JP5164907B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission mounted on, for example, a vehicle, and more particularly, an automatic transmission that can reliably prevent a malfunction caused by a solenoid valve abnormality caused by a driver short circuit, a harness short circuit, or the like. The present invention relates to a machine control device.

  2. Description of the Related Art Conventionally, a mechanism for shifting gears by switching a hydraulic circuit with excitation and non-excitation of a solenoid has been used for shift control of an automatic transmission for a vehicle. In such a technique, there is known a failure detection device configured to electrically detect an abnormality such as a short circuit failure of a solenoid and detect a failure of a solenoid valve (see Patent Document 1).

  The failure detection device described in Patent Document 1 includes first processing means for inverting the binary level of the command signal for a short time without affecting the operation of the device equipped with the solenoid; And a second processing means for detecting an output of the abnormality detection circuit in correspondence with the timing at which the first processing means is inverted and outputting a warning signal when the binary level does not correspond normally. ing. As a result, even if the disconnection failure cannot be identified because the solenoid is in the ON state (or OFF state), the binary level of the command signal is intentionally reversed without waiting for the next switching operation of the fastening element. By inverting -OFF, it is possible to actively create a state in which disconnection can be identified. In addition, since the output of the abnormality detection circuit in both the ON state and OFF state of the solenoid is OR-determined, the disconnection failure can be identified by the same procedure regardless of whether the solenoid is in the ON or OFF state.

Japanese Patent Laid-Open No. 08-293414

  However, the failure detection device described in Patent Document 1 can detect an abnormality such as a short circuit of the solenoid valve, but when the abnormality is detected, the alarm circuit is activated and the automatic transmission is turned off. Switch to fail-safe mode, and in this mode, the gear position is fixed at the 3rd forward speed to ensure the minimum required operation function, so that the current supply to the solenoid valve is cut off even if an abnormality is detected. It was difficult. For example, when the driver is operating in the neutral (N) range and is in the neutral state, if a solenoid valve abnormality (for example, driver short-circuit, harness short-circuit, etc.) occurs, There is a possibility of causing a problem that the current is continuously supplied.

  Accordingly, the present invention provides a control device for an automatic transmission that is configured to cut off a supply current when an abnormality relating to a solenoid valve is detected, thereby reliably preventing the occurrence of a malfunction, thereby further improving safety. It is intended to provide.

The present invention according to claim 1 (see, for example, FIG. 1 to FIG. 3 and FIG. 5 to FIG. 7) controls a solenoid valve (for example, SLC1) that adjusts pressure in response to an input of a drive signal (current signal). In the control device for the automatic transmission (1) that is controlled to shift by
A high-side switching unit (21) and a low-side switching unit (26) connected between a positive electrode side (+ B) and a negative electrode side (G) of a power source that supplies the drive signal to the solenoid valve (for example, SLC1);
One of the high-side switching unit (21) and the low-side switching unit (26) serves as a current path between the positive side (+ B) or negative side (G) of the power source and the solenoid valve (for example, SLC1). Power supply control means (55) for controlling to switch between an energized state and a cut-off state;
Drive control means (56) for controlling either one of the high-side switching unit (21) and the low-side switching unit (26) to supply the drive signal to the solenoid valve (for example, SLC1). ,
The solenoid valve (eg, SLC1) is switched to the energized state capable of supplying the drive signal to the solenoid valve (eg, SLC1) by the control of the power supply control means (55), and the solenoid valve (eg, SLC1) is controlled by the drive control means (56). In the state where the drive signal is supplied, the power supply control means (55) supplies the drive signal to the solenoid valve (for example, SLC1) by switching the current path to the cutoff state at a predetermined timing. Ri Na shut off the,
It is configured to be switchable to at least the neutral range (N range) according to the operation of the shift range operating means (47), and
The power supply control means (55) is configured such that when the shift range operation means (47) is switched from another range (for example, D range) to the neutral range, the one switching unit (21 Or 26) is switched to the shut-off state.
It is in the control apparatus of the automatic transmission (1) characterized by the above.

According to the second aspect of the present invention (see, for example, FIG. 6), the power supply control means (55) switches the one switching section (21 or 26) to the shut-off state for a predetermined delay time (t ) After running,
It exists in the control apparatus of the automatic transmission (1) of Claim 1 .

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

According to the first aspect of the present invention, in a state where the solenoid valve is switched to an energized state capable of supplying a drive signal to the solenoid valve by control by the power supply control means, and the drive signal is supplied to the solenoid valve by control by the drive control means, Since the power supply control means is configured to cut off the supply of the drive signal to the solenoid valve by switching the current path to the cut-off state at a predetermined trigger, even if an abnormality related to the solenoid valve has occurred, By controlling the switching part at a predetermined timing and cutting off the current path between the positive or negative side of the power source and the solenoid valve, there is a problem of continuing to supply current to the solenoid valve used during traveling Generation | occurrence | production can be blocked | prevented reliably and higher safety | security can be ensured. Further, it is configured to be switchable to at least the neutral range in accordance with the operation of the shift range operation means, and the power supply control means is a predetermined trigger when the shift range operation means is switched from another range to the neutral range, Since one switching unit is configured to switch to a shut-off state, when switching from another range, for example, the forward travel range to the neutral range, the power supply to the solenoid valve is securely shut off and used during travel It is possible to reliably prevent the occurrence of a problem that continues to supply current to the solenoid valve.

According to the second aspect of the present invention, the power supply control means executes the switching of the one switching unit to the cut-off state after a predetermined delay time has elapsed. By shutting off the other switching portion after the operation, the solenoid valve can be closed smoothly and the shock at the time of shift change can be reduced.

