JP4600821B2 - Control device for belt type continuously variable transmission - Google Patents

Description

  The present invention relates to a control device for a belt-type continuously variable transmission, and more particularly, a configuration for transmitting power between two variable pulleys by a belt and controlling a gear ratio by changing a belt winding radius. 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 and a secondary 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 pressing force 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, in order to accurately control the gear ratio, a rotational speed sensor for detecting the rotational speed of the primary pulley and the secondary pulley and the hydraulic pressure in the hydraulic chamber are detected. Generally, a hydraulic pressure sensor is provided. An example of such a rotational speed sensor is described in Non-Patent Document 1.

  This Non-Patent Document 1 discloses a rotation detection mechanism of a belt type continuously variable transmission. That is, the rotation detection mechanism is composed of a rotation detection unit provided by press molding on the end surface of the cylinder unit, and a rotation sensor arranged to detect the rotation of the cylinder unit.

Toyota Technological Collection, issue number 15491 (issue date 27 February 2004)

  However, the rotation detection mechanism described in Non-Patent Document 1 can surely detect the rotation speed of the primary pulley and the secondary pulley, but cannot detect the pressure in the hydraulic chamber.

  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 capable of estimating pressure.

  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 partition member that constitutes a hydraulic chamber that generates a pressing force in an axial direction on a movable sheave, and the partition member. It is characterized by comprising a deflection detection sensor arranged facing each other at a predetermined interval, and pressure estimation means for estimating the pressure in the hydraulic chamber based on an output signal from the deflection detection sensor.

  Here, the partition member may be provided with a rotation detection portion at a portion facing the deflection detection sensor.

  A pressure sensor provided in the oil passage to the hydraulic chamber; an abnormality determining hand for determining an abnormality of the pressure sensor based on a pressure value detected by the pressure sensor and an estimated pressure value by the pressure estimating means; May be provided.

  According to one aspect of the present invention, the partition member is displaced or bent in accordance with the pressure in the hydraulic chamber. Therefore, the interval between the deflection detection sensor disposed opposite to the partition member and facing the partition member is a pressure. The output signal from the deflection detection sensor also varies. Thus, the pressure estimating means estimates the pressure in the hydraulic chamber based on the fluctuation of the output signal. Therefore, the pressure can be estimated.

  Here, according to the aspect in which the partition member is formed with a rotation detection portion at a portion facing the deflection detection sensor, the rotation detection unit formed on the partition member and a predetermined interval with respect to the rotation detection unit The number of rotations can also be obtained by a deflection detection sensor arranged to face away from each other.

  A pressure sensor provided in an oil passage to the hydraulic chamber; an abnormality determination unit that determines an abnormality of the pressure sensor based on a pressure value detected by the pressure sensor and an estimated pressure value by the pressure estimation unit; According to the embodiment including the above, it is possible to easily determine whether the pressure sensor is abnormal.

  Here, an embodiment of the present invention will be specifically described with reference to the accompanying drawings.

  FIG. 1 is a skeleton diagram of a transaxle when a control device for a belt-type continuously variable transmission according to the present invention is applied to an FF vehicle (front-wheel drive vehicle in front of an engine). 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 mechanism (CVT) 9 and a final reduction gear 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 mechanism 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 27 meshed with the sun gear 25, A pinion 28 meshed with the pinion 27 and the ring gear 26, a carrier 29 that holds the pinions 27, 28 in a rotatable manner, and holds the pinions 27, 28 in an integrally revolving state around the sun gear 25. have. And this carrier 29 and the primary shaft 30 mentioned later of the belt-type continuously variable transmission mechanism 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 mechanism 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 is configured as a so-called push-type metal belt having a large number of metal pieces (elements) and a plurality of steel rings. A 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.

  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 drive gear 47 of the belt-type continuously variable transmission mechanism 9 and the final reduction gear 10. Yes. The intermediate shaft 50 is provided with a counter driven gear 53 that meshes with the 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 pinions 60 are attached is disposed inside the differential case 55. Two side gears 61 are meshed with the pinion 60 and communicated with wheels 63 via left and right drive shafts 62, respectively.

