Identification device and method for researching related parameters of thermal friction model

Abstract

The invention belongs to the technical field of friction parameter identification systems and methods, and discloses an identification device and method for researching related parameters of a thermal friction model. The device is composed of a fixed supporting structure, a vibration control system, a test piece fixing clamp, a load applying device, a temperature control device, a vibration excitation device and a vibration measuring device. The vibration control system is fixed on one side of the fixed supporting structure; the excitation device is located on one side of the vibration control system and used for generating excitation force. The test piece fixing clamp comprises a movable clamp and a fixed clamp; the fixed clamp is fixed on the fixed supporting structure; the top end of the movable clamp is in contact with the load applying device for loading, and the side face is connected with the excitation device for vibration. The load applying device provided by the invention can provide a relatively stable positive pressure load according to a required load, and no disorder is generated due to external vibration, so that the accuracy of an experimental result is ensured. The vibration structure with the variable mass can change the overall mass of the vibration structure, and meets the structural requirements of same-frequency vibration.

Description

Technical Field

[0001] The present invention relates to the technical field of friction parameter identification systems and methods, and in particular to a device and method for studying the identification of parameters related to a thermal friction model. Background Art

[0002] The existing friction parameter identification device is composed of an experimental platform base, a driver unit, a sensor unit and a load unit. Figure 1 As shown: the motor driver under test is fixed on the driver support frame, and the driver support frame is fixed on the base of the experimental platform; the dynamic torque sensor is installed on the sensor support frame, and the sensor support frame is installed on the base of the experimental platform; the load unit is set on the base of the experimental platform, and the power output end of the driver under test is connected to one output end of the dynamic torque sensor through a coupling, and the other output end of the dynamic torque sensor is connected to the load unit through a coupling.

[0003] Combination Figure 1 The structure designed for the load unit is a dumbbell-like structure, which is relatively heavy. The range of applied load is greatly constrained due to the structural dimensions of the test bench, and the measured shaft parameters are also limited, thereby reducing the benefits of the designed product.

[0004] Secondly, for this form of load application, the impact may be small in a stationary state, but it may become unstable during rotation due to the uneven application of load forces at both ends. This becomes more severe as the speed increases, and may even affect the user's personal safety. Summary of the invention

[0005] The purpose of the present invention is to provide an identification device and method for studying parameters related to thermal friction models, which can preliminarily obtain the contact parameters of a certain material contact interface by simulating the application of boundary conditions under actual conditions. The device has the advantages of convenient and fast testing method, accurate testing, and easy installation.

[0006] The technical solution of the present invention is as follows: an identification device for studying parameters related to a thermal friction model, comprising a fixed support structure, a vibration control system, a specimen fixing fixture, a load applying device, a temperature control device, a vibration exciting device and a vibration measuring device;

[0007] The vibration control system is fixed to one side of the fixed support structure; the excitation device is located on one side of the vibration control system and is used to generate an exciting force;

[0008] The specimen fixing fixture includes a movable fixture 24 and a fixed fixture 12; the specimen 13 is fixed between the movable fixture 24 and the fixed fixture 12; the fixed fixture 12 is fixed on the fixed support structure;

[0009] The top end of the movable clamp 24 contacts the load applying device to apply the load, and the side surface thereof is connected to the vibration excitation device, thereby vibrating;

[0010] The temperature control device is located on one side of the test piece 13 and is used to heat the test piece 13 to a set temperature; the temperature control device is connected to the data acquisition device;

[0011] The vibration measuring device is fixed on the other side of the fixed supporting structure and is used to receive the vibration signal generated by the excitation; the vibration measuring device is connected to the data acquisition device;

[0012] The data collector transmits each data to the calculator 31 .

[0013] The vibration control system includes a vibration block and a supporting spring plate 5; the vibration block is fixed on the supporting spring plate 5, and the supporting spring plate 5 is fixed on the vibration block base 6; the vibration block is spliced ​​by various plates, and the plates parallel to the load direction are evenly distributed with threaded holes for changing the mass of the vibration block; the excitation device is located on one side of the vibration control system and is used to generate an exciting force.

[0014] The specimen fixing fixture also includes a moving fixture tail 30; the moving fixture tail 30 is concentrically fixed on the flange bearing 34; the ball screw lead 32 passes through the axis of the moving fixture tail 30 and the flange bearing 34, and is fixed to the top of the side panel of the vibration block through the ball screw bearing 33; one end of the moving fixture tail 30 is connected to the moving fixture 24 through the fixture spring plate 28; the top of the moving fixture 24 contacts the load applying device; the fixed fixture 12 is connected to the base 7 through the force sensor 16 and the base support rod; one side of the fixed fixture 12 is connected to the fixed fixture base 18 through the force sensor 16; the force sensor 16 is connected to the data collector.

