DE10229455B4 - Single-track vehicle with electromechanical disc brake - Google Patents

Abstract

single track, especially bicycle or motorcycle, characterized by an electromechanical Disc brake (10) on the front wheel, which has an electric actuator (24) for operation the disc brake (10) and a self-boosting device, when braking the front wheel rotating in the forward direction the actuating force exerted by the actuator (24) boosted without assistance, wherein the self-boosting device between the actuator (24) and a friction lining (16) of the disc brake (10) comprises a wedge assembly (30) with a wedge (32) having a under a wedge angle (α) arranged wedge surface (34) which is fixed relative to a brake with respect to the brake Abutment (38) is displaceable and is supported on the abutment (38), and wherein the actuator (24) is in direct contact with one of the wedge surface (34). different area the wedge (32) is coupled and the introduction of the actuator (24) exercised operating force into the wedge (32) parallel to the wedge surface (34).

Description

The The present invention relates to single-track vehicles, in particular bicycles or Motorcycles.

Bicycles and motorcycles are now increasingly used as sports equipment. Although the brakes of bicycles and motorcycles have been significantly improved in recent years, are certain Things that are important in two-lane vehicles, especially motor vehicles, often already today belong to the standard equipment, with single-track vehicles still a rarity. Such is for example an anti-lock system for Bicycles not at all available and at motorcycles the size Exception. Nevertheless, that would be the benefit of such a slip control system especially for single-track vehicles especially high.

From the DE 101 54 178 A1 An electromechanical brake with self-boosting is known. In the embodiment described therein, however, this brake is not suitable for use in single-track vehicles due to the special requirements to be met.

From the DE 198 51 996 A1 a control system for a vehicle brake is known in which a braking request is detected by means of a fluid pressure difference and in response to the detected fluid pressure difference, an electric adjusting device is controlled so that a brake fluid pressure corresponding to the difference of the brake pressure is obtained.

Of the Invention has for its object to provide a single-track vehicle in a simpler way than before a brake system with slip control can be provided.

to solution this task strikes the invention is a single-track vehicle, in particular a bicycle or motorcycle, the front wheel an electromechanical disc brake with an electric actuator for actuating the brake and a self-boosting device which, when braking the front wheel rotating in the forward direction that exerted by the actuator operating force reinforced without assistance. The term "helpless" is stated here, that for reinforcement that exerted by the actuator Operating force none additional Power in the form of electricity, negative pressure or the like supplied must become. The self-reinforcing device includes a wedge assembly between the actuator and a friction lining of the brake with a wedge having a wedge surface arranged at a wedge angle, relative to a relative the brake fixed abutment is displaceable and attached to the Supports abutment, wherein the actuator is directly different from one of the wedge surface area the wedge is coupled and the initiation of the actuation force exerted by the actuator in the wedge parallel to the wedge surface he follows.

Electromechanical disc brakes of the type mentioned are known, for example from the DE 198 19 564 C2 , The basic principle of such an electromechanical disc brake is that an electrical actuator is used to move at least one friction lining of the disc brake from a rest position to a working position in which the friction lining contacts the brake disc. This is also referred to as the so-called brake application. As soon as the friction lining contacts the rotating brake disk, the self-energizing device comes into action. The friction lining is carried along by the rotating brake disk and runs along a wedge surface arranged obliquely to the brake disk, so that it continues to move towards the brake disk, ie it is pressed more strongly against the brake disk. An external force is not required for this. Due to the self-boosting device such brakes require only small actuation forces and consequently only a small electric actuator. For their operation, however, an electrical power supply is required.

The invention proposes for the first time the use of an electromechanical disc brake with self-boosting in a single-track vehicle. Conventional hydraulic disc brakes are known for both bicycles and motorcycles. It is also known to provide a hydraulic disc brake with a slip control. What is needed is a hydraulic pressure generating unit, several solenoid valves and a controller to perform the states pressure build-up, pressure hold and pressure reduction in the sense of a slip control. For motorcycles, such a solution is already commercially available, but it is expensive, relatively bulky and heavy and has therefore not yet prevailed on a broad front. Obviously, such a solution for bicycles ruled out from the outset. With the inventively proposed electromechanical disc brake with self-boost, however, can be realized even in a bicycle a slip-controlled brake system, because to be controlled needs only the small electric actuator, whereas a separate hydraulic pressure generating unit as mentioned above is not required. The required power supply can also be kept small due to the small actuator, so that batteries can be used, either during a non-use of the Bicycle or even in the operation of the bike can be charged, for example by the dynamo of the bicycle. Even with motorcycles, the use according to the invention of an electromechanical disc brake with self-boosting due to the elimination of the hydraulic pressure generating unit and the solenoid valves leads to a significant weight and cost savings.

by virtue of the fact that according to the invention of the Actuator exercised Operating force over a from the wedge surface different area is initiated into the wedge, feels the actuator of the occurring during braking, possibly high against forces practically nothing, these are rather in the respect of Brake fixed abutment initiated.

