JP6595364B2 - Continuously variable transmission - Google Patents

Description

  The present invention relates to a continuously variable transmission suitable for use in a vehicle power plant.

  In a continuously variable transmission including a driving pulley, a driven pulley, and a chain spanned between these pulleys, power is usually transmitted by frictional contact between the sheave surface of the pulley and the end of the link pin of the chain. To do.

  On the other hand, in Patent Document 1, a meshing portion that meshes with an uneven meshed portion on the inner periphery of the chain is provided on the outer periphery of the shaft portion of the pulley, and shear resistance (shearing force) by the meshing portion is used. Techniques have been proposed that enable power transmission without relying solely on frictional force due to frictional contact.

JP 2010-14269 A

  However, in the above technique, power can be transmitted by meshing of the meshing portion only when the chain is at the lowest or highest position where the chain is located at the minimum radius with respect to the pulley. If it depends on transmission and the thrust of the pulley for clamping the chain is not sufficient, the frictional force is insufficient and slippage occurs between the pulley and the chain.

  Therefore, for example, as shown in FIG. 7, a radial groove 122 is provided on the sheave surface 120 of the pulley, a space 114a is provided at the tip of the link pin 114 of the chain, and the inner pin 116 is installed in the space 114a so as to be able to appear and retract. A structure is conceivable.

  When the spring 118 is interposed at the base end of the inner pin 116 and the position of the tip of the inner pin 116 comes to the position of the groove 122 of the sheave surface 120, the tip of the inner pin 116 enters the groove 122 by the biasing force of the spring 118. Enter and mesh.

  Thereby, even when the chain is not at the minimum radius position, power transmission by meshing is added to power transmission by frictional contact, and the occurrence of slippage between the pulley and the chain can be suppressed.

  However, as shown in FIG. 7, when the tip position of the inner pin 116 deviates from the position of the groove 122 of the sheave surface 120, the inner pin 116 enters a state of “pushing back” the sheave surface 120 of the pulley by the biasing force of the spring 118. Part of the thrust applied from the sheave surface 120 of the pulley is used as a reaction force to the inner pin 116, and the necessary thrust for power transmission is increased.

  Therefore, the transmission torque capacity between the pulley and the chain varies depending on whether the tip of the inner pin 116 is engaged with the groove on the sheave surface, and in particular, a large number of inner pins 116 are in the groove on the sheave surface. If they are engaged or not engaged, the transmission torque capacity fluctuates greatly, causing vibrations. If the transmission torque capacity decreases greatly, slippage between the pulley and the chain tends to occur.

  The present invention has been devised in view of such problems, and enables transmission of power using a shearing force generated by meshing between a groove formed on a sheave surface of a pulley and an inner pin provided at an end of a link pin of the chain. However, an object of the present invention is to provide a continuously variable transmission capable of suppressing a decrease in transmission torque capacity between the pulley and the chain accompanying this.

  (1) In order to achieve the above object, a continuously variable transmission according to the present invention connects a pair of pulleys, a plurality of link plates, and the link plates to each other and makes contact with each sheave surface of the pair of pulleys. A chain formed of a plurality of link pins having distal end surfaces, and a chain wound around the pair of pulleys, wherein a radial groove is formed on the sheave surface of at least one of the pair of pulleys, The plurality of link pins have an accommodation space formed in the pin axial direction, and a convex portion that can mesh with the groove is formed at a tip portion, and the convex space can protrude and retract from the tip surface of the link pin. A plurality of first link pins having an inner pin housed therein, and a biasing means for biasing the inner pin toward the sheave surface, and a plurality of first links not having the inner pin and the biasing means. 2 It is characterized by having a Kupyn, the.

  (2) It is preferable that the installation interval between any two adjacent first link pins is different from the installation interval between the other two adjacent first link pins.

  (3) The first link pins are preferably arranged at random intervals along the traveling direction of the chain.

  (4) In the state in which the convex portion of the inner pin is immersed in the accommodation space, the biasing means has a biasing force with respect to the immersion stroke of the inner pin rather than a state in which the convex portion protrudes from the storage space. It is also preferable to have a non-linear characteristic in which the increase rate decreases.

