Differential pressure sensor

Abstract

The utility model belongs to the technical field of pressure detection equipment, and discloses a differential pressure sensor, which comprises a base body assembly, an overload protection diaphragm assembly, a mounting seat and a pipeline assembly. The base body assembly comprises a positive pressure base body, a middle base body and a negative pressure base body which are arranged in sequence; the overload protection diaphragm assembly comprises a first overload protection diaphragm located between the positive pressure base body and the middle base body and a second overload protection diaphragm located between the middle base body and the negative pressure base body. The mounting seat with the pressure sensing chip is arranged on the base body assembly; pressure guide liquid is arranged in the pipeline assembly, and the pipeline assembly enables the overload protection diaphragm assembly to play a role in protecting the pressure sensing chip. The differential pressure sensor is provided with the first overload protection diaphragm and the second overload protection diaphragm, and when the base body is subjected to instantaneous pressure, the first overload protection diaphragm and the second overload protection diaphragm can deform together to reduce the stress generated at the pressure sensing chip. And the two can generate enough deformation quantity in a short time so as to realize a better protection effect on the pressure sensing chip.

Description

TECHNICAL FIELD

[0001] The utility model relates to pressure detection equipment technical field especially relates to a differential pressure sensor. BACKGROUND

[0002] Differential pressure sensor is a kind of sensor for measuring the pressure difference between two positions or environments, widely used in fluid pressure and flow measuring device.Differential pressure sensor converts the two pressure signals of different positions of fluid into the change of electric signal, then analyzes the electric signal to obtain the differential pressure value of applied pressure.Differential pressure sensor usually includes the pressure measuring cavity in the base and mounting seat.The medium such as silicon oil in the base can generate corresponding pressure in the pressure measuring cavity when the two sides of the base are subjected to pressure, and the pressure measuring cavity includes detection chip, which can generate electric signal according to the pressure in the pressure measuring cavity.

[0003] In prior art, differential pressure sensor is usually provided with overload protection diaphragm, and the overload protection diaphragm is located in the base, and the medium such as silicon oil can enter the pressure measuring cavity after the buffering of the overload protection diaphragm when the base is subjected to pressure, to avoid damaging the detection chip due to excessive pressure, but sudden pressurization or pressure relief during field use can still cause excessive pressure to break the detection chip. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of differential pressure sensor, can reduce the stress generated at pressure sensing chip, to better protect the pressure sensing chip in differential pressure sensor.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] A kind of differential pressure sensor, wherein, including:

[0007] Base assembly, the base assembly includes the positive pressure base, intermediate base and negative pressure base arranged in sequence, the positive pressure base is provided with positive pressure surface on the side away from the negative pressure base, and the negative pressure base is provided with negative pressure surface on the side away from the positive pressure base;

[0008] Overload protection diaphragm assembly, the overload protection diaphragm assembly includes first overload protection diaphragm and second overload protection diaphragm, the first overload protection diaphragm is located between the positive pressure base and the intermediate base, and the second overload protection diaphragm is located between the intermediate base and the negative pressure base;

[0009] Mounting seat, the mounting seat is arranged on the base assembly, and the mounting seat is provided with pressure sensing chip, and the pressure sensing chip includes positive pressure detection surface and negative pressure detection surface isolated from each other;

[0010] The pipeline assembly is provided with a pressure guide liquid, and comprises a positive pressure pipeline assembly and a negative pressure pipeline assembly. The positive pressure pipeline assembly can make the positive pressure surface, the first overload protection diaphragm, the second overload protection diaphragm and the positive pressure detection surface communicate with each other. The negative pressure pipeline assembly can make the negative pressure surface, the first overload protection diaphragm, the second overload protection diaphragm and the negative pressure detection surface communicate with each other.

[0011] Preferably, the positive pressure pipeline assembly comprises a positive pressure pressure guide pipe which can make the positive pressure surface communicate with the first overload protection diaphragm. The negative pressure pipeline assembly comprises a negative pressure pressure guide pipe which can make the negative pressure surface communicate with the second overload protection diaphragm.

