Pressure sensor

Abstract

A pressure sensor capable of effectively reducing environmental liquid invasion comprises a housing defining a mounting cavity, the housing comprises a main housing body and an upper cover, the upper cover comprises a main body part substantially extending horizontally, the upper cover is provided with a vent hole, and the lower end of the vent hole is communicated to the mounting cavity and covered by a waterproof breathable film; one end of the inner side of the ventilation channel is communicated to the ventilation hole, and one end of the outer side of the ventilation channel is communicated to the environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a pressure sensor. BACKGROUND

[0002] When measuring gauge pressure, the pressure sensor needs to introduce the ambient or atmospheric pressure to the pressure sensitive element through the air passage. The air passage of the existing gauge pressure sensor is usually arranged on the upper cover. Since it is not effectively covered, when the environment is relatively harsh, especially when there is a jet flow outside the sensor, there is still a risk that the liquid will enter the inside of the sensor. CONTENT OF THE UTILITY MODEL

[0003] In view of the deficiencies of the prior art, the present application provides a pressure sensor to effectively reduce the invasion of environmental liquid into the inside of the sensor.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a pressure sensor, comprising:

[0005] a housing enclosing an installation cavity, comprising a main shell and an upper cover, the upper cover comprising a main body portion extending substantially horizontally, the upper cover being provided with an air hole, the lower end of the air hole being communicated to the installation cavity and being covered by a waterproof air permeable film;

[0006] and an air passage enclosed by the main shell and the upper cover, the inner side of the air passage being communicated to the air hole, and the outer side of the air passage being communicated to the environment.

[0007] Preferably, the pressure sensor further comprises:

[0008] a pressure introduction passage for introducing the medium to be measured, the inner side of the pressure introduction passage being communicated to the installation cavity;

[0009] a pressure measurement assembly arranged in the installation cavity, comprising at least one pressure sensitive element, one side of the pressure sensitive element being sealingly communicated to the inner side of the pressure introduction passage.

[0010] Preferably, the upper cover further comprises a plate member; the plate member comprises a vertical portion and a connecting portion; the vertical portion is arranged on the left and right sides of the main shell and encloses a first part of the air passage between the vertical portion and the side surface of the corresponding left and right sides of the main shell; one end of the connecting portion is integrally connected to the upper end of the vertical portion, and the other end extends to the upper side of the main body portion; the part of the connecting portion located above the main body portion is integrally connected to the main body portion through a ring of surrounding walls, and encloses a second part of the air passage with the surrounding walls and the main body portion; the air hole is communicated to one end of the second part upward, the other end of the second part is communicated to the upper end of the first part, and the lower end of the first part is communicated to the environment.

[0011] Preferably, the side surface is outwardly convex to form two side baffles facing each other in front and back directions, and the ends of the side baffles away from the side surface are close to the corresponding side wall of the plate member.

[0012] Preferably, the corresponding side wall of the plate member is convex to the side of the side surface to form a pair of first positioning ribs close to the inner sides of the two side baffles in front and back directions.

[0013] Preferably, the corresponding side wall of the plate member is convex to the side of the side surface to form a pair of second positioning ribs close to the outer sides of the two side baffles in front and back directions.

[0014] Preferably, the lower end of the vertical portion is convex to the side of the side surface and beyond the side surface to form a fastening portion, at least one pair of the positioning ribs is convex to the side of the side surface and beyond the side surface to form a supporting rib, the bottom surface of the main housing corresponding to the side surface stops the supporting rib from downward, and the lower end of the supporting rib is integrally connected to the upper end surface of the fastening portion.

[0015] Preferably, the side surface is outwardly convex to form at least one partition plate spaced in up and down directions, and each of the partition plates has a ventilation opening.

[0016] Preferably, the side surface is outwardly convex to form at least two partition plates spaced in up and down directions, and each of the partition plates has a ventilation opening; for each of the two partition plates adjacent in up and down directions, the ventilation opening of one of the partition plates is arranged on the front end portion of the corresponding partition plate, and the ventilation opening of the other of the partition plates is arranged on the rear end portion of the corresponding partition plate.

[0017] Preferably, the portions of the surrounding wall beyond the main body portion are downwardly extended to form side cover plates shielding the upper ends of the side baffles from the front and rear outer sides.

