WO2010150237A1

WO2010150237A1 - Parking brake system for electrically propelled scooters

Info

Publication number: WO2010150237A1
Application number: PCT/IB2010/052924
Authority: WO
Inventors: Antonio Bertini
Original assignee: Oxygen S.P.A.
Priority date: 2009-06-26
Filing date: 2010-06-25
Publication date: 2010-12-29
Also published as: ITRM20090333A1

Abstract

A method for activating and controlling a parking brake system in electrically propelled scooters allows to provide an effective parking brake, that at the same time can be operated simply and rapidly and comprises the steps of: generating an activation control (S_P); detecting speed and/or acceleration of the scooter following to the reception of said activation control (S_P); keeping the electric motor (EM) of the scooter stationary when the speed and/or the acceleration are substantially equal to zero at least for a predetermined stopping time (t_s).

Description

"Parking brake system for electrically propelled scooters"

DESCRIPTION

The present invention refers to a method for activating and controlling a parking brake system in electrically propelled scooters and to an electrically s propelled scooters comprising such parking brake system.

Traditionally, two-wheeled vehicles are not provided with a real parking brake allowing to keep the vehicle stationary during stops.

Only scooters, essentially used for urban uses, have a locking system of the brake lever which, substantially, allows to keep the brake pushed also with theO hands removed, avoiding the vehicle to proceed, e.g. during a downhill stop. For example, US Patent No. 4,629,206 A describes the use of a pin that, inserted in a suitable seat, allows to lock the brake lever. Once such parking brake is inserted, the running can be restarted by operating the brake lever, that will be accordingly unlocked, allowing the vehicle re-s running.

As an alternative, as described in the European Patent Applications EP 1 186 522 A2 or US 2008 0078601 Al, suitable levers operating on an auxiliary wheel locking system can be provided, so as to keep the vehicle stationary during stops. 0 It is evident that such systems, although being capable of maintaining the vehicle steady during stops, in particular in non planar road stretches, are little practical in their use, above all because if the vehicle is subjected to continuous stops and re-running, it requires to operate continuously on the locking system. s In the case of electrical scooters, that are particularly suitable for being used in transport services, e.g. postal or home delivery, the provision of a parking brake is almost indispensable and the use of such systems is surely little practical and anyhow problematic.

The International Patent Application WO 2006/050107, describes a parking brake for electrical vehicles. Such document discloses the use of electric brake 180, parallel operating with the motor 110 del vehicle, which is activated according to an activation signal. The electric brake keeps the vehicle stationary at a zero speed until the user does not decide the re-running. It is evident that the provision of a further component such as the electric brake represent a remarkable problem in a scooter wherein weight and dimensions should be maximally limited.

U.S. Patent Application No. 2006/047400 describes a system for realizing braking and stopping in electrical scooters. In this, a negative torque is applied to the motor in order to provide a braking torque. Nevertheless, following to the stop it is explicitly excluded that such system could be used for maintaining the vehicle stationary when the street is not perfectly plane. Hence, the technical problem underlying the present invention is to provide a parking brake per electrical scooters allowing to overcome the drawbacks mentioned above with reference to the known art. Such problem is solved by the method for activating and controlling a parking brake system in electrically propelled scooters according to claim 1 and by an electrically propelled scooters comprising the parking brake system according to claim 9. The present invention provides several relevant advantages. The main advantage lies in that the method according to the present invention allows to provide an effective parking brake, that at the same time can be activated easily and rapidly, without requiring bulky additional elements to be installed on the vehicle. In addition, it is possible to control the operative mode of the parking brake system so that it can be respectively activate and deactivated upon stop and re-running.

Other advantages, features and the operation modes of the present invention will be made apparent from the following detailed description of some embodiments thereof, given by way of a non-limiting example. Reference will be made to the figures of the appended drawings, wherein : Figure 1 is a block diagram of the method for activating and controlling a parking brake system in electrically propelled scooters according to the present invention.

With reference to figure 1, it is shown a block diagram summarizing the operation of a method for activating and controlling a parking brake system in electrically propelled scooters according to the present invention.

