JP2583733B2 - Continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission.
In particular, it relates to a combination of a speed change pulley mechanism and a differential gear mechanism.

[0002]

2. Description of the Related Art As an example of a speed change pulley mechanism which is a belt-type continuously variable transmission, a pair of rotating shafts arranged in parallel with each other are integrally rotatable with respect to the respective rotating shafts and cannot slide. Speed-change pulley, comprising: a fixed sheave fixed to the movable sheave; and a movable sheave rotatably integrated and slidably supported to face the rotating shaft so as to form a V-shaped belt groove between the fixed sheave and the fixed sheave. And a V-belt wound between the belt grooves of the two speed-change pulleys. The effective radius of the V-belt can be varied by moving the movable sheave in the axial direction. Is known in which the gear ratio of the motor is changed. Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 62-118159, a continuously variable gear provided with the above-described speed change pulley mechanism and a planetary gear mechanism (differential gear mechanism) as a gear mechanism for shifting. Transmissions have been proposed.

As described above, in the continuously variable transmission provided with the speed change pulley mechanism and the differential gear mechanism, when the output shaft is rotated from the stopped state by using the differential gear mechanism, the power transmission path is driven. It is divided into two, power and circulation power. That is, in the closed circuit differential gear device, one of the three gear elements of the differential gear mechanism is connected to the output shaft, and the rotational speed of the remaining one gear element of the differential gear mechanism is adjusted by adjusting the speed ratio of the pulley mechanism. By changing the rotational direction, the rotational direction and rotational speed between the gear element and the other gear elements are made different, and the rotational direction and rotational speed of the output gear element, that is, the output shaft, are determined. However, at that time, driving power and circulation power are generated as power, and the output power is obtained by subtracting the circulation power from the driving power. Which of the two power transmission paths from the input shaft to the output shaft becomes the driving power path or the circulating power path depends on the rotation speed of the gear element in the differential gear mechanism. A power path is provided, and both power paths are switched with each other in accordance with the forward / reverse rotation of the output shaft.

[0004]

By the way, in a continuously variable transmission provided with a transmission pulley mechanism and a differential gear mechanism,
When the driving power path and the circulating power path are switched as described above, the transmission direction of the power is reversed in the transmission pulley mechanism, and the relationship between the driving and the driven while the transmission pulleys are rotating in a certain direction. Is reversed. That is, when the transmission pulley mechanism is in the drive power path, the transmission pulley on the input shaft side is the driving pulley, and the transmission pulley on the output shaft side is the driven pulley. On the other hand, in the case of the circulation power path, the transmission pulley on the output shaft side is a drive pulley, and the pulley on the input shaft side is a driven pulley. Therefore, the tension side span and the loose side span between the two speed change pulleys are switched with each other in accordance with the switching of the power path, so that when the predetermined tension is applied to the belt, the span on the loose side becomes Must be able to be pressed alternatively.

Therefore, it is easily considered that a tension pulley movable between a position for pressing one of the spans and a position for pressing the other of the spans is provided, and the position of the tension pulley is adjusted to the correct position of the output shaft. The automatic switching is performed according to the reverse rotation.

However, in such a case, a mechanism for switching the position of the tension pulley is required, and it is also difficult to use the urging means because the directions of pressing the respective spans of the tension pulley are opposite. It is inevitable that the structure is complicated and the size is increased accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tension-side span and a slack between two transmission pulleys of a continuously variable transmission that combines a transmission pulley mechanism and a differential gear mechanism. An object of the present invention is to make it possible to automatically press the loose side span in response to the change of the side span, thereby making the continuously variable transmission compact.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, each span is pressed.
The two tension pulleys are connected by urging means and urged in directions away from each other, and one tension pulley is pushed back to the span changed from the loose side to the tight side,
The other tension pulley is moved to a position for pressing the span changed from the tension side to the loose side.

More specifically, according to the present invention, a belt is wound between first and second rotating shafts arranged in parallel with each other and both speed change pulleys arranged on these rotating shafts, so that both rotating shafts are rotated. A speed change pulley mechanism that is drivingly connected to change the speed; and first to third gear elements connected to each other. A first gear element is connected to the first rotation shaft, and a second gear element is connected to the second gear element. A differential gear mechanism connected to a rotary shaft, wherein one of the first rotary shaft or the third gear element is an input unit and the other is an output unit, and a change in a pulley ratio of the speed change pulley mechanism is provided. It is assumed that the continuously variable transmission is configured such that the output unit is switched to a normal rotation state, a neutral state, or a reverse rotation state with respect to the input unit to shift the speed in response to the input.

The first and second tension arms are provided so as to be capable of swinging about an axis parallel to the axis of the first and second rotation shafts, and the first and second tension arms are provided on the inner surface side of the belt. A first tension arm supported by each of the first and second tension arms so as to be rotatable about an axis parallel to the axis of the first and second rotation shafts;
And a second tension pulley, interposed between the first tension arm and the second tension arm, and urges the first tension pulley and the second tension pulley in a direction away from each other to thereby make one of the belts A first tension pulley is provided on the inner surface of the span, and a second tension pulley is provided on the inner surface of the other span.
A spring for pressing the tension pulleys is provided.

According to a second aspect of the present invention, in the first aspect of the invention, the second tension arm has a mounting arm portion provided integrally with the swing. Then, above
A spring is interposed between the mounting arm portion of the second tension arm and the first tension arm, and the spring is biased to swing the mounting arm portion and the first tension arm in a direction in which the angular interval between them becomes smaller. The first tension pulley and the second tension pulley are constituted by tension springs that urge the first and second tension pulleys away from each other.

According to a third aspect of the present invention, in the second aspect of the present invention, the first and second tension arms are provided so as to be swingable about one of the first and second rotation shafts, and the mounting arm portion is provided. Is provided so as to extend in a direction substantially perpendicular to the second tension arm main body.
And it arrange | positions along the substantially axis direction of a 2nd rotation shaft.

[0013]

According to the first aspect of the present invention, when the output portion is in a neutral state with respect to the input portion in accordance with a change in the pulley ratio of the speed change pulley mechanism, the first tension pulley and the first tension pulley of the first tension arm are provided. The inner surface of each span of the belt wound around the speed change pulley is pressed by the second tension pulley of the two tension arms with the same pressing force. The pulley ratio changes so as to switch from the neutral state to, for example, the normal rotation state, and the span pressed by the first tension pulley moves to the tension side, and the span pressed by the second tension pulley moves to the loose side. As each changes, the first tension pulley is pushed back by the tension span against the biasing force of the spring . Accordingly, the pressing force of the second tension pulley against the loose side span is increased by the spring, whereby the loose side span is pressed with a predetermined pressing force by the second tension pulley. On the contrary, the pulley ratio changes so as to switch from the neutral state to the reverse state, and the span pressed by the second tension pulley is on the tension side, and the span pressed by the first tension pulley is on the tension side. When each of the tensions has changed to the loose side, the second tension pulley is pushed back, so that the first tension pulley presses the loose side span with a predetermined pressing force.
Therefore, the operation of pressing the loose side span with a predetermined pressing force can be automatically switched in accordance with the interchange of the tension side span and the loose side span of the belt wound between the two shift pulleys.

According to a second aspect of the present invention, the first and second tension pulleys urge the tension spring to swing the first tension arm and the mounting arm portion of the second tension arm in a direction in which the angular interval between them becomes smaller. By doing so, they are urged in directions away from each other. Therefore, if you like each other angular distance of the first and second tension arm and disposed compression spring in the line parallel to the direction connecting the first and second tension pulley swings biased in a direction increases Compared to
Since the free length of the spring can be set without being restricted by the distance between the first and second tension pulleys, the free length cannot be sufficiently obtained and the spring constant becomes too high, so that the pressing force against the belt changes. This makes it possible to avoid the problem of buckling, and also to avoid the problem of buckling inherent to the compression spring.

