A pressure sensor

Abstract

A pressure sensor comprises: a pressure connector having a longitudinally extending pressure channel therein; a pressure-sensitive head having a longitudinal distal end recessed inwardly to form a connecting tube having a distal sensing cavity, and a corresponding elastic diaphragm formed on a longitudinal proximal end thereof; the proximal end of the connecting tube being sealedly connected to the pressure connector so that the proximal end of the pressure channel is connected to the sensing cavity; the distal outer edge of the pressure connector protruding outwardly and extending beyond the periphery of the pressure-sensitive head to form an assembly flange that, together with the housing and the pressure connector, encloses the terminal button and housing to form the mounting cavity; a mounting seat and a signal processing assembly disposed within the mounting cavity, the signal processing assembly being disposed on the mounting seat; the mounting seat having a pressure cylinder whose distal end presses against the pressure connector; the assembly flange supporting the inner wall of the pressure cylinder in a transverse plane, with a gap being left between the periphery of the pressure-sensitive head and the pressure cylinder. The pressure sensor can isolate the elastic diaphragm of the pressure-sensitive head from other components to avoid measurement deviation.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a pressure sensor. Background Art

[0002] Pressure sensors using pressure-sensitive heads measure pressure by introducing a pressure fluid through one side of a metal diaphragm and installing a Wheatstone bridge circuit composed of strain gauges or thick-film piezoresistors on the other surface. In the Chinese patent application with publication number CN115406565A, the pressure diaphragm and support member are susceptible to contact, leading to measurement errors.

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a pressure measurement assembly and a pressure sensor to isolate the elastic diaphragm of the pressure sensitive head from other components to avoid measurement deviation.

[0005] To achieve the above object, the present invention provides the following technical solution: a pressure sensor comprising:

[0006] A pressure joint having a longitudinally extending pressure channel therein;

[0007] The pressure sensitive head has a longitudinal distal end that is recessed inward to form a connecting tube with a distal sensing cavity, and a longitudinal proximal end that forms an elastic diaphragm. A pressure measuring circuit is provided on the longitudinal proximal end surface of the elastic diaphragm. The proximal end of the connecting tube is sealed to the pressure connector so that the proximal end of the pressure channel is connected to the sensing cavity; the distal outer edge of the pressure connector protrudes outward and passes over the periphery of the pressure sensitive head to form an assembly flange.

[0008] The terminal button and the housing together with the pressure connector form the installation cavity;

[0009] A mounting base and a signal processing assembly are disposed within the mounting cavity. The signal processing assembly is disposed on the mounting base and electrically connected to a pressure measurement circuit. The mounting base has a pressure cylinder whose distal end presses against the pressure connector. The mounting flange rests against the inner wall of the pressure cylinder in a transverse plane, with a gap being left between the periphery of the pressure sensitive head and the pressure cylinder.

[0010] and a plurality of electrical connectors, which penetrate the terminals and are electrically connected to the signal processing components.

[0011] Preferably, the shell includes a cylindrical shell extending longitudinally and sealedly connected to the pressure joint at the distal end, and a circle of pressing edge formed by the longitudinal proximal end of the cylindrical shell vertically gathered inward; the pressing edge is pressed against the periphery of the terminal button toward the distal end to press the terminal button and the mounting seat onto the pressure joint.

[0012] Preferably, the longitudinal proximal end of the pressure connector and the part close to the proximal end respectively protrude laterally outward to form a flange and a supporting connecting ring, and the connecting tube is fitted on the flange and supported and welded to the supporting connecting ring; the flange, the supporting connecting ring and the connecting tube form an annular cavity.

[0013] Preferably, the distal end of the metal base protrudes outward to form a circle of protrusions.

[0014] Preferably, the signal processing component includes a horizontal plate, a first flexible plate, a vertical plate, a second flexible plate and a first conductive connection part connected in sequence, and the horizontal plate, the vertical plate and the first conductive connection part are arranged in sequence from near to far; the first conductive connection part is electrically connected to the pressure measurement circuit.

[0015] Preferably, the mounting seat extends longitudinally and its side is recessed inward to form a receiving groove for accommodating the longitudinal plate, and its proximal end and distal end relatively form a top plate and a semicircular bottom plate; the horizontal plate is supported and fixed on the proximal surface of the top plate; the bottom plate is partially sealed to the proximal end of the pressure cylinder; the distal end of the pressure cylinder is pressed against a support step formed on the pressure joint.

[0016] Preferably, at least one first buckle connected to the longitudinal plate is provided on each of the two lateral sides of the accommodating groove.