In general, an electrically propelled scooters according to the present invention, comprises an electric motor EM, a control unit CU, that as will be shown in deeper detail in the following and it is directed to the activation of the electric motor EM of the scooter, a battery pack BP and a wheel, rim and tire assembly 4.

In addition, the scooter could be possibly provided with a mechanical transmission between motor EM and wheel.

Incidentally, the term scooter will mean that motorcycle category having the characteristic "step-through" shape, i.e. that can be crossed in the lowered portion between saddle and the front shield. Such vehicles are normally two- wheeled but, in some cases, three-wheeled and, the same inventive concepts that will be disclosed in the following could be applied also to this kind of vehicles.

The scooter according to the present invention further comprises mechanical brake control means B, realized by the operation lever of the mechanical brake, and operation mode selecting means M of the control unit CU, allowing to modify the operation mode of the motor set by the control unit CU, both for modifying the vehicle behaviour during run and, as will be seen in detail in the following, for activating the parking brake system. Moreover, more precisely and always according to a preferred embodiment, the operation mode selecting means M comprises a selection button that could be pushed in order to send an apposite signal to the control unit CU. As will be seen in further detail in the following, the mechanical brake operating means B and the operation mode selecting means M form activating means of a parking brake system.

Then, the above-identified activating means allows to send an activation signal Sp to the control unit CU which, upon receiving it, performs a speed and acceleration control of the motor EM. Such control is apt to verify if speed and acceleration are equal to zero at least for a predetermined stopping time t_s and, in such case, the control unit keeps the electric motor EM of the scooter stationary. In this way, the rotation of the wheel will be prevented and the vehicle will remain steady even if parked on a slope. The locking of the motor is performed by means of the control unit CU that will perform a zero speed control or a position control such that the motor does not rotate. In other words, when the parking brake mode is activated, as soon as a condition of non-zero speed, positive or negative, is detected, the control unit CU powers the electric motor so as to restore a zero speed. As an alternative, a position control can be provided such that the control unit CU, upon detecting a displacement, supply a tension or a current to the electric motor so as to oppose to such displacement.

The normal operation of the scooter, i.e. with the motor in propulsive mode, is restored upon operation of the accelerator control means A. In fact, when the accelerator hand grip is rotated, a respective acceleration signal S_A will be send to the control unit CU that will consequently operate the motor in order to be restored in rotating according to normal running conditions.

Nevertheless, in case of successive stop of the vehicle, in particular in the case that the condition of zero speed and acceleration is repeated at least for the above mentioned stopping time t_s, the control unit CU will keep again the motor stationary according to the same method previously shown. By way of example, the parking brake system can be automatically reactivated each time the accelerator is in resting position for a time higher than 2 s, and the speed detected remains zero for more than 2 s. In other words, the stopping time t_s can be fixed equal to 2 s. Obviously, with reference to the speed, an error inside which the speed is considered still zero can be provided. In deeper detail, the speed and acceleration control is performed by means of speed and acceleration detecting means of the motor EM that, always according to the present embodiment, comprises a speed sensor capable of detecting the scooter advancing speed and a sensor capable of detecting the rotation of an accelerator control hand grip A, respectively. In particular, the first function, i.e. the speed detection, can be provided by the tachymeter while the second, i.e. the acceleration detection, can be provided by the potentiometer controlling the acceleration as occurs in traditional electrical scooters.

In fact, contrary to the scooters according to the known art, a mechanical braking control B, e.g. realized by an operation lever, is also connected to the control unit CU in a such way that, upon operation of the mechanical brake, a control signal S_B is sent to the unit CU. A By way of example, the signal S_B can be generated by means of a micro-switch SW placed at the operation lever and switched upon rotation thereof. Analogously, when the selection button of the operative mode M is pushed, a control signal S_M is sent to the control unit.

In this way, the parking brake system according to the present invention, can be activated by simultaneously pushing the brake lever B and the selection button M, generating the respective signals S_B and S_M. Then, if the lever and the button are pushed at least for a predetermined activating time t_a, e.g. equal to 10 s, the activation signal of the parking mode S_P is generated which is sent to the control unit CU.