According to the third aspect of the present invention, the first and second tension arms are swingably provided around one of the first and second rotation shafts, and the tension springs are provided with the first and second rotation shafts. Are disposed along the substantially interaxial direction of
In addition, the second tension arm and the tension spring can be accommodated substantially in the frame of the belt running track, and the natural length of the tension spring can be made sufficiently long in the frame.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 show the overall configuration of a continuously variable transmission A according to an embodiment of the present invention. This transmission A is used in a vehicle such as a lawn mower or an agricultural machine to connect an engine E and drive wheels. And a power transmission path between them.

In FIGS. 1 and 2, reference numeral 1 denotes a casing of a continuously variable transmission A.
From the left side to the right side, the casing is divided into first to third divided casings 1a to 1c, which are first to third casing parts. In the casing 1, a first rotating shaft 2 and a second rotating shaft 12, which are arranged in parallel in a substantially horizontal plane, are rotatably supported.

The first rotating shaft 2 constitutes an input portion (input shaft), and is divided into a gear shaft portion 3 and a pulley shaft portion 4. One end (the left end in FIG. 2) of the gear shaft 3 projects outside the casing 1, while the other end is located between the first and second split casings 1a and 1b. A gear 5 having a boss 5a penetrating through the second split casing 1b is concentrically and rotationally welded to the other end of the second split casing 1b. The intermediate portion of the gear shaft portion 3 is supported by the first divided casing 1a, and the hollow boss portion 5a of the gear 5 is supported by the second divided casing 1b via bearings 6 and 7, respectively. On the other hand, the pulley shaft 4 is disposed between the second and third split casings 1b and 1c, and one end (the left end in FIG. 2) of the pulley shaft 4 has a small diameter. 3 is fitted into the boss 5a of the gear 5 integral with the gear 3 so as to be rotatable integrally and withdrawable. The other half of the pulley shaft portion 4 has a small-diameter portion. A sleeve 8 is externally fitted to the small-diameter portion on the side of the gear shaft portion 3, and a bush 9 is externally fitted on the opposite side of the gear shaft portion 3. The end of the sleeve 8 is fitted into a large-diameter portion 9 a formed on the bush 9. The pulley shaft 4 is supported by the bush 9 in the third divided casing 1c via a bearing 10.

The second rotating shaft 12 is similarly divided into a gear shaft 13 and a pulley shaft 14. As shown in FIG. 4, the gear shaft portion 13 penetrates through the second split casing 1b,
One end (the left end in FIG. 2) is attached to the first divided casing 1a.
The intermediate portion is supported by the second split casing 1b via bearings 15 and 16, respectively. On the other hand, the pulley shaft 14 is a cylindrical member disposed between the second and third split casings 1b and 1c, and has one end (the left end in FIG. 2).
The other end of the gear shaft portion 13 is spline-coupled so as to be rotatable and extractable, and the other end is supported by a third split casing 1c via a bearing 17. With this structure, the casing 1 is divided into first and second divided casings 1a and 1b and a third divided casing 1c, and each of the rotating shafts 2 and 12 is provided with a gear shaft portion 3 and a pulley shaft portion 4 respectively. 14 and the continuously variable transmission A
Are unitized into a planetary gear mechanism 19 and a speed change pulley mechanism 27, which will be described later, so that they can be divided into two.

As shown in FIGS. 13 and 14, a driven pulley 91 composed of a V-pulley is attached to the end of the first rotary shaft 2 protruding from the casing 1 so as to rotate integrally therewith. There is a V between the drive pulley 92 composed of a V pulley attached to the output shaft E1.
A belt 93 is wound around, and the power of the engine E is transmitted to the first rotating shaft 2 of the transmission A via the V-belt 93.

A tension pulley 94 for pushing the loose side span of the V-belt 93 from the rear side is disposed between the pulleys 91 and 92. The tension pulley 94 is rotatable about the tip shaft of a tension arm 95. The tension arm 95 is supported by the tension pulley 94 and the belt 9.
3 is urged to rotate by a spring or the like (not shown) in the direction in which the button 3 is pushed. Further, an actuator 96 such as an air cylinder that rotates the tension arm 95 in a direction opposite to the belt pressing direction against a biasing force of a spring or the like is provided. The tension pulley 94, the tension arm 95, the actuator 96, and the like are provided. A tension clutch 97 is provided to cut off the power transmission between the pulleys 91 and 92, that is, between the engine E and the transmission A, by eliminating the thrust on the V-belt 93.

Further, a limit switch 98 for detecting that the continuously variable transmission A is in a neutral state by switching an operation lever 66 to a neutral position described later.
The actuator 96 such as the air cylinder is operated in response to a neutral detection signal from the limit switch 98. When the continuously variable transmission A is in neutral, the transmission E and the engine E are shifted by the tension clutch 97. Shut off the power transmission to and from device A,
The transmission A is driven and connected only to the wheel side.

In the casing 1, a planetary gear mechanism 19 as a differential gear mechanism disposed on the left end of the second rotating shaft 12, and the two rotating shafts 2 and 12 are driven by a V-belt 38 so as to be able to change speed. The speed change pulley mechanism 27 to be connected is housed.

As shown in detail in FIG. 5, the planetary gear mechanism 19 includes a second rotating shaft 12 formed on a gear shaft portion 13 formed between the first and second split casings 1a and 1b. A sun gear 20 as a gear element, a plurality of pinions 21, 21,... Meshing with the sun gear 20, and bearings 24, 24 near the first split casing 1a of the gear shaft portion 13 of the second rotating shaft 12 are provided. An output gear 22 (pinion carrier) as a third gear element rotatably supported and rotatably supporting the pinions 21, 21,..., And bearings 25, 25 arranged at the outermost periphery and mounted on the gear shaft portion 13. , And a ring gear 23 as a first gear element that meshes with the pinions 21, 21,. Ring gear 2
An outer periphery 3 is meshed and connected to a gear 5 on the first rotating shaft 2. The output gear 22 forms an output portion of the transmission A, and is drivingly connected to driving wheels (not shown).

The speed change pulley mechanism 27 includes a first rotating shaft 2
Has a first speed change pulley 28 disposed on the pulley shaft 4 between the second and third split casings 1b and 1c. As shown in an enlarged detail in FIG. 3, the first speed change pulley 28 is keyed integrally with the sleeve 8 on the pulley shaft portion 4 of the first rotating shaft 2 so as to rotate integrally and non-slidably with the boss portion 29a. A flange-shaped fixed sheave 29 and a flange-shaped movable sheave supported on the sleeve 8 (first rotating shaft 2) by a boss portion 30a so as to be slidable and relatively rotatable so as to face the fixed sheave 29. A pulley groove 31 is formed between the sheaves 29 and 30. The boss portion 30a of the movable sheave 30 is formed integrally with the sheave body 30b by forging.

On the other hand, a second transmission pulley 33 having the same diameter as the first transmission pulley 28 is provided on the pulley shaft 14 of the second rotary shaft 12. The second speed change pulley 33 has the same configuration as the first speed change pulley 28 as shown in detail in FIG. 4, and the boss 3 is attached to the pulley shaft 14 of the second rotary shaft 12.
A flange-shaped fixed sheave 34, which is keyed integrally and non-slidably at 4a, and a pulley shaft 14, in which the movable sheave 30 faces a fixed sheave 29 of the first speed-change pulley 28 with respect to the fixed sheave 34. Flange-shaped movable sheave 35 slidably and relatively rotatably coupled at a boss 35a so as to face in a direction opposite to the direction.
A pulley groove 36 is formed between the sheaves 34 and 35.

