Pressure sensor

Abstract

A pressure sensor comprises a housing forming an installation cavity, the housing comprises a main housing body, and a pressure introduction channel is formed in the main housing body, and one end of the inner side of the pressure introduction channel is communicated with the installation cavity; the pressure measuring assembly comprises a pressure sensitive element plugged at one end of the inner side of the pressure introduction channel; a buffer cavity is defined by the buffer piece and the main shell, and the pressure introduction channel is communicated to the buffer cavity; the mounting cavity is provided with a receding cavity allowing at least one part of the buffering piece to be pressed and arched towards the side away from the buffering cavity. According to the pressure sensor, the buffering cavity communicated with the pressure introduction channel can be formed through the sealing part of the buffering piece and the sealing part which is pressed and sealed to the main shell, and pressure buffering is carried out through deformation of the elastic deformation part of the buffering piece under the condition that the pressure is too large; compared with a foaming pipe in the prior art, the foaming pipe can provide a larger buffering volume; in addition, no extra assembly process is required during combined assembly.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a pressure sensor. Background Art

[0002] Semiconductor pressure sensitive components such as pressure chips are widely used in pressure sensors. On the one hand, the pressure medium to be measured may have large pressure fluctuations, such as a sharp change in pressure caused by the water hammer effect; on the other hand, in a low-temperature environment, the pressure sensor may be subjected to a huge pressure caused by the volume change of the pressure medium to be measured during phase change when measuring the pressure medium to be measured, which has a great destructive effect on the pressure chip. For example, the urea solution used for selective catalytic reduction in the automobile exhaust emission system will expand by up to 10% in volume when the temperature is below -11°C, and higher requirements are placed on the sensor used at this time. If the measuring medium remains in the cavity of the sensor in a low-temperature environment, the measuring medium will generate huge pressure on the pressure sensitive chip when it is frozen, causing the chip to fail or even rupture.

[0003] In the prior art, in order to prevent the ice of the pressure medium to be measured from damaging the pressure sensitive element, a foaming tube is usually arranged in the pressure introduction channel to absorb the system expansion of the pressure medium to be measured, such as CN107588889A and CN211147927U. The volume change that this structure can absorb is relatively limited. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present application provides a pressure sensor to improve the pressure buffering effect.

[0005] To achieve the above objectives, the present application provides the following technical solution: a pressure sensor, comprising:

[0006] A housing for forming a mounting cavity comprises a main housing, wherein a pressure introduction channel is formed in the main housing at one inner end thereof and communicates with the mounting cavity;

[0007] A pressure measuring assembly, comprising a pressure sensitive element sealed at one inner end of the pressure introduction channel;

[0008] A buffer component forms a buffer cavity with the main shell, and the pressure introduction channel is connected to the buffer cavity; the installation cavity has a yield cavity that allows at least a portion of the buffer component to be pressurized and arched toward a side away from the buffer cavity.

[0009] Preferably, the buffer is substantially annular, and includes a circle of first sealing portions formed on the inner edge, a circle of second sealing portions formed on the outer edge, and an elastic deformation portion that closes and connects the first sealing portion and the second sealing portion.

[0010] Preferably, the first sealing portion and the second sealing portion are respectively located on different transverse planes, and the first sealing portion is located on the side closer to the pressure-sensitive element of the second sealing portion.

[0011] Preferably, an elastic deformation portion is integrally connected with a surrounding resilient portion.

[0012] Preferably, the first sealing portion and the second sealing portion are located on the same transverse plane.

[0013] Preferably, the first sealing portion surrounds the outer side of the inner end of the pressure introduction channel.

[0014] Preferably, the inner end of the pressure introduction channel is located outside the first sealing portion and the second sealing portion.

[0015] Preferably, the buffer member is pressed and sealed to the main housing to form the buffer cavity.

[0016] Preferably, the housing further includes a terminal button assembled longitudinally to the main housing, and the buffer member is directly or indirectly pressed and sealed to the main housing by the terminal button to form the buffer cavity.

[0017] Preferably, the pressure measurement assembly further includes a substrate, and the pressure-sensitive element communicates with the pressure introduction channel through a through hole formed in the substrate; the terminal button presses and seals the first sealing portion to the main housing indirectly through the substrate on the side facing the main housing.

[0018] The pressure sensor of the present invention can form a buffer cavity communicating with the pressure introduction channel by the sealing portion of the buffer member and the sealing portion being pressed and sealed to the main housing, and perform pressure buffering through the deformation of the elastic deformation portion of the buffer member in the case of excessive pressure, and it can provide a larger buffer volume compared with the foamed tube in the prior art; in addition, no additional assembly process is required during assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of the pressure sensor of the first embodiment.

[0020] Figure 2 is a schematic structural diagram of the pressure sensor of the second embodiment. DETAILED DESCRIPTION

[0021] The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application. In the following description, the same reference numerals are used to represent the same or equivalent elements, and repeated descriptions are omitted.

