JP5430532B2 - Continuously variable transmission mechanism - Google Patents

Description

  The present invention comprises an endless chain link and a pulley around which the endless chain link is wound so as to be continuously variable, and is urged radially outward by a spring means around the outer periphery of the central boss of the pulley. The present invention relates to a continuously variable transmission mechanism capable of preventing slipping at a transmission ratio capable of meshing by meshing between a movable tooth provided so as to be able to advance and retract and a movable tooth meshing groove provided on an endless chain link. .

As this type of continuously variable transmission mechanism, a V-belt continuously variable transmission is well known, and a power is obtained by spanning an endless chain link over a V groove defined between a fixed sheave and a movable sheave of a pulley. While being able to communicate,
During this power transmission, the movable sheave is slid in the pulley axial direction on the pulley center boss to change the groove width of the pulley V groove, thereby continuously changing the winding diameter of the endless chain link to the pulley. Thus, a continuously variable transmission is possible.

On the other hand, as a technique for preventing slippage of the continuously variable transmission mechanism and thereby improving transmission efficiency, conventionally, as described in Patent Document 1, for example, teeth are formed on the outer peripheral surface of the central boss portion of the pulley that defines the bottom surface of the pulley V groove. Project
While the tooth groove formed on the inner periphery of the endless chain link is in the transmission ratio that meshes with the teeth on the outer peripheral surface of the pulley center boss, the transmission efficiency of the continuously variable transmission mechanism is prevented by preventing slippage between the pulley and the endless chain link. A technique for improving the above has been proposed.

  On the other hand, Patent Document 1 discloses that the teeth provided on the outer peripheral surface of the pulley center boss portion are movable teeth that are urged radially outward by a spring means so as to be able to advance and retract in the radial direction. There has also been proposed a technique capable of preventing slippage at a transmission ratio meshed with a movable tooth meshing groove provided on a terminal chain link.

According to this proposed technique, when the above-mentioned movable tooth fails to mesh with the inner peripheral tooth groove of the endless chain link, it is retracted radially inward against the spring force of the spring means by the inner periphery of the endless chain link. From getting
Since the teeth on the outer periphery of the pulley center boss part do not damage the endless chain link due to interference with the endless chain link, this is advantageous in terms of durability.

JP 2010-014269 A

  By the way, when the movable teeth are urged radially outward by the spring means on the outer periphery of the pulley central boss portion as described above so as to be able to advance and retract in the radial direction, the limit of the movable teeth radially outward with respect to the pulley central boss portion. It is necessary to define the position.

  In the above-described proposed technique, the tip of the movable tooth is positioned radially outward from the inner peripheral surface of the movable sheave that is slidably fitted on the pulley center boss portion. Therefore, the limit position of the movable tooth in the radial direction is defined.

  For this reason, when the movable sheave is slid in the axial direction on the pulley central boss so that the groove width of the pulley V groove becomes narrow, the movable sheave has a diameter against the elastic force of the spring means via the tooth tip. The inner surface of the movable sheave and the movable tooth (tooth tip) are worn due to sliding and the durability deteriorates, and the diameter of the movable tooth is reduced. There is also a problem that the spring means is greatly bent when the direction is pushed inward and the durability is deteriorated due to the deterioration.

  In particular, the problem of durability due to deterioration of the spring means is that when the slide displacement of the movable sheave brings about the lowest speed ratio selection state of the continuously variable transmission mechanism, this lowest speed ratio selection state is maintained even when parked or stopped. In particular, it is particularly noticeable because it is maintained for a long time.

  The present invention prevents the movable sheave from pushing the movable teeth radially inward even when the movable sheave is slid in the axial direction on the pulley center boss so that the groove width of the pulley V groove becomes narrower. Thus, an object of the present invention is to provide a continuously variable transmission mechanism that does not cause the above problems.

For this purpose, the continuously variable transmission mechanism according to the present invention is constituted as follows.
First, a continuously variable transmission mechanism, which is the basic premise of the gist of the present invention, will be described. It comprises an endless chain link and a pulley around which the endless chain link is wound.
And among the axially opposed sheaves of the pulley that pinch the endless chain link, one fixed sheave is fixed to the pulley central boss portion, and the other movable sheave is slid in the axial direction on the pulley central boss portion. By making it, continuously variable transmission is possible.
Further, a movable tooth provided on the outer periphery of the pulley center boss portion by urging radially outward by a spring means and elastically supported at a radial limit position, and a movable tooth engagement groove provided on the endless chain link , And slip prevention at a transmission ratio where the meshing is possible.