[0012] Preferably, the positive pressure pipeline assembly further comprises a first positive pressure pipeline, a second positive pressure pipeline and a third positive pressure pipeline. The first positive pressure pipeline is arranged on the positive pressure base body and can make the first overload protection diaphragm and the third positive pressure pipeline communicate. The second positive pressure pipeline is arranged on the intermediate base body and can make the second overload protection diaphragm and the third positive pressure pipeline communicate. The third positive pressure pipeline is located in the mounting seat and communicates with the positive pressure detection surface.

[0013] Preferably, the negative pressure pipeline assembly further comprises a first negative pressure pipeline, a second negative pressure pipeline and a third negative pressure pipeline. The first negative pressure pipeline is arranged on the intermediate base body and can make the first overload protection diaphragm and the third negative pressure pipeline communicate. The second negative pressure pipeline is arranged on the negative pressure base body and can make the second overload protection diaphragm and the third negative pressure pipeline communicate. The third negative pressure pipeline is located in the mounting seat and communicates with the negative pressure detection surface.

[0014] Preferably, the mounting seat is fixed to the base body assembly by a positioning pin. The positioning pin is provided with a liquid passage hole. The first positive pressure pipeline and the second positive pressure pipeline communicate with the third positive pressure pipeline through the liquid passage hole.

[0015] Preferably, a first liquid passage groove is arranged between the mounting seat and the base body assembly. The first positive pressure pipeline communicates with the liquid passage hole through the first liquid passage groove.

[0016] Preferably, a second liquid passage groove is arranged between the mounting seat and the base body assembly. The first negative pressure pipeline communicates with the third negative pressure pipeline through the second liquid passage groove.

[0017] Preferably, a positive pressure liquid filling pipe and a negative pressure liquid filling pipe are arranged on the mounting seat respectively. The positive pressure liquid filling pipe can make the positive pressure detection surface communicate with the outside. The negative pressure liquid filling pipe can make the negative pressure detection surface communicate with the outside.

[0018] As preferably, the positive pressure surface is externally provided with a positive pressure isolation diaphragm, and a pressure guide liquid is arranged in the gap between the positive pressure surface and the positive pressure isolation diaphragm; the negative pressure surface is provided with a negative pressure isolation diaphragm, and a pressure guide liquid is arranged in the gap between the negative pressure surface and the negative pressure isolation diaphragm.

[0019] As preferably, the surfaces of the positive pressure surface and the negative pressure surface are corrugated surfaces.

[0020] Beneficial effects:

[0021] The utility model provides a kind of differential pressure sensor, it includes base component, overload protection diaphragm subassembly, mounting seat and pipeline subassembly.Base component includes the positive pressure base, intermediate base and negative pressure base that are sequentially arranged;Overload protection diaphragm subassembly includes first overload protection diaphragm and second overload protection diaphragm, first overload protection diaphragm is between positive pressure base and intermediate base, and second overload protection diaphragm is between intermediate base and negative pressure base;Mounting seat is set to one end of base component, and pressure sensing chip is arranged in mounting seat;Pipeline subassembly is provided with pressure guide liquid, and pipeline subassembly can make pressure sensing chip and overload protection diaphragm subassembly intercommunication, to make overload protection diaphragm subassembly to pressure sensing chip play protection effect.The above-mentioned differential pressure sensor is provided with first overload protection diaphragm and second overload protection diaphragm, and when instantaneous pressure is generated between positive pressure surface and negative pressure surface, pressure guide liquid in pipeline subassembly can make first overload protection diaphragm and second overload protection diaphragm jointly deform to reduce stress generated at pressure sensing chip, and both can jointly generate enough deformation amount in short time to realize better protection effect to pressure sensing chip. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 It is the front view of differential pressure sensor provided by the utility model;

[0023] Fig. 2 It is the side view of differential pressure sensor provided by the utility model;

[0024] Fig. 3 It is the pipeline subassembly position schematic view of differential pressure sensor provided by the utility model.

