JP3637546B2 - Continuously variable transmission - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a continuously variable transmission mounted on a vehicle.
[0002]
[Prior art and problems]
Conventionally, a continuously variable transmission mounted on a vehicle is configured as schematically shown in FIG. 5, and includes a driving pulley 52 provided on a driving shaft 51 and a driven pulley 56 provided on a driven shaft 57. Rotation sensors 54 and 59 are arranged on the outer peripheral side of the input gear 53 provided on the drive shaft 51 and on the outer periphery of the output gear 58 provided on the driven shaft 57, respectively. The output waveforms from the sensors 54 and 59 are input into the computer 60, the actual transmission ratio of the continuously variable transmission is calculated in the computer 60, and the computer 60 is arranged so that the obtained actual transmission ratio approaches the target transmission ratio. A command signal is output to the speed change actuator 55, and the movable pulley of the driving pulley 52 is moved via the speed change actuator 55 to control the speed change.
[0003]
In such a conventional continuously variable transmission, since an enlarged view of the output gear 58 and the rotation sensor 59 is shown in FIG. 6, teeth are formed on the outer periphery of the output gear 58 at equal intervals. As shown in FIG. 7, the output waveform detected by the rotation sensor 59 is a pulse having an equal pitch, which is the same output waveform regardless of whether the vehicle is moving forward or backward, such as when starting on a steep uphill. When the vehicle is lowered in the opposite direction to the shift position, the vehicle speed is increased by inertia until the clutch is engaged, a gear shift command signal for shifting to the Hi side is issued to the gear shift actuator 55, the gear ratio becomes the Hi side, and the vehicle lowering speed Increases, resulting in a shift control contrary to the will of the driver.
[0004]
[Means for Solving the Problems]
The present invention has been devised in view of the above-described conventional problems, and aims to provide a continuously variable transmission that can determine a traveling direction of a vehicle and can perform shift control in accordance with the traveling direction. The first gist is that the rotational speed of the drive shaft side and the driven shaft side is detected using a rotation sensor, the actual speed ratio of the continuously variable transmission is calculated by a computer, and the actual speed ratio is calculated as the target speed ratio. In a continuously variable transmission mounted on a vehicle that controls the transmission by sending a signal from the computer to the speed change actuator, the outer circumference of the rotation speed detection waveform detected by the rotation sensor is different between forward and reverse. of the spacing of teeth attached to the detection gear formed in different shapes regularly to the driven shaft side, to determine the traveling direction of the vehicle within the computer on the basis of the detected waveform of the rotation sensor, a shift position and該判Been when the traveling direction is the reverse direction is that which is configured to shift control so as not to Hi speed.
The second aspect is the driving force of the engine side is to have an electromagnetic powder clutch can be transmitted to the continuously variable transmission.
[0005]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a continuously variable transmission mounted on a vehicle. An input gear 3 is fixed to an end of a drive shaft 2 of the continuously variable transmission 1. The driving force is transmitted from the engine side (not shown) via an electromagnetic powder clutch, and the driving shaft 2 is provided with a fixed pulley 4 fixedly and a movable pulley 5 slidably movable. The pulley 4 and the movable pulley 5 constitute a driving pulley PA, and a rotation sensor 7 for detecting the rotation speed of the input gear 3 is disposed on the outer peripheral side of the input gear 3, and the rotation sensor 7 is a computer. 18 is connected. Further, the drive pulley PA is provided with a speed change actuator 6, and the movable pulley 5 is moved in a direction to be separated from and connected to the fixed pulley 4 via the speed change actuator 6 by a signal from the computer 18, thereby continuously variable speed change. The gear ratio of the machine can be changed.
The driven shaft 8 is also fixedly provided with a fixed pulley 9 and a movable pulley 10 that is movable. The fixed pulley 9 and the movable pulley 10 constitute a driven pulley PB. The output gear 11 is fixed to the vehicle, and the output gear 11 is engaged with a differential gear 15 attached to the axle 16. A vehicle tire is connected to an end of the axle 16.
[0006]
In this example, a detection gear 13 is attached to the driven shaft 8 concentrically with the output gear 11 outside the output gear 11, and a rotation sensor 14 is disposed on the outer peripheral side of the detection gear 13. The sensor 14 is composed of an electromagnetic pickup sensor and is connected to the computer 18.
When the enlarged view of the detection gear 13 is shown in FIG. 2, the teeth 13a, 13b, and 13c protruding from the outer periphery of the detection gear 13 are formed with regularly different intervals. The interval from the teeth 13a to the teeth 13b is a medium interval, and the interval from the teeth 13b to the teeth 13c is a small interval, indicated by arrows. The teeth 13a, 13b, and 13c are regularly and sequentially formed at different intervals of large, medium, and small along the forward direction.
[0007]
