Bed screen hardness testing equipment and method

Abstract

The invention discloses a bed screen hardness test device and method, and the device comprises a test frame which is used for placing a bed screen to be tested; a plurality of test points are preset on the bed screen; the test pressure head is used for testing the hardness of each test point of the bed screen; the loading device is mounted on the test frame and connected with the test pressure head so as to drive and adjust the test position of the test pressure head and collect load-displacement data of each test point; and the control unit is respectively connected with the test framework, the test pressure head and the loading device. The test frame, the test pressure head and the loading device are reasonably arranged, so that the load-displacement data of each test point of the bed screen can be accurately acquired, and the hardness of the bed screen can be evaluated according to the load-displacement data, so that the hardness test effect of the bed screen can be improved, and the test efficiency is improved. The problems that in the prior art, a testing method is not standard, subjectivity is high, real working conditions cannot be reflected, and testing equipment is poor in positioning precision and repeatability are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bed screen testing, in particular to a bed screen softness and hardness testing device and method. BACKGROUND

[0002] With the improvement of residents' living standards and the enhancement of national health awareness, bed screen products are increasingly widely used in home bedroom and other scenarios. As the basis and core furniture of the bedroom space, its comfort and support have become important indicators for consumers when making a purchase.

[0003] Among them, the softness and hardness matching relationship of the bed screen directly affects the lying comfort, waist and back support effect and fatigue when sitting and lying for a long time, and has become one of the key factors in consumers' purchase decisions.

[0004] Currently, there is no perfect systematic technical standard and unified evaluation standard for the testing and evaluation of bed screen softness and hardness in the industry. The evaluation method is still mainly based on subjective experience, that is, relying on manual touch, pressing and lying test, and then giving qualitative description such as "soft", "medium" and "hard" according to experience. This method is greatly influenced by factors such as sample individual difference, experience posture, psychological expectation, etc., and has problems such as inconsistent caliber, strong subjectivity, incomparable and non-reproducible results, which makes it difficult to support the research and development, production, testing and marketing of the upstream and downstream of the industry chain, and is not conducive to the optimization of product structure and quality control of enterprises. This situation not only leads to product homogenization competition and uneven quality, but also to a certain extent restricts the application and iteration of ergonomics design methods in the industry, making it difficult to provide transparent and verifiable purchasing basis for consumers, and is not conducive to the high-quality development of bed screen products.

[0005] In order to improve the above problems, some institutions in the industry have tried to introduce existing methods in the mattress field, that is, using a universal pressure testing machine with a flat or circular pressure head, and placing the bed screen on a rigid plane after being removed from the bed frame for compression test. However, the bed screen is usually installed at a certain angle on the bed frame in actual use, and is in a slope support state. This kind of test method simplifies the bed screen as horizontal placement, and the loading direction is fixed as "perpendicular to the plane", which is difficult to reflect the stress and deformation characteristics of the bed screen under the real slope working condition.

[0006] At the same time, the contact geometry between the commonly used flat or simple circular pressure head and the surface of the bed screen does not match the actual contact state of the human shoulder, back and waist, and the edge of the pressure head is easy to cause indentation or even damage to the surface fabric, stitches or binding of the bed screen during repeated loading process.

[0007] In addition, since the headboard is simply placed flat on the test table and the pressure head only compresses in a straight line in the vertical direction, the test equipment has insufficient freedom of spatial posture and limited ability to cover the test position on the headboard surface. In particular, it is difficult to conduct stable and repeatable loading tests on curved areas such as the upper edge of the headboard and the rounded corner transition section. Temporary support or repeated adjustment of the clamping method is often required, which is cumbersome and makes it difficult to guarantee positioning accuracy and repeatability.

[0008] With the continuous expansion of the bedroom space consumer market and the rapid development of personalized, online, and customized home furnishing production and sales models, the testing and evaluation of headboard hardness can no longer remain at the level of simple subjective feelings and qualitative descriptions, nor can it rely on scattered test data lacking unified standards, accuracy, and stability. In the research and development, structural optimization, production process quality control, and market selection of headboard products, the industry urgently needs a standardized testing method that can objectively, quantitatively, repeatably, and comparatively evaluate headboard hardness, especially its softness and hardness. Therefore, there is an urgent need to provide a quantitative testing device and method for headboard hardness to overcome the aforementioned technical deficiencies. Summary of the Invention

[0009] This invention provides a bed headboard hardness testing device and method, aiming to improve the testing effect of bed headboard hardness.

[0010] This invention provides a bed headboard hardness testing device, comprising: A test frame for placing the headboard to be tested; the headboard has multiple pre-set test points. A test indenter is used to perform softness and hardness tests on each test point of the bed headboard. A loading device is installed on the test frame and connected to the test head to drive and adjust the test position of the test head and collect load-displacement data at each test point; The control unit is connected to the test frame, test indenter and loading device respectively, and is used to control the soft and hardness test operation of the bed screen.

[0011] Furthermore, the testing framework includes: A testing platform for the headboard to be tested; The column guide rail is located on the side of the test platform; A portal-shaped column is slidably mounted on the column guide rail to accommodate different test positions along the length of the headboard; A rotating beam is installed across the portal column. The rotating beam can rotate and be positioned around the transverse axis, and the rotating beam can move up and down within the portal column.

[0012] Furthermore, the loading device is slidably mounted on the rotating beam, and the loading device can move laterally along the length direction of the rotating beam.

[0013] Furthermore, the loading device includes: A drive component is loaded and coaxially connected to the test head based on an axis, and is used to drive and adjust the test position of the test head; A force sensor, connected to the test pressure head, is used to collect load signals during the loading process; A displacement sensor, connected to the test head, is used to collect the displacement signal of the test head during the loading process.

[0014] Furthermore, the test indenter comprises a coaxially integrally formed cylindrical segment and a rotating ellipsoidal segment. One end of the cylindrical section is connected to the displacement sensor; The axial cross-sectional profile of the rotating ellipsoid segment is a semi-ellipse, and the major axis diameter of the semi-ellipse is the same as the diameter of the cylindrical segment.

[0015] This invention also provides a method for testing the hardness of a headboard, applied to the headboard hardness testing equipment described above, the method comprising: The bed headboard to be tested was subjected to environmental conditioning to stabilize the internal materials of the bed headboard. The bed headboard is mounted on the test frame; Based on the preset test points of the bed head, the load device drives the test head to perform softness and hardness tests on each test point to obtain the load-displacement data of each preset test point. The hardness of the bed screen is evaluated based on the load-displacement data.

[0016] Furthermore, mounting the headboard onto the test frame includes: Based on the preset test points of the headboard, the displacement and / or rotation control of the portal column, rotating beam and loading device are performed so that the axis of the test head is perpendicular to the top of the test point and a gap is left between the test head and the test point.

