JP4683323B2 - Hydraulic control device for belt type continuously variable transmission for vehicle - Google Patents

Description

  The present invention relates to a hydraulic control device for a belt-type continuously variable transmission for a vehicle, and in particular, transmits power between two variable pulleys by a belt and changes the belt winding radius to change the gear ratio. The present invention relates to a hydraulic control device for a belt type continuously variable transmission for a vehicle configured to be controlled.

  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, since the hydraulic chamber is provided on the outer peripheral side of the rotating member, hydraulic pressure generated by centrifugal force, so-called centrifugal hydraulic pressure, acts on the hydraulic chamber, May be higher than the control target hydraulic pressure. As a result, the pressing force of the belt increases, and it is known that the belt transmission efficiency is deteriorated and the belt durability is adversely affected. An example of a belt-type continuously variable transmission as a measure for solving such inconvenience due to centrifugal hydraulic pressure is described in Patent Document 1.

  In Patent Document 1, particularly in FIG. 2, a secondary pulley (driven pulley) provided on a secondary shaft (output shaft) includes a fixed sheave (fixed-side pulley half) integrally formed on the secondary shaft. A belt type continuously variable transmission having a movable sheave (movable pulley half) attached to a secondary shaft (output shaft) so as to be movable in the axial direction is described. Here, the outer cylinder member is fixed to the outer peripheral side surface of the movable pulley half, and the seal member provided on the outer periphery of the piston member is slidably brought into contact with the outer cylinder member, thereby moving the movable sheave. A hydraulic oil chamber that presses in the axial direction is defined between a movable pulley half, an outer cylinder member fixed to the movable pulley half, a piston member, and an output shaft. Further, a canceller oil that applies a pressing force in a direction opposite to the pressing force of the hydraulic oil chamber to the movable sheave when a sealing member provided on the inner periphery of the outer cylinder member is slidably contacted with the inner cylinder member. A chamber is defined between the piston member, the outer cylinder member, the inner cylinder member and the output shaft. The canceller oil chamber is configured to be supplied with lubricating oil through an oil hole provided in the output shaft.

  Thus, by forming the canceller oil chamber in an almost sealed state that does not communicate with the outside except for this oil hole, it is possible to increase the amount of centrifugal oil pressure cancellation and cancel out the centrifugal oil pressure at high speed rotation. Yes.

JP 2002-295613 A

  By the way, as in the belt-type continuously variable transmission described in Patent Document 1, it is effective to form the canceller oil chamber in a substantially hermetically sealed state in order to cancel the centrifugal hydraulic pressure at the time of high-speed rotation. However, as a contradiction, pressure is generated in the canceller oil chamber even during low-speed rotation. As a result, even during low-speed rotation where no centrifugal hydraulic pressure is generated, a centrifugal hydraulic pressure cancellation amount is generated due to the hydraulic pressure supplied to the canceller oil chamber, and the belt pressing force of the movable sheave may be less than the required pressing force. there were.

  The present invention has been made against the background of the above circumstances, and it is possible to reliably cancel the centrifugal hydraulic pressure at the time of high-speed rotation and to suppress a decrease in belt pressing force at the time of low-speed rotation. An object of the present invention is to provide a hydraulic control device for a continuously variable transmission.

  In order to achieve the above object, a hydraulic control device for a belt-type continuously variable transmission for a vehicle according to an aspect of the present invention is a control in which a control hydraulic pressure for generating a belt pressing force acting on a belt is supplied to a movable sheave of a pulley. In a hydraulic control device for a belt-type continuously variable transmission having a hydraulic chamber and a centrifugal hydraulic cancel chamber, the centrifugal hydraulic cancel chamber is depressurized when the pulley rotation speed is lower than a predetermined value, and the pressure is reduced when the pulley is larger than the predetermined rotation frequency. A valve device for stopping is provided.

  Here, the valve device is preferably operated in two stages.

  In order to achieve the above object, a hydraulic control device for a belt type continuously variable transmission for a vehicle according to another embodiment of the present invention supplies a control hydraulic pressure that generates a belt pressing force acting on the belt to a movable sheave of a pulley. In a hydraulic control device for a belt-type continuously variable transmission comprising a controlled hydraulic chamber and a centrifugal hydraulic cancel chamber, a predetermined hydraulic pressure is supplied to the centrifugal hydraulic cancel chamber, and the control hydraulic pressure is supplied by the supplied predetermined hydraulic pressure. Means for increasing and controlling the control oil pressure supplied to the chamber is provided.

  According to one aspect of the present invention, hydraulic control of a belt-type continuously variable transmission including a control hydraulic chamber to which a control hydraulic pressure for generating a belt pressing force acting on the belt is supplied to a movable sheave of a pulley and a centrifugal hydraulic pressure cancellation chamber is provided. The device is provided with a valve device that depressurizes the centrifugal oil pressure canceling chamber when the pulley rotation speed is less than or equal to the predetermined rotation speed and stops the pressure reduction when the pulley rotation speed is greater than the predetermined rotation speed, so that no cancellation of the centrifugal oil pressure is required. When the rotation speed is equal to or lower than the predetermined number of rotations, the centrifugal hydraulic pressure canceling chamber is depressurized, and a decrease in belt pressing force is suppressed. Further, since the pressure reduction is stopped when the rotation speed is higher than the predetermined rotation speed, the centrifugal hydraulic pressure is canceled.

