JP4711443B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission, and more particularly to neutral control (or non-control) that forms a neutral state when the vehicle is stopped with the forward travel position selected, the accelerator operation is not performed, and the brake operation is performed. The present invention relates to a control device for an automatic transmission that executes a creep control to improve fuel efficiency and accurately determines the reverse of a vehicle during the execution of neutral control.

As a conventional technique of this type of automatic transmission control device, a technique described in Patent Document 1 can be cited. In the technique described in Patent Document 1, a difference between a primary pulley rotational speed detection sensor that detects a pulse signal generated by rotation of a shaft of a primary pulley of a CVT, and a primary rotational speed and a turbine rotational speed of a torque converter. Based on the above, the release state of the input clutch is determined, and the pulse threshold value for determining the start of movement of the vehicle is configured to be larger before the release of the input clutch than after the release of the input clutch.
JP 2004-183843 A

  That is, it is possible to improve the fuel efficiency by executing the neutral control. On the other hand, when the vehicle starts moving, it is necessary to quickly end the neutral control and shift to the start control. In the prior art described above, when the transition from the normal state to the neutral control state occurs, the input clutch shifts from the engaged state to a state close to release, so that the torsion between the internal combustion engine and the transmission is released. In order to eliminate the inconvenience of erroneously determining the start of movement of the vehicle due to the input of a pulse, the pulse threshold for determining the start of movement of the vehicle is made larger before the release of the input clutch than after the release of the input clutch.

  By the way, recently, two magnetoelectric transducers that output two kinds of pulses with different phases for each predetermined rotation angle of the input shaft or output shaft of the transmission, and the rotation direction are detected from the two kinds of outputted pulses. A rotational speed sensor with a rotational direction detection function comprising a forward direction pulse and a rotational direction detection circuit that outputs a backward direction pulse that represents the traveling direction of the vehicle has been proposed. By using such a sensor, the vehicle Can be detected including its direction.

  However, even if such a sensor is used, it is difficult to avoid the occurrence of noise due to the displacement and swing of the transmission, as in the prior art. It is important to detect the reverse of the vehicle movement more accurately than the forward movement.

  Accordingly, the object of the present invention is to solve the above-mentioned inconvenience, execute neutral control for forming a neutral state, and accurately determine the reverse of the vehicle by using a rotational speed sensor with a rotational direction detection function. It is to provide a control device for an automatic transmission.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a control device for an automatic transmission that is mounted on a vehicle and that changes the speed of an internal combustion engine. Rotational speed detection means comprising two magnetoelectric transducers each outputting two types of pulses having different phases for each predetermined rotation angle, and the direction of travel of the vehicle by detecting the rotational direction from the two types of output pulses Rotation direction detection means that outputs as a forward pulse and a reverse pulse, and a neutral position that executes neutral control when the forward travel position is selected and the vehicle is stopped and the accelerator operation is not performed and the brake operation is performed Control execution means and pulse counting means for counting at least the number of the output backward pulses when the neutral control is being executed , The number of the counted backward pulse when more than a predetermined value, the vehicle is composed as and a vehicle backward determining means for determining that it has begun to retreat.

  In the control device for an automatic transmission according to claim 2, the pulse counting means counts the number of the forward pulse and the reverse pulse that are output when the neutral control is being executed, The vehicle reverse determination means is configured to determine that the vehicle has started reverse when the difference between the counted number of forward pulses and the number of reverse pulses is a predetermined value or more.

  In the control device for an automatic transmission according to claim 1, when neutral control is being executed, the number of reverse pulses output as a forward pulse and a reverse pulse, which indicate the traveling direction of the vehicle, from the rotational speed sensor is calculated. Since at least counting is performed, and when the counted reverse pulse is equal to or greater than a predetermined value, it is determined that the vehicle has started to reverse, so that the automatic transmission is displaced or swung when the neutral control is executed. However, erroneous determination can be prevented by appropriately setting the predetermined value.

