阅读说明：本技术 密封装置以及用于监测密封装置的方法 (Sealing device and method for monitoring a sealing device ) 是由 O·纳尔沃尔德 S·辛德林格 B·特拉伯 T·克劳斯 T·克拉默 F·劳尔 R·克雷斯迈 于 2020-01-09 设计创作，主要内容包括：本发明涉及一种密封装置(10)、一种用于监测密封装置的方法以及这样的密封装置作为瓣阀中的瓣密封件的应用。根据本发明,已认识到有利的是,间接测量密封元件的接触应力,即,通过测量在密封元件(1)与待密封构件(2)之间的距离(a)。为此,密封装置具有特殊的结构,所述结构包括测量装置(4)。提供一种密封装置,所述密封装置具有简单的结构,就制造技术而言可简单且低成有利地制造并且也能够检测密封装置的很小的变化。通过用于监测密封装置的方法能够以有利的方式可靠地说明密封元件的老化特性和尤其是收缩性。(The invention relates to a sealing device (10), a method for monitoring a sealing device and the use of such a sealing device as a flap seal in a flap valve. According to the invention, it has been recognized that it is advantageous to measure the contact stress of the sealing element indirectly, i.e. by measuring the distance (a) between the sealing element (1) and the component (2) to be sealed. For this purpose, the sealing device has a special construction which comprises a measuring device (4). A sealing device is provided which has a simple structure, can be produced easily and inexpensively in terms of production technology, and is also capable of detecting small changes in the sealing device. The aging behavior and in particular the shrinkage of the sealing element can be reliably described in an advantageous manner by the method for monitoring the sealing device.)

1. A sealing arrangement (10) comprising a sealing element (1) and a component (2) to be sealed, wherein the sealing element (1) is received on the component (2) such that there is a contact stress between the sealing element (1) and the component (2), and the sealing element (1) has a contact surface (3) with which it rests on the component (2), and further comprises a measuring device (4) for monitoring the ageing of the sealing element (1), characterized in that at least one measuring component (4.1, 4.2) of the measuring device (4) is integrated in the sealing element (1) and the component (2) respectively, and the contact surface (3) of the sealing element (1) has a surface geometry (5) with a plurality of recesses (5.1).

2. A sealing arrangement according to claim 1, characterized in that the measuring means (4.2) of the component (2) is integrated into the component (2) in such a way that it abuts against the contact surface (3) of the sealing element (1).

3. The sealing arrangement according to claim 1 or 2, characterized in that the measuring component (4.1) of the sealing element (1) is configured as a structure integrated in the volume of the sealing element (1).

4. The sealing device of any one of the preceding claims, wherein the integrated structure is electrically conductive or magnetic.

5. The sealing arrangement according to claim 3 or 4, characterized in that the integrated structure is made of the material of the sealing element (1) with the addition of additives.

6. The sealing arrangement according to any one of claims 3 to 5, characterized in that there is an insulation layer between the integrated structure and the contact surface (3) of the sealing element (1), in particular made of the material of the sealing element (1).

7. The sealing arrangement according to any of claims 3 to 6, characterized in that the integrated structure is introduced into a recess (5.1) of a surface geometry (5).

8. A sealing arrangement according to any one of the preceding claims, characterized in that the contact surface (3) of the sealing element (1) is located in a region of high contact stress.

9. Sealing device according to any of the preceding claims, characterized in that the surface geometry (5) forms with its recesses (5.1) bulges, honeycombs, meshes, grooves or cut-outs.

10. A method for monitoring a sealing device, in particular according to one of the preceding claims, wherein a distance (a) between a measuring component (4.1) of the sealing element (1) and a measuring component (4.2) of the component (2) is determined.

11. Method for monitoring a sealing device according to claim 10, characterized in that the distances (a) under different load conditions are detected and the difference (Δ a) between the distances is calculated.

12. Method for monitoring a sealing device according to claim 11, characterized in that the time (t) required for the sealing element (1) to relax between different load states is detected.

13. Method for monitoring a sealing device according to claim 10 or 11 or 12, characterized in that the values of the distance (a) and/or of the difference (Δ a) and/or of the time (t) determined when the sealing device (10) is put into operation are stored in a data memory of the measuring device (4).

14. Method for monitoring a sealing device according to claim 13, characterized in that the currently determined values of the distance (a) and/or of the difference (Δ a) and/or of the time (t) are compared with stored values.