  Further, 71 and 72 are rotational speed sensors for detecting the rotational speeds of the primary pulley 36 and the secondary pulley 37, respectively, and 73 is described in detail later, but the hydraulic chamber of the primary pulley 36 according to an embodiment of the present invention is provided. It is a deflection | deviation detection sensor arrange | positioned facing the rotation detection part formed in the partition member to comprise at predetermined intervals. In the present embodiment, the deflection detection sensor 73 is disposed at a predetermined distance away from the rotation detection portion formed on the partition wall member, as will be described later. It is configured as a gap sensor by detecting an eddy current that varies in response. However, the deflection detection sensor 73 may be configured to be shared with the above-described rotation speed sensor 71 or 72 as described in an embodiment 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, for example, diaphragm type 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 rotation speed sensors 71 and 72, the deflection detection sensor 73 and the 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 described later, based on the deformation amount of the partition wall member detected by the deflection detection sensor 73, the above-described control hydraulic pressures Ppri and Psec acting on the hydraulic chamber are obtained, and based on these, the above-described pressure sensor 81 and 82 abnormality diagnosis is performed.

  Here, the embodiment of the belt-type continuously variable transmission mechanism 9 described above will be described in more detail with reference to FIG. FIG. 2 is an enlarged cross-sectional view in the vicinity of the primary pulley 36.

  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. Furthermore, an oil passage 111 that extends in the radial direction toward the outer peripheral surface of the primary shaft 30 and communicates with the oil passage 108 is provided. The oil passage 111 is opened between the movable sheave 39 and the fixed sheave 38 and supplies oil for lubricating the belt 46.

  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 so as to face 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 an annular notch 115 formed on the outer peripheral surface of the primary shaft 30.

  An inner cylinder member 117 is disposed between the movable sheave 39 and the bearing 33. The inner cylinder member 117 is connected to the radial direction portion 117A constituting the inner peripheral side of the inner cylinder member 117 and the outer peripheral end of the radial direction portion 117A, and extends toward the radial direction portion 39B of the movable sheave 39. A cylindrical portion 117B, and a radial portion 117C that is continuous with the end portion of the cylindrical portion 117B and extends outward along the back surface of the radial portion 39B of the movable sheave 39. . The radial portion 117 </ b> A of the inner cylinder member 117 is disposed between the stepped portion 112 and the bearing 33. A resin seal ring 117D is attached to the outer peripheral end of the radial portion 117C of the inner cylinder 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 relative to each other in the axial direction. Contact is made in a movable state, and a sealing surface is formed at the contact portion. As described above, the first hydraulic chamber PC1 is formed in the space surrounded by the movable sheave 39 and the inner cylinder member 117. The first hydraulic chamber PC1 and the oil passage 116 are communicated with each other.

  An axial groove 123 is formed on the inner peripheral surface of the inner cylindrical portion 39 </ b> A of the movable sheave 39, and an axial groove 124 is formed on the outer peripheral surface of the primary shaft 30. A plurality of grooves 123 and 124 are formed at predetermined intervals in the circumferential direction. The primary shaft 30 and the movable sheave 39 are positioned so that each groove 123 and each groove 124 have the same phase in the circumferential direction, and a plurality of balls 125 straddling both the groove 123 and the groove 124 are arranged. Has been. The primary shaft 30 and the movable sheave 39 can be smoothly moved relative to each other in the axial direction by the grooves 123 and 124 and the ball 125, but the primary shaft 30 and the movable sheave 39 cannot be relatively moved in the circumferential direction. It is supposed to be in a state.

  Further, an annular outer cylinder member 126 is attached to the outer periphery of the primary shaft 30. The outer cylinder member 126 has a radial direction portion 126A and a cylindrical portion 126B that is continuous on the outer peripheral side of the radial direction portion 126A and extends in the axial direction toward the fixed sheave 38 side. The inner diameter of the cylindrical portion 126B is set larger than the outer diameter of the outer cylindrical portion 39C of the movable sheave 39.

