Display assembly explosion-proof sealing structure of temperature transmitter with digital display function

Abstract

The application relates to the technical field of temperature transmitters, in particular to a display assembly explosion-proof sealing structure of a temperature transmitter with digital display function, which comprises a shell, a glass window embedded in the front end opening of the shell and a pressing ring screw-connected to the front end of the shell, the inner wall of the front end opening of the shell is sequentially provided with an internal thread section, a first inner taper surface and a step surface from outside to inside, and the small end of the first inner taper surface is located on the inner side. The application realizes full-circle rigid constraint of the sealing ring through the annular sealing limiting groove, avoids the creep overflow and shear tearing of the sealing ring under long-term working conditions from the root, guarantees the long-term stability and explosion-proof reliability of the static sealing of the digital display area, realizes the automatic temperature difference compensation of the axial compression force of the glass window through the elastic sleeve with spring claws and the taper surface cooperation structure, always maintains the uniform compression of the glass window installation interface, and avoids the sealing gap exceeding the standard problem caused by the difference of linear expansion coefficients of heterogeneous materials.

Description

Technical Field

[0001] This invention relates to the field of temperature transmitter technology, specifically to an explosion-proof sealing structure for the display component of a temperature transmitter with digital display function. Background Technology

[0002] Mainstream temperature transmitters with digital display functions generally use mechanically clamped explosion-proof sealing covers as a protective barrier for the display components. The cover structure typically consists of a housing, a stepped mounting hole at the front end of the housing, a glass window embedded in the stepped hole, and a pressure ring tightened onto the housing by a threaded pair. Flat rubber sealing gaskets are clamped on both sides of the glass window. The axial tightening force of the pressure ring causes the gaskets to undergo elastic deformation, thereby simultaneously meeting the explosion-proof clearance requirements and process sealing requirements on site.

[0003] Although the mechanically pressed explosion-proof sealing cover has a mature design, the petrochemical environment is mostly open-air with large temperature differences between day and night. The linear expansion coefficients of the shell and the glass window are significantly different. During the frequent high and low temperature cycles of thermal expansion and contraction, the rubber sealing gaskets on both sides are easily subjected to non-uniform shear stress, which can cause creep or cracking. Once rainwater, salt spray or corrosive gases seep into the internal display cavity through tiny gaps, condensation and frost will form on the inside of the glass window, blurring the view, or even directly causing a short circuit and burning of the internal digital display circuit board.

[0004] To address the aforementioned issues, existing technologies offer several solutions. For example, injecting a fully sealed explosion-proof epoxy resin sealant between the glass window and the stepped surface of the housing can completely replace some gaskets to enhance sealing. While this method is initially effective, the stress between the dissimilar materials cannot be released, making the epoxy resin layer prone to microscopic peeling and cracking under temperature shocks. Furthermore, the cured rigid sealant layer directly transmits the thermal expansion and contraction stress of the housing to the brittle tempered glass edges, easily leading to stress concentration and localized breakage of the glass window. Another approach involves increasing the axial clamping force to forcibly compress the elastic gasket, or using multi-layer composite gaskets to attempt to improve the initial sealing level. However, the elastic deformation of rubber has its limits; excessive axial clamping force can cause permanent plastic deformation of the gasket, resulting in a loss of resilience. Moreover, excessive installation stress itself increases the risk of the glass window shattering entirely upon external mechanical impact, failing to achieve long-term stability in explosion-proof and sealing performance.

[0005] Therefore, there is an urgent need for an explosion-proof sealing structure for the display component of a temperature transmitter with digital display function, which can solve the problems of seal failure and glass damage caused by vibration loosening and temperature difference stress while ensuring long-term and high-level explosion-proof performance, so as to meet the sealing requirements of the petrochemical industry for long-term and high-reliability operation of instruments. Summary of the Invention

[0006] The purpose of this invention is to provide an explosion-proof sealing structure for the display component of a temperature transmitter with digital display function, so as to solve the problem mentioned in the background art that the existing explosion-proof sealing structure is prone to sealing failure at the joint surface between the transparent window and the housing due to the influence of temperature difference stress.

