JP5783055B2 - Transmission abnormality determination device - Google Patents

Description

  The present invention relates to an abnormality determination device for a transmission mounted on a vehicle.

  Conventionally, an automatic transmission that performs clutch-to-clutch shifting as a transmission mounted on a vehicle, or a belt-type continuously variable transmission (CVT: Continuously Variable Transmission) that can change the gear ratio steplessly. It has been known.

  Of these, the belt-type continuously variable transmission includes a primary pulley on the drive side, a secondary pulley on the driven side, a belt wound around these pulleys, and a pulley on the primary pulley side that controls the pulley width on the drive side. It is equipped with a hydraulic actuator and a secondary pulley side hydraulic actuator that controls the driven pulley width, and the gear ratio is changed steplessly by changing the pulley width by controlling the hydraulic pressure supplied to both hydraulic actuators. It is supposed to let you.

  Further, as a failure determination device for a vehicle equipped with a continuously variable transmission, a device that can easily identify a failed component is known (see, for example, Patent Document 1).

  The vehicle failure determination device disclosed in Patent Document 1 can select a normal mode and a garage mode, and an actual gear ratio (hereinafter also referred to as an actual gear ratio) is a target gear ratio in the normal mode. When it is determined that the range has not been reached, it is determined that there is an abnormality, and the garage mode is selected from the normal mode. The failure determination device determines that the linear solenoid valve has failed when the turbine rotation speed is greater than the rotation speed threshold, and determines that the shift solenoid valve has failed when the turbine rotation speed is equal to or less than the rotation speed threshold. It is like that.

JP 2010-96240 A

  However, in the conventional vehicle failure determination apparatus as described above, since only the deviation of the actual transmission ratio is monitored with respect to the target transmission ratio, the actual transmission ratio greatly deviates from the target transmission ratio. There is a problem that it can only be determined to be abnormal within a certain range, and it takes time to determine that it is abnormal.

  Specifically, a conventional belt-type continuously variable transmission is provided with a hydraulic control device that controls the hydraulic pressure supplied and discharged by the hydraulic actuators of both pulleys, and is driven by a shift solenoid valve that constitutes the hydraulic control device. Feedback control is performed to adjust the signal to bring the actual gear ratio closer to the target gear ratio. For this reason, since the target gear ratio is set based on the running state of the vehicle (for example, the accelerator opening and the vehicle speed) and a previously stored control map (optimum fuel consumption line, etc.), a large threshold value for determining abnormality is set. It is necessary, and it can be determined as abnormal only in a range where the actual gear ratio is greatly deviated from the target gear ratio, and it takes time to determine that the abnormality is abnormal. In addition, when the hydraulic oil for controlling the continuously variable transmission is in a low temperature state, the response is deteriorated, so that the threshold value must be set larger.

  In particular, in a conventional belt-type continuously variable transmission, for example, when a downshift occurs due to an abnormality such as an abnormality occurring in a transmission solenoid valve and a decrease in hydraulic pressure supplied to the hydraulic actuator on the primary pulley side, This will cause unintended deceleration of the vehicle. For this reason, it is preferable to perform fail-safe control so as to quickly determine that there is an abnormality even if a shift abnormality occurs and to avoid unintended deceleration. This is also the case when an abnormality occurs in, for example, a hydraulic control valve that controls the engagement and release of the friction engagement element in the conventional automatic transmission.

  The present invention has been made to solve the conventional problems as described above, and can shorten the time from the occurrence of shift abnormality to the abnormality determination as compared with the conventional case, and the abnormality determination It is an object of the present invention to provide an abnormality determination device for a transmission that can improve accuracy.

In order to achieve the above object, a transmission abnormality determination device according to the present invention is mounted on a vehicle equipped with a transmission that shifts rotational power input from an input shaft and outputs it to an output shaft. An abnormality determination device for a transmission that determines abnormality of the transmission based on a condition, wherein the abnormality determination condition is that an actual gear ratio obtained by the gear shift is a first target gear ratio with respect to a set target gear ratio. a first abnormality determination condition is satisfied when a predetermined value or more, the second abnormality determination condition is satisfied when the rate of change of the actual speed ratio is the second predetermined value or more, and the actual speed ratio A third abnormality determination condition that is satisfied when a change rate of a difference from the target speed ratio is equal to or greater than a third predetermined value , and a rate of change in the rotation speed of the output shaft corresponding to the vehicle speed of the vehicle is a negative value. fourth abnormality satisfied when the fourth less than the predetermined value is It includes a constant condition, and the first to fourth abnormality determination condition is when all been met, and judging the abnormality of the transmission.

  With this configuration, since the abnormality determination is made in combination with a plurality of abnormality determination conditions, the speed change is made in comparison with the conventional case where the abnormality is determined based only on the deviation of the actual speed ratio from the target speed ratio. The time from the occurrence of an abnormality to the determination of abnormality can be shortened, and the accuracy of the abnormality determination can be improved.

  Specifically, even if the first predetermined value is set smaller than the conventional value, the change ratio of the actual gear ratio is compared with the second predetermined value, so that it has not been used for the conventional abnormality determination. The transient phenomenon can be monitored in the initial stage of the abnormal shifting. For this reason, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination.

