PRESSURE SENSOR, SYSTEM FOR MOUNTING AND DEMOUNTING OF THE PRESSURE SENSOR AND USE OF THE PRESSURE SENSOR

A pressure sensor for measuring the pressure of a fluid medium includes a mounting device, a sensor device and a sealing element. The mounting device holds the sensor device and is mountable in a mounting bore of a wall. The sensor device includes a diaphragm and a sensor element, which generates a measurement signal for a pressure-dependent deformation of the diaphragm. The sealing element seals the mounting bore and includes a trunnion held by a socket of the sensor device.

FIELD OF THE INVENTION

The invention relates to a pressure sensor for measuring the pressure of a fluid medium confined by a wall that defines a mounting bore configured for mounting the pressure sensor in a manner that disposes the pressure sensor for measuring the pressure in the fluid medium. The invention also relates to a system for mounting and demounting of the pressure sensor and to a use of the pressure sensor.

BACKGROUND OF THE INVENTION

EP1146326A2 presents a pressure sensor for measuring the pressure of a fluid medium such as fuel and air in an internal combustion engine. When the fuel is combusted with atmospheric oxygen, a pressure of 200 MPa and higher is generated in the combustion chamber of the internal combustion engine. In order to operate the combustion engine as efficiently as possible, the pressure prevailing in the combustion chamber is measured and used as a parameter for controlling or regulating the combustion of the fuel with the atmospheric oxygen.

For mounting and demounting of the pressure sensor of EP1146326A2 on the combustion chamber, the wall of the combustion chamber comprises a mounting bore with an internal thread. The pressure sensor comprises a hollow mounting screw and a sensor device. The hollow mounting screw comprises a cavity for holding the sensor device and an external thread for screwing into the internal thread. The pressure sensor mounted in this way via its external thread in the internal thread of the wall is in direct contact with the fluid medium.

The sensor device of EP1146326A2 comprises a sensor housing, a diaphragm, a sealing surface and a sensor element. Said sensor housing, diaphragm and sealing surface are integrally formed. The sensor housing is of hollow cylindrical shape comprising a channel extending along a longitudinal axis between a first end and a second end of said sensor housing. At the first end towards the mounting bore, the channel is open so that the fluid medium can enter the channel. At the second end facing away from the mounting bore the diaphragm is arranged. The diaphragm is thin and deformable. On the side of the diaphragm facing away from the channel said sensor element is arranged. The sensor element is a strain gauge. Under the effect of the pressure of the fluid medium, the diaphragm deforms, which strain gauge generates a measurement signal for the pressure-dependent deformation of the diaphragm.

To prevent the fluid medium from escaping from the combustion chamber via the mounting bore, the pressure sensor of EP1146326A2 has a disk-shaped sealing element with a first and a second sealing element surface. With its first sealing element surface, the sealing element rests on a sealing surface of the mounting bore. In the mounted state of the pressure sensor, the first sealing element surface presses against the sealing surface of the mounting bore, and the sealing surface of the sensor device arranged at the first end of the sensor housing presses against the second sealing element surface.

Due to the high temperatures in the combustion chamber, the sensor element of EP1146326A2 is arranged as far away as possible from the combustion chamber at the second end of the channel, where the temperatures are comparatively lower. However, the sealing surface of the sensor device is arranged at the first end of the channel, which is close to the combustion chamber. The disadvantage of this is that the pressure in the channel generates acoustic oscillations which can falsify the measurement signal.

During each mounting and demounting of the pressure sensor of EP1146326A2 in the mounting bore, there is a risk of damaging both of sealing element surfaces of the sealing element as well as the sealing surfaces of the mounting bore and the sensor device. This is because the tool which is applied to the hollow mounting screw in order to screw the external thread of the hollow mounting screw into or out of the internal thread of the wall can tilt and then generate excessively high clamping forces on the sealing surfaces. The excessively high clamping forces in turn cause plastic deformation of the sealing surfaces, which results in non-reversible impairment of the tightness of the seals of the pressure sensor in the mounting bore.

