JP4810559B2 - Belt deterioration judging device for continuously variable transmission - Google Patents

Description

  The present invention relates to a belt deterioration determination device for a continuously variable transmission, and more particularly to a device for determining the deterioration degree of a belt of a continuously variable transmission over time.

As a technique for detecting damage to a belt of a belt-type continuously variable transmission, for example, a technique described in Patent Document 1 can be cited. In the technique described in Patent Document 1, the thrust ratio (pressure ratio of the hydraulic cylinder) and the speed ratio (speed ratio) of the drive pulley and the driven pulley are calculated, and belts with reduced rigidity may have the same speed ratio. Based on the knowledge that, for example, the thrust ratio is large and the speed ratio tends to be small if the thrust ratio is the same, it is detected that the belt is damaged from the relationship.
Japanese Patent Laid-Open No. 2003-42251

  Although it is possible to detect damage caused to the belt by the technique described in Patent Document 1, if it is possible to determine the degree of deterioration prior to damage over time, it is possible to prevent damage by repairing, It is desirable.

  Accordingly, an object of the present invention is to provide a belt deterioration determination device for a continuously variable transmission that eliminates the above-mentioned disadvantages and determines the deterioration degree before the belt is damaged over time.

  In order to achieve the above object, according to claim 1, the belt includes a belt composed of a ring and a plurality of elements held by the ring, and a winding radius determined in accordance with a supplied hydraulic pressure. In a continuously variable transmission comprising a pulley for clamping the pulley, an input torque calculation means for calculating an input torque input to the pulley, and a pulley rotation speed detection for detecting an input shaft rotation speed and an output shaft rotation speed of the pulley Means, gear ratio calculating means for calculating a gear ratio of the continuously variable transmission based on the detected input shaft rotational speed and output shaft rotational speed of the pulley, and calculating a command value of the supplied hydraulic pressure Based on at least the hydraulic command value calculation means, the calculated input torque, the detected pulley input shaft speed, the calculated gear ratio, and the hydraulic command value, A ring deterioration degree calculating means for calculating a deterioration degree of the ring; an axial thrust calculating means for calculating an axial thrust acting on the pulley; and a clamping force for clamping the element from the side based on the calculated axial thrust. Element clamping force calculation means for calculating the element, and the element pressing force calculation for calculating the pressing force of the element based on the calculated input torque, the detected input shaft rotational speed of the pulley, and the calculated gear ratio Means, element load calculation means for calculating an element load acting on the element based on at least the calculated element clamping force and element pressing force, and per belt n rotations based on the calculated element load. Element deterioration degree calculating means for calculating the deterioration degree of the element, and the calculated Deterioration degree product calculating means for integrating the deterioration degree exceeding the set threshold when the deterioration degree of the ring or the element deterioration degree exceeds a set threshold value, and the integrated ring deterioration degree or element deterioration degree And an operation execution means for executing a predetermined operation including a warning when the value exceeds the set allowable value.

  According to a second aspect of the present invention, there is provided a vehicle comprising: a ring, a belt composed of a plurality of elements held by the ring; and a pulley that clamps the belt with a winding radius determined according to a supplied hydraulic pressure. In the continuously variable transmission for shifting the output of the internal combustion engine mounted on the vehicle, an operation mode detecting means for detecting an operation mode including at least start acceleration of the vehicle and switching between forward and backward travel of the vehicle, and the detected operation The operation mode number counting means for counting the number of modes for each operation mode, and the degree of deterioration of the belt is calculated based on the number of times counted for each operation mode and the degree of deterioration preset for each operation mode. And a belt deterioration degree integrating means for integrating the calculated value, and a predetermined warning including a warning when the integrated belt deterioration degree exceeds a set allowable value. It was composed as and an operation execution unit for executing the work.

  In the belt degradation determination device for a continuously variable transmission according to claim 1, the degradation of the ring per n rotations of the belt is based at least on the basis of the input torque, the input shaft rotational speed of the pulley, the transmission gear ratio, and the hydraulic pressure command value. The degree of the element is calculated based on at least the element clamping force and the element pushing force, and the degree of deterioration of the element per n rotations of the belt is calculated based on the element load. When the degree of deterioration or the degree of deterioration of the element exceeds a set threshold value, integration is performed, and when the integrated degree of deterioration exceeds a set allowable value, a predetermined operation including a warning is executed. By repairing accordingly, the belt of the continuously variable transmission can be prevented from being damaged. In addition, the belt load can be reduced by fixing the input torque limit and belt usage area (high-load area, for example, the highest or low side use limit), etc. in the specified operation. It is also possible to have a belt in between.

