Friction coefficient testing device

Abstract

The utility model relates to the technical field of friction coefficient testing, in particular to a friction coefficient testing device. A friction coefficient testing device comprises a shell, a movement driving mechanism and a testing mechanism, the movement driving mechanism and the testing mechanism are arranged on the shell, and the movement driving mechanism is used for driving the friction coefficient testing device to move relative to a test sample; the testing mechanism comprises a friction testing assembly, a driving transmission assembly and a force value testing assembly; the friction testing assembly comprises a balancing weight, a connecting block, a mounting frame and a friction block, and one end of the connecting block is rotationally connected with the shell. The friction coefficient testing device can test a static friction coefficient and a dynamic friction coefficient at the same time without depending on other external conditions in a testing field environment, so that friction coefficient testing operation of a field ground material is facilitated; the technical problems that an existing friction coefficient testing device is complex in testing operation and has certain requirements for the testing site environment are solved.

Description

Technical Field

[0001] This utility model relates to the field of friction coefficient testing technology, and in particular to a friction coefficient testing device. Background Technology

[0002] Friction coefficient testing allows for the evaluation of the anti-slip performance of different flooring materials, determining whether they meet safety requirements and preventing slip-and-fall accidents. Therefore, friction coefficient testing devices provide quantifiable data on the anti-slip performance of flooring, playing a crucial role in ensuring the safety of flooring materials. However, testing flooring materials typically requires on-site testing of already laid surfaces, where laboratory friction coefficient testing devices are insufficient.

[0003] Existing friction coefficient testing devices also exist that can perform on-site ground testing. For example, utility model patent CN205941312U discloses a friction coefficient tester. However, during testing, the friction base needs to be placed on the surface to be tested, and then the traction belt is pulled out from the tester and fixed externally. The motor winds up the traction belt through a force conversion mechanism, and the control system calculates the force that causes the motor to shift, thereby obtaining the friction coefficient of the surface to be tested. This friction coefficient tester requires finding external conditions in the on-site testing environment to fix the traction belt, and the fixing operation of the traction belt is also required. The testing operation is complex and has certain requirements on the external conditions of the testing site. Utility Model Content

[0004] In response to the problems raised in the background technology, the purpose of this utility model is to propose a friction coefficient testing device that can simultaneously test the static friction coefficient and the dynamic friction coefficient without relying on other external conditions in the test site environment. This facilitates the testing of the friction coefficient of ground materials on site and solves the technical problems of existing friction coefficient testing devices being complex to operate and having certain requirements for the test site environment.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0006] A friction coefficient testing device includes a housing, a moving drive mechanism, and a testing mechanism disposed in the housing. The moving drive mechanism is used to drive the friction coefficient testing device to move relative to the test sample.

[0007] The testing mechanism includes a friction testing component, a drive transmission component, and a force testing component;

[0008] The friction testing assembly includes a counterweight, a connecting block, a mounting bracket, and a friction block. One end of the connecting block is rotatably connected to the outer shell, and the other end of the connecting block is fixedly connected to the end of the counterweight. A top rod is provided on the side wall of the end of the counterweight connected to the connecting block. The mounting bracket is rotatably connected to the bottom of the connecting block, and the friction block is mounted on the bottom end face of the mounting bracket.

[0009] The drive transmission assembly includes a first drive device and an eccentric wheel. The drive end of the first drive device is connected to the eccentric wheel. The bottom end face of the push rod abuts against the wheel surface of the eccentric wheel. The first drive device drives the eccentric wheel to rotate so that the eccentric wheel lifts the counterweight or presses the counterweight down.

[0010] The outer shell has a through hole, through which the friction block passes. When the counterweight is pressed down, the bottom surface of the friction block abuts against the test sample.

[0011] The force testing assembly includes a tension / compression sensor and a force transmission rod. The top of the tension / compression sensor is fixedly connected to the housing, the bottom of the tension / compression sensor is rotatably connected to one end of the force transmission rod, and the other end of the force transmission rod is rotatably connected to the bottom of the mounting bracket. The tension / compression sensor is used to collect the maximum static and dynamic friction forces of the friction block relative to the test sample.

[0012] Furthermore, the drive transmission assembly further includes a first transmission gear, a second transmission gear, and a rotating shaft. The output shaft of the first drive device is fixedly connected to the first transmission gear, the first transmission gear meshes with the second transmission gear, and the second transmission gear and the eccentric wheel are respectively fixedly connected to the rotating shaft.

[0013] The eccentric wheel has a support surface on its surface. The support surface is planar and is located near the rotation center of the eccentric wheel.

[0014] To further explain, the top rods are symmetrically arranged on both sides of the counterweight along its length, and the eccentric wheels are symmetrically arranged on both sides of the counterweight along its length. The two ends of the rotating shaft are respectively fixedly connected to the eccentric wheels, and the bottom end face of the top rod abuts against the wheel surface of the corresponding eccentric wheel.

[0015] The friction coefficient testing device further includes a first support frame, which is fixedly installed on the outer shell. The first support frames are symmetrically arranged on both sides of the counterweight along its length. The first drive device is fixedly installed on one of the first support frames. The two ends of the rotating shaft are rotatably connected to the two first support frames respectively.