  In this case, it is preferable that the urging means is a non-linear spring in which the increase rate of the urging force decreases as the deflection increases.

  The nonlinear spring preferably includes a first spring portion and a second spring portion that are connected in series, and a stopper that applies a compression set load to the second spring portion.

  The compression set load is larger than the compressive load applied to the nonlinear spring in the protruding state in which the convex portion of the inner pin enters the groove, and the convex portion of the inner pin contacts the sheave surface. It is preferably set smaller than the compressive load received by the non-linear spring in the immersed state where it is in contact and immersed in the accommodation space.

  According to the present invention, the inner pin of the first link pin is urged by the urging means, and the convex portion at the tip thereof is engaged with the groove on the sheave surface, so that power can be transmitted using shear force. Thus, it is possible to secure a transmission torque capacity between the link pin and the sheave surface while reducing a load such as a hydraulic pressure for increasing the pulley thrust.

  When the convex part does not mesh with the groove of the sheave surface, the urging force applied to the inner pin leads to an increase in the necessary thrust of the pulley. When all the pins are the first link pins by suppressing the number of the first link pins by using the second link pins having no inner pins and urging means (in the case of 100% of the first link pins). As compared with the above, an increase in the required thrust of the pulley can be suppressed.

  Furthermore, the transmission torque capacity between the pulley and the chain fluctuates depending on whether the convex portion engages with the groove on the sheave surface or not, and in particular, many inner pins engage or engage with the groove on the sheave surface. Otherwise, the transmission torque capacity fluctuates greatly, but a part of the link pin is used as the first link pin, and the rest is used as the second link pin having no inner pin and biasing means. By suppressing the number, the variation in the transmission torque capacity can be suppressed, the occurrence of vibration can be suppressed, and the transmission torque capacity can be secured.

It is a side view showing a schematic structure of a continuously variable transmission according to each embodiment of the present invention. It is a side view which shows the principal part structure of the continuously variable transmission which concerns on 1st, 2nd embodiment of this invention. FIG. 5 is a cross-sectional view of a main part showing a structure of a link pin of a chain of a continuously variable transmission according to the first and second embodiments of the present invention (a cross-sectional view of the main part taken along the line AA in FIG. 4A); It is a figure which shows the structure of the link pin of the chain of the continuously variable transmission which concerns on 1st, 2nd embodiment of this invention, Comprising: (a) is a partial side view of the chain which shows the end surface of a link pin, (b) is a link FIG. 4C is a longitudinal sectional view (a sectional view taken along the line B-B in FIG. 4A) of the pin, and FIG. 5C is a lateral sectional view of the link pin (a sectional view taken along the line C-C in FIG. 4B). It is a graph which shows the characteristic of the biasing member with which the link pin of the chain of the continuously variable transmission which concerns on 2nd Embodiment of this invention is equipped. It is a figure explaining the biasing member with which the link pin of the chain of the continuously variable transmission which concerns on 2nd Embodiment of this invention is equipped, (a) is a side view which shows the structure of a biasing member, (b) These are graphs showing the characteristics of the biasing member. It is principal part sectional drawing of the link pin explaining the subject of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the following embodiments can be implemented with various modifications without departing from the spirit thereof, and can be selected as necessary or can be appropriately combined.

[1. First Embodiment]
First, a first embodiment will be described with reference to FIGS.
[1-1. overall structure]
As shown in FIGS. 1 and 2, the continuously variable transmission according to this embodiment includes a pair of pulleys 2 and 4 and a chain 10 wound around the pulleys 2 and 4.

  The pulley 2 is a primary pulley (driving side pulley) connected to a driving source, and the pulley 4 is a secondary pulley (driven pulley) connected to a driving target side. 2 and 4 are also composed of a fixed pulley and a movable pulley.

  The fixed pulley and the movable pulley each have a sheave surface 20 (shown only on one side of each of the pulleys 2 and 4 in FIG. 1), and the sheave surface 20 of the fixed pulley and the sheave surface 20 of the movable pulley face each other to form a V groove. Is forming.

