CN100504345C - A small-scale scale bench friction testing machine - Google Patents

Abstract

The invention discloses new structural bench frictional testing machine for hand sample assembled not from 1:1 real objects. The technical scheme fixes the principal axis drive system (PADS), which simulates different inertia and provides different rotate speed, on a frame; also installs the sliding table system (STS), which determines relative position between sample of friction material to be tested and friction brake disc, on the frame. Distance between spindle axis of PADS and working face on the frame is equal to distance between axis of bearing head in STS and working face on the frame. Moreover, the spindle axis is parallel to the axis of bearing head. The disclosed testing machine possesses same or similar functions of inertia bench scale testing machine, and uses same standard of test procedure. Features are: attachable inertia, raised precision of hand sample test, lower price ratio, suitable to develop new product, and monitor quality of production.

Description

A small-scale scale bench friction testing machine

technical field

The invention relates to a friction and wear performance testing machine for friction materials, in particular to a small scale bench friction testing machine.

Background technique

Friction and wear performance tests of friction materials include sample tests and inertial bench tests. The small sample test takes the standard sample with a small size as the research object, and is carried out according to the small sample test method, focusing on the material characteristics of the friction material under specific conditions. The small sample test has the advantages of simplicity, rapidity, low equipment investment and test cost, but there is a certain gap between the test simulation conditions and the actual working conditions of the specific friction parts, and the test results have certain limitations. It is often used in the early stage of new product development. Formula research and intermediate quality monitoring of friction material production process. Its test equipment is a variety of small sample testing machines.

Inertial bench tests often use 1:1 physical assembly as the test object, and are carried out according to the inertial bench test method. The reliability of the friction parts under the conditions. Compared with the sample test, the simulated conditions are closer to the actual working conditions, the description of the friction and wear properties of the friction material is more comprehensive, and the test results are more authoritative. But its equipment investment and test cost are relatively large, and the test period is long.

Through a large number of comparative test studies, it is found that the results of the existing small sample test and the inertial bench test are quite different, and there is almost no comparability. It is difficult to predict and reflect the results of the inertial bench test through the small sample test, and it is impossible to predict and evaluate the friction material comprehensively. friction and wear performance.

The test results of the small sample test and the inertial bench test are different. In addition to the test method, the difference of the test equipment is also an important factor. At present, the friction material sample testing machines are mostly used: constant speed testing machine, Chase testing machine and MM1000 testing machine, etc. Neither the constant speed testing machine nor the Chase testing machine can add inertia to the small sample testing machine, and the range of test simulation conditions and test functions are far inferior to the inertial bench testing machine. The same test method as the frame test. The MM1000 testing machine adopts a scaled sample, which can add inertia, and the simulation of test conditions has been improved. However, it adopts the pneumatic loading method, the braking force control accuracy is low, and the constant torque output test mode cannot be simulated; when the braking pressure differs greatly, it needs Replacing different loading cylinders, the test efficiency is low; there is no cooling temperature control system, and due to the limitation of the technical level at that time, the original structure is complex, the reliability is poor, the test accuracy and automation level are low, and the same method as the inertial bench test cannot be used. experiment method. Based on the similarity theory, according to the same simulation criteria as the inertial bench testing machine, according to a certain scale ratio, design a new type of structure, which can add inertia, does not use 1:1 physical assembly, and has the same structure as the inertial bench. The small-sample testing machine with the same or similar function as the inertial bench testing machine performs the same test method as the inertial bench testing machine, so that it has the same comparable basis as the inertial bench testing machine, which is a prerequisite for improving the comparability of small-sample test data. At the same time, it can greatly save equipment investment and test costs. A small scale bench friction testing machine provided by the present invention is designed and developed based on this principle.

Contents of the invention

The technical problem to be solved by the present invention is to provide a friction and wear performance testing machine for friction materials, especially one that provides a new structure, can add inertia, does not use a 1:1 physical assembly but uses a scaled sample, and has the same characteristics as Inertial bench tester is a small scale bench friction tester that has the same or similar functions and can adopt the same test method standard as the inertial bench test.

Referring to Fig. 1, in order to solve the above-mentioned technical problems, the present invention adopts following technical scheme, promptly on the basis of existing frame, dedusting device, cooling device, computer control system and electric control system, will be used for simulating different inertia and provide The main shaft drive system of the test conditions of different speeds is fixed on the upper working surface of the machine base, and the slide table system used to determine the relative position of the friction material specimen to be tested and the friction brake disc is connected by longitudinally moving the flat guide key and The one that can move longitudinally is also installed on the upper working surface of the machine base. The distance between the main axis of the installed spindle drive system and the upper working surface of the machine base and the axis of the pressure head installed on the horizontal moving plate in the slide system The distance to the upper working surface of the machine base is equal and the two axes are parallel.

