DE102007052160A1 - Measuring device for detecting rotation angle/linear path in e.g. accelerator pedal value sensor of accelerator pedal module in motor vehicle, has springs with windings made of conducting material, where part of windings forms primary coils - Google Patents

Abstract

The device has coil springs (12, 14) with windings (28, 30) that are made of electrically conducting material. A part of the windings forms primary coils (32, 34) of a transformer (36) connected with a voltage source (44). Secondary coils (40, 42) of the transformer are connected with an evaluation mechanism (50) for production of one of the signals depending on a relative motion of driving pedal lever and a bearing mounting, which are prestressed against each other in an initial position. The windings are projected in a relative motion direction (x) over the secondary coils. An independent claim is also included for a pedal module comprising a pedal lever.

Description

State of the art

The The invention relates to a measuring device for non-contact Detecting a rotation angle or a linear path due to a Relative movement between at least two bodies, wherein the Body by existing of an electrically conductive material Windings having spring means against each other in their starting position are biased, according to the preamble of claim 1 and a pedal module including at least one relative to a bearing block pivoting pedal lever and a measuring device to control one of the rotational position of the pedal lever relative to Bearing dependent signal according to the preamble of claim 8th.

A such measuring device is for example in different systems of the vehicle area usable, in which linear paths or angles of rotation need to be measured, such as in a throttle position sensor, in an accelerator pedal in a pedal module, in a body spring or in an angle sensor of a windshield wiper drive.

A generic measuring device and a generic pedal module are for example from the DE 10 2005 013 442 A1 known. The measuring device is integrated in an accelerator pedal module including a pivotable about a pivot axis relative to a bearing block accelerator pedal lever, wherein the accelerator pedal lever is supported by coil springs relative to the bearing block and thereby biased to its initial position. The pivoting movements of the accelerator pedal lever relative to the bearing block are converted by a rotation angle sensor into an electrical signal, which represents the angle of rotation of the accelerator pedal lever relative to the bearing block. As a rotation angle sensor is at least one integrated Hall IC, which can detect a change in direction of a magnetic field. The magnetic field is generated by two bipolar magnets to which the Hall IC is symmetrically interposed.

Of the Hall effect belongs to the galvanomagnetic effects and is mainly using thin semiconductor chip evaluated. Will such a current-carrying semiconductor chip vertically penetrated by a magnetic field, can be transverse to the current direction a voltage proportional to the magnetic field can be tapped. in the Case of silicon as a base material you can simultaneously one Integrate signal processing electronics onto the semiconductor die, whereby such sensors are very inexpensive. Such integrated Hall IC's are mainly for the measurement of angles and paths by changing the fluctuating field strength detect the magnet connected to a moving rotor.

Disclosure of the invention

The Invention is based on the idea that at least part of the Windings of the spring means a primary coil connected to a voltage source form a transformer whose secondary coil with an evaluation device for generating one of the relative movement connected to the body dependent signal. The Function of such a transformer or transformer It is known that electrical power transmitted by magnetic coupling of two galvanically isolated circuits becomes.

The The measuring principle on which the measuring device is based uses the translation ratio of transformers or transformers, which in the present Case changed by the relative movement of the body becomes. Caused by the relative movement of the body the spring means and thus the turns of the primary coil compressed, which changes the number of turns, which geometrically overlap with the secondary coil or with their magnetic field lines, which in turn is a change in the gear ratio of the transformer or transformer. This change the gear ratio is from the evaluation in a dependent on the amount of relative movement signal convertible and thus evaluable.

Thereby lead the spring means a beneficial dual function on the one hand, making sure that the two Body to be preloaded into their initial position and simultaneously also form part of the measuring device, which is the relative position the body measures. Opposite the measuring equipment of the prior art thus results in a very simple structure with few components.

By the measures listed in the dependent claims are advantageous developments and improvements in the claim 1 indicated invention possible.

According to a preferred embodiment, the turns of the primary coil at least partially surround the secondary coil and protrude beyond the secondary coil in the direction of relative movement. Then as many field lines of the secondary coil are detected by the primary coil to achieve the strongest possible output signal. In this case, the primary coil and the secondary coil preferably have a common transformer core, which we the secondary coil at least partially encloses.

