An electric-powered loader bucket material mass measuring system

Abstract

The utility model discloses a kind of electric loader shovel material quality measuring systems, belong to loader technical field.The system solves the technical problem of big implementation difficulty, low precision caused by existing method relying on oil pressure measurement and complex mechanism mechanics analysis.Its technical scheme includes: in the four positions of loader front and rear axle and chassis connection, respectively arrange a set of quality dynamic monitoring device, each set of device is by upper connecting plate, lower connecting plate, strain sensing element, strain gauge assembly, strain processing circuit and computing processing module composition;Strain gauge assembly adopts eight strain gauges and is arranged orthogonally on square sensing element, and is connected by unique series connection pair of arms full-bridge circuit;Computing processing module calculates vertical force according to bridge output signal, and the difference of four sets of device total vertical force under no-load and load state is converted material quality.The utility model has the advantages of accurate measurement, strong anti-interference, simple structure, low cost, convenient for popularization and application.

Description

Technical Field

[0001] This utility model relates to the field of loader technology, and in particular to a material mass measurement system for the bucket of an electric loader. Background Technology

[0002] Electric loaders are indispensable equipment in engineering construction, and their main function is to load and transport materials. In actual operation, accurately grasping the weight of the material in the bucket is crucial for controlling the loading capacity of transport vehicles, avoiding overloading or underloading, and achieving refined operation management.

[0003] Currently, the mainstream method for measuring the material mass in the bucket of electric loaders is based on monitoring the hydraulic pressure of the lifting or tipping cylinders, combined with a complex mechanical model analysis of the loading mechanism, to indirectly deduce the material mass. However, this method has significant limitations: First, the mechanical analysis model itself is quite complex, requiring precise structural parameters such as the positions of numerous hinge points, component dimensions, and weights of the loader beforehand, making the modeling work tedious and demanding in terms of expertise. Second, the pressure in the hydraulic system is easily affected by various factors such as oil temperature, leakage, and internal friction, which impacts the stability and accuracy of the measurement signal. These factors make this technology difficult to implement in practice, lacking in universality, and difficult to guarantee measurement accuracy.

[0004] Therefore, there is an urgent need in this field for a measurement system that is simple in structure, easy to install, not constrained by complex mechanism models, and can stably and accurately reflect the bucket load directly, so as to overcome the shortcomings of existing technologies and meet the urgent needs of practical engineering applications. Utility Model Content

[0005] The purpose of this invention is to overcome the problems in the prior art and provide a material quality measurement system for the bucket of an electric loader.

[0006] The technical concept of this invention lies in directly measuring the vertical force on the axles by arranging dynamic monitoring devices at four connection points between the front and rear axles and the chassis of the loader. This device utilizes a uniquely arranged strain gauge array to form a full-bridge circuit, accurately calculating the total weight of the entire vehicle's superstructure by sensing the micro-strain of the load-bearing components between the chassis and the axles. By comparing the difference in total weight under no-load and loaded conditions, the mass of material in the bucket can be quickly and directly calculated, thus eliminating the need for complex structural force analysis and hydraulic pressure measurement.

[0007] To achieve the above-mentioned utility model objectives, the present utility model adopts the following technical solution: a material quality measurement system for the bucket of an electric loader, comprising four sets of identical dynamic quality monitoring devices, which are respectively arranged on the left side of the front axle, the right side of the front axle, the left side of the rear axle, and the right side of the rear axle of the electric loader at positions connected to the chassis.

[0008] Each of the aforementioned quality dynamic monitoring devices includes an upper connecting plate, a lower connecting plate, a strain sensing element, a strain gauge assembly, a strain processing circuit, and a calculation processing module;

[0009] The upper connecting plate is used to connect the electric loader chassis, the lower connecting plate is used to connect the electric loader axle, and the strain sensing element is disposed between the upper connecting plate and the lower connecting plate.

[0010] The strain gauge assembly consists of multiple metal foil strain gauges, which are attached to multiple sides of the strain sensing element.

