JP2008208861A - Belt-driven continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constitution in which a belt clamping pressure is fully produced in an operating stopping state of a belt-driven continuously variable transmission without adding other parts. <P>SOLUTION: In the belt-driven continuously variable transmission, a stopper 34A extending toward a cylinder member 75 is integrally formed in a contact part for the cylinder member 75 in an outside cylinder 34f provided in a movable sieve 34b of a primary pulley 34. In the operation stopping state of the continuously variable transmission, the movable sieve 34b is pressed against the cylinder member 75 via the stopper 34A to turn the cylinder member 75 elastically deformed, so that the belt clamping pressure is produced using the repulsion. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a belt-type continuously variable transmission used as, for example, an automobile transmission. In particular, the present invention relates to a measure for ensuring belt tension when the transmission is stopped.

  Conventionally, a belt-type continuously variable transmission (so-called “CVT”) is known as a transmission mounted on the output side of an automobile engine. This belt-type continuously variable transmission includes, for example, two shafts (primary shaft and secondary shaft) arranged in parallel to each other, as disclosed in Patent Document 1 and Patent Document 2 below, and each shaft individually. A primary pulley and a secondary pulley. Both the primary pulley and the secondary pulley have a combination of a fixed sheave and a movable sheave. Specifically, the fixed sheave is integrally provided on the outer periphery of each shaft, while the movable sheave is provided so as to be able to contact and separate from the fixed sheave.

  A V-shaped groove is formed between the fixed sheave and the movable sheave of each pulley. A V belt is wound around the V groove of the primary pulley and the V groove of the secondary pulley. A hydraulic chamber for generating a clamping pressure by both sheaves for the V-belt is provided separately for each pulley.

  In such a belt-type continuously variable transmission, by individually controlling the hydraulic pressure of each hydraulic chamber, the movable sheave of each pulley moves forward and backward toward the fixed sheave, and the groove width of the V groove of each pulley is reduced. Be changed. Thereby, the winding position of the V-belt in the radial direction of each pulley, in other words, the winding radius of the V-belt of each pulley is changed, and the gear ratio in the belt-type continuously variable transmission is changed steplessly. It has become.

  FIG. 4 is a cross-sectional view showing a configuration of a conventional general primary pulley side. In FIG. 4, a state in which the winding radius of the V belt b with respect to the primary pulley a is reduced is shown in the upper half, and a state in which the winding radius is increased is shown in the lower half.

  The primary pulley a includes a fixed sheave d formed integrally with the primary shaft c, and a movable sheave e disposed so as to be movable forward and backward with respect to the fixed sheave d. The movable sheave e includes an inner cylindrical portion e1 that slides along the outer peripheral surface of the primary shaft c, a radial direction portion e2 that is continuously formed from the end of the inner cylindrical portion e1 toward the outer peripheral side, and the radial direction It has a substantially cylindrical outer tube portion e3 which is formed continuously at the outer peripheral end of the portion e2 and extends in the direction opposite to the side where the fixed sheave d is disposed.

  Further, a cylinder member f is disposed on the back side of the movable sheave e. The cylinder member f is directed to the outside so as to be continuous with the inner radial direction portion f1 constituting the inner peripheral portion thereof and the inner radial direction portion f1 and facing the back surface of the radial direction portion e2 of the movable sheave e. The outer radial direction part f2 extended and the cylindrical part f3 which is continuously formed on the outer peripheral side of the outer radial direction part f2 and is located on the outer peripheral side of the outer cylindrical part e3 of the movable sheave e. . A step c1 is formed in the vicinity of the tip of the primary shaft c, and the inner radial direction portion f1 of the cylinder member f is connected to the primary shaft via the step c1 and the inner race of the bearing g. The primary shaft c is fixed by a lock nut h fastened to the outer periphery of c.

The position near the tip of the outer cylindrical portion e3 of the movable sheave e is in contact with the inner surface of the cylindrical portion f3 of the cylinder member f via the seal ring e4, and between the seal ring e4 and the inner surface of the cylindrical portion f3. A sealing surface is formed. As a result, a control hydraulic chamber i constituting the hydraulic actuator of the primary pulley a is formed in a space surrounded by the movable sheave e and the cylinder member f, and the hydraulic pressure of the control hydraulic chamber i is controlled (the amount of supplied oil is controlled). ) To change the forward / backward movement position of the movable sheave e with respect to the fixed sheave d.
Japanese Patent Laid-Open No. 10-205598 JP 2001-65652 A

  In the conventional primary pulley a configured as described above, the oil pressure acting on the control hydraulic chamber i is released by the stop of the oil pump accompanying the stop of the engine. For this reason, the movable sheave e moves to the retreat position farthest from the fixed sheave d, and accordingly, the winding position of the V belt b also moves to the inner peripheral side of the primary pulley a (the upper side in FIG. 4). See half-state). The reason why the movable sheave e moves backward in this way is, for example, due to the action of the urging force of the return spring provided in the secondary pulley. In other words, the winding position of the V belt b in the secondary pulley moves to the outer peripheral side by the urging force of the return spring arranged to apply belt clamping pressure to prevent the slip of the V belt b when the vehicle is towed. Accordingly, the winding position of the V belt b in the primary pulley a moves to the inner peripheral side and the movable sheave e moves backward.

