DE102013210562A1 - Brake system for a motorcycle and method of operating a brake system - Google Patents

Abstract

A brake system (2) for a motorcycle, comprising a first brake lever (44) and a first brake cylinder (50) which can be actuated by the first brake lever (44) to build up pressure in a first brake circuit (8), a first being based on the actuation of the first brake lever (44) responsive pressure sensor (158) is provided, and a second brake lever (186) and a second brake cylinder (180) which can be actuated by the second brake lever (186) to build up pressure in a second brake circuit (26), a second being actuated second brake lever (186) responsive pressure sensor (192) for measuring the pressure in the second brake circuit (24) is provided, and an electrohydraulic actuator through which pressure can be actively built up in the second brake circuit (24), and a control and regulating unit (164 ), which, in particular when the first brake lever (44) is actuated, controls the electro-hydraulic actuator for active pressure build-up in the second brake circuit (26), is intended to function as a Provide additional braking options in a flexible and structurally simple way. For this purpose, a third brake lever (258) is provided, the actuation of which actuates an electrical setpoint generator (264), which is connected on the input side to the control and regulating unit (164), an output signal from the electrical setpoint generator (264) being taken into account when the electrohydraulic actuator is actuated becomes.

Description

The invention relates to a brake system for a motorcycle, comprising a first brake lever and a first brake to the first brake lever operable to build up pressure in a first brake cylinder, wherein a first on the operation of the first brake lever responsive pressure sensor is provided, and a second brake lever and a Pressure build-up in a second brake circuit with the second brake lever operable second brake cylinder, wherein a second is provided on the actuation of the second brake lever responsive pressure sensor, and an electro-hydraulic actuator, through which pressure can be set up in the second brake circuit active, and a control unit, which, in particular on actuation of the first brake lever, the electro-hydraulic actuator for active pressure buildup in the second brake circuit controls. It also relates to an associated operating method.

Especially in sports or racing, it can happen in large slopes of a motorcycle in right-hander that the foot pedal of the rear brake for the driver is not usable. On the one hand, this is due to the fact that the right foot and the foot pedal are very close to the ground in the event of a steep incline so that there is no room for actuation. On the other hand, the sitting position commonly used in these turns, in particular the "hanging off", requires the right foot to be placed on the footrest and thus no longer available for the operation of the pedal.

In order to still allow access to the rear brake in these situations, so far a hydraulic thumb brake is designed and used. To the left end of the handlebar an additional hydraulic actuator with a hydraulic master cylinder and an actuator is attached, which is operated with the thumb of the left hand.

A disadvantage of said thumb brake is that a hydraulic connection of this brake to the rear wheel brake circuit, for example via a 3-way valve and at least one additional hydraulic line is complex and costly.

The invention is therefore based on the object to provide a brake system in which the functionality of an additional braking option is realized in a flexible and structurally simple way. Furthermore, a corresponding operating method should be provided.

With regard to the braking system, this object is achieved according to the invention by providing a third brake lever, the actuation of which actuates an electrical desired value transmitter, which is connected on the input side to the control and regulation unit (ECU), and wherein in the control of the electrohydraulic actuator an output signal of electrical setpoint generator is taken into account.

Advantageous embodiments of the invention are the subject of the dependent claims.

The invention is based on the consideration that in the typical application areas in which the generally the operation of a brake, especially the rear brake, the motorcycle is not or only to a limited extent possible, another brake lever should be available for operating the brake. In particular, a thumb brake is a comfortable and effective function transfer, but it brings in their previous hydraulic versions also significant disadvantages, for example, by additional and not negligible weight. Of course, especially in racing, the weight of the motorcycle has to be kept as low as possible.

As has now been recognized, partial integral brake systems in which actuation of a brake lever results in pressure buildup in both brake circuits (with pressure being actively built up by the brake system in at least one of the brake circuits) can be extended to include the functionality of a further brake lever by providing such brake as art "Brake by wire" is connected on the data side to the control and regulation unit. In addition to the installation of the brake lever and the setpoint generator only the laying of an electrical signal line is required. The usually complex laying of additional hydraulic lines and hydraulic connections to the rear wheel brake or the brake system can thus be omitted, and the weight of these lines and the required valves can be saved.

The integration of a "by-wire" brake in a partial integral braking system is particularly technically feasible because an actuator for the necessary pressure build-up already exists. The signal of the electrical setpoint generator can then be utilized by the control and regulation unit, so that the setpoint pressure to be set in the second brake circuit can also depend on this value.

In a further possible embodiment, a further electrohydraulic actuator is provided for the active pressure build-up in the first brake circuit. In this case, there is a full integral braking system. Both upon actuation of the first brake lever and on actuation of the second brake lever pressure is built up in each case in the other brake circuit. Also in this case can the signal of the electrical setpoint generator in the active pressure build-up in the second brake circuit are taken into account. Such a full integral brake system may be extended in a substantially similar manner to the third brake option with the partial integral brake system described above.