In the pressure sensor of EP1146326A2, said sensor housing, diaphragm and sealing surface of the sensor device as well as the disk-shaped sealing element are in direct contact with the fluid medium and are made of metallic material. If the fluid medium contains hydrogen, hydrogen from the fluid medium can penetrate the metallic material and cause hydrogen embrittlement in the metallic material. Hydrogen embrittlement is a change in the ductility and strength of the metallic material. Hydrogen embrittlement can lead to cracking with brittle fracture and failure of the pressure sensor.

OBJECTS AND SUMMARY OF THE INVENTION

The objects of the present invention are to provide a pressure sensor which is inexpensive to manufacture, which measures pressure as accurately as possible, which can be easily and quickly mounted and demounted in the mounting bore, whose seals in the mounting bore are subject to reduced risk of damage during mounting and demounting, and which has improved resistance to hydrogen embrittlement.

At least one of these objects is solved by the features described below.

The invention relates to a pressure sensor for measuring the pressure of a fluid medium; which pressure sensor comprises a mounting device, a sensor device and a sealing element, which mounting device holds said sensor device and which mounting device can be mounted in a mounting bore of a wall; which sensor device comprises a diaphragm and a sensor element, which fluid medium is in direct contact with the diaphragm of the pressure sensor mounted in the mounting bore via the mounting bore and which pressure acts on the sensor element via the diaphragm of the pressure sensor mounted in the mounting bore, which sensor element generates a measurement signal for a pressure-dependent deformation of the diaphragm; which sealing element a first sealing element of the pressure sensor mounted in the mounting bore in a first sealing seals the mounting bore with a sensor device surface of the sensor device and which sealing element of the pressure sensor mounted in the mounting bore in a second sealing seals the mounting bore with a wall surface of the wall; wherein the sealing element comprises a trunnion; wherein the sensor device comprises a socket; and wherein the socket permanently holds the trunnion by form fit.

In contrast to EP1146326A2, according to the invention the sealing element is held permanently by the sensor device. By the adjective “permanent” it is meant that the once formed form fit remains during the life time of the pressure sensor. The sealing element can therefore be mounted and demounted together with the pressure sensor in the mounting bore. Permanently combining the sealing element to the pressure sensor simplifies mounting and demounting of the pressure sensor. Also, during the mounting and demounting of the pressure sensor, the first seal formed by the sealing element with the sensor device surface is not detached, which ensures a temporally consistent quality of the first seal, because each time a seal is restored, the sealing surfaces can be damaged and the tightness of the seal can be impaired. If the pressure sensor is used to measure the pressure of a fluid medium containing hydrogen, the non-detachment of the first seal and the resulting preservation of the tightness of the first seal can also prevent hydrogen from escaping from a fluid medium containing hydrogen.

Advantageous improvements of the pressure sensor according to the invention are explained more fully below.

In an advantageous improvement, the sealing element has a first sealing element surface, which first sealing element surface is formed on the trunnion and the sensor device surface is formed in the socket.

This has the advantage that the first seal formed by the first sealing element surface with the sensor device surface occurs at the location of the form fit between the sealing element and the sensor device, which form fit ensures the time consistent quality of the first seal.

In an advantageous improvement, the pressure sensor has a longitudinal axis; wherein the trunnion is inserted into the socket in the axial direction.

The pressure sensor and the wall are rotationally symmetrical with respect to the longitudinal axis. Inserting the trunnion in axial direction into the socket simplifies the formation of the form fit between the socket and the trunnion.

In an advantageous improvement, the socket comprises a sensor device installation; wherein the trunnion comprises a sealing element installation; and wherein the sealing element installation and the sensor device installation are guide means during insertion of the trunnion into the socket.

These guide means also facilitate the formation of the form fit between the socket and the trunnion.

In an advantageous improvement, the socket comprises a socket base; wherein the trunnion comprises a trunnion head, which trunnion head is deformable; wherein, with an undeformed trunnion head inserted into the socket, there exists a trunnion head offset between the undeformed trunnion head and the socket base; and wherein the trunnion head offset is resolved by deformation of the non-deformed trunnion head into a deformed trunnion head, which deformed trunnion head abuts against the socket base in a planar manner and forms the permanent form fit with the socket base.