[0016] Furthermore, the friction coefficient testing device also includes a second support frame, which is fixedly mounted on the outer casing;

[0017] The tension / compression sensor is vertically arranged in the up-down direction, the force transmission rod is arranged in the horizontal direction, the bottom of the second support frame has a through-hole, the top of the tension / compression sensor is fixedly connected to the second support frame, the bottom of the tension / compression sensor extends to a position corresponding to the through-hole, and the force transmission rod is rotatably connected to the bottom of the tension / compression sensor within the through-hole.

[0018] Furthermore, the force testing component also includes a first mounting block and a second mounting block;

[0019] One end of the first mounting block is fixedly connected to the bottom of the tension / compression sensor, the other end of the first mounting block is rotatably connected to one end of the force transmission rod, the other end of the force transmission rod is rotatably connected to one end of the second mounting block, and the other end of the second mounting block is fixedly connected to the bottom of the mounting frame.

[0020] To further explain, the second support frame is disposed on the side of the counterweight away from the connecting block, and a limiting block is fixedly disposed on the top surface of the second support frame. The limiting block extends toward the counterweight and is provided with a limiting abutment portion. The end of the counterweight away from the connecting block is located below the limiting abutment portion.

[0021] Furthermore, the friction coefficient testing device also includes a third support frame, which is fixedly mounted on the outer shell and located on the side of the connecting block away from the counterweight. The end of the connecting block away from the counterweight is rotatably connected to the third support frame.

[0022] To further explain, the friction block includes a plug-in part and a friction part. The plug-in part is fixedly connected to the top surface of the friction part and is perpendicularly connected to the friction part. The bottom surface of the mounting bracket is provided with a plug-in interface. The plug-in interface is open and the plug-in part is detachably inserted into the plug-in interface.

[0023] A friction plate is fixedly connected to the bottom end face of the friction part.

[0024] To further explain, the mobile drive mechanism includes a second drive device and a drive wheel. The second drive device is fixedly mounted on the housing, and the output shaft of the second drive device is fixedly connected to the drive wheel. The second drive device drives the drive wheel to rotate.

[0025] The friction coefficient testing device further includes a guide wheel assembly. The moving drive mechanism is located at one end of the housing, and the guide wheel assembly is located at the other end of the housing. The guide wheel assembly includes a third mounting block and a guide wheel. The third mounting block is fixedly located on the housing, and the guide wheel is rotatably mounted on the third mounting block.

[0026] Furthermore, the friction coefficient testing device also includes a handle, a display screen, and a control circuit board;

[0027] The handle and the display screen are respectively fixedly mounted on the housing, and both the handle and the display screen are exposed outside the housing;

[0028] The control circuit board is fixedly disposed inside the housing, and the display screen, the drive transmission assembly, the first drive device and the tension and compression sensor are electrically connected to the control circuit board respectively.

[0029] Compared with the prior art, the embodiments of this utility model have the following beneficial effects:

[0030] The aforementioned friction coefficient testing device can simultaneously test both static and dynamic friction coefficients. When using ground materials as test samples, the friction coefficient testing device is placed in the test area, and the first drive device and the moving drive mechanism are activated to conduct the test. It does not rely on other external conditions in the test site environment, making it convenient to conduct on-site friction coefficient testing of ground materials. This solves the technical problems of existing friction coefficient testing devices having complex testing operations and certain requirements for the test site environment. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the friction coefficient testing device according to an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the internal structure of a friction coefficient testing device according to an embodiment of this utility model.

[0033] Figure 3 This is a schematic diagram of the internal structure of a friction coefficient testing device according to an embodiment of the present invention (with the first support frame on one side removed).

[0034] Figure 4 This is a schematic diagram of the internal structure of a friction coefficient testing device according to an embodiment of the present invention (excluding the first support frame, first drive device, first transmission gear and second transmission gear on one side).

[0035] Figure 5 This is a schematic diagram of the eccentric wheel of the drive transmission component of the friction coefficient testing device according to an embodiment of the present invention.

[0036] Figure 6 This is a schematic diagram of the assembly structure of the friction testing component and the force testing component of the friction coefficient testing device according to an embodiment of this utility model.

[0037] Figure 7 This is a schematic diagram of the mounting frame and friction block assembly structure of the friction testing component of the friction coefficient testing device according to an embodiment of the present invention.

[0038] Figure 8 This is a schematic diagram of the guide wheel assembly of a friction coefficient testing device according to an embodiment of the present invention.

[0039] Figure 9 This is a graph showing the data collected during the measurement process of the tension and compression sensors tested using the friction coefficient testing device of this invention.

