A near sample fluid constant temperature reciprocating friction force testing device

Abstract

The application discloses a near-sample fluid constant-temperature reciprocating friction force testing device, which comprises a frame, a sample fixing mechanism, a force applying mechanism, a six-dimensional force sensor and a reciprocating motion mechanism; the force applying mechanism is fixedly connected to the upper end of the frame; the sample fixing mechanism comprises an upper sample clamping device and a lower sample table; the upper sample clamping device is connected to the lower end of the force applying mechanism; the lower sample table is arranged on the reciprocating motion mechanism; the reciprocating motion mechanism is arranged at the lower end of the frame; and the six-dimensional force sensor is arranged between the upper sample clamping device and the force applying mechanism. The application can increase the stroke along the load direction and improve the testing precision of force applying / force receiving by designing a shear-brace lifting mechanism and a precision screw mechanism in series combination to apply a normal load; and the sample clamping device with an inner flow channel can quickly control the temperature of the sample in the friction testing process, and reduce the influence of heat generated by friction on the test results.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of friction force testing, in particular to a near-sample fluid constant-temperature reciprocating friction force testing device. BACKGROUND

[0002] Tribology includes the study of friction, wear and lubrication science. Friction is the physical force generated by the mutual action of two surfaces in contact with each other when they have mutual motion or mutual motion tendency. Friction force testing device is an important tool in tribology research. The existing friction force testing device includes atomic force microscope for measuring micro-nano friction and friction force tester for measuring macro friction, and the relative motion mode of friction is mainly linear reciprocating and rotating.

[0003] The existing macro friction force tester has the following problems:

[0004] 1. In the prior art, the friction force testing instruments used in engineering equipment can only use finished product friction ball heads as test samples. These samples usually have fixed materials or shape sizes. This has certain limitations for actual test experiments, and test experimenters cannot conduct research activities based on changes in sample materials or shapes.

[0005] 2. During the friction force testing experiment, a certain load needs to be applied perpendicular to the relative motion direction, i.e. normal direction, and then the force along the relative sliding direction is measured. Sometimes, in order to study the vibration noise in the friction process, the force perpendicular to the sliding direction also needs to be measured. In the prior art device, the normal load application process cannot be monitored in real time and the precision is low, and generally does not have the function of testing the force perpendicular to the sliding direction, which causes certain errors in the experimental results.

[0006] 3. During the friction force testing process, heat is generated due to friction, and the generated heat cannot be dissipated immediately, so the sample temperature often rises. The change in temperature will affect the accuracy of the test results and increase the uncertainty of the experiment. In the existing testing device, the environment is controlled in temperature, which on the one hand needs a long time to stabilize the temperature, and on the other hand it is difficult to eliminate the friction heat generated in the high-speed friction process due to the existence of material and interface thermal resistance. SUMMARY

[0007] The present application aims to solve the problems of existing friction force testing experiments, such as sample size and shape limitations, rapid sample temperature control, and real-time high-precision force measurement, by providing a near-sample fluid constant-temperature reciprocating friction force testing device.

[0008] To solve the above technical problems, the technical scheme of the present application is as follows:

[0009] A near-sample fluid isothermal reciprocating friction force testing device is characterized by comprising a frame, a sample fixing mechanism, a force application mechanism, a six-dimensional force sensor, and a reciprocating motion mechanism.

[0010] The force-applying mechanism is fixedly connected to the upper end of the frame and is used to apply a normal load to the upper sample;

[0011] The sample fixing mechanism includes an upper sample clamping device and a lower sample stage. The upper sample clamping device is connected to the lower end of the force application mechanism and is used to fix the upper sample. The lower sample stage is set on the reciprocating motion mechanism and is used to fix the lower sample and stabilize the temperature.

[0012] The reciprocating motion mechanism is located at the lower end of the frame and is used to drive the lower sample stage to perform linear reciprocating motion.

[0013] The six-dimensional force sensor is positioned between the upper sample clamping device and the force application mechanism to measure the force and torque generated during the friction test.

[0014] Furthermore, the frame includes four interconnected aluminum metal plates, namely a side plate, an upper top plate, and a lower bottom plate. The force-applying mechanism is fixedly connected to the lower side of the upper top plate, and the reciprocating motion mechanism is fixedly connected to the upper side of the lower bottom plate.

[0015] Furthermore, the force-applying mechanism includes a scissor-support lifting mechanism and a precision screw mechanism. The upper part of the scissor-support lifting mechanism is fixedly connected to the center position of the upper top plate, and the precision screw mechanism is fixedly connected to the center position of the lower part of the scissor-support lifting mechanism. The six-dimensional force sensor is connected to the center position below the precision screw mechanism.

