An identification device and method for studying relevant parameters of a thermal friction model

Abstract

The present application belongs to the technical field of friction parameter identification system and method, and discloses an identification device and method for studying thermal friction model related parameters. The device is composed of a fixed support structure, a vibration control system, a test piece fixing clamp, a load applying device, a temperature control device, an exciting device and a vibration measuring device. The vibration control system is fixed on one side of the fixed support structure. The exciting device is located on one side of the vibration control system and used for generating exciting force. The test piece fixing clamp includes a movable clamp and a fixed clamp. The fixed clamp is fixed on the fixed support structure. The top end of the movable clamp contacts the load applying device for loading, and the side surface of the movable clamp is connected with the exciting device so as to vibrate. The load applying device can give relatively stable normal pressure load according to the required load, and will not be disturbed due to external vibration, thereby ensuring the accuracy of experimental results. The variable mass vibration structure can change the overall mass of the vibration structure, meeting the needs of the same frequency vibration structure.

Description

Technical Field

[0001] This invention relates to the technical field of friction parameter identification systems and methods, and in particular to an apparatus and method for studying the identification of relevant parameters of thermal friction models. Background Technology

[0002] Existing friction parameter identification devices consist of an experimental platform base, a driver unit, a sensor unit, and a load unit, such as... Figure 1 As shown: The motor driver under test is fixed on the driver support frame, which is fixed on the experimental platform base; the dynamic torque sensor is mounted on the sensor support frame, which is mounted on the experimental platform base; the load unit is set on the experimental platform base; 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 load unit is designed with a dumbbell-like structure, which is quite heavy. The range of load application is greatly constrained by the structural dimensions of the test bench, and the axial parameters that can be measured are also limited, thus reducing the benefits of the designed product.

[0004] Secondly, this type of load application may have a smaller impact when stationary, but when rotating, it may become unstable due to uneven application of load forces at both ends. This becomes more severe as the speed increases, and may even affect the personal safety of the user. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for identifying parameters related to a thermal friction model. By simulating the application of boundary conditions under actual conditions, the contact parameters of a certain material interface can be initially obtained. This invention has the advantages of convenient and fast testing, accurate testing, and easy installation.

[0006] The technical solution of the present invention is as follows: an identification device for studying relevant parameters of a thermal friction model, comprising a fixed support structure, a vibration control system, a specimen fixing fixture, a load application device, a temperature control device, an excitation device, and a vibration measurement 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 excitation force.

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

[0009] The dynamic clamp 24 top end contacts the load applying device to apply load, and its side is connected with the exciting device to vibrate;

[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 with the data collector;

[0011] The vibration measuring device is fixed on the other side of the fixed support structure, and is used to receive the vibration signal generated by the exciting; the vibration measuring device is connected with the data collector;

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

[0013] The vibration control system comprises a vibration block and a support spring plate 5; the vibration block is fixed on the support spring plate 5, and the support spring plate 5 is fixed on a vibration block base 6; the vibration block is spliced by plates, and screw holes are uniformly distributed on the plates parallel to the load direction, which are used to change the mass of the vibration block; the exciting device is located on one side of the vibration control system, and is used to generate exciting force.

[0014] The test piece fixing clamp further comprises a dynamic clamp tail 30; the dynamic clamp tail 30 is concentrically fixed on a flange bearing 34; a ball screw screw rod 32 passes through the shaft centers of the dynamic clamp tail 30 and the flange bearing 34, and is fixed on the top of the side plate of the vibration block through a ball screw bearing 33; one end of the dynamic clamp tail 30 is connected with the dynamic clamp 24 through a clamp spring plate 28; the top end of the dynamic clamp 24 contacts the load applying device; the fixed clamp 12 is connected with the base 7 through a force sensor 16 and a base support rod; one side of the fixed clamp 12 is connected with a fixed clamp base 18 through the force sensor 16; the force sensor 16 is connected with the data collector.

[0015] The load applying device comprises a loading screw rod 35, a longitudinal load bearing 37, a spring 40 and a loading base 41; one end of the loading screw rod 35 is connected with a rack-longitudinal 23, and the other end is connected with a loading screw rod support plate 38 through the longitudinal load bearing 37; the loading screw rod support plate 38 is fixed on the loading base 41 through a stud 39, and a spring is sleeved on the stud 39 to buffer and absorb vibration; 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 be unchanged; a pin shaft 42 and a roller bearing 43 are installed below the loading base 41, and contact the upper part of the dynamic clamp 24.

