Piezoelectric pressure sensor for drop position visualization

Abstract

The application relates to the technical field of pressure sensors, in particular to a piezoelectric pressure sensor with visualized drop point position, which comprises a base, a piezoelectric element arranged at the bottom of the base and a carrier table ball-jointed to the top of the base; four U-shaped cavities are arranged on the base in a cross shape along the circumference; the U-shaped cavity comprises a first cavity in the base, a second cavity exposed on the outside of the base and a communication cavity for connecting the first cavity and the second cavity; the volume of the first cavity is much larger than that of the second cavity; the first cavity, the second cavity and the communication cavity are all filled with liquid; an elastic piston rod protruding out of the top of the base is arranged on the top of the first cavity; a piston ball head is arranged on the top of the piston rod; the piston ball head is in movable abutment with the bottom surface of the carrier table; an operator can directly perceive the approximate area of the drop point by observing the liquid level change, and can accurately obtain the polar coordinates of the drop point by combining coordinate calculation, so that positioning can be completed without relying on complex signal analysis.

Description

Technical Field

[0001] This invention relates to the field of pressure sensor technology, and more specifically to a piezoelectric pressure sensor with visualized impact point location. Background Technology

[0002] Existing piezoelectric pressure sensors primarily detect the magnitude of applied force through a sensing element and convert it into an electrical signal output. However, their core limitation lies in their ability to only quantify single-point or overall pressure, failing to correlate pressure values ​​with the location of the external force. This makes them unsuitable for applications requiring precise pressure location. When the point of force application changes on the stage or working surface, traditional solutions necessitate the placement of multiple independent sensing units and complex electronic signal acquisition and analysis systems to indirectly determine the force location. This not only increases hardware costs but also raises the risk of system failure due to the increased number of electronic components, reducing long-term reliability and ease of maintenance.

[0003] In addition, a single piezoelectric element can only output electrical signals and lacks intuitive mechanical feedback on the point of impact. Operators need to rely on specialized equipment to read and analyze data, and cannot quickly assess the location and distribution trend of pressure through simple observation, thus limiting the flexibility of use. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a piezoelectric pressure sensor with visualized landing point position.

[0005] To achieve the above objectives, the specific solution of the present invention is as follows:

[0006] A piezoelectric pressure sensor with visualized landing point position includes a base, a piezoelectric element disposed at the bottom of the base, and a stage on the top of the base with a ball attached to it.

[0007] The base has four U-shaped cavities arranged in a cross shape along the circumference; each U-shaped cavity includes a first cavity located inside the base, a second cavity exposed on the outside of the base, and a connecting cavity connecting the first cavity and the second cavity; the volume of the first cavity is much larger than the volume of the second cavity; the first cavity, the second cavity, and the connecting cavity are all filled with liquid;

[0008] The first cavity has a piston rod that is elastically movably extended from the top of the base; the top of the piston rod has a piston ball head; the piston ball head is movably abutting against the bottom surface of the platform.

[0009] The invention is further configured such that a return spring is provided in the first cavity; the two ends of the return spring abut against the bottom of the piston rod and the bottom wall of the first cavity, respectively.

[0010] The present invention is further configured such that the bottom of the piston rod is provided with a receiving hole; the upper end of the return spring is inserted into the receiving hole.

[0011] The present invention is further configured such that four U-shaped seats arranged in a cross shape are embedded in the circumferential direction of the base; one end of the U-shaped seat is embedded in the base, and the other end of the U-shaped seat is exposed on the outside of the base; each U-shaped seat is embedded with a U-shaped glass tube made of transparent or translucent material.

[0012] The U-shaped glass tube includes an integrally formed first tube body, a second tube body, and a connecting tube; the first tube body is embedded in one end of the U-shaped seat, and the second tube body is embedded in the other end of the U-shaped seat with its outer side exposed outside the U-shaped seat; the two ends of the connecting tube are respectively connected to the bottom of the first tube body and the bottom of the second tube body.

[0013] The first cavity, the second cavity, and the connecting cavity are respectively located inside the first tube, the second tube, and the connecting tube.

[0014] The invention is further configured such that the other end of the U-shaped seat is provided with a scale marking line on one side of the second tube.