[0011] The strain processing circuit connects the strain gauges in the strain gauge assembly in a Wheatstone bridge configuration.

[0012] The calculation and processing module is electrically connected to the strain processing circuit and is used to calculate the vertical force acting on the strain sensing element based on the output signal of the bridge.

[0013] Furthermore, the strain sensing element has a square structure. This square structure gives the strain sensing element symmetrical and stable mechanical properties, solving the problem of measurement inaccuracy caused by uneven stress distribution when irregularly shaped elements are subjected to force. This provides a stable and reliable strain field for the strain gauge, ensuring the accuracy of the vertical force measurement benchmark.

[0014] Furthermore, the strain gauge assembly includes eight identical metal foil strain gauges. Strain gauges R1, R2, R3, and R4 are attached to the front, rear, left, and right planes of the strain sensing element, respectively, along a direction perpendicular to the upper connecting plate. Strain gauges R5, R6, R7, and R8 are attached to the front, rear, left, and right planes of the strain sensing element, respectively, along a direction parallel to the upper connecting plate. This specific arrangement allows the strain gauges to simultaneously sense the comprehensive strain of the sensing element in both the vertical and lateral directions. This lays the foundation for solving the problem that single-direction measurements cannot effectively compensate for the Poisson effect and interference from non-vertical loads, and provides comprehensive raw data for subsequent high-precision signal processing.

[0015] Furthermore, the specific connection method of the strain processing circuit is as follows: strain gauges R1 and R3 are connected in series, strain gauges R2 and R4 are connected in series, strain gauges R5 and R7 are connected in series, and strain gauges R6 and R8 are connected in series; the series-connected strain gauges R1 and R3 and the series-connected R2 and R4 are located on opposite arms of the bridge, and the series-connected R5 and R7 and the series-connected R6 and R8 are located on opposite arms of the bridge. This unique series-connected opposite-arm full-bridge circuit design can automatically cancel common-mode interference signals caused by factors such as temperature changes and slight off-center loads during the measurement process, effectively solving the problems of traditional measurement methods being easily affected by environmental factors and having unstable measurement accuracy, and significantly improving the anti-interference ability and accuracy of vertical force measurement.

[0016] Furthermore, the formula for calculating the vertical force F by the calculation processing module is as follows:

[0017]

[0018] Where: u o U is the output voltage of the bridge, μ is Poisson's ratio, K is the strain gauge sensitivity coefficient, E is the elastic modulus of the strain sensing element, and u is the strain gauge output voltage. s The power supply voltage to the bridge is given, and A represents the transverse cross-sectional area of ​​the strain sensing element. This calculation formula establishes a direct and accurate physical and mathematical model between the bridge output and the vertical force, solving the problems of large errors and cumbersome implementation caused by relying on force analysis of complex mechanisms and empirical conversion. This makes the measurement results more objective, accurate, and easier to standardize.

[0019] Furthermore, the calculation and processing module is configured to: obtain the mass of the material in the bucket by calculating the difference between the sum of the vertical forces measured by the four sets of dynamic quality monitoring devices after scooping material and the sum of the vertical forces measured when unloaded, and dividing by the acceleration due to gravity. This method indirectly obtains the mass of the material in the bucket by measuring the overall weight change of the entire vehicle system under unloaded and loaded conditions, cleverly solving the problem of difficulty in directly measuring the force on the bucket. It achieves a simple, fast, and non-contact accurate measurement of the mass of the material in the bucket, greatly improving the practicality and operability of the system.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] 1. This utility model achieves direct and comprehensive measurement of the total vertical force exerted on the axles by the entire vehicle's superstructure by arranging dynamic quality monitoring devices at four key points connecting the front and rear axles of the electric loader to the chassis. By comparing the difference in total vertical force under no-load and loaded conditions, the material mass is calculated. This method abandons the traditional indirect approach relying on complex mechanism force analysis and hydraulic pressure measurement, thus solving the problems of high implementation difficulty and poor universality in existing technologies. The operation is simpler and more intuitive, and the accuracy is significantly improved.