Of the Actuator is advantageous a linear actuator, the position of the Wedge adjusted according to a braking request relative to the abutment. In other words, depending on how big the amount of braking demand is, the wedge is adjusted more or less far relative to the abutment, What a more or less strong pressing the friction lining to the Brake disc has the consequence. In its simplest embodiment can be a self-energizing electromechanical disc brake for a single-track vehicle exclusively be operated in a position-controlled manner. However, it is also possible that Brake over the acting normal force (force normal to the brake disc surface) or the frictional force to operate or regulate. For the latter two possibilities are corresponding sensors, i. a normal force sensor or a Friction force sensor, required.

Even though the single track vehicle according to the invention for the actual operation of the electromechanical disc brake with self-reinforcement no hydraulic pressure generating unit needed, is still preferred embodiments the one braking request to the electromechanical disc brake transmitting Organ a hydraulic system with a hydraulic pressure transducer. Compared to the especially for bicycles mostly usual Rope or bowden cables so can the transfer the desire to brake significantly loss-poor. Preferably is in the hydraulic system, a pressure sensor available, the measures pressure generated by the braking request in the hydraulic system and for controlling the actuator, a pressure corresponding to the measured emits electrical signal. The advantage of such an arrangement is that due to the initially hydraulic transmission a braking request a possible Leak in the hydraulic system is recognized immediately, because it then builds no or only insufficient Pressure on.

Especially Such a refinement is advantageous if the hydraulic system for emergency operation the electromechanical disc brake hydraulically with the latter connected is. In case of failure, for example, the electrical Actuator can still brake by means of the hydraulic pressure transducer actuated become.

The hydraulic emergency operation for example, can do this be that the disc brake has a brake piston, the springy in opposite direction is biased and the overcoming the resilient biasing force of the hydraulic pressure in the hydraulic system be moved and can act on the friction lining to him against to press the brake disc.

The resilient bias of the brake piston causes, in the normal case, i.e. with functioning electromechanical brake, the brake piston is virtually blocked, so that connected to the hydraulic pressure transducer actuating lever not noticeable emotional. The braking request is as hydraulic pressure to the pressure sensor passed whose output signal corresponding to the electromechanical brake controls. In case of a defect of the electromechanical brake, for example in case of failure of the electric actuator, the user must the operating force over the Increase the force of the resilient bias of the brake piston, only then the brake piston moves against the spring force and presses the friction lining against the brake disc.

The Spring preload leads to a practical transition between the electro-mechanical function of the brake and the hydraulic emergency operation. At the same time the change signals in the force-displacement characteristic of the operating lever the driver clearly the transition of one type of actuation to the other and lets therefore not in the dark about it, that there is a defect. The meterability of the hydraulic emergency operation is, apart from the generally higher Actuating force, very well.

Preferably has the brake piston against the actuating direction biasing Spring force a degressive characteristic, so that in the case of a Defect required operating force with increasing actuation path does not rise too much. Suitable for generating the resilient biasing force For example, disc springs, such as a plate spring package.

In preferred exemplary embodiments of the single-track vehicle according to the invention, the brake force of the electromechanical disc brake is limited in order to prevent the brake from being clamped during very heavy braking or even destruction of the brake. This can especially be done by a limitation of the application force or the frictional force achieved during braking can be achieved, for example by means of a control circuit which monitors the prevailing normal force or frictional force and the wedge by means of the actuator moves back slightly when exceeding a predetermined threshold, so as to apply the application force or frictional force decrease.

