JP2008069907A - Vehicular automatic transmission and control device for vehicular automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid over-revolution of an intermediate rotary element in a control device for a vehicular automatic transmission including a change gear mechanism including at least two planetary mechanisms and the intermediate rotary element connecting those structure elements. <P>SOLUTION: The control device for the vehicular automatic transmission executes gear change process securing an arbitrary gear position by controlling a hydraulic control device, detects rotation speed NM of the intermediate rotary element (S10), and executes a process performing fuel cut of an engine when the detection value gets to a predetermined threshold X or higher. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for an automatic transmission for a vehicle and an automatic transmission for a vehicle. In particular, the automatic transmission for a vehicle includes a transmission mechanism having at least two planetary mechanisms and an intermediate rotation element that connects the components, and this configuration is a premise of the present invention.

  2. Description of the Related Art Conventionally, there is an automatic transmission for a vehicle in which a plurality of gear planetary mechanisms are combined to perform a multi-stage shift (see, for example, Patent Document 1).

  The speed change mechanism in this vehicle automatic transmission includes three gear type planetary mechanisms, an intermediate rotation element that connects the components of the two gear type planetary mechanisms arranged upstream in the power transmission direction, and three gears. The structure includes a plurality of hydraulic engagement elements for establishing an appropriate power transmission path, that is, a gear position by switching the operation of the components of the planetary planetary mechanism and the intermediate rotation element.

  The hydraulic engagement element includes appropriate components in the three-gear planetary mechanism, a brake that makes the intermediate rotation element in a rotatable engagement state or a non-rotatable release state, and an engagement that can rotate integrally between the elements. The clutch is configured to be in a combined state or in a released state that allows relative rotation.

  The plurality of hydraulic engagement elements are individually driven by a hydraulic control device having the same number of linear solenoid valves. The linear solenoid valve is of a normally closed type, and opens the valve by supplying a voltage to the solenoid, and applies hydraulic pressure to the hydraulic engagement element to bring it into an engaged state.

  In this type of vehicle automatic transmission, so-called power-on / downshift may be performed. This power-on / downshift is, for example, changing the currently selected shift stage to a lower shift stage while the vehicle is traveling, and increasing the engine speed to accelerate the vehicle travel speed.

When this power-on / downshift is performed, in order to change from the current gear position to the lower gear position, the engagement of unnecessary hydraulic engagement elements is released and the necessary hydraulic engagement elements are engaged. It is necessary to match.
JP 2003-287122 A

  In the above conventional example, when performing a power-on / downshift, for example, the hydraulic engagement element (clutch or brake) related to the power-on / downshift is turned off, and the solenoid of the linear solenoid valve necessary for driving the hydraulic engagement element is turned off. If it becomes impossible to engage due to a failure, it may become in a neutral state (a state in which rotational power cannot be transmitted to the output), and the engine speed will rise rapidly and blow up, and accordingly the speed change mechanism There is a possibility that a situation (over lev) may occur in which the intermediate rotation element of the part rapidly rises until it exceeds the rev limit (maximum allowable rotation speed).

  Temporarily, it is also possible to take measures such as detecting the off-failure and stopping the speed change operation, for example. However, since this off-failure detection cannot be performed directly, there is a concern that it will take a long time to detect an off-fault, such as the need to monitor the presence or absence of a specific phenomenon caused by an off-fault. The For this reason, there is a possibility that the intermediate rotating element may be over-revised during the period required for this detection.

  For reference, conventionally, a technique (see Japanese Patent Application Laid-Open No. 5-44551) for avoiding engine overrev by performing fuel cut on the engine when the engine speed exceeds an appropriate rev limit has been proposed. ing.

  This prior art is merely for preventing overlevation of the engine, and is not for preventing overlevation of the intermediate rotation element provided in the transmission mechanism portion of the automatic transmission for vehicles as in the present invention.

  The present invention relates to a control device for an automatic transmission for a vehicle that includes a transmission mechanism having at least two planetary mechanisms and intermediate rotation elements that connect the components thereof. The aim is to avoid overrevs.

  More specifically, the present invention engages a hydraulic engagement element when an off-failure occurs in which a normally closed linear solenoid valve of a hydraulic control apparatus that controls a shift operation of an automatic transmission for a vehicle remains closed. An object of the present invention is to prevent over-revolution of an intermediate rotation element provided in a transmission mechanism even if a power-on / downshift is performed in a situation where it is impossible.

  The present invention relates to a transmission mechanism having at least two planetary mechanisms installed from an input shaft to an output shaft, and intermediate rotation elements for connecting appropriate components of the planetary mechanisms, and appropriate shifting in the transmission mechanism. A control device for an automatic transmission for a vehicle having a hydraulic control device that controls operations of a plurality of hydraulic engagement elements for establishing a gear, and controls the hydraulic control device to secure an arbitrary gear speed The speed change process is performed, the rotation speed of the intermediate rotation element is detected, and when the detected value exceeds a predetermined threshold value, the process of performing fuel cut on the engine is performed.

  According to this configuration, when a situation occurs in which the rotation speed of the intermediate rotation element included in the speed change mechanism portion suddenly increases, by performing a fuel cut on the engine, the rotation increase of the intermediate rotation element is limited. Is forced to descend. As a result, it is possible to avoid an excessive load from acting on the transmission mechanism regardless of the cause of the excessive rotation increase of the intermediate rotation element.

  Preferably, the threshold value is specified based on a predetermined rev limit defined for the intermediate rotation element.

  According to this configuration, if the rev limit of the intermediate rotation element is set to the number of revolutions of the breakage limit, the threshold value can be specified lower than the rev limit in anticipation of an appropriate margin. Therefore, as described above, even when the rotation of the intermediate rotation element suddenly increases and reaches the threshold value, the intermediate rotation element can be surely avoided from being damaged.

  Preferably, the hydraulic control device includes a normally closed type linear solenoid valve that is equal in number to the number of the hydraulic engagement elements used and that individually applies hydraulic pressure to the plurality of hydraulic engagement elements. It is said.