The present invention provides such a continuously variable transmission mechanism.
At the radial limit position of the movable tooth, the tip of the movable tooth is the same radial position as the inner peripheral surface of the movable sheave that is slidably fitted on the pulley center boss, or the radial position. It is characterized by a configuration in which the radial limit position of the movable tooth is determined so as to be a radially inward position.

In the continuously variable transmission mechanism of the present invention, the tip of the movable tooth has the same diameter as the inner peripheral surface of the movable sheave fitted axially slidably on the pulley central boss at the radial limit position of the movable tooth. Because it is in the directional position, or in the radially inner position than the radial position,
Even when the movable sheave is slid in the axial direction on the pulley central boss so that the groove width of the pulley V groove becomes narrow, the movable sheave does not push the movable teeth radially inward.

  Accordingly, it is possible to avoid the problem that the inner peripheral surface of the movable sheave and the movable tooth (tooth tip) wear due to sliding and deteriorate the durability, and the spring means is greatly bent by the inward pushing of the movable tooth in the radial direction. The problem that the durability deteriorates can also be avoided.

1 is an overall perspective view showing a secondary pulley of a continuously variable transmission mechanism according to a first embodiment of the present invention. FIG. 5 is a longitudinal sectional side view of a main part showing a winding transmission portion between an endless chain link and a secondary pulley when the continuously variable transmission mechanism according to the first embodiment is in the highest gear ratio selection state. FIG. 6 is a longitudinal sectional side view of a main part showing a winding transmission portion between an endless chain link and a secondary pulley when the continuously variable transmission mechanism according to the first embodiment is in the lowest gear ratio selection state. FIG. 5 is a perspective view showing a secondary pulley of the continuously variable transmission mechanism according to the first embodiment as viewed from the fixed sheave side, with the fixed sheave removed. FIG. 5 is a perspective view of a spring means used in the continuously variable transmission mechanism of the first embodiment shown in FIGS. FIG. 12 is a longitudinal sectional side view of a main part showing a winding transmission portion between an endless chain link and a secondary pulley when the continuously variable transmission mechanism according to the second embodiment is in the highest gear ratio selection state. FIG. 10 is a longitudinal sectional side view of a main part showing a winding transmission portion between an endless chain link and a secondary pulley when the continuously variable transmission mechanism according to the second embodiment is in the lowest gear ratio selection state. FIG. 12 is a longitudinal sectional side view of a main part showing a winding transmission portion between an endless chain link and a secondary pulley when the continuously variable transmission mechanism according to the third embodiment is in the highest gear ratio selection state. FIG. 10 is a longitudinal sectional side view of a main part showing a winding transmission portion between an endless chain link and a secondary pulley when the continuously variable transmission mechanism according to the third embodiment is in the lowest gear ratio selection state.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
<Configuration of the first embodiment>
FIGS. 1 to 5 show a continuously variable transmission mechanism according to a first embodiment of the present invention. This continuously variable transmission mechanism includes an endless chain link 1 in FIG. 2 and a secondary pulley on the driven side in FIGS. 2 and a similar drive-side primary pulley (not shown).

  In this embodiment, in particular, as shown in FIG. 2, the endless chain link 1 is wound around the innermost diameter portion of the secondary pulley 2 and the highest gear ratio is selected. The purpose is to improve the anti-slip structure to prevent slipping.

A primary pulley (not shown) and a secondary pulley 2 are similar to each other, and the secondary pulley 2 will be described with reference to FIGS. 1 to 3. A V-groove pulley having a pulley V-groove defined between sheaves 3 and 4 is used.
As shown in FIG. 2, the endless chain link 1 has a V-shaped cross section that crosses the traveling direction so as to be in surface contact with the opposing surface of the pulley V-groove. The power is transmitted between the primary pulley (not shown) and the secondary pulley 2.

  Of the sheaves 3 and 4 in the axial direction that form the primary pulley (not shown) and the secondary pulley 2, one sheave 3 is a fixed sheave fixed to the pulley shaft 5, and the other sheave 4 is attached to the pulley shaft 5. A movable sheave is rotatably engaged through a ball spline (not shown) so as to be axially slidable.

The primary pulley (not shown) and the secondary pulley 2 are arranged so that the fixed sheave 3 and the movable sheave 4 are located on the opposite sides in the axial direction.
Then, the movable sheave of the primary pulley (not shown) is moved closer to the fixed sheave to narrow the pulley V groove width, and at the same time, the movable sheave 4 of the secondary pulley 2 is moved away from the fixed sheave 3 as shown in FIG. As you increase the width,
In the endless chain link 1, the winding diameter of the primary pulley (not shown) is increased and the winding diameter of the secondary pulley 2 is reduced as shown in FIG. 2, and the continuously variable transmission mechanism is the maximum shown in FIG. Upshifting is possible under a continuously variable transmission toward the high gear ratio selection state.

