CN102146976A - Sliding block adjustment-based air spring vibration isolator with gas-solid damping coupling effect - Google Patents

Abstract

The air spring vibration isolator based on the gas-solid damping coupling effect of slider adjustment belongs to the field of ultra-precision measurement and processing. The circularly arranged strip-shaped damping sheets of the vibration isolator are assembled on the bottom of the inner cylinder, the radially evenly distributed sliders are assembled on the upper end surface of the inner bottom of the outer cylinder, and the worm gear device is installed under the inner bottom of the outer cylinder. On the end face, the orifice area adjustment device driven by the cam is fitted under the orifice on the inner wall of the outer cylinder. Use air throttling damping and orifice area adjustment device to reasonably adjust the total area of the orifice, and provide the best damping when there is strong vibration and impact load in the vertical direction; use Coulomb damping and strip damping plate relative to The reciprocating motion of the outer cylinder provides damping for the vibration isolator, and the size of Coulomb damping is changed by adjusting the position of the radial slider, so as to provide optimal damping when there are strong vibration, micro vibration and impact load in the vertical direction.

Description

Air Spring Vibration Isolator Based on Air-Solid Damping Coupling Based on Slider Adjustment

technical field

The invention belongs to the field of ultra-precision measurement and processing, and in particular relates to an air spring vibration isolator based on the gas-solid damping coupling effect adjusted by a slider.

Background technique

A vibration isolation device with excellent performance is one of the key technologies for ultra-precision measurement and processing. The air spring vibration isolator has the advantages of good ultra-low frequency vibration isolation performance, high bearing capacity, low equivalent stiffness, natural frequency insensitivity to load changes, easy system implementation, and low energy consumption. With the development of ultra-precision measurement and processing technology With the development of , nanotechnology and VLSI manufacturing technology, air spring isolators have been more and more widely used. Vibration isolation of a measurement frame such as a photolithography machine that carries all exposure elements.

The main indicators that affect the vibration isolation performance are the natural frequency and damping ratio of the vibration isolation device. Under the action of damping, the typical vibration transmission rate of the vibration isolation system is shown in Figure 1. It can be seen from Figure 1 that damping in the resonance region has a very significant suppression effect on vibration, and the situation is just the opposite outside the resonance region. Therefore, in order to ensure the vibration isolation performance of other vibration isolation systems, the system damping must be set reasonably according to the actual situation.

The patent US20030006540A1 "Self-aligning mechanism for pneumatic vibration isolators" uses a damper with a single damping hole to provide air throttling damping for the isolator. At present, typical air spring vibration isolators use throttling holes with fixed apertures to utilize air Throttle damping provides damping for vibration isolators, such as the air spring vibration isolator products of TMC, Newport in the United States and Meili Seiki in Japan.

Patent CN1670399 "Air Spring Isolator with Adjustable Stiffness and Damping" proposes to use multiple damping adjustment rods to adjust the size of multiple slit-shaped axial through holes respectively, so as to realize the adjustment of air throttling damping. The damping adjustment structure of this invention is relatively complicated, and the accuracy is not easy to guarantee. In addition, multiple damping adjustment rods work separately, so that the size of each group of axial through holes cannot be guaranteed to be consistent.

No matter whether the damping hole with a fixed aperture size or the adjustable damping hole is used to provide damping for the air spring vibration isolator, there is an obvious principle defect, which is aimed at damping the tiny vibration of ultra-low frequency, low speed, and micro-displacement. The hole basically does not work, because when the vibration isolator has low-speed and micro-displacement ultra-low frequency vibration, the pressure difference on both sides of the orifice is almost zero, and only a very small amount of air flows through the orifice, resulting in almost no damping force. to zero.

Comprehensively considering that the vibration isolator has strong vibration, micro vibration and impact load in the vertical direction, the damping link of the air spring vibration isolator described in the above invention has obvious shortcomings.

Contents of the invention

In order to make up for the deficiencies of the existing air spring isolators, the present invention proposes an air spring isolator based on slider adjustment of gas-solid damping coupling to meet the requirements of ultra-low frequency vibration isolation in the field of ultra-precision measurement, processing, assembly and debugging. need. In view of the structural characteristics of the positive and negative pendulum series mechanism and the existing air spring vibration isolator, the present invention proposes to install a cam-driven orifice area adjustment device under the orifice inside the outer cylinder, and install circularly arranged strips at the bottom of the inner cylinder. Shaped damping sheet, radially evenly distributed sliders are installed at the bottom of the outer cylinder, and a worm gear device is installed on the other side of the bottom of the outer cylinder to form an air spring isolator based on the air-solid damping coupling effect adjusted by the slider.