[0007] To achieve the above objectives, the present invention provides the following technical solution: An explosion-proof sealing structure for the display component of a temperature transmitter with digital display function includes a housing, a glass window embedded in the front opening of the housing, and a pressure ring threaded to the front end of the housing. The inner wall of the front opening of the housing is sequentially provided with an internal thread section, a first inner conical surface, and a stepped surface from the outside in. The small end of the first inner conical surface is located on the inner side. A sealing ring is laid flat on the stepped surface. The rear end face of the glass window is in contact with the sealing ring. The outer circumferential side of the glass window is provided with a surface corresponding to the first inner conical surface. The first outer conical surface fits into the glass window; a sleeve is sandwiched between the pressure ring and the glass window, the sleeve includes a top fixing ring, a middle elastic zone and a bottom conical ring, the top fixing ring is rigidly abutting against the rear end face of the pressure ring, the middle elastic zone has multiple axial hollow grooves evenly distributed along the circumferential direction, the axial hollow grooves divide the middle elastic zone into multiple spring claws, the rear end face of the bottom conical ring is provided with a second outer conical surface, and the front end edge of the glass window is provided with a second inner conical surface that fits into the second outer conical surface.

[0008] By creating axially hollowed-out grooves in the middle elastic zone to separate multiple spring claws, and cooperating with the No. 1 inner conical surface, No. 1 outer conical surface, No. 2 inner conical surface, and No. 2 outer conical surface, when the environment experiences drastic temperature fluctuations, the radial shear expansion stress between the shell and the glass window, which are dissimilar materials, is converted into a slight axial displacement of the glass window. This axial displacement pushes the bottom conical ring upwards, causing the circumferentially distributed spring claws to produce a large-stroke axial elastic bending. This long-stroke elastic deformation actively eliminates the temperature difference stress, thereby solving the problem of glass brittle fracture caused by stress concentration due to thermal expansion and contraction. At the same time, the compressed spring claws continuously accumulate and release a persistent and constant axial reverse elastic force, which is transmitted downwards through the No. 2 outer conical surface and the glass window to the bottom sealing ring in real time. Even if the sealing ring experiences slight material creep or thinning due to cold flow under long-term operating conditions, the stored elastic force of the spring claws can immediately compensate, ensuring that the bottom process static seal does not fail under alternating temperature environments.

[0009] Preferably, an annular sealing and limiting groove is formed on the stepped surface of the housing, the sealing ring is embedded in the annular sealing and limiting groove, and the axial thickness of the sealing ring before being compressed is greater than the axial depth of the annular sealing and limiting groove.

[0010] By creating an annular sealing and limiting groove on the stepped surface of the housing and embedding the sealing ring therein, since the axial thickness of the sealing ring before being compressed is greater than the axial depth of the annular sealing and limiting groove, when the sealing ring is subjected to axial tightening force through the glass window at the lower end face of the sleeve, the interference part of the sealing ring that protrudes above the groove opening first undergoes elastic compression deformation until the rear end face of the glass window and the stepped surface of the housing achieve rigid limiting fit. At this time, the annular sealing and limiting groove forms a completely closed receiving cavity at the bottom of the glass window, locking the elastic deformation of the sealing ring in the groove, providing a rigid mechanical boundary constraint around the sealing ring, effectively preventing the sealing ring from radially extruding, mechanically flowing or creeping out in harsh petrochemical environments, ensuring the long-term geometric stability and long-term explosion-proof sealing performance of the static process seal at the bottom of the display component.

[0011] Furthermore, when the temperature transmitter is in a field environment with alternating high and low temperatures, the radial shear stress generated by the thermal expansion and contraction of the outer casing will be preferentially absorbed and blocked by the rigid groove wall of the annular sealing limiting groove. This avoids the thermal stress directly acting on the deformation core area of ​​the sealing ring, effectively preventing the sealing ring from generating micro-gaps due to shear tearing. At the same time, the rigid support of the annular sealing limiting groove and the interference elastic deformation of the sealing ring work together to ensure that the center of the glass window is aligned during the reset process after axial slip compensation. This prevents the glass window from radially shifting or abnormally eccentric shaking during movement, thus maintaining a flexible and long-lasting static seal while ensuring the circumferential uniformity and explosion-proof dimensional accuracy of the gap between the heterogeneous explosion-proof joint surfaces.