[0017] Furthermore, based on the preset test points of the bed headboard, the loading device drives the test indenter to perform a hardness test on each test point to obtain load-displacement data for each preset test point, including: The loading device drives the test head to load the test point along its axis at a preset constant loading rate until the load reaches the first threshold, and displacement data is collected simultaneously. The unloading operation is performed at the same rate until the load reaches the second threshold, and displacement data is collected synchronously; wherein the first threshold is greater than the second threshold.

[0018] Furthermore, the evaluation of the hardness of the bed headboard based on the load-displacement data includes: A load-displacement curve is constructed based on the load-displacement data; the load-displacement curve includes a loading curve segment and an unloading curve segment. Key feature points are extracted from the load-displacement curve according to the preset displacement and / or preset load. The equivalent hardness and gradient correlation index are calculated by combining the loading curve segment and key feature points; Calculate the energy absorption and resilience related indicators by combining the loading curve segment and the unloading curve segment; The equivalent hardness and gradient correlation index and the energy absorption and resilience correlation index are standardized to obtain the corresponding standardized data. The headboard is classified into different hardness levels based on the standardized data.

[0019] Furthermore, the calculation of the equivalent hardness and gradient correlation index by combining the loading curve segment and key feature points includes: For the aforementioned loading curve segment, calculate the linear slope of the load-displacement curve within a specific load range; Based on the linear slope, the load-displacement curve corresponding to the key feature point or the loading curve segment is linearly fitted or differentiated, and the results of the linear fitting or differentiation are used to characterize the hardness and softness to obtain the equivalent hardness index. Based on the results of linear fitting or differential processing, the system is classified according to the set load range or displacement range, and the results of the classification are used to characterize the support gradient ratio to obtain the support gradient index.

[0020] Furthermore, the calculation of energy absorption and resilience indices by combining the loading curve segment and the unloading curve segment includes: Calculate the area of ​​the loading curve segment to characterize the energy absorption index per unit loading process; Calculate the area of ​​the unloading curve segment to characterize the energy release index per unit unloading process; The difference or ratio between the area of ​​the loading curve segment and the area of ​​the unloading curve segment is calculated to characterize the energy loss index. The ratio of the area of ​​the loading curve segment to the combined area of ​​the loading curve segment and the unloading curve segment is calculated to characterize the rebound and hysteresis index.

[0021] Furthermore, the step of classifying the headboard into different hardness levels based on the standardized data includes: The standardized data are weighted using a weighted composite index. The weighted composite index is nonlinearly mapped to a preset scoring range using an S-shaped function to obtain a softness / hardness score. The softness and hardness scores are graded according to a preset grading standard to obtain the corresponding softness and hardness levels.

[0022] This invention provides a bed headboard hardness testing device and method. The device includes: a test frame for placing the bed headboard to be tested; the bed headboard has multiple pre-set test points; a test indenter for performing hardness testing on each test point of the bed headboard; a loading device installed on the test frame and connected to the test indenter to drive and adjust the test position of the test indenter and collect load-displacement data for each test point; and a control unit connected to the test frame, test indenter, and loading device to control the hardness testing operation of the bed headboard. This invention, by reasonably setting the test frame, test indenter, and loading device, can accurately collect load-displacement data for each test point of the bed headboard, thereby evaluating the hardness of the bed headboard based on the load-displacement data. This improves the hardness testing effect of bed headboards and solves the problems of non-standard testing methods, strong subjectivity, inability to reflect real working conditions, and poor positioning accuracy and repeatability of testing equipment in existing technologies. It provides an objective, quantitative, repeatable, and comparable evaluation basis for bed headboard product research and development, production process quality control, and market selection. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a bed headboard hardness testing device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the test state of a bed headboard hardness testing device provided in an embodiment of the present invention; Figure 3 A schematic diagram of the moving mechanism of the column guide rail and the portal column in a bed headboard hardness testing device provided in an embodiment of the present invention; Figure 4 A schematic diagram of the vertical movement mechanism of the portal column in a bed headboard hardness testing device provided in an embodiment of the present invention; Figure 5 A schematic diagram of a rotating crossbeam in a bed headboard hardness testing device provided in an embodiment of the present invention; Figure 6 A schematic diagram of the test indenter in a bed head hardness testing device provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the test point distribution in a bed headboard hardness testing device provided in an embodiment of the present invention; Figure 8 A schematic flowchart of a bed headboard hardness testing method provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of a sub-process of a bed headboard hardness testing method provided in an embodiment of the present invention; Figure 10 This is an example diagram of the first index parameter in a bed headboard hardness testing method provided in an embodiment of the present invention; Figure 11 This is an example diagram of the second index parameter in a bed headboard hardness testing method provided in an embodiment of the present invention; Figure 12 An example diagram of the third index parameter in a bed headboard hardness testing method provided in an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0029] Please see below. Figure 1 This invention provides a bed headboard hardness testing device, comprising: A test frame for placing the headboard to be tested; the headboard has multiple pre-set test points. Test head 6 is used to perform softness and hardness tests on each test point of the bed screen. The loading device 5 is installed on the test frame and connected to the test head 6 to drive and adjust the test position of the test head 6 and collect load-displacement data at each test point; The control unit is connected to the test frame, the test head 6 and the loading device 5 respectively, and is used to control the soft and hardness test operation of the bed screen.

[0030] In this embodiment, the headboard hardness testing equipment comprises three main parts: a test frame, a test indenter 6, and a loading device 5. By reasonably setting the test frame, test indenter 6, and loading device 5, load-displacement data at each test point of the headboard can be accurately collected. Thus, the headboard hardness can be evaluated based on the load-displacement data. This improves the testing effect of headboard hardness and solves the problems of non-standard testing methods, strong subjectivity, inability to reflect real working conditions, and poor positioning accuracy and repeatability of testing equipment in the prior art. It provides an objective, quantitative, repeatable, and comparable evaluation basis for headboard product research and development, production process quality control, and market selection.

[0031] In one embodiment, the testing framework includes: Test platform 1, used for the headboard to be tested; The column guide rail 2 is located on the side of the test platform 1; The portal-shaped column 3 is slidably mounted on the column guide rail 2 to accommodate different test positions along the length of the headboard; A rotating beam 4 is installed across the portal column 3. The rotating beam 4 can rotate and be positioned around the transverse axis, and the rotating beam 4 can move up and down within the portal column 3.

[0032] Furthermore, the loading device 5 is slidably mounted on the rotating beam 4, and the loading device 5 can move laterally along the length direction of the rotating beam 4.