[0022] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present application is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In addition, the prefixes "first", "second", "third", etc. are only used for the purpose of distinguishing the objects to be modified, and should not be construed as indicating or implying relative importance.

[0023] In addition, the terms "mounted", "connected", and "coupled" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0024] It should be further understood that the term "and / or" used in the specification and corresponding claims of the present application refers to any combination of one or more of the listed items and all possible combinations.

[0025] As Figure 1 shown. The pressure sensor 100 of the first embodiment includes a housing (not labeled) and a pressure measurement assembly 2. Among them, an installation cavity 101 is formed inside the housing, and the pressure measurement assembly 2 is disposed inside the installation cavity 101. The housing may include a main housing 1, and a pressure introduction channel 120 with one end communicating with the inside of the installation cavity 101 is formed inside the main housing 1. Most of the pressure introduction channel 120 may be defined by the inner cavity of a pressure interface 12 formed on the main housing 1. The pressure measurement assembly 2 may include a pressure sensitive element 20 blocking the inner end of the pressure introduction channel 120. The pressure sensor 100 further includes a buffer member 4. A buffer cavity 4a is formed between the buffer member 4 and the main housing 1. The pressure introduction channel 120 communicates with the buffer cavity 4a. The installation cavity 101 has a relief cavity 4b that allows at least a part of the buffer member 4 to be arched toward the side away from the buffer cavity 4a under pressure.

[0026] The above-mentioned pressure sensor 100 can, when the pressure is too high, provide a larger volume to accommodate the pressure medium to be measured through the deformation generated by the buffer member 4 into the installation cavity 101. Especially in the case where the pressure medium to be measured in the pressure interface freezes, it can better avoid the damage to the pressure sensitive element 20 caused by freezing.

[0027] Preferably, the buffer member 4 is substantially annular, and may include a first sealing portion 41 formed on the inner edge, a second sealing portion 42 formed on the outer edge, and an elastic deformation portion 43 that is closed and integrally connected to the first sealing portion 41 and the second sealing portion 42. More preferably, the first sealing portion 41 and the second sealing portion 42 are respectively located on different transverse planes, and the first sealing portion 41 is located on the side closer to the pressure sensitive element 20 of the second sealing portion 42. Specifically, the inner end (i.e., Figure 1 the upper end in

[0028] the figure) of the pressure introduction channel 120 may protrude into the installation cavity 101 to form a boss 14. The upper end surface of the boss 14 forms a support surface 14a to support the pressure measurement assembly 2. The support surface 14a may be higher than the bottom of the installation cavity 101. A groove 141 for accommodating the sealing portion 41 is provided on the peripheral wall of the boss 14, and a groove 142 for accommodating the sealing portion 42 is formed on the bottom wall of the main housing 1 located in the installation cavity 101. Specifically, the main housing 1 may include a laterally extending plate body 11, the boss 14 is integrally connected to the upper end of the plate body 11, the pressure interface 12 is integrally connected to the lower end of the plate body 11, and the groove 142 is provided on the upper side surface of the plate body 11.

[0029] Among them, only by way of example, the pressure measurement assembly 2 may include a laterally extending substrate 21. The pressure sensitive element 20 and the processing circuit 22 are electrically connected and are both disposed on the upper side surface of the substrate 21. The processing circuit 22 may include some electronic components 24, which may be electrically connected to the terminal 321 provided on the terminal 3. Wherein, the inner end of the terminal 321 extends into the installation cavity 101 and is electrically connected to the processing circuit 22 through the electrical connection member 23. The outer end of the terminal 321 extends outward into the electrical plug portion 32 of the terminal 3. The above electrical connection member 23 is preferably a flexible circuit board or a flexible electrical connection member such as a conductive spring. The pressure sensitive element 20 can communicate with the pressure introduction channel 120 on the lower side of the substrate 21 through a through hole 210 formed on the substrate 21. A pressing portion 311 formed at the lower end of the terminal 3 can also indirectly press and seal the first sealing portion 41 against the main housing 1, that is, a pressure seal is also formed between the lower side surface of the substrate 21 and the sealing portion 41, so that no additional process is required during assembly. Preferably, a positioning structure is provided between the boss 14 and the substrate 21. For example, the top of the boss 14 is provided with an upwardly protruding positioning post or a hot riveting post.

[0030] In order to increase the area of the elastic deformation portion 43, the sealing portion 41 is preferably located radially inside the sealing portion 42. In this way, in the free state, the elastic deformation portion 43 can generally extend along a conical surface with the cone top facing upward. Among them, the buffer cavity 4a can communicate with the pressure introduction channel 120 through a communication groove 14b provided on the support surface 14a and the surface of the groove 141.