[0022] 2. The core strain gauge assembly of this utility model adopts a unique spatial arrangement and a series-connected full-bridge circuit design. This design enables the measurement system to synchronously sense and automatically compensate for measurement errors caused by factors such as temperature changes and off-center loading, effectively solving the problems of unstable accuracy and weak anti-interference ability of traditional sensors under complex working conditions, thereby greatly improving the accuracy and reliability of vertical force measurement at various positions of the front and rear axles.

[0023] 3. The entire measurement system has a clear structure, and its core sensing components are low-cost and stable in performance. Its principle of directly measuring force signals avoids cumbersome modeling and parameter calibration, making system construction, installation, and maintenance very convenient and highly practical. This not only significantly reduces the overall cost of the system but also lays a solid foundation for its widespread promotion and application in the field of engineering machinery. Attached Figure Description

[0024] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0025] Figure 1 This is a schematic diagram of the structural principle of the quality dynamic monitoring device of this utility model.

[0026] Figure 2 This is a schematic diagram of the layout structure of the quality dynamic monitoring device of this utility model.

[0027] Figure 3 This is a schematic diagram of the strain gauge assembly arrangement scheme of this utility model.

[0028] Figure 4 This is a schematic diagram of the strain processing circuit of this utility model.

[0029] The attached diagram is labeled as follows: 1. Upper connecting plate; 2. Lower connecting plate; 3. Strain sensing element; 4. Strain gauge assembly; 5. Strain processing circuit; 6. Calculation processing module. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are only for explaining this utility model and are not intended to limit it.

[0031] Example

[0032] See Figures 1 to 4This embodiment provides a material mass measurement system for an electric loader bucket. The core design idea of ​​this system is to abandon the traditional method of indirectly estimating material mass by measuring cylinder pressure and relying on complex mechanical analysis, and instead adopt a more direct and reliable measurement path: that is, by directly measuring the total vertical force acting on the front and rear axles of the loader's entire superstructure (including the cab, counterweight, bucket, and material, etc.), and calculating the difference between this total vertical force under no-load and loaded conditions, the mass of the material in the bucket can be directly calculated.

[0033] To achieve the above objectives, the system of this utility model includes four sets of identical dynamic quality monitoring devices. The arrangement of these four devices is fundamental to the system's comprehensive and accurate measurement capabilities. They are respectively installed on the left side of the front axle, the right side of the front axle, the left side of the rear axle, and the right side of the rear axle of the electric loader—key stress points above the four wheel suspensions connected to the chassis beam. By simultaneously measuring at these four support points, the total weight of the entire vehicle's superstructure can be comprehensively captured, effectively avoiding measurement errors caused by vehicle posture, uneven road surfaces, or uneven loading.

[0034] Each quality dynamic monitoring device is an independent unit integrating sensing, signal conditioning, and processing. Its core components include: upper connecting plate 1, lower connecting plate 2, strain sensing element 3, strain gauge assembly 4, strain processing circuit 5, and calculation processing module 6. The specific structure, connection relationship, and function of each component will be described in detail below.

[0035] The upper connecting plate 1 is the interface component between the device and the loader chassis structure. It is typically a thick rectangular steel plate, securely connected to the chassis beam of the electric loader using high-strength bolts. Its function is to provide a stable and reliable mounting base and to evenly distribute the load transmitted from the chassis to the sensing element below.

[0036] The lower connecting plate 2 is the interface component between the device and the axle structure, and its material and structural strength are similar to those of the upper connecting plate 1. It is connected to the axle of the electric loader by high-strength bolts (or to the axle through a transition structure). The upper connecting plate 1 and the lower connecting plate 2 are arranged parallel in space, forming a stable force transmission path, ensuring that the pressure from the chassis can be transmitted vertically and without eccentricity or bending moment interference to the core force measuring element.

