CN100445720C - Frequency-modulated and variable-amplitude vehicle suspension characteristic testing platform - Google Patents

Abstract

The invention discloses a frequency-modulation-amplitude-variable-amplitude-type automobile suspension characteristic testing platform which can adjust the vibration frequency and amplitude of the automobile and has a new technical solution for the over-the-road protection device. The technical solution adopted is to fix and install two sets of the same excitation table (2) with the functions of frequency modulation and variable amplitude on the two ends of the inline frame (1), and make the two sets of excitation table (2) The axes of the two rotating mandrels (21) contained in ) are collinear, and its function is realized by the frequency adjustment device (38) and the amplitude adjustment mechanism (7); the passing protection device is fixed on the base (10), It is located above the two vibration holders (13) and below the vibration plate (11) in the vibration holding and guiding mechanism (6). The frequency-modulated variable-amplitude vehicle suspension characteristic testing platform realizes the active vibration of the left and right excitation tables, and simulates the input characteristics of the actual road surface. Different models can use the function of the testing platform to conduct in-depth performance analysis and fault diagnosis of the vehicle suspension.

Description

Frequency-modulated and variable-amplitude vehicle suspension characteristic testing platform

technical field

The invention relates to a detection device for automobile performance, in particular to a detection platform for suspension characteristics of small automobiles.

Background technique

At present, domestic and foreign automobile suspension characteristic test benches generally adopt resonant test benches. According to the different detection parameters, the resonant testing platform can be divided into two types: force-measuring and amplitude-measuring testing platforms. Among them, the force-measuring test bench is widely used.

The automobile suspension characteristic dynamometer test bench uses the principle of detecting the wheel and road grounding force to quickly evaluate the quality and performance of the automobile suspension, and uses the measurement standards recommended by the European Shock Absorber Manufacturers Association (EUSAMA). The steady-state load on a car wheel is defined as the static ground force between the wheel and the road. When the automobile wheel vibrates under a certain external action, the changing load of the automobile wheel on the testing platform is defined as the dynamic load, and the ratio of the minimum value of the dynamic load to the static load is defined as the wheel grounding index (defined as the absorption rate in our country). The difference between the wheel grounding index and the wheel grounding index of the left and right suspensions on the same axle is used as the evaluation index of the automobile suspension device.

The dynamometer testing platform for automobile suspension characteristics uses a motor to drive the eccentric mechanism to rotate through a coupling, and uses the guiding mechanism to make the testing platform vibrate up and down, which also makes the automobile wheels on the testing platform produce forced vibration. When the motor reaches the maximum speed, it stops automatically, and the energy is released by the energy storage flywheel to maintain the continuous vibration of the car wheels, and at the same time sweep the frequency of the vibration of the car wheels. The initial frequency of the sweeping vibration is higher than the natural frequency of the car suspension, and when the sweeping frequency is the same as the natural frequency of the car suspension, the car will resonate. The measurement and control part of the testing platform uses the force sensor to collect the grounding force when the car is stationary and the minimum grounding force when the car is in resonance to judge the characteristics of the car suspension.

There are following deficiencies in the existing automobile suspension characteristic testing platform:

1. The existing vehicle suspension characteristic testing platform can only sweep the left and right wheels from high frequency to low frequency, and the vibration frequency cannot be controlled, and the sweep time cannot be controlled.

2. The eccentric distance of the eccentric mechanism of the existing automobile suspension characteristic testing platform cannot be adjusted, so the amplitude of the vibrating plate of the testing platform is fixed, and it cannot simulate the actual road conditions for real-time input.

3. The detection parameters are single, and the in-depth performance analysis and fault diagnosis of the automobile suspension cannot be carried out, and the technical status of the automobile suspension cannot be fully reflected. The detection results are not conducive to guiding the maintenance work of the automobile repair shop.

4. The vehicle axle load allowed to pass through one side of the existing vehicle suspension characteristic testing platform is 2t, so vehicles with excessive axle loads will not be able to pass through the testing platform.

Contents of the invention

The technical problem to be solved by the present invention is to provide a vehicle suspension performance detection device, especially to provide a frequency modulation variable amplitude vehicle suspension characteristic detection device that can adjust the vibration frequency and amplitude of the vehicle and has a new technical solution for over-passing protection tower.

Referring to Fig. 1, in order to solve the above-mentioned technical problem, the present invention adopts following technical scheme, namely on the basis of existing frame, measurement and control system, hydraulic station and gas pump station, two sets of identical excitation tables with variable amplitude function It is relatively fixedly installed on the two ends of the lower working surface in the inline frame, and the axes of the two rotating mandrels contained in the two sets of vibration tables are collinear. The vibration excitation table includes an amplitude adjustment mechanism and a vibration maintaining and guiding mechanism.

