Friction experiment device and method applied to crawl inhibition research

Abstract

The invention provides a friction experiment device and method applied to crawl inhibition research. The device comprises a motion control device, a balancing device, a friction device structure, a data acquisition device and a control unit. The stepping motor is controlled to realize low-speed movement, the change trend of displacement and friction force during crawling is detected, different system rigidities are provided by the spring, the friction force and displacement change of the friction pair in the movement process are recorded, so that the crawling degree of the friction pair is evaluated to find out crawling inhibition measures, and the device is simple in structure and convenient to operate. The observation is convenient.

Description

Technical Field

[0001] The invention relates to the field of mechanical design and automatic control, in particular to a friction experiment device and method used for creep inhibition research. Background Art

[0002] Creep refers to the phenomenon of alternating stillness and sliding between friction interfaces under low-speed driving. Creep is widely found in nature and engineering, and usually has adverse effects on mechanical systems, such as interface wear, energy loss, and harsh noise. For precision machinery, this effect can cause a decrease in motion accuracy and a reduction in working life, and is often fatal.

[0003] There are two main methods for studying creeping: mathematical method and physical method. The mathematical method starts from the concepts of velocity, elastic stiffness, and damping, and derives the differential equation of motion through mathematical methods such as derivation and solution to deal with idealized tribological problems. The physical method considers a simple oscillating system and conducts a detailed study of creeping in terms of tribology. Currently, there is no friction experimental device and specific test and analysis method used in the study of creeping inhibition. Summary of the invention

[0004] In order to solve the problems of the prior art, the present invention provides a friction experiment device and method for creep suppression research. Springs are used to provide different system stiffnesses. The friction force and displacement changes of the friction pair during movement are recorded to evaluate the creep degree of the friction pair and find measures to suppress creep.

[0005] A friction experiment device used for crawling inhibition research comprises a motion control device, a balancing device, a friction device structure, a data acquisition device and a control unit.

[0006] The motion control device includes a screw transmission structure controlled by a stepper motor, a lower fixture that follows the displacement of the screw transmission structure is installed on the screw transmission structure, and the stepper motor is connected to a control unit; The friction device structure comprises a linear guide rail connected by a support frame, the linear guide rail is located above the lower fixture, an upper fixture is installed on the linear guide rail, and the upper fixture slides along the linear guide rail in the same sliding direction as the lower fixture; The balancing device comprises a cross fixing block fixed to the ground by a fixing device, the cross fixing block is connected to a bearing by a shaft, the bearing is connected to a balancing rod by a bearing seat, one end of the balancing rod is connected to a support frame, and the other end is connected to a counterweight block for keeping the balancing rod balanced; The data acquisition device includes a photoelectric switch, a laser ranging sensor and a force sensor. The photoelectric switch is installed on the screw transmission structure to monitor the displacement of the lower clamp; a limit block is provided at one end of the upper clamp, and a force sensor is provided at the other end. A laser ranging sensor for monitoring the distance between the upper clamp and the support frame is provided on the support frame. A spring is provided between the force sensor and the support frame, and the laser ranging sensor is connected to the control unit.

[0007] Further improvement, the screw transmission structure in the motion control device includes a roller screw and a screw slider connected to the roller screw, the lower clamp is fixed on the screw slider, the roller screw is connected to the stepper motor through a coupling, and the stepper motor controls the rotation of the roller screw to control the displacement of the lower clamp along the roller screw.

[0008] Further improvement, the stepper motor includes a stepper motor driver pulse receiving end and a direction voltage receiving end, the stepper motor driver pulse receiving end is connected to the pulse generation port of the data acquisition card, the direction voltage receiving end is connected to the voltage output port, and the voltage output port is connected to a 220V to 24V switching power supply.

[0009] As a further improvement, the fixing device in the balancing device comprises an optical axis and a fixing footplate, the optical axis is vertically fixed to the ground through the fixing footplate, and a cross fixing block is fixedly connected to the optical axis.

[0010] Further improvement, the control unit adopts LabVIEW, the data in the laser ranging sensor is output to LabVIEW through the serial port via TTL to USB, the data in the force sensor is connected to the data acquisition card through the signal amplifier and filter, and the data acquisition card is connected to LabVIEW.

[0011] The present invention also provides a friction experiment method for crawling inhibition research, using the above-mentioned friction experiment device for crawling inhibition research, comprising the following steps: 1) Install the specimens on the upper and lower fixtures respectively, and adjust the height and balance of the upper fixture so that the specimen on the upper fixture contacts the specimen on the lower fixture; 2) The control unit generates pulses to the stepper motor to control the lower fixture to move linearly at different speeds. During the displacement of the lower fixture, friction is generated between the samples on the upper and lower fixtures. 3) The laser distance sensor is facing the upper fixture, and outputs the displacement data to Labview in real time according to the reflected light. The force sensor is directly connected to the upper fixture to measure the change of friction force during the friction movement, and uploads it to the control unit through the data acquisition card; 4) When the lead screw slider moves to the photoelectric switch, the photoelectric switch receives the reflected light due to the obstruction of the lead screw slider, causing data acquisition and stepper motor movement to stop.

