Differential pressure sensor diaphragm capsule and differential pressure sensor

Abstract

The invention relates to the technical field of sensors, in particular to a differential pressure sensor diaphragm capsule and a differential pressure sensor. The differential pressure sensor diaphragm capsule comprises a base body, a sensing unit, a pressure transmitting unit and an overload protection unit, the sensing unit comprises two first pressure sensing diaphragms and two second pressure sensing diaphragms, the pressure transmitting unit comprises a first pressure transmitting pipeline and a second pressure transmitting pipeline, and the first pressure transmitting pipeline and the second pressure transmitting pipeline are filled with pressure transmitting media respectively. The first pressure sensing diaphragm transmits pressure to the first chip through the first pressure transmitting pipeline, the second pressure sensing diaphragm transmits pressure to the second chip through the second pressure transmitting pipeline, and the overload protection unit is used for carrying out overload protection on the first chip and the second chip. According to the sensor diaphragm capsule, the wide-range requirement of the sensor is met, and high-precision output of a small range can be ensured. According to the differential pressure sensor provided by the invention, by arranging the differential pressure sensor diaphragm capsule, the measuring range and the measuring precision of the sensor are improved, and meanwhile, the product cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a differential pressure sensor diaphragm box and a differential pressure sensor. Background Art

[0002] A differential pressure sensor is a sensor used to measure the difference between two pressures. It is usually used to measure the pressure difference between the front and rear ends of a device or component. It can convert the pressure difference signal into an electrical signal for easy transmission and processing. Differential pressure sensors are widely used in industrial automation, environmental monitoring, automotive engineering and other fields.

[0003] In order to improve the measurement range and measurement accuracy, the differential pressure sensor products currently used choose to encapsulate two groups of chips with different ranges. The two groups of pressure-sensitive chips are encapsulated in the same pressure-sensitive cavity. The pressure-sensitive chips have different ranges and different upper pressure limits. Taking the combination of 40KPa and 250KPa chips as an example, when the test pressure reaches 250KPa, the 40KPa chip is damaged. If the 40KPa chip can withstand the pressure of 250KPa, a special chip needs to be customized, which is 10 times the price of the chip with the same precision performance, and it is not universal. Therefore, a differential pressure sensor diaphragm box is urgently needed to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a differential pressure sensor diaphragm box, which encapsulates two chips with different ranges into a whole to meet the measurement requirements of a wide range. When the pressure exceeds the bearing capacity of one of the chips, it can protect the chip, thereby achieving versatility and convenience in chip use.

[0005] Another object of the present invention is to provide a differential pressure sensor, which improves the measurement range and measurement accuracy of the sensor and reduces product costs by providing the above-mentioned differential pressure sensor diaphragm box.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A differential pressure sensor diaphragm box, used for cooperating with a first chip and a second chip to measure a pressure difference, comprises:

[0008] matrix;

[0009] The sensing unit comprises two first pressure-sensitive diaphragms and two second pressure-sensitive diaphragms, wherein the two first pressure-sensitive diaphragms are arranged in the base body at intervals, and the first pressure-sensitive diaphragms have a first gap with the inner wall of the base body, and the two second pressure-sensitive diaphragms are arranged on two outer walls at both ends of the base body, and the second pressure-sensitive diaphragms have a second gap with the outer wall of the base body, and the width of the second gap is greater than the width of the first gap, and the first gap and the second gap are both filled with pressure transmission medium;

[0010] The pressure transmission unit comprises a first pressure transmission pipeline and a second pressure transmission pipeline, wherein the first pressure transmission pipeline is arranged in a one-to-one correspondence with the first pressure-sensitive diaphragm, and the second pressure transmission pipeline is arranged in a one-to-one correspondence with the second pressure-sensitive diaphragm, and the first pressure transmission pipeline and the second pressure transmission pipeline are both filled with the pressure transmission medium, and the first pressure-sensitive diaphragm transmits the pressure to the first chip through the first pressure transmission pipeline, and the second pressure-sensitive diaphragm transmits the pressure to the second chip through the second pressure transmission pipeline;

[0011] An overload protection unit is disposed in the base, and is used to perform overload protection on the first chip and the second chip.

