A stone pressing module mechanism for a stone composition detector

Abstract

The utility model discloses a kind of stone pressing module mechanisms for stone composition detector, including stepper motor assembly, buffer sleeve assembly, linear bearing assembly, stone pressing assembly and stand assembly. Its core is, spring is built-in in the buffer sleeve assembly, it is connected between stepper motor output end and stone pressing assembly, the position control of stepper motor is converted into constant voltage control to stone sample. When working, stepper motor drive pressing head contact sample continue to press down a predetermined stroke, make the spring in buffer sleeve be compressed, generate and keep a stable preset pressure based on hooke's law. The method is through mechanical passive constant voltage principle, position feedback is combined with photoelectric switch, realizes the accurate, self-adapting control of pressure, effectively avoids rigid impact, ensures that stone sample is pressed constant in infrared spectrum analysis process, significantly improves the accuracy and reliability of detection result.

Description

Technical Field

[0001] This utility model relates to a medical stone composition detection device, and more particularly to a stone pressing module mechanism for automated infrared spectral analysis of stones. Background Technology

[0002] Traditional medical stone composition analyzers require stone samples to be compressed into thin slices suitable for testing before performing infrared spectroscopy analysis. In existing technologies, sample compaction largely relies on manual operation or a simple motor-driven rigid pressure head mechanism. Manual compaction methods suffer from low efficiency, high labor intensity, and poor consistency in compaction force, severely impacting testing throughput and result reliability.

[0003] While existing automated stone compaction mechanisms reduce manpower to some extent, they still have significant drawbacks: most employ rigid transmission and position control, meaning a motor drives the compactor head to a preset, fixed position. This "hard contact" method cannot adapt to stone samples of varying sizes, shapes, or even slight height differences, easily leading to fluctuations in compaction force. Furthermore, gaps and wear in the transmission system, as well as plastic deformation of the sample itself, can cause pressure to become inconsistent during testing. Infrared spectroscopy is extremely sensitive to the compaction state of the sample; pressure instability directly causes baseline drift and changes in characteristic peak intensity, severely impacting the accuracy and repeatability of component analysis.

[0004] Therefore, there is an urgent need in the field for a stone-pressing module structure that can provide and maintain a constant and controllable pressing force for stone samples, so as to fundamentally improve the analytical accuracy and stability of stone composition analyzers. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, this utility model proposes a stone pressing module mechanism. The technical solution of this utility model is: A stone-pressing module mechanism for a stone composition analyzer includes a stepper motor assembly 2.1, a buffer sleeve assembly 2.2, a linear bearing assembly 2.3, a stone-pressing assembly 2.4, and a column assembly 2.5; The stepper motor assembly 2.1 is fixed on the column assembly 2.5, and its output shaft is connected to the input end of the buffer sleeve assembly 2.2; The output end of the buffer sleeve assembly 2.2 is connected to the sample pressure head 2.44 of the pressure stone assembly 2.4 via the guide shaft 2.31 of the linear bearing assembly 2.3; The buffer sleeve assembly 2.2 includes an inner buffer sleeve 2.21, an outer buffer sleeve 2.22, and an elastic element disposed between the two; the inner buffer sleeve 2.21 is fixedly connected to the output shaft of the stepper motor 2.11, and the outer buffer sleeve 2.22 is connected to the guide shaft 2.31; The pressure stone module mechanism compresses the elastic element by controlling the downward stroke of the stepper motor 2.11 after the sample pressure head 2.44 contacts the sample, so as to generate and maintain a constant pressure applied to the sample.

[0006] The elastic element is a rectangular spring 2.23.

[0007] The pressing stone assembly 2.4 further includes a photoelectric sensing unit for detecting the position of the pressing head. The photoelectric sensing unit includes a pressing head sensing plate 2.42 fixed on the guide shaft 2.31 or the stepper motor assembly 2.1 and a photoelectric switch 2.43 fixed on the column 2.51. The photoelectric switch 2.43 is used to detect the initial position of the sample pressing head 2.44 contacting the sample.

[0008] The control system of the stepper motor 2.11 uses the initial position detected by the photoelectric switch 2.43 as a reference to control the motor to continue moving down a preset compression stroke, which corresponds to the required sample pressure.

[0009] The linear bearing assembly 2.3 includes a linear bearing housing 2.32, a linear bearing 2.33, and a guide shaft 2.31; the linear bearing 2.33 is installed inside the linear bearing housing 2.32, and the guide shaft 2.31 passes through the linear bearing 2.33 and slides with it.

[0010] The column assembly 2.5 includes a column 2.51, a column base plate 2.52, a column adjusting block 2.53, and a column adjusting plate 2.54; the column adjusting block 2.53 and the column adjusting plate 2.54 are provided with adjusting mechanisms for fine-tuning the coaxiality of the linear bearing 2.33 and the guide shaft 2.31.

