Spraying machine with high-precision flow display and monitoring method

Abstract

The invention discloses a high-precision flow display spraying machine, which comprises a motor, a plunger pump, an MCU (Microprogrammed Control Unit) controller assembly, a pressure sensor and a Hall sensing device, and is characterized in that the motor drives the plunger pump to work through a gear mechanism, and the gear mechanism adopts a fixed transmission ratio gear structure; the Hall sensing device is installed in the motor and transmits the motor rotating speed obtained in real time to the MCU controller assembly, and the pressure sensor is connected with the plunger pump and transmits the plunger pump conveying pressure obtained in real time to the MCU controller assembly. The invention further discloses a monitoring method adopting the spraying machine. The complex fluid mechanics and mechanical dynamics problems of non-Newtonian fluid are converted into a reliable software model based on a large amount of experimental data. A user can obtain an accurate measurement result comparable to that of a direct flow meter only by carrying out simple medium selection without knowing a complex back principle, and all reliability advantages brought by no flow meter are enjoyed at the same time.

Description

Technical Field

[0001] This invention relates to the field of spray painting machine technology, and in particular to a spray painting machine with high-precision flow display and a monitoring method thereon. Background Technology

[0002] Traditional spray painting machines, when directly measuring fluid flow rate using external flow meters, suffer from high flow meter failure rates, short lifespans, measurement channel blockages, difficult equipment cleaning and maintenance, and high costs due to the high pressure, high viscosity, and easy curing characteristics of the coating medium. Furthermore, existing simple indirect calculation schemes suffer from accuracy deficiencies: some schemes that rely solely on motor speed for theoretical calculations or only consider pressure compensation neglect the impact of pump speed on valve opening and closing efficiency, as well as the decisive influence of medium viscosity on leakage rate and valve response speed. This results in significant measurement errors across all operating conditions (especially under different media, high pressure, and low speed conditions), failing to meet the demands of precise construction. Therefore, improvements are urgently needed. Summary of the Invention

[0003] The purpose of this invention is to solve the problems mentioned in the background art and to provide a spraying machine and monitoring method with high-precision flow display.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A high-precision flow rate display spraying machine includes a motor and a plunger pump. The motor drives the plunger pump through a gear mechanism. The gear mechanism adopts a fixed transmission ratio gear structure and also includes an MCU controller assembly, a pressure sensor, and a Hall effect sensor. The Hall effect sensor is installed in the motor and transmits the acquired motor speed to the MCU controller assembly in real time. The pressure sensor is installed and connected to the plunger pump and transmits the acquired plunger pump delivery pressure to the MCU controller assembly in real time.

[0005] In the above-mentioned high-precision flow display spraying machine, the Hall sensor is connected to the MCU controller assembly via a circuit. The Hall sensor includes a Hall circuit board and a sensing magnetic ring. The Hall circuit board is mounted on the motor housing, and the sensing magnetic ring is mounted on the motor shaft and corresponds to the position of the Hall sensor on the Hall circuit board. The Hall sensor obtains the motor speed by sensing the sensing magnetic ring.

[0006] In the above-mentioned high-precision flow display spraying machine, the pressure sensor is connected to the MCU controller assembly via a circuit. The plunger pump has a high-pressure delivery pipe, and the pressure sensor is installed at the high-pressure delivery pipe to obtain the material delivery pressure in real time.

[0007] In the above-mentioned high-precision flow display spraying machine, the MCU controller assembly is equipped with a display screen.

