DE102013205227A1 - Method for operating a motor vehicle - Google Patents

Abstract

The invention relates to a method and an arrangement for operating a motor vehicle. The motor vehicle has a clutch arrangement (10) with an exclusively mechanical transmission of a force introduced at a clutch actuating element to a clutch (28), the clutch (28) being opened by actuating the clutch actuating element and the clutch via an additionally provided hydraulic unit (11) (28) is kept open.

Description

The invention relates to a method for operating a motor vehicle and a clutch assembly for carrying out the method. The described method is used in a motor vehicle having a clutch arrangement which has a mechanical transmission of the force introduced by a driver on a clutch actuating element onto a clutch.

State of the art

A mechanical transmission of the force introduced by the driver takes place, for example, by means of a cable. Such clutch arrangements are used regularly in two-wheeled vehicles. But also in other motor vehicles such as passenger cars and trucks such mechanical transmissions are used.

It should be noted that in motor vehicles a distinction is made between different driving conditions. Sailing is a driving condition that is already known in hybrid vehicles, such as, for example, in a parallel hybrid with a separating clutch between the internal combustion engine and the electric drive machine. However, it has been found that sailing is also beneficial in conventional motor vehicles, especially in the context of rising fuel prices and the need to reduce emissions.

Sailing, also known as freewheeling, high speed free rolling, coasting, etc., opens the drivetrain and decouples the combustion engine and transmission. Due to the missing engine drag torque, the vehicle unrestrainedly rolls further than with overrun fuel cutoff in the highest gear. The engine may continue to idle, referred to as idle sailing. Finally, the engine can also be turned off, which is called engine stoppage sailing. With a corresponding operating concept, the engine automatically restarts.

The powertrain of a motor vehicle means all components that transmit torque to the road. In a conventional powertrain, this includes the engine, the clutch with transmission, the drive shafts and the wheels.

The described idle sailing can be implemented without much additional effort. However, it can only expect low fuel savings. The engine stop sailing shows in real driving vehicle and driver-dependent fuel savings potential of up to 10% in addition to a start-stop operation.

In hybrid vehicles, the necessary conditions for a sailing operation already exist. In a conventional vehicle, on the other hand, the starter system, electrical system, steering system, braking system and transmission must be adapted to the additional requirements.

For manual gearboxes, sailing is possible. However, this requires a perceived as cumbersome operating concept. In order to clarify this, a possible operating concept is presented below.

To initiate sailing operation, the driver must actuate the clutch actuator, eg, pull the clutch lever, place the transmission in neutral, and release the clutch. To restart the engine, the clutch lever must be pulled again. Then, to reestablish a power connection between the engine and the transmission, a gear that is appropriate to the speed of the vehicle must be engaged and the clutch released again.

Disclosure of the invention

Against this background, a method having the features of claim 1 and a clutch arrangement according to claim 8 are presented. Embodiments result from the dependent claims and the description.

In the method presented is thus, at least in the presence of certain conditions, the clutch and thus the drive train held open by a valve. Keep open in this context means that the clutch and thus the drive train remain open, even if the clutch actuator is relieved. Relieved means that the driver no longer has more power Clutch actuator is initiated or the clutch is no longer pressed or operated. This means that when the force applied to actuate the clutch is removed, the clutch still remains open. The clutch and thus the drive train are closed again only when specific, predefinable events, such as, for example, an operation of the accelerator pedal or the brake, are detected.

An exclusively or purely mechanical path of action between the clutch actuating element and the clutch means that the force introduced by the driver when the clutch actuating element is actuated to open the clutch is transmitted purely mechanically to the clutch. The additionally provided hydraulic unit keeps the clutch and the drive train open, even if the clutch actuator is relieved again.

The method can be used for a sailing operation. A condition can be given by the fact that in a predetermined period no gear change takes place, no gas is given and / or a brake is not operated. The condition can also be given in the presence of a movement pattern of the clutch actuating element.

The method presented herein suggests a balance between the perceived cumbersome sailing in neutral gear position initiated by the driver and a fully automated operating concept. In the case of the fully automatic operating concept, it is intended to realize a sailing with a manual transmission fully automatically with the aid of a clutch actuator. In this case, it is provided to control at least one separating element of a coupling arrangement via a driver-operated actuating element and a control device. This system can basically be adapted to two or motorcycles. However, in comparison with the purchase price of a two-wheeler or an autoshicka, a tricycle, this system is in many cases too expensive.

The proposed clutch assembly provides a mechanical transmission, in particular a purely or exclusively mechanical transmission, for example. By means of a cable, the driver of the clutch actuator, in a motorcycle the clutch lever, initiated force on the clutch. This is an exclusively or purely mechanical path of action between the clutch actuator and clutch given.

