Friction test device and method applied to the study of the inhibition of the creep

Abstract

The application provides a friction experiment device and method applied to inhibiting crawling research. The device comprises a motion control device, a balancing device, a friction device structure, a data acquisition device and a control unit. The application controls a stepping motor to realize low-speed motion, detects displacement and friction force change trends when crawling occurs, provides different system stiffness by using a spring, records friction force and displacement changes of a friction pair during motion, evaluates the crawling degree of the friction pair, and finds out measures for inhibiting crawling. The structure is simple, and observation is convenient.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical design and automatic control, and particularly relates to a friction experiment device and method applied to the research of suppressing creep. BACKGROUND

[0002] Creep refers to the phenomenon that the static and sliding alternately appear between the friction interfaces under low-speed driving. The creep phenomenon widely exists in the nature and engineering fields, and usually brings adverse effects to the mechanical system, such as interface wear, energy loss and irritating noise. For the precision machinery, the effects often cause the decline of movement precision and the reduction of working life, and thus are often fatal.

[0003] At present, the research methods of the creep phenomenon mainly include two kinds: mathematical method and physical method. The mathematical method starts from the concepts of velocity, elastic stiffness and damping, and deduces the movement differential equation through the mathematical methods such as derivation and solution, and processes the idealized tribology problem. The physical method considers a simple oscillation system and makes a detailed study on the creep in the aspect of tribology. At present, there is no friction experiment device and specific test analysis method applied to the research of suppressing creep. SUMMARY

[0004] In order to solve the problems in the prior art, the present application provides a friction experiment device and method applied to the research of suppressing creep, which provides different system stiffness by using a spring, records the friction force and displacement change of the friction pair in the movement process, evaluates the creep degree of the friction pair, and finds out the measures for suppressing the creep.

[0005] A friction experiment device applied to the research of suppressing creep, comprising a movement control device, a balancing device, a friction device structure, a data acquisition device and a control unit.

[0006] The movement control device comprises a lead screw transmission structure controlled by a stepping motor, a lower clamp installed on the lead screw transmission structure and following the displacement of the lead screw transmission structure, and the stepping motor is connected with the control unit.

[0007] The friction device structure comprises a linear guide rail connected through a support frame, the linear guide rail is located above the lower clamp, and an upper clamp is installed on the linear guide rail and slides along the linear guide rail in the same direction as the lower clamp.

[0008] The balancing device comprises a cross-shaped fixed block fixed to the ground through a fixing device, the cross-shaped fixed block is connected with a bearing through a shaft, the bearing is connected with a balance bar through a bearing seat, one end of the balance bar is connected with the support frame, and the other end of the balance bar is connected with a counterweight for keeping the balance of the balance bar.

[0009] The data acquisition device includes a photoelectric switch, a laser ranging sensor and a force sensor, the photoelectric switch is installed on the screw rod transmission structure to monitor the displacement of the lower clamp; the upper clamp is provided with a limiting block at one end and a force sensor at the other end, the supporting frame is provided with a laser ranging sensor for monitoring the distance between the upper clamp and the supporting frame, a spring is arranged between the force sensor and the supporting frame, and the laser ranging sensor is connected with the control unit.

[0010] Further improvement, the screw rod transmission structure in the motion control device includes a roller screw and a screw block connected with the roller screw, the lower clamp is fixed on the screw block, the roller screw is connected with the stepping motor through a shaft coupling, and the stepping motor controls the rotation of the roller screw so as to control the displacement of the lower clamp along the roller screw.

[0011] Further improvement, the stepping motor includes a stepping motor driver pulse receiving end and a direction voltage receiving end, the stepping motor driver pulse receiving end is connected with a pulse generation port of the data acquisition card, the direction voltage receiving end is connected with a voltage output port, and the voltage output port is connected with a 220V-to-24V switching power supply.

[0012] Further improvement, the fixing device in the balancing device includes an optical axis and a fixed foot disc, the optical axis is vertically fixed on the ground through the fixed foot disc, and the cross fixing block is fixedly connected with the optical axis.

