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

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

[0002] When measuring gauge pressure, the gauge 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 interior of the sensor. CONTENT OF THE UTILITY MODEL

[0003] 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 entering the air passage.

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

[0005] A sensor body comprising a housing forming an installation cavity, a pressure interface for introducing a pressure medium to be measured and extending left and right, and a pressure sensitive element arranged in the installation cavity to receive the pressure medium to be measured, the lower part of the housing is provided with a through hole for ventilation connected to the installation cavity;

[0006] And a lower protective cover fixed to the lower part of the housing and surrounding the air passage with a rear end opening between the housing.

[0007] Preferably, the lower part of the housing and the front end of the pressure interface extend downward to form a first shell wall; the lower protective cover comprises a bottom plate and a second shell wall formed by the bottom plate extending upward; the first shell wall and the second shell wall are connected to form the air passage with a rear end opening from the side.

[0008] Preferably, the bottom plate can be connected to form a bottom plate first part, a bottom plate second part and a bottom plate third part in order from front to back, wherein the bottom plate first part is lifted upward relative to the bottom plate third part, and the rear end thereof is connected to the front end of the bottom plate third part through the bottom plate second part extending upward and downward.

[0009] Preferably, the front side wall of the pressure interface extends downward to form a partition plate partitioned from the rear end opening; the lower end of the partition plate and the bottom plate third part leave a first air passage gap allowing the ambient pressure to pass forward, and the partition plate and the front side bottom plate second part leave a second air passage gap allowing the ambient pressure to continue to pass upward.

[0010] Preferably, the rear end of the third portion of the bottom plate extends rearward beyond the partition plate, and a first baffle extending leftward and rightward is integrally connected to the upper side of the third portion of the bottom plate; the upper end of the first baffle extends into a wedge-shaped cavity between the lower side of the side wall of the pressure interface and the rear side surface of the partition plate, a fourth air permeation 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 at the rear side of the partition plate and a fifth air permeation gap is left between the first baffle and the partition plate.

[0011] Preferably, the upper side of the third portion of the bottom plate is integrally connected with a second baffle extending leftward and rightward, and a sixth air permeation gap allowing ambient pressure to enter is arranged on the second baffle.

[0012] Preferably, the left and right ends of the second baffle are left with second notches relative to the second shell wall on the corresponding side; the sixth air permeation gap and the second notches are staggered in the left-right direction.

[0013] Preferably, the sixth air permeation gap comprises a first notch arranged in the left and right middle part of the first baffle, allowing the to-be-measured pressure to pass forward; the upper end of the first baffle abuts or approaches the outer side wall of the pressure interface; the bottom edge of the first notch is a certain height away from the upper side surface of the second shell wall.

[0014] Preferably, the front side wall of the pressure interface protrudes forward to form a protruding part across the left and right middle part of the third air permeation gap, and the front end of the protruding part approaches the inner wall of the front end plate.

[0015] Preferably, a first support part is formed at the connection between the partition plate and the side wall, and an inner side surface of the third portion of the bottom plate protrudes upward to form a second support part, and the lower end of the first support part is supported on the upper end of the second support part. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a perspective view of the gauge pressure sensor of the first embodiment.

[0017] Figure 2 It is a sectional view of the gauge pressure sensor of the first embodiment along A-A shown in FIG. Figure 1

[0018] Figure 3 It is a perspective view of the lower protective cover of the gauge pressure sensor of the second embodiment.

[0019] Figure 4 It is a perspective view of the lower protective cover of the gauge pressure sensor of the third embodiment.

[0020] Figure 5 It is a sectional view of the gauge pressure sensor of the third embodiment.

[0021] ​Explanation of reference signs: 100, sensor body; 101a, via hole; 10, mounting cavity; 11b, vent via hole; 11, main housing; 12, cover body; 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 permeation gap; 19b, second air permeation gap; 19c, third air permeation gap; 19, partition plate; 1, housing; 201a, pressure hole; 201, base plate; 202a, accommodation part; 202, circuit board; 203a, hole; 203, gasket; 204, pressure sensitive element; 20, pressure measurement assembly; 3, waterproof air permeation film; 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 part; 22, second shell wall; 23a, first notch; 23, first baffle; 24a, second notch; 24b, cavity; 24c, hole; 24, second baffle; 25a, positioning column; 25, support part; 26, reinforcing rib; 27a, buckle protrusion; 27, buckle. DETAILED DESCRIPTION

[0022] 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 only to explain the present application, and cannot be interpreted as a limitation on 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.

[0023] In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", and the like 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 therefore cannot be understood as indicating or implying 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 a limitation on the present application. In addition, the antecedent adjectives "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.

[0024] In addition, the terms "mounting", "connected", "connection" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside 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.

[0025] 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.

