Pressure transmitter

Abstract

The utility model discloses a pressure transmitter which comprises a liquid receiving assembly, a sensing module assembly and an upper cover assembly. The sensing module assembly comprises a diaphragm base which is connected with the liquid receiving assembly and is suitable for installing a diaphragm; the cavity mounting seat is fixedly connected with the diaphragm base to form a mounting inner cavity; the sensor mounting seat is arranged in the mounting inner cavity; the sensor pressing and holding piece is propped against the sensor mounting seat so as to generate an axial pressing force on the pressure sensor; the sensor hold-down component is provided with a rotation stopping structure, and the rotation stopping structure and a limiting structure arranged on the diaphragm base form constraint fit. According to the pressure transmitter provided by the utility model, through the innovatively designed rotation stopping structure, the installation position of the pressure sensor is prevented from deviating due to torsion transmission during assembly or use, so that the connectivity of the diaphragm and the pressure sensor is prevented from being influenced, and finally, the measurement precision and the long-term reliability are remarkably improved.

Description

Technical Field

[0001] This utility model belongs to the field of instrumentation technology, specifically relating to a pressure transmitter. Background Technology

[0002] Pressure transmitters, as important sensors in industrial automation, are widely used in various industries such as petrochemicals, power, metallurgy, pharmaceuticals, food, and water treatment. They can be used to accurately measure the pressure of liquids, gases, or steam. Their basic function is to convert the sensed pressure signal into a corresponding electrical signal output (such as a 4-20mA current signal or a 1-5V voltage signal), which can be remotely transmitted to the control system to achieve real-time monitoring and control of pressure parameters during production.

[0003] However, in practical use, pressure transmitters have an unresolved problem: misalignment may occur between the diaphragm and the sensor. This misalignment can directly affect the accuracy of pressure measurement, leading to deviations in pressure control throughout the production process, impacting product quality and production safety, and potentially causing economic losses and risks. Utility Model Content

[0004] This invention aims to solve the problem of poor reliability in existing pressure transmitters caused by assembly stress leading to displacement or damage of the sensitive element. It can resist the possible displacement between the diaphragm and the sensor, thereby ensuring measurement accuracy.

[0005] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:

[0006] A pressure transmitter includes a liquid-receiving assembly, a sensing module assembly, and a top cover assembly. The sensing module assembly includes: a diaphragm base connected to the liquid-receiving assembly and adapted to mount a diaphragm sheet; a cavity mounting base fixedly connected to the diaphragm base to form an mounting cavity; a sensor mounting base disposed within the mounting cavity; and a sensor holding member abutting against the sensor mounting base to generate an axial clamping force on the pressure sensor. The sensor holding member is provided with an anti-rotation structure, which forms a constraint fit with a limiting structure disposed on the diaphragm base.

[0007] The pressure transmitter described above includes a pressure ring as the sensor holding member; the pressure ring is provided with at least one lug in the circumferential direction as the anti-rotation structure; the diaphragm base is provided with a limiting groove corresponding to the lug.

[0008] In the aforementioned pressure transmitter, the contact surface between the anti-rotation structure and the limiting structure is provided with an elastic buffer layer.

[0009] In the aforementioned pressure transmitter, the mounting cavity is threadedly connected to the sensor mounting base and the diaphragm base, respectively; the common contact surface of the sensor holder, the diaphragm base, and the mounting cavity adopts a conical sealing structure without a sealing ring, thereby forming a slope seal.

[0010] The pressure transmitter described above includes the following liquid-welding assembly: a connecting pipe, which is thermally fused to the diaphragm base; a beaded connector, which is pressed into the inner wall of the connecting pipe through interference fit and expands the connecting pipe to form a seal; and a female nut, which is fitted onto the outside of the connecting pipe.