The third brake lever is advantageously designed as a thumb brake lever for actuation by, in particular the left, thumb. In a motorcycle, it is preferably mounted on the left side of the handlebar under the handle.

The signal transmission between setpoint generator and ECU should preferably be done via CAN or via a CAN bus.

Preferably, the electrical setpoint generator is designed as a spring simulator and includes a displacement and / or force sensor whose respective signal is forwarded to the control and regulation unit. By training as a spring simulator with a compressible according to the Federgesetz elastic element, in particular with a compression spring, the driver undergoes a substantially proportional to the degree of actuation counterforce on actuation of the third brake lever, giving him a good and reproducible feeling for the degree of actuation taught. The braking request of the driver, which expresses itself in the strength of the operation of the brake lever, can be measured by a displacement sensor, which measures, for example, how much the spring has compressed. Alternatively or in combination there may also be provided a force sensor which measures the force exerted on the spring. If both sensors are used, they can be used as redundant sensors or simultaneously be used to determine the driver's request (for example, by averaging).

Advantageously, the first brake lever is designed as a hand brake lever and the second brake lever as a foot pedal. The first brake circuit then corresponds to the front wheel brake circuit and the second brake circuit corresponds to the rear wheel brake circuit, this is the usual embodiment of a partial integral or full integral brake system of a motorcycle.

With regard to the method, the abovementioned object is achieved according to the invention by determining a desired pressure in the second brake circuit on the basis of a characteristic as a function of the sensor signal of the respective sensor of the setpoint generator. The characteristic mediates in a known manner the relationship between the expression expressed by actuation of the third brake lever braking request - mapped to a measured force and / or a measured path - and the brake pressure to be set. The characteristic curve is advantageously stored in the control unit. In this way it is freely programmable. It is also possible to deposit several characteristic curves that correspond to different driver designs or vehicle dynamic settings. The characteristic curve can also be adapted to the current dynamic driving situation during ongoing driving operation, which is detected, for example, by the signals of further sensors, such as the wheel speed sensors.

Advantageously, the signals of the first and pressure sensor and the respective sensor of the setpoint generator are processed to set the pressure in the second brake circuit. The sensor value of the first pressure sensor or the "normal" actuation of the first brake, in particular of the front wheel brake, optionally generates an active pressure build-up in the second brake circuit. The pressure sensor of the actuation of the second brake circuit, in particular of the rear wheel brake circuit, provides information about the driver's request on the second brake lever, in particular on the brake pedal. The sensor value of the setpoint generator provides information about the driver's request at the third brake, in particular at the thumb brake. In this case, a maximum value formation preferably takes place, which is possibly limited by the vehicle-specific ideal distribution for one or all driver wishes.

The signals can be averaged, weighted or the maximum of the signals is determined. These types of processing can also be adapted dynamically to the respective driving situation. At high delays the braking force should follow the so-called ideal distribution. Since the rear wheel of the motorcycle is relieved by the dynamic Radlastverlagerung, it is recommended to lower the pressure in the rear wheel again from a vehicle-specific delay. This could mean that it makes sense to increase the pressure in the rear wheel, but lower, despite stronger activity.

The advantages of the invention are, in particular, that a flexible relationship between actuation travel and / or force and the pressure to be set at the rear wheel brake circuit can be created by a thumb brake in the "by wire" design.

Through the realization "by wire" and the omitted installation of relatively heavy hydraulic components both weight and cost can be saved.

An embodiment of the invention will be explained in more detail with reference to a drawing. In it show in a highly schematic representation:

1 a brake system with a thumb brake in a preferred embodiment, and

2 several examples of characteristics for use in a brake system according to 1 ,

An in 1 illustrated brake system 2 is designed for a motorcycle, especially a motorcycle. It includes a first brake circuit 8th with a front brake 14 for braking a front wheel 20 and a second brake circuit 26 with a rear wheel brake 32 for braking a rear wheel 38 , To build up pressure in the front brake, a first brake lever 44 , which is designed as a hand brake lever, operated by the driver, which in a first master cylinder 50 a first pressure piston 56 is moved. As a result, brake fluid or pressure fluid through a supply line 62 conveyed in the first brake circuit, where they pass through an open, in the supply line 62 switched inlet valve 68 and practice pure from the supply line 62 branching brake line 74 in the front brake 14 is encouraged. About one with the supply line 62 hydraulically connected discharge line 80 into which an exhaust valve 86 is switched, pressure medium from the first brake circuit 8th in a low-pressure accumulator 92 be directed.