Conversely, the movable sheave of the primary pulley (not shown) is moved away from the fixed sheave to widen the pulley V groove width, and at the same time, the movable sheave 4 of the secondary pulley 2 is moved closer to the fixed sheave 3 as shown in FIG. As the groove width is narrowed,
The endless chain link 1 has a smaller winding diameter for the primary pulley (not shown) and a larger winding diameter for the secondary pulley 2 (the endless chain link 1 is not visible in FIG. 3). The step-variable transmission mechanism can be downshifted under a continuously variable shift toward the lowest gear ratio selection state shown in FIG.

In order to improve the transmission efficiency of the continuously variable transmission mechanism by preventing the endless chain link 1 from slipping with respect to the secondary pulley 2 in the above-described highest gear ratio selection state of FIG.
As shown in FIGS. 1 to 4, a plurality of movable teeth 9 are provided on the central boss portion 8 of the secondary pulley 2 at regular intervals in the circumferential direction as shown in FIGS. 1 and 4.

The pulley central boss portion 8 of the secondary pulley 2 is formed by expanding the diameter of the pulley shaft 5 between the sheaves 3 and 4 as clearly shown in FIGS.
Each of the movable teeth 9 has its base portion 9a extending in the pulley axial direction so as to bridge between the sheaves 3 and 4 in the highest gear ratio selection state shown in FIG. 2, and this base portion 9a is connected to the pulley central boss portion. 8 is fitted in a movable tooth guide groove 11 provided on the outer peripheral surface so as to be able to advance and retract in the radial direction.
At this time, as shown in FIGS. 2 to 4, the tooth tip 9 b provided so as to project outward in the radial direction is the same level in the radial direction as the outer peripheral surface of the pulley center boss portion 8 as shown in FIGS. Alternatively, the radial position is set to a radially inward level.

The movable tooth 9 is urged radially outward as shown in FIGS. 2 and 3 by the spring means 12 as shown in FIG. 5, and the advancing limit position (radial limit position) is set in the radially outward direction. In defining it,
Both ends 9c, 9d of the movable tooth base 9a are positioned radially inward from the outer peripheral surface of the pulley center boss part 8, and both ends 9c, 9d of the movable tooth base 9a have a diameter with respect to the inner periphery of the sheaves 3, 4. The radial limit position of the movable tooth 9 is defined by abutting outward in the direction.
At the radial limit position, the movable tooth 9 is such that the tooth tip 9b is at the same level in the radial direction as the outer peripheral surface of the pulley center boss portion 8 or at the radial inner level.

As shown in FIGS. 2 and 3, a set of three spring means 12 is arranged, and these spring means 12 are dispersedly arranged in the longitudinal direction of the movable teeth 9, that is, in the axial direction of the pulley center boss portion 8.
In this distributed arrangement, it is preferable to disperse the spring means 12 so that the movable teeth 9 are equally divided in the longitudinal direction as much as possible.

All the spring means 12 are the same as shown in FIG. 5, and a linear U-shaped element 13 and a linear connecting element 14 are alternately arranged on the same circumference. And
The U-shaped element 13 is interposed between the outer peripheral groove 8a of the pulley center boss portion 8 and each movable tooth base portion 9a so as to extend in the generatrix direction of the pulley center boss portion 8.
Accordingly, the same number of U-shaped elements 13 as the movable teeth 9 are present, and these U-shaped elements 13 are seated on the movable teeth 9, and the connecting elements 14 are seated on the outer peripheral groove 8a of the pulley center boss portion 8.
Thus, the spring means 12 is of the torsion spring type in which the linear elements 13 and 14 are alternately combined, and each movable tooth 9 is moved radially outward through the U-shaped element 13 by the torsion spring action of the connecting element 14. Can be energized.

In order to define the radial limit position of the movable tooth 9 (extension limit position radially outward), both ends 9c and 9d of the movable tooth base 9a are opposed radially outward to the inner peripheral part of the sheaves 3 and 4. The contact structure will be described below.
Even if the sheave 3 is a fixed sheave, it is configured separately from the pulley shaft 5 as shown in FIGS. 2 and 3, and is located at the inner peripheral corner of the fixed sheave 3 near the endless chain link 1 as shown in FIGS. As shown, an annular notch 3a is formed, an inner peripheral surface 3b is set for the end 9c of the movable tooth base 9a to contact radially outward, and the sheave 3 thus molded is shown in FIGS. As shown, it is fixed to the pulley shaft 5 to form a fixed sheave.

