Oil-filled pressure core body and pressure sensor

Abstract

The invention discloses an oil-filled pressure core body, which comprises a mounting seat, an oil-filled pressure core body, an oil-filled pressure core body, an oil-filled pressure core body and an oil-filled pressure core body, the corrugated sheet sequentially comprises a flat center part, a fluctuating corrugated part and a flat edge part outwards in the radial direction, the radial outer side part of the edge part is upwards supported and fixed to the bottom edge of the concave cavity, and a pressure conduction cavity is defined between the edge part and the mounting base; the pressure conduction cavity is filled with the pressure conduction medium; a first support surface and a second support surface; the pressure sensitive element is arranged on the mounting seat; the first supporting surface is used for supporting the inner side part of the edge part, so that the situation that the corrugated sheet is damaged due to the fact that local part of the inner side part of the edge part is subjected to overlarge pressure intensity is avoided; the arranged second supporting face is used for supporting the corrugated part and / or the center part, and the situation that the corrugated sheet is damaged due to too large pressure is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure detection, and in particular relates to an oil-filled pressure core and a pressure sensor. Background Art

[0002] Pressure sensors are sensors used to measure the pressure of the environment or medium. Currently, they are mostly implemented through MEMS (micro-electromechanical systems), that is, pressure is measured through the piezoresistive effect of semiconductor silicon. Among them, the middle part of the silicon core is set to be a diaphragm. The pressure applied to the silicon diaphragm on both sides causes the resistance value of the doped resistor on the silicon diaphragm to change. The current or voltage signal output by the measurement circuit composed of several resistors can be further processed by the conditioning circuit and then output to the outside. When a vacuum cavity is set on one side of the diaphragm in the silicon chip, the measured pressure is the pressure applied on the other side relative to the vacuum, that is, the absolute pressure; when atmospheric pressure is introduced on one side of the diaphragm, the measured pressure is the pressure relative to the atmosphere, that is, the gauge pressure; when other pressures are introduced on both sides of the diaphragm, the measured pressure is the difference between the pressures on both sides, that is, the differential pressure. In some other sensors, temperature sensitive elements can also be integrated to measure the pressure and temperature of the medium at the same time.

[0003] A Chinese utility model patent with publication number CN213516135U discloses an isolated packaged pressure sensor, which includes a pressure ring, a shell and a corrugated sheet. The corrugated sheet and the pressure ring are crimped to the shell in sequence. The pressure ring, the corrugated sheet and the shell are connected together by argon arc welding, and the welding points between the pressure ring and the shell are not chamfered.

[0004] The corrugated sheet of this pressure sensor may be excessively deformed and damaged when subjected to excessive pressure shock. Summary of the invention

[0005] The object of the present invention is to provide an oil-filled pressure core and a pressure sensor to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An oil-filled pressure core, comprising:

[0008] A mounting seat, the bottom end of which is recessed inward to form a cavity;

[0009] A corrugated sheet fixedly sealed at the bottom of the cavity for receiving the pressure of the pressure medium to be measured, which includes a flat central portion, an undulating corrugated portion and a flat edge portion in order from radially outward, wherein the radially outer portion of the edge portion is supported upward and fixed to the bottom edge of the cavity and forms a pressure conduction cavity with the mounting seat; a gap is left between the inner wall of the cavity and the corrugated sheet;

[0010] A pressure-conducting medium filled in the pressure-conducting cavity;

[0011] a first supporting surface and a second supporting surface formed on the inner wall of the concave cavity, the first supporting surface being used to support the radial inner portion of the edge portion when the pressure is greater than a first pressure, and the second supporting surface being used to support the corrugated portion and / or the central portion when the pressure is greater than a second pressure, the second pressure being greater than the first pressure;

[0012] and a pressure sensitive element arranged on the mounting seat, which is used for receiving the pressure of the pressure-conducting medium and converting the pressure into an electrical signal.

[0013] The present invention uses a corrugated sheet to isolate the pressure medium to be measured from the pressure sensitive element, so that the pressure sensitive element can measure the pressure of the pressure medium to be measured without contacting the pressure medium to be measured, thereby preventing the pressure medium to be measured from corroding the pressure sensitive element; the edge of the corrugated sheet facilitates the sealing and fixing of the corrugated sheet and the mounting seat, and the corrugated portion of the corrugated sheet facilitates the deformation of the corrugated sheet to transmit the pressure of the pressure medium to be measured to the pressure sensitive element; the first supporting surface is used to support the inner part of the edge portion, thereby preventing the inner part of the edge portion from being locally subjected to excessive pressure and causing damage to the corrugated sheet; the second supporting surface is used to support the corrugated portion and / or the center portion, thereby preventing the corrugated sheet from being damaged due to excessive pressure.