The form fit is thus formed with a deformable trunnion head inserted into the socket by deforming the deformable trunnion head. The force required for this purpose can be easily generated when mounting the pressure sensor. The force can be generated by screwing the pressure sensor into an internal thread of the wall via an external thread of the mounting device.

In an advantageous improvement, the deformed trunnion head is plastically deformed.

The plastic deformation of the deformed trunnion head is not reversible, i.e., the permanent form fit between the deformed trunnion head and the socket base can only be separated again by damaging or destroying the trunnion head and socket base. The permanent form fit is therefore very durable and allows a large number of mountings and demountings of the pressure sensor in the mounting bore.

In an advantageous improvement, the first sealing element surface is deformable; wherein, when an undeformed first sealing element surface is inserted into the socket, a first angular offset exists between the undeformed first sealing element surface and the sensor device surface; and wherein the first angular offset is resolved into a deformed first sealing element surface by deforming the undeformed first sealing element surface, and the deformed first sealing element surface abuts against the sensor device surface in a planar manner.

Thus, the first seal of the first sealing element surface with the sensor device surface is formed in situ by deforming a deformable first sealing element surface by molding the deformable first sealing element surface to the shape of the sensor device surface. The deformable first sealing element surface thus adapts precisely to the shape of the sensor device surface. In turn, the force required for this can be easily generated when the pressure sensor is mounted. The force can be generated by screwing the pressure sensor via an external thread of the mounting device into an internal thread of the wall.

In an advantageous improvement, the second sealing element surface is deformable; wherein, with an undeformed second sealing element surface abutting against the wall surface, a second angular offset exists between the undeformed second sealing element surface and the wall surface; and wherein the second angular offset is resolved into a deformed second sealing element surface by deformation of the undeformed second sealing element surface, and the deformed second sealing element surface abuts against the wall surface in a planar manner.

Also, the formation of the second seal between the sealing element and the wall is formed in situ by deformation of a deformable first sealing element surface by forming a deformable second sealing element surface to the shape of the wall surface. The deformable second sealing element surface thus adapts precisely to the shape of the wall surface. The force required for this purpose can in turn be easily generated when the pressure sensor is mounted. The force can be generated by screwing the pressure sensor via an external thread of the mounting device into an internal thread of the wall.

In another advantageous improvement, the sensor device comprises a sensor housing; wherein the diaphragm comprises a hinge, by which hinge the diaphragm is deformable; wherein the diaphragm comprises a flange, which flange forms a material bond with the sensor housing; and wherein the socket is formed in the flange.

Thus, the diaphragm and the sensor housing are fabricated in multiple parts and are joined together by a material bond, which is inexpensive to fabricate, unlike the pressure sensor of EP1146326A2.

In another advantageous improvement, the flange absorbs clamping forces, which clamping forces are generated when the pressure sensor is mounted in the mounting bore and which clamping forces act from the wall on the sealing element and act on the flange via the trunnion.

The clamping forces are thus absorbed by the flange of the diaphragm and do not reach the joint of the diaphragm. The flange of the diaphragm has a thickness comparable to that of the sensor housing to form the material bond with the sensor housing. The joint, on the other hand, is thinner than the flange. Typically, the flange is one order of magnitude thicker than the joint. The clamping forces are therefore absorbed by a mechanically stable material thickening of the sensor device and cannot damage the mechanically sensitive material thinning of the joint.

In another advantageous improvement, the diaphragm and the sensor housing are made of metallic material; and wherein the material bond is formed as a weld seam, which weld seam is arranged on the side of the first seal and the second seal facing away from the mounting bore.

In comparison with the structure of the metallic material of the sensor housing and the diaphragm, hydrogen of the fluid medium can penetrate very quickly and easily into the metallic material via the weld seam and cause hydrogen embrittlement. However, since the weld seam is arranged on the side of the first seal and the second seal facing away from the mounting bore, hydrogen of the fluid medium cannot reach the weld seam and thus cannot penetrate into the metallic material via the weld seam.