Between the pulley groove 31 of the first speed change pulley 28 and the pulley groove 36 of the second speed change pulley 33, a V belt 38 composed of a block belt is wound. Each movable sheave 30, 3
5 is moved toward and away from the fixed sheaves 29, 34, respectively, to change the belt winding diameter of each pulley 28, 33. For example, when the movable sheave 30 of the first transmission pulley 28 approaches the fixed sheave 29 and the movable sheave 35 of the second transmission pulley 33 is separated from the fixed sheave 34, the belt winding diameter of the first transmission pulley 28 is reduced. By making the rotation larger than the second speed change pulley 33, the rotation of the first
The speed is transmitted to the rotating shaft 12. On the other hand, when the movable sheave 30 of the first transmission pulley 28 is separated from the fixed sheave 29 and the movable sheave 35 of the second transmission pulley 33 approaches the fixed sheave 34, the first transmission pulley 28
By reducing the belt winding diameter of the second transmission pulley 33 and increasing the belt winding diameter of the second speed change pulley 33, the rotation of the first rotary shaft 2 is reduced and transmitted to the second rotary shaft 12.

As shown in FIG. 3, the V-belt 38 has a pair of endless tensions formed by embedding a plurality of core wires in the upper and lower central portions of a shape-retaining layer made of fiber-reinforced rubber or fiber-reinforced plastic. Belts 39, 39 and fitting portions 40a, 40a for fitting the tension bands, respectively.
, And a plurality of substantially trapezoidal blocks 40, 40,... Which can be brought into contact with the side surfaces of the pulley grooves 31, 36. The blocks 40, 40,... Are fixed to the tension bands 39, 39 in the longitudinal direction of the belt by engaging concave-convex portions (not shown) formed on the upper and lower surfaces of the block 40a so as to correspond to each other. For high-load transmission,
It can withstand high lateral pressure.

The movable sheave 30 of the first transmission pulley 28
A torque cam mechanism 42 is disposed between the boss 30a of the first rotary shaft 2 and the pulley shaft 4 of the first rotary shaft 2. As shown in FIGS. 6 to 8, the torque cam mechanism 42 includes a torque pin 43 formed of a linear pin fixed to the first rotating shaft 2 so as to protrude from the outer peripheral surface in the diametrical direction so that the tip end protrudes from the outer peripheral surface.
A torque ring 44 rotatably fitted to the projecting end of the torque pin 43; and a boss 3 of the movable sheave 30.
0a, and torque cam holes 45, 45 respectively engaged with the torque ring 44 at the tip of the torque pin 43.
Consists of Each of the torque cam holes 45 is shown in FIGS.
As shown in the figure, one side wall has a predetermined lead angle θ1 with respect to a direction parallel to the axis of the rotating shaft 2.
(For example, θ1 = 26 °), the forward cam surface 45 inclined by
a is formed on the other side wall of the reverse side cam surface 45b similarly inclined by a lead angle θ2 (eg, θ2 = 8 ° <θ1) smaller than the forward side cam surface 45a. The torque cam mechanism 42 is operated at the time of each power transmission in the forward state and the reverse state of the A (vehicle), so that the thrust on the belt 38 is applied in the reverse direction between the forward state and the reverse state. Fixed sheaves 29, 34 so as to obtain
Side.

On the pulley shaft portion 4 of the first rotary shaft 2, on the back side of the movable sheave 30 of the first transmission pulley 28, there is provided a drive mechanism for moving the movable sheave 30 toward and away from the fixed sheave 29. A first cam mechanism 47 is provided. As shown in FIG. 5, the cam mechanism 47 has a rotating cam 48, which is externally fitted on the boss 30a of the movable sheave 30 so as to cover the torque cam holes 45. An outer fitting is supported on the cylindrical collar 51 via a bearing 49 so as to be relatively rotatable and move integrally in the axial direction. A pair of inclined cam surfaces 48a, 48a are formed at equal angular intervals (180 ° intervals) in the circumferential direction on an end surface of the rotary cam 48 opposite to the first speed-change pulley 28, and a rotary lever is provided on the outer periphery. 50 is provided so as to rotate integrally therewith.

A cylindrical fixed cam 51 as a cam follower integrally formed concentrically with the first rotary shaft 2 on the second split casing 1b is disposed on the rear side of the rotary cam 48. Rollers 52, 52 that roll on the cam surface 48 a of the rotating cam 48 are rotatably supported on the 51.

On the other hand, the movable sheave 3 of the second speed change pulley 33 is
A second cam mechanism 5 as a drive mechanism for moving the movable sheave 35 toward and away from the fixed sheave 34
4 are provided. The second cam mechanism 54 is connected to the first cam mechanism 54.
With the same configuration as the cam mechanism 47, a rotary cam 56 is provided on the boss portion 35a of the movable sheave 35 via a bearing 55 so as to be rotatable relative to each other and externally fitted and supported so as to move integrally in the axial direction. A pair of inclined cam surfaces 56a, 56a are formed on the end surface of the cam 56 opposite to the second speed-change pulley 33 at equal angular intervals in the circumferential direction, and a rotation lever 57 is integrally formed on the outer periphery. It is protruding.

On the back side of the rotating cam 56, a fixed cam 58 as a cam follower formed by expanding the third divided casing 1c outwardly and concentrically with the second rotating shaft 12 is disposed. Rollers 59 are rotatably supported by the cam 58 so as to be in contact with the respective cam surfaces 56a of the rotary cam 56.

As shown in FIGS. 1 and 9, one end of a link 62 is connected to the tip of the rotary lever 50 of the first cam mechanism 47 via a pin 61, and the other end of the link 62 is The tip of the turning lever 57 of the two-cam mechanism 54 is connected via a pin 63 to the turning lever 50, 5.
7, the link mechanism 64 by the link 62 and the pins 61 and 63
Is configured. By the interlocking mechanism 64, the cams 48 and 56 of the cam mechanisms 47 and 54 are linked with each other and are rotated around the bosses 30a and 35a of the movable sheaves 30 and 35, and the rollers 52 on the respective cam surfaces 48a and 56a. ,
By rolling the 59, the movable sheaves 30 and 35 are moved in the axial direction so as to be opposed to and separated from the fixed sheaves 29 and 34 in opposition to each other, and the effective radius of the pulley grooves 31, 36, that is, the pulleys 28, 33 Is variable, and the pulley ratio between the two speed change pulleys 28 and 33 is changed.

Further, as shown in FIG. 15, in the interlocking mechanism 64 of the speed change pulley mechanism 27, the second cam mechanism 54
One end of a rod 65 is connected to the tip of the turning lever 57, and the other end of the rod 65 is connected via a rod 67 to an operation lever 66 as a switching operation unit. The operation lever 66 swings back and forth between the forward maximum speed position, the neutral position, and the reverse maximum speed position around the swing axis, for example, and its shift pattern changes from the reverse maximum speed position to the neutral position. When it is moved to the forward highest speed position after that, it is once moved in the neutral position in the direction perpendicular to the turning direction. The rod 67 is connected to the end of the operating lever 66, and the switching operation of the operating lever 66 activates the interlocking mechanism 64 so that each of the rotary arms 50, The planetary gear mechanism 1 is rotated by rotating the gear 57 between the forward maximum speed position, the neutral position, and the reverse maximum speed position (see FIG. 1), and changing the speed ratio of the speed change pulley mechanism 27.
Output gear 22 (output section) as pinion carrier 9
Is switched to a forward rotation state, a neutral state, or a reverse rotation state with respect to the first rotating shaft 2 (input portion), and in the neutral state, the belt winding diameter of the first transmission pulley 28 becomes, for example, 108 mm, and the second transmission The belt winding diameter of the pulley 33 is set to, for example, 72 mm. Further, by setting the gear ratio with respect to the planetary gear mechanism 19, in a forward movement of the vehicle in which the output gear 22 is rotated in the reverse direction with respect to the first rotation shaft 2, the rotation speed of the ring gear 20 drivingly connected to the first rotation shaft 2 is reduced. The rotation speed of the sun gear 20 connected to the second rotation shaft 12 is higher than that of the sun gear 20.

