JP2006132753A - Controller for belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller for a belt type continuously variable transmission capable of providing more accurate input torque and belt clamping force by a simple composition. <P>SOLUTION: A deformation amount detecting means 73 is provided for detecting an axial deformation amount of a sheave composing a variable pulley, and a deriving means is provided for determining either one of torque acting on the sheave or the belt clamping force (an oil pressure) on the basis of the sheave deformation amount (a deflection amount) detected by the deformation amount detecting means 73. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for a belt-type continuously variable transmission, and in particular, a configuration for transmitting power between two variable pulleys by a belt and controlling a transmission ratio thereof by changing a winding radius of the belt. The present invention relates to a control device for a belt type continuously variable transmission.

  In general, a stepped or continuously variable transmission is provided on the output side of the engine for the purpose of operating the engine under optimum conditions according to the traveling state of the vehicle. An example of such a continuously variable transmission is a belt-type continuously variable transmission. This belt-type continuously variable transmission has two rotating members arranged in parallel, and a primary pulley as a driving pulley and a secondary pulley as a driven pulley separately attached to each rotating member. . Both the primary pulley and the secondary pulley are configured by combining a fixed sheave and a movable sheave, and a V-shaped groove is formed between the fixed sheave and the movable sheave.

  Further, a belt is wound around the groove of the primary pulley and the groove of the secondary pulley, and a hydraulic chamber for generating a holding pressure in the axial direction is separately provided on the movable sheave. By separately controlling the hydraulic pressure in each hydraulic chamber, the groove width of the primary pulley is controlled to change the belt wrapping radius and the gear ratio is changed, while the groove width of the secondary pulley is changed. The belt tension is controlled.

  By the way, in the belt type continuously variable transmission as described above, the contact friction force between the belt and each pulley is controlled according to the line pressure, and this line pressure is input to the belt type continuously variable transmission. It is set according to the torque. This is because if the line pressure is too small with respect to the input torque, slip occurs between the belt and the pulley, and if the line pressure is too large, a driving loss of a hydraulic pump or the like occurs. Therefore, Patent Document 1 discloses a shift control device for a belt-type continuously variable transmission in which appropriate line pressure control is performed by appropriately estimating the input torque.

  In the shift control device for a belt-type continuously variable transmission described in Patent Document 1, a primary pulley rotation speed Np by an output-side rotation speed sensor of a torque converter (hereinafter also referred to as T / C) and its From the engine speed Ne obtained by the input side speed sensor, the T / C speed ratio calculation unit obtains the speed ratio in the torque converter, and the T / C torque ratio calculation unit obtains the torque ratio from this speed ratio. Then, the input torque estimation unit estimates the input torque to the continuously variable transmission from the torque ratio and the engine output torque obtained by the engine torque calculation unit. Further, the T / C speed ratio calculation unit includes a correction amount calculation unit, and corrects the speed ratio when the accelerator pedal is depressed to be lower than Np / Ne. As a result, even a low-precision rotational speed sensor can reduce the deviation from the actual value of the speed ratio during the dead time of each rotational speed sensor, and can appropriately estimate the input torque.

JP 2002-106705 A

  By the way, in the shift control device for a belt type continuously variable transmission described in Patent Document 1, the T / C speed ratio calculation unit obtains the T / C speed ratio using a low-accuracy rotational speed sensor, and T The T / C torque ratio is calculated by the / C torque ratio calculation unit, and the input torque of the continuously variable transmission is estimated from the engine output torque calculated by the engine torque calculation unit and the above-described T / C torque ratio. . In calculating the T / C torque ratio, correction calculation for the low accuracy of the rotation speed sensor is performed in the T / C speed ratio calculation.

  However, in the shift control device for a belt-type continuously variable transmission described in Patent Document 1, a T / C torque ratio based on a T / C speed ratio obtained using a calculated engine output torque or a low-precision rotation speed sensor. Since the input torque to the continuously variable transmission is estimated using, many calculations are required and there is a problem that the control becomes complicated. Further, since there are many parts to be estimated, there is a difference between the estimated input torque and the actual input torque, and a technique that can obtain the input torque more accurately is required.

  The present invention has been made against the background of the above circumstances, and an object thereof is to provide a control device for a belt-type continuously variable transmission that can obtain more accurate input torque and belt clamping pressure with a simple configuration. Yes.

  In order to achieve the above object, a control device for a belt-type continuously variable transmission according to an aspect of the present invention includes a deformation amount detecting means for detecting an axial deformation amount of a sheave constituting a variable pulley, and the deformation amount detection unit. Derivation means for obtaining at least one of torque acting on the sheave and belt clamping pressure based on the sheave deformation detected by the means.

  Here, it is preferable that the deformation amount detecting means is provided in a portion where the sheave deformation amount is large.

  When the belt is a push type, the deformation amount detecting means is provided at the central portion of the belt winding around the drive side variable pulley or at the side position of the fixed sheave corresponding to the belt outlet portion of the driven side variable pulley. Is preferred.

  Further, when the belt is of a pulling type, the deformation amount detecting means is provided at a side position of the fixed sheave corresponding to the belt winding inlet portion of the driving side variable pulley or the belt outlet portion of the driven side variable pulley. Is preferred.

  Here, the deformation amount detection means may be a deflection detection sensor shared with at least one of the sensors for detecting the rotational speed of the drive side variable pulley or the driven side variable pulley.

  The belt-type continuously variable transmission further includes a clutch downstream of the driven variable pulley, and learning means for learning a relationship between the sheave deformation amount and the belt clamping pressure when the clutch is disengaged. Also good.

  According to one aspect of the present invention, the deformation amount detecting means detects the axial deformation amount of the sheave constituting the variable pulley. Since the sheave deformation amount has a predetermined relationship with the belt winding position, in other words, the gear ratio, the sheave deformation amount acts on the sheave by the derivation means based on the sheave deformation amount detected by the deformation amount detection means. At least one of torque and belt clamping pressure is required. Thus, since the torque or the belt clamping pressure is obtained based on the actually measured value of the sheave deformation amount, a more accurate value can be obtained with a simple configuration.

  Here, according to the embodiment in which the deformation amount detecting means is provided in a portion where the sheave deformation amount is large, it is possible to more accurately detect the sheave deformation amount.

  When the belt is a push type, the deformation amount detecting means is provided at the center portion of the belt winding around the drive side variable pulley or at the side position of the fixed sheave corresponding to the belt outlet portion of the driven side variable pulley. According to this, it is possible to detect the sheave deformation amount more accurately when the belt is a push type.

  Further, when the belt is of a pulling type, the deformation amount detecting means is provided at the side position of the fixed sheave corresponding to the belt winding inlet portion of the driving side variable pulley or the belt outlet portion of the driven side variable pulley. According to this, it becomes possible to detect the sheave deformation more accurately when the belt is of the pulling type.

  Here, according to the form in which the deformation amount detection means is a deflection detection sensor shared with at least one of the rotational speed detection sensors of the drive side variable pulley or the driven side variable pulley, the parts are shared. The cost can be reduced by the conversion.

  Further, the belt-type continuously variable transmission includes a clutch downstream of the driven variable pulley, and learning means for learning a relationship between the sheave deformation amount and the belt clamping pressure when the clutch is disengaged. According to the embodiment, even if there are variations in the component parts, the accuracy of estimation of the torque or the belt clamping pressure can be improved by this learning.

