A portable continuous hardness tester for automobile seats and a test method thereof

Abstract

The present invention discloses a portable continuous hardness tester and test method for automobile seats, belonging to the technical field of automobile seat surface hardness testing, comprising a force measuring module, a laser ranging module, a connecting bracket and a pressure plate connecting rod, wherein the force measuring module is used to measure the pressure value applied to the seat, and the laser ranging module is used to measure the deformation amount of the seat surface, and the bottom end of the force measuring module is connected to a pressure plate connecting rod, and the bottom end of the pressure plate connecting rod is threadedly connected to a pressure plate, and a connecting bracket is sleeved on the pressure plate connecting rod, and the two ends of the connecting bracket are connected to the laser ranging module. The hardness tester and test method solve the problems existing in the prior art that the test location and application scope are limited. The present invention adopts a laser ranging system to replace the traditional electric / pneumatic rigid body moving ranging system, which greatly increases the test accuracy and the flexibility of the use occasions.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile seat surface hardness testing, and in particular relates to a portable automobile seat continuous hardness tester and a testing method. Background Art

[0002] Most parts of a car seat affect its comfort, but the foam plays an important role in bearing the passengers. Whether it is the front or rear seat, the process from the passenger sitting down to the passenger sitting in the seat is the process of the passenger compressing the seat and deforming it. Among them, the carrier with the largest deformation is the foam. The deformation and hardness of the foam determine the body pressure distribution result that measures the combination state of the seat and the passenger, and determines the passenger's subjective driving perception.

[0003] When the driver and passengers sit down, the seat foam is continuously compressed. It is very important to know the compression performance during the compression process, such as the relationship between deformation and compression strength, compression modulus and hysteresis rate, for seat design. With the in-depth and intelligent development of ergonomic research during driving, different parts of the human body require different hardness of seats to meet consumers' requirements for seat comfort. It is necessary to quickly test the hardness of seats or foam bodies in multiple parts continuously to meet the needs of testing or monitoring seat quality now and in the future.

[0004] At present, most seat manufacturers use large equipment consisting of force sensors and displacement sensors that need to be fixed indoors to test the compression performance of seats or foams. The testing equipment is expensive, the operation process is complicated, and the testing equipment resources are limited. The test waiting period is long, and the test location and application scope are limited. Because the test equipment is fixed, the compression process of testing the local hardness of a certain area on the seat requires moving the seat, which is time-consuming, labor-intensive and inconvenient to operate. At the same time, it is not flexible to test small areas of the seat such as the wing part. The biggest defect is that it is impossible to directly obtain the continuous hardness of the objective evaluation index required for the comparison between seat design and subjective perception, that is, the soft hardness required in the early stage of driving and the strong support hardness required for long-term driving. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides a portable continuous hardness tester and a testing method for automobile seats to solve the problems existing in the prior art such as the limited testing location and application scope.

[0006] The present invention is achieved through the following technical solutions:

[0007] A portable continuous hardness tester for automobile seats comprises a force measuring module, a laser ranging module, a connecting bracket 5 and a pressure plate connecting rod 6. The force measuring module is used to measure the pressure value applied to the seat, and the laser ranging module is used to measure the deformation amount of the seat surface. The bottom end of the force measuring module is connected to the pressure plate connecting rod 6, and the bottom end of the pressure plate connecting rod 6 is threadedly connected to the pressure plate 7. The pressure plate connecting rod 6 is sleeved with a connecting bracket 5, and both ends of the connecting bracket 5 are connected to the laser ranging module.

[0008] Preferably, the force measuring module includes a signal processor, a controller, a display screen 2 and a force sensor 11. The force sensor 11 and the laser ranging sensor 4 are electrically connected to the signal processor, respectively. The signal processor, the display screen 2, the force sensor 11 and the laser ranging sensor 4 are electrically connected to the controller, respectively. The force sensor 11 and the laser ranging sensor 4 send the collected signals to the signal processor. After being processed by the signal processor, the controller transmits the processed signals to the display screen and displays the data on the display screen 2.

[0009] Preferably, a handle 1 is connected to the top of the force measuring module. When the handle 1 is held and pressure is applied, the pressure is transmitted to the seat or foam surface through the pressure plate connecting rod 6 and the pressure plate 7, causing compression deformation.