  Here, according to the mode in which the valve device is operated in two stages, when the pressure in the centrifugal oil pressure canceling chamber rises, the hydraulic oil in the centrifugal oil pressure canceling chamber can be quickly discharged, so that the speed change response Can be improved.

  According to another aspect of the present invention, the hydraulic pressure of the belt-type continuously variable transmission includes a control hydraulic pressure chamber that is supplied with a control hydraulic pressure that generates a belt pressing force acting on the movable sheave of the pulley, and a centrifugal hydraulic pressure cancellation chamber. In the control device, there is provided means for supplying a predetermined hydraulic pressure to the centrifugal hydraulic pressure cancellation chamber and increasing and controlling the control hydraulic pressure supplied to the control hydraulic chamber by the predetermined hydraulic pressure supplied. When the rotational speed is higher than the predetermined rotational speed, the centrifugal hydraulic pressure is canceled. When the rotational speed is lower than the predetermined rotational speed, which does not require the centrifugal hydraulic pressure to be canceled, the influence of the hydraulic pressure supplied to the centrifugal hydraulic pressure cancellation chamber is eliminated, Reduction is suppressed.

  Here, an embodiment of a hydraulic control device for a belt type continuously variable transmission for a vehicle according to the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing a part of a vehicle to which a belt type continuously variable transmission according to the present invention is applied. A vehicle 1 shown in FIG. 1 is configured as a so-called FF vehicle (front engine front drive: front wheel drive vehicle in front of the engine), and includes an engine 2 as a drive source. As the engine 2, a gasoline engine, a diesel engine, an LPG engine, a hydrogen engine, a bi-fuel engine, or the like can be adopted. Here, a description will be given assuming that a gasoline engine is used as the engine 2.

  As shown in FIG. 1, the vehicle 1 has a transaxle 3 that is disposed on the side of a horizontally placed engine 2 and connected to a crankshaft SC of the engine 2. The transaxle 3 includes a transaxle housing 4, a transaxle case 5, and a transaxle rear cover 6. The housing 4 is disposed on the side of the engine 2, and the case 5 is fixed to the opening end of the housing 4 on the side opposite to the engine 2. The rear cover 6 is fixed to the opening end of the case 5 on the side opposite to the housing 4. A torque converter 7 is disposed inside the transaxle housing 4, and a forward / reverse switching mechanism 8 and a belt type continuously variable transmission according to the present invention are disposed inside the transaxle case 5 and the transaxle rear cover 6. A (CVT) 9 and a final reduction gear (differential device) 10 are arranged.

  The torque converter 7 includes a drive plate 11 and a front cover 12 fixed to the crankshaft SC of the engine 2 via the drive plate 11. As shown in FIG. 1, a pump impeller 14 is attached to the front cover 12. The torque converter 7 includes a turbine runner 15 that can rotate while facing the pump impeller 14.

  The turbine runner 15 is fixed to an input shaft SI that extends substantially coaxially with the crankshaft SC. Further, a stator 16 is disposed inside the pump impeller 14 and the turbine runner 15, and the rotation direction of the stator 16 is set only in one direction by the one-way clutch 17. A hollow shaft 18 is fixed to the stator 16 via a one-way clutch 17, and the above-described input shaft SI is inserted into the hollow shaft 18. A lockup clutch 20 is attached to the end of the input shaft SI on the front cover 12 side via a damper mechanism 19.

  The pump impeller 14, the turbine runner 15, and the stator 16 described above define a hydraulic fluid chamber, and this hydraulic fluid chamber is operated from an oil pump 21 disposed between the torque converter 7 and the forward / reverse switching mechanism 8. Liquid is supplied. Then, when the engine 2 is operated and the front cover 12 and the pump impeller 14 are rotated, the turbine runner 15 starts to be dragged by the flow of the hydraulic fluid. Further, the stator 16 converts the flow of the hydraulic fluid into a direction that assists the rotation of the pump impeller 14 when the rotational speed difference between the pump impeller 14 and the turbine runner 15 is large.

  Thus, the torque converter 7 operates as a torque amplifier when the rotational speed difference between the pump impeller 14 and the turbine runner 15 is large, and operates as a fluid coupling when the rotational speed difference between the two becomes small. When the vehicle speed reaches a predetermined speed after the vehicle 1 starts, the lockup clutch 20 is operated so that the power transmitted from the engine 2 to the front cover 12 is mechanically and directly transmitted to the input shaft SI. Become. Further, the fluctuation of the torque transmitted from the front cover 12 to the input shaft SI is absorbed by the damper mechanism 19.

  The oil pump 21 between the torque converter 7 and the forward / reverse switching mechanism 8 has a rotor 22, and the rotor 22 is connected to the pump impeller 14 via a hub 23. The hub 23 is spline-fitted to the hollow shaft 18, and the main body 24 of the oil pump 21 is fixed to the transaxle case 5 side. Accordingly, the power of the engine 2 is transmitted to the rotor 22 via the pump impeller 14, thereby driving the oil pump 21.

  The forward / reverse switching mechanism 8 has a planetary gear mechanism 25 of a double pinion type. The planetary gear mechanism 25 includes a sun gear 26 attached to an end of the input shaft SI on the continuously variable transmission 9 side, a ring gear 27 disposed concentrically on the outer peripheral side of the sun gear 26, and a plurality of pinion gears that mesh with the sun gear 26. 28, a plurality of pinion gears 29 that mesh with both the ring gear 27 and the pinion gear 28, and a carrier 30 that holds each pinion gear 28 so as to be capable of rotating, and holds the pinion gear 28 in an integrally revolving state around the sun gear 26. Including.

