JP5779129B2 - Continuously variable transmission - Google Patents

Description

  The present invention relates to a continuously variable transmission.

  Conventionally, Patent Document 1 discloses a continuously variable transmission in which a pulley thrust is applied by a spring. In the continuously variable transmission of Patent Document 1, a compression spring is provided between a movable pulley piece and a sliding spring stopper that is movable in the axial direction, and a tension spring is provided between the sliding spring stopper and a fixed fixed piece. Is provided. As a result, when the movable pulley piece moves so that the width of the V-groove becomes large, the sliding spring stopper moves in the axial direction so that the thrust applied to the movable pulley piece becomes an appropriate value.

JP 05-149402 A

  However, in the above invention, since the sliding spring stopper moves only in the axial direction, the movable pulley piece is fixed by the tension spring and the compression spring as the movable pulley piece moves to increase the width of the V-groove. The force for urging the pulley on one side increases. For this reason, when the width of the V groove is increased, a large force is required to move the movable pulley piece, the mobility of the movable pulley piece is deteriorated, and the belt clamping force is excessive.

  The present invention was invented to solve such problems, and even when the movable pulley piece moves so as to increase the width of the V-groove, it is possible to suppress excessive belt clamping force. Objective.

In the continuously variable transmission according to an aspect of the present invention, the groove width of the V groove formed by the fixed pulley, the movable pulley that moves in the axial direction of the fixed pulley, and the fixed pulley and the movable pulley is changed. A continuously variable transmission including a belt whose contact radius with the fixed pulley and the movable pulley is changed, wherein one end abuts against the back surface of the movable pulley and expands and contracts in the axial direction of the fixed pulley. A plurality of elastic means, a holding means arranged in the circumferential direction of the fixed pulley, the other end of the first elastic means abuts and receiving a force in the axial direction by the first elastic means, and a movable pulley is the shaft of the fixed pulley A sliding mechanism for moving the holding means in the axial direction and the radial direction of the fixed pulley when moving in the direction, and a second elastic means for biasing the holding means toward the radial inner side of the fixed pulley. Continuously variable transmission

  According to this aspect, when the holding means moves, the slide mechanism can move in the radial direction in addition to the axial direction. Therefore, even when the movable pulley is moved so that the groove width of the V groove is increased, The movable pulley is easily moved by the centrifugal force generated by the rotation of the pulley, and the belt clamping force generated by the fixed pulley and the movable pulley can be prevented from being excessive.

It is a schematic sectional drawing of the continuously variable transmission of 1st Embodiment. It is the schematic of the II-II cross section of FIG. It is a figure which shows the connection state of the holding member of 2nd Embodiment. It is sectional drawing of the inclination part of 3rd Embodiment. It is a figure which shows the modification of 3rd Embodiment. It is sectional drawing of the inclination part of 4th Embodiment. It is a figure which shows the modification of 4th Embodiment.

  The configuration of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic sectional view of a continuously variable transmission according to this embodiment. FIG. 1 shows a state in which the gear ratio is the highest in the upper half of the primary pulley and the secondary pulley, and a state in which the gear ratio is the lowest in the lower half. FIG. 2 is a schematic view of the II-II cross section of FIG.

  The continuously variable transmission 1 includes a primary pulley 2 connected to a drive source, a secondary pulley 3 connected to a drive wheel, a belt 4, a holding member 5, a band 6, a spring 7, and a guide portion 9. Is provided.

  The primary pulley 2 includes a fixed pulley 2a and a movable pulley 2b disposed to face the fixed pulley 2a. The primary pulley 2 forms a V-shaped pulley groove by the sheave surface of the fixed pulley 2a and the sheave surface of the movable pulley 2b. The movable pulley 2b is moved along the shaft portion 2c by, for example, a centrifugal roller, and changes the groove width of the pulley groove.