[0010] Preferably, the laser ranging module includes a connecting plate 12 and a box body, the box body is fixed to the two ends of the connecting bracket 5 through the connecting plate 12, a laser and a laser ranging sensor 4 are integrated in the box body, an adjusting handle 3 is provided on the box body, the laser is used to emit a laser beam, the laser ranging sensor 4 is used to measure the distance of the laser emission, the adjusting handle 3 is used to adjust the position of the box body, a positioning groove 8 is provided on the connecting plate 12, the adjusting handle 3 adjusts the movement of the box body, the box body and the connecting plate move around the positioning groove, and after finding a suitable position, they are fixed through the small hole in the center of the positioning groove.

[0011] Preferably, the connecting plate 12 is connected to the connecting bracket 5 via a positioning pin 9 .

[0012] Preferably, level indicators 10 are installed on the upper surfaces of both ends of the connecting bracket 5, which are used to apply force to the pressure plate when the level indicator remains horizontal during the test.

[0013] Preferably, the diameter of the pressure plate 7 is 10-50 mm.

[0014] A method for testing the continuous hardness of a portable car seat comprises the following steps:

[0015] Step 1: Calibration of the laser ranging module:

[0016] Start the laser, repeatedly adjust the positioning groove, and use the laser distance sensor to measure the vertical distance a between the edge of the laser distance measurement module and the pressure plate connecting rod. When the deviation between the a value and the design value is less than 0.3mm, it means that the laser distance measurement module has been leveled, and the laser distance measurement modules on both sides have been calibrated and are ready for use;

[0017] Step 2: Adjust the adjustment handle on one side to focus the laser beam emitted by the laser on the junction of the pressure plate connecting rod and the pressure plate, and record the vertical distance x between the horizontal plane where the laser beam emission point is located and the horizontal plane where the pressure plate is located;

[0018] Step 3: Apply pressure to the seat and keep the level indicator in a horizontal position. Then adjust the adjustment handles on both sides to focus the laser beam projection point on a certain point on the seat. According to the formula y=n·sin[arccos[(n 2 +c 2 -e 2 ) / 2nc]] to obtain the distance y, where y is the vertical distance between the plane where the laser beam is emitted and the plane where the seat is, n is the distance from the emission point of the laser beam on one side to a certain point on the seat, e is the distance from the emission point of the laser beam on the other side to a certain point on the seat, c is the fixed distance between the two boxes, and the pressure value F at this time is recorded by the force sensor;

[0019] Step 4: Calculate the compression amount S of the seat cover or foam according to the formula S=yx;

[0020] Repeat steps 3 and 4 several times to fit the curve of pressure and compression. The controller of the laser ranging module will calculate the continuous hardness of the car seat according to the curve and display it on the display screen.

[0021] Preferably, the calculation formula for the continuous hardness of the car seat is g=(F2-F1) / (S2-S1), wherein F2 is the pressure value corresponding to the compression amount S2; F1 is the pressure value corresponding to the compression amount S1.

[0022] Preferably, when the compression amount S1 is 3-5 mm and the compression amount S2 is 10-15 mm, the hardness SH required for the initial driving of the car seat can be calculated; when S1 is 10-15 mm and S2 is 25-35 mm, the hardness PH required for long-term driving can be calculated; by calculating the difference between the hardness PH required for long-term driving and the hardness SH required for the initial stage, the comfort of the car seat can be evaluated. Specifically, when the difference between PH and SH is above 8, the comfort is excellent; when the difference between PH and SH is between 5-8, the comfort is good; when the difference between PH and SH is between 2-5, the comfort is general or acceptable; when the difference between PH and SH is between 0-2, the comfort is poor; when the difference between PH and SH is less than 0, the comfort is completely unacceptable.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] The portable continuous hardness tester and test method of the car seat of the present invention solve the problems of limited test location and application scope in the prior art. The present invention adopts a laser ranging system to replace the traditional electric / pneumatic rigid body moving ranging system, which greatly increases the test accuracy and flexibility of the application occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0026] Figure 1 It is a structural schematic diagram of a portable continuous hardness tester for automobile seats of the present invention;

[0027] Figure 2 It is a partial enlarged view of a portable continuous hardness tester for automobile seats of the present invention;

[0028] Figure 3 A calibration diagram of a portable continuous hardness testing method for a car seat according to the present invention;

[0029] Figure 4 A schematic diagram of leveling of a portable continuous hardness testing method for a car seat of the present invention;

[0030] Figure 5 A schematic diagram of a portable continuous hardness tester for a car seat of the present invention placed on a seat;

[0031] Figure 6 A test schematic diagram of a portable continuous hardness tester for automobile seats of the present invention;

[0032] In the figure: handle 1, display screen 2, adjustment handle 3, laser distance sensor 4, connecting bracket 5, pressure plate connecting rod 6, pressure plate 7, positioning groove 8, positioning pin 9, level indicator 10, force sensor 11, connecting plate 12. DETAILED DESCRIPTION