[0015] The invention is further configured such that: a groove is provided on the top of the base; a hinge seat is provided in the groove; a ball joint is provided at the center of the hinge seat; a spherical head is provided at the center of the bottom surface of the platform; and the spherical head is hinged to the ball joint.

[0016] The invention is further configured such that the groove is a polygonal structure; and the hinge seat is correspondingly configured as a polygonal structure.

[0017] The beneficial effects of this invention are as follows: This invention sets four U-shaped cavities arranged in a cross shape around the bottom surface of the stage. Each U-shaped cavity is movably connected to the bottom surface of the stage via a piston rod with a piston ball head. The volume of the first cavity of the U-shaped cavity is much larger than the volume of the second cavity. Thus, a coordinate reference is established through the four U-shaped cavities. Combined with the flexible offset characteristics of the ball-joint stage, the eccentric effect of the external force landing point can be transmitted to the corresponding piston rod through the stage, squeezing the liquid in the U-shaped cavity to form a liquid surface change. Utilizing the structural design that "the volume of the first cavity is much larger than that of the second cavity", the small piston displacement is transformed into a significant liquid surface change in the second cavity, achieving a displacement amplification effect. The operator can directly perceive the approximate area of ​​the landing point by observing the liquid surface change. Combined with coordinate calculation, the polar coordinates of the landing point can be accurately obtained. Positioning can be completed without relying on complex signal analysis, thereby achieving intuitive visualization and accurate positioning of the external force landing point. This simplifies the structure, reduces costs, and improves system reliability. It also solves the limitation of traditional piezoelectric sensors that "can only measure pressure and cannot intuitively reflect the landing point position." It is convenient to operate and highly adaptable. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is a cross-sectional schematic diagram of the present invention when the platform is unloaded or without external force.

[0020] Figure 3 This is a cross-sectional view of the present invention when the bearing surface of the stage is subjected to an eccentric external force.

[0021] Figure 4 This is a cross-sectional schematic diagram of the U-shaped seat, U-shaped tube, piston rod, and return spring of the present invention.

[0022] Figure 5 This is a cross-sectional schematic diagram of the U-shaped base of the present invention;

[0023] Figure 6 This is a cross-sectional schematic diagram of the U-shaped tube of the present invention;

[0024] Figure 7 This is a schematic diagram of the polar coordinates used in this invention to calculate the location of the point where an external force falls.

[0025] Explanation of reference numerals in the attached drawings: 1. Base; 11. Groove; 2. Piezoelectric element; 3. Stage; 31. Spherical head; 4. U-shaped seat; 41. Scale marking line; 5. U-shaped glass tube; 51. First tube body; 52. Second tube body; 53. Connecting tube; 54. U-shaped cavity; 541. First cavity body; 542. Second cavity body; 543. Connecting cavity; 6. Piston rod; 61. Piston ball head; 62. Receiving hole; 7. Return spring; 8. Hinge seat; 81. Ball joint seat. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this is not to limit the scope of the invention to this.

[0027] like Figures 1 to 6 As shown in the figure, the piezoelectric pressure sensor with visualized landing position described in this embodiment includes a base 1, a piezoelectric element 2, and a stage 3; the piezoelectric element 2 is fixedly installed at the bottom of the base 1 and is used to sense the overall pressure and realize the electrical signal conversion of the pressure signal; the stage 3 is ball-mounted on the top of the base 1.

[0028] To achieve visual detection of the landing point, four U-shaped cavities 54 arranged in a cross shape along the circumference are provided on the base 1. Each U-shaped cavity 54 includes a first cavity 541 located inside the base 1, a second cavity 542 exposed on the outside of the base 1, and a connecting cavity 543 connecting the first cavity 541 and the second cavity 542. The volume of the first cavity 541 is much larger than the volume of the second cavity 542. The first cavity 541, the second cavity 542, and the connecting cavity 543 are all filled with liquid.

[0029] The first cavity 541 has a piston rod 6 that protrudes from the top of the base 1; the top of the piston rod 6 has a piston ball head 61; the piston ball head 61 is in contact with the bottom surface of the platform 3.