  The carrier 30 of the forward / reverse switching mechanism 8 is fixed to a primary shaft SP included in the belt-type continuously variable transmission 9, and the power transmission path between the carrier 30 and the input shaft SI is connected using the forward clutch CL. Blocked. The forward / reverse switching mechanism 8 has a reverse brake BR that controls the rotation and fixation of the ring gear 27.

  On the other hand, a belt type continuously variable transmission 9 according to the present invention includes a primary shaft (driving side rotating shaft) SP that extends substantially coaxially with the input shaft SI, and a secondary shaft that is arranged in parallel with the primary shaft SP. (Driven rotation shaft) SS. The primary shaft SP is rotatably supported by the bearings 31 and 32, and the secondary shaft SS is rotatably supported by the bearings 33 and 34. The primary shaft SP is equipped with a primary pulley 35, and the secondary shaft SS is equipped with a secondary pulley 36.

  The primary pulley 35 includes a fixed sheave 37 that is integrally formed on the outer periphery of the primary shaft SP, and a movable sheave 38 that is slidably mounted on the outer periphery of the primary shaft SP. The fixed sheave 37 and the movable sheave 38 face each other, and a substantially V-shaped pulley groove 39 is formed between them. Further, the movable sheave 38 is movable in the axial direction of the primary shaft SP with respect to the fixed sheave 37, and the continuously variable transmission 9 moves the movable sheave 38 in the axial direction of the primary shaft SP to move with the movable sheave 38. A hydraulic actuator 40 is provided to approach and separate the fixed sheave 37.

  Similarly, the secondary pulley 36 also includes a fixed sheave 42 that is integrally formed on the outer periphery of the secondary shaft SS, and a movable sheave 43 that is slidably mounted on the outer periphery of the secondary shaft SS. The fixed sheave 42 and the movable sheave 43 face each other, and a substantially V-shaped pulley groove 44 is formed between them. The movable sheave 43 is also movable in the axial direction of the secondary shaft SS with respect to the fixed sheave 42. The continuously variable transmission 9 moves the movable sheave 43 in the axial direction of the secondary shaft SS to A hydraulic actuator 45 is provided to approach and separate the fixed sheave 42.

  Around the pulley groove 39 of the primary pulley 35 and the pulley groove 44 of the secondary pulley 36, a belt B composed of a number of metal pieces and a plurality of steel rings is wound. Then, the hydraulic pressures by the hydraulic actuators 40 and 45 are separately controlled, whereby the groove widths of the primary pulley 35 and the secondary pulley 36 are changed, and the winding radius of the belt B is changed. As a result, the speed ratio of the continuously variable transmission 9 is set to a desired value, and the tension of the belt B is adjusted. The bearing 34 that supports the secondary shaft SS is fixed to the transaxle rear cover 6, and a parking gear PG is provided between the bearing 34 and the secondary pulley 36.

  As shown in FIG. 1, a shaft 48 supported by bearings 46 and 47 is connected to the secondary shaft SS of the belt type continuously variable transmission 9. A drive gear 49 is fixed to the shaft 48, and power is transmitted from the belt-type continuously variable transmission 9 to the final reduction gear 10 via the drive gear 49. The final reduction gear 10 includes an intermediate shaft 50 that is arranged in parallel with the secondary shaft SS. The intermediate shaft 50 is supported by bearings 51 and 52, and a counter driven gear 53 that meshes with the drive gear 49 of the secondary shaft SS and a final drive gear 54 are fixed to the shaft 50.

  Further, the final reduction gear 10 has a hollow differential case 55. The differential case 55 is rotatably supported by bearings 56 and 57, and a ring gear 58 is formed on the outer periphery thereof. The ring gear 58 meshes with the final drive gear 54 of the intermediate shaft 50. Further, the differential case 55 supports a pinion shaft 59 therein, and two pinion gears 60 are fixed to the pinion shaft 59. Each of the pinion gears 60 is engaged with two side gears 61. Each side gear 61 is connected to a front drive shaft 62 separately. A wheel (front wheel) FW is fixed to each front drive shaft 62. ing.

  FIG. 2 is an enlarged cross-sectional view showing the main part of the belt-type continuously variable transmission 9 according to the present invention described above. FIG. 2 shows the configuration related to the primary pulley 35 and the primary shaft SP of the continuously variable transmission 9. Is shown. The primary shaft SP is rotatable about an axis, a fixed sheave 37 is integrally formed at one end of the primary shaft SP, and an oil passage SPA is formed inside in the axial direction. The primary shaft SP is rotatably supported by a bearing 31 fixed to the transaxle case 5 outside the fixed sheave 37. An oil passage SPA formed in the axial direction inside the primary shaft SP is communicated with a hydraulic circuit of the hydraulic control device. Further, the primary shaft SP is provided with an oil passage SPB extending in the radial direction toward the outer peripheral surface thereof and communicating with the oil passage SPA.

  On the other hand, the movable sheave 38 includes an inner cylindrical portion 38A that slides along the outer peripheral surface of the primary shaft SP, and a radial direction portion 38B that is continuous from the end on the fixed sheave 37 side of the inner cylindrical portion 38A toward the outer peripheral side. The outer cylindrical portion 38C is continuous to the outer peripheral end of the radial direction portion 38B and extended in the axial direction toward the bearing 33. The inner cylinder portion 38A is formed with an oil passage 38D penetrating from the inner peripheral surface to the outer peripheral surface. The oil passage 38D and the oil passage SPB are communicated with each other through a spline portion described later formed on the outer peripheral surface of the primary shaft SP.