According to one particularly preferable application, the spring means tension a relative to a stator rotatably mounted rotor in its initial position before, wherein the rotor, for example, rotatable on a bearing block stored accelerator pedal of an accelerator pedal module for controlling the power a prime mover of a vehicle.

According to one Further development is the accelerator pedal lever opposite the bearing block by at least two parallel and linearly extending spring elements biased to its initial position, each having a primary coil form a transformer whose secondary coil with the evaluation device is connected. In this case, two are redundant Output signals present because each of the two springs is a primary coil a separate transformer or transformer forms. As with accelerator pedal modules for safety reasons always provided two return springs for the accelerator pedal lever are, since in a failure of a single spring z. B. by breakage no return of the accelerator pedal lever possible would be, other components are not necessary to the redundant Generate measuring signals. The two measuring signals also allow a plausibility check in the measurement of the Angle of rotation, for example, by an error message or an interference signal is controlled when the two measurement signals by more than one differentiate given difference.

Around the rotational movement of the accelerator pedal lever relative to the bearing block in a simpler with respect to the measuring principle linear motion To convert, the spring elements can with their one end on a bearing surface formed on the bearing block and with its other end at one with respect to a pivot axis between the accelerator pedal lever and the bearing block a lever arm forming support arm support the accelerator pedal lever.

The The invention therefore also relates to a pedal module, in particular a Accelerator pedal module for controlling the power of an engine of a vehicle, including at least one pivotable relative to a bearing block Pedal lever and a measuring device for controlling one of the rotational position the pedal lever relative to the bearing block dependent signal, wherein the measuring device is designed as described above.

Of the exact structure of the measuring device and the pedal module is based on the following description of an embodiment clear.

drawing

One Embodiment of the invention are in the drawing shown and in the following description in more detail explained. In the drawing shows

1 a cross-sectional view of an accelerator pedal module of a vehicle with a measuring device according to a preferred embodiment of the invention;

2 a schematic representation of the essential components of the measuring device of 1 ,

Description of the embodiment

That in the 1 illustrated accelerator pedal module 1 as an example of a pedal module is used to control a prime mover, preferably an internal combustion engine of a motor vehicle whose throttle is adjustable by a servomotor. In this case, the accelerator pedal module is used 1 for generating electrical signals for the servomotor, depending on the position of an accelerator pedal lever 2 of the accelerator pedal module 1 to control the performance of the internal combustion engine. The prime mover can also be, for example, an electric motor controlled by electrical signals.

The accelerator pedal module 1 is foot-operated by the driver of the motor vehicle and includes the example hanging accelerator pedal lever 2 from which in 1 for reasons of scale, only a portion is shown and which preferably represents the accelerator pedal operated directly by the driver's foot. Furthermore, the accelerator pedal module includes 1 a bearing block 4 as a support structure for the accelerator pedal lever 2 which preferably directly in the foot of the driver by means of a bottom plate 6 of the bearing block laterally outstanding, in 1 invisible screw eyes is fastened. In addition, the accelerator pedal module 1 with a mechanical kick-down switch 8th be provided for an automatic transmission of the motor vehicle.

The accelerator pedal lever 2 is about a pivot axis 10 opposite the bearing block 4 swiveling, with the accelerator pedal lever 2 for example, two, in 1 arranged in parallel planes coil springs 12 . 14 opposite the bearing block 4 supported and thereby biased to its original position. Due to the side view of the accelerator pedal module in 1 is just one of the coil springs 12 representative of the other coil spring 14 visible, noticeable. To the rotation of the accelerator pedal lever 2 opposite the bearing block 4 to convert into a linear motion, are the coil springs 12 . 14 with one end to one on the bearing block 4 trained support surface 16 and with its other end at one with respect to the pivot axis 10 a lever arm forming support arm 18 of Accelerator lever 4 supported. Here is the support arm 18 of the accelerator pedal lever 4 and the other ends of the coil springs 12 . 14 one in the bearing block 4 in the tensioning direction of the coil springs 12 . 14 linearly guided pressure element 20 interposed.