  Furthermore, even if the first predetermined value is set smaller than the conventional value, the change ratio of the difference between the actual gear ratio and the target gear ratio is compared with the third predetermined value, so that the conventional abnormality determination The transient phenomenon can be monitored in the initial stage of the shift abnormality that has not been used for the transmission. For this reason, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination. Further, even if the change ratio of the actual transmission ratio that satisfies the second abnormality determination condition is in an abnormal range, if the change ratio of the difference between the actual transmission ratio and the target transmission ratio is smaller than the third predetermined value, an abnormality is indicated. Since determination is not performed, the accuracy of abnormality determination can be improved.

In addition, it is determined whether or not the rate of change in the rotational speed of the output shaft of the transmission corresponding to the vehicle speed of the vehicle is smaller than a fourth predetermined value that is a negative value for determining a decrease in the vehicle speed due to the downshift. Therefore, it is possible to monitor the transient phenomenon at the initial stage of the shift abnormality that has not been used in the conventional abnormality determination. For this reason, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination. For example, when a downshift due to a shift abnormality occurs and the rate of decrease in the vehicle speed is large as a transient phenomenon in the initial stage of the shift abnormality, it can be determined that there is an abnormality.

  In this way, by setting each predetermined value in the first to fourth abnormality determination conditions so that the time from the occurrence of a shift abnormality to the abnormality determination can be shortened, it is possible to suppress unnecessary determination of abnormality. Therefore, it is possible to achieve both shortening of the time until abnormality determination and improvement of abnormality determination accuracy.

Further, the malfunction determining device for a transmission according to the above (1), (2) the abnormality determination condition, the rotational speed of the rate of change of the output shaft before Symbol transmission, smaller than a predetermined value of the fourth This condition is established when the slippage of the driving wheel of the vehicle is smaller than a fifth predetermined value that can be determined as to whether or not the slipping state occurs .

With this configuration, since the fifth predetermined value smaller than the fourth predetermined value for determining the decrease in the vehicle speed due to the downshift is used, for example, when the grip is lost on the low μ road and the vehicle falls into the slip state, it is determined that there is an abnormality. It is possible to improve abnormality determination accuracy. Specifically, when a shift abnormality occurs on a low μ road and a driver's unintentional deceleration due to a sudden downshift occurs, the driving wheel tends to slip, and in such a situation, the behavior of the vehicle is stabilized. Therefore, it is necessary to execute fail-safe control immediately. Therefore, if it meets the abnormal determination condition using a predetermined value of the fifth, since it can be determined that abnormality, it is possible to improve the accuracy of abnormality determination.

  In the transmission abnormality determination device described in (1) or (2) above, (3) a first rotational speed sensor that detects the rotational speed of the input shaft, and a rotational speed of the output shaft. A second rotational speed sensor; and a calculation unit that calculates the actual speed ratio by dividing the detected rotational speed of the input shaft by the detected rotational speed of the output shaft. .

  With this configuration, the actual gear ratio can be calculated based on the detection result from the existing sensor provided in the transmission, so there is no need to provide a new sensor. As a result, it is possible to achieve a reduction in time from the occurrence of a shift abnormality to the determination of the abnormality and an improvement in the determination accuracy of the abnormality at a low cost.

In the transmission abnormality determination device described in (1) above, (4) a third rotation speed sensor that detects the rotation speed of the drive wheel of the vehicle and a rotation speed of the driven wheel of the vehicle. 4, wherein the abnormality determination condition corresponds to a case where the change rate of the rotation speed of the output shaft of the transmission is smaller than the fourth predetermined value . This is established when the absolute value of the difference between the rotational speed and the detected rotational speed of the driven wheel is equal to or greater than a sixth predetermined value.

  With this configuration, when a deviation occurs by comparing the detected rotational speed of the driving wheel with the detected rotational speed of the driven wheel, the driving wheel is in a slip state. It can be determined, and the accuracy of abnormality determination can be improved.

In the transmission abnormality determination device described in (1) above, (5) an acceleration sensor that detects vehicle acceleration, vehicle speed detection means that detects the vehicle speed, and acceleration detected from the detected vehicle speed. And an abnormality determination condition detected by the acceleration sensor corresponding to a rate of change in the number of rotations of the output shaft of the transmission being smaller than the fourth predetermined value . It is established when the absolute value of the difference between the detected acceleration and the calculated acceleration calculated by the acceleration calculating means is equal to or greater than a seventh predetermined value.

  With this configuration, by comparing the detected acceleration acquired from the acceleration sensor with the calculated acceleration calculated by the acceleration calculating means, it is possible to determine that the vehicle is in a slip state when there is a divergence. It is possible to improve the accuracy of abnormality determination.

  In the transmission abnormality determination device described in (1) to (5) above, (6) the transmission has a transmission belt wound around a pair of variable pulleys having variable effective diameters, and a pair of hydraulic pulleys It is characterized by comprising a belt type continuously variable transmission in which the gear ratio is continuously changed by changing the effective diameter of the variable pulley.

  According to the present invention, it is possible to provide an abnormality determination device for a transmission that can shorten the time from when a shift abnormality occurs to the abnormality determination as compared with the prior art and improve the accuracy of the abnormality determination. can do.

1 is a schematic block configuration diagram of a vehicle including a transmission abnormality determination device according to an embodiment of the present invention. It is a block diagram of the transmission which concerns on embodiment of this invention. It is a flowchart which shows the abnormality determination process which concerns on embodiment of this invention. It is a timing chart for demonstrating abnormality determination which concerns on embodiment of this invention.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described.
FIG. 1 is a schematic block configuration diagram of a vehicle provided with a control device according to a first embodiment of the present invention.

