JP2020070815A - Control device of automatic transmission - Google Patents

Abstract

To provide a control device of an automatic transmission which can secure the traveling performance of a vehicle at the occurrence of an abnormality at a range contact point.SOLUTION: At a normal time at which an abnormality does not occur at a range contact point, an SR switch valve 105, an SL1 solenoid valve 103 and an SL2 solenoid valve 104 can be normally controlled on the basis of a range contact point signal. When the abnormality occurs at the range contact point, it is determined whether or not a clutch C2 is engaged, and also it is determined whether a vehicle speed of a vehicle 1 is equal to a reverse inhibit vehicle speed or higher, or lower than the reverse inhibit vehicle speed. When the clutch C2 is engaged, or the vehicle speed is equal to the reverse inhibit vehicle speed or higher, the SL2 solenoid valve 104 is controlled so that SL2 pressure for making the clutch C2 engage is outputted in a state in which the SR switch valve 105 is turned off.SELECTED DRAWING: Figure 6

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a continuously variable transmission (CVT) having a continuously variable transmission ratio or a stepped automatic transmission (AT) having a continuously variable transmission ratio.

  In vehicles such as automobiles, for example, the power from the engine is input to the transmission, and the power shifted by the transmission is transmitted to the drive wheels. As a transmission, an automatic transmission in which a gear ratio is automatically changed according to a running condition of a vehicle is widely used.

  The automatic transmission has a shift range including, for example, a P range, an R range, an N range and a D range. A shift lever (select lever) is provided in a vehicle compartment of a vehicle equipped with an automatic transmission to instruct switching of a shift range. In the movable range of the shift lever, the P position, the R position, the N position and the D position are set corresponding to the shift range. A shift position sensor that outputs a detection signal (range contact signal) corresponding to the position of the shift lever is connected to the control device of the automatic transmission. The control device controls a valve included in the hydraulic circuit of the automatic transmission based on the range contact signal, and selectively engages / disengages the clutch according to the position of the shift lever.

JP, 2016-98902, A

  Therefore, when the shift position sensor malfunctions, a range contact abnormality, that is, a non-contact abnormality in which the range contact signal is not input from the shift position sensor to the control device or a multiple contact abnormality in which a plurality of range contact signals are simultaneously input, occurs, The control device may not be able to appropriately control the engagement / disengagement of the clutch, and the running performance of the vehicle may not be ensured.

  An object of the present invention is to provide a control device for an automatic transmission that can ensure the running performance of a vehicle when a range contact is abnormal.

  In order to achieve the above-mentioned object, a control device for an automatic transmission according to the present invention outputs power in a direction to advance a vehicle by releasing a first engaging element and engaging a second engaging element, A mechanism configured to output power in a direction to move the vehicle backward by engaging the first engagement element and releasing the second engagement element, and outputting / stopping hydraulic pressure according to a manual valve and on / off. The switch valve includes a switch valve, a first valve that outputs a hydraulic pressure that controls engagement / release of the first engagement element, and a second valve that outputs a hydraulic pressure that controls engagement / release of the second engagement element. When the switch is on and the manual valve is in the forward position, the hydraulic pressure output from the second valve is supplied to the second engagement element, the switch valve is on, and the manual valve is in the reverse position. The hydraulic pressure output from the manual valve is supplied to the first engagement element, the first engagement element is engaged, the switch valve is off, and the manual valve is in the forward position. The hydraulic pressure output from is supplied to the second engagement element, the second engagement element engages, the switch valve is off, and the manual valve is output from the first valve when in the reverse position. A control device for an automatic transmission, comprising: a hydraulic circuit configured to supply hydraulic pressure to a first engagement element; position detecting means for outputting a range contact signal according to the position of a manual valve; The control means determines whether or not a range contact abnormality in which the range contact signal is abnormal occurs, and the range contact abnormality does not occur. If it is determined that the range contact signal is controlled, the switch valve, the first valve, and the second valve are controlled, and if it is determined that the range contact abnormality has occurred, the second engagement element is engaged. It is further determined whether or not the vehicle speed of the vehicle is higher than or equal to or lower than a predetermined reverse inhibit vehicle speed, and it is determined that the second engagement element is engaged, or If it is determined that the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the second valve is controlled so that the hydraulic pressure for engaging the second engaging element is output while the switch valve is off, and the second engaging element Is determined not to be engaged and the vehicle speed is determined to be lower than the reverse inhibit vehicle speed, the hydraulic pressure for engaging the second engagement element is output while the switch valve is on. To the second valve Control.

  According to this configuration, the switch valve, the first valve, and the second valve can be normally controlled based on the range contact signal when the range contact abnormality is normal.

  On the other hand, when the range contact abnormality has occurred, the switch valve, the first valve and the second valve cannot be normally controlled based on the range contact signal, and the first engagement element and the second engagement element are manually operated. May not engage / disengage depending on valve position.

  Therefore, when it is determined that the range contact abnormality has occurred, it is further determined whether or not the second engagement element is engaged, and the vehicle speed of the vehicle is equal to or higher than the reverse inhibit vehicle speed or less. Is further determined.

  When the second engagement element is engaged, the second valve is controlled so that the hydraulic pressure for engaging the second engagement element is output with the switch valve being off regardless of the vehicle speed. It At this time, since the manual valve is located at the forward position, the hydraulic pressure for engaging the second engagement element can be output from the second valve. Since the switch valve is held in the off state, the engagement of the second engagement element is maintained. Therefore, even if a range contact abnormality occurs, the vehicle is driven by the forward power output from the automatic transmission. It is possible to continue traveling forward.

  Even when the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the second valve is controlled so that the hydraulic pressure for engaging the second engaging element is output while the switch valve is off. Since the switch valve is off, even if the manual valve is moved to the reverse position and the hydraulic pressure corresponding to the reverse position is output from the manual valve, the hydraulic pressure output from the manual valve is the first engagement element. Not supplied to. As a result, when the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the engagement of the first engagement element can be suppressed, that is, the reverse inhibit state can be realized.

  On the other hand, when the second engaging element is not engaged, that is, the second engaging element is released and the vehicle speed is lower than the reverse inhibit vehicle speed, the switch valve is in the ON state, The second valve is controlled so that the hydraulic pressure for engaging the two engaging elements is output. Therefore, when the manual valve is located at the forward position, the hydraulic pressure output from the second valve is supplied to the second engagement element and the second engagement element is engaged, and thus is output from the automatic transmission. The vehicle can be driven forward by the power in the forward direction. When the manual valve is in the reverse position, the hydraulic pressure output from the manual valve is supplied to the first engagement element and the first engagement element is engaged, so that the reverse direction output from the automatic transmission in the reverse direction is output. The vehicle can be driven backwards by the power.