Further, there is provided a dead zone 68 which makes it impossible to transmit the operation force of the operation lever 66 to the interlocking mechanism 64. This dead zone 68 includes, for example, a pin member 69 provided on the opposite side of the pivot lever 38 of the rod 65,
An engaging portion 7 provided on the operation lever 66 side of the rod 67 and engaged with the pin member 69 in the longitudinal direction of the rod 67.
0 is formed, and the engaging portion 70
Is formed by a long groove (or a long hole) that slidably engages the pin member 69 by a predetermined distance. When the operation lever 66 is in the neutral position by the relative movement of the pin member 69 in the engaging portion 70, The operation force of the operation lever 66 cannot be transmitted to the interlocking mechanism 64.

As a feature of the present invention, the first and second embodiments
By automatically pressing outward a slack side of a pair of spans 38a and 38b of the V-belt 38 stretched between the speed change pulleys 28 and 33 from its inner surface to apply tension to the belt 38. Tension mechanism 7 that generates belt thrust
3 are provided. This tension mechanism 73
And first and second tension arms 75, which are swingably provided around an axis parallel to the axis of the second rotation shafts 2, 12.
76, and is disposed on the inner surface side of the block V belt 38, and each of the first and second tension arms 75, 76 is rotated about an axis parallel to the axis of the first and second rotating shafts 2, 12. Possible first and second tension pulleys 78, 81
And a first tension pulley 78 interposed between the first tension arm 75 and the second tension arm 76.
And the second tension pulley 81 in a direction away from each other (the left-right direction in FIG. 1), and the first tension pulley 78 and the other ( the span 38b the inner surface of the drawing lower) field which presses the second tension pulley 81 respectively
And a tension spring 83 as a spring. Further, the second tension arm 76 has a mounting arm portion 82 provided so as to swing integrally, and the tension spring 83 is provided between the mounting arm portion 82 of the second tension arm 76 and the first tension arm 75. , And the mounting arm portion 82 and the first tension arm 75 are oscillated in a direction in which the angular interval between them becomes smaller, so that the first tension pulley 78 and the second tension pulley 81 are separated from each other. It is made to gain momentum. Further, the first and second tension arms 75 and 76 are provided so as to be able to swing around the axis of the second rotation shaft 12, and
2 extends in a direction substantially perpendicular to the main body of the second tension arm 76, and in this state, the tension spring 83 is disposed substantially along the direction between the first and second rotary shafts 2 and 12. .

Specifically, the tension mechanism 73
As shown in FIG. 4, a collar 7 is provided on a bearing portion protruding concentrically around the second rotary shaft 12 in the second split casing 1b.
A first tension arm 75 rotatably supported by the boss portion 75a through the first tension arm 75;
Boss 7 supported rotatably on the boss 75a
A second tension arm 76 having a second tension arm 6a.
A notch 76b through which the first tension arm 75 passes is formed in the boss portion 76a of the tension arm 76. As shown in FIG. 1, the first tension arm 75
Extends toward the first rotation shaft 2, and its tip is curved upward. As shown in detail in FIG. 10, one end of a tension shaft 77 extending in parallel with both rotation shafts 2 and 12 is attached and fixed to an intermediate portion of the first tension arm 75. The other end of the tension shaft 77 is A first tension pulley 78 capable of pressing the span 38a on one side (the upper side in FIG. 1) of the V-belt 38 from the inner surface thereof is located at the pulley grooves 31, 36 of the speed change pulleys 28, 33. It is rotatably supported via 79. On the other hand, the second
One end of a tension shaft 80 extending in parallel with both rotation shafts 2 and 12 is attached and fixed to the tip of the tension arm 76,
The other end of the tension shaft 80 is connected to each of the speed change pulleys 28 and 33.
And the other end (lower side of the figure) of the V-belt 38
A second tension pulley 81 capable of pressing b from the inner surface is rotatably supported via a bearing (not shown). The positions of the tension pulleys 78 and 81 are always at positions where the outer surfaces of the tension pulleys 78 and 81 can contact and press a part of the inner surface of the belt 38 irrespective of the movement of the belt 38 in the axial direction accompanying the speed change. Is set.

An upwardly extending spring mounting arm 82 is integrally attached to the boss portion 76 a of the second tension arm 76, and between the distal end of the spring mounting arm 82 and the distal end of the first tension arm 75. Is a tension spring 8
3, the first tension arm 75 is turned clockwise in FIG. 1 and the second tension arm 76 is turned counterclockwise in FIG. 1 by the spring force of the tension spring 83. The inner surfaces of the spans 38a and 38b of the V-belt 38 are pressed by the tension pulleys 78 and 81, respectively. The rotation urging force of the tension spring 83 on each of the tension arms 75 and 76 is such that each of the tension pulleys 78 and 81 causes the loosening spans 38 a and 3 of the belt 38 to move.
8b is set to be pressed with a tension larger than the maximum tension generated in the loose side spans 38a, 38b,
The belt thrust is generated by this tension.

Further, each of the tension pulleys 78, 8
1 is externally fitted and fixed to the outer surface of the outer race of the bearing, as shown in detail in FIGS. Both side surfaces of the cross-sectional shape of each tension pulley 78, 81 are parallel to the side surfaces of the pulley grooves 31, 36 of the speed change pulleys 28, 33, so that the inclination angle θ3 of the side surfaces of the tension pulleys 78, 81 is reduced by the pulley groove 31. , 36, the axial length of the outer circumference of each tension pulley 78, 81 is smaller than the width of the inner surface of the belt 38. Also,
Each of the tension pulleys 78, 81 is made of fiber reinforced resin mixed with polyamide fiber (specifically, for example, 66 nylon resin mixed with 30% of glass fiber), whereby the blocks 40, 40 of the block V belt 38 are formed. ,…
To reduce the contact sound to the user.

Next, the operation of the above embodiment will be described.

The vehicle engine E is drivingly connected to the first rotating shaft 2 of the continuously variable transmission A via drive and driven pulleys 92, 91 and a V-belt 93, and supports the pinions 21, 21,... Of the planetary gear mechanism 19. Since the output gear 22 as a pinion carrier is drivingly connected to the drive wheels of the vehicle, the rotational power of the engine E is transmitted to the drive wheels after being shifted by the continuously variable transmission A. At this time, in the transmission A, the planetary gear mechanism 19 and the transmission pulley mechanism 27 are arranged in parallel in the power transmission path between the first rotary shaft 2 as the input section and the output gear 22 as the output section. When the transmission A is operated, the power input from the first rotary shaft 2 is transmitted to the transmission pulley mechanism 27, the gear 5 on the first rotary shaft 2, and the planetary gear mechanism 19, and then the planetary gear The output power is output from an output gear 22 as a pinion carrier in the mechanism 19.

(At neutral) Specifically, when the operation lever 66 is located at the neutral position,
The output gear 22 of the planetary gear mechanism 19 has stopped rotating,
The continuously variable transmission A is in the neutral state and the engine E
Is not transmitted to the drive wheels, and the vehicle stops.

In the neutral state, the belt winding diameter of the first speed change pulley 28 of the speed change pulley mechanism 27 is, for example, 108 mm, the belt winding diameter of the second speed change pulley 33 is, for example, 72 mm, and the speed ratio is 0. .666, the first and second transmission pulleys 28 and 33 are both driven (or driven).

At this time, the first tension arm 75 is moved by the spring force of the tension spring 83 of the tension mechanism 73.
Is clockwise in FIG. 1 and the second tension arm 7
6 are respectively urged to rotate in the counterclockwise direction, so that when the operation lever 66 is in the neutral position, the first tension pulley 78 moves on the inner surface of the upper span 38a of the V-belt 38 in FIG. The second tension pulley 81 presses the inner surface of the lower span 38b with the same pressing force.

When the operating lever 66 is positioned at the neutral position, the operation is detected by the limit switch 98. In response to the neutral detection signal from the limit switch 98, the actuator 96 such as an air cylinder of the tension clutch 97 is operated. And
The tension arm 95 is rotated in a direction opposite to the direction in which the tension pulley 94 presses the belt 93 against the urging force of a spring or the like, and presses the V-belt 93 between the driving and driven pulleys 92 and 91 against the loose side span. Is stopped, and power transmission between the engine E and the transmission A is cut off.
The transmission A is in a state of being connected only to the drive wheel side.