at particularly preferred embodiments the Einspurfahrzeuges invention points the electromechanical disc brake on a slip control. Thus, which is particularly important in a single-track vehicle, prevents driving conditions be blocked in which the front wheel, which is a single-track vehicle as a bike or motorcycle almost inevitably leads to a fall. at a simple embodiment the slip control, a wheel speed sensor determines the rotational speed of the front wheel, and a sensor connected to the wheel speed control determined on the basis of given maximum values for the slowing down of the rotary movement of the front wheel under consideration the currently prevailing friction force on the brake, whether wheel slip is present or not. In other words, it becomes a plausibility check carried out to that effect, whether the change detected in the wheel spin due to the currently prevailing frictional force (or alternatively the currently prevailing normal force) has been effected can be. If the answer is no, then this change is by a change of Liability between the tire and the ground causes on the the tire unwinds, i. wheel slip obviously occurs. With "Radschlupf" is here a slip meant between the tire and the road surface, over the even under normal operating conditions always present, by the user of a vehicle goes beyond unnoticeable slip.

to clarification the Radschlupfbestimmung determined according to a development another Sensor the compression and rebound movements of the braked wheel and Forwards the result to the controller, the changes in the delay behavior of the braked wheel with the determined rebound and rebound movements correlated and thus comes to a more precise Radschlupfbestimmung. The compression and rebound movements have a great influence on the upstand load of the braked wheel and thus on the probability the occurrence of wheel slip. Be the compression and rebound movements of the braked wheel detected separately, so the slip measurement much more accurate, faster and more reliable.

According to one Continuing training is a reference speed of the slip control Einspurfahrzeuges determined. This is done according to one embodiment a speed of the rear wheel, i. of the not braked wheel detecting sensor, according to a another embodiment the speed over Basic detecting optical sensor, and according to still another embodiment a GPS (global positioning system) facility. Is this reference speed known, from the signals of the wheel speed sensor by comparison be easily determined with the reference speed, whether Wheel slip is present.

at a preferred embodiment the wheel speed sensor is a tachogenerator. As a measure of the wheel speed The frequency or voltage of the tachogenerator can be used. Preferably is such a tachogenerator built into the hub of the wheel, whose speed is to be measured, and also serves as Power source for charging a battery containing the electric actuator powered. With appropriate design of this tachogenerator power other electrical consumers as needed for example, the lighting system of a bicycle.

Yet more preferred embodiments the Einspurfahrzeuges invention have alternative or additional for slip control a rollover prevention scheme. For a bike or motorcycle it is important, for example to prevent a blocking of the front wheel, however, is with good friction coefficient ratios between tires and ground the risk of a rollover of the bicycle greater, because due to the high center of gravity of a unit consisting of driver and two-wheeler the dynamic axle load shift occurring during braking complete Discharge the rear wheel, long before the blocking limit of the front wheel is reached. Around To prevent this, has a provided with a rollover prevention control Electromechanical disc brake of a Einspurfahrzeuges invention according to a embodiment a pitch rate sensor connected to a controller. Such a Nick rate sensor can be integrated into the front brake and is switched so that after crossing a threshold for the pitch rate the braking force on the front wheel is immediately reduced, a rollover to avoid. According to one Continuing education is based on the braking force that has just been almost to a rollover guided would have, a braking force lower than the maximum by one safety distance Braking force set to safely avoid a rollover. It can be provided that this acts as an upper barrier maximum Braking force value cleared again will when the brake is complete released or the braking force is definitely reduced.

at a development of the rollover prevention scheme A sensor determines the rebound and rebound movements of the rear wheel and forwards the result to a controller, who then uses the current Aufstandskraft the rear wheel determined. The rollover prevention scheme is then preferably adjusted so that the braking force on the front wheel just get so big can ensure that the rear wheel still a minimum contact force is. The determination of the rebound and rebound movements of the rear wheel Sensor can, for example, a bearing of a rear swing arm be the rear wheel arranged rotational angle sensor. Out of such Angle of rotation sensor leaves information about the travel and over gain the speed of the rebound or rebound. There The rearing force of the rear wheel is the sum of the spring force and the damping force Consequently, the currently prevailing riot force can be determined solely from the data supplied by Drehwin kelsensor. Alternatively, a displacement sensor in which the rear swing arm associated spring damper element be used.

at the above explanations was assumed that at least on the front wheel an electromechanical Disc brake with self-amplification is used. The self-reinforcing device only needs in the forward direction to act, because a reverse drive operation does not occur in a two-wheeler practically. The main brake load is taken on a two-wheeler from the front wheel, which is why it in the Usually sufficient to provide there an electromechanical disc brake with self-boosting. additionally However, an electromechanical disc brake with self-boosting on Rear wheel can be provided, if necessary for further improvement the driving behavior desired becomes. The waiver of acting in the reverse direction self-energizing device simplifies self-reinforcement required wedge arrangement, for example, is a direct coupling between the wedge and one as a transmission element possible between the wedge and the actuator serving spindle. A Adjustment of the wedge due to friction lining wear can take place then also done by means of the spindle.