15. Method for monitoring a sealing device according to one of the claims 10 to 14, characterized in that a signal is output when there is a deviation above a threshold value.

16. Use of a sealing device according to any one of claims 1 to 9 as a flap seal in a flap valve.

Technical Field

The invention relates to a sealing arrangement according to the preamble of claim 1, a method for monitoring a sealing arrangement according to claim 10 and the use of a sealing arrangement according to claim 16.

Background

Various seals made of plastic and elastomer materials are known from the prior art. Such as a static seal formed by a planar seal, O-ring, flap seal, or other shaped seal.

DE 102010042340 a1 describes a flap seal (klapppendichtung) for a flap valve (klapppendentil), which may also be referred to as a disk valve. In order to understand the state of the seal or to avoid seal failure, it is desirable to monitor the state of the seal. For this purpose, various measurement methods are known from the prior art. The integration of the measuring device required for this purpose into the sealing device is particularly desirable, since this makes possible a particularly compact construction and low-cost production.

US 2012/0119448 a1 describes an O-ring with integrated measuring means. The wear, thermal changes, physical damage and structural damage of the seal should be able to be monitored by the measuring device. For this purpose, two conductive layers are integrated into the sealing element and the measured capacitance can be evaluated.

The difficulty with such a measuring device is that: since the distance between the conductive layers varies only very little, only a small change in capacitance can be measured. As a result, a very high accuracy of the measuring device is required, which is then accompanied by a risk of inaccurate measurements due to distortions.

Disclosure of Invention

Technical task

The object of the present invention is to provide a sealing device which has a simple structure, can be produced simply and cost-effectively in terms of production technology, and can also detect small changes in the sealing device.

A further object is to specify a method for monitoring a sealing arrangement which makes it possible to reliably characterize the aging behavior and in particular the shrinkage (Setzverhalten) of the sealing element.

Solution scheme

This object is achieved by a sealing arrangement having the features of claim 1.

According to the invention, it has been recognized that it is advantageous to measure the contact stress of the sealing element indirectly, i.e. by measuring the distance between the sealing element and the component to be sealed. For this purpose, the sealing device has a special construction.

The sealing device according to the invention has a sealing element and a component to be sealed. The sealing element may be a sealing ring, for example. The sealing element can in particular be made of an elastomer. The component to be sealed can be, for example, a housing or a machine element. The sealing element is received on the component in such a way that there is a contact stress between the sealing element and the component and the sealing element has a contact surface with which the sealing element rests on the component. The sealing device also has a measuring device for monitoring the aging of the sealing element. "ageing" here includes, in particular, the shrinkage of the sealing element, but may also include wear-induced wear.

Advantageously, at least one measuring component of the measuring device is integrated in each of the sealing element and the component. This results in a simple, compact and insensitive construction of the measuring device. The contact surface of the sealing element advantageously has a surface geometry with a plurality of recesses. The measuring element of the sealing element may be located in the recess itself or even integrated deeper into the sealing element, so that there is another layer of sealing element between the measuring element and the contact surface. The contact surface is particularly preferably located in a region of high contact stress between the sealing element and the component to be sealed, i.e. where a high compressive force is present. The contact surface is thus directly located in the force flow of the pressing force. The contact surface is preferably located in a master force lock (Hauptkraftschluss). Alternatively, it is located in the secondary force lock (nebekraftsless). A pressing surface is located on the opposite side of the sealing element from the contact surface, to which pressing force is applied.

In an advantageous further development of the sealing arrangement according to the invention, the measuring part of the component is integrated in the component in such a way that it abuts against the contact surface of the sealing element. The measuring component may be, for example, a conductive surface or a hall sensor. If the component is a housing, the housing can also be made of an electrically conductive material and the entire housing can form the measuring part. If the distance measurement is carried out by a capacitance measurement, the capacitance can be measured with respect to the ground line of the housing, which advantageously simplifies the construction of the measuring chain.

In an advantageous further development of the sealing arrangement, the measuring component of the sealing element is designed as a structure integrated into the sealing element volume. The structure can be configured in particular as a plane, a grid, a line or a strip or a body. The integrated structure may be electrically conductive or magnetic. If the integrated structure is conductive, capacitance measurements can be made. If the integrated structure is magnetic, the measurement can be carried out using the hall effect by means of a hall sensor.

