DE102004049283B4 - Method for operating a windshield wiper device - Google Patents

Abstract

Method for operating a windshield wiper device with an electric motor, at least one wiper driven by the electric motor and a controller which controls a movement of the electric motor or the wiper in dependence on a characteristic (M) describing the load condition of the electric motor, the electric motor exceeding a predetermined limit value (M _G ) of the parameter (M) is stopped, characterized in that the electric motor reverses after stopping and the wiper in a return position (S ₂ , S ₈ , S ₁₃ ) is moved back and that the electric motor then started again in its movement for which the limit value (M _G ) is increased from its previous value (M _Gmin ) to a new value (M _G1 ).

Description

The The invention relates to a method for operating a windshield wiper device with an electric motor, at least one of the electric motor driven Wiper and a controller, which controls a movement of the electric motor or the wiper depending on a load condition the electric motor descriptive parameter controls, wherein the electric motor when crossing a predetermined limit value of the characteristic is stopped.

Such a method is known from DE 26 00 468 A1 known. There is described a switching arrangement for wiper devices on vehicles, with a drive device for the wiper and an energy supply to the drive device. The energy supply line has an energy measuring device with downstream switching device, which causes their switching off when a certain energy absorption value of the drive device is exceeded.

hereby should be an automatic working shut-off device can be achieved, so that a manual Switching off the wiper device by the driver no longer necessary is.

A similar method for operating a windshield wiper device is known from DE 196 15 581 A1 known. In this case, a trapped state of the wiper, for example because it is frozen on the disc detected and recognized the effective torque of the electric motor, which is considerably larger in this pinching state than during a normal wiper operation, limited to a limit torque.

By This measure can the mechanical components interacting with the electric motor weaker in terms of durability and load capacity without mechanical damage to the system. however stays for the design is a value of the limit torque significantly, in which the wiper is still in the clamped state. A limitation of torque in operating conditions where the wiper is still in motion, can not by means of the known method be achieved.

From the DE 41 04 565 A1 a windshield wiper device is known, which detects an overcurrent of the electric motor in blocking the electric motor in a predetermined period of time. In this case, the direction of movement of the wiper is reversed when the overcurrent detection device continuously detects an overcurrent over the predetermined period of time. Also, the time period in which the overcurrent is detected, can be set to a shorter value, so that when a restart of the blocking triggering obstacle, the electric motor is in the overload state for a shorter period of time before a reversal is initiated.

Of the Invention is based on the object, a method of the initially mentioned type, which also in a stiff movement the electric motor and / or the wiper a component-saving operation the windshield wiper device allows and when obstacles occur in the trajectory of the wiper whose overcoming allows.

invention and beneficial effects

These The object is achieved by a A method for operating a windshield wiper device solved, at which reverses the electric motor after stopping and the wiper in a return position scaled back and for that The threshold has been increased from its previous value to a new value becomes.

By the reversing of the electric motor and the return of the wiper in one Reverse position can the wiper from the area where the obstacle is present, be brought out, so now the obstacle without impact can be eliminated on the wiper. Damage to the wiper or the Windscreen wiper device avoided when removing the obstacle become. As return position In the present case, for example, a parking position of the wiper is to be understood. Also can as a return position a position can be used which at a given distance to the stop position of the wiper when the limit value is exceeded lies.

The restarting the electric motor is particularly advantageous if the wiper at the previous start against an obstacle, eg. against ice or snow particles, has solved a part of it. When starting again, especially if the wiper previously off the area of the obstacle has been moved out or retracted, can then overcome the obstacle or removed.

By raising the value for the limit, the possibility is created that the wiper overcomes the obstacle, which has led to a stiff movement, in a second startup without switching off the electric motor. It It is possible that the limit is increased in discrete steps. As a result, the electric motor can be selectively operated only in the load state, by means of which the obstacle can be overcome without switching off the electric motor, so that in this way a particularly component-saving operation of the windshield wiper device is achieved.

By the procedure can the electric motor and the mechanical mechanisms interacting with it Components are already relieved during a stiff movement, when the preset limit is set to a corresponding value is. It can also with appropriate setting of the limit it is avoided that there is a component damaging blocking of the electric motor, for example due to trapping of the wiper comes. Also can with the appropriate setting of the limit a pinching of the wiper when it enters a possibly covered, Parking position are detected. Finally, the operator is the Windscreen wiper device the possibility given to finish the wiping process, since the wiper is still capable of movement.

From Advantage is when the values for the limit in a range between a given initial value and a predetermined maximum possible Value for lie the electric motor. This allows the limit to be targeted be limited to that range of values, which is an overuse avoid the mechanical components of the windscreen wiper device and at the same time overcoming an obstacle in the path of the wiper allows. In the present case, the output value is understood to be the value of the limit value which at the beginning of a wiping operation before reaching a first obstacle is present. As maximum possible Value, the value of the limit can be assumed at which the electric motor in the highest possible Load state is present.

alternative But it can also be provided that for the restart of the electric motor of the Limit value from a given initial value to a predetermined one maximum possible value is raised. The limit is thus directly on the maximum potential Value increased. This can prevent it from becoming a multiple one return the wiper comes to overcome the obstacle.