Sailing can be initiated by the driver actuating the clutch actuator, for example, for a predetermined period of time. Alternatively or additionally, the sailing can be initiated by actuating the clutch actuating element beyond a certain point. With a clutch pedal this is thus determined via the pedal travel. It is also possible that the sailing operation is initiated in a particular, pre-determined particular type of operation of the clutch actuator. For example. It may be necessary to operate the clutch actuator several times in a row. This is known to the driver in advance and he can initiate the sail operation by a certain type of operation of the clutch actuator. The introductory conditions mentioned can be combined as desired, used alternatively or in addition.

The proposed middle ground between sailing in neutral gear position and the fully automatic operating concept can be made possible in a two-wheeler by a hydraulic unit on the handlebars.

By pulling and holding, wherein in one embodiment the holding time t_halt is greater than 1 second of the clutch actuating element, for example the clutch lever, the engine control can recognize that it is not a switching operation. In addition, if the brake and the gas are not actuated, the system recognizes that a sailing operation is desired. The sailing operation is then initiated or activated. In this case, the internal combustion engine is controlled in design so that it goes to idle speed. During start-stop sailing, the combustion engine is switched off. The driver can now release the clutch lever, since the hydraulic unit in an embodiment causes the automatic holding of the clutch lever. The driver-terminated termination of sailing is done by an action of the driver, for example by an operation of the accelerator pedal or by braking. This is slowly engaged by the valve or throttle valve position. The driver can thus intuitively leave the sailing operation and at the same time in his desired driving mode, namely driving or braking. Alternatively, the sailing triggered by an action of the controller can be terminated.

In addition, an indicator light may be used to assist the driver, indicating to the driver if sailing is possible. This can also indicate whether the vehicle is currently in sail mode. This indicator light makes it possible to suggest and be a sailing to the customer Adapt driving behavior to a sailing system to gain an advantage in terms of CO ₂ emissions. Possible operating states are illustrated in Table 1 below: conditions lamp status system response Coupling holding functionality driver reaction 1 continuously Sailing operation active Engine control triggers the valve after 1 second to maintain pressure Pressure on fingers is reduced after the clutch lever is pressed for more than 1 second 2 flashing Sailing possible Engine control is waiting for the driver to hold the clutch lever for more than 1 second Display for driver to actuate the clutch actuation and thereby activate sailing 3 out Sailing operation not possible no action Sailing is currently not possible -> no actuation of the clutch actuator 4 off (previously state 1) Display for driving, the sailing is finished Engine control triggers the valve to close clutch Clutch actuator comes back automatically, no activation required by the driver Table 1

The presented method makes it possible to exploit the great potential for savings in terms of consumption by sailing and start-stop or stop-in-gear (SiG) at low cost.

In a start-stop function, the internal combustion engine is switched off, typically by the engine control unit, when the motor vehicle is stationary.

Stop-in-gear refers to an operating strategy in which the vehicle is turned off below a speed threshold and when the clutch lever and brake are actuated.

In the described method, the usual operation of the vehicle can be largely retained. The necessary actuation of the clutch actuating element leaves the driver with the decision sovereignty over the clutch. The clutch valve assists the driver in not having to constantly hold the clutch lever during sailing or even in a stop-in-gear phase. This also applies to engine stop sails, idle sails, as well as in stop-in-gear and idle mode.

In a two-wheeler, the hydraulic unit on the handlebar thus allows the driver a comfortable sailing, stop-in-gear operation and idling operation.

The termination of the sailing can be triggered by the engine control, among other things, if, for example, the battery state of charge or the virtual speed in the engaged state is too low. This is an effective protection against stalling. It should be noted that the driver can be surprised when the clutch lever automatically jumps quickly to its original position. By a proportional valve can be engaged softly from the sail and SiG operation or mode even with rapid release of the clutch actuating element of the engine. The release of the clutch actuator is then throttled, so that the driver is not surprised and even injured.

It should be noted that the presented method makes it possible by the simple operation that the driver can use the great savings potential in terms of consumption by sailing and stop-in-gear.

The presented method and the disclosed clutch arrangement hold the clutch via a hydraulic unit. In one embodiment, the clutch is actuated via a mechanical transmission means, such as a cable, and only the clutch actuator is held over the hydraulic unit, thereby holding the clutch open. In this case, the hydraulic unit acts on the Clutch actuator. The hydraulic unit can also act directly on the coupling. The hydraulic unit is introduced in particular for this holding and is not responsible for the power transmission for the clutch actuation.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

Brief description of the drawings

1 shows an embodiment of the coupling arrangement described.

2 shows in a flow chart a possible embodiment of the presented method.