  Therefore, it is possible to improve the fuel consumption by executing the neutral control only for the necessary time, and to cancel the neutral control by quickly and accurately determining the reverse start.

  The automatic transmission control apparatus according to claim 2 is configured to determine that the vehicle has started to reverse when the difference between the counted number of forward pulses and the number of reverse pulses is equal to or greater than a predetermined value. In addition to the effects described above, when a forward pulse and a backward pulse coexist, it is possible to reliably prevent erroneous determination by determining whether or not the difference is equal to or greater than a predetermined value.

  The best mode for carrying out the automatic transmission control apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing an overall control apparatus for an automatic transmission according to an embodiment of the present invention.

  In FIG. 1, reference numeral 10 indicates an internal combustion engine (hereinafter referred to as “engine”). The engine 10 is mounted on a vehicle (partially indicated by drive wheels W).

  A throttle valve (not shown) arranged in the intake system of the engine 10 is mechanically disconnected from an accelerator pedal (not shown) arranged in the vehicle driver's seat, and is a DBW (actuator) such as an electric motor. Drive By Wire) mechanism 16 is connected and driven.

  The intake air metered by the throttle valve flows through an intake manifold (not shown) and mixes with fuel injected from an injector (fuel injection valve) 20 near the intake port of each cylinder to form an air-fuel mixture, When an intake valve (not shown) is opened, it flows into a combustion chamber (not shown) of the cylinder. In the combustion chamber, the air-fuel mixture is ignited and combusted, and after driving a piston (not shown) to rotate the crankshaft 22, exhaust gas is discharged outside the engine 10.

  The rotation of the crankshaft 22 of the engine 10 is input to the automatic transmission 26 via the torque converter 24. In other words, the crankshaft 22 is connected to the pump / impeller 24a of the torque converter 24, while the turbine runner 24b disposed opposite thereto and receiving fluid (hydraulic oil) is connected to the main shaft (mission input shaft) MS. .

  The automatic transmission 26 includes a continuously variable transmission (hereinafter referred to as “CVT”), and includes a drive pulley 26a disposed on the main shaft MS and a driven pulley disposed on a counter shaft CS parallel to the main shaft MS. 26b and a metal belt 26c hung between them.

  The drive pulley 26a includes a fixed pulley half 26a1 disposed on the main shaft MS and a movable pulley half 26a2 that can move relative to the fixed pulley half 26a1 in the axial direction. The driven pulley 26b includes a fixed pulley half 26b1 fixed to the countershaft CS and a movable pulley half 26b2 that can move relative to the fixed pulley half 26b1 in the axial direction.

  The CVT 26 is connected to the forward / reverse switching device 30. The forward / reverse switching device 30 includes a forward clutch 30a, a reverse brake 30b, and a planetary gear mechanism 30c disposed therebetween.

  In the planetary gear mechanism 30c, the sun gear 30c1 is fixed to the main shaft MS, and the ring gear 30c2 is fixed to the fixed pulley half 26a1 of the drive pulley 26a via the forward clutch 30a.

  One pinion 30c3 is arranged between the sun gear 30c1 and the ring gear 30c2. Pinion 30c3 is coupled to sun gear 30c1 by carrier 30c4. The carrier 30c4 is fixed (locked) when the reverse brake 30b is operated.

  The rotation of the counter shaft CS is transmitted to the secondary shaft SS via the reduction gears 34 and 36, and the rotation of the secondary shaft SS is transmitted to the left and right drive wheels (tires, only shown on the right side) W via the gear 40 and the differential D. It is done. A disc brake 42 is disposed in the vicinity of the drive wheel W (and a driven wheel not shown).

  Switching between the forward clutch 30a and the reverse brake 30b is performed by the driver operating a shift lever 44 provided at a vehicle driver's seat, for example, having positions P, R, N, D, S, and L. That is, when any position of the shift lever 44 is selected by the driver, the selection operation is transmitted to a manual valve (not shown) of a hydraulic mechanism (not shown).

