Capacitive differential pressure sensor and leak detection device

Abstract

The utility model provides a capacitive differential pressure sensor, which comprises a shell in which an inner cavity is formed; the diaphragm is arranged in the shell and divides the inner cavity into two detection cavities; the two electrode assemblies are in one-to-one correspondence with the two detection cavities respectively, each electrode assembly comprises an electrode and a conducting rod, the electrode is arranged in the detection cavity, one face of the electrode is opposite to the membrane, the conducting rod comprises an outer connecting section, a fixing section and an inner contact section which are sequentially connected, the outer connecting section is located outside the shell, the fixing section is installed on the shell, and the inner contact section is located in the detection cavity; the inner contact section elastically abuts against the electrode; the shell is further provided with fluid channels in one-to-one correspondence with the detection cavities, one ends of the fluid channels are communicated with the corresponding detection cavities, and the other ends of the fluid channels are used for inputting pressure fluid. According to the capacitive differential pressure sensor provided by the embodiment of the invention, the stable contact between the electrode and the conducting rod can be ensured, the connection structure is simple, and the processing difficulty is greatly reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of seal detection, and more specifically, relates to a capacitive differential pressure sensor and a leakage detection device. Background Art

[0002] In a capacitive differential pressure sensor, two capacitors are formed by using a diaphragm in the housing and two electrodes on both sides of the diaphragm. When the pressure on one side of the diaphragm changes, the diaphragm will deform toward the side with smaller pressure, making the capacitance on both sides unequal. The small change in pressure on this side can be converted by detecting the capacitance difference at both ends.

[0003] In the related art, a conductive rod is used to pass through the housing to contact the electrode, and the electrode is led outside the housing for detection. In order to ensure stable contact between the conductive rod and the electrode, a connecting and fixing structure is set on the electrode and the conductive rod to fix the electrode and the conductive rod together. This connection method has a complex structure and is difficult to process. Utility Model Content

[0004] The embodiment of the present application provides a capacitive differential pressure sensor, which can ensure stable contact between the electrode and the conductive rod, and has a simple connection structure, greatly reducing the difficulty of processing.

[0005] The technical solution adopted in the embodiment of the present application is: to provide a capacitive differential pressure sensor, comprising:

[0006] a housing, wherein an inner cavity is formed in the housing;

[0007] a diaphragm, disposed in the housing and dividing the inner cavity into two detection cavities; and

[0008] Two electrode assemblies, corresponding to the two detection cavities one by one, respectively, the electrode assembly comprises an electrode and a conductive rod, the electrode is arranged in the detection cavity, one side of the electrode is opposite to the diaphragm, the conductive rod comprises an outer connecting section, a fixed section and an inner contact section connected in sequence, the outer connecting section is located outside the shell, the fixed section is installed on the shell, the inner contact section is located in the detection cavity, and the inner contact section elastically abuts against the electrode;

[0009] Wherein, the shell is further provided with two fluid channels, and the two fluid channels correspond to the two detection chambers one by one respectively, one end of the fluid channel is connected to the corresponding detection chamber, and the other end is used for inputting pressure fluid.

[0010] Furthermore, the shell is provided with two through holes, and the two through holes respectively connect the two detection chambers with the outside, and a fixed section is passed through the through holes and connected to the shell.

[0011] Furthermore, the electrode has a side surface opposite to the through hole, and the side surface includes a first circular surface, defining a plane, the plane is perpendicular to the axis of the first circular surface, the projection of the axis of the through hole on the plane intersects with the projection of the first circular surface on the plane and does not pass through the center of the projection of the first circular surface.

[0012] Furthermore, the electrode assembly also includes a hollow fixing sleeve, which is sleeved on the conductive rod and a first insulating fixing adhesive layer is filled between the inner wall of the fixing sleeve and the conductive rod, and the fixing sleeve is fixed to the outer end of the through hole.

[0013] Furthermore, the distance between the inner end of the through hole and the electrode is smaller than the length of the inner contact segment in a natural state, and the inner contact segment undergoes elastic deflection deformation.

[0014] Furthermore, a positioning groove is provided on the electrode, and the inner contact section is partially embedded in the positioning groove and abuts against the inner wall of the positioning groove.

[0015] Furthermore, the width of the positioning groove gradually increases from inside to outside.

