A method and system for measuring height difference by levitation

Abstract

The application discloses a floating type height difference measurement method and system, which is used for high-precision acquisition of height difference between product edge surface and inner cavity surface. The method comprises the following steps: placing a calibration block in a calibration groove of a floating platform, and completing zero point calibration by using a sensing probe to contact the lower surface of the calibration block; taking out the calibration block, placing a product, and making the edge surface of the product adhere to a limiting step; starting a pressing assembly to press the product, so that the floating platform and the product sink synchronously until the inner cavity surface of the product contacts the sensing probe, and a measurement signal is acquired; calculating a height difference value based on the calibration and measurement signals and outputting a judgment result; and through the common use of the same floating platform and the fixed sensing probe, one-time calibration and multi-point synchronous sampling are realized, repeated zero setting is not needed, micro-displacement and elastic deformation errors caused by multiple clamping are effectively eliminated, and the measurement precision and efficiency are significantly improved.

Description

Technical Field

[0001] This application relates to the technical field of testing methods, specifically to the technical field of a floating height difference measurement method and system. Background Technology

[0002] In the precision manufacturing of 3C electronic products, the step height formed by the bending and springback of the back shell frame is a key dimension affecting the flatness of the overall assembly. Currently, production lines generally use contact displacement sensors or laser rangefinders for detection, but their measurement methods still follow the traditional single-point zeroing, measurement, and re-measurement mode after movement.

[0003] However, this mode requires resetting the measurement point to zero or relying on mechanical positioning for repetitive operations each time the measurement point is switched. This not only prolongs the cycle time, but also introduces uncertainties such as micro-displacement and elastic rebound due to multiple clamping, resulting in distortion of the relative height data between multiple points and making it impossible to simultaneously obtain the height difference between multiple points.

[0004] Therefore, there is an urgent need for a measurement method that integrates product support, clamping and positioning, zero-point calibration and multi-point height sampling into the same workstation and continuous process, so as to achieve height difference detection with one calibration, synchronous measurement and no need for repeated zeroing. Summary of the Invention

[0005] This application proposes a floating height difference measurement method and system, which can obtain the height difference between the edge surface and the inner cavity surface of the product with high precision in a single clamping without repeated zeroing or moving of the product.

[0006] To achieve the above objectives, the present application adopts the following technical solution: In a first aspect, this application proposes a method for measuring the height difference by buoyancy, comprising the following steps: Step S1: Place the calibration block in the calibration slot on the floating platform. The calibration slot is flush with the limiting step of the floating platform. The limiting step is used to support the edge surface of the product. Step S2: The sensing probe contacts the lower surface of the calibration block to acquire the first height sensing signal and complete the zero-point calibration; Step S3: Take out the calibration block and place the product to be tested on the floating platform, so that the edge of the product fits against the limiting step; Step S4: Activate the pressing assembly to press the product from top to bottom, so that the floating platform sinks synchronously under the action of the return spring until the inner cavity surface of the product contacts the sensing probe and obtains the second height sensing signal; Step S5: Calculate the height difference between the inner cavity surface and the edge surface based on the first height sensing signal and the second height sensing signal; Step S6: Output the height difference value and determine whether it is within the preset tolerance range.

[0007] Thus, compared to the existing single-point successive measurement mode, this application integrates calibration and measurement on the same floating platform and a shared sensing probe, achieving single-point zero-point calibration, multi-point synchronous sampling, and eliminating the need for repeated zeroing. During the pressing process of the pressure assembly, the floating platform, in conjunction with the reset spring, adaptively sinks to ensure that the inner cavity surface and edge surface are measured in a stress-free deformation state, effectively eliminating the micro-displacement and elastic deformation errors introduced by multiple clamping.

[0008] In some possible implementations, prior to step S3, an automatic measurement program is triggered via the control panel, and the system automatically detects whether the calibration block has been removed.

[0009] In some possible implementations, the floating platform is provided with multiple calibration slots, each corresponding to a multiple measurement position of the product; in step S2, zero-point calibration is performed on each calibration slot synchronously or sequentially, and in step S4, the second height sensing signals of multiple inner cavity surfaces are acquired synchronously.