Here, an embodiment of the present invention will be specifically described with reference to the accompanying drawings.
(1) Configuration of Transaxle FIG. 1 is a skeleton diagram of a transaxle when the control device for a belt-type continuously variable transmission according to the present invention is applied to an FF vehicle (front-wheel drive vehicle for engine front). In FIG. 1, reference numeral 1 denotes an engine as a driving force source of a vehicle, and the type thereof is not particularly limited. In the following description, a case where a gasoline engine is used as the engine 1 will be described for convenience. A transaxle 3 is provided on the output side of the engine 1, and this transaxle 3 is attached to a transaxle housing 4 attached to the rear end side of the engine 1 and an open end opposite to the engine 1. A transaxle case 5 and a transaxle rear cover 6 attached to an opening end opposite to the transaxle housing 4 are sequentially provided. A torque converter (T / C) 7 is provided inside the transaxle housing 4. In the present embodiment, the transaxle case 5 and the transaxle rear cover 6 have a forward / reverse switching mechanism 8 and A belt type continuously variable transmission (CVT) 9 and a final speed reducer 10 are provided in this order.

  An input shaft 11 coaxial with the crankshaft 2 is provided inside the transaxle housing 4, and a turbine runner 13 is attached to an end of the input shaft 11 on the engine 1 side. On the other hand, a front cover 15 is connected to the rear end of the crankshaft 2 via a drive plate 14, and a pump impeller 16 is connected to the front cover 15. The turbine runner 13 and the pump impeller 16 are disposed to face each other, and a stator 17 is provided inside the turbine runner 13 and the pump impeller 16. An oil pump 20 is provided between the torque converter 7 and the forward / reverse switching mechanism 8.

  The forward / reverse switching mechanism 8 is provided in a power transmission path between the input shaft 11 and the belt type continuously variable transmission 9. The forward / reverse switching mechanism 8 has a planetary gear mechanism 24 of a double pinion type. The planetary gear mechanism 24 includes a sun gear 25 provided on the input shaft 11, a ring gear 26 disposed concentrically with the sun gear 25 on the outer peripheral side of the sun gear 25, a pinion gear 27 meshed with the sun gear 25, A pinion gear 28 meshed with the pinion gear 27 and the ring gear 26, a carrier 29 that holds the pinion gears 27, 28 so as to be able to rotate, and holds the pinion gears 27, 28 in a state where they can revolve integrally around the sun gear 25. have. And this carrier 29 and the primary shaft 30 mentioned later of the belt-type continuously variable transmission 9 are connected. A forward clutch CL for connecting / disconnecting the power transmission path between the carrier 29 and the input shaft 11 and a reverse brake BR for controlling rotation / fixation of the ring gear 26 are provided.

  The belt type continuously variable transmission 9 includes a primary shaft (drive side shaft) 30 disposed concentrically with the input shaft 11 and a secondary shaft (driven side shaft) 31 disposed in parallel to the primary shaft 30. ing. The primary shaft 30 is rotatably held by bearings 32 and 33, and the secondary shaft 31 is rotatably held by bearings 34 and 35, respectively.

  A primary pulley (driving side pulley) 36 is provided on the primary shaft 30 side, and a secondary pulley (driven pulley) 37 is provided on the secondary shaft 31 side. The primary pulley 36 has a fixed sheave 38 formed integrally with the primary shaft 30 and a movable sheave 39 configured to be movable in the axial direction of the primary shaft 30. A V-shaped groove 40 is formed between the opposed surfaces of the fixed sheave 38 and the movable sheave 39.

  In addition, a hydraulic actuator 41 that moves the movable sheave 39 and the fixed sheave 38 closer to and away from each other by operating the movable sheave 39 in the axial direction of the primary shaft 30 is provided. On the other hand, the secondary pulley 37 similarly has a fixed sheave 42 formed integrally with the secondary shaft 31 and a movable sheave 43 configured to be movable in the axial direction of the secondary shaft 31. A V-shaped groove 44 is formed between the surfaces facing the movable sheave 43. Further, a hydraulic actuator 45 that moves the movable sheave 43 and the fixed sheave 42 closer to and away from each other by operating the movable sheave 43 in the axial direction of the secondary shaft 31 is provided.

  A belt 46 is wound around the groove 40 of the primary pulley 36 and the groove 44 of the secondary pulley 37. The belt 46 according to the present embodiment has a large number of metal pieces (also referred to as elements and blocks) and a plurality of steel rings or the like (also referred to as hoops and bands). It is comprised as a metal belt (refer Unexamined-Japanese-Patent No. 2000-220697, Unexamined-Japanese-Patent No. 2002-257200 etc.). A counter drive gear 47 is fixed to the secondary shaft 31 and is held by bearings 48 and 49. Further, the bearing 35 described above is provided on the transaxle rear cover 6 side, and a parking gear PG is provided between the bearing 35 and the secondary pulley 37. The parking gear may be formed integrally with the fixed sheave of the secondary pulley as will be described later.

  Further, an intermediate shaft 50 parallel to the secondary shaft 31 is supported by bearings 51 and 52 in the power transmission path between the counter drive gear 47 and the final reduction gear 10 of the belt type continuously variable transmission 9. ing. The intermediate shaft 50 is provided with a counter driven gear 53 that meshes with the counter drive gear 47 and a final drive gear 54.

  On the other hand, the final reduction gear 10 has a hollow differential case 55 rotatably supported by bearings 56 and 57, and a ring gear 58 that meshes with the final drive gear 54 is provided on the outer periphery of the differential case 55. A pinion shaft 59 to which two pinion gears 60 are attached is disposed inside the differential case 55. Two side gears 61 are meshed with the pinion gear 60 and communicated with the wheels 63 via the left and right drive shafts 62, respectively.

  Further, reference numerals 71 and 72 denote rotational speed sensors for detecting the rotational speeds of the primary pulley 36 and the secondary pulley 37, respectively, and 73 denotes an axial deformation amount of the fixed sheave 42 of the secondary pulley 37 according to the embodiment of the present invention. It is a bending detection sensor as a deformation amount detecting means. In the present embodiment, the deflection detection sensor 73 has a detection end disposed at a predetermined distance from the side flat surface of the fixed sheave 42 and a vortex that varies according to a change in the distance between the two. It is configured as a single gap sensor by detecting current. However, the deflection detection sensor 73 may be configured in common with the above-described rotation speed sensor 71 or 72 as described in other embodiments described later.

  The hydraulic pressure generated by the oil pump 20 is controlled and supplied to the hydraulic actuator 41 of the primary pulley 36 and the hydraulic actuator 45 of the secondary pulley 37 via the hydraulic control circuit 200. Here, 81 and 82 are hydraulic sensors that detect control hydraulic pressures Ppri and Psec supplied to the hydraulic actuator 41 of the primary pulley 36 and the hydraulic actuator 45 of the secondary pulley 37, respectively.