[0016] Furthermore, the electrode divides the detection cavity into a first buffer zone and a second buffer zone, the second buffer zone is located between the electrode and the diaphragm, the first buffer zone is located on the side of the electrode away from the diaphragm, the fluid channel is connected to the first buffer zone, and the shell is also provided with a connecting channel connecting the first buffer zone and the second buffer zone.

[0017] Furthermore, the first buffer zone has a first circumferential inner wall, the inner end of the fluid channel is opened on the first circumferential inner wall, and the opening direction of the inner end of the fluid channel is tangent to the first circumferential inner wall.

[0018] Furthermore, the second buffer zone has a second circumferential inner wall, one end of the connecting channel is opened on the first circumferential inner wall and the opening direction is tangent to the first circumferential inner wall, and the other end of the connecting channel is opened on the second circumferential inner wall.

[0019] Furthermore, the capacitive differential pressure sensor also includes a sealing plug, the housing is provided with a diversion port, the diversion port is communicated with the detection cavity, and the sealing plug can detachably seal the diversion port.

[0020] Furthermore, the housing includes a first shell and a second shell fastened together, the diaphragm is clamped between the first shell and the second shell, a detection cavity is formed between the diaphragm and the first shell, and another detection cavity is formed between the diaphragm and the second shell.

[0021] Furthermore, the capacitive differential pressure sensor also includes a pressure ring, and the end faces of the first shell and the second shell close to the diaphragm are both provided with a circle of grooves, and the pressure ring is located on one side of the diaphragm and embedded in one of the grooves and presses the diaphragm into another groove.

[0022] Furthermore, the capacitive differential pressure sensor further includes two sealing members, one of which is disposed between the diaphragm and the first shell, and the other of which is disposed between the diaphragm and the second shell.

[0023] An embodiment of the present application also provides a leakage detection device, including the capacitive differential pressure sensor as described above.

[0024] The capacitive differential pressure sensor provided in the embodiment of the present application has the beneficial effect that: in the capacitive differential pressure sensor in the embodiment of the present application, an electrode assembly is arranged in each detection cavity, one side of the electrode of the electrode assembly is opposite to the diaphragm, and a capacitor is formed. A pressure fluid (such as gas) can be input into the detection cavity through a fluid channel. When the pressures on both sides are not equal, the diaphragm will be concave to the side with smaller pressure, and the capacity of the capacitor will also change accordingly. By detecting the change in the capacity of the capacitor, the pressure change in the detection chambers on both sides can be judged, thereby determining whether a leak occurs. In the embodiment of the present application, the conductive rod is connected to the housing through a fixed section, the external connection section can be connected to the external detection circuit to detect the capacitance, and the internal contact section elastically abuts against the electrode. The elastic force enables the internal contact section to continuously abut against the electrode, ensuring stable contact between the conductive rod and the electrode. The structure is simple and easy to process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0026] Figure 1 A schematic diagram of the three-dimensional structure of a capacitive differential pressure sensor provided in an embodiment of the present application;

[0027] Figure 2 An exploded schematic diagram of a capacitive differential pressure sensor provided in an embodiment of the present application;

[0028] Figure 3 A front view of a capacitive differential pressure sensor provided in an embodiment of the present application;

[0029] Figure 4 For along Figure 3 Sectional view of AA in the middle;

[0030] Figure 5 A schematic diagram of the contact three-dimensional structure of the electrode assembly provided in an embodiment of the present application;

[0031] Figure 6 A schematic diagram of a conductive rod provided in an embodiment of the present application being bent and deformed and abutting against an electrode;

[0032] Figure 7 For along Figure 3 Cross-sectional view of the middle BB;

[0033] Figure 8 For along Figure 3 Cross-sectional view of CC.

[0034] Among them, the reference numerals in the figure are:

[0035] 10. Shell; 11. First shell; 12. Second shell; 13. Inner cavity; 131. Detection cavity; 1311. First buffer zone; 1312. Second buffer zone; 1313. First circumferential inner wall; 1314. Second circumferential inner wall; 14. Fluid channel; 15. Through hole; 16. Connecting channel; 161. First straight section; 162. Second straight section; 163. Third straight section; 164. Sealing steel ball; 17. Diverter port; 18. Embossed groove; 19. Groove;

[0036] 20. Diaphragm;

[0037] 30. electrode assembly; 31. electrode; 311. side surface; 3111. first circumferential surface; 312. positioning groove; 32. conductive rod; 321. external connection section; 322. fixing section; 323. internal contact section; 33. fixing sleeve; 34. first insulating fixing adhesive layer; 35. second insulating fixing adhesive layer;

[0038] 40. Sealing plug;

[0039] 50. Pressure ring;

[0040] 60. Seals;

[0041] 70. Bolts;

[0042] 80. Remove the plug. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0045] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] See also Figure 1 and Figure 2 The capacitive differential pressure sensor provided in the embodiment of the present application is now described. The capacitive differential pressure sensor provided in the embodiment of the present application includes a housing 10 , a diaphragm 20 and two electrode assemblies 30 .