[0010] In some possible implementations, in step S4, the clamping force of the pressing assembly is monitored in real time; when the clamping force reaches a preset threshold, the pressing is stopped.

[0011] Secondly, this application also proposes a buoyancy-based height difference measurement system, configured to perform the buoyancy-based height difference measurement method as described above, including: The machine body is equipped with an operating table; A floating platform is located above the operating table. It has a limiting step for positioning the edge surface of the product, a calibration groove flush with the limiting step, and a through hole penetrating the middle of the calibration groove. A pressing assembly, located above the floating platform, is used to press down on the product; A sensing probe, the tip of which passes through the through hole and is fixedly exposed above the through hole, is used to contact the inner cavity surface of the product or the lower surface of the calibration block; A mounting plate is used to mount the sensing probe; A suspension column, with its upper end fixed to the operating table and its lower end connected to the fixing plate, is used to suspend and fix the sensing probe. The control unit is electrically connected to the sensing probe.

[0012] In some possible implementations, a base plate is provided below the floating platform, and multiple guide pins and multiple return springs are provided between the floating platform and the base plate for guiding and providing elastic return force.

[0013] In some possible implementations, a drive cylinder is also included for driving the pressing assembly to move up and down; the drive cylinder is connected to the pressing assembly via a connecting joint.

[0014] In some possible implementations, guide posts are also provided on both sides of the connecting joint, the guide posts being mounted on the machine body via linear bearings for vertically guiding the pressing assembly during driving.

[0015] In some possible implementations, a control panel is also included, which is electrically connected to the control unit, for displaying measurement results, receiving start commands, and triggering alarm prompts. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of the buoyancy-type height difference measurement system in this application; Figure 2 yes Figure 1 Enlarged view of a portion of point A in the middle; Figure 3 This is a side sectional view of the buoyancy height difference measurement system in this application; Figure 4 yes Figure 3 Enlarged view of a portion of point B in the middle; Figure 5 This is a front sectional view of the buoyancy height difference measurement system in this application; Figure 6 yes Figure 5 Enlarged view of a portion of point C in the middle; Figure 7 This is an overall schematic diagram of the product in this application; Figure 8 yes Figure 7 A magnified view of a portion of point D in the middle. Detailed Implementation

[0017] The following examples further illustrate the features of this application and other related features in detail, so as to facilitate understanding by those skilled in the art: It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions in the attached diagrams, while the terms “bottom surface,” “top surface,” “inner,” and “outer” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0018] Furthermore, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this case based on the specific circumstances.

[0019] First, the measurement system used in the floating height difference measurement method of this application will be described. The floating height difference measurement system in this application is used for high-precision step height detection of back covers of 3C electronic products. Please refer to... Figures 6 to 8 The product 100 is typically a framed structure formed by bending metal or composite materials. There is a height difference L between its edge surface 101 and inner cavity surface 102. This dimension directly affects the appearance flatness and structural stability of the assembled machine.

[0020] Please refer to Figure 1 The floating height difference measurement system of this application includes a body 200, which is fixed to a control base 500 to form a stable working platform. The body 200 is provided with an operating table 201, which is specifically set at the upper end of the control base 500.

[0021] Further, please refer to Figure 1 and Figure 2 The machine body 200 has a drive cylinder 4 at its top, the lower end of which is connected to the pressing assembly 3 via a connecting joint 5, and the upper end is connected to an external air source interface 300 for pneumatic drive. When working, the cylinder 4 pushes the pressing assembly 3 to move vertically, completing the pressing action on the product 100. Preferably, the connecting joint 5 is a universal joint, and guide posts 6 are provided on both sides of the connecting joint 5. The guide posts 6 pass through linear bearings 61 and are installed at the upper end of the machine body 200, thereby ensuring that the pressing assembly 3 maintains vertical guidance during lifting and lowering, avoiding deviation or shaking, and improving the stability and repeatability of the pressing process. Preferably, the linear bearing 61 has a flange structure for easy installation.