  Conventionally, when the movable sheave e of the primary pulley a moves to the most retracted position, the tip of the inner cylinder part e1 (the left end in the figure) comes into contact with the inner radial direction part f1 of the cylinder member f. The movement of the movable sheave e is regulated by the position. For this reason, it is not the structure which generate | occur | produces the clamping pressure with respect to the V belt b between the fixed sheave d and the movable sheave e which comprise the primary pulley a, Between this primary pulley a and the V belt b It was not configured to reliably prevent the occurrence of slips at the site.

  As a means for reliably preventing this slip, it is conceivable to provide a spring that urges the movable sheave e in the direction toward the V-belt b also in the primary pulley a. In other words, the primary pulley a includes a spring that applies belt clamping pressure even when the hydraulic pressure is released as the engine stops. However, this requires the provision of a new spring, which complicates the manufacturing work and increases the manufacturing cost accompanying an increase in the number of parts, and leads to an increase in the weight of the entire belt type CVT. Absent.

  The present invention has been made in view of such a point, and an object of the present invention is to sufficiently generate belt clamping pressure in the operation stop state of the transmission without adding new parts. The object is to provide a belt type continuously variable transmission.

-Solving principle-
The solution principle of the present invention taken in order to achieve the above object is to press the movable sheave against the cylinder member that forms the control hydraulic chamber with the movable sheave while the transmission is stopped. The cylinder member is elastically deformed, and the reaction force (elastic force) is used to generate belt clamping pressure.

-Solution-
Specifically, according to the present invention, belt means is stretched between a driving pulley and a driven pulley each provided with a fixed sheave and a movable sheave, and the rotational force of the driving pulley is transferred to the driven side via the belt means. In addition to being configured to transmit to the pulley, the movable sheave is moved forward and backward toward the fixed sheave to change the winding position of the belt means in the radial direction of each pulley so that the gear ratio can be changed. A belt type continuously variable transmission is assumed. With respect to this belt type continuously variable transmission, the outer peripheral side end of the movable sheave is brought into contact with the inner surface of a cylinder member disposed on the back side of the movable sheave so that the movable sheave and the cylinder member are not in contact with each other. A control oil pressure chamber is formed, and the hydraulic pressure applied to the control oil pressure chamber is controlled to adjust the forward / backward movement position of the movable sheave with respect to the fixed sheave. On the other hand, when the action of the hydraulic pressure to the control hydraulic chamber is released and the movable sheave moves to the most retracted position from the fixed sheave, the pressing force in the retracting direction of the movable sheave acts on the cylinder member. Thus, a stopper portion for elastically deforming the cylinder member is provided.

  As a more specific application form of this solution, the following can be cited as a configuration when applied to the movable sheave in the driving pulley. First, the premise is the same as that of the above solution. Then, the outer peripheral end of the movable sheave in the drive pulley is brought into contact with the inner surface of the cylinder member disposed on the movable sheave back side, and the control hydraulic chamber is set between the movable sheave and the cylinder member. By controlling the hydraulic pressure that is formed and applied to the control hydraulic chamber, the forward / backward movement position of the movable sheave with respect to the fixed sheave is adjusted. On the other hand, when the movable sheave in the drive pulley is released from the action of the hydraulic pressure to the control hydraulic chamber and the movable sheave moves to the most retracted position from the fixed sheave, the movable sheave moves backward in the movable sheave direction. A stopper is provided for elastically deforming the cylinder member by applying a pressing force.

  By these specific matters, the hydraulic pressure applied to the control hydraulic chamber is controlled (the amount of oil supplied to the control hydraulic chamber is controlled) when the transmission is operated, such as when the vehicle is running on the vehicle. As a result, the forward / backward movement position of the movable sheave with respect to the fixed sheave is adjusted, whereby the winding position of the belt means in the radial direction of each pulley is changed, and the gear ratio can be changed.