[0012] Preferably, each of the spring claws has a stress relief hole at the root near the top fixing ring, and the stress relief hole is connected to a corresponding axial hollow groove.

[0013] By creating stress relief holes at the root of each spring claw near the top fixing ring, and connecting these holes to adjacent axial perforated slots, when the temperature transmitter is subjected to extreme temperature difference impact conditions in a petrochemical environment, the adaptive displacement and sliding of the glass window along the axial direction will push upwards the bottom conical ring of the sleeve, thereby forcing the circumferentially distributed spring claws to undergo axial elastic bending deformation. During this process, because the stress relief holes are connected to the axial perforated slots, a smooth arc-shaped geometric edge is artificially constructed at the mechanical root of the cantilever structure. This allows the local shear stress and bending stress, which would normally easily accumulate at the rigid root interface of the spring claw, to be evenly dispersed and guided along the circumferential direction of the arc-shaped hole wall of the stress relief holes. This eliminates the stress concentration phenomenon caused by sudden deformation or alternating temperature difference stress at the root, effectively preventing microscopic metal fatigue cracking or rigid fracture at the root of the spring claw during long-term alternating deformation, and improving the overall mechanical service life of the elastic sleeve.

[0014] Furthermore, when facing long-term high-frequency, low-amplitude mechanical resonance generated by petrochemical pipelines and pumps, the interconnected perforated network formed by the stress relief holes and adjacent axial perforated grooves can effectively reduce the overall axial and circumferential stiffness of the elastic zone in the middle section of the casing, giving it excellent mechanical damping and self-absorbing vibration characteristics. It can convert the alternating energy of high-frequency, low-amplitude vibrations transmitted from the outside into micro-amplitude elastic creep of the hole wall and digest it, avoiding the rigid transmission of resonance energy to the top thread pair and causing the pressure ring to loosen. At the same time, the interconnected design of the stress relief holes and axial perforated grooves not only facilitates integrated forming by stamping or wire cutting in the processing technology, reducing the residual micro-burrs at the edge of the stress holes, but also ensures the absolute consistency of the mechanical elastic coefficient of each spring claw in the circumferential direction. This ensures that the multi-point clamping force of the casing always maintains circumferential symmetry and force balance when transmitting elastic force downwards, further ensuring that the glass window is subjected to uniform force and is not prone to local breakage.

[0015] Preferably, the front end face of the top fixing ring is provided with a plurality of axial anti-slip protrusions arranged in an alternating pattern, and the rear end face of the pressure ring is provided with anti-slip grooves that are matched and engaged with the axial anti-slip protrusions one by one.

[0016] By circumferentially interlacing multiple axial anti-slip protrusions on the front end face of the top fixing ring and anti-slip grooves on the rear end face of the pressure ring, during the process of tightening the pressure ring thread to the front end of the housing, the anti-slip grooves and axial anti-slip protrusions successively engage axially and mechanically. When the temperature transmitter is under severe low-frequency resonance or high-pressure medium pulsation conditions in a petrochemical site, external mechanical vibration attempts to induce a slight circumferential rotation and loosening of the threaded pair between the pressure ring and the housing. At this time, due to the rigid circumferential limiting effect between the axial anti-slip protrusions and the anti-slip grooves, the relative circumferential sliding between the pressure ring and the sleeve is cut off, and the circumferential self-loosening stress tendency of the pressure ring is rigidly and non-destructively converted into torsional shear damping in the elastic zone of the middle section of the sleeve. Due to the reverse circumferential torque, the internal stress of each spring claw will generate reverse locking frictional resistance, thereby preventing the pressure ring from loosening and the fastening force from weakening due to long-term strong vibration.