The amplitude adjustment mechanism includes a rotating spindle installed on the base by a bearing seat, and the same sprocket as the sprocket on the output shaft of the motor is installed on the left end of the rotating spindle, between the two supporting bearing seats of the rotating spindle From left to right, the inner cam cylinder cover and the rotary cylinder with the outer cam and roller bearings installed in the matching suit from the inside to the outside, and then the reverse movement matching suit is equipped with the outer cam and roller bearings from the inside to the outside. A double-circuit rotary joint is installed on the right end of the rotating spindle. The double-circuit rotary joint is connected to the hydraulic station through a pipeline, and the left end of the rotating spindle is connected to the output end of the motor through a sprocket coupling.

The vibration holding and guiding mechanism is fixedly connected with the force sensor and the vibration cage in turn on the lower working surface at both ends of the rectangular vibration plate, and the four linear bearings are respectively fixed at the two ends of the left and right vibration cages, and The linear bearing mandrel that restricts vibration of the vibrating plate in the vertical direction is fixed on the base with four linear bearings in motion, and one end of the four return springs that balance the vibration and return the vibrating plate is fixed on the vibrating cage. The other end is fixed on the base, and the positions of the four return springs are on the outside of the four linear bearings. The outer rings of the roller bearings are in contact.

The rotating mandrel contained in the amplitude adjustment mechanism described in the technical solution is composed of two synchronous pins fixed at both ends of the rotating mandrel to cooperate with the outer cam and a mandrel block fixed at the middle part of the rotating mandrel. The two oil holes of the spindle block on the rotating spindle respectively communicate with the oil passage 1 and the oil passage 2 processed along the axial direction of the rotating spindle.

The rotary cylinder contained in the amplitude adjustment mechanism described in the technical solution is composed of the rotary cylinder and the spindle block fixed on the inner wall of the rotary cylinder and the spindle stopper in the middle of the rotary spindle to connect the rotary spindle and the rotary cylinder. The space is divided into two chambers consisting of cylinder stops.

The invention proposes to add a frequency adjustment device on the basis of the previous technical solution of the amplitude-variable automobile suspension characteristic detection platform, so that it becomes a frequency-modulation variable-amplitude automobile suspension characteristic detection platform. The frequency adjustment device is composed of a computer, a frequency converter and a motor with an energy storage flywheel installed on an output shaft. The computer is connected to the frequency converter, the frequency converter and the motor are connected by wires, and the other output shaft of the motor is connected to One end of the rotating spindle is connected by a sprocket coupling.

The present invention also proposes a technical solution, that is, on the basis of the technical solution of the variable amplitude vehicle suspension characteristic detection platform or the technical solution of the frequency modulation and variable amplitude vehicle suspension characteristic detection platform, a vehicle passing protection device with a new technical solution is added, The over-the-vehicle protection device is a U-shaped support fixed on the front and rear rows of brackets formed by the support square tube, the support channel steel, the outer support channel steel and the support gasket, and is installed on the U-shaped support U-shaped Two identical support shafts in a plane are machined in the groove and along the axis direction, and the swing arms installed at both ends of the two support shafts are installed between the two swing arms at each end of the two support shafts to ensure that the two support shafts The connecting rod and piston rod connected by synchronous rotation are composed of a cylinder hinged with a swing arm at one end of two support shafts, and the other end of the cylinder is fixed on the frame. The channel steel is fixed on the base and is located between the two vibration cages in the vibration holding and guiding mechanism. The bottom surface of the board maintains a certain gap.

The beneficial effects of the present invention are:

1. The present invention utilizes frequency converters to control three-phase AC asynchronous motors to output different stable rotational speeds to realize active vibration of the left and right excitation tables. By setting the working mode of the frequency converter, the left and right excitation tables can be controlled separately or simultaneously; and the vibration frequency of the left and right vibration tables can be controlled arbitrarily. By setting the time parameters, the vibration control can be realized. time control.

2. The measurement and control system of the present invention controls the frequency adjustment device and the amplitude adjustment mechanism to output different frequencies and amplitudes, so that the left and right wheels input different amplitudes and frequencies simultaneously to simulate the input characteristics of the actual road surface. Therefore, the vibration provided by the new system for the wheel is more in line with the reality, so that the obtained detection results can more truly reflect the performance of the automobile suspension.

3. The present invention installs a set of over-the-road protection device implementing the new technical solution, and realizes that different vehicle types can pass through the function of the frequency-modulated-amplitude-variable-amplitude-type automobile suspension characteristic detection platform.