  In the belt degradation determination device for a continuously variable transmission according to claim 2, an operation mode including at least start acceleration and forward / reverse switching of the vehicle is detected, and the number of detected operation modes is determined for each operation mode. The belt degradation level is calculated and accumulated based on the number counted for each operation mode and the preset degradation level for each operation mode. Since the predetermined operation including the warning is executed when exceeding, damage to the belt can be prevented in advance by repairing according to the warning, for example. In addition, by limiting the input torque and the belt use area in the predetermined operation, the load on the belt can be reduced, and the belt before the repair can be provided.

  The best mode for carrying out a belt deterioration determining apparatus for a continuously variable transmission according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram generally showing a belt deterioration determining apparatus for a continuously variable transmission according to a first 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 or the like) 12.

  In the engine 10, a throttle valve (not shown) arranged in the intake system is mechanically disconnected from an accelerator pedal (not shown) arranged in the driver's seat of the vehicle 12, and an actuator (such as an electric motor) It is connected to and driven by a DBW (Drive By Wire) mechanism 14 comprising a not-shown).

  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) 16 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. The air-fuel mixture is ignited and combusted in the combustion chamber, and after driving a piston (not shown) to rotate a crankshaft (not shown), it is exhausted and discharged to the outside of the engine 10.

  The crankshaft of the engine 10 is fixed to the drive plate 20. The drive plate 20 is connected to a pump / impeller 22a of a torque converter 22 that also serves as a flywheel mass, and a turbine runner 22b that is disposed opposite to the drive plate 20 and receives fluid (hydraulic fluid) is connected to a main shaft (mission input shaft) MS. Connected. Reference numeral 22c denotes a lockup clutch.

  A continuously variable transmission (hereinafter referred to as “CVT”) 26 is connected downstream of the torque converter 22 via a forward / reverse switching mechanism 24.

  The CVT 26 includes a drive pulley 26a disposed on the main shaft MS, a driven pulley 26b disposed on a counter shaft CS parallel to the main shaft MS, and a metal belt 26c wound around the drive pulley 26a.

  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.

  FIG. 2 is an explanatory diagram obtained by photographing the element (block) 26c1 and the ring 26c2 constituting the belt 26c shown in FIG. 1, and FIG. 3 is a schematic diagram showing one of the elements 26c1 shown in FIG. FIG.

  As shown in FIG. 2, the belt 26c is composed of two bundles of rings 26c2 and a large number of, for example, about 400 elements 26c1 held by the rings 26c2, and the adjacent elements 26c1 are sequentially pushed to drive pulley 26a. Torque is transmitted to the driven pulley 26b.

  As shown in FIG. 3, the element 26c1 has a friction surface 26c1a on the front and back surfaces thereof, a locking edge 26c1b provided at the lower portion formed in a wedge shape on the front surface, saddles 26c1c on both sides of the shoulder portion, and a V-shape. A nose 26c1d formed on the front surface of the head portion 26c1e, and a dimple (not shown) formed on the back surface of the head portion 26c1e and accommodating the nose 26c1d. The two bundles of rings 26c2 are respectively placed on the saddle 26c1c in the gap between the shoulder portion and the head portion 26c1e.

  The forward / reverse switching mechanism 24 includes a ring gear 24a fixed to the main shaft MS, a sun gear 24b fixed to the fixed pulley half 26a1 of the drive pulley 26a of the CVT 26, a pinion gear carrier 24c disposed therebetween, and a ring gear 24a A forward clutch 24d capable of fastening the sun gear 24b and a reverse brake clutch 24e capable of fixing the pinion gear carrier 24c to a transmission case (not shown).

  A secondary drive gear 30 is fixed to the counter shaft CS, and the secondary drive gear 30 meshes with a secondary driven gear 32 fixed to the secondary shaft SS. A final drive gear 34 is fixed to the secondary shaft SS, and the final drive gear 34 meshes with a final driven gear 36 of the differential mechanism D.

  With the above configuration, the rotation of the counter shaft CS is transmitted to the secondary shaft SS through the gears 30 and 32, and the rotation of the secondary shaft SS is transmitted to the differential D through the gears 34 and 36, and is distributed there. It is transmitted to the drive wheel (tire, only shown on the right side) W. A disc brake 40 is disposed in the vicinity of the drive wheel W.

  FIG. 4 is a hydraulic circuit diagram schematically showing a hydraulic mechanism such as the CVT 26.

  As illustrated, a hydraulic pump 42a is provided in the hydraulic mechanism (indicated by reference numeral 42). The hydraulic pump 42a is driven by the engine 10, pumps up the hydraulic oil stored in the reservoir 42b, and pumps it to the PH control valve (PH REG VLV) 42c.