[0037] The strain sensing element 3 is the most critical force-to-electricity conversion component in this device. It is precisely installed between the upper connecting plate 1 and the lower connecting plate 2, directly bearing the vertical load from top to bottom. In this embodiment, the element is preferably a square structure made of alloy structural steel with high elastic modulus, good linearity, and low creep characteristics. The square structure is chosen because it possesses symmetrical and stable mechanical properties, with consistent stiffness in all directions, ensuring a uniform and predictable strain field under load. This design effectively solves the measurement nonlinearity and inaccuracy problems caused by stress concentration or uneven distribution in irregularly shaped elements under load, providing a stable and reliable reference plane for subsequent strain measurements.

[0038] The strain gauge assembly 4, as the core component for sensing strain, directly determines the measurement accuracy and anti-interference capability through its design and arrangement. This assembly consists of eight identical metal foil strain gauges, numbered R1 to R8. The placement of these eight strain gauges is carefully designed:

[0039] Strain gauges R1, R2, R3, and R4 are attached sequentially to the center positions of the front, back, left, and right sides of the strain sensing element 3, respectively, along a direction perpendicular to the upper connecting plate 1 (i.e., the main force direction). They are mainly used to sense axial strain caused by vertical force.

[0040] Strain gauges R5, R6, R7, and R8 are attached sequentially along the direction parallel to the upper connecting plate 1 (i.e., laterally) to the center positions of the front, back, left, and right sides of the strain sensing element 3. They are mainly used to sense the lateral strain caused by the Poisson effect, as well as any possible minute lateral disturbance forces.

[0041] This orthogonal, omnidirectional spatial arrangement allows the strain gauge assembly to synchronously and comprehensively sense strain information from the sensing elements in the main force direction and its orthogonal directions. This lays a solid foundation for obtaining higher bridge output sensitivity and compensating for vertical off-center load interference, providing comprehensive and reliable raw data for subsequent high-precision, high-stability signal processing.

[0042] The strain gauge processing circuit 5 is a key component for signal extraction and primary processing. It connects the eight strain gauges using an innovative Wheatstone bridge connection, specifically as follows:

[0043] Strain gauges R1 and R3 are connected in series to form a branch of the bridge circuit.

[0044] Strain gauges R2 and R4 are connected in series to form another branch of the bridge circuit, and this branch is located on the opposite arm of the (R1+R3) branch of the bridge.

[0045] Strain gauges R5 and R7 are connected in series to form the third branch of the bridge circuit.

[0046] Strain gauges R6 and R8 are connected in series to form the fourth branch of the bridge circuit, and this branch is located on the opposite arm of the bridge along with the (R5+R7) branch.

[0047] This unique "series-connected arm" full-bridge circuit design is the core of the system's high precision. Its advantages are: firstly, the full-bridge circuit itself has the highest sensitivity; secondly, the series design allows strain gauges on the same branch (such as R1 and R3) to automatically compensate for interference signals caused by minor vertical force offsets; and thirdly, the full-bridge arrangement gives the bridge extremely high common-mode rejection capability against common-mode interference such as temperature changes and minor creep of the elastic element itself. This effectively solves the problem that traditional sensors or simple bridge circuits are easily affected by environmental temperature fluctuations and uneven load distribution under complex working conditions, leading to unstable measurement accuracy and large zero-point drift, thus significantly improving the anti-interference capability and long-term stability of vertical force measurement.

[0048] The calculation and processing module 6 is the "brain" of the system, typically consisting of a microprocessor, an analog-to-digital converter, and necessary memory and interface circuitry. It is electrically connected to the strain processing circuit 5, responsible for receiving the real-time output voltage signal from the bridge circuit and performing calculations based on a preset physical mathematical model. The formula for calculating the vertical force F acting on a single strain sensing element 3 is as follows:

[0049]

[0050] Where: u o The output voltage of the bridge is μ, Poisson's ratio is K, strain gauge sensitivity coefficient is E, and elastic modulus of strain sensing element 3 is u. s The voltage supplied to the bridge is A, where A represents the transverse cross-sectional area of ​​the strain sensing element.

