Metal diaphragm capacitance combined type vacuum gaugeTechnical Field
The invention relates to the technical field of vacuum gauges, in particular to a metal diaphragm capacitance composite vacuum gauge.
Background
The vacuum gauge is a key instrument for measuring the gas pressure in the closed space, and is widely applied to technical scenes such as vacuum system running state monitoring, leakage detection, process control and the like, wherein the capacitance type vacuum gauge is widely adopted in medium-high vacuum measurement due to the advantages of sensitive response, high precision, wide applicable pressure range and the like. The vacuum gauge is usually deformed under the action of reference pressure and measured pressure through a metal diaphragm, and the displacement of the diaphragm is reflected by the capacitance change, so that the vacuum degree is indirectly measured;
However, in some industrial applications, vacuum systems are very prone to intense airflow shocks of short duration under the influence of on-off valves, sudden unloading, or high pressure section recoil airflows. The backflushing airflow can upwell into the vacuum gauge along a pipeline to cause excessive rapid stress or nonlinear deformation of a diaphragm, so that measurement errors are caused, even the internal precise structure of the vacuum gauge is damaged, the service life and measurement stability of the vacuum gauge are influenced, the traditional capacitance type vacuum gauge is lack of effective protection means under the transient abnormal interference, normal pressure change and backflushing interference cannot be distinguished frequently, and the reading is out of alignment or false alarm is caused to influence the reliable control of a vacuum system;
The traditional Chinese patent with publication number CN114459670A discloses a capacitance film vacuum gauge, the device is provided with an elastic diaphragm and a bracket, so that two ends of the bracket are respectively connected with the elastic diaphragm and an induction diaphragm, the condition that the center distance of the induction diaphragm is changed greatly and the outer edge shape distance is changed little can be avoided, the accuracy and the sensitivity of the capacitance film vacuum gauge are ensured, but when the device is used for dealing with backflushing air flow, the induction diaphragm is impacted by larger instantaneous air flow, the structural stability is influenced, and the reading drift is caused;
therefore, a compound vacuum gauge structure with recoil air flow relieving, protecting and auxiliary correcting capabilities is needed, physical buffering of air flow interference can be achieved, real readings can be reversely pushed through structural response and pressure difference information, and adaptability and measurement reliability of the system to complex working conditions are improved.
Disclosure of Invention
The invention aims to provide a metal diaphragm capacitance composite vacuum gauge so as to solve the problems in the background technology.
In order to solve the technical problems, the invention provides the technical scheme that the metal diaphragm capacitance composite vacuum gauge comprises a vacuum gauge body and a control module, wherein a lower sealing block is fixedly connected to the lower side of the vacuum gauge body, a connecting pipe is fixedly connected to the lower side of the lower sealing block, the connecting pipe is communicated with the inside of the vacuum gauge body, an electrode is fixedly connected to the upper side of the inner wall of the vacuum gauge body, a capacitance diaphragm is arranged on the lower side of the electrode, the electrode is not contacted with the capacitance diaphragm, a buffer cavity is formed in the connecting pipe, a buffer mechanism is arranged in the buffer cavity, and a detection mechanism is arranged on the outer side of the connecting pipe;
The inner diameter of the buffer cavity is larger than the inner diameter of the connecting pipe and the inner diameter of the lower sealing block, the inner cavity volume of the buffer cavity is smaller than the volume of the tested cavity, and the lower side of the connecting pipe is communicated with the lower side of the capacitance diaphragm through the inner sides of the buffer cavity and the lower sealing block.
According to the technical scheme, the buffer mechanism comprises a base, the lower surface of base and the inner wall downside fixed connection of buffering chamber, the upside fixedly connected with spring of base, the upper end fixedly connected with dog of spring, the dog is located lower sealing block middle part, the outer wall and the lower sealing block inner wall contact of dog, the air flue has been seted up to the inboard of dog.
According to the technical scheme, the inner diameter of the upper side of the inner wall of the lower sealing block is smaller than the outer diameter of the stop block, the air passage and the stop block form a Tesla-like valve body structure, and the flow blocking direction of the stop block is from bottom to top.