[0033] Specifically, the loading device 5 includes: Loading drive component 51, which is coaxially connected to the test head 6 based on an axis, is used to drive and adjust the test position of the test head 6; A force sensor, connected to the test head 6, is used to collect load signals during the loading process; A displacement sensor, connected to the test head 6, is used to collect the displacement signal of the test head 6 during the loading process.

[0034] The test framework described in this embodiment includes a test platform 1, a column guide rail 2, a portal-shaped column 3, and a rotating beam 4. The test platform 1 provides a stable base for the headboard under test, ensuring that the headboard will not shake or shift during testing, thus guaranteeing test accuracy. The column guide rail 2 is located on the side of the test platform 1, providing a track for the sliding of the portal-shaped column 3, allowing it to move flexibly along the length of the headboard to adapt to testing requirements at different positions. The portal-shaped column 3 is slidably mounted on the column guide rail 2, and its design allows for precise adjustment to a suitable test position based on the actual length of the headboard and the distribution of test points, further improving the flexibility and specificity of the test. The rotating beam 4 spans within the portal-shaped column 3, combined with… Figure 2 The rotating beam 4 can not only rotate 360° around the transverse axis for positioning and multi-angle testing and adjustment, but also move up and down within the portal column 3. This allows for precise adjustment of the height and angle of the test head 6 according to the height of the headboard and testing requirements, ensuring that the test head 6 can accurately perform soft and hardness tests on each test point of the headboard.

[0035] The loading device 5 is slidably mounted on the rotating beam 4 via a slide block, and can move laterally along the length of the rotating beam 4. This design allows the loading device 5 to slide freely on the rotating beam 4, thereby driving the test pressure head 6 to test points at different lateral positions on the bed screen. The loading device 5 mainly consists of a loading drive assembly 51, a force sensor, and a displacement sensor (such as...). Figure 6 As shown, the force sensor and displacement sensor can be integrated into... Figure 6 The test head 6 is composed of components labeled 52 (located in the diagram). The loading drive assembly 51 is coaxially connected to the test head 6, precisely driving and adjusting its test position to ensure it loads and unloads the test points on the bed screen according to preset requirements. A force sensor is connected to the test head 6; during loading, it acquires load signals in real time, providing accurate load data for subsequent analysis. A displacement sensor is also connected to the test head 6; during loading, it acquires displacement signals from the test head 6. Combined with the load signals acquired by the force sensor, load-displacement data for each test point can be obtained.

[0036] This embodiment utilizes a portal-shaped column 3 that can move along the length of the headboard, a rotating beam 4 with vertical lifting and rotation functions around its own axis, and a loading device 5 that can move along the width of the headboard to achieve three-dimensional adjustability of the test point position throughout the entire bed. Simultaneously, it can adapt to headboards of different sizes and structural forms, offering flexible and variable testing postures and excellent applicability. Furthermore, the rotation adjustment method of the rotating beam 4 allows the loading direction of the test indenter 6 to be perpendicular to the local normal direction of any position on the headboard surface, ensuring that the loading direction remains perpendicular at all times. This enables stable and repeatable loading tests on complex curved surfaces such as inclined surfaces, arc surfaces, and rounded corner transitions. This overcomes the technical shortcomings of existing testing methods, which require the sample to be removed and laid flat, and can only perform unidirectional compression tests perpendicular to a plane, resulting in insufficient degrees of freedom and difficulty in covering multiple test points, especially on curved areas of the headboard surface. This embodiment significantly improves the comparability and consistency of test results across different locations.

[0037] In a specific embodiment, multiple sets of lead screw-guide rail transmission mechanisms and their synchronous control can be used to achieve precise adjustment of various test positions on the bed head surface in three-dimensional space. This results in smooth movement, good synchronization, and high repeatability, which is beneficial for improving the consistency and repeatability of the bed head hardness test results. Specifically: (1) Longitudinal movement of portal column 3 Combination Figure 3 On the left and right sides of the test platform 1, a longitudinal guide rail (i.e., the column guide rail 2) is set along the length of the bed frame on each side to guide and constrain the movement direction of the portal column 3.

[0038] Below the test platform 1, two longitudinal transmission screws 11 are arranged along the longitudinal guide rail. These two longitudinal transmission screws 11 are located on the left and right sides of the test platform 1, respectively, and are fixed to the frame of the test platform 1 by support seats. Each longitudinal transmission screw 11 is fitted with a longitudinal screw nut seat 12, which is fixedly connected to the lower end of the corresponding column via a column connecting seat 13. The column connecting seat 13 is constrained to the longitudinal guide rail by a linear slider, so that the bottom of the column can slide smoothly on the longitudinal guide rail.

[0039] Each longitudinal drive screw 11 is connected to a longitudinal drive motor 14 at one end. Both longitudinal drive motors 14 are electrically connected to the control unit and are driven synchronously under the control of the control unit. When the longitudinal drive motor 14 drives the corresponding longitudinal drive screw 11 to rotate synchronously, the longitudinal screw nut seats 12 on the left and right sides will move along the axial direction of their respective longitudinal drive screws 11. Under the joint constraint of the longitudinal guide rail and the top "portal" crossbeam, the portal column 3 as a whole can achieve smooth linear movement along the length of the bed frame.

[0040] (2) Lifting mechanism inside the portal column 3 Combination Figure 4 The left and right columns of the portal-type column 3 are each equipped with a column lifting transmission screw 31, a column guide rail 32, and a column lifting slide 33 mounted on the column lifting transmission screw 31. Their function is to drive the rotating beam 4 to adjust its position in the height direction. The column lifting transmission screw 31 and the column guide rail 32 are arranged parallel to each other along the column height direction. The column lifting slide 33 slides against the two column guide rails 32 via a linear slider and is threadedly connected to the column lifting transmission screw 31 via a nut structure. Furthermore, the lower ends of the left and right column lifting transmission screws 31 are each connected to a column lifting motor 34, and both column lifting motors 34 are electrically connected to a control unit for synchronous drive. Preferably, to protect the column lifting transmission screws 31 and column guide rails 32 from dust, a dustproof curtain 35 can be fitted over them.

[0041] Meanwhile, the rotating mechanisms 41 at both ends of the rotating beam 4 are securely mounted on the corresponding column lifting slides 33, allowing the rotating mechanisms 41 to move up and down along the height of the column along with the column lifting slides 33. When the control unit drives the two column lifting motors 34, causing the two column lifting transmission screws 31 to rotate synchronously, the column lifting slides 33 on both sides move up and down synchronously in the vertical direction under the guiding constraint of the column guide rails 32. In this way, the rotating beam 4 moves smoothly up and down in the height direction, thereby achieving the adjustment of the test height.