[0017] Preferably, a side of the bottom plate is provided with a clearance opening extending to the bottom plate for the second flexible plate to pass through; a second flexible plate arrangement groove is provided on the proximal end side of the bottom plate and is laterally connected to the clearance opening.

[0018] Preferably, a first flexible plate arrangement groove is provided on the edge of the top plate, which extends longitudinally and is connected to the accommodating groove toward the distal side. The first flexible plate arrangement groove and the yielding opening are located at the same position in the circumferential direction of the mounting seat; the mounting seat protrudes toward the proximal side to form a guide column, and the guide column is provided with a first guide hole opened on the horizontal plate toward the proximal end.

[0019] Preferably, a plurality of fourth conductive connection parts are provided on the proximal surface of the transverse plate; the electrical connection member is an elastic member, the distal end of which passes through the terminal button and the end plate and then electrically contacts the fourth conductive connection part. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A front view of a pressure sensor according to a preferred embodiment of the present invention;

[0021] Figure 2 A pressure sensor according to a preferred embodiment of the present invention is provided along Figure 1 sectional view of AA shown in FIG;

[0022] Figure 3 A perspective view of a pressure sensor according to a preferred embodiment of the present invention (housing omitted);

[0023] Figure 4 The structure of the pressure sensor according to a preferred embodiment of the present invention is as follows Figure 1 The three-dimensional cutaway view shown in ;

[0024] Figure 5 A perspective view of a signal processing component according to a preferred embodiment of the present invention;

[0025] In the figure: 1. Pressure connector; 100. Pressure channel; 101. Connecting pipe; 102. Small diameter section; 103. Large diameter section; 104. Bell mouth; 105. Support connecting ring; 106. Flange; 107. Annular cavity; 108. Circumferential positioning portion; 109. Stress isolation groove; 110. Support step; 111. Assembly flange; 2. Pressure sensitive head; 201. Metal base; 202. Connecting cylinder; 203. Sensing cavity; 204. Elastic diaphragm; 205. Protrusion; 3. Terminal button; 304. Pressing portion; 305. Holding cavity; 306. Pressure-bearing area; 4. Mounting seat; 400. Mounting cavity; 401. Pressure cylinder; 402. Accommodating groove; 403. First buckle; 404. Disassembly hole; 405. Clearance opening; 407, second flexible board arrangement slot; 410, guide pillar; 411, first flexible board arrangement slot; 414, operation port; 416, second subtractive blind hole; 417, bottom plate; 418, top plate; 5, signal processing component; 501, vertical plate; 502, horizontal plate; 503, first flexible board; 504, second flexible board; 505, second conductive connection portion; 506, first conductive connection portion; 507, fourth conductive connection portion; 508, first guide hole; 510, third conductive connection portion; 511a, conditioning element; 511b, other electronic components; 512a, first protective adhesive; 512b, second protective adhesive; 513, frame; 6, electrical connector; 601, transition section; 7, housing; 702, edge press; DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. The following embodiments are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. In the following description, the same reference numerals are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0027] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component 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 invention.

[0028] Furthermore, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0029] It should be further understood that the term "and / or" used in the present description and the corresponding claims refers to any and all possible combinations of one or more of the listed items.

[0030] like Figure 2 As shown. The pressure sensor of this embodiment uses such a pressure measuring assembly, which includes a pressure connector 1 and a pressure sensitive head 2. Among them, a pressure channel 100 extending longitudinally (i.e., the up and down direction in the figure) is provided in the pressure connector 1. The longitudinal distal end (i.e., the bottom in the figure) of the pressure sensitive head 2 is recessed inward to form a connecting tube 202 having a distal sensing cavity 203, and the longitudinal proximal end of the pressure sensitive head 2 is correspondingly formed with an elastic diaphragm 204. A pressure measuring circuit is provided on the surface of the longitudinal proximal end of the elastic diaphragm 204. The proximal end of the connecting tube 202 is sealedly connected to the pressure connector 1 so that the proximal end of the pressure channel 100 is connected to the sensing cavity 203. The distal end of the pressure connector 1 is provided with a connecting pipe 101 connected to the container or pipeline to be measured. The side of the pressure connector 1 can be provided with a concave or straight circumferential positioning portion 108 to facilitate circumferential positioning when connected to the pipeline or container to be measured. Preferably, the above-mentioned pressure measurement circuit is composed of thick film piezoresistors.

[0031] The proximal end of the connecting tube 202 is welded (e.g., laser welded) to the pressure connector 1. The pressure measurement assembly of this embodiment provides a separate structure for the pressure connector 1 and the pressure sensitive head 2, which are connected together by welding, thereby partially isolating the pressure connector from assembly stress during installation.

