JP6493346B2 - Continuously variable transmission for vehicle - Google Patents

Description

  The present invention relates to a continuously variable transmission for a vehicle, and relates to a structure that suppresses a change in speed ratio caused by wear of a member that restricts movement of a movable sheave.

  In a vehicle transmission, a primary sheave including a fixed sheave integrally formed with the sheave shaft, a movable sheave that is relatively movable in the axial direction of the sheave shaft, and a secondary having the same structure as the primary sheave A vehicular continuously variable transmission including a sheave and a belt wound around the primary sheave and the secondary sheave is well known. In the continuously variable transmission for a vehicle disclosed in Patent Document 1, a cylinder member that forms a hydraulic chamber together with the movable sheave contacts the movable sheave at the maximum or minimum speed ratio and moves toward the cylinder member of the movable sheave. It functions as a stopper member that restricts the movement of the shaft in the axial direction.

JP 2008-208861 A

  By the way, when the transmission torque between the primary sheave and the secondary sheave increases, the force that bends the sheave shaft provided to each of the fixed sheave and the movable sheave facing each other outwards. Will occur. As a result, local contact occurs between the movable sheave and the stopper member adjacent thereto, and the pressure at the contact portion, that is, the contact surface pressure increases as the transmission torque increases. The increase in the contact surface pressure causes wear of the stopper member, and the gear ratio may fluctuate due to the increase in wear. On the other hand, the continuously variable transmission for a vehicle is required to be as small as possible from the viewpoint of mountability. In order to reduce the size, it is effective to reduce the angle of the sheave surfaces of the fixed sheave and the movable sheave and to reduce the axial dimension of the movable sheave. The above inconvenience becomes remarkable due to an increase in the force on the contact surface, that is, the contact surface pressure.

  The present invention has been made against the background of the above circumstances, and its object is to wear the stopper member and the movable sheave by reducing the contact surface pressure between the movable sheave and the stopper member. Is to reduce the fluctuation of the gear ratio. Furthermore, by reducing the contact surface pressure of the stopper member and the movable sheave, the angle of the sheave surface can be made smaller than before, and the axial dimension with the movable sheave can be made shorter than before, thereby An object of the present invention is to provide a structure that contributes to miniaturization of a continuously variable transmission for a vehicle.

The gist of the first invention is that (a) a fixed sheave integrally formed with the sheave shaft and the sheave shaft facing the fixed sheave are axially movable relative to the sheave shaft and relatively rotated about the axis. A vehicular belt type continuously variable transmission comprising: a pair of variable sheaves each having an impossibly spline-fitted movable sheave; and a transmission belt wound around the pair of variable sheaves; The movable sheave has a cylindrical boss projecting toward a fixed position stopper member located on the opposite side of the fixed sheave, and (c) an annular end surface of the boss facing the stopper member is , and the outer end surface of the annular, the inner end surface of the annular than the outer peripheral end face spaced in the rotational center line direction from the stopper member, the inner peripheral side of the annular and the inner periphery of the outer end face of the annular And an outer peripheral edge surface, and an annular connecting surface that connects with the tapered surface toward the inner peripheral side as it goes to the fixed sheave, R surface at the boundary line (d) and the outer peripheral side end face and the annular connecting surface It is characterized by having a catching part.

According to this configuration, the annular end surface of the boss portion facing the stopper member includes an annular outer peripheral side end surface and an annular inner peripheral side that is further away from the stopper member in the rotation center line direction than the outer peripheral end surface. An annular connection surface that connects an end surface, an inner peripheral edge of the annular outer peripheral side end surface, and an outer peripheral edge of the annular inner peripheral side end surface with a tapered surface toward the inner peripheral side toward the fixed sheave; Since the R chamfered portion is provided at the boundary between the outer peripheral side end surface and the annular connecting surface, the R chamfered portion abuts on the stopper member, so that the movable sheave and the stopper member It is possible to reduce the contact surface pressure at the contact portion, and by suppressing the wear of the stopper member and the movable sheave, the change in the transmission ratio is also suppressed. Further, by reducing the wear of the stopper member and the movable sheave, a stronger clamping force to the belt is allowed, the angle of the sheave surface is made smaller than before, and the axial dimension of the movable sheave is conventionally increased. Accordingly, it is possible to reduce the size of the vehicle belt type continuously variable transmission.

  According to a second aspect of the present invention, there is provided a vehicular belt type continuously variable transmission according to the first aspect of the present invention, wherein the sheave shaft and the movable sheave are engaged with the sheave by spline fitting including an involute spline, a ball spline, or a roller spline. Relative movement is possible in the axial direction of the shaft. If it does in this way, it becomes possible to ensure favorable relative movement in the axial direction of the sheave shaft between the fixed sheave formed integrally with the sheave shaft and the movable sheave.