  More specifically, the hydraulic fluid sucked from the oil tank or oil pan and discharged from the oil pump 20 is regulated by a pressure-regulating valve that is duty-controlled and controlled to the line pressure PL. The hydraulic oil having the line pressure PL is set to the above-described control hydraulic pressure Ppri by the duty-controlled primary side pressure reducing valve and supplied to the primary side hydraulic actuator 41. Further, the hydraulic oil having the line pressure PL is similarly duty-controlled and controlled by the secondary pressure reducing valve to obtain the control hydraulic pressure Psec, and is supplied to the secondary hydraulic actuator 45.

  Reference numeral 300 denotes a CVT electronic control unit (hereinafter referred to as CVT • ECU) that controls the transaxle 3, and 400 denotes an engine electronic control unit (hereinafter referred to as E / G • ECU) that controls the engine 1, An arithmetic processing unit (CPU or MPU), a storage unit (RAM and ROM), and a microcomputer mainly including an input / output interface are included.

  For this CVT / ECU 300, in addition to the signals from the rotational speed sensors 71 and 72, the deflection detection sensor 73 and the hydraulic pressure sensors 81 and 82, various parameters indicating the state of the transaxle 3, such as a torque converter Information such as a torque ratio of 7 and a vehicle speed V is input. On the other hand, the E / G • ECU 400 receives various parameters representing the operating state of the engine 1, such as engine speed, accelerator opening, throttle opening sensor signals, etc., and requires information on the calculation results. In response, it is input to the CVT / ECU 300. Thus, information such as the rotation speed Np of the primary shaft 30 and the rotation speed Ns of the secondary shaft 31 by the above-described rotation speed sensors 71 and 72, and the vehicle speed V, etc., are transmitted to the CVT / ECU 300 as signals of various sensors and calculation results. The above-described control oil pressure Ppri and control oil pressure Psec are formed in order to obtain a required gear ratio γ (= Np / Ns) and a belt clamping pressure based on a map or the like previously obtained through experiments or the like. . Further, as will be described later, the torque acting on the sheave and / or the belt clamping pressure is obtained based on the sheave deformation amount detected by the deflection detection sensor 73, and based on these, the above-described line pressure PL and control oil pressure Ppri are obtained. And correction control of the control oil pressure Psec is performed.

(2) Configuration of Primary Pulley 36 and Secondary Pulley 37 Here, the embodiment of the belt type continuously variable transmission 9 described above will be described in more detail with reference to FIG. FIG. 2 is an enlarged cross-sectional view of the vicinity of the primary pulley 36 and the secondary pulley 37.

  The primary pulley 36 is disposed on the outer periphery of the primary shaft 30 between a bearing 33 attached to the transaxle rear cover 6 and a bearing 32 attached to the transaxle case 5 side. The primary shaft 30 is rotatable about the axis A <b> 1, and two oil passages 107 and 108 are formed in the primary shaft 30 in the axial direction. The oil passages 107 and 108 communicate with the hydraulic circuit 200 of the hydraulic control device described above. Further, the primary shaft 30 is provided with oil passages 109 and 110 that extend in the radial direction toward the outer peripheral surface thereof and communicate with the oil passage 107. The oil passage 109 and the oil passage 110 are provided at different positions in the axial direction. Specifically, the oil passage 109 is disposed closer to the bearing 33 than the oil passage 110.

  On the other hand, a step 112 is formed between the opening of the oil passage 109 on the outer periphery of the primary shaft 30 and the bearing 33. The movable sheave 39 includes an inner cylindrical portion 39A that slides along the outer peripheral surface of the primary shaft 30, a radial direction portion 39B that continues from the end of the inner cylindrical portion 39A on the fixed sheave 38 side toward the outer peripheral side, The outer cylindrical portion 39C is continuous with the outer peripheral end of the direction portion 39B and extended in the axial direction toward the bearing 33 side. An oil passage 116 penetrating from the inner peripheral surface to the outer peripheral surface is formed in the inner cylindrical portion 39A. The oil passage 116 and the oil passage 110 communicate with each other via a spline portion formed on the outer peripheral surface of the primary shaft 30.

  A piston member 117 is disposed between the movable sheave 39 and the bearing 33. The piston member 117 is connected to the radial direction portion 117A constituting the inner peripheral side of the piston member 117 and the outer peripheral end of the radial direction portion 117A, and is extended toward the radial direction portion 39B side of the movable sheave 39. A cylindrical portion 117B and a radial direction portion 117C that is continuous with the end portion of the cylindrical portion 117B and that extends outward substantially along the back surface of the radial direction portion 39B of the movable sheave 39 are provided. The radial portion 117 </ b> A of the piston member 117 is fixed to the primary shaft 30 by a lock nut 130 that is fastened to the outer periphery of the primary shaft 30 via the step 112 and the inner race of the bearing 33. The bearing 33 is disposed between the primary shaft 30 and the transaxle rear cover 6. A resin seal ring 117D is attached to the outer peripheral end of the radial direction portion 117C of the piston member 117, and the seal ring 117D and the inner peripheral surface of the outer cylindrical portion 39C of the movable sheave 39 are relatively moved in the axial direction. Contact is possible, and a seal surface is formed at the contact portion. As described above, the control hydraulic chamber 41A constituting a part of the hydraulic actuator 41 of the primary pulley is defined in the space surrounded by the movable sheave 39 and the piston member 117, and the hydraulic chamber 41A and the oil passage are formed. 116 is communicated.

  An axial spline groove 123 is formed on the inner peripheral surface of the inner cylindrical portion 39 </ b> A of the movable sheave 39, and axial spline teeth 124 are formed on the outer peripheral surface of the primary shaft 30. A plurality of spline grooves 123 and spline teeth 124 are formed at predetermined intervals in the circumferential direction. The spline grooves 123 and the spline teeth 124 are coupled so as to have the same phase in the circumferential direction, and the primary shaft 30 and the movable sheave 39 can be relatively moved relative to each other in the axial direction. 30 and the movable sheave 39 are coupled in a state in which relative movement is impossible in the circumferential direction.

  On the other hand, the secondary shaft 31 of the secondary pulley 37 is rotatable about the axis B1, and oil passages 178 and 179 are formed in the inside from both ends in the axial direction. The oil passages 178 and 179 are communicated with the hydraulic control circuit 200 described above. Furthermore, an oil passage 180 that extends in the radial direction toward the outer peripheral surface of the secondary shaft 31 and communicates with the oil passage 178 is provided. Furthermore, an oil passage 181 that extends in the radial direction toward the outer peripheral surface of the secondary shaft 31 and communicates with the oil passage 179 is provided. Furthermore, a step portion 31 </ b> B is formed in the vicinity of the opening portion of the oil passage 181 on the outer periphery of the secondary shaft 31.

  And in this Embodiment, the fixed sheave 42 is fitted by the outer periphery of the secondary shaft 31, and is being fixed to the axial direction. Specifically, the fixed sheave 42 is continuous from the end on the movable sheave 43 side of the cylindrical portion 42A toward the outer peripheral side, and is formed integrally with a radial portion 42B having a cone surface. And this cylindrical part 42A is fitted in the outer periphery of the secondary shaft 31, and is fixed to the axial direction in the form contact | abutted to the step part 31D by the enlarged diameter part 31C formed in the end of the secondary shaft 31. As shown in FIG. A parking gear PG is integrally formed on the back surface of the cone surface in the radial direction portion 42B of the fixed sheave 42 as described later.