On the other hand, the end 9d of the movable tooth base 9a on the side close to the movable sheave 4 is in the radial direction with respect to the inner peripheral surface 4a of the movable sheave 4 that fits on the outer periphery of the pulley center boss 8 as shown in FIGS. Let them hit the outside.
The radial thicknesses of the end portions 9c and 9d of the movable tooth base 9a (the vertical thickness in FIGS. 2 and 3) are the inner peripheral surface of the movable sheave as shown in FIGS. The thickness is such that it is the same radial position as 4a, or the radial inner position relative to the radial position.

At the inner edge of each link plate that defines the inner peripheral edge of the endless chain link 1, a movable tooth meshing groove 1a for meshing the tip 9b of the movable tooth 9 as shown in FIG. Provided,
In the state in which the highest gear ratio is selected in FIG. 2, the mesh of the movable tooth 9 (tooth tip 9b) and the movable tooth meshing groove 1a prevents the endless chain link 1 from slipping with respect to the secondary pulley 2, and the continuously variable transmission mechanism. To improve the transmission efficiency.

  Accordingly, when the movable tooth 9 (tooth tip 9b) is not aligned with the movable tooth meshing groove 1a and cannot be meshed with the movable tooth meshing groove 1a, the pulley against the spring force of the spring means 12 is caused by the inner peripheral edge of the endless chain link 1. In the movable tooth guide groove 11 of the central boss part 8, it can be pushed further inward in the radial direction than the position of FIG. 2, and the endless chain link 1 is damaged due to interference with the movable tooth 9 (tooth tip 9b). Can be prevented.

<Operation of the first embodiment>
In the continuously variable transmission mechanism described above, when the movable sheave 4 of the secondary pulley 2 is moved away from the fixed sheave 3 and the pulley V groove width is increased as shown in FIG. The diameter is reduced as shown in FIG. 2 and continuously variable (upshifted) to the highest gear ratio selection state.

  At this time, as shown in FIG. 2, the movable tooth engagement groove 1a at the inner peripheral edge of the endless chain link 1 is engaged with the tip 9b of the movable tooth 9, thereby preventing the endless chain link 1 from slipping with respect to the secondary pulley 2. In addition, the transmission efficiency in the state where the highest gear ratio is selected can be improved.

  Here, if the movable tooth meshing groove 1a of the endless chain link 1 and the movable tooth 9 (tooth tip 9b) fail to mesh due to misalignment, the movable tooth 9 (tooth tip 9b) becomes the inner peripheral edge of the endless chain link 1 2 against the spring force of the spring means 12 and can be pushed further radially inward than the position of FIG. 2 in the movable tooth guide groove 11 of the pulley center boss portion 8. It can be prevented from being damaged by interference with 9 (tooth tip 9b).

When the movable sheave 4 of the secondary pulley 2 is moved closer to the fixed sheave 3 as shown in FIG.
As the endless chain link 1 protrudes from FIG. 3, the winding diameter of the secondary pulley 2 is increased, and the continuously variable transmission mechanism is continuously variable (downshift) to the lowest gear ratio selection state shown in FIG. Is done.

During the downshift to the lowest gear ratio selection state, the movable sheave 4 slides on the pulley center boss portion 8 in FIG. 3 and is displaced in the axial direction indicated by the arrow in FIG.
By the way, at the radial limit position of the movable tooth 9, the tooth tip 9b is at the same radial position as the movable sheave inner peripheral surface 4a as shown in FIGS. ,
During the axial displacement of the movable sheave 4 indicated by the arrow in FIG. 3, this movable sheave 4 pushes the movable tooth 9 (tooth tip 9b) radially inward against the spring force of the spring means 12 by the inner peripheral surface 4a. There is no.

<Effects of the first embodiment>
In the above-described embodiment, the radial limit position of the movable tooth 9 urged radially outward by the spring means 12 is shown, and the tip 9b of the movable tooth 9 has a movable sheave inner periphery as shown in FIGS. Because the limit position is the same radial position as the surface 4a, or a radial inner position than the radial position,
During the downshift to the lowest gear ratio selection state due to the axial displacement of the movable sheave 4 indicated by the arrow in FIG. 3, the inner peripheral surface 4a of the movable sheave 4 moves the movable tooth 9 (tooth tip 9b) to the spring of the spring means 12. It does not push inward in the radial direction against the force.