  Since the position of the manual valve corresponds to the position of the shift lever (select lever) arranged in the vehicle interior of the vehicle, the position detection means may directly detect the position of the manual valve. The position of the shift lever may be detected.

  After determining that the range contact abnormality has not occurred, the control means controls the second valve so that the hydraulic pressure for engaging the second engaging element is output while the switch valve is in the ON state. Whether one engagement element is engaged, whether the vehicle speed is equal to or greater than or less than a value obtained by adding a predetermined His vehicle speed to the reverse inhibit vehicle speed, and whether the second engagement element is engaged. If the vehicle speed is equal to or higher than the value obtained by adding the His vehicle speed to the reverse inhibit vehicle speed, or if the second engaging element is engaged, If it is determined that the second valve is on, the switch valve may be switched from on to off, and the second valve may be controlled so that the hydraulic pressure for engaging the second engagement element is output.

  As a result, when the first engagement element is engaged, the switch valve is kept on, so that the engagement of the first engagement element is maintained and the vehicle speed is changed to the reverse inhibit vehicle speed. Even if the value rises above the added value, the vehicle can continue to run backward. On the other hand, when the vehicle speed increases above the value obtained by adding the His vehicle speed to the reverse inhibit vehicle speed in the state where the first engaging element is not engaged, that is, the state where the first engaging element is released, or When the engagement element is engaged, the switch valve can be switched from ON to OFF, so that the engagement of the first engagement element is suppressed, that is, the reverse operation, while the vehicle is traveling forward at a vehicle speed equal to or higher than the reverse inhibit vehicle speed. An inhibit state can be realized.

  According to the present invention, the traveling performance of the vehicle can be ensured when the range contact is abnormal.

It is a skeleton diagram showing a configuration of a drive system of a vehicle. It is a figure which shows the state of each engaging element with which a transmission is equipped. FIG. 5 is a collinear chart showing the relationship among the rotational speeds of the sun gear, carrier, and ring gear of the planetary gear mechanism provided in the transmission. It is a figure which shows the relationship between the pulley ratio of the continuously variable transmission mechanism with which a transmission is equipped, and the unit gear ratio of the whole transmission. It is a figure which shows the structure of the control system which concerns on one Embodiment of this invention. It is a circuit diagram which shows the structure of the hydraulic circuit with which a transmission is equipped. It is a flowchart (the 1) which shows the flow of range contact abnormality processing. It is a flowchart (the 2) which shows the flow of range contact abnormality processing. It is a flowchart (the 3) which shows the flow of range contact abnormality processing. It is a flowchart (the 4) which shows the flow of range contact abnormality processing.

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

<Vehicle drive system>
FIG. 1 is a skeleton diagram showing a configuration of a drive system of a vehicle 1.

  The vehicle 1 is an automobile that uses the engine 2 as a drive source.

  The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) for injecting fuel into intake air, and an ignition plug for causing electric discharge in the combustion chamber. Has been. Also, the engine 2 is provided with a starter for starting the engine. The power of the engine 2 is transmitted to the differential gear 5 via the torque converter 3 and the transmission 4, and is transmitted from the differential gear 5 to the left and right drive wheels 7L and 7R via the left and right drive shafts 6L and 6R, respectively. ..

  The engine 2 includes an E / G output shaft 11. The E / G output shaft 11 is rotated by the power generated by the engine 2.

  The torque converter 3 includes a front cover 21, a pump impeller 22, a turbine runner 23, and a lockup mechanism 24. The E / G output shaft 11 is connected to the front cover 21, and the front cover 21 rotates integrally with the E / G output shaft 11. The pump impeller 22 is arranged on the side opposite to the engine 2 side with respect to the front cover 21. The pump impeller 22 is provided so as to be rotatable integrally with the front cover 21. The turbine runner 23 is disposed between the front cover 21 and the pump impeller 22 and is rotatably provided about a common rotation axis with the front cover 21.

  The lockup mechanism 24 includes a lockup piston 25. The lockup piston 25 is provided between the front cover 21 and the turbine runner 23. The lock-up mechanism 24 uses the differential pressure between the oil pressure in the release oil chamber 26 between the lock-up piston 25 and the front cover 21 and the oil pressure in the engagement oil chamber 27 between the lock-up piston 25 and the pump impeller 22. The lockup is turned on (engaged) / off (released). That is, when the oil pressure in the release oil chamber 26 is higher than the oil pressure in the engagement oil chamber 27, the lockup piston 25 separates from the front cover 21 due to the pressure difference, and the lockup is turned off. When the oil pressure in the engagement oil chamber 27 is higher than the oil pressure in the release oil chamber 26, the lockup piston 25 is pressed against the front cover 21 by the pressure difference, and the lockup is turned on.

  In the lock-up off state, when the E / G output shaft 11 is rotated, the pump impeller 22 is rotated. When the pump impeller 22 rotates, a flow of oil from the pump impeller 22 toward the turbine runner 23 occurs. This oil flow is received by the turbine runner 23, and the turbine runner 23 rotates. At this time, the amplifying action of the torque converter 3 occurs, and a torque larger than the torque of the E / G output shaft 11 is generated in the turbine runner 23.

  In the lock-up on state, when the E / G output shaft 11 is rotated, the E / G output shaft 11, the pump impeller 22 and the turbine runner 23 are integrally rotated.

  The transmission 4 includes an input shaft 31 and an output shaft 32, and is configured to branch the power input to the input shaft 31 into two paths and transmit the power to the output shaft 32. It is a split type transmission. To form two power transmission paths, the transmission 4 includes a continuously variable transmission mechanism 33, a front reduction gear mechanism 34, a planetary gear mechanism 35, and a split transmission mechanism 36.

  The input shaft 31 is connected to the turbine runner 23 of the torque converter 3 and is provided so as to be integrally rotatable about the same rotation axis as the turbine runner 23.

  The output shaft 32 is provided parallel to the input shaft 31. An output gear 37 is supported on the output shaft 32 so as not to rotate relative to it. The output gear 37 meshes with the differential gear 5 (the ring gear of the differential gear 5).

  The continuously variable transmission 33 has a configuration similar to that of a known belt type continuously variable transmission (CVT). Specifically, the continuously variable transmission mechanism 33 includes a primary shaft 41, a secondary shaft 42 provided in parallel with the primary shaft 41, a primary pulley 43 supported by the primary shaft 41 so as not to rotate relative to the primary shaft 41, and a secondary shaft 42. The secondary pulley 44 is supported so as to be relatively non-rotatable, and the belt 45 wound around the primary pulley 43 and the secondary pulley 44.