[0048] Reference Figure 3 and Figure 4 Referring to the figure, an inner cavity 13 is formed in the housing 10, and the inner cavity 13 is a closed structure. Except for the channel specifically used for inputting pressure fluid, the rest of the parts are sealed to prevent the leakage of the housing 10 itself from affecting the detection of leakage. The housing 10 can be a structure composed of two or more parts, which are sealed and connected to each other.

[0049] The diaphragm 20 is arranged in the housing 10 and divides the inner cavity 13 into two detection cavities 131. Both sides of the diaphragm 20 are detection cavities 131, and the two detection cavities 131 are completely separated and not connected to each other. When the pressure on both sides of the diaphragm 20 is equal, the diaphragm 20 remains flat. When the pressure on one side of the diaphragm 20 decreases (i.e., leakage occurs), the diaphragm 20 will deform and concave toward the side with smaller pressure. It can be understood that the diaphragm 20 can deform and recover within a certain range. Specifically, the diaphragm 20 can be a copper sheet.

[0050] Reference Figure 3 and Figure 7The housing 10 is also provided with two fluid channels 14, and the two fluid channels 14 correspond to the two detection chambers 131 one by one. One end of the fluid channel 14 is connected to the corresponding detection chamber 131, and the other end is used to input pressure fluid. Both detection chambers 131 can input pressure fluid, such as gas or liquid, through the corresponding fluid channels 14. During operation, one of the detection chambers 131 serves as a comparison end, and the other chamber serves as a test end. After the pressure fluid is input into the two detection chambers 131, the pressures of the two should be equal. If a slight leak occurs in the pipeline to be tested connected to the test end through the fluid channel 14, the diaphragm 20 will deform toward the detection chamber 131, and the capacitance will change accordingly. The deformation can be detected by the change in capacitance, thereby detecting the occurrence of a slight leak.

[0051] Reference Figure 4 , Figure 5 and Figure 6 The two electrode assemblies 30 correspond to the two detection cavities 131 one by one, respectively. The electrode assembly 30 includes an electrode 31 and a conductive rod 32. The electrode 31 is arranged in the detection cavity 131, and one side of the electrode 31 is opposite to the diaphragm 20. The conductive rod 32 includes an outer connecting section 321, a fixed section 322 and an inner contact section 323 connected in sequence. The outer connecting section 321 is located outside the outer shell 10, the fixed section 322 is installed on the outer shell 10, and the inner contact section 323 is located in the detection cavity 131. The inner contact section 323 elastically abuts against the electrode 31.

[0052] Reference Figure 4 , electrodes 31 are provided in both detection chambers 131, and each electrode 31 is opposite to the diaphragm 20. It is understandable that the electrodes 31 are opposite to the diaphragm 20, indicating that there is a gap between the two, rather than being fitted together, and the spacing between the two electrodes 31 and the diaphragm 20 is equal. The electrode 31 is fixed to the inner wall of the housing 10 on the side opposite to the diaphragm 20, and can be specifically connected and fixed by a connector, or fixed by adhesive bonding. The two electrodes 31 are opposite to the diaphragm 20 to form a capacitor structure. When the diaphragm 20 is deformed to one side, the capacity of the capacitor changes, which can be detected by the external circuit connected to the electrode 31, and then the occurrence of leakage is detected.