[0011] Compared with the prior art, the stone pressing module mechanism for a stone composition analyzer provided by this utility model has the following significant advantages: 1. Achieving constant pressure compaction significantly improves detection accuracy: This is the core effect of this invention. By utilizing the mechanical properties of the spring in the buffer sleeve assembly, the "position control" of the motor is transformed into "pressure control" of the sample. When the pressure head contacts the sample, the system applies and maintains a constant pressure by controlling the compression of the spring. This pressure does not fluctuate due to minute differences in sample size or mechanical vibration of the system, providing a stable and repeatable sample compaction state for infrared spectroscopy analysis, fundamentally ensuring the accuracy and reliability of the component analysis results.

[0012] 2. Excellent buffering and protection performance, improving equipment lifespan and sample integrity: The compression process of the spring is an effective energy absorption and buffering process. It can transform the rigid impact generated by the motor-driven downward pressure into a smooth and gentle pressurization, effectively avoiding the risk of brittle stone samples being crushed and splashing. At the same time, the buffering effect also significantly reduces the negative impact of impact loads on the stepper motor, transmission components, and linear bearings, improving the service life and long-term stability of the entire stone pressing module and even the testing equipment.

[0013] 3. Simplified control system, reduced cost, and improved reliability: This invention adopts a passive mechanical constant pressure principle, eliminating the need for complex pressure sensors and closed-loop feedback control algorithms. The motor only needs to perform two simple steps: "finding the contact point" and "pressing down the predetermined stroke," and the mechanical properties of the spring automatically ensure constant pressure. This results in a simple control system structure, rapid response, low cost, and avoids the instability factors that may arise from complex control algorithms, making the system more robust.

[0014] 4. Excellent self-adaptability and self-aligning ability ensure uniform pressure distribution: The spring element itself has a certain degree of radial and angular flexibility. When the sample surface is not perfectly flat or has a slight tilt, the spring's flexibility allows the sample indenter to produce a slight adaptive deflection, making the indenter surface better fit with the sample surface, thereby ensuring uniform pressure distribution and avoiding problems such as excessive local stress or uneven compaction, further improving the tablet compression quality.

[0015] 5. Compact structure, convenient adjustment, and easy maintenance: The entire module has a reasonable structural design and a high degree of modularity among its components. The adjustment mechanism in the column assembly can easily calibrate the coaxiality of the guide shaft and the linear bearing, ensuring motion accuracy. The buffer sleeve assembly, as an independent "compressible coupling," is easy to install and remove, and maintains well, especially when it is necessary to replace springs of different stiffness to adapt to different pressure requirements.

[0016] In summary, this utility model, by introducing a spring-based buffer sleeve assembly, has successfully solved the crucial technical challenge of "constant pressure compaction" in the detection of stone components with a simple, ingenious, low-cost, and highly reliable mechanical structure. It has brought about comprehensive and significant progress in improving analytical accuracy, protecting samples and equipment, and simplifying control logic. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the present invention and a sectional view of the buffer sleeve assembly (2.2). Figure 2 These are the front view and isometric view of the stepper motor assembly 2.1 and the stone pressing assembly 2.4 of this utility model; Figure 3This is an isometric view of the linear bearing assembly 2.3 of this utility model; Figure 4 These are the front view and isometric view of the column assembly 2.5 of this utility model; Figure 5 This is a flowchart of the pressure control method of this utility model.

[0018] Numbers in the attached drawings: Stepper motor assembly 2.1, buffer sleeve assembly 2.2, linear bearing assembly 2.3, pressure stone assembly 2.4, column assembly 2.5; Stepper motor 2.11, motor mounting base 2.12, inner buffer sleeve 2.21, outer buffer sleeve 2.22, rectangular spring 2.23, guide shaft 2.31, linear bearing seat 2.32, linear bearing 2.33, induction plate bracket 2.41, pressure head induction plate 2.42, photoelectric switch 2.43, sample pressure head 2.44, column 2.51, column base plate 2.52, column adjusting block 2.53, column adjusting plate 2.54, adjusting lug 2.55. Detailed Implementation

[0019] The following explanation, in conjunction with the accompanying drawings, further illustrates the points: like Figure 1 The present invention is illustrated in the schematic diagram and cross-sectional view of the buffer sleeve assembly 2.2, which includes the stepper motor assembly 2.1, the buffer sleeve assembly 2.2, the linear bearing assembly 2.3, the pressure stone assembly 2.4, and the column assembly 2.5.

[0020] The linear bearing assembly 2.3 is a fixed component, which contains an up-and-down transmission component. The stepper motor assembly 2.1 is a moving component. The linear bearing assembly 2.3 and the stepper motor assembly 2.1 can be quickly assembled and disassembled through the buffer sleeve assembly 2.2. The stone pressing assembly 2.4 completes the stone pressing action.