  When the transmission is in an operation stop state (for example, an operation stop state associated with the engine stop) and the action of the hydraulic pressure on the control hydraulic chamber is released, the movable sheave is moved backward from the fixed sheave. Become. At this time, the stopper portion provided on the movable sheave contacts the cylinder member, and the cylinder member is elastically deformed in the retracting direction of the movable sheave. Thereby, a restoring force (elastic force) accompanying this elastic deformation is generated in the cylinder member, and this elastic force acts in a direction to advance the movable sheave toward the fixed sheave. That is, since a clamping pressure with respect to the belt means is generated between the movable sheave and the fixed sheave, it is possible to avoid a slip between the pulley and the belt means in this state. That is, even when the transmission is in an operation stopped state, the belt tension can be sufficiently secured to prevent the slip. Moreover, in these solution means, it is possible to exert the above-mentioned action by providing the movable sheave with a stopper portion, so that the number of parts and the manufacturing cost are not increased.

  The following can also be cited as a configuration for more reliably exerting the above action. That is, the movable sheave is provided with an inner cylinder portion that is fitted to the outer periphery of the drive-side shaft so as to be movable back and forth, and the tip of the inner cylinder portion is opposed to the inner peripheral portion of the cylinder member. Then, when the action of the hydraulic pressure on the control hydraulic chamber is released and the movable sheave moves to the most retracted position from the fixed sheave, the inner cylinder portion of the movable sheave moves forward and backward with respect to the inner peripheral portion of the cylinder member. The position is set at a predetermined interval in the direction.

  In the conventional general belt-type continuously variable transmission, when the movable sheave moves to the position farthest from the fixed sheave, the inner cylinder portion of the movable sheave contacts the inner peripheral portion of the cylinder member, and this retraction is performed. The position was defined. On the other hand, in this solution means, in a state where the stopper portion of the movable sheave presses the cylinder member and elastically deforms the cylinder member, the inner cylinder portion of the movable sheave does not contact the inner peripheral portion of the cylinder member. The pressing force acting on the cylinder member from the movable sheave is in a state of acting on the cylinder member only from the stopper portion provided on the movable sheave. Therefore, it is possible to effectively elastically deform the cylinder member, and it is possible to obtain a large restoring force (elastic force) accompanying the elastic deformation and to generate a high clamping pressure on the belt means. Become.

  Moreover, the following is mentioned as a concrete structure for obtaining the contact state of the stopper part with respect to a cylinder member stably. First, the stopper portion is extended at the outer peripheral side end portion of the movable sheave along the forward / backward movement direction of the movable sheave, and the tip surface that contacts the cylinder member is a flat surface extending in a direction orthogonal to the forward / backward movement direction. To do. On the other hand, in the cylinder member, a portion where the tip end surface of the stopper portion abuts is also a flat surface extending in a direction orthogonal to the advancing / retreating direction of the movable sheave.

  With this configuration, when the stopper portion comes into contact with the cylinder member, the two flat surfaces come into surface contact with each other. Accordingly, it is possible to stably obtain the pressing force applied from the stopper portion to the cylinder member. For this reason, it is possible to stably obtain the clamping pressure against the belt means when the transmission is stopped, and to reliably prevent the slip between the pulley and the belt means.

  In the present invention, in the operation stop state of the belt type continuously variable transmission, the movable sheave is pressed against the cylinder member that forms the control hydraulic chamber with the movable sheave, and the elastic force of the cylinder member thereby is used. The belt clamping pressure is generated. For this reason, it is possible to avoid the occurrence of slip between the pulley and the belt means without causing an increase in the number of parts and an increase in manufacturing cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, an example in which the present invention is applied to a belt type continuously variable transmission for an automobile will be described. A belt type continuously variable transmission mounted on an FF (front engine / front drive) vehicle will be described as an example. 1 and 2, the side where the engine is disposed (right side in the figure) is the Fr (front) direction side, and the opposite side (left side in the figure) is the Rr (rear) direction side (actually Left and right direction of the vehicle).

(Overall structure of transaxle)
First, the overall configuration of the transaxle on which the belt type continuously variable transmission 30 is mounted will be described.

  FIG. 1 is a skeleton diagram of a transaxle. As shown in FIG. 1, the rotational power of the crankshaft 1 a of the engine 1 is transmitted to the wheels 3 via a power transmission system 2. The engine 1 and the power transmission system 2 are controlled by an engine control unit (ECU) 4.

  The power transmission system 2 includes a torque converter 10 as a clutch, a forward / reverse switching mechanism 20, a belt-type continuously variable transmission 30, a speed reduction mechanism 40, and a differential device 50. Hereinafter, these configurations will be briefly described.

  The torque converter 10 functions as a torque amplifier when the rotational speed difference between the pump impeller 13a and the turbine runner 13b is large, and functions as a fluid coupling when the rotational speed difference between the two becomes small.

  As the operation of the torque converter 10, the pump impeller 13 a rotates through the drive plate 11 and the front cover 12 as the crankshaft 1 a of the engine 1 rotates, and the turbine is driven by the flow of hydraulic fluid supplied from the oil pump 14. The runner 13b starts to rotate so as to be dragged. When the rotational speed difference between the pump impeller 13a and the turbine runner 13b is large, the stator 13c converts the flow of hydraulic fluid into a direction that assists the rotation of the pump impeller 13a.