  The output (PH pressure (line pressure)) of the PH control valve 42c, on the other hand, is driven from the oil passage 42d through the first and second regulator valves (DR REG VLV, DN REG VLV) 42e, 42f, and the drive pulley 26a of the CVT 26. Are connected to the piston chamber (DR) 26a21 of the movable pulley half 26a2 and the piston chamber (DN) 26b21 of the movable pulley half 26b2 of the driven pulley 26b, and on the other hand, the CR valve (CR VLV) via the oil passage 42g. 42h.

  The CR valve 42h reduces the PH pressure to generate a CR pressure (control pressure), and the first, second, and third (electromagnetic) linear solenoid valves 42j, 42k, 42l (LS-DR, LS) from the oil passage 42i. -DN, LS-CPC). The first and second linear solenoid valves 42j and 42k act on the first and second regulator valves 42e and 42f with the output pressure determined according to the excitation of the solenoids, and the PH pressure sent from the oil passage 42d. Hydraulic oil is supplied to the piston chambers 26a21 and 26b21 of the movable pulley halves 26a2 and 26b2, and a pulley side pressure is generated accordingly.

  Therefore, in the configuration shown in FIG. 1, the pulley side pressure that moves the movable pulley halves 26a2 and 26b2 in the axial direction is generated, the pulley widths of the drive pulley 26a and the driven pulley 26b change, and the winding radius of the belt 26c changes. 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.

  The output (CR pressure) of the CR valve 42h is also connected to a CR shift valve (CR SFT VLV) 42n, and from there through a manual valve (MAN VLV) 42o, the piston chamber (FWD) of the forward clutch 24d of the forward / reverse switching mechanism 24 ) 24d1 and the piston chamber (RVS) 24e1 of the reverse brake clutch 24e.

  The operation of the forward clutch 24d and the reverse brake clutch 24e is performed by the driver operating a select lever 44 provided in the driver's seat of the vehicle 12, for example, having a range (position) of P, R, N, D, S, and L. To be determined. That is, when one of the ranges of the select lever 44 is selected by the driver, the selection operation is transmitted to the manual valve 42o of the hydraulic mechanism 42.

  For example, when the D, S, L range, that is, the forward travel range is selected, the spool of the manual valve 42o moves accordingly, and hydraulic oil (hydraulic pressure) is discharged from the piston chamber 24e1 of the reverse brake clutch 24e. The hydraulic fluid is supplied to the piston chamber 24d1 of the forward clutch 24d, and the forward clutch 24d is fastened. When the forward clutch 24d is engaged, all the gears rotate together with the main shaft MS, and the drive pulley 26a is driven in the same direction as the main shaft MS (a direction corresponding to the direction in which the vehicle 12 moves forward).

  On the other hand, when the R range (reverse travel range) is selected, the hydraulic oil is discharged from the piston chamber 24d1 of the forward clutch 24d, while the hydraulic oil is supplied and fastened to the piston chamber 24e1 of the reverse brake clutch 24e. As a result, the pinion gear carrier 24c is fixed to the transmission case, the sun gear 24b is driven in the opposite direction to the ring gear 24a, and the drive pulley 26a is opposite to the main shaft MS (the direction corresponding to the direction in which the vehicle 12 moves backward). Driven.

  When the P or N range is selected, the hydraulic oil is discharged from both piston chambers, the forward clutch 24d and the reverse brake clutch 24e are both released, and the power transmission via the forward / reverse switching mechanism 24 is cut off. The power transmission between the engine 10 and the drive pulley 26a of the CVT 26 is cut off.

  The output of the PH control valve 42c is sent to the TC regulator valve (TC REG VLV) 42q through the oil passage 42p, and the output of the TC regulator valve 42q is LC shifted through the LC control valve (LC CTL VLV) 42r. Connected to valve (LC SFT VLV) 42s. The output of the LC shift valve 42s is connected to the piston chamber 22c1 of the lockup clutch 22c of the torque converter 22 on the one hand and to the chamber 22c2 on the back side on the other hand.

  The CR shift valve 42n and the LC shift valve 42s are connected to first and second (electromagnetic) on / off solenoids (SOL-A, SOL-B) 42u and 42v, and the oil to the forward clutch 24d is excited or de-energized. The switching of the road and the engagement (on) / release (off) of the lock-up clutch 22c are controlled.

  In the lockup clutch 22c, the hydraulic oil is supplied to the piston chamber 22c1 via the LC shift valve 42s, while the lockup clutch 22c is engaged (fastened on) when discharged from the chamber 22c2 on the back side. ) And supplied to the back side chamber 22c2 and released (not fastened, off) when discharged from the piston chamber 22c1. The slip amount of the lock-up clutch 22c, that is, the engagement capacity when the lock-up clutch 22c is slipped between engagement and release is determined by the amount of hydraulic oil (hydraulic pressure) supplied to the piston chamber 22c1 and the rear chamber 22c2. The

  The previously described third linear solenoid valve 42l is connected to the LC shift valve 42s via the oil passage 42w and the LC control valve 42r, and further connected to the CR shift valve 42n via the oil passage 42x. That is, the engagement capacity (slip amount) of the forward clutch 24d and the lockup clutch 22c is adjusted (controlled) by the excitation / non-excitation of the solenoid of the third linear solenoid valve 42l.