The skeleton figure which shows the automatic transmission which can apply this invention. Operation table of this automatic transmission. FIG. 2 is a circuit diagram schematically showing a part of the hydraulic control device of the automatic transmission. It is a diagram illustrating a reference example of the control device, (a) shows the diagram schematically showing a circuit configuration of the control apparatus, (b) is a diagram showing a feeding state of the linear solenoid valve. It is a figure explaining 1st Embodiment of this control apparatus, (a) is a figure which shows typically the circuit structure of this control apparatus, (b) is a figure which shows the electric power feeding state to a linear solenoid valve. It is a figure explaining 2nd Embodiment of this control apparatus, (a) is a figure which shows typically the circuit structure of this control apparatus, (b) is a figure which shows the electric power feeding state to a linear solenoid valve. The figure which shows typically the circuit structure etc. of 3rd Embodiment of this control apparatus. It is a figure explaining the control apparatus used as the foundation of this invention, (a) is a figure which shows typically the circuit structure of this control apparatus, (b) is a figure which shows the electric power feeding state to a linear solenoid valve.

< Reference example >
Hereinafter, a reference example will be described with reference to FIGS.

[Configuration of automatic transmission]
First, a schematic configuration of a multi-stage automatic transmission 1 (hereinafter simply referred to as “automatic transmission”) to which the present invention can be applied will be described with reference to FIG. As shown in FIG. 1, an automatic transmission 1 suitable for use in, for example, an FR type (front engine, rear drive) vehicle has an input shaft 11 of the automatic transmission 1 that can be connected to an engine (not shown). The torque converter 7 and the speed change mechanism 2 are provided around the axial direction of the input shaft 11.

  The torque converter 7 has a pump impeller 7a connected to the input shaft 11 of the automatic transmission 1, and a turbine runner 7b to which the rotation of the pump impeller 7a is transmitted via a working fluid. The runner 7 b is connected to the input shaft 12 of the transmission mechanism 2 that is arranged coaxially with the input shaft 11. Further, the torque converter 7 is provided with a lock-up clutch 10, and when the lock-up clutch 10 is engaged by hydraulic control of a hydraulic control device described later, the input shaft 11 of the automatic transmission 1 is The rotation is directly transmitted to the input shaft 12 of the speed change mechanism 2.

  The speed change mechanism 2 includes a planetary gear DP and a planetary gear unit PU on the input shaft 12 (and the intermediate shaft 13). The planetary gear DP includes a sun gear S1, a carrier CR1, and a ring gear R1, and the carrier CR1 has a pinion P1 that meshes with the sun gear S1 and a pinion P2 that meshes with the ring gear R1. This is a so-called double pinion planetary gear.

  The planetary gear unit PU has a sun gear S2, a sun gear S3, a carrier CR2 (CR3), and a ring gear R3 (R2) as four rotating elements, and the carrier CR2 meshes with the sun gear S2 and the ring gear R3. This is a so-called Ravigneaux type planetary gear having P4 and a short pinion P3 meshing with the long pinion P4 and the sun gear S3.

  The sun gear S1 of the planetary gear DP is connected to, for example, a boss portion 3b extending from an oil pump body 3a that is integrally fixed to the transmission case 3, and the rotation is fixed. The carrier CR1 is connected to the input shaft 12 so as to be the same rotation as the rotation of the input shaft 12 (hereinafter referred to as “input rotation”), and is connected to the fourth clutch C-4. ing. Further, the ring gear R1 is decelerated by the input rotation being decelerated by the fixed sun gear S1 and the input rotating carrier CR1, and is connected to the first clutch C-1 and the third clutch C-3. ing.

  The sun gear S2 of the planetary gear unit PU is connected to the first brake B-1 as a locking means and can be fixed to the transmission case 3, and the fourth clutch C-4 and the third clutch. Connected to C-3, the input rotation of the carrier CR1 can be input via the fourth clutch C-4, and the decelerated rotation of the ring gear R1 can be input via the third clutch C-3. Further, the sun gear S3 is connected to the first clutch C-1, so that the reduced rotation of the ring gear R1 can be input.

  Further, the carrier CR2 is connected to the second clutch C-2 to which the rotation of the input shaft 12 is input via the intermediate shaft 13, and the input rotation can be freely input via the second clutch C-2. In addition, it is connected to a one-way clutch F-1 and a second brake B-2 as locking means, and rotation in one direction with respect to the transmission case 3 is restricted via the one-way clutch F-1. At the same time, rotation can be fixed via the second brake B-2. The ring gear R3 is connected to an output shaft 15 that outputs rotation to a drive wheel (not shown).

[Transmission path of each gear stage]
Next, based on the above configuration, the operation of the speed change mechanism 2 will be described with reference to FIGS. 1 and 2. FIG. 2 is an operation table of the automatic transmission, where ◯ indicates ON (engagement, locking), and (◯) indicates ON (locking) during engine braking.

  For example, in the D (drive) range and in the first forward speed (1ST), as shown in FIG. 2, the first clutch C-1 and the one-way clutch F-1 are engaged. Then, as shown in FIG. 1, the rotation of the ring gear R1 decelerated by the fixed sun gear S1 and the carrier CR1 as the input rotation is input to the sun gear S3 via the first clutch C-1. Further, the rotation of the carrier CR2 is restricted in one direction (forward rotation direction), that is, the carrier CR2 is prevented from rotating in the reverse direction and is fixed. Then, the decelerated rotation input to the sun gear S3 is output to the ring gear R3 via the fixed carrier CR2, and the forward rotation as the first forward speed is output from the output shaft 15.

  During engine braking (coasting), the second brake B-2 is locked to fix the carrier CR2, and the forward first speed state is set in such a manner as to prevent the carrier CR2 from rotating forward. maintain. Further, at the first forward speed, the one-way clutch F-1 prevents the carrier CR2 from rotating in the reverse direction and enables forward rotation, so that the first forward speed when switching from the non-traveling range to the traveling range, for example. Can be smoothly achieved by the automatic engagement of the one-way clutch F-1.

