TW202601086A - Curved surface friction testing device - Google Patents

Abstract

A curved surface friction testing device has a first clamp applied to provide a pulling force to an object along a length direction; a second clamp applied to provide a clamping force to the object; a testing space with a bionic liquid therein, at least one part of the second clamp is immersed in the bionic liquid to simulate a usage environment of the object; and a sensor applied to detect a sensing data which is generated when the object is pulled by the first clamp.

Description

Curved surface friction testing device

A friction testing device, particularly a friction testing device for curved surfaces.

Current techniques primarily refer to "ASTM D1894 Test Method for Static and Dynamic Coefficients of Friction of Plastic Films and Sheets" to measure the static and dynamic friction coefficients of sheet/plate materials such as plastic films, sheets, and rubber. The methods for testing surface friction mostly involve using a universal testing machine or a tensile testing device to drag the sheet/plate material relative to a test plate, thereby calculating its static and dynamic friction coefficients.

However, the above-mentioned testing methods mostly target flat plates and obtain the static and dynamic friction coefficients of the surface through planar friction. Test items with curved surfaces (such as invasive medical devices like catheters or wires) need to be additionally processed from the same material into a flat shape before surface friction coefficient testing can be performed. This not only increases manufacturing costs and processes, but the shape made for testing is also not the same as the actual test item, which can easily lead to problems in confirming the quality of the test item.

In view of this, in order to develop a friction testing technique that can avoid manufacturing costs and process burdens and is applicable to test articles with curved surfaces, the present invention provides a curved surface friction testing device, comprising a tensioning part, a clamping part, and a simulation device arranged from top to bottom along a length direction, wherein the tensioning part includes a first clamp, the first clamp being displaceable relative to the clamping part along the length direction, the first clamp being used to provide friction testing for articles with curved surfaces. The device includes a first clamping part comprising a second clamping part for providing a clamping force to the test object along its length; a accommodating space containing a biomimetic fluid, wherein at least a portion of the second clamping part is immersed in the biomimetic fluid to simulate a usage scenario of the test object in use; and a sensor for detecting sensing data generated when the first clamping part pulls the test object.

The second clamp includes a biomimetic pad on one side corresponding to the object being tested.

The biomimetic pad is an elastic body containing rubber or silicone.

The surface of the biomimetic pad includes a textured structure.

Furthermore, a temperature control device is included to provide the second clamp and/or the simulation device with a temperature condition corresponding to the usage scenario.

Furthermore, a control center is included to provide a test command to the tensioning part, the clamping part, and the simulation device via wired or wireless means. The test command includes the tension of the first clamp, a displacement speed of the first clamp, the clamping force of the second clamp, and a temperature condition provided to the second clamp and/or the simulation device corresponding to the usage scenario.

The control center includes a database that records at least one test condition corresponding to the usage scenario. The test condition includes the bionic pad corresponding to the test condition, the friction coefficient of one of the pads corresponding to the bionic pad, the clamping force, the type of bionic liquid, the position of the second clamp relative to the bionic liquid, the temperature condition, and a test logic. The control center provides the test instructions based on the test condition and the test logic.

The clamping force of the second clamp corresponds to the pressure experienced by the test item in the usage scenario.

The pulling force and/or displacement speed of the first clamp correspond to the force or speed at which the test item is pulled during the usage scenario.

The stretching section is a common type of universal material machine or a stretching device.

The advantages of this invention are as follows: 1. By immersing at least a portion of the second clamp in the biomimetic liquid, the usage scenario of the test item during use is simulated. 2. The arc-shaped surface friction testing device can provide suitable test conditions for different test items, avoiding the problem of unreliable quality of the test item due to standardized test conditions. 3. By selecting the appropriate biomimetic pad, the tension of the first clamp, the displacement speed of the first clamp, the clamping force of the second clamp, and the temperature conditions according to the test conditions, the static and/or dynamic surface friction forces that may be generated by the biomimetic pad during expected use can be accurately detected.

Please refer to Figures 1 to 3, which are preferred embodiments of the arc-shaped surface friction testing device provided by the present invention. It includes a tensile part 10, a clamping part 20 and a simulation device 30, which are arranged from top to bottom along a length direction, and a control center 40 for providing a test command via wired or wireless means to control the tensile part 10, the clamping part 20 and the simulation device 30.