[0032] In other embodiments, the proximal longitudinal end of the pressure connector 1 preferably extends outward laterally to form a flange 106, and the portion of the pressure connector 1 near the proximal end extends outward laterally to form a support and connecting ring 105. The connecting tube 202 is fitted over the flange 106 and supported and welded to the support and connecting ring 105. The flange 106, the support and connecting ring 105, and the connecting tube 202 enclose an annular cavity 107.

[0033] In this way, the collapsed welding slag can be concentratedly accommodated through the annular cavity during welding, thereby preventing the welding slag from blocking the pressure channel.

[0034] To facilitate the flow of liquid out of the sensing cavity when measuring liquid pressure, the inner diameter of the proximal end of the pressure channel 100 can gradually expand to form a bell mouth 104. In the above-mentioned embodiments, the pressure channel 100 can be a stepped hole with a diameter that increases from proximal to distal. For example, it can be formed by connecting a small-diameter section 102 on the proximal end with a large-diameter section 103 on the distal end. This facilitates the entry of pressurized fluid into the sensing cavity 203. In other embodiments, the pressure channel 100 further includes a large-diameter section 103a connected to the distal end of the large-diameter section 103.

[0035] Please refer to Figures 1 to 4 In a preferred embodiment of the present invention, the pressure sensor includes, in addition to the above-mentioned pressure measuring assembly, a housing 7, a terminal 3, a mounting seat 4, and a signal processing assembly 5. The housing 7 includes a cylindrical shell extending longitudinally and hermetically connected to the pressure connector 1 at its distal end, and a circle of pressure edges 702 formed by vertically contracting the longitudinal proximal end of the cylindrical shell toward the inside. The pressure edge 202 is pressed against the pressure area 306 (e.g., a step surface) formed on the periphery of the terminal 3 toward the distal end, thereby pressing the terminal 3 and the mounting seat 4 onto the pressure connector 1 in turn.

[0036] The terminal 3, the shell 7 and the pressure connector 1 together form an installation cavity 400. The mounting seat 4 and the signal processing component 5 are both arranged in the installation cavity 400. The signal processing component 5 is arranged on the mounting seat 4 and electrically connected to the pressure measurement circuit. The signal from the signal processing component 5 is output outward through a plurality of electrical connectors 6, and one end of the electrical connector 6 is electrically connected to the signal processing component 5 after passing through the terminal 3 toward the distal side. Among them, the signal processing component 5 may include a horizontal plate 502, a first flexible plate 503, a vertical plate 501, a second flexible plate 504 and a first conductive connecting part 506 connected in sequence, and the horizontal plate 502, the vertical plate 501 and the first conductive connecting part 506 are arranged in sequence from near to far. The first conductive connecting part 506 and the pressure measurement circuit can be electrically connected by soldering. Among them, electronic components (such as conditioning components 511b and other electronic components 511a) can be arranged on the vertical plate 501. This arrangement, on the one hand, minimizes the lateral dimensions of the pressure sensor, making it easily adaptable for use in relatively confined spaces (such as centralized sensor modules in automobiles). It also allows for a smooth and convenient connection between the measurement circuitry, which must be arranged horizontally, and the longitudinal plate 501, thus avoiding the difficulties associated with existing bonding processes. These difficulties arise from the fact that the ends of the aluminum or gold wire used in the bonding process must be parallel and the drop must be controlled within 1 mm. Otherwise, bonding requires the use of custom equipment. This is especially true when the surfaces of the two connection points are perpendicular or even non-parallel, making efficient and accurate bonding difficult even with custom equipment. A first protective adhesive 512a can be applied to the other electronic components 512a, while a second protective adhesive 512b can be applied to the conditioning element 511b to protect the electronic components. A frame 513 can be provided around the first and / or second protective adhesives 512a, 512b, to prevent the adhesives from contaminating other parts of the longitudinal plate 501. The frame 513 is provided with adhesive injection holes.

