CN219532353U

CN219532353U - Novel double-sealing pressure core structure for pressure sensor

Info

Publication number: CN219532353U
Application number: CN202320316077.4U
Authority: CN
Inventors: 段荣; 周友佳
Original assignee: Ningbo Gavin Corp
Current assignee: Ningbo Gavin Corp
Priority date: 2023-02-14
Filing date: 2023-02-14
Publication date: 2023-08-15
Anticipated expiration: 2033-02-14

Abstract

The utility model discloses a novel double-sealing pressure core structure for a pressure sensor, which relates to the field of pressure sensors and comprises a sensor mounting seat, a small sealing ring, a pressing plate, a pressure MEMS element and a large sealing ring, wherein the pressing plate is fixed at the top of the sensor mounting seat in a sealing way, and a mounting cavity is formed between the pressing plate and the inner wall of the sensor mounting seat; an air channel is arranged on the pressing plate in a penetrating way, and a detection channel is arranged on the sensor mounting seat in a penetrating way; the pressing plate is pressed on the end face A, the small sealing ring is arranged between the end face B and the inner wall of the sensor mounting seat to form a first seal between the end face B and the end face A, and the large sealing ring is arranged between the outer wall of the pressure MEMS element and the inner wall of the sensor mounting seat to form a second seal between the end face B and the end face A. The utility model has two forms of end face axial sealing and side face sealing, the two sealing rings are in direct contact sealing with the pressure MEMS element, the contact area is large, the stress is more uniform, and the sealing performance and the sealing effect are more excellent than those of a single-direction sealing structure.

Description

Novel double-sealing pressure core structure for pressure sensor

Technical Field

The utility model relates to the field of pressure sensors, in particular to a novel double-sealing pressure core structure for a pressure sensor.

Background

In urban rail vehicles, the stability of the brake system is largely dependent on the reliability of the pressure sensor signals it collects, the pressure sensor being a critical component in the system, so it is important to increase the reliability of the pressure sensor and reduce the failure rate.

At present, the pressure sensor adopts a cylindrical surface radial seal or end surface axial seal single-direction seal structure, and gas leakage faults easily occur in the use process, so that the product is invalid.

Chinese patent document (CN 107843382 a) discloses a double-sealed pressure sensor comprising: pressure sensor body, first threaded connection pipe, second threaded connection pipe, turning block and line joint, the second threaded connection pipe sets up in the turning block the place ahead, first threaded connection pipe sets up in the place ahead of second threaded connection pipe, be provided with the limiting plate between first threaded connection pipe and the second threaded connection pipe, the limiting plate openly is provided with first sealing washer, be provided with a cover of strengthening on the second threaded connection pipe, the cover end extends to the limiting plate outside of strengthening, the cover end is provided with the second sealing washer. In this technical scheme, utilize the extrusion of limiting plate to first sealing washer, carry out first heavy seal, utilize the extrusion of strengthening the cover to the second sealing washer, outside the pressure vessel forms the second heavy seal, avoided the seepage problem.

However, in this structure, the sensor and the sealing assembly are designed in a split type and are connected through the through hole, so that not only are the parts more assembled, but also the connection between the through hole and the sensor is unreliable, and leakage is easy to occur, so that the pressure detection result is affected. In addition, the two sealing rings are sealed along the axial direction of the end face, the work compression amount of the sealing rings is difficult to adjust, and the sealing effect is poor.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art, and provides a novel double-seal pressure core structure for a pressure sensor, which has two sealing modes of end face axial sealing and side face sealing, wherein the two sealing rings are in direct contact sealing with a pressure MEMS element, so that the contact area is large and the stress is more uniform.