  Further, the gist of the third invention is that in the belt type continuously variable transmission for the vehicle according to the first invention or the second invention, less than half of the difference between the outer diameter and the inner diameter of the annular end surface of the boss portion. The R chamfered portion is formed in a range on the inner diameter side. In this way, even if the transmission torque is increased and a force is generated in which the movable sheave and the fixed sheave are spread in parallel to the axial direction of the sheave shaft, the R chamfered portion has a predetermined portion. By being limited to this, the contact surface of the boss end that comes into contact with the adjacent stopper component is sufficiently secured. By securing a large contact surface, the average surface pressure from the boss end to the stopper component is suppressed. As a result, wear of the stopper member and the movable sheave is suppressed, and a change in the gear ratio is also suppressed. Further, by reducing the wear of the stopper member and the movable sheave, the angle of the sheave surface can be made smaller than before, and the axial dimension of the movable sheave can be made shorter than before. The belt type continuously variable transmission can be downsized.

It is a figure explaining the schematic structure of the power transmission path from the engine which comprises the vehicle to which this invention was applied to a driving wheel. It is a figure explaining the change of the running pattern of the power transmission device in the vehicle of FIG. 2 is a cross-sectional view illustrating the structure of a pair of a movable sheave, a fixed sheave, and peripheral components in the belt-type production transmission of FIG. It is sectional drawing which expanded and showed the movable sheave and the sheave shaft of FIG. FIG. 4 is a cross-sectional view illustrating an example of a deformation mode of the pair of movable sheave, fixed sheave, and peripheral components in FIG. 3. It is sectional drawing which showed the detail of the boss | hub end part of a movable sheave in a conventional structure, and a spline end part equivalent to the figure which expanded FIG. 4 further. FIG. 5 is a cross-sectional view showing the details of a movable sheave having an R chamfered portion at the boss end to which the present invention is applied, further enlarging FIG. 4. It is a pressure distribution figure which shows the contact surface pressure which arises in a contact surface in a boss end part with an R chamfering part, and a boss end part without an R chamfering part based on a relative position with an opposed sheave. It is sectional drawing at the time of using a ball spline for the spline fitting of the movable sheave and the sheave shaft of FIG. It is the figure which looked at the area | region where the R chamfering part of the boss | hub edge part in FIG. 7 was formed from the axial direction.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied. In FIG. 1, a vehicle 10 includes an engine 12 such as a gasoline engine or a diesel engine that functions as a driving source for traveling, a driving wheel 14, and a power transmission device 16 provided between the engine 12 and the driving wheel 14. It has. The power transmission device 16 is connected to the torque converter 20 as a fluid transmission device connected to the engine 12, the input shaft 22 connected to the torque converter 20, and the input shaft 22 in a housing 18 as a non-rotating member. A belt type continuously variable transmission 24 (hereinafter referred to as a continuously variable transmission), a forward / reverse switching device 26 connected to the input shaft 22, and a continuously variable transmission connected to the input shaft 22 via the forward / reverse switching device 26. Gear transmission mechanism 28 as a gear transmission provided in parallel with the machine 24, the output shaft 30, which is a common output rotating member of the continuously variable transmission 24 and the gear transmission mechanism 28, the counter shaft 32, the output shaft 30, and the counter shaft A reduction gear device 34 composed of a pair of gears that are provided in mesh with each other and engaged with each other, and a differential 36 connected to a gear 36 provided with the counter shaft 32 so as not to be relatively rotatable. Ya 38 includes an axle 40 or the like of the pair coupled to a differential gear 38. In the power transmission device 16 configured as described above, the power of the engine 12 (synonymous with torque and force unless otherwise specified) is the torque converter 20, the continuously variable transmission 24 or the forward / reverse switching device 26, and the gear transmission mechanism. 28, the reduction gear device 34, the differential gear 38, the axle 40, and the like are sequentially transmitted to the pair of drive wheels 14. During operation of the engine 12, the output torque of the engine 12 is always input to the input shaft 22.

  As described above, the power transmission device 16 transmits the power of the engine 12 to the engine 12 (here, the input shaft 22 which is an input rotating member to which the power of the engine 12 is transmitted) and the driving wheel 14 (here, the driving wheel 14 is transmitted). A gear transmission mechanism 28 as a first transmission unit and a continuously variable transmission 24 as a second transmission unit, which are provided in parallel with the output shaft 30 which is an output rotating member for output. Therefore, the power transmission device 16 transmits the power of the engine 12 from the input shaft 22 to the drive wheel 14 side (that is, the output shaft 30) via the gear transmission mechanism 28, and the power of the engine 12 is transmitted. A plurality of power transmission paths PT, which are the second power transmission path PT2 that is transmitted from the input shaft 22 to the drive wheel 14 side (that is, the output shaft 30) via the continuously variable transmission 24, are connected to the input shaft 22 and the output shaft 30. In parallel between. The power transmission device 16 is switched between the first power transmission path PT1 and the second power transmission path PT2 in accordance with the traveling state of the vehicle 10. Therefore, the power transmission device 16 has a plurality of engagements for selectively switching the power transmission path PT for transmitting the power of the engine 12 to the drive wheel 14 side between the first power transmission path PT1 and the second power transmission path PT2. Equipment. This engagement device includes a first clutch C1 that connects and disconnects the first power transmission path PT1, and a second clutch C2 that serves as a second engagement device that connects and disconnects the second power transmission path PT2.