[0016] Furthermore, the sample clamping device includes a connecting part, a clamping part, a first aluminum block, a second aluminum block, a screw, a spring, and a fully threaded through-wire rod. The upper end of the connecting part is connected to the six-dimensional force sensor, and the clamping part is connected to the lower end of the connecting part. The first aluminum block and the second aluminum block are slidably connected to the groove of the clamping part. The screw is threadedly connected to the clamping part on the side near the first aluminum block, which can push the first aluminum block to slide. The fully threaded through-wire rod passes through the clamping part and is fixedly connected to the second aluminum block, which can pull the second aluminum block to slide. The spring is disposed between the second aluminum block and the clamping part.

[0017] Furthermore, a clamping plate and a chamfered nut are fixedly connected to the end of the fully threaded through-thread rod, and a flange nut is threadedly connected to the fully threaded through-thread rod.

[0018] Furthermore, the lower sample stage includes an upper sample clamping device and a lower temperature control device. The lower sample clamping device is used to fix the lower sample, and the temperature control device is installed on the reciprocating motion mechanism and has a constant temperature fluid inside it to maintain the lower sample at a constant temperature during the friction test.

[0019] Furthermore, the sample clamping device includes a sample stage body, a push rod, and a fixing block. The sample stage body is provided with a sample groove. One end of the push rod is connected to the fixing block, and the other end is threaded to the edge of the sample stage body, which can push the fixing block to slide in the sample groove. The temperature control device includes an upper base plate and a lower cover plate. The base plate is provided with a fluid circulation port for circulating injection of constant temperature fluid. The cover plate is connected to the reciprocating motion mechanism.

[0020] Furthermore, the reciprocating motion mechanism includes a motor, a guide rail, and a slider. The guide rail and motor are fixedly connected to the lower base plate, the slider is slidably connected to the guide rail, and the motor is connected to the slider through a coupling, enabling the slider to slide along the guide rail. The lower sample stage is fixedly connected to the slider.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention applies normal load by using a combination of a scissor-support lifting mechanism (coarse adjustment) and a precision screw mechanism (fine adjustment) in series, and uses a six-dimensional force sensor for force measurement, which can increase the stroke along the load direction and improve the test accuracy of force application / receiving. The use of a slider spring device to clamp the sample reduces the stringent requirements of traditional friction force testers on the size and shape of the test sample. The use of a sample clamp with an internal flow channel can quickly control the temperature of the sample during the friction test and reduce the impact of frictional heat on the test results. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the sample clamping device structure in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the reciprocating motion mechanism according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the sample stage structure according to an embodiment of the present invention;

[0026] The components are as follows: 1-Top plate; 2-Scissor brace lifting mechanism; 3-Side plate; 4-Precision screw mechanism; 5-Upper sample clamping device; 6-Reciprocating motion mechanism; 7-Connecting plate; 8-Six-dimensional force sensor; 9-Lower sample stage; 10-Lower base plate; 11-Upper sample; 51-Connecting part; 52-Clamping plate chamfered nut; 53-Fully threaded through-thread rod; 54-Flange nut; 55-Spring; 56-Second aluminum block; 57-Clamping part; 58-First aluminum block; 59-Screw; 61-Slider; 62-Guide rail; 63-Motor; 91-Push rod; 92-Fixing block; 93-Lower sample; 94-Sample stage body; 95-Base plate; 96-Cover plate; 97-Fluid circulation port. Detailed Implementation

[0027] To enhance understanding of the present invention, we will now describe it in further detail with reference to the accompanying drawings. These embodiments are for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0028] Figures 1-4 A specific embodiment of a near-sample fluid isothermal reciprocating friction force testing device is shown, including a frame, a sample fixing mechanism, a force application mechanism, a six-dimensional force sensor 8, and a reciprocating motion mechanism 6.

[0029] like Figure 1 As shown, the frame comprises four interconnected aluminum plates: left and right side plates 3, an upper top plate 1, and a lower bottom plate 10. The force application mechanism includes a scissor-support lifting mechanism 2 and a precision screw mechanism 4. The upper part of the scissor-support lifting mechanism 2 is fixedly connected to the center of the upper top plate 1, used for the vertical movement of the six-dimensional force sensor 8 and the upper sample 11. The precision screw mechanism 4 is fixedly connected to the lower center of the scissor-support lifting mechanism 2 via an aluminum connecting plate, used to apply a normal load after the upper sample 11 and the lower sample 93 come into contact. The six-dimensional force sensor 8 is connected to the center of the precision screw mechanism 4 below via a circular transition flange. The sensing element of the six-dimensional force sensor 8 is a resistance strain gauge, which can simultaneously measure force and torque in three directions in the Cartesian coordinate system. A reciprocating motion mechanism 6 is mounted on the lower bottom plate, used to drive the lower sample stage 9 to perform linear reciprocating motion.

