A high-precision four-column sensor

Abstract

A kind of high-precision four-column sensor, it is related to weighing sensor technical field, a kind of high-precision four-column sensor, from top to bottom include pressure head, steel ball, upper weighing seat, elastomer, lower weighing seat and bottom plate in order, steel ball is located between pressure head and upper weighing seat, and the contact surface of pressure head and upper weighing seat with steel ball is concave cambered surface, elastomer is located between upper weighing seat and lower weighing seat, elastomer is integrally machined with upper weighing seat and lower weighing seat, elastomer quantity is four and is evenly distributed in 2*2 matrix, strain gauge is pasted on elastomer, recess is provided on the top surface of lower weighing seat, recess is located between four elastomers, digital module is provided in recess, and signal line is provided on the side of lower weighing seat.The sensor of the utility model is integrally machined with the whole structure, without any assembly gap, precision is guaranteed by processing, the whole structure has no stress weak point, and the rigidity significantly improves sensor service life.

Description

Technical Field

[0001] This utility model relates to the field of weighing sensor technology, and in particular to a high-precision four-column sensor. Background Technology

[0002] Existing four-column load cells used for weighbridges employ a separate assembly with four elastic columns fixed by bolts. In practical applications, this presents several problems: 1. Bolted connections have assembly gaps. Long-term exposure to vibration, impact, or temperature changes can cause these gaps to widen, leading to relative displacement of the columns, directly compromising the steel ball centering reference and reducing sensor measurement accuracy. 2. The connection points between the bolts and the columns / base are stress concentration points with low stiffness. Long-term use can lead to bolt loosening and fatigue deformation at the column roots, shortening the sensor's lifespan. 3. The separate assembly requires individual calibration of the coaxiality and perpendicularity of each column, resulting in a cumbersome assembly process (requiring at least 3-5 repeated adjustments), low production efficiency, and the potential for human error to introduce additional accuracy deviations. Furthermore, long-term use can easily lead to further deviations.

[0003] In addition, existing weighing sensors use analog electrical signals. Their basic principle is to convert the mechanical force generated by the weight of an object into a small deformation of an elastic body, and then convert the deformation into a measurable analog electrical signal through a strain gauge, which is then transmitted to the instrument. The problems are: 1. Analog signals are susceptible to interference (such as electromagnetic interference during transmission, which leads to a decrease in accuracy); 2. They are not directly compatible with digital devices (microcontrollers, PLCs), requiring additional external conversion circuits, which increases the complexity of the system; 3. They lack data storage and calibration functions, and cannot achieve secondary optimization of sensor data. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a high-precision four-column sensor. It adopts an integral structure that is machined in one piece, with no assembly gaps. The accuracy is guaranteed by the machining process. The overall structure has no stress weak points, which significantly improves rigidity and extends the sensor's service life.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A high-precision four-column sensor comprises, from top to bottom, a pressure head, a steel ball, an upper weighing seat, an elastic body, a lower weighing seat, and a base plate. The steel ball is located between the pressure head and the upper weighing seat, and the contact surfaces between the pressure head, the upper weighing seat, and the steel ball are concave arc surfaces, used to limit the movable steel ball.

[0007] The elastic body is located between the upper and lower weighing seats, and is integrally formed with both seats. There are four elastic bodies evenly distributed in a 2x2 matrix, and strain gauges are attached to each. The four elastic bodies are symmetrically distributed, uniformly bearing external forces. This structural design makes the sensor more evenly stressed in all directions, greatly enhancing its resistance to eccentric loads. For example, under eccentric pressure, the four columns work together to disperse the eccentric load, thus ensuring measurement accuracy. When the elastic body deforms under stress, the resistance of the strain gauges changes accordingly. These resistance changes are converted into electrical signals by a Wheatstone bridge circuit: for example, when the elastic body is under tension, the column elongates, and the strain gauge resistance increases; when under pressure, the column shortens, and the strain gauge resistance decreases. The changes in the electrical signal accurately reflect the magnitude and direction of the external force.