According to the technical scheme, detection mechanism includes the seal ring, the inner wall and the connecting pipe outer wall fixed connection of seal ring, the right side of seal ring is connected with a seal section of thick bamboo, the left end of seal section of thick bamboo runs through the connecting pipe and extends to the inside of buffering chamber, the inside liquid that has filled of seal section of thick bamboo, the inner wall left side fixedly connected with sealing washer of seal section of thick bamboo, sealing washer inner wall fixedly connected with elastic metal film, the rear side fixedly connected with pressure detection mechanism of seal section of thick bamboo, pressure detection mechanism detection end is located the inside of seal section of thick bamboo.
According to the technical scheme, one end of the sealing cylinder, which is positioned at the outer side of the lower sealing block, is of a conical structure, the elastic metal film is made of elastic metal, the pressure detection mechanism is positioned at one side of the sealing cylinder, which is far away from the connecting pipe, and the outer side of the sealing cylinder is provided with the cooling mechanism.
According to the technical scheme, cooling body includes the liquid pipe, the both ends of liquid pipe respectively with the outer wall upside of seal tube and the outer wall downside fixed connection of seal tube, just the inside intercommunication setting of seal tube of liquid pipe, the middle part of liquid pipe and lower seal piece outer wall downside fixed connection, the motor of still fixedly connected with of lower seal piece downside, the output fixedly connected with carousel of motor, the outer wall of carousel articulates through the torsional spring has a plurality of linking arms, the one end that the motor was kept away from to the linking arm is connected with the pinch roller through the bearing rotation.
According to the technical scheme, the distance from the pressing wheel to the outer wall of the turntable is greater than the distance from the outer wall of the turntable to the outer wall of the liquid pipe, the motor can drive the turntable, the connecting arm and the pressing wheel to rotate, and the liquid pipe is positioned on the rotating path of the pressing wheel.
Compared with the prior art, the invention has the beneficial effects that by arranging the connecting pipe, the air passage and the stop block, the invention can effectively prevent high-speed gas from upwards rushing when the air flow backflushes, slow down the instant impact on the capacitance diaphragm and avoid the reading deviation or the damage of devices caused by the over-limit of the diaphragm deformation;
by arranging the springs and the air passages, part of air flow kinetic energy can be synchronously absorbed in the process that the recoil air flow pushes the stop block to move upwards, and energy is released through structural deformation, so that structural resonance caused by air flow transient fluctuation and interference to a sensing cavity are reduced;
By arranging the elastic metal film and the sealing cylinder, the instantaneous air pressure rise caused by backflushing air flow can be converted into hydraulic pressure change, the hydraulic pressure change rate is monitored in real time through the pressure detection mechanism, and whether an abnormal air flow event is judged, so that a reference basis is provided for data screening;
through being provided with liquid pipe, pinch roller and motor, can carry out dynamic circulation to the inside liquid of seal cylinder in the device operation in-process, and then take away the heat that elastic metal film produced because of frequent pressurized, avoid local overheated leading to the performance degradation.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:
FIG. 1 is a schematic perspective view of the present invention;
FIG. 2 is a schematic view of the structure of the present invention at the underside;
FIG. 3 is a schematic view of the internal structure of the present invention;
FIG. 4 is a schematic view of the internal structure of the lower block of the present invention;
FIG. 5 is a schematic diagram of the detection mechanism of the present invention;
FIG. 6 is an enlarged schematic view of the structure of FIG. 2A according to the present invention;
In the figure, 1, a vacuum gauge body; 2, lower sealing block, 3, connecting pipe, 4, electrode, 5, capacitance diaphragm, 6, buffer cavity, 7, buffer mechanism, 8, detecting mechanism, 701, base, 702, spring, 703, stop block, 704, air channel, 801, sealing ring, 802, sealing cylinder, 803, sealing ring, 804, elastic metal film, 805, pressure detecting mechanism, 806, cooling mechanism, 601, liquid pipe, 602, motor, 603, turntable, 604, connecting arm, 605, pinch roller.