  As shown in FIG. 1, a vehicle 10 according to the present embodiment includes an engine 11 as a power source, a crankshaft 15 as an output shaft that transmits power generated in the engine 11, and power generated in the engine 11. A transmission 20 having a belt-type continuously variable transmission (hereinafter simply referred to as “CVT”) 70 that transmits and continuously changes the gear ratio according to the traveling state of the vehicle 10, and controls the transmission 20 by hydraulic pressure. The hydraulic control device 30 for transmitting the power, the propeller shaft 25 for transmitting the power transmitted by the transmission 20, the differential mechanism 40 for transmitting the power transmitted by the propeller shaft 25, and the power transmitted by the differential mechanism 40. Drive shafts 43L and 43R as drive shafts for transmission, and drive shaft 43L Driving wheel 45L to drive the vehicle 10 by rotating with the power transmitted by 43R, it comprises a 45R, a.

  Furthermore, the vehicle 10 includes an ECU (Electronic Control Unit) 100 as a vehicle electronic control device for controlling the entire vehicle 10. In addition, the vehicle 10 is provided with a crank sensor 81, a shift sensor 82, a drive shaft rotational speed sensor 83, and other various sensors (not shown). Various sensors are configured to input detected signals to the ECU 100.

  The engine 11 is configured by a known power device that outputs power by burning a mixture of hydrocarbon fuel such as gasoline or light oil and air in a combustion chamber of a cylinder (not shown). The engine 11 reciprocates the piston in the cylinder by intermittently repeating the intake, combustion, and exhaust of the air-fuel mixture in the combustion chamber, and rotates the crankshaft 15 connected to the piston so that power can be transmitted. Power is transmitted to the machine 20. The fuel used for the engine 11 may be an alcohol fuel containing alcohol such as ethanol.

  The hydraulic pressure control device 30 has a known hydraulic pressure control circuit. The oil pumped up from the oil pan by the oil pump is controlled by a plurality of solenoid valves controlled by the ECU 100 and the hydraulic pressure is controlled. The transmission 20 is output to control the transmission 20.

  The differential mechanism 40 allows a difference in rotational speed between the drive wheel 45L and the drive wheel 45R when traveling on a curve or the like. The differential mechanism 40 transmits the power transmitted by the rotation of the propeller shaft 25 to the drive wheels 45L and 45R by rotating the drive shafts 43L and 43R. Note that the differential mechanism 40 may be capable of taking a differential lock state that does not allow a difference in rotational speed between the drive wheel 45L and the drive wheel 45R.

  The drive wheels 45L and 45R include, for example, a metal wheel attached to the drive shaft, and a resin tire, for example, attached so as to cover the outer periphery of the wheel. The drive wheels 45L and 45R are rotated by the power transmitted by the drive shafts 43L and 43R, and drive the vehicle 10 by the frictional action between the tire and the road surface.

  The ECU 100 is a central processing unit (CPU) as a central processing unit, a ROM (Read Only Memory) that stores fixed data, a backup memory that includes a rewritable nonvolatile memory, and temporarily stores data. A RAM (Random Access Memory) and an input / output interface circuit (both not shown) are included. Note that the ECU 100 controls the control of the vehicle 10.

  Further, the ECU 100 is connected to a crank sensor 81, a shift sensor 82, a drive shaft rotational speed sensor 83, and an accelerator opening sensor 88.

  The crank sensor 81 is controlled by the ECU 100 to detect the number of rotations of the crankshaft 15 and input the detected detection signal to the ECU 100. The ECU 100 acquires the rotation speed of the crankshaft 15 indicated by the detection signal input by the crank sensor 81 as the engine rotation speed Ne.

  The shift sensor 82 is controlled by the ECU 100 to detect which of the plurality of switching positions of the shift lever 21 is in the switching position, and input a detection signal indicating the switching position of the shift lever 21 to the ECU 100. It has become.

  The drive shaft rotational speed sensor 83 is controlled by the ECU 100 to detect the rotational speed of the drive shaft 43L (or 43R) and input a detection signal representing the rotational speed of the drive shaft 43L (or 43R) to the ECU 100. It has become. The ECU 100 calculates the traveling speed of the vehicle 10 based on the detection signal input by the drive shaft rotation speed sensor 83.

  The accelerator opening sensor 88 is controlled by the ECU 100 to detect an accelerator opening representing the accelerator operation amount of the driver and to input a detection signal representing the accelerator opening to the ECU 100.

Next, the configuration of the transmission 20 will be described with reference to FIG.
FIG. 2 is a configuration diagram of the transmission according to the embodiment of the present invention.

  First, power generated in the engine 11 is transmitted to the torque converter 50 via the crankshaft 15. The power transmitted to the torque converter 50 is further transmitted to the differential mechanism 40 via the forward / reverse switching device 60, the CVT 70, and the reduction gear 80, and is distributed to the left and right drive wheels 45L and 45R. That is, the CVT 70 is provided in a power transmission path from the engine 11 to the left and right drive wheels (for example, rear wheels) 45L and 45R.

  Further, the torque converter 50 rotates to a non-rotating member via a pump impeller 51p connected to the crankshaft 15, a turbine runner 51t connected to the forward / reverse switching device 60 via the turbine shaft 55, and a one-way clutch. The stator 51s is supported by a known torque converter that transmits power through a fluid.