[0013] Further improvement, the control unit adopts labview, the data in the laser ranging sensor is output to the labview through ttl-to-usb and serial port output, the data in the force sensor is connected with the data acquisition card through a signal amplifier and a filter, and the data acquisition card is connected with the labview.

[0014] The application also provides a friction experiment method applied to the inhibition of crawling research, and the friction experiment device applied to the inhibition of crawling research is used, and the method comprises the following steps:

[0015] 1) respectively installing samples on the upper clamp and the lower clamp, adjusting the height and balance of the upper clamp, so that the sample on the upper clamp is in contact with the sample on the lower clamp;

[0016] 2) the control unit generates pulses to the stepping motor, controls the linear motion of the lower clamp at different speeds, and generates friction between the samples on the upper clamp and the lower clamp during the displacement of the lower clamp;

[0017] 3) the laser ranging sensor is opposite to the upper clamp, real-time displacement data is output to the labview according to the reflected light, the force sensor is directly connected with the upper clamp, is used for measuring the change of friction force during the friction motion, and is uploaded to the control unit through the data acquisition card;

[0018] 4) The screw slide moves to the photoelectric switch, the photoelectric switch receives the reflected light due to the shielding of the screw slide, the data acquisition and the stepping motor movement are stopped.

[0019] Further improvement, the moving speed range of the lower clamp in step 2) is 0.01mm / s to 20mm / s.

[0020] The present application has the advantages that the stepping motor is controlled to realize low-speed movement, the change trend of displacement and friction force when the creep occurs is detected, different system stiffness is provided by the spring, the friction force and displacement change of the friction pair during the movement are recorded, the creep degree of the friction pair is evaluated to find out the creep inhibition measures, the structure is simple, and the observation is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0022] Figure 1 It is a functional principle diagram of the friction experiment machine;

[0023] Figure 2 It is a composition diagram of the control system and the data acquisition system based on labview;

[0024] Figure 3 It is a front view of the friction experiment device;

[0025] Figure 4 It is a plan view of the friction experiment device;

[0026] Figure 5 It is an experimental flowchart.

[0027] In the drawings, 1 is a stepping motor; 2 is a shaft coupling; 3 is a roller screw; 4 is a screw slide; 5 is a photoelectric switch; 6 is a lower clamp; 7 is a limit block; 8 is a linear guide rail; 9 is an upper clamp; 10 is a force sensor; 11 is a spring; 12 is a laser ranging sensor; 13 is a support frame; 14 is a balance bar; 15 is a counterweight; 16 is a bearing seat; 17 is a bearing; 18 is a cross fixed block; 19 is an optical axis; and 20 is a fixed foot plate. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0029] The working principle of the present application is shown in Figure 1 The control step motor realizes low-speed movement, detects displacement and friction force change trend when the creeping occurs, the spring provides different system stiffness, the friction force and displacement change of the friction pair in the movement process are recorded, the creeping degree of the friction pair is evaluated, and the creeping inhibition measures are found out, the structure is simple, and the observation is convenient.

[0030] The present application provides a friction experiment device applied to the study of creeping inhibition, and the structure is shown in Figure 3 and 4 The friction experiment device comprises a motion control device, a balancing device, a friction device structure, a data acquisition device and a control unit.

[0031] The motion control device comprises a lead screw transmission structure controlled by a step motor 1, a lower clamp 6 installed on the lead screw transmission structure and following the displacement of the lead screw transmission structure, and the step motor 1 is connected with the control unit.

[0032] The friction device structure comprises a linear guide rail 8 connected through a support frame 13, the linear guide rail 8 is located above the lower clamp 6, and an upper clamp 9 is installed on the linear guide rail 8, the upper clamp 9 slides along the linear guide rail 8 and has the same sliding direction as the lower clamp 6.