  On the other hand, the movable sheave 43 has an inner cylindrical portion 43A that slides along the outer peripheral surface of the secondary shaft 31, and a cone surface that is continuous from the end on the fixed sheave 42 side of the inner cylindrical portion 43A toward the outer peripheral side. It has a radial direction portion 43B and an outer cylindrical portion 43C that is continuous with the outer peripheral end of the radial direction portion 43B and extends in the axial direction.

  A plurality of spline grooves 43D are formed on the inner peripheral surface of the inner cylindrical portion 42A of the movable sheave 43, while a plurality of spline teeth 31K are formed on the outer peripheral surface of the secondary shaft 31 that slidably supports the movable sheave 43. Is formed. The spline teeth and the spline grooves are formed such that the tooth surfaces or groove surfaces form, for example, an involute curve, and the secondary shaft 31 and the movable sheave 43 can be relatively moved relative to each other in the axial direction. The movable sheave 43 is in a spline coupling state in which relative movement in the circumferential direction is impossible.

  Further, the secondary hydraulic actuator 45 of the secondary pulley 37 includes an annular piston member 190. As can be seen from FIG. 2, the piston member 190 includes a first radial base portion 190A extending in the radial direction of the secondary shaft 31, and a cylindrical portion 190B extending substantially parallel to the axis of the secondary shaft 31 from the first radial base portion 190A. And a second radial portion 190C extending in the radial direction of the secondary shaft 31 while being bent from the tubular portion 190B toward the back surface of the movable sheave 43. A seal member 190D is disposed on the outer edge portion of the second radial direction portion 190C so as to be in sliding contact with the inner peripheral surface of the outer cylindrical portion 43C of the movable sheave 43.

  Reference numeral 192 denotes a substantially funnel-shaped partition member, and the outer edge portion 192A on the large diameter side is fixed to the movable sheave 43 by the snap ring 192B in a state where the outer edge portion 192A is press-fitted into the inner peripheral surface of the outer cylindrical portion 43C of the movable sheave 43 Has been. On the other hand, reference numeral 194 denotes a substantially bowl-shaped guide member, which is close to the cylindrical portion 190B of the piston member 190 and is substantially parallel to the axial line of the secondary shaft 31 from the radial direction portion 194A in which a passage, which will be described later, is formed. It has a cylindrical part 194B extending in the direction. A drain gap is formed between the inner edge portion 192C on the small diameter side of the partition wall member 192 and the outer peripheral surface of the cylindrical portion 194B of the guide member 194.

  The piston member 190 and the guide member 194 have a small diameter portion at the tip of the secondary shaft 31 with respect to the center hole formed in the first radial base portion 190A of the piston member 190 and the radial direction portion 194A of the guide member 194. Is fixed together with a bearing 34 in the form of a ball bearing between the step portion 31B of the secondary shaft 31 using a lock nut 196.

  Thus, the control hydraulic chamber 45A constituting a part of the secondary hydraulic actuator 45 described above is defined by the inner cylindrical portion 43A, the radial direction portion 43B, the outer cylindrical portion 43C and the piston member 190 of the movable sheave 43. Yes. A compression spring 43E that urges the movable sheave 43 in the minimum gear ratio direction is provided between the piston member 190 and the movable sheave 43 in the control hydraulic chamber 45A. On the other hand, the second radial direction portion 190C of the piston member 190, the outer cylindrical portion 43C of the movable sheave 43, and the partition wall member 192 define a centrifugal hydraulic pressure cancellation chamber 45B that constitutes a part of the hydraulic actuator 45 described above. .

  Moreover, in this Embodiment, while making the oil path 178 of the secondary shaft 31 large diameter, it is lightly lightened in the inner periphery corresponding to the enlarged diameter part 31C of a shaft end, and the weight reduction is achieved. That is, an enlarged inner diameter portion 31H is formed concentrically with the oil passage 178 formed in the axial direction at the shaft end portion of the secondary shaft 31. A sleeve 31P is attached to the enlarged inner diameter portion 31H. The sleeve 31P is provided with a seal ring on the outer peripheral portion and is in contact with the inner peripheral surface of the enlarged inner diameter portion 31H to seal the oil passage 178. The small diameter portion extending from the sleeve 31 </ b> P is press-fitted and held in a fitting port communicating with an oil passage formed in the transaxle rear cover 6. Thus, the control oil pressure is supplied to the oil passage 178 from the oil passage formed in the transaxle rear cover 6 via the sleeve 31P. Furthermore, in the present embodiment, the above-described enlarged diameter portion 31C of the secondary shaft 31 is used as the inner ring of the bearing 35 in the form of a roller bearing.

  In the present embodiment, as shown in FIG. 2, on the primary pulley 36 side, the rotational speed sensor 71 has its detection end face on the outer peripheral side of the fixed sheave 38 of the primary pulley 36 at predetermined intervals. Is fixed to the transaxle case 5 so as to face the top surface of the convex tooth H formed in the above. On the other hand, on the secondary pulley 37 side, the rotation speed sensor 72 is configured to be shared with the deflection detection sensor 73 and fixed to the transaxle rear cover 6 as described in detail below.

(3) Deflection Detection Sensor Here, the structure, arrangement, and operation of the deflection detection sensor 73 used in the present invention will be described with reference to FIGS. First, the deflection detection sensor 73 is illustrated as an independent sensor in FIG. 1, but the deflection detection sensor used in the present embodiment is configured as a shared structure with the rotation speed sensor 72 (however, for convenience of description). When the deflection detecting function as the deformation detecting means for detecting the axial deformation of the sheave is used, it will be referred to as a bending detecting sensor 73). Here, as shown in FIGS. 3 (A) and 3 (B), the bending detection sensor 73 includes a permanent magnet 73A and an iron core 73B extending to the detection end, and a terminal 73D wound around the iron core 73B. The coil 73 </ b> C is mainly configured.

  Then, as shown in FIG. 4A (however, for ease of understanding, the deflection detection sensor 73 is rotated by 180 degrees from the state shown in FIG. 2). The transaxle rear cover 6 is fixed to the side surface of the parking gear PG formed integrally with the fixed sheave 42 of the pulley 37 at a predetermined distance D. As shown in FIG. 4B, the parking gear PG has convex teeth H arranged at predetermined intervals on the outer periphery thereof. The detection end surface of the iron core 73 </ b> B of the above-described deflection detection sensor 73 is arranged to face the side surface of the tooth H. That is, when viewed from the direction indicated by the arrow A in FIG. 4A, a black circle in FIG. 4B indicates a relationship serving as a detection end surface of the iron core 73B.

  Therefore, according to the rotation of the fixed sheave 42 in a no-load state (shown by a solid line in FIG. 4A), the rising and falling portions of the side surfaces of the teeth H are detected. As shown in FIG. 4B, a pulse voltage indicated by a solid line having a voltage V0 as a peak voltage is generated in synchronization with the proximity or separation in the circumferential direction. On the other hand, as will be described later, when a collapse occurs in the load state of the fixed sheave 42 (indicated by a broken line in FIG. 4A, the amount of axial deformation is indicated as a deflection amount δ). Accordingly, the distance between the detection end surface and the side surface of the tooth H is reduced, and the magnetic flux density passing through the iron core 73B and the tooth H is increased. As a result, a pulse voltage indicated by a broken line having the voltage Vδ as a peak voltage is generated. The peak voltage increases as the distance between the detection end face of the deflection detection sensor 73 and the side surface of the tooth H is shorter, that is, as the interval becomes smaller, in other words, as the deflection amount δ increases. Thus, by detecting this peak voltage Vδ, the amount of deflection δ of the fixed sheave 42 can be detected. When the deflection detection sensor 73 is shared as the rotation speed sensor 71 or 72 as described above, the primary shaft is based on the period of the pulse voltage in addition to the deflection amount δ of the fixed sheave 38 of the primary pulley 36. Needless to say, the rotational speed Np of 30 and the rotational speed Ns of the secondary shaft 31 are required.

