JPH0735155Y2 - Belt tension mechanism for V-belt type continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a belt tensioning mechanism for improving the tension of a V-belt in a V-belt type continuously variable transmission.

(Prior Art) Conventionally, V that can continuously change the engine output of an automobile or the like
As a belt type continuously variable transmission, there is one as shown in FIG. 4, for example. That is, in FIG. 4, the fixed pulley 5 having the conical surface 52a on the input shaft 51 rotated by the engine
2, the movable pulley 53 having a conical surface 53a facing the conical surface 52a of the fixed pulley 52 is provided on the input shaft 51 so as to be movable in the axial direction of the input shaft 51. A slider gear 54 is provided on the side surface of the movable pulley 53 opposite to the conical surface 53a by being screwed onto a slider shaft 56 fitted over a bearing 55 fitted on the input shaft 51. That is, the slider shaft 56 is the stopper plate 62.
Is fixed to the casing side of the continuously variable transmission, and a male screw is screwed on the outer periphery thereof. A female screw that is screwed on the inner peripheral surface of the slider gear 54 is screwed into this male screw, and the slider gear is attached to the slider shaft 56.
As the slider 54 rotates, the slider gear 54 shifts to the input shaft 51.
It is possible to move in the axial direction. The slider gear 54 is rotated by receiving the rotational force of the motor 57 via the drive gear 58 and the idler gear 59, and the slider gear 54 is rotated so that the female screw of the slider gear 54 is mounted on the male screw of the slider shaft 56. By rotating and screwing the slider gear 54 in the axial direction of the input shaft 51,
The movable pulley 53 is pressed toward the fixed pulley 52 along the input shaft 51 via the slider bearing 60, and the pulley pitch of the V groove formed by the conical surface 53a of the movable pulley 53 and the conical surface 52a of the fixed pulley 52. The diameter is changed.

In the figure, 61 is an idler shaft, 63 is a nut, and 64 is a cam follower. This cam follower 64 is slidably fitted in a guide groove 53b formed in the movable pulley 53,
A pulley that is fixed to the input shaft 51 to move the torque of the input shaft 51.
It is to be transmitted to 53.

On the other hand, a drum 68 is fixedly attached to the left end portion of the output shaft 66, which is provided in parallel with the input shaft 51, via a nut, and the driven pulley S of the right end portion of the drum 68 is fixed.
The back surface side of the conical surface of the fixed pulley 70 constituting the is fixed. Therefore, the V belt V wound around the V groove of the drive pulley D constituted by the fixed pulley 52 on the input side and the movable pulley 53 comes into contact with the conical surface of the fixed pulley 70 to rotate from the input shaft 51. One half of the force is transmitted to the fixed pulley 70, and the transmitted rotational force is transmitted to the output shaft 66 via the drum 68. A cam follower 69 is fixedly mounted inward on the drum 68. The cam follower 69 has a conical surface facing the conical surface of the fixed pulley 70 and slides in the axial direction of the output shaft 66. The movable pulley 71, which is movably installed, is fitted into a V-shaped groove of a cam drum 73 fixed to the left end portion in the figure through a snap ring. Therefore, one half of the rotational force transmitted from the input shaft 51 via the V belt V is transferred from the movable pulley 71 to the cam drum.
It is transmitted to the output shaft 66 from the drum 68 via the cam follower 69. The cam drum 73 is guided by the cam follower 69 to be movable in the axial direction of the output shaft 66, and the movement of the cam drum 73 causes the movable pulley 71 to move in the axial direction. A spring 74 is provided between the conical rear surface of the fixed pulley 70 and the inner surface of the cam drum 73. The cam drum 73 is constantly pressed by the urging force of the spring 74, and the movable pulley 71 becomes the fixed pulley. 70 side is urged. The V-shaped groove formed on the outer periphery of the cam drum 73 has a slope 73a and a slope 73b as shown in FIG. 6 in a developed state, and the cam follower 69 is pressed against either of the slopes 73a and 73b to cause a spring. Assist the urging force of 74.