[0053] Reference Figure 5 and Figure 6In the embodiment of the present application, a conductive rod 32 is provided corresponding to each electrode 31, and the electrode 31 located in the detection cavity 131 is connected to an external detection circuit through the conductive rod 32. The external connection section 321 of the conductive rod 32 is used to connect to an external detection circuit, the fixed section 322 is connected and fixed to the housing 10, and the inner contact section 323 is used to connect to the electrode 31. It can be understood that the conductive rod 32 is in the shape of an elongated cylinder. Since the fixed section 322 is connected and fixed to the housing 10, when the inner contact section 323 abuts against the electrode 31, the inner contact section 323 will produce a small elastic deformation due to the load received by the inner contact section 323 from the electrode 31. At this time, the degree of deformation is still within the elastic range of the material of the conductive rod 32 itself. Therefore, there is an elastic force at this abutting end to restore it to its original state, and this elastic force will keep the conductive rod 32 in contact with the electrode 31.

[0054] The elastic deformation of the inner contact segment 323 may be in an S-shape, an arc shape, etc.

[0055] Based on the above structure, the embodiment of the present application can maintain continuous contact between the conductive rod 32 and the electrode 31 by making the conductive rod 32 abut against the electrode 31 and undergo elastic deflection deformation. Compared with the method of setting a connecting structure on the electrode and the conductive rod and then fixing them in the related art, the structure is more streamlined and the processing difficulty is lower.

[0056] Reference Figure 5 and Figure 6 The housing 10 is provided with two through holes 15, which respectively connect the two detection chambers 131 with the outside, and a fixed section 322 is passed through the through holes 15 and connected to the housing 10. That is, the conductive rod passes through the through holes on the housing 10, thereby connecting the internal electrode 31 with the external circuit.

[0057] Reference Figure 5 and Figure 6 The electrode 31 has a side surface 311 opposite to the through hole 15, the inner contact section 323 abuts against the side surface 311, and the side surface 311 includes a first circumferential surface 3111, defining a plane that is perpendicular to the axis of the first circumferential surface 3111, and the projection of the axis of the through hole 15 on the plane intersects with the projection of the first circumferential surface 3111 on the plane and does not pass through the center of the projection of the first circumferential surface 3111.

[0058] Since the side surface 311 of the electrode 31 is opposite to the through hole 15, if the conductive rod 32 is directly inserted from the through hole 15, the end of the conductive rod 32 will directly press against the side surface 311 of the electrode 31 along the axial direction of the through hole 15. This method is difficult to ensure that the conductive rod 32 is in continuous contact with the electrode 31. In the embodiment of the present application, the conductive rod 32 is not connected to the electrode 31 by the end surface of the end, but after the conductive rod 32 abuts against the electrode 31, pressure is continuously applied so that the conductive rod 32 is bent by force and deviates from its own axis (the end of the conductive rod 32 and the side surface 311 of the electrode 31 are relatively displaced), resulting in elastic deformation. After bending, the circumference of the conductive rod 32 abuts against the side surface 311 of the electrode 31 or the edge of the end surface of the conductive plate abuts against the side surface 311 of the electrode 31, which is mainly determined by the length of the conductive rod 32. Since the conductive rod 32 is bent by elastic deformation, it has an elastic force that drives it to restore itself to straightness. This elastic force causes the inner contact section 323 of the conductive rod 32 to continuously abut against the side surface 311 of the electrode 31, ensuring continuous contact between the electrode 31 and the conductive rod 32.

[0059] The electrode 31 may be cylindrical, and its side surface 311 is a first circumferential surface 3111. The axial projection of the through hole 15 intersects with the circular projection of the first circumferential surface 3111, so that the conductive rod 32 can contact the first circumferential surface 3111 after being inserted from the through hole 15. The axial projection of the through hole 15 does not pass through the center of the circular projection, so that when the conductive rod 32 is further pressed in, it can slide along the first circumferential surface 3111, and then undergo elastic bending deformation, so that the inner contact section 323 of the conductive rod 32 is in continuous contact with the first circumferential surface 3111. If the axial projection of the through hole 15 is set to pass through the center of the circular projection, when the conductive rod 32 abuts against the first circumferential surface 3111, the direction of the force passes through the center of the circle, which is radial, and it is difficult to bend the conductive rod 32. When the inner contact section 323 of the conductive rod 32 abuts against the first circumferential surface 3111 and pressure is continued to be applied to the conductive rod 32, the end of the conductive rod 32 can slide along the first circumferential surface 3111, causing the conductive rod 32 to be elastically bent and deformed, thereby causing the inner contact section 323 of the conductive rod 32 to continue to abut against the first circumferential surface 3111.