(4) Relationship between Deflection Amount δ, Torque and Belt Clamping Pressure Next, the relationship between the torque and belt clamping pressure acting on the pulley sheave and the aforementioned deflection amount δ will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing the above-described secondary pulley 37 as an example. The control oil pressure P is supplied to the control oil pressure chamber 45A of the secondary hydraulic actuator 45 in the secondary pulley 37, and a predetermined gear ratio γ position is shown. The state where the torque T is acting on the belt 46 in FIG. In this state, based on the control oil pressure P, a belt clamping pressure proportional to the effective pressure receiving area of the hydraulic actuator 45 in the movable sheave 43 acts on the belt 46 and also acts on the fixed sheave 42 via the belt 46. Since the belt clamping pressure is uniquely determined by the control hydraulic pressure P as described above, the control hydraulic pressure P is used synonymously with the belt clamping pressure in the following description. On the other hand, due to the torque T acting on the belt 46 (in FIG. 5, the direction perpendicular to the paper surface), the belt 46 sinks by x in the radial direction so as to spread the fixed sheave 42 and the movable sheave 43. As a result, the outer peripheral portion of the fixed sheave 42 falls and the above-described deflection amount δ is generated.

  Thus, the deflection amount δ increases in proportion to the sinking amount x and the control hydraulic pressure P. By the way, since the sinking amount x is proportional to the torque T acting on the belt 46, the deflection amount δ is proportional to the torque T and the control oil pressure P. Therefore, a predetermined map in which the respective values are stored can be obtained by experimentally obtaining these relationships in advance. An example of the map is shown in FIG. A map Mγ shown in FIG. 6A is a three-dimensional map in which the relationship between the deflection amount δ, the torque T, and the control hydraulic pressure P is plotted on the orthogonal coordinates by fixing the speed ratio γ and plotted. It can be seen that the deflection amount δ shown on the vertical axis increases in proportion to the torque T and the control hydraulic pressure P, respectively.

  Then, the map fluctuates up and down as shown in FIG. 6B in accordance with the fluctuation of the winding position of the belt 46 resulting from the change of the speed ratio γ. Note that the direction Z of the variation differs depending on whether the primary pulley 36 side or the secondary pulley 37 side. That is, when the transmission gear ratio γ is on the maximum transmission gear ratio γmax side on the primary pulley 36 side, the winding radius is small as shown in FIG. ), Since the winding radius is large, the deflection amount δ of the fixed sheave 42 on the secondary pulley 37 side increases as the speed ratio γ increases. Conversely, when the transmission gear ratio γ is on the minimum transmission gear ratio γmin side on the secondary pulley 37 side, the winding radius is small as shown in FIG. 7B, whereas on the primary pulley 36 side, FIG. As shown in A), since the winding radius is large, the amount of deflection δ of the fixed sheave 38 on the primary pulley 36 side increases as the gear ratio γ decreases. Accordingly, when the deflection amount δ is detected on the secondary pulley 37 side and used for control, as the speed ratio γ increases, the deflection amount δ is detected on the primary pulley 36 side and used for control. As the gear ratio γ decreases, the map corresponding to the predetermined gear ratio γ is used while shifting from the lower map Mγl to the upper map Mγu. As described above, when the transmission gear ratio γ is known, a predetermined map Mγ is specified from among a plurality of maps prepared for each transmission gear ratio, and the relationship among the deflection amount δ, the torque T, and the control hydraulic pressure P is known.

(5) Installation Position of Deflection Detection Sensor Next, the optimal installation position of the above-described deflection detection sensor 73 will be described with reference to FIGS. 8 and 9. Here, the deflection detection sensor 73 is provided in a portion where the sheave deformation amount is large in order to enable more accurate detection of the sheave deformation amount.

  That is, FIG. 8 shows a case where the belt 46 is a so-called push-type metal belt having the above-described many metal pieces (elements, blocks) and a plurality of rings such as steel (hoops, bands). In this case, the primary pulley 36, which is a drive-side variable pulley, is provided at a side portion position of the fixed sheave 38 corresponding to the central portion of the belt around the primary pulley 36, which is a drive-side variable pulley. ing. Specifically, the central portion of the belt wrapping is a region in a range of approximately ± 45 ° with the axis A1 as the center with respect to a plane including the axis A1 of the primary shaft 30 and the axis B1 of the secondary shaft 31. Moreover, in the secondary pulley 37 which is a driven side variable pulley, it is provided in the side part position of the fixed sheave 42 corresponding to the belt exit part. Specifically, the belt outlet portion is a region in a range of approximately ± 45 ° around the axis B1 with respect to a plane orthogonal to the plane including the axis A1 of the primary shaft 30 and the axis B1 of the secondary shaft 31. 8B is a side view in the direction of arrow A in FIG. 4 and FIG. 8A and 8B, the rotation direction of the belt 46 is indicated by an arrow B.

  Further, when the belt is a pulling type such as a chain type (see JP-A-8-31725, JP-A-10-26188, JP-A-11-241753, etc.), The primary pulley 36, which is a drive-side variable pulley, is provided at the side position of the fixed sheave 38 corresponding to the inlet portion of the belt. Specifically, the belt-wrapped inlet portion is a region in a range of approximately ± 45 ° about the axis A1 with respect to a plane orthogonal to the plane including the axis A1 of the primary shaft 30 and the axis B1 of the secondary shaft 31. It is. Moreover, in the secondary pulley 37 which is a driven side variable pulley, it is provided in the side part position of the fixed sheave 42 corresponding to the belt exit part. Specifically, the belt outlet portion is a region in a range of approximately ± 45 ° around the axis B1 with respect to a plane orthogonal to the plane including the axis A1 of the primary shaft 30 and the axis B1 of the secondary shaft 31. This is a region indicated by hatching in FIG. 9B, which is a side view in the direction of arrow A in FIGS. 4 and 9A. 9A and 9B, the rotation direction of the belt 46 is indicated by an arrow B.

(6) Control / Operation The belt type continuously variable transmission 9 includes data stored in the CVT / ECU 300 and the E / G / ECU 400 (for example, an optimum fuel consumption curve using the engine speed Ne and the throttle opening as parameters), Based on a vehicle acceleration request determined from conditions such as the vehicle speed V and the accelerator opening, the gear ratio and the belt clamping pressure are controlled so that the operating state of the engine 1 becomes an optimum state. Specifically, the width of the groove 40 of the primary pulley 36 is adjusted by controlling the control oil pressure Ppri of the hydraulic actuator 41. As a result, the winding radius of the belt 46 in the primary pulley 36 changes, and the ratio of the input rotational speed Np and the output rotational speed Ns of the belt-type continuously variable transmission 9, that is, the speed ratio γ is stepless (continuous). Be controlled.