  Returning to the description of FIG. 1, a crank angle sensor 50 is provided at an appropriate position such as near the camshaft (not shown) of the engine 10 and outputs a pulse signal for each position near the TDC of the piston and a predetermined crank angle position. To do. An intake pressure sensor 52 is provided at an appropriate position downstream of the throttle valve in the intake system, and outputs a signal proportional to the intake pressure (engine load) PBA.

  The actuator of the DBW mechanism 14 is provided with a throttle opening sensor 54 that outputs a signal proportional to the throttle opening TH through the amount of rotation of the actuator, and an accelerator opening sensor 56 is provided near 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 60 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 system has an intake air temperature. A sensor 62 is provided to generate an output corresponding to the intake air temperature (outside air temperature) TA taken into the engine 10.

  The output of the crank angle sensor 50 and the like described above is sent to the engine controller 64. The engine controller 64 includes a microcomputer including a CPU, ROM, RAM, I / O, and a waveform shaping circuit. The engine controller 64 measures the output pulse interval of the crank angle sensor 50 to detect the engine speed NE, and determines the target throttle opening based on the detected engine speed NE and other sensor outputs. Then, the operation of the DBW mechanism 14 is controlled, the fuel injection amount is determined, and the injector 16 is driven.

  An NT sensor (rotational speed sensor) 66 is provided at an appropriate position in the vicinity of the main shaft MS, and outputs a pulse signal indicating the rotational speed of the main shaft MS corresponding to the rotational speed of the turbine runner 22b. An NDR sensor (rotational speed sensor) 70 is provided at an appropriate position in the vicinity of the drive pulley 26a to output a signal indicating the rotational speed (input shaft rotational speed) of the drive pulley 26a.

  A VEL sensor (rotational speed sensor) 72 is provided in the vicinity of the secondary driven gear 32 of the secondary shaft SS, and outputs a pulse signal indicating the output shaft rotational speed of the CVT 26 or the vehicle speed VEL through the rotational speed of the secondary driven gear 32. A select lever sensor 74 is provided in the vicinity of the select lever 44 described above, and outputs a signal corresponding to a range such as R, N, and D selected by the driver.

  In the hydraulic mechanism 42, an oil temperature sensor 76 is disposed in the reservoir 42b to generate an output corresponding to the temperature of the hydraulic oil (oil temperature), and is connected to the piston chamber 26b21 of the movable pulley half 26b2 of the driven pulley 26b. A hydraulic pressure sensor 78 is disposed in the oil path to generate an output corresponding to the pressure (hydraulic pressure) of the hydraulic oil supplied to the piston chamber 26b21.

  The output from the NT sensor 66 and the like described above is sent to the shift controller 80. Similarly to the engine controller 64, the shift controller 80 includes a microcomputer including a CPU, ROM, RAM, I / O, a waveform shaping circuit, and the like, and is configured to be communicable with the engine controller 64. The shift controller 80 includes a nonvolatile memory 80a.

  In the shift controller 80, the outputs of the NT sensor 66 and the NDR sensor 70 are input to the waveform shaping circuit, and the CPU detects the rotation speed from the outputs. The output of the VEL sensor 72 is input to the direction detection circuit after being input to the waveform shaping circuit. The CPU counts the output of the waveform shaping circuit to detect the output shaft rotational speed (and the vehicle speed) of the CVT 26 and detects the rotational direction of the CVT 26 from the output of the direction detection circuit.

  Based on these detected values, the shift controller 80 determines the supply hydraulic pressure of the CVT 26 and controls the operation of the CVT 26 by exciting / de-exciting the electromagnetic solenoid valve 42j of the hydraulic mechanism 42 and the lock-up clutch 22c of the torque converter 22. And the engagement / release of the forward clutch 24d and the reverse brake clutch 24e.

  Further, the shift controller 80 determines the deterioration of the belt 26c of the CVT 26.

  FIG. 5 is a flowchart showing the operation of the shift controller 80. The illustrated program is executed by the shift controller 80 every predetermined time.

  First, in S10, the deterioration degree of the belt 26c is calculated as the deterioration degree of the ring 26c2 and the deterioration degree of the element 26c1.

  FIG. 6 is a sub-routine flow chart showing the calculation process of the deterioration degree.