[0030] The sample fixing mechanism includes an upper sample clamping device 5 and a lower sample stage 9. The upper sample clamping device 5 is fixedly connected to the lower part of the six-dimensional force sensor 8 via a transition flange and is used to fix the upper sample 11. The lower sample stage 9 is set on the reciprocating motion mechanism 6 and is used to fix the lower sample 93 and stabilize the temperature.

[0031] like Figure 2As shown, the sample clamping device 5 includes a connecting part 51, a clamping part 57, a first aluminum block 58, a second aluminum block 56, a screw 59, a spring 55, a fully threaded through-hole rod 53, a chamfered nut 52, and a flange nut 54. The upper end of the connecting part 51 is connected to the six-dimensional force sensor 8, and the clamping part 57 is connected to the lower end of the connecting part 51. The first aluminum block 58 and the second aluminum block 56 are slidably connected to the groove of the clamping part 57. The screw 59 is threadedly connected to the clamping part 57 on the side near the first aluminum block 58, which can push the first aluminum block 58 to slide. The fully threaded through-hole rod 53 passes through the clamping part 57 and is fixedly connected to the second aluminum block 56, which can pull the second aluminum block 56 to slide. The spring 55 is disposed between the second aluminum block 56 and the clamping part 57. The end of the fully threaded through-hole rod 53 is fixedly connected to the chamfered nut 52, and the fully threaded through-hole rod 53 is threadedly connected to the flange nut 54.

[0032] like Figure 3 As shown, the reciprocating motion mechanism 6 includes a motor 63, a guide rail 62, and a slider 61. The guide rail 62 and the motor 63 are fixedly connected to the lower base plate 10. The slider 61 is slidably connected to the guide rail 62. The motor 63 is connected to the slider 61 through a coupling, which can drive the slider 61 to slide along the guide rail 62. The lower sample stage 9 is fixedly connected to the slider 61.

[0033] like Figure 4 As shown, the lower sample stage 9 includes a lower sample clamping device at the upper end and a temperature control device at the lower end. The lower sample clamping device is used to fix the lower sample 93 and includes a sample stage body 94, a push rod 91, and a fixing block 92. The sample stage body 94 is provided with a sample groove. One end of the push rod 91 is connected to the fixing block 92, and the other end is threaded to the edge of the sample stage body 94, which can push the fixing block 92 to slide in the sample groove. The temperature control device is provided on the reciprocating motion mechanism 6 and includes a base plate 95 at the upper end and a cover plate 96 at the lower end. The base plate 95 is provided with a fluid circulation port 97 for circulating and injecting constant temperature fluid. The cover plate 96 is connected to the reciprocating motion mechanism 6, and the cover plate 96 is filled with constant temperature fluid to keep the lower sample 93 at a constant temperature during the friction test.

[0034] The working process and principle of the above embodiments are as follows:

[0035] First, fix the upper sample 11: pull the chamfered nut 52 of the clamping plate outward, so that the threaded through bar 53 drives the second aluminum block 56 to move along the groove of the clamping part 57. At this time, the spring 55 is compressed. After placing the upper sample 11 to be tested between the first aluminum block 58 and the second aluminum block 56, release the chamfered nut 52 of the clamping plate. The spring 55 is released and pushes the second aluminum block 56 to clamp the upper sample 11. Adjust the position and orientation of the upper sample 11 so that it can have a suitable contact surface with the lower sample 93. After the adjustment is completed, tighten the flange nut 54 to fix the second aluminum block 56. Finally, use the corresponding Allen wrench to tighten the screw 59.

[0036] Then fix the lower sample 93: place the lower sample 93 in the sample slot of the sample stage body 94, rotate the push rod 91, and the fixing block 92 moves forward to fix the lower sample 93.

[0037] Next, the scissor brace lifting mechanism 2 is lowered so that the upper sample 11 and the lower sample 93 come into contact. Then, the precision screw mechanism 4 is adjusted to apply the set normal load to the upper sample 11.

[0038] Finally, motor 63 is started, causing slider 61 to reciprocate along guide rail 62, resulting in friction between upper sample 11 and lower sample 93. Simultaneously, a circulating, temperature-controlled fluid is introduced into base plate 95 to control the temperature of lower sample 93 during the friction process. The six-dimensional force sensor 8 simultaneously receives forces and torques in three directions and converts the pressure information into voltage signals, which are then transmitted to the host computer.