For returning brake fluid from the low-pressure accumulator to the brake circuit 8th or the first master cylinder 50 is a recuperation line 98 provided at a node 104 into the supply line 62 empties. In the return line is a suction path 110 realized with one of a motor 116 driven pump 122 , Through two, in the suction path 110 in front of and behind the pump 122 arranged check valves 128 . 134 is a (back) flow of the brake fluid via the return line 98 in the low-pressure accumulator 92 prevented. A damping chamber 140 , which is optional, is mainly used in passenger cars and is not required for a motorcycle or is no longer used in all motorcycle applications. In combination with a panel 146 it ensures a damping of the return pumping pulses of the pump.

The first master cylinder is with a brake fluid reservoir 152 hydraulically connected. The one in the first brake circuit 8th and thus in the supply line 62 present pressure is from a first pressure sensor 158 measured and is a measure of the strength of the operation of the first brake lever and for the driver's brake request. Another first pressure sensor 162 measures the brake pressure in the first brake circuit 8th , The valves 68 . 86 are transmitted in a known manner by an electronic control unit (ECU). 164 activated: to build up the pressure medium in the front brake 14 is - in the illustrated state - the inlet valve 68 opened, and the exhaust valve 86 will be closed. For pressure reduction, the inlet valve 68 closed, and the exhaust valve 86 is opened so that the pressure medium in the low-pressure accumulator 92 can drain away. For the return of brake fluid from the low-pressure accumulator 92 in the brake circuit 8th is from the control unit 164 the pump 122 driven.

Some of the components of the second brake circuit 26 , in the same place in the hydraulic circuit diagram and with the same function as in the first brake circuit 8th are provided are provided with the same reference numerals. A second master cylinder 180 is with a brake fluid reservoir 152 connected. By operation of a brake lever designed as a second brake lever 186 becomes a second pressure piston 192 in the second master cylinder 180 shifted, whereby pressure medium via a supply line 198 in the second brake circuit 26 is pressed. A pump 204 coming from the engine 116 is driven, is for the return promotion of brake fluid from the control unit 164 driven. A second pressure sensor 210 measures the pressure in the supply line 198 , and another second pressure sensor 216 measures the pressure in the brake circuit 26 ,

In contrast to the first brake circuit 8th can in the second brake circuit 26 active, ie without pressure from the driver or in addition to pressure. For this purpose, the supply line branches 198 in a line 222 into which a separating valve 228 is switched and in a line 234 into which a switching valve 240 is switched. In basic position, if in the second brake circuit 26 is to be built exclusively by the driver brake pressure is, as shown, the isolation valve 228 in its passage position and the switching valve 240 in its closed position. For an active pressure build-up, the valves 228 and 240 switched so that the isolation valve 228 closes and the changeover valve 240 opens. By controlling the pump 204 can now pressure medium in the brake circuit 26 be promoted, whereby by closing the separating valve 288 it is ensured that the pumped pressure medium is not in the direction of the second master cylinder 180 flows and is not available for the pressure build-up. A check valve 246 prevents the driver from braking into the low-pressure accumulator via a master cylinder.

The described brake system 2 is designed as a partial integral braking system. Operates the driver only the rear brake by pressing the brake pedal and the second brake lever 186 , be isolation valve 228 and changeover valve 240 switched into the illustrated positions, so that pressure medium from the second master cylinder via the lines 222 and 74 in the rear wheel brake 32 can flow. The driver presses the handbrake lever or first brake lever 44 , on the one hand brake means from the first master cylinder 50 in the front brake 14 postponed. On the other hand, on the input side with the control unit 14 connected first pressure sensor 158 and / or another first pressure sensor 162 determines the driver's brake request and built up in the rear brake, if necessary, active brake pressure.

In the case of a full integral braking system, the first brake circuit would be 8th in terms of its hydraulic lines and valves as the second brake circuit 26 constructed so that upon actuation of the second brake lever in the first brake circuit 8th active pressure can be built up.

The brake system 2 is with a thumb brake 252 equipped, which allows the driver in the rear brake 32 Pressure build, even if he can not operate the foot brake lever. This is the case in racing, for example, when the motorcycle is in a right-hand bend in a steep incline. On the one hand, the space between the right foot and the tarmac is very small, so positioning the foot for braking is extremely difficult to impossible. On the other hand, the driver's seating position (for example, "hanging off") requires the foot to be placed on the footrest. Furthermore, an operation of the foot brake may not be possible due to physical difficulties or disabilities of the driver.

The thumb brake 252 includes a brake lever 258 which is designed for operation with the thumb of the left hand. In contrast to known thumb brakes, the thumb brake according to the invention is designed in the manner "by wire". This is the brake lever 258 with a designed as a spring simulator electrical setpoint generator 264 connected such that an actuation of the brake lever 258 by the driver to a compression or compression of a spring of the setpoint generator 264 leads. The setpoint generator 264 includes a displacement sensor that measures the travel on which the spring was compressed. This path information is from the setpoint generator 264 converted in a known manner into an electrical signal, which via a signal line 270 to the control unit 164 is transmitted. This signal is now further processed and in the determination of the desired brake pressure in the second brake circuit 26 considered.