  The secondary pulley 3 includes a fixed pulley 3a and a movable pulley 3b disposed to face the fixed pulley 3a. The secondary pulley 3 forms a V-shaped pulley groove by the sheave surface of the fixed pulley 3a and the sheave surface of the movable pulley 3b. The movable pulley 3b moves along the shaft portion 3c by the difference between the force that pushes the movable pulley 3b to the opposite side of the fixed pulley 3a by the belt 4 and the force that pushes the movable pulley 3b to the fixed pulley 3a side via the spring 7. Change the groove width.

  The belt 4 is wound between the primary pulley 2 and the secondary pulley 3, and transmits power between the primary pulley 2 and the secondary pulley 3. The continuously variable transmission 1 changes the gear ratio steplessly by changing the contact radius between the primary pulley 2 and the belt 4 and the contact radius between the secondary pulley 3 and the belt 4.

  The guide portion 9 is disposed on the back side of the movable pulley 3b, is connected to the shaft portion 3c, and rotates integrally with the fixed pulley 3a. The guide portion 9 includes a tapered inclined portion 10 that expands in a direction opposite to the fixed pulley 3a side with respect to the movable pulley 3b, a convex portion 11 that protrudes radially outward, and a holding member 5 that is a fixed pulley. The 1st stopper 12 which restrict | limits moving to the opposite side to 3a side, and the 2nd stopper 13 which restrict | limits that the holding member 5 moves to the fixed pulley 3a side are provided.

  A plurality of inclined portions 10 are provided at predetermined intervals in the circumferential direction of the fixed pulley 3a. The convex part 11 is provided between the inclination parts 10 adjacent to the circumferential direction. In other words, the guide portion 9 is formed with a plurality of concave portions 14 in the circumferential direction, with the inclined portion 10 and the convex portion 11, with the inclined portion 10 as a bottom surface and the surface opposite to the convex portion 11 adjacent in the circumferential direction as a side surface.

  The holding member 5 includes a tapered bottom portion 5 a having the same shape as the inclined portion 10, and a plurality of holding members 5 are provided in the circumferential direction as much as the plurality of inclined portions 10. Note that the number of the holding members 5 is not necessarily the same as the number of the inclined portions 10, and may be smaller than the number of the inclined portions 10. The holding member 5 is disposed in a recess 14 formed in the guide portion 9. Since the bottom portion 5 a of the holding member 5 is in sliding contact with the inclined portion 10 and the holding member 5 moves, when the holding member 5 moves by receiving a force in the axial direction by the spring 7, the holding member 5 has a diameter along the inclined portion 10. Move also in the direction. The holding member 5 is biased radially inward by the band 6. Since the bottom portion 5a of the holding member 5 is in sliding contact with the inclined portion 10 and the diameter of the inclined portion 10 decreases toward the fixed pulley 3a, the holding member 5 receives a force toward the fixed pulley 3a by the band 6.

  The band 6 abuts on the outer peripheral wall of the plurality of holding members 5 provided, expands and contracts in the radial direction, and biases the holding member 5 inward in the radial direction. The urging force directed inward in the radial direction by the band 6 is the highest rotational speed when the rotational speed of the secondary pulley 3 is set at the lowest gear ratio at the position where the movable pulley 3b is at the lowest gear ratio. In this case, the movable pulley 3 b is set so that the secondary pulley 3 can hold the belt 4 without moving in the axial direction. Therefore, for example, a driving scene in which the rotation speed of the secondary pulley 3 is high at the lowest gear ratio (for example, a driving scene in which the vehicle starts and accelerates in a fixed state in the lowest gear ratio in the manual mode, or an accelerator pedal during high vehicle speed traveling) Even in a driving scene that is downshifted by a shift lever operation), the lowest transmission gear ratio can be maintained without the movable pulley 3b moving in the axial direction. At this time, since the contact radius of the belt 4 with respect to the secondary pulley 3 is large, the rotational speed of the secondary pulley 3 is relatively low. Therefore, the centrifugal force acting on the band 6 is also small, and the movable pulley 3b can be held. Here, the maximum rotation speed is, for example, 3000 rpm.