[0008] This invention also provides a high-precision flow rate monitoring method for a spraying machine, including the aforementioned spraying machine. The MCU controller assembly pre-stores identifiers and corresponding rheological parameter parameters for several commonly used spraying media. Simultaneously, a dedicated dynamic volumetric efficiency model is pre-stored for each medium. This model is a two-dimensional lookup table or fitting function that takes real-time acquired (P, N_pump) as input and η_v as output. These models are calibrated by comparing measured data from a high-precision flow meter under different pressures, speeds, and media to construct an accurate, multi-parameter coupled dynamic volumetric efficiency model (η_v). The actual output flow rate (Q_actual) is equal to the product of the theoretical flow rate (Q_theoretical) and the dynamically changing volumetric efficiency (η_v), i.e.: Q_actual = Q_theoretical * η_v. The specific steps are as follows: User input: Before operation, the operator selects the type of spraying medium to be used from the preset list through the user input interface on the MCU controller assembly. This operation is essentially selecting the preset rheological characteristic parameters and dynamic volumetric efficiency model corresponding to the current medium for the system. Real-time data acquisition: The MCU controller assembly obtains the motor speed (N_motor) in real time through the Hall sensor on the motor, and obtains the system pressure (P) in real time through the pressure sensor. Theoretical flow calculation: The MCU controller assembly performs calculations based on the fixed transmission ratio (i) of the motor, calculating the actual reciprocating speed of the plunger pump: N_pump = N_motor / i; and calculating the theoretical flow rate: Q_theoretical = N_pump * V_per_rev, where V_per_rev is the fixed displacement of the pump per reciprocation. Dynamic volumetric efficiency query and correction: The MCU controller assembly automatically calls the corresponding dynamic volumetric efficiency model based on the medium type selected by the user. It takes the real-time collected pressure (P) and pump speed (N_pump) as input, queries the two-dimensional lookup table specific to the medium or substitutes it into the fitting function, and calculates the accurate volumetric efficiency value η_v under the current operating conditions in real time. This value has comprehensively reflected the coupled influence of pressure, pump speed and rheological characteristics of the medium at a specific viscosity on efficiency. Actual flow calculation and output: Finally, the high-precision real-time flow rate is calculated as: Q_actual = Q_theoretical * η_v; the MCU controller assembly sends the Q_actual value to the display unit for real-time and accurate display.

[0009] Effects of the invention: This invention transforms complex fluid dynamics and mechanical dynamics problems involving non-Newtonian fluids into a reliable software operating model. Users do not need to understand the complex underlying principles; they only need to select a simple medium to obtain measurement results comparable to those of a direct flow meter.

[0010] It retains all the advantages of eliminating the external flow meter: high reliability, long lifespan, easy cleaning, and low cost.

[0011] It achieves unprecedented measurement accuracy: by introducing three core parameters—pressure, pump speed, and viscosity—to dynamically correct the volumetric efficiency of the plunger pump, the flow calculation model can truly reflect complex working conditions, and the measurement accuracy is far superior to any existing indirect calculation scheme.

[0012] It has a wide range of media adaptability: users can select different media (such as water-based paint, oil-based paint, high-viscosity anti-corrosion coating, thinner, etc.) through the interface, and the system can automatically call up the corresponding viscosity parameters and efficiency models, so that one device can accurately adapt to a variety of spraying materials, greatly expanding the application range of the equipment.

[0013] It enhances the product's intelligence and user experience: by hiding the complex physical model in the background and providing an extremely simple "medium selection" operation in the front end, it makes professional measurement functions user-friendly and easy to use for ordinary workers, lowering the technical threshold. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a perspective view of the present invention; Figure 2 This is a cross-sectional view of the present invention. Detailed Implementation

[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this specification are for illustrative purposes only and do not represent the only possible implementation.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0019] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0021] Please see Figure 1 , Figure 2 The present invention provides a high-precision flow display spraying machine, including a motor 1 and a plunger pump 2. The motor 1 drives the plunger pump 2 through a gear mechanism 3. The gear mechanism 3 adopts a fixed transmission ratio gear structure. The machine also includes an MCU controller assembly 4, a pressure sensor 5, and a Hall sensor 6. The Hall sensor 6 is installed in the motor 1 and transmits the acquired motor speed to the MCU controller assembly 4 in real time. The pressure sensor 5 is installed and connected to the plunger pump 2 and transmits the acquired plunger pump 2 material delivery pressure to the MCU controller assembly 4 in real time.

[0022] Furthermore, the Hall sensor 6 is connected to the MCU controller assembly 4 via a circuit. The Hall sensor 6 includes a Hall circuit board 7 and a sensing magnetic ring 8. The Hall circuit board 7 is mounted on the housing of the motor 1, and the sensing magnetic ring 8 is mounted on the rotating shaft 1-1 of the motor 1 and corresponds to the position of the Hall sensor on the Hall circuit board 7. The Hall sensor obtains the rotation speed of the motor 1 by sensing the sensing magnetic ring 8.

[0023] Furthermore, the pressure sensor 5 is connected to the MCU controller assembly 4 via a circuit. The plunger pump 2 has a high-pressure delivery pipe 9, and the pressure sensor 5 is installed at the high-pressure delivery pipe 9 to obtain the material delivery pressure in real time.

[0024] Furthermore, the MCU controller assembly 4 is equipped with a display screen 10.