The design of the thumb brake as "by wire" allows the functional relationship between the degree of actuation of the setpoint generator, for which a measure of the distance by which the spring was compressed, and the desired brake pressure or desired braking torque to define as a characteristic and in the control and control unit 164 to deposit. Examples of such characteristics are in 2 shown. On an x-axis 276 is that of one end of the spring of the setpoint generator 264 traveled path and on a y-axis 282 the desired brake pressure in the second brake circuit 26 applied. In the 2 are three possible or exemplary characteristics 286 . 293 . 298 applied. The characteristic 292 It expresses a substantially linear relationship. The characteristic 286 runs at higher deflections stiffer than the linear curve 292 , which means that at higher deflections, the target braking torque should increase more than linear. The characteristic 298 on the other hand flattens for higher deflections and opens in a horizontal course, so that for large deflections, the braking force - depending on the specific embodiment - no longer increases, or even decreases.

LIST OF REFERENCE NUMBERS

2

 braking system

8th

 first brake circuit

14

 front brake

20

 front

26

 second brake circuit

32

 rear brake

38

 rear wheel

44

 first brake lever

50

 first master cylinder

56

 first pressure piston

62

 supply line

68

 intake valve

74

 brake line

80

 discharge line

86

 outlet valve

92

 Low-pressure accumulator

98

 Return flow line

104

 junction

110

 suction path

116

 engine

122

 pump

128

 check valve

134

 check valve

140

 damping chamber

146

 cover

152

 Brake fluid reservoir

158

 first pressure sensor

162

 another first pressure sensor

164

 Control unit

180

 second master cylinder

186

 second brake lever

192

 second pressure piston

198

 supply line

204

 pump

210

 another second pressure sensor

216

 pressure sensor

222

 management

228

 isolation valve

234

 management

240

 switching valve

246

 check valve

252

 thumb brake

258

 brake lever

264

 Setpoint generator

270

 signal line

276

 X axis

282

 y-axis

286

 curve

292

 curve

298

 curve

Claims (8)

Brake system ( 2 ) for a motorcycle comprising a first brake lever ( 44 ) and one for pressure build-up in a first brake circuit ( 8th ) with the first brake lever ( 44 ) operable first brake cylinder ( 50 ), wherein a first on the operation of the first brake lever ( 44 ) appealing pressure sensor ( 158 ) is provided, and a second brake lever ( 186 ) and one for pressure build-up in a second brake circuit ( 26 ) with the second brake lever ( 186 ) operable second brake cylinder ( 180 ), with a second on the operation of the second brake lever ( 186 ) appealing pressure sensor ( 192 ) for measuring the pressure in the second brake circuit ( 24 ) is provided, and an electro-hydraulic actuator through which in the second brake circuit ( 24 ) active pressure can be built up, and a control unit ( 164 ), in particular when the first brake lever ( 44 ), the electrohydraulic actuator for active pressure build-up in the second brake circuit ( 26 ), wherein a third brake lever ( 258 ) is provided whose operation is an electrical setpoint generator ( 264 ), which on the input side with the control unit ( 164 ), and wherein in the control of the electro-hydraulic actuator, an output signal of the electrical setpoint generator ( 264 ) is taken into account. Brake system ( 2 ) according to claim 1, wherein a further electrohydraulic actuator is provided for the active pressure build-up in the first brake circuit ( 8th ). Brake system ( 2 ) according to claim 1 or 2, wherein the third brake lever ( 258 ) is designed as a thumb brake lever for actuation by, in particular the left, thumb. Brake system ( 2 ) according to one of claims 1 to 3, wherein the electrical setpoint generator ( 264 ) is designed as a spring simulator and comprises a displacement and / or force sensor whose respective signal to the control unit ( 164 ) is forwarded. Brake system ( 2 ) according to one of claims 1 to 4, wherein the first brake lever ( 44 ) as handbrake lever and the second brake lever ( 186 ) are designed as a foot pedal. Method for operating a brake system ( 2 ) according to one of the preceding claims, wherein based on a characteristic in dependence on the sensor signal of the respective sensor of the setpoint generator ( 264 ) a target pressure in the second brake circuit ( 24 ) is determined. Method according to Claim 5, in which, for setting the pressure in the second brake circuit ( 26 ) the signals of the first pressure sensor ( 158 ) and the respective sensor of the setpoint generator ( 264 ) are processed. Method according to Claim 6, in which, to set the pressure, the signals are averaged, weighted or the maximum of the signals determined.

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