[0021] Buffer sleeve assembly 2.2: The inner buffer sleeve 2.21 is fixedly sleeved onto the output shaft of the stepper motor 2.11. Therefore, it rotates / moves up and down synchronously with the motor output shaft. Its function is to serve as one of the internal support components and the mounting base for the spring, transmitting the driving force of the motor to the spring. The outer buffer sleeve 2.22 is connected to the sample pressure head 2.44 at the end via the guide shaft 2.31. It is not directly fixed to the motor output shaft, but is sleeved outside the inner buffer sleeve 2.21. Its function is to serve as an external transmission component, ultimately transmitting the pressure generated by the spring to the sample pressure head 2.44. It can slide axially within a limited range on the inner buffer sleeve 2.21. A rectangular spring 2.23 is installed in the cavity between the inner buffer sleeve 2.21 and the outer buffer sleeve 2.22. The spring is pre-compressed between the inner and outer buffer sleeves, absorbing energy, providing cushioning, and maintaining constant pressure through its elastic deformation.

[0022] The function of the buffer sleeve assembly 2.2 is to convert the rigid rotary / linear output of the stepper motor 2.11 into controllable, buffered linear pressure.

[0023] The buffer sleeve assembly 2.2 can be understood as a "compressible coupling". One end (inner buffer sleeve) is connected to the power source (stepper motor), and the other end (outer buffer sleeve) is connected to the actuator (sample pressure head). The spring is the "elastic bridge" connecting these two ends.

[0024] like Figure 2 The following are the front view and isometric view of the stepper motor assembly 2.1 and the stone pressing assembly 2.4 of this utility model. Figure 3 The isometric view of the linear bearing assembly 2.3 of this utility model is shown.

[0025] Stepper motor assembly 2.1: The stepper motor 2.11 is embedded in the motor mounting base 2.12 and fixed to the side of the column 2.51, and the output shaft is connected to the buffer sleeve assembly 2.2.

[0026] Linear bearing assembly 2.3: The linear bearing 2.33 is embedded in the linear bearing seat 2.32 and fixed to the side of the column 2.51, with the guide shaft 2.31 passing through it to ensure vertical movement accuracy.

[0027] The pressing stone assembly 2.4: The sample pressing head 2.44 is fixed to the end of the guide shaft 2.31; the pressing head sensing plate 2.42 is mounted on the stepper motor assembly 2.1 via the sensing plate bracket 2.41, corresponding to the position of the photoelectric switch 2.43. The pressing head sensing plate 2.42 and the photoelectric switch 2.43 work together to provide crucial position feedback for the control system, ensuring the automation, reliability, and safety of the pressing stone action, and preventing motor overshoot or failure to press the stone into position.

[0028] The core of this invention lies in achieving passive constant pressure control through the rectangular spring 2.23 in the buffer sleeve assembly 2.2. The pressure is determined by the spring's compression (i.e., stroke), following Hooke's Law: F=k⋅x in: F represents the pressure applied to the stone sample; k is the spring constant (N / mm); x represents the compression stroke of the spring (mm).

[0029] like Figure 5 As shown, the pressure and stroke control methods are as follows: 1. Spring selection and preload setting Select an appropriate spring stiffness k based on the physical properties of the stone sample (hardness, brittleness, etc.) and the compaction pressure range required for spectral analysis (usually 10–50 N).

[0030] The spring is pre-compressed during installation to ensure that it has a certain initial pressure when it first contacts the sample, thus avoiding impact.

[0031] 2. Stepper Motor Control Strategy The stepper motor 2.11 adopts a position control mode, which indirectly controls the spring compression stroke x by controlling the number of steps the motor rotates.

[0032] The control system presets two key positions: Contact position: The sample indenter 2.44 is just in contact with the sample surface. At this time, the spring is not compressed and the pressure is zero.

[0033] Target pressure position: The motor continues to press down, and the spring is compressed to the set stroke x, generating the target pressure F.

[0034] 3. Photoelectric switch feedback and travel calibration The pressure head sensor 2.42 works in conjunction with the photoelectric switch 2.43 to detect the pressure head position in real time.

[0035] The system uses photoelectric switch signals to determine whether the "contact position" has been reached, and uses this as a reference point to calculate the subsequent compression stroke.

[0036] If there are differences in sample height, the system can automatically adjust the total pressure of the motor to ensure that the spring compression x is constant, thereby ensuring consistent pressure F.

[0037] 4. Pressure Adaptability The spring's flexibility allows the indenter to automatically fine-tune its angle when the sample surface is uneven or slightly tilted, achieving uniform compaction. The spring's continuous compression capacity compensates for mechanical transmission errors and sample size fluctuations, ensuring stable pressure throughout the testing process.