[0037] Please refer to Figures 4 and 5. In order to ensure the reliable installation of the above-mentioned signal processing component 5, the mounting seat 4 extends longitudinally and its side is recessed inward to form a receiving groove 402 for accommodating the longitudinal plate 501, and its proximal end and distal end relatively form a top plate 418 and a semicircular bottom plate 417. The horizontal plate 502 is supported and fixed on the proximal surface of the top plate 418. The bottom plate 417 is partially blocked on the proximal end of a pressure cylinder 401. The distal end of the pressure cylinder 401 is pressed against a support step 110 formed on the pressure connector 1. A stress isolation groove 109 is formed between the support step 110 and the support connecting ring 105 to further isolate the installation stress of the pressure connector 1. At least one first buckle 403 that is clamped to the longitudinal plate 501 is provided on each of the lateral sides of the receiving groove 402, thereby avoiding the use of the glue bonding process widely used in the prior art and improving production efficiency. A disassembly hole 404 can be provided on the sidewall of the pressing cylinder 401, extending parallel to the second flexible plate arrangement slot 407. This disassembly hole 404 extends to the bottom of the receiving slot 402, facilitating removal of the longitudinal plate 501 within the receiving slot 402. A clearance opening 405 extending to the side of the bottom plate 417 is provided for the second flexible plate 504 to pass through. A second flexible plate arrangement slot 407 is provided on the proximal end of the bottom plate 417, laterally connected to the clearance opening 405. A plurality of second material reduction blind holes 416 can be provided on the side of the mounting base 4 facing away from the receiving slot 402.

[0038] A first flexible plate arrangement slot 411 is formed on the edge of the top plate 418 and extends longitudinally and is connected to the accommodating slot 402 toward the distal end. The first flexible plate arrangement slot 411 and the clearance opening 405 are located at the same position in the circumferential direction of the mounting seat 4.

[0039] In other embodiments, the distal periphery of the supporting connecting ring 105 may preferably protrude outward and extend beyond the periphery of the metal base 201 to form a mounting flange 111. The mounting flange 111 may be supported against the inner wall of the pressing cylinder 401 in a transverse plane, with a gap remaining between the periphery of the metal base 201 and the pressing cylinder 401. In this way, the mounting flange 111 and the mounting base 4 can be used for installation and positioning, and the mounting base 4 can be prevented from contacting the metal base 201 and causing deviations in measurement results.

[0040] In other embodiments, the distal end of the metal base 201 preferably extends outward to form a circle of protrusions 205, preferably having a stepped surface. This stepped surface on the outer wall further alleviates the axial transmission of the installation stress between the connecting tube 202 and the supporting connecting ring 105 to the elastic diaphragm 204, thereby reducing measurement errors.

[0041] The pressure cylinder 401 and the pressure sensitive head 2 may be provided with corresponding positioning structures. For example, the assembly flange 111 may be provided with a straight edge, a groove, or a ridge, and the pressure cylinder 401 may be provided with a corresponding straight edge, a groove, or a ridge. This facilitates circumferential positioning of the mounting base 4 and the pressure sensitive head 2.

[0042] The proximal surface of the horizontal plate 502 is provided with a plurality of fourth conductive connection portions 507. The electrical connector 6 is an elastic member, such as a conductive spring, whose distal end can be passed through the terminal button 3 and then pressed against and electrically contacted with the fourth conductive connection portion 507. Preferably, the electrical connector 6 is a conductive spring having two sections with different outer diameters, forming a tapered transition section 601 between the two sections. The terminal button 3 is correspondingly formed with a retaining cavity 305 for accommodating the conductive spring 6. The retaining cavity 305 has a pressing portion 304, which presses the transition section 601 toward the distal end against the fourth conductive connection portion 507. To ensure accurate positioning between the terminal button 3 and the mounting base 4, corresponding positioning structures are provided on the terminal button 3 and the mounting base 4. For example, a guide post 410 may be formed protruding toward the proximal end of the mounting base 4, and the terminal button 3 is correspondingly provided with a first guide hole. Alternatively or additionally, at least one guide foot may be formed protruding toward the mounting base 4 / terminal button 3 from the periphery of the terminal button 3 / mounting base 4, and the guide foot is inserted into a corresponding guide groove provided on the mounting base 4 / terminal button 3. A blind hole (not marked) is provided at the distal end of the terminal button 3 to accommodate the guide post 410.

[0043] In other embodiments, the mounting base 4 preferably extends toward the proximal end to form a guide post 410. The guide post 410 fits snugly into a second guide hole 508 defined in the transverse plate 502. An operating opening 414 is defined on the sidewall of the mounting base 4 opposite the clearance opening 405 to provide space for soldering.

[0044] In other embodiments, a third conductive connection portion 510 is preferably provided on the side of the horizontal plate 502. A second conductive connection portion 505 is provided on the side of the second flexible plate 504. The second conductive connection portion 505 is electrically connected to the metal housing 7 or the pressure connector 1 via a grounding path embedded in the mounting base 4 and then grounded. The third conductive connection portion 510 can be grounded via the housing 7.

[0045] The scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are construed as being included in the disclosure.