[0030] Specifically, in this embodiment, the piezoelectric pressure sensor with visualized landing point location uses a coordinate system established based on four U-shaped cavities 54 for ease of explanation. The straight line containing two relatively distributed U-shaped cavities 54 is set as one coordinate axis (e.g., the X-axis), and the straight line containing the other two relatively distributed U-shaped cavities 54 is set as another vertical coordinate axis (e.g., the Y-axis). The origin of the coordinate system coincides with the geometric center of the stage 3. This coordinate system divides the bearing surface of the stage 3 into four quadrants, providing a reference for positioning the landing point. Figure 2 As shown, when the stage 3 is unloaded or without external force, the liquid in each U-shaped cavity is in equilibrium. The liquid level in the first cavity 541 and the second cavity 542 is consistent. At this time, the liquid level can be used as the reference zero point to provide a reference for subsequent height change detection.

[0031] like Figure 3 As shown, when an eccentric external force is applied to the bearing surface of the stage 3, the stage 3 will shift slightly along the eccentric direction because the load point deviates from the center of the stage 3. Taking the external force point located in one of the quadrants as an example, the stage 3 tilts towards that quadrant, thereby generating a vertically downward compressive force on the piston ball heads 61 of the two piston rods 6 corresponding to that quadrant, forcing the two piston rods 6 to displace downward along the axial direction of the first cavity 541. As the piston rod 6 moves downward, it compresses the liquid in the first chamber 541, causing a slight drop in the liquid level. Due to the fluidity of the liquid and the conduction effect of the connecting chamber 543, the compressed liquid flows into the second chamber 542 through the connecting chamber 543, causing a significant rise in the liquid level in the second chamber 542. Since the volume of the first chamber 541 is much larger than that of the second chamber 542, according to the principles of fluid statics, the slight change in the liquid level in the first chamber 541 will create an amplified change in liquid level height in the second chamber 542. This amplification effect allows the operator to directly observe and read the liquid level change. At this time, by reading the liquid level height change values ​​of the two second chambers 542 in this quadrant region, such as... Figure 7 As shown, the specific location of the external force's impact point can be calculated: Let the change in liquid level in one of the second chambers 542 be ΔH1, and the change in liquid level in the other second chamber 542 be ΔΔH2. The offset angle of the external force's impact point can be calculated using the arctangent function, where a = arctan(ΔH2 / ΔH1). The offset radius is calculated using the Pythagorean theorem, where r = This ultimately forms the polar coordinates (r, a) of the point where the external force lands. If the point of impact is located in another quadrant, the calculation principle for its location is the same as described above, derived from the change in liquid level of the two second cavities 542 in the corresponding quadrant, which will not be elaborated here.

[0032] It should be noted that the tilt of the platform 3 in this embodiment is a micro-tilt structure, that is, the tilt angle is very small, the tilt angle θ≤5°, and the change of the vertical liquid level is approximately linearly mapped to the horizontal displacement. Therefore, the offset angle a and offset radius r of the position of the external force landing point are solved by using the difference in liquid level height ΔH1 and the difference in liquid level height ΔH2.

[0033] Specifically, the tilt angle θ is proportional to the pressure difference ΔP. When the platform 3 tilts by an angle θ, the pressure difference generated by the liquid column is: ΔP = pgH = pg(L·tanθ), where H is the liquid level difference. The liquid level difference is proportional to the horizontal displacement ΔX or ΔY. Since the tilt angle is very small, tanθ≈sinθ≈θ≈ΔX / L, therefore the liquid level difference H≈pgΔX / k. This shows that the horizontal displacement ΔX or ΔY, the tilt angle θ, and the liquid level difference H have a linear and reversible relationship, so the change in liquid level can be directly used to calculate the landing point position.