  For example, when the D, S, and L positions are selected, the spool of the manual valve moves accordingly, and hydraulic oil (hydraulic pressure) is discharged from the piston chamber of the reverse brake 30b, while hydraulic pressure is discharged to the piston chamber of the forward clutch 30a. Is supplied and the forward clutch 30a is engaged. When the forward clutch 30a is engaged, all gears rotate together with the main shaft MS, and the drive pulley 26a is driven in the same direction (forward direction) as the main shaft MS.

  On the other hand, when the R position is selected, hydraulic oil is discharged from the piston chamber of the forward clutch 30a, while hydraulic pressure is supplied to the piston chamber of the reverse brake 30b, and the reverse brake 30b is operated. As a result, the carrier 30c4 is fixed, the ring gear 30c2 is driven in the opposite direction to the sun gear 30c1, and the drive pulley 26a is driven in the opposite direction (reverse or backward direction) to the main shaft MS.

  When the P or N position is selected, the hydraulic oil is discharged from both piston chambers, the forward clutch 30a and the reverse brake 30b are both released, and the power transmission through the forward / reverse switching device 30 is cut off. Power transmission between the engine 10 and the drive pulley 26a of the CVT 26 is interrupted.

  In the CVT 26, when hydraulic oil is supplied from the hydraulic mechanism to the piston chambers of the movable pulley halves 26a2 and 26b2, and a pulley side pressure that moves the movable pulley halves 26a2 and 26b2 in the axial direction is generated, the drive pulley 26a and the driven pulley The pulley width of the belt 26b changes, and the winding radius of the belt 26c changes. Thus, by adjusting the side pressure of the pulley, the transmission gear ratio for transmitting the output of the engine 10 to the drive wheels W can be changed steplessly.

  A crank angle sensor 48 is provided at an appropriate position such as near the cam shaft (not shown) of the engine 10 and outputs a signal indicating the engine speed NE for each predetermined crank angle position of the piston. In the intake system, an absolute pressure sensor 50 is provided at an appropriate position downstream of the throttle valve, and outputs a signal proportional to the intake pipe absolute pressure (engine load) PBA.

  The actuator of the DBW mechanism 16 is provided with a throttle opening sensor 52 and outputs a signal proportional to the throttle opening TH through the amount of rotation of the actuator, and an accelerator opening sensor 54 is provided in the vicinity of the accelerator pedal. A signal proportional to the accelerator opening AP corresponding to the accelerator pedal operation amount is output.

  Further, a water temperature sensor 56 is provided in the vicinity of a cooling water passage (not shown) of the engine 10 to generate an output corresponding to the engine cooling water temperature TW, in other words, the temperature of the engine 10, and the intake air temperature in the intake system. A sensor 58 is provided and generates an output corresponding to the intake air temperature (outside air temperature) taken into the engine 10.

  The output of the crank angle sensor 48 and the like described above is sent to the engine controller 60. The engine controller 60 includes a microcomputer, determines the target throttle opening based on the sensor outputs, controls the operation of the DBW mechanism 16, and determines the fuel injection amount to drive the injector 20.

  The main shaft MS is provided with an NT sensor (rotational speed sensor) 62, which determines the rotational speed of the turbine runner 24b, specifically the rotational speed of the main shaft MS, more specifically the input shaft rotational speed of the forward clutch 30a. The pulse signal shown is output.

  An NDR sensor (rotational speed sensor) 64 is provided at an appropriate position in the vicinity of the drive pulley 26a of the CVT 26 to output a pulse signal corresponding to the rotational speed of the drive pulley 26a, in other words, the output shaft rotational speed of the forward clutch 30a. At the same time, an NDN sensor (rotational speed sensor) 66 is provided at an appropriate position near the driven pulley 26b to output a pulse signal indicating the rotational speed of the driven pulley 26b.

