Patent Application
20080077301
It should be understood that only structures considered necessary for illustrating selected embodiments of the present invention are described herein. Other conventional structures, and those of ancillary and auxiliary components of the system, will be known and understood by those skilled in the art.
A shift control device for a vehicle (such as a motorcycle) and a vehicle incorporating same according to illustrative embodiments of the present invention is described below in detail with reference to the accompanying drawings.
As shown in
The power unit 16 includes an engine 41 which forms a front portion of the power unit 16, a continuously variable transmission 42 integrally joined to the engine 41 and extending rearwardly therefrom, and a main control unit 43 which controls the engine 41 and the continuously variable transmission 42 mounted on a rear portion of the main upper frame 14.
The main control unit 43 includes an engine control unit 67 which controls the engine 41 and a shift control unit 58 which controls shifting of gear ratio of the continuously variable transmission 42.
The motorcycle 10 includes a shift control device 50 having the shift control unit 58. The engine control unit 67 and the shift control device 50 having the shift control unit 58 are explained with reference to
The shift control device 50 further includes a steering-angle angular velocity sensor 45 which detects an angular velocity of a steering angle of the handlebar 21. The steering-angle angular velocity sensor 45 is mounted on an upper portion of the head pipe 12.
The shift control device 50 also includes a rolling angular velocity sensor 46 which detects an angular velocity of rolling of the vehicle body. The rolling angular velocity sensor 46 is arranged on a rear portion of the vehicle body, i.e., the rolling angular velocity sensor is disposed above the rear wheel 18 and mounted on a rear portion of the main upper frame 14.
In other words, the rolling angle angular velocity sensor 46 is disposed at a position spaced away from the engine 41, as shown in
The shift control device 50 also includes an engine-rotational-speed sensor 51 which detects a rotational speed of the engine; and a vehicle speed sensor 52 which detects a vehicle speed of the vehicle. The shift control unit 58 of the shift control device 50 includes a memory unit 53 which stores a steering-angle angular velocity reference value Sstd and a rolling angular velocity reference value Rstd; and an arithmetic operation unit 54.
The arithmetic unit 54 receives inputs of an engine-rotational-speed signal ES, a vehicle speed signal VS, a steering-angle angular velocity signal SAV and a rolling angular velocity signal RAV which are outputted from the engine-rotational-speed sensor 51, the vehicle speed sensor 52, the steering-angle angular velocity sensor 45 and the rolling angular velocity sensor 46, respectively.
The arithmetic unit 54 performs an arithmetic operations including comparing the steering-angle angular velocity signal SAV with the steering-angle angular velocity reference value Sstd; and comparing the rolling angular velocity signal RAV with the rolling angular velocity reference value Rstd.
The shift control unit 58 also includes an actuator drive unit 56 which receives an arithmetic operation signal SC 1, an arithmetic operation result, generated by the arithmetic operation unit 54. An actuator 57, actuated by the actuator drive unit 56, performs shifting of gear ratio of the continuously variable transmission 42 in response to a drive signal SD from the actuator drive unit 56.
As shown in
The continuously variable transmission 42 includes a drive pulley 61 which is joined to a crankshaft 41a of the engine 41, a driven pulley 62 which is joined to a side a rear wheel 18 (see
The drive pulley 61 includes a fixed pulley half body 61a which is integrally mounted on the crankshaft 41a and a movable pulley half body 61b which is movably mounted on the crankshaft 41a such that the movable pulley half body 61b approaches or moves away from the fixed pulley half body 61a. The movable pulley half body 61b is driven by the actuator 57 to move towards or move away from the fixed pulley half body 61a.
The driven pulley 62 includes a fixed pulley half body 62a which is integrally mounted on an output shaft 65 and a movable pulley half body 62b which is movably mounted on the output shaft 65 such that the movable pulley half body 62b moves towards or moves away from the fixed pulley half body 62a in accordance with the operation of drive pulley 61. The output shaft 65 is joined to an axle of the rear wheel 18 via a plurality of gears.
The movable pulley half body 62b is pushed towards the fixed pulley half body 62a by a spring (not shown) by way of a belt 63.
When the movable pulley half body 61b of the drive pulley 61 approaches (moves towards) the fixed pulley half body 61a when actuated by the actuator 57, a groove width of the drive pulley 61 is decreased and a wrapping radius of the belt 63 which is wrapped around the drive pulley 61 is increased. Along with the increase in the wrapping radius of the belt 63, the movable pulley half body 62b of the driven pulley 62 is moved away from the fixed pulley half body 62a against a resilient force of the spring (not shown), and the wrapping radius of the belt 63 which is wrapped around the driven pulley 62 is decreased. Accordingly, a gear ratio (the wrapping radius of the belt on a driven-pulley-62 side/the wrapping radius of the belt on a drive-pulley-61 side) is decreased.
On the other hand, when the movable pulley half body 61b of the drive pulley 61 is moved away from the fixed pulley half body 61a when actuated by the actuator 57, the groove width of the drive pulley 61 is increased and the wrapping radius of the belt 63 on the drive-pulley-61 side is decreased. Along with the decrease of the wrapping radius of the belt 63 on the drive-pulley-61 side, the movable pulley half body 62b of the driven pulley 62 approaches the fixed pulley half body 62a due to the resilient force of the spring, and the wrapping radius of the belt 63 on the driven-pulley-62 side is increased. Accordingly, a gear ratio is increased.
The arithmetic operation unit 54 sends an arithmetic operation signal SC2 (which is a calculation result) to the engine control unit 67, which controls the engine 41 (for example, an engine rotational speed) based on the arithmetic operation signal SC2.