  The primary pulley 43 is arranged to face the fixed sheave 51 fixed to the primary shaft 41 and the fixed sheave 51 with the belt 45 sandwiched therebetween, and the movable sheave supported by the primary shaft 41 so as to be movable in the axial direction thereof and non-rotatable. And 52. A cylinder 53 fixed to the primary shaft 41 is provided on the side opposite to the fixed sheave 51 with respect to the movable sheave 52, and a hydraulic chamber 54 is formed between the movable sheave 52 and the cylinder 53.

  The secondary pulley 44 is arranged to face the fixed sheave 55 fixed to the secondary shaft 42 and the fixed sheave 55 with the belt 45 sandwiched therebetween, and the movable sheave supported by the secondary shaft 42 so as to be movable in its axial direction and non-rotatable. And 56. A cylinder 57 fixed to the secondary shaft 42 is provided on the side opposite to the fixed sheave 55 with respect to the movable sheave 56, and a hydraulic chamber 58 is formed between the movable sheave 56 and the cylinder 57. In the rotational axis direction, the positional relationship between the fixed sheave 55 and the movable sheave 56 is opposite to the positional relationship between the fixed sheave 51 and the movable sheave 52 of the primary pulley 43.

  In the continuously variable transmission mechanism 33, the hydraulic pressures supplied to the hydraulic chamber 54 of the primary pulley 43 and the hydraulic chamber 58 of the secondary pulley 44 are respectively controlled to change the groove widths of the primary pulley 43 and the secondary pulley 44. The gear ratio (the pulley ratio between the primary pulley 43 and the secondary pulley 44) is continuously and continuously changed.

  Specifically, when the gear ratio is reduced, the hydraulic pressure supplied to the hydraulic chamber 54 of the primary pulley 43 is increased. As a result, the movable sheave 52 of the primary pulley 43 moves to the fixed sheave 51 side, and the gap (groove width) between the fixed sheave 51 and the movable sheave 52 becomes smaller. Along with this, the winding diameter of the belt 45 around the primary pulley 43 increases, and the gap (groove width) between the fixed sheave 55 and the movable sheave 56 of the secondary pulley 44 increases. As a result, the pulley ratio between the primary pulley 43 and the secondary pulley 44 is reduced.

  When the gear ratio is increased, the hydraulic pressure supplied to the hydraulic chamber 54 of the primary pulley 43 is lowered. As a result, the thrust ratio, which is the ratio of the thrust of the primary pulley 43 (primary thrust) to the thrust of the secondary pulley 44 (secondary thrust), becomes smaller, and the distance between the fixed sheave 55 and the movable sheave 56 of the secondary pulley 44 becomes smaller. The gap between the fixed sheave 51 and the movable sheave 52 becomes large. As a result, the pulley ratio between the primary pulley 43 and the secondary pulley 44 increases.

  On the other hand, the thrust of the primary pulley 43 and the secondary pulley 44 needs to be large enough to prevent slippage (belt slip) between the belt 45 and the primary pulley 43 and secondary pulley 44. Therefore, the hydraulic pressures supplied to the hydraulic chamber 54 of the primary pulley 43 and the hydraulic chamber 58 of the secondary pulley 44 are controlled so that a necessary and sufficient clamping pressure that does not cause belt slippage is obtained.

  The front reduction gear mechanism 34 is configured to reverse and reduce the power input to the input shaft 31 and transmit the power to the primary shaft 41. Specifically, the front reduction gear mechanism 34 has an input shaft gear 61 supported by the input shaft 31 so as not to rotate relative to the input shaft gear 31, and has a larger diameter and a larger number of teeth than the input shaft gear 61, and is spline-fitted to the primary shaft 41. And a primary shaft gear 62 that meshes with the input shaft gear 61.

  The planetary gear mechanism 35 includes a sun gear 71, a carrier 72 and a ring gear 73. The sun gear 71 is supported by the secondary shaft 42 by spline fitting so as not to rotate relative to each other. The carrier 72 is fitted onto the output shaft 32 so as to be relatively rotatable. The carrier 72 rotatably supports a plurality of pinion gears 74. The plurality of pinion gears 74 are arranged on the circumference and mesh with the sun gear 71. The ring gear 73 has an annular shape that collectively surrounds the plurality of pinion gears 74, and meshes with each pinion gear 74 from the outside in the radial direction of rotation of the secondary shaft 42. Further, the output shaft 32 is connected to the ring gear 73, and the ring gear 73 is provided so as to be integrally rotatable about the same rotation axis as the output shaft 32.

  The split transmission mechanism 36 is a parallel shaft type gear mechanism including a split drive gear 81 and a split driven gear 82 that meshes with the split drive gear 81.

  The split drive gear 81 is fitted onto the input shaft 31 so as to be relatively rotatable.

  The split driven gear 82 is integrally rotatable about the same rotation axis as the carrier 72 of the planetary gear mechanism 35. The split driven gear 82 is formed to have a smaller diameter than the split drive gear 81 and has a smaller number of teeth than the split drive gear 81.

  Further, the transmission 4 includes clutches C1 and C2 and a brake B1.

  The clutch C1 is switched by hydraulic pressure between an engaged state in which the input shaft 31 and the split drive gear 81 are directly connected (integrally rotatably connected) and a released state in which the direct connection is released.

  The clutch C2 is switched by hydraulic pressure between an engaged state in which the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are directly connected (integrally rotatably connected) and a released state in which the direct connection is released.

  The brake B1 is switched by the hydraulic pressure between an engaged state for braking the carrier 72 of the planetary gear mechanism 35 and a released state for allowing the rotation of the carrier 72.

<Power transmission mode>
FIG. 2 is a diagram showing states of the clutches C1 and C2 and the brake B1 when the vehicle 1 is moving forward and backward. FIG. 3 is a collinear chart showing the relationship among the rotational speeds (rotational speeds) of the sun gear 71, the carrier 72, and the ring gear 73 of the planetary gear mechanism 35. FIG. 4 is a diagram showing a relationship between a belt gear ratio (pulley ratio) by the continuously variable transmission mechanism 33 and a reduction ratio (unit gear ratio) of the entire transmission 4.

  In FIG. 2, “◯” indicates that the clutches C1 and C2 and the brake B1 are in the engaged state. “X” indicates that the clutches C1, C2 and the brake B1 are in the released state.

  A shift lever (select lever) is arranged in a vehicle compartment of the vehicle 1 at a position where a driver can operate it. In the movable range of the shift lever, for example, a P (parking) position, an R (reverse) position, an N (neutral) position, a D (drive) position, an S (sports) position, and a B (brake) position are lined up in this order. They are arranged side by side.