[0060] After the inner contact section 323 of the conductive rod 32 abuts against the first circumferential surface 3111, the conductive rod 32 is tangent to the first circumferential surface 3111 when bending. The advantage of this is that the elastic force of the conductive rod 32 can be released along the tangent position, and can ensure good contact between the conductive probe rod and the electrode 31, thereby ensuring smooth conduction between the two.

[0061] The angle between the axis of the through hole 15 and the axis of the first circumferential surface 3111 may be 90° or less than 90°.

[0062] It should be noted that the first circumferential surface 3111 may be a complete circumferential surface or a partial circumferential surface (ie, not forming a complete circle).

[0063] Reference Figure 2 and Figure 6 The electrode assembly 30 also includes a hollow fixed sleeve 33, which is mounted on the conductive rod 32 and a first insulating fixed adhesive layer 34 is filled between the inner wall of the fixed sleeve 33 and the conductive rod 32. The fixed sleeve 33 is fixed to the outer end of the through hole 15. In order to ensure that the shell 10 can withstand a sufficiently large pressure, the shell 10 is made of metal, and an insulating connection is formed between the shell 10 and the electrode 31. In addition, an insulating connection is also required between the shell 10 and the conductive member. The fixed sleeve 33 is fixed to the outer end of the through hole 15, and the fixed sleeve 33 and the inner wall of the through hole 15 are sealed. The conductive rod 32 is inserted into the fixed sleeve 33 and filled with the first insulating fixed adhesive layer 34. After the first insulating fixed adhesive layer 34 is filled, it can insulate the conductive rod 32 and the fixed sleeve 33, and can also play a sealing role to prevent the pressure fluid in the detection cavity 131 from leaking.

[0064] Specifically, the fixing sleeve 33 is a hollow stud, and the threaded end of the fixing sleeve 33 is fixed on the through hole 15 after being coated with sealing and fastening glue.

[0065] The distance between the inner end of the through hole 15 and the electrode 31 is smaller than the length of the inner contact section 323 in the natural state, so that the inner contact end can inevitably abut against the electrode 31 after being inserted into the detection cavity 131, and after further pressure, the inner contact section undergoes elastic deflection deformation. This deformation is deflection deformation, that is, when the conductive rod 32 is deformed, each point on its axis is displaced in the normal plane of the axis at that point, the fixed section 322 of the conductive rod 32 is fixed, and its inner contact section 323 is loaded and bent, so that the conductive rod 32 bends to form an arc. It should be noted that this bending is still within the elastic deformation range of the conductive rod 32, so it has elastic force, and maintains abutment contact with the electrode 31 under the action of the elastic force.

[0066] Specifically, the shell 10 , the electrode 31 , and the conductive rod 32 may all be made of metal, such as copper or copper alloy.

[0067] Reference Figure 5The electrode 31 is provided with a positioning groove 312, and the inner contact section 323 is partially embedded in the positioning groove 312 and abuts against the inner wall of the positioning groove 312. After the conductive rod 32 abuts against the first circumferential surface 3111 of the electrode 31, it is possible to deviate along the axial direction of the first circumferential surface 3111. For example, the axial direction is the up-down direction. After the conductive rod 32 undergoes elastic bending deformation, it bends to the right. However, since the first circumferential surface 3111 is a circumferential surface, the inner contact section 323 of the conductive rod 32 cannot be stable. It may deviate to the side close to the diaphragm 20 under the action of elastic force, so that the conductive rod 32 exceeds the end surface of the electrode 31 and no longer contacts the electrode 31. To this end, in an embodiment of the present application, a positioning groove 312 is provided on the first circumferential surface 3111, so that the conductive rod 32 falls into the positioning groove 312 after elastic bending deformation and abuts against the inner wall of the positioning groove 312, thereby achieving positioning and continuous abutment along the axial direction, thereby preventing the conductive rod 32 from being offset and separated from the electrode 31 due to the action of elastic force.

[0068] Reference Figure 5 The width of the positioning groove 312 gradually increases from the inside to the outside, that is, the positioning groove 312 is narrow inside and wide, and its cross section may be similar to a "<" shape. Specifically, the inner wall of the positioning groove 312 includes two conical surfaces, and the smaller ends of the two conical surfaces are connected together to form the positioning groove 312. The inner contact section 323 of the conductive rod 32 abuts against the two conical surfaces at the same time.