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1-6, the invention provides a metal diaphragm capacitance composite vacuum gauge, which comprises a vacuum gauge body 1 and a control module, wherein the lower side of the vacuum gauge body 1 is fixedly connected with a lower sealing block 2, the lower side of the lower sealing block 2 is fixedly connected with a connecting pipe 3, the connecting pipe 3 is communicated with the inside of the vacuum gauge body 1, the upper side of the inner wall of the vacuum gauge body 1 is fixedly connected with an electrode 4, the lower side of the electrode 4 is provided with a capacitance diaphragm 5, the electrode 4 is not contacted with the capacitance diaphragm 5, the inside of the connecting pipe 3 is provided with a buffer cavity 6, the inside of the buffer cavity 6 is provided with a buffer mechanism 7, the outside of the connecting pipe 3 is provided with a detection mechanism 8, the inner diameter of the buffer cavity 6 is larger than the inner diameter of the connecting pipe 3 and the inner diameter of the lower sealing block 2, the inner cavity volume of the buffer cavity 6 is smaller than the volume of a measured cavity, and the lower side of the connecting pipe 3 is communicated with the lower side of the capacitance diaphragm 5 through the buffer cavity 6 and the inner side of the lower sealing block 2;
In practical application, the upper side and the lower side of the inside of the vacuum gauge body 1 are isolated into two chambers by the capacitance diaphragm 5, namely a measuring chamber connected with a vacuum system to be measured and a reference pressure chamber connected with a high vacuum system, when in measurement, the high vacuum pumping system is used for pumping the space at two sides of the capacitance diaphragm 5 to the reference pressure pb, and meanwhile, a measuring bridge circuit is regulated to balance, namely an indicating instrument is zeroed, and then the measuring chamber is connected with the vacuum system to be measured to finish the subsequent detection operation;
The buffer mechanism 7 comprises a base 701, the lower surface of the base 701 is fixedly connected with the lower side of the inner wall of the buffer cavity 6, the upper side of the base 701 is fixedly connected with a spring 702, the upper end of the spring 702 is fixedly connected with a stop block 703, the stop block 703 is positioned in the middle of the lower sealing block 2, the outer wall of the stop block 703 is in contact with the inner wall of the lower sealing block 2, an air passage 704 is formed in the inner side of the stop block 703, the inner diameter of the upper side of the inner wall of the lower sealing block 2 is smaller than the outer diameter of the stop block 703, the air passage 704 and the stop block 703 form a Tesla-like valve body structure, and the flow blocking direction of the stop block 703 is from bottom to top;
In the subsequent detection process, the gas on the upper side of the baffle 703 can be smoothly discharged downwards through the air passage 704, if the backflushing of the gas flow occurs, the backflushing gas flow enters the buffer cavity 6 in the lower sealing block 2 through the connecting pipe 3, and when the upwelling gas flow passes through the baffle 703, the baffle 703 is provided with a plurality of backflow tongues, flow dividing cavities and surge slots by virtue of the nonlinear deflection paths of the special air passage 704 in the baffle 703, so that the fluid in the reverse flow process is continuously disturbed, deflected and backflow interfered, and obvious dynamic pressure loss and path blocking effects are formed;
the rising resistance of the air flow is increased, the stop block 703 is driven to move upwards, meanwhile, the traction spring 702 deforms to store energy, the impact vibration of the air flow to the device is reduced, the damage probability of the internal components of the vacuum gauge body 1 is reduced, the blocked air flow can enable the local air pressure in the buffer cavity 6 to rise relatively instantaneously, then the air flow is balanced with the air at the upper side through the air channel 704, the subsequent detection is completed, and the subsequent abnormal reading caused by the direct impact of the air flow on the capacitance diaphragm 5 is avoided;
The detection mechanism 8 comprises a sealing ring 801, the inner wall of the sealing ring 801 is fixedly connected with the outer wall of the connecting pipe 3, the right side of the sealing ring 801 is connected with a sealing cylinder 802, the left end of the sealing cylinder 802 penetrates through the connecting pipe 3 and extends to the inside of the buffer cavity 6, liquid is filled in the sealing cylinder 802, the left side of the inner wall of the sealing cylinder 802 is fixedly connected with a sealing ring 803, the inner wall of the sealing ring 803 is fixedly connected with an elastic metal film 804, the rear side of the sealing cylinder 802 is fixedly connected with a pressure detection mechanism 805, the detection end of the pressure detection mechanism 805 is positioned in the sealing cylinder 802, one end of the sealing cylinder 802 positioned at the outer side of the lower sealing block 2 is of a conical structure, the elastic metal film 804 is made of elastic metal material, the pressure detection mechanism 805 is positioned at one side of the sealing cylinder 802 far away from the connecting pipe 3, and the outer side of the sealing cylinder 802 is provided with a cooling mechanism 806;