[0022] Please refer to the reference. Figures 3 to 6 The pressing assembly 3 consists of an upper pressing plate 31 and a lower pressing plate 32. The projected area of ​​the upper pressing plate 31 is smaller than that of the lower pressing plate 32, resulting in a gradual expansion of the pressure surface from the connecting joint 5 to the lower pressing plate 32. Simultaneously, the surface of the upper pressing plate 31 is provided with an adjustment groove 33, allowing for fine-tuning of its position according to the dimensions of different product models, thus improving the equipment's versatility. The lower pressing plate 32 adopts a double-layer structure, with the upper and lower plates connected by bolts, enhancing overall rigidity and helping to evenly distribute the pressure from the upper pressing plate 31, preventing elastic deformation of the pressing mechanism itself.

[0023] Furthermore, in the lower direction, a base plate 2 is provided at the upper end of the operating table 201, and a floating platform 1 that can be raised and lowered vertically is provided on the base plate 2. Multiple guide pins 21 and return springs 22 are provided between the base plate 2 and the floating platform 1. In this embodiment, four guide pins 21 are used at the four corners. Specifically, the guide pins 21 and return springs 22 are installed on the base plate 2. The guide pins 21 serve to limit and guide the floating platform 1 between the floating platform 1 and the base plate 2, ensuring that the floating platform 1 can only move vertically. The return springs 22 provide upward elastic support, giving the floating platform 1 a certain buoyancy characteristic. The number of return springs 22 can be increased or decreased according to the size of the product 100 and measurement requirements. It should be noted that in this embodiment, "buoyancy" refers to the floating platform 1 adaptively fitting with the product 100 under the action of the return springs during the measurement process, and its dynamic adjustment capability relative to the initial position. It does not mean that the floating platform 1 actively moves upward; the actual direction of movement is downward pressure from the pressure material assembly 3.

[0024] When product 100 is placed on floating platform 1 and pressed down by pressure assembly 3, floating platform 1 automatically adapts and conforms to the bottom of product 100 under the action of spring force, eliminating measurement errors caused by improper clamping. Furthermore, product 100 can also sink and float with floating platform 1, providing conditions for measuring height differences. Simultaneously, when pressure assembly 3 moves upward after measurement, return spring 22 lifts floating platform 1, making it easier to retrieve product 100.

[0025] Furthermore, the upper end of the floating platform 1 is provided with a limiting step 13 for engaging the edge surface 101 of the product 100, forming a reliable positioning contact with the bent edge of the product 100 to prevent the product from slipping during measurement. Simultaneously, the inner side of the floating platform 1 is provided with multiple calibration slots 11 flush with the limiting step 13. The bottom of these calibration slots 11 is at the same level as the limiting step 13, and can be used to place a calibration block 8 as a zero-point reference, achieving zero-point calibration before measurement. In specific applications, multiple calibration slots 11 are set according to the characteristics of the product 100 and measurement requirements, allowing simultaneous measurement at different positions. A through hole 12 is provided in the middle of the calibration slot 11 for the sensing probe 7 to pass through, with its front end directly contacting the calibration block 8 or the inner cavity surface 102 of the product 100 to collect height data.

[0026] The calibration block 8 can be customized to different sizes according to the shape of the calibration slot 11, ensuring that its lower surface fits snugly against the bottom of the calibration slot 11, thereby guaranteeing calibration accuracy. The sensing probe 7 is an inductive displacement sensor, with its front contact passing through the through hole 12 and exposed above it. The sensing probe 7 is rigidly mounted on the fixing plate 71, which is suspended below the operating table 201 by the suspension column 72. The upper end of the suspension column 72 is fixed to the operating table 201, and the lower end is connected to the fixing plate 71, forming a stable suspension structure. In this way, the sensing probe 7 remains stationary relative to the operating table 201 throughout the measurement process, without the need for any driving mechanism to move it, fundamentally eliminating the repeatability error and dynamic disturbance introduced by probe movement.

[0027] Furthermore, the control unit is electrically connected to the drive cylinder 4 and the sensing probe 7, and is configured to perform the aforementioned measurement method. In actual operation, the operator can start the measurement program through the control panel 510 set on the control base 500. The control panel 510 is equipped with a start switch 520, an indicator light 530, a buzzer 540, and an emergency switch 550 for human-machine interaction and safety control.