The stretching portion 10 includes a first clamp 11, which can be moved closer to or further away from the clamping portion 20 by adjusting its displacement along the length direction through the control center 40. The arcuate surface friction testing device clamps a test item A with an arcuate surface through the first clamp 11 of the stretching portion 10, and the first clamp 11 applies a pulling force to drag the test item A relative to the clamping portion 20 along the length direction.

The clamping part 20 includes a second clamp 21, at least a portion of which is disposed within the simulation device 30. The second clamp 21 clamps the test item A and applies a clamping force to the test item A.

The test item A can be a generally cylindrical material such as a rod or tube. Preferably, the test item A is a medical catheter, guide wire, or prosthesis.

The stretching section 10 can be a common universal material machine or a stretching device. The stretching section 10, the clamping section 20, the simulation device 30, and the control center 40 are detachably combined.

The second clamp 21 includes a biomimetic pad 22 on one side corresponding to the object A being tested, to simulate a usage scenario where the object A is pulled out relative to a living organism.

For example, the biomimetic pad 22 can be an elastic body such as rubber or silicone to simulate the elasticity of human skin or organs; or the surface of the biomimetic pad 22 can be formed with an uneven structure to simulate the uneven texture of human surfaces such as the esophagus and stomach.

The simulation device 30 includes a receiving space 31, in which a biomimetic liquid 32 is disposed. At least a portion of the second clamp 21 is immersed in the biomimetic liquid 32 to simulate the usage scenario of the test item A when in use.

For example, another part of the second clamp 21 protrudes from the surface of the biomimetic liquid 32 to simulate the usage scenario when the test item A moves from inside the organism to outside the organism (or vice versa), traversing different environments. Alternatively, when the entire second clamp 21 is immersed in the biomimetic liquid 32, the usage scenario when the test item A moves inside the organism can be simulated.

Referring to Figure 3, the control center 40 includes a database 41, at least one sensor 42, and a temperature control device 43, wherein the temperature control device 43 provides a temperature condition for the second clamp 21 and/or the simulation device 30 to accurately simulate the usage scenario.

The database 41 records at least one test condition determined based on the expected usage scenario of the test item A, and records the biomimetic pad corresponding to the test condition, the friction coefficient of one of the pads corresponding to the biomimetic pad, the clamping force, the type of biomimetic liquid 32, the position of the second clamp 21 relative to the biomimetic liquid 32, the temperature condition, and a test logic.

The sensor 42 is used to detect sensing data such as resistance or distance moved per unit time when the first clamp 11 pulls the object A to be tested, and transmits the sensing data to the control center 40.

The control center 40 determines the test command based on the selection of test conditions and the test logic. The test command includes the tension of the first clamp 11, the displacement speed of the first clamp 11, the magnitude of the clamping force of the second clamp 21, and the temperature conditions provided by the temperature control device 43 for the second clamp 21 and/or the simulation device 30. By adjusting or changing the tension of the first clamp 11 and/or the clamping force of the second clamp 21 in the test command, the static friction coefficient and/or dynamic friction coefficient of the test object A under the corresponding test conditions can be measured.

It is worth noting that the clamping force setting of the second clamp 21 can simulate the pressure provided by the test item A in the test conditions when it is used in a usage scenario, such as being covered, squeezed, or pressed against by the organism. The pulling force or displacement speed provided by the first clamp 11 can also simulate the force or speed applied by medical personnel when pulling the test item A in the test conditions.

In addition, whether at least a portion of the second clamp 21 is immersed in the biomimetic liquid 32 also significantly affects the measured static and/or dynamic friction coefficients of the test item A. This invention detects the difference in the coefficient of friction of a PVC pipe at a point 2 cm below and above the surface of the biomimetic liquid 322 when it is displaced relative to the second clamp, under the conditions of the same pulling force and displacement speed provided by the first clamp 11 and the same clamping force provided by the second clamp 21. The PVC pipe is continuously displaced, and the dynamic friction coefficients at a point 2 cm below and above the surface of the biomimetic liquid 322 are obtained for each 1 cm movement of the PVC pipe. As shown in Figure 3, the coefficient of dynamic friction of the PVC pipe at 2 cm above the surface of the biomimetic liquid 32 when it is 4 cm from the start is significantly different from the coefficient of dynamic friction measured below the surface of the biomimetic liquid 322. This indicates that the positional relationship between the second clamp 21 and the biomimetic liquid 32 is crucial in determining the usage scenario of the test item A. The values of the static and/or dynamic friction coefficients of the test item A, measured by the second clamp 21 below and above the surface of the biomimetic liquid 322, can be used to select reference values for the static and/or dynamic friction coefficients based on the intended use of the test item A (e.g., whether for use inside or outside a living organism).