[0018] Preferably, the side wall of the connecting portion toward the side of the main housing is a cylindrical surface axially and forwardly and rearwardly extended. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a perspective view of the pressure sensor of the first embodiment;

[0020] Figure 2 It is a front view of the partial structure of the pressure sensor of the first embodiment; Figure 1 It is a sectional view of the pressure sensor of the first embodiment along A-A shown in FIG. 2;

[0021] Figure 3 It is a front view of the partial structure of the pressure sensor of the first embodiment;

[0022] Figure 4Fig. 3 is a left view of a partial structure of a main housing of a second embodiment;

[0023] Figure 5 Fig. 4 is a perspective view of a partial structure of a main housing of a third embodiment;

[0024] Figure 6 Fig. 5 is a left view of a partial structure of a main housing of a third embodiment;

[0025] Figure 7 Fig. 6 is a perspective view of a partial structure of an upper cover of a third embodiment;

[0026] Figure 8 Fig. 7 is a sectional view of a pressure sensor of a fourth embodiment;

[0027] BRIEF DESCRIPTION OF DRAWINGS 100, pressure sensor; 10, mounting cavity; 111, side surface; 112, bottom surface; 113, side baffle; 11, main body portion; 120, pressure introduction passage; 121, sealing sleeve; 12, pressure interface; 13, end knob; 1, main housing; 200, pressure sensor; 201, side wall; 20, plate member; 21a, vent hole; 21, main body portion; 22a, positioning protrusion; 22, sealing flange; 230, connecting portion; 231, enclosing wall; 234, side cover plate; 240, vertical portion; 241a, notch; 241, positioning rib; 242a, notch; 242, positioning rib; 243, groove; 244, support rib; 245, snap portion; 2, upper cover; 30, pressure sensitive element; 31a, pressure via hole; 31, substrate; 32, enclosing frame; 33, protective gel; 34, lead wire; 36, lead wire; 39a, inner side end; 39, insertion pin; 3, pressure measurement assembly; 5, waterproof and air permeable membrane; 61, second portion; 621a, air vent opening; 621b, air vent opening; 621c, air vent opening; 622, positioning opening; 62a, partition; 62b, partition; 62c, partition; 62, first portion; 6, air permeable passage. DETAILED DESCRIPTION

[0028] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. The following examples are exemplary and are used to explain the present application, but cannot be interpreted as a limitation of the present application. In the following description, the same reference signs are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0029] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the prepositions "first", "second", "third", etc. are only used for the purpose of distinguishing the objects being modified, and cannot be understood as indicating or implying relative importance.

[0030] In addition, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] It should be further understood that the term "and / or" used in the present application specification and corresponding claims means any combination of one or more of the listed items and all possible combinations.

[0032] Please refer to Figures 1 to 4 A pressure sensor 100 of the first embodiment includes a housing (not labeled) which encloses a mounting cavity 10. Specifically, the housing can include a main housing 1 including a main body portion 11 and an upper cover 2. The upper cover 2 includes a main body portion 21 extending generally horizontally. The upper cover 2 is provided with an air hole 21a. The lower end of the air hole 21a communicates with the mounting cavity 10 and is covered by a waterproof air permeable film 5. The lower end of the main housing 1 can be provided with a pressure port 12, the inner cavity of the pressure port 12 forms a pressure introduction passage 120 for introducing the medium to be measured, and the inner side end thereof communicates with the mounting cavity 10. The pressure sensor further includes a pressure measurement assembly 3 disposed in the mounting cavity 10, the pressure measurement assembly 3 includes a pressure sensitive element 30. One side of the pressure sensitive element 30 is sealingly communicated with the inner side end of the pressure introduction passage 120 to obtain the pressure of the medium to be measured. The main housing 1 and the upper cover 2 enclose an air permeable passage 6 for obtaining the ambient pressure (reference pressure) from the environment, the inner side end of the air permeable passage 6 communicates with the air hole 21a, and the outer side end of the air permeable passage 6 communicates with the environment.

[0033] The pressure sensitive element 30 and the pressure introduction channel 120 can also be two or more, for example, two pressure interfaces 12 can be provided to obtain two pressures of the pressure medium to be measured, which can be the same or different, and the relative pressures of the above-mentioned pressures with respect to the ambient pressure are measured by two corresponding pressure sensitive elements 30 respectively and independently, and the difference value or the processed pressure value after the redundancy processing is measured by the processing circuit.