One embodiment an electromechanical disc brake with self-boosting device for installation in a single-track vehicle is described below with reference to the accompanying schematic figures explained in more detail. It shows:

1 a cross section through the interest here part of an electromechanical disc brake with self-boosting device, and

2 a more detailed view of the wedge assembly of the disc brake 1 ,

1 shows a general with 10 designated electromechanical disc brake with a self-energizing device and hydraulic emergency operation, which is intended to cooperate with a front wheel or rear wheel of a two-wheeler, not shown. The disc brake 10 has a rotatable about an axis A brake disc 12 coming from a caliper 14 , which is designed here as a floating caliper, is attacked.

In the usual way has the disc brake 10 a directly operated friction lining 16 and one on the other side of the brake disc 12 acting indirectly actuated friction lining 18 ,

A not shown here hydraulic transmitter with an actuating lever, which may be mounted, for example, on the handlebar of a bicycle, is via a hydraulic line 20 with the brake 10 connected and serves primarily to forward a braking request to the brake. A hydraulic pressure sensor 22 measures the means of the hydraulic pressure transmitter in the hydraulic line 20 generated hydraulic pressure, which is a measure of the braking request, and outputs a signal corresponding to the measured pressure to a control, not shown. The controller evaluates this signal and in turn has an electric actuator 24 in the illustrated embodiment, a linear actuator with an electric motor 26 , a spindle 28 and a spindle nut, not shown, on, one of a wedge assembly 30 associated wedge 32 to move accordingly (see 2 ).

The wedge arrangement 30 with the wedge 32 is a central part of the self-reinforcing device, with the help of which of the actuator 24 on the wedge 32 transmitted actuating force automatically, that is amplified without supplying external power. The wedge 32 has one at an angle α to the brake disc 12 arranged wedge surface 34 resting on a complementary inclined surface 36 an abutment 38 supports, with respect to the brake 10 is stationary. Between the surfaces 34 and 36 of the wedge 32 or the abutment 38 For example, rollers or other friction-reducing elements may be arranged to reduce friction.

Upon a request for braking, the actuator adjusts 24 the wedge 32 on the abutment surface 36 along the brake disc 12 out so that the directly operated friction lining 16 in contact with the brake disc 12 device. The resulting reaction force over the wedge 32 and the abutment 38 in the brake 10 is initiated, leads to a corresponding displacement of the floating caliper 14 , so that also the indirectly actuated friction lining 18 at the brake disc 12 invests. This general operating principle of a floating caliper disc brake is well known to those skilled in the art and will therefore not be discussed further here.

Once the friction lining 16 the brake disc 12 touches, takes the rotating disc 12 the directly operated friction lining 16 something in the direction of rotation, ie the wedge 32 slips on the abutment surface 36 a little further in the direction of actuation, with the result that the friction linings 16 . 18 even firmer against the brake disc 12 be pressed. This is the self-energizing principle of the illustrated electromechanical disc brake, for which no external auxiliary forces are required. Should the directly operated friction lining 16 Due to the prevailing friction conditions tend to be too far from the brake disc 12 to be taken, which in extreme cases to a brake lock 10 or lead to their destruction, controls the actuator 24 on the other hand, ie it drives over the spindle 28 the wedge 32 back in time accordingly. Also the release of the brake 10 happens this way.

Should the electric actuator 24 fail, the hydraulic emergency operation comes into play. It includes one in the caliper 14 absorbed hydraulic piston 40 that by means of a spring 42 is biased against the direction of actuation. The feather 42 Make sure that the hydraulic piston 40 Normally, ie with a functioning actuator 24 , not moved. Only when building up the force of the spring 42 excessive counterforce in the hydraulic line 20 becomes the hydraulic piston 40 shifted in the direction of actuation. He then acts on a pestle 44 on the wedge 32 one, so that the directly operated friction lining 16 by means of hydraulic pressure against the brake disc 12 is pressed. The feather 42 has a degressive spring characteristic, so that the user to be overcome counterforce with failed electric actuator 24 does not rise too much.