[0028] In this technical respect, a floating height difference measurement method of this application includes the following steps. Step S1: Place the calibration block 8 in the calibration slot 11 on the floating platform 1. The calibration slot 11 is flush with the limiting step 13 of the floating platform 1. The limiting step 13 is used to support the edge surface 101 of the product 100.

[0029] Step S2: The sensing probe 7 contacts the lower surface of the calibration block 8 to acquire the first height sensing signal and complete the zero-point calibration; Step S3: The calibration block 8 is removed, and the product 100 to be tested is placed on the floating platform 1, so that the edge surface 101 of the product 100 is in contact with the limiting step 13; Step S4: The pressing assembly 3 is activated to press the product 100 from top to bottom, so that the floating platform 1 sinks synchronously under the action of the return spring 22 until the inner cavity surface 102 of the product 100 contacts the sensing probe 7 and acquires the second height sensing signal; Step S5: The height difference value of the inner cavity surface 102 relative to the edge surface 101 is calculated based on the first height sensing signal and the second height sensing signal; Step S6: The height difference value is output and it is determined whether it is within the preset tolerance range.

[0030] Specifically, the calibration block 8 is first placed into the calibration slot 11 on the floating platform 1. The calibration block 8 can be a standard part of different specifications customized according to the shape of the calibration slot 11, ensuring that its lower surface is on the same horizontal reference plane as the limiting step 13. Since the front end of the sensing probe 7 is already fixed and exposed above the through hole 12, after the calibration block 8 is in place, its lower surface naturally contacts the sensing probe 7. Without any driving mechanism, the first height sensing signal can be obtained, completing the zero-point calibration. This design avoids the repetitive positioning error introduced by probe movement in traditional solutions.

[0031] After calibration and before placing product 100, the operator can trigger the automatic measurement program via control panel 510. The system will then automatically detect whether there are still calibration blocks 8 remaining in calibration tank 11; if they are detected and not removed, the system will prevent the next stage from proceeding and will issue an audible and visual warning via buzzer 540 to improve equipment operation safety.

[0032] Subsequently, the product 100 to be tested is placed on the floating platform 1, ensuring its edge surface 101 accurately fits against the limiting step 13, achieving reliable initial positioning. Next, the pressing assembly 3 is activated, driven by the cylinder 4 to move downwards, pressing the product 100. During this process, the product 100 and the floating platform 1 sink synchronously, compressing the return spring 22. Because the floating platform 1 can only move vertically under the guidance of the guide pin 21, its sinking process can adapt to the bottom shape of the product 100, achieving stress-free fitting and avoiding elastic deformation caused by rigid clamping.

[0033] During the pressing process, the system monitors the clamping force applied by the pressing component 3 in real time. This clamping force can be collected by the pressure sensor built into the drive cylinder 4 or by an external force sensor. When the clamping force reaches a preset threshold, the control unit immediately stops the drive cylinder 4 to prevent overpressure from causing elastic deformation of the product 100.

[0034] As the pressure assembly 3 continues to press down, the inner cavity surface 102 of the product 100 gradually approaches and eventually contacts the fixed sensing probe 7, at which point a second height sensing signal is acquired. The height sensing signal output by the sensing probe 7 is amplified and converted from analog to digital by the size amplifier 400 before being transmitted to the control unit. The control unit calculates the height difference between the inner cavity surface 102 and the edge surface 101 based on the difference between the first height sensing signal (calibrated value) and the second height sensing signal (measured value), and outputs the judgment result.

[0035] When the floating platform 1 is equipped with multiple calibration slots 11, zero-point calibration can be performed on each calibration slot 11 sequentially or simultaneously in one process. During the pressing stage, the second height sensing signals of multiple inner cavity surfaces 102 are acquired simultaneously, realizing a one-time measurement of the height difference at multiple points. This method not only significantly improves detection efficiency, but also significantly enhances the consistency between multi-point data by sharing the same reference and sensing path, avoiding the cumulative error in traditional multi-point step-by-step measurement.