  Therefore, sliding between the movable sheave inner peripheral surface 4a and the movable tooth 9 (tooth tip 9b) does not occur, and this sliding causes the movable sheave inner peripheral surface 4a and the movable tooth 9 (tooth tip 9b) to wear and become durable. In addition to avoiding the problem of deterioration, the wear of the movable sheave inner peripheral surface 4a causes the shift control hydraulic pressure to leak from the slide fitting portion between this and the pulley center boss portion 8, and the sheaves 3 and 4 are endless. It is possible to avoid the problem that the transmission efficiency decreases due to a decrease in the clamping pressure of the chain link 1.

  Further, the inner peripheral surface 4a of the movable sheave 4 does not push the movable tooth 9 (tooth tip 9b) inward in the radial direction against the spring force of the spring means 12, so that the movable tooth 9 is pushed inward in the radial direction. This can also avoid the problem that the spring means 12 is greatly bent and its durability is deteriorated.

In particular, in this embodiment, since the axial displacement of the movable sheave 4 indicated by the arrow in FIG. 3 brings about the lowest speed ratio selection state of the continuously variable transmission mechanism, the movable sheave 4 is movable in this lowest speed ratio selection state. The teeth 9 can be prevented from being bent inward in the radial direction so that the spring means 12 is largely bent.
By the way, the lowest gear ratio selection state is a gear ratio selection state that continues to be maintained for a long time even when parked or stopped, and the spring means 12 is greatly bent at the lowest gear ratio selected for this long time. If it is in a state, its durability is remarkably lowered, and the spring means 12 is deteriorated at an early stage.
However, in this embodiment, as described above, the movable tooth 9 is not pushed inward in the radial direction in the state where the lowest gear ratio is selected, and the spring means 12 is not greatly deflected. Avoiding the problem that the spring means 12 is not left in a largely bent state, and the radial pushing force of the movable tooth 9 is weakened due to the early deterioration accompanying this, and the effect of improving the transmission efficiency is hindered. can do.

Furthermore, in this embodiment, when defining the radial limit position of the movable tooth 9 urged radially outward by the spring means 12, both ends 9c, 9d of the movable tooth 9 (base 9a) are connected to the sheave 3, 4 butt against the inner peripheral part 3b, 4a radially outward,
Further, by adjusting the radial thickness of both ends of the movable teeth 9c, 9d, the radial limit position of the movable tooth 9 is set to the same radial position where the tip 9b of the movable tooth 9 is the same as the inner peripheral surface 4a of the movable sheave, or In order to achieve a limit position that is a radially inward position rather than a radial position,
By using existing parts (sheaves 3 and 4) effectively, the radial limit position of the movable tooth 9 can be specified at a low cost, and it is inexpensive with a simple method that just adjusts the radial thickness of the movable tooth ends 9c and 9d. Further, the tooth tip 9b of the movable tooth 9 can be set to the same radial position as the movable sheave inner peripheral surface 4a or a radially inner position than the radial position.

<Second embodiment>
FIGS. 6 and 7 are winding transmission portions of the endless chain link 1 and the secondary pulley 2 constituting the continuously variable transmission mechanism according to the second embodiment of the present invention, and are the same portions as in FIGS. Are denoted by the same reference numerals.

6 is a view similar to FIG. 2, showing the winding transmission portion of the endless chain link 1 and the secondary pulley 2 when the continuously variable transmission mechanism is in the highest gear ratio selection state.
FIG. 7 is a view similar to FIG. 3, showing the winding transmission portion of the endless chain link 1 and the secondary pulley 2 when the continuously variable transmission mechanism is in the lowest speed ratio selection state.

In this embodiment, a cylindrical movable movable member, which is an additional part, is used to define the radially outward advance limit position (radial limit position) of the movable tooth 9 urged radially outward by the spring means 12. A tooth guide 21 is used.
The cylindrical movable tooth guide 21 has a diameter that is positioned radially inward from the outer peripheral surface of the pulley center boss portion 8, and is fitted into the pulley center boss portion 8 so that the pulley center boss portion 8 Provide to maintain concentricity.

The movable tooth guide 21 is provided with a guide hole (not shown) through which the tooth tip 9b of the movable tooth 9 penetrates radially outward from the inner peripheral side thereof, and the base 9a of the movable tooth 9 is provided inside the movable tooth guide 21. The advancing limit position (radial limit position) of the movable tooth 9 to the radially outward direction is defined by making contact with the peripheral surface radially outward.
The tip 9b of the movable tooth 9 at the radial limit position of the movable tooth 9 is the same radial position as the inner peripheral surface 4a of the movable sheave 4 as shown in FIGS. The height is such that it is in the right direction.

<Operation of Second Embodiment>
When the movable sheave 4 of the secondary pulley 2 is moved away from the fixed sheave 3 as shown in FIG. Continuously variable shift (upshift) to the ratio selection state.