  At the second forward speed (2ND), as shown in FIG. 2, the first clutch C-1 is engaged and the first brake B-1 is locked. Then, as shown in FIG. 1, the rotation of the ring gear R1 decelerated by the fixed sun gear S1 and the carrier CR1 as the input rotation is input to the sun gear S3 via the first clutch C-1. Further, the rotation of the sun gear S2 is fixed by the locking of the first brake B-1. Then, the carrier CR2 is decelerated and rotated at a speed lower than that of the sun gear S3, the decelerated rotation input to the sun gear S3 is output to the ring gear R3 via the carrier CR2, and the forward rotation as the second forward speed is output shaft. 15 is output.

  At the third forward speed (3RD), as shown in FIG. 2, the first clutch C-1 and the third clutch C-3 are engaged. Then, as shown in FIG. 1, the rotation of the ring gear R1 decelerated by the fixed sun gear S1 and the carrier CR1 as the input rotation is input to the sun gear S3 via the first clutch C-1. Further, the reduced rotation of the ring gear R1 is input to the sun gear S2 by the engagement of the third clutch C-3. In other words, since the reduced rotation of the ring gear R1 is input to the sun gear S2 and the sun gear S3, the planetary gear unit PU is directly connected to the reduced rotation, and the reduced rotation is output to the ring gear R3 as it is, and the forward rotation as the third forward speed is performed. Output from the output shaft 15.

  At the fourth forward speed (4TH), as shown in FIG. 2, the first clutch C-1 and the fourth clutch C-4 are engaged. Then, as shown in FIG. 1, the rotation of the ring gear R1 decelerated by the fixed sun gear S1 and the carrier CR1 as the input rotation is input to the sun gear S3 via the first clutch C-1. Further, the input rotation of the carrier CR1 is input to the sun gear S2 by the engagement of the fourth clutch C-4. Then, the carrier CR2 is decelerated and rotated at a speed higher than that of the sun gear S3, the decelerated rotation input to the sun gear S3 is output to the ring gear R3 via the carrier CR2, and the forward rotation as the fourth forward speed is output shaft. 15 is output.

  At the fifth forward speed (5TH), as shown in FIG. 2, the first clutch C-1 and the second clutch C-2 are engaged. Then, as shown in FIG. 1, the rotation of the ring gear R1 decelerated by the fixed sun gear S1 and the carrier CR1 as the input rotation is input to the sun gear S3 via the first clutch C-1. Further, the input rotation is input to the carrier CR2 by the engagement of the second clutch C-2. Then, due to the decelerated rotation input to the sun gear S3 and the input rotation input to the carrier CR2, the decelerated rotation is higher than the fourth forward speed and is output to the ring gear R3, and the forward rotation as the fifth forward speed is performed. Is output from the output shaft 15.

  At the sixth forward speed (6TH), as shown in FIG. 2, the second clutch C-2 and the fourth clutch C-4 are engaged. Then, as shown in FIG. 1, the input rotation of the carrier CR1 is input to the sun gear S2 by the engagement of the fourth clutch C-4. Further, the input rotation is input to the carrier CR2 by the engagement of the second clutch C-2. That is, since the input rotation is input to the sun gear S2 and the carrier CR2, the planetary gear unit PU is directly connected to the input rotation, and the input rotation is output to the ring gear R3 as it is, and the forward rotation as the sixth forward speed (direct connection stage). Is output from the output shaft 15.

  At the seventh forward speed (7TH), as shown in FIG. 2, the second clutch C-2 and the third clutch C-3 are engaged. Then, as shown in FIG. 1, the rotation of the ring gear R1 decelerated by the fixed sun gear S1 and the carrier CR1 as the input rotation is input to the sun gear S2 via the third clutch C-3. Further, the input rotation is input to the carrier CR2 by the engagement of the second clutch C-2. Then, the decelerated rotation input to the sun gear S2 and the input rotation input to the carrier CR2 result in a speed-up slightly higher than the input rotation, which is output to the ring gear R3. In addition, the forward rotation as the overdrive speed 1) is output from the output shaft 15.

  At the eighth forward speed (8TH), as shown in FIG. 2, the second clutch C-2 is engaged, and the first brake B-1 is locked. Then, as shown in FIG. 1, the input rotation is input to the carrier CR2 by the engagement of the second clutch C-2. Further, the rotation of the sun gear S2 is fixed by the locking of the first brake B-1. Then, the input rotation of the carrier CR2 becomes higher than the forward seventh speed by the fixed sun gear S2, and is output to the ring gear R3, and the forward eighth speed (overdrive second speed higher than the direct connection speed) is output. The forward rotation as the stage) is output from the output shaft 15.

  In the reverse speed (REV), as shown in FIG. 2, the fourth clutch C-4 is engaged and the second brake B-2 is locked. Then, as shown in FIG. 1, the input rotation of the carrier CR1 is input to the sun gear S2 by the engagement of the fourth clutch C-4. Further, the rotation of the carrier CR2 is fixed by the locking of the second brake B-2. Then, the input rotation input to the sun gear S2 is output to the ring gear R3 via the fixed carrier CR2, and the reverse rotation as the reverse gear is output from the output shaft 15.

  In this automatic transmission, the reverse gear is formed by engaging the fourth clutch C-4 and the second brake B-2 in the reverse range by hydraulic control by the hydraulic control device 6 described in detail later. However, the reverse gear may be formed by engaging the third clutch C-3 and the second brake B-2, or both reverse gears may be formed to achieve the reverse second speed.

