A linear self-compensating pressure measurement sensor structure and manufacturing method thereof

Abstract

The present invention discloses a linear self-compensating pressure measurement sensor structure and a manufacturing method thereof, comprising a cylinder, a pressure joint is installed at the lower end of the cylinder, four square through holes are symmetrically opened around the side wall of the cylinder, the four square through holes form a column structure one at the center of the cylinder, and column structure two, column structure three, column structure four and column structure five are respectively formed around the cylinder, the column structure one has two circular countersunk holes symmetrically opened at the side wall corresponding to the cylinder, and a resistance strain gauge is installed at the bottom of the circular countersunk hole. This scheme significantly improves the inherent linearity of the pressure sensor; friction welding and surface contact welding are adopted, the whole elastic element is integrated, no sealing ring is needed, no friction contact, and the sensor has good hysteresis performance; no sealing ring saves cost, no sealing ring aging problem, environmental protection, integrated design, no accessories assembly, and simple production process.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure measuring sensors, and in particular to a linear self-compensating pressure measuring sensor structure and a manufacturing method thereof. Background Art

[0002] Pressure sensors are a type of sensor used to measure the pressure of liquids and gases. The main types are piezoelectric, strain gauge, and capacitive.

[0003] The existing strain type pressure sensor structures mainly include: flat plate type and barrel type, and their disadvantage is inherent linearity difference, so they need to be improved. Summary of the invention

[0004] The purpose of the present invention is to solve the defects in the prior art and to propose a linear self-compensating pressure measurement sensor structure and a manufacturing method thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A linear self-compensating pressure measurement sensor structure comprises a cylinder, a pressure joint is installed at the lower end of the cylinder, four square through holes are symmetrically opened around the side wall of the cylinder, the four square through holes form a column structure one at the center of the cylinder, and a column structure two, a column structure three, a column structure four and a column structure five are respectively formed around the cylinder, the column structure one has two circular countersunk holes symmetrically opened at the side wall corresponding to the cylinder, a resistance strain gauge is installed at the bottom of the circular countersunk hole, a cavity is opened at the bottom end of the cylinder corresponding to the position of the pressure joint, a pressure inlet hole is opened at the center of the pressure joint, and the pressure inlet hole is connected to the cavity, and the bottom end of the pressure joint is installed with a pressure source device through a thread.

[0007] Furthermore, the cylinder and the pressure joint are fixedly installed by friction welding.

[0008] A method for manufacturing a linear self-compensating pressure measurement sensor structure, the method comprising the following steps:

[0009] S1: Four square through holes are processed vertically and symmetrically at appropriate positions on the side of the cylinder to form a square column structure 1 at the center of the cylinder and four surrounding column structures 2, 3, 4 and 5;

[0010] S2: Two symmetrical circular countersunk holes with smooth bottoms are processed on the column structure 1 for installing strain gauges for measuring strain;

[0011] S3: A countersunk hole is machined at the bottom of the cylinder, and the bottom is smooth. A pressure joint is also machined. There is an external pressure-introducing hole at the center of the pressure joint. The pressure joint and the cylinder are friction welded to form an internal cavity, and pressure, either air pressure or hydraulic pressure, is introduced through the pressure-introducing hole.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] This solution significantly improves the inherent linearity of the pressure sensor; it adopts friction welding and surface contact welding, and the entire elastic element is integrated into one, without the need for sealing rings, no friction contact, and good sensor hysteresis performance; no sealing ring saves costs, no sealing ring aging problems, environmental protection, integrated design, no accessories assembly, and simple production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0015] Figure 1 A front view of a linear self-compensating pressure measurement sensor structure proposed by the present invention;

[0016] Figure 2 It is a left view of a linear self-compensating pressure measurement sensor structure proposed by the present invention;

[0017] Figure 3 for Figure 1 Middle AA section;

[0018] Figure 4 for Figure 3 Schematic diagram of the D direction;

[0019] Figure 5 A schematic diagram of a process for manufacturing a linear self-compensating pressure measurement sensor structure proposed by the present invention;

[0020] Figure 6 It is a stress-strain curve diagram of the cross section of a column structure in the prior art;

[0021] Figure 7 is the pressure P of the thin plate structure in the prior art - force F 1 Graphs;

[0022] Figure 8 This is a pressure P-strain curve diagram of the combined structure proposed by the present invention.

[0023] In the figure: 1 cylinder, 2 pressure joint, 3 square through hole, 301 column structure one, 302 column structure two, 303 column structure three, 304 column structure four, 305 column structure five, 4 circular countersunk hole, 5 cavity, 6 pressure-inducing hole, 7 thread. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] Reference Figure 1-5 A linear self-compensating pressure measurement sensor structure comprises a cylinder 1, characterized in that a pressure joint 2 is installed at the lower end of the cylinder 1, four square through holes 3 are symmetrically opened around the side wall of the cylinder 1, the four square through holes 3 form a column structure 1 301 at the center of the cylinder 1, and a column structure 2 302, a column structure 3 303, a column structure 4 304 and a column structure 5 305 are respectively formed around the cylinder 1, two circular countersunk holes 4 are symmetrically opened at the side wall of the column structure 1 301 corresponding to the cylinder 1, a resistance strain gauge is installed at the bottom of the circular countersunk hole 4, a cavity 5 is opened at the bottom end of the cylinder 1 corresponding to the position of the pressure joint 2, a pressure inlet hole 6 is opened at the center of the pressure joint 2, and the pressure inlet hole 6 is connected to the cavity 5, and the bottom end of the pressure joint 2 is installed with a pressure source device through a thread 7.