[0033] The balancing device comprises a cross fixed block 18 fixed to the ground through a fixing device, the cross fixed block 18 is connected with a bearing 17 through a shaft, the bearing 17 is connected with a balance bar 14 through a bearing seat 16, one end of the balance bar 14 is connected with the support frame 13, and the other end of the balance bar 14 is connected with a counterweight 15 for keeping the balance of the balance bar 14.

[0034] The data acquisition device is shown in Figure 2 The data acquisition device comprises a photoelectric switch 5, a laser ranging sensor 12 and a force sensor 10, the photoelectric switch 5 is installed on the lead screw transmission structure to monitor the displacement of the lower clamp 6, one end of the upper clamp 9 is provided with a limit block 7, and the other end of the upper clamp 9 is provided with the force sensor 10, the support frame 13 is provided with the laser ranging sensor 12 for monitoring the distance between the upper clamp 9 and the support frame 13, the spring 11 is arranged between the force sensor 10 and the support frame 13, and the laser ranging sensor is connected with the control unit.

[0035] The screw transmission structure in the motion control device comprises a roller screw 3 and a screw block 4 connected with the roller screw 3, the lower clamp 6 is fixed on the screw block 4, the roller screw 3 is connected with the stepping motor 1 through the shaft coupling 2, the stepping motor 1 controls the rotation of the roller screw 3 so as to control the displacement of the lower clamp 6 along the roller screw 3.

[0036] The stepping motor 1 comprises a stepping motor driver pulse receiving end and a direction voltage receiving end, the stepping motor driver pulse receiving end is connected with a pulse generation port of the data acquisition card, the direction voltage receiving end is connected with a voltage output port, and the voltage output port is connected with a 220v-to-24v switching power supply.

[0037] The fixing device in the balancing device comprises an optical axis 19 and a fixing foot plate 20, the optical axis 19 is vertically fixed on the ground through the fixing foot plate 20, and the cross fixing block 18 is fixedly connected with the optical axis 19.

[0038] The control unit adopts labview, the data in the laser ranging sensor 12 is output to the labview through ttl-to-usb and serial port output, the data in the force sensor 10 is connected with the data acquisition card through a signal amplifier and a filter, and the data acquisition card is connected with the labview.

[0039] The method also provides a friction experiment method applied to the inhibition of crawling research, as shown in the figure, comprising the following steps: Figure 5 As shown in the figure, comprising the following steps:

[0040] 1) respectively mounting the test samples on the upper clamp and the lower clamp, adjusting the height and balance of the upper clamp, so that the test sample on the upper clamp is in contact with the test sample on the lower clamp;

[0041] 2) the control unit generates pulses to the stepping motor, controls the linear motion of the lower clamp at different speeds, the moving speed of the lower clamp ranges from 0.01mm / s to 20mm / s; the test samples on the upper and lower clamps generate friction during the displacement of the lower clamp;

[0042] 3) the laser ranging sensor is opposite to the upper clamp, the displacement data is output to the labview in real time according to the reflected light, the force sensor is directly connected with the upper clamp, used for measuring the change of the friction force during the friction motion, and uploaded to the control unit through the data acquisition card;

[0043] 4) the screw block moves to the position of the photoelectric switch, the photoelectric switch receives the reflected light due to the shielding of the screw block, so that the data acquisition and the stepping motor stop moving.

[0044] The various embodiments described in this specification are presented as examples of the application. Each embodiment is presented in a way that emphasizes the differences between the embodiments and the other embodiments. In particular, the device embodiments are described in less detail than the method embodiments because they are substantially similar to the method embodiments. The above description is presented in terms of preferred embodiments of the application, but the scope of the application is not limited to the preferred embodiments. Any person skilled in the art who understands the technology described in this specification can easily make changes or replacements within the scope of the technology disclosed in this specification, without departing from the principles of the application. Therefore, the scope of the application should be determined by the scope of the claims.