  The torque converter 20 is provided coaxially with the input shaft 22 around the input shaft 22, and includes a pump impeller 20 p connected to the engine 12 and a turbine impeller 20 t connected to the input shaft 22. ing. The pump impeller 20p is supplied with hydraulic pressure for controlling the transmission of the continuously variable transmission 24, operating the plurality of engagement devices, and supplying lubricating oil to each part of the power transmission device 16. A mechanical oil pump 42 that is generated by being driven by rotation is connected. During operation of the engine 12, the output torque of the engine 12 is constantly input to the input shaft 22 via the torque converter 20.

  The forward / reverse switching device 26 is provided around the input shaft 22 in the first power transmission path PT1 and coaxially with the input shaft 22, that is, on the first shaft RC1, and is a double pinion type planetary gear device 26p, A first clutch C1 and a first brake B1 are provided. The planetary gear device 26p is a differential mechanism having three rotating elements: a carrier 26c as an input element, a sun gear 26s as an output element, and a ring gear 26r as a reaction force element. The carrier 26c is integrally connected to the input shaft 22, the ring gear 26r is selectively connected to the housing 18 via the first brake B1, and the sun gear 26s is coaxial with the input shaft 22 around the input shaft 22. It is connected to a small-diameter gear 44 provided so as to be relatively rotatable. The carrier 26c and the sun gear 26s are selectively connected via the first clutch C1. Therefore, the first clutch C1 is an engagement device that selectively connects two of the three rotating elements for forward gear travel, and the first brake B1 is used for the reverse travel. This is an engagement device for selectively connecting a ring gear 26r as a reaction force element to the housing 18.

  The gear transmission mechanism 28 includes a small-diameter gear 44 and a large-diameter gear 48 that is provided around the gear mechanism counter shaft 46 so as not to rotate relative to the gear mechanism counter shaft 46 and meshes with the small-diameter gear 44. ing. The gear transmission mechanism 28 includes an idler gear 50 provided around the gear mechanism counter shaft 46 so as to be relatively rotatable coaxially with the gear mechanism counter shaft 46, and the output shaft 30 with respect to the output shaft 30. An output gear 52 that is provided on the coaxial center so as not to rotate relative to the idler gear 50 is provided. The output gear 52 has a larger diameter than the idler gear 50. Accordingly, the gear transmission mechanism 28 is a gear transmission mechanism in which one speed ratio (speed stage) as a predetermined speed ratio (speed stage) is formed in the power transmission path PT between the input shaft 22 and the output shaft 30. It is. Around the gear mechanism counter shaft 46, a meshing clutch D <b> 1 is provided between the large-diameter gear 48 and the idler gear 50 to selectively connect and disconnect between them. The meshing clutch D1 is provided in the power transmission device 16 and is disposed in a power transmission path between the forward / reverse switching device 26 (which also agrees with the first friction clutch C1) and the output shaft 30 (in other words, the first clutch D1). A third engagement device that is connected to and disconnected from the first power transmission path PT1 (in other words, the first power transmission path by being engaged together with the first clutch C1). The third engagement device that forms PT1) is included in the plurality of engagement devices.

  Specifically, the meshing clutch D1 includes a clutch hub 54 provided around the gear mechanism counter shaft 46 so as not to rotate relative to the gear mechanism counter shaft 46, an idler gear 50, and a clutch hub 54. A clutch gear 56 disposed between and fixed to the idler gear 50 is spline-fitted (engaged) with the clutch hub 54 so that the gear mechanism counter shaft 46 cannot rotate relative to the center of the gear mechanism counter shaft 46. And a cylindrical sleeve 58 provided so as to be relatively movable in a direction parallel to the axis. The sleeve 58 that is always rotated integrally with the clutch hub 54 is moved to the clutch gear 56 side and meshed with the clutch gear 56, whereby the idler gear 50 and the gear mechanism counter shaft 46 are connected. Further, the meshing clutch D1 includes a known synchromesh mechanism S1 as a synchronizing mechanism that synchronizes rotation when the sleeve 58 and the clutch gear 56 are engaged. In the meshing clutch D1 configured as described above, the fork shaft 60 is operated by the hydraulic actuator 62, whereby the sleeve 58 is connected to the shaft of the gear mechanism counter shaft 46 via the shift fork 64 fixed to the fork shaft 60. It is slid in a direction parallel to the center, and the engaged state and the released state are switched.