(Problems to be solved by the invention) In the conventional structure as described above, the fixed pulley 70 and the V
Between the belt V and between the movable pulley 71 and the V belt V,
The movable pulley 71 is fixed to the fixed pulley 70 by the urging force of the spring 74.
It is pressed to the side to give a frictional force, and when rotating at a constant speed, the V-belt V does not slip, and the fixed pulley
The 70 and the movable pulley 71 rotate at the same rotation.

However, when accelerating, torque is input from the drive pulley D to the driven pulley S, and the V belt V
Has a tension side to which a tensile force is applied and a contraction side to which a compression force is applied.

Further, the driven pulley S acts as a brake during deceleration, and torque is input from the driven pulley S to the drive pulley D, and the tension side and the contraction side of the V belt V are opposite to those in the above-described acceleration.

At the time of such acceleration or deceleration, a tension side and a contraction side are generated in the V belt in both forward and backward movements, and particularly in the case of sudden acceleration and deceleration, the pulling force and the contracting force are strongly applied to the V belt V, A force exceeding the frictional force due to the pressing force of the spring 74 acts on the V-belt V, and slippage occurs particularly between the fixed pulley 70 and the V-belt V. When this slip occurs, the rotation of the movable pulley 71 becomes faster than the rotation of the fixed pulley 70, and the relative rotation between the fixed pulley 70 and the movable pulley 71 occurs. When this relative rotation occurs, in the case of forward movement, the cam follower 69 is momentarily moved to the cam drum as shown in FIG.
The slope 73a of the 73 moves from the slope 73a to the slope 73b, and during this movement, the cam follower 69 floats in the air and cannot be pressed against any of the slopes 73a and 73b, and the movable pulley 71 is fixed by the pressing force of the spring 74. Since the pressing force is applied to the 70 side, the fixing force cannot be obtained, the V belt V further slips, and immediately after the cam follower 69 contacts the slope 73 of the cam drum 73, the V belt V suddenly stops slipping,
A shock occurs in the driving condition. Further, in the case of a reverse drive, there is a problem that the cam follower 69 momentarily moves from the slope 73b to the slope 73a side at the time of gear shifting, an impact is generated, and the operation is not smoothly performed at the time of gear shifting.

(Means for Solving Problems) The present invention has been devised in view of the above problems, and it is a V-belt that allows a smooth shift operation by keeping the slope of the groove of the cam drum and the cam follower always in contact with each other. The purpose of the invention is not to provide a belt tensioning mechanism for a continuously variable transmission, and its gist is to have a fixed pulley having a conical surface and fixed to the input shaft, and a conical surface similar to this fixed pulley. The drive pulley is composed of a movable pulley formed by forming a V groove with the fixed pulley so as to be movable in the axial direction of the input shaft, and is moved by the moving means in a direction away from and in contact with the fixed pulley, and a conical surface. A moving means that is attached so as to be movable in the axial direction of the output shaft by forming a V groove between the fixed pulley that is fixed to the output shaft and the fixed pulley that has the same conical surface as this fixed pulley. Harder It has a driven pulley composed of a movable pulley which is moved in a direction away from and in contact with a constant pulley, and a V belt wound around each V groove of the driven pulley and the driving pulley, and continuously changes the rotation of the input shaft. In a V-belt type continuously variable transmission for transmitting to an output shaft, a moving means of the driven pulley is fixed to the movable pulley of the driven pulley, and a drum having a cam follower standing on the outer peripheral surface, and an outer peripheral side of the drum. And two cam drums each of which is formed in a slanting shape so as to intersect with each other in opposite directions and has respective grooves with which the carofollower engages, and teeth projectingly provided on respective outer peripheral surfaces of the cam drums. And a ring disposed on the outer peripheral side of the cam drum having teeth on the inner peripheral surface that can be fitted in conjunction with the rotational force of the fixed pulley. By fixing one of said cam drum through, wherein the movable pulley along one of the grooves is moved in the axial direction of the output shaft of the cam follower is that configured to move.