  Further, by controlling the control oil pressure Psec of the hydraulic actuator 45, the width of the groove 44 of the secondary pulley 37 changes. That is, the belt clamping pressure (in other words, thrust) in the axial direction of the secondary pulley 37 with respect to the belt 46 is controlled. The tension of the belt 46 is controlled by this belt clamping pressure, and the contact pressure between the primary pulley 36 and the secondary pulley 37 and the belt 46 is controlled. This control oil pressure Psec is controlled based on the torque T input to the primary shaft 30 of the belt type continuously variable transmission 9, the gear ratio γ, and the like.

  (A) Therefore, a first embodiment in which the torque T input to the belt type continuously variable transmission 9 is estimated based on the above-described deflection amount δ and the control hydraulic pressure Psec of the secondary pulley 37 is controlled is illustrated in FIG. This will be described with reference to FIG.

  First, when control is started, in step S101, based on the signals from the rotational speed sensors 71 and 72, the rotational speed Np of the primary shaft 30 and the rotational speed Ns of the secondary shaft 31 are calculated and obtained. In the next step S102, the gear ratio γ (= Np / Ns) at that time is calculated. Further, the process proceeds to step S103, and a deflection amount δ is calculated based on a signal from the deflection detection sensor 73.

  In step S104, at least one of the control hydraulic pressure Ppri supplied to the hydraulic actuator 41 of the primary pulley 36 and the control hydraulic pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is the hydraulic sensor 81 or the hydraulic sensor. 82. Here, which control hydraulic pressure is detected depends on which deflection amount δ is detected. Of course, both may be detected. However, in the present embodiment, the control hydraulic pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is detected by the hydraulic sensor 82. The detected oil pressure is referred to as sensor oil pressure Psensor in the following description.

  Therefore, in the next step S105, the map exemplified in FIG. 6B is referred to using the speed ratio γ, the deflection amount δ and the sensor hydraulic pressure Psensor obtained in each of the above steps, and the primary pulley 36 is referred to. The actual torque Tin that will be input and transmitted to the secondary pulley 37 is acquired. Then, in step S106, the control hydraulic pressure Psec necessary for obtaining the optimum clamping pressure between the secondary pulley 37 and the belt 46 is calculated using the actual torque Tin, and in the next step S107, the necessary control hydraulic pressure Psec is supplied. It is controlled accordingly. Thus, according to the present embodiment, the necessary control hydraulic pressure Psec can be obtained using the actual torque Tin that is closer to the actual torque acting on the pulley, so that the excess hydraulic pressure in anticipation of the safety factor can be reduced. The pump loss can be reduced and the efficiency can be improved.

  (B) Next, without using the hydraulic pressure sensor used in the first embodiment, the supplied hydraulic pressure is estimated based on the above-described deflection amount δ (secondary pulley side), and the control hydraulic pressure Psec of the secondary pulley 37 is estimated. A second embodiment for controlling the above will be described with reference to the flowchart of FIG.

  In this control mode, when control is started, first, in step S111, based on the signals from the rotational speed sensors 71 and 72, the rotational speed Np of the primary shaft 30 and the rotational speed Ns of the secondary shaft 31 are obtained. In S112, the gear ratio γ (= Np / Ns) at that time is calculated, and further, the process proceeds to Step S113, and the deflection amount δ is calculated based on the signal from the deflection detection sensor 73. This is the same as S103. In step S114, the estimated value of the output torque of the engine 1, that is, the estimated input torque TinE to the primary pulley 36 is input as information from the E / G • ECU 400. The estimated torque value TinE may be obtained by multiplying the output torque of the engine 1 by the torque ratio of the torque converter 7.

  Therefore, in the next step S115, the map illustrated in FIG. 6B is referred to using the speed ratio γ, the deflection amount δ, and the torque estimation value TinE obtained in each of the above steps, and the actual deflection is performed. The actual hydraulic pressure PsecR supplied to the hydraulic actuator 45 of the secondary pulley 37 that causes the amount δ is acquired. Then, the process proceeds to step S116, and the required oil pressure PsecN required for calculation is compared with the actual oil pressure PsecR based on the estimated torque value TinE. As a result of the comparison, when the actual oil pressure PsecR is greater than or equal to the required oil pressure PsecN, the process proceeds to step S117, and it is further determined whether or not both are equal. If it is determined in step S117 that they are not equal, that is, if the actual oil pressure PsecR is greater than the required oil pressure PsecN, the process proceeds to step S118, and the supply control oil pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is set to a predetermined value. A down signal is output, and the process returns to step S116. On the other hand, if both are equal in the determination in step S117, this routine is temporarily terminated to maintain this state. If it is determined in step S116 that the actual hydraulic pressure PsecR is smaller than the required hydraulic pressure PsecN, the process proceeds to step S119, and a signal for increasing the supply control hydraulic pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 by a predetermined value (up). Similarly, the process returns to step S116. In this manner, the supply control oil pressure Psec is increased or decreased until the actual oil pressure PsecR becomes equal to the required oil pressure PsecN.

  Thus, according to the present embodiment, it is possible to compare the required hydraulic pressure PsecN with the actual hydraulic pressure PsecR that actually causes the deflection amount δ without using a hydraulic pressure sensor, so that the control hydraulic pressure can be supplied with high accuracy. And efficiency can be improved.

  (C) Next, the input torque and the supplied hydraulic pressure are estimated with higher accuracy based on the detected hydraulic pressure value by the hydraulic pressure sensor, the estimated engine torque value and the above-described deflection amount δ. A third embodiment for controlling the control oil pressure Psec will be described with reference to the flowchart of FIG.

  In this control mode, when control is started, first, in step S1201, the rotation speed Np of the primary shaft 30 and the rotation speed Ns of the secondary shaft 31 are obtained based on the signals from the rotation speed sensors 71 and 72. In step S1202, the gear ratio γ (= Np / Ns) at that time is calculated. Further, the process proceeds to step S1203, where the deflection amount δ is calculated based on the signal from the deflection detection sensor 73, and the step of the previous embodiment. This is the same as S101 to S103 and steps S201 to S203. In step S1204, the control oil pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is detected and read as a sensor oil pressure Psensor by the oil pressure sensor 82. In step S1205, the output torque of the engine 1, that is, the estimated value TinE of the input torque to the primary pulley 36 is input as information from the E / G • ECU 400. The estimated torque value TinE may be obtained by multiplying the output torque of the engine 1 by the torque ratio of the torque converter 7 as in the previous embodiment.

  In the next step S1206, the map illustrated in FIG. 6B is referred to using the speed ratio γ, the deflection amount δ, the sensor hydraulic pressure Psensor, and the estimated torque TinE obtained in each of the above steps. The respective “deviation amounts” in the hydraulic pressure and torque are calculated. Here, the hydraulic pressure deviation amount is referred to as Pdiff, and the torque deviation amount is referred to as Tdiff.