  The first power transmission path PT1 is formed by engaging the meshing clutch D1 and the first clutch C1 (or the first brake B1) provided closer to the input shaft 22 than the meshing clutch D1. . In the power transmission device 16, when the first power transmission path PT <b> 1 is formed, the power transmission state in which the power of the engine 12 can be transmitted from the input shaft 22 to the output shaft 30 via the gear transmission mechanism 28 is set. The On the other hand, the first power transmission path PT1 is in a neutral state (power transmission) that interrupts power transmission when at least the first clutch C1 and the first brake B1 are both released or at least the meshing clutch D1 is released. It is said that it is in a cut-off state.

  The continuously variable transmission 24 is provided on the input shaft 22 that rotates together with the engine 12 even when the engine 12 is in operation while the engine 12 is connected to the engine via the torque converter 20 and the second clutch C2 is released. A primary sheave (primary pulley) 66 having a variable effective diameter, a secondary sheave (secondary pulley) 70 having a variable effective diameter provided on a rotary shaft 68 coaxial with the output shaft 30, and the sheaves 66, 70. And a transmission belt 72 wound around the belt, and power is transmitted through frictional force (belt clamping pressure) between the sheaves 66, 70 and the transmission belt 72. In the primary sheave 66, the sheave hydraulic pressure supplied to the primary sheave 66 (that is, the primary pressure Pin supplied to the hydraulic cylinder 66c) is regulated by a hydraulic control circuit (not shown), whereby the fixed sheave 66a and the movable sheave 66b. A primary thrust Win (= primary pressure Pin × pressure receiving area) is applied to change the V groove width therebetween. Further, in the secondary sheave 70, the sheave hydraulic pressure supplied to the secondary sheave 70 (that is, the secondary pressure Pout supplied to the secondary hydraulic actuator 70c) is regulated by the hydraulic control circuit, so that the fixed sheave 70a and the movable sheave 70 Secondary thrust Wout (= secondary pressure Pout × pressure receiving area) for changing the V groove width between 70 b is applied. In the continuously variable transmission 24, the primary thrust Win (primary pressure Pin) and the secondary thrust Wout (secondary pressure Pout) are controlled, so that the V-groove widths of the sheaves 66 and 70 change and the transmission belt 72 is engaged. The diameter (effective diameter) is changed, the gear ratio γcvt (= primary sheave rotation speed Npri / secondary sheave rotation speed Nsec) is changed, and the sheaves 66 and 70 and the transmission belt are prevented from slipping. The frictional force with 72 is controlled.

  The output shaft 30 is disposed around the rotation shaft 68 so as to be rotatable relative to the rotation shaft 68 coaxially. The second clutch C2 is provided on the drive wheel 14 (here, the output shaft 30 also agrees) side with respect to the continuously variable transmission 24 (that is, provided between the secondary sheave 70 and the output shaft 30). The secondary sheave 70 (rotary shaft 68) and the output shaft 30 are selectively connected or disconnected. The second power transmission path PT2 is formed by engaging the second clutch C2. In the power transmission device 16, when the second power transmission path PT <b> 2 is formed, a power transmission possible state in which the power of the engine 12 can be transmitted from the input shaft 22 to the output shaft 30 via the continuously variable transmission 24. Is done. On the other hand, the second power transmission path PT2 is set to the neutral state when the second clutch C2 is released.

  FIG. 2 is a diagram for explaining the switching of the travel pattern using the engagement table of the engagement device for each travel pattern (travel mode) of the power transmission device 16. In FIG. 2, C1 corresponds to the operating state of the first clutch C1, C2 corresponds to the operating state of the second clutch C2, B1 corresponds to the operating state of the first brake B1, and D1 corresponds to the meshing clutch D1. Corresponding to the operating state, “◯” indicates engagement (connection), and “×” indicates release (cutoff).

  In FIG. 2, a gear travel mode that is a travel mode in which the power of the engine 12 is transmitted to the output shaft 30 via the gear transmission mechanism 28 (that is, a travel mode using the first power transmission path PT <b> 1 via the gear transmission mechanism 28). Then, the first clutch C1 and the meshing clutch D1 are engaged, and the second clutch C2 and the first brake B1 are released. In this gear travel mode, forward travel is possible. Note that when the first brake B1 and the meshing clutch D1 are engaged and the second clutch C2 and the first clutch C1 are released, the vehicle can travel backward.