(Operation) A cam follower is fixed to a movable pulley that constitutes a driven pulley, and this cam follower can be engaged with any groove of two cam drums. The grooves of each cam drum have different inclination directions. It is a groove formed with an inclined surface, and one of the two cam drums is fixed via the switching means in conjunction with the direction of the rotational force of the fixed pulley, and the groove of any of the fixed cam drums and the above-mentioned groove are formed. Since the cam followers are engaged, the cam followers can move while being in contact with the slopes in the grooves in any of the inclination directions, and the cam followers are always in contact with the slopes of the grooves in any of the drums. The cam follower is securely pressed along the groove of the cam drum in the axial direction of the output shaft without interrupting the engagement of the movable pulley with the fixed pulley side. By pressing and fixing, slippage of the V-belt during gear shifting on the conventional pulley side is effectively prevented, and operation is smoothed.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention, in which, in this embodiment, a fixed pulley 70 which constitutes a driven pulley S and a sliding movement of an output shaft 66 facing the fixed pulley 70. The movable pulley 71 that can be provided is the same as the conventional one, but the output shaft 66 is on the rear surface side of the conical surface 70a of the fixed pulley 70 and the output shaft 66 has a nut 67 at the left end portion in the figure.
The cover 1 is fixedly provided on the 66.
The rollers 2 are fitted and fixed in the four roller grooves 1a formed on the inner surface of the peripheral portion of the roller. A drum 3 is arranged on the outer peripheral side of the cover 1, and the right end portion of the drum 3 in the figure is fixed to the rear surface side of the conical surface 70a of the fixed pulley 70. A flange 4 is fixedly provided on the left end portion of the drum 3 in the drawing, and the drum 3 covers the cover 1 through the flange 4.
It is possible to rotate with respect to. Further, four key grooves 3a are formed on the inner peripheral surface of the drum 3 along the axial direction of the output shaft 66. On the other hand, a drum 6 is fixedly installed on the left end portion of the movable pulley 71 in the figure via a snap ring 5 and a spline, and a spring 7 is provided between the inner wall surface of the drum 6 and the opposite side surface of the conical surface 70a of the fixed pulley 70. The drum 6 is always urged to the left in the drawing by the urging force of the spring 7, and the movable pulley 71 is urged to the fixed pulley 70 side. A cam follower 8 is fixedly mounted on each of four shafts 6a provided upright on the outer peripheral surface of the drum 6, and each of the cam followers 8 includes two cam drums 9 arranged on the outer peripheral surface side of the drum 6. Grooves 9 and 4 formed in each of 10 and 10
It is engaged in a and 10a. The grooves 9a and 10a are formed in an inclined shape so as to intersect with each other in opposite directions.

The cam drums 9 and 10 are provided with teeth 9b and 10b integrally projecting along the outer peripheral surface thereof, and a ring having teeth 11a formed on the inner peripheral surface that can be fitted to either of the teeth 9b and 10b. 11 is arranged on the outer peripheral side of the cam drums 9 and 10. Therefore, the ring 11 is interposed between the cam drums 9 and 10 and the inner peripheral surface of the cover 1, and the keys 12 are fitted in the four key grooves 11c formed on the outer peripheral surface of the ring 11. The key 12 is fixed and is slidably fitted in each groove 3a of the drum 3. In addition, the roller 2 fixed to the cover 1
Is a groove 11b formed in an inclined shape on the outer peripheral surface of the ring 11.
Since the ring 11 is movable in the axial direction of the output shaft 66 along the grooves 3a of the drum 3 via the key 12, and the groove 11b of the ring 11 is formed in an inclined shape, The ring 11 is structured so as to be pushed and moved in the axial direction of the output shaft 66 via the roller 2 as the ring 11 rotates.