  According to this configuration, when the power-on downshift is performed in a situation where the solenoid-off failure of the linear solenoid valve, that is, the corresponding hydraulic engagement element cannot be engaged, the neutral state ( (The state in which the rotational power cannot be transmitted to the output), and the number of rotations of the intermediate rotation element can rapidly increase. When such a situation occurs, it is possible to limit the increase in rotation of the intermediate rotation element and decrease the rotation speed by the above-described countermeasure according to the present invention.

  Preferably, the one planetary mechanism arranged on the upstream side in the power transmission direction is a double pinion type geared planetary mechanism, the input shaft is connected to the carrier, and the downstream in the power transmission direction. The other planetary mechanism arranged on the side is a Ravigneaux type geared planetary mechanism, the output shaft is connected to the ring gear, and the intermediate rotation element is arranged at one end side in the axial direction of the Ravinio type gear. The large-diameter sun gear in the planetary planetary mechanism is integrally connected, and is arranged on the outer diameter side of the ring gear in the double-pinion type gear-type planetary mechanism, and then the hydraulic engagement elements are respectively connected to the ring gear and the carrier. And a state in which they can rotate integrally or through a clutch.

  As in this configuration, the configuration of the transmission mechanism can be specifically specified.

  Further, the present invention provides at least two planetary mechanisms installed from the input shaft to the output shaft, a transmission mechanism unit having an intermediate rotation element that connects between appropriate components of each planetary mechanism, and a transmission mechanism unit as appropriate. For a vehicle including a hydraulic control device that controls the operation of a plurality of hydraulic engagement elements for establishing a gear position, and a control device that performs a shift process for controlling the hydraulic control device to secure an arbitrary gear position In the automatic transmission, the hydraulic engagement element includes a brake that makes appropriate components of the planetary mechanisms rotatable or non-rotatable, and two components of the planetary mechanisms. It has a clutch that can be rotated integrally or in a relatively rotatable state, and the control device is configured as described above.

  In this configuration, the automatic transmission for a vehicle is an object of the invention, and can be dealt with by the control device as described above. Therefore, it is possible to contribute to the improvement of durability and reliability of the automatic transmission for a vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the overrev of the intermediate | middle rotation element with which the transmission mechanism part of the automatic transmission for vehicles is equipped can be avoided. As a result, an excessive load is not applied to the vehicle automatic transmission, which can contribute to improving the durability and reliability of the vehicle automatic transmission.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 21 show an embodiment of the present invention.

  First, prior to the description of the features of the present invention, the configuration of the vehicle automatic transmission 1 to which the features of the present invention are applied will be described.

  FIG. 1 is a diagram showing a schematic configuration of a vehicle power train using a vehicular automatic transmission 1 to be used in the present invention, and FIG. 2 is a skeleton diagram showing an example of the vehicular automatic transmission 1 of FIG. FIG. 3 is a perspective view schematically showing the transmission mechanism unit 3 of FIGS. 1 and 2.

  An automatic transmission 1 for a vehicle shown in FIG. 1 mainly includes a torque converter 2 as a fluid transmission device, a transmission mechanism unit 3, a hydraulic control device 4, a transmission control device 5, and an oil pump 6, and includes eight forward speeds and two reverse gears. It is configured to be able to change gears.

  In FIG. 1, 7 is an engine (internal combustion engine), and 8 is an engine control device that controls the operation of the engine 7. The engine control device 8 is connected to the transmission control device 5 so as to be able to transmit and receive each other. A powertrain is configured including the vehicular automatic transmission 1 and the engine 7.

  The torque converter 2 is rotationally connected to the engine 7 and includes a pump impeller 21, a turbine runner 22, a stator 23, a one-way clutch 24, a stator shaft 25, and a lockup clutch 26.

  The one-way clutch 24 supports the stator 23 while allowing the stator 23 to rotate only in one direction on the case 1a of the transmission mechanism unit 3. The stator shaft 25 fixes the inner race of the one-way clutch 24 to the case 1a. The lockup clutch 26 directly connects the pump impeller 21 and the turbine runner 22.

  The speed change mechanism 3 shifts the rotational power input from the torque converter 2 to the input shaft 9 and outputs it to the output shaft 10. As shown in FIGS. 2 and 3, the front planetary 31 and the rear planetary 32 are provided. And an intermediate drum 33 as an intermediate rotation element, first to fourth clutches C1 to C4, and first and second brakes B1 and B2.

  The front planetary 31 is a gear type planetary mechanism called a double pinion type, and includes a first sun gear S1, a first ring gear R1, a plurality of inner pinion gears P1, and a plurality of outer pinion gears P2. The configuration includes the first carrier CA1.

  The first sun gear S1 is fixed to the case 1a and cannot be rotated, and the first ring gear R1 can be rotated integrally with the intermediate drum 33 via the third clutch C3 or in a relatively rotatable state. The first sun gear S1 is supported concentrically on the inner diameter side of the first ring gear R1.

  The plurality of inner pinion gears P1 and the plurality of outer pinion gears P2 are interposed at several circumferential positions in the opposed annular space between the first sun gear S1 and the first ring gear R1. P1 is meshed with the first sun gear S1, and the plurality of outer pinion gears P2 are meshed with the inner pinion gear P1 and the first ring gear R1.

  The first carrier CA1 rotatably supports both pinion gears P1, P2, and the central shaft portion of the first carrier CA1 is integrally connected to the input shaft 9, and both the pinion gears P1 in the first carrier CA1. , P2 are supported by the intermediate drum 33 via the fourth clutch C4 so as to be integrally rotatable or relatively rotatable.

  The intermediate drum 33 is rotatably disposed on the outer diameter side of the first ring gear R1, and is supported by the case 1a via the first brake B1 so as not to rotate or to be relatively rotatable. Yes.

  The rear planetary 32 is a gear-type planetary mechanism called a Ravinio type, and includes a large-diameter second sun gear S2, a small-diameter third sun gear S3, a second ring gear R2, a plurality of short pinion gears P3, The configuration includes a plurality of long pinion gears P4 and a second carrier CA2.

