JP6472535B2 - Continuously variable transmission with improved controllability - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission (a continuously variable transmission) having greatly improved controllability and adjustability.

  Continuously variable transmissions (CVT) are known in various configurations from the prior art. With a continuously variable transmission, an appropriate gear ratio can be obtained each time in a vehicle compared to a transmission with a constant gear. A special field of application of such a type of continuously variable transmission is a small vehicle, for example a two-wheeled vehicle, a three-wheeled vehicle, so-called tuk-tuk, snowmobile, quad or scooter. In this type of continuously variable transmission, a centrifugal force adjusting device is often used to adjust the position of the belt in the conical pulley pair. In this case, the centrifugal weight of the centrifugal force adjusting device moves its radial position in accordance with the number of rotations, thereby changing the axial interval between the two pulleys, thereby changing the transmission gear ratio. Is changed. However, a disadvantage of this type of device is that it cannot provide a controlled or adjusted effect on the transmission ratio of the continuously variable transmission. As a result, continuously variable transmissions equipped with a prior art centrifugal force adjustment device are usually not operated at an optimum point, thus degrading the fuel consumption and / or emissions of the vehicle. Therefore, it would be desirable to be able to take advantage of this ability of a continuously variable transmission with centrifugal force adjustment and to reduce fuel and reduce emissions. Furthermore, the continuously variable transmission that adjusts the centrifugal force does not have an optimum configuration with respect to vehicle dynamics. In particular, in the acceleration of the vehicle from the stop state and in the acceleration of the running vehicle, the gear ratio of the continuously variable transmission that is adjusted by the centrifugal force is optimum in the adaptability from the first speed to the second speed, for example. There is still a lot of room for improvement.

DISCLOSURE OF THE INVENTION The continuously variable transmission according to the present invention having the features described in claim 1 has the advantage that the emission characteristics and fuel consumption of the vehicle can be greatly improved. Furthermore, it is possible to obtain greatly improved driving performance in driving dynamics, in particular with regard to acceleration from a standstill and with respect to the acceleration of the vehicle during driving. According to the invention, this is achieved by the fact that the continuously variable transmission can be operated in an optimum position. According to the present invention, in this case, the continuously variable transmission has one pulley pair having a pulley whose position is fixed and an axially movable pulley. The present invention further includes an adjusting device for adjusting the position of the axially movable pulley. The adjusting device has a spindle transmission and an adjusting rod connected to an axially movable pulley. In this case, the spindle transmission device can adjust the axial direction of the adjusting rod. As a result, an extremely compact and space-saving structure can be obtained. The control unit is adapted to operate the adjusting device to change the position of the axially movable pulley. Thereby, since the position of the winding means of the pulley pair is changed, the gear ratio of the continuously variable transmission is changed. Therefore, in the present invention, the control unit can act on the continuously variable transmission, and thus the continuously variable transmission can be operated at an optimum operating point.

  The dependent claims show further advantageous configurations of the invention.

  Preferably, the adjusting device has an adjusting drive for driving the spindle transmission to apply a pulling force or a pressing force to the adjusting rod. As a result, the adjusting rod is moved in the axial direction, so that the position of the axially movable pulley connected to the adjusting rod is also changed.

  The transmission according to the invention further comprises at least one centrifugal force element movably arranged on an axially movable pulley. Further, the axially movable pulley is provided with a support wall, and the centrifugal force element is disposed between the support wall and the axially movable pulley back wall. Thus, the centrifugal force provides a position that depends on the rotation of the axially movable pulley and fine adjustment of the positioning is carried out by the adjusting device, so that for example the gear ratio adapted to the corresponding running mode is adjusted. Is done. The support wall is preferably connected to the crankshaft.

  Particularly preferably, the support wall has a tapered contact surface that contacts the centrifugal force element. The tapered contact surface of the support wall is preferably conical. Accordingly, when the rotational speed increases, the centrifugal force acting on one or a plurality of centrifugal force elements becomes higher, so that the centrifugal force elements move radially outward. In this case, the centrifugal force element rolls on the tapered contact surface of the support wall, thereby generating an axial sliding component that moves the movable pulley in the axial direction.

  More preferably, the driven shaft of the adjusting drive of the adjusting device is arranged parallel to the crankshaft. This provides a particularly compact configuration.

  More preferably, the driven shaft of the adjusting drive is parallel to the adjusting rod and in particular coaxial to the central axis of the pulley pair. Therefore, the adjustment driving device and the adjustment rod can be provided in a linear arrangement. Particularly preferably, since the crankshaft is also positioned in a straight line beside the adjustment rod and the driven shaft of the adjustment drive device, a particularly space-saving structure is possible.

  The adjusting rod is preferably arranged partly in the crankshaft, so that a simple and compact structure is obtained, in particular in the axial direction.