When such a detection gear 13 rotates as the driven shaft 8 rotates, the detection waveform detected by the rotation sensor 14 indicates that when the detection gear 13 is rotated in the forward direction, as shown in FIG. , 13b, 13c corresponding to the intervals of large, medium, small, large, medium, small, and the output waveform continues, and conversely, when the detection gear 13 rotates in the reverse direction, as shown in FIG. , Medium, large, small, medium, and large, the output waveform is continuous. Therefore, a difference occurs in the output waveform from the rotation sensor 14 between forward and backward movement of the vehicle. It is possible to determine whether the vehicle is moving forward or backward.
[0008]
Further, the rotational speed can be read simultaneously from the interval time of the three teeth 13a, 13b, 13c having large, medium and small intervals, and the computer 18 can read the rotational speed of the driven shaft 8 well.
[0009]
The rotation speed is detected by the rotation sensors 7 and 14 to calculate the actual transmission ratio of the continuously variable transmission 1 in the computer 18, and the computer 18 makes the actual transmission ratio close to the preset target transmission ratio. A command signal is output to the speed change actuator 6, the movable pulley 5 is moved along the drive shaft 2 via the speed change actuator 6, the speed change control of the continuously variable transmission 1 is performed, and the vehicle speed increases, the target speed ratio becomes Since it is set to change to the Hi side at any time, if the vehicle speed increases, the shift control is performed so as to shift the actual gear ratio to the Hi side via the speed change actuator 6 according to the command of the computer 18. As described above, the traveling direction of the vehicle is also added to the control conditions in the computer 18, so that, for example, when starting uphill, an electromagnetic powder clutch is used. If the creep torque is weak, the vehicle will go down. In such a situation, even if the vehicle speed increases, the computer 18 will not shift to the Hi side if the shift position and the traveling direction of the vehicle are opposite. It is possible to prevent the vehicle from dropping even a little by applying the engine brake.
As described above, in this example, since the traveling direction of the vehicle can be added to the control condition and more accurate shift control of the continuously variable transmission can be performed, the shift control suitable for the driver's intention is possible.
[0010]
【The invention's effect】
The present invention detects the rotational speeds of the drive shaft side and the driven shaft side using a rotation sensor, calculates the actual gear ratio of the continuously variable transmission with a computer, and brings the actual gear ratio close to the target gear ratio. In a continuously variable transmission mounted on a vehicle that controls the transmission by sending a signal from the computer to the speed change actuator, the teeth of the outer periphery are adjusted so that the difference between the forward speed and the reverse speed of the vehicle occurs in the rotational speed detection waveform detected by the rotation sensor. Detection gears that are regularly spaced in different shapes are attached to the driven shaft side, the traveling direction of the vehicle is determined in the computer based on the detection waveform of the rotation sensor, and the shift position and the determined traveling direction are determined. by the time a reverse direction which is configured to shift control so as not to Hi speed, such as when the vehicle has proceeded to the shift position and the reverse direction at, for example steep hill Without resulting in a shift to the Hi side as in the prior art, it shall be able to prevent the vehicle descends in steep slope, has a shift control can be performed effectively to suit the driver's intention.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a continuously variable transmission mounted on a vehicle.
FIG. 2 is an enlarged configuration diagram of a detection gear in FIG.
FIG. 3 is an output waveform diagram of a rotation sensor when the vehicle moves forward.
FIG. 4 is an output waveform diagram of a rotation sensor when the vehicle is moving backward.
FIG. 5 is a schematic configuration diagram of a conventional continuously variable transmission.
FIG. 6 is an enlarged configuration diagram of a conventional output gear.
FIG. 7 is an output waveform diagram of a conventional rotation sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Continuously variable transmission 2 Drive shaft 5 Movable pulley 6 Shift actuator 7 Rotation sensor 8 Drive shaft 13 Detection gear 13a, 13b, 13c Teeth 14 Rotation sensor 18 Computer PA Drive side pulley PB Drive side pulley

Claims (2)

The rotational speed of the drive shaft side and the driven shaft side is detected using a rotation sensor, the actual speed ratio of the continuously variable transmission is calculated by a computer, and the speed is changed from the computer so that the actual speed ratio approaches the target speed ratio. In a continuously variable transmission mounted on a vehicle that outputs a signal to an actuator and performs shift control, the interval between the teeth on the outer periphery is regularly set so that the rotation speed detection waveform detected by the rotation sensor differs depending on whether the vehicle is moving forward or backward. A detection gear formed in a different shape is attached to the driven shaft side, the traveling direction of the vehicle is determined in the computer based on the detection waveform of the rotation sensor, and the shift position and the determined traveling direction are opposite to each other. A continuously variable transmission configured to perform shift control so that sometimes Hi shift is not performed . The continuously variable transmission according to claim 1, further comprising an electromagnetic powder clutch capable of transmitting a driving force on the engine side to the continuously variable transmission.

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