[0034] In this embodiment, four U-shaped cavities 54 arranged in a cross shape are set around the bottom surface of the stage 3. Each U-shaped cavity 54 is movably abutted against the bottom surface of the stage 3 by a piston rod 6 with a piston ball head 61. The volume of the first cavity 541 of the U-shaped cavity 54 is much larger than the volume of its second cavity 542. Thus, a coordinate reference is established through the four U-shaped cavities. Combined with the flexible offset characteristics of the ball-joint stage 3, the eccentric effect of the external force landing point can be transmitted to the corresponding piston rod 6 through the stage 3, squeezing the liquid in the U-shaped cavity to form a liquid level change; utilizing the fact that "the volume of the first cavity 541 is much larger than the volume of the second cavity 542", the system can effectively achieve this. The "two-chamber 542" structural design transforms minute piston displacement into significant liquid level changes in the second chamber 542, achieving a displacement amplification effect. Operators can directly perceive the approximate landing area by observing liquid level changes, and accurately obtain the polar coordinates of the landing point by combining coordinate calculations. Positioning can be completed without relying on complex signal analysis, thus achieving intuitive visualization and precise positioning of the landing point of external force. This simplifies the structure, reduces costs, and improves system reliability, while also overcoming the limitation of traditional piezoelectric sensors that "can only measure pressure and cannot intuitively reflect the landing point position." It is easy to operate and highly adaptable.

[0035] like Figures 2 to 4 As shown, this embodiment features a piezoelectric pressure sensor with visualized landing point location. A return spring 7 is installed within the first cavity 541. The two ends of the return spring 7 abut against the bottom of the piston rod 6 and the bottom wall of the first cavity 541, respectively. This configuration ensures the sensor's reusability and measurement accuracy. When the external force is removed, the return spring 7, under the action of elastic restoring force, pushes the piston rod 6 upwards until it returns to its initial position. Simultaneously, it causes the liquid levels in the first cavity 541 and the second cavity 542 to return to the reference zero point, preparing for the next measurement.

[0036] like Figures 2 to 4 As shown, this embodiment features a piezoelectric pressure sensor with visualized landing point location. The piston rod 6 has a receiving hole 62 at its bottom; the upper end of the return spring 7 is inserted into the receiving hole 62. This embodiment, through the above-described design, further improves the installation stability and transmission accuracy of the return spring 7. This structural design effectively limits the radial displacement of the return spring 7, preventing the spring from shifting or twisting during extension and retraction, ensuring that the vertical movement of the piston rod 6 always proceeds axially, and improving force transmission efficiency and measurement stability.

[0037] like Figures 1 to 7 As shown, this embodiment of the piezoelectric pressure sensor visualizes the landing point. Four U-shaped seats 4 arranged in a cross shape are embedded circumferentially on the base 1. One end of each U-shaped seat 4 is embedded inside the base 1, while the other end is exposed outside the base 1. Each U-shaped seat 4 is fitted with a U-shaped glass tube 5 made of transparent or semi-transparent material, ensuring that the operator can clearly observe changes in the liquid level inside the tube. The U-shaped glass tube 5 includes an integrally formed first tube body 51, a second tube body 52, and a connecting tube 53. The first tube body 51 is embedded in one end of the U-shaped seat 4, and the second tube body 52 is embedded in the other end of the U-shaped seat 4 with its outer side exposed for easy observation. Its internal space forms a second cavity 542 of the U-shaped cavity. The two ends of the connecting tube 53 are seamlessly connected to the bottom of the first tube body 51 and the bottom of the second tube body 52, forming a complete fluid channel. Its internal space forms the connecting cavity 543 of the U-shaped cavity. The first tube body 51, the second tube body 52, and the connecting tube 53 are integrally formed. Not only is it easy to process and manufacture, but it also effectively reduces assembly difficulty. At the same time, the transparent glass tube provides a good field of view for observing the liquid surface. The first cavity 541, the second cavity 542, and the connecting cavity 543 are respectively disposed in the first tube 51, the second tube 52, and the connecting tube 53.

[0038] like Figure 2 , Figure 4 and Figure 5As shown in the illustration, this embodiment features a piezoelectric pressure sensor with visualized landing point location. The other end of the U-shaped base 4 is equipped with a scale marking line 41 on one side of the second tube 52. The accuracy of the scale value is set according to measurement requirements to ensure accurate reading of changes in liquid level. By comparing the positions of the liquid level in the second tube 52 on the scale marking line 41 before and after applying external force, the operator can quickly obtain the specific values ​​of ΔX and ΔY, providing precise data support for calculating the landing point location.