[0015] The load applying device includes a loading screw 35, a longitudinal load bearing 37, a spring 40 and a loading base 41; one end of the loading screw 35 is connected to the frame-longitudinal 23, and the other end is connected to the loading screw support plate 38 through the longitudinal load bearing 37; the loading screw support plate 38 is fixed to the loading base 41 with a stud 39, and the stud 39 is provided with a spring for buffering and vibration absorption; guide rail columns 36 are symmetrically provided on both sides of the loading base 41 to control the relative direction of the loading base 41 to remain unchanged; a pin shaft 42 and a roller bearing 43 are installed at the bottom of the loading base 41, which are in contact with the top of the moving clamp 24.

[0016] The fixed support structure includes a vibration block base 6, a base 7, a fixed fixture base 18 and two frames; the vibration block base 6 and the fixed fixture base 18 are respectively fixed on the base 7; the two frames are respectively fixed to the side of the vibration block base 6, the side of the fixed fixture base 18 and the side of the base 7; the top ends of the two frames are connected by a frame-longitudinal 23.

[0017] The eddy current heating device in the temperature control device is located on one side of the test piece 13 to heat the test piece 13 to a set temperature. The temperature sensor 9 is located on the other side of the test piece 13 to measure the heating temperature of the test piece 13. The temperature sensor 9 is connected to the data acquisition device.

[0018] The vibration measuring device is a displacement sensor 19, which is located at the front end of the movable fixture 24, fixed on the fixed fixture base 18, and receives the vibration signal generated by the excitation.

[0019] The clamp spring plate 28 and the support spring plate 5 are both steel plates; the support spring plate 5 is used to support the mass block and can produce deformation in the excitation direction; the clamp spring plate 28 ensures that the tangential excitation force is accurately applied to the contact plane when the clamp is horizontal, and no additional bending moment is generated.

[0020] A method for identifying an identification device for studying parameters related to a thermal friction model comprises the following steps: debugging two force sensors 16 to zero, observing the output signal value of the longitudinal force sensor, adjusting the load application device to a certain calibrated pressure value, and setting the excitation frequency to a certain known value; adjusting the high-frequency heater in the temperature control device to a predetermined temperature, observing the temperature signal value output by the temperature sensor, and turning on the exciter 1 to provide vibration excitation when the value reaches the required temperature; observing the pressure transient value signal output by the force sensor, and gradually increasing the frequency of the exciter; the value of the lateral force sensor gradually increases, and when it reaches a certain value, the value becomes smaller, indicating that the static friction force limit of the specimen surface has been reached and becomes micro sliding friction, and then gradually reducing the frequency of the exciter, and the maximum value of the static friction force generated is the maximum friction force that can be generated by the final static friction force, corresponding to the corresponding friction coefficient.

[0021] Beneficial effects of the present invention: A specimen fixture provided can be installed with specimens of different volume sizes, and the fixing bolts at the end of the fixture can firmly fix the required specimen inside the fixture, thereby completing the test. Compared with the existing test methods, the design structure and test method of the present invention have a wider test range and are more convenient and accurate. The load application device of the present invention can give a relatively stable positive pressure load according to the required load, and will not be disturbed by external vibration, thereby ensuring the accuracy of the experimental results. The variable mass vibration structure can change the overall mass of the vibration structure, meeting the structural requirements of the same frequency vibration. The electromagnetic exciter is used to simulate the vibration load generated when the machine is working normally, and the amplitude, frequency and other related parameters of the exciting force can be continuously and accurately controlled through the function generator according to the actual load. The fixed base can be connected with other structures through the positioning hole, avoiding unnecessary errors during installation, realizing quick installation and improving the efficiency of the experiment. The adjustable specimen fixture can realize stepless adjustment of the height of the moving half fixture, providing excellent experimental convenience. The longitudinal load application device with a buffer structure avoids the influence of the longitudinal force during vibration, resulting in inaccurate data. The contact part between the longitudinal load applying device and the movable fixture is equipped with a roller bearing to avoid the longitudinal load applying device affecting the movable fixture when it has micro-slip. The bracket part adopts an "I"-shaped structure, which saves considerable space resources for positioning and installing other experimental structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a background technology device;

[0023] Figure 2 is a schematic diagram of an identification device for studying parameters related to a thermal friction model;

[0024] Figure 3 This is a schematic diagram of fixing the tail of the moving fixture;

[0025] Figure 4 Schematic diagram of the load application device.

