BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a perspective view of a device for energy conversion;
FIG. 2 is a sectional view of a decoupling device for lateral movements where the displacement is small;
FIG. 3 is a sectional view of a decoupling device for lateral and vertical movements where the displacement is small;
FIG. 4 is a sectional view of a decoupling device with a wire link;
FIG. 5 is a sectional view of a decoupling device with bearings, for lateral movements where the displacement is small; and
FIG. 6 is a sectional view of a device with a deformable circuit board.
DETAILED DESCRIPTION OF THE INVENTION
In the following description of a preferred form of embodiment of the present invention, the same reference marks are used for components which are the same or similar, and which are functionally equivalent.
Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a device for energy conversion such as is arranged for example in a tire pressure measurement system on a vehicle. The device comprises a rigidly mounted component 1, a movable component 2 and a mechanical-electrical energy converter 3. The rigidly mounted component 1 and the movable component 2 are linked by a movement-damping device 4. Typically, the device moves in the indicated direction 6, 7. The movement-damping device 4 consists, for example, of two leaf springs, with each of their ends clamped between the rigidly mounted component 1 and the movable component 2. The mechanical-electrical energy converter 3 can take the form of a piezo-ceramic, capacitive or inductive energy converter. Here, the piezo-ceramic energy converter 3 can be realized in various forms such as, for example, a purely ceramic beam, a bimorph-beam and/or a metal/ceramic-bimorph-beam, wherein the relative movement is manifest as a deformation. Also attached to the mechanical-electrical energy converter is a mass 5, which ensures pre-stressing of the mechanical-electrical energy converter 3 and can be rigidly linked to the rigidly mounted first component 1, 5. Furthermore, it would be possible to use a capacitive and/or inductive mechanical-electrical energy converter 3. The relative movement would induce a charge displacement between the plates in the case of a capacitive converter, and a change in the magnetic flux density in the case of an inductive converter.
For energy conversion the most important characteristic is the electrical attenuation of the energy conversion material/joint or the energy conversion system. However, in order to generate the best possible relative movement, and thus a high mechanical energy, this being realized by the structural interface joint, the complete system must be laid out with an oscillatory capability. In this, the spring stiffness/oscillatory capability has an enormous influence. Decoupling enables the parameters of the spring stiffness/oscillatory capability and the damping of the total system to be optimized/arranged independently of each other. This leads to an optimal spring stiffness/oscillatory capability of the structural interface joint, and an optimal relative movement and an optimal damping of the mechanical-electrical energy converter is achieved for the extraction of energy with a relatively small cross influence.
In addition, the decoupling means that the energy conversion system is loaded as little as possible, because the complete oscillatable mass, and hence the total force, is absorbed by the structural interface joint. The energy conversion system is only loaded by the force which results from its own weight and acceleration.
In a further preferred form of embodiment of the invention, the first component 1, the second component 2 or the additional mass 5 each takes the form of a circuit board, a housing, an antenna or another component which is already present in an existing measuring device.
Here, the components should continue to carry out their previous functions, and should have in addition multiple functions. For example, the “oscillatable” mass can be realized by a circuit board, on which are arranged the components of the measuring unit. In addition, the bending beam could as its supplementary function be the link between the housing and the circuit board, and improve the damping. Another example could be that the fixed clamping for the bending beam has the function of a “housing”, and thus protects against external influences.
Advantages of using an integrated generator system:
- no additional mass with the ability to oscillate is required;
- weight reduction of the measuring unit in the wheel/tire (lower unsprung weight);
- more compact construction; and
- additional mechanical load reduction on some components of the measuring unit (such as for example: lower risk of damage to the HW components).
FIG. 2 shows a decoupling device for lateral movements when the displacement is small. A rigidly mounted component 22 is linked to a movable component 21 via a movement damping device 23, e.g. leaf springs. As a consequence the movable component 21 makes a lateral movement 24 with a small displacement relative to the rigidly mounted component 22.
FIG. 3 shows a decoupling device for lateral and vertical movements when the displacement is small. A rigidly mounted component 32 is linked to a movable component 31 via movement damping devices 33, 34, e.g. helical springs. As a consequence the movable component 31 makes lateral and vertical movements 35 with a small displacement relative to the rigidly mounted component 32. Consideration can also be given to deformable plastic elements for the movement damping devices 33, 34.
FIG. 4 shows a decoupling device with a wire link. Here, a movable component 41 is linked to a fixed component 42 via a wire 43. In operation, the movable component 41 is pre-stressed in a vertical direction 45, so that during a movement the wire 43 functions in addition as a fixing in terms of the displacement. The movable component 41 thus makes a movement 44 relative to the rigidly mounted component 42, without the disadvantageous influence of a spring stiffness in component 43, which damps the oscillation.
FIG. 5 shows a decoupling device for lateral movements, with bearings. A rigidly mounted component 52 is linked to a movable component 51 via a movement-damping device 53, e.g. a floating bearing/restrained bearing combination. As a consequence the movable component 51 makes a lateral movement 54 with a small displacement relative to the rigidly mounted component 52.
FIG. 6 shows a device with a deformable circuit board. It shows a circuit board 61 in its undisplaced state (i.e., its position of repose) and in the displaced deformed state. The deformable circuit board 61 is fixed on both sides at opposite end regions.
The invention and the forms of embodiment described lead to the following advantages compared to the prior art, especially in comparison with battery powered measuring systems:
- no service life reductions due to the influence of temperature
- increased service life
- no additional oscillatable mass is required
- reduction in weight of the measuring unit in the wheel/tire (lower unsprung weight)
- more compact construction
- additional mechanical load reduction on some components of the measuring unit (such as for example lower risk of damage to the hardware components)
- can be used for other products such as for example access control systems for vehicles.
The present invention is particularly suitable for a tire pressure monitoring system for vehicles.
Patent Application
20070267946
