CN201083616Y - Simple harmonic excitation test stand - Google Patents

Abstract

The utility model relates to a simple harmonic excitation test bench, the purpose of which is to eliminate the motion error caused by the approximate simple harmonic motion of the crank connecting rod mechanism used in the traditional mechanical excitation test bench, to realize the accurate simple harmonic excitation test bench, and to realize the simple harmonic excitation test bench. On the eccentric shaft, double bearings are used to bear force in one direction to eliminate the gap caused by direction change and maintain the rolling friction between the outer ring of the driving bearing and the gear bar to reduce the direction-finding friction force generated during the driving process. The test bench is driven by a motor with frequency conversion speed regulation, and adopts a horizontal structure to lower the center of gravity and facilitate installation and adjustment. It is suitable for motorcycle shock absorber test and other occasions that need to provide simple harmonic excitation test.

Description

A simple harmonic excitation test bench

technical field

The utility model relates to a mechanical damping test device, in particular to a simple harmonic excitation test bench.

Background technique

According to my country's "Technical Conditions for Motorcycle Shock Absorbers" (QC/T62-1993), "Test Methods for Motorcycle Shock Absorbers" (QC/T63-1993), and "Special Requirements for Voluntary Products" of China Quality Certification Center According to the Special Requirements for Motorcycle Shock Absorbers (CQC/RY094-2003) and the Bench Test Method for Automobile Shock Absorbers (QC/T545-1999), standard simple harmonic motion excitation should be applied to one end of the shock absorber during the test. , and on this basis, the indicator performance and speed characteristics of the shock absorber are detected. At present, there are two excitation methods of shock absorber test benches: hydraulic excitation and mechanical excitation. The hydraulic excitation shock absorber test bench uses a servo hydraulic cylinder as the excitation force source, and the mechanical excitation test bench mechanism generally uses a crank connection. The rod mechanism is used as an excitation system, and the motion generated by the crank-link mechanism is an approximate simple harmonic motion, which will produce a certain motion error. The mechanism motion error refers to the deviation between the approximate simple harmonic motion generated by the crank-link mechanism and the standard simple harmonic motion. This deviation includes displacement deviation, speed deviation and phase deviation. According to the structural size of the crank-link mechanism of the test bench, the deviation between the approximate simple harmonic motion and the standard simple harmonic motion can be calculated. Compared with the standard harmonic, the approximate simple harmonic motion has The peak speed is too high, and the phase lags (the phase angle is too small). The error of the mechanism movement will lead to the deviation of the shock absorber's indicator performance and speed characteristics.

The law of simple harmonic motion is that when a particle moves at a uniform speed on a circle, the motion formed by its projection on the diameter of the circle is called simple harmonic motion. When the follower performs simple harmonic motion, its acceleration changes according to the cosine law, so it is also called the cosine acceleration law.

The utility model patent "Vehicle Shock Absorber Test Bench" (ZL95226272.X) provides a structural form of a crank-connecting rod mechanically excited shock absorber test bench, which is driven by a motor through a first-stage pulley to decelerate an eccentric disc and The piston is driven by the connecting rod to realize the up and down exciting motion, and the motion law generated by it is approximate simple harmonic motion.

The American MTS shock absorber test bench adopts servo hydraulic cylinder as the vibration exciter, and the beam adopts double oil cylinders to realize the up and down adjustment synchronously. The test bench is a vertical structure with double columns and single beam. The servo-hydraulic vibration-excited shock absorber test bench is controlled by a computer to realize simple harmonic motion through a hydraulic servo valve. Although simple harmonic excitation can be achieved, it involves a hydraulic servo system and its control. Vibration motion accuracy depends on the performance of the hydraulic servo system.

Contents of the invention

The purpose of the utility model is to solve the problems existing in the prior art, and provide a mechanically accurate simple harmonic excitation test bench.

The purpose of this utility model is to be realized by following scheme:

Drive the drive wheel shaft 17 by the built-in frequency conversion motor 3 in the table body 1 through the small pulley 40 and the large pulley 19. It is characterized in that: an eccentric disc 18 and an eccentric shaft 28 are embedded on the disc of the drive wheel shaft 17, and are driven by Place the double bearing 15 on the eccentric shaft 28 of the external measurement of the eccentric disc 18, and apply the exciting force to the shock absorber 12 under test through the front bar 14 and the rear bar 26 respectively arranged on the slide table 36; The slide table 36 is guided by the linear guide rail 16, and the test is completed by the encoder 37 connected to the end of the drive wheel shaft 17 and the force sensor 10 during the test; the sensor support 5 is also arranged on the table body 1.