In another advantageous improvement, the fluid medium is located within a container, which container comprises the wall, and which wall closes the container; that the mounting bore comprises an inlet, via which inlet fluid medium enters the mounting bore from the inside the container; and that the diaphragm of the pressure sensor mounted in the mounting bore is the end of the pressure sensor facing the inlet.

While in the pressure sensor of EP1146326A2 the diaphragm is arranged at the end of a channel within the sensor housing, the diaphragm of the present invention is located at the foremost end of the pressure sensor. Due to the absence of the channel in an embodiment of the pressure sensor of the present invention, there are therefore no acoustic oscillations which can falsify the measurement signal.

In another advantageous improvement, only the diaphragm and the sealing element of the pressure sensor mounted in the mounting bore are in direct contact with the fluid medium via the mounting bore.

Thus, only two components of the pressure sensor are in direct contact with the fluid medium, in particular the sensor housing is not in contact with the fluid medium and thus need not be composed of material that is resistant to hydrogen. This is of particular importance for a fluid medium containing hydrogen, because only the materials of the diaphragm and the sealing element then have to be resistant to hydrogen, so that the pressure sensor can be manufactured at low costs.

Identical elements are marked with the same reference symbols in the drawings.

The pressure sensor1shown in the longitudinal section ofFIG.1is used to measure the pressure P of a fluid medium M. The fluid medium M can be gaseous or liquid. The pressure P can be up to 1000 bar. The fluid medium M may contain hydrogen. In the following, a fluid medium M containing hydrogen is understood to be a fluid medium M which contains at least one volume percent (vol %) of hydrogen.

As schematically shown inFIG.1, the fluid medium M is located within a container that is generally designated by the numeral10. The container10may be a combustion chamber of an internal combustion engine, a pressure vessel, and so on. The container10comprises a wall11. Said wall11defines and closes the interior space of the container10. The wall11is pressure-tight and gas-tight, i.e. during the lifetime of the container10and under the permissible operating conditions of the container10, the wall11resists the pressure P and allows only negligible amounts of the fluid medium M to escape. For the purposes of the present invention, a gas-tight wall11has a leakage rate to helium of less than 10−6mbar l/s. The wall11is made of resistant material such as stainless steel, fiber reinforced plastic, etc.

The pressure sensor1and the wall11are shown inFIGS.1-3with respect to a longitudinal axis103and a transverse plane104perpendicular thereto. The pressure sensor1and the wall11are rotationally symmetrical with respect to the longitudinal axis103. In the following description, the components of the pressure sensor1are explained in an axial direction along the longitudinal axis103and in a radial direction perpendicular to the longitudinal axis103.

The wall11defines a mounting bore100. The mounting bore100is a through hole permitting fluid communication between the interior of the container10and the space external to the container10. The mounting bore100defines an inlet101through which fluid medium M enters the mounting bore100from inside the container10. The inlet101is located in a region of the mounting bore100close to the container. The mounting bore100has a wall surface106. The wall surface106is also located in the region of the mounting bore100that is close to the container. Further spaced apart from the container10, the wall surface106passes into a mounting section105. In the mounting section105, the mounting bore100defines an internal thread107. The internal thread107is used for mounting the pressure sensor1in the mounting bore100. Thus, the mounting bore100extends in an axial direction from the interior of the container10to the pressure sensor1mounted in the mounting bore100. By mounting the pressure sensor1in the mounting bore100, the mounting bore100forms a mounting gap102in the region of the mounting section105. The end of the pressure sensor1facing the inlet101is exposed to the fluid medium M and the pressure P in the mounting bore100, and the end of the pressure sensor1facing away from the inlet101is in an environment0of the container10. Atmospheric pressure prevails in the environment0of the container10. The container10and the pressure sensor1mounted in the mounting bore100form a system1000.

The pressure sensor1comprises a mounting device2and a sensor device3.

The mounting device2is hollow and cylindrical in shape and is made of a resistant metallic material such as a pure metal, a nickel alloy, a cobalt alloy, an iron alloy, etc. The mounting device2may be a hollow mounting screw as known from EP1146326A2. The mounting device2holds the sensor device3. Thus, the mounting device2may hold the sensor device3via a form fit. The mounting device2has an external thread27for fastening in the internal thread107. To mount the pressure sensor1in the mounting bore100, the external thread27is screwed into the internal thread107. This produces clamping forces. The mounting of the pressure sensor1in the mounting bore100is reversible, i.e., the mounted pressure sensor1can be demounted by being screwed in reverse rotation out of the internal thread107via the external thread27.