  That is, as shown in FIG. 2, a plurality of spline teeth (grooves) 38 </ b> S are formed on the inner peripheral surface of the inner cylindrical portion 38 </ b> A of the movable sheave 38. On the other hand, a plurality of spline grooves (teeth) SPG are formed on the outer peripheral surface of the primary shaft SP that slidably supports the movable sheave 38. The spline teeth 38S and the spline grooves SPG are formed such that the tooth surfaces or groove surfaces form an involute curve, and the primary shaft SP and the movable sheave 38 can be relatively moved relative to each other in the axial direction. And the movable sheave 38 are in a state in which relative movement is impossible in the circumferential direction.

  The radial oil passage SPB is formed on the outer side in the axial direction from the spline groove SPG formed in the primary shaft SP. In this case, the radial oil passage SPB is positioned outside the transmission path of the torque transmitted from the belt B to the primary shaft SP via the movable sheave 38. Stress concentration does not occur, and the strength of the primary shaft SP can be ensured.

  Further, the belt type continuously variable transmission 9 includes a cylinder member 70 that is an annular partition member. As can be seen from FIG. 2, the cylinder member 70 includes a first radial portion 70A extending in the radial direction of the primary shaft SP, and a first cylindrical portion extending substantially parallel to the axis of the primary shaft SP from the first radial direction portion 70A. 70B, a second radial portion 70C extending in the radial direction of the primary shaft SP along the back surface of the movable sheave 38 from the first cylindrical portion 70B, and an outer cylindrical portion of the movable sheave 38 from the second radial direction portion 70C. It has a second cylindrical portion 70D extending substantially parallel to the axis of the primary shaft SP via a curved portion for escape with respect to 38C.

  A small-diameter portion at the front end of the primary shaft SP is press-fitted into a center hole formed in the first radial direction portion 70 </ b> A of the cylinder member 70, and the cylinder member 70 uses a lock nut 80 to form a step portion of the primary shaft SP. It is fixed between. The first cylindrical portion 70B of the cylinder member 70 is rotatably supported by a bearing 32 fixed to the transaxle rear cover 6 by an annular bearing retainer and a bolt (not shown). Accordingly, the primary shaft SP is rotatably supported by the bearing 32 through the cylinder member 70 (first cylindrical portion 70B) together with the above-described bearing 31.

  A seal member 72 is disposed on the outer edge portion of the outer cylindrical portion 38C of the movable sheave 38 so as to be in sliding contact with the inner peripheral surface of the second cylindrical portion 70D of the cylinder member 70. On the other hand, on the outer peripheral side of the axial end portion of the inner cylindrical portion 38A of the movable sheave 38, a second sliding portion described later that slidably contacts the inner peripheral side of the first cylindrical portion 70B of the cylinder member 70. 38F is formed. Thus, the inner cylinder portion 38A, the radial direction portion 38B, the outer cylinder portion 38C, and the cylinder member 70 of the movable sheave 38 define the first control hydraulic chamber 40A that constitutes the hydraulic actuator 40 described above. On the other hand, the second control that constitutes the hydraulic actuator 40 described above is constituted by the first radial direction portion 70A of the cylinder member 70, the first cylindrical portion 70B, the axial end portion of the inner cylindrical portion 38A of the movable sheave 38 and the primary shaft SP. A hydraulic chamber 40B is defined. By controlling the hydraulic pressure in the first control hydraulic chamber 40A and the second control hydraulic chamber 40B, the movable sheave 38 is moved with respect to the fixed sheave 37, and the winding radius of the belt B is changed. A gear ratio can be obtained.

  The movable sheave 38 is provided with a first sliding portion 38E and the above-described second sliding portion 38F that are spaced apart in the axial direction of the primary shaft SP. Of the two sliding portions of the movable sheave 38, the first sliding portion 38E is provided on the fixed sheave 37 side in the axial direction of the primary shaft SP with respect to the spline 38S and on the inner peripheral surface of the movable sheave 38. In contact with the outer peripheral surface of the primary shaft SP. On the other hand, as described above, the second sliding portion 38F is spaced apart from the first sliding portion 38E in the axial direction, and on the outer peripheral surface of the axial end portion of the inner cylindrical portion 38A of the movable sheave 38. Is provided. And the 2nd sliding part 38F contacts the internal peripheral surface of the 1st cylindrical part 70B of the cylinder member 70 instead of the primary shaft SP, as FIG. 2 shows.

(Embodiment according to one embodiment of the present invention)
On the other hand, FIG. 3 is an enlarged half sectional view showing another main part of the belt-type continuously variable transmission 9 according to the present invention described above. The figure shows the secondary pulley 36 and the secondary shaft SS of the continuously variable transmission 9. A related configuration is shown. The secondary shaft SS is rotatable about an axis, a fixed sheave 42 is integrally formed at one end of the secondary shaft SS, and oil passages SSA and SSB are formed in the axial direction inside. As described above, the secondary shaft SS is rotatably supported together with the parking gear PG by the bearing 34 fixed to the transaxle rear cover 6 outside the fixed sheave 42. The oil passages SSA and SSB formed in the axial direction inside the secondary shaft SS are communicated with a hydraulic circuit of the hydraulic control device. Further, the secondary shaft SS is provided with oil passages SSC and SSD that extend in the radial direction toward the outer peripheral surface thereof and communicate with the oil passage SSA, and an oil passage SSE that communicates with the oil passage SSB. .