  In the following, the ratio (transmission ratio) is calculated in S100. The ratio is calculated by dividing the input shaft rotation speed (input rotation) of the drive pulley 26 a detected from the NDR sensor 70 by the output shaft rotation speed of the CVT 26 detected from the VEL sensor 72 to obtain a ratio.

  Next, the process proceeds to S102, and a graph showing the characteristics shown in FIG. 7 is retrieved from the calculated ratio to calculate the belt winding diameter (winding radius) of the belt 26c on the drive pulley 26a side.

  Next, in S104, a graph showing the characteristics shown in FIG. 8 is retrieved from the calculated ratio, and the belt winding angle on the drive pulley 26a side is similarly calculated. When the ratio is 1.0, the winding angle is 180 degrees or a value in the vicinity thereof.

  Next, the process proceeds to S106 and S108, and axial thrusts on the drive pulley 26a side and the driven pulley 26b side are calculated based on the hydraulic pressure command value.

  Next, in S110, the rotation number (total number of rotations) of the belt 26c per predetermined time is calculated based on the input shaft rotation number of the drive pulley 26a detected from the NDR sensor 70.

  Next, in S112, the deterioration degree of the ring 26c2, that is, the ring deterioration degree is calculated.

  FIG. 9 is a sub-routine flowchart showing the calculation process.

  Referring to FIG. 10, the degree of deterioration of the ring 26c2 per one rotation of the belt 26c (ring deterioration degree, anonymous number) based on the input torque, input rotation, ratio, and hydraulic pressure command value in S200 is shown in FIGS. Search from the table showing the characteristics.

  That is, the table showing the characteristics shown in FIG. 10 is searched from the input torque input to the drive pulley 26a, the input shaft rotational speed of the drive pulley 26a, and the ratio, and the degree of ring deterioration per rotation of the belt 26c is calculated. .

  Next, a correction coefficient is calculated by searching a table having characteristics shown in FIG. 11 from the command value of the hydraulic pressure supplied to the driven pulley 26b, more precisely the ratio between the command value of the hydraulic pressure and the reference value, and the calculated one rotation Correction is performed by multiplying the ring degradation degree of the hit by a correction coefficient. The reference value indicates an oil pressure command value when the input torque, the input rotation, and the ratio are in a steady state. The characteristics shown in FIGS. 10 and 11 are obtained in advance through experiments and stored in the ROM.

  Next, in S202, the calculated ring deterioration degree is converted into an integrated ring deterioration degree per unit time.

  That is, the rotation speed (total number of rotations) of the belt 26c per unit time of integration is calculated from the rotation speed of the input shaft or output shaft of the pulley detected from the NDR sensor 70 or the VEL sensor 72. Next, the calculated number of rotations of the belt 26c is multiplied by the degree of ring deterioration calculated in S200, thereby converting to an integrated degree of ring deterioration per unit time.

  Returning to the description of the flow chart of FIG. 6, the process then proceeds to S114, and the deterioration degree of the element 26c1, that is, the element deterioration degree is calculated.

  FIG. 12 is a sub-routine flowchart showing the calculation process.

  If it demonstrates with reference to the figure, the rotation direction of the belt 26c will be detected in S300, and a calculation formula (formula which calculates the element load mentioned later) will be selected according to it (it changes).

  In the CVT 26, torque is transmitted to the belt 26c that is wound between pulleys by sequentially pressing a large number of elements 26c1, but the travel range is switched (from the reverse travel range R to the forward travel range D). When the pulley reverses in response to the reverse (or vice versa), the gap generated between the elements 26c1 on the side that did not contribute to torque transmission is pushed and clogged, and at that time, a large stress is generated in the element 26c1.

  At that time, the rotation of the drive pulley 26a suddenly decreases and temporarily stops, and then starts to rotate in the reverse direction. Accordingly, the interval of pulses output from the NDR sensor 70 gradually opens and rotation detection is once disabled, and then narrows again to enable rotation detection.

  Therefore, in S300, the output of the NDR sensor 70 is monitored, and it is detected whether or not it is in the inversion period from when detection becomes impossible to when it becomes possible again. When affirmative, choose a different formula.

  Next, in S302, the clamping force per element 26c1 is calculated. This is obtained by dividing the axial thrust force of the drive pulley 26b calculated in S106 of the flowchart of FIG. 6 by the number of elements 26c1 in the pulley.

  Next, in S304, the table showing the characteristics in FIG. 13 is retrieved from the input torque, input rotation, and ratio, and the pressing force of the element 26c1 is calculated. This pushing force is a force in the circumferential direction (indicated by an arrow A in FIG. 2) along the ring 26c2 that transmits torque.