The sensor device3comprises a diaphragm31and a sensor housing35. The sensor housing35is hollow and desirably cylindrical in shape. The diaphragm31desirably is disc-shaped. The diaphragm31and the sensor housing35desirably are made of a resistant metallic material such as a pure metal, a nickel alloy, a cobalt alloy, an iron alloy, etc. Preferably, the diaphragm31and the sensor housing35are joined together by a material bond. In the longitudinal section ofFIG.1, the material bond is formed as a weld seam41extending 360° around the longitudinal axis103.

The diaphragm31of the pressure sensor1mounted in the mounting bore100is the end of the pressure sensor1facing the inlet101. Thus, the diaphragm31is configured and disposed to be in direct contact with the fluid medium M of the mounting bore100.

The side of the diaphragm31facing the inlet101is located in the transverse plane104. The transverse plane104confines the sensor device3of the pressure sensor1mounted in the mounting bore100in the direction towards the inlet101. In the longitudinal section ofFIGS.1to3, the mounting bore100is located above the transverse plane104in the axial direction, and the components of the sensor device3are located below the transverse plane104in the axial direction.

The side of the diaphragm31facing the inlet101is located in the transverse plane104. The transverse plane104confines the sensor device3of the pressure sensor1mounted in the mounting bore100in the direction towards the inlet101. In the longitudinal section ofFIGS.1to3, the mounting bore100is located above the transverse plane104in the axial direction, and the components of the sensor device3are located below the transverse plane104in the axial direction.

The sensor device3comprises a sensor element33. The sensor element33serves to generate a measurement signal for the pressure P to be measured. The sensor element33is arranged in the recess30. The sensor element33may be a piezoelectric sensor element or a piezoresistive sensor element.

The pressure P acts on the sensor element33via the diaphragm31. The diaphragm31is thin in certain areas and deformable. The diaphragm31comprises a punch36, a joint39and a flange40as shown inFIG.1. In the area of the longitudinal axis103, the diaphragm31is formed as a punch36. Said punch36serves for the uniform introduction of the pressure5to be measured into the sensor element33. For this reason, the punch36forms a material thickening in the axial direction, thereby compensating for pressure peaks acting locally on the diaphragm31on the way to the sensor element33. In the radial direction, the punch36transitions into the joint39. The joint39is configured to allow the diaphragm31to deform. Therefore, the joint39is formed as a thinning of material in the axial direction. The joint39may have a thickness of less than 200 μm in the axial direction. The joint39is arranged at a constant radial distance from the longitudinal axis103and extends 360° around the punch36at this radial distance. In the radial direction, the joint39transitions into the flange40in its region facing away from the punch36. At the flange40, said weld seam41with the sensor housing35is welded. Therefore, the flange40forms a material thickening in the axial direction. The flange40may have a thickness of more than 2 mm in the axial direction. Thus, the flange40is an order of magnitude thicker in the axial direction than the joint39. As a result, the flange40has a thickness comparable to that of the sensor housing35, whereby when welding said weld seam41, the flange40and the sensor housing35absorb equal amounts of heat, and accordingly there is no excessive heating of either of these components of the sensor arrangement3. Excessive heating of these components during welding would be detrimental to the life of the weld seam41.

The sensor element33is arranged on the side of the diaphragm31facing away from the inlet101on the longitudinal axis103on the punch36. Under the effect of the pressure P, the diaphragm31deforms in the area of the joint39, thereby the punch36presses in the axial direction on the sensor element33. During this deformation, the joint39is supported on the sensor housing35via the flange40.

The sensor element33is configured to generate a measurement signal for a pressure-dependent deformation of the diaphragm31. The measurement signal is proportional to the acting pressure P. The piezoelectric sensor element generates an electric charge quantity as the measurement signal. The piezoresistive sensor element generates an electrical voltage as the measurement signal.