  The second sun gear S2 is connected to the intermediate drum 33, and the third sun gear S3 is connected to the first ring gear R1 of the front planetary 31 via the first clutch C1 so as to be integrally rotatable or relatively rotatable. The two ring gear R2 is integrally connected to the output shaft 10.

  The plurality of short pinion gears P3 are meshed with the third sun gear S3, and the plurality of long pinion gears P4 are meshed with the second sun gear S2 and the second ring gear R2 and are connected via the short pinion gear P3. 3 meshed with sun gear S3.

  Further, the second carrier CA2 rotatably supports a plurality of short pinion gears P3 and a plurality of long pinion gears P4, and a central shaft portion thereof is coupled to the input shaft 9 via the second clutch C2. The support shafts that support the pinion gears P3 and P4 in the second carrier CA2 are supported by the case 1a via the second brake B2 and the one-way clutch F1.

  The first to fourth clutches C1 to C4 and the first and second brakes B1 and B2 correspond to the hydraulic engagement elements recited in the claims, and here, wet using oil viscosity It is a multi-plate friction engagement device.

  The first clutch C1 is configured to bring the third sun gear S3 of the rear planetary 32 into an engaged state in which the third sun gear S3 can rotate integrally with the first ring gear R1 of the front planetary 31 or a released state in which relative rotation is possible.

  The second clutch C <b> 2 sets the second carrier CA <b> 2 of the rear planetary 32 in an engaged state in which the second carrier CA <b> 2 can rotate integrally with the input shaft 9 or in a released state in which relative rotation is possible.

  The third clutch C <b> 3 sets the first ring gear R <b> 1 of the front planetary 31 to an engaged state in which the first ring gear R <b> 1 can rotate integrally with the intermediate drum 33 or a released state in which relative rotation is possible.

  The fourth clutch C <b> 4 sets the first carrier CA <b> 1 of the front planetary 31 to an engaged state where the first carrier CA <b> 1 can rotate integrally with the intermediate drum 33 or a released state which allows relative rotation.

  The first brake B1 integrates the intermediate drum 33 with respect to the case 1a of the vehicle automatic transmission 1 so as to be in a non-rotatable engaged state or a relatively rotatable disengaged state.

  The second brake B <b> 2 integrates the second carrier CA <b> 2 of the rear planetary 32 with respect to the case 1 a so as to be in a non-rotatable engaged state or a relatively rotatable disengaged state.

  The one-way clutch F1 allows rotation of the rear planetary 32 in only one direction of the second carrier CA2.

  The hydraulic control device 4 controls the speed change operation of the speed change mechanism unit 3, and mainly includes a pressure control valve 41, a manual valve 42, and a plurality of linear solenoid valves SLC1, SLC2, SLC3, SLC4 as shown in FIG. The configuration includes SLB1, B2 control valve 44, cutoff valves 45, 46, 47 as fail-safe valves, switching valves 48, 49, and the like.

  The pressure control valve 41 controls the hydraulic pressure from the oil pump 6 to a predetermined line pressure and supplies it to the port PL of the manual valve 42.

  The manual valve 42 is appropriately connected to the linear solenoid valves SLC1, SLC2, SLC3, SLC4 from the port D in order to secure a neutral range N, forward travel range D or reverse travel range R corresponding to the operation of the shift lever by the driver. The hydraulic pressure is supplied to the SLB 1 and from the port R to the B2 control valve 44.

  The plurality of linear solenoid valves SLC1, SLC2, SLC3, SLC4, and SLB1 individually drive the first to fourth clutches C1 to C4 and the first brake B1 in the transmission mechanism unit 3, and the basic configuration thereof is a known configuration Therefore, detailed illustration and explanation are omitted here.

  In addition, the meaning of the code | symbol of linear solenoid valve SLC1, SLC2, SLC3, SLC4, SLB1 is a reference code which shows each hydraulic-type engagement element (1st-4th clutch C1-C4 and 1st brake B1) respectively corresponding. It is displayed after SL.

  The solenoids (reference numerals omitted) of the linear solenoid valves SLC1, SLC2, SLC3, SLC4, and SLB1 are operated in response to a control signal (control current) supplied from the transmission control device 5, and a valve body (not shown) is operated. Move to a position that balances with the spring force of the compression spring, and open and close the necessary ports.

  The B2 control valve 44 drives the second brake B2.

  The first cut-off valve 45 is interposed between the first clutch C1 and the linear solenoid valve SLC1, and when the hydraulic pressure is supplied to the two input ports, the first cut-off valve 45 passes through the output port from the linear solenoid valve SLC1. Thus, the hydraulic pressure supplied to the first clutch C1 is cut off, and the fail-safe valve is discharged from the drain port into the case 1a.

  The second cutoff valve 46 is interposed between the fourth clutch C4 and the linear solenoid valve SLC4, and when the hydraulic pressure is supplied from the linear solenoid valve SLC3 to a single input port, the linear solenoid valve SLC4. Is configured as a fail-safe valve that shuts off the hydraulic pressure supplied to the fourth clutch C4 from the drain port and discharges it from the drain port into the case 1a.

  The third cutoff valve 47 is interposed between the first brake B1 and the linear solenoid valve SLB1, and when hydraulic pressure is supplied from the linear solenoid valve SLC3 or SLC4 to one of the two input ports. The hydraulic pressure supplied from the linear solenoid valve SLB1 to the first brake B1 via the output port is shut off, and the failsafe valve is discharged from the drain port into the case 1a.

  The switching valves 48 and 49 are disposed in series between the linear solenoid valve SLB1 and one input port of the first cut-off valve 45.

  The two input ports of the first switching valve 48 are connected in parallel with the hydraulic piping of the linear solenoid valve SLB1 and the hydraulic piping of the linear solenoid valve SLC4. The two input ports of the second switching valve 49 are connected in parallel with the output piping of the first switching valve 48 and the hydraulic piping of the linear solenoid valve SLC3. The first and second switching valves 48 and 49 are configured to output the supplied hydraulic pressure from the output port when hydraulic pressure is supplied to one of the input ports.