4. The present invention retains the energy storage flywheel while increasing the frequency adjustment device and the amplitude adjustment mechanism, so that the frequency modulation and amplitude variable automobile suspension characteristic detection platform can not only meet the detection of automobile suspension characteristics stipulated by the current national standard, but also can By simulating the input characteristics of different road surfaces, in-depth performance analysis and fault diagnosis of automobile suspension can be carried out. And lay the foundation for the formulation of new national standards in the future and the provision of testing equipment that supports new national standards.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a frequency modulation variable amplitude vehicle suspension characteristic testing platform;

Fig. 2 is a schematic diagram of the structural principle of the frequency adjustment device of the measurement and control system of the frequency modulation variable amplitude automobile suspension characteristic detection platform;

Fig. 3 is the three-dimensional structural schematic diagram of the excitation table of the frequency modulation and variable amplitude type automobile suspension characteristic testing platform;

Fig. 4 is a three-dimensional structural schematic diagram of the vibration holding and guiding mechanism of the frequency modulation variable amplitude automobile suspension characteristic testing platform;

Fig. 5 is a three-dimensional structural schematic diagram of the amplitude adjustment mechanism of the frequency modulation variable amplitude type automobile suspension characteristic testing platform;

Fig. 6 is an assembly schematic diagram of the three-dimensional structure of the rotating mandrel of the amplitude adjustment mechanism of the frequency modulation and variable amplitude automobile suspension characteristic detection platform;

Fig. 7 is a schematic diagram of the assembly of the three-dimensional structure of the rotating cylinder of the amplitude adjustment mechanism of the frequency modulation variable amplitude automobile suspension characteristic detection platform;

Fig. 8 is a cross-sectional view of the amplitude adjustment mechanism of the frequency modulation variable amplitude type automobile suspension characteristic testing platform;

Fig. 9 is a three-dimensional structure schematic diagram of a vehicle suspension characteristic detection platform with frequency modulation and variable amplitude;

In the figure: 1. Rack, 2. Exciting table, 3. Measurement and control system, 4. Energy storage flywheel, 5. Electric motor, 6. Vibration holding and guiding mechanism, 7. Amplitude adjustment mechanism, 8. Over-the-road protection device, 9. Roller bearing, 10. Base, 11. Vibration plate, 12. Load cell, 13. Vibration cage, 14. Linear bearing, 15. Return spring, 16. Linear bearing mandrel, 17. Chain wheel coupling Device, 18. Inner cam cylinder cover, 19. Rotary cylinder, 20. Outer cam, 21. Rotary mandrel, 22. Double circuit rotary joint, 23. Bearing seat, 24. Synchronization pin, 25. Mandrel block, 26 .Cylinder block, 27. Oil passage one, 28. Oil passage two, 29. U-shaped support, 30. Support shaft, 31. Connecting rod, 32. Swing arm, 33. Cylinder, 34. Support channel steel, 35 .Supporting square tube, 36. Supporting gasket, 37. Outer supporting channel steel, 38. Frequency adjustment device, 39. Frequency converter, 40. Rotating cylinder.

Detailed ways

The present invention has several implementation modes. Firstly, the specific implementation mode of the over-vehicle protection device combined with the prior art and having frequency modulation, variable amplitude and implementation of new technical solutions will be described.

From the installation position, the frequency modulation and variable amplitude vehicle suspension characteristic testing platform can be divided into the main machine part installed on the foundation in the pit. The other working part is the measurement and control part, which is installed in a place that is convenient for operation and observation of test conditions, and it mainly solves data collection, analysis and processing, and instruction issuance. The part of the main machine installed on the foundation in the pit is composed of a frame 1 and two sets of the same excitation table 2. This part is the vibration source, which provides input characteristics for simulating the actual road surface for the test, and provides variable frequency and variable amplitude as required. vibration source, so as to conduct in-depth performance analysis and fault diagnosis of automobile suspension. In addition, this part provides over-the-vehicle protection devices for the frequency modulation variable amplitude vehicle suspension characteristic testing platform, so that the frequency modulation variable amplitude vehicle suspension characteristic testing platform can work safely and reliably.

Referring to Fig. 1, the frame 1 is a frame structure welded into an inline shape by section steel, and two sets of the same excitation table 2 with the functions of frequency modulation and variable amplitude are relatively fixedly installed at both ends of the lower working surface in the inline frame , and make the axes of the two rotating mandrels 21 included in the same two sets of vibrating tables 2 collinear.