[0016] The fixed support structure comprises the vibration block base 6, the base 7, the fixed clamp base 18 and two racks; the vibration block base 6 and the fixed clamp base 18 are respectively fixed on the base 7; the two racks are respectively fixed on the side of the vibration block base 6, the side of the fixed clamp base 18 and the side of the base 7; the top ends of the two racks are connected through the rack-longitudinal 23.

[0017] The vortex heating device in the temperature control device is located on one side of the test piece 13, and is used for heating 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 for measuring the heating temperature of the test piece 13. The temperature sensor 9 is connected to the data collector.

[0018] The vibration measuring device is a displacement sensor 19 located at the front end of the movable clamp 24 and fixed on the fixed clamp base 18 to receive 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 for supporting the mass block and can be deformed 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] An identification method of an identification device for studying related parameters of a thermal friction model, comprising the following steps: adjusting two force sensors 16 to zero, observing the output signal value of the longitudinal force sensor, setting the load applying device to a certain calibration pressure value, 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 give vibration excitation when the value reaches the required temperature; observing the pressure transient value signal output by the force sensor, gradually increasing the frequency of the exciter; the value of the transverse force sensor gradually increases, and when it reaches a certain value, the value will decrease, which represents that the limit of the static friction force on the surface of the test piece is reached, and it becomes micro sliding friction. Then gradually reduce the frequency of the exciter, and the maximum value of the generated static friction force is the maximum friction force that can be generated by the final static friction force. The corresponding friction coefficient is obtained.

[0021] The beneficial effects of the present application: the provided test piece clamp can install test pieces of different volume sizes, the fixing bolts at the end of the clamp can firmly fix the required test piece inside the clamp, and then complete the test. The design structure and test method of the present application have wider test range and more convenient and accurate test compared with the existing test method. The load applying device can give relatively stable normal pressure load according to the required load, and will not be disturbed due to 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 needs of the same frequency vibration structure. The electromagnetic exciter is used to simulate the vibration load generated by the normal working of the machine, which can realize continuous and accurate control of the excitation force amplitude, frequency and other related parameters according to the actual load through the function generator. The fixed form base can be positioned and connected with other structures through the positioning hole, avoiding unnecessary errors during installation, realizing fast installation and improving the efficiency of the experiment. The adjustable test piece clamp can realize stepless adjustment of the height of the moving half clamp, providing excellent experimental convenience. The longitudinal load applying device with buffer structure avoids the influence of vibration on the longitudinal force, resulting in inaccurate data. The longitudinal load applying device and the contact part of the moving clamp are provided with a roller bearing, which avoids the influence of the longitudinal load applying device on the moving clamp when the moving clamp produces micro-slippage. The bracket part adopts an "H" shaped structure, which saves considerable space resources for positioning and installing other structures for the experiment. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0024] Figure 3 It is a fixed schematic diagram of the moving clamp tail;

[0025] Figure 4 It is a schematic diagram of the load applying device.

[0026] 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 screw; 11 - support spring plate pad; 12 - fixed clamp; 13 - test piece; 14 - base support rod upper half; 15 - base support rod lower half; 16 - force sensor; 17 - data collector; 18 - fixed clamp base; 19 - displacement sensor; 20 - heating wire clamp; 21 - high-frequency heating machine; 22 - frame - horizontal; 23 - frame - vertical; 24 - movable clamp; 25 - vibration block - main plate; 26 - clamp spring plate pad; 27 - vibration block - left side plate; 28 - clamp spring plate; 29 - movable clamp tail pad; 30 - movable clamp tail; 31 - calculator; 32 - ball screw screw rod; 33 - ball screw bearing; 34 - flange bearing; 35 - loading rod; 36 - guide rail column; 37 - vertical load bearing; 38 - loading screw support plate; 39 - stud bolt; 40 - spring; 41 - loading base; 42 - pin shaft; 43 - roller bearing. DETAILED DESCRIPTION

[0027] The identification device for studying the parameters related to the hot friction model of the application is composed of a fixed support structure, a vibration control system, a test piece fixing clamp, a load applying device, a temperature control device, an excitation device and a vibration measuring device. The specific implementation is shown in Figure 2 、 Figure 3 、 Figure 4

[0028] As shown in Figure 2 , the identification device for studying the parameters related to the hot friction model is composed of the following parts: a fixed support structure, a vibration control system, a test piece fixing clamp, 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 excitation force;

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

[0030] The top end of the movable clamp 24 contacts the load applying device for load application, and the side surface thereof is connected with the excitation device so as to vibrate;

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

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

[0033] ​The data collector transmits the data to the computer 31.