[0040] In the attached diagram: 1-outer shell, 11-through hole, 12-base plate, 2-moving drive mechanism, 21-second drive device, 22-drive wheel, 3-test mechanism, 31-friction test assembly, 311-counterweight block, 3111-top rod, 312-connecting block, 313-mounting bracket, 3131-insertion interface, 314-friction block, 3141-insertion part, 3142-friction part, 3143-friction plate, 32-drive transmission assembly, 321-first drive device, 322-eccentric wheel, 3221-support surface 323-First transmission gear, 324-Second transmission gear, 325-Rotating shaft, 33-Force value testing assembly, 331-Tension and compression sensor, 332-Force transmission rod, 333-First mounting block, 334-Second mounting block, 4-First support frame, 5-Second support frame, 51-Connecting port, 52-Limiting block, 521-Limiting abutment part, 522-Abutment piece, 6-Third support frame, 7-Guide wheel assembly, 71-Third mounting block, 72-Guide wheel, 73-Encoder, 8-Handle, 9-Display screen. Detailed Implementation

[0041] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0042] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" and "second" may explicitly or implicitly include one or more of these features, used to distinguish descriptive features, without any order or emphasis.

[0043] like Figures 1 to 8 As shown, a friction coefficient testing device includes a housing 1, a moving drive mechanism 2 and a testing mechanism 3 disposed on the housing 1, wherein the moving drive mechanism 2 is used to drive the friction coefficient testing device to move relative to the test sample.

[0044] The testing mechanism 3 includes a friction testing component 31, a drive transmission component 32, and a force testing component 33;

[0045] The friction testing assembly 31 includes a counterweight 311, a connecting block 312, a mounting bracket 313, and a friction block 314. One end of the connecting block 312 is rotatably connected to the outer shell 1, and the other end of the connecting block 312 is fixedly connected to the end of the counterweight 311. A top rod 3111 is provided on the side wall of the end where the counterweight 311 is connected to the connecting block 312. The mounting bracket 313 is rotatably connected to the bottom of the connecting block 312, and the friction block 314 is mounted on the bottom end face of the mounting bracket 313.

[0046] The drive transmission assembly 32 includes a first drive device 321 and an eccentric wheel 322. The drive end of the first drive device 321 is connected to the eccentric wheel 322. The bottom end face of the push rod 3111 abuts against the wheel surface of the eccentric wheel 322. The first drive device 321 drives the eccentric wheel 322 to rotate so that the eccentric wheel 322 lifts the counterweight 311 or presses the counterweight 311 down.

[0047] The outer casing 1 has a through hole 11, the friction block 314 passes through the through hole 11, and when the counterweight block 311 is pressed down, the bottom surface of the friction block 314 abuts against the test sample.

[0048] The force testing assembly 33 includes a tension / compression sensor 331 and a force transmission rod 332. The top of the tension / compression sensor 331 is fixedly connected to the housing 1, the bottom of the tension / compression sensor 331 is rotatably connected to one end of the force transmission rod 332, and the other end of the force transmission rod 332 is rotatably connected to the bottom of the mounting bracket 313. The tension / compression sensor 331 is used to collect the maximum static friction force and dynamic friction force of the friction block 314 relative to the test sample.

[0049] In the friction coefficient testing device, by setting the moving drive mechanism 2 and the testing mechanism 3, when the friction coefficient is tested, the first drive device 321 drives the eccentric wheel 322 to rotate. Since the bottom end face of the push rod 3111 abuts against the wheel surface of the eccentric wheel 322, under the eccentric characteristic of the eccentric wheel 322, when the position on the wheel surface of the eccentric wheel 322 away from the rotation center contacts the bottom end face of the push rod 3111 during the rotation process, the eccentric wheel 322 will push up the counterweight 311. When the eccentric wheel 322 continues to rotate, the position on the wheel surface of the eccentric wheel 322 away from the rotation center separates from the bottom end face of the push rod 3111. At this time, the position on the wheel surface of the eccentric wheel 322 close to the rotation center abuts against the bottom end face of the push rod 3111, and the eccentric wheel 322 causes the counterweight 311 to press down. When the first driving device 321 drives the eccentric wheel 322 to rotate to the position where the counterweight 311 is pressed down, since the counterweight 311 is connected to the connecting block 312 and the bottom of the connecting block 312 is rotatably connected to the mounting bracket 313, the weight of the counterweight 311 presses onto the friction block 314 at the bottom of the mounting bracket 313. The bottom surface of the friction block 314 contacts the test sample, and the friction block 314 is subjected to a constant static pressure perpendicular to the surface of the test sample. F a When the friction block 314 is subjected to a constant static pressure F a Then, the friction coefficient testing device is moved relative to the test sample by the moving drive mechanism 2. The tension and compression sensor 331 collects the maximum static friction force and dynamic friction force of the friction block 314 relative to the test sample, and the static friction coefficient and dynamic friction coefficient can be calculated by the following formula:

[0050] μ 静 = f j / F a ,in μ 静 The static friction coefficient is f jThe maximum static friction force of the friction block 314 relative to the test sample, collected by the tension / compression sensor 331. F a The friction block 314 is subjected to a constant static pressure;

[0051] μ 动 = f d / F a ,in μ 动 The coefficient of kinetic friction is . f d The dynamic friction force of the friction block 314 relative to the test sample is collected by the tension / compression sensor 331. F a The friction block 314 is subjected to a constant static pressure.