  When the shift lever is in the P position, all of the clutches C1, C2 and the brake B1 are released, and the parking lock gear (not shown) is fixed, which is one of the shift ranges of the transmission 4. A P range is constructed. Further, when the shift lever is in the N position, all of the clutches C1 and C2 and the brake B1 are released, and the parking lock gear is not fixed, so that the N range, which is one of the shift ranges of the transmission 4, is changed. Composed. In a state where both the clutch C1 and the brake B1 are released, the power of the engine 2 is transmitted to the secondary shaft 42 and the secondary shaft 42 rotates, but the sun gear 71 and the pinion gear 74 of the planetary gear mechanism 35 idle and the engine rotates. The power of 2 is not transmitted to the drive wheels 7L and 7R.

  When the shift lever is in the D position, S position, or B position, the forward range, which is one of the shift ranges of the transmission 4, is configured. The power transmission mode in the forward range includes a belt mode and a split mode. The belt mode and the split mode are switched by switching between a state in which the clutch C1 is engaged and a state in which the clutch C2 is engaged (replacement of the clutches C1 and C2).

  In the belt mode, as shown in FIG. 2, the clutch C1 and the brake B1 are released and the clutch C2 is engaged. As a result, the split drive gear 81 is separated from the input shaft 31, the carrier 72 of the planetary gear mechanism 35 becomes free (free rotation state), and the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are directly connected.

  The power input to the input shaft 31 is reversely rotated and decelerated by the front reduction gear mechanism 34, is transmitted to the primary shaft 41 of the continuously variable transmission mechanism 33, and rotates the primary shaft 41 and the primary pulley 43. The rotation of the primary pulley 43 is transmitted to the secondary pulley 44 via the belt 45 to rotate the secondary pulley 44 and the secondary shaft 42. Since the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are directly connected, the sun gear 71, the ring gear 73, and the output shaft 32 rotate integrally with the secondary shaft 42. Therefore, in the belt mode, as shown in FIGS. 3 and 4, the speed reduction ratio (unit speed ratio) of the transmission 4 is the belt speed ratio (the pulley ratio between the primary pulley 43 and the secondary pulley 44) of the continuously variable transmission mechanism 33. ) Multiplied by the front reduction ratio (the rotation speed of the input shaft 31 / the rotation speed of the primary shaft 41).

  In the split mode, as shown in FIG. 2, the clutch C1 is engaged and the clutch C2 and the brake B1 are released. As a result, the input shaft 31 and the split drive gear 81 are coupled to each other, and the rotation of the input shaft 31 can be transmitted to the carrier 72 of the planetary gear mechanism 35 via the split drive gear 81 and the split driven gear 82. The sun gear 71 of 35 and the ring gear 73 are separated.

  The power input to the input shaft 31 is accelerated and transmitted from the split drive gear 81 to the carrier 72 of the planetary gear mechanism 35 via the split driven gear 82. The power transmitted to the carrier 72 is divided and transmitted from the carrier 72 to the sun gear 71 and the ring gear 73. The power of the sun gear 71 is transmitted to the primary shaft gear 62 via the secondary shaft 42, the secondary pulley 44, the belt 45, the primary pulley 43, and the primary shaft 41, and is transmitted from the primary shaft gear 62 to the input shaft gear 61. Therefore, in the belt mode, the input shaft gear 61 serves as a driving gear and the primary shaft gear 62 serves as a driven gear, whereas in the split mode, the primary shaft gear 62 serves as a driving gear and the input shaft gear 61 serves as a driven gear. ..

  Since the gear ratio between the split drive gear 81 and the split driven gear 82 is constant and invariable (fixed), in the split mode, if the power input to the input shaft 31 is constant, the rotation of the carrier 72 of the planetary gear mechanism 35 will rotate. Is maintained at a constant speed. Therefore, when the gear ratio is increased, the rotation speed of the sun gear 71 of the planetary gear mechanism 35 decreases, so that the rotation speed of the ring gear 73 (output shaft 32) of the planetary gear mechanism 35 decreases as shown by the broken line in FIG. Go up. As a result, in the split mode, as shown in FIG. 4, as the belt speed ratio of the continuously variable transmission mechanism 33 increases, the speed reduction ratio of the transmission 4 decreases, and the sensitivity of the speed reduction ratio to the belt speed ratio (belt speed ratio The ratio of the amount of change in the speed reduction ratio to the amount of change in (1) is lower than that in the belt mode.

  The rotation of the output shaft 32 in the belt mode and the split mode is transmitted to the differential gear 5 via the output gear 37. As a result, the drive shafts 6L, 6R and the drive wheels 7L, 7R of the vehicle 1 rotate in the forward direction.

  It should be noted that regardless of whether the shift lever is in the D position, the S position, or the B position, in the forward drive range, shift control for automatically and continuously changing the gear ratio is performed continuously. However, in the state in which the shift lever is in the S position (S range), the gear ratio is changed so that the engine speed is maintained higher than in the state in which the shift lever is in the D position (D range). To be done. As a result, in the S range, the driver can enjoy sporty traveling as compared with the D range, and strong engine braking can be obtained during deceleration. When the shift lever is in the B position (B range), the gear ratio is changed so that the engine speed is maintained higher than that in the S range, and engine braking stronger than that in the S range is obtained during deceleration. ..

  When the shift lever is in the R position, the reverse range, which is one of the shift ranges of transmission 4, is formed. In the reverse range, as shown in FIG. 2, the clutches C1 and C2 are released and the brake B1 is engaged. As a result, the split drive gear 81 is separated from the input shaft 31, the sun gear 71 and the ring gear 73 of the planetary gear mechanism 35 are separated, and the carrier 72 of the planetary gear mechanism 35 is braked.

  The power input to the input shaft 31 is reverse-rotated and decelerated by the front reduction gear mechanism 34, and is transmitted to the primary shaft 41 of the continuously variable transmission mechanism 33 so that the primary shaft 41 drives the primary pulley 43, the belt 45, and the secondary pulley 44. It is transmitted to the secondary shaft 42 via the secondary shaft 42 and rotates the sun gear 71 of the planetary gear mechanism 35 integrally with the secondary shaft 42. Since the carrier 72 of the planetary gear mechanism 35 is braked, when the sun gear 71 rotates, the ring gear 73 of the planetary gear mechanism 35 rotates in the opposite direction to the sun gear 71. The rotation direction of the ring gear 73 is opposite to the rotation direction of the ring gear 73 during forward movement (belt mode and split mode). Then, the output shaft 32 rotates integrally with the ring gear 73. The rotation of the output shaft 32 is transmitted to the differential gear 5 via the output gear 37. As a result, the drive shafts 6L, 6R and the drive wheels 7L, 7R of the vehicle 1 rotate in the reverse direction.