[0011] The pressure transmitter described above includes the following upper cover assembly: an upper cover fixedly connected to the cavity mounting base; a sealing nut sleeved on the outer end of the upper cover to form a housing seal; a sealing plug disposed between the upper cover and the sealing nut to form a line seal with the opening of the upper cover; and the sealing plug is hollow and together with the opening of the upper cover to form a lead wire channel.

[0012] In the aforementioned pressure transmitter, a control circuit board is fixedly connected above the sensor mounting base and connected to external leads via the lead wire channel; the pressure sensor and the control circuit board have a pre-set distance reserved for soldering pin space, and a pre-set distance reserved for lead wire space with the sensor base.

[0013] In the aforementioned pressure transmitter, the cavity mounting base and the upper cover are respectively provided with guide grooves and protrusions suitable for installation guidance at the docking assembly point; the cavity mounting base and the upper cover are sealed together by a sealing ring.

[0014] To achieve the above objectives, another specific embodiment of this utility model provides the following technical solution:

[0015] A pressure transmitter includes a liquid-receiving assembly, a sensing module assembly, and a top cover assembly. The sensing module assembly includes: a diaphragm base connected to the liquid-receiving assembly and adapted to mount a diaphragm sheet; a cavity mounting seat fixedly connected to the diaphragm base to form an mounting cavity; and a sensor mounting seat disposed within the mounting cavity, adapted to generate an axial clamping force on a pressure sensor. The sensor mounting seat has an anti-rotation structure at its contact end with the diaphragm base, and forms a constraint fit with a limiting structure disposed on the diaphragm base.

[0016] To achieve the above objectives, the technical solution provided by another specific embodiment of this utility model is as follows:

[0017] A pressure transmitter includes a liquid-receiving assembly, a sensing module assembly, and a top cover assembly. The sensing module assembly includes: a diaphragm base connected to the liquid-receiving assembly and adapted to mount a diaphragm sheet; a cavity mounting base fixedly connected to the diaphragm base to form an mounting cavity; a sensor mounting base disposed within the mounting cavity; and a sensor holding member abutting against the sensor mounting base to generate an axial clamping force on the pressure sensor. The contact surface between the sensor holding member and the diaphragm base is coated with a friction coating or an adhesive coating.

[0018] Compared with the prior art, the pressure transmitter of this utility model has an innovative anti-rotation structure to prevent the installation position of the pressure sensor from shifting due to torque transmission during assembly or use, which would affect the connection between the pressure sensor and the diaphragm, thereby significantly improving measurement accuracy and long-term reliability.

[0019] Furthermore, in the sensing module assembly, by setting a sensor holding member with a lug anti-rotation structure and a limiting groove on the diaphragm base, the transmission path of the installation torque to the pressure sensor is effectively blocked, and it is easy to manufacture and assemble.

[0020] Furthermore, after the lug is embedded in the limiting groove, the elastic buffer layer added to the contact surface not only eliminates the assembly gap but also absorbs residual stress, ensuring that the installation stress is only converted into axial clamping force acting on the sensor, thus avoiding the risk of adhesive layer deformation caused by traditional threaded connections.

[0021] Meanwhile, this solution employs a beveled sealing design, replacing traditional O-rings with a precision-machined conical contact interface to create a sealing system between the diaphragm base, sensor holder, and cavity mounting base. This design not only eliminates the risk of rubber aging failure, but its self-compensating characteristics also adapt to material thermal deformation under harsh operating conditions, ensuring low leakage rate and sealing performance under high operating pressure. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is an exploded view of a pressure transmitter in one embodiment of the present invention;

[0024] Figure 2 for Figure 1 A cross-sectional view of the pressure transmitter in the illustrated embodiment;

[0025] Figure 3 for Figure 1 A schematic diagram of the internal structure of the pressure transmitter in the illustrated embodiment.