[0052] Due to the maximum static friction force f j Usually greater than the kinetic friction force f d Therefore, a greater force is needed to initiate motion (to overcome static friction), and less force (i.e., kinetic friction) is needed to maintain motion once the object begins to move. Thus, the force required to initiate motion (overcoming static friction) between the friction block 314 and the test sample, i.e., the maximum static friction force, is collected by the tension / compression sensor 331. f j And the force required to move and maintain the friction block 314 relative to the surface of the test sample (overcoming kinetic friction), i.e., kinetic friction force. f d Therefore, the static friction coefficient and the dynamic friction coefficient can be calculated using the above formula. The friction block 314 is subjected to a constant static pressure. F a The device is pre-configured so that by suspending the outer shell 1 and supporting it with an object, the bottom surface of the moving drive mechanism 2 (i.e., the surface of the moving drive mechanism 2 that contacts the surface of the test sample during actual testing) is on the same plane as the measuring surface of the balance. The first drive device 321 drives the eccentric wheel 322 to rotate until the counterweight 311 is pressed down, causing the friction block 314 to press against the measuring surface of the balance (at this time, the measuring surface of the balance is equivalent to the surface of the test sample). The balance then measures the constant static pressure exerted on the friction block 314. F a .

[0053] Specifically, the value measured by the balance is the mass value. This mass value is then converted into a force value F in Newtons (N) using the formula F = m × g, where m is the mass value measured by the balance (in kg) and g is the acceleration due to gravity (in m / s²). 2 On Earth, the standard value of g is 9.80665 m / s². 2 Here, g is taken as 9.8 m / s 2 The acceleration due to gravity (m / s²) 2 The mass (kg) measured by the balance can be substituted into the formula.

[0054] It should be noted that when the moving drive mechanism 2 is started, an acceleration can be set to initiate the movement of the friction coefficient testing device. After starting, the friction coefficient testing device moves on the test sample at a constant speed. Furthermore, since the surface of the test sample may be uneven, the dynamic friction force... f d The force value may exist within a certain range, at which point... f d The average dynamic friction force required to maintain the movement of the friction coefficient testing device.

[0055] Furthermore, combined Figure 4 , Figure 6 and Figure 9 As explained, the tension / compression sensor 331 collects the maximum static friction force of the friction block 314 relative to the test sample. f j and kinetic friction f d The principle is as follows:

[0056] Phase 1: Collecting the maximum static friction force under stationary conditions f j .

[0057] (1) Initial state: The friction coefficient testing device is stationary relative to the test sample, and the friction block 314 is in contact with and squeezed against the test sample.

[0058] (2) The friction coefficient testing device starts to move forward: the moving drive mechanism 2 drives the outer shell 1 to move forward, so that it has a tendency to move forward. Since the tension and compression sensor 331 is fixedly connected to the outer shell 1, the tension and compression sensor 331 is also dragged forward.

[0059] (3) Static friction is generated and transmitted to the force transmission rod 332: Since the friction block 314 is installed on the bottom surface of the mounting bracket 313, and the mounting bracket 313 is rotatably connected to the bottom of the connecting block 312, at the moment of startup, the friction block 314 tends to remain stationary due to inertia. That is, relative to the forward-moving tension and compression sensor 331, the friction block 314 tends to move backward. This tendency generates static friction between the friction block 314 and the surface of the test sample. The direction of this static friction is opposite to the direction of the relative motion tendency. That is, the test sample gives the friction block 314 a forward static friction force. This forward static friction force acts on the friction block 314, and the friction block 314 transmits the forward static friction force to the bottom of the tension and compression sensor 331 through the force transmission rod 332.

[0060] (4) The tension / compression sensor 331 measures the maximum static friction force. f j Data Acquisition: Because the bottom end of the tension / compression sensor 331 is subjected to a forward force from the force transmission rod 332, the elastic body of the tension / compression sensor 331 deforms. Based on the change in resistance of the strain gauge caused by the deformation of the elastic body under force, the tension / compression sensor 331 converts the physical tension signal into a measurable electrical signal. As the outer shell 1 moves, the static friction gradually increases (e.g., ...). Figure 9 As shown, the static friction gradually increases from time 0s to 2s. When the driving force applied by the moving drive mechanism 2 to the housing 1 increases to a certain critical value, the maximum static friction between the friction block 314 and the surface of the test sample is reached. f j The maximum static friction force is overcome at the instant when the friction blocks 314 are about to slide relative to each other but have not yet done so. The peak force measured by the tension / compression sensor 331 is the maximum static friction force. f j (like Figure 9 As shown, the peak force was measured at 2 seconds, which is also the sensor pressure value, i.e., the maximum static friction force. f j (90N).

[0061] Phase 2: Collecting dynamic friction under relative sliding conditions f d .

[0062] (1) State transition: When the friction block 314 begins to slide relative to the surface of the test sample, the friction force changes from static friction to dynamic friction;

[0063] (2) Kinetic friction f dThe force is generated and transmitted to the force transmission rod 332: at this time, the frictional force exerted by the test sample surface on the friction block 314 becomes kinetic friction. f d kinetic friction f d The direction is still forward (resisting relative motion), kinetic friction. f d The magnitude is usually smaller than the maximum static friction force. f j And maintain a relatively stable forward kinetic friction force f d The force continues to act forward on the bottom end of the tension / compression sensor 331 through the friction block 314 and the force transmission rod 332;

[0064] (3) The tension and compression sensor 331 is sensitive to dynamic friction. f d Data acquisition: The reading of the tension / compression sensor 331 decreases from the peak force of static friction to a smaller and more stable force value, which is the dynamic friction force. f d (like Figure 9 As shown, during the period from 2s to 4s, the sensor pressure value gradually decreases from the peak force of static friction, and then stabilizes at a force value between 4s and 14s.