[0025] In the drawing:

[0026] 1, base component;11, positive pressure base;111, positive pressure surface;12, intermediate base;13, negative pressure base;131, negative pressure surface;

[0027] 2, overload protection diaphragm subassembly;21, first overload protection diaphragm;22, second overload protection diaphragm;

[0028] 3, mounting seat;31, silicon seat;32, adapter platform;33, welded sleeve;

[0029] 4. pressure sensing chip;

[0030] 5. positive pressure pipeline assembly; 51. positive pressure pressure lead pipe; 52. first positive pressure pipeline; 53. second positive pressure pipeline; 54. third positive pressure pipeline;

[0031] 6. negative pressure pipeline assembly; 61. negative pressure pressure lead pipe; 62. first negative pressure pipeline; 63. second negative pressure pipeline; 64. third negative pressure pipeline;

[0032] 7. positioning pin;

[0033] 8. positive pressure liquid filling pipe;

[0034] 9. negative pressure liquid filling pipe. DETAILED DESCRIPTION

[0035] The utility model will be described in further detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the utility model, and not to limit the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.

[0036] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0037] In the utility model, unless otherwise explicitly specified and limited, the first feature is "on" or "below" the second feature, which can include that the first and second features are in direct contact, or the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0038] In the description of the present embodiment, the terms "upper", "lower", "right", and the like, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description, and have no special meaning.

[0039] As Figs. 1-3 shown, the present embodiment provides a differential pressure sensor, which comprises a base assembly 1, an overload protection diaphragm assembly 2, a mounting seat 3 and a pipeline assembly. The base assembly 1 comprises a positive pressure base 11, an intermediate base 12 and a negative pressure base 13 arranged in sequence, and the positive pressure base 11 is provided with a positive pressure surface 111 away from the negative pressure base 13, and the negative pressure base 13 is provided with a negative pressure surface 131 away from the positive pressure base 11. The positive pressure surface 111 is used to accept the positive pressure generated by the outside world, and the negative pressure surface 131 is used to accept the negative pressure generated by the outside world. The overload protection diaphragm assembly 2 comprises a first overload protection diaphragm 21 and a second overload protection diaphragm 22, the first overload protection diaphragm 21 is located between the positive pressure base 11 and the intermediate base 12, and the second overload protection diaphragm 22 is located between the intermediate base 12 and the negative pressure base 13. The overload protection diaphragm assembly 2 is welded and fixed with the base assembly 1 to make the whole have enough structural strength. The mounting seat 3 is arranged on the base assembly 1, and a pressure sensing chip 4 is arranged in the mounting seat 3, the pressure sensing chip 4 comprises a positive pressure detection surface and a negative pressure detection surface which are isolated from each other, and when the positive pressure detection surface and the negative pressure detection surface of the pressure sensing chip 4 change, the resistance value of the pressure sensing chip 4 will change, and then corresponding electrical signals will be generated, and finally the positive pressure and the negative pressure are obtained. The pipeline assembly is provided with a pressure guide liquid, and the pipeline assembly comprises a positive pressure pipeline assembly 5 and a negative pressure pipeline assembly 6, the positive pressure pipeline assembly 5 can make the positive pressure surface 111, the first overload protection diaphragm 21, the second overload protection diaphragm 22 and the positive pressure detection surface communicate with each other, and the negative pressure pipeline assembly 6 can make the negative pressure surface 131, the first overload protection diaphragm 21, the second overload protection diaphragm 22 and the negative pressure detection surface communicate with each other.