When the back flushing airflow causes the air pressure in the buffer cavity 6 to increase, the air in the buffer cavity 6 can impact the elastic metal film 804 to deform the elastic metal film 804, so that the pressure change of the liquid in the seal cylinder 802 is caused, and because the air pressure in the buffer cavity 6 is lower before, and because one side of the seal cylinder 802 is of a conical structure, the deformation of the elastic metal film 804 caused by the rising air pressure in the buffer cavity 6 can cause the change of the liquid pressure in the seal cylinder 802 to be more obvious at the pressure detection mechanism 805, so that the pressure detection mechanism 805 detects that the change amount of the liquid pressure in the seal cylinder 802 in unit time exceeds a conventional value, and because the pressure detection mechanism 805 is electrically connected with the control module, the control module is electrically connected with the vacuum gauge body 1, the control module can judge that the abnormal time section is used for recording and marking the reading of the time vacuum gauge body 1 as the abnormal reading, the later discrimination is convenient, and the sealing environment in the buffer cavity 6 is not destroyed;
And when the back flushing of the air flow into the buffer cavity 6 causes the large change in the reading of the pressure detection mechanism 805 in a short time, the reading of the pressure detection mechanism 805 is raised to generate a pressure difference, and the pressure difference is calculated by a pressure difference driving free flow rate model:
Wherein: buffer the pressure difference before and after the recoil in the cavity,The density of the gas is shown in the specification,Upwelling gas velocity;
The upwelling speed of the backflushing airflow can be obtained;
and substituting the kick-up speed of the recoil air flow into a local resistance model of the tesla valve:
Wherein: The pressure drop of the reverse air flow when passing through the tesla valve,The local resistance coefficient of the tesla valve,The density of the gas is shown in the specification,The velocity of the backflushing gas stream;
Substitution intoObtaining:
the pressure drop caused by the available stops 703;
The real value of the backflushing airflow can be judged in an auxiliary way through the pressure drop value;
The cooling mechanism 806 comprises a liquid pipe 601, two ends of the liquid pipe 601 are fixedly connected with the upper side of the outer wall of a sealing cylinder 802 and the lower side of the outer wall of the sealing cylinder 802 respectively, the inside of the liquid pipe 601 is communicated with the inside of the sealing cylinder 802, the middle part of the liquid pipe 601 is fixedly connected with the lower side of the outer wall of a lower sealing block 2, the lower side of the lower sealing block 2 is fixedly connected with a motor 602, the output end of the motor 602 is fixedly connected with a turntable 603, the outer wall of the turntable 603 is hinged with a plurality of connecting arms 604 through torsion springs, one end of the connecting arms 604, which is far away from the motor 602, is rotatably connected with a pressing wheel 605 through a bearing, the distance from the pressing wheel 605 to the outer wall of the turntable 603 is greater than the distance from the outer wall of the turntable 603 to the outer wall of the liquid pipe 601, the motor 602 can drive the turntable 603, the connecting arms 604 and the pressing wheel 605 to rotate, and the liquid pipe 601 is positioned on a rotating path of the pressing wheel 605;
In the working process of the device, the turntable 603, the connecting arm 604 and the pressing wheel 605 are driven to rotate through the motor 602, so that the pressing wheels 605 are continuously led to the middle of the liquid pipe 601, the distance from the pressing wheels 605 to the outer wall of the turntable 603 is larger than that from the outer wall of the turntable 603 to the outer wall of the liquid pipe 601, the pressing wheels 605 can be contacted with the outer wall of the liquid pipe 601 and are extruded upwards, the inner side liquid of the liquid pipe 601 is continuously moved through extrusion between the pressing wheels 605 and the outer wall of the lower sealing block 2 in the continuous rotating process, the liquid in the sealing cylinder 802 is in a circulating state, heat generated by frequent deformation of the elastic metal film 804 is taken away by liquid circulation, and the failure of the elastic metal film 804 due to high temperature is avoided, so that the detection of the pressure detection mechanism 805 is more accurate.
It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
It should be noted that the above-mentioned embodiments are merely preferred embodiments of the present invention, and the present invention is not limited thereto, but may be modified or substituted for some of the technical features thereof by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.