  The chain 10 is formed in a continuous annular shape from a large number of link plates 12 arranged in the chain width direction and the chain traveling direction, and a plurality of link pins 14 that connect these link plates 12 in a daisy chain.

  Link pin insertion holes 12a are formed in the front and rear portions of each link plate 12 in the chain traveling direction, and the link pin insertions of the plurality of link plates 12 forming a link row are arranged side by side in the chain width direction. A common link pin 14 is inserted through the hole 12a.

  A plurality of such link rows are provided with the phases shifted in the chain traveling direction, and these link rows are also connected by link pins 14 inserted through the link pin insertion holes 12a and configured in a continuous annular shape.

[1-2. Configuration of link pin and sheave surface]
Next, the link pin 14 and the sheave surface 20 having a specific configuration in the continuously variable transmission will be described with reference to FIGS. In addition, although the following structure shall be provided in both the pulleys 2 and 4 here, you may provide only in one of the pulleys 2 and 4. FIG.

  As shown in FIG. 2, a large number of grooves 22 a and 22 b having the same cross-sectional shape are formed on the sheave surface 20 radially and at intervals in the circumferential direction. Further, on the facing sheave surface 20, similar grooves 22a and 22b (hereinafter denoted by reference numeral 22 if they are not distinguished) are formed at the same rotational phase position.

  Here, long grooves 22a extending from the outer peripheral portion of the sheave surface 20 toward the center are provided at equal intervals, and short grooves 22b formed only in the vicinity of the outer peripheral portion of the sheave surface 20 are arranged between the long grooves 22a. It is provided at intervals.

Moreover, as shown in FIGS. 2-4, in this embodiment, the link pin 14 is arrange | positioned and penetrated by each link pin insertion hole 12a substantially 2 symmetrically adjacent to the chain advancing direction.
As shown in FIG. 2, the link pin 14 has two types, a first link pin 14A having an inner pin 16 and a coil spring 18, and a second link pin 14B having no inner pin 16 and a coil spring 18. is doing.

  The first link pin 14A will be described as an example. When the chain 10 is attached to a pair of pulleys 2 and 4, as shown in FIG. 4B, both end surfaces (tip surfaces) 14a and 14b of the link pin 14A are Opposite the sheave surface 20 of the pulleys 2 and 4, both end surfaces 14 a and 14 b of the link pin 14 are inclined so as to be parallel to the sheave surface 20.

  Each link pin 14A is formed with a receiving space 14c in the pin axial direction so as to penetrate both end faces 14a and 14b of the link pin 14A. Inside the receiving space 14c, inner pins 16 and 16 and a coil spring ( Urging means) 18 is accommodated.

  The coil spring 18 is disposed in the pin axial direction intermediate portion in the housing space 14c, and the inner pins 16 and 16 are disposed on both end surfaces 14a and 14b side in the housing space 14c so as to sandwich the coil spring 18, respectively.

  In the present embodiment, two identical coil springs 18 are arranged in parallel, but the number of coil springs 18 may be one or more than two. In addition, a general linear spring having a linear characteristic is used for the coil spring 18 of the present embodiment.

  Each inner pin 16 is movable in the pin axis direction in the accommodation space 14c, and the base portion 16b is accommodated in the accommodation space 14c in a state where the coil spring 18 is compressed.

  A convex portion 16a that can mesh with the grooves 22a and 22b is formed at the distal end portion of each inner pin 16, and the convex portion 16a accommodates the base portion 16b in the accommodating space 14c so as to be able to protrude and retract from the end surfaces 14a and 14b of the link pin. Has been.

  Therefore, each inner pin 16 is urged toward the sheave surface 20 by the coil spring 18, and the protrusion 16a at the tip of the inner pin 16 does not match the rotational phase with the grooves 22a and 22b of the sheave surface 20. The convex portion 16a is pressed by the sheave surface 20 and is immersed in the accommodation space 14c.

  Conversely, when the convex portion 16a at the tip of the inner pin 16 is aligned in rotation with the grooves 22a and 22b of the sheave surface 20, the convex portion 16a protrudes outward from the accommodation space 14c and enters the grooves 22a and 22b. Mesh.