[0034] Specifically, the upper cover 2 further comprises a plate member 20. The plate member 20 comprises a vertical portion 240 and a connecting portion 230. The vertical portion 240 is arranged on the left and right sides of the main housing 1, and the vertical portion 240 and the left and right corresponding side surfaces 111 of the main body portion 11 form a first part 62 of the air passage 6. One end of the connecting portion 230 is integrally connected to the upper end of the vertical portion 240, and the other end of the connecting portion 230 extends to the upper side of the main body portion 21. The part of the connecting portion 230 located above the main body portion 21 is integrally connected to the main body portion 21 by a surrounding wall 231, and the connecting portion 230, the surrounding wall 231 and the main body portion 21 form a second part 61 of the air passage 6. The air vent 21a is connected to one end of the second part 61, the other end of the second part 61 is connected to the upper end of the first part 62, and the lower end of the first part 62 is connected to the environment. In this way, the ambient pressure enters the first part 62 from the lower end of the first part 62, then passes through the second part 61, the air vent 21a and the waterproof air permeable membrane 5, and enters the installation cavity 10, and is obtained by the other side of the pressure sensitive element 30. The pressure sensitive element 30 converts the measured pressure relative to the ambient pressure according to the ambient pressure and the pressure to be measured on both sides. The second part 61 can extend in the left and right directions.

[0035] The connecting portion 230 of the pressure sensor and the vertical first part 62 formed by the main body portion 11 and the left and right extending second part 61 formed inside the upper cover 2 can be effectively connected to the environment, so the structure is simple, and liquid can be effectively prevented from entering the installation cavity 10 by the "L" shaped channel structure.

[0036] In other embodiments, preferably, the side surfaces 111 are outwardly protruded to form two side baffles 113 facing each other in front and back. The ends of the side baffles 113 away from the side surfaces 111 are close to the corresponding side walls 201 of the plate member 20. In this way, liquid can be prevented from entering the inside of the first part 62 from the front and back.

[0037] More preferably, the corresponding side walls 201 of the plate member 20 protrude towards the side surfaces 111 to form a pair of first positioning ribs 241 corresponding to the inner sides of the two side baffles 113.

[0038] In some other embodiments, preferably, the lower end of the vertical portion 240 is extended to one side of the side surface 111 and beyond the side surface 111 to form a clamping portion 245. The positioning rib 241 is extended to one side of the side surface 111 and beyond the side surface 111 to form a supporting rib 244. The bottom surface 112 of the main body portion 11 corresponding to the side surface 111 is extended downward to abut against the supporting rib 244, and the lower end of the supporting rib 244 is integrally connected to the upper end surface of the clamping portion 245. In this way, the lower end of the vertical portion 240 can be fixed to the main body portion 11 by the clamping portion 245, and a third portion (not labeled) of the air passage 6 can be formed by the gap between the two supporting ribs 244 and the bottom surface 112. The third portion of the air passage 6 extends in the left-right direction, with one end connected to the lower end of the first portion 62 and the other end (outlet end) connected to the environment. Moreover, since the outlet end of the third portion is hidden on the lower side of the main body portion 11, the risk of liquid entering the interior of the sensor is further reduced.

[0039] In some other embodiments, preferably, the clamping portion 245 and the vertical portion 240 can be combined into a clasp, and the vertical portion 240 is the main flexible deformation portion when the clasp is connected to the main body portion 11. In order to improve the flexibility of the vertical portion 240, the vertical portion 240 can be made thinner, and / or notches 241a can be provided on the positioning rib 241 and spaced apart in the extending direction.

[0040] In some other embodiments, preferably, the front and rear edges of the surrounding wall 231 extending downward beyond the main body portion 21 form side cover plates 234 that cover the upper end of the side baffle 113 from the front and rear sides, thereby preventing liquid from entering the interior of the sensor from the upper end of the side baffle 113. In this case, the lower edge 234a of the side cover plate 234 is preferably extended downward beyond the upper end of the side baffle 113 and the upper end of the positioning rib 241.

[0041] For example, the edge of the main body portion 21 can be extended downward to form a sealing flange 22, which can be inserted into a sealing groove (not labeled) provided around the upper end opening of the main body portion 11, and the sealing groove can be filled with sealing glue. The outer side surface of the sealing flange 22 can be provided with at least one circumferentially spaced positioning protrusion 22a. In this case, since the positioning between the vertical portion 240 and the clamping portion 245 and the main body portion 11 can be achieved, the left side portion of the sealing flange 22 can be omitted from the positioning protrusion 22a.