The main shaft driving system described in the technical solution is composed of a friction brake disc, a driving motor, a temperature measuring device, a rotating speed measuring device and a flywheel device for simulating inertia; the driving motor described is a double output shaft motor, and the right side of the motor The protruding shaft is connected with the flange of the sleeve with which the flywheel is installed through a key, and the flywheel group is fixedly connected with the flange of the sleeve with which the flywheel is installed.

The temperature measuring device includes a shaft sleeve flange with a friction brake disc fixed on the shaft protruding from the left side of the drive motor through a key connection, and spacers that are sequentially sleeved on the outer surface of the shaft sleeve flange from left to right. Heat material, heat insulation material fixing plate, insulating sleeve, copper ring, stop washer, fastening nut, small toothed pulley for speed measurement, and fix the thermocouple probe in the small axial hole of the friction brake disc, thermoelectric The other end of the couple is drawn out through the heat insulation material, the heat insulation material fixing plate, the rectangular wire groove on the outer surface of the shaft sleeve flange, and the inner ring surface of the copper ring is fixed, and the outer ring surface of the copper ring is fixed on the carbon brush fixing plate carbon brush sliding contact.

The measuring device for measuring the rotating speed of the main shaft is fixed on the casing of the driving motor through a mounting bracket. On the bracket, the speed measuring large-toothed pulley is set on the left end of the rotating shaft through a key connection, the photoelectric encoder is fixed on the right end of the shaft sleeve, the speed measuring shaft of the photoelectric encoder is connected with the rotating shaft through threads, and the speed measuring large toothed pulley passes through the toothed belt Connects to the pinion pulley belt on the spindle drive system.

The sliding table system described in the technical solution is composed of a sliding table, a loading arm assembly used to install and fix the friction material specimen to be tested, a pressure control loading device, and a measuring device for friction force or friction torque; The table is composed of a longitudinally movable flat plate slidingly connected to the base through keys and a horizontally movable flat plate slidingly connected with the upper working surface of the longitudinally moving flat through keys, which can move longitudinally on the working surface of the machine base.

The loading arm assembly used to install and fix the tested friction material specimen is connected to the front vertical plate and the rear vertical plate through the rotating shaft, parallel to the main axis of the main shaft drive system and The main axis of the spindle drive system is relative to the right end of the support shaft at the same height as the working surface on the machine base, while the front vertical plate and the rear vertical plate are fixed on the laterally movable flat plate that can move laterally; the loading arm assembly is processed by one end. It is used to install the rectangular groove of the positioning mounting block of the test piece, the hole matching the positioning shaft and the hole for installing the spring and the spring compression screw, and the other end is forked and processed with a through hole matching the rotating shaft. The rotating shaft, the test piece positioning mounting block, the positioning shaft, the spring and the spring compression screw are composed; the end of the rotating shaft is processed with threads, and the rotating shaft, the bearing and the positioning sleeve are installed in the hole at the end of the supporting shaft, and then tightened with nuts.

The pressure control loading device is composed of a brake cylinder fixed in the round hole on the front vertical plate for installing the brake cylinder, a force sensor connected with the threaded coaxial line at the front end of the piston rod of the brake cylinder, a thread It consists of a pressure head connected to the other end of the force sensor and a hydraulic system connected with pipelines.

The friction force or friction moment measuring device is composed of a force measuring rod set on the supporting shaft connected by a key and fixed on a transversely moving flat plate, and an adjustable pressure bearing is installed on the upper end directly below the two ends of the force measuring rod. The force sensor of the head is composed.

The beneficial effects of the present invention are:

1) The present invention provides a testing machine suitable for testing the friction and wear properties of friction materials in the form of a small sample. This testing machine overcomes the shortcomings of the previous small sample testing machine without additional inertia, poor simulation of test conditions, single function, and small application range. , has the advantages of good simulation of inertial bench testing machine, complete functions and wide application range. The test efficiency is greatly improved, and the test cost is also greatly reduced.

2) The design principle of the present invention adopts the similarity theory, and the geometric reduction ratio is the ratio of the area of the friction material sample to the friction area of the actual disc brake pad. On this basis, a kinematics and dynamics similar reduction ratio is designed. A small scale bench friction testing machine. The geometric size of the appearance of the equipment is greatly reduced, and the equipment investment and test costs are far lower than the inertial bench testing machine.

3) Utilize the present invention to detect the friction and wear performance of the friction material, which can consider the influence of factors of different vehicle types and different working conditions on the performance of the friction material, can improve the accuracy of the small sample test and the credibility of the test data, and improve the accuracy of the test with the inertial platform The comparability level of the test data of the inertial bench is predicted and reflected by the test results of the inertial bench through the small sample test.

4) The present invention is applicable to formula research in the early stage of new product development and intermediate quality monitoring in the production process of friction materials. In particular, the friction and wear performance of the friction material can be fully tested according to the standards and methods of the inertial bench test, which is different from the characteristics of the current small sample testing machine.