[0033] In order to clearly and completely describe the technical solution and its specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings of the specification:

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a portable continuous hardness tester for automobile seats, including a force measuring module, a laser ranging module, a connecting bracket 5 and a pressure plate connecting rod 6, wherein the force measuring module is used to measure the pressure value applied to the seat, and the laser ranging module is used to measure the deformation amount of the seat surface. The bottom end of the force measuring module is connected to the pressure plate connecting rod 6, and the bottom end of the pressure plate connecting rod 6 is threadedly connected to the pressure plate 7, and the connecting bracket 5 is sleeved on the pressure plate connecting rod 6, and the two ends of the connecting bracket 5 are connected to the laser ranging module.

[0039] The force measuring module includes a signal processor, a controller, a display screen 2 and a force sensor 11. The force sensor 11 and the laser ranging sensor 4 are electrically connected to the signal processor, respectively. The signal processor, the display screen 2, the force sensor 11 and the laser ranging sensor 4 are electrically connected to the controller, respectively. The force sensor 11 and the laser ranging sensor 4 send the collected signals to the signal processor. After being processed by the signal processor, the controller transmits the processed signals to the display screen and displays the data on the display screen 2.

[0040] The top of the force measuring module is connected with a handle 1. When the handle 1 is held by hand and pressure is applied, the pressure is transmitted to the seat or foam surface through the pressure plate connecting rod 6 and the pressure plate 7, causing compression deformation.

[0041] like Figure 2 As shown, the structure of the laser ranging module is introduced in detail. The laser ranging module includes a connecting plate 12 and a box. The box is fixed to the two ends of the connecting bracket 5 through the connecting plate 12. A laser and a laser ranging sensor 4 are integrated in the box. An adjusting handle 3 is provided on the box. The laser is used to emit a laser beam, and the laser ranging sensor 4 is used to measure the distance of laser emission. The adjusting handle 3 is used to adjust the position of the box. A positioning groove 8 is provided on the connecting plate 12. The adjusting handle 3 adjusts the movement of the box. The box and the connecting plate move around the positioning groove. After finding a suitable position, they are fixed through the small hole in the center of the positioning groove.

[0042] The connecting plate 12 is connected to the connecting bracket 5 via the positioning pins 9 .

[0043] Level indicators 10 are installed on the upper surfaces of both ends of the connecting bracket 5, which are used to apply force to the pressure plate when the level indicator remains horizontal during the test.

[0044] The diameter of the pressure plate 7 is 10-50 mm.

[0045] The testing principle of a portable continuous hardness tester for automobile seats of the present invention is as follows:

[0046] The force measurement principle of the force measurement module is to apply force by holding the handle with your thumb, and press the "On" test button to start the force sensor and laser distance sensor at the same time; during the pressing process, the pressure plate deforms the seat surface, and the display stores the force value while the two laser distance sensors cooperate with the control algorithm to obtain the corresponding seat surface deformation, that is, the amount of depression; during the test, the visual level indicator is kept horizontal and the pressure is applied to the pressure plate. The storage display in the force measurement system can input the project information and the force value interval of the picked-up force and depression amount specified before the test through the typing keys to obtain a series of force values ​​and depression amount values ​​or the relationship between the two. The laser distance sensor can control the position through the positioning pin, and then rotate the angle adjustment handle in the range of -60° to 60° to eliminate the influence of the flank or shape on the laser shooting during the test. The seat designer can set the corresponding depression amount series of the picked-up force value according to different positions of the passenger car or truck seat (such as shoulders, waist and under the buttocks, etc.) to achieve continuous hardness testing. The continuous hardness can be the softness of the seat surface at the moment when the driver and passenger sit down or the hardness of the deep support after sitting down. It can also be the hardness of the driver and passenger waist that needs to test a larger depression amount to examine the support reliability, and the shoulder that needs a smaller depth support but good surface softness. The present invention uses a laser ranging system to replace the traditional electric / pneumatic rigid body moving ranging system, which greatly increases the test accuracy and flexibility of use occasions.