  On the other hand, the movable sheave 43 includes an inner cylindrical portion 43A that slides along the outer peripheral surface of the secondary shaft SS, and a radial portion that is continuous from the end on the fixed sheave 42 side of the inner cylindrical portion 43A toward the outer peripheral side. 43B and an outer cylindrical portion 43C which is continuous with the outer peripheral end of the radial portion 43B and extends in the axial direction toward the bearing 33.

  That is, a plurality of spline teeth (grooves) are formed on the inner peripheral surface of the inner cylindrical portion 43A of the movable sheave 43, while a plurality of spline teeth (grooves) are formed on the outer peripheral surface of the secondary shaft SS that slidably supports the movable sheave 43. Spline grooves (teeth) are 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 SS and the movable sheave 43 can be smoothly moved relatively in the axial direction. The movable sheave 43 cannot move relative to the circumferential direction.

  Further, the belt type continuously variable transmission 9 includes an annular piston member 90. As can be seen from FIG. 3, the piston member 90 includes a first radial base portion 90A extending in the radial direction of the secondary shaft SS, and a cylindrical portion 90B extending substantially parallel to the axis of the secondary shaft SS from the first radial base portion 90A. The second radial portion 90 </ b> C extends in the radial direction of the secondary shaft SS while being bent from the tubular portion 90 </ b> B toward the back surface of the movable sheave 43. A seal member 92 is disposed on the outer edge portion of the second radial direction portion 90 </ b> C so as to be in sliding contact with the inner peripheral surface of the outer cylindrical portion 43 </ b> C of the movable sheave 43. Further, the piston member 90 is further formed with an oil passage 90D communicating from the first radial base portion 90A to the tubular portion 90B to the oil passage SSE described above and a centrifugal oil pressure canceling chamber described later.

  The piston member 90 has a small-diameter portion at the tip of the secondary shaft SS press-fitted into the center hole formed in the first radial base portion 90 </ b> A of the piston member 90, and the lock shaft 95 is used to It is being fixed with the bearing 33 between the step parts.

  Further, 100 is a substantially bowl-shaped partition wall member, and the outer edge portion 100A on the large diameter side is brought into contact with a step portion formed on the inner peripheral surface near the free end of the outer cylindrical portion 43C of the movable sheave 43. In this state, it is fixed to the movable sheave 43 by the snap ring 102. A seal member 94 that contacts the inner peripheral surface of the outer cylindrical portion 43C of the movable sheave 43 is disposed on the outer edge portion 100A. On the other hand, a seal member 96 is disposed at the inner edge portion 100B on the small diameter side of the partition wall member 100 so as to be in sliding contact with the outer peripheral surface of the cylindrical portion 90B of the piston member 90.

  Thus, a control hydraulic chamber 45A constituting the 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 90 of the movable sheave 43. On the other hand, the first hydraulic base portion 90A, the cylindrical portion 90B, the second radial portion 90C of the piston member 90, the outer cylindrical portion 43C of the movable sheave 43, and the partition member 100 constitute the centrifugal hydraulic pressure that constitutes the hydraulic actuator 45 described above. A cancel room 45B is defined. In this control hydraulic chamber 45A, the hydraulic pressure controlled by the hydraulic circuit of the hydraulic control device via the oil passage SSA formed in the axial direction of the secondary shaft SS and the oil passages SSC and SSD formed in the radial direction is also provided. Oil is supplied. On the other hand, the centrifugal hydraulic pressure cancellation chamber 45B is lubricated via an oil passage SSB formed in the axial direction of the secondary shaft SS, an oil passage SSE formed in the radial direction, and an oil passage 90D formed in the piston member 90. Is supplied with hydraulic oil.

  Further, in the embodiment according to one aspect of the present invention, the centrifugal hydraulic pressure cancellation chamber is provided in the outer cylindrical portion 43C that defines a part of the centrifugal hydraulic pressure cancellation chamber 45B when the secondary pulley 36 has a predetermined number of rotations or less. A two-stage check valve 200 is provided as a valve device according to the present invention that depressurizes 45B and stops the depressurization when the pressure is greater than a predetermined number of revolutions.

  As shown in detail in FIG. 4, the check valve 200 includes a bottomed cylindrical valve body 210 having a flange attached to a counterbore hole 202 formed in the outer cylindrical portion 43 </ b> C, and the inside of the valve body 210. The check ball 220, the check plate 230, the low-pressure setting spring 240, and the high-pressure setting spring 250, which are installed in the above, are configured to be capable of two-stage operation. A drain hole 204 is formed at the center of the counterbore 202 in the outer cylindrical portion 43C, and a valve seat 206 for the check ball 220 is formed at the upper end thereof. Furthermore, the valve seat 206 is formed with communication grooves 208 that allow the hydraulic oil to flow out from the centrifugal hydraulic pressure cancellation chamber 45B into the valve body 210 when the check ball 220 is seated.

  On the other hand, the check plate 230 has a through hole 232 and a conical seat surface 234 connected to the through hole 232 at the center. Further, the lower edge portion of the check plate 230 is chamfered so as to be able to come into contact with a conical seat surface 212 formed in the valve body 210. In this contact state, the valve seat 206 is seated. The positional relationship is such that a flow path is formed between a certain check ball 220 and the conical seat surface 234 of the check plate 230. A hydraulic oil discharge hole 214 is formed in the cylinder side portion of the valve body 210.