Description of drawings

Below in conjunction with accompanying drawing, the present invention will be further described:

Fig. 1 is the front view of a kind of small scale bench friction testing machine;

Fig. 2 is a top view of a small-scale scale bench friction testing machine;

Fig. 3 is a front view of the main shaft drive system of a small scale bench friction testing machine;

Fig. 4 is a left view of the main shaft drive system of a small scale bench friction testing machine;

Fig. 5 is a top view of the main shaft drive system of a small scale bench friction testing machine;

Fig. 6 is a front view of a sliding table system of a small scale bench friction testing machine;

Fig. 7 is a left view of the sliding table system of a small scale bench friction testing machine;

Fig. 8 is a top view of the sliding table system of a small scale bench friction testing machine;

Fig. 9 is a front view of a loading arm of a small scale bench friction testing machine;

Fig. 10 is an A-A cross-sectional view of a loading arm of a small-scale bench friction testing machine;

Fig. 11 is a top view of the loading arm of a small scale scale bench friction testing machine;

Fig. 12 is a schematic diagram of friction force or friction torque test of a small scale bench friction tester;

In the figure: 1. Machine base, 2. Flywheel cover, 3. Spindle drive system, 4. Dust removal assembly, 5. Air blowing cooling assembly, 6. Protective cover, 7. Sliding table system, 8. Computer control system and electrical Control box, 9. Pressure control loading device, 10. Shaft sleeve flange, 11. Flywheel group, 12. Drive motor, 13. Speed measuring small toothed pulley, 14. Fastening nut, 15. Stop washer, 16. Copper ring, 17. Insulation sleeve, 18. Shaft sleeve flange, 19. Heat insulation material fixing plate, 20. Heat insulation material, 21. Thermocouple, 22. Friction brake disc, 23. Toothed belt, 24. Speed measurement Large toothed pulley, 25. End cover, 26. Mounting bracket, 27. Bearing, 28. Shaft sleeve, 29. Rotating shaft, 30. Photoelectric encoder, 31. Photoelectric encoder speed measuring shaft, 32. Carbon brush assembly Fixed bracket, 33. Carbon brush fixed plate, 34. Carbon brush, 40. Vertical mobile plate, 41. Horizontal mobile plate, 42. Front vertical plate, 43. Support shaft, 44. Vertical mobile plate guide key, 45. Installation plate , 46. Force sensor, 47. Bearing head, 48. Rear vertical plate, 49. Scale, 50. Pointer, 51. Handwheel, 52. End cover, 53. Bearing, 54. Connection fixed plate, 55. Through cover , 56. Adjusting sleeve, 57. Measuring rod, 58. Key, 59. Through cover, 60. Bearing, 61. End cover, 62. Loading arm assembly, 63. Locking screw, 64. Locking screw, 65. Hand wheel, 66. Pressure head, 67. Force sensor, 68. Brake cylinder piston rod, 69. Brake cylinder, 70. Laterally moving plate guide key, 75. Positioning sleeve, 76. Bearing, 77. Rotation Shaft, 78. Loading arm, 79. Locking jackscrew, 80. Positioning shaft, 81. Spring compression screw, 82. Spring, 83. Specimen positioning mounting block, 84. Tried friction material specimen.

Detailed ways

Referring to Fig. 1 and Fig. 2, a small-scale bench friction testing machine adopts an overall structure, mainly consisting of a box-type machine base 1, a spindle drive system 3, a dust removal assembly 4, a blower cooling assembly 5, and a sliding table system 7 , computer control system and electrical control box 8, pressure control loading device 9 components. The box-type base 1 can be welded by profiles and steel plates according to the size of the production batch, or it can be assembled by casting in parts and then fixed. No matter which method is used, it must have sufficient rigidity and strength. The working surface shall be machined, and a keyway shall be machined longitudinally. First, the sliding table system 7 used to determine the relative position of the friction material sample 84 to be tested and the friction brake disc 22 is connected via a key. The longitudinally moving flat plate 40 in the system 7 can move longitudinally on the upper working surface of the machine base 1; then, the self-contained main shaft drive system 3 for simulating different inertias and providing different rotating speed test conditions is driven through it. The base of the motor 12 is also fixed on the upper working surface of the support 1 with bolts. The distance between the axis of the pressure bearing head 66 and the upper working surface of the base 1 is equal and the two axes are parallel. Fix the blowing cooling assembly 5 and the dust removal assembly 4 on the lower working surface of the box-type frame 1 with bolts. The blowing cooling assembly 5 is composed of an adjustable-speed fan and a cooling air pipe. 1 through the upper working surface, the air outlet pipe of the terminal is located directly above the friction brake disc 22, and the air outlet pipe mouth is vertically downward. On the working surface of the machine base directly below the friction brake disc 22, there is a rectangular hole, which is connected with the suction pipe of the dust removal blower below, so that friction debris such as dust produced by hot air and friction are discharged in time. The pressure control loading device 9 is composed of a hydraulic system and a hydraulic actuator connected to a force sensor 67 and a pressure bearing head 66, namely a brake cylinder 69. The hydraulic system is mainly composed of a pump, a servo valve, a pressure regulating valve and pipelines. Install them In a control box, the control box is placed on the rear side of the machine base 1, connected to the machine base 1 by screws, and then connected to the brake cylinder 69 with pipelines, and the pressure control loading device 9 is connected to the whole machine. . Then the computer control system and the electrical control box 8 are also connected to the rear side of the machine base 1 by screws, adjacent to the pressure control loading device 9, and finally a protective cover 6 is installed on the front of the main shaft drive system 3, a small scale The bench friction testing machine is assembled.