Referring to Fig. 3, Fig. 5 to Fig. 8, the excitation table 2 is composed of an amplitude adjustment mechanism 7, a vibration holding and guiding mechanism 6, a vehicle passing protection device 8, and a base 10. First, the amplitude adjustment mechanism 7 is installed, and the amplitude adjustment mechanism 7 contains two bearing blocks 23, a rotating spindle 21, two synchronizing pins 24, a spindle block 25, a sprocket wheel, an outer cam 20, two roller bearings 9, a rotating Cylinder 19 , cylinder block 26 , rotating cylinder 40 and two inner cam cylinder heads 18 . Wherein, the inner cam cylinder head 18 is a long tube part with a flange at one end for fixed installation with the rotary cylinder 19, and a cam is processed at the other end. Roller bearing 9 is installed on the sleeve, and the relative position of cam and outer cam 20 is changed to change the amplitude of amplitude adjustment mechanism 7; the rotating mandrel 21 is processed with oil passage 1 27 and oil passage 2 28 along the axial direction. The two ends of 21 are threadedly fixed with two synchronizing pins 24 matched with the outer cam 20 that is processed with a groove at the end, and the middle part of the rotating mandrel 21 is fixed with a mandrel stopper 25 with a screw, and on the mandrel stopper 25 The two oil holes of the two oil holes communicate with oil passage one 27 and oil passage two 28 respectively; the rotary cylinder 19 is composed of a rotary cylinder barrel 40 and a cylinder stopper 26 fixed on the inner wall of the rotary cylinder barrel 40 with screws, and the rotary cylinder 19 suit In the middle of the rotating spindle 21, the cylinder stopper 26 on the inner wall of the rotating cylinder 40 and the spindle stopper 25 at the middle part of the rotating spindle 21 divide the space between the rotating spindle 21 and the rotating cylinder 40 into two parts. chambers. The rotating mandrel 21 that the mandrel block 25 and two synchronous pins 24 are housed is fixed on the rectangular plate base 10 by two bearing blocks 23, bearings and screws, and the rotating mandrel 21 between the two bearing blocks 23 From left to right, move and fit the upper inner cam cylinder cover 18 (the outer cam 20 and the roller bearing 9 have been installed from the inside to the outside at the end where the cam is processed) and the rotary cylinder 19 (the rotating cylinder barrel of its assembly Cylinder block 26 has been housed on the 40 inner wall), and another identical inner cam cylinder cover 18 (the end that is processed with cam has been equipped with outer cam 20 and roller from the inside to the outside on another identical inner cam cylinder cover 18) Bearing 9), two inner cam cylinder covers 18 are fixedly connected with the rotary cylinder 19 with screws, and the left end of the rotary spindle 21 is connected with the same sprocket wheel as the sprocket wheel on the output shaft of the motor 5 in the frequency adjustment device 38 through a key connection, Two sprockets will be connected to form a sprocket coupling 17 by a double-row roller chain, and a double-circuit rotary joint 22 is installed on the right-hand side of the rotating mandrel 21 .

With reference to Fig. 3 and Fig. 4, on the basis of installing the amplitude adjustment mechanism 7, install the vibration holding and guiding mechanism 6, the vibration holding and guiding mechanism 6 consists of a vibrating plate 11, two load cells 12, two vibration holding frames 13, Four linear bearings 14, four return springs 15, and four linear bearing mandrels 16 are formed. The vibrating plate 11, the load cell 12, and the vibrating cage 13 are fixedly connected into one body with screws. The four linear bearings 14 are respectively fixed on the two ends of the left and right vibrating cages 13, and the linear bearing mandrel 16 is fixed on the base 10, so that the four linear bearings 14 and the four linear bearing mandrels 16 are kept in motion fit, limiting The vibration plate 11 can only vibrate in the vertical direction. One end of the four return springs 15 is fixedly connected to the vibration cage 13, and the other end is fixedly connected to the base 10 to balance the vibration and return the vibration plate. The four return springs 15 are respectively located on the four linear bearings 14. outside. The lower working surface between the two linear bearings 14 on each vibrating cage 13 is in contact with the outer ring of the roller bearing 9 on the outer cam 20 of the amplitude adjustment mechanism 7 . The whole vibration holding and guiding mechanism 6 is located on the amplitude adjusting mechanism 7, four linear bearings 14, four linear bearing mandrels 16 and four return springs 15 are in the amplitude adjusting mechanism 7 to rotate the mandrel 21. There are two on each side, in a riding style.

