Gauge pressure sensor

Abstract

A gauge pressure sensor comprises a sensor body, the sensor body comprises a shell forming a mounting cavity, a pressure interface used for introducing a pressure medium to be measured and extending left and right, and a pressure sensitive element arranged in the mounting cavity to receive the pressure medium to be measured, and the lower part of the shell is provided with a ventilation via hole communicated to the mounting cavity; and the lower protective cover is fixed at the lower part of the shell, and a ventilation channel with an opening at the rear end is enclosed between the lower protective cover and the shell. The gauge pressure sensor can reduce the risk that liquid in the environment passes through a ventilation channel.

Description

Technical Field

[0003] The present application relates to the technical field of pressure sensors, and in particular to a gauge pressure sensor. Background Art

[0004] 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

[0005] In view of the deficiencies of the prior art, the present application provides a gauge pressure sensor to reduce the risk of liquid in the environment passing through a breathable channel.

[0006] To achieve the above purpose, the present application provides the following technical solution: a gauge pressure sensor, comprising:

[0007] The sensor body includes a housing forming a mounting cavity, a pressure interface extending left and right for introducing the pressure medium to be measured, and a pressure sensitive element arranged in the mounting cavity to receive the pressure medium to be measured, and a ventilation hole connected to the mounting cavity is arranged at the lower part of the housing;

[0008] and a lower protective cover, which is fixed to the lower part of the shell and forms a ventilation channel with a rear end opening with the shell.

[0009] Preferably, the lower portion of the shell and the front end of the pressure interface extend downward to form a first shell wall; the lower protective cover includes a base plate and a second shell wall formed by extending upward from the base plate; the first shell wall and the second shell wall are cooperatively connected to enclose the air permeable passage having a rear end opening from the side.

[0010] Preferably, the base plate can be connected in sequence from front to back to form a first base plate part, a second base plate part and a third base plate part, wherein the first base plate part is raised upward relative to the third base plate part, and its rear end is connected to the front end of the third base plate part through the second base plate part extending up and down.

[0011] Preferably, the front side wall of the pressure interface extends downward to form a partition blocking the above-mentioned rear end opening; a first air-permeable gap is left between the lower end of the partition and the third part of the bottom plate to allow ambient pressure to pass forward, and a second air-permeable gap is left between the partition and the second part of the bottom plate on the front side to allow ambient pressure to continue to pass upward.

[0012] Preferably, the rear end of the third part of the bottom plate passes over the partition backwards, and its upper side is integrally connected with a first baffle extending left and right; the upper end of the first baffle extends into a wedge-shaped cavity surrounded by the lower side wall of the pressure interface and the rear surface of the partition, a fourth air permeable gap is left between the upper end of the first baffle and the outer side wall of the pressure interface, and the first baffle is located on the rear side of the partition and a fifth air permeable gap is left between the first baffle and the partition.

[0013] Preferably, a second baffle plate extending leftward and rightward is integrally connected to the upper side of the third portion of the bottom plate, and a sixth air permeable gap allowing ambient pressure to enter may be provided on the second baffle plate.

[0014] Preferably, a second notch is left between the left and right ends of the second baffle and the second shell wall on the corresponding side; the sixth air permeable gap and the second notch are staggered with each other in the left-right direction.

[0015] Preferably, the sixth air-permeable gap includes a first notch arranged in the middle of the left and right parts of the first baffle plate to allow the pressure to be measured to pass forward; the upper end of the first baffle plate abuts or approaches the outer wall of the pressure interface upward; the bottom edge of the first notch forms a certain height from the upper surface of the second shell wall.

[0016] Preferably, the front side wall of the pressure interface protrudes forward to form a raised portion that spans the left and right middle parts of the third air permeable gap, and the front end of the raised portion is close to the inner wall of the front end plate.

[0017] Preferably, a first supporting portion is formed at the connection between the partition and the side wall, and the inner surface of the third portion of the bottom plate protrudes upward to form a second supporting portion, and the lower end of the first supporting portion is supported on the upper end of the second supporting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of the gauge pressure sensor of the first embodiment.

[0019] Figure 2 The gauge pressure sensor of the first embodiment is Figure 1 A cross-sectional view of AA is shown in FIG.

[0020] Figure 3 It is a three-dimensional view of the lower protective cover of the gauge pressure sensor of the second embodiment.

[0021] Figure 4 It is a three-dimensional view of the lower protective cover of the gauge pressure sensor of the third embodiment.