  The low-pressure setting spring 240 is supported at one end by a spring receiver 216 formed at the bottom of the valve body 210, and the check ball 220 is attached to the valve seat 206 through the through hole 232 of the check plate 230. It is fast. The high-pressure setting spring 250 is interposed between the bottom of the valve body 210 and the check plate 230 and biases the check plate 230 against the conical seat surface 212 formed on the valve body 210.

  Here, the relationship between the mass of the check ball 220 and the spring constant of the low pressure setting spring 240 is that the check ball 220 is a conical seat of the check plate 230 at a predetermined rotational speed of the secondary pulley 36 that requires cancellation of the centrifugal hydraulic pressure. It is set to be seated in close contact with the surface 234. That is, in low-speed rotation that does not require the cancellation of centrifugal hydraulic pressure, a gap is generated between the check ball 220 and the conical seat surface 234 of the check plate 230, and the hydraulic oil that has passed through the gap and the through hole 232 from the drain hole 204 operates. The oil is discharged from the oil discharge hole 214 to prevent or reduce the pressure increase in the centrifugal oil pressure cancellation chamber 45B.

  Further, in the high speed rotation of the secondary pulley 36 that requires cancellation of the centrifugal hydraulic pressure, centrifugal force acts on the check ball 220, and the check ball 220 overcomes the urging force of the low pressure setting spring 240 and moves to the check plate 230 side. Then, it is seated in close contact with the conical seat surface 234. Thus, the through hole 232 is closed and the decompression of the centrifugal hydraulic pressure cancellation chamber 45B is stopped. As a result, the pressure in the centrifugal hydraulic pressure cancellation chamber 45B is increased, and the centrifugal hydraulic pressure canceling action is exhibited.

  On the other hand, the spring constant of the high pressure setting spring 250 is such that the check plate 230 is moved when a pressure higher than the centrifugal hydraulic pressure in the centrifugal hydraulic pressure cancellation chamber 45B generated at the maximum rotation speed of the secondary pulley 36 is applied to the check plate 230. It is set to be done. That is, when the pressure in the centrifugal hydraulic pressure cancellation chamber 45B increases as the pressure in the control hydraulic pressure chamber 45A increases during a sudden shift (rapid deceleration), this high pressure overcomes the urging force of the high pressure setting spring 250 and the check plate 230 Is moved to create a gap between the chamfered lower edge of the check plate 230 and the conical seat surface 212, and the hydraulic oil in the centrifugal hydraulic pressure cancellation chamber 45B is quickly discharged. As a result, the speed change is performed promptly.

(Embodiment according to another embodiment of the present invention)
Next, an embodiment according to another embodiment of the present invention will be described with reference to FIG. In this embodiment, the centrifugal hydraulic pressure cancellation chamber 45B is depressurized when the secondary pulley 36 is equal to or lower than the predetermined rotational speed in the outer cylindrical portion 43C that defines a part of the centrifugal hydraulic pressure cancellation chamber 45B in the previous embodiment. In contrast to the provision of the two-stage check valve 200 for stopping the pressure reduction when the rotational speed is greater than the predetermined rotational speed, a predetermined hydraulic pressure is supplied to the centrifugal hydraulic pressure cancel chamber 45B, and the supplied predetermined hydraulic pressure is supplied. The difference is that means for increasing and controlling the control oil pressure supplied to the control oil pressure chamber 45A is provided. Therefore, the configuration of the secondary pulley 36 is the same as that of the previous embodiment except that the check valve 200 is not provided in the outer cylindrical portion 43C that defines a part of the centrifugal hydraulic pressure cancellation chamber 45B. Since they are the same, the same reference numerals as those used in FIG. 3 are used for the same components, and redundant explanation is avoided.

  Therefore, a hydraulic circuit 300 according to another embodiment of the present invention will be described with reference to FIG. In the figure, reference numeral 21 denotes the above-described oil pump. In the present embodiment, hydraulic oil sucked from an oil tank or an oil pan and discharged from the oil pump 21 is supplied to an oil passage 302. The oil passage 302 is connected to a ratio control valve RCV for controlling the transmission ratio of the CVT 9 and the belt pressing force and a belt pressing force control valve BPCV. The oil passage 302 is further connected to a clutch pressure control valve CPCV that controls the engagement pressure of the forward clutch CL and the reverse brake BR of the forward / reverse switching mechanism 8.

  PRV is a primary regulator valve provided in an oil passage 304 branched from the oil passage 302, and SRV is a secondary regulator valve arranged in series with a drain system oil passage 306 of the primary regulator valve PRV. An oil passage 308 is branched from the oil passage 306, and the oil passage 308 is connected to a lockup control valve LUCV that controls the engagement pressure of the lockup clutch of the torque converter 7. The secondary regulator valve SRV includes first and second drain systems. The first drain system communicates with the lubricating oil passage 310, and the second drain system communicates with the return oil passage 312 to the oil pump 21. An oil passage 314 is branched from an oil passage 308 connected to the above-described torque converter system, and the oil passage 314 is provided with an orifice for adjusting the flow rate and joined to the lubricating oil passage 310.

  A lubricating oil passage 316 for supplying hydraulic oil to various lubricating parts is branched from the lubricating oil passage 310 downstream of the joining portion. From this lubricating oil path 316, for example, various kinds of bearings 31, 32, 33, 34, etc., which are the lubricating parts described above, and the forward / reverse switching mechanism 8 and the final speed reducer 10, etc., are hydraulic oil for lubrication. The lubricating oil passages 316A, 316B, 316C and the like for supplying the water are branched. Each of these lubricating oil passages 316A, 316B, 316C is provided with a flow rate adjusting orifice set to a hole diameter for controlling to a required amount of hydraulic oil. Further, a communication oil passage 318 that communicates with the return oil passage 312 is branched from the lubricating oil passage 310 downstream of the branch portion, and a check valve 320 that is opened at a predetermined pressure is provided in the communication oil passage 318. .