  When the convex portion 16a of the inner pin 16 enters and meshes with the grooves 22a and 22b, the power transmission between the chain 10 and the pulleys 2 and 4 is caused by friction between the both end surfaces 14a and 14b of the link pin 14 and the sheave surface 20. In addition to power transmission using force, power transmission using shear resistance (shearing force) by the convex portions 16a, the grooves 22a and 22b and the meshing portions is added.

  In the case of power transmission using a frictional force, it is necessary to increase the thrust of the pulleys 2 and 4 to secure the pressure contact force between the link pin 14A and the sheave surface 20, such as hydraulic pressure for increasing the thrust of the pulleys 2 and 4. Although the burden becomes extremely large, in the power transmission using the shearing force, a large force can be easily transmitted without increasing the thrust so much.

  As described above, in this embodiment, a part of the link pin 14 is the first link pin 14A having the inner pin 16 and the coil spring 18, and the rest is the first link pin 14A having no inner pin 16 and the coil spring 18. Two link pins 14B are provided.

  In the case of the first link pin 14 </ b> A having the inner pin 16, if the inner pin 16 is engaged in the groove 22, the link pin 14 and the sheave surface 20 are reduced while reducing a load such as hydraulic pressure for increasing the thrust of the pulleys 2 and 4. The transmission torque capacity can be secured.

  On the other hand, if the inner pin 16 is brought into pressure contact with the sheave surface 20 without meshing with the groove 22, the necessary thrust for power transmission applied from the sheave surface 20 is increased, so that the thrust load on the pulleys 2 and 4 is reduced. In some cases, the inner pin 16 provided in the above increases the thrust load of the pulleys 2 and 4.

  The transmission torque capacity between the pulleys 2 and 4 and the chain 10 varies depending on whether the inner pin is engaged in the groove 22 or not, and in particular, a large number of inner pins are engaged or engaged with the groove 22. If not, the variation in the transmission torque capacity becomes large, causing vibrations. If the transmission torque capacity is greatly reduced, slippage between the pulleys 2 and 4 and the chain 10 is likely to occur.

  In this regard, if the urging force of the urging means for urging the inner pin toward the sheave surface 20 is suppressed, and the meshing with the groove 22 of the sheave surface 20 of the inner pin can be maintained, the fluctuation of the transmission torque capacity can be maintained. The thrust load of the pulleys 2 and 4 when the inner pin does not mesh with the groove 22 can be reduced.

  However, if the urging force that urges the inner pin toward the sheave surface 20 is suppressed, the necessary urging force may not be obtained due to a slight component error or assembly error. I want to secure only a certain size.

  Therefore, in the present embodiment, by mixing the first link pin 14A having the inner pin and the second link pin 14B not having the inner pin, the probability that the inner pin meshes with the groove 22 decreases, An increase in required thrust applied from the sheave surface 20 due to the pressure contact of the inner pin to the sheave surface 20 is suppressed.

  In this case, if the ratio of the first link pin 14A to the entire pin is made too low (closer to 0%), the number of inner pins to be engaged decreases, and the effect of improving the transmission torque capacity due to the engagement of the inner pins can be obtained. Absent. This effect tends to increase as the proportion of the first link pin 14A increases.

On the other hand, if the ratio of the first link pin 14A is too high (closer to 100%), a situation in which a large number of inner pins are engaged or not engaged with the groove 22 is likely to occur, and the transmission torque capacity is reduced. Variation (variation) increases. For example, when the ratio of the first link pins is 100%, the effect of suppressing variation in the transmission torque capacity is zero, and this effect tends to increase as the ratio of the first link pins 14A decreases.

  From the standpoint of suppressing fluctuations in the number of inner pins engaged in this way, the first link pin for the entire pin is able to achieve both suppression of fluctuations in transmission torque capacity and improvement in transmission torque capacity due to engagement of the inner pins. It is preferable to set the ratio (number) of 14A.

  Although the ratio of the first link pin to the entire pin is not limited, it is preferable to select the following ratio when it is desired to improve the transmission torque capacity and suppress the variation in the transmission torque capacity.