[0026] Figure 4 for Figure 1 The diagram shown is a partially enlarged view of the contact surfaces of the diaphragm base, the cavity mounting base, and the sensor holder in the embodiment shown. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0028] The terms "coupled," "connected," or "linked" in this specification include both direct and indirect connections. Indirect connections are those made through an intermediate medium, such as those made through an electrically conductive medium, which may have parasitic inductance or capacitance. Indirect connections may also include connections made through other active or passive devices to achieve the same or similar functional purpose, such as connections through switches, follower circuits, or other circuits or components. Furthermore, in this specification, terms such as "first" and "second" are primarily used to distinguish one technical feature from another, and do not necessarily require or imply any actual relationship, quantity, or order between these technical features.

[0029] In the detailed description of this specification, reference is made to the accompanying drawings, which form a part thereof, wherein like reference numerals always denote like parts, and wherein exemplary embodiments are shown by way of example that may be implemented. It should be understood that other embodiments may be utilized, and structural or logical changes may be made, without departing from the scope of this application. Therefore, the following detailed description should not be considered limiting.

[0030] The various operations in the specification may be described sequentially as multiple discrete actions or operations in a manner most conducive to understanding the claimed subject matter. However, the order of description should not be construed as implying that these operations must be sequentially related. Specifically, these operations may not be performed in the order presented. The described operations may be performed in a different order than in the described embodiments. Various additional operations may be performed in additional embodiments and / or the described operations may be omitted.

[0031] For the purposes of this application, the phrase "A and / or B" means (A), (B), or (A and B). For the purposes of this application, the phrase "A, B and / or C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

[0032] Various components and devices may be mentioned or shown in the singular form herein, but only for the convenience of discussion, and any element mentioned in the singular form may include multiple such elements as taught herein.

[0033] The description uses the phrases "in one embodiment," "in other embodiments," or "in some embodiments," each of which may refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," etc., used in relation to embodiments of this application are synonymous.

[0034] like Figure 1 As shown, the pressure transmitter of this utility model has an overall structure including a liquid-receiving assembly 1, a sensing module assembly 2, and a top cover assembly 3. The liquid-receiving assembly 1 includes a beaded connector 11, a connecting pipe 12, and a female nut 13; the sensing module assembly 2 includes a diaphragm base 21, a sensor 22, a sensor holder 23, a sensor mounting base 24, a control circuit board 25, and a cavity mounting base 26; the top cover assembly 3 includes a top cover 31, a sealing nut 32, and a sealing plug 33.

[0035] In practical implementation, the bead insert 11 can be pressed into the inner wall of the PFA connecting pipe 12 through interference fit, thereby opening the connecting pipe 12 to form a seal. The interference amount is controlled to be a suitable proportion to the inner diameter of the pipe to ensure sealing while avoiding material damage.

[0036] In practice, the connecting pipe 12 is glued to the diaphragm base 21 and then fixed by hot-melt welding. The welding end face is provided with an annular boss (not shown in the figure). The inner and outer diameter tolerances and welding allowance of the welding boss are controlled within a preset range. After welding, a permanent seal is achieved with the PFA connecting pipe 12 through hot-melt welding, ensuring no leakage of the medium.

[0037] In practical implementation, the liquid-contacting component 1, as the part that may come into contact with the measured medium, is usually made of the aforementioned fluoropolymer material (Perfluoroalkoxy, PFA) to give it excellent high-temperature resistance and excellent corrosion resistance. Other non-liquid-contacting parts, such as the sensor module component 2 and the top cover component 3, can be made of optional fluoropolymer material (Polyvinylidene Fluoride, PVDF) to give it high mechanical strength, good electrical insulation and corrosion resistance.