[0014] Furthermore, the first supporting surface is formed by the inner wall of the concave cavity near the edge and is inclined radially from the outside to the inside toward the side away from the corrugated sheet, so that the connection between the inner wall of the concave cavity and the bottom surface of the mounting seat has a smooth transition. When the corrugated sheet is deformed, the contact area with the corrugated sheet can be increased to provide better support. By increasing the contact area, the local pressure is reduced to protect the corrugated sheet.

[0015] Furthermore, when the pressure is greater than the second pressure, the first supporting portion of the second supporting surface is supported on at least one crest portion of the corrugated portion to protect the corrugated sheet. When the pressure is overloaded, the first supporting portion of the second supporting surface provides support for the corrugated sheet to prevent the corrugated sheet from rupturing or making it difficult for the corrugated sheet to rebound. After the pressure is restored to a range that the corrugated sheet can withstand, the corrugated sheet can still continue to work and transfer the pressure to the pressure sensitive element.

[0016] Furthermore, when the pressure is greater than the second pressure, the second supporting surface includes a flat second supporting portion, which is supported on the central portion to protect the corrugated sheet. When the pressure is overloaded, the corrugated sheet is provided with support to prevent the corrugated sheet from rupturing or permanent deformation. After the pressure is restored to a range that the corrugated sheet can withstand, the corrugated sheet can continue to work and transmit the pressure to the pressure sensitive element.

[0017] Furthermore, the inner wall of the pressure receiving cavity is concave to form a pressure detection cavity, and the pressure sensitive element is installed in the pressure detection cavity, with the pressure sensing surface on one side thereof exposed in the pressure cavity, and can be used to measure absolute pressure.

[0018] Furthermore, it also includes a processing circuit arranged on the surface of the mounting base away from the corrugated sheet, and the pressure sensitive element is electrically connected to the processing circuit.

[0019] Furthermore, the pressure sensitive element is electrically connected to the processing circuit through a plurality of leads which are sealed and penetrate the mounting seat, and the provided leads are used to transmit the electrical signal of the pressure sensitive element to the processing circuit.

[0020] Furthermore, a connecting hole connecting to the concave cavity is longitudinally opened on the upper surface of the mounting seat, and the pressure sensitive element is arranged on the upper surface of the mounting seat and blocks the connecting hole. The connecting hole is used to guide the pressure to the pressure sensitive element. The pressure sensitive element is installed on the upper surface of the mounting seat and can be used to measure the gauge pressure.

[0021] Furthermore, a pressure ring is provided on the lower surface of the edge portion to press the edge portion of the corrugated sheet against the mounting seat.

[0022] The present invention also claims protection for a pressure sensor comprising the above-mentioned oil-filled pressure core.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention provides a corrugated sheet to isolate the pressure medium to be measured from the pressure sensitive element, so that the pressure sensitive element can measure the pressure of the pressure medium to be measured without contacting the pressure medium to be measured, thereby preventing the pressure medium to be measured from corroding the pressure sensitive element; the edge of the corrugated sheet facilitates the sealing and fixing of the corrugated sheet and the mounting seat, and the corrugated portion of the corrugated sheet facilitates the deformation of the corrugated sheet to transmit the pressure of the pressure medium to be measured to the pressure sensitive element.

[0025] (2) In the prior art, the connection between the bottom surface of the mounting seat and the concave cavity is generally not chamfered or subjected to transition treatment such as chamfering. The corrugated sheet is subjected to a large pressure at this connection and is easily damaged. The present invention provides a first supporting surface to support the inner part of the edge portion to prevent the inner part of the edge portion from being locally subjected to excessive pressure and causing damage to the corrugated sheet; and provides a second supporting surface to support the corrugated portion and / or the center portion to prevent the corrugated sheet from being damaged due to excessive pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of a pressure sensor in the prior art;

[0027] Figure 2 It is a structural schematic diagram of the oil-filled pressure core in Example 1;

[0028] Figure 3 for Figure 2 A partial enlarged view of the middle part;

[0029] Figure 4 It is a structural schematic diagram of the oil-filled pressure core in Example 2;

[0030] In the figure: 3', shell; 6', pressure ring; 7', corrugated sheet; 1, mounting seat; 101, concave cavity; 102, pressure transmission cavity; 103, first supporting surface; 104, second supporting surface; 104a, second supporting part; 104b, first supporting part; 2, corrugated sheet; 201, central part; 202, corrugated part; 203, edge part; 3, pressure-conducting medium; 4, pressure sensitive element; 5, pressure detection cavity; 6, processing circuit; 7, connecting hole; 8, pressure ring; 9, circuit board; 10, glass; 11, lead. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] refer to Figure 1 The outer shell 3' of the pressure sensor in the prior art generally has no chamfer at the inner edge, and the contact area between the corrugated sheet 7' and the inner edge of the outer shell 3' is small. The corrugated sheet 7' is subjected to a large pressure and is easily damaged.