[0040] Taking the differential pressure sensor under positive pressure as an example, the positive pressure surface 111 is subjected to positive pressure, which is transmitted through the pressure-conducting fluid to the first overload protection diaphragm 21, the second overload protection diaphragm 22, and the positive pressure detection surface. The pressure-conducting fluid fills the pipeline assembly, and when positive pressure is generated, it can quickly complete the transmission of positive pressure. Therefore, when the positive pressure is transmitted to the positive pressure detection surface, it is also transmitted to the first overload protection diaphragm 21 and the second overload protection diaphragm 22. The first overload protection diaphragm 21 and the second overload protection diaphragm 22 deform under pressure, absorbing and reducing the instantaneous pressure inside the pressure-conducting fluid. The instantaneous pressure generated by the pressure-conducting fluid on the positive pressure detection surface is also reduced, preventing the pressure-sensing chip 4 from being damaged due to excessive instantaneous pressure. The working principle of the differential pressure sensor under negative pressure is similar to the above principle, and will not be described in detail in this embodiment.

[0041] The overload protection diaphragm assembly 2 is existing technology. Taking one type of overload protection diaphragm as an example, the overload protection diaphragm is made of metal, and there is a certain gap between the diaphragm and the substrate on both sides. When pressure is generated at the overload protection diaphragm, it will deform and bulge towards the low-pressure side to reduce the instantaneous pressure of the pressure-conducting fluid. When the deformation is at its maximum, it will adhere to the corresponding substrate to achieve overload protection. Those skilled in the art can select specific types of overload protection diaphragms according to actual needs, and this embodiment does not limit this.

[0042] In existing technologies, a single overload protection diaphragm is used for overload protection. When the differential pressure sensor is suddenly pressurized or depressurized, the single overload protection diaphragm may not be able to generate sufficient deformation in time to reduce the pressure in the pressure-conducting fluid, which can easily cause the pressure-conducting fluid to break down the pressure-sensing chip 4. Compared with the differential pressure sensor in the prior art, this embodiment is provided with a first overload protection diaphragm 21 and a second overload protection diaphragm 22. When the positive pressure surface 111 and the negative pressure surface 131 generate instantaneous pressure, the first overload protection diaphragm 21 and the second overload protection diaphragm 22 can deform together to reduce the stress generated at the pressure-sensing chip 4. The two can generate sufficient deformation together in a short time to achieve a better protection effect for the pressure-sensing chip 4.

[0043] Specifically, in this embodiment, the positive pressure pipeline assembly 5 includes a positive pressure tap 51, which connects the positive pressure surface 111 to the first overload protection diaphragm 21; the negative pressure pipeline assembly 6 includes a negative pressure tap 61, which connects the negative pressure surface 131 to the second overload protection diaphragm 22. When the positive pressure surface 111 and the negative pressure surface 131 are subjected to force, the positive pressure tap 51 and the negative pressure tap 61 can directly transmit the force to the overload protection diaphragm assembly 2 through the pressure-conducting fluid. The buffering effect of the overload protection diaphragm assembly 2 can prevent the pressure-sensing chip 4 from being subjected to excessive force, thereby preventing it from being punctured and damaged. Furthermore, there are two positive pressure taps 51 and two negative pressure taps 61. The two positive pressure taps 51 are located in the positive pressure base 11 and are respectively spaced apart at the upper and lower parts of the first overload protection diaphragm 21. The two negative pressure taps 61 are located in the negative pressure base 13 and are respectively spaced apart at the upper and lower parts of the second overload protection diaphragm 22. The two positive pressure taps 51 and the two negative pressure taps 61 facilitate the timely and sufficient transmission of pressure by the pressure-conducting fluid.