[0038] In this application, the core feature of the sensing module assembly 2 lies in the design of blocking the stress transmission path. Currently, the pressure sensor 22 and the diaphragm (not shown in the figure) are typically connected and fixed by a layer of filler. However, in the installation of related components, the mounting cavity of the cavity mount 26 is currently mostly fixed to the sensor mount 24, the diaphragm base 21, and the PCB circuit control board 25 via threaded connections. The applicant has discovered that excessive installation torque may be transmitted to the pressure sensor 22, causing the filler between the pressure sensor 22 and the diaphragm to tear and break, disrupting the connection between them and thus affecting the measurement. Therefore, in specific implementation, a sensor holding member 23 is provided between the sensor mounting base 24 and the diaphragm base 21. The sensor holding member 23 is provided with an anti-rotation structure, which can cooperate with the corresponding limiting structure provided on the diaphragm base 21 to form a constraint, so as to avoid the torque transmission caused by the installation of the sensor mounting base 24, which would result in torque on the pressure sensor 22. When the bottom plane of the sensor mounting base 24 presses on the sensor holding member 23, the pressure sensor 22 can be pressed by the sensor holding member 23 with axial clamping force.

[0039] Specifically, the sensor holder 23 is a pressure ring structure. An extension section is provided at the upper end of the pressure ring, which can contact and press the pressure sensor 22, forming a mounting position for the pressure sensor 22. Furthermore, as... Figure 1 and Figure 3 As shown, at least one lug 231 is provided in the circumferential direction of the pressure ring as an anti-rotation structure, and a limiting groove corresponding to the lug 231 is provided on the diaphragm base 21. When the sensor holder 23 is assembled with the diaphragm base 21, the lug 231 is placed into the limiting groove to achieve a stable connection between the sensor holder 23 and the diaphragm base 21, preventing relative sliding between the two. Thus, when the cavity mounting base 26, sensor mounting base 24, diaphragm, and PCB control circuit board 25 are installed, even if there is stress transmission, only a downward axial clamping force will be generated on the pressure sensor 22, ensuring that the pressure transmitter 22 and the diaphragm remain stably installed. While ensuring smooth assembly, it can also effectively block the transmission of rotational stress.

[0040] To achieve better uniform distribution of contact stress between the pressure ring and the sensor mounting base 24, the lugs 231 can be configured symmetrically, such as in one or more pairs, or in other equally spaced configurations (e.g., 120°). While this embodiment includes an anti-rotation structure outside the pressure ring, which essentially isolates the transmitted torque, gaps between the anti-rotation structure and the limiting structure can cause the torque isolation to fail, transmitting the torque to the pressure sensor 22. Therefore, an elastic buffer layer is provided on the contact surface between the anti-rotation structure (lug 231) and the limiting structure, filling the gap between the lugs 231 and the limiting structure.

[0041] The sensor holder 23 and the sensor mounting base 24 can also be integrally formed. On the one hand, the integrated sensor mounting base 24 is also provided with an extension section that can press the pressure sensor 22 at the installation position of the pressure sensor 22, thus achieving the pressing installation of the pressure sensor 22. On the other hand, the sensor mounting base 24 is also provided with the anti-rotation structure as described above at the contact end with the diaphragm base 21, and forms a constraint cooperation with the limiting structure provided on the diaphragm base 21.

[0042] In specific implementations, the sensor retaining ring can also mate with the diaphragm base 21 without the lug 231. Specifically, a friction coating or an adhesive coating can be applied to the contact surface between the sensor holding component 23 and the diaphragm base. The friction coating can be a coating with a high coefficient of friction or a textured structure. A high coefficient of friction can be a rubber coating, polyurethane coating, etc., which can significantly increase the friction between the two, thereby effectively preventing relative sliding. A textured coating can be a granular coating, a mesh coating, etc., which increases the friction by increasing the microscopic unevenness of the contact surface, and can also prevent relative sliding. Alternatively, a chemical adhesive can be used to form a strong adhesive layer between the retaining ring and the sensor mounting base, making the two tightly bonded together and preventing relative sliding.

[0043] In practical implementation, the pressure transmitter's cavity mounting base 26, diaphragm base 21, and sensor holding member 23 employ a ringless conical surface seal design for their sealing mechanism. Sealing is achieved by constructing mutually mating inclined surface seals at the contact interfaces of these three components. For example... Figure 4 As indicated by the dashed line, the upper contact points of the diaphragm base 21 and the sensor holder 23 form a continuous connecting section. The cavity mounting base 26 is conical at the corresponding assembly position, ensuring a precise fit between the three components. The conical structure is precision machined to ensure that the flatness and angular tolerance of the contact surface are controlled within the micrometer level, ensuring that each component can form a uniform contact force during assembly.