  A VEL sensor (rotational speed sensor) 70 is provided in the vicinity of the gear 36 fixed to the output shaft of the secondary shaft SS, in other words, the CVT 26, and the rotational speed of the output shaft of the CVT 26 or the vehicle speed VEL is determined through the rotational speed of the gear 36. The pulse signal shown is output.

  Further, a shift lever position sensor 72 is provided in the vicinity of the shift lever 44, and outputs a POS signal corresponding to the position of R, N, D, etc. operated (selected) by the driver. A brake switch 74 is disposed in the vicinity of the disc brake 42 disposed in the vicinity of each of the driving wheel W and the driven wheel, and outputs an ON signal when a brake operation is performed by the driver.

  The output of the NT sensor 62 and the like described above is sent to the shift controller 76 including the outputs of other sensors (not shown). The shift controller 76 also includes a microcomputer and is configured to be able to communicate with the engine controller 60.

  In addition, an inclination sensor 80 is disposed in an appropriate position of the vehicle 14, for example, in a case 78 that accommodates the shift controller 76, and generates an output corresponding to the inclination of the place where the vehicle 14 travels, that is, the gradient of the travel path. The output of the tilt sensor 80 is also sent to the shift controller 76.

  In the shift controller 76, the outputs of the NT sensor 62 and the NDN sensor 66 described above are input to the waveform shaping circuit, and the shift controller 76 counts the output of the waveform shaping circuit to detect the rotational speed. The outputs of the NDR sensor 64 and the VEL sensor 70 are input to the waveform shaping circuit and the rotation direction detection circuit, and the shift controller 76 detects the rotation speed (vehicle speed) and the rotation direction from the outputs.

  Here, to supplement the description of the VEL sensor 70, as shown in FIG. 2, the VEL sensor 70 has a plurality of, more specifically 12 protrusions formed on the circumference of the gear 36, and in the vicinity thereof. Includes two magnetoelectric conversion elements (MRE elements) 70a for outputting two kinds of pulses having different phases for each predetermined rotation angle of the gear 36, and two kinds of outputted pulses are inputted via shaping circuits A and B. And a rotation direction detection circuit 70b that detects the rotation direction from them and outputs it as a forward pulse and a backward (reverse) pulse that mean the traveling direction of the vehicle 14. Although not shown, the NDR sensor 64 has a similar structure.

  The shift controller 76 controls the operation of the torque converter 24 and the CVT 26 by exciting / de-energizing an electromagnetic solenoid (not shown) of the hydraulic mechanism based on the output of the NT sensor 62 and the like, and determines whether the shift lever position detection is correct or not. Then, an operation amount such as a belt transmission torque command value is determined.

  Further, the shift controller 76 executes neutral control and determines whether or not the vehicle is moving backward during execution of the neutral control.

  FIG. 3 is a flowchart showing an operation for determining whether or not the vehicle is moving backward during the neutral control of the shift controller 76. The illustrated program is executed by the shift controller 76 every predetermined time, for example, every 10 msec.

  In the following, first, in S10, it is determined whether or not neutral control is being executed.

  As described above, the shift controller 76 selects the forward travel position in which the vehicle 14 is one of D, S, and L based on the outputs of the shift lever position sensor 72, the accelerator opening sensor 54, and the brake switch 74, and stops. In addition, when the accelerator operation is not performed and the brake operation is performed, the neutral control (or non-creep control) is executed to form the same neutral state when the position is N for the purpose of improving fuel efficiency. To do.

  When the result is affirmative in S10, the process proceeds to S12, and it is determined whether or not a backward pulse is output. When the result is affirmative, the process proceeds to S14 and the backward pulse (and the forward pulse output by incrementing the pulse counter is output). Count the number of forward pulses). If the determination at S12 is No, the process at S14 is skipped.

  To explain this, when the vehicle 14 is completely stopped, if the position changes from N to D, the torque change caused by this causes a displacement in the power plant (input side of the CVT 26). Output a pulse.