The pressure sensor1comprises a hollow cylindrical sealing element5. The sealing element5of the pressure sensor1mounted in the mounting bore100serves to prevent fluid medium M from escaping from the container10into the environment0of the container10via the mounting bore100. The sealing element5is arranged on the side of the diaphragm31facing the inlet101on the longitudinal axis103between the sensor device3and the wall11. As shown inFIG.1for example, the sealing element5comprises a feed50in the region of the longitudinal axis103. Said feed50is a through hole. The feed50extends in the axial direction from the inlet101to the diaphragm31. Fluid medium M passes from the inlet101to the diaphragm31via the feed50. The sealing element5is made of resistant, metallic material such as a pure metal, a nickel alloy, a cobalt alloy, an iron alloy, etc.

The sensor device3permanently holds the sealing element5by form fit. For this purpose, the sensor device3comprises a socket34and the sealing element5comprises a trunnion54. The trunnion54confines the sealing element5in the direction of the sensor device3. The trunnion54is inserted into the socket34in the axial direction.

Preferably, said socket34is formed in the flange40. In the radial direction, the socket34is formed in the flange40outside of the punch36. In the axial direction, the socket34is formed below the transverse plane104. Said socket34is arranged in the flange40at a constant radial distance from the longitudinal axis103and extends 360° around the diaphragm31at this radial distance.

Preferably, socket34is groove-shaped, comprising a sensor device installation37, a socket base38, and a sensor device surface32. The socket base38is formed outside of the sensor device installation37in the radial direction, and said sensor device surface32is formed outside of the socket base38in the radial direction. In the longitudinal section ofFIGS.1to3, the socket base38has the shape of a circular arc of 135°+/−10°. An end of the socket base38that is radially inward with respect to the longitudinal axis103passes into the sensor device installation37, and an end of the socket base38that is radially outward with respect to the longitudinal axis103passes into the sensor device surface32. The sensor device installation37extends substantially parallel to the longitudinal axis103, and the sensor device surface32is conical. The sensor device surface32extends at an angle of 45°+/−10° with respect to the longitudinal axis103.

The trunnion54is formed on the sealing element5in the radial direction outside of the feed50. Said trunnion54is arranged at a constant radial distance from the longitudinal axis103and preferably extends 360° around the feed50at this radial distance.

The trunnion54preferably comprises a sealing element installation57, a trunnion head58, and a first sealing element surface52. The trunnion head58is formed outside of the sealing element installation57in the radial direction, and the first sealing element surface52is formed outside of the trunnion head58in the radial direction. In the longitudinal section ofFIGS.1to3, the trunnion head58has the shape of a circular arc of 135°+/−10°. An end of the trunnion head58that is radially inward with respect to the longitudinal axis103passes into the sealing element installation57, and an end of the trunnion head58that is radially outward with respect to the longitudinal axis103passes into the first sealing element surface52. The sealing element installation57extends substantially parallel to the longitudinal axis103, and the first sealing element surface52is conical. The first sealing element surface52extends at an angle of 45°+/−10° to the longitudinal axis103.

The sealing element installation57and the sensor device installation37serve as guide means during insertion of the trunnion54into the socket34. For this purpose, the sealing element installation57and the sensor device installation37abut against each other in a planar manner in the longitudinal section ofFIGS.1to3.

Compared to the material of the diaphragm31, the material of the sealing element5has a lower compressive strength, which means that the material tends to be less resistant to compressive forces. Also, the geometries of the interacting components of the sealing element5and the diaphragm31are selected in such manner that the geometry of the trunnion head58resists deformation less than the geometry of the socket base38and that the geometry of the first sealing element surface52resists deformation less than the geometry of the sensor device surface32.