[0044] Compared to traditional O-ring sealing methods, beveled sealing effectively eliminates the risk of failure caused by aging and creep of rubber seals, significantly extending product lifespan. Secondly, the conical sealing structure has self-compensating properties, effectively adapting to material deformation caused by temperature changes and maintaining stable sealing under wide operating conditions. Thirdly, the integrated metal contact interface avoids the structural strength reduction caused by groove machining of the seal ring, improving overall pressure resistance, making it particularly suitable for corrosive media applications.

[0045] The upper cover assembly 3 includes an upper cover 31 fixedly connected to the cavity mounting base 26; a sealing nut 32 sleeved on the outer end of the upper cover 31 to form a shell seal; and a sealing plug 33 disposed between the upper cover 31 and the sealing nut 32. The sealing plug 33 forms a line seal with the opening of the upper cover 31 and is hollow, allowing it to form a lead wire channel together with the opening of the upper cover 31, facilitating lead wire connection and sealing power lines and other leads. The material can be silicone rubber or similar. In terms of assembly sequence, the wiring is first arranged, then the sealing plug 33 is sleeved and the sealing nut 32 is installed, and finally the upper cover 31 is fixedly installed to the cavity mounting base 26 to complete the assembly. A sealing ring 34 is provided between the upper cover 31 and the cavity mounting base 26 to ensure the sealing performance of the assembly. The sealing ring 34 between the upper cover 31 and the cavity mounting base 26 allows for an end face compression ratio of up to 21%. Since the sealing ring 34 does not come into contact with the relevant medium, it can be made of fluorinated synthetic rubber (FKM).

[0046] Assembly is completed by pressing the upper cover 31 into the cavity mounting base 26. In specific implementations, such as... Figure 1 and Figure 3 As shown, at the corresponding mating assembly points of the upper cover 31 and the cavity mounting base 26, the inner cavity of the cavity mounting base 26 is provided with a guide groove 261, and the upper cover 31 is provided with a matching protrusion 311, thus serving as a guide for installation and also preventing rotation. After the upper cover 31 and the cavity mounting base 26 are assembled into place along the guide device, the cavity mounting base 26 and the upper cover 31 are connected and sealed by the sealing ring 34.

[0047] like Figure 1 As shown, a PCB control circuit board 25 is also fixedly connected above the sensor mounting base 24, and external leads are connected via the aforementioned lead channels. The PCB control circuit board 25 can be mounted above the sensor mounting base 24 via copper studs 27. A preset distance is reserved between the pressure sensor 22 and the control circuit board 25, generally allowing for approximately 8-12mm of solder pin space and approximately 20-24mm of lead wire space.

[0048] This utility model's pressure transmitter significantly improves measurement accuracy and long-term reliability through an innovative anti-rotation structure. In the sensing module assembly 2, the sensor holder 23 with its anti-rotation lug 231 and the limiting groove of the diaphragm base 21 are constrained, effectively blocking the transmission path of installation torque to the pressure sensor 22. After the lug 231 is embedded in the limiting groove in an axisymmetric layout, combined with the added elastic buffer layer on the contact surface, it eliminates assembly gaps and absorbs residual stress, ensuring that installation stress is only converted into axial clamping force acting on the pressure sensor 22, avoiding the risk of adhesive layer deformation caused by traditional threaded connections.

[0049] Meanwhile, a beveled sealing design is adopted, replacing the traditional O-ring with a precision-machined conical contact interface to construct a sealing system between the diaphragm base 21, the sensor holder 23, and the cavity mounting base 26. This design not only eliminates the risk of rubber aging failure, but its self-compensating characteristics can also adapt to the thermal deformation of materials under harsh working conditions, ensuring low leakage rate and sealing performance under high working pressure.