[0026] In the figure: 1-exciter; 2-vibration block-back plate; 3-vibration block-right side plate; 4-vibration block-bottom plate; 5-support spring plate; 6-vibration block base; 7-base; 8-frame-vertical; 9-temperature sensor; 10-fastening screws; 11-support spring plate pad; 12-fixed fixture; 13-test piece; 14-upper half of base support rod; 15-lower half of base support rod; 16-force sensor; 17-data collector; 18-fixed fixture base; 19-displacement sensor; 20-heating wire fixture; 21-high frequency heating machine; 22- Frame - horizontal; 23 - frame - vertical; 24 - moving fixture; 25 - vibration block - main board; 26 - fixture spring plate pad; 27 - vibration block - left side plate; 28 - fixture spring plate; 29 - moving fixture tail pad; 30 - moving fixture tail; 31 - calculator; 32 - ball screw lead; 33 - ball screw bearing; 34 - flange bearing; 35 - loading rod; 36 - guide rail column; 37 - longitudinal bearing; 38 - loading screw support plate; 39 - stud; 40 - spring; 41 - loading base; 42 - pin; 43 - roller bearing. DETAILED DESCRIPTION

[0027] The identification device for studying the parameters related to the thermal friction model of the present invention is composed of a fixed support structure, a vibration control system, a specimen fixing fixture, a load applying device, a temperature control device, a vibration excitation device and a vibration measuring device. Figure 2 , Figure 3 , Figure 4 shown.

[0028] like Figure 2 As shown, the identification device for studying the parameters related to the thermal friction model consists of the following parts: a fixed support structure, a vibration control system, a specimen fixing fixture, a load applying device, a temperature control device, an excitation device and a vibration measuring device; the vibration control system is fixed on one side of the fixed support structure; the excitation device is located on one side of the vibration control system and is used to generate an exciting force;

[0029] The specimen fixing fixture includes a movable fixture 24 and a fixed fixture 12; the specimen 13 is fixed between the movable fixture 24 and the fixed fixture 12; the fixed fixture 12 is fixed on the fixed support structure;

[0030] The top end of the movable clamp 24 contacts the load applying device to apply the load, and the side surface thereof is connected to the vibration excitation device, thereby vibrating;

[0031] The temperature control device is located on one side of the test piece 13 and is used to heat the test piece 13 to a set temperature; the temperature control device is connected to the data acquisition device;

[0032] The vibration measuring device is fixed on the other side of the fixed supporting structure and is used to receive the vibration signal generated by the excitation; the vibration measuring device is connected to the data acquisition device;

[0033] The data collector transmits each data to the calculator 31 .

[0034] Furthermore, in one embodiment, the identification device for studying the parameters related to the thermal friction model includes an exciter 1, a vibration block-back plate 2, a vibration block-right side plate 3, a vibration block-bottom plate 4, a support spring plate 5, a vibration block base 6, a base 7, a frame-vertical 8, a temperature sensor 9, a fastening screw 10, a support spring plate pad 11, a fixed fixture 12, a test piece 13, an upper half of a base support rod 14, a lower half of a base support rod 15, a force sensor 16, a data collector 17, a fixed fixture base 18, a displacement sensor 19, and a heating wire clamp Tool 20, high-frequency heating machine 21, frame - horizontal 22, frame - vertical 23, movable clamp 24, vibration block - main board 25, clamp spring plate pad 26, vibration block - left side plate 27, clamp spring plate 28, movable clamp tail pad 29, movable clamp tail 30, calculator 31, ball screw lead 32, ball screw bearing 33, flange bearing 34, loading rod 35, guide column 36, longitudinal load bearing 37, loading screw support plate 38, stud 39, spring 40, loading base 41, pin 42, roller bearing 43.

[0035] In the fixed support structure, the vibration block base 6 and the fixed clamp base 18 are fixed to the upper surface of the base 7 with bolts, the lower ends of the four frame-vertical 8 are respectively fixed to the sides of the vibration block base 6, the base 7 and the fixed clamp base 18 with bolts, two frame-transverse 22 are fixed to the upper ends of the four frame-vertical 8 with bolts, and one frame-longitudinal 23 is fixed to the middle part of the frame-transverse 22 with bolts.

[0036] The vibration control system includes a vibration block-main board 25, a vibration block-back board 2 fixed to the upper ends of the two support spring plates 5 by two support spring plate pads 11 and bolts, the lower ends of the two support spring plates 5 are fixed to the front and rear upper ends of the vibration block base 6 by support spring plate pads 11 and bolts, the vibration block-bottom board 4 is fixed between the vibration block-main board 25 and the vibration block-back board 2 by bolts, the vibration block-left side board 27 and the vibration block-right side board 3 are fixed to the two sides of the vibration block-main board 25, the vibration block back board 2 and the vibration block-bottom board 4 by bolts, and the vibration block-left side board 27 and the vibration block-right side board 3 are evenly distributed with threaded holes for changing the mass of the entire vibration block.