  The spring 7 is disposed between the movable pulley 3 b and the holding member 5, and one end thereof is in contact with the back surface of the movable pulley 3 b and the other end is in contact with the holding member 5. The spring 7 expands and contracts in the axial direction to generate a biasing force so that the movable pulley 3b and the holding member 5 are separated from each other. The spring 7 is disposed so as to contact the vicinity of the radially inner end of the holding member 5 when the holding member 5 comes into contact with the first stopper 12. Thereby, the moment concerning the holding member 5 from the spring 7 can be made small. If the diameter of the spring 7 is set to be large and the spring 7 and the holding member 5 come into contact with each other in the vicinity of the radially outer end of the holding member 5, the moment applied to the holding member 5 from the spring 7 becomes large, and the inclined portion Although there is a possibility that the holding member 5 may be tilted so that 10 and the bottom portion 5a are separated from each other, the above configuration can suppress the holding member 5 from being tilted.

  Next, the operation of this embodiment will be described.

  The transmission ratio of the continuously variable transmission 1 is set by the balance between the belt clamping force by the primary pulley 2 and the belt clamping force by the secondary pulley 3. When the belt clamping force by the primary pulley 2 increases and the groove width of the pulley groove of the primary pulley 2 decreases, the groove width of the pulley groove of the secondary pulley 3 is expanded by the belt 4, and the movable pulley 3b is separated from the fixed pulley 3a. Move in the opposite direction. Therefore, the gear ratio is changed to the High side.

  On the other hand, when the belt clamping force by the primary pulley 2 is reduced, the movable pulley 3b is moved to the fixed pulley 3a side by the force generated by the band 6 and the spring 7, and the groove width of the pulley groove of the secondary pulley 3 is reduced. Therefore, the gear ratio is changed to the Low side.

  In the present embodiment, the movable pulley 3b of the secondary pulley 3 moves according to the belt clamping force in the primary pulley 2, and the gear ratio is changed. The movable pulley 3b is held at a position where the force pushing the movable pulley 3b in the opposite direction to the fixed pulley 3a via the belt 4 and the force pushing the movable pulley 3b toward the fixed pulley 3a by the spring 7 and the band 6 are balanced. The

  When the gear ratio is changed to the High side, the movable pulley 3b moves in the axial direction opposite to the fixed pulley 3a and the spring 7 contracts, so that the holding member 5 is moved in the direction opposite to the fixed pulley 3a. The pushing force increases in the axial direction.

  Since the bottom portion 5a of the holding member 5 is in sliding contact with the inclined portion 10, when the force pushing the holding member 5 in the axial direction opposite to the fixed pulley 3a is increased, the reaction force received by the holding member 5 from the inclined portion 10 is also increased. The force toward the radially outer side, which is a component of the reaction force, also increases. And if the force which goes to a radial direction outer side becomes larger than the urging | biasing force by the band 6, the band 6 will expand in diameter and the holding member 5 will move toward the axial direction opposite to the fixed pulley 3a, and a radial direction outer side. .

  When the band 6 expands in diameter, the urging force by the band 6 increases, and the holding member 5 stops at a position where the urging force by the band 6 and the force directed radially outward are balanced.

  As described above, the spring 7 contracts when the movable pulley 3b moves in the opposite direction to the fixed pulley 3a. However, the amount of contraction of the spring 7 is reduced by moving the holding member 5 in the axial direction and the radial direction. Thus, the belt clamping force by the secondary pulley 3 is reduced, and the belt clamping force can be prevented from becoming excessive.