[0012] As an optional technical solution, a first sensing cavity and a second sensing cavity are provided in the base, the first sensing cavity and the second sensing cavity are both filled with pressure transmission medium, the first sensing cavity and the first pressure transmission pipeline are provided in one-to-one correspondence, and the first sensing cavity is connected to the first pressure transmission pipeline;

[0013] The overload protection unit includes a first overload protection diaphragm and two second overload protection diaphragms, the first overload protection diaphragm is located between the two first pressure-sensitive diaphragms, the first overload protection diaphragm is sandwiched between the two first sensing cavities, the second sensing cavities are arranged in a one-to-one correspondence with the second overload protection diaphragms, the second overload protection diaphragm is located between the first pressure-sensitive diaphragms and the second pressure-sensitive diaphragms, the second sensing cavity is located on one side of the second overload protection diaphragm, a pressure-leading pipeline is arranged in the base, the pressure-leading pipeline is filled with the pressure transmission medium, the pressure-leading pipeline is arranged in a one-to-one correspondence with the second overload protection diaphragms, the pressure-leading pipeline is located on the other side of the second overload protection diaphragm, and the pressure-leading pipeline is connected to the second pressure transmission pipeline.

[0014] As an optional technical solution, the differential pressure sensor membrane box also includes an air permeable pipeline, which is arranged in a one-to-one correspondence with the second sensing cavity, one end of the air permeable pipeline is connected to the second sensing cavity, and the other end of the air permeable pipeline is connected to the outside atmosphere.

[0015] As an optional technical solution, a waterproof breathable plug is provided at one end of the breathable pipeline away from the second sensing cavity.

[0016] As an optional technical solution, the substrate includes a first substrate, a second substrate and a third substrate, two of the first substrate, the second substrate and the third substrate are respectively provided, the two first substrates are clamped between the two second substrates, and one third substrate is respectively provided on the other side of the two second substrates, the first overload protection diaphragm is clamped between the two first substrates, the first sensing cavity is formed between the first substrate and the first overload protection diaphragm, the first pressure-sensitive diaphragm is clamped between the first substrate and the second substrate, the first gap is respectively formed between the first pressure-sensitive diaphragm and the first substrate and the second substrate, the second overload protection diaphragm and the second sensing cavity are arranged on the second substrate, the pressure-conducting pipeline is arranged on one side of the third substrate, and the second pressure-sensitive diaphragm is arranged on the other side of the third substrate.

[0017] As an optional technical solution, the first pressure-sensitive diaphragm and the second pressure-sensitive diaphragm are both corrugated diaphragms, a side of the first substrate close to the first pressure-sensitive diaphragm and a side of the second substrate close to the first pressure-sensitive diaphragm both have corrugations that are the same as those of the first pressure-sensitive diaphragm, and a side of the third substrate close to the second pressure-sensitive diaphragm has corrugations that are the same as those of the second pressure-sensitive diaphragm.

[0018] As an optional technical solution, the first substrate and the first overload protection diaphragm are connected by welding;

[0019] and / or, the first substrate, the second substrate and the first pressure-sensitive diaphragm are connected by welding; and / or, the second overload protection diaphragm and the second substrate are connected by welding;

[0020] and / or, the second substrate is connected to the third substrate by welding;

[0021] And / or, the second pressure-sensitive diaphragm is connected to the third substrate by welding.

[0022] As an optional technical solution, the first pressure-sensitive diaphragm and the second pressure-sensitive diaphragm are both made of metal.

[0023] As an optional technical solution, the pressure transmission medium is silicone oil.

[0024] The present invention adopts the following technical solutions:

[0025] A differential pressure sensor comprises a first chip, a second chip and a differential pressure sensor diaphragm as described in any of the above schemes, wherein the first chip is connected to the differential pressure sensor diaphragm through the first pressure transmission pipeline, and the second chip is connected to the differential pressure sensor diaphragm through the second pressure transmission pipeline.

[0026] Beneficial effects of the present invention:

[0027] The embodiment of the present invention provides a differential pressure sensor diaphragm box, which includes a base, a sensing unit, a pressure transmission unit and an overload protection unit, wherein the sensing unit includes two first pressure-sensitive diaphragms and two second pressure-sensitive diaphragms, the two first pressure-sensitive diaphragms are arranged in the base at intervals, the first pressure-sensitive diaphragms and the inner wall of the base have a first gap, the two second pressure-sensitive diaphragms are arranged on the two outer walls at both ends of the base, the second pressure-sensitive diaphragms and the outer wall of the base have a second gap, and the width of the second gap is greater than the width of the first gap, and the first gap and the second gap are filled with Full of pressure transmission medium; the pressure transmission unit includes a first pressure transmission pipeline and a second pressure transmission pipeline, the first pressure transmission pipeline is set in one-to-one correspondence with the first pressure-sensitive diaphragm, the second pressure transmission pipeline is set in one-to-one correspondence with the second pressure-sensitive diaphragm, the first pressure transmission pipeline and the second pressure transmission pipeline are both full of pressure transmission medium, the first pressure-sensitive diaphragm transmits pressure to the first chip through the first pressure transmission pipeline, and the second pressure-sensitive diaphragm transmits pressure to the second chip through the second pressure transmission pipeline; the overload protection unit is set in the base, and the overload protection unit is used to overload the first chip and the second chip. The differential pressure sensor diaphragm box distinguishes the pressure transmission pipelines of the two chips with different ranges, can protect the small-range chip from being damaged, which not only meets the requirements of the wide range of the sensor, but also ensures the high-precision output of the small range.

[0028] The present invention also provides a differential pressure sensor, which includes a first chip, a second chip and the above-mentioned differential pressure sensor diaphragm box. The first chip is connected to the differential pressure sensor diaphragm box through a first pressure transmission pipeline, and the second chip is connected to the differential pressure sensor diaphragm box through a second pressure transmission pipeline. The differential pressure sensor packages two chips with different ranges together, thereby improving the measurement range and measurement accuracy of the sensor and reducing the cost of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of a differential pressure sensor diaphragm box provided in an embodiment of the present invention.

[0030] In the figure:

[0031] 1. substrate; 11. first sensing cavity; 12. second sensing cavity; 13. first substrate; 14. second substrate; 15. third substrate;

[0032] 2. Sensing unit; 21. First pressure-sensitive diaphragm; 22. Second pressure-sensitive diaphragm;

[0033] 31. The first pressure transmission pipeline; 32. The second pressure transmission pipeline; 33. The pressure guide pipeline;

[0034] 41. a first overload protection diaphragm; 42. a second overload protection diaphragm;

[0035] 5. Ventilation pipeline; 51. Waterproof vent plug;

[0036] 10. First chip; 101. First chip substrate; 20. Second chip; 201. Second chip substrate. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0041] Combine the following Figure 1 The technical solution of the present invention is described in detail through specific implementation methods.

[0042] The embodiment of the present invention provides a differential pressure sensor diaphragm box, which is used to cooperate with a first chip and a second chip to measure a pressure difference. The differential pressure sensor diaphragm box includes a substrate 1, a sensing unit 2, a pressure transmission unit and an overload protection unit, wherein the sensing unit 2 includes two first pressure-sensitive diaphragms 21 and two second pressure-sensitive diaphragms 22, the two first pressure-sensitive diaphragms 21 are arranged in the substrate 1 at intervals, and the first pressure-sensitive diaphragms 21 and the inner wall of the substrate 1 have a first gap, and the two second pressure-sensitive diaphragms 22 are arranged on the two outer walls at both ends of the substrate 1, and the second pressure-sensitive diaphragms 22 and the outer wall of the substrate 1 have a second gap, and the width of the second gap is greater than the width of the first gap, and the first gap and the second gap are greater than the first gap. The two gaps are both filled with pressure-transmitting medium; the pressure-transmitting unit comprises a first pressure-transmitting pipeline 31 and a second pressure-transmitting pipeline 32, the first pressure-transmitting pipeline 31 is arranged in a one-to-one correspondence with the first pressure-sensitive diaphragm 21, the second pressure-transmitting pipeline 32 is arranged in a one-to-one correspondence with the second pressure-sensitive diaphragm 22, the first pressure-transmitting pipeline 31 and the second pressure-transmitting pipeline 32 are both filled with pressure-transmitting medium, the first pressure-sensitive diaphragm 21 transmits the pressure to the first chip 10 through the first pressure-transmitting pipeline 31, and the second pressure-sensitive diaphragm 22 transmits the pressure to the second chip 20 through the second pressure-transmitting pipeline 32; the overload protection unit is arranged in the substrate 1, and the overload protection unit is used to perform overload protection on the first chip 10 and the second chip 20.