  Next, in S306, a table search is performed for the nth root of the element pressing force calculated in S304, and a correction coefficient used in the calculation formula described in S300 is calculated from the searched value, axial thrust, and friction coefficient μ. . The correction coefficient is used for either of the two types of calculation formulas selected in S300.

  Next, in S308, the element load is calculated according to the calculation formula touched in S300 from the correction coefficient calculated in S306, the clamping force calculated in S302 and S304, and the element pressing force. This element load means a load for evaluating the life of the element 26c1.

  Next, the process proceeds to S310, and a table showing the characteristics in FIG. 14 is searched from the calculated element load to calculate the degree of deterioration of the element 26c1 per one rotation of the belt (element deterioration degree, anonymous number). The characteristics shown in FIGS. 13 and 14 are also obtained in advance through experiments and stored in the ROM.

  Next, in S312, the calculated element deterioration degree is converted into an element deterioration degree per unit time of integration.

  That is, the rotation speed (total number of rotations) of the belt 26c per unit time of integration is calculated from the rotation speed of the input shaft or output shaft of the pulley detected from the NDR sensor 70 or the VEL sensor 72. Next, the calculated number of rotations of the belt 26c is multiplied by the element deterioration degree calculated in S310, thereby converting the element deterioration degree per unit time of integration.

  Returning to the description of the flow chart of FIG. 5, the process then proceeds to S12, where it is determined whether or not the calculated ring deterioration level or element deterioration level exceeds a set threshold value (set separately for the ring deterioration level and the element deterioration level). To do.

  When it is determined that the ring deterioration level or element deterioration level calculated in affirmative in S12 exceeds the corresponding setting threshold value, the process proceeds to S14, and the deterioration level exceeding the corresponding setting threshold value, for example, the ring deterioration level, for example. When is exceeded, the ring deterioration degree is integrated. When the element deterioration degree is exceeded, the element deterioration degree is integrated. The integrated value is stored in the nonvolatile memory 80a.

  On the other hand, when the result in S12 is negative, the program proceeds to S16 and the integration is stopped. Thus, by appropriately setting the set threshold value, it is possible to eliminate integration when the calculated degree of deterioration is too small.

  Next, in S18, it is determined whether or not the deterioration degree integrated value, that is, the integrated ring deterioration degree or element deterioration degree exceeds a set allowable value (set separately for the ring deterioration degree and the element deterioration degree).

  If it is determined in S18 that one (or both) of the ring deterioration level and the element deterioration level accumulated in an affirmative state exceeds the corresponding set allowable value, the process proceeds to S20, and a predetermined operation including a warning is executed. On the other hand, when the result in S18 is negative, the program proceeds to S22, and such an operation is not executed.

  The predetermined operation including this warning means warning, limitation of input torque, limitation of belt use area, and the like.

  In other words, the belt 26c of the CVT 26 has deteriorated beyond the set allowable value, and the driver (user) is informed visually or by voice through an indicator or a buzzer (both not shown), and prompts repair. In the control of the CVT 26, an input torque to the CVT 26 or a belt use region (a high load region, for example, a restriction on use on the highest or low side) is limited, thereby reducing the load on the belt 26c.

  As described above, in the first embodiment, the belt 26c is composed of the ring 26c2 and the belt 26c composed of a plurality of elements 26c1 held by the ring, and the winding radius determined in accordance with the supplied hydraulic pressure. In a CVT (continuously variable transmission) 26 provided with pulleys (drive pulley 26a, driven pulley 26b) for clamping the input torque, input torque calculation means (shift controller 80) for calculating input torque input to the pulley, Pulley rotational speed detecting means (shift controller 80) for detecting the input shaft rotational speed and the output shaft rotational speed of the pulley, and the ratio of the CVT 26 based on the detected input shaft rotational speed and output shaft rotational speed of the pulley ( Transmission ratio calculating means (shift controller 80) for calculating the transmission ratio) and oil for calculating the command value of the supplied hydraulic pressure N of the belt 26c based at least on the command value calculating means (shift controller 80), the calculated input torque, the detected input shaft speed of the pulley, the calculated ratio ratio, and the hydraulic pressure command value. Ring deterioration degree calculation means (shift controller 80, S10, S100 to S112, S200 to S202) for calculating the deterioration degree (ring deterioration degree) of the ring 26c2 per rotation (specifically, once), the pulley An axial thrust calculation means (shift controller 80, S10, S106 to S108) for calculating an acting axial thrust, and an element clamping force calculation for calculating a clamping force for clamping the element from the side based on the calculated axial thrust. Means (shift controllers 80, S10, S302) and the calculated input torque An element pushing force calculation means (shift controller 80, S10, S304) for calculating the pushing force of the element based on the detected input shaft rotational speed of the pulley and the calculated ratio, and the calculated element clamp Element load calculating means (shift controller 80, S10, S300 to S308) for calculating an element load acting on the element based at least on the force and the element pressing force; and n on the belt based on the calculated element load. Element deterioration degree calculation means (shift controller 80, S10, S300 to S310) for calculating the deterioration degree (element deterioration degree) of the element per rotation (specifically, once), and the calculated ring deterioration Degree or element deterioration exceeds the set threshold Deterioration degree product calculating means (shift controller 80, S12 to S16) for integrating deterioration degrees exceeding the set threshold value, and the integrated ring deterioration degree or element deterioration degree exceeds a set allowable value. Since it is configured to include operation execution means (shift controller 80, S18 to S20) for executing a predetermined operation including a warning, damage to the belt 26c of the CVT 26 can be prevented by repairing according to the warning, for example. can do. In addition, the load of the belt 26c can be reduced and repaired by putting a restriction on the input torque and a belt use area (a high load area, such as a use restriction on the highest or low side) in a predetermined operation. It is also possible to provide the belt 26c up to this point.