At this time, in the speed change pulley mechanism 27, the fixed sheaves 29, 34 and the movable sheaves 30, 35 of the speed change pulleys 28, 33 are arranged so as to be located on opposite sides in the axial direction. Since the cam mechanisms 47 and 54 for moving the movable sheaves 30 and 35 from the back side to the opposing fixed sheaves 29 and 34 respectively are linked by the interlocking mechanism 64, in the neutral state, both the shift pulleys 28 and 33 are either. Also on the driving side (or the driven side), the tension distribution of the belt 38 between the two pulleys 28 and 33 is balanced, and the belt thrust becomes the same.

Then, in this neutral state,
The rotation of the output gear 22 with respect to the first rotating shaft 2 slightly changes to the normal rotation side or the reverse rotation side due to an external load from the driving wheels, and the belt winding diameter of one of the first and second speed change pulleys 28 and 33 is the other. When it is larger than
8 and 33, the tension distribution of the belt 38 becomes unbalanced, and the belt thrust of the pulley 28 (or 33) on the side where the belt winding diameter is increased is reduced, and the pulley 33 on the side where the belt winding diameter is reduced is reduced.
(Or 28), and the difference in belt thrust increases as the load increases. This means that if the continuously variable transmission A changes slightly from the true neutral state,
Due to the difference between the belt thrusts, a pulling force of the pulley 28 (or 33) on the side where the belt winding diameter is increased changes so as to decrease, and a restoring force for automatically returning to the neutral state acts. Means that. In this embodiment, a dead zone 68 is provided in the operation force transmission path from the operation lever 66 to the interlocking mechanism 64 so that the operation force of the operation lever 66 cannot be transmitted to the interlocking mechanism 64 in the neutral state. When trying to return to the neutral state, the pin member 69 in the dead zone 68 is freely moved by the engaging part 70, and the restoration to the neutral state is not restricted. Since the continuously variable transmission A itself has a self-locking function for restoring the neutral state, the neutral state can be stabilized as long as the power on the input side (engine E side) is shut off by the tension clutch 97. And the vehicle does not move inadvertently at all, and the stopping stability in neutral can be improved.

Since the rotating levers 50 and 57 of the cam mechanisms 47 and 54 on the side of the transmission pulleys 28 and 33 are linked by the link 62, the gear ratio of the transmission pulley mechanism 27 is changed by the switching operation of the operation lever 66. , The output gear 22 of the planetary gear mechanism 19, that is, the output of the continuously variable transmission A can be changed to the forward or reverse rotation state, and the rotation speed can be increased and changed.

When the operation lever 66 is moved to the forward position from the neutral state, the operation lever 66 is connected to the rotation lever 57 on the outer periphery of the rotation cam 56 of the second cam mechanism 54. Therefore, in the state of switching to the forward position, the cam 56 rotates around the boss 35a of the movable sheave 35 in the second shift pulley 33 while rolling the cam rollers 59, 59 on the cam surfaces 56a, 56a, respectively. Rotate in one direction. As a result, the cam surface 56a is pushed by the roller 59 and the cam 56
Moves on the second rotating shaft 12, and the movable sheave 35 integrally movable with the cam 56 via the bearing 55 moves in the same direction to approach the fixed sheave 34. As a result, the second speed-change pulley 33 is closed, and the belt winding diameter increases from 72 mm in the neutral state to a maximum of 120 mm, and the V-belt 38 is drawn toward the second speed-change pulley 33 due to the increase in the belt winding diameter. Can be

At the same time, the operation lever 66
Of the second speed change pulley 33
In synchronization with the movement of the movable sheave 35 of the first cam mechanism 47.
Of the second cam mechanism 5 on the first rotary shaft 2
4 in the same one direction as the cam 56. The rotation of the cam 48 eliminates the pressing on the cam roller 52.
Therefore, the cam 48 and the bearing 49 are moved by the tension of the belt 38 moving toward the second speed-change pulley 33.
The movable sheave 30 connected through the fixed sheave 2
9, the first speed change pulley 28 is opened by the separation between the sheaves 29 and 30, and the belt winding diameter is reduced from 108 mm in the neutral state to a minimum of 60 mm. As a result, the belt wrapping diameter of the second speed change pulley 33 becomes larger than that of the first speed change pulley 28, and the rotation of the second rotating shaft 12 is increased so that the first speed change is performed.
The power is transmitted to the rotating shaft 2. At this speed ratio, the output gear 22 serving as the pinion carrier rotates in a reverse rotation state with respect to the first rotating shaft 2, and the driving wheels are driven to rotate in the forward direction of the vehicle by the output power of the engine E, thereby increasing the speed ratio. By changing the output gear 22 to the highest speed position, the rotation speed of the output gear 22 in the normal rotation direction, that is, the forward speed, can be increased.

At this time, the path of the input power through the gear 5 and the ring gear 23 of the planetary gear mechanism 19 to the output gear 22 is used as a drive power path, and the input power is transmitted from the sun gear 20 of the planetary gear mechanism 19 to the second rotary shaft 12 or Speed change pulley mechanism 27
Is transmitted as a circulating power path. That is, in general, the frequency of use of the vehicle in the forward state is higher than that of the reverse movement, and the driving pulley mechanism 27 forms a circulating power path during the forward movement, so that the driving power is applied to the belt 38 with high frequency over a long period as a whole. A smaller circulating power can be transmitted, and the transmission load of the belt 38 can be reduced even at the time of high output in a forward state frequently used.

In the state where the speed change pulley mechanism 27 is a circulating power path, the second speed change pulley 33 is a drive side pulley, while the first speed change pulley 28 is a driven side pulley, and the upper side of the belt 38 in FIG. Of the first tension pulley 78 is V-belt 3
8, both tension arms 75 and 76 are rotationally urged by tension springs 83 in the reverse direction so that the upper tension span 38a and the second tension pulley 81 press the lower tension span 38b. The second tension pulley 81 pressing the inner surface of the tension side span 38b moves upward in FIG. 1, and the second tension arm 76 rotates clockwise, whereby the tension spring 83 is extended. Accordingly, the first tension arm 75 also rotates clockwise, and the first tension pulley 78 presses the inner surface of the upper span 38a in FIG. , Belt tension is obtained. The tension arms 75 and 76 are rotated and urged in the opposite directions by the urging force of the tension springs 83 of the tension mechanism 73, and the tension pulleys 78 and 81 at the ends thereof are respectively provided on the inner surfaces of the loosening spans 38a and 38b of the belt 38. , And the tension is applied to the belt 38 by this pressing. This tension is larger than the maximum tension generated in the loose side spans 38a and 38b.
A wedge effect is generated on the pulleys 8 and 33 to generate thrust, and power is transmitted between the pulleys 28 and 33 via the belt 38 by the thrust.

Further, the boss 30a of the movable sheave 30 of the first transmission pulley 28 and the pulley shaft 4 of the first rotary shaft 2
A torque cam mechanism 42 is disposed between the transmission cam mechanism 45 and the front and rear cam surfaces 45a and 45b formed on both side walls of each torque cam hole 45 of the torque cam mechanism 42. When the movable sheave 30 and the first rotating shaft 2 rotate relative to each other due to the transmission load, the forward cam surface 45a of each of the torque cam holes 45 comes into contact with the torque ring 44 at the tip of the torque pin 43 and the movable sheave 3
0 is pushed in the axial direction and moves in a direction away from the fixed sheave 29, and the movement of the movable sheave causes the first cam mechanism 4
7, the rotary cam 48, the interlocking mechanism 64, and the second cam mechanism 54.
The movable sheave 35 of the second speed-change pulley 33 is pressed toward the fixed sheave 34 via the rotary cam 56, so that the thrust of the speed-change pulley 33 against the belt 38 can be increased.