  Furthermore, the spindle transmission device has a sleeve nut connected to the adjusting rod, so that the spindle sleeve can be moved in the axial direction by rotation of the spindle of the spindle transmission device. Directional movement is also possible. The adjusting rod is preferably connected to an axially movable pulley via a transverse rod.

  Preferably the control unit is adapted to control the adjusting device based on the characteristic value of the prime mover. As the prime mover characteristic values, the prime mover speed and / or prime mover torque and / or temperature and / or air pressure are preferably used. The characteristic value for controlling the adjusting device may in this case be detected directly at the prime mover or may be detected at a component connected to the prime mover. The prime mover is preferably an internal combustion engine.

  More preferably, the control unit is adapted to control the adjusting device based on the selection of the driving mode by the driver. For example, it is possible to store predefined transmission settings that are taken by the adjusting device when a driving mode, for example a sports mode or a gasoline saving mode, is selected accordingly.

  More preferably, the crankshaft extends through the pulley pair. This results in a particularly compact structure of the continuously variable transmission, and in particular of the unit comprising the continuously variable transmission and the prime mover.

  More preferably, in this case, the fixed position pulley is directly connected to the crankshaft, so that in the axial direction of the crankshaft, the construction space required for the continuously variable transmission is minimally required. .

  More preferably, the control unit and the adjustment drive device are arranged in the housing of the continuously variable transmission. This provides a particularly compact configuration.

  Furthermore, the present invention relates to a vehicle including a continuously variable transmission according to the present invention. This vehicle is preferably a small vehicle, in particular a two-wheeled vehicle or a three-wheeled vehicle, or a snowmobile, quad, or scooter.

  More preferably, the adjustment drive is arranged on the housing surface of the transmission. In this case, preferably, the driven shaft of the adjustment drive device projects into the housing, and an intermediate transmission device is preferably arranged inside the housing for adjusting the support wall.

In the following, preferred embodiments of the invention will be described in detail with reference to the drawings.

1 is a schematic cross-sectional view of a continuously variable transmission according to a preferred embodiment of the present invention.

Next, a continuously variable transmission 1, that is, a continuously variable continuously variable transmission according to a first embodiment will be described in detail with reference to FIG.

  As is apparent from FIG. 1, the continuously variable transmission 1 includes a conical pulley pair 2 having a conical pulley 20 and a conical pulley 21 that are movable in the axial direction. ing.

  The pulley 20 whose position is fixed is fixed to the crankshaft 11. More precisely, as can be seen in FIG. 1, the fixed pulley 20 is arranged at the end of the crankshaft 11. The crankshaft 11 is connected to a prime mover 10, particularly an internal combustion engine, as schematically shown in FIG.

  The continuously variable transmission 1 is a transmission whose centrifugal force is adjusted, and has a plurality of centrifugal force elements 3 disposed on an axially movable pulley 21. In this embodiment, the centrifugal element is a ball. Optionally, the centrifugal element is a cylinder with a through hole.

  Furthermore, the continuously variable transmission 1 has an axially immobile support wall 4 disposed on an axially movable pulley. The support wall 4 rotates with the crankshaft 11. The axial position of the axially movable pulley 21 in the axial direction XX is defined by the radial position of the centrifugal force element 3.

  In order to adjust the pulley 21 which is movable in the axial direction, the adjusting device 5 connected to the control unit 6 is provided in the present invention. The adjusting device 5 includes an adjusting driving device 50, a driven shaft 51 of the adjusting driving device, and a spindle transmission device 7. The spindle transmission device 7 includes a spindle 70 and a sleeve nut 71 disposed on the spindle 70 so as to be movable in the axial direction XX. Since the sleeve nut 71 is connected to the adjusting rod 8 via the bearing 81, when the sleeve nut 71 moves in the axial direction, the adjusting rod 8 moves in the axial direction in the axial direction XX.

  At the opposite end of the adjusting rod 8, a lateral rod 80 is connected to the adjusting rod 8, and this lateral rod 80 is connected to an axially movable pulley 21. As a result, the axial movement of the adjusting rod 8 is transmitted to the axially movable pulley 21 via the lateral rod 80, so that the axially movable pulley 21 is schematically shown by a double arrow A in FIG. It can move in the axial direction. The sleeve nut 71 is prevented from rotating with the spindle 70 by a device not shown.

  As can further be seen from FIG. 1, the adjusting rod 8 is partly arranged in the crankshaft 11. This provides a particularly compact configuration. In this case, the crankshaft 11 has a slit or a hole.

  The support plate 4 has a tapered contact surface 40, which is in contact with the centrifugal force element 3.

  The adjustment drive 50 is preferably an electric motor. Optionally, however, the adjusting device 5 comprises a pneumatically operated adjusting drive or a hydraulically operated adjusting drive or an electromagnetic adjusting drive.

  A winding means 12, for example a belt, is arranged between the pulleys 20, 21. The winding means 12 is connected to a driven element 13, preferably also a pulley pair. However, the driven element 13 may be, for example, a directly driven wheel.