[0012] Further improvement, in step 2), the moving speed range of the lower clamp is 0.01 mm / s to 20 mm / s.

[0013] The beneficial effects of the present invention are: controlling the stepper motor to achieve low-speed movement, detecting the changing trends of displacement and friction when creeping occurs, using springs to provide different system stiffnesses, and recording the changes in friction and displacement of the friction pair during movement to evaluate the creep degree of the friction pair and find measures to suppress creeping. The structure is simple and observation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 This is the functional principle diagram of the friction testing machine; Figure 2 This is a diagram of the control system and data acquisition system based on LabVIEW; Figure 3 This is the front view of the friction experiment device; Figure 4 It is the top view of the friction experiment device; Figure 5 The experimental flow chart is shown in Figure 2.

[0016] In the figure, 1-stepping motor; 2-coupling; 3-roller screw; 4-screw slider; 5-photoelectric switch; 6-lower clamp; 7-limit block; 8-linear guide; 9-upper clamp; 10-force sensor; 11-spring; 12-laser ranging sensor; 13-support frame; 14-balance bar; 15-counterweight; 16-bearing seat; 17 bearing; 18-cross fixing block; 19-optical axis; 20-fixed foot plate. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] The working principle of the present invention is as follows Figure 1As shown, the stepper motor is controlled to achieve low-speed movement, and the changing trends of displacement and friction force when creeping occurs are detected. Different system stiffnesses are provided by springs. By recording the changes in friction force and displacement of the friction pair during movement, the creep degree of the friction pair is evaluated to find measures to suppress creeping. The structure is simple and easy to observe.

[0019] The present invention provides a friction experimental device for crawling inhibition research, the structure of which is as follows: Figure 3 and 4 As shown, it includes 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 transmission structure controlled by a stepper motor 1, a lower fixture 6 following the displacement of the screw transmission structure is mounted on the screw transmission structure, and the stepper motor 1 is connected to a control unit; The friction device structure includes 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 the upper clamp 9 slides along the linear guide rail 8 and in the same sliding direction as the lower clamp 6; The balancing device includes a cross fixing block 18 fixed to the ground by a fixing device, the cross fixing block 18 is connected to a bearing 17 through an axis, the bearing 17 is connected to a balancing rod 14 through a bearing seat 16, one end of the balancing rod 14 is connected to a support frame 13, and the other end is connected to a counterweight block 15 for keeping the balancing rod 14 balanced; The data acquisition device is as follows Figure 2 As shown, it includes a photoelectric switch 5, a laser ranging sensor 12 and a force sensor 10. The photoelectric switch 5 is installed on the screw transmission structure to monitor the displacement of the lower clamp 6; a limit block 7 is provided at one end of the upper clamp 9, and a force sensor 10 is provided at the other end. The support frame 13 is provided with a laser ranging sensor 12 for monitoring the distance between the upper clamp 9 and the support frame 13. A spring 11 is provided between the force sensor 10 and the support frame 13, and the laser ranging sensor is connected to the control unit.

[0020] The screw transmission structure in the motion control device includes a roller screw 3 and a screw slider 4 connected to the roller screw 3. The lower clamp 6 is fixed on the screw slider 4. The roller screw 3 is connected to the stepper motor 1 through a coupling 2. The stepper motor 1 controls the rotation of the roller screw 3 to control the displacement of the lower clamp 6 along the roller screw 3.

[0021] The stepper motor 1 includes a stepper motor driver pulse receiving end and a direction voltage receiving end. The stepper motor driver pulse receiving end is connected to the pulse generating port of the data acquisition card, and the direction voltage receiving end is connected to the voltage output port. The voltage output port is connected to a 220V to 24V switching power supply.

[0022] The fixing device in the balancing device includes 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 a cross fixing block 18 is fixedly connected to the optical axis 19 .

[0023] The control unit uses LabVIEW, and the data in the laser ranging sensor 12 is output to LabVIEW through the serial port via TTL to USB. The data in the force sensor 10 is connected to the data acquisition card through a signal amplifier and a filter, and the data acquisition card is connected to LabVIEW.