[0017] Furthermore, the individual matching and locking of the axial anti-slip protrusions and anti-slip grooves ensures that the axial tightening torque applied by the pressure ring can be transmitted to the top retaining ring and then evenly distributed from the top retaining ring to each of the lower spring claws. This avoids the problem of axial clamping force eccentricity caused by uneven local friction coefficients in traditional planar friction contact. At the same time, when the circumferential resonant torque is transmitted to the root of the spring claw through the anti-slip protrusions, the stress relief hole at the root can effectively alleviate and release the circumferential shear stress generated by the anti-loosening self-locking mechanism. This ensures that while achieving ultimate thread mechanical anti-loosening locking, the root of the spring claw will not undergo torsional tearing or plastic deformation due to torsional overload, thus achieving a synergistic effect of anti-loosening performance and fatigue life.

[0018] Preferably, an annular pressure-reducing and energy-releasing groove is formed on the first inner conical surface of the shell, and the pressure-reducing and energy-releasing groove is located in the axial overlapping area of ​​the first outer conical surface.

[0019] By creating an annular pressure-relief groove on the inner conical surface of the housing, and with the groove located within the axial overlap region of the outer conical surface, when the temperature transmitter is in extremely cold conditions or in an environment where the medium rapidly cools, the outer metal housing, due to its much larger coefficient of linear expansion than the brittle glass window, will experience severe radial inward contraction stress. In this situation, the presence of the pressure-relief groove artificially constructs a geometric cavity buffer zone in the middle section of the explosion-proof joint surface where the inner and outer conical surfaces are rigidly fitted. This prevents the radial rigid compressive stress generated by the rapid contraction of the housing from being continuously transmitted on the inner conical surface. Instead, the pressure-relief groove interrupts the stress, forming a stress-release edge. It even allows for extremely slight inward yielding deformation of the local groove wall metal to absorb and dissipate the strain energy from the housing contraction. This blocks the direct rigid transmission of compressive stress to the outer edge of the brittle glass window during traditional continuous planar fits, effectively preventing the glass window edge from cracking or microscopic chipping due to radial local stress concentration, thus ensuring the structural safety of the brittle non-metallic transparent component under extreme temperature difference impacts.

[0020] Furthermore, since the pressure relief and energy release groove is precisely defined within the axial overlap area of ​​the first outer conical surface, the first inner conical surfaces on both sides of the groove body still maintain a tight, rigid face-to-face fit with the first outer conical surface, ensuring that the legal total axial overlap length of the explosion-proof joint surface is not reduced.

[0021] Preferably, a friction-reducing damping pad is covered on the second outer conical surface of the bottom conical ring, and the friction-reducing damping pad is sandwiched between the second outer conical surface and the second inner conical surface.

[0022] By covering the second outer conical surface of the bottom conical ring with a friction-reducing damping pad, sandwiched between the second outer and second inner conical surfaces, the frictional resistance of the conical mating surfaces when the glass window undergoes slight axial displacement can be significantly reduced. This avoids metal fretting wear caused by long-term dry friction between the conical surfaces. At the same time, the damping pad can absorb some mechanical vibration energy, further weakening the rigid transmission of external vibration to the glass window. In addition, the friction-reducing damping pad can also fill the microscopic gaps generated during the processing of the second outer and second inner conical surfaces. Combined with the compression characteristics of the conical surfaces themselves, it can improve the auxiliary sealing effect at the conical surface joint, prevent corrosive media from seeping into the subsequent mating surfaces from the conical surface gaps, and improve the overall corrosion resistance and sealing reliability of the structure.

[0023] Preferably, a positioning hole is provided on the outer side wall of the housing, and multiple locking grooves are provided on the outer side wall of the threaded end of the pressure ring and the internal thread section, the locking grooves being used for the insertion of the positioning pin.