<Vehicle control system>
FIG. 5 is a block diagram showing the configuration of the control system of the vehicle 1.

  The vehicle 1 is provided with an ECU (Electronic Control Unit) 91 having a configuration including a microcomputer (micro controller unit). Although only one ECU 91 is shown in FIG. 5, the vehicle 1 is equipped with a plurality of ECUs having the same configuration as the ECU 91 in order to control each unit. A plurality of ECUs including the ECU 91 are connected so as to be capable of bidirectional communication according to a CAN (Controller Area Network) communication protocol.

  The ECU 91 controls an electronic throttle valve, an injector, an ignition plug and the like provided in the engine 2 for starting, stopping and adjusting the output of the engine 2. Further, for lock-up control of the torque converter 3 and shift control of the transmission 4, etc., various valves included in a hydraulic circuit 92 for supplying hydraulic pressure to various parts of the unit including the torque converter 3 and the transmission 4 are controlled. To do.

  Various sensors required for control are connected to the ECU 91, and detection signals are input from these sensors. The sensor connected to the ECU 91 includes, for example, an output rotation sensor 93 that outputs a pulse signal synchronized with the rotation of the output shaft 32 as a detection signal, and a pulse signal synchronized with the rotation of the secondary shaft 42 as a detection signal. The secondary rotation sensor 94 that outputs, the SL2 current sensor 95 that detects the current supplied to the SL2 solenoid valve 104 (see FIG. 6), and the shift position that outputs a detection signal (range contact signal) according to the position of the shift lever. A sensor 96 is included.

<Hydraulic circuit>
FIG. 6 is a circuit diagram showing the configuration of the hydraulic circuit 92.

  The hydraulic circuit 92 includes a manual valve 101, a relay valve 102, an SL1 solenoid valve 103, an SL2 solenoid valve 104, an SR switch valve 105, a C1 cut valve 106, a C2 cut valve 107 and a fail safe valve 108.

  The manual valve 101 is a valve that outputs hydraulic pressure corresponding to the position of the shift lever.

  The relay valve 102 supplies the D pressure and the R pressure selectively output from the manual valve 101 to the SL1 solenoid valve 103, and outputs the SL1 pressure output from the SL1 solenoid valve 103 to the clutch C1 and the brake B1. It is a valve for switching. The clutch original pressure is input to the manual valve 101, and the D pressure and the R pressure are the clutch original pressure.

  The SL1 solenoid valve 103 is a normally closed type linear solenoid valve. The SL1 solenoid valve 103 outputs SL1 pressure (control pressure) obtained by adjusting the clutch original pressure input from the relay valve 102 by controlling the energization of the electromagnetic coil.

  The SL2 solenoid valve 104 is a normally closed type linear solenoid valve. The D pressure is input from the manual valve 101 to the SL2 solenoid valve 104. The SL2 solenoid valve 104 outputs SL2 pressure (control pressure) obtained by adjusting the D pressure that is the clutch original pressure by controlling the energization of the electromagnetic coil.

  The SR switch valve 105 is a normally closed type on / off solenoid valve. The SR switch valve 105 is turned on (opened) by energizing the electromagnetic coil, and turned off (closed) by de-energizing the electromagnetic coil.

  The C1 cut valve 106 is a valve that switches the spool position between the C1 position (transient position) and the C2 position.

  The C2 cut valve 107 is a valve that switches the spool position between the C1 position and the C2 position (transitional position).

  The fail-safe valve 108 is a valve that switches the spool position between a normal position (P, N, D, R transient position) and a fail position (R position).

  When the SR switch valve 105 is on, the hydraulic pressure output from the SR switch valve 105 is input to the C1 cut valve 106 and the C2 cut valve 107. As a result, the spool position of the C1 cut valve 106 becomes the C1 position, and the spool position of the C2 cut valve 107 becomes the C2 position. In this state, the SL1 pressure output from the SL1 solenoid valve 103 is input to the C1 cut valve 106 via the C2 cut valve 107, and the SL1 pressure is supplied from the C1 cut valve 106 to the clutch C1. The SL2 pressure output from the SL2 solenoid valve 104 is input to the C1 cut valve 106 via the C2 cut valve 107, and the SL2 pressure is supplied from the C1 cut valve 106 to the clutch C2. Therefore, by controlling the energization of the SL1 solenoid valve 103 and the SL2 solenoid valve 104 to increase or decrease the SL1 pressure and the SL2 pressure, it is possible to increase or decrease the hydraulic pressure supplied to the clutches C1 and C2. Can be switched between engaged and disengaged.

  Further, when the SR switch valve 105 is on, the hydraulic pressure output from the SR switch valve 105 is input to the fail safe valve 108. As a result, in the fail-safe valve 108, the spool position becomes the fail position. Therefore, when the R pressure is output from the manual valve 101, the R pressure is input to the fail safe valve 108, and the R pressure is supplied from the fail safe valve 108 to the brake B1. As a result, the brake B1 is engaged.

  When the SR switch valve 105 is turned off while the clutch C1 is engaged by the SL1 pressure and the clutch C2 is released, the spool of the C2 cut valve 107 moves from the C2 position to the C1 position. On the other hand, the spool of the C1 cut valve 106 is held at the C1 position by the urging force of the spring built in the C1 cut valve 106. As a result, the D pressure output from the manual valve 101 is input to the C2 cut valve 107, the D pressure is input from the C2 cut valve 107 to the C1 cut valve 106, and the D pressure is supplied from the C1 cut valve 106 to the clutch C1. To be done. Therefore, even if the output of the SL1 pressure from the SL1 solenoid valve 103 is stopped, the engaged state of the clutch C1 is maintained.

  When the SR switch valve 105 is turned off in the state where the clutch C2 is engaged by the SL2 pressure and the clutch C1 is released, the C2 cut valve 107 is biased by the spring built in the C2 cut valve 107. The spool 107 is held at the C2 position. On the other hand, the spool of the C1 cut valve 106 moves from the C1 position to the C2 position due to the SL2 pressure. As a result, the D pressure output from the manual valve 101 is input to the C1 cut valve 106 without passing through the C2 cut valve 107, and the D pressure is supplied from the C1 cut valve 106 to the clutch C2. Therefore, even if the output of the SL2 pressure from the SL2 solenoid valve 104 is stopped, the engaged state of the clutch C2 is maintained.

  When the SR switch valve 105 is off, the position of the spool of the fail safe valve 108 is the normal position. Therefore, when the R pressure is output from the manual valve 101, it is input to the SL1 solenoid valve 103 via the relay valve 102, and the SL1 pressure from the SL1 solenoid valve 103 is input to the failsafe valve 108 via the relay valve 102. The SL1 pressure is supplied to the brake B1 from the fail-safe valve 108. As a result, the brake B1 is engaged.