Claims

1. A pressure sensor, characterized in that: include: A pressure connector (1) having a longitudinally extending pressure channel (100) disposed therein; The pressure sensitive head (2) has a longitudinal distal end that is recessed inward to form a connecting tube (202) having a distal sensing cavity (203), and a longitudinal proximal end that is correspondingly formed with an elastic diaphragm (204). A pressure measuring circuit is provided on the longitudinal proximal end surface of the elastic diaphragm (204). The proximal end of the connecting tube (202) is sealedly connected to the pressure connector (1) so that the proximal end of the pressure channel (100) is connected to the sensing cavity (203). The distal outer edge of the pressure connector (1) protrudes outward and passes over the peripheral edge of the pressure sensitive head (2) to form an assembly flange (111). A terminal button (3) and a housing (7) which together with the pressure connector (1) form a mounting cavity (400); A mounting seat (4) and a signal processing assembly (5) are arranged in the mounting cavity (400), wherein the signal processing assembly (5) is arranged on the mounting seat (4) and is electrically connected to a pressure measuring circuit; the mounting seat (4) has a pressure cylinder (401) whose distal end presses against the pressure connector (1); the assembly flange (111) is supported on the inner wall of the pressure cylinder (401) in a transverse plane, and a gap is left between the periphery of the pressure sensitive head (2) and the pressure cylinder (401); and a plurality of electrical connectors (6) which penetrate the terminals (3) and are electrically connected to the signal processing components (5); The signal processing component (5) includes a transverse plate (502), a first flexible plate (503), a longitudinal plate (501), a second flexible plate (504) and a first conductive connection portion (506) connected in sequence, wherein the transverse plate (502), the longitudinal plate (501) and the first conductive connection portion (506) are arranged in sequence from near to far; the first conductive connection portion (506) is electrically connected to the pressure measurement circuit; the mounting seat (4) extends longitudinally and its side is recessed inward to form a receiving groove (402) for accommodating the longitudinal plate (501), and its proximal end and distal end are opposite to form a top plate (418) and a semicircular bottom plate (417).

2. The pressure sensor according to claim 1, wherein The housing (7) comprises a cylindrical shell extending longitudinally and hermetically connected to the pressure connector (1) at its distal end, and a circle of pressing edges (702) formed by vertically contracting the longitudinal proximal end of the cylindrical shell toward the inside; the pressing edges (702) are pressed against the peripheral edge of the terminal button (3) toward the distal end to press the terminal button (3) and the mounting seat (4) onto the pressure connector (1).

3. The pressure sensor according to claim 1, wherein The longitudinal proximal end of the pressure connector (1) and the portion close to the proximal end thereof are laterally extended outward to form a flange (106) and a supporting connecting ring (105); the connecting tube (202) is fitted on the flange (106) and supported and welded to the supporting connecting ring (105); the flange (106), the supporting connecting ring (105) and the connecting tube (202) form an annular cavity (107).

4. The pressure sensor according to claim 1, wherein The distal end of the metal base (201) protrudes outward to form a circle of protrusions (205).

5. The pressure sensor according to claim 4, characterized in that The horizontal plate (502) is supported and fixed on the proximal surface of the top plate (418); the bottom plate (417) partially blocks the proximal end of the pressure cylinder (401); the distal end of the pressure cylinder (401) is pressed against a supporting step (110) formed on the pressure joint (1); and the electrical connector (6) is an elastic member.

6. The pressure sensor according to claim 1, wherein At least one first buckle (403) that is clamped to the longitudinal plate (501) is provided on each of the two transverse sides of the accommodating groove (402).

7. The pressure sensor according to claim 1, wherein A side of the bottom plate (417) is provided with a clearance opening (405) extending to the bottom plate (417) for the second flexible plate (504) to pass through; a second flexible plate arrangement groove (407) is provided on the proximal end of the bottom plate (417) and is laterally connected to the clearance opening (405).

8. The pressure sensor according to claim 1, wherein A first flexible plate arrangement groove (411) is provided on the edge of the top plate (418) and extends longitudinally and is connected to the accommodating groove (402) toward the distal end. The first flexible plate arrangement groove (411) and the clearance opening (405) are located at the same position in the circumferential direction of the mounting seat (4). The mounting seat (4) protrudes toward the proximal end to form a guide column (410). The guide column (410) is provided with a first guide hole (508) formed on the transverse plate (502) toward the proximal end.

9. The pressure sensor according to claim 1, wherein The proximal surface of the transverse plate (502) is provided with a plurality of fourth conductive connection parts (507); the electrical connection part (6) is an elastic part, the distal end of which passes through the terminal button (3) and the end plate (701) and then electrically contacts the fourth conductive connection part (507).

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