  Further, between the pump impeller 51p and the turbine runner 51t, a lock-up clutch (directly connected) that allows the pump impeller 51p and the turbine runner 51t to be integrally connected to each other and integrally rotated to improve fuel efficiency. Clutch) 52 is provided.

  The forward / reverse switching machine 60 is constituted by a double pinion type planetary gear device. The sun gear 61s is connected to the turbine shaft 55 of the torque converter 50, and the carrier 62c is connected to a primary shaft 71 that is an input shaft of the CVT 70.

  When the forward clutch 64 disposed between the carrier 62c and the sun gear 61s is engaged by hydraulic pressure, the sun gear 61s, the carrier 62c, and the ring gear 63r are integrally rotated, so that the turbine shaft 55 is the primary shaft. The driving force in the forward direction is transmitted to the drive wheels 45L and 45R.

  When the reverse brake 66 disposed between the ring gear 63r and the housing 65 is engaged by hydraulic pressure and the forward clutch 64 is released, the sun gear 61s that rotates integrally with the turbine shaft 55 is rotated in the rotational direction. On the other hand, the sun gear 61 s revolves while rotating relatively, so that the carrier 62 c rotates in a direction opposite to the rotation direction of the turbine shaft 55. Accordingly, since the primary shaft 71 connected to the carrier 62c is rotated in the reverse direction with respect to the turbine shaft 55, the drive force in the reverse direction is transmitted to the drive wheels 45L and 45R.

  On the other hand, the CVT 70 includes a primary pulley 72 having a variable effective diameter provided on the primary shaft 71, a secondary pulley 77 having a variable effective diameter provided on a secondary shaft 79 that is an output shaft of the CVT 70, a primary pulley 72, and a secondary pulley. And a transmission belt 75 wound around a V-groove formed in each of the pulleys 77. With this configuration, the CVT 70 transmits power to the transmission belt 75 functioning as a power transmission element by using a frictional force between the inner pulley wall surfaces of the primary pulley 72 and the secondary pulley 77.

  Specifically, the primary pulley 72 has a movable sheave 72a that faces each other and forms a V-groove by an opposing surface, and a fixed sheave 72b, and the V-groove formed by the movable sheave 72a and the fixed sheave 72b. A transmission belt 75 is wound around the belt.

  Further, the secondary pulley 77 includes a movable sheave 77a and a fixed sheave 77b that are opposed to each other and form a V-groove by an opposing surface. It is wrapped around.

  The primary pulley 72 and the secondary pulley 77 have an input side hydraulic cylinder 73 formed on the movable sheave 72a and an output side formed on the movable sheave 77a in order to change the V groove width, that is, the engagement diameter of the transmission belt 75. A hydraulic cylinder 78 is provided.

The flow rate of the oil supplied to or discharged from the input side hydraulic cylinder 73 of the movable sheave 72 a is controlled by the hydraulic control device 30, so that the V groove widths of the primary pulley 72 and the secondary pulley 77 change to transmit power. The hanging diameter (effective diameter) of the belt 75 is changed. As a result, the speed ratio γ (= actual rotational speed N _IN of the primary shaft 71 of the primary pulley 72 / actual rotational speed N _OUT of the secondary shaft 79 of the secondary pulley 77) can be changed continuously, that is, steplessly. it can.

  The hydraulic pressure PB in the output side hydraulic cylinder 78 of the movable sheave 77a corresponds to the clamping pressure of the secondary pulley 77 against the transmission belt 75 and the tension of the transmission belt 75, and the tension of the transmission belt 75, that is, Since it is closely related to the pressing force of the primary pulley 72 and the secondary pulley 77 of the transmission belt 75 against the inner wall surface of the V-groove, it can also be called a belt tension control pressure, a belt clamping pressure control pressure, or a belt pressing force control pressure. Yes, the hydraulic control device 30 adjusts the pressure so that the transmission belt 75 does not slip.

  Here, a turbine shaft speed sensor 84, an input shaft speed sensor 85, and an output shaft speed sensor 86 are connected to the ECU 100.

  The turbine shaft rotational speed sensor 84 detects the rotational speed of the turbine shaft 55 connected to the turbine runner 51 t of the torque converter 50. Further, the turbine shaft rotational speed sensor 84 inputs a detection signal indicating the rotational speed of the turbine shaft 55 to the ECU 100.

  The input shaft rotational speed sensor 85 detects the rotational speed of the primary shaft 71 of the primary pulley 72 connected to the carrier 62c. Further, the input shaft rotation speed sensor 85 inputs a detection signal indicating the rotation speed of the primary shaft 71 to the ECU 100.

  The output shaft rotation speed sensor 86 detects the rotation speed of the secondary shaft 79 of the secondary pulley 77 connected to the reduction gear 80. Further, the output shaft rotation speed sensor 86 inputs a detection signal indicating the rotation speed of the secondary shaft 79 to the ECU 100.

  Here, the ECU 100 detects the rotational speed Nin of the primary shaft 71 indicated by the detection signal input by the input shaft rotational speed sensor 85 and the rotational speed Nout of the secondary shaft 79 indicated by the detection signal input by the output shaft rotational speed sensor 86. Based on the above, the actual gear ratio γ (= actual rotational speed Nin of the primary shaft 71 of the primary pulley 72 / actual rotational speed Nout of the secondary shaft 79 of the secondary pulley 77) is calculated. Thus, ECU 100 calculates the actual gear ratio γ by dividing the rotational speed Nin of the input shaft by the rotational speed Nout of the output shaft, and thus constitutes a calculation unit according to the present invention.