  The transmission control device 5 controls the hydraulic control device 4 to establish an appropriate shift stage, that is, a power transmission path in the transmission mechanism unit 3, and is generally a known ECU (Electronic Control Unit).

  That is, the transmission control device 5 includes a central processing unit (CPU) 51, a read only memory (ROM) 52, a random access memory (RAM) 53, a backup RAM 54, an input interface 55, as shown in FIG. The output interface 56 is connected to each other by a bidirectional bus 57.

  The engine control device 8 has the same hardware configuration as the transmission control device 5.

  The CPU 51 executes arithmetic processing based on various control programs and control maps stored in the ROM 52. The ROM 52 stores various control programs for controlling the speed change operation of the speed change mechanism unit 3 and the fail safe operation to which the features of the present invention are applied. The fail safe operation will be described in detail later. The RAM 53 is a memory that temporarily stores calculation results in the CPU 51, data input from each sensor, and the like. The backup RAM 54 is a non-volatile memory that stores various data to be saved.

  Connected to the input interface 55 are at least an engine speed sensor 11, an input shaft speed sensor 12, an output shaft speed sensor 13, a range position sensor 14, a throttle opening sensor 15, an intermediate drum speed sensor 16, and the like. Yes. Further, at least the components of the hydraulic control device 4 (pressure control valve 41, manual valve 42, linear solenoid valves SLC1, SLC2, SLC3, SLC4, SLB1, B2 control valve 44) are connected to the output interface 56. .

  The engine speed sensor 11 detects the engine speed NE of the torque converter 2 to which the engine speed is transmitted. The input shaft rotational speed sensor 12 detects the rotational speed NT of the input shaft 9. The output shaft rotational speed sensor 13 detects the rotational speed NO of the output shaft 10. The range position sensor 14 sends out a detection signal when the manual valve 42 is shifted to the forward travel range D and the neutral range N. The throttle opening sensor 15 detects the amount of accelerator depression. The intermediate drum rotation speed sensor 16 detects the rotation speed NM of the intermediate drum 33 of the transmission mechanism unit 3.

  Here, conditions for establishing the respective gear positions in the above-described transmission mechanism unit 3 will be described with reference to FIGS. 6 to 17.

  FIG. 6 is an engagement table showing the relationship between the engagement state or the disengagement state in the first to fourth clutches C1 to C4, the first and second brakes B1 and B2, and the one-way clutch F1, and the respective shift speeds. In this engagement table, ◯ indicates an “engaged state”, x indicates a “released state”, ◎ indicates an “engaged state during engine braking”, and Δ indicates an “engaged state only during driving”.

  FIG. 7 is a table showing the rotation state for each gear position in the components of the front planetary 31. In this figure, the counterclockwise direction when each component is viewed from the downstream side in the power transmission direction (right side of the drawing in FIG. 3) to the upstream side (left side in the drawing in FIG. 3) is set as the positive rotation direction, and the inner pinion gear P1. The rotation direction of the outer pinion gear P2 is indicated by the rotation direction with respect to the first carrier CA1.

  FIG. 8 is a table showing the rotation state for each gear position in the components of the rear planetary 32. In this figure, the counterclockwise direction when each component is viewed from the downstream side in the power transmission direction (the right side of the drawing in FIG. 3) to the upstream side (the left side in the drawing in FIG. 3) is set as the positive rotation direction, and the short pinion gear P3. The rotation direction of the long pinion gear P4 is indicated by the rotation direction with respect to the second carrier CA2.

  FIG. 9 shows the shift speeds (first speed to eighth speed, reverse first speed) established by engagement of the first to fourth clutches C1 to C4, the first and second brakes B1 and B2, and the one-way clutch F1. It is a speed diagram which shows the relationship between the rotation speed ratio of each component in two planetary 31 and 32 before and behind at that time (speed stage, reverse 2nd speed stage). In FIG. 9, each vertical axis direction is a speed ratio of each component in the two planetaries 31 and 32, and the interval between the vertical axes is set according to the gear ratio of each element. In addition, C1 to C4, B1, B2, and F1 are written at points where the first to fourth clutches C1 to C4, the first and second brakes B1 and B2, and the one-way clutch F1 are engaged. Further, the input 1 to the input 4 shown in FIG. 9 indicate the input position of the rotational power from the input shaft 9, and the output shown in FIG. 9 is the rotation output to the output shaft 10. The output position of power is shown.

  FIGS. 10 to 17 show hydraulic paths for establishing the first speed to the eighth speed in the hydraulic control device 4, respectively. In these figures, a dot pattern is given to the hydraulic pressure supplied from the linear solenoid valve to the clutch or brake.

(First gear: 1st)
The first speed 1st is established by engagement of the first clutch C1 and automatic engagement of the one-way clutch F1.

  That is, as shown in FIG. 10, only the hydraulic path from the linear solenoid valve SLC1 to the first clutch C1 is secured and the first clutch C1 is engaged.

  In this case, the engagement of the first clutch C1 allows the first ring gear R1 of the front planetary 31 and the third sun gear S3 of the rear planetary 32 to be rotated together, and the one-way clutch F1 automatically engages the rear. The rotation of the second carrier CA2 of the planetary 32 is stopped.

  Accordingly, the third sun gear S3 rotated from the first carrier CA1 directly connected to the input shaft 9 via the first ring gear R1, the second carrier CA2 prevented from reverse rotation by the one-way clutch F1, and free rotation is possible. With the engagement with the second sun gear S2, the second ring gear R2 and the output shaft 10 are rotated at the gear ratio of the first gear. The rotation direction is as shown in FIGS.

(2nd speed: 2nd)
The second speed stage 2nd is established by engagement of the first clutch C1 and the first brake B1.

  That is, as shown in FIG. 11, a hydraulic path from the linear solenoid valve SLC1 to the first clutch C1 is secured to engage the first clutch C1, and a hydraulic path from the linear solenoid valve SLB1 to the first brake B1 is set. Ensuring and engaging the first brake B1.