Embodiments of the invention

The invention is schematically illustrated by means of embodiments in the drawings and will be described in detail below with reference to the drawings.

1 shows an embodiment of the coupling assembly, in total with the reference numeral 10 is designated, with a hydraulic time 11 , The illustration shows a valve 12 , a cylinder 14 , a clutch lever 16 as a clutch actuator, whose operation by an arrow 18 is clarified, a motor control or a control unit 20 , an indicator light or sail indicator light 22 on the dashboard, an accumulator 24 , a cable 26 and a clutch 28 , Between the clutch lever 16 as a clutch actuator and the clutch is for transmission on the clutch lever 16 initiated force thus only the cable provided. This represents a mechanical, in particular a purely or exclusively mechanical action path.

The coupling 28 is used for releasable torsionally rigid or elastic connection of two aligned machine parts, usually two waves, for transmitting a torque which is applied by the internal combustion engine (not shown) and to be transmitted to the road.

The valve 12 between the cylinder 14 , which is also referred to as the master cylinder, and the accumulator 24 , which is also referred to as a storage cylinder, may be a 2/2-way valve. With this directional valve, the pressure can only be kept digital or drained. The engine control 20 shows over the indicator light 22 on whether sailing is possible. If the conditions for sailing operation are met and the driver for a predetermined period, for example. More than 1 second, the clutch lever 16 pressed, then closes the valve 12 and holds the clutch lever 16 , The vehicle is then in sailing mode.

As an alternative to the 2/2-way valve, a 2/2-proportional valve can be used, which is electrically controlled. This variably fulfills the throttle function, namely a defined, slow release of the clutch lever 16 , and can additionally hold and quickly open the clutch lever 16 make. The proportional valve offers the possibility of pressure reduction and buildup and thus the closing speed of the clutch 28 directly to regulate. The throttle function can now be varied depending on the situation. It should be noted that a very simple proportional position is achieved by quickly opening or closing the simple directional control valve.

A possible procedure of the method is based on a flowchart in FIG 2 played.

In a first step 50 The sail indicator light indicates to the driver that sailing is possible. The driver moves in a next step 52 the clutch lever to sail. In this case, the valve in its standard position, namely normally open, allows the hydraulic oil to flow unhindered into the accumulator or hydraulic accumulator. Once the sailing conditions have been met, the next step will be 54 the valve is closed and the pressure is maintained. Without effort of the driver, the clutch lever is held.

If the engine control or the driver stops sailing, the valve opens in one step 56 , The energized coupling cable or the cable can thus the clutch lever in a final step 58 pull back to its original position.

Claims (12)

Method for operating a motor vehicle with an internal combustion engine, which is connected via a clutch arrangement ( 10 ) with a transmission of a force applied to a clutch actuating element force to a clutch ( 28 ), wherein between the clutch actuator and the clutch ( 28 ) an exclusively mechanical action path is provided, and wherein by actuation of the clutch actuating element, the clutch ( 28 ) and via an additionally provided hydraulic unit ( 11 ) the coupling ( 28 ) is kept open. Method according to Claim 1, in which the hydraulic unit ( 11 ) acts on the clutch actuator. Method according to Claim 1 or 2, in which, after the clutch has been kept open ( 28 ) the internal combustion engine is operated at idle speed. Method according to Claim 1 or 2, in which, after the clutch has been kept open ( 28 ) the internal combustion engine is switched off. Method according to one of claims 1 to 4, in which the holding open of the coupling ( 28 ) is terminated triggered by a detected actuation of the brake. Method according to one of claims 1 to 4, in which the holding open of the coupling ( 28 ) is terminated triggered by a detected operation of the accelerator pedal. Method according to one of claims 1 to 4, in which the holding open of the coupling ( 28 ) by an action of a controller ( 20 ) is terminated. Coupling arrangement with a clutch actuating element, a clutch ( 28 ) and an additionally provided hydraulic unit ( 11 ), wherein the coupling arrangement ( 10 ) for a transmission of a force applied to the clutch actuator force to the clutch ( 28 ) is formed, wherein between the clutch actuating element and the clutch ( 28 ) an exclusively mechanical action path is provided, wherein the hydraulic unit ( 11 ) is designed to hold open an opened by operating the clutch actuator coupling. Coupling arrangement according to Claim 8, in which the hydraulic unit ( 11 ) a valve ( 12 ) and at least one cylinder ( 14 ). Coupling arrangement according to claim 8 or 9, which via a cable ( 26 ) for mechanical transmission of the force introduced by the driver. Clutch arrangement according to one of Claims 8 to 10, in which a clutch lever ( 16 ) serves. Coupling arrangement according to one of Claims 8 to 11, in which an indicator lamp ( 22 ) is provided to assist the driver.

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