  On the other hand, the lubricating oil passage 310 communicates with the above-described centrifugal hydraulic pressure cancellation chamber 45B, and a constant supply hydraulic pressure Pc controlled by the check valve 320 opened at the above-described predetermined pressure is supplied to the centrifugal hydraulic pressure cancellation chamber 45B through the oil passage SSB. The oil passage SSE and the oil passage 90D formed in the piston member 90 are supplied.

  On the other hand, the hydraulic oil supplied to the oil passage 302 is provided in an oil passage 304 branched from the oil passage 302, and is controlled by a primary regulator valve PRV controlled according to a gear ratio, input torque, and the like, to a predetermined line pressure PL. Pressure is adjusted. The hydraulic oil drained from the primary regulator valve PRV to the oil passage 306 is then regulated to a predetermined secondary pressure by the secondary regulator valve SRV that is similarly controlled according to the gear ratio, input torque, and the like.

  The hydraulic oil having the line pressure PL is set to the control hydraulic pressure Pdr by the ratio control valve RCV and is supplied to the primary hydraulic actuator 41. This ratio control valve RCV controls the line pressure PL to the control oil pressure Pdr by the duty controlled solenoid valves DS1 and DS2. This solenoid valve DS1 controls the inflow flow rate of the line pressure PL to the primary hydraulic actuator 41 according to the wheel speed and the accelerator opening, and the solenoid valve DS2 similarly corresponds to the wheel speed and the accelerator opening. The flow rate of the line pressure PL to the hydraulic actuator 45 on the secondary side is controlled.

  Further, the hydraulic oil having the line pressure PL is controlled by the belt pressing force control valve BPCV to be the control hydraulic pressure Pdn, and is supplied to the secondary hydraulic actuator 45. The belt pressure control valve BPCV is controlled by the solenoid valve SLS in accordance with the input shaft torque, and controls the line pressure PL to the control oil pressure Pdn.

  Further, the hydraulic oil having the line pressure PL is controlled by the clutch pressure control valve CPCV and supplied to the forward clutch CL or the reverse brake BR. The clutch pressure control valve CPCV is controlled by the solenoid SLC according to the input shaft torque, and controls the engagement pressure of the forward clutch CL or the reverse brake BR.

  On the other hand, the hydraulic oil controlled to the secondary pressure by the secondary regulator valve SRV is sent to the lockup control valve LUCV via the oil passage 308, and is thereby controlled and supplied to the torque converter 7. The lockup control valve LUCV controls ON / OFF control of the lockup clutch by the lockup solenoid valve SL, and gradually increases or decreases the lockup engagement hydraulic pressure by the lockup engagement solenoid valve DSU.

  Reference numeral 400 denotes a controller that controls the entire vehicle, and includes an arithmetic processing unit (CPU or MPU), a storage unit (RAM and ROM), and a microcomputer mainly including an input / output interface.

  For this controller 400, various parameters indicating the operating state of the engine 2, for example, engine speed, accelerator opening, throttle opening sensor signal, various parameters indicating the state of the transaxle 3, for example, Information such as the torque ratio of the torque converter 7, the rotational speed Nin of the primary shaft SP and the rotational speed Nout of the secondary shaft SS, and the vehicle speed V are input as various sensors and signals of calculation results, and are obtained in advance through experiments or the like. In order to obtain a required gear ratio γ (= Nin / Nout) and belt pressing force, the above-described solenoid valves DS1, DS2, and SLS are controlled to form the above-described control hydraulic pressure Pdr and control hydraulic pressure Pdn. Is done.

  Further, the controller 400 also stores data for performing shift control of the engine 2, the lockup clutch, and the belt type continuously variable transmission 9 based on various signals. For example, by controlling the gear ratio of the belt-type continuously variable transmission 9 based on the traveling state such as the accelerator opening and the vehicle speed, data for selecting the optimum operating state of the engine 2 and the accelerator opening A lock-up clutch control map using the speed and the vehicle speed as parameters is stored in the controller 400, and the lock-up clutch is controlled to each of engagement / release / slip states based on the lock-up clutch control map. Then, based on various signals input to the controller 400 and data stored in the controller 400, a control signal is output from the controller 400 to the hydraulic control device.

  The input torque is obtained from the map based on the throttle opening and the engine speed, and the speed ratio is calculated from the input / output speed of the torque converter 7, and the torque ratio is obtained from the map based on the speed ratio. It is obtained by multiplying the engine torque by the torque ratio.

  Next, the operation of the above embodiment will be described. A predetermined discharge hydraulic pressure is generated in the oil passage 302 by the rotation of the oil pump 21 based on the rotation of the engine 2, and the hydraulic pressure is adjusted to the line pressure PL by controlling the primary regulator valve PRV. At the same time, the secondary pressure PS supplied to the torque converter 7 through the oil passage 308 is regulated to a predetermined pressure by the secondary regulator valve SRV arranged in series with the primary regulator valve PRV. The secondary regulator valve SRV regulates the secondary pressure PS while releasing the working oil from the first drain system to the lubricating oil passage 310 during the rotation of the engine 2 where the discharge amount of the oil pump 21 is small, and at the time of high rotation where the discharge amount is large. Then, the pressure is adjusted while letting hydraulic oil escape from the second drain system to the oil passage 312 as well.