  For example, in the P (parking) range and the N (neutral) range, the first clutch C-1, the second clutch C-2, the third clutch C-3, and the fourth clutch C-4 are released. Then, the carrier CR1 and the sun gear S2, and the ring gear R1, the sun gear S2, and the sun gear S3, that is, the planetary gear DP and the planetary gear unit PU are disconnected. Further, the input shaft 12 (intermediate shaft 13) and the carrier CR2 are disconnected. Thereby, the power transmission between the input shaft 12 and the planetary gear unit PU is disconnected, that is, the power transmission between the input shaft 12 and the output shaft 15 is disconnected.

[Configuration of shift control portion in hydraulic control device]
Next, a portion that mainly performs shift control in the hydraulic control device 6 according to the present invention will be described with reference to FIG. FIG. 3 is a circuit diagram schematically showing an excerpt of the hydraulic control device 6 of the automatic transmission 1.

  The hydraulic control device 6 includes a hydraulic servo 41 for the clutch C-1, a hydraulic servo 42 for the clutch C-2, a hydraulic servo 43 for the clutch C-3, a hydraulic servo 46 for the clutch C-4, and a hydraulic servo for the brake B-1. 44, five linear solenoid valves SLC1, SLC2, SLC3, SLC4 for directly supplying the output pressure adjusted as the engagement pressure to each of the six hydraulic servos of the hydraulic servo 45 of the brake B-2. , SLB1. Further, a switching valve 27 for switching the output pressure of the linear solenoid valve SLC2 to the hydraulic servo 42 of the clutch C-2 or the hydraulic servo 45 of the brake B-2 is provided. Note that the switching valve 27 is not actually a single valve but is drawn in a form in which solenoid valves (not shown), clutch apply relay valves, and the like are integrated.

Oil path a1 to linear solenoid valve SLC1, oil path a2 to linear solenoid valve SLC2, oil path a3 to linear solenoid valve SLC3, oil path a4 to linear solenoid valve SLC4, oil path a5 to linear solenoid valve SLB1 respectively, solenoid valves, and is configured so that the parking switch valve or other switching line is switched to the oil passage in the shift-by-wire made of a valve or the like pressure P _L can be entered.

The linear solenoid valve SLC1 is a normally closed type which is in the non-output state when de-energized, the input port SLC1a for inputting the line pressure P _L via the oil paths a1, hydraulic pressure by regulating the line pressure P _L and an output port SLC1b for outputting a control pressure _{P SLC1} to the servo 41 as an engagement pressure _{P C1.}

The linear solenoid valve SLC2 is a normally closed type, an input port SLC2a for inputting the line pressure _{P L} via the oil passage a2, the control pressure _{P SLC2} to the hydraulic servo 42 by regulating the line pressure _{P L} And an output port SLC2b that outputs the engagement pressure P _C2 (or engagement pressure P _B2 ).

The linear solenoid valve SLC3 is a normally closed type, an input port SLC3a which inputs the line pressure _{P L} via the oil passage a3, the control pressure _{P SLC3} to the hydraulic servo 43 by regulating the line pressure _{P L} and an output port SLC3b for outputting as an engagement pressure _{P C3.}

The linear solenoid valve SLC4 is a normally closed type, an input port SLC4a for inputting the line pressure _{P L} via the oil passage a4, the control pressure _{P SLC4} to the hydraulic servo 46 by regulating the line pressure _{P L} and an output port SLC4b to output as the engagement pressure _{P C4.}

The linear solenoid valve SLB1 is of a normally closed type, an input port SLB1a for inputting the line pressure _{P L} via the oil passage a5, the control pressure _{P SLB1} to the hydraulic servo 44 by regulating the line pressure _{P L} and an output port SLB1b to output as the engagement pressure _{P B1.}

The linear solenoid valves SLC2 to SLC4 and the linear solenoid valve SLB1 including the linear solenoid valve SLC1 are provided in the hydraulic pressure control device 6 and are supplied with the supplied hydraulic pressure (line pressure P _L ). The control oil pressure is adjusted and output as a control oil pressure corresponding to the (current signal).

[Composition of command system]
Next, the configuration of the control device of this reference example will be described with reference to FIG. An automatic transmission 1 (see FIG. 1) that roughly includes a transmission mechanism 2, a torque converter 7, and a hydraulic control device 6 includes a shift operation lever (shift range operation means) 47 installed near the driver's seat of a vehicle (not shown). The computer 71 which consists of MPU (Micro Processing Unit) etc. which were connected to etc. is provided. The control device of the automatic transmission 1 according to the present invention controls the shift by controlling linear solenoid valves (solenoid valves) SL1 to SL5 and SLB1 that perform pressure adjustment operations according to the input of a drive signal (current signal). It is configured.

  In accordance with the operation of the shift operation lever 47 disposed in the driver's seat of the automobile on which the control device is mounted, the present control device is provided with a P (parking) range, R (reverse) range, N (neutral) range, and D (drive). ) The range can be switched. The shift operation lever 47 is configured to be able to select and operate the P range, the R range, the N range, and the D range in the order in which the shift operation lever 47 moves.

  As shown in FIG. 4A, the computer 71 includes power supply control means 55, PWM control means 56 (drive control means) 56, abnormality detection means 57, and current detection means 58. A shift position signal from the shift position sensor 48 is input to the computer 71. The shift position sensor 48 is configured to detect the operation position and output a shift position signal in conjunction with the operation of the shift operation lever 47 to the P range, R range, N range, and D range. The computer 71 receives an output shaft rotation speed signal detected by an output shaft rotation speed (vehicle speed) sensor 59 based on the rotation of the output shaft 15 (see FIG. 1).