Referring to Fig. 3, described main shaft driving system 3 is made up of friction brake disc 22, driving motor 12, temperature measuring device, rotational speed measuring device and the flywheel device of simulation inertia; What described driving motor 12 adopted is double output shaft For the motor, first extend the shaft end on the right side of the drive motor 12 and install the shaft sleeve flange 10 for installing the flywheel through a key connection. The flywheel group 11 is sleeved on the shaft sleeve flange 10 and fixedly connected with screws. Cover flange 10 and flywheel group 11 come off, fix with retaining ring and screw at shaft end face, add a flywheel cover 2 again for safety, cover on flywheel group 11, be fixed on the machine base 1 with screw when assembling.

Referring to Fig. 3 to Fig. 5, the temperature measuring device includes a shaft sleeve flange 18 installed on the left side of the drive motor 12 through a key connection sleeve and fixed with a friction brake disc 22 at the big end, from The large end is successively set on the heat insulating material 20, the heat insulating material fixing plate 19, the insulating sleeve 17, the copper ring 16, the stop washer 15, the fastening nut 14, the speed measuring small toothed belt on the outer surface of the shaft sleeve flange 18 Wheel 13, wherein: the friction brake disc 22 for testing is installed on the left end face of the shaft sleeve flange 18 by screws, in order to prevent the friction brake disc 22 and the shaft sleeve flange 18 from falling off from the shaft, a The retaining ring and screws fix it, the heat insulating material 20 and the heat insulating material fixing plate 19 are fixedly connected with the right end face of the friction brake disc 22 by screws, and the speed measuring small toothed pulley 13 is also fixed on the sleeve flange 18 by screws. on the right end face. A small through hole is machined in the axial direction of the friction brake disc 22 at the friction radius of the end face of the friction brake disc 22 (calculated according to the vehicle model and the scaling ratio), and a thread is machined radially on the outer surface of the friction brake disc 22 hole, and make the two holes connected, insert the thermocouple probe into the small axial hole at the friction radius of the friction brake disc 22, make the thermocouple probe be about 0.5-1mm away from the friction surface of the friction brake disc 22. A screw is adorned in the 22 radial threaded holes of the moving disk, which presses the thermocouple detection head and makes it fixed. The other end of the thermocouple is drawn out through the small through hole processed on the heat insulating material 20 and the heat insulating material fixing plate 19, the rectangular line groove on the outer surface of the sleeve flange 18 and the inner ring surface of the copper ring 16 is welded and fixed. The surface of the outer ring of the ring 16 is in sliding and reliable contact with the carbon brush 34 fixed on the carbon brush fixing plate 33 to ensure reliable transmission of the temperature signal for the thermocouple test. The carbon brush fixed plate 33 that carbon brush 34 is housed is to be fixed on the fixed support 32 by screw, and fixed support 32 is fixed on the left end top of motor casing by screw.

Referring to FIG. 5 , the measuring device for measuring the rotational speed of the spindle is fixed on the casing of the driving motor 12 through a mounting bracket 26 . First, two bearings 27 are used to install the rotating shaft 29 into the axle sleeve 28, and then it and the end cover 25 are fixed on the right and left sides of the mounting bracket 26 that has been fixed on the drive motor 12 shell with screws. The pulley 24 is set on the left end of the rotating shaft 29 through a key connection, and is fixed on the left end face of the rotating shaft 29 with a retaining ring and screws to prevent falling off. The photoelectric encoder 30 is fixed on the right end of the shaft sleeve 28 with screws, and the photoelectric encoder measures the speed. The left end of shaft 31 links to each other with rotating shaft 29 right ends by screw thread, and speed measuring large toothed belt pulley 24 is connected with small toothed belt pulley 13 on the main shaft drive system 3 by toothed belt 23.