The eccentric shaft 28 on the disc of the drive wheel shaft 17 adopts double bearings 15 for one-way force, so that there is no gap when the movement is changed and the outer ring of the drive bearing in the double bearings 15 is kept in contact with the front bar 14 and the rear. There is rolling friction between the bars 26, which reduces the direction-finding force generated during the driving process.

In order to change the cylinder-piston guide method of the traditional test bench, two linear guide rails 16 and guide rail seat 32 are used as the linear motion guide of the exciter, and it is rolling friction, with high precision and no lubrication.

The sensor support 5 can slide to adjust the position in the trapezoidal groove, and the guide key 31 provides guidance when shifting, and the hand wheel 8 drives the screw mandrel 6 and the nut 4 to facilitate the movement of the sensor support 5 .

The utility model changes the vertical structure of the traditional shock absorber test bench with double columns and cross beams, and adopts a horizontal structure, which lowers the center of gravity and facilitates the installation of the tested parts.

Driven by a variable frequency motor 2, the driving wheel shaft 17 and the large pulley 19 double as a flywheel to stabilize the speed of the test so that the test speed remains stable.

The beneficial effects of the utility model are:

1. Simple structure, easy to process and manufacture, low cost, high precision, no lubrication.

2. On the eccentric shaft of the driving wheel, double bearings are used to bear the force in one direction respectively, so as to ensure that the gap is eliminated when the direction of the vibration is changed, and the rolling friction between the outer ring of the driving bearing and the bar is maintained, so as to reduce the direction measurement generated during the driving process. friction.

3. Change the vertical structure of the traditional shock absorber test bench with double columns and beams, and adopt a horizontal structure to lower the center of gravity and facilitate the installation of the tested parts.

Description of drawings

Accompanying drawing 1 is a front sectional view of the utility model;

Accompanying drawing 2 is the left view of Fig. 1;

Accompanying drawing 3 is the top view of Fig. 1;

Accompanying drawing 4 is A-A sectional view among Fig. 1;

Accompanying drawing 5 is B-B sectional view among Fig. 1;

Accompanying drawing 6 is the C-C sectional view of Fig. 2.

1. Table body 16. Linear guide rail 30. T-slot screws

2. Motor base 17. Drive axle 31. Guide key

3. Frequency conversion motor 18. Eccentric disc 32. Linear guide rail seat

4. Nut 19. Large pulley 33. Guide rail bottom plate

5. Sensor support 20, scale 34a, spacer

6. Screw rod 21. Flange sleeve 34b, spacer sleeve

7. Bearing seat 22. Round nut 35. Joint

8. Hand wheel 23. Support seat 36. Sliding table

9. Flange cover 24. Ball bearing 37. Encoder

10. Force sensor 25a, pin shaft 38, flexible coupling

11. Head fixture 25b, pin shaft 39. Encoder bracket

12. Shock absorber 26. Rear bar 40. Small pulley

13. Tail clamp 27. Locating pin

14. Front bar 28. Eccentric shaft

15. Double bearing 29. Slider support

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described:

Figure 1 is the main view. It can be seen from the figure that the test bench consists of a bench body 1, a drive variable frequency motor 3, a small pulley 40, a large pulley 19, a drive wheel shaft 17, an eccentric disc 18, an eccentric shaft 28, a slide table 36, a straight line Guide rail 16, force sensor 10 screw rod 6, nut 4, position adjustment mechanism, etc.; spoke type force sensor 10 is fixedly connected with sensor support 5 through flange cover 9.

Figure 2 is a left view, the motor 3 is placed on the motor base 2 in the table body 1, the power is transmitted from the small pulley 40 to the large pulley 19 through the V-belt, and the driving torque can be increased by using the speed reduction belt transmission, and the movement can be maintained smoothness. The T-shaped slot on the motor base 2 can change the installation position of the variable frequency motor 3, thereby realizing the tensioning of the V-belt.

Fig. 3 is a top view, as can be seen from the figure, the variable frequency motor 3 placed in the platform body 1 transmits power to the drive wheel shaft 17 through a belt drive. The shock absorber 12 to be tested is installed between the head fixture 11 and the tail fixture 13 , and the tail fixture 13 is fixedly connected with the slide table 36 through the joint 35 and the positioning pin 27 . When the installation length of the shock absorber 12 under test changes, it is necessary to adjust the position of the sensor support 5, first loosen the four T-slot screws 30, turn the hand wheel 8 outside the bearing seat 7, and drive the nut 4 through the screw rod 6 Move the sensor support 5, and determine the moving distance by the two guide keys 31 according to the scale 20 when moving.