Thus, said trunnion head58is deformable. In the longitudinal section ofFIGS.1and2, an undeformed trunnion head58is inserted into the socket34, and there is a trunnion head offset51between the trunnion head58and the socket base38according toFIG.2. The trunnion head58of the trunnion54inserted into the socket34is located below the transverse plane104in the axial direction. The trunnion head offset51is a gap where the undeformed trunnion head58does not abut against the socket base38in a planar manner. Only after deformation of the undeformed trunnion head58into a deformed trunnion head58′ according toFIG.3, does the deformed trunnion head58′ abut against the socket base38in a planar manner. The force required to form the deformed trunnion head58′ is generated during mounting of the pressure sensor1. Advantageously, the force is generated by screwing the pressure sensor1via the external thread27into the internal thread107. The deformed trunnion head58′ is plastically deformed, i.e., its deformation is not reversible; when the pressure sensor1is demounted, the deformation of the deformed trunnion head58′ persists. The deformed trunnion head58′ forms a permanent form fit with the socket base38, which form fit can only be separated again by damaging or destroying the trunnion head58and the socket base38.

The first sealing element surface52and the sensor device surface32form a first seal5′ of the mounting bore100with respect to the mounting gap102, to prevent fluid medium M from escaping from the mounting bore100through the feed line50to the mounting gap102into the environment0of the container10. The first sealing element surface52is also deformable. In the longitudinal section ofFIGS.1and2, an undeformed first sealing element surface52and the sensor device surface32are in contact with each other, and there is a first angular offset53between the undeformed first sealing element surface52and the sensor device surface32according toFIG.2. The first angular offset53is a gap where the undeformed first sealing element surface52does not abut against the sensor device surface32in a planar manner. Only after deformation of the undeformed first sealing element surface52into a deformed first sealing surface52′ according toFIG.3, does the deformed first sealing element surface52′ abut against the sensor device surface32in a planar manner and form the first seal5′. The deformation of the undeformed first sealing element surface52occurs in situ, and the deformable first sealing element surface52thus adapts exactly to the shape of the sensor device surface32. The force required to form the deformed first sealing element surface52′ is generated during mounting of the pressure sensor1. Advantageously, the force is generated by screwing the pressure sensor1via the external thread27into the internal thread107. The deformed first sealing element surface52′ is plastically deformed, i.e., its deformation is not reversible. Thus, when the pressure sensor1is unscrewed from the internal thread107via the external thread27, the deformation of the deformed first sealing element surface52′ persists.

The sealing element5comprises a second sealing element surface56. The second sealing element surface56confines the sealing element5in a direction towards the wall11. The second sealing element surface56cooperates with the wall surface106. The second sealing element surface56and the wall surface106are conical. The second sealing element surface56and the wall surface106form a second seal5″ of the mounting bore100with respect to the mounting gap102, to prevent fluid medium M from escaping from the mounting bore100to the mounting gap102into the environment0of the container10.

The second sealing element surface56is also deformable. In the longitudinal section ofFIGS.1and4, an undeformed second sealing element surface56and the wall surface106abut against each other, and there is a second angular offset55between the undeformed second sealing element surface56and the wall surface106according toFIG.4. The second angular offset55is a gap where the undeformed second sealing element surface56does not abut against the wall surface106in a planar manner. Only after deformation of the undeformed second sealing element surface56into a deformed second sealing element surface56′ according toFIG.5, does the deformed second sealing element surface56′ abut against the wall surface106in a planar manner and form the second seal5″. The deformation of the undeformed second sealing element surface56takes place in situ, and the deformable second sealing element surface56thus exactly adapts to the shape of the wall surface106. The force required to form the deformed second sealing element surface56′ is generated during mounting of the pressure sensor1. Advantageously, the force is generated by screwing the pressure sensor1via the external thread21into the internal thread107. The deformed second sealing element surface56′ is plastically deformed, i.e., its deformation is not reversible. Thus, after the pressure sensor1has been unscrewed from the internal thread107via the external thread27, the deformation of the deformed second sealing element surface56′ persists.

The flange40also absorbs clamping forces K, which clamping forces K are generated when the pressure sensor1is mounted in the mounting bore100and which clamping forces K act on the flange40via the trunnion54as schematically shown inFIG.1. In the longitudinal section ofFIG.1, the clamping forces act from the wall surface106of the wall11onto the second sealing element surface56of the sealing element5and are conducted in the sealing element5to the trunnion54.

LIST OF REFERENCE NUMERALS