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 field of sensor technology, and in particular to a pressure sensor. Background Art

[0002] When measuring gauge pressure, the gauge pressure sensor needs to introduce ambient or atmospheric pressure to the pressure sensitive element through the air permeable channel. The air permeable channel of the existing gauge pressure sensor is usually set on the upper cover. Since it is not effectively covered, in harsh environments, especially when there is a jet outside the sensor, these liquids still have a greater risk of entering the sensor. Summary of the invention

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

[0004] To achieve the above objectives, the present application provides the following technical solution: a pressure sensor, comprising:

[0005] A housing enclosing an installation cavity comprises a main shell and an upper cover, wherein the upper cover comprises a main body portion extending substantially horizontally, and the upper cover is provided with a vent hole, the lower end of the vent hole is connected to the installation cavity and is covered by a waterproof breathable membrane;

[0006] and a ventilation channel surrounded by the main shell and the upper cover, wherein one inner end of the ventilation channel is connected to the ventilation hole and one outer end of the ventilation channel is connected to the environment.

[0007] Preferably, the pressure sensor further comprises:

[0008] A pressure introduction channel for introducing a medium to be measured, one inner end of which is connected to the installation cavity;

[0009] The pressure measuring assembly arranged in the installation cavity includes at least one pressure sensitive element, and one side of the pressure sensitive element is sealedly connected to one end of the inner side of the pressure introduction channel.

[0010] Preferably, the upper cover also includes a plate; the plate includes a vertical portion and a connecting portion; the vertical portion is arranged on the left and right sides of the main shell and forms the first portion of the air permeable channel between the side surfaces of the left and right corresponding 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 directly above the main body; the portion of the connecting portion located directly above the main body is integrally connected to the main body through a circle of surrounding walls, and forms the second portion of the air permeable channel together with the surrounding walls and the main body; the air vent is connected upward to one end of the second portion, the other end of the second portion is connected to the upper end of the first portion, and the lower end of the first portion is connected to the environment.

[0011] Preferably, the side surface protrudes outward to form two side baffles spaced apart from each other front to back, and one end of the side baffle away from the side surface abuts against a corresponding side wall of the plate.

[0012] Preferably, a corresponding side wall of the plate protrudes toward one side of the side surface to form a pair of first positioning ribs corresponding to the front and rear inner sides of the two side baffles.

[0013] Preferably, a corresponding side wall of the plate protrudes toward one side of the side surface to form a pair of second positioning ribs correspondingly close to the front and rear outer sides of the two side baffles.

[0014] Preferably, the lower end of the vertical portion protrudes toward one side of the side surface and exceeds the side surface to form a snap-fit ​​portion, at least one pair of the positioning ribs protrude toward one side of the side surface and exceeds the side surface to form a supporting rib, the bottom surface of the main shell corresponding to the side surface blocks the supporting rib downward, and the lower end of the supporting rib is integrally connected to the upper end surface of the snap-fit ​​portion.

[0015] Preferably, the side surface protrudes outward to form at least one partition spaced apart from each other, and each of the partitions has a ventilation opening.

[0016] Preferably, the side surface protrudes outward to form at least two partitions spaced apart vertically, and each partition has a ventilation opening; for each two adjacent partitions vertically, the ventilation opening of one partition is arranged on the front end part of the corresponding partition, and the ventilation opening of the other partition is arranged on the rear end part of the corresponding partition.

[0017] Preferably, the front and rear edges of the portion of the surrounding wall that exceeds the main body portion extend downward to form a side cover plate that blocks the upper end of the side baffle plate from the front and rear outer sides.

[0018] Preferably, the side wall of the connecting portion facing the main shell is a cylindrical surface extending axially forward and backward. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional diagram of the pressure sensor of the first embodiment;

[0020] Figure 2 The pressure sensor of the first embodiment is Figure 1 A cross-sectional view of AA shown in FIG.

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

[0022] Figure 4It is a left side view of a part of the structure of the main housing of the second embodiment;

[0023] Figure 5 A three-dimensional diagram of a partial structure of a main housing of a third embodiment;

[0024] Figure 6 It is a left side view of a part of the structure of the main housing of the third embodiment;

[0025] Figure 7 A three-dimensional diagram of a partial structure of an upper cover of the third embodiment;

[0026] Figure 8 is a cross-sectional view of a pressure sensor according to a fourth embodiment;