On the other hand, when the operating lever 66 is positioned at the reverse position, the cam 48 of the first cam mechanism 47 is moved to the reverse position by switching the operation lever 66 to the reverse position.
The first transmission pulley 28 rotates in the other direction around the boss 30a of the movable sheave 30 while rolling the cam roller 52 on the 8a. As a result, the cam surface 48a is pressed by the roller 52, and the cam 48 moves on the first rotating shaft 2, and the movable sheave 30 integrated with the cam 48 moves in the same direction to approach the fixed sheave 29. . As a result, the first speed change pulley 28 closes and the belt winding diameter increases from 108 mm in the neutral state to a maximum of 120 mm, and the V belt 38 is pulled toward the first speed change pulley 28 due to the increase in the belt winding diameter. Can be

Further, with the switching of the operation lever 66 to the reverse position, the cam 56 of the second cam mechanism 54 is moved to the second position.
The first cam mechanism 47 rotates on the rotating shaft 12 in the same other direction as the cam 48. The rotation of the cam 56 eliminates the pressing against the cam roller 59. For this reason, the first
Due to the tension of the belt 38 moving to the speed change pulley 28 side,
The cam 56 and the movable sheave 35 connected thereto via the bearing 55 move on the second rotary shaft 12 in a direction away from the fixed sheave 34, and the second shift pulley 33 is opened by the separation between the sheaves 32 and 33. As a result, the belt winding diameter is reduced from 72 mm in the neutral state to a minimum of 60 mm. As a result, the belt winding diameter of the first speed change pulley 28 becomes larger than that of the second speed change pulley 33,
The rotation speed of the rotating shaft 2 is increased and transmitted to the second rotating shaft 12. At this speed ratio, the rotation direction of the output gear 22 is the first direction.
When the rotation of the output gear 22 is made to rotate in the forward direction with respect to the rotating shaft 2 and the output power of the engine E drives the driving wheels in the reverse direction of the vehicle and changes the gear ratio to the reverse highest speed position, the rotation speed of the output gear 22 in the reverse direction is reduced. The reverse speed can be increased.

At this time, on the contrary to the above-mentioned forward movement, the input power of the planetary gear mechanism 19 is set such that the path extending from the transmission pulley mechanism 27 or the second rotary shaft 12 to the sun gear 20 of the planetary gear mechanism 19 is used as the drive power path. , Ring gear 2 from output gear 22 as a pinion carrier
3, a path extending to the first rotary shaft 2 via the gear 5 is transmitted as a circulating power path.
Is a driving power path, a large driving power acts on the V-belt 38, and there is a concern that the durability of the V-belt 38 may be reduced. Since it is low, the state in which a high transmission load is applied to the V-belt 38 is only for a short time, and the durability of the belt 38 is not greatly reduced.

In this reverse state, the first transmission pulley 28 becomes a driving pulley, the second transmission pulley 33 becomes a driven pulley, and the lower span 38b of the belt 38 in FIG. Become. Also at this time, since the tension arms 75 and 76 are rotationally urged in the reverse direction by the tension spring 83, the first tension pulley 78 pressing the inner surface of the tension side span 38a is also in the same manner as described above. 1, the first tension arm 75 rotates counterclockwise, and the second tension arm 76 also rotates counterclockwise by the spring force of the tension spring 83.
The second tension pulley 81 presses the inner surface of the lower span 38b in FIG. 1 on the loose side of the belt 38 with a predetermined pressing force, whereby the belt tension can be obtained.

In this reverse state, when the movable sheave 30 of the first transmission pulley 28 and the first rotary shaft 2 rotate relative to each other due to the transmission load of the transmission pulley mechanism 27, the reverse cam surface 45b of each of the torque cam holes 45 is formed. Comes into contact with the torque ring 44 at the tip of the torque pin 43, and the movable sheave 30 moves in the axial direction in the direction toward the fixed sheave 29, and the movement of the movable sheave 30 causes the belt 3 on the first transmission pulley 28 to move.
8 can be increased.

Therefore, in this embodiment, as described above, the planetary gear is set so that the rotation speed of the ring gear 23 is always higher than the rotation speed of the sun gear 20 on the forward side, which is frequently used in the forward or reverse state of the vehicle. Since the gear ratio for the mechanism 19 is set, the frequency at which small circulating power is transmitted to the belt 38 of the transmission pulley mechanism 27 is increased, and the frequency at which large driving power is transmitted to the belt 38 is increased. Therefore, the forward / reverse rotation state of the continuously variable transmission A can be easily obtained without requiring a separate forward / reverse rotation mechanism while reducing the load on the belt 38.

The boss portion 30 of the movable sheaves 30, 35 in each of the speed change pulleys 28, 33 of the speed change pulley mechanism 27.
a, 35a, the rotating cams 48 of the respective cam mechanisms 47, 54,
56 is supported via bearings 49 and 55, and the rotating levers 50 and 57 on the outer periphery of the rotating cams 48 and 56 are connected to each other by one link 62. A force acts on the cam surfaces 48a, 56a of the rotating cams 48, 56 in the direction perpendicular to the cam surfaces 48a, 56a from the rollers 52, 59 supported by the fixed cams 51, 58, and the rotating shafts 2, 12 At right angles to the line connecting the axis of the rotating shafts 2 and 12 and the connection point to the link 62 when the perpendicular component force acts on the axis of the rotating shafts 2 and 12 and the connection point to the link 62 at right angles. , Regardless of the change in the pulley ratio, a cam rotation reaction force is generated at a right angle and opposite to the right component force. The cam rotation reaction force is generated by the rotation cams 48 and 56.
Boss 30 of movable sheaves 30, 35 on which is supported
The boss portion 30 is located at the center position of the range where the belt 38 of the pulleys 28 and 33 is wound around the
a, 35a. That is, the cam rotation reaction force on the bosses 30a and 35a is
When the movable sheaves 30, 35 receive a thrust from the belt 38, the movable sheaves 30, 35 are rotated by the clearances at the sliding portions between the rotary shafts 2, 35.
The moment acting in a direction opposite to the direction of tilting with respect to 12 acts to generate a moment in the opposite direction, and the original moment is canceled out and reduced by this moment, and the rotation of the inner periphery of the boss portions 30a and 35a of the movable sheaves 30 and 35 is rotated. Axis 2,
The surface pressure distribution on the outer circumference 12 is dispersed in the axial direction, and the sliding resistance of the boss portions 30a and 35a is reduced. The rotation cam 4 of the thrust generated by the belt is reduced by the reduced sliding resistance.
Load applied to the fixed point by 8, 56 (that is, extraction thrust)
In other words, the belt-generated thrust is transmitted to the rotating cams 48 and 56 as a take-out thrust without great resistance. And when changing the pulley ratio,
Since the difference between the belt-generated thrust and the take-out thrust is the load (operating force) required for the gear shifting operation, the larger the take-out thrust, the smaller the operation force. As a result, the resistance at the time of shifting to the neutral state due to the thrust balance of the belt 38 between the two speed change pulleys 28 and 33 in the speed change pulley mechanism 27 is reduced, and the neutral state is smoothly adjusted, thereby further improving the neutral state. It can be stably held.

The first tension pulley 78 corresponds to the upper span 38a of the V-belt 38 in FIG. 1, and the second tension pulley 81 corresponds to the lower span 38b of the V-belt 38.
So that both tension arms 7 are always pressed.
5, 76 are rotationally urged in the reverse direction by a tension spring 83,
Since the pressing force against the loose side span 38b (or 38a) is obtained by the return of the tension side span 38a (or 38b) of the belt 38, the tension of the belt 38 is changed as described above with the switching between forward and reverse. Even if the side and loose side spans are switched, both tension pulleys 7
The slack side span can be automatically pressed while keeping the distance between 8, 81 constant, and stable belt tension can be obtained.