[0042] (3) Rotating mechanism 41 Combination Figure 5 The rotating mechanisms 41 at both ends of the rotating beam 4 are securely mounted on the corresponding column lifting slides 33. The rotating mechanisms 41 are symmetrically distributed on both sides of the portal column 3, and their function is to support and drive the rotating beam 4 to rotate around its own axis. The rotating mechanism 41 specifically includes a rotary drive motor 411, a reduction gear assembly 412, and a rotary flange 413. One end of the rotary flange 413 is coaxially fixed to the output shaft of the reduction gear assembly 412, and the other end is fixedly connected to the connecting flange 414 at the end of the rotating beam 4 by bolts. Both rotary drive motors 411 are electrically connected to the control unit, enabling synchronous control under the coordination of the control unit. When the rotary drive motor 411 drives the corresponding rotary flange 413 to rotate, the two rotary flanges 413, under synchronous control, simultaneously drive the rotating beam 4 to rotate around its axis, thereby achieving 360° rotational positioning of the rotating beam 4.

[0043] (4) Lateral movement inside the rotating beam 4 A rotating beam 4 is positioned between the portal columns 3. Each side of the rotating beam 4 has an internal set of transverse transmission screws 42 and transverse guide rails 43. The transverse transmission screws 42 and transverse guide rails 43 are arranged parallel to the length of the rotating beam 4, with the two transverse transmission screws 42 positioned symmetrically on both sides of the rotating beam 4. Simultaneously, the loading device 5 has two transverse slides 53 on one side, connecting to the transverse transmission screws 42 and transverse guide rails 43 on that side. The mounting base of the loading device 5 is installed on a platform rigidly connected by four transverse slides 53 on both sides.

[0044] Each end of the transverse transmission screw 42 on both sides is equipped with a transverse drive motor 44. Both transverse drive motors 44 are electrically connected to the control unit, which drives them synchronously. When the control unit drives the two transverse drive motors 44 simultaneously, causing the corresponding transverse transmission screws 42 to rotate synchronously, the four transverse slides 53 on both sides will move synchronously along the length of the rotating beam 4 under the guidance and constraint of the transverse guide rail 43, thereby driving the loading device 5 to achieve smooth and unbiased transverse movement in the width direction of the headboard.

[0045] In addition, the test indenter 6 includes a coaxially integrally formed cylindrical section and a rotating ellipsoidal section. One end of the cylindrical section is connected to the displacement sensor; The axial cross-sectional profile of the rotating ellipsoid segment is a semi-ellipse, and the major axis diameter of the semi-ellipse is the same as the diameter of the cylindrical segment.

[0046] Combination Figure 6 The test indenter 6 mentioned in this embodiment can specifically be a rigid indenter. This rigid indenter is an integral rigid component, and its shape is a rotating body formed by rotating around the same axis. The outer contour is composed of a continuous transition between an upper cylindrical segment and a lower rotating ellipsoidal segment.

[0047] The upper cylindrical segment, with a diameter of 100mm, is connected to a displacement sensor at its top. The lower rotating ellipsoidal segment is coaxial with and integrally formed with the upper cylindrical segment, and its upper end face has the same diameter as and coincides with the bottom end face of the cylindrical segment. The rotating ellipsoidal segment is formed by rotating an ellipse around its minor axis, and its axial cross-sectional profile is a semi-ellipse. The major axis diameter of this ellipse is the same as the diameter of the cylindrical segment, both being 100mm, and the minor axis diameter is 25mm. The outer surface of the rotating ellipsoidal segment transitions smoothly with the side surface of the cylindrical segment through a circular arc, without sharp edges, steps, or surface defects.

[0048] The test indenter 6 proposed in this embodiment is continuously composed of coaxial cylindrical segments and rotating ellipsoidal segments. Compared to flat or circular indenters, the contact surface of this geometry is closer to the pressing shape of the human body's shoulders, back, waist, etc., when they come into contact with the headboard. On the one hand, this helps to improve the correlation between the test results and the human body's subjective "backing feeling," comfort, and support experience, making it more in line with actual usage conditions; on the other hand, since the edges of the test indenter 6 are smoothly rounded, it can effectively reduce local stress concentration and avoid the problem of traditional indenters causing obvious indentations or even mechanical damage to the headboard surface fabric, seams, or edging during repeated loading, thus balancing the requirements of test authenticity and sample protection.

[0049] In practical applications, taking a typical headboard product as an example, the arrangement of pre-set test points for the headboard is explained. First, based on the headboard's primary support function for different parts of the body during actual use, the front surface of the headboard is divided vertically into several functional zones, preferably including at least: the neck and shoulder area, the upper back area, and the lumbar area. The test points for each functional zone should cover the main stress and contact points within that area. Within each functional zone, at least three test points are selected as valid test points. When the headboard is large or has a complex design, the number of test points can be appropriately increased. The horizontal or diagonal spacing between the centers of any adjacent test points should not be less than 100mm, and each test point should avoid seams, zippers, buttons, trims, quilted seams, decorative parts, and other local structures that may affect the contact between the pressure head and the test surface to avoid interfering with the test results.

[0050] To facilitate standardized positioning of test points and subsequent repeated testing, this embodiment establishes the following longitudinal positioning benchmark: Using the mattress placement plane on the bed frame in actual use as the reference zero point, the height of each test point on the front surface of the headboard is measured vertically upwards. The reference height range for the center test points of each functional zone is as follows: The height range of the central test point in the neck and shoulder area is 590–630 mm. The height range of the test point at the center of the upper back area is 365–405 mm. The height range of the test point at the center of the waist area is 140–180 mm.

[0051] After determining the height of the central test point, the remaining test points can be set horizontally or on a curved surface in a symmetrical or equidistant manner within the corresponding functional zones, ensuring that each test point is located within the main human contact area of ​​that functional zone. For headboards with curved upper edges or rounded corner transitions, test points can be selected near the corresponding height along their contour lines. This ensures that the test points represent the actual stress conditions in that area without being too close to the structural edge, thus reducing the impact of edge effects on the test results.

[0052] After determining the test point locations, mark the center position of each test point on the front surface of the headboard using a non-destructive marking method (such as removable markers or a dedicated marker pen). Note the functional area where each test point is located and its height relative to the reference plane in the test record. A schematic diagram of the distribution of headboard firmness test points can be shown below. Figure 7 As shown.

[0053] like Figure 8 As shown, this embodiment of the invention also provides a method for testing the softness and hardness of a headboard, which is applied to the headboard softness and hardness testing equipment described above. The method includes steps S101 to S104.

[0054] Step S101: Adjust the environment of the bed headboard to be tested so that the internal material of the bed headboard is in a stable state; Step S102: Install the bed headboard onto the test frame; Step S103: Based on the preset test points of the bed head, the loading device 5 drives the test head 6 to perform a softness and hardness test on each test point to obtain the load-displacement data of each preset test point. Step S104: Evaluate the hardness of the bed screen based on the load-displacement data.