  In order to improve the transmission torque capacity, the ratio of the first link pins is preferably 50%, more preferably 60% or more, and still more preferably 70% or more. As the ratio increases, the transmission torque capacity increases.

  On the other hand, in order to suppress variation in transmission torque capacity, the ratio of the first link pins is preferably 90% or less, more preferably 80% or less, and still more preferably 70% or less.

  In order to achieve both improvement in transmission torque capacity and suppression of variation in transmission torque capacity, the lower limit and the upper limit may be appropriately selected from the options. However, when weight is given to improvement in transmission torque capacity, the ratio of the first link pin is It is preferably 70% or more and less than 90%.

  In the present embodiment, as shown in FIG. 2, the first link pins 14A and the second link pins 14B are randomly mixed.

  That is, the link pins 14 including the first link pins 14A and the second link pins 14B are arranged so as to be regularly arranged in the chain traveling direction, and the first link pins 14A are the chains. Rather than being arranged at equal intervals along the traveling direction, they are irregularly arranged at random intervals along the chain traveling direction.

  In other words, the installation interval (pitch) of the first link pins 14A is not uniform, and at least some of the pitches are different from other pitches. Therefore, the number of second link pins 14B disposed between two adjacent first link pins 14A is a random number including zero. When the pitch is random, it is possible to suppress the occurrence of a state in which the plurality of inner pins and the plurality of grooves 22 are not meshed at the same time.

[1-3. Action and Effect]
Since the continuously variable transmission according to the first embodiment of the present invention is configured as described above, what kind of operation and effect can be obtained.

Regardless of the position of the chain 10 in the radial direction of the pulleys 2 and 4, that is, not only at the highest level or the lowest level, but also at any gear ratio, the convex portion 16a of the inner pin 16 of the link pin 14A has the groove 22. It can enter and mesh.
When the convex portion 16a of the inner pin 16 enters into the groove 22 and meshes, the power transmission between the chain 10 and the pulleys 2 and 4 causes a frictional force due to the pressure contact between the both end surfaces 14a and 14b of the link pin 14 and the sheave surface 20. In addition to the power transmission utilized, power transmission utilizing the shearing force generated by the convex portions 16a, the grooves 22, and the meshing portions is added, and the transmission torque capacity is improved.

  That is, in the case of power transmission using frictional force, it is necessary to secure a high pressure contact force between the link pin 14 and the sheave surface 20, and the load of hydraulic pressure or the like for increasing the thrust of the pulleys 2 and 4 becomes extremely large. In power transmission using shearing force, a large force can be easily transmitted.

  Therefore, it is possible to secure a transmission torque capacity between the link pin 14 and the sheave surface 20 while reducing a load such as a hydraulic pressure for increasing the thrust of the pulleys 2 and 4.

  In the present embodiment, since the first link pin 14A having the inner pin and the second link pin 14B having no inner pin are mixed, the probability that the inner pin meshes with the groove 22 decreases. Although the effect of the above is reduced, the inner pin is pressed against the sheave surface 20 by reducing the number of inner pins that are pressed against the sheave surface 20 while ensuring the urging force that urges the inner pin toward the sheave surface 20. The increase in required thrust applied from the sheave surface 20 can be suppressed.

  Therefore, by suppressing the increase in the necessary thrust, it is possible to reduce the burden of hydraulic pressure or the like for securing the thrust of the pulleys 2 and 4.

  Further, the transmission torque capacity between the pulleys 2 and 4 and the chain 10 varies depending on whether the convex portion of the inner pin of the first link pin 14A is engaged with the groove 22 of the sheave surface 20 or not. If the torque capacity is greatly reduced, slippage between the pulleys 2 and 4 and the chain 10 is likely to occur.

  Therefore, if all the link pins 14 are the first link pins 14A, the variation in the transmission torque capacity between the pulleys 2 and 4 and the chain 10 increases, but in this embodiment, only a part of the link pins 14 is used. Since the first link pin 14A is used, fluctuations in the transmission torque capacity can be suppressed, and the level of vibration generated in the continuously variable transmission due to this can be suppressed.