Referring to Figure 9, install the over-the-road protection device, the over-the-road protection device mainly consists of eight identical U-shaped supports 29, two identical support shafts 30, four identical swing arms 32, and two identical connecting rods 31, cylinder 33, 6 identical support gaskets 36, 2 identical support square pipes 35, 6 identical support channel steels 34 and 4 identical outer support channel steels 37 etc. form. 8 identical U-shaped supports 29, 6 identical support spacers 36, 2 identical support square tubes 35, 6 identical support channel steels 34 are fixedly connected together, and 4 identical outer support channel steels 37 Two rows of brackets are formed, which are fixed on the base 10 with bolts on both sides of the rotating spindle 21 in the amplitude adjustment mechanism 7 . The support shaft 30 is divided into a plane part, a cylindrical part and a shaft diameter part matched with the U-shaped groove. The shaft diameter part is placed in the U-shaped groove of the U-shaped support 29, and swing arms 32 are fixedly installed at both ends thereof. Rod 31 connects the swing arms 32 of two support shafts 30 to ensure that the two support shafts 30 rotate synchronously. The position of the entire over-the-road protection device is on the amplitude adjustment mechanism 7, which is also a riding type; but under the vibration plate 11 in the vibration holding and guiding mechanism 6, two vibration holding frames 13 in the vibration holding and guiding mechanism 6 above the range. When the over-vehicle protection device is in a non-working state, the plane part of the support shaft 30 is upward, and the plane part is parallel to the bottom surface of the vibrating plate 11, and there is a certain gap between the plane part of the support shaft 30 and the bottom surface of the vibrating plate, which does not affect the vibrating plate. normal vibration. When the cylinder 33 drives the swing arm 32 to turn 90 degrees, the arc portion of the support shaft 30 not only eliminates the gap between the plane part of the support shaft and the bottom surface of the vibration plate, but also supports the vibration plate 11 at a certain distance. The vibrating plate 11 drives the load cell 12 and the vibrating cage 13 to rise a certain distance, so that the lower working surface of the vibrating cage 13 is out of contact with the outer ring of the roller bearing 9 . At this time, the weight of the vehicle pressed on the vibrating plate 11 is transmitted to the base 10 by two support shafts 30, a series of support spacers 36, support square tubes 35, and support channel steel 34, so that the load cell 12 is not stressed. The load cell 12 is thereby protected.

In order for the vibration excitation table 2 to output a controllably variable frequency, the vibration excitation table 2 comprising the amplitude adjustment mechanism 7 , the vibration holding and guiding mechanism 6 and the overrun protection device 8 is connected to a frequency adjustment device 38 . Referring to Fig. 2, described frequency regulator 38 is made up of computer, frequency converter 39 and the motor 5 that energy storage flywheel 4 is installed on an output shaft, computer and frequency converter 39, between frequency converter 39 and motor 5 is The wires are connected, the computer and the frequency converter 39 are installed in the measurement and control cabinet containing the measurement and control system 3, and the motor 5 is installed on the base 10, so that the other output shaft of the motor 5 passes through the sprocket and the amplitude adjustment mechanism 7 installed by the key to rotate the spindle 21 One end is connected by a double-row roller chain with a sprocket mounted on a key. In this way, the operator can send instructions to the frequency converter 39 through the computer, and the frequency converter 39 will analyze and process the instructions after receiving the instructions, and provide power to the motor 5 after frequency modulation, so that the motor 5 can work under the new frequency condition.

At this time, the two sets of identical excitation tables 2 that have been assembled can be relatively fixedly installed on the two ends of the lower working surface in the inline frame, and the two rotating centers contained in the two identical excitation tables 2 can The axes of the shaft 21 are collinear. Then the installed host part is fixed on the foundation in the pit.

The remaining load cell 12 is connected with the measurement and control system line, the cylinder 33 is connected with the gas pump station of the measurement and control system 3 with pipelines, and the double-circuit rotary joint 22 is connected with the hydraulic station of the measurement and control system 3 through pipelines. A complete frequency-modulated-amplitude-variable-amplitude vehicle suspension characteristic testing platform that can adjust the frequency and amplitude of vehicle vibration and has a new over-the-road protection technology solution has been implemented.

The rest of several implementations are different due to different technical solutions, such as: only provide the function of variable amplitude, only provide the function of variable amplitude and over-vehicle protection, only provide the function of variable amplitude and frequency conversion, and provide the function of variable frequency, variable amplitude and over-vehicle protection at the same time Function, then do not adorn the frequency adjustment device 38 and have the over-the-vehicle protection device 8 of the new over-the-road protection technical scheme, do not adorn the frequency adjustment device 38 or do not adorn the over-the-vehicle protection device 8 when assembling. The rest is the same as before, so I won’t go into details here, and it is always much simpler than the previous assembly.

The frequency adjustment device 38 adopts a three-phase asynchronous AC motor 5 with dual output shafts, and retains an energy storage flywheel 4 on one of the output shafts. By simulating the input characteristics of different road surfaces, it can perform in-depth performance analysis and fault diagnosis of automobile suspension. And lay the foundation for the formulation of new national standards in the future and the provision of testing equipment that supports new national standards.