  In addition, a CVT travel mode which is a travel mode in which the power of the engine 12 is transmitted to the output shaft 30 via the continuously variable transmission 24 (that is, a travel mode using the second power transmission path PT2 via the continuously variable transmission 24). In (also referred to as a belt running mode), the second clutch C2 is engaged and the first clutch C1 and the first brake B1 are released. In this CVT travel mode, forward travel is possible. Among the CVT traveling modes, the meshing clutch D1 is engaged in the CVT traveling (medium vehicle speed) mode, while the meshing clutch D1 is released in the CVT traveling (high vehicle speed) mode. The meshing clutch D1 functions as a driven input cutoff clutch that blocks input from the drive wheel 14 side.

  The gear travel mode is selected, for example, in a low vehicle speed region including when the vehicle is stopped. In the power transmission device 16, the speed ratio γ gear (also referred to as speed ratio EL) formed in the first power transmission path PT1 via the gear transmission mechanism 28 is the second power transmission path PT2 via the continuously variable transmission 24. Is set to a value (that is, the low-side transmission ratio) larger than the maximum transmission ratio (that is, the lowest-speed transmission ratio that is the transmission ratio on the lowest vehicle speed side) γmax. That is, in the second power transmission path PT2, a speed ratio γcvt on the higher vehicle speed side (high side) than the speed ratio EL formed in the first power transmission path PT1 is formed. For example, the gear ratio EL corresponds to the first speed gear ratio γ1 which is the gear ratio γ of the first speed gear stage in the power transmission device 16, and the lowest gear ratio γmax of the continuously variable transmission 24 is equal to that in the power transmission device 16. This corresponds to the second speed gear ratio γ2 that is the speed ratio γ of the second speed gear. Therefore, the gear travel mode and the CVT travel mode are switched, for example, according to a shift line for switching between the first speed shift stage and the second speed shift stage in the shift map of the stepped transmission. Further, in the CVT travel mode, a gear shift in which the gear ratio γcvt is changed based on a travel state such as an accelerator opening degree or a vehicle speed is executed.

  FIG. 3 is a sectional view of the primary sheave 66 of the continuously variable transmission 24 of FIG. The primary sheave 66 is formed in a V-shape between a disk-shaped fixed sheave 66a integrally formed on a sheave shaft 78 rotatably supported by the housing 18 via a bearing 74 and a bearing 76, and the fixed sheave 66a. A movable sheave 66b that cannot rotate relative to the sheave shaft 78 and that can move in the axial direction so that the first pulley groove 80 having a shape is formed, and the movable sheave 66b is moved in the axial direction in accordance with the supplied hydraulic pressure. Thus, a hydraulic cylinder 66c that changes the groove width of the first pulley groove 80 by moving the fixed sheave 66a and the movable sheave 66b closer to or away from each other in the axial direction is provided. The sheave shaft 78 is rotatably supported around the first axis RC1 by a bearing 74 and a bearing 76 whose outer peripheral ends are fitted to the housing 18. A groove having an involute curve on the inner surface of the movable sheave 66b is formed, and the groove formed on the movable sheave 66b and the groove formed on the outer diameter of the sheave shaft 78 are involute spline fitting (hereinafter referred to as spline fitting). As a result, the movable sheave 66b and the sheave shaft 78 cannot be rotated relative to each other.

  The fixed sheave 66 a of the primary sheave 66 is a disk-shaped member that protrudes radially from the outer peripheral surface of the sheave shaft 78. The fixed sheave 66a is formed with a conical tapered surface 82 formed in a direction away from the movable sheave 66b in the radial direction.

  The movable sheave 66b of the primary sheave 66 includes a boss portion 88 whose inner peripheral portion is spline-fitted so as to be axially movable relative to the sheave shaft 78 and non-rotatable about the first axis RC1, and its boss. A disk part 90 projecting radially from the end on the fixed sheave 66a side in the axial direction of the part 88, and extends in parallel to the first axial center RC1 in a direction away from the fixed sheave 66a in the axial direction from the outer peripheral part of the disk part 90. And an outer peripheral cylindrical portion 92. The disk portion 90 is formed with a conical tapered surface 94 that is formed in a direction away from the fixed sheave 66a in the radial direction. The first pulley groove 80 is formed by the tapered surface 94 formed on the movable sheave 66b and the tapered surface 82 formed on the fixed sheave 66a.