[0043] Specifically, in this embodiment, the first chip 10 and the second chip 20 are two chips with different measuring ranges, and the measuring range of the first chip 10 is smaller than the measuring range of the second chip 20. The two chips are packaged in the same differential pressure sensor. Figure 1Pressure is input on both sides of the diaphragm box in the direction of the arrow. When the pressure difference between the two sides is less than the range of the first chip 10, the first pressure-sensitive diaphragm 21 transmits the pressure to the first chip 10 through the first pressure transmission pipeline 31, and the second pressure-sensitive diaphragm 22 transmits the pressure to the second chip 20 through the second pressure transmission pipeline 32. The first chip 10 and the second chip 20 can both sense the pressure difference on both sides. The printed circuit board (PCB) connected to the sensor When the input pressure continues to increase, when the pressure difference on both sides exceeds the range of the first chip 10, under the action of the overload protection unit, the first pressure-sensitive diaphragm 21 is tightly fitted with the substrate 1, and the first pressure transmission pipeline 31 cannot continue to transmit pressure. At this time, the first chip 10 cannot sense the pressure. When the input pressure continues to increase, the first chip 10 is protected from damage. The PCBA outputs the sensed value of the second chip 20; when the input pressure value continues to increase, when the pressure difference on both sides exceeds the range of the second chip 20, under the action of the overload protection unit, the second pressure-sensitive diaphragm 22 is tightly fitted with the substrate 1, and the second pressure transmission pipeline 32 cannot continue to transmit pressure. At this time, the second chip 20 cannot sense the pressure, and the second chip 20 is protected from damage; when the input pressure is unloaded, the first pressure-sensitive diaphragm 21 and the second pressure-sensitive diaphragm 22 are restored to their initial states. The differential pressure sensor diaphragm box distinguishes the pressure transmission pipelines of chips with different ranges, which can protect small-range chips from damage. It not only meets the requirements of wide-range sensors, but also ensures high-precision output of small-range chips.

[0044] Furthermore, a first sensing cavity 11 and a second sensing cavity 12 are provided in the base body 1, and the first sensing cavity 11 and the second sensing cavity 12 are both filled with a pressure transmission medium. The first sensing cavity 11 and the first pressure transmission pipeline 31 are provided one-to-one, and the first sensing cavity 11 is communicated with the first pressure transmission pipeline 31; the overload protection unit includes a first overload protection diaphragm 41 and two second overload protection diaphragms 42, the first overload protection diaphragm 41 is located between the two first pressure sensing diaphragms 21, and the first overload protection diaphragm 41 is sandwiched between the two first sensing cavities 11. The second sensing cavity 12 is arranged in one-to-one correspondence with the second overload protection diaphragm 42, the second overload protection diaphragm 42 is located between the first pressure-sensing diaphragm 21 and the second pressure-sensing diaphragm 22, the second sensing cavity 12 is located on one side of the second overload protection diaphragm 42, a pressure-leading pipeline 33 is arranged in the base body 1, the pressure-leading pipeline 33 is arranged in one-to-one correspondence with the second overload protection diaphragm 42, the pressure-leading pipeline 33 is located on the other side of the second overload protection diaphragm 42, the pressure-leading pipeline 33 is filled with pressure transmission medium, and the pressure-leading pipeline 33 is connected to the second pressure transmission pipeline 32. In this embodiment, when the difference between the input pressures on both sides exceeds the range of the first chip 10, the first overload protection diaphragm 41 deforms toward the side with smaller input pressure, and the first pressure-sensitive diaphragm 21 approaches the substrate 1 on the side with smaller input pressure and fits tightly with the substrate 1, so that the first pressure transmission pipeline 31 cannot continue to transmit pressure. At this time, the first chip 10 cannot sense the pressure, thereby protecting the first chip 10 from damage; when the difference between the input pressures on both sides exceeds the range of the second chip 20, the second overload protection diaphragm 42 deforms toward the side close to the second sensing cavity 12, and the second pressure-sensitive diaphragm 22 approaches the substrate 1 and fits tightly with the substrate 1, so that the second pressure transmission pipeline 32 cannot continue to transmit pressure. At this time, the second chip 20 cannot sense the pressure, thereby protecting the second chip 20 from damage. When the input pressure is unloaded, the first overload protection diaphragm 41 and the second overload protection diaphragm 42 both return to their initial state. When the pressure exceeds the carrying capacity of the chip, the chip can be protected from damage by the first overload protection diaphragm 41 and the second overload protection diaphragm 42.