The utility model aims at being completed by the following technical scheme: the novel double-sealing pressure core structure for the pressure sensor comprises a sensor mounting seat, a small sealing ring, a pressing plate, a pressure MEMS element and a large sealing ring, wherein the pressing plate is fixed at the top of the sensor mounting seat in a sealing manner, and a mounting cavity is formed between the pressing plate and the inner wall of the sensor mounting seat and used for placing the pressure MEMS element; an air channel is arranged on the pressing plate in a penetrating way and is used for leading outside air to the end face A of the pressure MEMS element, which faces the pressing plate; the sensor mounting seat is provided with a detection channel in a penetrating way, and is used for leading the detected gas to the end face B of the pressure MEMS element, which is away from the pressing plate, and the pressure MEMS element is used for detecting and outputting the pressure difference between the end face A and the end face B; the small sealing ring and the large sealing ring are coaxially arranged with the detection channel, and the small sealing ring is closer to the detection channel than the large sealing ring; the pressing plate is pressed on the end face A, the small sealing ring is arranged between the end face B and the inner wall of the sensor mounting seat to form a first seal between the end face B and the end face A, and the large sealing ring is arranged between the outer wall of the pressure MEMS element and the inner wall of the sensor mounting seat to form a second seal between the end face B and the end face A.

As a further technical scheme, a first annular groove used for placing a large sealing ring and a second annular groove used for placing a small sealing ring are formed in the inner wall, close to the end face B, of the sensor mounting seat.

As a further technical scheme, the working compression amount of the small sealing ring is 10% -30%, and the working compression amount is controlled by the machining depth of the second annular groove.

As a further technical scheme, set up the inclined plane on the outer wall of pressure MEMS component, one side that first ring channel kept away from the second ring channel sets up the fillet, makes big sealing washer compressed tightly between fillet and inclined plane.

As a further technical scheme, the working compression amount of the large sealing ring is 10% -30%, and the working compression amount is controlled by the size of the round angle and the inclination angle of the inclined plane.

As a further technical scheme, an upper detection area for accommodating air is formed on the end face a, and a lower detection area for accommodating detected gas is formed on the end face B.

As a further technical scheme, the pressing plate is fixedly connected with the sensor mounting seat through pan head screws and studs.

The beneficial effects of the utility model are as follows:

1. the end face axial seal and the side face seal of the pressure MEMS element are formed by adopting a large sealing ring and a small sealing ring, and when one sealing ring fails, the other sealing ring continuously plays a role in sealing, so that the reliability of a product is improved;

2. the contact area between the two sealing rings and the pressure MEMS element is larger, the stress is more uniform, and the output signal of the sensor is more stable;

3. the end face axial sealing is implemented at the forefront end of the measured pressure inlet by adopting a small sealing ring, the compression amount of the small sealing ring can be precisely controlled through the depth dimension processed by the second annular groove, so that the compression amount of the small sealing ring reaches 10% -30% of the optimal working compression amount, a first seal is formed, the measured air pressure is directly borne, and the sealing strength is high;

4. an R fillet is additionally arranged at the bottom of the cylindrical surface of the inner cavity of the sensor mounting seat, so that the inner cavity is formed into an inclined surface with a certain gradient, a large sealing ring is placed at the R fillet, and compression is controlled by extrusion of the R fillet and the inclined surface on the pressure MEMS element, so that the optimal working compression is 10% -30%, a second seal is formed, and the sealing effect is improved.

Drawings

Fig. 1 is an exploded view of the structure of the present utility model.

Fig. 2 is a sectional view of the assembled structure of the present utility model, shown in fig. 1.

Fig. 3 is a cross-sectional view of the assembled structure of the present utility model, shown in fig. 2.

Fig. 4 is an enlarged partial schematic view of the area a in fig. 3.

Reference numerals illustrate: sensor mount 1, detection channel 11, lower detection area 12, fillet 13, first annular groove 14, second annular groove 15, installation cavity 16, small seal ring 2, clamp plate 3, air channel 31, pan head screw 4, stud 5, pressure MEMS element 6, upper detection area 61, bevel 62, end face B63, end face a64, large seal ring 7.

Detailed Description

The utility model will be described in detail below with reference to the attached drawings:

examples: as shown in fig. 1 to 4, the novel double-seal pressure core structure for the pressure sensor comprises a sensor mounting seat 1, a detection channel 11, a lower detection area 12, a round corner 13, a first annular groove 14, a second annular groove 15, a mounting cavity 16, a small sealing ring 2, a pressing plate 3, an air channel 31, a pan head screw 4, a stud 5, a pressure MEMS element 6, an upper detection area 61, an inclined surface 62, an end surface B63, an end surface a64 and a large sealing ring 7.