[0039] like Figure 2 and Figure 3 As shown, this embodiment of the piezoelectric pressure sensor with visualized landing point position has a groove 11 on the top of the base 1; a hinge seat 8 is provided in the groove 11; a ball joint seat 81 is provided at the center of the hinge seat 8; a spherical head 31 is provided at the center of the bottom surface of the stage 3; the spherical head 31 is hinged to the ball joint seat 81, forming a spherical joint structure that can rotate in all directions. This invention can ensure that the stage 3 can flexibly shift around the hinge point between the spherical head 31 and the ball joint seat 81 when subjected to an eccentric external force in any direction, and always maintain effective contact with the piston ball head 61 of each piston rod 6 during the shifting process, ensuring lossless force transmission and ensuring measurement accuracy.

[0040] This embodiment features a piezoelectric pressure sensor with visualized impact point location. The groove 11 has a polygonal structure, and the hinge seat 8 is correspondingly configured as a polygonal structure. Specifically, conventional polygonal structures such as squares or hexagons can be selected based on actual processing requirements. The polygonal structure effectively restricts the rotational freedom of the hinge seat 8 within the groove 11, ensuring its position remains fixed after installation. This, in turn, guarantees that the four U-shaped cavities maintain a precise cross-shaped distribution, ensuring accurate impact point location detection. Simultaneously, the polygonal design facilitates the positioning and installation of the hinge seat 8, improving assembly efficiency.

[0041] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included within the protection scope of this patent application.

Claims

1. A piezoelectric pressure sensor for drop location visualization, characterized by Includes a base, a piezoelectric element located at the bottom of the base, and a stage with a ball bearing on top of the base; The base has four U-shaped cavities arranged in a cross shape along the circumference; each U-shaped cavity includes a first cavity located inside the base, a second cavity exposed on the outside of the base, and a connecting cavity connecting the first cavity and the second cavity; the volume of the first cavity is much larger than the volume of the second cavity; the first cavity, the second cavity, and the connecting cavity are all filled with liquid; The first cavity has a piston rod that is elastically movably extended from the top of the base; the top of the piston rod has a piston ball head; the piston ball head movably abuts against the bottom surface of the platform. The first cavity is equipped with a return spring; the two ends of the return spring abut against the bottom of the piston rod and the bottom wall of the first cavity, respectively. The base is circumferentially embedded with four U-shaped seats arranged in a cross shape; one end of each U-shaped seat is embedded in the base, and the other end of each U-shaped seat is exposed on the outside of the base; each U-shaped seat is embedded with a U-shaped glass tube made of transparent or semi-transparent material. The U-shaped glass tube includes an integrally formed first tube body, a second tube body, and a connecting tube; the first tube body is embedded in one end of the U-shaped seat, and the second tube body is embedded in the other end of the U-shaped seat with its outer side exposed outside the U-shaped seat; the two ends of the connecting tube are respectively connected to the bottom of the first tube body and the bottom of the second tube body. The first cavity, the second cavity, and the connecting cavity are respectively disposed inside the first tube, the second tube, and the connecting tube; A coordinate system is established with the straight line containing two relatively distributed U-shaped cavities as the X-axis and the straight line containing two other relatively distributed U-shaped cavities as the Y-axis. The geometric center of the stage is used as the origin of the coordinate system. The bearing surface of the stage is divided into four quadrant regions to provide a reference for the positioning of the landing point.

2. A piezoelectric pressure sensor for drop position visualization according to claim 1, characterized in that The piston rod has a receiving hole at its bottom; the upper end of the return spring is inserted into the receiving hole.

3. A piezoelectric pressure sensor for drop position visualization according to claim 1, characterized in that The other end of the U-shaped seat has a scale marking line on one side of the second tube.

4. A piezoelectric pressure sensor with visualized impact point location according to claim 1, characterized in that, The base has a groove at its top; a hinge seat is provided in the groove; a ball joint is provided at the center of the hinge seat; a spherical head is provided at the center of the bottom surface of the platform; the spherical head is hinged to the ball joint.

5. A piezoelectric pressure sensor with visualized impact point location according to claim 4, characterized in that, The groove is a polygonal structure; the hinge seat is correspondingly set as a polygonal structure.

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