  The inner peripheral part of the radial direction part 126A of the outer cylinder member 126 configured as described above is disposed between the bearing 33 and the radial direction part 117A of the inner cylinder member 117. Further, a lock nut 130 is fastened and fixed to the outer periphery of the primary shaft 30, and the bearing 33, the outer cylinder member 126, and the inner cylinder member 117 are moved in the axial direction of the primary shaft 30 by the lock nut 130 and the step portion 112. And is positioned and fixed in the axial direction.

  Further, between the cylindrical portion 117B of the inner cylinder member 117 and the cylindrical portion 126B of the outer cylinder member 126, and between the radial direction portion 126A of the outer cylinder member 126 and the outer cylindrical portion 39C of the movable sheave 39. Is provided with a piston member 131. The piston member 131 is formed in a substantially disc shape. An O-ring 131A made of a rubber-like elastic material is attached to the inner periphery of the piston member 131, and a resin seal ring is attached to the outer periphery of the piston member 131. 131B is attached. The piston member 131 is configured to be movable in the axial direction with respect to the inner cylinder member 117 and the outer cylinder member 126, and the O-ring 131A comes into contact with the outer peripheral surface of the cylindrical portion 117B of the inner cylinder member 117 to form a sealing surface. The seal ring 131B is in contact with the inner peripheral surface of the cylindrical portion 126B of the outer cylinder member 126 to form a seal surface. Furthermore, a cylindrical sleeve 131 </ b> C that extends in the axial direction toward the bearing 33 side is formed at the inner peripheral end of the piston member 131.

  Thus, the second hydraulic chamber PC2 is formed in the annular space surrounded by the outer cylinder member 126, the inner cylinder member 117, and the piston member 131, and the outer cylinder member 126 is the hydraulic chamber according to the present invention. It is set as the partition member which comprises. In addition, an oil passage 135 penetrating the inner cylinder member 117 in the thickness direction is formed at a boundary portion between the radial direction portion 117A and the cylindrical portion 117B of the inner cylinder member 117, and the first hydraulic chamber PC1 is connected to the first hydraulic chamber PC1. The second hydraulic chamber PC2 communicates with the oil passage 135. An air chamber 136 is formed in a space surrounded by the inner cylinder member 117, the piston member 131, and the outer cylindrical portion 39 </ b> C of the movable sheave 39, and an air passage that communicates the air chamber 136 with the outside of the outer cylinder member 126. 137 is provided.

  Further, on the outer surface of the radial direction portion 126A of the outer cylinder member 126 described above, ribs 126C as rotation detecting portions are radially formed at equal angles. The rib 126 </ b> C as the rotation detection unit is press-molded so that irregularities exist at equal intervals in the rotation direction of the outer cylinder member 126. The above-described deflection detection sensor 73 configured as a shared structure with the rotational speed sensor 71 is disposed on the transaxle rear cover 6 so as to be separated from the outer cylinder member 126 formed with the rib 126C by a predetermined distance. Has been.

  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 rotational speed sensor 71 (however, for convenience of description). When the deflection detection function as the deformation amount detecting means for detecting the axial deformation amount of the outer cylinder member 126 as the partition wall member is used, it will be referred to as a deflection detection sensor 73). Here, as shown in FIGS. 3A and 3B, the deflection detection sensor 73 includes a permanent magnet 73A and an iron core 73B extending from the inside to the detection end, and a terminal 73D wound around the iron core 73B. The coil 73 </ b> C mainly includes the coil 73 </ b> C.

  Then, as shown in FIG. 4A, the deflection detection sensor 73 has a detection end face of the iron core 73B separated from the top face of the rib 126C formed on the outer cylinder member 126 by a certain distance D. The transaxle rear cover 6 is fixed. As shown in FIG. 4B, the rib 126C forms teeth H that are arranged at predetermined intervals in the circumferential direction and protrude from the bottom surface. The detection end surface of the iron core 73 </ b> B of the above-described deflection detection sensor 73 is disposed so as to face the top surface of the tooth H. In other words, when viewed from the direction of arrow A in FIG. 4A, the top surface of the tooth H shown in FIG. 4B is a detection end surface of the iron core 73B.