Claims (21)

Single-track vehicle, in particular bicycle or motorcycle, characterized by an electromechanical disc brake ( 10 ) on the front wheel, which is an electric actuator ( 24 ) for actuating the disc brake ( 10 ) and a self-reinforcing device which, when braking the front wheel rotating in the forward direction, that of the actuator ( 24 ) exerted auxiliary force, the self-boosting device between the actuator ( 24 ) and a friction lining ( 16 ) the disc brake ( 10 ) a wedge arrangement ( 30 ) with a wedge ( 32 ), which has a wedge surface arranged at a wedge angle (α) ( 34 ), which relative to a fixed relative to the brake abutment ( 38 ) is displaceable and on the abutment ( 38 ) and wherein the actuator ( 24 ) directly with one of the wedge surface ( 34 ) different area of the wedge ( 32 ) and the initiation of the by the actuator ( 24 ) exerted actuation force in the wedge ( 32 ) parallel to the wedge surface ( 34 ) he follows. Single-track vehicle according to claim 1, characterized in that the actuator ( 24 ) is a linear actuator which determines the position of the wedge ( 32 ) corresponding to a braking request relative to the abutment ( 38 ) adjusted. Single-track vehicle according to claim 1 or 2, characterized in that the one braking request to the electromechanical disc brake ( 10 ) transmitting means is a hydraulic system with a hydraulic pressure generator. Single-track vehicle according to claim 3, characterized in that in the hydraulic system a pressure sensor ( 22 ), which measures the pressure in the hydraulic system and to control the actuator ( 24 ) emits an electrical signal corresponding to the measured pressure. Single-track vehicle according to claim 3 or 4, characterized in that the hydraulic system for emergency actuation of the electromechanical disc brake ( 10 ) is hydraulically connected to the latter. Single-track vehicle according to claim 5, characterized in that the disc brake ( 10 ) a brake piston ( 40 ) which is resiliently biased in the opposite direction of actuation and which are displaced after overcoming the resilient biasing force of the hydraulic pressure in the hydraulic system and on the friction lining ( 16 ) can act. Single-track vehicle according to Claim 6, characterized that the resilient biasing force has a degressive characteristic. Single-track vehicle according to claim 6 or 7, characterized that the resilient biasing force generated by a cup spring package becomes. Single-track vehicle according to one of the preceding claims, characterized in that the application force and / or the frictional force of the electromechanical disc brake ( 10 ) is limited, in particular by a control circuit with a normal force and / or friction force sensor. Single track vehicle according to one of the preceding claims, characterized in that the electromechanical disc brake ( 10 ) has a slip control. Single-track vehicle according to claim 10, characterized characterized in that a wheel speed sensor detects the rotational speed of the front wheel and determines a controller connected to the sensor based on predetermined maximum values for the deceleration of the rotational movement of the front wheel, taking into account the current frictional force, whether wheel slip is present or not. Single-track vehicle according to claim 11, characterized in that that another sensor braked the rebound and rebound movements of the Rades determined and forwarded to the controller, the changes in the delay behavior the braked wheel with the determined rebound and rebound movements correlated to specify the Radschlupfbestimmung. Single-track vehicle according to one of claims 10 to 12, characterized in that for determining a reference speed the Einspurfahrzeuges a the speed of the rear wheel detecting Sensor and / or optical speed sensing the ground above ground Sensor and / or a GPS device is present. Single-track vehicle according to one of claims 10 to 13, characterized in that the wheel speed sensor is a tachometer generator is. Single-track vehicle according to claim 14, characterized that the tachogenerator is built into the hub of the wheel and additionally acts as an energy source for charging a battery. Single track vehicle according to one of the preceding claims, characterized in that the electromechanical disc brake ( 10 ) has a rollover prevention control. Single-track vehicle according to claim 16, characterized in that the electromechanical disc brake ( 10 ) has a pitch rate sensor connected to a controller. Single-track vehicle according to Claim 16, characterized that a sensor the rebound and rebound movements of the rear wheel determined and forwarded to a controller, the resulting current Aufstandskraft the rear wheel determined. Single-track vehicle according to claim 18, characterized in that that the sensor is a bearing of a rear swing arm of the rear wheel arranged angle of rotation sensor is. Single-track vehicle according to claim 18 or 19, characterized in that the controller is the electromechanical disc brake ( 10 ) in a braking such that a predetermined minimum contact force of the rear wheel is maintained. Single-track vehicle according to one of the preceding claims, characterized in that an electromechanical disc brake ( 10 ) is also present on the rear wheel.