To In a further development of the invention, it is provided that the limit value is reduced, preferably to the initial value, as soon as the value of the parameter decreases. This can be done the engine after overcoming an obstacle with now load operated, which is also gentle on components, affects.

From The advantage is that the limit value is gradually reduced. This allows the limit value specifically for each required Value to be set or adjusted, whichever does not lead to a shutdown of the electric motor. Again, this is a measure to the wiping operation as possible gentle to components.

To An idea of the invention is provided when the lowering the limit only once during the duration of a wiping cycle takes place. Unless after overcoming an obstacle and lowering the limit a new obstacle in the track of the wiper during the Wischzyklusses should occur, there is no reduction of the Limit value more. As a result, the switching operations of Motors reduced, so that respect the engine a continuous, and thus component-saving operation of the engine is reached.

It it is provided that the values of the limit value are stored. This gives you access to these values, for example, for driving over from subsequent obstacles, easily possible.

According to one embodiment of the invention, it is provided that the limit values are obtained by a mathematical function that depends on parameters such as temperature, humidity and the like environmental influences. This results in an adaptation to the respective environmental conditions, so that, for example, during the colder seasons, the limit values, ie both the lowest limit value M _Gmin and the individual steps for increasing the limit value can be calculated. Preferably, the M _Gmax predetermined by the motor itself _should not be exceeded, since otherwise the motor may be damaged.

From Advantage is, if the initial value and the maximum possible value the limit value stored captive. This can almost the same upper and lower limits for each wiping operation the limit value become. It is thereby a sufficient security of the whole Systems guaranteed.

To a development of the invention it is provided that the electric motor or wiper in the return position remains if the value of the parameter is the maximum possible Value exceeds the limit. This measure prevents overloading the electric motor and thus its lasting damage.

It is also provided according to the invention that the wiper is moved to a parking position, as soon as the windshield wiper device is switched off. It is thereby ensured a proper termination of the wiping operation.

From The advantage is, if as characteristic the current consumption or the torque of the electric motor is used. In case of Use of power consumption can both rotary electric motors and linear motors by means of the method.

The Task is further by means of a device for performing the the method described above, wherein the device comprises a characteristic quantity detection device, a microprocessor and a memory.

Further Advantages and applications The present invention will become apparent from the following description an embodiment based on a drawing.

The single FIGURE is a diagram for explaining the operation of a method for operating a windscreen wiper device with an electric motor, a wiper driven by the electric motor and a controller which controls a movement of the electric motor in dependence on its torque. Shown are two superimposed diagrams, wherein shown in the lower diagram, applied by the electric motor torque M for driving the wiper in response to a travel of the wiper and in the upper diagram, a limit M _{G of} the torque in dependence on the travel of the wiper ,

During wiper operation, the wiper is driven with a torque M _{1 of} the electric motor and moved over a disk to be cleaned.

It is assumed that the wiper at the position F _{1 of} its travel S meets an obstacle which extends to a position S _{5 of} the travel S. The obstacle is formed in this embodiment such that the resistance caused by it increases in proportion to the length of the obstacle over the travel S and remains the same when reaching a maximum value to the end of the obstacles, in which case the resistance drops abruptly.

After the wiper has reached the position S ₁ , the torque of the electric motor rises linearly from its initial value M ₁ under an increasingly stiff movement of the wiper or up to a position S ₃ . In this position, a predetermined limit value M _Gmin for the torque M is reached. If the limit value M _Gmin is exceeded, the electric motor is stopped by the controller, reversed and returned to an initial position S _{2 of} the travel path S. The predetermined limit value M _Gmin is, at the beginning of the wiping operation, an output value M _Gmin which is stored in captive memory.

In the starting position S ₂ , the limit value M _{G is raised} to the value M _G1 . Thereafter, the wiper or the electric motor is restarted in its movement and reaches the position S ₃ for the second time. Due to the increased limit value M _G to the value M _G1 the electric motor is no longer stopped upon reaching the position S ₃ , but continues to move to a position S ₄ , in which a value M _{3 of} the torque M is reached by means of The wiper is moved to the end of the obstacle in the position S ₅ . After passing through the position S ₅ falls - in the embodiment chosen here - the obstacle leaps away, and for further movement of the wiper or the electric motor now only the value M _{1 of} the torque is needed again. Due to the sinking of the torque M, the limit value M _{g is} gradually reduced from the value M _G1 to the output value M _Gmin until the position S _{6 is reached} .

If the wiper encounters a second obstacle, the process described above begins again. In the present case - for the sake of simplicity - the second obstacle is designed in the same way as the first obstacle, so that the electric motor at a position S ₇ at the beginning of the obstacle to a position S ₉ in its torque from the initial value M ₁ to the value M ₂ rises linearly to keep the wiper in motion. Since the value M _{2 of} the torque M corresponds to the value M _{Gmin of} the predetermined limit value, the electric motor is stopped when this value is exceeded, reserved and is moved to a further return position S ₈ . The traversed travel of the wiper or the electric motor corresponds in this case a fixed predetermined distance.