[0050] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A pressure transmitter, characterized in that, It includes a liquid-receiving assembly, a sensing module assembly, and a top cover assembly; the sensing module assembly includes: A diaphragm base, connected to the liquid receiving assembly, is suitable for mounting diaphragm sheets; A cavity mounting base is fixedly connected to the diaphragm base to form an installation cavity; A sensor mounting base is disposed within the mounting cavity; The sensor holding member abuts against the sensor mounting base, thereby generating an axial clamping force on the pressure sensor; the sensor holding member is provided with an anti-rotation structure, which forms a constraint cooperation with the limiting structure provided on the diaphragm base.

2. The pressure transmitter according to claim 1, characterized in that, The sensor holding member includes a pressure ring; the pressure ring is provided with at least one lug in the circumferential direction as the anti-rotation structure; The diaphragm base is provided with a limiting groove corresponding to the lug.

3. The pressure transmitter according to claim 1 or 2, characterized in that, The contact surface between the anti-rotation structure and the limiting structure is provided with an elastic buffer layer.

4. The pressure transmitter according to claim 1, characterized in that, The mounting cavity is connected to the sensor mounting base and the diaphragm base respectively via threads; The sensor holder, the diaphragm base, and the mounting cavity share a common contact surface with a conical sealing structure without a sealing ring, thereby forming a sloping seal.

5. The pressure transmitter according to claim 1, characterized in that, The liquid-wetting component includes: The connecting pipe is thermally fused to the diaphragm base; The beaded connector is pressed into the inner wall of the connecting tube through interference fit, and expands the connecting tube to form a seal; The female nut is fitted onto the outside of the connecting pipe.

6. The pressure transmitter according to claim 1, characterized in that, The upper cover assembly includes: The top cover is fixedly connected to the cavity mounting base; A sealing nut is fitted onto the outer end of the upper cover to form a housing seal. A sealing plug is disposed between the upper cover and the sealing nut, forming a line seal with the opening of the upper cover; and the sealing plug is hollow, forming a lead wire channel together with the opening of the upper cover.

7. The pressure transmitter according to claim 6, characterized in that, The control circuit board is fixedly connected to the top of the sensor mounting base and is connected to external leads via the lead channel; The pressure sensor has a pre-set distance between its soldering pins and the control circuit board, and a pre-set distance between its lead wires and the sensor base.

8. The pressure transmitter according to claim 6, characterized in that, The cavity mounting base and the upper cover are respectively provided with guide grooves and protrusions suitable for installation guidance at the docking assembly point; the cavity mounting base and the upper cover are sealed and connected by a sealing ring.

9. A pressure transmitter, characterized in that, It includes a liquid-receiving assembly, a sensing module assembly, and a top cover assembly; the sensing module assembly includes: A diaphragm base, connected to the liquid receiving assembly, is suitable for mounting diaphragm sheets; A cavity mounting base is fixedly connected to the diaphragm base to form an installation cavity; A sensor mounting base is disposed within the mounting cavity and is adapted to generate an axial clamping force on the pressure sensor; the sensor mounting base has an anti-rotation structure at the contact end with the diaphragm base, and forms a constraint fit with the limiting structure disposed on the diaphragm base.

10. A pressure transmitter, characterized in that, It includes a liquid-receiving assembly, a sensing module assembly, and a top cover assembly; the sensing module assembly includes: A diaphragm base, connected to the liquid receiving assembly, is suitable for mounting diaphragm sheets; A cavity mounting base is fixedly connected to the diaphragm base to form an installation cavity; A sensor mounting base is disposed within the mounting cavity; The sensor holding member abuts against the sensor mounting base, thereby generating an axial clamping force on the pressure sensor; the contact surface between the sensor holding member and the diaphragm base is coated with a friction coating or an adhesive coating.

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