[0055] In this embodiment, when conducting a hardness test on the headboard, the environment of the headboard to be tested is first conditioned to ensure that its internal materials reach a stable state. Next, the headboard is installed on the test frame. Then, based on the preset test points on the headboard, the loading device 5 drives the test indenter 6 to perform a hardness test on each test point, thereby obtaining load-displacement data for each preset test point. Finally, the hardness of the headboard is evaluated based on the obtained load-displacement data. This effectively improves the accuracy and reliability of the headboard hardness test, avoiding test errors caused by unstable materials or improper testing operations.

[0056] Specifically, in the environmental conditioning step, the headboard can be placed in an environment with a temperature of 23±2℃ and a relative humidity of 50±5%RH for at least 24 hours to allow the physical properties of the headboard's internal materials to stabilize, so as to ensure that the test results can truly reflect the headboard's softness and hardness characteristics under normal use conditions.

[0057] In one embodiment, step S102 includes: Based on the preset test points of the headboard, the displacement and / or rotation control of the portal column 3, the rotating beam 4 and the loading device 5 are performed so that the axis of the test head 6 is perpendicular to the test point above, and a gap is left between the test head 6 and the test point.

[0058] In this embodiment, when installing the headboard onto the test frame, it is essential to ensure that the headboard is placed stably and in full contact with the test platform 1 to prevent shaking or displacement during testing, which could affect the accuracy of the test data. For example, the headboard to be tested can be installed on the bed frame according to its actual usage state; the position of the bed frame can be adjusted so that the entire headboard to be tested is within the effective testing area of ​​the test platform 1; and the bed frame can be fixed relative to the test platform 1 to prevent relative slippage during testing.

[0059] Then, for each preset test point on the headboard, the multi-level linkage positioning is achieved by the portal column 3 moving longitudinally along the column guide rail 2, the rotating beam 4 moving vertically and rotating at an angle, and the loading device 5 moving longitudinally and laterally, so that the axis of the test pressure head 6 can be perpendicular to the headboard surface at the test point and maintain a certain gap between it and the headboard surface.

[0060] In one embodiment, step S103 includes: The loading device 5 drives the test head 6 to load the test point along its axis at a preset constant loading rate until the load reaches the first threshold, and displacement data is collected simultaneously. The unloading operation is performed at the same rate until the load reaches the second threshold, and displacement data is collected synchronously; wherein the first threshold is greater than the second threshold.

[0061] In this embodiment, the loading device 5 drives the test pressure head 6 to load the test points on the bed screen surface at a constant loading rate (e.g., 50 mm / min) along its axial direction until the load reaches a first threshold, such as 450 N. Then, the unloading process is immediately executed at the same rate until the load reaches a second threshold, such as 0 N. Simultaneously, load and displacement data are collected during the loading-unloading process.

[0062] Furthermore, following the loading-unloading conditions described above, the above operation can be repeated multiple times (e.g., three times) for each test point. Then, for each test point, the load-displacement curve of the last loading-unloading process (e.g., the third time) can be used as the valid test data for that test point. The tests for each test point of the bed screen are completed sequentially, resulting in a set of load-displacement data for each test point. Of course, other suitable loading-unloading cycles and valid data acquisition methods can also be selected, as long as the accuracy and reliability of the test data are guaranteed.

[0063] In one embodiment, such as Figure 9 As shown, step S104 includes steps S201 to S206.

[0064] Step S201: Construct a load-displacement curve based on the load-displacement data; the load-displacement curve includes a loading curve segment and an unloading curve segment; Step S202: Extract key feature points from the load-displacement curve according to the preset displacement and / or preset load; Step S203: Calculate the equivalent hardness and gradient correlation index by combining the loading curve segment and key feature points; Step S204: Calculate the energy absorption and resilience related indicators by combining the loading curve segment and the unloading curve segment; Step S205: Standardize the equivalent hardness and gradient correlation index and the energy absorption and resilience correlation index to obtain the corresponding standardized data; Step S206: Divide the bed headboard into softness and hardness grades according to the standardized data.

[0065] This embodiment processes and analyzes the load-displacement data collected from various test points to comprehensively and accurately evaluate the stiffness of the headboard. First, a load-displacement curve, including loading and unloading segments, is constructed based on the load-displacement data; this forms the basis for subsequent analysis. Next, key feature points are extracted from this curve according to preset displacements and / or preset loads. These key feature points reflect the mechanical properties of the headboard at different loading stages. After obtaining the key feature points, equivalent stiffness and gradient-related indices are calculated by combining the loading segment and the key feature points. Equivalent stiffness directly reflects the headboard's ability to resist deformation, while the gradient index reflects the change in headboard stiffness under different loading levels. For example, when a person is lying down or leaning against the headboard, different parts of the body have different requirements for headboard stiffness; the gradient index helps assess whether the headboard can provide appropriate support. Simultaneously, energy absorption and resilience-related indices are calculated by combining the loading and unloading segments. The energy absorption index reflects the headboard's ability to absorb energy under pressure, which is crucial for reducing the impact on the body and improving comfort. The resilience index reflects the headboard's ability to return to its original shape after being unloaded. Good resilience ensures that the headboard can maintain a stable firmness after long-term use.

[0066] To facilitate comparison and comprehensive evaluation of indicators from different headboards or different test points on the same headboard, it is necessary to standardize the equivalent hardness and gradient-related indicators, as well as the energy absorption and resilience-related indicators, to obtain corresponding standardized data. Standardization eliminates differences in dimensions and numerical ranges between different indicators, making them comparable. Finally, the headboards are classified into softness and hardness grades based on the standardized data. Reasonable softness and hardness grading standards can be developed based on actual needs and market feedback, dividing headboards into different hardness grades, such as soft, medium-soft, medium-firm, and firm. This allows consumers to choose headboards with appropriate hardness grades based on their preferences and physical conditions, while manufacturers can optimize and improve their products based on the grading results.

[0067] Through the above series of steps, the headboard hardness testing method provided in this embodiment can provide a scientific and objective basis for the research, development, production and sales of headboards, and promote the headboard industry to develop in a more standardized and regulated direction.

[0068] In a specific embodiment, step S202 includes: Obtain the feature points corresponding to the preset displacement or load from the load-displacement curve, such as: Obtain the load value at a predetermined displacement (e.g., 20mm, 40mm, 60mm, 80mm, 100mm) on the loading curve segment; Obtain the displacement value at a predetermined load (e.g., 50N, 100N, 200N, 300N, 450N) on the loading curve segment; Obtain key points such as the maximum load point and the maximum displacement point on the loading curve segment.