  Therefore, when the control oil pressure P of the hydraulic chambers PC1 and PC2 is 0, that is, when the outer cylinder member 126 rotates in a no-load state (shown by a solid line in FIG. 4A), the rising and falling portions of the teeth H As shown in FIG. 4B, a pulse voltage indicated by a solid line with a voltage V0 as a peak voltage is generated in synchronization with the proximity or separation of the detection end surface of the iron core 73B of the deflection detection sensor 73 in the circumferential direction. . On the other hand, as will be described later, when the outer cylinder member 126 falls in a loaded state (indicated by a broken line in FIG. 4A, the amount of axial deformation is indicated as a deflection amount δ). As a result, the distance between the detection end face and the top face 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 top 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 outer cylinder member 126 can be detected. As described above, when the deflection detection sensor 73 is shared as the rotation speed sensor 71 or 72, the primary sensor 36 is based on the pulse voltage cycle in addition to the deflection amount δ of the outer cylinder member 126 of the primary pulley 36. Needless to say, the rotational speed Np of the shaft 30 or the rotational speed Ns of the secondary shaft 31 is obtained.

  Since the deflection amount δ of the outer cylinder member 126 increases in proportion to the control hydraulic pressure P supplied to the hydraulic chambers PC1 and PC2, the relationship between the deflection amount δ and the control hydraulic pressure P is obtained in advance by experiments or the like, and the ROM You can map it to and save it. Therefore, the CVT / ECU 300 receives the voltage Vδ, which is an output signal from the deflection detection sensor 73 that fluctuates according to the deflection amount δ, and reads the value of the control hydraulic pressure P corresponding to the voltage Vδ from the map, whereby the hydraulic chamber PC1. And the control oil pressure P in the PC 2 is estimated. Therefore, the control oil pressure P supplied to the hydraulic chambers PC1 and PC2 can be obtained without necessarily requiring the pressure sensor 81 described later. In the present embodiment, in this way, the functional part of the CVT / ECU 300 that performs the function of receiving the output voltage Vδ from the deflection detection sensor 73 and reading the map of the control oil pressure P corresponding to the output voltage Vδ is the pressure estimation means. Is configured.

  In the above-described embodiment, the deflection detection sensor 73 is disposed so as to face the radial direction portion 126A of the outer cylinder member 126 as a partition wall member. However, the deflection detection sensor 73 is a cylindrical portion 126B of the outer cylinder member 126 as a partition wall member. You may arrange | position so that it may oppose.

  Next, a pressure sensor 81 is provided in the oil passages to the hydraulic chambers PC1 and PC2, and based on the detected pressure value by the pressure sensor 81 and the estimated pressure value by the pressure estimating means using the deflection detection sensor 73, An embodiment provided with an abnormality determination means for determining an abnormality of the pressure sensor 81 will be described with reference to the flowchart of FIG.

  Here, the belt type continuously variable transmission mechanism 9 includes data stored in the CVT / ECU 300 and the E / G / ECU 400 (for example, an optimal fuel consumption curve using the engine speed Ne and the throttle opening as parameters), the vehicle speed V, and The gear ratio and the belt clamping pressure are controlled so that the operating state of the engine 1 becomes an optimum state based on a vehicle acceleration request determined from conditions such as the accelerator opening. Specifically, the width of the groove 40 of the primary pulley 36 is adjusted by controlling the control oil pressure Ppri of the hydraulic chambers PC1 and PC2 of the hydraulic actuator 41. As a result, the wrapping 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 mechanism 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. The control oil pressure Psec is controlled based on the torque T and the gear ratio γ input to the primary shaft 30 of the belt type continuously variable transmission mechanism 9.

  Therefore, in the present embodiment, first, when control is started, in step S501, the deflection amount δ is calculated based on the signal from the deflection detection sensor 73, the estimated pressure value P2 is obtained from the map, and the diaphragm is calculated. The pressure value P1 detected by the pressure sensor 81 is obtained. Then, in the next step S502, whether or not the ratio “| (P1-P2) / P1 |” of the error between the detected pressure value P1 and the estimated pressure value P2 with respect to the detected pressure value P1 is within the allowable value α. Determined. The allowable value α is determined on the assumption that there is no failure in the deflection detection sensor 73, the pressure sensor 81, and the hydraulic system. If it is within the allowable value α, the process proceeds to step S503, and the detected pressure value P1 detected by the pressure sensor 81 is used as the actual control oil pressure Ppri supplied to the hydraulic chambers PC1 and PC2 of the hydraulic actuator 41 of the primary pulley 36. Is used.