[0026] As shown in Figure 1 , Figure 2 The first embodiment of the gauge pressure sensor includes a sensor body 100 for measuring gauge pressure. The sensor body 100 includes a housing 1 and a pressure measuring assembly 20 arranged inside the housing 1. The housing 1 can be formed by a main housing 11 and a cover 12 arranged on an upper end opening of the main housing 11, and the pressure measuring assembly 20 is arranged in a mounting cavity 10 formed by the main housing 11 and the cover 12. The sensor body 100 further 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 housing 11, and is preferably connected to the lower end rear portion of the main housing 11. The length direction of the main housing 11 can be arranged in the front-rear direction.

[0027] The inner cavity 130 of the pressure interface 13 communicates with the pressure measuring assembly 20 through a through hole 101a arranged at the bottom of the mounting cavity 10, and specifically, it is sealingly communicated to the pressure sensitive element 204 of the pressure measuring assembly 20. The first pressure sensing surface of 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 sensing surface of the other side of the pressure sensitive element 204 obtains the reference pressure in the mounting cavity 10, so that the pressure sensitive element 204 measures the relative pressure of the medium to be measured relative to the reference pressure, i.e. the gauge pressure.

[0028] Among them, the bottom of the mounting cavity 10 is provided with a downward air vent through hole 11b, and the air vent through hole 11b is covered with a waterproof air permeable film 3 on the top (preferably the inner end).

[0029] The gauge pressure sensor of the present embodiment further includes a lower protective cover 200 arranged at the bottom of the main housing 11. The lower protective cover 200 and the bottom of the main housing 11 form an air permeable passage. The air vent through hole 11b is downwardly and directly communicated to the upper end of the air permeable passage. Please refer to 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 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 passage with a rear end opening (not labeled) from the side.

[0030] In particular, the first housing wall 16 includes two side walls 16c arranged opposite to each other, and a front wall 16a connected to the front ends of the two side walls 16c. The second housing wall 22 includes two side plates 22c arranged opposite to each other, and a front end plate 22a connected to the front ends of the two side plates 22c. Preferably, the air passage is zigzag-shaped. For example, the bottom plate 21 can be substantially Z-shaped, including three parts connected in sequence to form a Z shape, i.e., a first part 21a, a second part 21b, and a third part 21c of the bottom plate, wherein the first part 21a is raised upward relative to the third part 21c, and the rear end of the first part 21a is connected to the front end of the third part 21c through the second part 21b extending upward and downward.

[0031] At least one part of the bottom plate 21 is located in 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 plate 19 partitioning the above-mentioned rear end opening. The lower end of the partition plate 19 and the third part 21c of the bottom plate leave a first air passage gap 19a allowing the ambient pressure to pass forward, and the partition plate 19 and the second part 21b of the bottom plate leave a second air passage gap 19b allowing the ambient pressure to continue to pass upward. The first part 21a of the bottom plate is downward opposite to the air passage through hole 11b and leaves a third air passage gap 19c between the bottom of the first part 21a and the bottom of the main housing 11, allowing the ambient pressure to continue to pass forward to the bottom of the air passage through hole 11b. The pressure interface 13 can have two opposite ports.

[0032] The ambient pressure (which can also be referred to as ambient pressure medium) entering from the above-mentioned rear end opening passes forward through the first air passage gap 19a, upward through the second air passage gap 19b, and then forward through the third air passage gap 19c to the bottom of the air passage through hole 11b, and finally enters the installation cavity 10 through the waterproof air permeable film 3. In this way, due to the blocking of the partition plate 19 and the vertical height limitation of the front wall 16a and the second part 21b of the bottom plate, the liquid in the environment is difficult to enter the installation cavity 10 through the above-mentioned air passage and follow the atmospheric pressure to enter the installation cavity 10.

[0033] Preferably, as shown in Figure 2As shown, the rear end of the third portion 21c of the bottom plate extends rearward beyond the partition 19, and the upper side of the third portion 21c is integrally connected with a leftward and rightward extending first baffle 23. The upper end of the first baffle 23 extends into a wedge-shaped cavity 20a formed between the lower side of the side wall of the pressure port 13 and the rear side surface of the partition 19, and a fourth air permeation gap (not labeled) is left between the upper end of the first baffle 23 and the outer side wall of the pressure port 13. The first baffle 23 is located at the rear side of the partition 19 and a fifth air permeation gap (not labeled) is left between the first baffle 23 and the partition 19. In this way, the ambient pressure needs to pass through the fourth air permeation gap obliquely upward and then pass through the fifth air permeation gap downward before entering the cavity 19a, thereby further enhancing the ability of the air permeation passage to prevent ambient liquid from entering. Additionally or alternatively, the upper side of the third portion 21c of the bottom plate is integrally connected with a leftward and rightward extending second baffle 24, which is arranged near the rear end opening described above. The second baffle 24 can be provided with a sixth air permeation gap that allows ambient pressure to enter, and the sixth air permeation gap can be a hole 24c provided on the second baffle 24.