[0069] In a specific embodiment, step S203 includes: For the aforementioned loading curve segment, calculate the linear slope of the load-displacement curve within a specific load range; Based on the linear slope, the load-displacement curve corresponding to the key feature point or the loading curve segment is linearly fitted or differentiated, and the results of the linear fitting or differentiation are used to characterize the hardness and softness to obtain the equivalent hardness index. Based on the results of linear fitting or differential processing, the system is classified according to the set load range or displacement range, and the results of the classification are used to characterize the support gradient ratio to obtain the support gradient index.

[0070] In this embodiment, when calculating the equivalent hardness and gradient correlation index, the linear slope of the load-displacement curve within a specific load range (e.g., 50-450N) of the loading curve segment is first calculated. Then, based on this linear slope, linear fitting or differentiation is performed on several key feature points or the entire curve on the loading curve segment, and the sum or average is taken. The result obtained in this way can characterize the hardness, thus obtaining the equivalent hardness index. Simultaneously, for the loading curve segment, linear fitting or differentiation is performed on several key feature points or the entire curve, and categories are formed according to the load range or displacement range. This yields the support gradient ratio, which reflects the change in support from the surface to the interior of the bed screen, thus obtaining the support gradient index.

[0071] In practical applications, this embodiment proposes an equivalent surface hardness index (SHR) for quantifying the support performance of a bed headboard throughout the loading process, and provides a calculation method for this index. By determining the coordinate points corresponding to loads of 50N and 450N on the loading curve segment, with the horizontal axis representing the displacement value and the vertical axis representing the load value, the slope between the two points is calculated. A schematic diagram of the calculation parameters for the bed headboard's equivalent surface hardness (SHR) can be seen as follows: Figure 10 As shown. Specifically, the equivalent surface hardness SHR of the bed screen can be calculated using the following formula: ; In the formula, SHR represents the equivalent surface hardness, with units of N / mm; Y 450 This indicates the y-coordinate value (i.e., the load value) of the corresponding coordinate point when the load reaches 450N, in N; Y 50 This indicates the y-coordinate value (i.e., the load value) of the corresponding coordinate point when the load reaches 50N, in N; X 450 This indicates the x-coordinate value (i.e., displacement value) of the corresponding coordinate point when the load reaches 450N, in mm; X 50 This indicates the x-coordinate value (i.e., displacement value) of the corresponding coordinate point when the load reaches 50N, in mm.

[0072] Here, if the equivalent surface hardness SHR value is large, it means that the load increment corresponding to the unit displacement is large within the loading range of 50N to 450N, which is manifested as "harder" and "stronger support"; if the equivalent surface hardness SHR value is small, it means that the displacement change is large under the same load increment, which corresponds to a more soft or easier sinking feeling.

[0073] Furthermore, this embodiment proposes a comprehensive support stiffness index T for quantitatively characterizing the support performance of the headboard within a typical stress range, and provides a calculation method for this index. In this embodiment, the comprehensive support stiffness index T is constructed by examining the tangent slopes of the load-displacement curve at multiple representative load points during loading. A schematic diagram of the calculation parameters for the comprehensive support stiffness T of the headboard is shown below. Figure 11 As shown. Specifically, the overall support stiffness T of the headboard can be calculated using the following formula: ; In the formula, T 100N T 200N T 300N These are the tangent slopes of the loading curves at loads of 100N, 200N, and 300N, respectively, in N / mm, used to characterize the instantaneous equivalent stiffness of the bed head near the corresponding load.

[0074] Here, the larger the overall support stiffness T value, the stronger the support and the smaller the deformation of the headboard within the load range; the smaller the overall support stiffness T value, the easier it is for the headboard to deform within the load range, which corresponds to a softer subjective feeling.

[0075] In a specific embodiment, step S204 includes: Calculate the area of ​​the loading curve segment to characterize the energy absorption index per unit loading process; Calculate the area of ​​the unloading curve segment to characterize the energy release index per unit unloading process; The difference or ratio between the area of ​​the loading curve segment and the area of ​​the unloading curve segment is calculated to characterize the energy loss index. The ratio of the area of ​​the loading curve segment to the combined area of ​​the loading curve segment and the unloading curve segment is calculated to characterize the rebound and hysteresis index.

[0076] In this embodiment, when calculating the energy absorption and resilience-related indicators, the area under the loading curve is first calculated, which characterizes the energy absorbed during a unit loading process; simultaneously, the area under the unloading curve is calculated, which characterizes the energy released during the rebound process; then, the difference or ratio of the two areas is calculated as an indicator of resilience and energy loss. Furthermore, the area enclosed by the unloading curve and the loading curve, and the ratio of this area to the total area under the loading curve, can be calculated to characterize rebound and hysteresis characteristics.

[0077] In practical applications, this embodiment proposes an elastic recovery ratio η for quantifying the resilience of a bed screen, and provides a method for calculating this index. This index reflects the bed screen's ability to recover deformation under pressure and the resilience characteristics of the material and structure by comparing the energy relationship between the loading and unloading processes. A schematic diagram illustrating the calculation parameters of the bed screen's elastic recovery ratio η can be seen as follows: Figure 12 As shown. Specifically, the bed screen elastic recovery ratio η can be calculated using the following formula: ; In the formula, The elastic recovery ratio of the headboard is used to measure its resilience and is a dimensionless value between 0 and 1. W1 represents the compression work, which is the total work done on the headboard by external forces during loading. Its value corresponds to the area under the loading curve and can be calculated using numerical integration (such as the trapezoidal rule), with units of joules (J). W2 represents the rebound work, which is the total work done by the headboard on the external environment during unloading. Its value corresponds to the area under the unloading curve and can be calculated using numerical integration (such as the trapezoidal rule), with units of joules (J).

[0078] Here, the closer the elastic recovery ratio η is to 1, the greater the energy input during the loading process is released during the unloading phase, which indicates that the elastic recovery capability of the bed screen is stronger; the smaller the elastic recovery ratio η is, the greater the energy loss, which in turn shows a more obvious viscoelasticity and hysteresis.

[0079] In a specific embodiment, step S206 includes: The standardized data are weighted using a weighted composite index. The weighted composite index is nonlinearly mapped to a preset scoring range using an S-shaped function to obtain a softness / hardness score. The softness and hardness scores are graded according to a preset grading standard to obtain the corresponding softness and hardness levels.

[0080] The standardized data described in this embodiment specifically involves standardizing or normalizing the aforementioned softness and hardness related indicators, converting indicators with different dimensions into dimensionless values ​​within the range of 0-1 or 0-10. Based on these standardized values, weighting coefficients can be set according to comfort and support evaluation requirements to combine multiple indicators into a comprehensive softness and hardness score. Then, based on the comprehensive score range, the headboard softness and hardness are divided into several levels (such as 0-10 levels or multiple ranges), achieving a graded and quantitative evaluation of headboard softness and hardness.