The advantages of this invention are as follows: 1. By immersing at least a portion of the second clamp 21 in the biomimetic liquid 32, the usage scenario of the test item A during use is simulated. 2. The arc-shaped surface friction testing device can provide suitable test conditions for different test items A, avoiding the problem of unreliable quality of the test item due to standardized test conditions. 3. By selecting the appropriate biomimetic pad, the tension of the first clamp 11, the displacement speed of the first clamp 11, the clamping force of the second clamp 21, and the temperature conditions according to the test conditions, the static and/or dynamic surface friction forces that may be generated by the biomimetic pad during expected use can be accurately detected.

10: Tensile section 11: First clamp 20: Clamping section 21: Second clamp 22: Bionic pad 30: Simulation device 31: Accommodation space 32: Bionic fluid 40: Control center 41: Database 42: Sensor 43: Temperature control equipment A: Item to be tested

Figure 1 is a three-dimensional cross-sectional view of a preferred embodiment provided by the present invention. Figure 2 is a diagram showing the usage state of a preferred embodiment provided by the present invention. Figure 3 is a block diagram of a preferred embodiment system provided by the present invention. Figure 4 is a graph showing experimental data of a preferred embodiment provided by the present invention.

20: Clamping section

21: Second clamp

22: Bionic Pads

30: Simulation Device

31: Storage space

Claims (10)

A curved surface friction testing device includes a stretching portion, a clamping portion, and a simulation device arranged from top to bottom along a length direction, wherein: The stretching portion includes a first clamp, the first clamp being displaceable relative to the clamping portion along the length direction, the first clamp being used to provide a tensile force along the length direction to a test object having a curved surface; The clamping portion includes a second clamp, the second clamp being used to provide a clamping force to the test object; and The simulation device includes a receiving space containing a biomimetic fluid, at least a portion of the second clamp being immersed in the biomimetic fluid to simulate a usage scenario of the test object in use; and A sensor is used to detect sensing data generated when the first clamp pulls the test object. As described in claim 1, the arcuate surface friction testing apparatus includes a biomimetic pad on one side of the clamp corresponding to the object being tested. As described in claim 2, the biomimetic pad is an elastic body comprising rubber or silicone. The arc-shaped surface friction testing device as described in claim 2 has a surface with an uneven structure. The arc-shaped surface friction testing apparatus as described in claim 1 includes a temperature control device to provide the second fixture and/or the simulation device with a temperature condition corresponding to the usage scenario. The arc-shaped surface friction testing device as described in any of claims 1 to 5 includes a control center that provides a test command, either wired or wirelessly, to the tension section, the clamping section, and the simulation device. The test command includes the tension of the first clamp, a displacement speed of the first clamp, the clamping force of the second clamp, and a temperature condition provided to the second clamp and/or the simulation device corresponding to the usage scenario. As described in claim 6, the arc-shaped surface friction testing device includes a control center containing a database that records at least one test condition corresponding to the usage scenario. The test condition includes the biomimetic pad corresponding to the test condition, the friction coefficient of one of the pads corresponding to the biomimetic pad, the clamping force, the type of biomimetic liquid, the position of the second clamp relative to the biomimetic liquid, the temperature condition, and a test logic. The control center provides the test instructions based on the test condition and the test logic. As described in claim 7, the clamping force of the second clamp corresponds to the pressure experienced by the test item in the usage scenario in the arc-shaped surface friction test apparatus. As described in claim 7, the arc-shaped surface friction testing apparatus, wherein the pulling force and/or displacement velocity of the first clamp corresponds to the force or velocity applied to the test item when it is pulled during the use scenario. As described in claim 7, the arc-shaped surface friction testing device, the tensile section is a common universal material machine or a tensile device.