In a particularly advantageous and therefore preferred further development of the sealing arrangement according to the invention, the integrated structure is produced from the material of the sealing element with the addition of additives. In other words, the electrically conductive or magnetic structure is formed by the sealing material by locally limited addition of, for example, electrically conductive or magnetic particles or magnetized particles.

In the sealing device according to the invention, an isolating layer may be present between the integrated structure and the contact surface of the sealing element, which isolating layer is in particular made of the material of the sealing element, i.e. of the sealing material.

In an alternative embodiment, a web, i.e. a projection, made of sealing material can be present in the recess of the surface geometry, and the integrated structure can be applied to the end face of the web. By means of such a design, the integrated structure for distance measurement is closer to the measuring component of the component, and therefore higher measuring accuracy and signal quality can be achieved with a noise-free measuring signal.

In a special embodiment of the sealing device, the integrated structure is introduced into a recess of the surface geometry. Such a sealing device is particularly advantageous in terms of production technology, since the sealing device can be produced from a sealing material in a first production step and the structure can be applied in a second production step by coating, spraying or printing into the recess of the sealing device.

In the above-described sealing device, the surface geometry may form projections, honeycombs, meshes, grooves or cutouts with their recesses. The recess may in particular be in the order of 0.5 to 2 mm.

The invention also relates to a method for monitoring a sealing arrangement, in particular as described above, wherein the distance between a measuring component of the sealing element and a measuring component of the component is determined. The aging and in particular the shrinkage and the wear of the sealing element can then be inferred from the measured distance. As a measuring method, for example, capacitive measurement or the change in current in a hall sensor can be used.

In the method according to the invention for monitoring a sealing arrangement, the distances under different load conditions, in particular under two different load conditions, are indirectly detected and the difference between the distances is calculated. The indirect measurement can be performed by capacitive measurement or in the case of hall sensors. If the sealing device is configured as a valve seal, the load conditions may be "valve open" and "valve closed". When configured as a flap seal for a flap valve, the load conditions are "flap open" and "flap closed". It has surprisingly been shown that evaluating the difference in distance, as opposed to measuring the absolute value of the distance, enables a better indication of the state of the sealing device. The absolute value of the distance changes only slightly over time and is therefore hardly evaluable, but the difference in distance is a larger and better evaluable value. In other words, the geometric changes caused by the relaxation of the sealing element in the static state are very small. Thus, a greater difference between the two load states is utilized. "relaxation" is understood here to mean either a stress-relief and return of the sealing element into its uncompressed state or a change in the response behavior of the plastic or elastomer to an applied force over time. This provides a time-dependent response characteristic and reaches a final or absolute value once the force is removed. The final value is changed by aging.

In a further development of the method according to the invention for monitoring a sealing arrangement, the time required for the sealing element to relax between different load states can additionally also be detected. If, for example, two load states, valve closed and valve open, are used, the time required for the sealing element to relax after the valve has opened can be detected. That is, the time for the sealing element to be destressed after the valve is detected to be open and thus the flap no longer applies a pressing force to the sealing element.

It is particularly advantageous if the values of the distance and/or of the difference and/or of the time determined when the sealing device is put into operation are stored in a data memory of the measuring device. That is, an initial value is stored which is suitable for a new and intact sealing device without aging phenomena. If the distance and/or difference and/or time is detected at some later point in time, these current values may be compared to stored initial values. The value of the distance in the "valve closed" state in the loaded state can additionally also be used to detect wear of the sealing surface between the flap and the sealing element, since the value of the distance increases with increasing wear. The losses lead to a reduction in the size of the sealing element, which in turn leads to a lower force when the flap is closed.

In a further development of the method for monitoring a sealing device, a signal is output in the presence of deviations above a defined and stored threshold value or in the event of a strongly increasing offset in the values of distance and/or difference and/or time. The signal may be, for example, an alarm signal or a request to replace the sealing element or an automatic ordering of spare parts, etc.

The invention also relates to the use of a sealing device as described above as a flap seal in a flap valve. In this case, the valve flap or the valve plate is arranged pivotably in the sealing ring and the sealing ring has a sealing surface on its inner diameter and is received in the housing on its outer diameter. The contact surface is located between the outer diameter of the sealing ring and the housing, so that there is a special surface geometry with a recess and the measuring device is positioned there.

The described invention and the described advantageous further developments of the invention can also be combined with one another to form advantageous further developments of the invention, provided that this is technically expedient.