[0038] During operation, stepper motor 2.11 drives guide shaft 2.31 downward, causing sample indenter 2.44 to contact the stone sample. Once sample indenter 2.44 contacts the sample, stepper motor 2.11 continues to press down, compressing rectangular spring 2.23. Through elastic deformation, it absorbs the impact force, keeping the pressure on the sample constant. Indenter sensor 2.42 moves synchronously with guide shaft 2.31, and photoelectric switch 2.43 detects its position change in real time. After stone analysis is completed, stepper motor 2.11 reverses, rectangular spring 2.23 pushes inner buffer sleeve 2.21 and outer buffer sleeve 2.22 to reset, and sample indenter 2.44 lifts away from the sample.

[0039] like Figure 4 The front view and isometric view of the column assembly 2.5 of this utility model are shown.

[0040] Column assembly 2.5: Column 2.51 is fixed to column adjusting plate 2.54 via column base plate 2.52. During adjustment, loosen the hexagon socket head cap screws, move column adjusting block 2.53 and column adjusting plate 2.54 until the guide shaft 2.31 is strictly coaxial with the linear bearing 2.33, then tighten the locking screws. The adjusting lug 2.55 is fixed to the bottom surface of column adjusting plate 2.54.

[0041] The pressing module mechanism of this invention can also be applied to other fields that require pressing powder or small block solid samples into uniform thin sheets for analysis.

[0042] For example, in the pharmaceutical industry, it can be used to compress tablet intermediates for quality control of active pharmaceutical ingredients; in the field of polymer materials, it can be used to prepare polymer slices for composition or crystallinity analysis. In the field of food safety, it can be used to press and dry food samples for the detection of additives or contaminants.

[0043] In these application scenarios, the best constant pressure compaction effect for this type of sample can be achieved simply by adjusting the stiffness coefficient (k value) of the spring in the buffer sleeve assembly and the preset compression stroke (x value) of the stepper motor according to the typical physical characteristics (such as hardness and toughness) of the sample to be tested.

[0044] Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A stone-pressing module mechanism for a stone composition analyzer, characterized in that, It includes a stepper motor assembly (2.1), a buffer sleeve assembly (2.2), a linear bearing assembly (2.3), a pressure stone assembly (2.4), and a column assembly (2.5). The stepper motor assembly (2.1) is fixed on the column assembly (2.5), and its output shaft is connected to the input end of the buffer sleeve assembly (2.2); The output end of the buffer sleeve assembly (2.2) is connected to the sample pressure head (2.44) of the pressure stone assembly (2.4) via the guide shaft (2.31) of the linear bearing assembly (2.3); The buffer sleeve assembly (2.2) includes an inner buffer sleeve (2.21), an outer buffer sleeve (2.22), and an elastic element disposed between the two; the inner buffer sleeve (2.21) is fixedly connected to the output shaft of the stepper motor (2.11), and the outer buffer sleeve (2.22) is connected to the guide shaft (2.31); The pressing module mechanism compresses the elastic element by controlling the stepper motor (2.11) during the downward stroke after the sample indenter (2.44) contacts the sample, so as to generate and maintain a constant pressure applied to the sample.

2. The stone-pressing module mechanism according to claim 1, characterized in that, The elastic element is a rectangular spring (2.23).

3. The stone-pressing module mechanism according to claim 1 or 2, characterized in that, The pressing stone assembly (2.4) further includes a photoelectric sensing unit for detecting the position of the pressing head. The photoelectric sensing unit includes a pressing head sensing plate (2.42) fixed on the guide shaft (2.31) or the stepper motor assembly (2.1) and a photoelectric switch (2.43) fixed on the column (2.51). The photoelectric switch (2.43) is used to detect the initial position of the sample pressing head (2.44) contacting the sample.

4. The stone-pressing module mechanism according to claim 3, characterized in that, The control system of the stepper motor (2.11) uses the initial position detected by the photoelectric switch (2.43) as a reference to control the motor to continue moving down a preset compression stroke, which corresponds to the required sample pressure.

5. The stone-pressing module mechanism according to claim 1, characterized in that, The linear bearing assembly (2.3) includes a linear bearing housing (2.32), a linear bearing (2.33), and a guide shaft (2.31); the linear bearing (2.33) is installed in the linear bearing housing (2.32), and the guide shaft (2.31) passes through the linear bearing (2.33) and slides with it.

6. The stone-pressing module mechanism according to claim 5, characterized in that, The column assembly (2.5) includes a column (2.51), a column base plate (2.52), a column adjusting block (2.53), and a column adjusting plate (2.54); the column adjusting block (2.53) and the column adjusting plate (2.54) are provided with adjusting mechanisms for fine-tuning the coaxiality of the linear bearing (2.33) and the guide shaft (2.31).

Images