Referring to Figures 6 to 8, the slide table system 7 is composed of a slide table, a loading arm assembly 62 for installing and fixing the friction material specimen 84 to be tested, a pressure control loading device 9, friction force or friction torque The measuring device is composed of; the slide table is composed of parts such as a longitudinally movable flat plate 40 that can move longitudinally on the machine base and a horizontally movable flat plate 41 that can move laterally. The longitudinally moving flat plate 40 of the slide table is the base of the whole slide table system. On the working surface of the machine base 1, a guiding rectangular keyway perpendicular to the axis of the main shaft drive system 3 is machined longitudinally. A guiding key 44 is installed in the groove, and the longitudinally moving flat plate 40 is a rectangular flat plate. Process a through rectangular keyway to cooperate with the guide key 44. By turning the handwheel 65 fixed on the machine base 1, the entire slide system can move longitudinally along the guide key 44. A pointer 50 is housed on the left side end surface of the longitudinally moving flat plate 40, which cooperates with the scale 49 fixed on the working surface of the machine base 1 to display the distance of the slide table moving longitudinally. On the working surface of the longitudinally movable flat plate 40, a rectangular guide key groove parallel to the axis of the main shaft drive system is formed along the transverse direction, and a guide key 70 is housed in the groove. On the lower working surface of the horizontally movable flat plate 41, a rectangular guide keyway is also processed in the horizontal direction, and cooperates with the guide key 70. By rotating the hand wheel 51 fixed on the longitudinally movable flat plate 40, the horizontally movable flat plate 41 is moved vertically on the flat plate 40. The upper working surface can be moved laterally. After the position of the slide table system is determined, the vertically movable flat plate 40 is fixed on the support 1 with four screws 63 , and the horizontally movable flat plate 41 is fixed on the longitudinally movable flat plate 40 with four screws 64 .

Referring to Fig. 6, Fig. 9 and Fig. 10, the loading arm assembly 62 used for installing and fixing the tested friction material specimen is connected to the front vertical plate 42 and the rear vertical plate 48 through the rotating shaft 77. The right end of the support shaft 43 that is parallel to the main axis of the main shaft drive system 3 and is equal to the upper working surface of the base 1 with the main axis of the main shaft drive system 3, and the front vertical plate 42 and the rear vertical plate 48 are fixed Installed on the laterally movable flat plate 41 that can move laterally; the loading arm assembly 62 is processed by one end with a rectangular groove for installing the positioning mounting block 83 of the test piece, a hole that matches the positioning shaft 80 and a mounting spring 82 and the hole of the spring compression screw 81, the other end becomes a fork shape and is processed with the loading arm 78 of the through hole matched with the rotating shaft 77, the rotating shaft 77, the bearing 76, the positioning sleeve 75, the test piece positioning mounting block 83 , The tested friction material specimen 84, the positioning shaft 80, the spring 82 and the spring compression screw 81 are composed. Among them: there are four locking jackscrews 79 on the test piece positioning mounting block 83 for tightening the tested friction material test piece 84; one end of the rotating shaft 77 is processed with threads, the rotating shaft 77, two bearings 76, and a positioning sleeve 75 After being installed in the hole of support shaft 43 ends, tighten with nut.

Referring to Fig. 8 and Fig. 2, described pressure control loading device 9 is by the brake oil cylinder 69 in the round hole that is used to install brake oil cylinder 69 on the front vertical plate 42, the piston rod that passes brake oil cylinder 69 The force sensor 67 that the threaded coaxial line of 68 front ends is connected, the pressure bearing head 66 that is threaded on the other end of force sensor 67 and the hydraulic system that connects with pipeline are made up. In fact, a part of the pressure control loading device 9 is placed on the rear side of the machine base 1, and it is fixed with screws, and then it is connected with the brake oil cylinder 69 fixed on the front vertical plate 42 with a pipeline. The control loading device 9 is installed. Wherein the brake cylinder 69 is fixed on the front vertical plate 42 with screws.

Referring to Fig. 6, the described frictional force or frictional moment measuring device is connected with the force measuring rod 57 sleeved on the support shaft 43 with the key 58 and is fixed on the transversely moving flat plate 41 and directly below the two ends of the force measuring rod 57. The upper end of which is equipped with a force sensor 46 with an adjustable bearing head 47. The specific installation position of the force measuring rod 57 on the support shaft 43 is: the horizontally moving flat plate 41 is a welded square structure, and the front vertical plate 42 and the rear vertical plate 48 are respectively welded on the working surface of the horizontally moving flat plate 41, and the connecting plate is fixed 54 connections. Two circular holes on the same axis are respectively processed on the front vertical plate 42 and the rear vertical plate 48, and the bearing 53, the end cover 52 and the transparent cover 55 are sequentially installed in the circular holes of the rear vertical plate 48, and fixed with screws , then pass the left end of the support shaft 43 through the round hole on the front vertical plate 42 and sequentially install the key 58, the transparent cover 59, the force measuring rod 57 and the adjustment sleeve 56 into the hole of the bearing 53 at last, then from the support The right-hand end of axle 43 packs into bearing 60 and end cover 61, is connected with screw through cover 59 and end cover 61 and also bearing 60 is fixed in the hole of front vertical plate 42 simultaneously. After assembly, the axis of the support shaft 43 and the axis of the friction brake disc 22 are at the same height as the main axis of the main shaft drive system 3 . Finally, the loading arm assembly 62 for installing and fixing the tested friction material sample 84 is connected to the hole at the right end of the supporting shaft 43 through the rotating shaft 77 . The force sensor (46) that is fixed on the transversely moving flat plate 41 and the upper end directly below the two ends of the load cell 57 is equipped with an adjustable bearing head 47 is realized by the mounting plate 45 and screws.