[0069] Reference Figure 3 , Figure 4 , Figure 7 and Figure 8 , the pressure fluid has a relatively high pressure, and when it is input into the detection chamber 131, it may impact the diaphragm 20, causing the diaphragm 20 to deform, thereby affecting the detection of the capacitance, resulting in a misjudgment of a leak. To this end, in the embodiment of the present application, the electrode 31 separates the detection chamber 131 into a first buffer zone 1311 and a second buffer zone 1312, the second buffer zone 1312 is located between the electrode 31 and the diaphragm 20, the first buffer zone 1311 is located on the side of the electrode 31 away from the diaphragm 20, the fluid channel 14 is connected to the first buffer zone 1311, and the housing 10 is further provided with a connecting channel 16 connecting the first buffer zone 1311 and the second buffer zone. That is, the detection cavity 131 is divided into a first buffer zone 1311 and a second buffer zone 1312 by the electrode 31. The pressure fluid first enters the first buffer zone 1311 from the fluid channel 14. The pressure fluid does not directly contact the diaphragm 20 in the first buffer zone 1311, and will not cause impact deformation to the diaphragm 20. The pressure fluid is buffered and decelerated in the first buffer zone 1311 and then enters the second buffer zone 1312 from the connecting channel 16. Due to the buffering of the first buffer zone 1311, the speed of the pressure fluid is reduced, which greatly reduces the impact on the diaphragm 20, thereby avoiding deformation of the diaphragm 20 and causing misjudgment.

[0070] Specifically, the detection cavity 131 can be set to have one end large and the other end small, the end close to the diaphragm 20 is large, and the end away from the diaphragm 20 is small. A circle of steps is formed at the connection between the large and small ends. The electrode 31 can be fixed on this circle of steps to separate the detection cavity 131 into two buffer cavities. The smaller end is the first buffer cavity, and the larger end is the second buffer cavity. The electrode 31 is fixed to the step by a circle of second insulating fixing glue layer 35.

[0071] Reference Figure 4 The housing 10 is also provided with a disassembly opening on the inner wall of the first buffer zone 1311, and a disassembly plug 80 is provided on the disassembly opening to seal the disassembly. If there is a problem with the bonding between the electrode 31 and the step, the disassembly plug 80 can be removed, and then a tool can be inserted from the disassembly opening to push the electrode 31 out of the step and disassemble it. Specifically, the disassembly opening is provided on the inner wall of the first buffer zone 1311 opposite to the diaphragm 20.

[0072] Reference Figure 4 and Figure 7 The first buffer zone 1311 has a first circumferential inner wall 1313, the inner end of the fluid channel 14 is opened on the first circumferential inner wall 1313, and the opening direction of the inner end of the fluid channel 14 is tangent to the first circumferential inner wall 1313. That is, the first buffer zone 1311 is a cylindrical space, and the opening direction of the inner end of the fluid channel 14 is tangent to the first circumferential inner wall 1313, so that the pressure fluid can flow along the first circumferential inner wall 1313 when entering the first buffer zone 1311. The circumferential shape of the first circumferential inner wall 1313 can guide and buffer the pressure fluid, so as to reduce the impact on the diaphragm 20.

[0073] Reference Figure 4 and Figure 8 The second buffer zone 1312 has a second circumferential inner wall 1314, one end of the connecting channel 16 is opened on the first circumferential inner wall 1313 and the opening direction is tangent to the first circumferential inner wall 1313, and the other end of the connecting channel 16 is opened on the second circumferential inner wall 1314. That is, the second buffer zone 1312 is a cylindrical space, and the opening directions of the two ends of the connecting channel 16 are tangent to the first circumferential inner wall 1313 respectively, so that the pressure fluid can flow along the second circumferential inner wall 1314 when entering the second buffer zone 1312 from the first buffer zone 1311. The circumferential shape of the second circumferential inner wall 1314 can guide and buffer the pressure fluid to reduce the impact on the diaphragm 20. The direction of the opening of the connecting channel 16 on the second circumferential inner wall 1314 can also be tangent to the second circumferential inner wall 1314, further improving the buffering effect on the pressure fluid.

[0074] Reference Figure 4The connecting channel 16 is mainly divided into three sections, namely a first straight section 161, a second straight section 162 and a third straight section 163. One end of the first straight section 161 is connected to the first buffer zone 1311, one end of the third straight section 163 is connected to the second buffer zone 1312, one end of the second straight section 162 is connected to the first straight section 161, and the other end is connected to the third straight section 163.