  The power supply control means 55 is configured to switch the high-side switch (high-side switching unit) 21 to the shut-off state when the abnormality detection means 57 detects an abnormality. That is, the power supply control means 55 is configured to operate the high side switch 21 (Tr1) to switch the current path between the positive side (+ B) of the power source and the linear solenoid valve SLC1 between the energized state and the interrupted state. The high side switch 21 is switched to the cut-off state with a predetermined trigger when the abnormality detection means 57 detects the abnormality. Then, the state is switched to an energized state where the drive signal (current signal) can be supplied to the linear solenoid valve SLC1 by the control by the power supply control means 55, and the drive signal is supplied to the linear solenoid valve SLC1 by the control by the PWM control means 56. Thus, the power supply control means 55 is configured to forcibly cut off the supply of the drive signal to the linear solenoid valve SLC1 by switching the current path to a cut-off state at a predetermined trigger.

In this reference example , PWM (Pulse Width Modulation) control means 56 PWM-controls the low-side switch 26 (Tr2) as the low-side switching unit so as to supply a drive signal (current signal) to the linear solenoid valve SLC1. The linear solenoid valves SL2 to SL5 and SLB1 other than the linear solenoid valve SLC1 are also PWM controlled in the same manner as the linear solenoid valve SLC1, but in this reference example , the PWM control means 56 for PWM control of the linear solenoid valve SLC1 will be described. Description of control means for PWM control of the linear solenoid valves SL2 to SL5 and SLB1 is omitted.

  The PWM control means 56 changes the pulse duty ratio (on-time ratio) by changing the ratio of high (High “1”) and low (Low “0”) of the pulse signal (PWM signal) with a constant period, By performing feedback control while variably controlling the average output of the passing time, the spool (not shown) of the linear solenoid valve SLC1 is linearly driven back and forth. Therefore, the PWM control unit 56 gives a PWM signal having a PWM pulse width (that is, a high pulse width) to the low-side switch 26 via the wiring 29 at a constant cycle. Then, since the PWM signal is applied to the base of the bipolar transistor, the low side switch 26 operates so as to be turned on when the pulse of the PWM signal is High (+) and turned off when it is Low (−). Therefore, when the high side switch 21 is turned on, a drive signal (current signal) corresponding to the PWM signal is supplied to the coil 14 of the linear solenoid valve SLC1, passes through the harness H, the shunt resistor 24, and the collector of the low side switch 26. -It flows to the negative electrode side (G) through the current path between emitters.

In this reference example , power bipolar transistors are used for the high-side switch 21 and the low-side switch 26, respectively, but instead, a power MOSFET or other switch means may be used.

  The abnormality detection means 57 compares the shift position signal from the shift position sensor 48 with the output shaft rotational speed signal detected by the output shaft rotational speed sensor 59, and the vehicle speed is in spite of being in the N range. When detected, it detects that an abnormality relating to the linear solenoid valve SLC1 due to a short-circuit failure such as a driver or a harness H has occurred.

  The current detection means 58 detects the signal amplified by the operational amplifier 23 and sent via the low-pass filter 25, and sends the signal to the PWM control means 56 as an average current value flowing through the coil 14 of the linear solenoid valve SLC1. . Further, the current detection means 58 is configured to detect a failure of the drive circuit including the low side switch 26 and the like while the current is cut off due to the off operation of the high side switch 21.

  The high side switch 21 and the low side switch 26 are connected between a positive electrode side (+ B) and a negative electrode side (G) of a power supply that supplies a PWM signal to the linear solenoid valve SLC1. The linear solenoid valve SLC1 has the above-described configuration, but is schematically illustrated as a coil 14 in the drawing. In the linear solenoid valve SLC1, one terminal 18 and the other terminal 19 of the coil are respectively connected to terminals 16 and 17 via a harness H which is an electrical connection cable.

In this reference example , the high-side switch 21 made of a power bipolar transistor has a base connected to the wiring 28, a collector connected to the positive side (+ B) of the power supply, and an emitter connected to the terminal 16. The low-side switch 26 in this reference example is also composed of a power bipolar transistor, the base is connected to the wiring 29, the collector is connected to a connection node 31 described later, and the emitter is connected to the negative side (G) of the power source. In this reference example , the high side switch 21 constitutes a cut circuit, the low side switch 26 constitutes a switching circuit, and the low pass filter 25 constitutes a current monitor.

  The terminal 17 is connected to a connection node 30 between the non-inverting input terminal (+) of the operational amplifier 23 and one end of the shunt resistor 24, and the collector of the low-side switch 26 is connected to the inverting input terminal (− ) And the other end of the shunt resistor 24. The output of the operational amplifier 23 is connected to a computer 71 via a low pass filter (LPF) 25. The cathode of the flywheel diode 22 having the anode connected to the connection node 31 is connected to the wiring 34 between the emitter of the high side switch 21 and the terminal 16.

When a drive signal (current signal) is applied to the coil 14 via the harness H and the terminals 18 and 19, the linear solenoid valve SLC1 excites the coil 14 according to the current value of the current signal, and the spool (not shown) by moving linearly against the spring (not shown), and outputs from the output port SLC1b as the engagement pressure P _C1 in which the line pressure P _L tone.

In this reference example , while the high-side switch 21 is turned on by the power supply control means 55, the PWM control means 56 supplies the PWM signal to the low-side switch 26 and performs PWM control of the linear solenoid valve SLC1, thereby detecting an abnormality. The high-side switch 21 is turned off under the control of the power supply control means 55 with the fact that the means 57 has detected an abnormality, and the supply of the drive signal (current signal) to the linear solenoid valve SLC1 is forcibly cut off. Configured to do.

Next, the operation of this reference example will be described with reference to FIGS. 4 (a) and 4 (b). In FIG. 6B, the broken line indicates a current output waveform at the time of normal D → N switching, and the solid line indicates a current output waveform when it is assumed that an ON failure has occurred in the linear solenoid valve SLC1.