[0065] The friction coefficient testing device can simultaneously test the static friction coefficient and the dynamic friction coefficient. When using ground material as the test sample, the friction coefficient testing device is placed in the test area, and the first drive device 321 and the moving drive mechanism 2 are started to perform the test. It does not rely on other external conditions in the test site environment, which facilitates the on-site friction coefficient testing of ground materials. It solves the technical problems of the existing friction coefficient testing devices being complicated to operate and having certain requirements on the test site environment.

[0066] To further explain, the drive transmission assembly 32 also includes a first transmission gear 323, a second transmission gear 324, and a rotating shaft 325. The output shaft of the first drive device 321 is fixedly connected to the first transmission gear 323. The first transmission gear 323 meshes with the second transmission gear 324. The second transmission gear 324 and the eccentric wheel 322 are respectively fixedly connected to the rotating shaft 325.

[0067] The eccentric wheel 322 has a support surface 3221 on its wheel surface. The support surface 3221 is planar and is located near the rotation center of the eccentric wheel 322.

[0068] By setting the first transmission gear 323, the second transmission gear 324, and the rotating shaft 325, when the first driving device 321 drives the first transmission gear 323 to rotate, the first transmission gear 323 drives the second transmission gear 324 to rotate, and the second transmission gear 324 drives the eccentric wheel 322 to rotate through the rotating shaft 325, thereby realizing the transmission connection between the driving end of the first driving device 321 and the eccentric wheel 322, and realizing the first driving device 321 driving the eccentric wheel 322 to rotate.

[0069] Specifically, the first driving device 321 is a rotary motor, which drives the first transmission gear 323 to rotate.

[0070] Furthermore, by providing the support surface 3221 on the wheel surface of the eccentric wheel 322, when the first driving device 321 drives the eccentric wheel 322 to rotate to the position where the counterweight 311 is pressed down, the wheel surface of the eccentric wheel 322 near the center of rotation (i.e., the support surface 3221) abuts against the bottom end face of the top rod 3111. At this time, the planar support surface 3221 can more stably support the top rod 3111 compared to the arc surface structure, ensuring the stability of the testing process.

[0071] To further explain, the top rods 3111 are symmetrically arranged on both sides of the counterweight 311 along its length, and the eccentric wheels 322 are symmetrically arranged on both sides of the counterweight 311 along its length. The two ends of the rotating shaft 325 are respectively fixedly connected to the eccentric wheels 322, and the bottom end face of the top rod 3111 abuts against the wheel surface of the corresponding eccentric wheel 322.

[0072] The friction coefficient testing device also includes a first support frame 4, which is fixedly mounted on the outer shell 1. The first support frames 4 are symmetrically arranged on both sides of the counterweight 311 along its length. The first drive device 321 is fixedly mounted on one of the first support frames 4. The two ends of the rotating shaft 325 are rotatably connected to the two first support frames 4 respectively.

[0073] The symmetrically arranged top rod 3111 and eccentric wheel 322 can simultaneously press down the counterweight 311 on both sides of the counterweight 311 along its length, improving the accuracy of the test. In addition, by setting the first support frame 4, the first support frame 4 can realize the installation of the first drive device 321 and support the rotating shaft 325.

[0074] Specifically, the friction coefficient testing device further includes a second support frame 5, which is fixedly mounted on the outer casing 1;

[0075] The tension / compression sensor 331 is vertically arranged in the up-down direction, the force transmission rod 332 is arranged in the horizontal direction, the bottom of the second support frame 5 has a through-hole 51, the top of the tension / compression sensor 331 is fixedly connected to the second support frame 5, the bottom of the tension / compression sensor 331 extends to a position corresponding to the connection port 51, and the force transmission rod 332 is rotatably connected to the bottom of the tension / compression sensor 331 in the connection port 51.

[0076] By setting the second support frame 5, which is fixedly installed on the outer shell 1, the top of the tension / compression sensor 331 is fixedly connected to the outer shell 1. When the outer shell 1 moves forward, the tension / compression sensor 331 also moves forward synchronously. The connection port 51 provides a position for the force transmission rod 332 to connect to the tension / compression sensor 331. Since the test sample (ground material) is usually horizontal, the force transmission rod 332 is set in the horizontal direction, which can transmit the horizontal frictional force to the tension / compression sensor 331. The bottom end of the vertically set tension / compression sensor 331 deforms under the force transmission, thereby realizing the collection of frictional force.