[0045] Furthermore, the differential pressure sensor capsule also includes a breathable pipeline 5, which is arranged in a one-to-one correspondence with the second sensing cavity 12, one end of the breathable pipeline 5 is connected to the second sensing cavity 12, and the other end of the breathable pipeline 5 is connected to the outside atmosphere. When the difference in the input pressures on both sides exceeds the range of the second chip 20, the second overload protection diaphragm 42 deforms toward the side close to the second sensing cavity 12, connecting the second sensing cavity 12 with the breathable pipeline 5, providing space for the deformation of the second overload protection diaphragm 42, avoiding deformation of the second overload protection diaphragm 42 in a confined space, and thus ensuring the overload protection effect of the second overload protection diaphragm 42 on the second chip 20.

[0046] Optionally, a waterproof vent plug 51 is provided at one end of the vent pipe 5 away from the second sensing cavity 12 , which prevents water from entering the differential pressure sensor diaphragm box and ensures its normal use.

[0047] In order to facilitate the processing of the substrate 1, in this embodiment, the substrate 1 includes a first substrate 13, a second substrate 14 and a third substrate 15, and two of the first substrate 13, the second substrate 14 and the third substrate 15 are respectively provided. The first substrate 13 is clamped between the two second substrates 14, and a third substrate 15 is respectively provided on the other side of the two second substrates 14. The first overload protection diaphragm 41 is clamped between the two first substrates 13, and a first sensing cavity 11 is formed between the first substrate 13 and the first overload protection diaphragm 41. The first pressure-sensitive diaphragm 21 is clamped between the first substrate 13 and the second substrate 14, and a first gap is respectively provided between the first pressure-sensitive diaphragm 21 and the first substrate 13 and the second substrate 14. The second overload protection diaphragm 42 and the second sensing cavity 12 are arranged on the second substrate 14, the pressure-conducting pipeline 33 is arranged on one side of the third substrate 15, and the second pressure-sensitive diaphragm 22 is arranged on the other side of the third substrate 15. Specifically, two first substrates 13, two second substrates 14 and two third substrates 15 are combined to form a symmetrical substrate 1, the two first substrates 13 are located between the two second substrates 14, and the two third substrates 15 are located on both sides of the two second substrates 14. The first substrate 13 is provided with a first groove on one side facing the first overload protection diaphragm 41, and the first overload protection diaphragm 41 and the first groove are arranged to form a first sensing cavity 11, the other side edge of the first substrate 13 and the one side edge of the second substrate 14 clamp the first pressure-sensitive diaphragm 21, the other side of the second substrate 14 is provided with a second groove, and the second overload protection diaphragm 42 and the second groove are arranged to form a second sensing cavity 12, a pressure-conducting pipeline 33 is arranged on one side of the third substrate 15, and the other side edge of the third substrate 15 is connected to the second pressure-sensitive diaphragm 22.

[0048] Furthermore, the first pressure-sensitive diaphragm 21 and the second pressure-sensitive diaphragm 22 are both corrugated diaphragms, and the side of the first substrate 13 close to the first pressure-sensitive diaphragm 21 and the side of the second substrate 14 close to the first pressure-sensitive diaphragm 21 both have the same corrugations as the first pressure-sensitive diaphragm 21, and the side of the third substrate 15 close to the second pressure-sensitive diaphragm 22 has the same corrugations as the second pressure-sensitive diaphragm 22. The corrugated diaphragm has high reliability, can adapt to different working environments and requirements, and has low production costs. The first substrate 13 and the second substrate 14 are provided with the same corrugations as the first pressure-sensitive diaphragm 21. When the input pressure difference exceeds the carrying capacity of the first chip 10, the first pressure-sensitive diaphragm 21 can be tightly fitted with the first substrate 13, thereby protecting the first chip 10 from damage. The third substrate 15 is provided with the same corrugations as the second pressure-sensitive diaphragm 22. When the input pressure difference exceeds the carrying capacity of the second chip 20, the second pressure-sensitive diaphragm 22 can be tightly fitted with the third substrate 15, thereby protecting the second chip 20 from damage.

[0049] Further, the first substrate 13 is welded to the first overload protection diaphragm 41; and / or, the first substrate 13, the second substrate 14 and the first pressure-sensitive diaphragm 21 are welded to each other; and / or, the second overload protection diaphragm 42 is welded to the second substrate 14; and / or, the second substrate 14 is welded to the third substrate 15; and / or, the second pressure-sensitive diaphragm 22 is welded to the third substrate 15. In this embodiment, the first substrate 13, the second substrate 14 and the third substrate 15 are all made of stainless steel, which is easy to process and has good corrosion resistance. The substrate 1 is welded to ensure the stability of the performance of the differential pressure sensor diaphragm box and facilitate the processing of the substrate 1.