[0034] Further, in one embodiment, the identification device for studying the parameters of the thermal friction model includes a vibration 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 rack-vertical 8, a temperature sensor 9, a fastening screw 10, a support spring plate pad 11, a fixed clamp 12, a test piece 13, a base support rod upper half 14, a base support rod lower half 15, a force sensor 16, a data collector 17, a fixed clamp base 18, a displacement sensor 19, a heating wire clamp 20, a high-frequency heating machine 21, a rack-horizontal 22, a rack-longitudinal 23, a moving clamp 24, a vibration block-main plate 25, a clamp spring plate pad 26, a vibration block-left side plate 27, a clamp spring plate 28, a moving clamp tail pad 29, a moving clamp tail 30, a computer 31, a ball screw 32, a ball screw bearing 33, a flange bearing 34, a loading rod 35, a guide rail column 36, a longitudinal loading bearing 37, a loading screw support plate 38, a double-end stud 39, a spring 40, a loading base 41, a pin shaft 42, a roller bearing 43.

[0035] The vibration block base 6 and the fixed clamp base 18 are bolted to the upper surface of the base 7 in the fixed support structure, the lower ends of the four rack-verticals 8 are bolted to the side surfaces of the vibration block base 6, the base 7, and the fixed clamp base 18, respectively, the two rack-horizontals 22 are bolted to the upper ends of the four rack-verticals 8, and the rack-longitudinal 23 is bolted to the middle of the rack-horizontal 22.

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

[0037] The test piece fixing clamp comprises a movable clamp tail 30 connected with the middle part of the vibration block-main plate 25 through a ball screw structure and a ball screw bearing 33. The ball screw bearing 34 is concentrically fixed in the middle part of the movable clamp tail 30 by bolts. The ball screw rod 32 is fixed in the middle part of the vibration block-main plate 25 by the ball screw bearing 33. The movable clamp tail 30 is connected with one end of the clamp spring plate 28 through the movable clamp tail pad 29 and bolts. The other end of the clamp spring plate 28 is connected with the movable clamp 24 through the clamp spring plate pad 26 and bolts. The fixed clamp 12 is connected with the fixed clamp base 6 through the force sensor 16 and threads.

[0038] The load applying device comprises a loading screw 35 connected with the rack-longitudinal plate 23 through a threaded hole matching connection. The loading screw 35 is connected with the loading screw support plate 38 through a longitudinal load bearing 37. The loading screw support plate 38 is fixed on the loading base 41 by double-headed studs 39 and supported by springs 40. Four springs are sleeved on the four double-headed studs between the loading screw support plate 38 and the loading base 41 for buffering and absorbing vibration. The loading base 41 is symmetrically provided with guide rail columns 36 on both sides to control the relative direction of the loading base to be unchanged. The pin shaft 42 and the roller bearing 43 are installed below the loading base 41 to adapt to the micro-slippage of the movable clamp.

[0039] The temperature control device comprises an eddy current heating device located on one side of the test piece. The eddy current heating device comprises a heating wire clamp 20 and a high-frequency heating machine 21 for heating the test piece to a certain temperature. The temperature sensor 9 is located on the other side of the test piece for measuring the heating temperature of the test piece.

[0040] The excitation device electromagnetic exciter 1 is located at the rear side of the vibration control system for generating an excitation force.

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

[0042] The method for testing the surface friction coefficient of the experimental specimen comprises the following steps: adjusting two force sensors to zero, observing the output signal value of the longitudinal force sensor, adjusting the load applying device to a certain calibration pressure value, adjusting the signal generator connected with the power amplifier to a certain known frequency value, adjusting the high-frequency heating machine to a predetermined temperature, observing the temperature signal value output by the temperature sensor, starting the exciter to give vibration excitation when the value reaches the required temperature, observing the pressure transient value signal output by the force sensor, gradually increasing the frequency of the exciter, and gradually increasing the value of the transverse force sensor, when the value reaches a certain value, the value will decrease, at this time, the static friction force limit of the surface of the specimen becomes micro sliding friction, then gradually reducing the frequency of the exciter, the maximum value of the generated static friction force is the maximum friction force that can be generated by the final static friction force, and the corresponding friction coefficient can be obtained. The surface friction coefficients under different temperatures and different materials can be obtained by using the same method.