That is, when in the P range or N range, or when switched from the D range to the N range, the first clutch C-1, the second clutch C-2, the third clutch C-3, the fourth clutch C -4, the first brake B-1, Ri do a second state in which the brake B-2 is released all at this time, a failure such as a short circuit occurs in the harness H, etc., not controlled by the control device The case might be as follows:

  For example, when the shift operation lever 47 is operated and switched to the D range, the high-side switch 21 is turned on by the power supply control means 55 and the energization of the linear solenoid valve SLC1 is permitted (energized state). Since the PWM control means 56 performs feedback control while applying the PWM signal to the low-side switch 26, the spool of the linear solenoid valve SLC1 is linearly driven forward and backward.

  At this time, a high signal (On in FIG. 4A) is applied to the base of the high-side switch 21, so that the terminal 16 and the harness H pass from the positive electrode side (+ B) through the collector and emitter current paths. The current supplied to the coil 14 via the terminal 18 is driven by the low-side switch 26 in response to the PWM signal from the PWM control means 56. Therefore, a drive signal (current signal) corresponding to the PWM signal is supplied. Is supplied to the linear solenoid valve SLC1 from the flywheel diode 22 to the terminal 16, harness H, terminal while flowing from the terminal 19, harness H, terminal 17 to the negative side (G) through the shunt resistor 24, low side switch 26. Reflux via 18.

Then, the linear solenoid valve SLC1 to be supplied to the input port SLC1a the line pressure _{P L} via the oil passage a1 is, outputs a control pressure _{P SLC1} that the line pressure _{P L} is regulated to the hydraulic servo 41 as an engagement pressure _{P C1} Then, the first clutch C-1 is engaged, and coupled with the engagement of the one-way clutch F-1, a first forward speed is formed. The current change at this time is as shown by a broken line A (solid line a) in FIG. In this case, the high side switch 21 is turned on by receiving a high signal from the power supply control means 55 as a base, and the low side switch 26 is at the maximum (Max) by receiving a PWM signal from the PWM control means 56 as a base. And the linear solenoid valve SLC1 is opened to fully engage the first clutch C-1.

  From this state, for example, when the shift operation lever 47 is operated from the D range to the N range, if it is normal, the current change at this time is the current as shown by the broken line B (solid line b) in FIG. After the value gradually decreases and is reduced as indicated by broken line C (solid line c) and broken line D, the PWM signal to the low-side switch 26 becomes minimum (Min), the linear solenoid valve SLC1 is closed, and the first Clutch C-1 is released.

  However, for example, when the harness H of the terminal 17 and the terminal 19 is caught in the vehicle body, or when the low side switch 26 is turned on, or when the present invention is not applied, the high side switch 21 is turned on and the energized state. As a result, the linear solenoid valve SLC1 is opened again, and the current output waveform changes as shown by the solid line d in FIG. 4B. In this case, an attempt is made to shift to the first forward speed. However, according to the control device to which the present invention is applied, the abnormality detection means 57 detects the shift position signal from the shift position sensor 48 and the output shaft from the output shaft rotational speed sensor 59. When the occurrence of an abnormality is detected based on the comparison with the rotation speed signal, at that time, the power supply control means 55 stops the signal to the high side switch 21 (Off in FIG. 4A), and the switch 21 Set the base to low. For this reason, the high side switch 21 is turned off, and the current path to the linear solenoid valve SLC1 is forcibly cut off.

  As described above, the power supply control means 55 forcibly cuts off the current signal to the high-side switch 21 when an abnormality occurs, so that the linear solenoid valve can be operated even if the low-side switch 26 operates according to the PWM signal. Since the drive signal (current signal) supplied to the coil 14 of the SLC 1 is reliably cut off, the current output waveform is as shown by the solid line e in FIG. 4B, and the transition to the neutral state is ensured. .

As described above, in this reference example , the power supply control means 55 switches to an energized state that can supply a drive signal to the linear solenoid valve SLC1, and the PWM control means 56 sends a drive signal to the linear solenoid valve SLC1. In the supplied state, the power supply control means 55 is configured to forcibly cut off the supply of the drive signal to the linear solenoid valve SLC1 by switching the current path to the cut-off state at a predetermined trigger. As a result, even if an abnormality relating to the linear solenoid valve SLC1 occurs, the high side switch 21 is controlled at a predetermined trigger, and the positive side (+ B) or the negative side (G) of the power source and the linear solenoid valve SLC1 By forcibly cutting off the current path between the two, it is possible to reliably prevent the occurrence of a problem that continues to supply current to the solenoid valve SLC1 used during traveling, and to ensure higher safety Can do.

In addition, according to the present reference example , the abnormality detection unit 57 that detects an abnormality related to the linear solenoid valve SLC1 is provided, and the power supply control unit 55 is activated when the abnormality detection unit 57 detects an abnormality. Since the side switch 21 is switched to the cut-off state, when no abnormality is detected, the normal control can be executed as it is.

Further, according to the present reference example , while the high-side switch 21 is turned on by the power supply control means 55, the PWM control means 56 gives the PWM signal to the low-side switch 26 to perform the PWM control of the linear solenoid valve SLC1. Then, the power supply control means 55 turns off the high-side switch 21 at a predetermined trigger to forcibly cut off the power supply to the linear solenoid valve SLC1. This ensures the power supply to the linear solenoid valve SLC1 in the N range with a simple configuration in which the high side switch 21 and the low side switch 26 are interposed between the positive side (+ B) and the negative side (G) of the power source. Therefore, it is possible to realize a configuration capable of reliably preventing the occurrence of a problem that continues to supply current to the solenoid valve SLC1 used during traveling.

<First Embodiment>
Next, the first embodiment in which the method of cutting off the current signal by the high-side switch 21 is different will be described with reference to FIG. 5, but the first embodiment is compared with the previous reference example . Since the other parts are substantially the same except that there is no abnormality detection means 57 and the trigger of current interruption by the power supply control means 55, the same reference numerals are assigned to the main parts and the description is omitted. In FIG. 5B, the broken line indicates a current output waveform at the time of normal D → N switching, and the solid line indicates a current output waveform when it is assumed that an ON failure has occurred in the linear solenoid valve SLC1.