[0022] Figure 5 It is a cross-sectional view of the gauge pressure sensor of the third embodiment.

[0023] Explanation of reference numerals: 100, sensor body; 101a, through hole; 10, mounting cavity; 11b, ventilation through hole; 11, main shell; 12, cover; 130, inner cavity; 13, pressure interface; 140, fisheye-shaped connecting part; 14a, first pin; 14b, second pin; 14, electrical connector; 16a, front wall; 16b, extension part; 16c, side wall; 16, first shell wall; 17a, protrusion; 17, support part; 18, hot riveting column; 19a, first air permeable gap; 19b, second air permeable gap; 19c, third air permeable gap; 19, partition; 1, shell; 201a, pressure hole; 201, substrate; 202a, give way; 202, circuit board; 203a, hole ; 203, sealing gasket; 204, pressure sensitive element; 20, pressure measuring component; 3, waterproof breathable membrane; 200, lower protective cover; 20a, wedge-shaped cavity; 21a, first part of bottom plate; 21b, second part of bottom plate; 21c, third part of bottom plate; 21, bottom plate; 221c, first part of side plate; 222c, second part of side plate; 22a, front end plate; 22c, side plate; 22d, third part of side plate; 22e, extension; 22, second shell wall; 23a, first notch; 23, first baffle; 24a, second notch; 24b, cavity; 24c, hole; 24, second baffle; 25a, positioning column; 25, supporting part; 26, reinforcing rib; 27a, buckle protrusion; 27, buckle. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] like Figure 1 , Figure 2 As shown. The gauge pressure sensor of the first embodiment includes a sensor body 100 for measuring gauge pressure. The sensor body 100 includes a shell 1 and a pressure measuring assembly 20 arranged inside the shell 1. The shell 1 can be composed of a main shell 11 and a cover body 12 covering an upper end opening of the main shell 11, and the pressure measuring assembly 20 is arranged in an installation cavity 10 surrounded by the main shell 11 and the cover body 12. The sensor body 100 also includes a tubular pressure interface 13 extending in the left-right direction. The upper side wall of the pressure interface 13 is connected to the lower end of the main shell 11, and it is preferably connected to the rear side portion of the lower end of the main shell 11. The length direction of the main shell 11 can be set along the front-to-back direction.

[0029] The inner cavity 130 of the pressure interface 13 is connected to the pressure measuring assembly 20 through a through hole 101a provided at the bottom of the installation cavity 10, and specifically, it is sealedly connected to the pressure sensitive element 204 of the pressure measuring assembly 20. The first pressure-sensitive surface on one side of the pressure sensitive element 204 obtains the pressure of the pressure medium to be measured introduced by the pressure sensitive element 204, and the second pressure-sensitive surface on the other side of the pressure sensitive element 204 obtains the reference pressure in the installation cavity 10, so that the pressure sensitive element 204 measures the relative pressure of the medium to be measured relative to the reference pressure, that is, the gauge pressure.

[0030] The bottom of the installation cavity 10 is provided with a downwardly facing ventilation hole 11 b , and the ventilation hole 11 b (preferably the inner end) is covered with a waterproof breathable membrane 3 .

[0031] The gauge pressure sensor of this embodiment also includes a lower protective cover 200 disposed at the bottom of the main housing 11. The lower protective cover 200 and the bottom of the main housing 11 form a ventilation channel. The ventilation hole 11b is downwardly connected to the upper end of the ventilation channel. Figure 2The lower part of the main housing 11 and the front end of the pressure interface 13 extend downward to form a first housing wall 16. The lower protective cover 200 includes a bottom plate 21 and a second housing wall 22 formed by extending upward from the bottom plate 21. The first housing wall 16 and the second housing wall 22 are connected to form the above-mentioned air permeable passage with a rear end opening (not marked) from the side.

[0032] Specifically, the first shell wall 16 includes two side walls 16c arranged opposite to each other on the left and right sides, and a front wall 16a connected to the front ends of the two side walls 16c. The second shell wall 22 includes two side panels 22c arranged opposite to each other on the left and right sides, and a front end panel 22a connected to the front ends of the two side panels 22c. The air permeable passage is preferably tortuous, for example, the bottom plate 21 can be substantially Z-shaped, and includes three parts connected in sequence from front to back to form a Z shape, namely, the first bottom plate part 21a, the second bottom plate part 21b and the third bottom plate part 21c, wherein the first bottom plate part 21a is lifted upward relative to the third bottom plate part 21c, and its rear end is connected to the front end of the third bottom plate part 21c through the second bottom plate part 21b extending up and down.