[0050] Furthermore, the first pressure-sensitive diaphragm 21 and the second pressure-sensitive diaphragm 22 are both metal parts. Optionally, in this embodiment, the material of the first pressure-sensitive diaphragm 21 and the second pressure-sensitive diaphragm 22 is stainless steel, so that the first pressure-sensitive diaphragm 21 and the second pressure-sensitive diaphragm 22 have good mechanical properties and good welding performance. In other embodiments, the material of the first pressure-sensitive diaphragm 21 and the second pressure-sensitive diaphragm 22 can also be ceramic, polymer, etc., which is not specifically limited here.

[0051] Furthermore, in this embodiment, the pressure transmission medium is silicone oil, which has good stability and anti-interference ability. Using silicone oil as the pressure transmission medium can greatly improve the measurement accuracy and stability of the differential pressure sensor diaphragm box. In other embodiments, the pressure transmission medium can also be glycerin, transformer oil, etc., which is not specifically limited here.

[0052] The present invention also provides a differential pressure sensor, which includes a first chip 10, a second chip 20 and the above-mentioned differential pressure sensor diaphragm box, the first chip 10 is connected to the differential pressure sensor diaphragm box through a first pressure transmission pipeline 31, the second chip 20 is connected to the differential pressure sensor diaphragm box through a second pressure transmission pipeline 32, and the range of the first chip 10 is smaller than the range of the second chip 20, the first chip 10 and the second chip 20 can both sense the difference in input pressure at both ends of the differential pressure sensor diaphragm box, when the difference in input pressure at both ends exceeds the carrying capacity of the chip, the overload protection unit can protect the chip. The differential pressure sensor packages two chips with different ranges together, improves the measurement range and measurement accuracy of the sensor, and reduces the cost of the product.

[0053] Furthermore, the first chip 10 is disposed on the first chip substrate 101 , and the second chip 20 is disposed on the second chip substrate 201 . The first chip substrate 101 and the second chip substrate 201 can provide support for the first chip 10 and the second chip 20 to ensure normal operation of the chips.

[0054] Furthermore, the differential pressure sensor is connected to the PCBA, and the PCBA can select the one with higher accuracy to output according to the sensed values ​​of the first chip 10 and the second chip 20 .

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A differential pressure sensor capsule, used for cooperating with a first chip (10) and a second chip (20) to measure differential pressure, characterized in that: include: Matrix (1); The sensing unit (2) comprises two first pressure-sensitive diaphragms (21) and two second pressure-sensitive diaphragms (22), wherein the two first pressure-sensitive diaphragms (21) are arranged in the substrate (1) at intervals, and a first gap is formed between the first pressure-sensitive diaphragms (21) and the inner wall of the substrate (1), and the two second pressure-sensitive diaphragms (22) are arranged on two outer walls at both ends of the substrate (1), and a second gap is formed between the second pressure-sensitive diaphragms (22) and the outer wall of the substrate (1), and the width of the second gap is greater than the width of the first gap, and the first gap and the second gap are both filled with a pressure transmission medium; A pressure transmission unit, comprising a first pressure transmission pipeline (31) and a second pressure transmission pipeline (32), wherein the first pressure transmission pipeline (31) is arranged in a one-to-one correspondence with the first pressure-sensitive diaphragm (21), and the second pressure transmission pipeline (32) is arranged in a one-to-one correspondence with the second pressure-sensitive diaphragm (22), and the first pressure transmission pipeline (31) and the second pressure transmission pipeline (32) are both filled with the pressure transmission medium, the first pressure-sensitive diaphragm (21) transmits pressure to the first chip (10) through the first pressure transmission pipeline (31), and the second pressure-sensitive diaphragm (22) transmits pressure to the second chip (20) through the second pressure transmission pipeline (32); An overload protection unit is arranged in the base body (1), and is used to provide overload protection for the first chip (10) and the second chip (20).