[0031] In some other technical solutions, the first sealing portion 41 and the second sealing portion 42 are also located on the same horizontal plane. For example, the groove 141 is also provided on the upper side surface of the plate body 11. Preferably, the first sealing portion 41 surrounds the outside of the inner end of the pressure introduction channel 120, so that the inner end of the pressure introduction channel 120 is located inside the sealing portion 41, which can increase the area of the elastic deformation portion 43; in some deteriorated embodiments, the inner end of the pressure introduction channel 120 can also be located outside the sealing portion 41 and the sealing portion 42, that is, it does not pass through the inside of the sealing portion 41 and the sealing portion 42.

[0032] The above pressure sensor 100 can be an absolute pressure sensor or a gauge pressure sensor. For example, the pressure sensitive element 20 also receives the ambient pressure as the reference pressure through the reference pressure channel 3a provided on the terminal 3. The pressure sensor 100 can also be a differential pressure sensor, that is, an additional pressure sensitive element 20 can be added as a reference to receive the pressure introduced into another pressure introduction channel.

[0033] Please refer to Figure 2。Compared with the first embodiment, in the second embodiment, a circle of resilient parts 44 may be integrally connected to the elastic deformation part 43 of the pressure sensor 100. This can relatively improve the ability of the elastic deformation part 43 to return to its original state, avoid the situation where the elastic deformation part 43 cannot rebound or rebounds incompletely, or avoid excessive deformation of the elastic deformation part 43. Additionally, in order to make the substrate 21 have as large a lateral dimension as possible to increase the area for arranging the processing circuit 22, a circle of pressing parts 311 at the lower end of the terminal 3 presses the first sealing part 41 against the main housing 1 indirectly through the substrate 21 towards the main housing 1 side. In some other solutions, a circle of pressing parts 312 formed at the lower end of the terminal 3 can also press the sealing part 42 against the main housing 1 indirectly through the substrate 21 towards the main housing 1 side.

[0034] Additionally, in this embodiment, a communication hole 14c provided inside the boss 14 can be used to replace the communication groove 14b to achieve the communication between the pressure introduction channel 120 and the buffer cavity 4a. Correspondingly, in order to facilitate the fabrication of the communication groove 14b, the lower end of the cylinder 13 can be connected to the plate body 11 by welding instead of integrally connecting the lower end of the cylinder 13 to the plate body 11.

[0035] The scope of the present disclosure is not defined 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 present disclosure.

Claims

1. A pressure sensor (100), characterized in that: include: A housing forming a mounting cavity (101) comprises a main housing (1), wherein a pressure introduction channel (120) is formed in the main housing (1) and one inner end of the pressure introduction channel is connected to the mounting cavity; A pressure measuring assembly (2), comprising a pressure sensitive element (20) sealed at one end of the inner side of the pressure introduction channel (120); A buffer component (4) is formed with the main housing (1) to form a buffer cavity (4a), and the pressure introduction channel (120) is connected to the buffer cavity (4a); the installation cavity (101) has a clearance cavity (4b) that allows at least a portion of the buffer component (4) to be pressed and arched toward a side away from the buffer cavity (4a).

2. The pressure sensor (100) according to claim 1, characterized in that: The buffer (4) is roughly annular, and includes a circle of first sealing parts (41) formed on the inner edge, a circle of second sealing parts (42) formed on the outer edge, and an elastic deformation part (43) that closes and connects the first sealing part (41) and the second sealing part (42).

3. The pressure sensor (100) according to claim 2, characterized in that: The first sealing portion (41) and the second sealing portion (42) are respectively located on different transverse planes, and the first sealing portion (41) is located on a side of the second sealing portion (42) close to the pressure sensitive element (20).

4. The pressure sensor (100) according to claim 3, characterized in that: The elastic deformation portion (43) is integrally connected to a circle of springback portion (44).

5. The pressure sensor (100) according to claim 3, characterized in that: The first sealing portion (41) and the second sealing portion (42) are located on the same transverse plane.

6. The pressure sensor (100) according to claim 5, characterized in that: The first sealing portion (41) surrounds the outer side of an inner end of the pressure introduction channel (120).

7. The pressure sensor (100) according to claim 5, characterized in that: An inner end of the pressure introduction channel (120) is located outside the first sealing portion (41) and the second sealing portion (42).

8. The pressure sensor (100) according to any one of claims 1 to 7, characterized in that: The buffer member (4) is compressed and sealed to the main housing (1) to form the buffer chamber (4a).

9. The pressure sensor (100) according to claim 8, characterized in that: The housing further comprises a terminal button (3) longitudinally assembled to the main housing (1), and the buffer member (4) is directly or indirectly compressed and sealed to the main housing (1) by the terminal button (3) to form the buffer chamber (4a).

10. The pressure sensor (100) according to claim 9, characterized in that: The pressure measuring assembly (2) further comprises a substrate (21), and the pressure sensitive element (20) is connected to the pressure introduction channel (120) via a through hole (210) formed on the substrate (21); the terminal (3) indirectly presses and seals the first sealing portion (41) to the main housing (1) through the substrate (21) toward one side of the main housing (1).

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