  Accordingly, the hydraulic pressure deviation amount Pdiff and the torque deviation amount Tdiff will be described with reference to FIG. FIG. 13A shows the relationship that the torque T and the control hydraulic pressure P can take at a specific deflection amount δx in the map Mγ in which the predetermined speed ratio γ shown in FIG. 6A is fixed. This is shown as a line segment L where the map Mγ and the deflection amount δx intersect. In other words, when the deflection amount δx is generated, it means that the values of the torque T and the control hydraulic pressure P must be on this line segment L. FIG. 13B is a two-dimensional map in which the line segment L is projected onto the plane coordinates of the torque T and the control hydraulic pressure P. The torque T when the specific gear ratio γ is a specific deflection amount δx. And the control oil pressure P are indicated by a line segment L ′.

  As can be seen from FIG. 13B, the oil pressure value corresponding to the estimated torque value TinE at the deflection amount δ in step S1206 is Psensor ′, and the torque value corresponding to the sensor oil pressure Psensor is TinE ′. Therefore, there is a hydraulic pressure deviation amount Pdiff between the sensor oil pressure Psensor and the oil pressure value Psensor ′ corresponding to the estimated torque value TinE, and between the estimated torque value TinE and the torque value TinE ′ corresponding to the sensor oil pressure Psensor. There is a torque deviation amount Tdiff.

Therefore, in order to reduce or converge these deviation amounts, in step S1207, for example, a torque correction value TinEC and a hydraulic pressure correction value PsensorC are respectively calculated by the following equations.
Hydraulic pressure correction value PsensorC = (Psensor + Psensor ′) / 2
Torque correction value TinEC = (TinE + TinE ′) / 2

  In step S1208, the necessary hydraulic pressure PsecN required for calculation is calculated based on the torque correction value TinEC. Further, in the next step S1209, the hydraulic pressure correction value PsensorC is compared with the necessary hydraulic pressure PsecN required for calculation based on the torque correction value TinEC.

  Therefore, as a result of the comparison, when the hydraulic pressure correction value PsensorC is greater than or equal to the required hydraulic pressure PsecN, the process proceeds to step S1210, and it is further determined whether or not both are equal. If it is determined in step S1210 that they are not equal, that is, if the hydraulic pressure correction value PsensorC is larger than the required hydraulic pressure PsecN, the process proceeds to step S1211 and the supply control hydraulic pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is set. A signal for reducing the predetermined value (down) is output, and the process returns to step S1209. On the other hand, if both are equal in the determination in step S1210, this routine is temporarily terminated to maintain this state.

  If it is determined in step S1209 that the hydraulic pressure correction value PsensorC is smaller than the required hydraulic pressure PsecN, the process proceeds to step S1212, and a signal for increasing the supply control hydraulic pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 by a predetermined value (up). Is similarly output to step S1209. In this way, the supply control oil pressure Psec is increased or decreased until the oil pressure correction value PsensorC becomes equal to the required oil pressure PsecN.

  Thus, according to the present embodiment, the amount of deflection δ is actually generated even when a hydraulic sensor whose output characteristics may change with time or an estimated engine torque value with a large estimation error is used. Since the hydraulic pressure correction value PsensorC can be used for comparison with the required hydraulic pressure PsecN, more accurate control hydraulic pressure can be supplied, and the efficiency can be improved.

(7) Other Configuration Examples of Transaxle In the above-described transaxle shown in FIG. 1, the forward / reverse switching mechanism 8 is provided in the power transmission path between the input shaft 11 and the belt type continuously variable transmission 9. However, the forward / reverse switching mechanism 8 may be provided in a power transmission path between the belt-type continuously variable transmission 9 and the final reduction gear 10 as shown in FIG. In this case, the sun gear 25 of the planetary gear mechanism 24 in the forward / reverse switching mechanism 8 is provided on the secondary shaft 31 of the belt type continuously variable transmission 9, and is arranged concentrically with the sun gear 25 on the outer peripheral side of the sun gear 25. The ring gear 26, the pinion gear 27 meshed with the sun gear 25, the pinion gear 28 meshed with the pinion gear 27 and the ring gear 26, and the pinion gears 27 and 28 are rotatably held, and the pinion gears 27 and 28 are And a carrier 29 that is held in a state where it can revolve integrally. The carrier 29 is connected to the final reduction gear 10. Further, a forward clutch CL for connecting / disconnecting the power transmission path between the secondary shaft 31 and the carrier 29 and a reverse brake BR for controlling rotation / fixation of the ring gear 26 are provided. Since the other configuration is the same as that of the transaxle shown in FIG. 1, the same parts are denoted by the same reference numerals to avoid redundant description.

  According to another configuration example of the transaxle, the primary pulley 36 and the secondary pulley 37 of the belt-type continuously variable transmission 9 can be maintained in a constantly rotating state even when the vehicle is stopped. Control can be performed. Therefore, in another embodiment of the present invention described below, a learning means that uses this function to learn the relationship between the sheave deformation amount and the belt clamping pressure, that is, the relationship between the deflection amount δ and the control oil pressure P. It has.

  (A) Therefore, a first embodiment of this learning control will be described with reference to the flowchart of FIG.

  First, when the control is started, in step S1501, the rotation speed Np of the primary shaft 30 and the rotation speed Ns of the secondary shaft 31 are calculated based on signals from the rotation speed sensors 71 and 72, and the speed ratio γ ( = Np / Ns) is calculated. Further, the process proceeds to step S1502, and it is determined whether or not the vehicle is in the N range. When not in the N range, the routine is terminated and this learning control is not performed. Whether or not the vehicle is in the N range can be determined based on the supply signal to the forward clutch CL described above.

  If it is in the N range, the process proceeds to step S1503, and the control oil pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is detected by the oil pressure sensor 82 as the above-described sensor oil pressure Psensor. Here, the actual torque Tin input to the primary pulley 36 and transmitted to the secondary pulley 37 can be regarded as substantially zero because it is in the N range. Accordingly, the map illustrated in FIG. 6B is referred to, and the speed ratio γ at this time is determined from the relationship between the speed ratio γ obtained in step S1501 and the actual torque Tin = 0 and the sensor oil pressure Psensor. A deflection amount δy that is a map value in the corresponding map Mγ is obtained.

  Next, proceeding to step S1504, the actual deflection amount δr is calculated based on the signal from the deflection detection sensor 73. Then, an error Δδ (= δy−δr) between the actual deflection amount δr and the deflection amount δy in the map Mγ corresponding to the gear ratio γ is obtained. When this error Δδ exists, a correction coefficient K (= (δy−Δδ) / δy = δr / δy) is obtained from the actual deflection amount δr and the deflection amount δy in the map Mγ, and the deflection that is the map value is obtained. By multiplying the amount δy by this correction coefficient K, the actual amount of deflection δr is corrected.

  The above description has been made with respect to the value of a specific sensor oil pressure Psensor for easy understanding. However, when this is generalized, as shown in the block of step S1504 in FIG. 15 and as shown in FIG. The value of the map Mγ including the deflection amount value δmap calculated and stored in the map is rewritten in correspondence with the values of the plurality of sensor oil pressures Psensor, and is corrected to the map Mγc including the corrected deflection amount value δmapc. . Note that FIG. 17 is represented by two-dimensional coordinates of the deflection amount δ and the hydraulic pressure P because the torque T is zero.

  (B) Next, the second embodiment in which the learning control is performed using the command hydraulic value output from the CVT / ECU 300 without using the hydraulic sensor used in the first embodiment of the learning control. This will be described with reference to the flowchart of FIG.