  That is, when the vehicle 14 is stopped, the accelerator operation is not performed, and the position is switched from N to D while the brake operation is performed, the neutral control is executed, but a pulse is output at that time. As far as the inventors have found, the number of pulses corresponding to the displacement of the CVT 26 was three.

  This will be described with reference to FIG. 4 time chart.

  FIG. 4A shows the output of the VEL sensor 70 when the CVT 26 is displaced as described above, and FIG.

  In the case shown in FIG. 4A, since the total value of the number of reverse pulses is three pulses corresponding to the displacement of the CVT 26, it can be determined that the displacement of the CVT 26 is not the reverse of the vehicle 14.

  Therefore, in the case of the backward movement of the vehicle 14 shown in (b), it is usually determined that the vehicle 14 has started backward when the first backward pulse is output. However, during the neutral control execution, (a) In consideration of the above, it is determined that the vehicle 14 has started to reverse when a predetermined value, that is, 3 pulses exceeds 4 pulses or more. As a result, even if displacement or swinging occurs in the CVT 26 during the neutral control, the vehicle 14 will not be erroneously determined to start moving backward.

  As described with reference to the flowchart of FIG. 3, only the backward pulse is originally output during execution of the neutral control. However, the forward pulse may be mixed due to the swing of the CVT 26 or the like.

  Therefore, in this case, as shown in FIGS. 4A and 4B, when the forward pulse is negative and the backward pulse is positive when the difference between the forward pulse and the backward pulse is equal to or greater than the predetermined value (4 pulses). It is determined that the vehicle 14 has started to reverse. Thereby, even if the forward pulse is mixed into the backward pulse due to the swing of the CVT 26, the erroneous determination of the backward start of the vehicle 14 can be prevented more reliably.

  Returning to the description of the flow chart of FIG. 3, the process then proceeds to S16, where it is determined whether or not the value of the pulse counter exceeds the predetermined value (four pulses). If the result is affirmative, the process proceeds to S18, and the vehicle 14 moves backward. Is determined to have started.

  FIG. 5 is a time chart showing the processing of FIG. 4. As shown in the figure, it is determined that the vehicle 14 has started to reverse when the number of reverse pulses reaches four.

  On the other hand, when the result in S10 is negative, the process proceeds to S20, the value of the pulse counter is reset (cleared), the process proceeds to S22, and the process waits for the reverse pulse to be output. Is determined to have started retreat. That is, when the result in S10 is negative, since it is difficult for displacement or the like to occur in the CVT 26, it is determined that the vehicle 14 has started to reverse immediately when the reverse pulse is output.

  When the shift controller 76 determines that the vehicle 14 has started to reverse, the shift controller 76 releases the neutral control and engages (engages) the forward clutch 30a.

  As described above, this embodiment is mounted on the vehicle 14 and in the shift controller (control device) 76 of the CVT (automatic transmission) 26 that changes the speed of the engine (internal combustion engine) 10, the input shaft of the CVT 26 or The rotation speed detecting means (VEL sensor 70) comprising two magnetoelectric conversion elements 70a for outputting two kinds of pulses having different phases for each predetermined rotation angle of the output shaft, more specifically, the output shaft, and the output Rotation direction detection means (rotation direction detection circuit 70b of the VEL sensor 70) for detecting the rotation direction from the two types of pulses and outputting them as a forward pulse and a backward pulse that mean the traveling direction of the vehicle 14, and a forward travel position D , S, L is selected and the vehicle is stopped, the accelerator operation is not performed, and the brake operation is performed. A neutral control execution means (S10) to perform, a pulse count means (S12, S14) for counting at least the number of the output backward pulses when the neutral control is being executed, and a counter of the counted backward pulses. When the number is equal to or greater than a predetermined value (for example, 4), the vehicle 14 is provided with vehicle reverse determination means (S16, S18) for determining that the vehicle 14 has started reverse movement. Even if displacement or swinging occurs, erroneous determination can be prevented by appropriately setting a predetermined value.