[0034] The lower protective cover 200 can be connected to the sensor body 100 by means of snap connection, for example, the bottoms of two upward extending snaps 27 can be fixed one by one to the second shell wall 22, the upper ends of the snaps 27 protrude inward leftward and rightward to form a snap protruding portion 27a, and the snap protruding portion 27a is downward stopped on the top end left and right edges of the cover body 12 and / or the main shell 11.

[0035] The pressure measuring assembly 20 can include a substrate 201 with a pressure hole 201a formed therein. The bottom of the substrate 201 is sealed to the bottom of the mounting cavity 10 by a ring-shaped sealing gasket 203. The upper end of a hole 203a formed in the sealing gasket 203 is in communication with the pressure hole 201a, and the lower end of the hole 203a is in communication with the through hole 101a. A pressure sensitive element 204 is fixed to the top surface of the substrate 201 and covers the top of the pressure hole 201a. The first pressure sensing surface of the pressure sensitive element 204 receives the pressure of the pressure medium from outside to inside through the inner cavity 130, the through hole 101a, the hole 203a and the pressure hole 201a. The lower end of the pressure hole 201a can be relatively enlarged to accommodate a first protective gel (not labeled) for isolating the first pressure sensing surface from the pressure medium while conducting the pressure of the pressure medium to the first pressure sensing surface. The pressure measuring assembly 20 can also include a circuit board 202 with a processing circuit formed on the upper surface thereof. A hole-shaped accommodation portion 202a is formed in the circuit board 202 for accommodating the pressure sensitive element 204. The pressure sensitive element 204 is electrically connected to the processing circuit by leads (not labeled). Preferably, the circuit board 202 can be a multi-layer circuit board. The accommodation portion 202a can be a stepped hole with a larger upper portion and a smaller lower portion. The stepped hole has an upwardly facing step surface with another portion of the processing circuit formed thereon. The pressure sensitive element 204 is directly electrically connected to the processing circuit on the step surface by leads. The processing circuit on the step surface is connected by a circuit board through hole formed in the circuit board 202. The stepped hole is filled with a second protective gel for protecting the second pressure sensing surface of the pressure sensitive element 204 and the leads. The sealing pressure of the sealing gasket 203 can be provided by a heat staking structure and / or a fish eye structure. For example, the main housing 11 can be upwardly protruding to form a plurality of heat staking posts 18. The heat staking posts 18 are heat staked to the circuit board 202 after passing through the circuit board 202 from the top. The sensor body 100 further includes a plurality of first pins 14a fixed to the main housing 11. The outer ends of the first pins 14a extend into an electrical connector 14 connected to the front end of the main housing 11. The inner ends of the first pins 14a form fish eye-shaped connection portions 140 extending into the mounting cavity 10 and being in interference connection with the metalized through holes on the front side of the circuit board 202. In addition, at least one second pin 14b fixed to the main housing 11 also has an end forming a fish eye-shaped connection portion 140 extending into the mounting cavity 10 and being in interference connection with another metalized through hole on the rear side of the circuit board. In other embodiments, the pressure measuring assembly 20 can have other known structures, which are not described herein.

[0036] Please refer to Figure 3In the second embodiment, based on the first embodiment, a first gap 23a allowing the pressure to be measured to pass forward can be arranged in the middle of the first baffle 23. At this time, the fourth air gap between the upper end of the first baffle 23 and the outer side wall of the pressure interface 13 can be omitted, i.e., the upper end of the first baffle 23 can abut or approach the outer side wall of the pressure interface 13 upward, so that the fourth air gap is completely or substantially closed. In addition, the sixth air gap can be replaced by a second gap 24a between the left and right ends of the second baffle 24 and the second shell wall 22 on the corresponding side. The second gap 24a and the first gap 23a are preferably staggered in the left-right direction, so that the ambient pressure entering from the rear end opening passes through the second gap 24a, the cavity 24b, and the first gap 23a in turn from outside to inside and then enters the first air gap 19a. In this way, a part of the air passage is also formed to be tortuous in the horizontal plane.

[0037] The side plate 22c can include three parts connected in sequence from front to back, i.e., a first side plate part 221c, a second side plate part 222c, and a third side plate part 22d. The first side plate part 221c and the third side plate part 22d correspond to the first bottom plate part 21a and the third bottom plate part 21c, respectively, and approach them downward in the front-back direction. The second side plate part 222c can approach the second bottom plate part 21b forward. The second side plate part 222c can be substantially a right triangle, one of whose right-angle sides is integrally connected to the left-right corresponding side edge of the second bottom plate part 21b, and the other of whose right-angle sides is integrally connected to the left-right outer side surface of the third side plate part 22d on the left-right corresponding side. After the lower protective cover 200 is combined with the sensor body 100, the top of the third side plate part 22d approaches the bottom of the side wall 16c upward, the side plate 22c and the buckle 27 are located outside the extension part 16b, and the first side plate part 221c is located inside the side wall 16c. In this way, the buckle 27 can be conveniently arranged, and the second shell wall 22 and the first shell wall 16 can be combined more stably. At this time, the front end plate 22a is located inside the front wall 16a.