[0033] Example 1

[0034] like Figure 2 and Figure 3 As shown, this embodiment provides an oil-filled pressure core, including a mounting seat 1, a corrugated sheet 2 and a pressure sensitive element 4.

[0035] The bottom end of the mounting seat 1 is recessed inward to form a cavity 101. The corrugated sheet 2 is fixedly sealed at the bottom of the cavity 101 to receive the pressure of the pressure medium to be measured. The corrugated sheet 2 includes a flat central portion 201, an undulating corrugated portion 202 and a flat edge portion 203 in sequence radially outward. The radially outer portion of the edge portion 203 is supported upward and fixed to the bottom edge of the cavity 101 and forms a pressure transmission cavity 102 with the mounting seat 1. The pressure transmission cavity 102 is filled with a pressure-conducting medium 3. Preferably, the pressure-conducting medium 3 can be silicone oil. A gap is left between the inner wall of the cavity 101 and the corrugated sheet 2. Furthermore, the oil-filled pressure core also includes a processing circuit 6 arranged on the surface of the mounting seat 1 away from the corrugated sheet 2. The pressure sensitive element 4 is electrically connected to the processing circuit 6. Preferably, a circuit board 9 can be arranged on the surface of the mounting seat 1 away from the corrugated sheet 2, and the processing circuit 6 is arranged on the circuit board 9.

[0036] A first supporting surface 103 and a second supporting surface 104 are formed on the inner wall of the cavity 101. The first supporting surface 103 is used to support the radial inner part of the edge portion 203 when the pressure of the medium to be measured is greater than the first pressure, and the second supporting surface 104 is used to support the corrugated portion 202 and / or the central portion 201 when the pressure of the medium to be measured is greater than the second pressure, wherein the second pressure is greater than the first pressure. Further, the first supporting surface 103 is formed by the inner wall of the cavity 101 near the edge and tilted radially from the outside to the inside toward the side away from the corrugated sheet 2, so that the connection between the inner wall of the cavity 101 and the bottom surface of the mounting seat 1 is smoothly transitioned, and when the corrugated sheet 2 is deformed, the contact area with the corrugated sheet 2 can be increased to provide better support, and the pressure borne locally can be reduced by increasing the contact area, thereby protecting the corrugated sheet 2. Further, the corrugated portion 202 includes a plurality of continuous wave crests. When the pressure of the medium to be measured is greater than the second pressure, the first supporting portion 104b of the second supporting surface 104 is supported on at least one wave crest of the corrugated portion 202 to protect the corrugated sheet 2. When the pressure is overloaded, the first supporting portion 104b of the second supporting surface 104 is supported on at least one wave crest of the corrugated portion 202 to protect the corrugated sheet 2. When the pressure is overloaded, the first supporting portion 104b of the second supporting surface 104 is supported on at least one wave crest of the corrugated sheet ...

[0037] The pressure sensitive element 4 is arranged on the mounting seat 1, and is used to receive the pressure of the pressure-conducting medium 3 and convert the pressure into an electrical signal. Preferably, the inner wall of the pressure receiving cavity can be concave to form a pressure detection cavity 5, and the pressure sensitive element 4 is installed in the pressure detection cavity 5, and the pressure sensing surface on one side is exposed in the pressure cavity. The pressure sensitive element 4 is electrically connected to the processing circuit 6 through a plurality of leads 11 that are sealed and penetrated through the mounting seat 1. Preferably, a glass seed 10 can be sintered between the leads 11 and the mounting seat 1 for sealing and insulation. The provided leads 11 are used to transmit the electrical signal of the pressure sensitive element 4 to the processing circuit 6, which can be used to measure absolute pressure.

[0038] The present invention uses a corrugated sheet 2 to isolate the pressure medium to be measured from the pressure sensitive element 4, so that the pressure sensitive element 4 can measure the pressure of the pressure medium to be measured without contacting the pressure medium to be measured, thereby preventing the pressure medium to be measured from corroding the pressure sensitive element 4; the edge portion 203 of the corrugated sheet 2 facilitates the sealing and fixing of the corrugated sheet 2 and the mounting seat 1, and the corrugated portion 202 of the corrugated sheet 2 facilitates the deformation of the corrugated sheet 2 to transfer the pressure of the pressure medium to be measured to the pressure sensitive element 4; the first supporting surface 103 is used to support the inner part of the edge portion 203 to prevent the inner part of the edge portion 203 from being locally subjected to excessive pressure and causing damage to the corrugated sheet 2; the second supporting surface 104 is used to support the corrugated portion 202 and / or the center portion 201 to prevent the corrugated sheet 2 from being damaged due to excessive pressure.