  At this time, the movable tooth meshing groove 1a of the endless chain link 1 comes to mesh with the tooth tip 9b of the movable tooth 9, which can prevent the endless chain link 1 from slipping with respect to the secondary pulley 2, and the highest gear ratio is selected. The transmission efficiency in the state can be improved.

  Here, when the movable tooth meshing groove 1a of the endless chain link 1 fails to engage with the movable tooth 9 (tooth tip 9b), the movable tooth 9 (tooth tip 9b) of the spring means 12 is moved by the inner peripheral edge of the endless chain link 1. In the movable tooth guide groove 11 of the pulley center boss 8 against the spring force, the endless chain link 1 can be pushed inward in the radial direction from the position of FIG. ) Can be prevented from being damaged.

When the movable sheave 4 of the secondary pulley 2 is brought closer to the fixed sheave 3 as shown in FIG.
As the endless chain link 1 protrudes from FIG. 7, the winding diameter of the secondary pulley 2 is increased, and the continuously variable transmission mechanism is continuously variable (downshift) to the lowest gear ratio selection state shown in FIG. Is done.

During the downshift to the lowest gear ratio selection state, the movable sheave 4 slides on the pulley center boss portion 8 in FIG. 7 and is displaced in the axial direction indicated by the arrow in FIG.
By the way, at the radial limit position of the movable tooth 9, the tooth tip 9b is at the same radial position as the movable sheave inner peripheral surface 4a as shown in FIGS. ,
During the axial displacement of the movable sheave 4 indicated by an arrow in FIG. 7, the movable sheave 4 pushes the movable tooth 9 (tooth tip 9b) radially inward against the spring force of the spring means 12 by the inner peripheral surface 4a. There is no.

<Effect of the second embodiment>
Also in this embodiment described above, the radial limit position of the movable tooth 9 urged radially outward by the spring means 12 is shown as the tip 9b of the movable tooth 9 as shown in FIGS. Because the limit position is the same radial position as the surface 4a, or a radial inner position than the radial position,
During the downshift to the lowest speed ratio selection state due to the axial displacement of the movable sheave 4 indicated by the arrow in FIG. 7, the inner peripheral surface 4a of the movable sheave 4 moves the movable tooth 9 (tooth tip 9b) to the spring of the spring means 12. It does not push inward in the radial direction against the force.

  Therefore, sliding between the movable sheave inner peripheral surface 4a and the movable tooth 9 (tooth tip 9b) does not occur, and this sliding causes the movable sheave inner peripheral surface 4a and the movable tooth 9 (tooth tip 9b) to wear and become durable. In addition to avoiding the problem of deterioration, the wear of the movable sheave inner peripheral surface 4a causes the shift control hydraulic pressure to leak from the slide fitting portion between this and the pulley center boss portion 8, and the sheaves 3 and 4 are endless. It is possible to avoid the problem that the transmission efficiency decreases due to a decrease in the clamping pressure of the chain link 1.

Further, the inner peripheral surface 4a of the movable sheave 4 does not push the movable tooth 9 (tooth tip 9b) inward in the radial direction against the spring force of the spring means 12, so that the movable tooth 9 is pushed inward in the radial direction. As a result, the problem that the spring means 12 is greatly bent and its durability deteriorates can be avoided,
The state in which the spring means 12 is greatly bent continues for a long time during selection of the lowest speed ratio, and the spring means 12 can weaken the radial pushing force of the movable tooth 9 due to the early deterioration accompanying this. Thus, it is possible to avoid the problem that the effect of improving the transmission efficiency is hindered.

Further, in this embodiment, when the radial limit position of the movable tooth 9 urged radially outward by the spring means 12 is defined, it is fitted inward in the radial direction from the outer peripheral surface of the pulley center boss portion 8. To use the combined cylindrical movable tooth guide 21,
It is not necessary to provide the fixed sheave 3 with the annular notch 3a as shown in FIGS. 2 and 3, and it is possible to prevent the strength reduction of the fixed sheave 3 due to the formation of the annular notch 3a.

<Third embodiment>
FIGS. 8 and 9 are winding transmission portions of the endless chain link 1 and the secondary pulley 2 constituting the continuously variable transmission mechanism according to the third embodiment of the present invention, and are the same portions as in FIGS. Are denoted by the same reference numerals.

FIG. 8 is a view similar to FIG. 2 showing the winding transmission portion of the endless chain link 1 and the secondary pulley 2 when the continuously variable transmission mechanism is in the highest gear ratio selection state.
FIG. 9 is a view similar to FIG. 3, showing the winding transmission portion of the endless chain link 1 and the secondary pulley 2 when the continuously variable transmission mechanism is in the lowest speed ratio selection state.