[0024] This method also provides a friction experiment method for crawling inhibition research, such as Figure 5 As shown, the following steps are included: 1) Install the specimens on the upper and lower fixtures respectively, and adjust the height and balance of the upper fixture so that the specimen on the upper fixture contacts the specimen on the lower fixture; 2) The control unit generates pulses to the stepper motor to control the lower fixture to move linearly at different speeds. The moving speed range of the lower fixture is 0.01mm / s to 20mm / s. During the displacement of the lower fixture, friction is generated between the samples on the upper and lower fixtures. 3) The laser distance sensor is facing the upper fixture, and outputs the displacement data to Labview in real time according to the reflected light. The force sensor is directly connected to the upper fixture to measure the change of friction force during the friction movement, and uploads it to the control unit through the data acquisition card; 4) When the lead screw slider moves to the photoelectric switch, the photoelectric switch receives the reflected light due to the obstruction of the lead screw slider, causing data acquisition and stepper motor movement to stop.

[0025] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field is within the technical scope disclosed by the present invention. For ordinary technicians in the technical field, changes or replacements that can be easily thought of should be covered within the protection scope of the present invention without departing from the principle of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A friction experimental device used in creep inhibition research, characterized in that: It includes 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 transmission structure controlled by a stepper motor (1), a lower clamp (6) which follows the displacement of the screw transmission structure is installed on the screw transmission structure, and the stepper motor (1) is connected to a control unit; The friction device structure comprises a linear guide rail (8) connected via a support frame (13), the linear guide rail (8) being located above the lower fixture (6), an upper fixture (9) being mounted on the linear guide rail (8), and the upper fixture (9) sliding along the linear guide rail (8) in the same sliding direction as the lower fixture (6); The balancing device comprises a cross fixing block (18) fixed to the ground via a fixing device, the cross fixing block (18) being connected to a bearing (17) via a shaft, the bearing (17) being connected to a balancing rod (14) via a bearing seat (16), one end of the balancing rod (14) being connected to a support frame (13), and the other end being connected to a counterweight block (15) for maintaining the balance of the balancing rod (14); The data acquisition device comprises a photoelectric switch (5), a laser distance sensor (12) and a force sensor (10); the photoelectric switch (5) is mounted on the screw transmission structure to monitor the displacement of the lower clamp (6); a limit block (7) is arranged at one end of the upper clamp (9), and a force sensor (10) is arranged at the other end; a laser distance sensor (12) is arranged on the support frame (13) to monitor the distance between the upper clamp (9) and the support frame (13); a spring (11) is arranged between the force sensor (10) and the support frame (13); and the laser distance sensor is connected to the control unit.

2. The friction experiment device for crawling inhibition research according to claim 1 is characterized in that: The screw transmission structure in the motion control device comprises a roller screw (3) and a screw slider (4) connected to the roller screw (3); a lower clamp (6) is fixed on the screw slider (4); the roller screw (3) is connected to a stepper motor (1) via a coupling (2); the stepper motor (1) controls the rotation of the roller screw (3) and thus controls the displacement of the lower clamp (6) along the roller screw (3).

3. The friction experiment device for crawling inhibition research according to claim 1 or 2, characterized in that: The stepper motor (1) comprises a stepper motor driver pulse receiving end and a direction voltage receiving end, the stepper motor driver pulse receiving end is connected to a pulse generating port of a data acquisition card, the direction voltage receiving end is connected to a voltage output port, and the voltage output port is connected to a 220V to 24V switching power supply.

4. The friction experiment device for crawling inhibition research according to claim 1 is characterized in that: 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 via the fixing foot plate (20), and the cross fixing block (18) is fixedly connected to the optical axis (19).

5. The friction experiment device for crawling inhibition research according to claim 1 is characterized in that: The control unit uses LabVIEW, the data in the laser distance sensor (12) is output to LabVIEW via the serial port through TTL to USB, the data in the force sensor (10) is connected to the data acquisition card through the signal amplifier and filter, and the data acquisition card is connected to LabVIEW.

6. A friction test method for inhibiting crawling research, using the friction test device for inhibiting crawling research as claimed in claim 1, characterized in that The following steps are involved: 1) Install the specimens on the upper and lower fixtures respectively, and adjust the height and balance of the upper fixture so that the specimen on the upper fixture contacts the specimen on the lower fixture; 2) The control unit generates pulses to the stepper motor to control the lower fixture to move linearly at different speeds. During the displacement of the lower fixture, friction is generated between the samples on the upper and lower fixtures. 3) The laser distance sensor is facing the upper fixture, and outputs the displacement data to Labview in real time according to the reflected light. The force sensor is directly connected to the upper fixture to measure the change of friction force during the friction movement, and uploads it to the control unit through the data acquisition card; 4) When the lead screw slider moves to the photoelectric switch, the photoelectric switch receives the reflected light due to the obstruction of the lead screw slider, causing data acquisition and stepper motor movement to stop.

7. The friction test method for creep inhibition research according to claim 6, characterized in that: Step 2) The moving speed of the lower fixture ranges from 0.01 mm / s to 20 mm / s.

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