[0036] Thus, by integrating calibration and measurement at the same workstation, sharing the fixed sensing probe 7, and utilizing the adaptive sinking characteristics of the floating platform 1, this method achieves high-precision drop detection without repeated zeroing or moving the product 100, fully meeting the needs of 3C manufacturing production lines for efficient and stable online measurement.

[0037] As stated above, this case protects a floating height difference measurement method and system, and all technical solutions that are the same as or similar to this case should be considered to fall within the scope of protection of this case.

Claims

1. A method for measuring the height difference using a floating mechanism, characterized in that, Includes the following steps: Step S1: Place the calibration block (8) in the calibration slot (11) on the floating platform (1), the calibration slot (11) being flush with the limiting step (13) of the floating platform (1), the limiting step (13) being used to support the edge surface (101) of the product (100). Step S2: The sensing probe (7) contacts the lower surface of the calibration block (8) to obtain the first height sensing signal and complete the zero-point calibration; Step S3: Take out the calibration block (8), place the product to be tested (100) on the floating platform (1), and make the edge surface (101) of the product (100) fit against the limiting step (13). Step S4: Start the pressing assembly (3) to press the product (100) from top to bottom, so that the floating platform (1) sinks synchronously under the action of the return spring (22) until the inner cavity surface (102) of the product (100) contacts the sensing probe (7) to obtain the second height sensing signal; Step S5: Calculate the height difference between the inner cavity surface (102) and the edge surface (101) based on the first height sensing signal and the second height sensing signal; Step S6: Output the height difference value and determine whether it is within the preset tolerance range.

2. The buoyancy-based height difference measurement method as described in claim 1, characterized in that, Before step S3, the automatic measurement program is triggered through the control panel (510), and the system automatically detects whether the calibration block (8) has been removed.

3. The buoyancy-based height difference measurement method as described in claim 1, characterized in that, The floating platform (1) is provided with multiple calibration slots (11), which correspond to multiple measurement positions of the product (100). In step S2, zero-point calibration is performed on each calibration slot (11) synchronously or sequentially, and in step S4, the second height sensing signals of multiple inner cavity surfaces (102) are acquired synchronously.

4. The buoyancy-based height difference measurement method as described in claim 1, characterized in that, In step S4, the clamping force of the pressing component (3) is monitored in real time; when the clamping force reaches a preset threshold, the pressing is stopped.

5. A buoyancy-type height difference measurement system, characterized in that, For performing the height difference measurement method as described in any one of claims 1 to 4, comprising: The main body (200) is provided with an operating table (201); A floating platform (1) is located above the operating table (201), and is provided with a limiting step (13) for positioning the edge surface (101) of the product (100), a calibration groove (11) flush with the limiting step (13), and a through hole (12) penetrating the middle of the calibration groove (11). The pressing assembly (3) is located above the floating platform (1) and is used to press down the product (100). The sensing probe (7), whose front end passes through the through hole (12) and is exposed above the through hole (12), is used to contact the inner cavity surface (102) of the product (100) or the lower surface of the calibration block (8); A mounting plate (71) is used to mount the sensing probe (7); A suspension column (72) is fixed at its upper end to the operating table (201) and at its lower end to the fixing plate (71) to suspend and fix the sensing probe (7); The control unit is electrically connected to the sensing probe (7).

6. The buoyancy-type height difference measurement system as described in claim 5, characterized in that, The floating platform (1) is provided with a base plate (2) below it. Multiple guide pins (21) and multiple return springs (22) are provided between the floating platform (1) and the base plate (2) for guiding and providing elastic return force.

7. The buoyancy-type height difference measurement system as described in claim 5, characterized in that, It also includes a drive cylinder (4) for driving the pressing assembly (3) to move up and down; the drive cylinder (4) is connected to the pressing assembly (3) through a connecting joint (5).

8. The buoyancy-type height difference measurement system as described in claim 7, characterized in that, It also includes guide posts (6) disposed on both sides of the connecting joint (5), the guide posts (6) being mounted on the machine body (200) via linear bearings (61) for vertically guiding the pressing assembly (3) during the driving process.

9. The buoyancy-type height difference measurement system as described in claim 5, characterized in that, It also includes a control panel (510), which is electrically connected to the control unit and is used to display measurement results, receive start commands, and trigger alarm prompts.

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