In addition, since each tension arm 75, 76 is rotationally biased by using the tension spring 83, there is no danger of spring buckling unlike the case of using a compression spring, and an appropriate spring constant is obtained. This is advantageous for stabilizing the belt tension. Note that, as described above, both spans 38 of the belt 38 are
a and 38b are connected to tension pulleys 78 and 81, respectively.
Instead of pressing the tension pulleys, a pair of tension pulleys are disposed so that the back surfaces of the spans 38a and 38b of the belt 38 can be pressed, respectively, and the tension arms supporting these tension pulleys are rotated by tension springs in the belt pressing direction. An urging force may be applied.

Further, the two tension pulleys 7
The axial length of each of the peripheral surfaces of the belts 8 and 81 is smaller than the width of the inner surface of the belt 38, and both tension pulleys 78 and 8
1 is arranged between the two spans 38a and 38b of the belt 38 and presses the respective spans 38a and 38b from the inner surface side to apply the belt thrust. The tension pulleys 78 and 81 can be arranged using the dead space, and the transmission A can be made compact.

In addition, each of the tension pulleys 78, 8
The pulley groove 3 of the transmission pulleys 28 and 33 has an inclination angle of one side.
1 and 36, the pulley grooves 3 of the speed change pulleys 28 and 33
1 and 36 does not interfere with the side surfaces of the pulley grooves 31 and 36, and the spans 38a and 3 of the belt 38 are formed by using the tension pulleys 78 and 81 having large outer diameters.
8b, the distance between the two rotating shafts 2 and 12 is reduced while the bending ratio of the rotating shafts 2 and 12 is reduced.
2 can be made compact in the direction between the axes.

The position of each of the tension pulleys 78 and 81 can be determined regardless of the movement of the belt 38 in the axial direction accompanying the speed change.
Since the outer surfaces of the tension pulleys 78 and 81 are always in a position where the outer surfaces of the tension pulleys 78 and 81 can contact and press a part of the inner surface of the belt 38, the width of the tension pulleys 78 and 81 is
8 is smaller than the width of the inner surface, and the belt 38 moves in the axial direction along the side surface of the pulley grooves 31, 36 on the fixed sheave 29, 34 side while the winding diameter is changed by opening and closing the speed change pulleys 28, 33. However, tension pulleys 78 and 8
The belt 3 is not displaced in the axial direction from the position of the belt 38 so that the loose spans 38a and 38b cannot be pressed.
8 can be stably pressed.

Each of the tension pulleys 78, 81
Is made of fiber reinforced resin mixed with polyamide fiber, the wear of the block V belt 38 due to the contact with the tension pulleys 78, 81 can be reduced, and the inner surface of the block V belt 38 becomes uneven by the blocks 40, 40,. Even if the block belt 38 is
The hitting noise when the 0 intermittently contacts the tension pulleys 78 and 81 can be reduced, and the noise can be reduced.

First speed change pulley 28 of speed change pulley mechanism 27
The boss portion 30a of the movable sheave 30 is subjected to a high surface pressure by the torque cam mechanism 42, so that it is not forged but cast, but the boss portion 30a and the sheave body 30b
Are formed integrally with each other, so that compared to a case where both are formed separately and then welded and integrated, the roundness of the movable sheave 30 can be improved without welding distortion, and high load transmission can be achieved. The run-out of the V-belt 38 can be reduced, the wear thereof can be suppressed, and the reliability can be improved.

The movable sheave 30 of the first transmission pulley 28
A torque cam mechanism 42 is provided between the boss portion 30a of the first rotary shaft 2 and the pulley shaft portion 4 of the first rotary shaft 2. Each of the torque cam holes 45 of the torque cam mechanism 42 has forward and reverse cam surfaces 45a and 45b. Each of the movable sheaves 30 and 35 is fixed by the torque cam mechanism 42 when the vehicle is moving forward as well as when the vehicle is moving backward.
The belt can be moved axially to increase the belt thrust.

At this time, on the forward side, the pulley ratio of the transmission pulley mechanism 27 is in the Lo state where the belt winding diameter of the first transmission pulley 28 is smaller than that of the second transmission pulley 33,
The difference in belt thrust between the driving side and the driven side pulleys increases, while the pulley ratio of the transmission pulley mechanism 27 is Hi on the reverse side.
Although the belt thrust difference between the driving side and the driven side pulleys 28 and 33 is reduced, the lead angle of the forward cam surface 45a in each of the torque cam holes 45 is reduced.
Since the lead angle θ2 is set to be larger than the lead angle θ2 of 5b, an appropriate belt thrust can be obtained in accordance with the characteristic of the belt thrust difference at the time of forward / backward travel.

In addition, the torque pin 43 of the torque cam mechanism 42 is diametrically supported by the pulley shaft portion 4 of the second rotary shaft 12 and the torque ring 44 is supported by the tip protrusions on both sides thereof. The degree of perpendicularity of the torque ring 43 itself can be increased, and the torque ring 44 can be prevented from coming into contact with the cam surfaces 45a and 45b in the torque cam hole 45.

The pinions 21, 21,... In the planetary gear mechanism 19 are connected to the output gear 22 on the second rotary shaft 12.
And the output gear 22 is drivingly connected to the drive wheels, so that the output gear 22 can also be used as a pinion carrier to reduce the number of parts, and the pinion carrier as an output unit is mounted on the second rotating shaft 12. The length of the second rotating shaft 12 can be reduced as compared with the case where the second rotating shaft 12 is connected to the driving wheel side, and the axially compact of the continuously variable transmission A can be achieved.

Further, the casing 1 of the continuously variable transmission A is divided into first to third divided casings 1a, 1b and 1c, and the first and second rotating shafts 2 and 12 are respectively divided into the first and second rotating shafts 1 and 2.
Gear shaft portions 3, 13 located between the first and second divided casings 1a, 1b, and the second and third divided casings 1b, 1c
The gear shafts 3 and 13 are divided into two parts, the planetary gear mechanism 19 and the gear 5, and the pulley shafts 4 and 14 are provided with a transmission pulley mechanism 27. Since the gears are arranged, the continuously variable transmission A can be divided into two parts by disposing the gears in the arrangement parts of the transmission pulley mechanism 27 and the planetary gear mechanism 19. For this reason, when inspecting or repairing the belt 38 of the speed change pulley mechanism 27, for example, or replacing parts of the planetary gear mechanism 19, it is only necessary to remove and disassemble only the unit on the necessary side while leaving the remaining parts of both units as they are. In addition, maintenance and inspection of parts and steel pipes can be easily performed.

A sleeve 8 is provided on the gear shaft portion 3 side at a small diameter portion of the pulley shaft portion 4 of the first rotary shaft 2 on the side of the transmission pulley mechanism 27, and a bush 9 is provided on the opposite side of the gear shaft portion 3.
Are fixed to each other, the fixed sheave 29 of the first transmission pulley 28 is supported on the sleeve 8, and the bush 9 is supported by the third split casing 1 c via the bearing 10. The partial sleeve 8 is separated from a bush 9 for supporting the bearing 10. Therefore, when an axial load is applied to the fixed sheave 29 from the V-belt 38, the fixed sheave 29 faces inward with the position of the bearing 10 as a fulcrum, ie, the outer peripheral edge of the fixed sheave 29 as in the case of the non-separable structure. Is the pulley groove 31
The belt 38 can be prevented from tilting toward the side.
And the abrasion of the fixed sheave 29 can be suppressed.

Further, a sleeve 8 is externally fitted on the pulley shaft portion 4 on which the torque pin 43 of the torque cam mechanism 42 is mounted on the first rotary shaft 2. Since both the movable sheaves 29 and 30 are fitted and supported, as in the case where the fixed sheave 29 is directly key-coupled to the pulley shaft 4, the force from the belt 38 and the force applied to the movable sheaves 29 and 30 are reduced. The relative rotation between the movable sheave 30 and the pulley shaft portion 4 of the first rotary shaft 2 is not impaired by the action, and the pulley shafts of the movable sheave 30 and the first rotary shaft 2 are obtained while the belt thrust is obtained by both sheaves 29 and 30. The operation of the torque cam mechanism 42 can be properly ensured by enabling relative rotation with the portion 4.