[0077] Specifically, the force testing component 33 further includes a first mounting block 333 and a second mounting block 334;

[0078] One end of the first mounting block 333 is fixedly connected to the bottom of the tension / compression sensor 331, the other end of the first mounting block 333 is rotatably connected to one end of the force transmission rod 332, the other end of the force transmission rod 332 is rotatably connected to one end of the second mounting block 334, and the other end of the second mounting block 334 is fixedly connected to the bottom of the mounting bracket 313.

[0079] Specifically, the force transmission rod 332 can be rotatably connected to the first mounting block 333 and the second mounting block 334 via a bearing. For example, in the structure where the force transmission rod 332 is rotatably connected to the first mounting block 333, the inner ring of the bearing is fixedly connected to the first mounting block 333, and the outer ring of the bearing is fixedly connected to the force transmission rod 332. The structure where the force transmission rod 332 is rotatably connected to the second mounting block 334 is similar.

[0080] By setting the first mounting block 333 and the second mounting block 334, the bottom of the tension / compression sensor 331 is rotatably connected to one end of the force transmission rod 332, and the other end of the force transmission rod 332 is rotatably connected to the bottom of the mounting frame 313. It should be noted that, since the counterweight 311 presses down, it also presses down the mounting frame 313 and the friction block 314. The rotatable connection between the mounting frame 313 and the force transmission rod 332, and between the tension / compression sensor 331 and the force transmission rod 332, prevents breakage at the connection points when the mounting frame 313 presses down, as the connection between the mounting frame 313 and the force transmission rod 332, and between the tension / compression sensor 331 and the force transmission rod 332, is fixed. In actual testing, the pressing distance of the mounting frame 313 and the friction block 314 is very small (approximately 2mm), therefore the force transmission rod 332 can remain essentially horizontal.

[0081] To further explain, the second support frame 5 is disposed on the side of the counterweight 311 away from the connecting block 312. A limiting block 52 is fixedly disposed on the top surface of the second support frame 5. The limiting block 52 extends toward the counterweight 311 and is provided with a limiting abutment portion 521. The end of the counterweight 311 away from the connecting block 312 is located below the limiting abutment portion 521.

[0082] Since the counterweight 311 can rise or fall under the action of the eccentric wheel 322, by setting the limiting block 52, when the push rod 3111 is lifted by the eccentric wheel 322, the counterweight 311 also rises synchronously and abuts against the limiting abutment part 521. The limiting abutment part 521 can limit the height of the counterweight 311 and play a limiting role for the counterweight 311. Under the action of the limiting abutment part 521 and the eccentric wheel 322, the position of the counterweight 311 can be fixed, avoiding the counterweight 311 from jumping up and down during the process of moving the friction coefficient testing device.

[0083] Preferably, the limiting abutment portion 521 has an abutment piece 522 on its end face facing the counterweight block 311. The abutment piece 522 can be made of a material with a certain elasticity, such as a rubber sheet or a polyurethane sponge sheet, so that when the counterweight block 311 abuts against the limiting abutment portion 521, it can contact the abutment piece 522. Under the elastic action of the abutment piece 522, the counterweight block 311 can avoid direct hard contact with the limiting abutment portion 521, which would damage the device components. This reduces the wear of the counterweight block 311 and prevents the counterweight block 311 from being affected by wear, thus ensuring the accuracy of the test.

[0084] To further explain, the friction coefficient testing device also includes a third support frame 6, which is fixedly mounted on the outer shell 1 and is located on the side of the connecting block 312 away from the counterweight 311. The end of the connecting block 312 away from the counterweight 311 is rotatably connected to the third support frame 6.

[0085] By setting the third support frame 6, the third support frame 6 can support the end of the connecting block 312. At the same time, since the end of the connecting block 312 away from the counterweight 311 is rotatably connected to the third support frame 6, when the counterweight 311 is pressed down, it can drive the connecting block 312 to be pressed down, thereby driving the mounting frame 313 and the friction block 314 to be pressed down, so that the friction block 314 comes into contact with the test sample.

[0086] Optionally, the connecting block 312 is rotatably connected to the third support frame 6 via a rotating shaft, the rotating shaft is rotatably connected to the third support frame 6 via a bearing, and the connecting block 312 is fixedly connected to the rotating shaft.

[0087] Optionally, the mounting bracket 313 can be rotatably connected to the bottom of the connecting block 312 via a pin. Since the mounting bracket 313 is rotatably connected to the connecting block 312, when the counterweight block 311 is pressed down, the friction block 314 will press vertically downwards onto the surface of the test sample due to gravity.

[0088] To further explain, the friction block 314 includes a plug-in portion 3141 and a friction portion 3142. The plug-in portion 3141 is fixedly connected to the top surface of the friction portion 3142 and is perpendicularly connected to the friction portion 3142. The bottom surface of the mounting bracket 313 is provided with a plug-in interface 3131. The plug-in interface 3131 is open, and the plug-in portion 3141 is detachably inserted into the plug-in interface 3131.

[0089] The friction plate 3143 is fixedly connected to the bottom end face of the friction part 3142.