  Further, when the gear ratio is on the High side, the rotational speed of the secondary pulley 3 is increased, so that the centrifugal force applied to the holding member 5 is increased. Therefore, the reaction force that the holding member 5 receives from the inclined portion 10 is reduced, and the force that pushes the movable pulley 3b toward the fixed pulley 3a via the spring 7 is reduced. That is, the centrifugal force applied to the holding member 5 acts to move the holding member 5 in the direction opposite to the fixed pulley 3a, so that the amount of contraction of the spring 7 can be reduced, and the belt clamping force by the secondary pulley 3 is reduced. The belt clamping force can be suppressed from becoming excessive.

  When the brake pedal is depressed from the state where the gear ratio is high and the gear ratio is changed to low, the vehicle is decelerated by depressing the brake pedal, and the rotational speed of the secondary pulley 3 is increased. Become slow. Thereby, the centrifugal force applied to the holding member 5 is reduced, the urging force by the band 6 is greater than the force directed radially outward, and the band 6 is reduced in diameter. Then, the holding member 5 moves to the fixed pulley 3a side, the spring 7 contracts, the force by which the movable pulley 3b is axially pushed toward the fixed pulley 3a by the spring 7 increases, and the movable pulley 3b moves to the fixed pulley 3a side. To do.

  Thus, when the brake pedal is depressed from a state where the gear ratio is on the high side, it can be assisted to change the gear ratio to the low side.

  The effect of 1st Embodiment of this invention is demonstrated.

  The continuously variable transmission 1 includes an inclined portion 10 that moves the holding member 5 in the axial direction and the radial direction when the gear ratio is changed to the High side and the holding member 5 moves in the axial direction. As a result, the amount of movement of the holding member 5 in the axial direction can be reduced compared to the case of moving only in the axial direction, and the length of the continuously variable transmission 1 in the axial direction can be shortened. The step transmission 1 can be reduced in size (effect described in claim 1).

  The holding member 5 is also movable in the radial direction, the holding member 5 rotates together with the fixed pulley 3a and the movable pulley 3b, and the holding member 5 receives a centrifugal force directed outward in the radial direction. Thereby, the load which the holding member 5 applies to the inclined part 10 becomes small, and the frictional force between the holding member 5 and the inclined part 10 is reduced. Therefore, the holding member 5 can be easily moved in the axial direction. For example, the movable pulley 3b and the holding member 5 can be easily moved in the axial direction opposite to the fixed pulley 3a. That is, when the movable pulley 3b moves in the axial direction opposite to the fixed pulley 3a, the force for pushing the movable pulley 3b toward the fixed pulley 3a is reduced, and the belt clamping force is prevented from becoming excessive. (Effect described in claim 1).

  Even in the prior art not using this embodiment, centrifugal force acts by rotation of a fixed pulley or the like, but the holding member cannot move in the radial direction, so the holding member and the surface on which the holding member slides The conventional technology that does not reduce the frictional force and does not use this embodiment cannot provide the effects of this embodiment.

  By urging the holding member 5 inward in the radial direction by the band 6, it is possible to give the holding member 5 a force toward the fixed pulley 3a, and to appropriately maintain the belt clamping force. Moreover, the movement of the holding member 5 to the outer side in the radial direction due to the centrifugal force related to the holding member 5 can be suppressed. Further, when the brake pedal is depressed from a state in which the gear ratio is high, it is possible to assist changing the gear ratio to the low side, and the gear can be quickly shifted to the low side. (Effects described in 2, 3, 4).

  By providing the first stopper 12 that restricts the movement of the holding member 5 to the side opposite to the fixed pulley 3a, it is possible to prevent the holding member 5 from being detached from the recess 14 (the effect of claim 6). ).

  When the holding member 5 comes into contact with the first stopper 12, the spring 7 comes into contact with the vicinity of the radially inner end of the holding member 5. Thereby, even when the holding member 5 moves to the fixed pulley 3a side, it is possible to suppress the holding member 5 from being inclined due to the moment by the spring 7 (effect described in claim 7).