  In this case, first, the engagement of the first clutch C1 allows the first ring gear R1 of the front planetary 31 and the third sun gear S3 of the rear planetary 32 to rotate together, and the engagement of the first brake B1. As a result, the intermediate drum 33 and the second sun gear S2 of the rear planetary 32 are fixed to the case 1a so that they cannot rotate.

  Accordingly, the third sun gear S3 rotated from the first carrier CA1 directly connected to the input shaft 9 via the first ring gear R1, the second sun gear S2 made non-rotatable, and the second carrier capable of free rotation. Along with the meshing with CA2, the second ring gear R2 and the output shaft 10 are rotated at the gear ratio of the second speed stage.

(3rd speed: 3rd)
The third speed stage 3rd is established by engagement of the first clutch C1 and the third clutch C3.

  That is, as shown in FIG. 12, a hydraulic path from the linear solenoid valve SLC1 to the first clutch C1 is secured to engage the first clutch C1, and a hydraulic path from the linear solenoid valve SLC3 to the third clutch C3 is set. Ensuring and engaging the third clutch C3.

  In this case, first, the engagement of the first clutch C1 allows the first ring gear R1 of the front planetary 31 and the third sun gear S3 of the rear planetary 32 to rotate together, and the engagement of the third clutch C3. As a result, the first ring gear R1 of the front planetary 31 and the intermediate drum 33 and the second sun gear S2 of the rear planetary 32 can be rotated together.

  Accordingly, the second sun gear S2 and the third sun gear S3 rotated from the first carrier CA1 directly connected to the input shaft 9 via the first ring gear R1 and the intermediate drum 33, and the second carrier CA2 capable of free rotation. Along with the meshing, the second ring gear R2 and the output shaft 10 are rotated at the gear ratio of the third speed stage.

(4th speed: 4th)
The fourth speed stage 4th is established by engagement of the first clutch C1 and the fourth clutch C4.

  That is, as shown in FIG. 13, the hydraulic path from the linear solenoid valve SLC1 to the first clutch C1 is secured and the first clutch C1 is engaged, and the hydraulic path from the linear solenoid valve SLC4 to the fourth clutch C4 is set. Ensuring and engaging the fourth clutch C4.

  In this case, first, the engagement of the first clutch C1 allows the first ring gear R1 of the front planetary 31 and the third sun gear S3 of the rear planetary 32 to rotate together, and the engagement of the fourth clutch C4. Thus, the first carrier CA1 of the front planetary 31 and the intermediate drum 33 and the second sun gear S2 of the rear planetary 32 can be rotated together.

  Accordingly, the second sun gear S2 rotated through the first carrier CA1 and the intermediate drum 33 directly connected to the input shaft 9 and the first carrier CA1 directly connected to the input shaft 9 are rotated through the first ring gear R1. The second ring gear R2 and the output shaft 10 are rotated at a gear ratio of the fourth speed stage in accordance with the meshing of the third sun gear S3 and the second carrier CA2 that can freely rotate.

(5th gear: 5th)
The fifth speed stage 5th is established by engagement of the first clutch C1 and the second clutch C2.

  That is, as shown in FIG. 14, the hydraulic path from the linear solenoid valve SLC1 to the first clutch C1 is secured and the first clutch C1 is engaged, and the hydraulic path from the linear solenoid valve SLC2 to the second clutch C2 is set. Ensuring and engaging the second clutch C2.

  In this case, first, the engagement of the first clutch C1 allows the first ring gear R1 of the front planetary 31 and the third sun gear S3 of the rear planetary 32 to rotate together, and the engagement of the second clutch C2. Thus, the input shaft 9 and the second carrier CA2 of the rear planetary 32 can be rotated together.

  As a result, the third sun gear S3 rotated from the first carrier CA1 directly connected to the input shaft 9 via the first ring gear R1, the second sun gear S2 that can rotate freely, and the second sun gear S2 that rotates integrally with the input shaft 9. Along with the meshing with the carrier CA2, the second ring gear R2 and the output shaft 10 are rotated at the gear ratio of the fifth speed stage.

(6th speed: 6th)
The sixth speed stage 6th is established by engagement of the second clutch C2 and the fourth clutch C4.

  That is, as shown in FIG. 15, the hydraulic path from the linear solenoid valve SLC2 to the second clutch C2 is secured and the second clutch C2 is engaged, and the hydraulic path from the linear solenoid valve SLC4 to the fourth clutch C4 is set. Ensuring and engaging the fourth clutch C4.

  In this case, first, the input shaft 9 and the second carrier CA2 of the rear planetary 32 can be rotated together by the engagement of the second clutch C2, and the front planetary 31 is engaged by the engagement of the fourth clutch C4. The first carrier CA 1, the intermediate drum 33, and the second sun gear S 2 of the rear planetary 32 can be rotated together.

  Accordingly, the second sun gear S2 rotated through the first carrier CA1 and the intermediate drum 33 directly connected to the input shaft 9, the second carrier CA2 rotated integrally with the input shaft 9, and the third sun gear S3 capable of free rotation. , The second ring gear R2 and the output shaft 10 are rotated at the sixth gear ratio.

(7th gear: 7th)
The seventh speed stage 7th is established by engagement of the second clutch C2 and the third clutch C3.

  That is, as shown in FIG. 16, a hydraulic path from the linear solenoid valve SLC2 to the second clutch C2 is secured to engage the second clutch C2, and a hydraulic path from the linear solenoid valve SLC3 to the third clutch C3 is set. Ensuring and engaging the third clutch C3.

  In this case, first, the input shaft 9 and the second carrier CA2 of the rear planetary 32 can be integrally rotated by the engagement of the second clutch C2, and the front planetary 31 is engaged by the engagement of the third clutch C3. The first ring gear R 1, the intermediate drum 33, and the second sun gear S 2 of the rear planetary 32 can be rotated together.

  Thus, the second sun gear S2 rotated from the first carrier CA1 directly connected to the input shaft 9 via the first ring gear R1 and the intermediate drum 33, the second carrier CA2 rotated integrally with the input shaft 9, and the free Along with the meshing with the rotating third sun gear S3, the second ring gear R2 and the output shaft 10 are rotated at the gear ratio of the seventh speed stage.