[0024] By creating positioning holes on the outer wall of the housing and setting multiple locking grooves on the outer wall of the threaded end of the pressure ring and the internal thread section for the insertion of positioning pins, after the pressure ring is tightened to the front end of the housing through the threaded pair and reaches the legally prescribed preload torque, the operator can align the positioning hole with the nearest locking groove in the radial or axial direction, and then rigidly insert the hard positioning pin between the positioning hole and the locking groove. When the temperature transmitter is under long-term and severe external pipeline vibration, mechanical impact, or low-frequency resonance caused by medium pressure pulsation in the petrochemical site, the external disturbance stress attempts to drive the pressure ring to rotate and loosen circumferentially along the internal thread section. At this time, since the positioning pin forms a rigid physical limiting pin between the positioning hole of the housing and the locking groove of the pressure ring, any circumferential loosening torque will be directly and rigidly intercepted by the positioning pin in the form of shear stress, cutting off the threaded retraction path of the pressure ring relative to the housing at any angle, ensuring the attenuation of the initial assembly clamping force, and solving the safety hazard of excessive internal explosion-proof gap or process seal failure caused by pressure ring loosening.

[0025] Furthermore, the locking grooves are provided on the outer side wall of the pressure ring in a circumferentially staggered or evenly distributed manner. This ensures that after the pressure ring is screwed in after the thread assembly is completed, no matter what fine-tuning angle it is ultimately at, at least one locking groove can be precisely aligned with the positioning hole on the housing, which improves the convenience and fault tolerance of the on-site blind insertion positioning pin assembly process.

[0026] Preferably, a limiting inner liner is also embedded in the internal cavity of the sleeve. The front end of the limiting inner liner is fixedly connected to the top fixing ring, and the rear end is suspended and has a safe axial gap between it and the inner wall of the bottom conical ring.

[0027] By embedding a limiting inner liner in the internal cavity of the sleeve, the front end of the limiting inner liner is fixedly connected to the top fixing ring, and the rear end is suspended and leaves a safe axial gap between it and the inner wall of the bottom conical ring. When the temperature transmitter is in a harsh petrochemical site, when the pipeline generates severe water hammer, sudden external mechanical gravity impact, or sudden instantaneous gas overpressure impact due to internal failure, the rigid impact load will be forcibly applied to the sleeve instantly through the pressure ring and the glass window. At this time, each spring claw in the elastic zone of the middle section of the sleeve undergoes violent axial elastic compression to absorb energy until the safety axial gap is instantly closed. The inner wall of the bottom conical ring is directly and rigidly pressed against the rear end face of the limiting liner. Once contact is established, the subsequent continuous influx of overload impact stress will be rigidly convectively transmitted through the rigid bypass channel of the top fixing ring, the limiting liner and the bottom conical ring, blocking the continued input of overload stress to each spring claw, preventing the spring claw from over-compression, root shear fracture or irreversible plastic collapse deformation, and achieving mechanical explosion-proof safety redundancy.

[0028] Furthermore, since the front end of the limiting inner liner is fixedly connected to the top fixing ring, its cylindrical body is rigidly embedded in the internal cavity of the sleeve. This provides internal radial geometric support to the originally hollow sleeve structure, effectively improving the torsional and instability resistance of the elastic zone in the middle section of the sleeve under complex three-dimensional alternating stress, and preventing asymmetrical circumferential tilting of the spring claws due to uneven force distribution. Simultaneously, because the limiting inner liner and the inner wall of the bottom conical ring maintain a precise safety axial clearance under normal conditions, it ensures that during normal thermal expansion and contraction caused by daily high and low temperature cycles, the spring claws can still freely perform axial micro-deformation and energy storage within their set elastic stroke range. This provides the structure with rigid protection against sudden extreme destructive conditions while retaining the system's adaptive dynamic compensation for temperature differences and long-term planar sealing function.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention achieves full-circumference rigid constraint on the sealing ring through an annular sealing limiting groove, fundamentally preventing creep overflow and shear tearing of the sealing ring under long-term working conditions, ensuring the long-term stability and explosion-proof reliability of the static seal in the digital display area; at the same time, through the elastic sleeve with spring claw and the conical surface mating structure, automatic temperature difference compensation of the axial clamping force of the glass window is realized, always maintaining uniform clamping of the glass window installation interface, avoiding the problem of excessive sealing gap caused by the difference in linear expansion coefficients of heterogeneous materials.