[0027] Furthermore, the cylinder 1 and the pressure joint 2 are fixedly installed by friction welding.

[0028] A method for manufacturing a linear self-compensating pressure measurement sensor structure, the method comprising the following steps:

[0029] S1: Four square through holes 3 are processed vertically and symmetrically at appropriate positions on the side of the cylinder 1, forming a square column structure 1 301 in the center of the cylinder 1 and four surrounding column structures 2 302, column structure 3 303, column structure 4 304 and column structure 5 305;

[0030] S2: Two symmetrical circular countersunk holes 4 are processed on the column structure 301, and the bottoms thereof are smooth, for installing strain gauges for measuring strain;

[0031] S3: A countersunk hole is machined at the bottom of the cylinder 1, and the bottom is smooth. A pressure joint 2 is also machined, and an external pressure-introducing hole 6 is provided at the center of the pressure joint 2. The pressure joint 2 and the cylinder 1 are friction welded to form an internal cavity 5, and pressure, either air pressure or hydraulic pressure, is introduced through the pressure-introducing hole 6.

[0032] During machining, the position of the symmetrical circular countersunk hole 4 in the vertical direction is adjusted to increase or decrease the thickness of the junction between the thin plate and the columnar structure 301 to adjust the area S of the thin plate ( Figure 4 The stiffness of the

[0033] The pressure P in the cavity 5 increases linearly, and the area S of the planar membrane structure increases, generating a force F greater than the linear change. 1 , F 1 The strain applied to the columnar structure 301 makes the strain on the cross section tend to change linearly, and the output signal of the sensor tends to change linearly, thereby improving the inherent linearity of the sensor.

[0034] Working principle of the present invention:

[0035] 1. Reference Figure 6 , the stress-strain curve of the cross section of the column structure in the prior art; the force F of the column structure increases linearly, due to the cross-sectional area S 1 As the pressure increases, the strain generated on the cross section is smaller than the linear change. To make the strain change linearly, a force greater than the linear change is required.

[0036] 2. Reference Figure 7 , is the pressure P-force F of the thin plate structure in the prior art 1 Curve graph: When the pressure P on the thin plate structure increases linearly, due to the increase in area S, the force F1 generated by the pressure P on S is greater than the linear change.

[0037] 3. Reference Figure 8 This is the pressure P-strain curve of the combined structure proposed by the present invention; this scheme combines the above two structural forms, and the linearly changing pressure P produces a force F on the surface S that is greater than the linearly changing force F 1 , F 1 Applied to the columnar structure, the strain on the cross section tends to change linearly.

[0038] Reference Figure 4 In this scheme, by adjusting the stiffness of the thin plate area S, the smaller the stiffness, the greater the force F 1 The larger the increment, the more the pressure-force curve can be adjusted, and adjusting the pressure-force curve can correct the stress-strain curve of the column structure.

[0039] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A linear self-compensating pressure measurement sensor structure, comprising a cylinder (1), characterized in that: A pressure joint (2) is installed at the lower end of the cylinder (1), and four square through holes (3) are symmetrically opened around the side wall of the cylinder (1), and the four square through holes (3) form a column structure one (301) at the center of the cylinder (1), and a column structure two (302), a column structure three (303), a column structure four (304) and a column structure five (305) are respectively formed around the cylinder (1), and the column structure one (301) has two circular countersunk holes (4) symmetrically opened at the side wall corresponding to the cylinder (1), and a resistance strain gauge is installed at the bottom of the circular countersunk hole (4), and a cavity (5) is opened at the bottom end of the cylinder (1) corresponding to the position of the pressure joint (2), and a pressure induction hole (6) is opened at the center of the pressure joint (2), and the pressure induction hole (6) is connected to the cavity (5), and the bottom end of the pressure joint (2) is installed with a pressure source device through a thread (7).

2. A linear self-compensating pressure measurement sensor structure according to claim 1, characterized in that: The cylinder (1) and the pressure joint (2) are fixedly installed by friction welding.

3. A method for manufacturing a linear self-compensating pressure measurement sensor structure, characterized in that: The method comprises the following steps: S1: Four square through holes (3) are processed vertically and symmetrically at appropriate positions on the side of the cylinder (1), so as to form a square column structure 1 (301) at the center of the cylinder (1) and four surrounding column structures 2 (302), 3 (303), 4 (304) and 5 (305); S2: Two symmetrical circular countersunk holes (4) are machined on the column structure 1 (301), and the bottoms of the two countersunk holes are smooth, for installing strain gauges for measuring strain; S3: A countersunk hole is machined at the bottom of the cylinder (1), and the bottom is smooth. A pressure joint (2) is also machined, and an external pressure inlet hole (6) is provided at the center of the pressure joint (2). The pressure joint (2) and the bottom of the cylinder (1) are friction welded to form an internal cavity (5) through the countersunk hole at the bottom of the cylinder (1), and air pressure or hydraulic pressure is introduced through the pressure inlet hole (6).

Images