The working principle of the frequency modulation variable amplitude vehicle suspension characteristic testing platform:

Turn on the power supply of the measurement and control system of the frequency-modulated variable-amplitude vehicle suspension characteristic testing platform (hereinafter referred to as the testing platform), start the computer, and preheat the system for 30 minutes. The default state of the detection station is the passing state, that is, any vehicle is allowed to pass. To this end, the automatic detection program is started, and the system first performs a self-inspection to detect whether there are hardware problems in the host computer and the measurement and control system. If there is no hardware problem, the measurement and control system drives the over-the-road protection device to enter the default state. The process is that the computer program controls the action of the electromagnetic reversing valve of the pneumatic control system in the over-vehicle protection device, and the air pump station inflates the cylinder 33 through the electromagnetic reversing valve. The piston rod of the cylinder 33 drives the swing arm 32 to turn over a certain angle, and then the two support shafts 30 also turn over a certain angle. The cylindrical portion of the support shaft 30 supports the vibrating plate 11 by a certain distance. The vibrating plate 11 drives the load cell 12 and the vibrating cage 13 to rise a certain distance, so that the vibrating cage 13 is separated from the outer ring of the roller bearing 9 . At this time, the weight of the vehicle pressed on the vibrating plate 11 is transmitted to the base by two support shafts 30, a series of support spacers 36, support square tubes 35, and support channel steel 34, so that the load cell 12 is not stressed, thereby The load cell 12 is protected. The operator inputs the model information of a certain car into the computer, and the computer program judges whether the car of this model can be detected according to the model database input in advance. If the car of a certain type cannot be detected, the measurement and control system of the detection station will not act, and the detection station will continue to be in the passing state.

If the input vehicle type (such as a car) needs to be tested for suspension characteristics, the computer program controls the action of the electromagnetic reversing valve of the pneumatic control system in the over-travel protection device. gas. The piston rod of the cylinder 33 drives the swing arm 32 and the two support shafts 30 to reversely rotate through a certain angle. When the plane portion of the support shaft 30 is turned upward, the bottom surface of the vibration plate 11 is separated from the cylindrical portion of the support shaft 30 , and there is a certain gap between the plane portion of the support shaft 30 and the bottom surface of the vibration plate 11 . Due to its own gravity and the action of the return spring, the vibrating plate 11 drives the load cell 12 and the vibrating cage 13 to move downward, so that the vibrating cage 13 is in contact with the outer ring of the roller bearing 9. state. The computer program notifies the driver through the display screen to drive the car onto the testing platform so that the car wheels are located at the center of the vibrating plate 11, and the measurement and control system collects the static loads of the left and right wheels at this time.

If it is necessary to detect the characteristics of the automobile suspension according to the national standard, the operator gives instructions to the computer program to set a required fixed frequency for the three-phase asynchronous AC motor 5 through the frequency adjustment device 38, and can detect the three-phase asynchronous AC motor 5 After the rotating speed reaches 1500 rpm, the three-phase asynchronous AC motor 5 is controlled to stop. Simultaneously, the computer program controls the amplitude adjustment mechanism 7 to maintain a constant amplitude. The detection principle of this method is: the three-phase asynchronous AC motor 5 drives the amplitude adjustment mechanism 7 to rotate through the sprocket coupling 17, and under the limitation of the vibration holding and guiding mechanism 6, the cam of the rotating spindle 21 in the amplitude adjustment mechanism 7 Part of the vibrating plate 11 is made to vibrate in the vertical direction, so that the vehicle wheels on the vibrating plate 11 are forced to vibrate. When the rotational speed of the three-phase asynchronous AC motor 5 reaches the frequency set by the program and is stable, the program controls the three-phase asynchronous AC motor 5 to stop, and the energy storage flywheel 4 releases energy to sweep and vibrate the vehicle suspension. Since the initial frequency of the sweeping vibration is higher than the natural frequency of the car suspension, the car will resonate when the vibration frequency is the same as the natural frequency of the car suspension. The measurement and control part of the detection platform judges the performance of the automobile suspension through the ground force when the automobile is stationary and the minimum ground force when the automobile resonates collected by the load cell 12 and the vibration curve drawn.

If further testing of vehicle suspension characteristics is required, the control computer program is loaded with input characteristics of typical road surfaces. According to the typical road surface input characteristics loaded, the computer program controls the frequency adjustment device 38 to set different vibration frequencies for the three-phase asynchronous AC motors 5 of the left and right vibration excitation tables 2 respectively. While vibrating, the computer program controls the amplitude adjustment mechanism 7 in real time through the hydraulic system to change the relative position of the outer cam 20 and the inner cam, that is, to change the amplitude of the vibration excitation table 2 . After the vibration is stabilized, the computer program collects the force on the load cell 12, and draws a vibration curve through transformation, and then compares it with the output characteristics of a typical road surface to further analyze the problems existing in the suspension.

The working principle of the frequency adjusting device 38 is: the computer controls the frequency converter 39 to output different power frequencies, and then the three-phase asynchronous AC motor 5 rotates according to the power frequency output by the frequency converter 39, which realizes the adjustment of the vibration frequency.