  On the other hand, if it is determined in step S502 that the allowable value α is exceeded, the process proceeds to step S504, and it is determined which of the detected pressure value P1 and the estimated pressure value P2 is larger. When the detected pressure value P1 is smaller than the estimated pressure value P2, the process proceeds to step S505, where it is determined that the diaphragm pressure sensor 81 is in a failure state due to deterioration over time or the like. In the next step S506, a warning is given to the effect that the pressure sensor 81 is in a failure state. In step S507, the detected pressure value P1 detected by the pressure sensor 81 is used as the control hydraulic pressure Ppri supplied to the hydraulic chambers PC1 and PC2 of the hydraulic actuator 41. As described above, in this embodiment, the pressure sensor is based on the detected pressure value by the pressure sensor 81 provided in the oil passages to the hydraulic chambers PC1 and PC2, the estimated pressure value by the pressure estimating means, and the allowable value α. The functional part of the CVT / ECU 300 that performs the abnormality determination function 81 constitutes the abnormality determination means of the pressure sensor.

  If it is determined in step S504 that the detected pressure value P1 is larger than the estimated pressure value P2, the process proceeds to step S508, where the deflection detection sensor 73 is in a failure state or the hydraulic system downstream from the pressure sensor 81 is hydraulic oil. It is determined that there is a failure state such as a leak. As described above, when the deflection detection sensor 73 is in a failure state and is shared as the rotation speed sensor 71 as described above, the rotation speed cannot be measured, and the speed ratio control or the shift cannot be performed. In addition, when the hydraulic system is in a failed state, the generation of a predetermined control hydraulic pressure is disabled, and as a result, the transmission torque capacity is reduced, so that it is impossible to travel at a high vehicle speed or a speed increasing side gear ratio. Accordingly, in the next step S509, a setting is made so as to limit the fixed gear ratio on the deceleration side at a low vehicle speed and a warning is given to that effect.

  Thus, according to the present embodiment, not only the abnormality of the pressure sensor can be easily determined, but also the failure state of the deflection detection sensor or the like can be determined. Measures can be taken.

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). Sectional drawing when it sees from a visual direction and the output voltage waveform of a bending detection sensor are shown. It is a flowchart which shows one form of control in the control apparatus of the belt-type continuously variable transmission of this invention.

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 117 Inner cylinder member 126 Outer cylinder member (partition wall member)
131 Piston member 200 Hydraulic control circuit 300 CVT / ECU
400 E / G • ECU
PC1 1st hydraulic chamber PC2 2nd hydraulic chamber

Claims (3)

A partition wall member constituting a hydraulic chamber for generating a pressing force in the axial direction to the movable sheave, and a deflection detection unit provided in the partition wall member, and faces separated by a predetermined distance from the 該撓seen detector of the partition wall member It is arranged, and the deflection detecting sensor for detecting the deflection of the axial direction of the bending detection section which varies by hydraulic pressure of the hydraulic chamber, the pressure of the hydraulic chamber on the basis of the deflection of the output signal is detected by該撓viewed detection sensor A control device for a belt-type continuously variable transmission, comprising: a pressure estimating means for estimating. The deflection detection unit, wherein also formed as a rotation detecting section by ribs formed in the partition wall member, wherein the deflection detecting sensor is a feature that you detect the rotational speed of the deflection detection unit and detects the deflection The control device for a belt-type continuously variable transmission according to claim 1.   A pressure sensor provided in an oil passage to the hydraulic chamber; and an abnormality determining unit that determines an abnormality of the pressure sensor based on a pressure value detected by the pressure sensor and an estimated pressure value by the pressure estimating unit. 3. The control device for a belt type continuously variable transmission according to claim 1, wherein the control device is a belt type continuously variable transmission.

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