  Further, the ECU 100 determines whether the operating state of the engine 11 is based on conditions such as the speed of the vehicle 10 and the driver's accelerator opening calculated as described above and a map (optimum fuel consumption curve) stored in the ROM. The gear ratio of the CVT 70 is controlled via the hydraulic control device 30 so as to be optimal.

  The ECU 100 sets the target gear ratio so that the operating state of the engine 11 is optimal, and calculates the hydraulic pressure supplied to the input-side hydraulic cylinder 73 and the output-side hydraulic cylinder 78 so that the actual gear ratio is brought close to the target gear ratio. The hydraulic control device 30 is controlled based on the calculation result.

  Next, a characteristic configuration of the vehicle 10 including the transmission abnormality determination device according to the embodiment of the present invention will be described.

ECU100 is adapted to calculate the actual gear ratio gamma _R based on the rotation speed of the rotation speed and the secondary shaft 79 of the primary shaft 71 detected by the input shaft rotational speed sensor 85 and the output shaft speed sensor 86. The ECU 100 compares the calculated actual gear ratio γ _R with the target gear ratio γ _T added with a _first predetermined value P ₁ (hereinafter also referred to as a first reference value). . Specifically, ECU 100, the actual gear ratio gamma _R is adapted to determine whether the target gear ratio gamma _T first predetermined value added value than that to. That, ECU 100, when the actual gear ratio gamma _R of the first reference value _{P 1} than the target speed ratio gamma _T, determining that the first abnormality determination condition is satisfied. Therefore, ECU 100, the actual gear ratio constitute a first abnormality determining means for determining whether the first reference value P ₁ or more with respect to the target speed ratio.

Further, ECU 100, when the first abnormality determination condition is satisfied, being adapted to calculate a change rate Δγ actual gear ratio, calculated actual speed prescribed value change rate Δγ is the second ratio P ₂ ( Hereinafter, it is also determined whether or not it is also a second reference value. That is, the ECU 100 determines that the second abnormality determination condition is satisfied when the change ratio Δγ of the actual gear ratio is equal to or greater than the _second reference value P2. Therefore, the ECU 100 constitutes a second abnormality determination unit that determines whether or not the change ratio of the actual gear ratio is equal to or greater than the second reference value.

Further, when the second abnormality determination condition is satisfied, the ECU 100 calculates a change ratio ΔP of a value obtained by subtracting the target speed ratio from the actual speed ratio, and the change ratio ΔP is a third predetermined value. It is determined whether or not it is greater than or equal to P ₃ (hereinafter also referred to as a third reference value). That is, the ECU 100 determines that the third abnormality determination condition is satisfied when the change rate ΔP of the difference between the actual speed ratio and the target speed ratio is equal to or greater than the _third reference value P3. Therefore, the ECU 100 constitutes a third abnormality determination unit that determines whether or not the change rate of the difference between the actual speed ratio and the target speed ratio is greater than or equal to the third reference value.

Further, when the third abnormality determination condition is satisfied, the ECU 100 changes the change rate (change rate) of the output shaft speed of the transmission based on the speed of the secondary shaft 79 detected by the output shaft speed sensor 86. ) Is calculated, and it is determined whether or not the calculated change ratio is smaller than a fourth predetermined value P4 (hereinafter also referred to as a fourth reference value). That is, ECU 100 determines that the fourth abnormality determination condition is satisfied when the change rate of the rotation speed of the output shaft of the transmission is less than fourth reference value P4. Therefore, the ECU 100 constitutes a fourth abnormality determination unit that determines whether or not the rate of change in the rotational speed of the output shaft of the transmission is smaller than the fourth reference value P4. Here, it is preferable that the fourth reference value is set to a value that is less than zero and set to a negative value, and that can detect a decrease in vehicle speed due to a downshift caused by a shift abnormality.

Further, ECU 100 is configured to determine an abnormality of the transmission based on the abnormality determination condition, and includes first to fourth abnormality determination conditions as the abnormality determination conditions. Therefore, the ECU 100 determines that the transmission is abnormal when all of the first to fourth abnormality determination conditions are satisfied. Here, each predetermined value in the first to fourth abnormality determination conditions is experimentally determined in advance in consideration of the accuracy of the abnormality determination and the determination time, and is stored in advance in the ROM. For example, the CVT 70 according to the present embodiment has a first reference value P when the transmission gear ratio γ is configured by a transmission that can take between 0.4 (γmax) and 2.5 (γmin). ₁ is set to 0.3, the second reference value _{P 2} is set to 0.02, the third reference value _{P 3} is preferably set to 0.02. Note that the predetermined time interval at which the abnormality determination process is executed by the ECU 100 is 16 msec.

  The ECU 100 may determine that the transmission is abnormal based on at least two or three abnormality determination conditions among the first to fourth abnormality determination conditions. In this case, each predetermined value in each abnormality determination condition is set in consideration of the accuracy of the abnormality determination and the determination time.