  FIG. 15 is a flowchart similar to FIG. 5 showing the operation of the belt deterioration determining apparatus for a continuously variable transmission according to the second embodiment of the present invention.

  The illustrated program is also executed by the shift controller 80 every predetermined time.

  Explained below, in S400, predetermined operation modes such as start acceleration of the vehicle 12, forward / reverse switching of the vehicle 12 (via the forward / reverse switching mechanism 24), in-gear from high engine rotation, and start immediately after in-gear are performed. The number of detected operation modes is counted for each operation mode, and the degree of deterioration of the belt 26c of the CVT 26 is calculated based on the number counted for each operation mode and a preset degree of deterioration. At the same time, the calculated values are integrated.

  Here, the operation mode means an operation of the vehicle 12 (or CVT 26) that causes a load of a certain level or more on the belt 26c of the CVT 26 to promote deterioration.

  As described above, the number of times is counted for each operation mode, i.e., start acceleration, forward / reverse switching, in-gear from high revolution, and start immediately after in-gear, and the degree of deterioration is preset for each operation mode. Is done.

  The degree of deterioration is classified according to the difference in operation time lag such as the accelerator opening (or throttle opening), the time from when the gear is in-geared until the throttle opening is opened, and the value per operation is set in advance. Unlike the first embodiment, in the second embodiment, the degree of deterioration is set as a single value for the belt 26c.

  Next, in S402, it is determined whether or not the deterioration degree integrated value, that is, the integrated deterioration degree exceeds a set allowable value (appropriately set), and it is determined that the integrated deterioration degree exceeds the set allowable value. If YES, the process proceeds to S404, and a predetermined operation including a warning is executed as in the first embodiment. On the other hand, if NO, the process proceeds to S406, and such an operation is not executed.

  As described above, in the second embodiment, the belt 26c including the ring 26c2 and a plurality of elements 26c1 held by the ring 26c2, and the winding radius determined in accordance with the supplied hydraulic pressure. In a CVT (continuously variable transmission) 26 that includes a pulley (drive pulley 26a, driven pulley 26b) that clamps 26c and shifts the output of an engine (internal combustion engine) 10 mounted on the vehicle 12, the vehicle 12 is started. Operation mode detection means (shift controller 80, S400) for detecting an operation mode including at least acceleration and switching between forward and backward movement of the vehicle 12, and an operation mode for counting the number of detected operation modes for each operation mode. Counting means (shift controller 80, S400) and counting for each operation mode The belt deterioration degree integrating means (shift controller 80, S400) calculates the belt deterioration degree (belt deterioration degree) on the basis of the number of times and the deterioration degree preset for each operation mode, and integrates the calculated values. ) And an operation executing means (shift controller 80, S402, S404) for executing a predetermined operation including a warning when the accumulated degree of belt deterioration exceeds a set allowable value. Similar to the embodiment, for example, the belt 26c of the CVT 26 can be prevented from being damaged by repairing according to a warning. In addition, by limiting the input torque and the belt use area in the predetermined operation, the load on the belt 26c can be reduced, and the belt 26c before the repair can be provided.