[0044] Furthermore, in this embodiment, the positive pressure pipeline assembly 5 also includes a first positive pressure pipeline 52, a second positive pressure pipeline 53, and a third positive pressure pipeline 54. The first positive pressure pipeline 52 is disposed on the positive pressure base 11 and connects the first overload protection diaphragm 21 and the third positive pressure pipeline 54. The second positive pressure pipeline 53 is disposed on the intermediate base 12 and connects the second overload protection diaphragm 22 and the third positive pressure pipeline 54. The third positive pressure pipeline 54 is located in the mounting base 3 and connects to the positive pressure detection surface. Specifically, one end of the first positive pressure pipeline 52 is connected to the side of the first overload protection diaphragm 21 near the positive pressure base 11, and the other end is used to connect to the third positive pressure pipeline 54; one end of the second positive pressure pipeline 53 is connected to the side of the second overload protection diaphragm 22 near the intermediate base 12, and the other end is used to connect to the third positive pressure pipeline 54; while the third positive pressure pipeline 54 itself is connected to the positive pressure detection surface. Therefore, the first overload protection diaphragm 21, the second overload protection diaphragm 22, and the positive pressure detection surface are all connected. When the positive pressure surface 111 is subjected to pressure, the pressure first acts on the first overload protection diaphragm 21 through the positive pressure tapping pipe 51, and then is transmitted through the first positive pressure pipe 52 to the second positive pressure pipe 53 and the third positive pressure pipe 54, respectively acting on the second overload protection diaphragm 22 and the positive pressure detection surface. The first overload protection diaphragm 21 and the second overload protection diaphragm 22 deform together to reduce the instantaneous pressure on the positive pressure detection surface. It can be understood that the pressure-conducting fluid fills the above-mentioned pipes and can conduct pressure without large-scale flow. Therefore, the above description describes the direction of force transmission and the working mechanism of the overload protection diaphragm, rather than limiting the specific flow of the pressure-conducting fluid. It does not mean that the pressure-conducting fluid in the positive pressure tapping pipe 51 enters the positive pressure detection surface after passing through the first overload protection diaphragm 21 and the second overload protection diaphragm 22.

[0045] Furthermore, in this embodiment, the negative pressure pipeline assembly 6 also includes a first negative pressure pipeline 62, a second negative pressure pipeline 63, and a third negative pressure pipeline 64. The first negative pressure pipeline 62 is disposed on the negative pressure base 13 and connects the first overload protection diaphragm 21 and the third negative pressure pipeline 64. The second negative pressure pipeline 63 is disposed on the intermediate base 12 and connects the second overload protection diaphragm 22 and the third negative pressure pipeline 64. The third negative pressure pipeline 64 is located in the mounting base 3 and connects to the negative pressure detection surface. Specifically, one end of the first negative pressure pipeline 62 is connected to the side of the second overload protection diaphragm 22 near the negative pressure base 13, and the other end is used to connect to the third negative pressure pipeline 64; one end of the second negative pressure pipeline 63 is connected to the side of the first overload protection diaphragm 21 near the intermediate base 12, and the other end is used to connect to the third negative pressure pipeline 64; while the third negative pressure pipeline 64 itself is connected to the negative pressure detection surface. Therefore, the first overload protection diaphragm 21, the second overload protection diaphragm 22, and the negative pressure detection surface are all connected. When the negative pressure surface 131 is subjected to negative pressure, the negative pressure first acts on the second overload protection diaphragm 22 through the negative pressure tapping pipe 61, and then is transmitted to the first negative pressure pipe 62 and the third negative pressure pipe 64 through the second negative pressure pipe 63, acting on the first overload protection diaphragm 21 and the negative pressure detection surface respectively. The first overload protection diaphragm 21 and the second overload protection diaphragm 22 deform together to reduce the magnitude of the instantaneous force on the negative pressure detection surface. It can be understood that the pressure-conducting fluid fills the above-mentioned pipes and can conduct pressure without large-scale flow. Therefore, the above description describes the direction of force transmission and the working mechanism of the overload protection diaphragm, rather than limiting the specific flow of the pressure-conducting fluid. It does not mean that the pressure-conducting fluid in the negative pressure tapping pipe 61 enters the negative pressure detection surface after passing through the first overload protection diaphragm 21 and the second protection diaphragm.