  In the present embodiment, since the first link pins 14A and the second link pins 14B are randomly mixed, fluctuations in the transmission torque capacity and vibrations generated in the continuously variable transmission due to the fluctuations are transmitted. The level can be suppressed.

  When the first link pins 14A are regularly arranged, the convex portions of the inner pins of the first link pins 14A are synchronized with the grooves 22 regularly arranged in the circumferential direction. At the same time, it may protrude or immerse, and the fluctuation of the transmission torque capacity between the pulleys 2 and 4 and the chain 10 becomes large, which may cause a resonance phenomenon.

  On the other hand, since the first link pins 14A are randomly arranged, it is possible to suppress the increase in the fluctuation of the transmission torque capacity, and to reduce the level of vibration generated in the continuously variable transmission due to this. It is possible to suppress the possibility of causing a resonance phenomenon.

[2. Second Embodiment]
Next, a second embodiment will be described with reference to FIGS. The continuously variable transmission of the second embodiment is different from that of the first embodiment only in the coil spring 18 and the other configuration is the same as that of the first embodiment, and therefore the description thereof is omitted.

  In the second embodiment, a coil spring 18 having a specific configuration will be described with reference to FIGS.

  FIG. 5 is a diagram showing the spring characteristics of the coil spring 18. The horizontal axis indicates the amount of distortion (shrinkage stroke) of the coil spring 18, and the vertical axis indicates the load applied to the coil spring 18. In other words, the reaction force of the coil spring 18 against the load. (Energizing force)] is shown respectively.

  Although the natural length S1, S2 is described on the horizontal axis of FIG. 5, the natural length indicates a state in which the coil spring 18 does not receive any external force such as compressive force or tensile force, and S1 indicates that the coil spring 18 is between the sheave surfaces 20, 20. S2 indicates a state where the coil spring 18 is extended to the maximum (state in which the convex portion 16a protrudes to the maximum), and S2 indicates a state in which the coil spring 18 contracts to a minimum between the sheave surfaces 20 and 20 (a state where the convex portion 16a is immersed in the accommodation space 14c). Is shown.

  In FIG. 5, the solid line indicates the spring characteristic of the coil spring 18, and the broken line indicates the general spring characteristic of the coil spring. The inclination of each characteristic line indicates the contraction stroke of the coil spring 18 (that is, the inner pin 16 This corresponds to the rate of increase of the reaction force (biasing force) of the coil spring 18 with respect to the (immersion stroke) and corresponds to the spring constant of the coil spring 18.

  As shown by a solid line in FIG. 5, the coil spring 18 has the inner pin 16 in a state in which the convex portion 16a of the inner pin 16 is immersed in the accommodating space 14c than in a state in which the convex portion 16a protrudes from the accommodating space 14c. A non-linear spring having a non-linear characteristic in which the increasing rate of the urging force with respect to the immersing stroke (the contracting stroke of the coil spring 18) decreases is used.

  When the convex portions 16a of the inner pins 16 at both ends of the coil spring 18 are in phase with the grooves 22a and 22b of the sheave surface 20, the convex portions 16a protrude outward from the accommodation space 14c and enter the grooves 22a and 22b. Mesh. In the protruding state of the inner pin 16, the coil spring 18 is in the maximum extension state of the contraction stroke S1 shown in FIG.

  Also, if the convex portions 16a of the inner pins 16 at both ends of the coil spring 18 are not aligned in rotation with the grooves 22a and 22b of the sheave surface 20, the convex portions 16a are pressed by the sheave surface 20 and are immersed in the accommodation space 14c. To do. When the inner pin 16 is immersed, the coil spring 18 is in the minimum contracted state with the contraction stroke S2 shown in FIG.

  When the coil spring 18 has a non-linear characteristic as shown by a solid line in FIG. 5, compared with a normal linear spring having a linear characteristic as shown by a broken line in FIG. 5, the inner spring 16 is engaged with the grooves 22 a and 22 b. The urging force when the inner pin 16 is immersed can be reduced while securing the urging force.

  That is, the rate of increase of the urging force with respect to the immersing stroke of the inner pin 16, that is, the slope of the characteristic line of the coil spring 18 shown by a solid line in FIG. Set smaller than the linear spring.