  The hydraulic cylinder 66c includes a bottomed cylindrical cylinder member 96 disposed on the back side of the tapered surface 94 in the axial direction of the movable sheave 66b. The cylinder member 96 is tightened with a nut 98 in a state in which the inner peripheral portion is sandwiched in the axial direction between the stepped portion of the sheave shaft 78 and the bearing 52 via a disk-shaped cylinder seat 100 that functions as a stopper member. As a result, it is fixed so that it cannot move in the axial direction. The movable sheave 66b comes into contact with the cylinder seat 100, which is an abutting counterpart provided in a fixed position in the direction of the first axis RC1, so that the distance between the movable sheave 66b and the fixed sheave 66a is maximized. γcvt forms the lowest speed, that is, the speed ratio on the lowest vehicle speed side. The cylinder member 96 has a bent shape, and a cylindrical portion concentric with the first axis RC <b> 1 is formed on the outer peripheral side of the cylinder member 96. The inner peripheral surface of the cylindrical portion and the outer peripheral end portion of the outer peripheral cylindrical portion 92 of the movable sheave 66b are configured to be slidable via an oil seal. As a result, an oil-tight hydraulic chamber 97 is formed between the cylinder member 96 and the movable sheave 66b. The hydraulic chamber 97 is supplied with hydraulic pressure from a hydraulic control circuit (not shown) through an oil passage formed in the sheave shaft 78 and an oil passage formed in the movable sheave 66b.

  FIG. 4 is an enlarged view of a portion surrounded by an elliptical broken line in FIG. 3, that is, the boss portion 88 of the movable sheave 66b, the cylinder seat 100, and the portion A that is the periphery thereof. Inner peripheral spline teeth are formed on the inner diameter side of the cylindrical boss part 88, and the boss part 88 has a boss part inner peripheral surface 88i passing through the top of the inner diameter spline tooth and a boss having a constant outer diameter. The outer peripheral surface 88o is provided on the cylinder seat 100 side.

  FIG. 5 is a diagram exaggerating the deformation to facilitate understanding of an example of the deformation mode that occurs when the transmission torque from the primary sheave 66 to the secondary sheave 70 is large. FIG. 5 shows a primary sheave 66 in which the opening of the first pulley groove 80 on the upper side of the first axis RC1 is larger than the normal position and on the lower side of the first axis RC1. The opening of the first pulley groove 80 is smaller than the normal position. At the same time, the first axis RC1 is curved upward in FIG.

FIG. 6 corresponds to a region surrounded by a circular broken line in FIG. 4 and indicated as B, that is, including a portion where the boss portion 88 and the cylinder seat 100 are in contact with each other and a boss portion inner peripheral surface 88i of the boss portion 88 It is FIG. B1. Enlarged view B1 is a view showing a conventional end face, and an end face 102 of the boss portion 88 facing the cylinder seat 100 has an annular inner peripheral end face 108 C-chamfered on the inner diameter side, and an inner peripheral end face 108. The outer peripheral side end surface 104 is formed on the outer side in the radial direction and on the outer side in the axial direction and contacts the cylinder seat 100, and the annular connection surface 106 that connects the inner peripheral side end surface 108 and the outer peripheral side end surface 104. . Further, the inner peripheral end face 108 and the annular connecting face 106 are connected by, for example, an R shape formed with a predetermined curvature radius R1 or a gentle curve.

  As shown in the enlarged view B1 of FIG. 6, the boundary between the outer peripheral side end surface 104 and the annular connecting surface 106 forms a ridge line connected in a straight line in the cross section, and the inner peripheral edge of the outer peripheral side end surface 104 is in contact with the cylinder seat 100. . Therefore, the deformation shown in FIG. 5, that is, the deformation in which the first pulley groove 80 expands from the normal position as the distance from the secondary sheave 70 increases as the transmission torque from the primary sheave 66 to the secondary sheave 70 increases is the same as that of the fixed sheave 66a. When it occurs in the movable sheave 66b, in the conventional end surface in FIG. 6, the ridge line between the outer peripheral side end surface 104 and the annular connecting surface 108 locally contacts the cylinder seat 100, and a large contact surface pressure at the contact portion. (MPa) will be produced.

  The difference between the enlarged view B2 of FIG. 7 of this embodiment and the enlarged view B1 of FIG. 6 is that an R-shaped portion 110 formed with a curvature of approximately R2 is provided between the outer peripheral end face 104 and the annular connecting face 106. Other than the R-shaped portion 110, it has the same cross-sectional shape as the enlarged view B1. When the deformation shown in FIG. 5 occurs in the fixed sheave 66a and the movable sheave 66b due to a large transmission torque from the primary sheave 66 to the secondary sheave 70, the outer peripheral side end face 104 and the annular connecting face in FIG. 108, that is, the R-shaped portion 110 has a predetermined radius of curvature R2, the area of the contact portion with the cylinder seat 100 is increased and the contact surface pressure is reduced as compared with the cross-sectional shape of the enlarged view B1. The By reducing the contact surface pressure, it is possible to reduce the wear of the cylinder seat 100 and the outer peripheral side end surface 104 of the movable sheave 66b that are in contact with each other, and the variation of the speed ratio γcvt is reduced. Although the R-shaped portion 110 has a predetermined radius of curvature R2, in particular, when the deformation shown in FIG. 5 occurs in the fixed sheave 66a and the movable sheave 66b, the cylinder seat 100 on the outer peripheral side end face 104 is formed. It may be formed of a curve or a polygon made up of a plurality of surfaces capable of reducing the contact surface pressure.