[0046] Furthermore, in this embodiment, the mounting base 3 is fixed to the base assembly 1 by a positioning pin 7. The positioning pin 7 has a fluid passage hole, through which the first positive pressure pipe 52 and the second positive pressure pipe 53 communicate with the third positive pressure pipe 54. The surface of the positioning pin 7 is threaded; one end of the positioning pin 7 is threaded to the intermediate base 12, and the other end is threaded to the mounting base 3. This allows the positioning pin 7 to fix the mounting base 3 to the intermediate base 12, achieving relative fixation between the mounting base 3 and the base assembly 1. Simultaneously, the positioning pin 7 has a fluid passage hole, through which the first positive pressure pipe 52 and the second positive pressure pipe 53 communicate with the third positive pressure pipe 54 within the mounting base 3. The area directly above the third positive pressure pipe 54 is the positive pressure detection surface. It can be understood that the positive pressure detection surface is the bottom surface of the pressure-sensing chip 4. When the positive pressure surface 111 is not under pressure, the pressure-conducting fluid contacts the positive pressure detection surface but does not apply pressure to the positive pressure detection surface or the applied pressure is very small; when the positive pressure surface 111 is under pressure, the positive pressure is conducted through the pressure-conducting fluid, so that the positive pressure detection surface is subjected to upward pressure, causing the resistance of the pressure sensing chip 4 to change and generate an electrical signal.

[0047] Furthermore, in this embodiment, the positioning pin 7 is a damping positioning pin 7, which has a damping effect, reduces the relative movement between the mounting base 3 and the base component 1, and improves the stability and durability of the system.

[0048] Furthermore, the mounting base 3 includes an adapter platform 32, a silicon substrate 31, and a welding sleeve 33. The adapter platform 32 is directly connected to the intermediate substrate 12 via a damping positioning pin 7. The silicon substrate 31 is disposed on the upper surface of the adapter platform 32, and the pressure-sensitive chip 4 is disposed inside the silicon substrate 31. The welding sleeve 33 is fitted onto the outer peripheral surfaces of the adapter platform 32 and the silicon substrate 31 to achieve relative fixation between the silicon substrate 31 and the adapter platform 32. At the same time, the bottom of the welding sleeve 33 abuts against the substrate assembly 1. Welding at the outer edge of the contact between the welding sleeve 33 and the substrate assembly 1 can improve the sealing between the mounting base 3 and the substrate assembly 1.

[0049] Furthermore, in this embodiment, a first liquid passage groove is provided between the mounting base 3 and the base component 1, and the first positive pressure pipe 52 communicates with the liquid passage hole through the first liquid passage groove. Specifically, the adapter 32 and the base component 1 have a first liquid passage groove, one end of which is connected to the first positive pressure pipe 52, and the other end is connected to the liquid passage hole. Specifically, the positioning pin 7 includes a vertically penetrating liquid passage hole, the second positive pressure pipe 53 enters from bottom to top and communicates with the liquid passage hole, and the positioning pin 7 includes a transverse liquid passage hole, which communicates with the vertically penetrating liquid passage hole. The first positive pressure pipe 52 is connected to the transverse liquid passage hole through the first liquid passage groove. The first liquid passage groove can be a recess on the adapter 32; it can also be a recess on the intermediate base 12; or it can be a combination of two recesses to form a complete first liquid passage groove. This embodiment does not limit this.

[0050] Furthermore, in this embodiment, a second liquid passage groove is provided between the mounting base 3 and the base assembly 1, and the first negative pressure pipe 62 is connected to the third negative pressure pipe 64 through the second liquid passage groove. Specifically, one end of the second liquid passage groove is connected to the first negative pressure pipe 62, and the other end is connected to the bottom of the third negative pressure pipe 64. Specifically, the third negative pressure pipe 64 can be divided into three sections: a first section directly connected to the pressure-sensing chip 4, a second section directly connected to the first section and horizontally arranged, and a third section connected to the second section at one end and passing through the mounting base 3 and connected to the base assembly 1 at the other end. The bottom of the second liquid passage groove is connected to the third section. In order to avoid the vertically arranged first positive pressure pipe 52, the first negative pressure pipe 62 is at a certain angle to the vertical direction and extends to the second liquid passage groove. At the same time, the mounting base 3 and the corresponding position of the second negative pressure pipe 63 are also provided with a liquid passage structure for connecting the third negative pressure pipe 64, which will not be described in detail here. It is understandable that the third negative pressure pipe 64 is connected to the negative pressure detection surface, which is the top surface of the chip. When the negative pressure surface 131 is not under force, since the third negative pressure pipe 64 is filled with pressure-conducting fluid, the first section has a certain liquid column that exerts a certain downward initial pressure on the pressure-sensing chip 4. When the negative pressure surface 131 is under pressure, the negative pressure is conducted through the pressure-conducting fluid, which reduces the downward initial pressure on the pressure-sensing chip 4 or generates an upward negative pressure so that the pressure-sensing chip 4 generates an electrical signal.