  By providing the second stopper 13 that restricts the movement of the holding member 5 toward the fixed pulley 3 a, it is possible to prevent the holding member 5 from being detached from the recess 14. Further, for example, when the transmission gear ratio is at the lowest level, the movement of the holding member 5 to the fixed pulley 3a side is restricted so that the spring 7 is not excessively contracted, thereby suppressing an excessive belt clamping force. (Effect of claim 8).

  By providing the holding member 5, the inclined portion 10, and the like in the secondary pulley 3, the belt clamping force in the secondary pulley 3 can be set to an appropriate force according to the gear ratio. When the gear ratio is changed to the high side, the groove width of the pulley groove of the secondary pulley 3 is increased, and the holding member 5 moves in the axial direction opposite to the fixed pulley 3a. When the gear ratio is changed to the High side, the rotational speed of the secondary pulley 3 increases and the centrifugal force of the holding member 5 increases. As a result, the holding member 5 can easily move along the inclined portion 10 to the side opposite to the fixed pulley 3a, and the belt clamping force can be prevented from becoming excessive. Further, when the gear ratio is changed to the Low side, the rotational speed of the secondary pulley 3 becomes slow and the centrifugal force of the holding member 5 becomes small. Therefore, the holding member 5 is easily moved to the fixed pulley 3 side by the urging force of the band 6, and it is possible to suppress the belt clamping force from being insufficient (effect according to claim 11).

  Next, a second embodiment of the present invention will be described.

  In this embodiment, as shown in FIG. 3, the holding members 20 adjacent in the circumferential direction are connected by a spring 21. The spring 21 generates a tensile force that brings the holding members 20 closer to each other in the circumferential direction. The holding member 20 is biased radially inward by this tensile force.

  The effect of 2nd Embodiment of this invention is demonstrated.

  The same effect as that of the first embodiment can also be obtained by connecting the holding member 20 with the spring 21.

  Next, a third embodiment of the present invention will be described.

  In the present embodiment, as shown in FIG. 4, the inclined portion 30 is composed of a plurality of surfaces having different inclination angles. FIG. 4 is a cross-sectional view of the inclined portion 30 in the axial direction. The inclination angle refers to an angle inclined with respect to the shaft portion 3 c of the secondary pulley 3.

  The inclined portion 30 includes a first inclined portion 31 and a second inclined portion 32 that is disposed closer to the fixed pulley than the first inclined portion 31 and has a smaller inclination angle than the first inclined portion 31.

  The inclined portion 30 may have a concave curved shape as shown in FIG.

  The effect of the third embodiment of the present invention will be described.

  By configuring the inclined portion 30 with a plurality of surfaces having different inclination angles, the force for pushing the movable pulley toward the fixed pulley can be changed also by the surface of the inclined portion 30. In particular, in this embodiment, the inclined portion 30 is disposed on the fixed pulley side with respect to the first inclined portion 31 and the second inclined portion 32 having a smaller inclination angle than the first inclined portion 31. When the holding member is in contact with the second inclined portion 32, the movable pulley can be easily moved in the axial direction opposite to the fixed pulley, and the gear ratio can be quickly changed to the High side. (Effect corresponding to claim 9). In addition, the inclined portion 30 has a curved surface shape, and the first inclined portion 31 and the second inclined portion 32 described above are formed by making the curvature radius on the first stopper 12 side smaller than the second stopper 13 side in the inclined portion 30. The same effects as those described above can be obtained (effect corresponding to claim 10).

  Next, a fourth embodiment of the present invention will be described.

  In the present embodiment, as shown in FIG. 6, the inclined portion 40 is composed of a plurality of surfaces having different inclination angles. FIG. 6 is a cross-sectional view of the inclined portion 40 in the axial direction. The inclination angle refers to an angle inclined with respect to the shaft portion 3 c of the secondary pulley 3.

  The inclined portion 40 includes a first inclined portion 41 and a second inclined portion 42 that is disposed closer to the fixed pulley than the first inclined portion 41 and has a larger inclination angle than the first inclined portion 41.