[0039] The present invention can measure forces ranging from 0 to 10 N with a resolution of 0.1 N. The reciprocating motion mechanism has a speed range of 0 to 520 mm / s and an effective stroke of 105 mm. The force-applying mechanism has a vertical stroke of 70 mm and an accuracy of 0.02 mm.

[0040] The above specific embodiments are only for illustrating the technical concept and structural features of the present invention, and are intended to enable those skilled in the art to implement them. However, the above content does not limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit and essence of the present invention should fall within the scope of protection of the present invention.

Claims

1. A near-sample fluid isothermal reciprocating friction force testing device, characterized in that: Includes a frame, a sample fixing mechanism, a force application mechanism, a six-dimensional force sensor (8), and a reciprocating motion mechanism (6); The force-applying mechanism is fixedly connected to the upper end of the frame and is used to apply a normal load to the upper sample (11); The sample fixing mechanism includes an upper sample clamping device (5) and a lower sample stage (9). The upper sample clamping device (5) is connected to the lower end of the force application mechanism and is used to fix the upper sample (11). The lower sample stage (9) is set on the reciprocating motion mechanism and is used to fix the lower sample (93) and stabilize the temperature. The reciprocating motion mechanism (6) is located at the lower end of the frame and is used to drive the lower sample stage (9) to perform linear reciprocating motion. The six-dimensional force sensor (8) is disposed between the upper sample clamping device (5) and the force application mechanism, and is used to measure the force and torque generated in the friction test; The sample clamping device (5) includes a connecting part (51), a clamping part (57), a first aluminum block (58), a second aluminum block (56), a screw (59), a spring (55), and a fully threaded through-wire rod (53). The upper end of the connecting part (51) is connected to the six-dimensional force sensor (8), and the clamping part (57) is connected to the lower end of the connecting part (51). The first aluminum block (58) and the second aluminum block (56) are slidably connected to the groove of the clamping part (57). The screw (59) is threadedly connected to the clamping part (57) on the side near the first aluminum block (58) and can push the first aluminum block (58) to slide. The fully threaded through-wire rod (53) passes through the clamping part (57) and is fixedly connected to the second aluminum block (56) and can pull the second aluminum block (56) to slide. The spring (55) is disposed between the second aluminum block (56) and the clamping part (57). The lower sample stage (9) includes an upper sample clamping device and a lower temperature control device. The lower sample clamping device is used to fix the lower sample (93). The temperature control device is set on the reciprocating motion mechanism (6) and has a constant temperature fluid inside, which is used to keep the lower sample (93) at a constant temperature during the friction test. The sample clamping device includes a sample stage body (94), a push rod (91), and a fixing block (92). The sample stage body (94) is provided with a sample slot. One end of the push rod (91) is connected to the fixing block (92), and the other end is threaded to the edge of the sample stage body (94), which can push the fixing block (92) to slide in the sample slot. The temperature control device includes an upper base plate (95) and a lower cover plate (96). The base plate (95) is provided with a fluid circulation port (97) for circulating and injecting constant temperature fluid. The cover plate (96) is connected to the reciprocating motion mechanism (6).

2. The near-sample fluid isothermal reciprocating friction force testing device according to claim 1, characterized in that: The frame includes four interconnected aluminum metal plates, namely a side plate (3), an upper top plate (1), and a lower bottom plate (10). The force application mechanism is fixedly connected to the lower side of the upper top plate (1), and the reciprocating motion mechanism (6) is fixedly connected to the upper side of the lower bottom plate (10).

3. The near-sample fluid isothermal reciprocating friction force testing device according to claim 2, characterized in that: The force-applying mechanism includes a scissor-support lifting mechanism (2) and a precision screw mechanism (4). The upper part of the scissor-support lifting mechanism (2) is fixedly connected to the center of the upper top plate (1), and the precision screw mechanism (4) is fixedly connected to the center of the lower part of the scissor-support lifting mechanism (2). The six-dimensional force sensor (8) is connected to the center of the lower part of the precision screw mechanism (4).

4. The near-sample fluid isothermal reciprocating friction force testing device according to claim 1, characterized in that: The end of the fully threaded through-wire rod (53) is fixedly connected to a clamping plate chamfer nut (52), and a flange nut (54) is threaded onto the fully threaded through-wire rod (53).

5. The near-sample fluid isothermal reciprocating friction force testing device according to claim 2, characterized in that: The reciprocating motion mechanism (6) includes a motor (63), a guide rail (62), and a slider (61). The guide rail (62) and the motor (63) are fixedly connected to the lower base plate (10). The slider (61) is slidably connected to the guide rail (62). The motor (63) is connected to the slider (61) through a coupling and can drive the slider (61) to slide along the guide rail (62). The lower sample stage (9) is fixedly connected to the slider (61).

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