[0051] Specifically, in this embodiment, the mounting base 3 is respectively provided with a positive pressure filling pipe 8 and a negative pressure filling pipe 9. The positive pressure filling pipe 8 connects the positive pressure detection surface to the outside, and the negative pressure filling pipe 9 connects the negative pressure detection surface to the outside. The positive pressure pipeline assembly 5 and the negative pressure pipeline assembly 6 of the differential pressure sensor are filled with pressure-conducting fluid through the positive pressure filling pipe 8 and the negative pressure filling pipe 9, respectively, and the pressure-conducting fluid is evenly distributed in the pipeline assembly. The pressure-conducting fluid can be silicone oil, fluorinated oil, vegetable oil, or other media; this embodiment does not limit this.

[0052] Specifically, in this embodiment, a positive pressure isolation diaphragm is provided outside the positive pressure surface 111, and a pressure-conducting fluid is provided in the gap between the positive pressure surface 111 and the positive pressure isolation diaphragm; a negative pressure isolation diaphragm is provided on the negative pressure surface 131, and a pressure-conducting fluid is provided in the gap between the negative pressure surface 131 and the negative pressure isolation diaphragm. Taking the positive pressure surface 111 as an example, when the positive pressure surface 111 is subjected to positive pressure, the positive pressure isolation diaphragm approaches the positive pressure surface 111, and the two together squeeze the pressure-conducting fluid in the gap. The pressure in the pressure-conducting fluid is then transmitted through the positive pressure guiding pipe. That is, there is a liquid cavity of pressure-conducting fluid between the positive pressure surface 111 and the positive pressure isolation diaphragm, and the positive pressure guiding pipe is connected to this liquid cavity to transmit positive pressure. The working principle of the negative pressure surface 131 is similar to the above principle, and will not be described in detail in this embodiment.

[0053] Furthermore, in this embodiment, the surfaces of the positive pressure surface 111 and the negative pressure surface 131 are corrugated surfaces. Both the positive pressure substrate 11 and the negative pressure substrate 13 are rigid structures, while the positive pressure isolation diaphragm and the negative pressure isolation diaphragm have a certain degree of elasticity. When subjected to external force, the corrugated surface is more conducive to the rebound of the positive pressure isolation diaphragm and the negative pressure isolation diaphragm.

[0054] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A differential pressure sensor, characterized in that, include: The matrix assembly (1) includes a positive pressure matrix (11), an intermediate matrix (12) and a negative pressure matrix (13) arranged sequentially. The positive pressure matrix (11) has a positive pressure surface (111) on the side away from the negative pressure matrix (13), and the negative pressure matrix (13) has a negative pressure surface (131) on the side away from the positive pressure matrix (11). An overload protection diaphragm assembly (2) includes a first overload protection diaphragm (21) and a second overload protection diaphragm (22). The first overload protection diaphragm (21) is located between the positive pressure substrate (11) and the intermediate substrate (12), and the second overload protection diaphragm (22) is located between the intermediate substrate (12) and the negative pressure substrate (13). Mounting base (3), the mounting base (3) is disposed on the base assembly (1), and a pressure sensing chip (4) is disposed inside the mounting base (3). The pressure sensing chip (4) includes a positive pressure detection surface and a negative pressure detection surface that are isolated from each other. The pipeline assembly contains a pressure-conducting fluid and includes a positive pressure pipeline assembly (5) and a negative pressure pipeline assembly (6). The positive pressure pipeline assembly (5) enables the positive pressure surface (111), the first overload protection diaphragm (21), the second overload protection diaphragm (22), and the positive pressure detection surface to communicate with each other. The negative pressure pipeline assembly (6) enables the negative pressure surface (131), the first overload protection diaphragm (21), the second overload protection diaphragm (22), and the negative pressure detection surface to communicate with each other.