[0008] The top surface of the lower weighing base has a groove located between the four elastic bodies. A digital module is installed within the groove, and a signal line is provided on one side of the lower weighing base. The digital module adopts the latest AD conversion technology, can output 1 million codes, and has ESD protection for the interface, which can greatly reduce the damage rate of the interface. It also has reverse power connection protection, surge protection, electrostatic discharge protection up to 15KV, and lightning protection functions.

[0009] Preferably, the lower end or both ends of the elastomer are configured as a gradually increasing arc transition section. The arc transition structure at the transition point between the elastomer and the upper and lower weighing seats reduces stress concentration and improves structural rigidity.

[0010] Preferably, the cross-section of the elastomer is square, that is, the elastomer is a square column.

[0011] Preferably, the strain gauges are two or four in number, distributed on two or four opposite sides of the elastic body, and the strain gauges are symmetrically distributed on the elastic body.

[0012] Preferably, the elastic body is provided with a shell, the upper and lower ends of which are connected to the upper weighing base and the lower weighing base, respectively. The shell can be circular, square, or other shapes to suit different occasions, and is made of high-strength, corrosion-resistant materials or has been treated with anti-corrosion materials. This not only protects the internal structure but also reduces the impact of external factors on the sensor performance, such as waterproofing, dustproofing, and electromagnetic interference protection.

[0013] Preferably, a protective cover is provided outside the upper weighing seat, with the upper end of the cover extending to the top surface area outside the concave arc surface of the upper weighing seat, so as not to interfere with the steel ball.

[0014] The beneficial effects of this utility model are as follows: 1. It adopts an integral structure formed by one-piece processing, with no assembly gaps, and the precision is guaranteed by processing;

[0015] 2. The overall structure has no stress-prone points, significantly improving rigidity and extending the sensor's service life;

[0016] 3. There is no need to calibrate the coaxiality and perpendicularity of each column individually, the assembly process is simple, and deviations are not easily generated during long-term use;

[0017] 4. The digital module completes the AD conversion directly inside the sensor, and the sensor directly outputs digital signals, overcoming the shortcomings of analog sensors in the transmission of small analog signals that are easily interfered with, and enhancing the system's anti-interference capability.

[0018] 5. High measurement accuracy: The digital module adopts AD conversion technology and can output 1 million codes, which improves the resolution and stability of the signal and achieves a finer precision that traditional analog sensors cannot achieve.

[0019] 6. Easy to debug: The digital module has the function of automatically identifying and manually setting the type, quantity, and installation position of the sensor, and can also perform automatic / semi-automatic / manual angle difference correction, making debugging simple;

[0020] 7. High safety: The digital module interface has ESD protection, which can greatly reduce the damage rate of the interface. It also has reverse power connection protection to prevent damage to the digital sensor due to wiring errors. It also has power surge protection, electrostatic protection up to 15KV and lightning protection.

[0021] 8. Long transmission distance: The sensor and instrument use digital communication technology, such as RS485, with a communication distance of about 1,000 meters, which can realize long-distance measurement and control. Attached Figure Description

[0022] Figure 1 This is a front view (partial sectional view) of the present invention.

[0023] Figure 2 yes Figure 1 Sectional view along the AA direction.

[0024] Explanation of the main component symbols in the figure: 1. Pressure head; 2. Steel ball; 3. Upper weighing seat; 4. Elastic body; 4.1. Circular arc transition section; 5. Lower weighing seat; 5.1. Groove; 6. Base plate; 7. Strain gauge; 8. Digital module; 9. Signal line; 10. Housing; 11. Protective cover. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0026] Example 1: As Figure 1-2 As shown, a high-precision four-column sensor includes, from top to bottom, a pressure head 1, a steel ball 2, an upper weighing seat 3, an elastic body 4, a lower weighing seat 5, and a base plate 6.

[0027] The steel ball 2 is located between the pressure head 1 and the upper weighing seat 3, and the contact surfaces between the pressure head 1, the upper weighing seat 3 and the steel ball 2 are concave arc surfaces.