[0033] At least one portion of the bottom plate 21 is located at the lower part of the pressure interface 13. The rear end of the bottom plate 21 and the outer side wall of the pressure interface 13 form the above-mentioned rear end opening. The front side wall of the pressure interface 13 extends downward to form a partition 19 that blocks the above-mentioned rear end opening. A first air-permeable gap 19a is left between the lower end of the partition 19 and the third part 21c of the bottom plate to allow the ambient pressure to pass forward, and a second air-permeable gap 19b is left between the partition 19 and the second part 21b of the bottom plate on the front side to allow the ambient pressure to continue to pass upward. The first part 21a of the bottom plate faces downwardly directly opposite the ventilation hole 11b and has a third air-permeable gap 19c with the bottom of the main shell 11 to allow the ambient pressure to continue to communicate forward to the bottom of the ventilation hole 11b. The pressure interface 13 can have two left and right ports that are arranged opposite to each other.

[0034] The ambient pressure (or ambient pressure medium) entering from the rear opening passes forward through the first air-permeable gap 19a, upward through the second air-permeable gap 19b, and then forward through the third air-permeable gap 19c to reach the bottom of the ventilation hole 11b, and finally enters the installation cavity 10 through the waterproof breathable membrane 3. In this way, due to the obstruction of the partition 19 and the vertical height limitation of the front wall 16a and the second part 21b of the bottom plate, it is difficult for the liquid in the environment to enter the installation cavity 10 through the above-mentioned air-permeable channel and enter the installation cavity 10 following the atmospheric pressure.

[0035] Preferably, if Figure 2As shown, the rear end of the third part 21c of the bottom plate passes over the partition 19 backward, and the upper side thereof is integrally connected with a first baffle 23 extending left and right. The upper end of the first baffle 23 extends into a wedge-shaped cavity 20a formed between the lower side wall of the pressure interface 13 and the rear side surface of the partition 19, and a fourth air permeable gap (not marked) is left between the upper end of the first baffle 23 and the outer side wall of the pressure interface 13, and the first baffle 23 is located at the rear side of the partition 19 and a fifth air permeable gap (not marked) is left between the first baffle 23 and the partition 19. In this way, before the ambient pressure enters 19a, it needs to pass through the fourth air permeable gap obliquely upward and then pass through the fifth air permeable gap downward, thereby further enhancing the ability of the air permeable channel to prevent the entry of ambient liquid. Additionally or alternatively, a second baffle 24 extending left and right is integrally connected to the upper side of the third portion 21c of the base plate. The second baffle 24 is arranged near the above-mentioned rear end opening. The second baffle 24 may be provided with a sixth air permeable gap allowing ambient pressure to enter. The sixth air permeable gap may be a hole 24c provided on the second baffle 24.

[0036] Among them, the lower protective cover 200 can be connected to the sensor body 100 by a snap connection. For example, the bottoms of the two upwardly extending snaps 27 can fix the second shell wall 22 one by one, and the upper ends protrude toward the left and right inner sides to form a snap protrusion 27a, which stops downward at the left and right edges of the top of the cover body 12 and / or the main shell body 11.