  In addition, as shown in FIG. 7, it is good also as a curved surface shape from which the center part of the inclination part 43 protrudes.

  The effect of 4th Embodiment of this invention is demonstrated.

  The inclined portion 40 is configured by a first inclined portion 41 and a second inclined portion 42 that is disposed on the fixed pulley side with respect to the first inclined portion 41 and has a larger inclination angle than the first inclined portion 41. When the member is in contact with the second inclined portion 42, the belt clamping force can be increased (effect corresponding to claim 9). Further, the inclined portion 30 has a curved surface shape, and the first inclined portion 41 and the second inclined portion 42 described above are formed by increasing the curvature radius on the first stopper 12 side from the second stopper 13 side in the inclined portion 30. The same effects as those described above can be obtained (effect corresponding to claim 10).

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

  In the present embodiment, the holding member 5 and the like are provided on the secondary pulley 3, but may be provided on the primary pulley 2.

DESCRIPTION OF SYMBOLS 1 Continuously variable transmission 2 Primary pulley 3 Secondary pulley 3a Fixed pulley 3b Movable pulley 4 Belts 5, 20 Holding member (holding means)
5a Bottom (slide mechanism)
6 Band (second elastic means)
7 Spring (first elastic means)
10, 30, 33, 40, 43 Inclined part (sliding mechanism)
12 First stopper 13 Second stopper 21 Spring (second elastic means)

Claims (10)

The fixed pulley, the movable pulley that moves in the axial direction of the fixed pulley, and the groove width of the V groove formed by the fixed pulley and the movable pulley are changed, so that the fixed pulley and the movable pulley A continuously variable transmission comprising a belt whose contact radius is changed,
A first elastic means whose one end abuts on the back surface of the movable pulley and expands and contracts in the axial direction of the fixed pulley;
A plurality of arranged in the circumferential direction of the fixed pulley, the other end of the first elastic means abuts, and holding means for receiving a force in the axial direction by the first elastic means;
A slide mechanism for moving the holding means in the axial direction and the radial direction of the fixed pulley when the movable pulley moves in the axial direction of the fixed pulley ;
A continuously variable transmission comprising: second elastic means for urging the holding means toward the radially inner side of the fixed pulley . 2. The continuously variable transmission according to claim 1 , wherein the second elastic means is an annular elastic member that abuts on an outer peripheral wall of the holding means and can expand and contract in the radial direction. The continuously variable transmission according to claim 2 , wherein the annular elastic member is a band. The continuously variable transmission according to claim 1 , wherein the second elastic means is a spring that connects the holding means adjacent to each other in the circumferential direction of the fixed pulley. The continuously variable transmission according to any one of claims 1 to 4 , further comprising a fixed pulley opposite side movement restriction stopper for restricting movement of the holding means to the side opposite to the fixed pulley . The said 1st elastic means contacts the edge part of the said radial inside of the said holding means, when the said holding means contact | abuts to the fixed pulley opposite side movement control stopper, The Claim 5 characterized by the above-mentioned. Continuously variable transmission. The continuously variable transmission according to any one of claims 1 to 6 , further comprising a fixed pulley side movement restricting stopper that restricts movement of the holding means toward the fixed pulley side . The slide mechanism is formed by a first inclined surface provided in the holding means and a second inclined surface provided in a guide portion connected to the fixed pulley,
The continuously variable transmission according to any one of claims 1 to 7 , wherein the second inclined surface is formed by a plurality of surfaces having different inclination angles. The slide mechanism, any one of claims 1 to 7 for the first curved surface provided in said holding means, characterized in that it is formed by a second curved surface formed in the guide portion connected to the fixed pulley The continuously variable transmission described in 1. A primary pulley coupled to the drive source;
A secondary pulley coupled to the drive wheel;
A belt hung between the primary pulley and the secondary pulley;
The continuously variable transmission according to any one of claims 1 to 9 , wherein the fixed pulley and the movable pulley constitute the secondary pulley.

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