<Range contact error processing>
7A, 7B, 7C and 7D are flowcharts showing the flow of range contact abnormality processing.

  In the transmission 4, as described above, the engagement / release of the clutches C1 and C2 and the brake B1 is controlled according to the position of the shift lever. Therefore, if the range contact signal output from the shift position sensor 96 is normal, engagement / release of the clutches C1 and C2 and the brake B1 can be normally controlled based on the range contact signal.

  However, when an abnormality (failure) occurs such as a failure of the shift position sensor 96, a disconnection of a connecting line connecting the shift position sensor 96 and the ECU 91, or a failure of a multiplexer interposed between the ECU 91 and the shift position sensor 96. There is. In this case, the range contact signal input to the ECU 91 becomes abnormal (hereinafter referred to as "range contact abnormality"). When the range contact abnormality occurs, the ECU 91 cannot correctly recognize the position of the shift lever, and thus the engagement / release of the clutches C1 and C2 and the brake B1 may not be normally controlled.

  Therefore, while the ignition switch of the vehicle 1 is on, the ECU 91 executes the range contact abnormality processing shown in FIGS.

  In the range contact abnormality processing, first, it is determined whether or not a range contact abnormality has occurred (step S1). For example, when the shift position sensor 96 fails and a range contact signal is not input from the shift position sensor 96 to the ECU 91, it is determined that a range contact abnormality (non-contact abnormality) has occurred. Further, when a plurality of range contact signals are simultaneously input from the shift position sensor 96 to the ECU 91, it is determined that a range contact abnormality (multiple input abnormality) has occurred.

  When the range contact abnormality has not occurred (NO in step S1), "0" is stored in the memory such as the RAM built in the ECU 91 as the fail safe state (step S2). The fail safe state “0” represents a normal state in which no range contact abnormality has occurred.

  Then, the position of the shift lever is acquired from the range contact signal, and the SL1 solenoid valve 103, the SL2 solenoid valve 104, and the SR switch are arranged so that the clutches C1, C2 and the brake B1 are engaged / released according to the position of the shift lever. The valve 105 and the like are controlled (step S3).

  On the other hand, when the range contact abnormality has occurred (step S1: YES), it is determined whether the current clutch control state is the split mode (step S4). In the split mode, as described above, the larger the belt gear ratio (the pulley ratio of the continuously variable transmission mechanism 33), the smaller the unit gear ratio (the reduction gear ratio of the transmission 4). When the ratio is lowered, the belt gear ratio is raised, and when the unit gear ratio is raised, the belt gear ratio is lowered. On the other hand, in the belt mode, the larger the belt gear ratio, the larger the unit gear ratio. Therefore, in the belt mode control state, the belt gear ratio is lowered when the unit gear ratio is decreased, and the belt gear ratio is increased when the unit gear ratio is increased. The ratio is raised.

  When the clutch control state is the split mode (step S4: YES), continuation of the split mode is prohibited, and switching from the split mode of the clutch control state to the belt mode is started (step S5). For this switching, the target belt gear ratio, which is the target of the belt gear ratio, is set to the minimum belt gear ratio (highest), and the belt gear ratio is controlled.

  Then, it is determined whether or not the mode switching condition is satisfied (step S6). The mode switching condition is, for example, that the actual belt speed ratio is smaller than a predetermined switching determination speed ratio, and the rotation speed of the input shaft 31 after switching from the split mode to the belt mode is a predetermined value or less. It is set. The actual belt gear ratio can be calculated by dividing the rotation speed of the primary shaft 41 by the rotation speed of the secondary shaft 42. The rotation speed of the primary shaft 41 can be calculated from the detection signal of the primary rotation sensor provided with a primary rotation sensor that outputs a pulse signal synchronized with the rotation of the primary shaft 41 as a detection signal. The rotation speed of the secondary shaft 42 can be calculated from the detection signal of the secondary rotation sensor 94. The rotation speed of the input shaft 31 after switching from the split mode to the belt mode can be estimated from the current rotation speed of the input shaft 31 and the actual belt gear ratio.

  If the mode switching condition is not satisfied (NO in step S6), the clutch control state is maintained in the split mode (step S7), the range contact abnormality processing is once ended, and then the range contact abnormality processing is performed again. Be started.

  When the mode switching condition is satisfied (YES in step S6), the power transmission mode of the transmission 4 is switched from the split mode to the belt mode, so that the clutch C1 is engaged and the clutch C2 is engaged. The clutch control for switching between is started (step S8). That is, when the SR switch valve 105 is turned on and the energization of the SL1 solenoid valve 103 and the SL2 solenoid valve 104 is controlled, the PL1 pressure supplied to the clutch C1 is reduced and the PL2 supplied to the clutch C2 is reduced. The pressure is increased.

  Then, it is determined whether or not the clutch control state is switched to the belt mode (step S9). In the clutch control state, the split mode is switched to the belt mode when the instruction value of the PL1 pressure supplied to the clutch C1 becomes the minimum and the instruction value of the PL2 pressure supplied to the clutch C2 becomes the maximum. When the clutch control state is not switched to the belt mode (step S9: NO), the range contact abnormality processing is once ended, and then the range contact abnormality processing is started again.

  When the clutch control state is switched to the belt mode (YES in step S9), it is determined whether or not the fail safe state is "1" (step S10 in FIG. 7B). If the fail-safe state is not "1" (NO in step S10), then it is determined whether or not the fail-safe state is "2" (step S11 in FIG. 7C).

  When the fail-safe state is neither "1" nor "2" (NO in step S11), that is, when the fail-safe state is "0", it is determined whether the clutch C2 is engaged (FIG. 7D). Step S12). Whether or not the clutch C2 is engaged can be determined from the actual current value supplied to the SL2 solenoid valve 104 and the differential rotation generated in the clutch C2. For example, when the SR switch valve 105 is on and the actual current value supplied to the SL2 solenoid valve 104 is equal to or greater than the threshold value, the SL2 pressure output from the SL2 solenoid valve 104 causes the clutch C2 to be engaged. It can be estimated that Further, when the differential rotation occurring in the clutch C2 is less than or equal to the threshold value, it can be estimated that the clutch C2 is engaged. Therefore, for example, when the actual current value supplied to the SL2 solenoid valve 104 is equal to or greater than the threshold value and the differential rotation occurring in the clutch C2 is equal to or less than the threshold value, it is determined that the clutch C2 is engaged. It The differential rotation that occurs in the clutch C2 is the difference between the rotation of the output shaft 32 and the rotation of the secondary shaft 42. In the ECU 91, the rotation speed of the output shaft 32 is calculated from the detection signal of the output rotation sensor 93, and the rotation speed of the secondary shaft 42 is calculated from the detection signal of the secondary rotation sensor 94.