[0075] The first straight section 161 and the third straight section 163 may be horizontal, and the second straight section 162 may be vertical. The first straight section 161, the second straight section 162, and the third straight section 163 may form process holes on the outer surface of the housing 10 during processing, and the process holes need to be blocked in actual use. For example, process holes are formed on the side of the housing 10 of the first straight section 161 and the third straight section 163, and the process holes may be sealed by placing a sealing steel ball 164 in the process holes.

[0076] The process hole of the second straight section 162 is formed on the end surface opposite to the diaphragm 20. The process hole at this position can be placed with a sealing steel ball 164, which can also be replaced by a screw and a fastening sealant. If a sealing member 60 is provided between the diaphragm 20 and the housing 10 outside this position, the process hole is inside the sealing member 60 and can be sealed by the sealing member 60, then the steel ball may not be placed in the process hole.

[0077] Reference Figure 7 The capacitive differential pressure sensor further includes a sealing plug 40. The housing 10 is provided with a diversion port 17, which is connected to the detection chamber 131. The sealing plug 40 can detachably block the diversion port 17. The diversion port 17 is used to detect the pressure of the detection chamber 131 and to divert the pressure. When not in use, the sealing plug 40 can be used to block it, and when in use, the sealing locking joint can be connected.

[0078] Reference Figure 2 and Figure 4 The housing 10 includes a first housing 11 and a second housing 12 that are fastened together, a diaphragm 20 is clamped between the first housing 11 and the second housing 12, a detection cavity 131 is formed between the diaphragm 20 and the first housing 11, and another detection cavity 131 is formed between the diaphragm 20 and the second housing 12. The housing 10 is formed by two housings connected and fixed, and an inner cavity 13 is formed between the two housings. The diaphragm 20 is clamped between the first housing 11 and the second housing 12, thereby dividing the inner cavity 13 into two detection cavities 131.

[0079] The first housing 11 and the second housing 12 can be connected and fixed by bolts 70. Specifically, the first housing 11 and the second housing 12 are both provided with holes for screws to pass through, and the screws pass through the holes from the same surface of the housing 10 and are locked and fixed with nuts.

[0080] Reference Figure 2 and Figure 4 The capacitive differential pressure sensor further includes a pressure ring 50. The end surfaces of the first housing 11 and the second housing 12 close to the diaphragm 20 are each provided with a circle of grooves 19. The pressure ring 50 is located on one side of the diaphragm 20 and is embedded in one groove 19 and presses the diaphragm 20 into another groove 19. That is, the pressure ring 50 cooperates with the two housings to press the diaphragm 20 between the two housings to ensure that the diaphragm 20 is straightened. The use of two grooves 19 to fix the pressure ring 50 can fully ensure the roughness and flatness of the end surface of the housing, and the processing requirements are relatively low.

[0081] Reference Figure 4 The capacitive differential pressure sensor further includes two seals 60, one seal 60 is disposed between the diaphragm 20 and the first housing 11, and the other seal 60 is disposed between the diaphragm 20 and the second housing 12. That is, the seals 60 are used to seal the two housings and the diaphragm 20 to prevent leakage. In some embodiments, the first housing 11 and the second housing 12 are provided with an embedding groove 18 on the end surface close to the diaphragm 20 for the seal 60 to be partially embedded and fixed. Specifically, the embedding groove 18 is located on the inner side of the first groove 19 or the second groove 19.

[0082] The process hole during the processing of the second straight section 162 of the connecting channel 16 mentioned above can be formed on the end surfaces of the first shell 11 and the second shell 12 close to the diaphragm 20, and the process hole is located within the circle of the sealing member 60, and the sealing member 60 can also play a sealing role (the sealing member 60 does not block the process hole, but surrounds it), so there is no need to put a sealing steel ball 164 in the process hole.

[0083] An embodiment of the present application also provides a leakage detection device, comprising the capacitive differential pressure sensor in any of the above embodiments.

[0084] Since the leakage detection device of the embodiment of the present application includes the capacitive differential pressure sensor in any of the above embodiments, it has the beneficial effects brought by the capacitive differential pressure sensor in any of the above embodiments, which will not be elaborated here.