That is, in the reference example , when the abnormality detection unit 57 detects an abnormality, the current interruption is triggered, but in the first embodiment, the power supply control unit 55 includes the shift operation lever 47 in another range. The high side switch 21 (Tr1) is configured to be switched to a cut-off state with a predetermined trigger when the (for example, D range) is switched to the N range.

  Therefore, for example, in a state where the first clutch C-1 is completely engaged and the first forward speed is formed, the current output waveform is as indicated by a broken line A (and a solid line a) in FIG. In this case, the high side switch 21 is turned on in response to a high signal from the power supply control means 55, and the low side switch 26 receives a PWM signal from the PWM control means 56 and operates to the maximum (Max), and the linear solenoid The valve SLC1 is opened.

  From this state, for example, when the shift operation lever 47 is operated from the D range to the N range, the high side switch 21 is always turned off by the control of the power supply control means 55. That is, regardless of whether it is in a normal state or in an abnormal state, the high-side switch 21 receives a low signal and is turned off, and the low-side switch 26 has a minimum (Min) PWM signal from the PWM control unit 56. Thus, the current output waveform is as shown by solid lines f and g in FIG. As a result, the linear solenoid valve SLC1 is closed and the first clutch C-1 is released.

  When the shift operation lever 47 is operated again from the N range to the D range, the high side switch 21 receives the high signal and is turned on again, and the low side switch 26 receives the PWM signal from the minimum (Min) and loosens. After the control (solid line h) is performed, the first clutch C-1 operates to the maximum (Max) to move the linear solenoid valve SLC1 from the closed state to the open state to form the first forward speed. (Refer to the solid line i in FIG. 4B for the current output waveform at this time).

As described above, according to the first embodiment, the power supply control means 55 operates the shift operation lever 47 to the N range even when an abnormality has occurred or during normal times when no abnormality has occurred. In this case, the high side switch 21 is always turned off to forcibly cut off the drive signal (current signal) to the linear solenoid valve SLC1, so that the neutral state can be reliably shifted.

  Furthermore, according to the present embodiment, it is configured to be switchable to at least the N range in accordance with the operation of the shift operation lever 47, and the power supply control means 55 switches the shift operation lever 47 from the other range to the N range. Since the high-side switch 21 is switched to the shut-off state at a predetermined timing, for example, when the D range (forward travel range) is switched to the N range, power is supplied to the linear solenoid valve SLC1. Can be reliably cut off, and it is possible to reliably prevent the occurrence of a problem that continues to supply current to the solenoid valve SLC1 used during traveling.

<Second Embodiment>
Continuing along the FIG. 6, a description will be given of a second embodiment having different ways of interrupting the current signal by the high-side switch 21, the second embodiment, the first embodiment previously The power supply control means 55 is different in that the high-side switch 21 is turned off after release control for a preset time, and the other parts are substantially the same. Therefore, the description is omitted. In FIG. 6B, the broken line indicates the current output waveform when D → N is switched normally, and the solid line indicates the current output waveform when it is assumed that an ON failure has occurred in the linear solenoid valve SLC1.

That is, in the first embodiment, when the shift operation lever 47 is operated to the N range, the power supply control means 55 immediately turns off the high side switch 21, whereas in the second embodiment. The power supply control means 55, when the shift operation lever 47 is operated, after the preset time t (predetermined delay time), that is, after delaying by the preset time, the high side switch 21. By turning off, the linear solenoid valve SLC1 is smoothly closed to reduce the shock at the time of shift change.

  For example, in the state where the first forward speed is formed, the current output waveform is as shown by a broken line A (and a solid line a) in FIG. 6B. In this case, the high-side switch 21 is connected from the power supply control means 55. The low side switch 26 receives the PWM signal from the PWM control means 56 and operates to the maximum (Max) to open the linear solenoid valve SLC1 to completely open the first clutch C-1. Engaged. From this state, for example, when the shift operation lever 47 is operated from the D range to the N range, the high-side switch 21 is always turned off after the preset time t has elapsed under the control of the power supply control means 55. To be. In other words, the current output waveform changes from a solid line k to a solid line 1 in FIG. 6B regardless of whether it is in a normal state or in an abnormal state, and the high side switch 21 outputs a low signal in this solid line l portion. Receive and turn off. The low-side switch 26 closes the linear solenoid valve SLC1 to release the first clutch C-1 because the PWM signal from the PWM control means 56 becomes minimum (Min).

  When the shift operation lever 47 is operated again from the N range to the D range, the high side switch 21 receives the high signal and is turned on again, and the low side switch 26 receives the PWM signal from the minimum (Min) and loosens. After the control (solid line h) is performed, it operates toward the maximum (Max), the linear solenoid valve SLC1 is moved from the closed state to the open state, and the first clutch C-1 is engaged (in FIG. 6B). (See solid line i).

As described above, according to the second embodiment, the power supply control means 55 operates the shift operation lever 47 to the N range even when an abnormality occurs, even when the abnormality does not occur. In this case, the high-side switch 21 is always turned off after the release control for a preset time t, and the current signal to the linear solenoid valve SLC1 is forcibly cut off. Can do.

According to the second embodiment, the power supply control means 55 performs the switching of the high side switch 21 to the cutoff state after a preset time (predetermined delay time) t has elapsed. When this is done, the linear solenoid valve SLC1 can be closed smoothly by forcibly shutting off the high side switch 21 after being delayed by a predetermined time, thereby reducing the shock at the time of shift change.