(8th gear: 8th)
The eighth speed stage 8th is established by engagement of the second clutch C2 and the first brake B1.

  That is, as shown in FIG. 17, the hydraulic path from the linear solenoid valve SLC2 to the second clutch C2 is secured to engage the second clutch C2, and the hydraulic path from the linear solenoid valve SLB1 to the first brake B1 is set. Ensuring and engaging the first brake B1.

  In this case, first, the input shaft 9 and the second carrier CA2 of the rear planetary 32 can be rotated together by the engagement of the second clutch C2, and the intermediate drum 33 and the second brake CA are engaged by the engagement of the first brake B1. The second sun gear S2 of the rear planetary 32 is fixed to the case 1a and cannot rotate.

  As a result, the second carrier CA2 that rotates integrally with the input shaft 9, the intermediate drum 33 and the second sun gear S2 that are made non-rotatable, and the third sun gear S3 that is free to rotate are engaged with the second ring. The gear R2 and the output shaft 10 are rotated at the gear ratio of the eighth speed stage.

(Reverse first speed: R1)
The reverse first speed R1 is established by engagement of the third clutch C3 and the second brake B2.

  That is, although not shown, a hydraulic path from the linear solenoid valve SLC3 to the third clutch C3 is secured to engage the third clutch C3, and a hydraulic path from the B2 control valve 44 to the second brake B2 is secured. Then, the second brake B2 is engaged.

  In this case, first, the engagement of the third clutch C3 allows the first ring gear R1 of the front planetary 31 and the intermediate drum 33 and the second sun gear S2 of the rear planetary 32 to be integrally rotated. Due to the engagement of the brake B2, the second carrier CA2 of the rear planetary 32 is fixed to the case 1a and cannot rotate.

  Thus, the second sun gear S2 rotated from the first carrier CA1 directly connected to the input shaft 9 via the first ring gear R1 and the intermediate drum 33, the second carrier CA2 made non-rotatable, and free rotation With the engagement with the third sun gear S3, the second ring gear R2 and the output shaft 10 are rotated in reverse at the gear ratio of the reverse first speed.

(Reverse second speed: R2)
The second reverse speed R2 is established by engagement of the fourth clutch C4 and the second brake B2.

  That is, although not shown, a hydraulic path from the linear solenoid valve SLC4 to the fourth clutch C4 is secured to engage the fourth clutch C4, and a hydraulic path from the B2 control valve 44 to the second brake B2 is secured. Then, the second brake B2 is engaged.

  In this case, first, engagement of the fourth clutch C4 allows the first carrier CA1 of the front planetary 31 and the intermediate drum 33 and the second sun gear S2 of the rear planetary 32 to be integrally rotated, and the second brake. Due to the engagement of B2, the second carrier CA2 of the rear planetary 32 is fixed to the case 1a so that it cannot rotate.

  Thus, the second sun gear S2 rotated through the first carrier CA1 and the intermediate drum 33 directly connected to the input shaft 9, the second carrier CA2 made non-rotatable, and the third sun gear S3 that is free to rotate. As a result, the second ring gear R2 and the output shaft 10 are rotated in reverse at the gear ratio of the second reverse speed.

  Next, the part to which the feature of the present invention is applied, that is, the fail-safe operation by the transmission control device 5, will be described in detail with reference to the flowchart shown in FIG. 18 and the time chart shown in FIG.

  In the first place, if a power-on / downshift is performed, the clutch or brake for establishing the target power transmission path, that is, the gear position, will be off, and the linear solenoid valve for driving will remain closed. When the engagement becomes impossible due to the occurrence of the engine, a neutral state (a state in which the rotational power cannot be transmitted to the output) may occur, and the rotational speed of the engine 7 suddenly increases and blows up. There is a possibility that an overrev may occur such that the rotational speed of the intermediate drum 33 in the speed change mechanism unit 3 of the machine 1 suddenly increases and exceeds the rev limit RL.

  In the present invention, in consideration of such circumstances, the vehicle automatic transmission 1 is devised so as not to be damaged by preventing the intermediate drum 33 from being overrevised.

  Therefore, the rotational speed of the intermediate drum 33 is monitored, and when the rotational speed of the intermediate drum 33 increases to a predetermined threshold value X or more, fuel cut is performed on the engine 7 to limit the rotational increase of the engine 7. At the same time, the rotation of the intermediate drum 33 is restricted.

  Specifically, the fail-safe operation by the transmission control device 5 is performed on the engine 7 when it is determined that the rotational speed NM of the intermediate drum 33 is equal to or higher than a predetermined threshold value X based on input signals from the various sensors 11 to 16. When it is determined that the rotation speed NM of the intermediate drum 33 is less than a predetermined threshold value Y after the fuel cut is performed and the process of preventing the transmission mechanism unit 3 from being damaged by performing the fuel cut. A process for enabling the engine 7 to resume operation by releasing the fuel cut is performed.

  The threshold value X described above is specified as a value (RL−α) obtained by subtracting the margin α from the rev limit RL of the intermediate drum 33. As shown in FIG. 19B, the margin α is set to be larger than the overshoot due to the inertial rotation of the intermediate drum 33 after the fuel cut. That is, in order to prevent the intermediate drum 33 from reaching the rev limit RL even if the intermediate drum 33 overshoots when the fuel cut is performed after the rotational speed NM of the intermediate drum 33 reaches the threshold value X, the overshoot is performed. It is preferable to determine the margin α as a margin allowing for the above.

  Further, the threshold value Y described above is specified as a value (X−β) obtained by subtracting the margin β from the threshold value X for performing the fuel cut. If the fuel cut return threshold value Y is set to be the same as the fuel cut threshold value X, the rotational speed NM of the intermediate drum 33 once overshoots and decreases with the fuel cut. When the engine speed is less than the threshold value X, the rotational speed NM of the intermediate drum 33 increases immediately after restarting the engine 7, and reaches the threshold value X again, so that the fuel cut must be performed again. There is a concern that the rotation of 33 will hunt. In order to avoid the occurrence of such a hunting phenomenon, the above-mentioned margin β is set.