  Therefore, it is possible to improve the fuel consumption by executing the neutral control only for the necessary time, and to cancel the neutral control by quickly and accurately determining the reverse start of the vehicle 14.

  The pulse counting means counts the number of forward pulses and backward pulses that are output when the neutral control is executed (S12, S14), and the vehicle reverse determination means counts the number. When the difference between the number of forward pulses and the number of reverse pulses is equal to or greater than a predetermined value (for example, 4), the vehicle is configured to include vehicle reverse determination means (S16, S18) for determining that the vehicle 14 has started reverse. Even when the forward pulse and the backward pulse are mixed due to the swing of the CVT 26, it is possible to reliably prevent erroneous determination by determining whether or not the difference is equal to or greater than a predetermined value.

  In the above description, the VEL sensor 70 includes the rotation direction detection circuit 70a and detects the rotation direction. However, the shift controller 76 may detect the rotation direction. In the above description, “the rotational speed detection means including two magnetoelectric conversion elements 70a that output two kinds of pulses having different phases for each predetermined rotation angle of the input shaft or output shaft of the CVT 26, more specifically, the output shaft ( VEL sensor 70) and a rotation direction detecting means for detecting a rotation direction from the two kinds of outputted pulses and outputting as a forward pulse and a backward pulse that mean the traveling direction of the vehicle 14 (rotation direction detection of VEL sensor 70) "Circuit 70b)" indicates its intent.

  Further, although the rotation speed of the output shaft of the CVT 26 is detected by the output of the VEL sensor 70, the rotation speed of the input shaft of the CVT 26 may be detected by the output of the NDR sensor 64.

  Moreover, although CVT26 was mentioned as an example of an automatic transmission, it is an illustration and this invention is not limited to it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an entire automatic transmission control apparatus according to an embodiment of the present invention. It is a block diagram which shows the structure of the VEL sensor (rotation speed sensor) shown in FIG. It is a flowchart which shows operation | movement of the apparatus shown in FIG. It is a time chart which shows the pulse output from the VEL sensor shown in FIG. It is a time chart explaining the process of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Internal combustion engine (engine), 14 Vehicle, 16 DBW mechanism, 24 Torque converter, 26 Automatic transmission (continuously variable transmission. CVT), 30 Forward / reverse switching device, 30a Forward clutch, 44 Shift lever, 54 Accelerator opening sensor , 60 engine controller, 62 NT sensor, 64 NDR sensor, 70 VEL sensor (rotational speed sensor), 72 shift lever position sensor, 74 brake switch, 76 shift controller

Claims (2)

In a control device for an automatic transmission that is mounted on a vehicle and that changes the rotation of an internal combustion engine,
a. A rotational speed detection means comprising two magnetoelectric conversion elements that respectively output two kinds of pulses having different phases for each predetermined rotational angle of the input shaft or output shaft of the automatic transmission;
b. Rotation direction detection means for detecting a rotation direction from the two kinds of outputted pulses and outputting as a forward pulse and a backward pulse, which means the traveling direction of the vehicle,
c. A neutral control execution means for executing a neutral control when the forward drive position is selected and the vehicle is stopped, the accelerator operation is not performed, and the brake operation is performed;
d. Pulse counting means for counting at least the number of output backward pulses when the neutral control is being performed;
e. Vehicle reverse determination means for determining that the vehicle has started reverse when the counted number of reverse pulses is equal to or greater than a predetermined value;
A control device for an automatic transmission, comprising:   The pulse counting means counts the number of forward pulses and backward pulses that are output when the neutral control is being executed, and the vehicle reverse determination means counts the number of forward pulses and backwards that are counted. 2. The control device for an automatic transmission according to claim 1, wherein when the difference in the number of pulses is equal to or greater than a predetermined value, it is determined that the vehicle has started to reverse.

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