The ECU 100 replaces the fourth abnormality determination condition with a fifth predetermined value P ₅ (hereinafter referred to as the first predetermined value) in which the change rate of the secondary shaft 72 (output shaft of the transmission) is set to be smaller than the fourth predetermined value. It may be determined as a fifth abnormality determination condition whether it is smaller than a reference value of 5). In this case, the ECU 100 determines that the fifth abnormality determination condition is satisfied when the change rate of the rotation speed of the secondary shaft 72 (output shaft of the transmission) is less than the _fifth reference value P5. Therefore, the ECU 100 constitutes a fifth abnormality determination means for determining whether the change rate of the rotation speed of the output shaft of the transmission is less than the fifth reference value. As described above, the ECU 100 can determine the slip state of the drive wheel when the fifth abnormality determination condition is satisfied. The ECU 100 determines that the transmission is abnormal when all of the first to fifth abnormality determination conditions are satisfied except for the fourth abnormality determination condition. The fifth predetermined value is experimentally determined in advance so that it can be determined that the vehicle has slipped.

  Further, when it is determined that the transmission is abnormal, the ECU 100 executes fail-safe control independently of the abnormality determination control. For example, the ECU 100 performs fail-safe control so that the forward clutch 64 that constitutes the transmission 20 is released and the primary shaft 71 is switched to a non-transmission state in which the rotational power from the engine 11 is not transmitted. Further, the ECU 100 controls the fail-safe valve that constitutes the hydraulic control device 30 so that a constant hydraulic pressure is supplied to the input-side hydraulic cylinder 73 and the output-side hydraulic cylinder 78 instead of the above-described fail-safe control. So as to obtain a desired gear ratio capable of retreating.

Next, the operation will be described.
FIG. 3 is a flowchart showing an outline of transmission abnormality determination processing according to the present embodiment. The following processing is executed at predetermined time intervals by the CPU constituting the ECU and realizes a program that can be processed by the CPU. In the present embodiment, the predetermined time interval is 16 msec.

First, ECU 100, the actual gear ratio gamma _R is, whether or not the target gear ratio gamma _T first value or more obtained by adding the predetermined value P _1, namely, the actual gear ratio gamma _R is the target gear ratio gamma _T first whether or not a predetermined value _{P 1} or more, it determines (step S1). Therefore, when the actual speed ratio γ _R is larger than the first predetermined value P _{1 with} respect to the target speed ratio γ _{T at} step S1, the process proceeds to step S2, and when it is smaller, it is not determined as abnormal and the process returns. Migrate to

Next, the ECU 100 determines whether or not the actual transmission ratio change rate Δγ is equal to or greater than a _second predetermined value P2 (step S2). Therefore, in step S2, when the change rate Δγ actual gear ratio is greater than the second predetermined value P _2, the process proceeds to step S3, when it is smaller, the process proceeds to the return without being determined as abnormal.

Next, ECU 100, the actual gear ratio gamma _R - change rate ΔP of the target gear ratio gamma _T is, whether a third predetermined value P ₃ or more, i.e., the rate of change of the difference between the actual speed ratio and the target speed ratio ΔP is determined third whether the predetermined value _{P 3} or more, (step S3). Thus, in step S3, the change rate ΔP of the difference between the actual speed ratio and the target gear ratio, if a third larger than the predetermined value P _3, the process proceeds to step S4, if small, not determined to be abnormal Move to return.

Next, ECU 100, the change rate of the secondary shaft 72 (output shaft of the transmission) is, fourth predetermined value P ₄ whether the difference is less than, i.e., the change ratio of the secondary shaft 72 (output shaft of the transmission) is , fourth predetermined value _{P 4} whether the difference is less than, determines (step S4). Accordingly, the determination in step S4, the rate of change of the rotational speed of the output shaft, when the fourth predetermined value P ₄ is less than is determined to be abnormal proceeds to step S5 (step S5), and if large, abnormal Instead return to return. In addition, each process order from step S1 to step S4 is an illustration, it is not limited to this, As long as each determination process is included, you may perform in any order.

FIG. 4 is a timing chart for explaining the abnormality determination processing according to the embodiment.
As shown in FIG. 4, when an abnormality occurs at time t1 due to an abnormality of a transmission solenoid valve (not shown) constituting the hydraulic control device 30, the primary sheave pressure supplied to the input side hydraulic cylinder 73 formed in the movable sheave 72a. 103 then begins to drop sharply. Thereafter, when the primary sheave pressure 103 decreases to 0 kPa, the actual speed ratio 101 starts to deviate from the target speed ratio 102 as indicated by the dotted line A region. As a result, the ECU 100 determines that the first abnormality determination condition is satisfied.

  Then, the arrow B representing the change ratio of the actual gear ratio gradually increases, and the arrow C representing the change ratio of the difference between the actual gear ratio and the target gear ratio also gradually increases. Therefore, ECU 100 determines that the second abnormality determination condition and the third abnormality determination condition are satisfied.

  Thereafter, the actual gear ratio of the CVT 70 shifts to the low side and a sudden downshift occurs, so the rotational speed 104 of the secondary shaft 79 decreases, that is, the vehicle speed begins to decrease. For this reason, the arrow D indicating the rate of change in the rotational speed of the secondary shaft 79 as the output shaft of the CVT 70 also gradually increases, which satisfies the fourth abnormality determination condition.

  Thus, ECU 100 satisfies all of the first to fourth abnormality determination conditions, and therefore determines that CVT 70 is abnormal at time t2.

  As described above, the transmission abnormality determination device according to the embodiment of the present invention makes a complex abnormality determination based on a plurality of abnormality determination conditions. Compared to the case where the abnormality is determined based only on the time, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination.