[0081] In practical applications, the equivalent surface hardness SHR, comprehensive support stiffness T, and elastic recovery ratio are calculated. After obtaining the relevant indicators, multiple test points can be spatially aggregated to obtain the corresponding indicators for each functional zone and the whole. For example, for all valid test points within the same functional zone (such as the neck and shoulders, upper back, and waist), the equivalent surface hardness SHR and comprehensive support stiffness T are calculated separately, and their arithmetic mean is taken as the corresponding indicator SHR for that functional zone. 分区 and T 分区 : ; ; Therefore, the equivalent surface hardness (SHR) of the shoulder and neck can be obtained respectively. 肩颈部 ), comprehensive support stiffness (T) 肩颈部 ); Upper back equivalent surface hardness (SHR) 上背部 ), comprehensive support stiffness (T) 上背部 Waist equivalent surface hardness (SHR) 腰部 ), comprehensive support stiffness (T) 腰部 ).

[0082] Then, the corresponding indicators of all test points on the entire bed are averaged or weighted averaged (different weights can be set according to the importance of each functional area in ergonomics) to obtain the equivalent surface hardness (SHR) of the entire headboard. 整体 ), elastic recovery ratio ( ).

[0083] Based on this, this embodiment proposes a comprehensive scoring and grading method for the softness and hardness of a headboard. This method is based on the overall equivalent surface hardness (SHR) of the headboard. 整体 Comprehensive support stiffness T 整体 Through normalization, weighted combination, and S-shaped function mapping, multidimensional physical indicators are converted into a comprehensive hardness score of 1 to 10 levels, achieving a quantitative grading evaluation of bed headboard hardness. Specifically: (1) Index normalization processing (min-maximum method) To eliminate the influence of different indicator dimensions and numerical ranges, this embodiment employs the min-max normalization method to convert each indicator into a dimensionless value within the range of 0 to 1. The specific steps are as follows: SHR was calculated from the results of multiple tests. 整体 T 整体 Two overall indicators are used as the evaluation sample set; for each type of indicator, the maximum and minimum values ​​are counted in the sample set.

[0084] The bed screen to be tested, its raw metric SHR 整体 T 整体 Normalization is performed according to the following formula to obtain the corresponding dimensionless index SHR. n T n : ; ; To integrate multiple indicators with different physical meanings into a single overall softness and hardness evaluation index, this embodiment introduces a weighted comprehensive index K, which is defined as a linear combination of normalized indices: ; In the formula, K represents the weighted comprehensive index of the headboard's softness and hardness; w1 and w2 represent the weight coefficients corresponding to each index, satisfying w1≥0, w2≥0, and w1+w2=1. Here, the weight coefficients can be calibrated through methods such as expert scoring, correlation analysis between user subjective evaluation and objective indicators, etc. Those skilled in the art can adjust the above weights according to different product positioning and the preferences of target user groups.

[0085] The weighted index K is still in the range of 0 to 1. The larger the value, the higher the overall hardness level, and the smaller the value, the softer the overall level.

[0086] Furthermore, to make the comprehensive index K easier to apply in engineering and understand by consumers, this embodiment uses a sigmoid function (preferably a logistic function) to nonlinearly map K to a softness / hardness rating S in the range of 1 to 10. The mapping formula is: ; In the formula, S represents the hardness score of the headboard, with a theoretical value range of 1 to 10; a and b are the slope parameter and translation parameter of the S-shaped function, respectively, and are constant values.

[0087] After obtaining the headboard's hardness rating Then, the headboard hardness can be divided into several levels according to preset grading standards. For example: 1.0≤ <4.0: The hardness level is 1, indicating that it is generally soft; 4.0≤ <7.0: The hardness level is 2, and the overall hardness is moderate; 7.0≤ ≤10.0: The hardness level is 3, which is generally hard.

[0088] The above-mentioned grading boundaries are merely examples. Those skilled in the art can adjust the boundaries of each level according to different brand positioning or target market needs to achieve more detailed or coarser grading.

[0089] In summary, compared with the prior art, this embodiment has the following beneficial effects: (1) This embodiment provides a method for quantitative testing and evaluation of headboard hardness, which breaks through the limitations of traditional subjective and qualitative evaluation of headboard hardness, and transforms the evaluation of headboard hardness from "feeling" and "experience" to quantifiable and repeatable objective test results.

[0090] (2) Compared with the practice of inferring the hardness of the headboard based solely on the mechanical properties of the material, this embodiment directly applies to the finished headboard structure, which can comprehensively reflect the combined effects of multiple factors such as material, layer structure, and shape. It is more suitable for product optimization design, quality control, and horizontal comparison between different models of products.

[0091] (3) This embodiment proposes a spatial loading architecture with multi-degree-of-freedom adjustment capability. The portal column 3 can move along the length of the headboard, the rotating beam 4 has the functions of vertical lifting and rotation around its own axis, and the loading device 5 can move along the width of the headboard, realizing three-dimensional adjustment of the test point position within the entire bed range. At the same time, it can also adapt to headboards of different sizes and structural forms, and the test posture is flexible and adjustable, with strong applicability.

[0092] (4) The rotation adjustment of the rotating beam 4 proposed in this embodiment allows the loading direction of the rigid indenter to be perpendicular to the local normal direction at any position on the bed head surface, ensuring that the loading direction always remains perpendicular. This enables stable and repeatable loading tests on complex curved surface areas such as inclined surfaces, arc surfaces, and rounded corner transitions. This overcomes the technical defects of existing testing methods, which require the sample to be removed and laid flat, and can only perform unidirectional compression tests perpendicular to the plane, resulting in insufficient degrees of freedom and difficulty in covering multiple test points, especially the curved surface area of ​​the bed head surface. This significantly improves the comparability and consistency of test results at different positions.

[0093] (5) The test indenter 6 proposed in this embodiment is continuously composed of coaxial cylindrical segments and rotating ellipsoidal segments. Compared with flat or circular indenters, the contact surface of this geometry is closer to the pressing shape of the human body's shoulders, back, waist, etc. when they come into contact with the headboard. On the one hand, it helps to improve the correlation between the test results and the human body's subjective "backing feeling", comfort and support experience, and is more in line with actual use conditions; on the other hand, since the edge of the test indenter 6 is a smooth arc transition, it can effectively reduce local stress concentration and avoid the problem of obvious indentations or even mechanical damage to the headboard surface fabric, seams or edging during repeated loading of traditional indenters, thus taking into account both the test authenticity and the protection requirements of the sample.