  First, when control is started, in step S1601, the speed ratio γ (= Np / N) at that time is determined by the rotation speed Np of the primary shaft 30 and the rotation speed Ns of the secondary shaft 31 based on the signals from the rotation speed sensors 71 and 72. Ns) is calculated, and in step S1602, it is determined whether or not the vehicle is in the N range. When the vehicle is not in the N range, the routine is terminated and the learning control is not performed. This is the same as the embodiment.

  When in the N range, the process proceeds to step S1603, and the command hydraulic pressure value Psignal output from the CVT / ECU 300 to obtain the control hydraulic pressure Psec supplied to the hydraulic actuator 45 of the secondary pulley 37 is obtained. Note that, as described above, the actual torque Tin input to the primary pulley 36 and transmitted to the secondary pulley 37 is in the N range and can be regarded as substantially zero. Therefore, the map illustrated in FIG. 6B is referred to, and the gear ratio γ at this time is determined from the relationship between the gear ratio γ obtained in step S1601 and the actual torque Tin = 0 and the command hydraulic pressure value Psignal. The amount of deflection δs, which is the map value in the map Mγ corresponding to.

  Next, proceeding to step S1604, the actual deflection amount δr is calculated based on the signal from the deflection detection sensor 73. Then, an error Δδ (= δs−δr) between the actual deflection amount δr and the deflection amount δs in the map Mγ corresponding to the gear ratio γ is obtained in the same manner as in the previous embodiment. Then, a correction coefficient K (= δr / δs) is obtained from the actual deflection amount δr and the deflection amount δs in the map Mγ, and the actual value is obtained by multiplying the deflection amount δs, which is a map value, by this correction factor K. The amount of deflection δr is corrected. When this is generalized as in the previous embodiment, it is obtained experimentally in advance as shown in the block of step S1604 in FIG. 16 and in FIG. 17 (where δs and Psignal are shown in parentheses). Thus, the value of the map Mγ including the deflection amount value δmap stored in the map is rewritten and corrected to the map Mγc including the corrected deflection amount value δmapc.

  The map value correction described above is executed every time the N range is selected. Thus, according to the present embodiment, the map value obtained by experiments based on the model is learned and corrected in accordance with the actual machine. Alternatively, it is possible to improve the estimation accuracy of the belt clamping pressure.

It is a skeleton figure which shows an example of the transaxle to which the control apparatus of the belt-type continuously variable transmission of this invention is applied. It is sectional drawing which shows the principal part of one Embodiment of the control apparatus of the belt-type continuously variable transmission of this invention. It is sectional drawing which shows an example of the deflection | deviation detection sensor used for the control apparatus of the belt-type continuously variable transmission of this invention, (A) shows the state of high magnetic flux, (B) has shown the state of small magnetic flux. It is explanatory drawing for demonstrating the relationship between arrangement | positioning of the bending detection sensor in embodiment of this invention, bending amount, and an output, (A) is sectional drawing which shows bending amount, (B) is A arrow of (A). The side view when it sees from a viewing direction and the output voltage waveform of a bending detection sensor are shown. It is sectional drawing for demonstrating the relationship between deflection amount (delta), a torque, and belt clamping pressure. FIG. 4 is a three-dimensional map in which the relationship between the deflection amount δ, the torque T, and the control oil pressure P is shown in Cartesian coordinates with the speed ratio γ fixed, (A) is when the speed ratio γ is fixed, A state in which the map moves depending on a change in the speed ratio γ is shown. It is sectional drawing for demonstrating the direction where a map moves with the change of gear ratio (gamma), (A) shows the primary side and (B) shows the secondary side. In the case of a push-type metal belt, it is (A) a perspective view for showing the optimal installation position of the bending detection sensor which enables more accurate detection of sheave deformation, and (B) the A arrow view. In the case of a pulling belt, (A) a perspective view and (B) an A arrow view for showing an optimal installation position of a deflection detection sensor that enables more accurate detection of the sheave deformation amount. It is a flowchart which shows one form of control in the control apparatus of the belt-type continuously variable transmission of this invention. It is a flowchart which shows the other form of control in the control apparatus of the belt-type continuously variable transmission of this invention. It is a flowchart which shows the further another form of control in the control apparatus of the belt-type continuously variable transmission of this invention. FIG. 7 is a diagram for explaining a hydraulic pressure deviation amount Pdiff and a torque deviation amount Tdiff. FIG. 5A shows a torque T and a control hydraulic pressure P when a predetermined deflection amount δx is obtained in a map Mγ in which a predetermined gear ratio γ is fixed. (B) is a two-dimensional map in which the line segment L in (A) is projected as a line segment L ′ on the plane coordinates of the torque T and the control hydraulic pressure P, and a specific speed change is shown. The relationship between the torque T and the control oil pressure P when the ratio γ is a specific deflection amount δx is shown. It is a skeleton figure which shows the other example of the transaxle to which the control apparatus of the belt-type continuously variable transmission of this invention is applied. It is a flowchart which shows 1st embodiment of learning control in the control apparatus of the belt-type continuously variable transmission of this invention. It is a flowchart which shows 2nd embodiment of the learning control in the control apparatus of the belt-type continuously variable transmission of this invention. It is a two-dimensional map showing how the deflection value δmap previously obtained experimentally and stored in the map is rewritten and corrected to the deflection value δmapc.

Explanation of symbols

30 Primary shaft 31 Secondary shaft 36 Primary pulley 37 Secondary pulley 38 Primary side fixed sheave 39 Primary side movable sheave 42 Secondary side fixed sheave 43 Secondary side movable sheave 71 Primary side rotational speed sensor 72 Secondary side rotational speed sensor 73 Deflection detection sensor 81 Primary Side pressure sensor 82 Secondary side pressure sensor 200 Hydraulic control circuit 300 CVT / ECU
400 E / G • ECU

Claims (6)

Deformation amount detecting means for detecting the axial deformation amount of the sheave constituting the variable pulley;
Derivation means for obtaining at least one of torque acting on the sheave or belt clamping pressure based on the sheave deformation detected by the deformation detection means;
A control device for a belt-type continuously variable transmission.   2. The control device for a belt-type continuously variable transmission according to claim 1, wherein the deformation amount detecting means is provided in a portion where the sheave deformation amount is large.   When the belt is a push type, the deformation amount detecting means is provided at the side portion of the fixed sheave corresponding to the central portion of the belt around the driving side variable pulley or the belt outlet portion of the driven side variable pulley. The control device for a belt type continuously variable transmission according to claim 1 or 2.   The deformation amount detecting means is provided at the side position of the fixed sheave corresponding to the belt winding inlet portion of the driving side variable pulley or the belt outlet portion of the driven side variable pulley when the belt is a pulling type. The control device for a belt type continuously variable transmission according to claim 1 or 2.   5. The deflection detection sensor according to claim 1, wherein the deformation amount detection unit is a deflection detection sensor shared with at least one of a rotation speed detection sensor of the driving variable pulley and the driven variable pulley. The control apparatus of the belt type continuously variable transmission according to any one of the above. The belt-type continuously variable transmission includes a clutch downstream of the driven variable pulley, and includes learning means for learning a relationship between the sheave deformation amount and the belt clamping pressure when the clutch is disengaged. A control device for a belt-type continuously variable transmission according to any one of claims 1 to 5.

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