[0030] 2. This invention, by setting a stress relief hole at the root of the spring claw that communicates with the axial hollow groove, not only disperses and eliminates stress concentration during alternating deformation, thus improving the fatigue life of the spring claw, but also reduces the overall stiffness of the elastic zone, thereby improving the damping and shock absorption capacity of the structure and preventing the threaded pair from loosening due to resonance energy; combined with the anti-slip convex groove engagement structure between the top fixing ring and the pressure ring, it further realizes the circumferential rigidity of the threaded pair to prevent loosening, ensuring the stability of the preload under long-term working conditions.

[0031] 3. By opening a pressure-reducing and energy-releasing groove in the overlapping area of ​​the inner conical surface of the shell, the present invention absorbs and releases the radial compressive stress generated by the extreme cold contraction of the shell without reducing the effective length of the explosion-proof joint surface, thus avoiding the stress being directly transmitted to the edge of the glass window and causing cracking, thereby improving the structural safety of brittle transparent parts under extreme temperature difference conditions. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the temperature transmitter of the present invention; Figure 2 This is a full sectional view of the temperature transmitter of the present invention; Figure 3 for Figure 2 A magnified view of a section at point A in the middle; Figure 4 This is an exploded view of the temperature transmitter of the present invention; Figure 5 This is a full sectional view of the housing in the temperature transmitter of the present invention; Figure 6 for Figure 5 A magnified view of a section at point B in the middle; Figure 7 This is a schematic diagram of the pressure ring in the temperature transmitter of the present invention; Figure 8 This is a schematic diagram of the sleeve structure in the temperature transmitter of the present invention.

[0033] In the diagram: 1. Pressure ring; 11. Anti-slip groove; 12. Locking groove; 2. Sleeve; 21. Top fixing ring; 211. Anti-slip ridge; 22. Middle elastic zone; 221. Axial hollow groove; 222. Spring claw; 223. Stress relief hole; 23. Bottom conical ring; 231. Second outer conical surface; 232. Friction-reducing damping pad; 3. Glass window; 31. First outer conical surface; 32. Second inner conical surface; 4. Sealing ring; 5. Housing; 51. Internal thread section; 52. First inner conical surface; 521. Pressure relief and energy release groove; 53. Stepped surface; 531. Sealing limit groove; 54. Positioning hole; 6. Limiting inner liner. Detailed Implementation

[0034] Please see Figures 1 to 8 This invention provides an explosion-proof sealing structure for the display component of a temperature transmitter with digital display function. The technical solution is as follows: For an explosion-proof sealing structure of the display component of a temperature transmitter with digital display function, please refer to [link / reference]. Figures 1 to 4 , Figure 6The device includes a housing 5, a glass window 3 embedded in the front opening of the housing 5, and a pressure ring 1 threaded to the front end of the housing 5. The inner wall of the front opening of the housing 5 has, from the outside to the inside, an internal thread section 51, a first inner conical surface 52, and a stepped surface 53. The small end of the first inner conical surface 52 is located on the inner side. A sealing ring 4 is laid flat on the stepped surface 53. An annular sealing groove 531 is formed on the stepped surface 53 of the housing 5. The sealing ring 4 is embedded in the annular sealing groove 531, and the axial thickness of the sealing ring 4 before being compressed is greater than the axial depth of the annular sealing groove 531. The rear end face of the glass window 3 is in contact with the sealing ring 4. The outer circumferential side of the glass window 3 has a first outer conical surface 31 that fits against the first inner conical surface 52; a sleeve 2 is sandwiched between the pressure ring 1 and the glass window 3. The sleeve 2 includes a top fixing ring 21, a middle elastic region 22, and a bottom conical surface ring 23. The top fixing ring 21 rigidly abuts against the rear end face of the pressure ring 1. The middle elastic region 22 has multiple axially hollowed-out grooves 221 evenly distributed along the circumferential direction, which divide the middle elastic region 22 into multiple spring claws 222. The rear end face of the bottom conical surface ring 23 has a second outer conical surface 231, and the edge of the front end face of the glass window 3 has a second inner conical surface 32 that fits against the second outer conical surface 231. Please refer to Figure 5 and Figure 7 The outer side wall of the housing 5 is provided with a positioning hole 54, and the outer side wall of the threaded end of the pressure ring 1 and the internal thread section 51 is provided with a plurality of locking grooves 12, which are used for the insertion of the positioning pin.