2. The differential pressure sensor according to claim 1, characterized in that, The positive pressure pipeline assembly (5) includes a positive pressure tap (51), which connects the positive pressure surface (111) to the first overload protection diaphragm (21); the negative pressure pipeline assembly (6) includes a negative pressure tap (61), which connects the negative pressure surface (131) to the second overload protection diaphragm (22).

3. The differential pressure sensor according to claim 2, characterized in that, The positive pressure pipeline assembly (5) further includes a first positive pressure pipeline (52), a second positive pressure pipeline (53), and a third positive pressure pipeline (54). The first positive pressure pipeline (52) is disposed on the positive pressure base (11) and can connect the first overload protection diaphragm (21) and the third positive pressure pipeline (54). The second positive pressure pipeline (53) is disposed on the intermediate base (12) and can connect the second overload protection diaphragm (22) and the third positive pressure pipeline (54). The third positive pressure pipeline (54) is located in the mounting base (3) and is connected to the positive pressure detection surface.

4. The differential pressure sensor according to claim 2, characterized in that, The negative pressure pipeline assembly (6) further includes a first negative pressure pipeline (62), a second negative pressure pipeline (63), and a third negative pressure pipeline (64). The first negative pressure pipeline (62) is disposed in the intermediate substrate (12) and can connect the first overload protection diaphragm (21) and the third negative pressure pipeline (64). The second negative pressure pipeline (63) is disposed in the negative pressure substrate (13) and can connect the second overload protection diaphragm (22) and the third negative pressure pipeline (64). The third negative pressure pipeline (64) is located in the mounting base (3) and is connected to the negative pressure detection surface.

5. The differential pressure sensor according to claim 3, characterized in that, The mounting base (3) is fixed to the base assembly (1) by a positioning pin (7). The positioning pin (7) is provided with a liquid passage hole. The first positive pressure pipe (52) and the second positive pressure pipe (53) are connected to the third positive pressure pipe (54) through the liquid passage hole.

6. The differential pressure sensor according to claim 5, characterized in that, A first liquid passage groove is provided between the mounting base (3) and the base component (1), and the first positive pressure pipe (52) is connected to the liquid passage hole through the first liquid passage groove.

7. The differential pressure sensor according to claim 4, characterized in that, A second liquid passage is provided between the mounting base (3) and the base assembly (1), and the first negative pressure pipe (62) is connected to the third negative pressure pipe (64) through the second liquid passage.

8. The differential pressure sensor according to any one of claims 1-6, characterized in that, The mounting base (3) is provided with a positive pressure filling pipe (8) and a negative pressure filling pipe (9). The positive pressure filling pipe (8) can connect the positive pressure detection surface to the outside, and the negative pressure filling pipe (9) can connect the negative pressure detection surface to the outside.

9. The differential pressure sensor according to any one of claims 1-6, characterized in that, A positive pressure isolation diaphragm is provided outside the positive pressure surface (111), and a pressure guiding fluid is provided in the gap between the positive pressure surface (111) and the positive pressure isolation diaphragm; a negative pressure isolation diaphragm is provided on the negative pressure surface (131), and a pressure guiding fluid is provided in the gap between the negative pressure surface (131) and the negative pressure isolation diaphragm.

10. The differential pressure sensor according to claim 9, characterized in that, The surfaces of the positive pressure surface (111) and the negative pressure surface (131) are corrugated surfaces.

Images