  When the vehicle speed reaches a predetermined speed after the vehicle starts, the lockup clutch 15 is operated, and the power transmitted from the engine 1 to the front cover 12 is mechanically and directly transmitted to the input shaft 16. . In addition, fluctuations in torque transmitted from the front cover 12 to the input shaft 16 are absorbed by the damper mechanism 17.

  The forward / reverse switching mechanism 20 includes a double pinion planetary gear mechanism 21, a forward clutch 22, and a reverse brake 23.

  The sun gear 21a of the planetary gear mechanism 21 is connected to the input shaft 16 and the carrier 21b of the planetary gear mechanism 21 is connected to the primary shaft (drive side shaft) 31 of the belt-type continuously variable transmission 30, respectively. By controlling the reverse brake 23, the power transmission path is changed to switch between forward rotation power (forward rotation direction) and reverse rotation power (reverse rotation direction).

  The belt type continuously variable transmission 30 changes the rotation of the primary shaft 31 that is an input shaft (drive shaft) steplessly and transmits it to the secondary shaft 32 that is an output shaft (driven shaft). A V belt (belt means) 33 is wound around a primary pulley (driving pulley) 34 of the primary shaft 31 and a secondary pulley (driven pulley) 35 of the secondary shaft 32. Both the primary pulley 34 and the secondary pulley 35 are configured by combining fixed sheaves 34a and 35a and movable sheaves 34b and 35b. The primary shaft 31 and the secondary shaft 32 are made of metal such as iron, for example. The V-belt 33 has a large number of metal pieces and a plurality of steel rings.

  The primary shaft 31 is supported by a partition wall portion 81 a and an Rr case 82 that are provided integrally with the Fr case 81 via bearings 61 and 62 so as to be substantially coaxial with the input shaft 16 of the torque converter 10. The secondary shaft 32 is supported by a partition wall portion 81 b and an Rr case 82 that are provided integrally with the Fr case 81 via bearings 63 and 64 so as to be parallel to the primary shaft 31.

  The primary pulley 34 includes a fixed sheave 34a integrally formed on the outer periphery of the primary shaft 31, and a movable sheave 34b mounted on the outer periphery of the primary shaft 31 so as to be axially displaceable. The fixed sheave 34a and the movable sheave 34 The V-belt 33 is clamped by 34b. Then, by driving the movable sheave 34b by the hydraulic actuator 36, the V groove width between the sheaves 34a and 34b is changed. Thereby, the winding position of the V belt 33 in the radial direction of the primary pulley 34, in other words, the winding radius of the V belt 33 of the primary pulley 34 is changed.

  The secondary pulley 35 includes a fixed sheave 35a that is integrally formed on the outer periphery of the secondary shaft 32 and a movable sheave 35b that is mounted on the outer periphery of the secondary shaft 32 so as to be axially displaceable. The fixed sheave 35a and the movable sheave The V belt 33 is clamped by 35b. Then, by driving the movable sheave 35b with the hydraulic actuator 37, the V groove width between the sheaves 35a and 35b is changed. Thereby, the winding position of the V belt 33 in the radial direction of the secondary pulley 35, in other words, the winding radius of the V belt 33 of the secondary pulley 35 is changed. A parking gear 38 is provided on the Rr direction side of the secondary pulley 35 of the secondary shaft 32.

  As described above, in the belt type continuously variable transmission 30, the movable sheaves 34b and 35b of the pulleys 34 and 35 are moved forward and backward by the hydraulic actuators 36 and 37 toward the fixed sheaves 34a and 35a. By adjusting the V groove width, the winding position of the V belt 33 in the radial direction of the pulleys 34 and 35 is changed, and the gear ratio by the belt type continuously variable transmission 30 is changed.

  The speed reduction mechanism 40 has two counter driven gears 41 and 42 that mesh with each other and a final drive gear 43. The first counter driven gear 41 is fixed to a shaft 44 connected to the secondary shaft 32 of the belt type continuously variable transmission 30. The second counter driven gear 42 and the final drive gear 43 are respectively fixed to an intermediate shaft 45 disposed substantially parallel to the secondary shaft 32 so as to be separated from each other in the axial direction. The shaft 44 is supported via bearings 65 and 66, and the intermediate shaft 45 is supported via bearings 67 and 68, respectively.

  The differential device (final speed reduction device) 50 distributes and transmits the rotational power transmitted from the speed reduction mechanism 40 to the wheels 3 connected to the pair of left and right axle shafts 51 and 52 at an appropriate ratio. The differential case 53 is disposed.