In such a structure, a relative rotational force acts between the drum 3 and the cover 1 depending on the direction of the rotational force from the V belt V applied to the fixed pulley 70. In that case, since the rotational force of the drum 3 is also transmitted to the ring 11 via the key 12,
The relative rotational force also acts between the ring 11 and the cover 1. At that time, the roller 2 fixed to the cover 1 is a ring.
Since the ring 11 is fitted in the slanted groove 11b of the shaft 11, the ring 11 is moved in the axial direction of the output shaft 66 through the groove 11b in the roller 2 by the relative rotational force. ),
As shown in (c), the ring 11 is moved from the neutral position in FIG.
The teeth 11a of the ring 11 and the teeth 10b of the cam drum 10 are fitted as shown in FIG. 2B, and in this case, the cam drum 10 is fixed to the fixed pulley 70 side via the ring 11. . At that time, as shown in FIG. 3, the cam follower 8 has the slope 10aa of the groove 10a of the fixed cam drum 10.
It becomes possible to move along. On the other hand, the ring 11 is a groove with the roller 2.
When it is moved to the right in the figure via 11b, it is shown in Fig. 2 (C).
As described above, the teeth 9b of the cam drum 9 and the teeth 11a of the ring 11 are fitted to each other, and the cam drum 9 is fixed to the fixed pulley 70 side via the ring 11. At that time, as shown in FIG. 3, the cam follower 8 becomes movable along the slope 9aa of the groove 9a of the fixed cam drum 9.

Next, between the fixed pulley 70 and the movable pulley 71, the V belt V
When there is a rotation difference due to the slip of the
The cam follower 8 fixed to the drum 6 fixed to 71 fits into the groove 9a or 10a of any of the cam drums 9 and 10 in the fixed state as described above, and the slope 9aa or the groove in this groove 9a is fitted. A force that moves in the axial direction of the output shaft 66 is applied by being pressed against any of the slopes 10aa in 10a.
Therefore, the urging force of the spring 7 is assisted by the moving force of the cam follower 8, and the pressing force of the movable pulley 71 on the fixed pulley 70 is strengthened, and the slip of the V belt V is stopped. Also, when the direction of the rotational force applied to the fixed pulley 70 changes, an opposite relative rotational force acts between the drum 3 and the cover 1, and the ring 11 acts in the opposite direction, which is the opposite of the above. Either the cam drum 9 or 10 is fixed, and the cam follower 8 is guided to the groove 9a or 10a of any fixed cam drum, and the cam floor is formed according to the slopes 9aa and 10aa of the grooves 9a and 10a. 8 is moved, and the movable pulley 71 is moved according to the movement of the drum 6. Also at this time, the cam follower 8 is caused by the rotation difference due to the slip of the V belt generated between the fixed pulley 70 and the movable pulley 71.
Is pressed against one of the slopes 9aa and 10aa of the groove 9a or 10a to assist the biasing force of the spring 9, so that the V-belt V is effectively prevented from slipping.

That is, in this example, the cam follower 8 is guided by the groove 9a or 10a of the cam drum 9 or 10 and is always in contact with the slope 9aa or 10aa of the groove, and the slope 9aa or 10aa of the groove 9a or 10aa.
Since the movement is performed along the inclination of the contact state in the contact state, the cam follower and the cam drum are not momentarily interrupted as in the conventional case, there is no shock during the shift, and the tension of the belt during the shift is smooth. It is controlled.