[0037] For example, the pressure measurement assembly 20 may include a substrate 201, on which a pressure hole 201a is provided. The bottom of the substrate 201 is sealed to the bottom of the installation cavity 10 through an annular sealing gasket 203. The upper end of the hole 203a on the sealing gasket 203 is connected to the pressure hole 201a, and the lower end is connected to the through hole 101a. A pressure sensitive element 204 is fixed on the top surface of the substrate 201 and blocked at the top of the pressure hole 201a. The first pressure-sensitive surface on the lower side of the pressure-sensitive element 204 receives the pressure of the pressure medium to be measured that passes through the inner cavity 130, the through hole 101a, the hole 203a and the pressure hole 201a from the outside to the inside. The lower end of the pressure hole 201a may be relatively enlarged to accommodate a first protective gel (not marked). The first protective gel is used to isolate the first pressure-sensitive surface from the pressure medium to be measured and transmit the pressure of the pressure medium to be measured to the first pressure-sensitive surface. The pressure measurement assembly 20 may also include a circuit board 202, and a processing circuit is disposed on the upper surface of the circuit board 202. A preferably hole-shaped clearance portion 202a for accommodating the pressure sensitive element 204 is provided on the circuit board 202. The pressure sensitive element 204 is electrically connected to the processing circuit through a lead (not marked). More preferably, the circuit board 202 may be a multi-layer circuit board. The clearance portion 202a may be a stepped hole with a larger upper portion and a smaller lower portion, the stepped hole having an upward step surface, another portion of the processing circuit being disposed on the step surface, the pressure sensitive element 204 being directly electrically connected to the processing circuit on the step surface through a lead, and the processing circuit on the step surface being connected through a circuit board via disposed in the circuit board 202. The stepped hole is filled with a second protective gel for protecting the second pressure-sensitive surface and the lead of the pressure sensitive element 204. Among them, the sealing pressure of the sealing gasket 203 can be provided by a hot riveting structure and / or a fisheye structure. For example, the main shell 11 can protrude upward to form a plurality of hot riveting columns 18, and the hot riveting columns 18 pass upward through the circuit board 202 and are hot-riveted to the circuit board 202, and / or the sensor body 100 also includes a plurality of first pins 14a fixed on the main shell 11, and the outer end of the first pin 14a extends into an electrical connector 14 preferably connected to the front end of the main shell 11, and the inner end of the first pin 14a forms a fisheye-shaped connecting portion 140 that extends upward into the installation cavity 10 and is interference-connected with the metallized through-hole on the front side of the circuit board 202. In addition, one end of at least one second pin 14b fixed on the main shell 11 also forms a fisheye-shaped connecting portion 140 and extends upward into the installation cavity 10 and is interference-connected with another metallized through-hole on the rear side of the circuit board. In some other solutions, the pressure measurement component 20 may also be other known structures, which will not be described in detail here.

[0038] Please refer to Figure 3Based on the first embodiment, in the second embodiment, a first notch 23a may be provided in the left and right middle parts of the first baffle 23 to allow the pressure to be measured to pass forward. At this time, the fourth air-permeable gap between the upper end of the first baffle 23 and the outer wall of the pressure interface 13 may be omitted, that is, the upper end of the first baffle 23 may be upwardly abutted against or close to the outer wall of the pressure interface 13, so that the four air-permeable gaps are completely or substantially closed. In addition, the sixth air-permeable gap may be the hole 24c provided on the second baffle 24, which may be replaced by the second notch 24a provided between the left and right ends of the second baffle 24 and the second shell wall 22 on the corresponding side. Among them, the second notch 24a and the first notch 23a are preferably staggered in the left and right directions, so that the ambient pressure entering from the rear end opening passes through the second notch 24a forward, passes through the cavity 24b to the left and right, and passes through the first notch 23a forward from the outside to the inside, and then enters the first air-permeable gap 19a. In this way, a part of the air-permeable passage that is tortuous on the horizontal plane can also be formed.

[0039] The side panel 22c may include three parts connected in sequence from front to back, namely, the first side panel part 221c, the second side panel part 222c and the third side panel part 22d. The first side panel part 221c and the third side panel part 22d correspond one by one in the front-to-back direction and approach the first bottom panel part 21a and the third bottom panel part 21c downward, and the second side panel part 222c may approach the second bottom panel part 21b forward. The second side panel part 222c may be substantially a right triangle, with one right-angled side integrally connected to the left and right corresponding side edges of the second bottom panel part 21b, and the other right-angled side integrally connected to the left and right outer surfaces of the third side panel part 22d on the left and right corresponding sides. After the lower protective cover 200 is assembled to the sensor body 100, the top of the third part 22d of the side plate can be upwardly close to the bottom of the side wall 16c, and the side plate 22c and the buckle 27 are located outside the extension part 16b, and the first part 221c of the side plate is located inside the side wall 16c. This can facilitate the arrangement of the buckle 27 and make the second shell wall 22 and the first shell wall 16 more stable when assembled. At this time, the front end plate 22a is located inside the front wall 16a.

[0040] See also Figure 4 On the basis of the second embodiment, in the third embodiment, the upper end of the first baffle 23 can abut or approach the outer side wall of the pressure interface 13. At the same time, the bottom edge of the first notch 23a forms a certain height from the upper side surface of the second shell wall 22. In other words, the fourth air permeable gap between the upper end of the first baffle 23 and the outer side wall of the pressure interface 13 is limited to the first notch 23a at the middle position.

[0041] See also Figure 5On the basis of the second embodiment, in the fourth embodiment, the front side wall of the pressure interface 13 can protrude forward to form a protrusion 17a that spans the left and right middle parts of the third air permeable gap 19c, and the front end of the protrusion 17a is close to the inner wall of the front end plate. In this way, the protrusion 17a limits the environmental medium to the left and right side parts of the third air permeable gap 19c.