[0027] Explanation of reference numerals: 100, pressure sensor; 10, mounting cavity; 111, side surface; 112, bottom surface; 113, side baffle; 11, main body; 120, pressure introduction channel; 121, sealing sleeve; 12, pressure interface; 13, terminal; 1, main housing; 200, pressure sensor; 201, side wall; 20, plate; 21a, vent hole; 21, main body; 22a, positioning protrusion; 22, sealing flange; 230, connecting portion; 231, surrounding wall; 234, side cover plate; 240, vertical portion; 241a, notch; 241, positioning rib; 242a , notch; 242, positioning rib; 243, groove; 244, supporting rib; 245, buckle part; 2, upper cover; 30, pressure sensitive element; 31a, pressure via; 31, substrate; 32, frame; 33, protective gel; 34, lead; 36, lead; 39a, inner end; 39, pin; 3, pressure measurement component; 5, waterproof breathable membrane; 61, second part; 621a, ventilation opening; 621b, ventilation opening; 621c, ventilation opening; 622, positioning opening; 62a, partition; 62b, partition; 62c, partition; 62, first part; 6, ventilation channel. DETAILED DESCRIPTION

[0028] The technical solution of the present application 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 application, and cannot be interpreted as limiting the present application. In the following description, the same symbols 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 directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or the directions or positional relationships in which the products of the present application are usually placed when in use, or the directions or positional relationships usually understood by those skilled in the art, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the equipment or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limitations on the present application. In addition, the prepositive terms "first", "second", "third", etc. are only used to distinguish the modified objects, and cannot be understood as indicating or implying relative importance.

[0030] In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] It should be further understood that the term “and / or” used in the specification and corresponding claims of this application refers to any and all possible combinations of one or more of the listed items.

[0032] Please refer to Figures 1 to 4 . A pressure sensor 100 of the first embodiment includes a shell (not marked) which encloses a mounting cavity 10. Specifically, the shell may include a main shell 1 and an upper cover 2, and the main shell 1 includes a main body 11. The upper cover 2 includes a main body 21 extending substantially horizontally. A vent 21a is provided on the upper cover 2. The lower end of the vent 21a is connected to the mounting cavity 10 and is covered by a waterproof breathable membrane 5. A pressure interface 12 may be provided at the lower end of the main shell 1, and the inner cavity of the pressure interface 12 forms a pressure introduction channel 120 for introducing a medium to be measured, and one inner end thereof is connected to the mounting cavity 10. The pressure sensor also includes a pressure measurement assembly 3 arranged in the mounting cavity 10, and the pressure measurement assembly 3 includes a pressure sensitive element 30. One side of the pressure sensitive element 30 is sealedly connected to one inner end of the pressure introduction channel 120 to obtain the pressure of the medium to be measured. The main shell 1 and the upper cover 2 form a ventilation channel 6 for obtaining ambient pressure (reference pressure) from the environment. An inner end of the ventilation channel 6 is connected to the vent hole 21a, and an outer end of the ventilation channel 6 is connected to the environment.

[0033] Among them, 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 set to respectively obtain two pressures (which can be the same or different) of the pressure medium to be measured, and the relative pressures of the above pressures relative to the ambient pressure are independently measured by two corresponding pressure sensitive elements 30. Then, the difference is taken or redundant processing is performed through the processing circuit to measure the processed pressure value such as the difference between the above two pressures.

[0034] Specifically, the upper cover 2 may further include a plate 20. The plate 20 may include a vertical portion 240 and a connecting portion 230. The vertical portion 240 is disposed on the left and right sides of the main housing 1, and the vertical portion 240 and the side surface 111 on the left and right corresponding sides of the main body 11 form a first portion 62 of the air permeable channel 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 top of the main body 21. The portion of the connecting portion 230 located just above the main body 21 is integrally connected to the main body 21 through a circle of surrounding walls 231, and the connecting portion 230, the surrounding walls 231, and the main body 21 form a second portion 61 of the air permeable channel 6. The vent 21a is upwardly connected to one end of the second portion 61, the other end of the second portion 61 is connected to the upper end of the first portion 62, and the lower end of the first portion 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 vent hole 21a and the waterproof breathable membrane 5, 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 pressure to be measured into the relative pressure of the ambient pressure according to the ambient pressure and the pressure to be measured on both sides. The second part 61 can generally extend in the left-right direction.

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

[0036] In some other solutions, preferably, the side surface 111 protrudes outward to form two side baffles 113 spaced apart from each other in the front and rear directions. One end of the side baffle 113 away from the side surface 111 is close to the corresponding side wall 201 of the plate 20. In this way, liquid can be prevented from invading the interior of the first portion 62 from both the front and rear sides.

[0037] More preferably, the corresponding side wall 201 of the plate 20 protrudes toward the side surface 111 to form a pair of first positioning ribs 241 corresponding to and close to the front and rear inner sides of the two side baffles 113 .