< Third Embodiment>
Continuing along 7, a third embodiment having different ways of interrupting the current signal by the high-side switch 21 will be described, but the third embodiment, the foregoing reference example, the first and Compared to the second embodiment, the only difference is that the high-side switch is PWM controlled and the low-side switch is energized / cut-off, and the other parts are substantially the same. A description thereof will be omitted.

That is, in the third embodiment, the high-side switch 66 interposed between the positive side (+ B) of the power source and the linear solenoid valve SLC1 is PWM-controlled by the PWM control means 56, and the negative side (G ) And the linear solenoid valve SLC1 is configured to be energized / cut off by the power supply control means 55. In this embodiment, the timing of energization / cutoff control by the power supply control unit 55, also be configured as shown in FIG. 5 (b) in the first embodiment, FIG. 6 in the second embodiment ( It can also be configured as in b), and the same effect can be obtained by any control method.

In the third embodiment, when the linear solenoid valve SLC1 is driven, PWM is applied to the base of the high-side switch 66 via the wiring 69 in a state where a high signal is applied to the base of the low-side switch 61 via the wiring 68. When a signal is applied, current flows from the linear solenoid valve SLC1 side through the current path of the terminal 19, harness H, terminal 17, shunt resistor 24, and low-side switch 61 to the negative side (G) of the power supply. On the other hand, the flywheel diode 22 circulates through the terminal 16, the harness H, and the terminal 18.

Also in the third embodiment, when the shift operation lever 47 is operated to the N range, the power supply control means 55 turns off the low-side switch 61, so that the linear solenoid valve SLC1 is connected. The current signal can be forcibly cut off and the neutral state can be reliably transferred. In the third embodiment, the computer 71 may be provided with the abnormality detection means 57, and the power supply / cutoff control timing by the power supply control means 55 may be configured as shown in FIG. 4B in the reference example . In that case, the high-side switch 66 can be switched to the cut-off state when the abnormality detection means 57 detects the abnormality.

  Here, a problem caused by the technology underlying the present invention when the present invention is not applied will be described with reference to FIG. 8 and in comparison with FIG.

  8 does not include the power supply control means 55, the current detection means 58, and the low-side switch 61 provided in FIG. 7, and includes the inverting input terminal (−) of the operational amplifier 23 and one end of the shunt resistor 24. Are connected to the ground (that is, connected to the negative side (G) of the power source).

Therefore, the current output waveform is as shown in FIG. That is, the linear solenoid valve SLC1 is, when outputs a control pressure _{P SLC1} that the line pressure _{P L} is regulated to the hydraulic servo 41 as an engagement pressure _{P C1,} first clutch C1 is engaged, the one-way clutch F-1 The first forward speed is formed in combination with the engagement. The current output waveform at this time is as shown by a broken line A (and a solid line a) in FIG. In this case, the high side switch 66 receives the PWM signal from the PWM control means 56 and operates to the maximum (Max) to open the linear solenoid valve SLC1 and completely engage the first clutch C-1.

  From this state, for example, when the shift operation lever 47 is operated from the D range to the N range, if it is normal, the current change at this time is the current value as shown by the broken line B (solid line b) in FIG. Gradually decreases and is reduced as indicated by a broken line C (solid line c), and then as indicated by a broken line D, the PWM signal applied to the high-side switch 66 becomes minimum (Min), and the linear solenoid valve SLC1 is closed and the first clutch C-1 is released.

  However, if an abnormality relating to the linear solenoid valve SLC1 occurs, for example, because the harness H is short-circuited, the connection node between the inverting input terminal (−) of the operational amplifier 23 and one end of the shunt resistor 24 is grounded. When the high side switch 66 is turned on from the Min) state, the linear solenoid valve SLC1 is opened again, and the current output waveform at this time becomes as shown by the solid line m in FIG. There is a possibility of causing a problem that the current is continuously supplied to the solenoid valve SLC1.

  In the above-described embodiment, the case where the hydraulic control device 6 is applied to the multi-stage automatic transmission 1 that enables the eighth forward speed and the first reverse speed has been described as an example. The present invention is not limited to this, and can be applied to any stepped automatic transmission.

  The control device for an automatic transmission according to the present invention is suitable for use in an automatic transmission mounted on a passenger car, a truck, a bus, an agricultural machine, or the like.

1 Automatic transmission 21, 66 High side switching part (High side switch)
26, 61 Low side switching part (Low side switch)
47 Shift range operation means (shift operation lever)
55 Power supply control means 56 Drive control means (PWM control means)
57 Abnormality detection means + B Positive side of power supply G Negative side of power supply SLC1 Solenoid valve (linear solenoid valve)

Claims (2)

In a control device for an automatic transmission that performs shift control by controlling a solenoid valve that regulates pressure according to an input of a drive signal,
A high-side switching unit and a low-side switching unit connected between a positive electrode side and a negative electrode side of a power source that supplies the drive signal to the solenoid valve;
Power supply control for controlling one of the high-side switching unit and the low-side switching unit to switch a current path between the positive or negative side of the power source and the solenoid valve between an energized state and a shut-off state Means,
Drive control means for controlling either one of the high-side switching unit and the low-side switching unit to supply the drive signal to the solenoid valve;
The power supply is switched to the energized state where the drive signal can be supplied to the solenoid valve by the control of the power supply control means, and the drive signal is supplied to the solenoid valve by the control of the drive control means. by the control means switches said current path at a predetermined trigger in the blocking state, Ri Na shut off the supply of the drive signal to the solenoid valve,
It is configured to be switchable to at least the neutral range according to the operation of the shift range operating means, and
The power supply control unit is configured to switch the one switching unit to the cut-off state when the shift range operation unit is switched from another range to the neutral range, as the predetermined trigger.
A control device for an automatic transmission. The power supply control means is configured to execute the switching of the one switching unit to the cutoff state after a predetermined delay time has elapsed.
The control device for an automatic transmission according to claim 1 .

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