Pressure sensor

Abstract

The utility model belongs to the technical field of sensors, and discloses a pressure sensor. The pressure sensor comprises a first welding table, an isolation diaphragm, a second welding table, a cup base and a connecting pipe. A connecting hole is formed in the first welding table; the isolation diaphragm is arranged at the bottom of the first welding table, and the isolation diaphragm is arranged opposite to the opening of the connecting hole; the second welding table is welded to the end, away from the isolation diaphragm, of the first welding table, and the second welding table and the first welding table are made of different materials. The cup base and the second welding table are welded, a positive pressure oil cavity is defined in the cup base and the second welding table, and the cup base and the second welding table are made of the same material. One end of the connecting pipe is communicated with the positive pressure oil cavity, the other end of the connecting pipe penetrates through the second welding table and is arranged in the connecting hole, and the positive pressure oil cavity is communicated with the connecting hole through the connecting pipe. According to the utility model, the problems of welding compatibility and reliability after the pressure sensing core body of the pressure sensor is made of different materials can be solved, and the cost is reduced at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a pressure sensor. Background Art

[0002] Pressure sensors are a widely used type of sensor. They are widely used in various industrial automation environments, involving many industries such as water conservancy and hydropower, railway transportation, intelligent buildings, production automation, aerospace, military industry, petrochemicals, oil wells, electricity, ships, machine tools, pipelines, etc. A pressure sensor is a device that can sense pressure signals and convert them into a usable output electrical signal according to certain rules.

[0003] In the existing pressure sensor, the pressure sensor includes a pressure-sensitive core, wherein the pressure-sensitive core includes a cup seat and a diaphragm welding base, and the cup seat and the diaphragm welding base are welded.

[0004] At present, in order to ensure the welding quality and avoid cracking, the cup holder and the diaphragm welding base are usually required to be made of the same material. For example, if the cup holder and the diaphragm welding base are both made of stainless steel, but in some specific usage scenarios, the diaphragm welding base is often required to be made of special materials. Due to the welding compatibility issues between the special material and the stainless steel material, the molecules of the two materials are not tightly combined. After welding, capillary pores will appear between the cup holder and the diaphragm welding base, causing cracking, or cracking due to high pressure, which will cause oil leakage in the pressure sensor and cause the pressure sensor to fail to work normally. On the other hand, if the cup holder and the diaphragm welding base are both made of special materials, the cost of the special material is much higher than that of stainless steel, which will cause the problem of increased cost. Utility Model Content

[0005] The purpose of the utility model is to provide a pressure sensor for solving the welding compatibility and reliability problems of the pressure sensing core of the pressure sensor after adopting different materials, while taking into account cost reduction.

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

[0007] Pressure sensor, including:

[0008] a first soldering station, wherein a connecting hole is provided on the first soldering station;

[0009] An isolation diaphragm is provided at the bottom of the first soldering station, and the isolation diaphragm is arranged opposite to the opening of the connecting hole;

[0010] a second soldering station welded to an end of the first soldering station away from the isolation diaphragm, and the second soldering station and the first soldering station are made of different materials;

[0011] A cup holder is welded to the second welding station and encloses a positive pressure oil chamber therein, wherein the cup holder is made of the same material as the second welding station;

[0012] A connecting pipe, one end of which is connected to the positive-pressure oil chamber, and the other end of which passes through the second welding platform and is placed in the connecting hole, and the positive-pressure oil chamber is connected to the connecting hole through the connecting pipe.

[0013] As an optional solution for the pressure sensor, a substrate is provided inside the cup holder, and a connecting hole is opened on the substrate. The pressure sensor also includes a pressure chip provided in the substrate, and the pressure chip separates the connecting hole into a first hole and a second hole. The first hole is connected to the positive pressure oil chamber, and the second hole is connected to the external atmosphere.

[0014] As an optional solution for the pressure sensor, the substrate is made of ceramic material.

[0015] As an optional solution of the pressure sensor, an insulating plate is connected to a side of the second soldering station away from the first soldering station, and the insulating plate is arranged opposite to the pressure chip.

[0016] As an optional solution for the pressure sensor, a mounting hole is provided on the side wall of the cup holder, the mounting hole is communicated with the positive pressure oil chamber, and a breathing plug is provided in the mounting hole.

[0017] As an optional solution of the pressure sensor, the pressure sensor further includes a sleeve, the cup holder is arranged inside the sleeve, the sleeve is provided with an air vent, and the second hole is connected to the external atmosphere through the air vent.

[0018] As an optional solution of the pressure sensor, the pressure sensor further includes a shell, which is connected to the sleeve. A through hole is provided on the shell, which is opposite to the isolation diaphragm, and the liquid or gas to be measured is introduced through the through hole.