[0047] Example 2

[0048] This embodiment provides a portable car seat continuous hardness testing method, which specifically includes the following steps:

[0049] Step 1: Calibration of the laser ranging module:

[0050] Start the laser, repeatedly adjust the positioning groove, and use the laser distance sensor to measure the vertical distance a between the edge of the laser distance measuring module and the connecting rod of the pressure plate. When the deviation of the a value from the design value is less than 0.3mm, it means that the laser distance measuring module has been leveled, and the laser distance measuring modules on both sides have been calibrated and are ready for use. After calibration, fix the connecting plate and the connecting bracket through the small hole in the center of the positioning groove;

[0051] Step 2: Adjust the adjustment handle on one side to focus the laser beam emitted by the laser on the junction of the pressure plate connecting rod and the pressure plate, and record the vertical distance x between the horizontal plane where the laser beam emission point is located and the horizontal plane where the pressure plate is located;

[0052] Step 3: Apply pressure to the seat and keep the level indicator in a horizontal position. Then adjust the adjustment handles on both sides to focus the laser beam projection point on a certain point on the seat. According to the formula y=n·sin[arccos[(n 2 +c 2 -e 2) / 2nc]] to obtain the distance y, where y is the vertical distance between the plane where the laser beam is emitted and the plane where the seat is, n is the distance from the emission point of the laser beam on one side to a certain point on the seat, e is the distance from the emission point of the laser beam on the other side to a certain point on the seat, c is the fixed distance between the two boxes, and the pressure value F at this time is recorded by the force sensor;

[0053] Step 4: Calculate the compression amount S of the seat cover or foam according to the formula S=yx;

[0054] Repeat steps 3 and 4 several times to fit the curve of pressure and compression. The controller of the laser ranging module will calculate the continuous hardness of the car seat according to the curve and display it on the display screen.

[0055] The calculation formula for the continuous hardness of the car seat is g=(F2-F1) / (S2-S1), where F2 is the pressure value corresponding to the compression amount S2; F1 is the pressure value corresponding to the compression amount S1.

[0056] When the compression amount S1 is 3-5 mm and the compression amount S2 is 10-15 mm, the hardness SH required for the initial driving of the car seat can be calculated. When S1 is 10-15 mm and S2 is 25-35 mm, the hardness SH required for long-term driving can be calculated.

[0057] According to the fitting curve, S1 is 3 mm, S2 is 15 mm, and the display shows that the hardness SH required for the car seat in the initial stage of driving is 7.81 N / mm; if S1 = 15 mm, S2 is 35 mm, and the displayed value is equal to or less than 7.81 N / mm, you need to use the keyboard to change S2 to 10 mm and recalculate. If the hardness required for long-term driving is still equal to or less than the hardness required for the initial stage of driving, it means that the seat does not have the hardness required for the initial stage of driving.

[0058] By calculating the difference between the hardness PH required for long-term driving and the hardness SH required initially, the comfort of the car seat can be evaluated. Specifically, if the difference between PH and SH is above 8, the comfort is excellent; if the difference between PH and SH is between 5-8, the comfort is good; if the difference between PH and SH is between 2-5, the comfort is average or acceptable; if the difference between PH and SH is between 0-2, the comfort is poor; if the difference between PH and SH is less than 0, the comfort is completely unacceptable.

[0059] Example 3

[0060] It is the same as Example 2, except that the hardness display value required for long-term driving is greater than the hardness required for the initial driving, which means that this seat has the hardness required for the initial driving and the hardness required for long-term driving.

[0061] Example 4

[0062] It is the same as Example 2, except that according to the fitting curve, S1 is 3 mm, S2 is 10 mm, and the display shows a softness value of 7.81 N / mm. If S1=15 mm, S2 is 25 mm, the displayed value of the hardness required for long-term driving is equal to less than the hardness required for the initial driving, indicating that this seat does not have the strong hardness required for long-term driving.