[0038] In some other schemes, preferably, the lower end of the vertical portion 240 protrudes toward the side surface 111 and crosses the side surface 111 to form a buckle portion 245. The positioning rib 241 protrudes toward the side surface 111 and crosses the side surface 111 to form a support rib 244. The bottom surface 112 of the main body 11 corresponding to the side surface 111 blocks the support rib 244 downward, and the lower end of the support rib 244 is integrally connected to the upper end surface of the buckle portion 245. In this way, the lower end of the vertical portion 240 can be fixed to the main body 11 through the buckle portion 245, and the third part (not marked) of the air permeable channel 6 is formed by the gap between the two support ribs 244 and the bottom surface 112. The third part of the air permeable channel 6 extends left and right, one end of which is connected to the lower end of the first part 62, and the other end (the outlet end) is connected to the environment. Furthermore, since one end of the outlet of the third portion is hidden at the lower side of the main body 11, the risk of liquid intruding into the interior of the sensor is further reduced.

[0039] The buckle portion 245 and the vertical portion 240 can be combined into a buckle, and the vertical portion 240 is the main flexible deformation portion when the buckle is connected to the main body 11. In order to improve the flexibility of the vertical portion 240, the vertical portion 240 can be set to be thinner, and / or notches 241a distributed at intervals along the extension direction can be set on the positioning rib 241.

[0040] In some other solutions, preferably, the front and rear edges of the part of the surrounding wall 231 that exceeds the main body 21 extend downward to form a side cover plate 234 that shields the upper end of the side baffle plate 113 from the front and rear outer sides, thereby preventing liquid from invading the interior of the sensor from the upper end of the side baffle plate 113. Among them, the lower edge 234a of the side cover plate 234 is preferably able to pass downward over the upper end of the side baffle plate 113 and the upper end of the positioning rib 241.

[0041] For example, the edge of the main body 21 may protrude downward to form a circle of sealing flange 22, and the sealing flange 22 may be inserted into a circle of sealing groove (not marked) arranged around an upper end opening of the main body 11, and the sealing groove is filled with sealant. The outer surface of the sealing flange 22 may be provided with at least one circumferentially spaced positioning protrusion 22a, wherein, since the positioning between the sealing flange 22 and the main body 11 can be achieved by the vertical portion 240 and the buckle portion 245, the positioning protrusion 22a may be omitted on the left side of the sealing flange 22.

[0042] For example, the pressure measurement assembly 3 may include a substrate 31, which is sealed and fixed to one end of the inner side of the pressure introduction channel 120 (i.e. Figure 2The substrate 31 is provided with a pressure hole 31a for allowing the medium to be measured 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. 1 may be provided with a processing circuit (not labeled), which is connected to the upper surface of the first lead (see FIG. 1 ). Figure 8 The substrate 31 is electrically connected to the pressure sensitive element 30 (mark 36 in the figure). 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 (e.g., the front and rear sides) of the main body 11.

[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 a partition 62a, a partition 62b and a partition 62c spaced apart from each other. 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 arranged on the left and right sides. For example, the vent opening 621a of the partition 62a can be arranged on the rear end portion of the corresponding partition 62a, the vent opening 621b of the partition 62b can be arranged on the front end portion of the corresponding partition 62a, and the vent opening 621c of the partition 62c can be arranged on the rear end portion of the corresponding partition 62a. In this way, the liquid needs to be arranged along the inner side of the first part 62 Figure 4 The sensor passes 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 Figure 5 to Figure 7Compared with the first embodiment, in the third embodiment, the side wall 201 of the corresponding side of the plate 20 may also protrude toward the side surface 111 to form a pair of positioning ribs 242 correspondingly close to the front and rear outer sides of the two side baffles 113. In this way, it is more difficult for liquid to invade the interior of the first part 62 from the front and rear sides. Among them, when a pair of first positioning ribs 241 and a pair of positioning ribs 242 are provided at the same time, a groove 243 may be formed between a positioning rib 241 and a positioning rib 242 on the front and rear sides, and the end of the side baffle 113 away from the side surface 111 may be accommodated in the groove 243. Preferably, the positioning rib 242 is provided with notches 242a spaced apart along the extension direction, and the positioning rib 242 may also be provided with a supporting rib 244. In some other schemes, the positioning rib 242 and the positioning rib 241 may also be provided selectively.

[0045] Compared with the second embodiment, in the third embodiment, when there are positioning ribs 241 , the partitions 62 a - 62 c may be further provided with positioning openings 622 for making way for the positioning ribs 241 .