(Specific configuration around the primary pulley 34)
Next, a specific configuration of the primary pulley 34 and its peripheral part in the belt type continuously variable transmission 30 will be described with reference to FIG.

  FIG. 2 is a cross-sectional view showing a specific configuration of the primary pulley 34 and its peripheral portion of the belt type continuously variable transmission 30. The upper half of FIG. 2 shows a state in which the winding radius of the V belt 33 with respect to the primary pulley 34 is reduced, and the lower half shows a state in which the winding radius of the V belt 33 with respect to the primary pulley 34 is increased. .

  As shown in FIGS. 1 and 2, the primary shaft 31 includes partition walls 81 a and Rr integrally provided on the Fr case 81 via an Fr bearing 61 on the Fr direction side and an Rr bearing 62 on the Rr direction. It is supported by the case 82. Hereinafter, the partition wall portion 81 a and the Rr case 82 of the Fr case 81 that supports the primary shaft 31 are referred to as a transmission case 80. The transmission case 80 is made of a metal such as an aluminum alloy, for example.

  The primary pulley 34 is provided on the primary shaft 31 and is disposed between the Fr bearing 61 and the Rr bearing 62. In other words, the Fr bearing 61 and the Rr bearing 62 are respectively arranged on both sides of the primary pulley 34 on the primary shaft 31. Thereby, the primary shaft 31 and the primary pulley 34 provided thereon can be rotated about the axis A <b> 1 with respect to the transmission case 80.

  The primary shaft 31 has a distal end portion 31a to which the Fr bearing 61 is mounted on the Fr direction side of the fixed sheave 34a, a fixed sheave 34a, an intermediate portion 31b to which the movable sheave 34b is mounted, and more than the movable sheave 34b. A cylinder member 75 (described later) and a rear end portion 31c to which the Rr bearing 62 is attached are provided on the Rr direction side. A step 31d is formed at the boundary between the intermediate portion 31b and the rear end portion 31c. A lock nut 31f is fastened to the Rr direction side of the Rr bearing 62 of the rear end portion 31c. By tightening the lock nut 31f, the movable sheave 34b, the cylinder member 75, and the Rr bearing 62 provided on the primary shaft 31 are assembled together.

  Further, the input shaft 16 of the torque converter 10 is spline-fitted on the inner peripheral side of the primary shaft 31. An oil passage 71 extending in the axial direction is formed inside the primary shaft 31. The oil passage 71 is open at the rear end surface of the primary shaft 31, and hydraulic oil from a hydraulic circuit (not shown) is circulated through the oil passage 71 via the hydraulic actuator 36. Oil passages 73 and 74 that extend in the radial direction of the primary shaft 31 and open to the outer peripheral surface of the primary shaft 31 are communicated with the oil passage 71.

  The fixed sheave 34 a of the primary pulley 34 is integrally formed on the outer periphery of the intermediate portion 31 b of the primary shaft 31.

  On the other hand, the movable sheave 34b is provided so as to move forward and backward toward the fixed sheave 34a. Specifically, the movable sheave 34b is formed continuously at the thick inner tube portion 34c and the end portion of the inner tube portion 34c on the fixed sheave 34a side, and forms a V-groove with the fixed sheave 34a. A radial direction portion 34d and an outer cylindrical portion 34f extending from the position near the outer peripheral end of the radial direction portion 34d toward the Rr direction, that is, toward the outer peripheral portion 75c of the cylinder member 75 are provided. An annular protrusion 34g whose outer peripheral surface abuts on the inner peripheral surface of the outer peripheral portion 75c of the cylinder member 75 is formed in the vicinity of the end portion on the Rr direction side of the outer cylindrical portion 34f. A resin seal ring 34h is attached to the outer periphery of the annular protrusion 34g. The inner cylinder portion 34c is formed with a through hole 34j that penetrates the inside and outside in the radial direction. The through hole 34j is open to an inner wall surface forming a hydraulic chamber 70 described later.

  The cylinder member 75 is an annular member that is mounted between the movable sheave 34 b and the Rr bearing 62. The cylinder member 75 is fitted into the rear end portion 31c of the primary shaft 31 and extends radially outward, and a cylindrical outer peripheral portion 75c that comes into contact with the annular protrusion 34g of the movable sheave 34b. The curved portion 75b extends from the outer peripheral end of the radial portion 75a while being curved toward the outer peripheral side, and connects the radial portion 75a and the outer peripheral portion 75c. A space surrounded by the movable sheave 34 b and the cylinder member 75 is formed as a hydraulic chamber 70 for generating a clamping pressure by the sheaves 34 a and 34 b on the V belt 33.