  In the present embodiment, in defining the advance limit position (radial limit position) of the movable tooth 9 urged radially outward by the spring means 12 in the radial outward direction, the first shown in FIGS. Similarly to the embodiment, both ends 9c and 9d of the movable tooth base 4a are brought into contact radially outward with the inner peripheral surfaces 3b and 4a of the sheaves 3 and 4 to define the radial limit position of the movable tooth 9. To do.

  However, at the radial limit position of the movable tooth 9, among the tooth tips 9b, 9e of the movable tooth 9, the same radial position as the movable sheave inner peripheral surface 4a, or a radially inner position than the radial position. The tooth tip 9b is a tooth in a region covered by the inner surface 4a of the movable sheave when the movable sheave 4 strokes between the highest gear ratio selection position shown in FIG. 8 and the lowest gear ratio selection position shown in FIG. Only the tip part.

Then, the tooth tip 9e of the movable tooth 9 in the remaining region has a larger diameter than the tooth tip 9b, and the movable tooth 9 has a stepped tooth tip composed of a small diameter tooth tip 9b and a large diameter tooth tip 9e. Provide.
The movable tooth meshing groove 1a meshing with the small diameter tooth tip 9b is the same as that of the first embodiment shown in FIG. 2, and the movable tooth meshing groove 1b meshing with the large diameter tooth tip 9e is a tooth as shown in FIG. The transmission efficiency is increased by meshing with the tip 9e.

<Operation of the third embodiment>
When the movable sheave 4 of the secondary pulley 2 is moved away from the fixed sheave 3 as shown in FIG. Continuously variable shift (upshift) to the ratio selection state.

  At this time, the movable tooth meshing grooves 1a, 1b of the endless chain link 1 are engaged with the tooth tips 9b, 9e of the movable tooth 9, respectively, and the slip of the endless chain link 1 with respect to the secondary pulley 2 can be prevented, It is possible to improve the transmission efficiency when the highest gear ratio is selected.

  Here, if the movable tooth meshing grooves 1a, 1b of the endless chain link 1 fail to mesh with the movable teeth 9 (tooth tips 9b, 9e), the movable teeth 9 (tooth tips 9b, 9e) The endless chain link 1 is movable because it can be pushed further radially inward than the position of FIG. 8 in the movable tooth guide groove 11 of the pulley center boss 8 against the spring force of the spring means 12 by the peripheral edge. It is possible to prevent damage due to interference with the teeth 9 (tooth tips 9b, 9e).

When the movable sheave 4 of the secondary pulley 2 is moved closer to the fixed sheave 3 as shown in FIG.
As the endless chain link 1 protrudes from FIG. 9, the winding diameter of the secondary pulley 2 is increased, and the continuously variable transmission mechanism is continuously shifted to the lowest gear ratio selection state shown in FIG. 9 (downshift). Is done.

During the downshift to the lowest gear ratio selection state, the movable sheave 4 slides on the pulley center boss portion 8 in FIG. 9 and is displaced in the axial direction indicated by the arrow in FIG.
By the way, at the radial limit position of the movable tooth 9, the tooth tip 9b is at the same radial position as the movable sheave inner peripheral surface 4a, as shown in FIGS. ,
During the axial displacement of the movable sheave 4 indicated by the arrow in FIG. 9, the movable sheave 4 pushes the movable tooth 9 (tooth tip 9b) radially inward against the spring force of the spring means 12 by the inner peripheral surface 4a. There is no.

<Effect of the third embodiment>
Also in the present embodiment described above, the radial limit position of the movable tooth 9 urged radially outward by the spring means 12, the tip 9b of the movable tooth 9 as shown in FIGS. Because the limit position is the same radial position as the surface 4a, or a radial inner position than the radial position,
During the downshift to the lowest gear ratio selection state due to the displacement in the axial direction of the movable sheave 4 indicated by the arrow in FIG. It does not push inward in the radial direction against the force.

  Therefore, sliding between the movable sheave inner peripheral surface 4a and the movable tooth 9 (tooth tip 9b) does not occur, and this sliding causes the movable sheave inner peripheral surface 4a and the movable tooth 9 (tooth tip 9b) to wear and become durable. In addition to avoiding the problem of deterioration, the spring means 12 is greatly bent due to the radially inward pushing of the movable tooth 9 to deteriorate its durability, or the spring means 12 is greatly bent for a long time. Thus, the problem of early deterioration can be avoided.