Such automatic activation of the parking brake could be deactivated with the same method than the activation, i.e. keeping the brake lever and the selection button M simultaneously pushed for at least 10 s, or a possible deactivation time t_d.

Finally, it should be noted that the activation of the parking brake mode could be indicated by means of a suitable luminous signal of the instrument board that will activate when the activation signal S_P is sent to the control unit CU. Then, it should be comprised that the parking brake system activated by the method according to the present invention allows to automatically keep the vehicle stationary during stops, even short ones, without requiring any intervention by the driver at re-running. Moreover, the present invention does not envisage any wear of mechanical parts for the operation of the parking brake as unavoidably occurs in scooters according to the known art.

The present invention has hereto been described with reference to preferred embodiments thereof. It is understood that there could be other embodiments referable to the same inventive kernel, all falling within the protective scope of the claims set forth hereinafter.

Claims

1. A method for activating and controlling a parking brake system in electrically propelled scooters, comprising the step of: a) generating a activation control (S_P); 5 b) detecting speed and/or acceleration of the scooter following to the reception of said activation control (S_P); c) keeping the electric motor (EM) of the scooter stationary when speed and/or acceleration is/are substantially equal to zero at least for a predetermined stopping time (t_s); io characterized in that said step of keeping the motor (EM) of the scooter stationary comprises a further step of controlling the speed of the motor (EM) so that upon detecting a non-zero speed said control unit (CU) powers the motor (EM) so as to restore a zero speed.

2. The method according to claim 1, wherein the motor rotation is i5 restarted again following to the activation of an accelerator control means (A) of the scooter, and said step of keeping the motor stationary is repeated any time a speed and/or acceleration condition substantially equal to zero is maintained at least for said predetermined stopping time (t_s)

20 3. The method according to claim 1 or 2, wherein said step of generating an activation control (S_P) takes place by simultaneously activating a mechanical brake control means (B) and operation mode selecting means (M) of a control unit (CU) at least for a predetermined activating time (t_a). 5 4. The method according to any of the preceding claims, wherein said step of keeping the motor (EM) of the scooter stationary comprises a further step of controlling the motor (EM) position, such that upon detecting a displacement, said control unit (CU) powers the motor (EM) so as to oppose to said displacement. 5. The method according to any of the preceding claims, wherein said zero acceleration condition is detected by means of the position of an accelerator hand grip (A) of the scooter.

6. The method according to any of the preceding claims, wherein said zero speed condition is detected by means of speed detecting means of the scooter.

7. The method according to any of the preceding claims, wherein said predetermined stopping time (t_s) is equal to 2 s.

8. The method according to any of the preceding claims, wherein said mechanical brake control means (B) and said operation mode selecting means (M) comprises a brake operation lever and a selection button, respectively, said step of generating an activation control (S_P) being carried out by keeping simultaneously pushed said lever and said button.

9. An electrically propelled scooters, comprising • an electric motor (EM);

• a motor (EM) control unit (CU);

• speed and acceleration detecting means of the motor (EM);

• activating means (B, M) of a parking brake system; said control unit being apt to control the locking and the rotation of the motor (EM), respectively, said locking of the motor (EM) taking place following to a stop of the scooter at least for a predetermined stopping time (t_s), the motor rotation (EM) re-running following to the operation of a scooter accelerator (A) control, characterized in that said control unit (CU), upon detecting a displacement of the electric motor (EM), supply a current to the electric motor (EM) so as to oppose to such displacement. lO.The scooter according to claim 10, wherein said activating means comprises mechanical brake control means (B) and operation mode selecting means (M) of said control unit (CU). ll.The scooter according to claim 11, wherein said mechanical brake control means and said operation mode selecting means comprises an brake operation lever (B) and a selection button (M), respectively.

12. The scooter according to claim 10, wherein said speed detecting means of the motor (EM) comprises a speed sensor capable of detecting the scooter advancing speed and said acceleration detecting means comprising a sensor capable of detecting the rotation of a control hand grip of said accelerator control (A).