[0019] As an optional solution for the pressure sensor, a ventilation plug is provided in the ventilation hole, and the external atmosphere is connected to the ventilation hole through the ventilation plug.

[0020] As an optional solution of the pressure sensor, a fixing ring is provided on the outer periphery of the isolation diaphragm, and the fixing ring is welded to the first welding platform to fix the isolation diaphragm on the first welding platform.

[0021] As an optional solution for the pressure sensor, the cup holder is provided with a liquid injection hole, which is communicated with the positive pressure oil chamber.

[0022] Beneficial effects:

[0023] In the present invention, the first welding station is used to secure the isolation diaphragm. The first welding station can be made of a special material to accommodate the specific application of the pressure sensor. The second welding station can be made of stainless steel to reduce costs. The second welding station is connected to the first welding station by welding. Furthermore, the cup holder and the second welding station are welded together to form a positive pressure oil chamber. The cup holder can also be made of stainless steel. Since the second welding station and the cup holder are made of the same material, the welded connection of the same material has a better connection state and quality, effectively preventing cracking and further avoiding oil leakage between the cup holder and the second welding station. On the other hand, one end of the connecting tube is connected to the positive pressure oil chamber, and the other end of the connecting tube passes through the second welding station and is placed in the connecting hole, that is, the pressure oil can flow directly through the connecting tube without flowing through the weld between the first welding station and the second welding station. Therefore, even if the first welding station and the second welding station are welded with different materials, or cracking occurs at the connection, there will be no oil leakage between the first welding station and the second welding station. The welding between the first welding station and the second welding station is only used to ensure a reliable connection between the two, and will not have no effect on defects such as cracking. Therefore, the present application effectively solves the welding compatibility and reliability issues of the pressure sensor after using different materials, while also further reducing manufacturing costs and improving the price advantage of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional view of a pressure sensor provided by an embodiment of the present utility model.

[0025] In the picture:

[0026] 1. First welding station; 2. Isolation diaphragm; 21. Fixed ring; 3. Second welding station; 31. Insulation plate; 4. Cup holder; 41. Positive pressure oil chamber; 42. Breathing plug; 43. Injection hole; 5. Connecting pipe; 6. Base plate; 61. Connecting hole; 62. Pressure chip; 611. First hole; 612. Second hole; 7. Sleeve; 71. Breathing plug; 8. Shell; 81. Through hole. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0028] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0029] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0031] Please see the attached Figure 1 This embodiment relates to a pressure sensor, specifically a gauge pressure sensor, comprising a first welding platform 1, an isolation diaphragm 2, a second welding platform 3, a cup holder 4, and a connecting tube 5. The first welding platform 1 is provided with a connecting hole; the isolation diaphragm 2 is disposed at the bottom of the first welding platform 1, and is disposed opposite the opening of the connecting hole; the second welding platform 3 is welded to the end of the first welding platform 1 away from the isolation diaphragm 2, and the second welding platform 3 and the first welding platform 1 are made of different materials; the cup holder 4 is welded to the second welding platform 3 and encloses a positive pressure oil chamber 41 therein; the cup holder 4 is made of the same material as the second welding platform 3; one end of the connecting tube 5 is connected to the positive pressure oil chamber 41, and the other end of the connecting tube 5 passes through the second welding platform 3 and is disposed in the connecting hole, with the positive pressure oil chamber 41 being connected to the connecting hole via the connecting tube 5.

[0032] In this embodiment, the first welding platform 1 and the second welding platform 3 are both circumferential rotating bodies, wherein the first welding platform 1 is used to fix the isolation diaphragm 2. The first welding platform 1 can be made of special materials to adapt to the special use occasions of the pressure sensor. The second welding platform 3 can be made of 316 stainless steel to reduce costs. At the same time, the second welding platform 3 and the first welding platform 1 can be connected by brazing. Furthermore, the cup holder 4 is welded to the second welding station 3 and enclosed within the two to form a positive pressure oil chamber 41. The cup holder 4 can also be made of 316 stainless steel. Since the second welding station 3 and the cup holder 4 are made of the same material, the welding connection of the same material has a better connection state and connection quality, effectively solving the cracking problem, thereby further avoiding the oil leakage problem between the cup holder 4 and the second welding station 3. On the other hand, one end of the connecting pipe 5 is connected to the positive pressure oil chamber 41, and the other end of the connecting pipe 5 passes through the second welding station 3 and is placed in the connecting hole, and the pressure oil can flow directly through the connecting pipe 5 without flowing through the weld between the first welding station 1 and the second welding station 3. Therefore, even if the first welding station 1 and the second welding station 3 are welded with different materials and cracking occurs, the pressure oil will not leak between the first welding station 1 and the second welding station 3. The welding between the first welding station 1 and the second welding station 3 is only used to ensure a reliable connection between the two and will not have no effect on defects such as cracking. This application effectively solves the welding compatibility and reliability issues of pressure sensors after using different materials, while also further reducing manufacturing costs and improving the price advantage of the product.