The contact surface of the support arm 18 of the accelerator pedal lever 2 with the pressure element 20 is as preferably convex convex rolling surface 22 formed so that the pressure element 20 on this rolling surface 22 can roll off when the accelerator pedal lever 2 around the pivot axis 10 pivoted and thereby a slight radial relative movement between the support arm 18 and the pressure element 20 takes place. This can prevent the coil springs 12 . 14 buckle during cocking during an accelerator pedal movement. Because of the linear positive guidance of the pressure element 20 in the bearing block 4 is parallel to the center axes of the coil springs 12 . 14 extending linear clamping direction X predetermined (see 2 ). The rolling of the support arm 18 on the pressure element 20 occurring lateral forces are then through the guides, where the pressure element 20 is guided, in the bearing block 4 derived and not on the spring elements 12 . 14 transferred, which are then free of lateral forces.

The pressure element 20 can by the action of the coil springs 12 . 14 exerted pressure forces in the initial position of the accelerator pedal lever 4 , ie in an idle position, against a stop 24 on the bearing block 4 be supported so that essentially no spring forces on the accelerator pedal lever 2 Act. In the starting position of the accelerator pedal lever 2 Consequently, the spring forces are over the stop 24 in the bearing block 4 supported. Thus, the support arm 18 in the starting position the pressure element 20 and the stop 24 interposed almost without force. Upon actuation of the accelerator pedal lever 2 the support arm moves 18 from the stop 24 away and tensions over the pressure element 20 the coil springs 12 . 14 , Which then one of the actuating force directed counter spring force on the accelerator pedal lever 2 exercise.

The pivoting movements of the accelerator pedal lever 2 relative to the bearing block 4 are characterized by a substantially in 2 shown measuring device 26 converted into an electrical signal, which is the angle of rotation of the accelerator pedal lever 2 relative to the bearing block 4 represents.

At least part of the turns 28 . 30 the coil springs 12 . 14 each form a primary coil 32 . 34 of transformers or transformers 36 . 38 as part of the measuring device 26 out, their secondary coils 40 . 42 with an evaluation device 38 for generating the of the rotation of the accelerator pedal lever 2 relative to the bearing block 4 dependent signal is connected as out 2 evident. The coil springs 12 . 14 are as primary coils 32 . 34 while to a voltage source 44 connected.

The turns wrap around 28 . 30 the primary coils the secondary coils 42 . 44 at least partially and protrude in the relative direction of movement or clamping direction X seen on the secondary coils 42 . 44 out. Furthermore, the primary coils 32 . 34 and the secondary coils 42 . 44 of each transformer 36 . 38 each preferably a common transformer core 46 . 48 on which the secondary coils 42 . 44 each at least partially enclose. More precisely, these are the primary coils 32 . 34 forming coil springs 12 . 14 preferably over its free ends to the voltage source 44 connected. Lies on the primary coils 32 . 34 a voltage, for example a sinusoidal voltage of 2 volts and with a frequency of, for example, 30 MHz, so are in the secondary coils 42 . 44 Secondary voltages induced proportional to the number of turns of the turns 28 . 30 the primary coils 32 . 34 are. The secondary coils controlling the secondary voltages 40 . 42 in turn stand with an evaluation device 50 in connection.

wobei:

N₁

die Windungszahl der Primärspule,

N₂

die Windungszahl der Sekundärspule,

U₁

die Spannung an der Primärspule, und

U₂

die Spannung an der Sekundärspule ist.

The following applies to the transformation ratio n of a transformer:

in which:

N ₁

the number of turns of the primary coil,

N ₂

the number of turns of the secondary coil,

U ₁

the voltage at the primary coil, and

U ₂

the voltage at the secondary coil is.

Due to the relative movement of the accelerator pedal lever 2 to the bearing block 4 become the coil springs 12 . 14 and with it the turns 28 . 30 the primary coils 32 . 34 compressed in the clamping direction X, which increases the number of turns 28 . 30 changes, which deals with the secondary coils 40 . 42 or geometrically overlap with their magnetic field lines, which in turn means a change in the transmission ratio of the transformers or the transformer 36 . 38 conditionally. The respective change of the transmission ratio can be done by the evaluation device 50 detected and converted into a dependent on the scope of the relative movement signal, which z. B. can be controlled via a data bus in an engine control unit.