  Further, it is determined whether or not the vehicle speed of the vehicle 1 is equal to or higher than a predetermined reverse inhibit vehicle speed (step S12). Since the frequency of the detection signal (pulse signal) of the output rotation sensor 93 corresponds to the vehicle speed, the vehicle speed is calculated from the frequency of the detection signal.

  When the clutch C2 is engaged (YES in step S12), a current having a predetermined value is supplied to the SL2 solenoid valve 104 regardless of the vehicle speed (step S13). The predetermined value is set to a current value sufficient for the SL2 solenoid valve 104 to output the SL2 pressure required to engage the clutch C2, for example, the maximum current value that can be supplied to the SL2 solenoid valve 104. Since the clutch C2 is engaged, the D pressure is output from the manual valve 101, and the shift lever is in the D position. Since the D pressure output from the manual valve 101 is supplied to the SL2 solenoid valve 104, the SL2 solenoid valve 104 can output the SL2 pressure required for engaging the clutch C2 by supplying a current of a predetermined value. Is. After that, the fail-safe state "1" is stored in the built-in memory of the ECU 91 (step S14), and the range contact abnormality processing is ended.

  Even if the clutch C2 is not engaged, if the vehicle speed is equal to or higher than the reverse inhibit vehicle speed (YES in step S12), the SL2 solenoid valve 104 is supplied with a current having a predetermined value (step S13). At this time, no current is supplied to the SR switch valve 105, and the SR switch valve 105 is in the off state. Since the SR switch valve 105 is off, even if the R pressure is output from the manual valve 101, the R pressure is not input to the fail-safe valve 108 and the R pressure is not supplied to the brake B1. Therefore, when the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the brake B1 is not engaged even if the shift lever is moved to the R position.

  When the clutch C2 is not engaged and the vehicle speed is lower than the reverse inhibit vehicle speed (NO in step S12), the SL2 solenoid valve 104 is supplied with a current of a predetermined value and the SR switch valve 105 is supplied. Electric current is supplied (step S15). The predetermined value is set to a current value sufficient for the SL2 solenoid valve 104 to output the SL2 pressure required to engage the clutch C2, for example, the maximum current value that can be supplied to the SL2 solenoid valve 104. By supplying the current to the SR switch valve 105, the SR switch valve 105 is turned on, and the hydraulic pressure is output from the SR switch valve 105. After that, the fail-safe state "2" is stored in the built-in memory of the ECU 91 (step S16), and the range contact abnormality processing is ended.

  When the range contact abnormality process is performed again and the range contact abnormality has occurred (YES in step S1 of FIG. 7A), and the clutch control state is the belt mode (YES in step S9), the fail safe state is " 1 ”(YES in step S10 of FIG. 7B), it is determined whether or not the clutch C2 is engaged, and also it is determined whether or not the vehicle speed is equal to or higher than the reverse inhibit vehicle speed (step S17). ..

  If the clutch C2 is engaged or the vehicle speed is equal to or higher than the reverse inhibit vehicle speed (YES in step S12), the SL2 solenoid valve 104 is supplied with a current having a predetermined value (step S18). At this time, no current is supplied to the SR switch valve 105, and the SR switch valve 105 is in the off state. Therefore, even if the shift lever is moved to the R position, the R pressure output from the manual valve 101 is not supplied to the brake B1 and the brake B1 is not engaged. In this case, the fail-safe state "1" is stored in the built-in memory of the ECU 91 (step S19), and the range contact abnormality processing ends.

  When the clutch C2 is not engaged and the vehicle speed is lower than the reverse inhibit vehicle speed (NO in step S17), the SL2 solenoid valve 104 is supplied with a current of a predetermined value and the SR switch valve 105 is supplied. Electric current is supplied (step S20). The predetermined value is set to a current value sufficient for the SL2 solenoid valve 104 to output the SL2 pressure required to engage the clutch C2, for example, the maximum current value that can be supplied to the SL2 solenoid valve 104. By supplying the current to the SR switch valve 105, the SR switch valve 105 is turned on, and the hydraulic pressure is output from the SR switch valve 105. After that, the fail-safe state "2" is stored in the built-in memory of the ECU 91 (step S21), and the range contact abnormality processing is ended.

  When the range contact abnormality process is performed again and the range contact abnormality has occurred (YES in step S1 of FIG. 7A), and the clutch control state is the belt mode (YES in step S9), the fail safe state is " 2 "(YES in step S11 of FIG. 7C), it is determined whether the brake B1 is engaged, and whether the vehicle speed is equal to or higher than the value obtained by adding a predetermined hiss vehicle speed to the reverse inhibit vehicle speed. It is determined whether or not (step S22). Further, it is determined whether or not the clutch C2 is engaged (step S22).

  If the brake B1 is engaged, the vehicle speed is less than a value obtained by adding a predetermined hiss vehicle speed to the reverse inhibit vehicle speed, or if the clutch C2 is not engaged (NO in step S22), the SL2 solenoid A current having a predetermined value is supplied to the valve 104 and the SR switch valve 105 is kept supplied with the current (step S23). Then, the range contact abnormality processing is ended while the fail-safe state "2" is stored in the built-in memory of the ECU 91 (step S24).

  When the brake B1 is not engaged and the vehicle speed is equal to or higher than the value obtained by adding the predetermined His vehicle speed to the reverse inhibit vehicle speed (YES in step S22), the SL2 solenoid valve 104 is supplied with a predetermined current value. The current supply to the SR switch valve 105 is stopped as it is (step S25). By stopping the supply of the current to the SR switch valve 105, the SR switch valve 105 is switched from on to off. Therefore, thereafter, even if the shift lever is moved to the R position, the R pressure output from the manual valve 101 is not supplied to the brake B1 and the brake B1 is not engaged. In this case, the fail-safe state "1" is stored in the built-in memory of the ECU 91 (step S26), and the range contact abnormality processing ends.

<Effect>
As described above, in the normal state where the range contact abnormality does not occur, the SR switch valve 105, the SL1 solenoid valve 103, and the SL2 solenoid valve 104 can be normally controlled based on the range contact signal.

  On the other hand, when the range contact abnormality has occurred, the SR switch valve 105, the SL1 solenoid valve 103 and the SL2 solenoid valve 104 cannot be normally controlled based on the range contact signal, and the brake B1 and the clutch C2 are not operated by the manual valve 101. May not be engaged / disengaged depending on the position.

  Therefore, when it is determined that the range contact abnormality has occurred, it is further determined whether the clutch C2 is engaged, and whether the vehicle speed of the vehicle 1 is equal to or higher than or equal to the reverse inhibit vehicle speed. Further judgment is made.