Claims

1. A friction experiment device applied to a creeping inhibition study, characterized in that: It comprises a motion control device, a balancing device, a friction device structure, a data acquisition device and a control unit. The motion control device comprises a screw rod transmission structure controlled by a stepping motor (1), a lower clamp (6) installed on the screw rod transmission structure and following the displacement of the screw rod transmission structure, and the stepping motor (1) is connected with the control unit. The friction device structure comprises a linear guide rail (8) connected by a support frame (13), the linear guide rail (8) is located above the lower clamp (6), an upper clamp (9) is installed on the linear guide rail (8) and slides along the linear guide rail (8) in the same direction as the lower clamp (6). The balancing device comprises a cross fixed block (18) fixed to the ground by a fixing device, the cross fixed block (18) is connected with a bearing (17) through a shaft, the bearing (17) is connected with a balance bar (14) through a bearing seat (16), one end of the balance bar (14) is connected with the support frame (13), and the other end of the balance bar (14) is connected with a counterweight (15) for keeping the balance of the balance bar (14). The data acquisition device comprises a photoelectric switch (5), a laser ranging sensor (12) and a force sensor (10), the photoelectric switch (5) is installed on the screw rod transmission structure to monitor the displacement of the lower clamp (6); one end of the upper clamp (9) is provided with a limit block (7), and the other end of the upper clamp (9) is provided with the force sensor (10); the support frame (13) is provided with the laser ranging sensor (12) for monitoring the distance between the upper clamp (9) and the support frame (13); the force sensor (10) and the support frame (13) are provided with a spring (11) therebetween; and the laser ranging sensor is connected with the control unit.

2. The friction test device for use in the inhibition of crawling study according to claim 1, characterized by: The screw rod transmission structure in the motion control device comprises a roller screw (3) and a screw rod slider (4) connected with the roller screw (3), the lower clamp (6) is fixed on the screw rod slider (4), the roller screw (3) is connected with the stepping motor (1) through a shaft coupling (2), and the stepping motor (1) controls the rotation of the roller screw (3) to control the displacement of the lower clamp (6) along the roller screw (3).

3. The friction test device for use in the inhibition of crawling study according to claim 1 or 2, characterized by: The stepping motor (1) comprises a stepping motor driver pulse receiving end and a direction voltage receiving end, the stepping motor driver pulse receiving end is connected with a pulse generation port of a data acquisition card, the direction voltage receiving end is connected with a voltage output port, and the voltage output port is connected with a switch power supply for converting 220V into 24V.

4. The friction testing device for use in inhibiting the study of creeping according to claim 1, characterized in that: The fixing device in the balancing device comprises an optical shaft (19) and a fixed foot disc (20), the optical shaft (19) is vertically fixed to the ground through the fixed foot disc (20), and the cross fixed block (18) is fixedly connected with the optical shaft (19).

5. The friction testing device for use in inhibiting the study of creeping according to claim 1, characterized in that: The control unit adopts labview, the data in the laser ranging sensor (12) is output to the labview through ttl conversion usb and serial port output, the data in the force sensor (10) is connected with a data acquisition card through a signal amplifier and a filter, and the data acquisition card is connected with the labview.

6. A method for a friction experiment applied to a study of stick-slip, using the friction experiment device for a study of stick-slip according to claim 1, characterized by It comprises the following steps: 1) installing samples on the upper clamp and the lower clamp respectively, adjusting the height and balance of the upper clamp, and making the samples on the upper clamp contact with the samples on the lower clamp; 2) The control unit generates pulses to the stepper motor to control the linear motion of the lower clamp at different speeds. During the displacement of the lower clamp, friction occurs between the samples on the upper and lower clamps. 3) The laser ranging sensor is directly opposite the upper clamp. It outputs displacement data to the labview in real time according to the reflected light. The force sensor is directly connected to the upper clamp to measure the change in friction during the frictional motion and is uploaded to the control unit through the data acquisition card. 4) When the screw block moves to the photoelectric switch, the photoelectric switch receives the reflected light due to the blocking of the screw block, so that the data acquisition and the motion of the stepper motor stop.

7. The friction test method for use in the inhibition of crawling study according to claim 6, characterized by: The moving speed of the lower clamp in step 2) ranges from 0.01 mm / s to 20 mm / s.

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