  8 shows a case where there is no R-shaped portion 110 at the boundary between the outer peripheral end face 104 and the annular connecting surface 106 (described as “No R” in FIG. 8), and an R shape at the boundary between the outer peripheral end face 104 and the annular connecting face 106. FIG. 9 is a diagram comparing contact surface pressures when a portion 110 is included (described as R addition in FIG. 8). The phase (deg) shown as the horizontal axis represents the rotation angle (rotation phase) of the primary sheave 66. The angles farthest from the secondary sheave 70 paired with the primary sheave 66 are 0 ° and 360 °. An example of the distribution of contact surface pressure in the circumferential direction applied from the outer peripheral end surface 104 to the cylinder seat 100 with the angle closest to the sheave 70 being 180 ° is shown. The contact surface pressure is measured by a surface pressure sensor, and is measured under the condition that the same force is applied to the primary sheave 66 by the transmission belt 72. Under the measured conditions, the contact surface pressure is 1.6 times to 1 when the R-shaped portion 110 is not present at the boundary between the outer peripheral end surface 104 and the annular connecting surface 106 as compared with the case where the R-shaped portion 110 is present. The value is about 8 times, and by having the R-shaped portion 110, it is possible to reduce the wear of the cylinder seat 100 and the outer peripheral end surface 104 of the movable sheave 66b, and the change in the gear ratio γcvt can be reduced. It is suppressed. The contact surface pressure in the radial direction is the largest 0 ° or 360 °, that is, the contact surface pressure at the position farthest from the secondary sheave 70 paired with the primary sheave 66 is 180 °, that is, the position closest to the secondary sheave 70. Compared with the contact surface pressure, a value of about 3.8 times to 4.1 times is shown, and the outer periphery of the cylinder seat 100 and the movable sheave 66b in which the primary sheave 66 contacts with each other at the position farthest from the secondary sheave 70. Wear with the side end face 104 is increased.

  According to the present embodiment, the inner peripheral side end face 108 chamfered on the inner diameter side at the axially outer end of the movable sheave 66b that is relatively movable in the axial direction of the sheave shaft 78 of the continuously variable transmission 24, An outer peripheral side end surface 104 formed on the radially outer side and axially outer side from the inner peripheral side end surface 108, an annular connection surface 108 connecting the inner peripheral side end surface 108 and the outer peripheral side end surface 104, and the outer peripheral side end surface 104 And an R-shaped portion 110 having an inner peripheral edge having an R shape. Even when the transmission torque from the primary sheave 66 to the secondary sheave 70 is large and the first pulley groove 80 is deformed to expand from the normal position as the distance from the secondary sheave 70 increases, the fixed sheave 66a and the movable sheave 66b are also deformed. By forming the R-shaped portion 110 having an R shape on the inner peripheral edge of the end surface 104, it is possible to reduce the contact surface pressure applied from the outer peripheral side end surface 104 to the cylinder seat 100, and the outer peripheral side end surface 104 and the cylinder seat 100 are reduced. Thus, the change in the gear ratio γcvt is also suppressed. Further, by reducing the wear, a stronger clamping force to the belt is allowed, and the angles of the tapered surfaces 82 and 94 of the fixed sheave 66a and the fixed sheave 66b are made smaller than before, and the shaft of the movable sheave 66b The directional dimension can be made shorter than that of the prior art, and thus the continuously variable transmission 24 can be miniaturized.

  Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 9 is a cross-sectional view showing the primary sheave 66 only on the upper side of the first axis RC1 that is the rotation axis. In the primary sheave 66 shown in FIG. 3, the sheave shaft 78 and the movable sheave 66b are spline-fitted (engaged) by grooves having an involute curve, that is, by an involute spline. On the other hand, in FIG. 9, a semicircular cross-sectional groove is formed in the sheave shaft 78 and the movable sheave 66b, and torque is transmitted in the radial direction by enclosing a plurality of balls made of steel balls inside the groove. On the other hand, spline fitting, that is, ball spline fitting is performed by a ball spline having a high sliding ability in the axial direction. In addition, spline fitting, that is, roller spline fitting, may be performed by sliding a cylindrical roller inside the groove in the axial direction of the cylinder instead of the plurality of balls. In this way, the fixed sheave 66a formed integrally with the sheave shaft 78 and the movable sheave 66b are relatively unrotatable about the first axis RC1 and ensure good relative movement in the axial direction of the sheave shaft 78. be able to.