The working principle of the amplitude adjustment mechanism 7 is: the computer program controls the hydraulic system to supply oil to a certain working chamber formed by the rotating spindle 21 and the rotating cylinder barrel 40 of the amplitude adjustment mechanism 7 through the double-circuit rotary joint 22 and the oil passage one 27; The hydraulic oil in the first working chamber flows back to the hydraulic station through the second oil passage 28 and the double-circuit rotary joint 22. Due to the effect of the hydraulic oil, the whole composed of the left and right inner cam cylinder heads 18 and the rotary cylinder 19 rotates with the rotary spindle 21 and rotates relative to the rotary spindle 21 at the same time. The outer cam 20 is kept rotating synchronously due to the limitation of the synchronous pin 24 and the rotating mandrel 21. Therefore, the two inner cam cylinder heads 18 respectively rotate relative to the outer cam 20 sleeved on their cam parts, thus changing the eccentricity of the entire cam part. distance, which changes the amplitude of the vibration

Theoretical and structural analysis of frequency modulation variable amplitude vehicle suspension characteristic testing platform:

The output characteristics of the actual road surface are irregular, and the fixed eccentricity, that is, the fixed amplitude excitation table used in the existing automobile suspension test bench, cannot truly reflect the output characteristics of the road surface. However, the present invention uses a measurement and control system to control two sets of independent vibrating platforms respectively, and the amplitude and frequency of the left and right vibrating platforms can be changed, which can more truly reflect the output characteristics of the actual road surface. advanced nature.

The amplitude adjustment mechanism 7 of the present invention adopts the principle that the hydraulic system drives two nested cams to rotate relative to each other, so that the eccentricity of the superimposed two cams changes constantly to realize the adjustment of the amplitude. This method is theoretically feasible. The specific structure is that the integral body consisting of the inner cam cylinder cover 18 and the rotary cylinder 19, which is fixedly connected to the left and right sides of the rotary cylinder 19, is placed on the rotary spindle 21, and the space between the rotary spindle 21 and the rotary cylinder 19 is fixed on the The spindle block 25 on the rotating spindle 21 and the cylinder block 26 fixedly connected on the rotating cylinder 40 are divided into two working chambers, and the two working chambers can be formed by the oil passage 27 and the oil passage 27 on the rotating spindle 21 respectively. Oil passage two 28 supply oil. Two left and right outer cams 20 are sleeved on the cams of the left and right inner cam cylinder heads 18 respectively, and due to the limitation of the synchronous pin 24 on the rotating mandrel 21, the outer cam 20 will rotate synchronously with the rotating mandrel 21 . The eccentricity of the whole mechanism is the eccentricity formed by the superimposition of two inner and outer cams. The hydraulic system is used to supply oil to one of the above two working chambers, and the other working chamber returns oil. The inner cam cylinder head 18 on the left and right sides of the rotary cylinder 19 and the rotary cylinder 19 form a whole to rotate relative to the rotary spindle 21 . At this moment, the outer cam 20 moves synchronously with the rotating mandrel 21, therefore, a relative rotation occurs between the cam part of the inner cam cylinder cover 18 and the outer cam 20, that is, the change of the total eccentricity of the cam part is realized. The hydraulics and control systems that power this mechanism are mature technology and fully achievable. The processing accuracy and assembly accuracy and sealing of the rotating spindle 21, the rotating cylinder 19, the inner cam cylinder head 18 and the outer cam 20, etc. can also be realized by using existing processing methods and materials, so the whole amplitude adjustment mechanism 7 has theoretical and Feasibility of manufacturing installation.

The frequency adjusting device 38 of the present invention sets a certain frequency for the frequency converter 39 by the computer, and the frequency converter 39 converts the power supply with a frequency of 50 Hz into the frequency set by the computer, and then sends the power supply converted by the frequency converter 39 to the three-phase The asynchronous motor 5, so that the three-phase asynchronous motor 5 can output different rotational speeds, that is, the vibration frequency of the excitation table can be adjusted. The technology of controlling the rotational speed of the three-phase asynchronous motor 5 by changing the frequency of the power supply through the frequency converter 39 is also a mature technology.

The over-the-vehicle protection device 8 of the present invention adopts a special support method, the main feature is that the support shaft 30 is composed of a plane, a cylindrical surface and a shaft diameter part, and the cylindrical part is used to eliminate the gap between the plane part and the bottom surface of the vibrating plate 11 and drive the vibrating plate 11 moves up a certain distance, so that the vibration cage 13 is out of contact with the roller bearing 9, so that the pressure of the vehicle on the vibration plate 11 is transmitted to the base 10 when passing the vehicle, and the load cell located under the vibration plate 11 12 No force. Driving the support shaft 30 to rotate is realized by using the cylinder 33 to push and pull the swing arm 32 fixedly connected to the end of the support shaft 30 to rotate. Cylinder 33, air pump and pneumatic control system belong to stereotyped components and mature technology, while support shaft 30, swing arm 32, support channel steel 34, etc. It is also feasible.