[0025] A high-precision flow rate monitoring method for a spraying machine includes the aforementioned spraying machine. The MCU controller assembly pre-stores identifiers and corresponding rheological parameter parameters for several commonly used spraying media. Simultaneously, a dedicated dynamic volumetric efficiency model is pre-stored for each medium. This model is a two-dimensional lookup table or fitting function that takes real-time acquired (P, N_pump) as input and η_v as output. These models are calibrated by comparing measured data from a high-precision flow meter under different pressures, speeds, and media to construct an accurate, multi-parameter coupled dynamic volumetric efficiency model (η_v). The actual output flow rate (Q_actual) is equal to the product of the theoretical flow rate (Q_theoretical) and the dynamically changing volumetric efficiency (η_v), i.e.: Q_actual = Q_theoretical * η_v. The specific steps are as follows: User input: Before operation, the operator selects the type of spraying medium to be used from the preset list through the user input interface on the MCU controller assembly. This operation is essentially selecting the preset rheological characteristic parameters and dynamic volumetric efficiency model corresponding to the current medium for the system. Real-time data acquisition: The MCU controller assembly obtains the motor speed (N_motor) in real time through the Hall sensor on the motor, and obtains the system pressure (P) in real time through the pressure sensor. Theoretical flow calculation: The MCU controller assembly performs calculations based on the fixed transmission ratio (i) of the motor, calculating the actual reciprocating speed of the plunger pump: N_pump = N_motor / i; and calculating the theoretical flow rate: Q_theoretical = N_pump * V_per_rev, where V_per_rev is the fixed displacement of the pump per reciprocation. Dynamic volumetric efficiency query and correction: The MCU controller assembly automatically calls the corresponding dynamic volumetric efficiency model based on the medium type selected by the user. It takes the real-time collected pressure (P) and pump speed (N_pump) as input, queries the two-dimensional lookup table specific to the medium or substitutes it into the fitting function, and calculates the accurate volumetric efficiency value η_v under the current operating conditions in real time. This value has comprehensively reflected the coupled influence of pressure, pump speed and rheological characteristics of the medium at a specific viscosity on efficiency. Actual flow calculation and output: Finally, the high-precision real-time flow rate is calculated as: Q_actual = Q_theoretical * η_v; the MCU controller assembly sends the Q_actual value to the display unit for real-time and accurate display.

[0026] The core of this invention lies in its first explicit proposal and resolution of the complex influence of non-Newtonian fluid media on volumetric efficiency. Unlike traditional models for Newtonian fluids such as water, the coatings and paints used in spraying are mostly non-Newtonian fluids, whose viscosity (μ) is not constant but varies with shear rate (related to pump speed) and pressure. This results in three key variables affecting volumetric efficiency (η_v): system pressure (P), pump speed (N_pump), and medium viscosity (μ), i.e.: η_v = f(P,N_pump, μ).

[0027] Effect of pressure (P): Increased pressure exacerbates the compressibility effect of the medium and leakage within the pump body, leading to a decrease in η_v.

[0028] The effect of pump speed (N_pump): Changes in speed directly affect the opening and closing response speed and duration of the inlet and outlet valves. Speed ​​mismatch can cause valves to fail to close completely in time (causing backflow) or open fully (causing insufficient filling), thus significantly reducing η_v.

[0029] The Influence of Medium Viscosity (μ) (A Further Explanation of This Point): 1. Valve opening and closing delay: The higher the viscosity of the medium, the greater its internal friction, and the greater the resistance to the movement of the check valve (ball valve) inside the pump, resulting in a delay in the valve's closing action. This delay directly increases the backflow time from the high-pressure chamber to the low-pressure chamber, causing serious flow loss. Therefore, under the same pressure and speed, the higher the viscosity, the lower the volumetric efficiency ηv is usually.

[0030] 2. Non-Newtonian fluid characteristics: The shear thinning (pseudoplasticity) properties of coatings and paints mean that their apparent viscosity changes dynamically with the shear rate during pump operation. This creates a coupling relationship between viscosity (μ) and pump speed (N_pump), a complex interaction that traditional models cannot describe.

[0031] 3. The double-edged sword effect of internal leakage: Although high-viscosity media have poor flowability, they can reduce leakage in the precision fit clearances within the pump to some extent; while low-viscosity media, although easy to flow, will have more severe internal leakage. The model of this invention scientifically determined the relationship between pressure and leakage at different viscosities through experiments.