Through the two coil springs 12 . 14 as a respective component of a transformer or transformer 36 . 38 are two redundant output Signals present because each of the two coil springs 12 . 14 a primary coil 32 . 34 a separate transformer or transformer 36 . 38 formed. This is in the evaluation 50 redundant measurement signals available, which a plausibility check in the measurement of the angle of rotation between the accelerator pedal lever 2 and the bearing block 4 allow by the evaluation device 50 For example, an error message or an interference signal is controlled when the two measurement signals differ by more than a predetermined difference. In addition, in case of failure of a transformer 36 . 38 to use the other's signal as a substitute.

Instead of the described coil springs 12 . 14 Any spring elements are conceivable, which have turns of an electrically conductive material, which on the one hand generate a spring force during compression and on the other hand can simultaneously form a magnetic field generating coil of a transformer or transformer.

The described measuring device 26 is except in accelerator pedal modules 1 usable in all systems in which angles of rotation or linear paths have to be measured, in the motor vehicle sector, for example, in a throttle position sensor, in a body spring position sensor or in an angle sensor of a windshield wiper drive.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - DE 102005013442 A1 [0003]

Claims (9)

Measuring device ( 26 ) for non-contact detection of a rotation angle or a linear path due to a relative movement between at least two bodies ( 2 . 4 ), whereby the bodies ( 2 . 4 ) by turns of an electrically conductive material ( 28 . 30 ) having spring means ( 12 . 14 ) are biased against each other to their initial position, characterized in that at least a portion of the turns ( 28 . 30 ) the spring means ( 12 . 14 ) one with a voltage source ( 44 ) connected primary coil ( 32 . 34 ) of a transformer ( 36 . 38 ) whose secondary coil ( 40 . 42 ) with an evaluation device ( 50 ) for generating one of the relative movement of the bodies ( 2 . 4 ) dependent signal is connected. Measuring device according to claim 1, characterized in that the turns ( 28 . 30 ) of the primary coil ( 32 . 34 ) the secondary coil ( 40 . 42 ) at least partially enclose and seen in the relative direction of movement (X) via the secondary coil ( 40 . 42 ) protrude. Measuring device according to claim 1, characterized in that the primary coil ( 32 . 34 ) and the secondary coil ( 40 . 42 ) a common transformer core ( 46 . 48 ), which the secondary coil ( 40 . 42 ) at least partially encloses. Measuring device according to one of the preceding claims, characterized in that the spring means ( 12 . 14 ) one opposite a stator ( 4 ) rotatably mounted rotor ( 2 ) bias into its initial position. Measuring device according to claim 4, characterized in that the rotor ( 2 ) on a bearing block ( 4 ) as a stator rotatably mounted accelerator pedal lever ( 2 ) of an accelerator pedal module ( 1 ) for controlling the power of an engine of a vehicle. Measuring device according to claim 5, characterized in that the accelerator pedal lever ( 2 ) relative to the bearing block ( 4 ) by at least two parallel and linearly extending spring elements ( 12 . 14 ) is biased to its initial position, each having a primary coil ( 32 . 34 ) of a separate transformer ( 36 . 38 ) whose secondary coil ( 40 . 42 ) each with the evaluation device ( 50 ) connected is. Measuring device according to claim 5 or 6, characterized in that the spring elements ( 12 . 14 ) with one end to one on the bearing block ( 4 ) formed support surface ( 16 ) and with its other end at one with respect to a pivot axis ( 10 ) between the accelerator pedal lever ( 2 ) and the bearing block ( 4 ) a lever arm forming support arm ( 18 ) of the accelerator pedal lever ( 2 ). Pedal module ( 1 ), including at least one relative to a bearing block ( 4 ) swiveling pedal lever ( 2 ) as well as a measuring device ( 26 ) to control one of the rotational position of the pedal lever ( 2 ) relative to the bearing block ( 4 ) dependent signal, characterized in that the measuring device ( 26 ) is designed according to one of the preceding claims. Pedal module according to claim 8, characterized in that it comprises an accelerator pedal module ( 1 ) for controlling the power of an engine of a vehicle.