[0090] By fixing the friction plate 3143 to the bottom end face of the friction part 3142, the friction plate 3143 can simulate the relative friction medium used in daily life. For example, when it is necessary to simulate the use of a general shoe sole, a high-hardness rubber friction plate can be used for simulation testing; when it is necessary to simulate the bare foot state, a medium-hardness rubber friction plate can be used for simulation testing. Since the friction block 314 is provided with the insertion part 3141, the friction block 314 is detachably connected to the insertion interface 3131 of the mounting bracket 313 through the insertion part 3141, and different friction blocks 314 can be replaced according to actual testing needs.

[0091] In addition, depending on the different usage scenarios, different media such as water, shampoo, and oil can be applied between the friction plate 3143 and the test sample to conduct friction coefficient tests under different media conditions.

[0092] Specifically, the bottom end of the outer casing 1 is provided with a base plate 12. The moving drive mechanism 2, the testing mechanism 3, the second support frame 5, and the third support frame 6 are all disposed on the base plate 12. The through hole 11 is opened on the base plate 12. The second support frame 5 and the third support frame 6 are respectively fixedly connected to the base plate 12. One end of the first support frame 4 is fixedly connected to the second support frame 5, and the other end of the first support frame 4 is fixedly connected to the third support frame 6. The first support frame 4 is suspended, which can avoid interference between the first transmission gear 323 and the second transmission gear 324 and the base plate 12 when rotating, so that the friction coefficient testing device can smoothly complete the testing process.

[0093] Specifically, the mobile drive mechanism 2 includes a second drive device 21 and a drive wheel 22. The second drive device 21 is fixedly installed on the housing 1. The output shaft of the second drive device 21 is fixedly connected to the drive wheel 22. The second drive device 21 drives the drive wheel 22 to rotate.

[0094] The friction coefficient testing device further includes a guide wheel assembly 7. The moving drive mechanism 2 is disposed at one end of the housing 1, and the guide wheel assembly 7 is disposed at the other end of the housing 1. The guide wheel assembly 7 includes a third mounting block 71 and a guide wheel 72. The third mounting block 71 is fixedly disposed on the housing 1, and the guide wheel 72 is rotatably mounted on the third mounting block 71.

[0095] By setting the second driving device 21 and the driving wheel 22, the outer shell 1 is driven to move relative to the test sample. In addition, the guide wheel assembly 7 can guide the other end of the outer shell 1 to maintain the stability of the movement process.

[0096] Specifically, the second driving device 21 is a driving motor, and the two ends of the driving motor are respectively provided with output shafts. The output shafts at both ends of the driving motor are respectively connected to a driving wheel 22. The guide wheel assembly 7 is symmetrically arranged on both sides of the length direction of the third support frame 6 to realize the stable movement of the friction coefficient testing device on the surface of the test sample.

[0097] Preferably, the guide wheel assembly 7 further includes an encoder 73, which is fixedly connected to the guide wheel 72. By setting the encoder 73, the moving distance of the friction coefficient testing device during the test can be recorded according to the number of rotations of the guide wheel 72. Since the test sample may be non-uniform, the tester can set the moving distance according to the test requirements (for example, for samples that may be non-uniform, a certain test distance needs to be ensured to ensure the reliability of the test) and verify whether the moving distance requirement has been met by using the recorded data of the encoder 73.

[0098] Furthermore, the friction coefficient testing device also includes a handle 8, a display screen 9, and a control circuit board;

[0099] The handle 8 and the display screen 9 are respectively fixedly disposed on the housing 1, and both the handle 8 and the display screen 9 are exposed outside the housing 1;

[0100] The control circuit board is fixedly disposed inside the housing 1, and the display screen 9, the drive transmission assembly 32, the first drive device 321 and the tension and compression sensor 331 are electrically connected to the control circuit board.

[0101] By providing the handle 8, the tester can easily move the friction coefficient testing device by simply gripping the handle 8. Furthermore, the control circuit board enables the activation control of the drive transmission assembly 32 and the first drive device 321. The tester can start the test via button operation on the display screen 9. The control circuit board receives test data from the tension / compression sensor 331, automatically calculates the static and dynamic friction coefficients, and displays the test results on the display screen 9, making operation convenient.

[0102] Specifically, the second drive device 21 is electrically connected to the control circuit board.

[0103] Preferably, the friction coefficient testing device is further provided with a battery, which is fixedly disposed inside the housing 1. The battery is electrically connected to the control circuit board. By providing the battery, power can be supplied to the control circuit board and the display screen 9, the first drive device 321, the second drive device 21 and the tension and compression sensor 331 that are electrically connected to the control circuit. This makes the friction coefficient testing device not require an external power supply, making it more adaptable to the testing environment and more convenient to use.

[0104] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without any inventive effort, and these embodiments will all fall within the scope of protection of this utility model.