  A groove 34e extending in the axial direction is formed on the inner peripheral surface of the inner cylindrical portion 34c of the movable sheave 34b. On the other hand, a groove 31e extending in the axial direction is formed on the outer peripheral surface of the intermediate portion 31b of the primary shaft 31. A plurality of the grooves 34e and 31e are formed at predetermined intervals in the circumferential direction. The movable sheave 34b and the primary shaft 31 are positioned so that the groove 34e on the movable sheave 34b side and the groove 31e on the primary shaft 31 side have the same phase in the circumferential direction, and straddle both the grooves 34e and 31e. A plurality of balls (not shown) are arranged. As a result, the movable sheave 34b can move smoothly relative to the primary shaft 31, in other words, relative to the fixed sheave 34a on the primary shaft 31 in the axial direction, but relative to the circumferential direction. It is impossible to move.

  The hydraulic pressure from the hydraulic actuator 36 is supplied to the hydraulic chamber 70 via the oil passage 71. Here, the hydraulic pressure from the hydraulic actuator 36 is supplied through the oil passage 73 and the through hole 34j in the case of the upper half in FIG. 2 and the oil passage 74 in the case of the lower half in FIG. It is like that. The hydraulic pressure in the hydraulic chamber 70 acts toward the fixed sheave 34a side (in this case, the Fr direction side) with respect to the movable sheave 34b. When the hydraulic pressure in the hydraulic chamber 70 acts on the movable sheave 34 b, the movable sheave 34 b receives a pressing force toward the fixed sheave 34 a, whereby the clamping pressure by both sheaves 34 a and 34 b is applied to the V belt 33. Is granted.

  Further, when the axial position of the movable sheave 34b on the primary shaft 31 is determined according to the oil pressure in the hydraulic chamber 70 and the oil pressure in the hydraulic chamber 70 changes, the movable sheave 34b is fixed on the primary shaft 31 by a fixed sheave. It moves forward and backward toward 34a. Accordingly, the V-groove width between the sheaves 34a and 34b is changed. Specifically, when the hydraulic pressure in the hydraulic chamber 70 increases, the movable sheave 34b moves on the primary shaft 31 to the Fr direction side. As a result, the movable sheave 34b advances (approaches) toward the fixed sheave 34a, and as shown in the lower half of FIG. 2, the width of the V-groove is reduced and the winding radius of the V-belt 33 is increased. Conversely, when the oil pressure in the hydraulic chamber 70 decreases, the movable sheave 34b moves on the primary shaft 31 toward the Rr direction. Thereby, the movable sheave 34b is retracted (separated) from the fixed sheave 34a, and as shown in the upper half of FIG. 2, the width of the V-groove is increased and the winding radius of the V-belt 33 is decreased.

  A radial portion 75a of the cylinder member 75 is interposed between the Rr bearing 62 and the step 31d of the primary shaft 31. Since the lock nut 31f is fastened to the rear end portion 31c of the primary shaft 31, the Rr bearing 62 and the cylinder member 75 are assembled on the rear end portion 31c of the primary shaft 31 in a positioned state.

(Specific configuration of movable sheave 34b)
A feature of this embodiment is the configuration of the movable sheave 34b of the primary pulley 34. This will be specifically described below.

  As described above, the outer cylindrical portion 34f of the movable sheave 34b of the primary pulley 34 is integrally formed with the annular protrusion 34g that contacts the inner peripheral surface of the outer peripheral portion 75c of the cylinder member 75. A stopper portion 34A that protrudes toward the curved portion 75b of the cylinder member 75 is integrally formed on the distal end surface (end surface on the Rr direction side) of the annular projecting portion 34g. The stopper portion 34A has a substantially rectangular cross section, and has a ring shape (annular shape) extending along the outer cylindrical portion 34f of the movable sheave 34b. Further, the tip surface 34B of the stopper portion 34A, that is, the surface facing the curved portion 75b of the cylinder member 75 is a flat surface (a flat surface extending vertically) extending in a direction orthogonal to the advancing / retreating movement direction of the movable sheave 34b. ) 34B.

  Further, the protruding dimension of the stopper portion 34A is set as follows. That is, when the operation of the belt-type continuously variable transmission 30 stops due to the stop of the oil pump 14 accompanying the stop of the engine 1, the action of the hydraulic pressure on the hydraulic chamber 70 is released, and the movable sheave 34b is fixed. It moves to the most retracted position from the sheave 34a. That is, the state shown in the lower half in FIG. 2 is changed to the state shown in the upper half. In this case, the stopper portion 34A is arranged so that the stopper portion 34A contacts the curved portion 75b of the cylinder member 75 without the inner cylinder portion 34c of the movable sheave 34b contacting the radial direction portion 75a of the cylinder member 75. Projection dimensions are set. That is, conventionally, as shown in FIG. 4, when the movable sheave e of the primary pulley a moves to the most retracted position, the tip (left end in the figure) of the inner cylinder part e1 is located inside the cylinder member f. Abutting on the radial portion f1, the movement of the movable sheave e is restricted at this position. On the other hand, in the present embodiment, when the movable sheave 34b moves to the most retracted position, the stopper portion 34A of the movable sheave 34b abuts on the curved portion 75b of the cylinder member 75, and a pressing force is applied to the curved portion 75b. The movement of the movable sheave 34b is restricted in the state where the pressure is applied.