[0046] In the above embodiments, in order to facilitate the molding of the upper cover 2, the right end of the second part 61 can be made to penetrate the outer surface of the surrounding wall 231 to form a through hole (not marked). When assembling the pressure sensor 200, the sealing groove can be filled with sealant first, and then the upper cover 2 is assembled to the main housing 1, and then the sealant is applied to the through hole. The sealant can be cured in the same subsequent process. In the above embodiments, the positioning rib 242 can also be arranged on the same plane as the side cover plate 234, and can be further connected in an integral manner from top to bottom.

[0047] Please refer to Figure 8 On the basis of the above embodiments, in the pressure sensor 200 of the fourth embodiment, in order to facilitate the molding of the upper cover 2, the side wall 201 of the connecting portion 230 facing the main housing 1 is a cylindrical surface extending axially forward and backward. This is conducive to the rotation demoulding of the mold core used to mold the second part 61.

[0048] 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 housing enclosing a mounting cavity (10) comprises a main housing (1) and an upper cover (2), wherein the upper cover (2) comprises a main body (21) extending substantially horizontally, and the upper cover (2) is provided with a vent hole (21a), the lower end of the vent hole (21a) being connected to the mounting cavity (10) and covered by a waterproof breathable membrane (5); and a ventilation channel (6) surrounded by the main shell (1) and the upper cover (2), wherein one inner end of the ventilation channel is connected to the ventilation hole (21a) and one outer end of the ventilation channel is connected to the environment.

2. The pressure sensor according to claim 1, characterized in that: The pressure sensor also includes: A pressure introduction channel (120) for introducing a medium to be measured, one inner end of which is connected to the installation cavity (10); and a pressure measuring assembly (3) disposed in the installation cavity (10), comprising at least one pressure sensitive element (30), one side of the pressure sensitive element (30) being sealedly connected to an inner end of the pressure introduction channel (120).

3. The pressure sensor according to claim 1, characterized in that: 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 shell (1) and forms a first portion (62) of the air permeable passage (6) between the side surfaces (111) on the left and right sides of the main shell (1); one end of the connecting portion (230) is integrally connected to the upper end of the vertical portion (240), and the other end extends to the top of the main body (21); The portion of the connecting portion (230) located directly above the main body (21) is integrally connected to the main body (21) via a circle of surrounding walls (231), and together with the surrounding walls (231) and the main body (21) forms a second portion (61) of the air permeable passage (6); the air hole (21a) is connected upward to one end of the second portion (61), the other end of the second portion (61) is connected to the upper end of the first portion (62), and the lower end of the first portion (62) is connected to the environment.

4. The pressure sensor according to claim 3, characterized in that: The side surface (111) protrudes outward to form two side baffles (113) spaced apart from each other and facing each other in the front and rear directions, and one end of the side baffle (113) away from the side surface (111) abuts against a corresponding side wall (201) of the plate (20).

5. The pressure sensor according to claim 3, characterized in that: A corresponding side wall (201) of the plate (20) protrudes toward the side surface (111) to form a pair of first positioning ribs (241) corresponding to the front and rear inner sides of the two side baffles (113).

6. The pressure sensor according to claim 5, characterized in that: A corresponding side wall (201) of the plate (20) protrudes toward the side surface (111) to form a pair of second positioning ribs (242) correspondingly close to the front and rear outer sides of the two side baffles (113).

7. The pressure sensor according to claim 6, characterized in that: The lower end of the vertical portion (240) protrudes toward the side surface (111) and exceeds the side surface (111) to form a snap-fit ​​portion (245), at least one pair of the positioning ribs protrude toward the side surface (111) and exceeds the side surface (111) to form a support rib (244), and the bottom surface (112) of the main shell (1) corresponding to the side surface (111) blocks the support rib (244) downward, and the lower end of the support rib (244) is integrally connected to the upper end surface of the snap-fit ​​portion (245).

8. The pressure sensor according to claim 4, characterized in that: The side surface (111) protrudes outward to form at least one partition (62a) spaced apart from each other, and each of the partitions (62a) has a ventilation opening (621a).

9. The pressure sensor according to claim 4, characterized in that: The side surface (111) protrudes outward to form at least two partitions (62a) spaced apart from each other, each of the partitions (62a) having a ventilation opening (621a); ​​for each two adjacent partitions (62a) above and below, the ventilation opening (621a) of one partition (62a) is arranged on the front end portion of the corresponding partition (62a), and the ventilation opening (621a) of the other partition (62a) is arranged on the rear end portion of the corresponding partition (62a).

10. The pressure sensor according to claim 4, characterized in that: The front and rear edges of the portion of the surrounding wall (231) that exceeds the main body (21) extend downward to form a side cover plate (234) that blocks the upper end of the side baffle plate (113) from the front and rear outer sides.

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