  Specifically, the flowchart shown in FIG. 18 is a part of the main flowchart related to the shift control of the vehicle automatic transmission 1, and is repeated at regular intervals.

  First, when an entry is made in step S10, it is determined whether or not the rotational speed NM of the intermediate drum 33 is equal to or greater than a threshold value X. The rotational speed NM of the intermediate drum 33 is directly detected by the intermediate drum rotational speed sensor 16, and this detected value is input to the transmission control device 5.

  If it is determined that the rotational speed NM of the intermediate drum 33 is equal to or greater than the threshold value X, an affirmative determination is made in step S10 and the process proceeds to step S11, the fuel cut execution flag F for the engine 7 is turned on, In subsequent step S12, a command for causing the engine control device 8 to perform fuel cut on the engine 7 is sent, and the engine control device 8 causes fuel cut on the engine 7 to be performed. Thereafter, the process returns to the main flowchart.

  On the other hand, if it is determined that the rotational speed NM of the intermediate drum 33 is less than the threshold value X, a negative determination is made in step S10 and the process proceeds to step S13 to determine whether or not the fuel cut execution flag F is on. To do.

  If a negative determination is made in step S13, the process returns to the main flowchart. If an affirmative determination is made, the process proceeds to the subsequent step S14, where it is determined whether the rotational speed NM of the intermediate drum 33 is less than the threshold value Y.

  When a negative determination is made in step S14, the process returns to the main flowchart. However, when an affirmative determination is made, the process proceeds to subsequent step S15, the fuel cut execution flag F is turned off, and then in subsequent step S16, the engine. The control device 8 is instructed to release the fuel cut for the engine 7 and resume the operation of the engine 7, and the process returns to the main flowchart.

  For reference, for example, as shown in the time chart of FIG. 19, the speed NE of the engine 7 and the speed NM of the intermediate drum 33 are increased by the accelerator opening being fully opened by the driver at time t1. Will do. Thus, for example, if the rotational speed NM of the intermediate drum 33 reaches the threshold value X at time t2, the fuel cut execution flag F is turned on, and the fuel cut for the engine 7 is executed by the engine control device 8. As a result, the rotational speed NE of the engine 7 decreases, and the rotational speed NM of the intermediate drum 33 also decreases accordingly.

  Then, when the rotational speed NM of the intermediate drum 33 decreases and becomes less than the threshold value Y at time t3, the fuel cut execution flag F is turned off, and the fuel cut to the engine 7 is canceled by the engine control device 8.

  Specifically, for example, when the vehicle is running at the sixth speed, and the fifth speed is achieved by performing a power-on / downshift, the second clutch C2 is kept engaged to establish the fifth speed. It is necessary to disengage the fourth clutch C4 and engage the first clutch C1. When this speed change operation is normal, a speed alignment chart as shown in FIG. 20 is obtained.

  However, if the first clutch C1 cannot be engaged due to an OFF failure of the solenoid of the linear solenoid valve SLC1 for driving the first clutch C1 during the speed change process, the neutral state (outputs rotational power). Since the engine speed NE continues to rise, as shown by the two-dot chain line in FIG. 21, the second clutch CA2 can rotate integrally with the input shaft 9 as shown in FIG. As the rotation continues to rise, the second sun gear S2 and the intermediate drum 33 integral with the second sun gear S2 are excessively rotated at a higher speed, and the rotational speed NM of the intermediate drum 33 may exceed the rev limit RL. is expected.

  When such an abnormality occurs, if the engine speed NE reaches the engine rev limit, the relationship is such that the speed NM of the intermediate drum 33 exceeds the rev limit RL.

  Incidentally, the rotation speed NM of the intermediate drum 33 can be obtained by the following equation.

NM = (3a / a). (NT-NO) + NO
However, a is a constant specified by the structural calculation of the two planetaries 31 and 32, NT is the rotational speed of the input shaft 9 (≈engine rotational speed NE), and NO is the rotational speed of the output shaft 10.

  However, even in such a situation, according to the present embodiment, as shown by the thick solid line in FIG. 21, there is a margin before the rotational speed NM of the intermediate drum 33 and the rotational speed of the second sun gear S2 reach the rev limit RL. It is possible to detect the increase in rotation with α and to perform a fuel cut with respect to the engine 7 immediately to limit the increase in the rotation speed NM of the intermediate drum 33 to forcibly decrease it. Can do.

  Therefore, as described above, when the solenoid of the specific linear solenoid valve in the hydraulic control device 4 is in the off-failure state, the power-on / downshift is performed, whereby the rotational speed NE of the engine 7 and the rotation of the intermediate drum 33 are performed. Even if the number NM rises rapidly, it is possible to reliably prevent the intermediate drum 33 from being overlevated and to prevent an excessive load from acting on the transmission mechanism unit 3.

  In the above embodiment, as a situation where the rotational speed NM of the intermediate drum 33 rapidly increases, a case where a power-on / downshift from the sixth speed to the fifth speed is taken as an example. In the situation, it is possible to cope with the case where the sudden increase in the rotation of the intermediate drum 33 occurs in the same manner as described above.

  As described above, according to the embodiment to which the feature of the present invention is applied, the rotational speed NM of the intermediate drum 33 in the transmission mechanism 3 of the automatic transmission 1 for a vehicle is directly detected by the intermediate drum rotational speed sensor 16. Therefore, when a situation occurs in which the rotational speed NM of the intermediate drum 33 increases rapidly, the rotational speed NM of the intermediate drum 33 is forced by performing fuel cut on the engine 7 regardless of the cause of the occurrence. As a result, the durability and reliability of the vehicle automatic transmission 1 can be improved.

  In addition, this invention is not limited only to the said embodiment, Various application and deformation | transformation can be considered.

  In the above embodiment, an example in which the present invention is applied to the vehicle automatic transmission 1 set to eight forward speeds and two reverse speeds is given. However, in other vehicle automatic transmissions, the speed change mechanism unit 3 includes The present invention can be applied to any configuration that includes at least two planetaries and that is configured so that power can be transmitted between the planetary components by an intermediate rotation element (intermediate drum 33).