  Furthermore, another embodiment of the present invention will be described. In the following description, parts common to those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 10 is a view of the boss portion 88 as viewed from the cylinder seat 100 side, and a range in which the R-shaped portion 110 is formed on the outer peripheral side end face 104 is set. The median value of the outer diameter of the boss portion outer peripheral surface 88o, that is, the outer peripheral side end surface 104, and the inner diameter of the boss portion inner peripheral surface 88i, that is, the inner peripheral side end surface 108 is defined as a center line 88c. The R-shaped portion 110 is formed only in the range, that is, in the region on the inner diameter side that is not more than half of the difference between the outer diameter and the inner diameter of the annular end surface 102 of the boss portion 88. In this way, even if the transmission torque is increased and a force that causes the fixed sheave 66a and the movable sheave 66b to expand in the direction parallel to the first axis RC1 is generated, the R-shaped portion 110 remains within a predetermined range. Therefore, the contact area between the cylinder seat 100 and the outer peripheral side end face 104 is reliably ensured. As a result, the average surface pressure at the contact portion is reduced, wear due to contact between the cylinder seat 100 and the outer peripheral end face 104 is suppressed, and the change in the gear ratio is also reduced by suppressing wear. Further, by suppressing wear due to contact between the cylinder seat 100 and the outer peripheral side end face 104, the angles of the tapered surfaces 82 and 94 are made smaller than before, and the axial dimension of the movable sheave 66b is made shorter than before. Thus, the continuously variable transmission 24 can be reduced in size.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the R chamfered portion 108 is provided on the outer peripheral side end surface 104 of the movable sheave 66b of the primary sheave 66, but the outer peripheral side end surface of the movable sheave 70b of the secondary sheave 70 is not limited to the primary sheave 66. It is good also as having the R chamfering part 104 in 104, and it can expect the effect similar to the primary sheave 66 also to the secondary sheave 70 by this.

  In the above-described second and third embodiments, the primary sheave 66 has been described. However, the present invention can be applied not only to the primary sheave 66 but also to the secondary sheave 70.

  Furthermore, in the above-described embodiment, the cylinder seat 100 is brought into contact with the outer peripheral side end face 104 and functions as a stopper member. However, the cylinder seat 100 is not limited to the cylinder seat 100 and is used for fixing the position in the direction of the first axis RC1. A member that functions as a stopper member such as hydraulic cylinders 66c and 70c may be used as the stopper.

  In the continuously variable transmission of the above-described embodiment, power is transmitted by the transmission belt 72. However, the transmission is not necessarily limited to the transmission belt. For example, the continuously variable transmission can be wound around each pulley such as a chain. There is no particular limitation.

  Further, in the above-described embodiment, the fixed sheave 66a is integrally formed with the sheave shaft 78. However, it is not necessary to be integrally formed and is integrally formed by a mechanical method as long as rigidity is ensured. Anything is fine.

What has been described above is merely an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

24: continuously variable transmission (belt type continuously variable transmission)
66a, 70a: fixed sheaves 66b, 70b: movable sheave 72: transmission belt 78: sheave shaft 88: boss portion 100: cylinder seat (stopper member)
104: outer peripheral end face 106: annular connecting face 108: inner peripheral end face 110: R-shaped part (R chamfered part)

Claims (3)

A pair of a fixed sheave integrally formed with the sheave shaft and a movable sheave that is spline-fitted to the sheave shaft in a state of being axially movable relative to the sheave shaft and non-rotatable around the shaft. A vehicular belt type continuously variable transmission comprising a variable sheave and a transmission belt wound around the pair of variable sheaves,
The movable sheave has a cylindrical boss protruding toward a stopper member located on the opposite side of the fixed sheave,
The end face of the annular facing the stopper member of the boss portion, and the outer end surface of the annular, and the outer peripheral end face annular inner end face spaced in the rotational center line direction from said stopper member than of the annular the inner periphery of the outer peripheral side end face and the outer peripheral edge of the inner peripheral side end surface of the annular, and an annular connecting surface that connects with the tapered surface toward the inner peripheral side more toward the fixed sheave,
A belt type continuously variable transmission for a vehicle, comprising an R chamfered portion at a boundary line between the outer peripheral side end surface and the annular connecting surface. 2. The vehicle belt-type non-vehicle type according to claim 1, wherein the sheave shaft and the movable sheave can be relatively moved in the axial direction of the sheave shaft by spline fitting including an involute spline, a ball spline, or a roller spline. Step transmission. The vehicular belt type according to claim 1 or 2, wherein the R chamfered portion is formed in a range on the inner diameter side that is not more than half of a difference between an outer diameter and an inner diameter of the annular end surface of the boss portion. Continuously variable transmission.

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