[0028] The elastic body 4 is located between the upper weighing seat 3 and the lower weighing seat 5. The elastic body 4 is integrally formed with the upper weighing seat 3 and the lower weighing seat 5. There are four elastic bodies 4, which are evenly distributed in a 2*2 matrix. Strain gauges 7 are attached to the elastic body 4.

[0029] The lower weighing seat 5 has a groove 5.1 on its top surface, which is located between the four elastic bodies 4. A digital module 8 is installed in the groove 5.1, and a signal line 9 is installed on one side of the lower weighing seat 5.

[0030] Example 2: Combination Figure 1-2 As shown, based on Embodiment 1, the lower end or both ends of the elastic body 4 are configured as a gradually increasing arc transition section 4.1.

[0031] Example 3: Combination Figure 2 As shown, based on Embodiment 1 or Embodiment 2, the cross-section of the elastomer 4 is square.

[0032] Example 4: Combination Figure 2 As shown, based on Embodiment 3, the number of strain gauges 7 is two or four, distributed on two or four opposite sides of the elastic body 4.

[0033] Example 5: Combination Figure 1-2 As shown, based on the above embodiment, the elastic body 4 is provided with a shell 10, and the upper and lower ends of the shell 10 are respectively connected to the upper weighing base 3 and the lower weighing base 5. The shell 10 can be circular, square, or other shapes to suit different occasions, and is made of high-strength, corrosion-resistant materials or has its surface treated with anti-corrosion treatment. It not only protects the internal structure, but also reduces the influence of external factors on the sensor performance, such as waterproofing, dustproofing, and electromagnetic interference prevention.

[0034] The upper weighing seat 3 is provided with a protective cover 11, the upper end of which extends to the top surface area outside the concave arc surface of the upper weighing seat 3.

[0035] The above description is only a specific embodiment of the present utility model, but the structural features of the present utility model are not limited thereto. The present utility model can be used in similar products. Any changes or modifications made by those skilled in the art within the scope of the present utility model are covered by the patent scope of the present utility model.

Claims

1. A high-precision four-column sensor, characterized in that: From top to bottom, it includes a pressure head (1), a steel ball (2), an upper weighing seat (3), an elastic body (4), a lower weighing seat (5), and a base plate (6). The steel ball (2) is located between the pressure head (1) and the upper weighing seat (3), and the contact surfaces of the pressure head (1) and the upper weighing seat (3) with the steel ball (2) are concave arc surfaces; The elastic body (4) is located between the upper weighing seat (3) and the lower weighing seat (5). The elastic body (4) is integrally formed with the upper weighing seat (3) and the lower weighing seat (5). There are four elastic bodies (4) and they are evenly distributed in a 2*2 matrix. Strain gauges (7) are attached to the elastic body (4). The top surface of the lower weighing seat (5) is provided with a groove (5.1), the groove (5.1) is located between the four elastic bodies (4), a digital module (8) is provided in the groove (5.1), and a signal line (9) is provided on one side of the lower weighing seat (5).

2. The high-precision four-column sensor according to claim 1, characterized in that: The lower end or both ends of the elastomer (4) are configured as a circular arc transition section (4.1) with gradually increasing size.

3. A high-precision four-column sensor according to claim 1, characterized in that: The cross-section of the elastomer (4) is square.

4. A high-precision four-column sensor according to claim 3, characterized in that: The strain gauges (7) are in the number of two or four, distributed on two or four opposite sides of the elastic body (4).

5. A high-precision four-column sensor according to any one of claims 1-4, characterized in that: The elastic body (4) is provided with a shell (10), and the upper and lower ends of the shell (10) are respectively connected to the upper weighing seat (3) and the lower weighing seat (5).

6. A high-precision four-column sensor according to any one of claims 1-4, characterized in that: The upper weighing seat (3) is provided with a protective cover (11), the upper end of which extends to the top surface area outside the concave arc surface of the upper weighing seat (3).

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