[0042] In the above embodiments, the side wall 16c of the first shell wall 16 can be integrally connected to the outer side wall of the inner cavity 130. The left and right ends of the partition 19 can be integrally connected to the inner side of the side wall 16c. The connection between the partition 19 and the side wall 16c can form a support portion 17 extending up and down, and the cross section of the support portion 17 can be columnar. Correspondingly, the inner surface of the third part 21c of the bottom plate can be convex upward to form a support portion 25, and the lower end of the support portion 17 can be supported on the upper end of the support portion 25. More preferably, a positioning hole (not shown) extending up and down can be formed on the support portion 17, and the top of the support portion 25 protrudes upward to form a positioning column 25a, and the positioning column 25a is inserted into the above positioning hole in a matching manner. In addition, the upper end of the support portion 25 can extend upward to form a reinforcing rib 26 integrally connected to the second part 21b of the bottom plate, and the reinforcing rib 26 is located on the inner side of the second part 222c of the side plate. The pressure interface 13 can also have only one port.

[0043] 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 gauge pressure sensor, characterized in that: include: The sensor body includes a housing forming a mounting cavity, a pressure interface extending left and right for introducing the pressure medium to be measured, and a pressure sensitive element arranged in the mounting cavity to receive the pressure medium to be measured, and a ventilation hole connected to the mounting cavity is arranged at the lower part of the housing; and a lower protective cover, which is fixed to the lower part of the shell and forms a ventilation channel with a rear end opening with the shell.

2. The gauge pressure sensor according to claim 1, characterized in that: The lower part of the shell and the front end of the pressure interface extend downward to form a first shell wall; the lower protective cover includes a bottom plate and a second shell wall formed by extending upward from the bottom plate; the first shell wall and the second shell wall are connected in cooperation to enclose the air permeable passage with a rear end opening from the side.

3. The gauge pressure sensor according to claim 2, characterized in that: The base plate can be generally connected in sequence from front to back to form a first base plate part, a second base plate part and a third base plate part, wherein the first base plate part is raised upward relative to the third base plate part, and its rear end is connected to the front end of the third base plate part through the second base plate part extending up and down.

4. The gauge pressure sensor according to claim 3, characterized in that: The front side wall of the pressure interface extends downward to form a partition that blocks the above-mentioned rear end opening; a first air-permeable gap is left between the lower end of the partition and the third part of the bottom plate to allow ambient pressure to pass forward, and a second air-permeable gap is left between the partition and the second part of the bottom plate on the front side to allow ambient pressure to continue to pass upward.

5. The gauge pressure sensor according to claim 4, characterized in that: The rear end of the third part of the bottom plate passes over the partition backwards, and its upper side is integrally connected with a first baffle extending left and right; the upper end of the first baffle extends into a wedge-shaped cavity surrounded by the lower side wall of the pressure interface and the rear surface of the partition, and a fourth air permeable gap is left between the upper end of the first baffle and the outer side wall of the pressure interface, and the first baffle is located on the rear side of the partition and a fifth air permeable gap is left between the first baffle and the partition.

6. The gauge pressure sensor according to claim 3, characterized in that: A second baffle plate extending leftward and rightward is integrally connected to the upper side of the third portion of the bottom plate, and a sixth air permeable gap allowing ambient pressure to enter may be provided on the second baffle plate.

7. The gauge pressure sensor according to claim 6, characterized in that: A second notch is left between the left and right ends of the second baffle and the second shell wall on the corresponding side; the sixth air-permeable gap and the second notch are staggered with each other in the left-right direction.

8. The gauge pressure sensor according to claim 7, characterized in that: The sixth air-permeable gap includes a first notch arranged in the left and right middle parts of the first baffle plate to allow the pressure to be measured to pass forward; the upper end of the first baffle plate abuts or approaches the outer wall of the pressure interface upward; the bottom edge of the first notch forms a certain height from the upper surface of the second shell wall.

9. The gauge pressure sensor according to any one of claims 1 to 8, characterized in that: The front side wall of the pressure interface protrudes forward to form a convex portion that spans the left and right middle parts of the third air-permeable gap, and the front end of the convex portion is close to the inner wall of the front end plate.

10. The gauge pressure sensor according to any one of claims 1 to 8, characterized in that: A first supporting portion is formed at the connection between the partition and the side wall, and an inner surface of the third portion of the bottom plate protrudes upward to form a second supporting portion, and a lower end of the first supporting portion is supported on an upper end of the second supporting portion.

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