[0033] Preferably, the pressure oil is silicone oil.

[0034] Optionally, a base plate 6 is provided inside the cup holder 4, and a connecting hole 61 is opened on the base plate 6. The pressure sensor also includes a pressure chip 62 provided in the base plate 6. The pressure chip 62 separates the connecting hole 61 into a first hole 611 and a second hole 612. The first hole 611 is connected to the positive pressure oil chamber 41, and the second hole 612 is connected to the external atmosphere.

[0035] In this embodiment, substrate 6 is made of ceramic and occupies most of the space within positive-pressure oil chamber 41, thereby conserving pressure oil. Furthermore, since substrate 6 has a much lower thermal expansion coefficient than pressure oil, this not only reduces the need for additional pressure oil but also further reduces the sensitivity of the pressure sensor's accuracy to temperature. A connecting hole 61 is located in the center of substrate 6, with a pressure chip 62 positioned horizontally within the center. Pressure chip 62 operates on the principle of piezoresistive resistance. When the pressure at the measured location changes, the resistance value changes, and the pressure value is then determined through changes in an electrical signal (such as voltage or current).

[0036] In this embodiment, the connecting hole 61 is a strip-shaped hole, wherein the two sides of the pressure chip 62 separate the connecting hole 61 into a first hole 611 and a second hole 612. The first hole 611 is connected to the positive pressure oil chamber 41, that is, the positive pressure oil chamber 41 can generate pressure changes through the deformation of the isolation diaphragm 2, and the second hole 612 is connected to the external atmosphere, so that the other side of the pressure chip 62 uses the atmospheric pressure as the reference air pressure, thereby forming a relationship between the pressure to be measured and the reference air pressure.

[0037] Optionally, an insulating plate 31 is connected to a side of the second soldering station 3 away from the first soldering station 1 , and the insulating plate 31 is arranged opposite to the pressure chip 62 .

[0038] In this embodiment, an insulating plate 31 is also provided on the second soldering station 3. The material of the insulating plate 31 is also ceramic. The insulating plate 31 is arranged between the pressure chip 62 and the second soldering station 3. Since the second soldering station 3 is made of metal, the insulating plate 31 can ensure that there is sufficient insulation gap between the pressure chip 62 and the second soldering station 3, and the volume of the entire pressure sensor can be further reduced.

[0039] Optionally, a mounting hole is provided on the side wall of the cup holder 4, and a breathing plug 42 is provided in the mounting hole. The breathing plug 42 is a metal breathing plug. The breathing plug 42 can prevent sparks caused by weak electricity inside the pressure sensor from leaking outward, thereby playing an explosion-proof role and increasing the reliability of the sensor.

[0040] Optionally, the pressure sensor further includes a sleeve 7 , the cup holder 4 is disposed inside the sleeve 7 , the sleeve 7 is provided with an air vent, and the second hole 612 is connected to the external atmosphere through the air vent.

[0041] In this embodiment, the sleeve 7 is also a circumferentially rotating body, and the cup holder 4 is located inside the sleeve 7, so that the breathing plug 42 can be stably fixed in the mounting hole and prevented from falling off. In addition, the outer wall of the sleeve 7 is provided with a vent hole, and the second hole 612 is connected to the external atmosphere through the vent hole.

[0042] Furthermore, the pressure sensor further includes a housing 8 , which is connected to the sleeve 7 . A through hole 81 is provided on the housing 8 , which is opposite to the isolation diaphragm 2 , and through which the liquid or gas to be measured is introduced.

[0043] In this embodiment, the housing 8 is also a circumferentially rotating body. The housing 8 and sleeve 7 are threadedly connected. Furthermore, the housing 8 defines a through hole 81 relative to the isolation diaphragm 2. External gas or liquid to be subjected to the side pressure can directly pass through the through hole 81 and act on the isolation diaphragm 2, causing deformation of the isolation diaphragm 2. The outer wall of the housing 8 also has external threads for threading other components to be subjected to the pressure measurement.

[0044] Furthermore, a ventilation plug 71 is provided in the ventilation hole, and the external atmosphere is connected to the ventilation hole through the ventilation plug 71.

[0045] The vent plug 71 does not affect the connection between the vent hole and the external atmosphere, so the atmospheric pressure is on both sides of the vent hole. In addition to having a ventilating function, the vent plug 71 can further prevent liquid from passing through, thereby achieving the purpose of waterproofing. The vent plug 71 can adopt an existing conventional structure. The specific working principle of the vent plug 71 will not be elaborated in this embodiment.