In the further starting position S ₈ , in turn, the limit value M _{G is raised} from the value M _Gmin to the value M _G1 . Subsequently, the electric motor is started again in its movement and driven over a position S ₁₀ to a position S ₁₁ , which marks the end of the obstacle. After passing this position S ₁₁ , the torque M required for moving the wiper again drops to the value M ₁ . Since it is provided in the embodiment chosen here that the lowering of the limit value M _g only once during a wiperbetriebetrie bes occurs, the limit M _G remains on the increased value M _G1 .

At a position S ₁₂ , the wiper now reaches a third obstacle. The obstacle is designed such that it opposes a linearly increasing resistance to the wiper via the travel path S, the resistance rising to such a high value that the wiper is blocked. The electric motor therefore increases the torque M from the value M ₁ to a value M ₃ from the position F ₁₂ . The value M ₃ corresponds to the value M _{G1 of} the limit value M _G , so that when the value M _{3 is} exceeded, the electric motor is stopped, then reversed and returned to an initial position F ₁₃ . Since the value M _{G1 is} already close to a maximum possible value M _Gmax for the electric motor, in the present case the limit value M _G in the starting position is increased from the value M _G1 to the value M _G2 , which corresponds to the maximum possible value M _Gmax and then the electric motor started to move again.

Due to the great resistance of the obstacle, when the position S ₁₄ is exceeded, the now predetermined limit value M _G , which corresponds to the maximum possible value M _Gmax , is exceeded, and thus the electric motor is stopped again, reversed and moved to an initial position S ₁₃ . In this initial position S ₁₃ , the wiper or the electric motor now remains until a new wiping command is issued.

M

torque

M ₁

value of torque

M ₂

value of torque

M _G

limit of torque

M _Gmin

value the limit value

M _G1

value the limit value

M _G2

value the limit value

M _Gmax

maximum potential value

S

displacement

S ₁

position in the displacement path

S ₂

starting position

S ₃

position in the displacement path

S ₄

position in the displacement path

S ₅

position in the displacement path

S ₆

position in the displacement path

S ₇

position in the displacement path

S ₈

starting position

S ₉

position in the displacement path

S ₁₀

position in the displacement path

P ₁₁

position in the displacement path

S ₁₂

position in the displacement path

S ₁₃

starting position

S ₁₄

position in the displacement path

Claims (12)

Method for operating a windshield wiper device with an electric motor, at least one wiper driven by the electric motor and a controller which controls a movement of the electric motor or the wiper in dependence on a characteristic (M) describing the load condition of the electric motor, the electric motor exceeding a predetermined limit value (M _G ) of the parameter (M) is stopped, characterized in that the electric motor reverses after stopping and the wiper in a return position (S ₂ , S ₈ , S ₁₃ ) is moved back and that the electric motor then started again in its movement for which the limit value (M _G ) is increased from its previous value (M _Gmin ) to a new value (M _G1 ). A method according to claim 1, characterized in that the values (M _Gmin , M _G1 ) of the limit value (M _G ) are in a range between a predetermined output value (M _Gmin ) and a maximum possible value (M _Gmax ) for the electric motor. A method according to claim 1 or 2, characterized in that for the restart of the electric motor, the limit value (M _G ) is increased to a predetermined maximum possible value (M _Gmax ) to a predetermined output value (M _Gmin ). Method according to one of the preceding claims, characterized in that the limit value (M _G ) is reduced, preferably down to the initial value (M _Gmin ), as soon as the value of the parameter (M) decreases. A method according to claim 4, characterized in that the limit value (M _G ) is gradually reduced. A method according to claim 4 or 5, characterized in that the lowering of the limit value (M _G ) takes place only once during the duration of a wiping cycle of a wiping operation. Method according to one of the preceding claims, characterized in that the values (M _Gmin , M _G1 , M _G2 ) of the limit value (M _G ) are stored. Method according to one of the preceding claims, characterized in that the limit values (M _Gmin , M _G1 , M _G2 ...., M _Gmax ) are obtained by a mathematical function which _depends on parameters, such as, for example, temperature, humidity and the like environmental influences , is dependent. Method according to one of Claims 2 to 8, characterized in that the output value (M _Gmin ) and the maximum possible value (M _Gmax ) of the limit value (M _G ) are stored in captive memory. Method according to one of the preceding claims, characterized in that the wiper in the return position (S ₁₃ ) remains when the value of the characteristic (M) _exceeds the maximum possible value (M _Gmax ) of the limit value (M _G ). Method according to one of the preceding claims, characterized characterized in that the wiper is moved to a parking position, as soon as the windshield wiper device is switched off. Method according to one of the preceding claims, characterized characterized in that the characteristic (M) the Current consumption or the torque of the electric motor is.