[0042] For example, the pressure measurement assembly 3 can include a substrate 31, which is sealingly fixed to the inner side end of the pressure introduction passage 120 (i.e. Figure 2The substrate 31 is provided with a pressure hole 31a for allowing the medium to pass through. The pressure sensitive element 30 is sealed and fixed to the upper end of the pressure hole 31a. The lower end of the pressure hole 31a is connected to the inner end of the pressure introduction channel 120. The side surface of the substrate 31 away from the pressure introduction channel 120 (i.e. Figure 2 The upper surface shown in FIG) may be provided with a processing circuit (not labeled), which is connected to the first lead (see FIG) Figure 8 36 in the figure) is electrically connected to the pressure sensitive element 30. A frame 32 may also be fixed to the upper surface of the substrate 31, and the frame 32 is filled with a protective gel 33 covering the first lead and the pressure sensitive element 30. The protective gel 33 may be silicone gel or fluorosilicone gel. A terminal button 13 may be connected to the right side of the main body 11, and a plurality of pins 39 are molded in the terminal button 13. The inner end 39a of the pin 39 is passed through the terminal button 13 inwardly and is electrically connected to the processing circuit through the lead 34. A sealing sleeve 121 may be provided on the outside of the pressure interface 12. Several positioning portions 15 may also be provided on the side of the main body 11 (for example, the front and rear sides).

[0043] See also Figure 4 On the basis of the first embodiment, in the pressure sensor of the second embodiment, its side surface 111 protrudes outward to form upper and lower partitions 62a, 62b and 62c. A vent opening 621a is provided on the partition 62a, a vent opening 621b is provided on the partition 62b, and a vent opening 621c is provided on the partition 62c. Preferably, the vent openings of the partitions 62a to 62c are alternately provided on the left and right sides. For example, the vent opening 621a of the partition 62a can be provided on the rear end portion of the corresponding partition 62a, the vent opening 621b of the partition 62b can be provided on the front end portion of the corresponding partition 62a, and the vent opening 621c of the partition 62c can be provided on the rear end portion of the corresponding partition 62a. In this way, the liquid needs to flow along the inner side of the first part 62 Figure 4 The sensor is passed in the direction of the broad arrow shown in the figure, thereby reducing the risk of liquid intrusion into the interior of the sensor.

[0044] See also Figures 5 to 7Compared with the first embodiment, in the third embodiment, the corresponding side wall 201 of the plate member 20 can further protrude towards one side of the side surface 111 to form a pair of positioning ribs 242 corresponding to the front and rear outer sides of the two side baffles 113. In this way, the liquid can be less likely to intrude into the first portion 62 from the front and rear sides. When the pair of first positioning ribs 241 and the pair of positioning ribs 242 are provided at the same time, a groove 243 can be formed between one of the positioning ribs 241 and the positioning rib 242 on the front and rear sides, and the end of the side baffle 113 away from the side surface 111 can be accommodated in the groove 243. Preferably, the positioning rib 242 is provided with a plurality of notches 242a distributed at intervals along the extending direction, and the positioning rib 242 can also be provided with a supporting rib 244. In other schemes, the positioning rib 242 and the positioning rib 241 can be provided alternatively.

[0045] Compared with the second embodiment, in the third embodiment, when the positioning rib 241 is provided, the partition plates 62a-62c can also be provided with positioning openings 622 for giving way to the positioning rib 241.

[0046] In the above embodiments, in order to facilitate the molding of the upper cover 2, the right end of the second portion 61 can pass through to the outer side surface of the surrounding wall 231 to form a through port (not labeled). When assembling the pressure sensor 200, the sealing glue can be filled in the sealing groove first, and then the upper cover 2 is combined to the main shell 1, and the sealing glue is applied at the through port, and the above sealing glue can be cured in the same subsequent process. In the above embodiments, the positioning rib 242 can also be arranged coplanarly with the side cover plate 234, and can be further integrally connected up and down.

[0047] Please refer to Figure 8 On the basis of the above embodiments, in the fourth embodiment of the pressure sensor 200, in order to facilitate the molding of the upper cover 2, the side wall 201 of the connecting portion 230 towards the side of the main shell 1 is an axially front and rear extending cylindrical surface. In this way, it is beneficial for the rotation demolding of the mold core for molding the second portion 61.