Claims (3)

1. frequency-regulation amplitude-variable automobile suspension characteristic detection table, it mainly is made up of frame, the TT﹠C system that comprises the actuating vibration table of car hanger and comprise a frequency regulation arrangement, it is characterized in that: have the actuating vibration table (2) that becomes the amplitude function and relatively be fixedly mounted in the in-line frame (1) two ends of workplace down two covers are identical, and make the axis conllinear of two live spindles (21) that two cover actuating vibration tables (2) are contained;

Described TT﹠C system contains a frequency regulation arrangement (38), described frequency regulation arrangement (38) is made up of computing machine, frequency converter (39) and motor (5) that accumulated energy flywheel (4) are installed on an output shaft, computing machine and frequency converter (39), be that electric wire connects between frequency converter (39) and the motor (5), an end of the live spindle (21) in another output shaft of motor (5) and the amplitude adjusting mechanism (7) is connected by sprocket wheel shaft coupling (17);

Described actuating vibration table (2) contains amplitude adjusting mechanism (7) and vibration keeps and guiding mechanism (6);

Described amplitude adjusting mechanism (7) contains by bearing seat (23) and is installed in live spindle (21) on the base (10), the left end of live spindle (21) be equipped with motor (5) axle on the identical sprocket wheel of sprocket wheel, the cam ring cylinder cap (18) of suit movingly successively from left to right on the live spindle (21) between the diaxon bearing (23), rotating cylinder (19), the reverse cam ring cylinder cap (18) of suit movingly, two cam ring cylinder cap (18) one ends are processed with cam respectively, suit external cam (20) and roller bearing (9) from the inside to the outside on the cam, two cam ring cylinder cap (18) other ends have ring flange respectively, be used for fixedlying connected with rotating cylinder (19), install two-circuit swivel adapter head (22) at the right-hand member of live spindle (21), two-circuit swivel adapter head (22) is connected with Hydraulic Station by pipeline, and the left end of live spindle (21) is connected with the output terminal of motor by sprocket wheel shaft coupling (17);

Described vibration maintenance and guiding mechanism (6) are to be fixedly connected sequentially with force cell (12) and vibration retainer (13) on the following workplace at rectangle oscillating plate (11) two ends, the two ends of two vibration retainers (13) about four linear bearings (14) are separately fixed at, the linear bearing axle (16) that the constrained vibration plate (11) that disposes movingly with four linear bearings (14) vibrates in vertical direction is fixed on the base (10), playing balance vibration is fixed on the vibration retainer (13) with four retracing springs (15) one ends that make oscillating plate (11) return effect, the other end is fixed on the base (10), the position of four retracing springs (15) is in the outside of four linear bearings (14), and the following workplace between each vibration retainer (13) last two linear bearings (14) contacts with the outer shroud of roller bearing (9) on being fixedly arranged on the middle live spindle (21) of amplitude adjusting mechanism (7);

2. according to the described frequency-regulation amplitude-variable automobile suspension characteristic detection table of claim 1, it is characterized in that: the live spindle (21) that described amplitude adjusting mechanism (7) contains by two that are fixed in that live spindle (21) two ends match with external cam (20) synchronously pin (24) and the axle block (25) that is fixed in live spindle (21) middle part form, two oilholes that are fixed in the axle block (25) on the live spindle (21) communicate with oil duct one (27) and the oil duct two (28) processed along live spindle (21) axis direction respectively;

The rotating cylinder (19) that described amplitude adjusting mechanism (7) contains is made of the cylinder barrel block (26) that the space between live spindle (21) and the rotating sleeve (40) is divided into two chambers rotating sleeve (40) and the axle block (25) with live spindle (21) middle part that is fixed on rotating sleeve (40) inwall.

3. according to the described frequency-regulation amplitude-variable automobile suspension characteristic detection table of claim 2, it is characterized in that: described car hanger is by being fixed on by supporting square tube (35), support channel-section steel (34), the outer U type that supports on channel-section steel (37) and the affixed front and back that form of support pad (36) the two row's supports supports (29), be installed in two identical back shafts (30) that the U type supports in (29) U type groove and processes a plane along its axis direction, the swing arm (32) of installing at two back shafts (30) two ends, for guaranteeing that two back shafts (30) rotate the connecting rod (31) that connects two back shafts (30), two swing arms of each end (32) synchronously, cylinder (33) is formed, swing arm (32) on the tailpiece of the piston rod of cylinder (33) and a back shaft (30) right-hand member is hinged, the other end of cylinder (33) is fixed on the frame (1), whole car hanger is to support channel-section steel (34) and support channel-section steel (37) outward by front and back two rows to be fixed on the base (10), be arranged on vibration maintenance and guiding mechanism (6) two vibrations retainer (13), plane on two back shafts (30) of car hanger makes progress when off working state, and keeps certain interval with the bottom surface that vibrates oscillating plate (11) in maintenance and the guiding mechanism (6).

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