With regard to further advantages and embodiments of the invention which are advantageous in terms of construction and function, reference is made to the dependent claims and to the exemplary illustrations with reference to the drawings. Examples

The invention will be explained in more detail using a flap seal as an example. When the contact stress is reduced and below the pressing force of the applied media pressure, the flap seal will leak. It is therefore desirable to predict when a seal will leak in the sense of predictive maintenance so that customers can replace the seal in a timely manner before a leak occurs.

Therefore, the problem is: how is the loss of contact stress detected as continuously as possible? The invention is based on the idea of detecting a geometric change that can be measured as a change in length.

In order to achieve a sufficiently large change in length, which can be detected by measurement techniques, the sealing device is structured by the recess, which brings about a surprising improvement.

Simulations show that the geometric changes caused by physical relaxation in the static state are very small. In this case, it is difficult to distinguish geometric differences measured only under such load conditions. If the difference between the load conditions of the opening and closing of the flap is taken into account, a significantly larger difference is measured. These differences should remain constant at all times without aging effects.

It has been shown that when the recess is larger, the length change that occurs when the flap is closed or opened is greater.

Due to aging, i.e. the loss of the relaxation capacity (i.e. the restoring force) of the material, the sealing material will spring back more slowly when the flap opens, wherein this can be measured in the slower distance change (Δ a per unit time t). In aged sealing materials, the absolute level of Δ a will also be lower and lower, since the restoring force is lost due to physical and chemical aging.

It has been found to be advantageous if the change in distance can be measured either in the open state of the flap (as the absolute value of Δ a) or as a curve over time when the flap is open. That is, the speed at which the seal returns to its unloaded shape after de-stressing is measured.

Drawings

The invention shall be elucidated in more detail with reference to the accompanying drawings. Corresponding elements and components are provided with the same reference numerals in the figures. To the extent that the drawings are more clear, they are not shown to scale. Here, it is shown in a schematic view:

FIG. 1 shows a cross-sectional view of a sealing element;

FIG. 2 shows different design possibilities of the surface geometry of the sealing element contact surface;

3a-b show a sealing device with two different measuring devices;

fig. 4a-e show possible variants of the integrated structural design of the measuring component of the sealing element;

FIG. 5 illustrates compression, relaxation, and aging of the sealing element;

fig. 6 shows the relaxation behavior of the sealing element over time in a graph.

Detailed Description

Fig. 1 shows a sectional view of a sealing element 1, i.e. a sealing ring of a flap seal. The two upper and lower through-openings 8 provide a pivot axis for a flap 9, not shown here. The valve flap 9 is located in the sealing element 1 and the sealing element 1 has a sealing surface on its inner diameter, which sealing surface causes a seal against the valve flap 9. The sealing element 1 is received on its outer diameter on a component 2, for example, in a groove of a housing. The housing 2 is not shown in fig. 1, but only its position. The sealing element 1 has a contact surface 3 on its outer diameter, with which the sealing element 1 rests on the component 2. In the region of this contact surface 3, there is a high contact stress between the sealing element 1 and the component 2. In fig. 4a-4e a partial cross section of the sealing element 1 at the position indicated by the arrow is shown in more detail.

Fig. 2 shows different design possibilities of the surface geometry 5 of the contact surface 3 of the sealing element 1. The recesses 5.1 can be located, for example, between round, honeycomb-shaped or square elevations. Alternatively, the recess 5.1 is formed by a linear groove.

Fig. 3a-b show a sealing device 10 with two different measuring devices 4.

Fig. 3a shows a sealing device 10 with a surface geometry 5 according to the invention in a cross-sectional view: as an integrated structure of the measuring component 4.1 of the sealing element 1, a conductive layer is used, which follows the surface geometry 5. In addition, a circuit diagram of a capacitor is also drawn here, which should indicate that a capacitance measuring device is used as the measuring device 4. The relative movement of the conductive layer 4.1 with respect to the measuring part 4.2 of the component 2 causes a measurable change in the capacitance. From this change in capacitance, a change in distance between the measuring parts 4.1, 4.2 can be inferred.

Fig. 3b also shows a sealing device 10, wherein a circuit diagram of a hall sensor is shown here, which is intended to indicate the use of a hall sensor as measuring device 4. Instead of the electrically conductive layer, a magnetic layer is used as measuring means 4.1. The relative movement of the magnetic layer with respect to the field of the hall sensor causes a measurable change in current. From this change in current, a change in distance between the measuring parts 4.1, 4.2 can be inferred.