[0051] When measuring the material mass of an electric loader bucket using the material mass measurement system provided by this utility model, firstly, when the electric loader bucket is stationary after being lifted off the ground, the vertical forces of four sets of dynamic quality monitoring devices arranged at the connection points between the left and right sides of the front and rear axles and the chassis of the electric loader are measured. Then, the vertical forces measured at the four locations are summed as the initial vertical force of the electric loader's superstructure. Next, when the material is removed and the bucket remains stationary, the vertical forces of the four sets of dynamic quality monitoring devices arranged at the connection points between the left and right sides of the front and rear axles and the chassis of the electric loader are measured again. Then, the vertical forces measured at the four locations are summed as the vertical force of the superstructure containing the removed material. Finally, the vertical force of the material is obtained by subtracting the initial vertical force of the superstructure from the vertical force of the superstructure containing the removed material. Dividing this vertical force by the gravitational acceleration gives the mass of the material in the bucket.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A material mass measurement system for an electric loader bucket, characterized in that, It includes four sets of identical quality dynamic monitoring devices, which are respectively arranged on the left side of the front axle, the right side of the front axle, the left side of the rear axle, and the right side of the rear axle of the electric loader at the position where they are connected to the chassis; Each of the aforementioned quality dynamic monitoring devices includes an upper connecting plate (1), a lower connecting plate (2), a strain sensing element (3), a strain gauge assembly (4), a strain processing circuit (5), and a calculation processing module (6); The upper connecting plate (1) is used to connect the electric loader chassis, the lower connecting plate (2) is used to connect the electric loader axle, and the strain sensing element (3) is disposed between the upper connecting plate (1) and the lower connecting plate (2). The strain gauge assembly (4) is composed of multiple metal foil strain gauges and is attached to multiple sides of the strain sensing element (3); The strain processing circuit (5) connects the strain gauges in the strain gauge assembly (4) in a Wheatstone bridge configuration. The calculation processing module (6) is electrically connected to the strain processing circuit (5) and is used to calculate the vertical force acting on the strain sensing element (3) based on the output signal of the bridge.

2. The material mass measurement system for an electric loader bucket according to claim 1, characterized in that, The strain sensing element (3) has a square structure.

3. The material mass measurement system for an electric loader bucket according to claim 1, characterized in that, The strain gauge assembly (4) includes eight identical metal foil strain gauges, wherein strain gauges R1, R2, R3 and R4 are attached to the front, back, left and right planes of the strain sensing element (3) in a direction perpendicular to the upper connecting plate (1), and strain gauges R5, R6, R7 and R8 are attached to the front, back, left and right planes of the strain sensing element (3) in a direction parallel to the upper connecting plate (1).

4. The material mass measurement system for an electric loader bucket according to claim 3, characterized in that, The specific connection method of the strain processing circuit (5) is as follows: strain gauge R1 and strain gauge R3 are connected in series, strain gauge R2 and strain gauge R4 are connected in series, strain gauge R5 and strain gauge R7 are connected in series, and strain gauge R6 and strain gauge R8 are connected in series; the series-connected strain gauges R1 and R3 and R2 and R4 are located on opposite arms of the bridge, and the series-connected R5 and R7 and R6 and R8 are located on opposite arms of the bridge.

5. The material mass measurement system for an electric loader bucket according to claim 1, characterized in that, The formula for calculating the vertical force F by the calculation module (6) is as follows: Where: u o The output voltage of the bridge is μ, Poisson's ratio is K, strain gauge sensitivity coefficient is E, and elastic modulus of strain sensing element 3 is u. s The voltage supplied to the bridge is A, which represents the transverse cross-sectional area of ​​the strain sensing element 3.

6. The material mass measurement system for an electric loader bucket according to claim 1, characterized in that, The calculation processing module (6) is configured to: obtain the mass of the material in the bucket by calculating the difference between the sum of the vertical forces measured by the four sets of dynamic quality monitoring devices after digging the material and the sum of the vertical forces measured when unloaded, and dividing it by the gravitational acceleration.

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