  Therefore, when the engine 2 is rotated, and hence when the input shaft SI is rotated, the lubricating oil path 316 and the branch from the lubricating oil path 310 to which the first drain system hydraulic oil of the secondary regulator valve SRV is supplied. The various flow rates of the bearings 31, 32, 33, 34, etc. connected through the lubricating oil passages 316A, 316B, 316C, the forward / reverse switching mechanism 8 and the lubrication part of the final reduction gear 10 are controlled to the required flow rate by the orifice. Hydraulic fluid is supplied. At the same time, hydraulic oil controlled to a constant supply oil pressure Pc is supplied to the oil passage SSB and the oil passage SSE by a check valve 320 opened at a predetermined pressure provided in the communication oil passage 318 branched downstream of the branch portion. Then, the oil is supplied to the centrifugal oil pressure cancel chamber 45B through an oil passage 90D formed in the piston member 90.

  The secondary side hydraulic actuator 45 has an execution control hydraulic pressure PdnA (= Pdn + Pc) obtained by adding this constant supply hydraulic pressure Pc to the theoretically required control hydraulic pressure Pdn supplied to the control hydraulic chamber 45A. Is controlled. By doing so, the actual oil pressure acting on the control oil pressure chamber 45A becomes PdnA−Pc = Pdn, and the influence of the supply oil pressure acting on the centrifugal oil pressure canceling chamber 45B can be eliminated. That is, even when the secondary pulley 36 does not require cancellation of the centrifugal hydraulic pressure, the desired centrifugal hydraulic pressure can be canceled in the entire rotation region without being affected by the supply hydraulic pressure Pc.

  Here, the control at the time of sudden downshift at the time of sudden acceleration or sudden braking of the vehicle will be described. The traveling state of the vehicle that requires this sudden downshift, that is, the traveling state or the driving condition with a relatively small gear ratio. At the time of sudden acceleration request or sudden downshift during sudden braking, the movable sheave 39 on the primary side is moved away from the fixed sheave 38 in the direction of increasing the groove width so as to increase the gear ratio γ, and the secondary side It is necessary to quickly move the movable sheave 43 toward the fixed sheave 42 in the direction in which the groove width becomes narrower.

  In the present embodiment, when the controller 400 determines this sudden downshift, the above-described execution control oil pressure PdnA is supplied to the control oil pressure chamber 45A via the oil passage SSC and the oil passage SSD, and at the same time, the centrifugal oil pressure cancellation chamber 45B. The hydraulic oil is drained through the check valve 320. Accordingly, the movable sheave 43 is moved quickly, and the responsiveness of the sudden downshift is improved.

It is a skeleton figure which shows the transaxle to which the hydraulic control apparatus of the belt-type continuously variable transmission which concerns on this invention is applied. It is sectional drawing which shows an example of a structure of the primary pulley of the hydraulic control apparatus of the belt-type continuously variable transmission which concerns on this invention. It is sectional drawing which shows the structure of the secondary pulley used as embodiment of the hydraulic control apparatus of the belt-type continuously variable transmission which concerns on one form of this invention. It is an expanded sectional view of the check valve in FIG. It is sectional drawing which shows the structure of the secondary pulley used as embodiment of the hydraulic control apparatus of the belt-type continuously variable transmission which concerns on the other form of this invention. It is a hydraulic circuit diagram of an embodiment of a hydraulic control device of a belt type continuously variable transmission according to another embodiment of the present 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 45A Control hydraulic chamber 45B Centrifugal hydraulic cancel chamber 200 Two-stage operation check valve 240 Low pressure setting Spring 250 High-pressure setting spring 300 Hydraulic circuit 310 Lubricating oil path 320 Check valve 400 Controller

Claims (3)

In a hydraulic control device for a belt-type continuously variable transmission, comprising a control hydraulic chamber to which a control hydraulic pressure for generating a belt pressing force acting on a belt is applied to a movable sheave of a pulley, and a centrifugal hydraulic pressure cancel chamber to which a predetermined hydraulic pressure is supplied ,
A valve device that allows the hydraulic oil to flow out when the pulley rotation speed is lower than the predetermined pressure and depressurizes the centrifugal oil pressure canceling chamber, and stops the pressure reduction when the pulley rotation speed is higher than the predetermined rotation speed. Is provided on a member defining the centrifugal hydraulic pressure canceling chamber . The hydraulic control device for a belt-type continuously variable transmission for a vehicle. 2. The valve device according to claim 1, wherein the valve device is a two-stage operation that quickly discharges hydraulic oil when the pressure in the centrifugal hydraulic pressure cancellation chamber rises high at a rotational speed greater than the predetermined rotational speed . Hydraulic control device for a belt type continuously variable transmission for a vehicle. In a hydraulic control device for a belt-type continuously variable transmission, comprising a control hydraulic chamber to which a control hydraulic pressure for generating a belt pressing force acting on a belt is applied to a movable sheave of a pulley, and a centrifugal hydraulic pressure cancel chamber to which a predetermined hydraulic pressure is supplied ,
The vehicle is provided with means for increasing and controlling the control hydraulic pressure supplied to the control hydraulic chamber while supplying a predetermined hydraulic pressure to the centrifugal hydraulic pressure canceling chamber. Hydraulic control device for belt type continuously variable transmission.

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