The spindle drive system 3 used in the present invention is used to simulate test conditions with different inertias and different rotational speeds. The main shaft drive system is self-contained, using the double output shaft drive motor 12 as the power source, the friction brake disc 22 for the test is installed on the left end of the output shaft on the left side of the drive motor 12, and the small axial hole of the friction brake disc 22 is equipped with The thermocouple is used to measure the temperature of the surface of the friction brake disc 22 during the friction process. The right end of the output shaft on the right side of the driving motor 12 is equipped with a flywheel group 11 for the simulation of test inertia. The driving motor 12 is also a speed-regulating motor (including AC frequency conversion speed regulation, DC speed regulation and electromagnetic speed regulation), and realizes various rotating speeds of the main shaft. The present invention has two methods for inertia simulation. The mechanical simulation inertia of a combination of multiple mechanical flywheels is used. In addition, the electrical simulation technology can be used to simulate mechanical inertia, that is, the electrical simulation of mechanical inertia that uses the continuous output energy of the motor to replace the kinetic energy stored by the flywheel. . Therefore, the method of electrically simulating mechanical inertia is also within the protection scope of the present invention.

The sliding platform system 7 is used for determining the relative position of the tested friction material sample 84 and the friction brake disc 22 and for clamping the tested friction material sample 84 . By rotating the handwheels 51, 65, the slide table can be moved horizontally and vertically, and the vertical moving distance is displayed by the scale 49 and the pointer 50. Various force sensors are installed in the sliding table system 7 for the measurement of braking force and frictional force (or frictional moment).

The pressure control loading device adopts servo control to realize the automatic control of the braking force. That is, through feedback, the braking force on the surface of the tested friction material test piece 84 is kept constant, and the braking force can also be followed, so that the friction force (or friction force) generated by the working surface of the tested friction material test piece 84 during the friction process torque) remains constant. In order to simulate different braking conditions.

The temperature control system is used for measuring and controlling the surface friction temperature of the friction brake disc 22 . Use the thermocouple installed in the small axial hole of the friction brake disc 22 to measure the temperature of the friction surface of the friction brake disc 22 during the friction process, and use the speed-regulating fan to simulate the air-cooling mode similar to the actual working condition. According to the requirements of the test The cooling wind speed and friction temperature are controlled by the computer to automatically control the speed of the adjustable fan to achieve the cooling air volume.

The computer control system and the electrical control box 8 are used for the control of the electrical analog mechanical inertia, the operation and control of the test program, data collection, processing and storage, and the display and printing of test data and test curves.

A method of operating a small scale bench friction testing machine:

1) First, install the tested friction material specimen 84 in the specimen positioning mounting block 83, and fix it with the locking jack screw 79, and then install the positioning mounting block 83 with the specimen in the rectangular concave of the loading arm 78. In the groove, make it in good contact with the positioning shaft 80, and utilize the spring 82 and the spring compression screw 81 so that the test piece positioning mounting block 83 will not escape from the rectangular groove, and can rotate slightly around the positioning shaft 80 at the same time. Adjust the front and rear positions of the pressure head 47 at the front end of the force sensor 46. One end of the pressure head is a thread, which is connected to the force sensor by the screw thread. level state.

2) The relative position of the rectangular friction material specimen 84 to be tested and the friction brake disc should meet the test requirements. Adjust the longitudinal position of the sliding table by turning the vertically moving handwheel 65, which can be determined according to the position of the pointer 50 on the scale 49; adjust the lateral position of the sliding table by turning the laterally moving handwheel 51, so that the tested friction material specimen 84 rubs against the working surface The distance between the friction working surface and the friction brake disc 22 meets the test requirements and is about 0.5 mm. After the position of the tested friction material sample 84 relative to the friction brake disc 22 is determined, the longitudinally movable plate 40 and the laterally movable plate 41 are locked with four screws 63 and four screws 64 .

3) According to the test requirements, select the flywheel or enable the electric simulation system, and set and adjust the test parameters such as pressure, torque, speed and control mode in the test program, that is, the preparatory work before the test is completed.