  Specifically, even if the first predetermined value is set smaller than the conventional value, the change ratio of the actual gear ratio is compared with the second predetermined value, so that it has not been used for the conventional abnormality determination. The transient phenomenon can be monitored in the initial stage of the abnormal shifting. For this reason, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination.

  Furthermore, even if the first predetermined value is set smaller than the conventional value, the change ratio of the difference between the actual gear ratio and the target gear ratio is compared with the third predetermined value, so that the conventional abnormality determination The transient phenomenon can be monitored in the initial stage of the shift abnormality that has not been used for the transmission. For this reason, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination. Further, even if the change ratio of the actual transmission ratio that satisfies the second abnormality determination condition is in an abnormal range, if the change ratio of the difference between the actual transmission ratio and the target transmission ratio is smaller than the third predetermined value, an abnormality is indicated. Since determination is not performed, the accuracy of abnormality determination can be improved.

  In addition, since it is determined whether or not the change rate of the rotational speed of the output shaft of the transmission is smaller than a fourth predetermined value for determining a decrease in the vehicle speed due to the downshift, it has not been used for the conventional abnormality determination. The transient phenomenon can be monitored in the initial stage of the abnormal shifting. For this reason, it is possible to shorten the time from the occurrence of the shift abnormality to the abnormality determination, and to improve the accuracy of the abnormality determination. For example, when a downshift due to a shift abnormality occurs and the rate of decrease in the vehicle speed is large as a transient phenomenon in the initial stage of the shift abnormality, it can be determined that there is an abnormality.

  As described above, the transmission abnormality determination device according to the embodiment of the present invention provides each predetermined value in the first to fourth abnormality determination conditions so that the time from the occurrence of the shift abnormality to the abnormality determination can be shortened. Since it is possible to suppress unnecessary determination of abnormality, it is possible to achieve both reduction in time until abnormality determination and improvement of abnormality determination accuracy.

  In addition, the abnormality determination device for a transmission according to the embodiment of the present invention particularly enables an abnormality determination during high-speed traveling with a relatively large deceleration, that is, in a region where the rotation speed inertia greatly contributes to the deceleration. It is beneficial. Furthermore, the abnormality determination device for a transmission according to the embodiment of the present invention limits the abnormality determination by a change in deceleration. Therefore, when an unintended deceleration does not occur, an abnormality determination is not performed, so that the fail-safe is accurately performed. Control can be executed.

  Instead of the fourth abnormality determination condition in the first embodiment described above, an abnormality determination condition described below may be used to determine the slip state of the drive wheel. The configuration of the transmission abnormality determination device according to the second embodiment is substantially the same as the configuration of the transmission abnormality determination device according to the first embodiment described above. Description will be made using the same reference numerals as those in the first embodiment shown in FIGS. 1 to 4, and only differences will be described in detail.

(Second Embodiment)
The vehicle 10 according to the present embodiment includes a drive shaft rotational speed sensor 83 that detects the rotational speed of the drive wheel 45 of the vehicle 10 and a driven shaft rotational speed sensor (not shown) that detects the rotational speed of the driven wheel of the vehicle. I have. The drive shaft rotational speed sensor 83 and the moving shaft rotational speed sensor constitute a third rotational speed sensor and a fourth rotational speed sensor according to the present invention.

  The ECU 100 calculates the difference between the detected rotational speed of the drive wheel 45 and the detected rotational speed of the driven wheel. The ECU 100 replaces the fourth abnormality determination condition with the absolute value of the difference between the first to third abnormality determination conditions and the detected rotational speed of the driving wheel 45 and the detected rotational speed of the driven wheel. The shift abnormality is determined based on an abnormality determination condition including a sixth abnormality determination condition for determining whether or not the predetermined value is 6 or more. Therefore, when the third abnormality determination condition is satisfied, the ECU 100 calculates the difference between the detected rotational speed of the driving wheel 45 and the detected rotational speed of the driven wheel, and the absolute value thereof is calculated. When it is larger than the sixth predetermined value, the slip state of the drive wheel 45 is determined and it is determined that the transmission is abnormal.

  As described above, in the transmission abnormality determination device according to the present embodiment, when the detected rotational speed of the driving wheel 45 is compared with the detected rotational speed of the driven wheel, a deviation occurs. Therefore, it can be determined that the drive wheel is in a slip state, and the accuracy of abnormality determination can be improved.

  Instead of the fourth abnormality determination condition in the first embodiment described above, the slip condition of the drive wheels may be determined using an abnormality determination condition described below. The configuration of the transmission abnormality determination device according to the third embodiment is substantially the same as the configuration of the transmission abnormality determination device according to the first embodiment described above. Description will be made using the same reference numerals as those in the first embodiment shown in FIGS. 1 to 4, and only differences will be described in detail.

(Third embodiment)
The vehicle 10 according to the present embodiment includes an acceleration sensor that detects the acceleration of the vehicle 10 and vehicle speed detection means that detects the speed of the vehicle 10. The ECU 100 constitutes a vehicle speed detection means together with the drive shaft rotational speed sensor 83, calculates the vehicle speed based on the detection result detected by the drive shaft rotational speed sensor 83, and calculates the acceleration from the calculated vehicle speed. Yes. Thus, ECU100 also comprises the acceleration calculation means which concerns on this invention.