  Therefore, according to the present invention, the position of the movable pulley 21 is adjusted via the control unit 6, thereby adjusting the axial distance between the two pulleys 20, 21, whereby the desired transmission of the continuously variable transmission is adjusted. A transmission ratio is provided. For this purpose, the adjustment driving device 50 is driven, and the driven shaft 51 of the adjustment driving device 50 directly drives the spindle 70. Note that the driven shaft 51 may be formed integrally with the spindle 70. By rotation of the spindle 70 (arrow D in FIG. 1), the sleeve nut 71 moves in the axial direction XX according to the rotation direction of the spindle 70 (bidirectional arrow C). Since the sleeve nut 71 is fixedly coupled to the adjusting rod 8, the adjusting rod 8 similarly moves in the axial direction XX (bidirectional arrow B). Subsequently, the axially movable pulley 21 moves through the lateral rod 80 connected to the adjusting rod 8 (bidirectional arrow A).

  Therefore, the adjustment of the winding means 12 between the pulleys 20 and 21 can be changed according to the rotation direction, and a stepless speed change ratio can be changed.

  Therefore, according to the present invention, fine adjustment of the gear ratio basically defined by the centrifugal force element 3 can be realized. According to the present invention, the best transmission gear ratio can be realized according to the characteristic value, for example, the rotation speed and / or torque of the prime mover 10. In this case, the transmission gear ratio can be selected with regard to optimization of vehicle fuel consumption or emission or acceleration. Any combination of output values that are desired to be optimized can also be selected, and the optimum transmission gear ratio of the continuously variable transmission can be adjusted accordingly.

  In this case, as a result of the test using the continuously variable transmission 1 according to the present invention, the fuel consumption can be saved in the range of 10%, compared with a continuously variable transmission that is adjusted with a normal centrifugal force. The acceleration in the range of / hour can be improved up to 17%, and the adaptability of the acceleration in the range of 20 to 50 km / hour can be improved by 19%. Certainly, the continuously variable transmission according to the present invention requires a relatively large mechanical and electrical structure by means of the adjusting device, which is more than offset by the above-mentioned improvements and savings.

Claims (14)

A continuously variable transmission,
A pulley pair (2) having a pulley (20) fixed in position and an axially movable pulley (21);
An adjusting device (5) for adjusting the position of the axially movable pulley (21), comprising a spindle transmission (7) and an adjusting rod (8) connected to the axially movable pulley (21). And an adjusting device (5) comprising:
Wherein the adjusting device (5) by operating said axial movable pulley (21) adapted to have the control unit to change the position of (6), have a,
The adjusting device has an adjusting driving device (50) for driving the spindle transmission (7) so as to apply a tensile force or a pressing force to the adjusting rod (8),
The driven shaft (51) of the adjustment drive device (50) is parallel to the adjustment rod (8);
The adjusting rod (8) is partially disposed in the crankshaft (11);
Continuously variable transmission. At least one centrifugal element (3) movably arranged on said axially movable pulley (21);
A support wall (4) disposed on the axially movable pulley (21),
The centrifugal force element (3) is disposed between the support wall (4) and a back wall (22) of the axially movable pulley (21).
Continuously variable transmission of claim 1 Symbol placement. The continuously variable transmission according to claim 2 , wherein the support wall (4) has a tapered contact surface (40) in contact with the centrifugal force element (3). The driven shaft of the adjusting drive (50) (51) is parallel to the crankshaft (11), continuously variable transmission according to claim 1. The crankshaft is the pulley pair (2) through which extends and / or the position is fixed pulley (20) is connected the direct to the crankshaft (11), according to claim 1 The continuously variable transmission according to any one of claims 1 to 4 . The continuously variable transmission according to claim 5 , wherein the pulley (20) having the fixed position is directly connected to the crankshaft (11) at an end of the crankshaft (11). The driven shaft (51) of the adjustment driving device (50) is coaxial with the central axis (XX) of the pulley pair (2), according to any one of claims 4 to 6 . Continuously variable transmission. The continuously variable transmission according to any one of claims 1 to 7 , wherein the spindle transmission (7) is connected to the adjusting rod (8) via a sleeve nut (71). The continuously variable transmission according to any one of claims 1 to 8 , wherein the adjusting rod (8) is connected to the axially movable pulley (21) by a lateral rod (80). The continuously variable transmission according to any one of claims 1 to 9 , wherein the control unit (6) is adapted to control the adjusting device (5) based on a characteristic value of the prime mover (10). Machine. The continuously variable transmission according to claim 10 , wherein the characteristic value of the prime mover (10) is the rotational speed and / or torque and / or temperature and / or air pressure of the prime mover. A vehicle comprising the continuously variable transmission according to any one of claims 1 to 11 . The vehicle according to claim 12 , wherein the vehicle is a small vehicle. The vehicle according to claim 13 , wherein the small vehicle is a two-wheeled vehicle, a three-wheeled vehicle, a snowmobile, or a quad.

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