[0085] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A capacitive differential pressure sensor, characterized in that: include: a housing, wherein an inner cavity is formed in the housing; A diaphragm is disposed in the housing and divides the inner cavity into two detection cavities; as well as Two electrode assemblies, corresponding to the two detection cavities one by one, respectively, the electrode assembly comprises an electrode and a conductive rod, the electrode is arranged in the detection cavity, one side of the electrode is opposite to the diaphragm, the conductive rod comprises an outer connecting section, a fixed section and an inner contact section connected in sequence, the outer connecting section is located outside the shell, the fixed section is installed on the shell, the inner contact section is located in the detection cavity, and the inner contact section elastically abuts against the electrode; Wherein, the shell is further provided with two fluid channels, and the two fluid channels correspond to the two detection chambers one by one respectively, one end of the fluid channel is connected to the corresponding detection chamber, and the other end is used for inputting pressure fluid.

2. The capacitive differential pressure sensor according to claim 1, characterized in that: The shell is provided with two through holes, and the two through holes respectively connect the two detection chambers with the outside world. A fixed section is passed through the through holes and connected to the shell.

3. The capacitive differential pressure sensor according to claim 2, characterized in that: The electrode has a side surface opposite to the through hole, and the side surface includes a first circumferential surface, defining a plane, the plane is perpendicular to the axis of the first circumferential surface, the projection of the axis of the through hole on the plane intersects with the projection of the first circumferential surface on the plane and does not pass through the center of the projection of the first circumferential surface.

4. The capacitive differential pressure sensor according to claim 2, characterized in that: The electrode assembly further comprises a hollow fixing sleeve, which is sleeved on the conductive rod and a first insulating fixing adhesive layer is filled between the inner wall of the fixing sleeve and the conductive rod, and the fixing sleeve is fixed at the outer end of the through hole.

5. The capacitive differential pressure sensor according to claim 2, characterized in that: The distance between the inner end of the through hole and the electrode is smaller than the length of the inner contact segment in a natural state, and the inner contact segment undergoes elastic deflection deformation.

6. The capacitive differential pressure sensor according to claim 1, characterized in that: The electrode is provided with a positioning groove, and the inner contact section is partially embedded in the positioning groove and abuts against the inner wall of the positioning groove.

7. The capacitive differential pressure sensor according to claim 6, characterized in that: The width of the positioning groove gradually increases from inside to outside.

8. The capacitive differential pressure sensor according to claim 1, characterized in that: The electrode divides the detection cavity into a first buffer zone and a second buffer zone, the second buffer zone is located between the electrode and the diaphragm, the first buffer zone is located on the side of the electrode away from the diaphragm, the fluid channel is connected to the first buffer zone, and the shell is also provided with a connecting channel connecting the first buffer zone and the second buffer zone.

9. The capacitive differential pressure sensor according to claim 8, characterized in that: The first buffer zone has a first circumferential inner wall, the inner end of the fluid channel is opened on the first circumferential inner wall, and the opening direction of the inner end of the fluid channel is tangent to the first circumferential inner wall.

10. The capacitive differential pressure sensor according to claim 9, characterized in that: The second buffer zone has a second circumferential inner wall, one end of the connecting channel is opened on the first circumferential inner wall and the opening direction is tangent to the first circumferential inner wall, and the other end of the connecting channel is opened on the second circumferential inner wall.

11. The capacitive differential pressure sensor according to claim 1, characterized in that: The capacitive differential pressure sensor further comprises a sealing plug, the housing is provided with a diversion port, the diversion port is communicated with the detection cavity, and the sealing plug can detachably seal the diversion port.

12. The capacitive differential pressure sensor according to any one of claims 1 to 11, characterized in that: The housing comprises a first shell and a second shell fastened together, the diaphragm is clamped between the first shell and the second shell, a detection cavity is formed between the diaphragm and the first shell, and another detection cavity is formed between the diaphragm and the second shell.

13. The capacitive differential pressure sensor according to claim 12, characterized in that: The capacitive differential pressure sensor also includes a pressure ring. The end faces of the first shell and the second shell close to the diaphragm are both provided with a circle of grooves. The pressure ring is located on one side of the diaphragm and is embedded in one of the grooves and presses the diaphragm into another groove.

14. The capacitive differential pressure sensor according to claim 12, characterized in that: The capacitive differential pressure sensor further includes two sealing members, one of which is disposed between the diaphragm and the first housing, and the other of which is disposed between the diaphragm and the second housing.

15. A leakage detection device, characterized in that: Comprising a capacitive differential pressure sensor as claimed in any one of claims 1 to 14.

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