Claims

1. An identification device for studying parameters related to a thermal friction model, characterized in that, The identification device comprises a fixed support structure, a vibration control system, a test piece fixing clamp, a load applying device, a temperature control device, a vibration exciting device and a vibration measuring device; The vibration control system is fixed on one side of the fixed support structure; the vibration exciting device is located on one side of the vibration control system and is used for generating an exciting force; The test piece fixing clamp comprises a movable clamp (24) and a fixed clamp (12); the test piece (13) is fixed between the movable clamp (24) and the fixed clamp (12); the fixed clamp (12) is fixed on the fixed support structure; The top end of the movable clamp (24) contacts the load applying device for load application, and the side surface of the movable clamp (24) is connected with 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 for heating the test piece (13) to a set temperature; the temperature control device is connected with a data collector; The vibration measuring device is fixed on the other side of the fixed support structure and is used for receiving the vibration signal generated by the exciting; the vibration measuring device is connected with the data collector; The data collector transmits each data to a computer (31); The test piece fixing clamp further comprises a movable clamp tail (30); the movable clamp tail (30) is concentrically fixed on a flange bearing (34); a ball screw (32) passes through the shaft centers of the movable clamp tail (30) and the flange bearing (34) and is fixed on the top of the side surface of a vibration block through a ball screw bearing (33); one end of the movable clamp tail (30) is connected with the movable clamp (24) through a clamp spring plate (28); the top end of the movable clamp (24) contacts the load applying device; the fixed clamp (12) is connected with a base (7) through a force sensor (16) and a base support rod; one side of the fixed clamp (12) is connected with a fixed clamp base (18) through the force sensor (16); the force sensor (16) is connected with the data collector.

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

3. The identification device for studying the parameters related to the model of thermal friction according to claim 1, characterized in that, The load applying device comprises a loading screw (35), a vertical load bearing (37), a spring (40) and a loading base (41); one end of the loading screw (35) is connected with a rack-vertical (23), and the other end is connected with a loading screw support plate (38) through the vertical load bearing (37); the loading screw support plate (38) is fixed on the loading base (41) by means of a double-end stud (39), and the double-end stud (39) is sleeved with a spring for buffering and absorbing vibration; 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 be unchanged; a pin shaft (42) and a roller bearing (43) are installed below the loading base (41) and contact the upper side of the movable clamp (24).

4. The identification device for studying the parameters related to the thermal friction model according to claim 3, characterized in that, The fixed support structure comprises a vibrating block base (6), a base (7), a fixed clamp base (18) and two racks; the vibrating block base (6) and the fixed clamp base (18) are fixed on the base (7) respectively; the two racks are fixed on the side of the vibrating block base (6), the side of the fixed clamp base (18) and the side of the base (7) respectively; the two racks are connected through a rack-longitudinal (23) at the top ends.

5. The identification device for studying the parameters related to the model of thermal friction according to claim 4, characterized in that, The temperature control device is provided with an eddy current heating device on one side of the test piece (13) for heating the test piece (13) to a set temperature, and a temperature sensor (9) on the other side of the test piece (13) for measuring the heating temperature of the test piece (13); the temperature sensor (9) is connected to a data collector.

6. The identification device for studying the parameters related to the model of thermal friction according to claim 5, characterized in that, The vibration measuring device is a displacement sensor (19) located at the front end of the movable clamp (24) and fixed on the fixed clamp base (18) for receiving the vibration signal generated by the excitation.

7. The identification device for studying the parameters of a thermal friction model according to any one of claims 1 to 6, 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 for supporting the mass block and can be deformed 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.

8. An identification method using the identification device for identifying parameters related to a thermal friction model according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: adjusting the two force sensors (16) to zero, observing the output signal value of the longitudinal force sensor, setting the load applying device to a certain calibration pressure value, setting the excitation frequency to a certain known value; setting 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 give vibration excitation when the value reaches the required temperature; observing the pressure transient value signal output by the force sensor, gradually increasing the frequency of the exciter; the value of the transverse force sensor gradually increases, and when it reaches a certain value, the value will decrease, which represents that the limit of the static friction force on the surface of the test piece is reached, and becomes micro sliding friction, and 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 is obtained.

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