(Effect of the Invention) The belt tensioning mechanism of the V-belt type continuously variable transmission of the present invention has a fixed pulley having a conical surface and fixed to the input shaft, and a conical surface similar to this fixed pulley. The drive pulley is composed of a movable pulley formed by forming a V groove with the fixed pulley so as to be movable in the axial direction of the input shaft, and is moved by the moving means in a direction away from and in contact with the fixed pulley, and a conical surface. A moving means that is attached so as to be movable in the axial direction of the output shaft by forming a V groove between the fixed pulley that is fixed to the output shaft and the fixed pulley that has the same conical surface as this fixed pulley. The driven pulley, which is a movable pulley that is moved in a direction away from and in contact with the fixed pulley by the drive pulley, and the V belt that is wound around each V groove of the driven pulley and the drive pulley, have no rotation of the input shaft. In a V-belt type continuously variable transmission that shifts in stages and transmits to an output shaft, a driven pulley moving means is fixed to the movable pulley of the driven pulley, and a drum in which a cam follower is provided upright on an outer peripheral surface, Two cam drums, which are arranged on the outer peripheral side of the drum and each of which has a groove engaged with the carofollower and are formed so as to intersect with each other in opposite directions, are provided on the outer peripheral surface of each of the cam drums. A ring disposed on the outer peripheral side of the cam drum having teeth on the inner peripheral surface that can be fitted in association with the direction of the rotational force of the fixed pulley is provided on any of the protruding teeth, and the ring is interposed therebetween. By fixing any of the cam drums,
By configuring the cam follower to move in the axial direction of the output shaft along any one of the grooves so that the movable pulley moves, the cam follower fixed to the movable pulley contacts the inclined groove of any cam drum. Since the cam follower moves smoothly, the V-belt can be effectively prevented from slipping during gear shifting of the transmission, and the operation can be extremely smooth without any impact during gear shifting.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention, and FIG. 1 (a) is an assembly configuration diagram showing a belt tensioning mechanism of a driven pulley on an output shaft side of a V-belt type continuously variable transmission. (B) is 1
Exploded block diagram of Figure (a), Figure 2 (a), (b), (c)
Is a development explanatory view showing a fitting state of the ring and the cam drum in FIG. 1, FIG. 3 is a development explanatory view showing a fitting state of the cam follower and a groove formed in the cam drum, and FIGS. 4 to 7 are Fig. 4 shows a conventional example, Fig. 4 is an overall configuration diagram of a conventional V-belt type continuously variable transmission, Fig. 5 is a configuration diagram of a belt tensioning mechanism on the output shaft side of Fig. 4, and Fig. 6 is a conventional cam drum. FIG. 7 is a development explanatory view showing a contact state with a cam follower, and FIG. 7 is a perspective view of a conventional drum, a cam drum and a cam follower. 1 …… Cover 2 …… Roller 3 …… Drum 4 …… Flange 6 …… Drum, 7 …… Spring 8 …… Cam follower, 9,10 …… Cam drum 9a, 10a …… Groove, 9aa, 10aa …… Slope 9b, 10b …… Tooth, 11 …… Ring 11a …… Ring tooth, 12 …… Key 66 …… Output shaft, 70 …… Fixed pulley 71 …… Movable pulley, V …… V belt

Claims (1)

[Scope of utility model registration request] 1. A V-groove is formed between a fixed pulley having a conical surface and fixed to an input shaft, and a fixed pulley having a conical surface similar to this fixed pulley to form a V groove in the input shaft. A drive pulley composed of a movable pulley that is mounted so as to be movable in the axial direction and is moved in a direction away from and in contact with the fixed pulley by moving means, a fixed pulley that has a conical surface and is fixed to the output shaft, and this fixed pulley. A follower driven by a movable pulley having a similar conical surface and formed with a V groove between the fixed pulley and the movable pulley so as to be movable in the axial direction of the output shaft and moved by the moving means in the direction away from and in contact with the fixed pulley. A V-belt type continuously variable transmission which has a pulley and a V-belt wound around each of the V-grooves of the driven pulley and the driving pulley and which continuously changes the rotation of the input shaft and transmits the rotation to the output shaft. In the above, the driven means for moving the driven pulley is fixed to the movable pulley 71 of the driven pulley S, and the drum 6 having the cam follower 8 provided upright on the outer peripheral surface thereof and the drum 6 disposed on the outer peripheral side of the drum 6 are opposed to each other. The carofollower 8 is formed so as to be inclined so as to intersect in the direction
Two cam drums 9 and 10 having respective grooves 9a and 10a engaging with each other, and teeth 9 protruding from the outer peripheral surface of each of the cam drums 9 and 10.
b, 10b, a ring 11 disposed on the outer peripheral side of the cam drum 9, 10 having teeth 11a on the inner peripheral surface that can be fitted in association with the direction of the rotational force of the fixed pulley 70, By fixing one of the cam drums 9 and 10 via the ring 11, the cam follower 8 is moved in the axial direction of the output shaft 66 along any one of the grooves 9a and 10a, and the movable pulley 71 is moved. V characterized by being configured as
Belt tension mechanism for belt type continuously variable transmission.