4) Start the speed-regulating drive motor 12 to drive the main shaft drive system 3 to rotate, so that the friction brake disc 22 installed on the main shaft drive system 3 rotates. Start the pressure control loading device 9, the oil pressure is controlled by the pressure regulating valve, the hydraulic oil acts on the rodless chamber of the brake cylinder 69 through the servo valve, and pushes the piston rod 68 and the force sensor 67 connected with it, the pressure bearing head 66 Move forward, push the loading force arm 78 to produce a slight rotation around the rotating shaft 77, so that the tested friction material specimen 84 installed in the rectangular groove of the loading force arm 78 is pressed to the working friction surface of the rotating friction brake disc 22, and the The test piece positioning mounting block 83 with the tested friction material test piece 84 is slightly rotated around the positioning shaft 80, so that the surface of the tested friction material test piece 84 and the working surface of the friction brake disc automatically tend to be parallel and contact, and the brake force increases with the braking force. increase, so that the tested friction material specimen 84 is in close contact with the friction brake disc 22 over a large area to generate friction, and enter the test state.

During the test, the rotational speed of the friction brake disc 22 is measured by the photoelectric encoder 30; the temperature is measured by the thermocouple 21 mounted on the friction brake disc 22. The vehicle type and the scale ratio are calculated, and the temperature of the friction brake disc 22 is measured by a thermocouple, and the data is processed and converted by the computer control system, and displayed on the computer screen. The computer control system can automatically judge whether the temperature of the friction brake disc meets the test requirements. If the temperature is too high and does not meet the test requirements, the blower cooling assembly 5 is automatically activated to cool the friction brake disc to make it meet the test requirements. The cooling air volume of this cooling system can be adjusted; the braking force produced by brake oil cylinder 69 is measured by force sensor 67; the friction force (torque) produced by friction braking is measured by force sensor 46, and its test principle is referring to Fig. 12, The friction brake disc rotates in the direction shown in the figure at the speed n, the braking force in the horizontal direction generated by the brake oil cylinder is F, and the braking friction force generated by the friction between the tested friction material specimen 84 and the friction brake disc 22 is f , the braking torque is M, the force measured by the force sensor 46 is F _f , and there is the following mathematical relationship between them:

Braking friction f＝F _f ·L ₁ /L ₂

Braking torque M=f·R=F _f ·R·L ₁ /L ₂

Friction material friction coefficient μ = f/F

A small scale scale bench friction testing machine can realize speed-related (different rotating speeds of friction brake discs 22) friction braking tests, pressure-dependent (under different braking pressures) friction braking tests, constant torque ( The braking force is automatically adjusted with the change of the friction coefficient, so that the output friction force or friction torque remains constant) friction braking test, temperature-related (at different friction temperatures) friction braking test, etc.

The working principle of the pressure control loading device 9 of a small scale bench friction testing machine:

After the friction material specimen 84 to be tested is installed, the automatic test program is started, and the speed-regulating drive motor 12 drives the spindle drive system 3 to rotate. When the rotational speed specified (set) for the test is reached, the pressure control loading device starts automatically, the pressure of the oil is controlled by the pressure regulating valve, and the hydraulic oil acts on the rodless cavity of the brake cylinder 69 through the servo valve, pushing the piston rod 68 and The force sensor 67 and the pressure bearing head 66 connected thereto move forward, pushing the loading force arm 78 to produce a small rotation around the rotation axis 77, so that the tested friction material specimen 84 installed in the rectangular groove of the loading force arm is pressed to rotate The working friction surface of the friction brake disc 22 makes the friction material specimen 84 to be tested contact with the friction brake disc 22 to generate friction and enter the test state. In the constant pressure test mode, the braking force F is required to be constant, and the servo valve will automatically adjust its output oil pressure according to the measured value of the force sensor 67 to keep the braking force F constant. In the constant torque test mode, the braking torque M is required to be constant, and the servo valve will automatically adjust its output oil pressure according to the measured value of the force sensor 46 to keep the braking torque M constant.

Various test parameters during the test, such as brake pressure, brake force, speed, temperature, brake torque, brake time, brake deceleration, and brake distance can be measured and calculated. Its data is stored and can be displayed on a computer screen.

After the braking process is over, the oil fluid acts on the rod chamber of the brake cylinder 69 through the servo valve, pushing the piston rod 68, the force sensor 67 connected thereto, and the pressure bearing head 66 to retreat, so that the brake cylinder returns to its original position. Due to the slight unevenness on the contact surface between the tested friction material specimen 84 and the friction brake disc 22, the rotating friction brake disc 22 produces a thrust component force opposite to the loading direction on the tested friction material specimen 84, so that the loading The force arm 78 rotates slightly around the rotation shaft 77 to make the friction material specimen 84 to be tested out of contact with the friction brake disc 22 . Prepare for the next braking action.