[0046] Optionally, a fixing ring 21 is provided on the outer periphery of the isolation diaphragm 2 , and the fixing ring 21 is welded to the first welding platform 1 so that the isolation diaphragm 2 is fixed on the first welding platform 1 .

[0047] The fixing ring 21 is sleeved on the circumferential outer edge of the isolation diaphragm 2, and is welded to the first welding platform 1 by the fixing ring 21, so that the isolation diaphragm 2 is reliably fixed on the first welding platform 1. Of course, in other embodiments, other fixing methods can also be used to fix the isolation diaphragm 2 on the first welding platform 1. For example, threaded fasteners or rivets are used to fasten the isolation diaphragm 2 to the first welding platform 1.

[0048] Optionally, a liquid injection hole 43 is provided on the cup holder 4, and the liquid injection hole 43 is connected to the positive pressure oil chamber 41. No liquid injection tube can be set in the liquid injection hole 43. The pressure oil can be added to the positive pressure oil chamber 41 through the liquid injection hole 43. After the liquid injection is completed, the liquid injection hole 43 needs to be sealed.

[0049] The working principle of this pressure sensor is as follows:

[0050] First, the liquid or gas to be measured pressure is passed into the through hole 81. The liquid or gas acts on the isolation diaphragm 2, causing it to deform and squeeze the pressure oil in the positive pressure oil chamber 41. Since the volume of the pressure oil remains unchanged, it will further act on the pressure chip 62, and the force signal will be converted into an electrical signal through the pressure chip 62, thereby realizing the pressure detection of the liquid or gas.

[0051] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A pressure sensor, characterized in that include: A first soldering platform (1), wherein the first soldering platform (1) is provided with a connection hole; An isolation diaphragm (2) is provided at the bottom of the first welding platform (1), and the isolation diaphragm (2) is arranged opposite to the opening of the connection hole; a second welding platform (3) welded to an end of the first welding platform (1) away from the isolation diaphragm (2), and the second welding platform (3) and the first welding platform (1) are made of different materials; A cup seat (4) is welded to the second welding platform (3) and encloses a positive pressure oil chamber (41) therein; the cup seat (4) and the second welding platform (3) are made of the same material; A connecting pipe (5), one end of which is connected to the positive-pressure oil chamber (41), the other end of which passes through the second welding platform (3) and is placed in the connecting hole, and the positive-pressure oil chamber (41) is connected to the connecting hole through the connecting pipe (5).

2. The pressure sensor according to claim 1, wherein A base plate (6) is provided inside the cup holder (4), and a communication hole (61) is provided on the base plate (6). The pressure sensor further comprises a pressure chip (62) provided inside the base plate (6), and the pressure chip (62) separates the communication hole (61) into a first hole (611) and a second hole (612). The first hole (611) is communicated with the positive pressure oil chamber (41), and the second hole (612) is communicated with the external atmosphere.

3. The pressure sensor according to claim 2, wherein: The substrate (6) is made of ceramic material.

4. The pressure sensor according to claim 2, wherein: An insulating plate (31) is connected to a side of the second soldering station (3) away from the first soldering station (1), and the insulating plate (31) is arranged opposite to the pressure chip (62).

5. The pressure sensor according to claim 2, wherein: A mounting hole is provided on the side wall of the cup holder (4), the mounting hole is communicated with the positive pressure oil chamber (41), and a breathing plug (42) is provided in the mounting hole.

6. The pressure sensor according to claim 2, wherein: The pressure sensor further comprises a sleeve (7), the cup holder (4) is arranged inside the sleeve (7), the sleeve (7) is provided with an air vent, and the second hole (612) is connected to the external atmosphere through the air vent.

7. The pressure sensor according to claim 6, characterized in that The pressure sensor further comprises a housing (8), the housing (8) being connected to the sleeve (7), the housing (8) being provided with a through hole (81), the through hole (81) being opposite to the isolation diaphragm (2), and the liquid or gas to be measured pressure being introduced through the through hole (81).

8. The pressure sensor according to claim 6, wherein: A vent plug (71) is provided in the vent hole, and the external atmosphere is communicated with the vent hole through the vent plug (71).

9. The pressure sensor according to any one of claims 1 to 8, characterized in that: A fixing ring (21) is provided on the outer periphery of the isolation diaphragm (2), and the fixing ring (21) is welded to the first welding platform (1) so that the isolation diaphragm (2) is fixed on the first welding platform (1).

10. The pressure sensor according to any one of claims 1 to 8, characterized in that: The cup seat (4) is provided with a liquid injection hole (43), and the liquid injection hole (43) is communicated with the positive pressure oil chamber (41).

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