[0039] Furthermore, a pressing ring 8 is provided on the lower surface of the edge portion 203 to press the edge portion 203 of the corrugated sheet 2 against the mounting seat 1. The edge portion 203 can be welded to the pressing ring 8 and the mounting seat 1.

[0040] This embodiment also provides a pressure sensor, which is based on the above-mentioned oil-filled pressure core.

[0041] Example 2

[0042] like Figure 4 As shown, the difference between this embodiment and the embodiment is that a connecting hole 7 connecting the concave cavity 101 is opened in the upper surface of the mounting seat 1 along the longitudinal direction, and the pressure sensitive element 4 is arranged on the upper surface of the mounting seat 1 and blocks the connecting hole 7. The connecting hole 7 is used to guide the pressure to the pressure sensitive element 4. The pressure sensitive element 4 is installed on the upper surface of the mounting seat 1 and can be used to measure the gauge pressure. In this embodiment, when the pressure of the medium to be measured is greater than the second pressure, the second supporting part 104a can be supported on the central part, and the first supporting part 104b does not have to be supported on the corrugated part 202. In some other schemes, when the pressure of the medium to be measured is greater than the second pressure, the second supporting part 104a is not supported on the central part, and the first supporting part 104b is supported on at least one crest of the corrugated part 202.

[0043] It should be noted that although the present invention is disclosed as above by specific embodiments, the above embodiments are not intended to limit the present invention. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined in the claims.

Claims

1. An oil-filled pressure core, characterized in that: include: A mounting seat, the bottom end of which is recessed inward to form a cavity; A corrugated sheet fixedly sealed at the bottom of the cavity for receiving the pressure of the pressure medium to be measured, which includes a flat central portion, an undulating corrugated portion and a flat edge portion in order from radially outward, wherein the radially outer portion of the edge portion is supported upward and fixed to the bottom edge of the cavity and forms a pressure conduction cavity with the mounting seat; a gap is left between the inner wall of the cavity and the corrugated sheet; A pressure-conducting medium filled in the pressure-conducting cavity; a first supporting surface and a second supporting surface formed on the inner wall of the concave cavity, the first supporting surface being used to support the radial inner portion of the edge portion when the pressure is greater than a first pressure, and the second supporting surface being used to support the corrugated portion and / or the central portion when the pressure is greater than a second pressure, the second pressure being greater than the first pressure; and a pressure sensitive element arranged on the mounting seat, which is used for receiving the pressure of the pressure-conducting medium and converting the pressure into an electrical signal.

2. The oil-filled pressure core according to claim 1, characterized in that: The first supporting surface is formed by the inner wall of the concave cavity close to the edge and is inclined radially from the outside to the inside toward the side away from the corrugated sheet.

3. The oil-filled pressure core according to claim 1, characterized in that: When the pressure is greater than the second pressure, the first supporting portion of the second supporting surface is supported on at least one crest of the corrugated portion.

4. The oil-filled pressure core according to claim 1, characterized in that: When the pressure is greater than the second pressure, the second supporting surface includes a flat second supporting portion, and the second supporting portion is supported on the central portion.

5. The oil-filled pressure core according to claim 1, characterized in that: The inner wall of the pressure receiving cavity is concave to form a pressure detection cavity. The pressure sensitive element is installed in the pressure detection cavity, and the pressure sensing surface on one side of the pressure sensitive element is exposed in the pressure cavity.

6. The oil-filled pressure core according to claim 1, characterized in that: The device also includes a processing circuit disposed on a surface of the mounting base away from the corrugated sheet, and the pressure sensitive element is electrically connected to the processing circuit.

7. The oil-filled pressure core according to claim 6, characterized in that: The pressure sensitive element is electrically connected to the processing circuit via a plurality of leads that are sealed and pass through the mounting base.

8. The oil-filled pressure core according to claim 1, characterized in that: A communication hole communicating with the concave cavity is longitudinally opened on the upper surface of the mounting seat, and the pressure sensitive element is arranged on the upper surface of the mounting seat and blocks the communication hole.

9. The oil-filled pressure core according to claim 1, characterized in that: A pressure ring is provided on the lower surface of the edge portion.

10. A pressure sensor, characterized in that: An oil-filled pressure core comprising any one of claims 1-9.

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