  Thereby, in the maximum extension state (S1) of the coil spring 18 in which the inner pin 16 is in the protruding state, the load (biasing force) L1 is larger than that in the linear spring, and the minimum contraction state (in the coil spring 18 in which the inner pin 16 is in the immersion state) In S2), the load (biasing force) L2 can be made smaller than that of the linear spring.

  Such a non-linear spring includes, for example, a first coil spring (first spring portion) 18a and a second coil spring (second spring portion) 18b connected in series, as shown in FIG. A stopper 18c that applies a compression set load LS to the coil spring 18b can be used.

  The compression set load LS of the second coil spring 18b is larger than the compression load L1 received by the coil spring 18 in the protruding state of the inner pin 16 in which the convex portion 16a enters the grooves 22a and 22b, and the convex portion 16a is in the sheave surface 20. Is set smaller than the compressive load L2 received by the coil spring 18 when the inner pin 16 that is in contact with the inner ring 16 is immersed.

  That is, the stopper 18c restrains the second coil spring 18b in a compressed state with the compression set load LS, and the second coil spring 18b does not contract (elastically deform) even when a compression load equal to or less than the compression set load LS is received.

  Both ends of the coil spring 18 are regulated by the sheave surfaces 20 and 20 and the inner pins 16 and 16 at both ends of the coil spring 18, and as described above, the contraction stroke S1 and the compression load L1 that are the protruding state of the inner pin 16 are obtained. It expands and contracts between the maximum extension state and the contraction stroke S2, which is the immersion state of the inner pin 16, and the minimum contraction state of the compression load L2.

  The coil spring 18 contracts from the maximum extension state of the compression load L1, and until the compression load of the coil spring 18 increases to the compression set load LS or more, only the first coil spring 18a contracts and exhibits a reaction force (biasing force). .

  When the coil spring 18 further contracts and the compression load of the coil spring 18 becomes larger than the compression set load LS, both the first coil spring 18a and the second coil spring 18b contract and exert a reaction force (biasing force).

Here, the spring constant of the first coil spring 18a and _{k 1,} when the spring constant of the second coil spring 18b and _{k 2,} the spring constant k of the combined spring where the first coil spring 18a and the second coil spring 18b is arranged series It becomes as follows.
1 / k = 1 / k ₁ + 1 / k ₂

The spring constant of the coil spring 18 that functions as a combined spring k is the spring constant _{k 2} becomes small spring constant _{k 1} and the second coil spring 18b of the first coil spring 18a.

  The spring constant is a value obtained by dividing the change amount of the load applied to the coil by the stroke change amount of the coil, and as described above, the increasing rate of the urging force with respect to the contraction stroke of the coil corresponds to this spring constant.

  Therefore, as shown by a solid line in FIG. 6B, when the compression load of the coil spring 18 becomes larger than the compression set load LS, the spring constant becomes smaller than when the compression load of the coil spring 18 is equal to or less than the compression set load LS. The increasing rate of the urging force with respect to the contraction stroke of the coil spring 18 (immersion stroke of the inner pin 16) decreases.

  If the coil spring 18 is a synthetic spring in which, for example, three coil springs are connected in series, the characteristics of the coil spring 18 can be set as shown by a two-dot chain line in FIG. The characteristics of the spring can be set as appropriate.

[2-2. Action and Effect]
Since the continuously variable transmission according to the second embodiment of the present invention is configured as described above, the following operations and effects can be obtained.

  In the state in which the convex portion 16a of the inner pin 16 is immersed in the accommodation space 14c, the coil spring 18 has a smaller increase rate of the urging force with respect to the immersion stroke of the inner pin 16 than in the state in which the convex portion 16a protrudes from the accommodation space 14c. Since it has a non-linear characteristic, compared with a normal linear spring having a linear characteristic, the urging force when the inner pin 16 is immersed is secured while ensuring the urging force when the inner pin 16 is engaged with the grooves 22a and 22b. Can be reduced.

