clutch in a torque converter. It is a flowchart explaining the control action which determines the principal part of the control action of the electronic controller of FIG. 5, ie, the switching abnormality of a lockup relay valve.

Explanation of symbols

10: Automatic transmission 28 for vehicle: Torque converter (fluid transmission)
30: Lock-up clutch (lock-up mechanism)
72: Shift lever (operating device)
112: Lock-up relay valve (relay valve)
160: Electronic control device (hydraulic control device)
168: Switching abnormality determining means 174: Engagement prohibiting means C1 to C4: Clutch (hydraulic friction engagement device)
B1, B2: Brake (hydraulic friction engagement device)
SLU: Linear solenoid valve (single solenoid valve)

Claims (3)

A hydraulic control device for a vehicular automatic transmission that includes a fluid transmission device with a lockup mechanism and that establishes a plurality of gear stages having different gear ratios by selectively engaging a plurality of hydraulic friction engagement devices. There,
An engagement pressure of a predetermined hydraulic friction engagement device engaged to obtain an engine braking action among the plurality of hydraulic friction engagement devices and a torque capacity of the lockup mechanism are alternatively controlled. A single solenoid valve,
The first oil passage for controlling the engagement pressure of the predetermined hydraulic friction engagement device according to the output hydraulic pressure of the solenoid valve and the torque capacity of the lockup mechanism according to the output hydraulic pressure of the solenoid valve a relay valve which can be switched without involving the second oil passage for controlling the shifting operation of the vehicle automatic transmission,
A switching abnormality determining means for determining whether or not a switching abnormality has occurred in which the relay valve is disabled and fixed to the second oil passage;
And an engagement prohibiting means for prohibiting engagement of the predetermined hydraulic frictional engagement device when the switching abnormality determining means determines that the switching abnormality has occurred. Hydraulic control device. 2. The automatic transmission for a vehicle according to claim 1, wherein the engagement prohibiting means is means for not outputting a control pressure for engaging a predetermined hydraulic friction engagement device engaged to obtain the engine braking action. Hydraulic control device for the machine. An operating device capable of switching between a travel position for switching the automatic transmission to a power transmission enabled state and a non-travel position for switching the automatic transmission to a power transmission cutoff state;
The switching abnormality determining means is configured to switch to the first oil passage and output hydraulic pressure from the solenoid valve when the operating device is switched to the non-running position and to output the predetermined hydraulic frictional engagement. The hydraulic pressure of the vehicle automatic transmission according to claim 1 or 2 , wherein it is determined whether or not the switching abnormality has occurred based on a detection result of hydraulic pressure from the solenoid valve for controlling the engagement pressure of the combined device. Control device.

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