Claims

1. A friction coefficient testing device, characterized in that, It includes a housing and a moving drive mechanism and a testing mechanism disposed on the housing, wherein the moving drive mechanism is used to drive the friction coefficient testing device to move relative to the test sample; The testing mechanism includes a friction testing component, a drive transmission component, and a force testing component; The friction testing assembly includes a counterweight, a connecting block, a mounting bracket, and a friction block. One end of the connecting block is rotatably connected to the outer shell, and the other end of the connecting block is fixedly connected to the end of the counterweight. A top rod is provided on the side wall of the end of the counterweight connected to the connecting block. The mounting bracket is rotatably connected to the bottom of the connecting block, and the friction block is mounted on the bottom end face of the mounting bracket. The drive transmission assembly includes a first drive device and an eccentric wheel. The drive end of the first drive device is connected to the eccentric wheel. The bottom end face of the push rod abuts against the wheel surface of the eccentric wheel. The first drive device drives the eccentric wheel to rotate so that the eccentric wheel lifts the counterweight or presses the counterweight down. The outer shell has a through hole, through which the friction block passes. When the counterweight is pressed down, the bottom surface of the friction block abuts against the test sample. The force testing assembly includes a tension / compression sensor and a force transmission rod. The top of the tension / compression sensor is fixedly connected to the housing, the bottom of the tension / compression sensor is rotatably connected to one end of the force transmission rod, and the other end of the force transmission rod is rotatably connected to the bottom of the mounting bracket. The tension / compression sensor is used to collect the maximum static and dynamic friction forces of the friction block relative to the test sample.

2. The friction coefficient testing device according to claim 1, characterized in that, The drive transmission assembly further includes a first transmission gear, a second transmission gear, and a rotating shaft. The output shaft of the first drive device is fixedly connected to the first transmission gear. The first transmission gear meshes with the second transmission gear. The second transmission gear and the eccentric wheel are respectively fixedly connected to the rotating shaft. The eccentric wheel has a support surface on its surface. The support surface is planar and is located near the rotation center of the eccentric wheel.

3. The friction coefficient testing device according to claim 2, characterized in that, The top rods are symmetrically arranged on both sides of the counterweight along its length, and the eccentric wheels are symmetrically arranged on both sides of the counterweight along its length. The two ends of the rotating shaft are respectively fixedly connected to the eccentric wheels, and the bottom end face of the top rod abuts against the wheel surface of the corresponding eccentric wheel. The friction coefficient testing device further includes a first support frame, which is fixedly installed on the outer shell. The first support frames are symmetrically arranged on both sides of the counterweight along its length. The first drive device is fixedly installed on one of the first support frames. The two ends of the rotating shaft are rotatably connected to the two first support frames respectively.

4. The friction coefficient testing device according to claim 1, characterized in that, The friction coefficient testing device further includes a second support frame, which is fixedly mounted on the outer casing. The tension / compression sensor is vertically arranged in the up-down direction, the force transmission rod is arranged in the horizontal direction, the bottom of the second support frame has a through-hole, the top of the tension / compression sensor is fixedly connected to the second support frame, the bottom of the tension / compression sensor extends to a position corresponding to the through-hole, and the force transmission rod is rotatably connected to the bottom of the tension / compression sensor within the through-hole.

5. The friction coefficient testing device according to claim 4, characterized in that, The force testing component also includes a first mounting block and a second mounting block; One end of the first mounting block is fixedly connected to the bottom of the tension / compression sensor, the other end of the first mounting block is rotatably connected to one end of the force transmission rod, the other end of the force transmission rod is rotatably connected to one end of the second mounting block, and the other end of the second mounting block is fixedly connected to the bottom of the mounting frame.

6. The friction coefficient testing device according to claim 4, characterized in that, The second support frame is disposed on the side of the counterweight away from the connecting block. A limit block is fixedly disposed on the top surface of the second support frame. The limit block extends toward the counterweight and is provided with a limit abutment. The end of the counterweight away from the connecting block is located below the limit abutment.

7. The friction coefficient testing device according to claim 1, characterized in that, The friction coefficient testing device further includes a third support frame, which is fixedly mounted on the outer shell and located on the side of the connecting block away from the counterweight. The end of the connecting block away from the counterweight is rotatably connected to the third support frame.

8. The friction coefficient testing device according to claim 1, characterized in that, The friction block includes a plug-in part and a friction part. The plug-in part is fixedly connected to the top surface of the friction part and is perpendicularly connected to the friction part. The bottom surface of the mounting bracket is provided with a plug-in interface. The plug-in interface is open and the plug-in part is detachably inserted into the plug-in interface. A friction plate is fixedly connected to the bottom end face of the friction part.

9. The friction coefficient testing device according to claim 1, characterized in that, The mobile drive mechanism includes a second drive device and a drive wheel. The second drive device is fixedly mounted on the housing. The output shaft of the second drive device is fixedly connected to the drive wheel. The second drive device drives the drive wheel to rotate. The friction coefficient testing device further includes a guide wheel assembly. The moving drive mechanism is located at one end of the housing, and the guide wheel assembly is located at the other end of the housing. The guide wheel assembly includes a third mounting block and a guide wheel. The third mounting block is fixedly located on the housing, and the guide wheel is rotatably mounted on the third mounting block.

10. The friction coefficient testing device according to claim 1, characterized in that, The friction coefficient testing device also includes a handle, a display screen, and a control circuit board; The handle and the display screen are respectively fixedly mounted on the housing, and both the handle and the display screen are exposed outside the housing; The control circuit board is fixedly disposed inside the housing, and the display screen, the drive transmission assembly, the first drive device and the tension and compression sensor are electrically connected to the control circuit board respectively.

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