[0032] Therefore, through extensive preliminary experimental calibration, this invention establishes different two-dimensional efficiency characteristic maps based on (P, N_pump) for media with different rheological properties, and converts them into functions or lookup tables stored in the MCU. During system operation, by monitoring P and N_pump in real time and combining them with the viscosity parameter μ corresponding to the media type selected by the user, the current accurate η_v value can be dynamically obtained, thereby calculating the actual flow rate with high precision.

[0033] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0034] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the patent protection scope of the present invention should be determined by the appended claims.

Claims

1. A high-precision flow rate display spraying machine, comprising a motor (1) and a plunger pump (2), wherein the motor (1) drives the plunger pump (2) to work via a gear mechanism (3), characterized in that: The gear mechanism (3) adopts a fixed transmission ratio gear structure and also includes an MCU controller assembly (4), a pressure sensor (5), and a Hall sensor (6). The Hall sensor (6) is installed at the tail of the motor (1) and transmits the acquired motor (1) speed to the MCU controller assembly (4) in real time. The pressure sensor (5) is installed and connected to the plunger pump (2) and transmits the acquired plunger pump (2) material conveying pressure to the MCU controller assembly (4) in real time.

2. The high-precision flow rate display spraying machine according to claim 1, characterized in that: The Hall sensor (6) is connected to the MCU controller assembly (4) via a line. The Hall sensor (6) includes a Hall circuit board (7) and a sensing magnetic ring (8). The Hall circuit board (7) is mounted on the motor (1) housing. The sensing magnetic ring (8) is mounted on the motor (1) shaft (1-1) and corresponds to the position of the Hall sensor on the Hall circuit board (7). The Hall sensor obtains the rotation speed of the motor (1) by sensing through the sensing magnetic ring (8).

3. A high-precision flow rate display spraying machine according to claim 1, characterized in that: The pressure sensor (5) is connected to the MCU controller assembly (4) via a line. The plunger pump (2) has a high-pressure delivery pipe (9). The pressure sensor (5) is installed at the high-pressure delivery pipe (9) and obtains the material delivery pressure in real time.

4. A high-precision flow rate display spraying machine according to claims 1 to 3, characterized in that: The MCU controller assembly (4) is equipped with a display screen (10).

5. A high-precision flow rate monitoring method for a spraying machine, characterized in that: The spraying machine described in claims 1 to 4 has several commonly used spraying media identifiers and their corresponding rheological characteristic parameters pre-stored in the MCU controller assembly. Simultaneously, a dedicated dynamic volumetric efficiency model is pre-stored for each medium. This model is a two-dimensional lookup table or fitting function that takes real-time acquired (P, N_pump) as input and η_v as output. These models are calibrated by comparing measured data from high-precision flow meters under different pressures, speeds, and media to construct an accurate, multi-parameter coupled dynamic volumetric efficiency model (η_v). Its actual output flow rate (Q_actual) is equal to the product of the theoretical flow rate (Q_theoretical) and the dynamically changing volumetric efficiency (η_v), i.e.: Q_actual = Q_theoretical * η_v; the specific steps are as follows: User input: Before operation, the operator selects the type of spraying medium to be used from the preset list through the user input interface on the MCU controller assembly. This operation is essentially selecting the preset rheological characteristic parameters and dynamic volumetric efficiency model corresponding to the current medium for the system. Real-time data acquisition: The MCU controller assembly obtains the motor speed (N_motor) in real time through the Hall sensor on the motor, and obtains the system pressure (P) in real time through the pressure sensor. Theoretical flow calculation: The MCU controller assembly performs calculations based on the fixed transmission ratio (i) of the motor, calculating the actual reciprocating speed of the plunger pump: N_pump = N_motor / i; and calculating the theoretical flow rate: Q_theoretical = N_pump * V_per_rev, where V_per_rev is the fixed displacement of the pump per reciprocation. Dynamic volumetric efficiency query and correction: The MCU controller assembly automatically calls the corresponding dynamic volumetric efficiency model based on the medium type selected by the user. It takes the real-time collected pressure (P) and pump speed (N_pump) as input, queries the two-dimensional lookup table specific to the medium or substitutes it into the fitting function, and calculates the accurate volumetric efficiency value η_v under the current operating conditions in real time. This value has comprehensively reflected the coupled influence of pressure, pump speed and rheological characteristics of the medium at a specific viscosity on efficiency. Actual flow calculation and output: Finally, the high-precision real-time flow rate is calculated as: Q_actual = Q_theoretical * η_v; the MCU controller assembly sends the Q_actual value to the display unit for real-time and accurate display.

Images