Referring to fig. 3, the pressing plate 3 is sealed and fixed on the top of the sensor mount 1 by two copper studs 5 and a pan head screw 4, a mounting cavity 16 is formed between the pressing plate 3 and the inner wall of the sensor mount 1, and the pressure MEMS element 6 is placed in the mounting cavity 16. The pressure MEMS element 6 is a thin film element that deforms when subjected to pressure, and this deformation can be measured by a strain gauge (piezoresistive sensing) or by capacitive sensing of the change in distance between the two faces. An air channel 31 is formed through the platen 3 in the axial direction, and the air channel 31 is capable of leading outside air to the end face a64 (i.e., the side surface of the pressure MEMS element 6 facing the platen 3), and preferably an upper detection area 61 is formed on the end face a64 for accommodating air. A detection channel 11 is formed through the sensor mount 1 in the axial direction, and the detection channel 11 can lead the detected gas to the end face B63 (i.e., a surface of the pressure MEMS element 6 facing away from the platen 3), and preferably a lower detection region 12 is formed on the end face B63 for accommodating the detected gas. The axial center of the air passage 31 is collinear with the axial center of the detection passage 11, and the pressure difference between the end face a64 (upper detection region 61) and the end face B63 (lower detection region 12) can be detected and outputted by the pressure MEMS element 6. As shown in fig. 4, the small sealing ring 2 and the large sealing ring 7 are coaxially arranged with the detection channel 11, and the small sealing ring 2 is closer to the detection channel 11 than the large sealing ring 7, and the small sealing ring 2 and the end face B63 form an end face axial seal, namely a first seal. The pressing plate 3 presses on the end face A64, a downward pressing force F1 is applied to the pressure MEMS element 6, the small sealing ring 2 is arranged between the end face B63 and the inner wall of the sensor mounting seat 1, and the small sealing ring 2 provides an upward supporting force F3 for the pressure MEMS element 6. The large sealing ring 7 is arranged between the outer wall of the pressure MEMS element 6 and the inner wall of the sensor mounting seat 1, and is contacted with the inclined surface 62 on the outer wall of the pressure MEMS element 6 to form an inclined surface seal, namely a second seal. The large sealing ring 7 provides an upward supporting force F2 for the pressure MEMS element 6, and the resultant force of the supporting force F2 and the supporting force F3 is balanced with the pressing force F1, i.e. f1=f2×sin α+f3, where α is an included angle formed between the supporting force F2 and the horizontal direction. The large sealing ring and the small sealing ring bear pressure together, the stress position of one sealing ring is one circle in the middle of the pressure MEMS element 6, the stress position of the other sealing ring is one circle around the pressure MEMS element 6, and the two annular surfaces are in contact with each other, so that the stability and the distribution are good, and the sealing service life is prolonged.

Preferably, the small seal ring 2 and the large seal ring 7 are O-shaped seal rings. Further, a first annular groove 14 and a second annular groove 15 are formed in the inner wall, close to the end face B63, of the sensor mounting seat 1, the small sealing ring 2 is placed in the second annular groove 15, and the working compression amount of the small sealing ring 2 can be controlled by adjusting the machining depth of the second annular groove 15, so that the optimal working compression amount, namely 10% -30%, is achieved. The large sealing ring 7 is placed in the first annular groove 14, a round angle 13 is arranged on the outer side of the first annular groove 14 (namely, on the side far away from the second annular groove 15), the large sealing ring 7 is pressed between the round angle 13 and the inclined surface 62, and the working compression amount of the large sealing ring 7 can be controlled by adjusting the size of the round angle 13 and the inclination angle of the inclined surface 62, so that the working compression amount is the best, namely, 10% -30%.