  Further, the portion of the curved portion 75b of the cylinder member 75 where the tip end surface 34B of the stopper portion 34A abuts is also formed of a similar flat surface 75d. For this reason, when the stopper portion 34A of the movable sheave 34b comes into contact with the curved portion 75b of the cylinder member 75, the two flat surfaces 34B and 75d come into surface contact with each other.

  3A is an enlarged view of the periphery of the stopper portion 34A when the stopper portion 34A of the movable sheave 34b is not in contact with the curved portion 75b of the cylinder member 75, and FIG. 3B is a view showing the movable sheave 34b. FIG. 6 is an enlarged view of the periphery of the stopper portion 34A when the stopper portion 34A is in contact with the curved portion 75b of the cylinder member 75 (applying a pressing force). 3B indicates the shape of the cylinder member 75 in a state before the stopper portion 34A comes into contact with the curved portion 75b of the cylinder member 75.

  As can be seen from FIG. 3, when the movable sheave 34b moves to the most retracted position, the stopper portion 34A abuts against the curved portion 75b of the cylinder member 75 to give a pressing force. It will be elastically deformed. Then, a restoring force (elastic force) accompanying the elastic deformation is generated in the cylinder member 75, and this elastic force acts in a direction to advance the movable sheave 34b toward the fixed sheave 34a (FIG. 3). (See arrow F in (b)). For this reason, the clamping pressure with respect to the V belt 33 arises between the movable sheave 34b and the fixed sheave 34a. For this reason, in this state (the state where the operation of the belt type continuously variable transmission 30 is stopped), the occurrence of slip between the fixed sheave 34a and the movable sheave 34b of the primary pulley 34 and the V belt 33 is avoided. The That is, even when the belt type continuously variable transmission 30 is in an operation stop state, the belt tension can be sufficiently secured to prevent the slip.

  The principle that the stopper portion 34A abuts against the curved portion 75b of the cylinder member 75 to apply a pressing force is based on the action of a biasing force of a return spring (not shown) provided in the secondary pulley 35. This return spring has been conventionally provided, and is arranged so as to apply belt clamping pressure to prevent slippage of the V-belt 33 when the vehicle is towed. When the belt-type continuously variable transmission 30 is in the non-operating state, the urging force of the return spring moves the winding position of the V belt 33 on the secondary pulley 35 to the outer peripheral side, and accordingly, the V belt 33 on the primary pulley 34. The movable sheave 34b is moved backward by moving the winding position of the movable sheave 34b, and the stopper 34A comes into contact with the curved portion 75b of the cylinder member 75 by the urging force of the return spring acting via the V belt 33. This gives a pressing force.

  As described above, in the present embodiment, the slip can be prevented only by integrally forming the stopper portion 34A on the movable sheave 34b of the primary pulley 34. For this reason, a special urging means such as a spring is not required, and the operation stop state of the belt-type continuously variable transmission 30 can be stably obtained without increasing the number of parts and increasing the manufacturing cost. be able to.

  Further, as described above, the distal end surface 34B of the stopper portion 34A is a flat surface extending in a direction orthogonal to the advancing / retreating movement direction of the movable sheave 34b, and the distal end surface of the stopper portion 34A in the curved portion 75b of the cylinder member 75. Since the portion where 34B abuts is formed by the same flat surface 75d, both the flat surfaces 34B and 75d come into surface contact with each other when the operation of the belt type continuously variable transmission 30 is stopped. Accordingly, it is possible to stably obtain the pressing force applied to the cylinder member 75 from the stopper portion 34A. For this reason, the clamping pressure with respect to the V belt 33 in the operation stop state of the belt-type continuously variable transmission 30 can also be stably obtained, and the occurrence of slip between the primary pulley 34 and the V belt 33 can be reliably avoided. .

-Other embodiments-
In the embodiment described above, the case where the present invention is applied to the belt type continuously variable transmission 30 for automobiles has been described. The present invention is not limited to this, and can also be applied to a belt-type continuously variable transmission used for purposes other than automobiles. Further, the present invention is not limited to automobiles using a gasoline engine as a drive source, but can be applied to automobiles and hybrid cars using a diesel engine as a drive source.