2. The differential pressure sensor capsule according to claim 1, characterized in that: A first sensing cavity (11) and a second sensing cavity (12) are arranged in the base body (1); the first sensing cavity (11) and the second sensing cavity (12) are both filled with a pressure transmission medium; the first sensing cavity (11) and the first pressure transmission pipeline (31) are arranged in a one-to-one correspondence; and the first sensing cavity (11) and the first pressure transmission pipeline (31) are in communication; The overload protection unit comprises a first overload protection diaphragm (41) and two second overload protection diaphragms (42), the first overload protection diaphragm (41) being located between the two first pressure-sensitive diaphragms (21), the first overload protection diaphragm (41) being sandwiched between the two first sensing cavities (11), the second sensing cavities (12) being arranged in one-to-one correspondence with the second overload protection diaphragms (42), the second overload protection diaphragms (42) being located between the first pressure-sensitive diaphragms (21) and the second The second sensing cavity (12) is located on one side of the second overload protection diaphragm (42), a pressure-guiding pipeline (33) is arranged in the base body (1), the pressure-guiding pipeline (33) is filled with the pressure transmission medium, the pressure-guiding pipeline (33) and the second overload protection diaphragm (42) are arranged in a one-to-one correspondence, the pressure-guiding pipeline (33) is located on the other side of the second overload protection diaphragm (42), and the pressure-guiding pipeline (33) is connected to the second pressure transmission pipeline (32).

3. The differential pressure sensor capsule according to claim 2, characterized in that: The differential pressure sensor membrane box also includes a breathable pipeline (5), which is arranged in a one-to-one correspondence with the second sensing cavity (12), one end of the breathable pipeline (5) is connected to the second sensing cavity (12), and the other end of the breathable pipeline (5) is connected to the outside atmosphere.

4. The differential pressure sensor capsule according to claim 3, characterized in that: A waterproof vent plug (51) is provided at one end of the vent pipe (5) away from the second sensing cavity (12).

5. The differential pressure sensor capsule according to claim 2, characterized in that: The base (1) comprises a first base (13), a second base (14) and a third base (15); two of the first base (13), two of the second base (14) and two of the third base (15) are provided respectively; the two first bases (13) are sandwiched between the two second bases (14); one of the third bases (15) is provided on the other side of the two second bases (14); the first overload protection diaphragm (41) is sandwiched between the two first bases (13); a first base (13) and the first overload protection diaphragm (41) form a The first sensing cavity (11) and the first pressure-sensitive diaphragm (21) are sandwiched between the first substrate (13) and the second substrate (14); the first gap is respectively formed between the first pressure-sensitive diaphragm (21) and the first substrate (13) and the second substrate (14); the second overload protection diaphragm (42) and the second sensing cavity (12) are arranged on the second substrate (14); the pressure-conducting pipeline (33) is arranged on one side of the third substrate (15); and the second pressure-sensitive diaphragm (22) is arranged on the other side of the third substrate (15).

6. The differential pressure sensor capsule according to claim 5, characterized in that: The first pressure-sensitive diaphragm (21) and the second pressure-sensitive diaphragm (22) are both corrugated diaphragms; a side of the first substrate (13) close to the first pressure-sensitive diaphragm (21) and a side of the second substrate (14) close to the first pressure-sensitive diaphragm (21) both have corrugations identical to those of the first pressure-sensitive diaphragm (21); and a side of the third substrate (15) close to the second pressure-sensitive diaphragm (22) has corrugations identical to those of the second pressure-sensitive diaphragm (22).

7. The differential pressure sensor capsule according to claim 5, characterized in that: The first substrate (13) and the first overload protection diaphragm (41) are connected by welding; and / or, the first substrate (13), the second substrate (14) and the first pressure-sensitive diaphragm (21) are connected by welding; and / or, the second overload protection diaphragm (42) and the second base body (14) are connected by welding; and / or, the second substrate (14) and the third substrate (15) are connected by welding; And / or, the second pressure-sensitive diaphragm (22) and the third substrate (15) are connected by welding.

8. The differential pressure sensor capsule according to any one of claims 1 to 7, characterized in that: The first pressure-sensitive diaphragm (21) and the second pressure-sensitive diaphragm (22) are both made of metal.

9. The differential pressure sensor capsule according to any one of claims 1 to 7, characterized in that: The pressure transmission medium is silicone oil.

10. A differential pressure sensor, characterized in that The invention comprises a first chip (10), a second chip (20) and a differential pressure sensor diaphragm box as described in any one of claims 1 to 9, wherein the first chip (10) is connected to the differential pressure sensor diaphragm box via the first pressure transmission pipeline (31), and the second chip (20) is connected to the differential pressure sensor diaphragm box via the second pressure transmission pipeline (32).

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