The working process of the utility model comprises the following steps: referring to fig. 3, during testing, the detecting channel 11 is communicated with the gas to be tested, the gas to be tested enters the lower detecting area 12 along the direction of the arrow of the dotted line in the figure, the pressure is acted on the end face B63, the air channel 31 is communicated with the outside air, the air enters the upper detecting area 61 along the direction of the arrow of the solid line in the figure, the pressure is acted on the end face a64, and the pressure difference between the end face B63 and the end face a64 is the pressure of the gas to be tested. Part of air enters the mounting cavity 16 through a gap between the end face A64 and the pressing plate 3, but the air cannot pass through the large sealing ring and the small sealing ring due to the existence of two seals; likewise, the gas to be measured cannot enter the mounting cavity 16 through the small sealing ring and the large sealing ring, so that the relative sealing between the end face A64 and the end face B63 is ensured. If the small sealing ring 2 fails, the large sealing ring 7 can continuously isolate the tested gas and air, thereby achieving the effect of double sealing.

It should be understood that equivalents and modifications to the technical scheme and the inventive concept of the present utility model should fall within the scope of the claims appended hereto.

Claims

1. A novel double containment pressure core structure for pressure sensor, its characterized in that: the pressure sensor comprises a sensor mounting seat (1), a small sealing ring (2), a pressing plate (3), a pressure MEMS element (6) and a large sealing ring (7), wherein the pressing plate (3) is fixed at the top of the sensor mounting seat (1) in a sealing manner, a mounting cavity (16) is formed between the pressing plate (3) and the inner wall of the sensor mounting seat (1) and is used for placing the pressure MEMS element (6); an air channel (31) is formed on the pressing plate (3) in a penetrating way and is used for leading outside air to the end face A (64) of the pressure MEMS element (6) facing the pressing plate (3); a detection channel (11) is arranged on the sensor mounting seat (1) in a penetrating manner and is used for leading the detected gas to an end face B (63) of the pressure MEMS element (6) which is away from the pressing plate (3), and the pressure MEMS element (6) is used for detecting and outputting the pressure difference between the end face A (64) and the end face B (63); the small sealing ring (2) and the large sealing ring (7) are coaxially arranged with the detection channel (11), and the small sealing ring (2) is closer to the detection channel (11) than the large sealing ring (7); the pressing plate (3) is pressed on the end face A (64), the small sealing ring (2) is arranged between the end face B (63) and the inner wall of the sensor mounting seat (1) to form a first seal between the end face B (63) and the end face A (64), and the large sealing ring (7) is arranged between the outer wall of the pressure MEMS element (6) and the inner wall of the sensor mounting seat (1) to form a second seal between the end face B (63) and the end face A (64).

2. The novel dual seal pressure core structure for a pressure sensor of claim 1, wherein: the inner wall, close to the end face B (63), of the sensor mounting seat (1) is provided with a first annular groove (14) used for placing the large sealing ring (7) and a second annular groove (15) used for placing the small sealing ring (2).

3. The novel dual seal pressure core structure for a pressure sensor of claim 2, wherein: the working compression amount of the small sealing ring (2) is 10% -30%, and the working compression amount is controlled by the machining depth of the second annular groove (15).

4. The novel dual seal pressure core structure for a pressure sensor of claim 2, wherein: an inclined surface (62) is arranged on the outer wall of the pressure MEMS element (6), and a round angle (13) is arranged on one side, away from the second annular groove (15), of the first annular groove (14), so that the large sealing ring (7) is pressed between the round angle (13) and the inclined surface (62).

5. The novel dual seal pressure core structure for a pressure sensor of claim 4, wherein: the working compression amount of the large sealing ring (7) is 10% -30%, and the working compression amount is controlled by the size of the round angle (13) and the inclination angle of the inclined surface (62).

6. The novel dual seal pressure core structure for a pressure sensor according to any one of claims 1 to 5, characterized in that: an upper detection area (61) for containing air is formed on the end face A (64), and a lower detection area (12) for containing detected gas is formed on the end face B (63).

7. The novel dual seal pressure core structure for a pressure sensor of claim 6, wherein: the pressing plate (3) is fixedly connected with the sensor mounting seat (1) through a pan head screw (4) and a stud (5).