[0035] Please see Figure 8 Each spring claw 222 has a stress relief hole 223 at its root near the top fixing ring 21, and the stress relief hole 223 is connected to the corresponding axial hollow groove 221. Multiple axial anti-slip protrusions 211 are circumferentially staggered on the front end face of the top fixing ring 21, and anti-slip grooves 11 are formed on the rear end face of the pressure ring 1 to match and engage with the axial anti-slip protrusions 211 one by one. An annular pressure-reducing and energy-releasing groove 521 is formed on the first inner conical surface 52 of the housing 5, and the pressure-reducing and energy-releasing groove 521 is located within the axial overlapping area of ​​the first outer conical surface 31; a friction-reducing and damping pad layer 232 is covered on the second outer conical surface 231 of the bottom conical surface ring 23, and the friction-reducing and damping pad layer 232 is sandwiched between the second outer conical surface 231 and the second inner conical surface 32.

[0036] The inner cavity of the sleeve 2 is also fitted with a limiting inner liner 6. The front end of the limiting inner liner 6 is fixedly connected to the top fixing ring 21, and the rear end is suspended and has a safe axial gap between it and the inner wall of the bottom conical ring 23.

[0037] Working principle: During assembly, the sealing ring 4 is first embedded into the annular sealing and limiting groove 531 of the stepped surface 53 of the housing 5 to complete the positioning. Then, the glass window 3 is installed into the front opening of the housing 5, so that the first outer conical surface 31 of the glass window 3 is in contact with the first inner conical surface 52 of the housing 5, and the rear end face is pre-pressed with the sealing ring 4. Then, the sleeve 2 with the pre-fixed limiting inner liner 6 is placed into the opening of the housing 5, so that the second outer conical surface 231 of the bottom conical surface ring 23 is aligned and in contact with the second inner conical surface 32 of the glass window 3 through the friction-reducing damping pad 232. Then, the pressure ring 1 is screwed into the internal thread section 51 of the housing 5. During the process of gradually tightening the pressure ring 1, the pressure ring 1 pushes the top fixing ring 21 and the sleeve 2 to be axially fed as a whole. Through the cooperation between the bottom conical surface ring 23 and the conical surface of the front end of the glass window 3, the axial pressing force is evenly transmitted to the glass window 3, and finally the glass window 3 is pressed on the rear sealing ring 4, completing the initial assembly. After tightening, insert the positioning pin into the aligned positioning hole 54 of the housing 5 and the locking groove 12 of the pressure ring 1 to complete the circumferential anti-loosening fixation.

[0038] During long-term operation, when the ambient or medium temperature changes, the shell 5 and the glass window 3 have different coefficients of linear expansion due to the dissimilar materials. If the temperature rises, the radial expansion of the shell 5 is greater than that of the glass window 3. At this time, each spring claw 222 in the elastic zone 22 of the middle section of the sleeve 2 will automatically compensate for the axial gap caused by the expansion difference through its own axial elastic elongation, and always maintain a uniform pressing force on the glass window 3. If the temperature drops, the shrinkage of the shell 5 is greater than that of the glass window 3, and the spring claw 222 will undergo adaptive axial compression deformation, still maintaining stable axial pressing, avoiding the sealing gap from exceeding the standard due to the expansion and contraction difference of dissimilar materials, and ensuring the explosion-proof sealing performance. When encountering extremely cold conditions or a rapid drop in the medium temperature, when the shell 5 generates severe radial inward contraction stress, the pressure relief and energy release groove 521 of the first inner cone surface 52 will cut off the continuous transmission path of the contraction stress, and absorb the strain energy through local micro-deformation, preventing the edge of the glass window 3 from cracking due to stress concentration. When the equipment encounters severe vibration or impact conditions, the friction-reducing damping pad 232 can absorb some of the vibration energy in advance, and the stress relief hole 223 at the root of the spring claw 222 can release the circumferential shear stress. Together with the anti-slip protrusion 211 groove engagement structure between the top fixing ring 21 and the pressure ring 1, and the rigid limiting structure of the positioning pin and the locking groove 12, they jointly block the circumferential loosening path of the pressure ring 1 and avoid the preload attenuation. When a sudden extreme overload impact occurs, after the spring claw 222 is compressed to the safe axial clearance closure, the impact stress will be transmitted through the rigid bypass formed by the limiting inner liner 6, avoiding the overtravel damage of the spring claw 222 and further ensuring structural safety.