Claims (5)

1. friction test machine for small sample contracting ratio table, mainly by frame, dust arrester, cooling device, computer control system and electric-control system are formed, it is characterized in that: the spindle drive systems (3) that will be used to simulate different inertia and the operating condition of test of different rotating speeds is provided is fixed on the last workplace of support (1), the slide unit system (7) that will be used for determining tested friction material test specimen (84) and friction brake disk (22) relative position is by vertically moving the last workplace that also is installed in support (1) that dull and stereotyped feather key (44) key is connected and can vertically moves, the main axis of the spindle drive systems after the installation (3) relative to the distance of the last workplace of support (1) be installed in slide unit system (7) in the distance of last workplace of the horizontal relative support of axis (1) that moves the pressure bearing head (66) on the flat board (41) equal and two axial lines is parallel;

Described spindle drive systems (3) is made up of the flywheel gear of friction brake disk (22), drive motor (12), temperature measuring equipment, rotation-speed measuring device and simulated inertia; What described drive motor (12) adopted is the double output shaft motor, and motor right side projecting shaft connects the axle sleeve flange (10) that the installation flywheel is housed by key, and flywheel group (11) is fixedlyed connected with the axle sleeve flange (10) that flywheel is installed;

Described slide unit system (7) by slide unit, the measurement mechanism that is used for loading force arm assembly (62), pressure control charger (9), friction force or moment of friction that tested friction material test specimen (84) installs and fixes forms; Described slide unit by pass through of can on support (1) is gone up workplace, vertically moving key (44) and support (1) be slidingly connected vertically move flat board (40) and transversely movable by key (70) with vertically move flat board (40) and go up the horizontal mobile flat board (41) that workplace is slidingly connected and form;

Described pressure control charger (9) by be packed in brake cylinder (69) in the circular hole that is used to install brake cylinder (69) on the front vertical plate (42), the force transducer (67), the pressure bearing head (66) that is threadedly connected to force transducer (67) other end of screw thread coaxial cable connection of piston rod (68) front end by brake cylinder (69) formed with the hydraulic system that is connected with pipeline.

2. according to the described a kind of friction test machine for small sample contracting ratio table of claim 1, it is characterized in that: described temperature measuring equipment includes the axle sleeve flange (18) that is fixed with friction brake disk (22) that connects suit on the projecting shaft of drive motor (12) left side by key, be sleeved on the heat-barrier material (20) on axle sleeve flange (18) outside surface from left to right successively, heat-barrier material fixed head (19), insulation sleeve (17), copper ring (16), stop washer (15), clamp nut (14), little profile of tooth belt wheel (13) tests the speed, and thermopair (21) detecting head is fixed in the axial aperture of friction brake disk (22), the other end of thermopair is by heat-barrier material (20), heat-barrier material fixed head (19), square molded lines groove on axle sleeve flange (18) outside surface draw and copper ring (16) inner ring surface affixed, the outer ring surface of copper ring (16) be fixed on carbon brush (34) sliding contact on the carbon brush fixed head (33).

3. according to the described a kind of friction test machine for small sample contracting ratio table of claim 1, it is characterized in that: the described measurement mechanism that is used to measure the speed of mainshaft is the shell that is fixed on drive motor (12) by mounting bracket (26), at first use bearing (27) that rotation axis (29) is packed in the axle sleeve (28), again it is packed on the mounting bracket (26) that is fixed on drive motor (12) shell, the big profile of tooth belt wheel (24) that tests the speed is contained in the left end of rotation axis (29) by the key adapter sleeve, photoelectric encoder (30) is fixed on axle sleeve (28) right-hand member, the photoelectric encoder axle (31) that tests the speed links to each other with rotation axis (29) by screw thread, and the big profile of tooth belt wheel (24) that tests the speed passes through cog belt (23) and is with the little profile of tooth belt wheel (13) on the spindle drive systems (3) and is connected.

4. according to the described a kind of friction test machine for small sample contracting ratio table of claim 1, it is characterized in that: describedly be used for loading force arm assembly (62) that tested friction material test specimen (84) installs and fixes and be connected in by rotation axis (77) and be installed on front vertical plate (42) and the back vertical plate (48), with the main axis of spindle drive systems (3) parallel and go up the right-hand member of the contour back shaft (43) of workplace with the relative support of main axis (1) of spindle drive systems (3), and front vertical plate (42) and back vertical plate (48) are packed in and transversely movablely laterally move on the flat board (41); Loading force arm assembly (62) is the hole that is processed with the rectangular recess that is used to install test specimen location and installation piece (83), the hole that cooperates with locating shaft (80) and mounting spring (82) and spring compression screw (81) by an end, and the other end becomes fork-shaped and be processed with the loading arm of force (78) of the through hole that matches with rotation axis (77), rotation axis (77), test specimen location and installation piece (83), locating shaft (80), spring (82) and spring compression screw (81) to form; And rotation axis (77) one ends are processed with screw thread, and rotation axis (77), bearing (76), locating sleeve (75) are used nut screwing clamping after being installed in the hole of back shaft (43) end.

5. according to the described a kind of friction test machine for small sample contracting ratio table of claim 1, it is characterized in that: described friction force or moment of friction measurement mechanism by connect with key (58) be sleeved on the dynamometer link (57) on the back shaft (43) and be packed in laterally move dull and stereotyped (41) upward and the force transducer (46) that adjustable pressure bearing head (47) are housed of the upper end under dynamometer link (57) two ends form.

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