[0037] The specimen fixing fixture includes a movable fixture tail 30 connected to the middle part of the vibration block-main board 25 through a ball screw structure through a ball screw bearing 33, the flange bearing 34 in the ball screw is concentrically fixed to the middle part of the movable fixture tail 30 with bolts, the ball screw lead 32 is fixed to the middle part of the vibration block-main board 25 with a ball screw bearing 33, the movable fixture tail 30 is connected to one end of the fixture spring plate 28 through the movable fixture tail pad 29 and bolts, the other end of the fixture spring plate 28 is connected to the movable fixture 24 through the fixture spring plate pad 26 with bolts, and the fixed fixture 12 is threadedly connected to the fixed fixture base 6 through the force sensor 16.

[0038] The load applying device includes a loading screw 35 which is connected to the frame-longitudinal 23 through a threaded hole. The loading screw 35 is connected to the loading screw support plate 38 through a longitudinal load bearing 37. The loading screw support plate 38 is fixed to the loading base 41 with a double-headed stud 39 and supported by a spring 40 in the middle. Four springs are sleeved on the four double-headed screws between the loading screw support plate 38 and the loading base 41 for buffering and vibration absorption. Guide rail columns 36 are symmetrically arranged on both sides of the loading base 41 to control the relative direction of the loading base to remain unchanged. A pin shaft 42 and a roller bearing 43 are installed under the loading base 41 to adapt to the micro-slippage of the dynamic clamp.

[0039] The eddy current heating device in the temperature control device is located on one side of the test piece, and the eddy current heating device includes a heating wire fixture 20 and a high-frequency heating machine 21, which are used to heat the test piece to a certain temperature. The temperature sensor 9 is located on the other side of the test piece to measure the heating temperature of the test piece.

[0040] The electromagnetic exciter 1 of the excitation device is located at the rear side of the vibration control system and is used to generate the excitation force;

[0041] The displacement sensor 19 of the vibration measuring device is located at the front end of the movable clamp 24 and receives the vibration signal generated by the excitation and transmits it to the calculator 31 through the data collector 17-b. The force sensor 16 is located directly below the fixed clamp and is connected to the base and the fixed clamp by a support rod, and the tail of the fixed clamp is connected to the base of the fixed clamp and transmits it to the computer 31 through the data collector 17-a.

[0042] The test method for the friction coefficient of the surface of the experimental specimen includes the following steps: debugging two force sensors to zero, observing the output signal value of the longitudinal force sensor, adjusting the load application device to a certain calibrated pressure value, debugging the excitation frequency of the signal generator connected to the power amplifier to a certain known value, adjusting the high-frequency heating machine to a predetermined temperature, observing the temperature signal value output by the temperature sensor, turning on the exciter to give vibration excitation when the value reaches the required temperature, observing the pressure transient numerical signal output by the force sensor, gradually increasing the frequency of the exciter, and the lateral force sensor value gradually increases. When it reaches a certain value, the value will decrease. At this time, the static friction force limit of the specimen surface has been reached and becomes micro-sliding friction. Then the frequency of the exciter is gradually reduced. The maximum value of the static friction force generated is the maximum friction force that can be generated by the final static friction force, and the corresponding friction coefficient can be obtained. The same method can be used to obtain the surface friction coefficient of different materials at different temperatures.

Claims

1. An identification device for studying parameters related to a thermal friction model, characterized in that: The identification device includes a fixed support structure, a vibration control system, a specimen fixing fixture, a load applying device, a temperature control device, a vibration exciting device and a vibration measuring device; The vibration control system is fixed to one side of the fixed support structure; the excitation device is located on one side of the vibration control system and is used to generate an exciting force; The specimen fixing fixture comprises a movable fixture (24) and a fixed fixture (12); the specimen (13) is fixed between the movable fixture (24) and the fixed fixture (12); the fixed fixture (12) is fixed on a fixed support structure; The top end of the movable clamp (24) contacts the load applying device to apply the load, and the side surface thereof is connected to the vibration exciting device so as to vibrate; The temperature control device is located on one side of the test piece (13) and is used to heat the test piece (13) to a set temperature; the temperature control device is connected to a data acquisition device; The vibration measuring device is fixed on the other side of the fixed supporting structure and is used to receive the vibration signal generated by the excitation; the vibration measuring device is connected to the data acquisition device; The data collector transmits each data to the calculator (31).