  In the above-described embodiment, the tip surface 34B of the stopper portion 34A and the partial surface 75d of the curved portion 75b of the cylinder member 75 are flat surfaces and are in surface contact with each other. The present invention is not limited to this. The curved portion 75b of the cylinder member 75 is a curved surface similar to the conventional one, and the shape of the distal end surface 34B of the stopper portion 34A is a curved surface along the shape of the curved portion 75b. May be.

  Alternatively, the distal end portion of the annular protrusion 34g may be brought into contact with the curved portion 75b of the cylinder member 75 by setting the length dimension of the outer cylindrical portion 34f of the movable sheave 34b to be long. In other words, the annular protrusion 34g may function as a stopper.

It is a skeleton figure which shows the whole structure of the transaxle to which the belt type continuously variable transmission which concerns on embodiment is applied. It is sectional drawing which shows the structure of the primary shaft and its peripheral part of a belt-type continuously variable transmission. FIG. 3A is an enlarged view of the periphery of the stopper portion, FIG. 3A shows a state where the stopper portion is not in contact with the curved portion of the cylinder member, and FIG. 3B shows that the stopper portion is in contact with the curved portion of the cylinder member. FIG. It is sectional drawing which shows the structure of the primary shaft in the conventional belt-type continuously variable transmission, and its peripheral part.

Explanation of symbols

30 Belt type continuously variable transmission 31 Primary shaft (drive side shaft)
33 V belt (belt means)
34 Primary pulley (drive pulley)
34a, 35a Fixed sheave 34c Inner cylinder part 34A Stopper part 34B End face 35 Secondary pulley (driven pulley)
34b, 35b Movable sheave 70 Hydraulic chamber 75 Cylinder member 75a Radial portion (inner peripheral part of cylinder member)
75d flat surface

Claims (4)

Belt means is stretched between a driving pulley and a driven pulley, each having a fixed sheave and a movable sheave, so that the rotational force of the driving pulley can be transmitted to the driven pulley via the belt means. And a belt-type continuously variable transmission in which the gear ratio can be changed by changing the winding position of the belt means in the radial direction of each pulley by moving the movable sheave toward and away from the fixed sheave. ,
An outer peripheral side end of the movable sheave is brought into contact with an inner surface of a cylinder member disposed on the back side of the movable sheave, and a control hydraulic chamber is formed between the movable sheave and the cylinder member. While the hydraulic pressure applied to the chamber is controlled, the movable sheave is adjusted to move forward and backward relative to the fixed sheave.
When the hydraulic sheave is released from the control hydraulic chamber and the movable sheave moves to the most retracted position from the fixed sheave, the movable sheave acts on the cylinder member in the movable sheave retracting direction. A belt type continuously variable transmission is provided, which is provided with a stopper portion that elastically deforms the cylinder member. Belt means is stretched between a driving pulley and a driven pulley, each having a fixed sheave and a movable sheave, so that the rotational force of the driving pulley can be transmitted to the driven pulley via the belt means. And a belt-type continuously variable transmission in which the gear ratio can be changed by changing the winding position of the belt means in the radial direction of each pulley by moving the movable sheave toward and away from the fixed sheave. ,
An outer peripheral side end portion of the movable sheave in the drive pulley is brought into contact with an inner surface of a cylinder member disposed on the movable sheave rear side, and a control hydraulic pressure chamber is formed between the movable sheave and the cylinder member. On the other hand, by controlling the hydraulic pressure applied to the control hydraulic chamber, the forward / backward movement position of the movable sheave with respect to the fixed sheave is adjusted,
The movable sheave in the drive pulley has a movable sheave retracting direction relative to the cylinder member when the hydraulic sheave is released from the fixed sheave and the movable sheave moves to the most retracted position. A belt type continuously variable transmission, characterized in that a stopper portion is provided for elastically deforming the cylinder member by applying a pressing force. In the belt type continuously variable transmission according to claim 1 or 2,
The movable sheave includes an inner cylinder portion that is fitted to the outer periphery of the drive-side shaft so as to be movable forward and backward, and the tip of the inner cylinder portion faces the inner peripheral portion of the cylinder member,
When the action of the hydraulic pressure on the control hydraulic chamber is released and the movable sheave moves to the position farthest away from the fixed sheave, the inner cylindrical portion of the movable sheave moves in the above-described forward / backward movement direction with respect to the inner peripheral portion of the cylinder member. A belt type continuously variable transmission configured to be set at a position having a predetermined interval. In the belt type continuously variable transmission according to claim 1, 2, or 3,
The stopper portion extends along the forward / backward movement direction of the movable sheave at the outer peripheral side end portion of the movable sheave, and the tip surface that contacts the cylinder member is a flat surface extending in a direction orthogonal to the forward / backward movement direction. While
The belt-type continuously variable transmission according to claim 1, wherein the cylinder member has a flat surface extending in a direction orthogonal to the advancing / retreating movement direction of the movable sheave.

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