Further, in the present embodiment, at the radial limit position of the movable tooth 9, among the tooth tips 9b, 9e of the movable tooth 9, the same radial position as the movable sheave inner peripheral surface 4a, or more radial than the radial position. When the movable sheave 4 strokes between the highest gear ratio selection position shown in FIG. 8 and the lowest gear ratio selection position shown in FIG. 9, the inner peripheral surface 4a of the movable sheave is Because only the tooth tip portion of the covered region, the tooth tip 9e of the movable tooth 9 in the remaining region is larger than the tooth tip 9b,
Engagement with the large-diameter tooth tip 9b and the movable tooth meshing groove 1b increases the transmission torque capacity between the endless chain link 1 and the secondary pulley 2, further improving the efficiency of transmission efficiency by the movable tooth 9. can do.

<Other examples>
As shown in FIGS. 8 and 9, only the tip portion 9b in the tip region of the movable tooth 9 covered by the movable sheave inner peripheral surface 4a during the stroke of the movable sheave 4 is the same radial position as the movable sheave inner peripheral surface 4a. Or the radial inner position than the radial position, the idea of making the tooth tip portion 9e in the other region larger than the tooth tip portion 9b,
Needless to say, the present invention can be applied to a configuration in which the radial limit position of the movable tooth 9 is defined by the cylindrical movable tooth guide 21 as shown in FIGS.

In each of the first to third embodiments, the slip between the endless chain link 1 and the secondary pulley 2 is prevented in order to prevent the slip between the endless chain link 1 and the secondary pulley 2 in the highest gear ratio selection state. Although the idea of the present invention was applied to the case where a prevention mechanism (movable tooth 9, movable tooth meshing groove 1a) exists,
In order to prevent slip between the endless chain link 1 and the primary pulley (not shown) in the state where the lowest gear ratio is selected, the above-described idea of the present invention is also provided when a similar anti-slip mechanism exists between them. It is needless to say that the same effect as described above can be obtained by this application.

1 Endless chain link
1a, 1b Movable tooth meshing groove
2 Secondary pulley
3 Fixed sheave
3a annular notch
3b Inner circumferential surface of annular notch
4 Movable sheave
4a Movable sheave inner surface
5 Pulley shaft
8 Pulley center boss
9 Movable teeth
9a base
9b, 9e tooth tip
11 Movable tooth guide groove
12 Spring means
21 Movable tooth guide

Claims (4)

It consists of an endless chain link and a pulley around which this endless chain link is wound.
Among the axially opposed sheaves of the pulley that pinch the endless chain link, one fixed sheave is fixed to the pulley central boss portion, and the other movable sheave is slid in the axial direction on the pulley central boss portion. Can be continuously variable,
A movable tooth that is urged radially outward by a spring means on the outer periphery of the pulley center boss portion and elastically supported at a radial limit position, and a movable tooth meshing groove provided on the endless chain link In the continuously variable transmission mechanism that enables slip prevention at a transmission ratio that enables the meshing,
At the radial limit position of the movable tooth, the tip of the movable tooth has the same radial position as the inner peripheral surface of the movable sheave that is slidably fitted on the pulley center boss, or the radial position. A continuously variable transmission mechanism characterized in that a radial limit position of the movable tooth is determined so as to be a radially inward position. In the continuously variable transmission mechanism according to claim 1,
The pulley is configured such that both ends of the movable teeth in the axial direction of the pulley are brought into contact radially outward with respect to the inner peripheral portion of the axially opposed sheave, thereby defining a radial limit position of the movable teeth,
The radial thickness at both ends of the pulley in the axial direction of the movable tooth is set so that the tip of the movable tooth is the same radial position as the inner peripheral surface of the movable sheave at the radial limit position of the movable tooth, or more than the radial position. A continuously variable transmission mechanism characterized by being determined to be a radially inward position. In the continuously variable transmission mechanism according to claim 1,
The movable teeth are brought into contact with the inner periphery of a cylindrical movable tooth guide provided by being fitted to the outer periphery of the pulley center boss, and the radial limit position of the movable teeth is defined.
With the inner diameter of the movable tooth guide, the tip of the movable tooth is the same radial position as the inner peripheral surface of the movable sheave at the radial limit position of the movable tooth, or a radially inner position than the radial position. A continuously variable transmission mechanism characterized in that it is determined as follows. In the continuously variable transmission mechanism according to any one of claims 1 to 3,
The tip of the movable tooth has the same radial position as the inner peripheral surface of the movable sheave or a diameter larger than the radial position only in the region covered by the inner peripheral surface of the movable sheave during the axial sliding of the movable sheave. A continuously variable transmission mechanism characterized in that it is set in a direction inward direction.

Images