[0039] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. An explosion-proof sealing structure for the display component of a temperature transmitter with digital display function, comprising a housing (5), a glass window (3) embedded in the front opening of the housing (5), and a pressure ring (1) threadedly connected to the front end of the housing (5), characterized in that, The inner wall of the front opening of the housing (5) is provided with an internal thread section (51), an inner conical surface (52) and a stepped surface (53) in sequence from the outside to the inside. The small end of the inner conical surface (52) is located on the inside. A sealing ring (4) is laid flat on the stepped surface (53). The rear end face of the glass window (3) is in contact with the sealing ring (4). The outer circumferential side of the glass window (3) is provided with an outer conical surface (31) that is in contact with the inner conical surface (52). A sleeve (2) is sandwiched between the pressure ring (1) and the glass window (3). The sleeve (2) includes a top fixing The ring (21), the middle elastic zone (22) and the bottom conical ring (23) are provided. The top fixing ring (21) is rigidly abutted against the rear end face of the pressure ring (1). The middle elastic zone (22) has multiple axial hollow grooves (221) evenly distributed along the circumferential direction. The axial hollow grooves (221) divide the middle elastic zone (22) into multiple spring claws (222). The rear end face of the bottom conical ring (23) is provided with a second outer conical surface (231). The front end face edge of the glass window (3) is provided with a second inner conical surface (32) that fits with the second outer conical surface (231).

2. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 1, characterized in that, An annular sealing groove (531) is provided on the stepped surface (53) of the housing (5). The sealing ring (4) is embedded in the annular sealing groove (531), and the axial thickness of the sealing ring (4) before being compressed is greater than the axial depth of the annular sealing groove (531).

3. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 1, characterized in that, Each of the spring claws (222) has a stress relief hole (223) at the root near the top fixing ring (21), and the stress relief hole (223) is connected to the corresponding axial hollow groove (221).

4. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 3, characterized in that, The front end of the top fixing ring (21) is provided with multiple axial anti-slip protrusions (211) arranged in an alternating pattern, and the rear end of the pressure ring (1) is provided with anti-slip grooves (11) that match and engage with the axial anti-slip protrusions (211) one by one.

5. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 3, characterized in that, An annular pressure relief and energy release groove (521) is provided on the first inner conical surface (52) of the housing (5), and the pressure relief and energy release groove (521) is located in the axial overlapping area of ​​the first outer conical surface (31).

6. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 5, characterized in that, A friction-reducing damping pad (232) is covered on the second outer conical surface (231) of the bottom conical ring (23), and the friction-reducing damping pad (232) is sandwiched between the second outer conical surface (231) and the second inner conical surface (32).

7. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 4, characterized in that, The outer side wall of the housing (5) is provided with a positioning hole (54), and the outer side wall of the threaded end of the pressure ring (1) and the internal thread section (51) is provided with a plurality of locking grooves (12), which are used for the insertion of the positioning pin.

8. The explosion-proof sealing structure of the display component of a temperature transmitter with digital display function according to claim 3, characterized in that, The inner cavity of the sleeve (2) is also fitted with a limiting inner liner (6). The front end of the limiting inner liner (6) is fixedly connected to the top fixing ring (21), and the rear end is suspended and has a safe axial gap between it and the inner wall of the bottom conical ring (23).

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