Further, since the torque cam mechanism 42 is provided on the side of the first transmission pulley 28 which is driven by the circulating power in the forward state of the continuously variable transmission A, even if the lead angle of the torque cam hole 45 is constant. The required belt thrust according to the gear ratio can be easily taken out.

The movable sheave 3 of the first transmission pulley 28
A cylindrical collar 51 is fitted on the boss portion 30a of the cylinder 50 so as to cover each torque cam hole 45, and a bearing 49 is mounted thereon.
Since the rotary cam 48 of the first cam mechanism 47 is supported via the shaft, the torque cam hole 45 of the torque cam mechanism 42 can be sealed with the collar 51, and the lubricating oil filled in the torque cam hole 45 is directed to the outside. Can be effectively prevented from scattering.

Although the ring gear 23 of the planetary gear mechanism 19 is connected to the first rotating shaft 2 in the above embodiment, the gear 22 as a pinion carrier is connected to the first rotating shaft 2 so that the ring gear 23 is connected. It may be an output gear. In addition, the sun gear 20 may be used as the output unit. In short, one of the sun gear 20, the pinion carrier, and the ring gear 23 of the planetary gear mechanism 19 is provided on the first rotating shaft 2, and the other is provided on the second rotating shaft 12, respectively. What is necessary is just to be connected and let the remainder be an output part.

Further, it is possible to use the pinion carrier of the planetary gear mechanism 19 as the power input portion and the first rotary shaft 2 as the output portion.

In the above-described embodiment, the circulating power is transmitted to the speed change pulley mechanism 27 when the vehicle is moving forward. In this state, the circulating power may act on the belt 38.

[0082]

As described above, according to the first aspect of the present invention, a speed change pulley mechanism in which a belt is wound between two speed change pulleys disposed on a pair of rotating shafts parallel to each other, and First and second tensions that can swing about axes parallel to the axis of each of the rotating shafts with respect to a continuously variable transmission that is disposed in combination with a differential gear mechanism having a third gear element. Arms are provided, and first and second tension pulleys supported on each of the first and second tension arms so as to be rotatable about an axis parallel to the axis of each rotation shaft are arranged on the inner surface side of the belt. And a spring for urging the first and the tension pulleys in directions away from each other is disposed between the first and second tension arms, and a first tension pulley is provided on one inner surface of the span of the belt, and the other is provided on the inner surface of the belt. Inside the span of Since each of the second tension pulleys is pressed, one of the first and second tension pulleys is pushed back to the tension side span, so that the other of the first and second tension pulleys presses the loose side span with a predetermined pressing force. The belt can be pressed and has a simple structure in which a spring is interposed between the first and second tension arms. However, when the tension side span and the loose side span of the belt are switched, the loose side span is automatically changed. Can be pressed, so that the continuously variable transmission can be downsized.

According to the second aspect of the present invention, the mounting arm portion is swingably provided on the second tension arm, and the tension spring as the spring is interposed between the mounting arm portion and the first tension arm. The first and second tension pulleys are urged in directions away from each other by swingingly urging the mounting arm portion and the first tension arm in a direction in which the angular interval becomes smaller. Can be set without being restricted by the distance between the first and second tension pulleys, the spring length can be reduced by making the free length sufficient, and, unlike the compression spring, the seat length can be reduced. Since no buckling occurs, in the invention of claim 1 described above, it is possible to suppress a change in the pressing force on the belt and to apply the predetermined tension to the belt stably and reliably. Door can be.

According to the third aspect of the present invention, the first and second tension arms are provided so as to be swingable about one of the first and second rotation shafts, and the mounting arm portion is provided with the second arm.
The tension spring is arranged to extend in a direction substantially perpendicular to the tension arm main body, and the tension spring is disposed along a direction substantially between the first and second rotation shafts. The tension spring can be accommodated substantially in the frame of the belt running track, and the natural length of the tension spring can be made sufficiently long in the frame. Can be even higher.

[Brief description of the drawings]

FIG. 1 is a front view showing a structure of a speed change pulley mechanism in a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a plan sectional view showing the entire configuration of the continuously variable transmission.

FIG. 3 is an enlarged sectional view showing a structure around a first speed change pulley of the speed change pulley mechanism.

FIG. 4 is an enlarged sectional view showing a structure around a second speed change pulley of the speed change pulley mechanism.

FIG. 5 is an enlarged sectional view showing a structure around a differential gear mechanism.

FIG. 6 is an enlarged sectional view of a movable sheave of a first transmission pulley.

FIG. 7 is an enlarged front view of a movable sheave.

FIG. 8 is an enlarged front view of a torque cam groove.

FIG. 9 is an enlarged plan view showing a link of an interlocking mechanism.

FIG. 10 is an enlarged sectional view showing a state in which a spring is attached to a first tension arm.

FIG. 11 is a sectional view of a tension pulley of the tension mechanism.

FIG. 12 is a front view of a tension pulley of the tension mechanism.

FIG. 13 is a plan view showing a drive connection state of the continuously variable transmission to the engine.

FIG. 14 is a front view showing a drive connection state of the continuously variable transmission with respect to the engine.

FIG. 15 is a diagram schematically showing a connection structure between an interlocking mechanism and an operation lever.

[Explanation of symbols]

A continuously variable transmission 2 first rotating shaft 12 second rotating shaft 19 planetary gear mechanism (differential gear mechanism) 20 sun gear (second gear element) 22 output gear (third gear element) 23 ring gear (first gear element) 27 speed change pulley mechanism 28, 33 speed change pulley 38 block V belt (belt) 38a, 38b span 75 first tension arm 76 second tension arm 78 first tension pulley 81 second tension pulley 82 mounting arm section 83 tension spring (spring)

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yutaka Furukawa 3-2-1-15 Meiwadori, Hyogo-ku, Kobe City, Hyogo Prefecture Inside Bando Chemical Co., Ltd. (56) References JP-A-62-118159 (JP, A) Kaikai 47-25678 (JP, U)

Claims (3)

(57) [Claims] 1. A transmission in which a belt is wound between first and second rotating shafts arranged in parallel with each other and both shifting pulleys arranged on the both rotating shafts, and the two rotating shafts are drivingly connected so as to be shiftable. A pulley mechanism having first to third gear elements connected to each other, wherein a first gear element is connected to the first rotation shaft while a second gear element is connected to the second rotation shaft; One of the first rotating shaft and the third gear element is an input unit, and the other is an output unit. The output unit is input according to a change in the pulley ratio of the transmission pulley mechanism. A continuously variable transmission configured to switch the forward rotation state, the neutral state, or the reverse rotation state with respect to the portion, and swingable about an axis parallel to the axis of the first and second rotation shafts. First and second tension arms provided on the A first and a second tension pulleys disposed on the inner surface side of the first and second tension arms and rotatably supported on respective first and second tension arms around an axis parallel to the axis of the first and second rotation shafts; The first tension arm and the second tension arm are interposed between the first tension arm and the second tension arm. A continuously variable transmission comprising a pulley and a spring on the other inner surface of the span for pressing the second tension pulley. 2. The continuously variable transmission according to claim 1, wherein the second tension arm has a mounting arm portion provided integrally with the swing, and a spring is connected to the mounting arm portion of the second tension arm. A direction interposed between the first tension arm and the first tension arm, and urges the mounting arm portion and the first tension arm to swing in a direction in which an angular interval between them becomes smaller to separate the first tension pulley and the second tension pulley from each other. A continuously variable transmission, wherein the transmission is a tension spring that biases the transmission. 3. The continuously variable transmission according to claim 2, wherein the first and second tension arms are provided so as to be able to swing around one of the first and second rotation shafts, and the mounting arm portion is provided. A continuously variable transmission, wherein the tension spring extends in a direction substantially perpendicular to the second tension arm main body, and the tension spring is disposed substantially along a direction between the first and second rotating shafts.