[0063] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0064] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0065] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A portable continuous hardness test method for a car seat, which is implemented by a portable continuous hardness test system for a car seat, wherein the test system comprises a force measuring module, a laser ranging module, a connecting bracket (5) and a pressure plate connecting rod (6), wherein the force measuring module is used to measure the pressure value applied to the seat, and the laser ranging module is used to measure the deformation amount of the seat surface, wherein the bottom end of the force measuring module is connected to the pressure plate connecting rod (6), the bottom end of the pressure plate connecting rod (6) is threadedly connected to the pressure plate (7), the pressure plate connecting rod (6) is sleeved with a connecting bracket (5), and the two ends of the connecting bracket (5) are connected to the laser ranging module; It is characterized in that The specific steps include: Step 1: Calibration of the laser ranging module: Start the laser, repeatedly adjust the positioning groove, and use the laser distance sensor to measure the vertical distance a between the edge of the laser distance measurement module and the pressure plate connecting rod. When the deviation between the a value and the design value is less than 0.3mm, it means that the laser distance measurement module has been leveled, and the laser distance measurement modules on both sides have been calibrated and are ready for use; Step 2: Adjust the adjustment handle on one side to focus the laser beam emitted by the laser on the junction of the pressure plate connecting rod and the pressure plate, and record the vertical distance x between the horizontal plane where the laser beam emission point is located and the horizontal plane where the pressure plate is located; Step 3: Apply pressure to the seat and keep the level indicator in a horizontal position. Then adjust the adjustment handles on both sides to focus the laser beam projection point on a certain point on the seat. According to the formula y=n·sin[arccos[(n 2 +c 2 -e 2 ) / 2nc]] to obtain the distance y, where y is the vertical distance between the plane where the laser beam is emitted and the plane where the seat is, n is the distance from the emission point of the laser beam on one side to a certain point on the seat, e is the distance from the emission point of the laser beam on the other side to a certain point on the seat, c is the fixed distance between the two boxes, and the pressure value F at this time is recorded by the force sensor; Step 4: Calculate the compression amount S of the seat cover or foam according to the formula S=xy; Repeat steps 3 and 4 several times to fit the curve of pressure and compression. The controller of the laser ranging module will calculate the continuous hardness of the car seat according to the curve and display it on the display screen.

2. A portable continuous hardness testing method for a car seat as claimed in claim 1, characterized in that: The calculation formula for the continuous hardness of the car seat is g=(F2-F1) / (S2-S1), where F2 is the pressure value corresponding to the compression amount S2; F1 is the pressure value corresponding to the compression amount S1.

3. A portable continuous hardness testing method for a car seat as claimed in claim 1, characterized in that: When the compression amount S1 is 3-5 mm and the compression amount S2 is 10-15 mm, the hardness SH required for the initial driving of the car seat can be calculated. When S1 is 10-15 mm and S2 is 25-35 mm, the hardness PH required for long-term driving can be calculated. By calculating the difference between the hardness PH required for long-term driving and the hardness SH required at the initial stage, the comfort of the car seat can be evaluated. Specifically, when the difference between PH and SH is above 8, the comfort is excellent; when the difference between PH and SH is between 5-8, the comfort is good; when the difference between PH and SH is between 2-5, the comfort is average or acceptable; when the difference between PH and SH is between 0-2, the comfort is poor; when the difference between PH and SH is less than 0, the comfort is completely unacceptable.

4. A portable continuous hardness testing method for a car seat as claimed in claim 1, characterized in that: The force measurement module comprises a signal processor, a controller, a display screen (2) and a force sensor (11); the force sensor (11) and the laser distance sensor (4) are respectively electrically connected to the signal processor; the signal processor, the display screen (2), the force sensor (11) and the laser distance sensor (4) are respectively electrically connected to the controller; the force sensor (11) and the laser distance sensor (4) send collected signals to the signal processor; after being processed by the signal processor, the controller transmits the processed signals to the display screen, and displays the data on the display screen (2).

5. A portable car seat continuous hardness tester method as claimed in claim 1, characterized in that: The top of the force measuring module is connected to a handle (1). When the handle (1) is held and pressure is applied, the pressure is transmitted to the seat or foam surface through the pressure plate connecting rod (6) and the pressure plate (7), causing compression deformation.

6. A portable car seat continuous hardness tester method as claimed in claim 1, characterized in that: The laser distance measuring module comprises a connecting plate (12) and a box body, wherein the box body is fixed to two ends of a connecting bracket (5) via the connecting plate (12), wherein a laser and a laser distance measuring sensor (4) are integrated in the box body, wherein an adjusting handle (3) is provided on the box body, wherein the laser is used to emit a laser beam, wherein the laser distance measuring sensor (4) is used to measure the distance of laser emission, wherein the adjusting handle (3) is used to adjust the position of the box body, wherein a positioning groove (8) is provided on the connecting plate (12), wherein the adjusting handle (3) adjusts the movement of the box body, wherein the box body and the connecting plate move around the positioning groove, and after finding a suitable position, the box body and the connecting plate are fixed via a small hole in the center of the positioning groove.

7. A portable car seat continuous hardness tester method as claimed in claim 6, characterized in that: The connecting plate (12) is connected to the connecting bracket (5) via a positioning pin (9).

8. A portable car seat continuous hardness tester method as claimed in claim 7, characterized in that: Level indicators (10) are installed on the upper surfaces of both ends of the connecting bracket (5) for applying force to the pressure plate when the level indicator remains horizontal during the test.

9. A portable car seat continuous hardness tester method as claimed in claim 1, characterized in that: The diameter of the pressure plate (7) is 10-50 mm.

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