[0048] The scope of the disclosure is not limited by the detailed description, but is defined by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are interpreted as being included in the disclosure.

Claims

1. A pressure sensor, characterized by, The application relates to a pressure sensor, comprising: an outer shell enclosing an installation cavity (10), which comprises a main shell (1) and an upper cover (2), wherein the upper cover (2) comprises a main body part (21) extending horizontally, and a vent hole (21a) is arranged on the upper cover (2), the lower end of the vent hole (21a) is communicated with the installation cavity (10) and is covered by a waterproof and air-permeable film (5); and an air-permeable channel (6) enclosed by the main shell (1) and the upper cover (2), the inner end of the air-permeable channel (6) is communicated with the vent hole (21a), and the outer end of the air-permeable channel (6) is communicated with the environment.

2. The pressure sensor of claim 1, wherein, The pressure sensor further comprises: a pressure introduction channel (120) for introducing a medium to be measured, the inner end of the pressure introduction channel (120) is communicated with the installation cavity (10); and a pressure measurement assembly (3) arranged in the installation cavity (10), which comprises at least one pressure sensitive element (30), one side of the pressure sensitive element (30) is sealedly communicated with the inner end of the pressure introduction channel (120).

3. The pressure sensor of claim 1, wherein, The upper cover (2) further comprises a plate member (20), the plate member (20) comprises a vertical part (240) and a connecting part (230), the vertical part (240) is arranged on the left and right sides of the main shell (1) and encloses a first part (62) of the air-permeable channel (6) with the side surfaces (111) on the left and right sides of the main shell (1), one end of the connecting part (230) is integrally connected to the upper end of the vertical part (240), and the other end extends to the upper side of the main body part (21), the part of the connecting part (230) above the main body part (21) is integrally connected to the main body part (21) through a surrounding wall (231) and encloses a second part (61) of the air-permeable channel (6) with the surrounding wall (231) and the main body part (21), the vent hole (21a) is communicated with one end of the second part (61) in the upward direction, the other end of the second part (61) is communicated with the upper end of the first part (62), and the lower end of the first part (62) is communicated with the environment.

4. The pressure sensor of claim 3, wherein, The side surfaces (111) are outwardly protruded to form two side baffles (113) which are spaced apart in the front and back directions, and the ends of the side baffles (113) away from the side surfaces (111) are close to the corresponding side walls (201) of the plate member (20).

5. The pressure sensor of claim 4, wherein, The corresponding side walls (201) of the plate member (20) are protruded towards the side surfaces (111) to form a pair of first positioning ribs (241) which are close to the inner sides of the two side baffles (113) in the front and back directions.

6. The pressure sensor of claim 5, wherein, The corresponding side walls (201) of the plate member (20) are protruded towards the side surfaces (111) to form a pair of second positioning ribs (242) which are close to the outer sides of the two side baffles (113) in the front and back directions.

7. The pressure sensor of claim 6, wherein, The lower end of the vertical portion (240) protrudes toward and beyond the side surface (111) to form a fastening portion (245), and at least one pair of positioning ribs protrudes toward and beyond the side surface (111) to form a supporting rib (244), the bottom surface (112) of the main housing (1) corresponding to the side surface (111) blocks the supporting rib (244) from below, and the lower end of the supporting rib (244) is integrally connected to the upper end surface of the fastening portion (245).

8. The pressure sensor of claim 4, wherein, The side surface (111) protrudes outward to form at least one partition plate (62a) spaced vertically, and each partition plate (62a) has a ventilation opening (621a).

9. The pressure sensor of claim 4, wherein, The side surface (111) protrudes outward to form at least two partition plates (62a) spaced vertically, and each partition plate (62a) has a ventilation opening (621a); for each pair of two vertically adjacent partition plates (62a), the ventilation opening (621a) of one partition plate (62a) is arranged on the front end portion of the corresponding partition plate (62a), and the ventilation opening (621a) of the other partition plate (62a) is arranged on the rear end portion of the corresponding partition plate (62a).

10. The pressure sensor of claim 4, wherein, The front and rear edges of the portion of the surrounding wall (231) beyond the main body portion (21) extend downward to form side cover plates (234) shielding the upper end of the side baffle (113) from the front and rear sides.

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