It is a figure which shows schematic structure of the powertrain of the vehicle using the automatic transmission for vehicles used as this invention. It is a skeleton figure of the automatic transmission for vehicles of FIG. FIG. 3 is a perspective view schematically showing a transmission mechanism unit in FIG. 2. It is a figure which shows the structure of the hydraulic control apparatus of FIG. It is a figure which shows the structure of the transmission control apparatus of FIG. FIG. 3 is an engagement table for each gear position of each clutch and each brake in the speed change mechanism portion of FIG. It is a table | surface which shows the rotation state for every gear stage in the component of the front planetary of FIG. It is a table | surface which shows the rotation state for every gear stage in the component of the rear planetary of FIG. FIG. 3 is a velocity diagram showing a rotational speed ratio of each component in each planetary of FIG. 2 for each gear position. FIG. 5 is a diagram corresponding to the hydraulic control device of FIG. 4 and shows a hydraulic path for establishing the first speed stage. It is a figure corresponding to the hydraulic control apparatus of FIG. 4, and shows the hydraulic path for establishing the second gear. FIG. 5 is a diagram corresponding to the hydraulic control device of FIG. 4 and shows a hydraulic path for establishing the third speed stage. It is a figure corresponding to the hydraulic control apparatus of FIG. 4, and shows the hydraulic path for establishing the fourth speed. It is a figure corresponding to the hydraulic control apparatus of FIG. 4, and shows the hydraulic path for establishing the fifth gear. It is a figure corresponding to the hydraulic control apparatus of FIG. 4, and shows the hydraulic path for establishing the sixth gear. FIG. 9 is a diagram corresponding to the hydraulic control device of FIG. 4 and shows a hydraulic path for establishing the seventh speed stage. It is a figure corresponding to the hydraulic control apparatus of FIG. 4, and shows the hydraulic path for establishing the eighth gear. 6 is a flowchart for explaining operations related to detection and handling of a shift abnormality by the transmission control device of FIG. 5. It is a time chart relevant to operation | movement description of FIG. FIG. 10 is a velocity diagram in a normal case where no abnormality has occurred in the specific shift process in FIG. 9. FIG. 10 is a velocity diagram when an abnormality occurs in the specific shift process in FIG. 9.

Explanation of symbols

1 Automatic transmission for vehicles
1a Automatic transmission case for vehicles
3 Transmission mechanism
31 Front planetary (upstream planetary mechanism)
32 Rear planetary (downstream planetary mechanism)
33 Intermediate drum (intermediate rotating element)
C1 1st clutch
C2 Second clutch
C3 3rd clutch
C4 4th clutch
B1 First brake
B2 Second brake
F1 one-way clutch
4 Hydraulic control device
41 Pressure control valve
42 Manual valve
SLC1 ~ SLC4 Linear solenoid valves for the 1st to 4th clutches
SLB1 Linear solenoid valve for the first brake
44 B2 control valve
5 Transmission control device
6 Oil pump
7 engine
8 Engine control device
9 Input shaft
10 Output shaft
11 Engine speed sensor
12 Input shaft speed sensor
13 Output shaft speed sensor
14 Range position sensor
15 Throttle opening sensor
16 Intermediate drum rotation speed sensor

Claims (5)

A transmission mechanism having at least two planetary mechanisms installed from the input shaft to the output shaft and intermediate rotating elements connecting between appropriate components of each planetary mechanism, and an appropriate shift stage in the transmission mechanism are established. A control device for an automatic transmission for a vehicle having a hydraulic control device for controlling the operation of a plurality of hydraulic engagement elements for
The hydraulic control device is controlled to perform a shift process for securing an arbitrary shift stage, and the rotation speed of the intermediate rotation element is detected. When the detected value exceeds a predetermined threshold value, the fuel cut to the engine is performed. A control device for an automatic transmission for a vehicle, characterized by performing processing to be executed. The control device for an automatic transmission for a vehicle according to claim 1,
The control apparatus for an automatic transmission for a vehicle, wherein the threshold value is specified based on a predetermined rev limit defined for the intermediate rotation element. The control device for an automatic transmission for a vehicle according to claim 1 or 2,
The hydraulic control device has a normally closed type linear solenoid valve for applying hydraulic pressure individually to the plurality of hydraulic engagement elements, which is the same number as the number of the hydraulic engagement elements used. A control device for an automatic transmission for a vehicle. In the control apparatus of the automatic transmission for vehicles in any one of Claim 1 to 3,
One planetary mechanism arranged on the upstream side in the power transmission direction is a double pinion type gear planetary mechanism, and the input shaft is connected to the carrier,
The other planetary mechanism disposed on the downstream side in the power transmission direction is a Ravigneaux type geared planetary mechanism, and the output shaft is connected to the ring gear,
The intermediate rotating element is integrally connected to one end side in the axial direction with a large-diameter sun gear in the Ravigneaux type geared planetary mechanism, and is arranged on the outer diameter side of the ring gear in the double pinion type geared planetary mechanism. And a control device for an automatic transmission for a vehicle, wherein the ring gear and the carrier are brought into an integrally rotatable state or a relatively rotatable state through a clutch as a hydraulic engagement element. A transmission mechanism having at least two planetary mechanisms installed from the input shaft to the output shaft and intermediate rotating elements connecting between appropriate components of each planetary mechanism, and an appropriate shift stage in the transmission mechanism are established. An automatic transmission for a vehicle including a hydraulic control device that controls operations of a plurality of hydraulic engagement elements and a control device that performs a shift process for controlling the hydraulic control device to ensure an arbitrary shift speed. ,
The hydraulic engagement element includes a brake that makes a suitable component of each planetary mechanism rotatable or non-rotatable, and a state in which the two components of each planetary mechanism can rotate integrally or relative to each other. And a clutch that can rotate.
An automatic transmission for a vehicle, wherein the control device has the configuration according to any one of claims 1 to 4.

Images