2. The identification device for studying parameters related to thermal friction model according to claim 1, characterized in that: The vibration control system comprises a vibration block and a supporting spring plate (5); the vibration block is fixed on the supporting spring plate (5), and the supporting spring plate (5) is fixed on the vibration block base (6); the vibration block is formed by splicing various plates, and the plates parallel to the load direction are evenly distributed with threaded holes for changing the mass of the vibration block; the excitation device is located on one side of the vibration control system and is used to generate an exciting force.

3. The identification device for studying parameters related to thermal friction model according to claim 2, characterized in that: The specimen fixing fixture further comprises a movable fixture tail (30); the movable fixture tail (30) is coaxially fixed on the flange bearing (34); a ball screw lead (32) passes through the axis of the movable fixture tail (30) and the flange bearing (34), and is fixed to the top of the side panel of the vibration block through the ball screw bearing (33); one end of the movable fixture tail (30) is connected to the movable fixture (24) through a fixture spring plate (28); the top end of the movable fixture (24) contacts the load applying device; the fixed fixture (12) is connected to the base (7) through a force sensor (16) and a base support rod; one side of the fixed fixture (12) is connected to the fixed fixture base (18) through the force sensor (16); and the force sensor (16) is connected to a data acquisition device.

4. The identification device for studying parameters related to thermal friction model according to any one of claims 1 to 3, characterized in that: The load applying device comprises a loading screw (35), a longitudinal bearing (37), a spring (40) and a loading base (41); one end of the loading screw (35) is connected to the frame-longitudinal (23), and the other end is connected to the loading screw support plate (38) through the longitudinal bearing (37); the loading screw support plate (38) is fixed to the loading base (41) by a stud (39), and a spring is sleeved on the stud (39) for buffering and vibration absorption; guide rail columns (36) are symmetrically arranged on both sides of the loading base (41) to control the relative direction of the loading base (41) to remain unchanged; a pin shaft (42) and a roller bearing (43) are installed below the loading base (41) to contact the top of the movable clamp (24).

5. The identification device for studying parameters related to thermal friction model according to claim 4, characterized in that: The fixed support structure comprises a vibration block base (6), a base (7), a fixed fixture base (18) and two frames; the vibration block base (6) and the fixed fixture base (18) are respectively fixed on the base (7); the two frames are respectively fixed to the side surface of the vibration block base (6), the side surface of the fixed fixture base (18) and the side surface of the base (7); and the top ends of the two frames are connected via a frame-longitudinal (23).

6. The identification device for studying parameters related to thermal friction model according to claim 5, characterized in that: The eddy current heating device in the temperature control device is located on one side of the test piece (13) and is used to heat the test piece (13) to a set temperature. The temperature sensor (9) is located on the other side of the test piece (13) and is used to measure the heating temperature of the test piece (13). The temperature sensor (9) is connected to a data acquisition device.

7. The identification device for studying parameters related to thermal friction model according to claim 6, characterized in that: The vibration measuring device is a displacement sensor (19), which is located at the front end of the movable fixture (24), fixed on the fixed fixture base (18), and receives the vibration signal generated by the excitation.

8. The identification device for studying parameters related to thermal friction model according to any one of claims 3 to 7, characterized in that: The clamp spring plate (28) and the support spring plate (5) are both steel plates; the support spring plate (5) is used to support the mass block and can generate deformation in the excitation direction; the clamp spring plate (28) ensures that the tangential excitation force is accurately applied to the contact plane when the clamp is horizontal, and no additional bending moment is generated.

9. An identification method using the identification device for studying parameters related to a thermal friction model as claimed in any one of claims 1 to 8, characterized in that: The method comprises the following steps: debugging two force sensors (16) to zero, observing the output signal value of the longitudinal force sensor, adjusting the load application device to a certain calibrated pressure value, and setting the excitation frequency to a certain known value; adjusting the high-frequency heating machine in the temperature control device to a predetermined temperature, observing the temperature signal value output by the temperature sensor, and starting the exciter (1) to provide vibration excitation when the value reaches the required temperature; observing the pressure transient value signal output by the force sensor, and gradually increasing the frequency of the exciter; the value of the lateral force sensor gradually increases, and when it reaches a certain value, the value decreases, indicating that the static friction force limit of the test piece surface has been reached and becomes micro sliding friction, and then gradually decreasing the frequency of the exciter, and the maximum value of the static friction force generated is the maximum friction force that can be generated by the final static friction force, and the corresponding friction coefficient is obtained.

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