Fig. 4a-e show possible variants of the design of the measuring component 4.1 of the sealing element 1 as an integrated structure.

In fig. 4a, the integrated structure 4.1 is arranged as a planar layer lying flat behind the surface geometry 5. Thereby simplifying the manufacturing process.

In fig. 4b, in contrast to fig. 4a, only very small recesses 5.1 are provided.

Fig. 4c shows a device in which the integrated structure 4.1 is introduced as a line into the recess 5.1, i.e. into the channel of the surface geometry 5. The lines may be formed, for example, by coating or printing.

Fig. 4d shows the sealing device 10 in cross section, in which a raised web 6 is provided in the recess 5.1. That is to say, the web 6 is raised relative to the recess 5.1, but the web end face is still at a distance from the component 2. An integrated structure 4.1 is provided on the end face of the web 6. The integrated structure 4.1 is not in contact with the housing 2 and is therefore not subjected to any contact stresses. Due to the deformation of the flap 9 during opening and closing, the distance a between the integrated structure 4.1 and the housing 2 changes, and the air located there acts as a barrier between the integrated structure 4.1 on the web 6 and the housing 2. This configuration of the sealing device 10 is used when the design of the measuring device 4 only allows for measuring small distances between the components 4.1, 4.2.

Fig. 4e shows another embodiment of the sealing device 10.

The body of the sealing element 1 itself serves here as a measuring means 4.1 of the sealing element 1. For the capacitance measuring method, the sealing element 1 is made of a conductive sealing material. In the case of using a hall sensor, the sealing member 1 is made of a magnetic sealing material. The sealing element 1 is provided with a barrier coating 7 on the contact surface 3.

The measuring element 4.1 of the sealing element 1 is of an electrically conductive or magnetic material, depending on the measuring method to be used. For the capacitive measurement, electrically conductive materials are used, and in the case of hall sensors, magnetic materials are used.

If the measuring component of the sealing element is constructed as an integrated structure, it is also made of the sealing material of the sealing element 1, but with the addition of electrically conductive or magnetic particles.

Fig. 5 shows the compression, relaxation and aging of the sealing element 1, i.e. the change in the distance (a) to the surface of the housing 2 or, more precisely, the change in the distance (a) between the sealing element 1 and the measuring parts 4.1, 4.2 of the component 2. This is illustrated by the flap seal of the flap valve:

in the uppermost illustration, the valve is open and the sealing element 1 is not compressed but in a relaxed state. The state is shown in a new sealing device 10, i.e. at or shortly after initial installation.

In the middle illustration, the valve is closed and the sealing element 1 is compressed by the applied pressing force F. This results in a smaller distance a 1.

In the following illustration, the valve is also open, but due to the reduced contact stress after a certain period of use, the sealing element 1 is no longer restored to the initial state and a2 is less than a.

Fig. 6 shows the relaxation behavior of the sealing element 1 over time in a graph. The upper curve shows the behavior in the new sealing device 10. The lower curve shows the behavior in the sealing device 10 after a certain period of use. Two curves are shown of the distance a measured between the sealing element 1 and the measuring means 4.1, 4.2 of the member 2 over time during relaxation of the sealing element 1, i.e. after the valve is opened. It can be seen in the above curve that the sealing element 1 recovers quickly and well shortly after the valve is opened. The lower curve shows the characteristics of the sealing element 1 when the recovery characteristics are significantly reduced. The recovery behavior is significantly slower and the sealing element 1 can no longer recover as well.

The evaluation of the graphs was as follows: based on aging, i.e. the loss of the relaxation capacity of the sealing element material and its restoring force, the sealing material springs back more slowly when the flap opens, which can be measured in a slower distance change (Δ a per time unit t). In aged sealing materials, the absolute level of Δ a will also be lower and lower, since the restoring force is lost due to physical and chemical aging.

List of reference numerals

1 sealing element

2 member to be sealed

3 contact surface

4 measuring device

4.1 measuring component of sealing element (e.g. integrated structure)

4.2 measuring parts of the component

5 surface geometry

5.1 recess

6 connecting piece

7 coating layer

8 through hole

9 position of the valve flap

10 sealing device

a distance

F pressing force