Fig. 4 is the A-A cross-sectional view of the vibration exciter and the force applying device of the shock absorber test bench, the driving force is transmitted from the large pulley 19 to the driving wheel shaft 17, and the driving wheel shaft 17 is composed of the support seat 23, the flange sleeve 21 and two angular contact balls The bearing 24 is supported, and the pre-tightening is realized by the difference in length and size of the inner and outer spacers 34a, 34b, and is fixed by two round nuts 22 . The outer end of the driving wheel shaft 17 is connected with the encoder 37 installed on the encoder bracket 39 through a flexible coupling 38, and the eccentric disk 18 and the eccentric shaft 28 are embedded in the disk, and the double bearings 15 on the eccentric shaft 28 are passed through respectively. The front bar 14 and the rear bar 26 drive the slide table 36 to move along the linear guide rail 16 installed on the guide rail base plate 33 to do simple harmonic reciprocating linear movement.

The eccentricity of the eccentric shaft 28 relative to the driving wheel shaft 17 is adjustable in steps. In most cases, as long as the eccentricity of the stepwise adjustment is satisfied, such as 5mm, 10mm, 15mm, 20mm, 25mm, etc., the requirements of the test stroke can be met. Torque transmission and positioning of the eccentric disk 18 are realized by screwing the two threaded pin shafts 25 a and 25 b provided on the driving wheel shaft 17 into several pairs of pin holes radially distributed on the circumference of the eccentric disk 18 .

FIG. 5 is a cross-sectional view of the position adjustment structure of the force sensor. It can be seen from the figure that the sensor support 5 is connected to the table body 1 with T-slot screws 30 .

Fig. 6 is the C-C sectional view of Fig. 2, mainly shows the installation structure of the eccentric shaft 28 of the driving slide 36 and the double bearing 15 on the front bar 14 and the rear bar 26.

Claims (6)

1. A simple harmonic excitation test bench, comprising a built-in variable frequency motor (3) in the platform body (1), drives the drive wheel shaft (17) by a small pulley (40) and a large pulley (19), its characteristics Yes: an eccentric disc (18) and an eccentric shaft (28) are embedded on the disc of the driving wheel shaft (17), and the double bearings (15) on the eccentric shaft (28) outside the eccentric disc (18) ), the exciting force is applied to the measured shock absorber (12) by the front bar (14) and the rear bar (26) respectively on the slide table (36); the slide table (36) is composed of The linear guide rail (16) is guided, and the encoder (37) connected to the end of the driving wheel shaft (17) and the force sensor (10) cooperate to complete the test during the test; the sensor support (5 ). 2. A kind of simple harmonic excitation test bench according to claim 1, characterized in that: the eccentric shaft (28) on the disc of the drive wheel shaft (17) adopts double bearings (15) as a one-way bearing Force, between the outer ring of the driving bearing in the described double bearing (24) and the front bar (14) and the back bar (26) is rolling friction. 3. A simple harmonic excitation test bench according to claim 1 or 2, characterized in that: the eccentricity of the eccentric shaft (28) relative to the driving wheel shaft (17) is adjustable in stages, and the driving wheel shaft Two threaded pin shafts (25a, 25b) provided on (17) are screwed into some pairs of pin holes distributed radially on the circumference of the eccentric disc (18) to realize transmission of torque and positioning of the eccentric disc (18). 4. A simple harmonic excitation test bench according to claim 1, characterized in that two of the linear guide rails (16) are used as guides for the excitation motion. 5. A simple harmonic excitation test bench according to claim 1, characterized in that: the sensor support (5) can slide in the trapezoidal groove on the table body (1) so as to adjust the position, and the time is shifted by The guide key (31) provides guidance, and it is convenient to realize by relying on the hand wheel (8) to drive the screw mandrel (6) and the nut (4). 6. a kind of simple harmonic excitation test bench according to claim 1, is characterized in that: described bench body (1) adopts horizontal type, to reduce the center of gravity, be convenient to the installation of measured shock absorber (12); Large belt pulley (19) and driving wheel shaft (17) double as flywheel, play the effect of stabilizing speed.

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