The operation shift control device 50 is discussed below.
When the motorcycle starts slalom traveling, the arithmetic operation unit 54 confirms whether the engine rotation speed and the vehicle speed are zero or not (that is, whether the vehicle is stopped or not). When it is confirmed that the vehicle is not stopped, a steering-angle angular velocity of the vehicle in such a state is compared with the steering-angle angular velocity reference value Sstd stored in the memory unit 53, and at the same time, the rolling angular velocity is compared with the rolling angular velocity reference value Rstd stored in the memory unit 53.
When the detected steering-angle angular velocity is found greater than or equal the steering-angle angular velocity reference value Sstd; and the detected rolling angular velocity is found greater than or equal to the rolling angular velocity reference value Rstd, the arithmetic operation unit 54 sends the arithmetic operation signal SC1 to the actuator drive unit 56, which then sends the drive signal SD to the actuator 57 to maintain the position of the movable pulley half body 61b of the drive pulley 61 so as to inhibit shifting (changing) of the gear ratio.
Accordingly, the groove width of the drive pulley 61 is not changed and the shifting of the gear the continuously variable transmission 42 is not performed so that the gear ratio is maintained. For example, even when the throttle opening of the intake device is changed, only the engine rotational speed is changed resulting only in change in vehicle speed and not in change in the gear ratio, i.e., the gear ratio is maintained.
In contrast, in a conventional system, when the shifting of the gear ratio of the continuously variable transmission 42 is performed during slalom traveling, a driving force of the rear wheel 18 is changed. As a result, a smooth and comfortable turning operation of the vehicle is may not be achieved
According to the present invention, as described above, when the vehicle is rolling at a faster speed (a rolling speed above a threshold value) and the steering of the handlebar is quickly turned during slalom traveling of the vehicle (motorcycle), by performing an operation controlling inhibiting the shifting of the gear ratio of the continuously variable transmission 42, the change of the driving force of the rear wheel attributed to the shifting can be eliminated thereby realizing smoother and more comfortable traveling of the vehicle.
In the first step ST01, it is determined whether the vehicle speed V has a positive value (e.g., V>0) or not; and whether the engine rotational speed has a positive value (e.g., Ne>0) or not.
If both the vehicle speed is greater than zero, i.e., V>0; and the engine rotational speed is greater than zero, i.e., Ne>0, the processing advances to a second step ST02.
In the first step ST 01, if V □ 0 and Ne □ 0, that is, if the vehicle speed V=0 and the engine rotational speed Ne=0 (e.g., the motorcycle being in a stopped state), processing is terminated.
In the step ST02, it is determined whether the steering-angle angular velocity S is greater than or equal to the steering-angle angular velocity reference value Sstd, i.e., whether S≧Sstd or not.
If the steering-angle angular velocity S is greater than or equal to the steering-angle angular velocity reference value Sstd, i.e., S≧Sstd, processing advances to the step ST03.
If S □ Sstd, that is, if the steering-angle angular velocity S is less than the steering-angle angular velocity reference value Sstd, i.e., if S<Sstd, processing advances to step ST06.
In the step ST03, it is determined whether the rolling angular velocity R is greater than or equal to the rolling angular velocity reference value Rstd, i.e., whether R≧Rstd or not.
If the rolling angular velocity R is greater than or equal to rolling angular velocity reference value Rstd, i.e., R≧Rstd, processing advances to the step ST04.
If R□Rstd, that is, the rolling angular velocity R is less than rolling angular velocity reference value, i.e., if R<Rstd, processing advances to step ST06.
In the step ST04, the engine rotational speed Ne is held at a fixed value.
In step ST05, by inhibiting the shifting of gear ratio using the actuator, the gear ratio is maintained.
In step ST06, by executing the shifting of the gear ratio using the actuator, the gear ratio is changed.
With the above-mentioned steps, the shift control by the shift control device 50 is completed.
As described above, by inhibiting the shifting of the gear ratio and holding the engine rotational speed Ne at the fixed value, it is possible to further reduce a driving manipulation load imposed on a rider of the vehicle.
As discussed hereinabove in conjunction with
In this manner, the change of the driving force of wheel during rolling of the vehicle and/or acute sudden steering of the handlebar of the vehicle can be eliminated thereby realizing the smoother and more-comfortable traveling of the vehicle.
The present invention is secondly characterized in that the rolling angular velocity sensor 46 is arranged on the rear portion of the vehicle body and disposed above the rear wheel 18.
Due to such a constitution, the rolling angular velocity sensor 46 is arranged at the position spaced away (remote) from the engine 41. Hence, the rolling angular velocity sensor 46 is hardly influenced, i.e., is affected minimally, by vibrations generated by the engine 41. Accordingly, it is possible to detect the rolling angular velocity of the vehicle body with higher accuracy.
Here, in the embodiment, as shown in
However, the present invention is not limited to the above-mentioned embodiments. For example, as in the case in which the throttle valve is quickly opened, when an opening change ratio of the throttle opening exceeds a predetermined value, a control for suppressing the behavior of the vehicle by decreasing an increase rate of the engine rotational speed to a fixed rate may be performed.
The shift control device of the present invention is applicable to a vehicle such as a motorcycle or the like.
Although the present invention has been described herein with respect to a number of specific illustrative embodiments, the foregoing description is intended to illustrate, rather than to limit the invention. Those skilled in the art will realize that many modifications of the illustrative embodiment could be made which would be operable. All such modifications, which are within the scope of the claims, are intended to be within the scope and spirit of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-256006 | Sep 2006 | JP | national |