  When the clutch C2 is engaged, the SL2 solenoid valve 104 is controlled so that the SL2 pressure that engages the clutch C2 is output with the SR switch valve 105 turned off regardless of the vehicle speed. At this time, since the manual valve 101 is located at the forward position, the SL2 pressure for engaging the clutch C2 can be output from the SL2 solenoid valve 104. Since the engagement of the clutch C2 is maintained by holding the SR switch valve 105 in the OFF state, even if the range contact abnormality occurs, the vehicle 1 is driven by the forward power output from the transmission 4. It is possible to continue traveling forward.

  Even when the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the SL2 solenoid valve 104 is controlled so that the SL2 pressure for engaging the clutch C2 is output while the SR switch valve 105 is off. Since the SR switch valve 105 is off, even if the manual valve 101 is moved to the reverse position and the R pressure is output from the manual valve 101, the R pressure output from the manual valve 101 is applied to the brake B1. Not supplied. As a result, when the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the engagement of the brake B1 can be suppressed, that is, the reverse inhibit state can be realized.

  On the other hand, when the clutch C2 is not engaged, that is, the clutch C2 is released and the vehicle speed is lower than the reverse inhibit vehicle speed, the SR switch valve 105 is in the on state and the clutch C2 is engaged. The SL2 solenoid valve 104 is controlled so that the SL2 pressure to be output is output. Therefore, when the manual valve 101 is in the forward position, the SL2 pressure output from the SL2 solenoid valve 104 is supplied to the clutch C2 and the clutch C2 is engaged, so that the forward direction output from the transmission 4 is applied. The vehicle 1 can be driven forward by power. When the manual valve 101 is in the reverse position, the R pressure output from the manual valve 101 is supplied to the brake B1 and the brake B1 is engaged, so that the vehicle is driven by the reverse power output from the transmission 4. 1 can be run backwards.

  Since the position of the manual valve 101 corresponds to the position of the shift lever (select lever) arranged in the vehicle interior of the vehicle 1, the position detection means directly detects the position of the manual valve 101. Alternatively, the position of the shift lever may be detected.

  After determining that the range contact abnormality has not occurred, the control means controls the SL2 solenoid valve 104 so that the SL2 pressure for engaging the clutch C2 is output while the SR switch valve 105 is on, It is determined whether or not the brake B1 is engaged, whether or not the vehicle speed is equal to or greater than or equal to a value obtained by adding a predetermined His vehicle speed to the reverse inhibit vehicle speed, and whether or not the clutch C2 is engaged. If the brake B1 is not engaged and the vehicle speed is equal to or higher than the value obtained by adding the His vehicle speed to the reverse inhibit vehicle speed, or if it is determined that the clutch C2 is engaged, the SR switch valve 105 is turned on. The SL2 solenoid valve 104 may be controlled so that the SL2 pressure for engaging the clutch C2 is output by switching from ON to OFF.

  As a result, when the brake B1 is engaged, the SR switch valve 105 is held on, so that the engagement of the brake B1 is maintained and the vehicle speed is equal to or higher than the value obtained by adding the hiss vehicle speed to the reverse inhibit vehicle speed. Even if the vehicle 1 goes up, the reverse running of the vehicle 1 can be continued. On the other hand, in the state where the brake B1 is not engaged, that is, in the state where the brake B1 is released, when the vehicle speed increases above the value obtained by adding the His vehicle speed to the reverse inhibit vehicle speed, or the clutch C2 is engaged. In this case, since the SR switch valve 105 is switched from ON to OFF, the engagement of the brake B1 can be suppressed, that is, the reverse inhibit state can be realized while the vehicle 1 is traveling forward at a vehicle speed equal to or higher than the reverse inhibit vehicle speed.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms.

  For example, in the above-described embodiment, the single ECU 91 controls the hydraulic circuit 92 of the engine 2 and the torque converter 3 and the CVT 4, but the engine 2 and the hydraulic circuit 92 are controlled by different ECUs. Good.

  Further, although the power split type (torque split type) transmission is taken as the transmission 4, the present invention is not limited to the power split type transmission, but may be a continuously variable transmission (CVT) or a continuously variable transmission. The present invention can be applied to various types of automatic transmissions such as a stepped automatic transmission (AT).

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1: Vehicle 4: Transmission 91: ECU (control means)
92: Hydraulic circuit 96: Shift position sensor (position detecting means)
101: Manual valve 103: SL1 solenoid valve (first valve)
104: SL2 solenoid valve (second valve)
105: SR switch valve (switch valve)
B1: Brake (first engaging element)
C2: Clutch (second engagement element)

Claims (1)

Disengagement of the first engagement element and engagement of the second engagement element outputs power in a direction for advancing the vehicle, and engagement of the first engagement element and release of the second engagement element cause A mechanism configured to output power in a direction for moving the vehicle backward,
Manual valve, switch valve that outputs / stops hydraulic pressure according to ON / OFF, first valve that outputs hydraulic pressure that controls engagement / release of the first engagement element, and engagement / disengagement of the second engagement element When the switch valve is on and the manual valve is in the forward position, the hydraulic pressure output from the second valve is included in the second engaging element. When supplied, the switch valve is on, and the manual valve is in the reverse position, the hydraulic pressure output from the manual valve is supplied to the first engagement element to engage the first engagement element. Output from the manual valve when the switch valve is off and the manual valve is in the forward position. Is supplied to the second engagement element, the second engagement element is engaged, the switch valve is off, and the manual valve is in the reverse position. A control device for an automatic transmission, comprising: a hydraulic circuit configured to supply an output hydraulic pressure to the first engagement element,
Position detecting means for outputting a range contact signal according to the position of the manual valve,
Including control means,
The control means is
The range contact signal is abnormal to determine whether there is a range contact abnormality,
When it is determined that the range contact abnormality has not occurred, the switch valve, the first valve and the second valve are controlled based on the range contact signal,
When it is determined that the range contact abnormality has occurred, it is determined whether the second engagement element is engaged, and whether the vehicle speed of the vehicle is equal to or higher than a predetermined reverse inhibit vehicle speed or less. Further judge whether,
When it is determined that the second engagement element is engaged, or when the vehicle speed is equal to or higher than the reverse inhibit vehicle speed, the second engagement is performed while the switch valve is off. Controlling the second valve to output hydraulic pressure for engaging the elements,
When it is determined that the second engagement element is not engaged and the vehicle speed is less than the reverse inhibit vehicle speed, the switch valve is in the ON state, and the second engagement element is A control device for controlling the second valve so that a hydraulic pressure for engaging the valve is output.

Images