  The ECU 100 calculates the difference between the detected acceleration detected by the acceleration sensor and the calculated acceleration. The ECU 100 determines whether or not the absolute value of the difference between the first to third abnormality determination conditions and the detected acceleration and the calculated acceleration is equal to or greater than a seventh predetermined value instead of the fourth abnormality determination condition. An abnormality determination condition is determined based on an abnormality determination condition including the abnormality determination condition. Accordingly, when the third abnormality determination condition is satisfied, the ECU 100 calculates the difference between the detected acceleration detected by the acceleration sensor and the calculated acceleration, and the absolute value thereof is greater than the seventh predetermined value. If it is larger, the slip state of the drive wheel 45 is determined to determine that the CVT 70 is abnormal.

  As described above, the transmission according to the first to third embodiments is configured by a belt-type continuously variable transmission, but by engaging and releasing a friction engagement element such as a clutch or a brake. The present invention can also be applied to a so-called automatic transmission that constitutes a desired shift stage.

  Even in the case of such an automatic transmission, a clutch or brake that should not be engaged is engaged due to a failure of a hydraulic control valve or a linear solenoid valve that constitutes a hydraulic control device that performs shift control. In some cases, a shift stage different from the instruction shift stage may be formed, and an unintended deceleration may occur. Therefore, it is useful to apply a transmission abnormality determination device. In this case, the target gear ratio can be obtained from the gear stage supported by the ECU.

  As described above, the control device for a continuously variable transmission according to the present invention can shorten the time from the occurrence of a shift abnormality to the determination of abnormality as compared with the conventional case, and improves the accuracy of the abnormality determination. It is useful for an abnormality determination device for a transmission mounted on a vehicle.

11 Engine 15 Crankshaft 30 Hydraulic control device 50 Torque converter 55 Turbine shaft 60 Forward / reverse switching machine 70 CVT (continuously variable transmission)
71 Primary shaft 72 Primary pulley 75 Transmission belt 77 Secondary pulley 79 Secondary shaft 81 Crank sensor 83 Drive shaft rotation speed sensor (third rotation speed sensor, vehicle speed detection means)
85 Input shaft speed sensor (first speed sensor)
86 Output shaft speed sensor (second speed sensor)
87 Turbine shaft rotation speed sensor 100 ECU (vehicle speed detection means, acceleration calculation means, calculation unit)

Claims (6)

A transmission abnormality determination device that is mounted on a vehicle including a transmission that shifts rotational power input from an input shaft and outputs the rotational power to an output shaft, and that determines abnormality of the transmission based on abnormality determination conditions. ,
The abnormality determination condition is a first abnormality determination condition that is satisfied when an actual speed ratio obtained by the shift is equal to or greater than a first predetermined value with respect to a set target speed ratio;
A second abnormality determination condition that is satisfied when the change ratio of the actual gear ratio is equal to or greater than a second predetermined value;
A third abnormality determination condition that is satisfied when a change rate of a difference between the actual speed ratio and the target speed ratio is equal to or greater than a third predetermined value;
A fourth abnormality determination condition that is satisfied when the rate of change in the rotation speed of the output shaft corresponding to the vehicle speed of the vehicle is smaller than a fourth predetermined value that is a negative value ;
A transmission abnormality determination device that determines that the transmission is abnormal when all of the first to fourth abnormality determination conditions are satisfied . Or the fourth abnormality determining condition is pre-Symbol transmission output shaft speed of the rate of change corresponds to the fourth smaller than the predetermined value Itoki, slip state of the drive wheels of the vehicle occurs The transmission abnormality determination device according to claim 1, wherein the abnormality determination device is established when it is smaller than a fifth predetermined value capable of determining whether or not . A first rotational speed sensor for detecting the rotational speed of the input shaft;
A second rotational speed sensor for detecting the rotational speed of the output shaft;
The calculation unit that calculates the actual gear ratio by dividing the detected rotation speed of the input shaft by the detected rotation speed of the output shaft. The transmission abnormality determination device according to claim 2. A third rotational speed sensor for detecting the rotational speed of the drive wheel of the vehicle;
A fourth rotational speed sensor for detecting the rotational speed of the driven wheel of the vehicle,
The fourth abnormality determining condition, the rotational speed of the rate of change of the output shaft of the transmission corresponds to a time less than a predetermined value of the fourth, the speed and the detection of the detected said drive wheel malfunction determining device for a transmission according to claim 1, the absolute value of the difference between the rotational speed of the driven wheel is characterized in that it satisfied when it is the sixth higher than a predetermined value. An acceleration sensor for detecting the acceleration of the vehicle;
Vehicle speed detection means for detecting the speed of the vehicle;
Acceleration calculation means for calculating acceleration from the detected vehicle speed,
The fourth abnormality determination condition corresponds to a detected acceleration detected by the acceleration sensor and the acceleration calculating means corresponding to a change rate of the rotation speed of the output shaft of the transmission being smaller than the fourth predetermined value. The transmission abnormality determination device according to claim 1, wherein the abnormality determination device is established when an absolute value of a difference from the calculated acceleration calculated by the step is equal to or greater than a seventh predetermined value.   The transmission is a belt type in which a transmission belt is wound around a pair of variable pulleys having a variable effective diameter, and a gear ratio is continuously changed by changing an effective diameter of the pair of variable pulleys by a hydraulic actuator. The transmission abnormality determination device according to claim 1, wherein the transmission abnormality determination device is configured by a continuously variable transmission.

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