[0038] Please refer to Figure 4 In the third embodiment, based on the second embodiment, the upper end of the first baffle 23 can abut or approach the outer side wall of the pressure interface 13 upward. At the same time, the bottom edge of the first gap 23a is away from the upper side surface of the second shell wall 22 by a certain height. Alternatively, the fourth air gap between the upper end of the first baffle 23 and the outer side wall of the pressure interface 13 is limited at the first gap 23a in the middle position.

[0039] Please refer to Figure 5In the fourth embodiment, based on the second embodiment, the front side wall of the pressure interface 13 can be protruded forward to form a protrusion 17a across the middle of the third air gap 19c, and the front end of the protrusion 17a can be close to the inner wall of the front end plate, so that the protrusion 17a can limit the ambient medium to the left and right sides of the third air gap 19c.

[0040] 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 17 extending upward and downward, and the cross section of the support 17 can be columnar. Accordingly, the inner side surface of the third part 21c of the bottom plate can be protruded upward to form a support 25, and the lower end of the support 17 can be supported on the upper end of the support 25. More preferably, the support 17 can be formed with a positioning hole (not shown) extending upward and downward, and the top of the support 25 can be protruded upward to form a positioning column 25a, which is fitted into the positioning hole. In addition, the upper end of the support 25 can be extended upward to form a reinforcing rib 26 integrally connected with 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.

[0041] 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 gauge pressure sensor, characterized in that, include: The sensor body includes a housing forming a mounting cavity, a pressure port for introducing the pressure medium to be measured and extending to the left and right, and a pressure sensitive element disposed in the mounting cavity to receive the pressure medium to be measured. The lower part of the housing is provided with a vent hole communicating with the mounting cavity. The lower protective cover is fixed to the lower part of the housing and forms a ventilated channel with a rear opening between the housing and the housing.

2. The gauge pressure sensor according to claim 1, characterized in that, The lower part of the housing and the front end of the pressure port extend downward to form a first housing wall; the lower protective cover includes a base plate and a second housing wall extending upward from the base plate; the first housing wall and the second housing wall are connected to form a venting channel with a rear end opening from the side.

3. The gauge pressure sensor according to claim 2, characterized in that, The base plate is connected from front to back to form a first part, a second part, and a third part. The first part is raised relative to the third part, and its rear end is connected to the front end of the third part through the second part, which extends vertically.

4. The gauge pressure sensor according to claim 3, characterized in that, The front sidewall of the pressure port extends downward to form a partition that blocks the rear opening; a first ventilated gap is left between the lower end of the partition and the third part of the base plate to allow environmental pressure to pass forward, and a second ventilated gap is left between the partition and the second part of the front base plate to allow environmental 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 base plate extends beyond the partition, and a first baffle extending to the left and right is integrally connected to its upper side; the upper end of the first baffle extends into a wedge-shaped cavity formed between the lower side wall of the pressure port and the rear surface of the partition; a fourth venting gap is left between the upper end of the first baffle and the outer side wall of the pressure port; the first baffle is located on the rear side of the partition and a fifth venting gap is left between it and the partition.

6. The gauge pressure sensor according to claim 5, characterized in that, A second baffle extending to the left and right is integrally connected to the upper side of the third part of the base plate. The second baffle may be provided with a sixth venting gap that allows environmental pressure to enter.

7. The gauge pressure sensor according to claim 6, characterized in that, The second baffle has a second notch between its left and right ends and the second shell wall on the corresponding side; the sixth vent gap is offset from the second notch in the left and right direction.

8. The gauge pressure sensor according to claim 7, characterized in that, The sixth venting gap includes a first notch located in the middle left and right sides of the first baffle, allowing the pressure to be measured to pass forward; the upper end of the first baffle abuts or approaches the outer wall of the pressure port; the bottom edge of the first notch is at 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 sidewall of the pressure port protrudes forward to form a protrusion that spans the middle of the left and right sides of the third vent gap, with the front end of the protrusion abutting against the inner wall of the front end plate.

10. The gauge pressure sensor according to claim 4, characterized in that, The connection between the partition and the side wall forms a first support portion, and the inner surface of the third part of the bottom plate protrudes upward to form a second support portion, with the lower end of the first support portion supporting the upper end of the second support portion.

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