Vibrating sensor

Abstract

The invention relates to a vibrating sensor with a diaphragm (2) that can be set into vibration; and with a transformer device (4) for setting the diaphragm (2) into vibration and/or for tapping a vibration S in the diaphragm; and with a vibrating body (3) and/or a diaphragm (2) in the form of a vibrating body, for transmitting the vibrations (S) of the diaphragm (2) to an ambient space (7) and/or for transmitting the vibrations (S) from an ambient space (7) to the diaphragm (2). The transformer device (4) exhibits a coil (8) and a bolt (6), such that the bolt (6) is connected to the diaphragm (2) in order to transmit the vibrations (S) to or from the diaphragm (2), and the coil (8) and the bolt (6) are positioned to so interact that a vibration (S) in the bolt (6) induces a flow of current in the coil (8) and/or a flow of current in the coil induces a magnetic field (B) and brings about a vibration in the bolt (6).

Description

An exemplary embodiment will next be described in greater detail on the basis of the drawing, which shows:

FIG. 1 an initial embodiment of a preferred vibrating sensor, in a sectional view

FIG. 2 a second embodiment of the vibrating sensor, in a sectional view

FIG. 3 an exemplary vibrating sensor of the prior art, in a sectional view

FIG. 1 gives a sectional view through a preferred embodiment of a vibrating sensor. In order to elucidate the basic principle only the fundamental components are shown. Other components, such as the connecting cable or housing lid, are omitted for the sake of clarity. The depicted components—for example, the housing wall—can be modified in their concrete form.

The figure shows an exemplary housing 1, with a housing wall, preferably of cylindrical shape. Secured to the face of the housing 1 is a diaphragm 2, which, with respect to its dimensions, method of attachment, and/or material, is designed to permit vibration. Ideally, but not as a required feature, vibrating forks 3 will project from the diaphragm in order to transmit a vibration S in the diaphragm to the space 7 surrounding the vibrating forks 3. In addition, or as an alternative, it is possible for vibrations to be transmitted from the space 7 to the diaphragm 2 via the vibrating forks, or directly from the space 7 to the diaphragm 2, so that said diaphragm 2 is set into vibration S.

Positioned in the interior 5 of the housing 1 is a transformer device 4, which serves as a drive device and converts applied electrical signals into a vibration; this vibration, in turn, is transmitted to the diaphragm 2. In addition, or as an alternative, vibrations can also be transmitted from the diaphragm 2 to the transformer device 4 and be converted into currents.

According to a particularly preferred embodiment, the transformer device 4 consists of a coil 8, which surrounds a bolt 6; this bolt 6 can be magnetized. The bolt 6 is positioned between the inner walls of the coil 8, in a fashion that permits movement in the direction of a magnetic field B that is induced by the coil 8. A gap d between the outer circumference of the bolt 6 and the inner circumference of the coil 8 will preferably be kept small, both to allow the bolt to move freely in its longitudinal direction and as to afford a structural design that is as compact as possible.

On its one face the bolt 6 is firmly connected to the diaphragm 2, e.g., through adhesion or welding, in order to allow that movement, relative to the housing, that is imposed on the bolt by the magnetic field B of the coil 8 to be transmitted to the diaphragm 2. In the reverse direction, a vibration S in the diaphragm 2 will lead to a corresponding movement of the bolt 6 within the coil, with the result that a flow of current corresponding to the vibration is induced in the coil 8.

Various modifications can be made in the preferred embodiments. For example, the transitional area from the housing 1 to the diaphragm 2 can be provided with an attenuation 10, particularly in the case of a single-piece design, in order to avoid too rigid a coupling between the diaphragm 2 and the wall of the housing 1. It is also possible to position the diaphragm 2 on an inner wall of the housing or on the housing itself through the use of an additional coupling element. Also possible, in principle, is a single-piece design for the diaphragm 2 and the bolt 6, to thereby to avoid a two-piece manufacturing process and the further need to attach the bolt 6 to the diaphragm 2.

In principle, the vibrating forks 3 can also be omitted if the diaphragm 2 is so designed that vibrations S in the diaphragm 2 can be directly transmitted from the diaphragm 2 into the space 7, or can be received by it from the space 7.