[0094] (6) This embodiment analyzes the load-displacement curves during the loading-unloading process to construct a multi-dimensional performance index-based evaluation approach for headboards. It further demonstrates that after normalization and weighted combination of multiple indicators, a comprehensive evaluation value and grading system for headboard hardness can be formed, enabling dynamic comprehensive evaluation of headboard hardness. This transforms specialized data into quantifiable levels that designers and consumers can understand, providing a scientific theoretical basis and data support for standardized production, customized design, and production, sales, and service of headboards for enterprises.

[0095] (7) This embodiment provides a theoretical basis and data foundation for the standardized production, customized design and quality management of headboards and headboard products through a standardized and repeatable testing and adjustment mechanism and a multi-index quantitative evaluation system. On the one hand, it can be used by enterprises to build headboard hardness grading standards and formulate product series development strategies, guiding material selection, structural design and process optimization; on the other hand, the test results are objective, comparable and traceable, which helps consumers make purchases, and can also provide experimental basis and data support for the formulation of headboard hardness evaluation standards or group standards at the industry level, thereby promoting the high-quality development of the headboard industry in a wider range.

[0096] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0097] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A bed headboard hardness testing device, characterized in that, include: A test frame for placing the headboard to be tested; the headboard has multiple pre-set test points. A test indenter is used to perform softness and hardness tests on each test point of the bed head; A loading device is installed on the test frame and connected to the test head to drive and adjust the test position of the test head and collect load-displacement data at each test point; The control unit is connected to the test frame, test indenter and loading device respectively, and is used to control the soft and hardness test operation of the bed screen.

2. The bed headboard hardness testing device according to claim 1, characterized in that, The testing framework includes: A testing platform for the headboard to be tested; The column guide rail is located on the side of the test platform; A portal-shaped column is slidably mounted on the column guide rail to accommodate different test positions along the length of the headboard; A rotating beam is installed across the portal column. The rotating beam can rotate and be positioned around the transverse axis, and the rotating beam can move up and down within the portal column.

3. The bed headboard hardness testing device according to claim 2, characterized in that, The loading device is slidably mounted on the rotating beam, and the loading device can move laterally along the length of the rotating beam.

4. The bed headboard hardness testing device according to claim 3, characterized in that, The loading device includes: A drive component is loaded and coaxially connected to the test head based on an axis, and is used to drive and adjust the test position of the test head; A force sensor, connected to the test pressure head, is used to collect load signals during the loading process; A displacement sensor, connected to the test head, is used to collect the displacement signal of the test head during the loading process.

5. The bed headboard hardness testing device according to claim 4, characterized in that, The test indenter comprises a coaxially integral cylindrical section and a rotating ellipsoidal section. One end of the cylindrical section is connected to the displacement sensor; The axial cross-sectional profile of the rotating ellipsoid segment is a semi-ellipse, and the major axis diameter of the semi-ellipse is the same as the diameter of the cylindrical segment.

6. A method for testing the hardness of a headboard, applied to the headboard hardness testing equipment as described in any one of claims 1-5, characterized in that, The method includes: The bed headboard to be tested was subjected to environmental conditioning to stabilize the internal materials of the bed headboard. The bed headboard is mounted on the test frame; Based on the preset test points of the bed head, the loading device drives the test head to perform softness and hardness tests on each test point to obtain the load-displacement data of each preset test point. The hardness of the bed screen is evaluated based on the load-displacement data.

7. The method for testing the softness and hardness of a headboard according to claim 6, applied to the headboard softness and hardness testing equipment according to claim 2, characterized in that, The step of mounting the bed headboard onto the test frame includes: Based on the preset test points of the headboard, the displacement and / or rotation control of the portal column, rotating beam and loading device are performed so that the axis of the test head is perpendicular to the top of the test point and a gap is left between the test head and the test point.

8. The method for testing the hardness of a bed headboard according to claim 6, characterized in that, The test points based on the bed headboard are used to perform hardness and softness tests on each test point by driving the test head through a loading device, so as to obtain load-displacement data for each of the preset test points, including: The loading device drives the test head to load the test point along its axis at a preset constant loading rate until the load reaches the first threshold, and displacement data is collected simultaneously. The unloading operation is performed at the same rate until the load reaches the second threshold, and displacement data is collected synchronously; wherein the first threshold is greater than the second threshold.

9. The method for testing the hardness of a bed headboard according to claim 8, characterized in that, The evaluation of the bed headboard's hardness based on the load-displacement data includes: A load-displacement curve is constructed based on the load-displacement data; the load-displacement curve includes a loading curve segment and an unloading curve segment. Key feature points are extracted from the load-displacement curve according to the preset displacement and / or preset load. The equivalent hardness and gradient correlation index are calculated by combining the loading curve segment and key feature points; Calculate the energy absorption and resilience related indicators by combining the loading curve segment and the unloading curve segment; The equivalent hardness and gradient correlation index and the energy absorption and resilience correlation index are standardized to obtain the corresponding standardized data. The headboard is classified into different hardness levels based on the standardized data.

10. The method for testing the hardness of a bed headboard according to claim 9, characterized in that, The calculation of the equivalent hardness and gradient correlation index by combining the loading curve segment and key feature points includes: For the aforementioned loading curve segment, calculate the linear slope of the load-displacement curve within a specific load range; Based on the linear slope, the load-displacement curve corresponding to the key feature point or the loading curve segment is linearly fitted or differentiated, and the results of the linear fitting or differentiation are used to characterize the hardness and softness to obtain the equivalent hardness index. Based on the results of linear fitting or differential processing, the system is classified according to the set load range or displacement range, and the results of the classification are used to characterize the support gradient ratio to obtain the support gradient index.

11. The method for testing the hardness of a bed headboard according to claim 9, characterized in that, The calculation of energy absorption and resilience indices by combining the loading curve segment and the unloading curve segment includes: Calculate the area of ​​the loading curve segment to characterize the energy absorption index per unit loading process; Calculate the area of ​​the unloading curve segment to characterize the energy release index per unit unloading process; The difference or ratio between the area of ​​the loading curve segment and the area of ​​the unloading curve segment is calculated to characterize the energy loss index. The ratio of the area of ​​the loading curve segment to the combined area of ​​the loading curve segment and the unloading curve segment is calculated to characterize the rebound and hysteresis index.

12. The method for testing the hardness of a bed headboard according to claim 9, characterized in that, The step of classifying the headboard into different hardness levels based on the standardized data includes: The standardized data are weighted using a weighted composite index. The weighted composite index is nonlinearly mapped to a preset scoring range using an S-shaped function to obtain a softness / hardness score. The softness and hardness scores are graded according to a preset grading standard to obtain the corresponding softness and hardness levels.

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