  When the convex portion 16 a of the inner pin 16 is displaced from the position of the groove 22 of the sheave surface 20, the inner pin 16 “pushes back” the sheave surface 20 of the pulley by the biasing force of the spring 18, and therefore is applied from the sheave surface 20 of the pulley. Although the required thrust for power transmission is increased, the reduction of the biasing force can suppress an increase in the required thrust applied from the sheave surface 20 of the pulley, and a load such as hydraulic pressure for securing the thrust of the pulleys 2 and 4 can be suppressed. Can be reduced.

[3. Others]
As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, It implemented by using a part of this embodiment or changing a part of this embodiment. Also good.

  For example, in each of the above embodiments, the sheave surface 20 is provided with two types of grooves: a long groove 22a extending from the outer periphery to the center and a short groove 22b formed only near the outer periphery of the sheave surface 20. However, only the long groove 22a may be used, or three or more kinds of grooves having different lengths may be combined.

  In the second embodiment, the coil spring is used as the nonlinear characteristic urging means. However, the urging means is not limited to this as long as it has the required nonlinear characteristic.

  In each of the above embodiments, the groove 22 is formed linearly toward the complete radial direction. However, the groove 22 may be radial, and may be inclined or curved with respect to the complete radial direction. Or you may.

  Furthermore, in each said embodiment, although the accommodation space 14c is formed toward the pin axial direction so that the both end surfaces 14a and 14b of the link pin 14 may be penetrated, this accommodation space is the both end surfaces of the link pin 14. It may be a hole with a bottom opening to each of 14a and 14b.

  In this case, the inner pin and the coil spring (biasing means) are accommodated in the bottomed holes that open to the end faces 14a and 14b, respectively. The coil spring is interposed between the base portion of the inner pin and the bottom portion of the bottomed hole.

  Moreover, in the said embodiment, with respect to the link pin 14 arrange | positioned at regular intervals along the advancing direction of a chain, the 1st link pin 14A is arrange | positioned at random intervals along the advancing direction of a chain. However, all of the first link pins 14A need not be regularly spaced.

  That is, the number of the first link pins installed between the adjacent second link pins 14A may not be constant (a random number including 0), in other words, any two adjacent link pins The installation interval between the first link pins may be different from the installation interval between the other two adjacent first link pins.

2 Primary pulley (drive pulley)
4 Secondary pulley (driven pulley)
DESCRIPTION OF SYMBOLS 10 Chain 12 Link board 12a Link pin insertion hole 14, 14A, 14B Link pin 14a, 14b Both end surfaces (tip surface) of link pin 14
14c Housing space 16 Inner pin 16a Convex part of inner pin 16 18 Coil spring (biasing means)
18a First coil spring (first spring part)
18b Second coil spring (second spring part)
18c Stopper 20 Sheave surface 22, 22a, 22b Groove 26 Inner pin 26a Convex portion of inner pin 26 26c Taper engagement surface 28 Coil spring (biasing means)
28a End portion of coil spring 28

Claims (4)

A pair of pulleys;
A plurality of link plates, and a plurality of link pins that connect the link plates and have tip surfaces that come into contact with the sheave surfaces of the pair of pulleys, and each has a chain wound around the pair of pulleys. And
A radial groove is formed on the sheave surface of at least one of the pair of pulleys,
The plurality of link pins are:
An inner space in which a housing space formed in the pin axis direction and a convex portion that can mesh with the groove are formed at a tip portion, and the convex portion is housed in the housing space so as to be able to protrude and retract from the tip surface of the link pin. A plurality of first link pins having a pin and biasing means for biasing the inner pin toward the sheave surface;
A continuously variable transmission comprising: the inner pin and a plurality of second link pins not having the urging means. The installation interval between any two adjacent first link pins is different from the installation interval between the other two adjacent first link pins. Continuously variable transmission. The continuously variable transmission according to claim 2, wherein the first link pins are arranged at random intervals along the traveling direction of the chain. In the state where the convex portion of the inner pin is immersed in the accommodating space, the biasing means has a rate of increase of the biasing force with respect to the immersion stroke of the inner pin than in a state where the convex portion protrudes from the accommodating space. The continuously variable transmission according to any one of claims 1 to 3, wherein the continuously variable transmission has a decreasing non-linear characteristic.

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