In addition to positioning the coil 8, by means of its outer circumference, on an inner wall of the housing 1, the coil 8 may also be positioned on a coil base 9, which is secured to the wall of the housing 1 or which forms a single piece with that wall. This will permit the selection of a special coil, in accordance with the specific application, or the exchange of coils 8, for example when a given coil 8 is no longer functioning securely due to age or the effects of heat.

For use at higher temperatures the use of a coil 8 with a temperature-resistance jacket for the coil conductor is preferred. This kind of temperature-resistant jacket can consist of, e.g., a ceramic material, which electrically insulates the coil conductor and permits usage at temperatures up to 350° C., particularly up to 450° C., or at even higher temperatures.

FIG. 2 shows an embodiment that has been modified vis-à-vis that of FIG. 1. In the following, only differing components are described.

In the first embodiment a bolt 6 that can be magnetized is attached to the diaphragm as a pull bolt, so that the bolt 6 is drawn inwardly through the coil, without stiffening the diaphragm 2 in the process. In the second, modified embodiment a magnetized bolt 6* is attached to the diaphragm 2. This kind of magnetic or magnetized bolt 6* very advantageously permits the vibrating diaphragm 2 to be driven in both of the bolt's vibrating directions.

In the modified embodiment the bolt 6* is additionally coupled to a plunger-type capacitor C. This makes it possible to tap a vibrating movement of the diaphragm 2 or. as the case may be, the bolt 6* directly at the bolt 6* and not by the indirect induction of an electric current in the coil 8. In addition to a configuration involving this kind of plunger-type capacitor C on the face of the bolt 6*, comparable capacitor arrangements may be provided, e.g., at the side of the bolt 6*, for example in an area on the front of the coil 8, between said coil 8 and the diaphragm 2.

Vibrating sensors of this kind can be employed to advantage, particularly when there are elevated ambient temperatures. A corrosion measurement can be advantageously executed with the vibrating fork 3, such that the measuring signal is derived from the resonant frequency of the vibrating fork 3 and/or the diaphragm 2. This is especially advantageous and is made possible by the fact that the resonant frequency, or vibrating frequency, is not influenced by undesired secondary effects caused by a rigid drive device or one that is braced firmly against the diaphragm.

Claims

1. A vibrating sensor with a diaphragm (2) that can be set into vibration,a transformer device (4) for setting the diaphragm (2) into vibration (S) and/or for tapping a vibration S in the diaphragm, anda vibrating body (3) and/or a diaphragm (2) in the form of a vibrating body, for transmitting the vibrations (S) of the diaphragm (2) to an ambient space (7) and/or for transmitting the vibrations (S) from an ambient space (7) to the diaphragm (2),

2. A vibrating sensor according to claim 1, whereinthe bolt (6) consists of a material that can be magnetized.

3. A vibrating sensor according to claim 1, whereinthe bolt (6*) consists of a magnetic material.

4. A vibrating sensor according to claim 1, whereinthe bolt (6; 6*) is secured directly to the diaphragm (2) or is designed to form a single piece with the diaphragm (2).

5. A vibrating sensor according to claim 1, whereinthe bolt (6; 6*) is positioned on the diaphragm (2) and at its center.

6. A vibrating sensor according to claim 1, whereinthe bolt (6*) is coupled to a plunger-type capacitor (C) in order to tap a vibration in the bolt (6*) as a measuring signal.

7. A vibrating sensor according to claim 1, whereinthe coil (8) is secured to one wall of a housing (1).

8. A vibrating sensor according to claim 1, whereinthe coil (8) is seated on a coil support (9), such that the coil support (9) secures the coil relative to one wall of the housing (1).

9. A vibrating sensor according to claim 1, whereinthe diaphragm (2) is positioned on, and specifically fastened to, one wall of a housing (1).

10. A vibrating sensor according to claim 1, whereina coil conductor is electrically insulated with a temperature-resistant jacket.

11. A vibrating sensor according to claim 10, whereinthe coil body is made of ceramic material.

12. A vibrating sensor according to claim 1, whereinthe components, particularly the coil conductor, are temperature-resistant up to at least 350° C. and particularly up to 450° C.