  The configuration illustrated above is merely an example, and the present invention is not limited thereto. For example, the command value of the hydraulic pressure supplied to the driven pulley 26b is used as the command value of the hydraulic pressure in the process of S200 in the flowchart of FIG. However, it may be a command value for the hydraulic pressure supplied to the drive pulley 26a. In addition, the degree of deterioration per rotation of the belt 26c is calculated, but the degree of deterioration at two or more rotations may be calculated. The other processes are the same.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating an overall belt degradation determination device for a continuously variable transmission according to an embodiment of the present invention. 2 is a photograph of elements and rings constituting a belt of the continuously variable transmission shown in FIG. FIG. 3 is an explanatory diagram schematically showing one of the elements shown in FIG. 2. FIG. 2 is a hydraulic circuit diagram schematically showing a hydraulic mechanism such as a continuously variable transmission (CVT) shown in FIG. 1. It is a flowchart which shows operation | movement of the apparatus shown in FIG. FIG. 6 is a sub-routine flow chart showing a process for calculating a belt deterioration degree in FIG. 5. FIG. FIG. 7 is an explanatory graph showing table characteristics of a winding diameter of a belt used in the process of FIG. 6. 7 is an explanatory graph showing table characteristics of a belt winding angle used in the process of FIG. 6. FIG. 7 is a sub-routine flow chart showing a ring deterioration degree calculation process of FIG. 6. FIG. It is a graph which shows the table characteristic of the ring degradation degree used by the process of FIG. It is a graph which shows the table characteristic of the correction coefficient of the ring degradation degree of FIG. FIG. 7 is a sub-routine flow chart showing an element deterioration degree calculation process of FIG. 6. FIG. It is a graph which shows the table characteristic of the element pushing force used by the process of FIG. FIG. 13 is an explanatory graph showing a table characteristic of an element deterioration degree calculated by the process of FIG. 12. FIG. 6 is a flow chart similar to FIG. 5 showing the operation of the belt deterioration determining device for a continuously variable transmission according to the second embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Internal combustion engine (engine), 12 Vehicle, 22 Torque converter, 24 Forward / reverse switching mechanism, 24a Ring gear, 24b Sun gear, 24c Pinion gear carrier, 24d Forward clutch, 24e Reverse brake clutch, 26 Continuously variable transmission (CVT), 26a Drive Pulley, 26b Driven pulley, 26c Belt, 26c1 element, 42 Hydraulic mechanism, 44 Select lever, 64 Engine controller, 66 NT sensor, 70 NDR sensor, 72 VEL sensor, 80 Shift controller, MS main shaft, CS counter shaft, SS secondary Shaft, D differential, W drive wheel (tire)

Claims (2)

In a continuously variable transmission comprising a ring and a belt composed of a plurality of elements held by the ring, and a pulley that clamps the belt with a winding radius determined according to a supplied hydraulic pressure,
a. An input torque calculating means for calculating an input torque input to the pulley;
b. Pulley rotational speed detection means for detecting the input shaft rotational speed and the output shaft rotational speed of the pulley;
c. Gear ratio calculating means for calculating a gear ratio of the continuously variable transmission based on the detected input shaft speed and output shaft speed of the pulley;
d. Oil pressure command value calculating means for calculating the command value of the supplied oil pressure;
e. A ring that calculates the degree of deterioration of the ring per n rotations of the belt based at least on the calculated input torque, the detected input shaft rotational speed of the pulley, the calculated transmission gear ratio, and a hydraulic pressure command value. A deterioration degree calculating means;
f. Shaft thrust calculating means for calculating shaft thrust acting on the pulley;
g. Element clamping force calculating means for calculating a clamping force for clamping the element from the side based on the calculated axial thrust;
h. An element pushing force calculation means for calculating a pushing force of the element based on the calculated input torque, the detected input shaft rotational speed of the pulley, and the calculated gear ratio;
i. Element load calculating means for calculating an element load acting on the element based at least on the calculated element clamping force and element pressing force;
j. Element deterioration degree calculating means for calculating a deterioration degree of the element per n rotations of the belt based on the calculated element load;
k. When the calculated ring degradation level or element degradation level exceeds a set threshold value, degradation level integration means for integrating the degradation level exceeding the set threshold value;
l. An operation executing means for executing a predetermined operation including a warning when the integrated ring deterioration level or element deterioration level exceeds a set allowable value;
A belt deterioration determining device for a continuously variable transmission. An output of an internal combustion engine mounted on a vehicle, comprising: a ring, a belt composed of a plurality of elements held by the ring; and a pulley that clamps the belt with a winding radius determined in accordance with a supplied hydraulic pressure. In a continuously variable transmission that changes speed,
a. Operation mode detection means for detecting an operation mode including at least start acceleration of the vehicle and switching between forward and backward travel of the vehicle;
b. Operation mode number counting means for counting the number of detected operation modes for each operation mode;
c. A belt deterioration degree integrating means for calculating the degree of deterioration of the belt based on the number of times counted for each operation mode and a degree of deterioration set in advance for each operation mode, and for integrating the calculated values;
d. An operation executing means for executing a predetermined operation including a warning when the accumulated degree of deterioration of the belt exceeds a set allowable value;
A belt deterioration determining device for a continuously variable transmission.