The purpose of the present invention is achieved like this:

A mechanical model of an air spring isolator with air-solid damping coupling based on slider adjustment is shown in Figure 1. The air spring vibration isolator is equipped with an inner cylinder inside the outer cylinder, and the air spring airbag is set outside the upper end of the inner cylinder. The cover plate is sealed and connected with the upper end of the air spring airbag, the air inlet is set on the outer wall of the outer cylinder, a group of throttle holes arranged in a circle is arranged on the inner wall of the outer cylinder, and the lower end of the outer cylinder is sealed and equipped with a circular bottom plate, and the support rod passes through the ring cover The plate is installed in the inner cylinder cavity, the upper end of the cable-stayed wire rope is fixedly connected with the annular cover plate, the lower end of the cable-stayed steel wire rope is fixedly connected with the lower end of the support rod, the cable-stayed wire rope constitutes a single pendulum mechanism, and the load-bearing plate is fixed on the upper end of the support rod. The steel spring is installed at the bottom of the inner cylinder, the piston is in contact with the steel spring, the lower end of the flexible hinge is fitted on the upper end of the piston, the upper end of the flexible hinge is fitted on the lower end of the support rod, and the flexible hinge, piston and steel spring form an inverted swing mechanism; Circumferentially arranged strip-shaped damping sheets are installed on the bottom of the inner cylinder, and radially evenly distributed sliders are assembled on the upper end surface of the inner bottom of the outer cylinder. The worm device is assembled on the lower end surface of the inner bottom of the outer cylinder, and is located on the same side as the air intake hole. The outer part of the slider group is in contact with the strip damping sheet, and the inner part of the slider group is in contact with the tapered boss worm. The worm gear shaft It is rotatably fitted on the worm wheel shaft seat, and the conical boss worm is fitted at the center of the inner bottom of the outer cylinder in a liftable manner, and its lower end is in contact with the worm gear shaft; the throttle hole area adjustment device driven by the cam is fitted on the inner wall of the outer cylinder Below the throttle hole on the top, and on the same side as the air intake hole, the throttle hole area adjustment device of the cam drive is composed of a retaining ring, a flange, a camshaft seat, and a camshaft, and the retaining ring is set on the inner wall of the outer cylinder in a liftable manner , the flange is fixed on the inner wall of the outer cylinder, the camshaft seat is installed on the flange, the camshaft is rotatably fitted on the camshaft seat, and the cam of the camshaft is in contact with the retaining ring.

The present invention has following characteristics and good effect:

1. The present invention proposes to install circularly arranged bar-shaped damping sheets at the bottom of the inner cylinder, install radially uniform sliders at the bottom of the outer cylinder, and install a worm gear device at the bottom of the outer cylinder, using Coulomb damping and strip-shaped damping sheets relative to the outer The reciprocating motion of the cylinder provides damping for the vibration isolator, and the radial slider is driven by the worm gear device, which can realize the adjustment of Coulomb damping, and provide optimal damping in the case of strong vibration, micro vibration and impact load in the vertical direction , to overcome the shortcomings of single or multiple damping holes that cannot provide a suitable damping force in the case of low-speed and micro-displacement ultra-low-frequency vibrations.

The Coulomb damping force f _d output by the strip damping sheet depends on the following factors, as shown in the following formula.

f _d =μN

In the formula: μ is the dynamic friction coefficient, which is positively related to the contact area and relative velocity; N is the normal pressure.

When the vertical vibration from the environment is transmitted to the inner cylinder, the vertical vibration of the bar-shaped damping plate is caused, and the bar-shaped damping plate rubs against the slider to provide Coulomb damping for the air spring vibration isolator. The use of multiple bar-shaped damping plates is beneficial in limited The space increases the contact area between the bar-shaped damping sheet and the slider, so as to ensure the output of sufficient damping force under the condition of low speed and slight displacement.

2. Utilize the air throttling damping and orifice area adjustment device to reasonably adjust the total area of the orifice, and provide the best damping in the case of strong vibration and impact load in the vertical direction. The orifice area adjustment device The sizes of all the orifices can be adjusted at the same time in a consistent manner, which overcomes the disadvantage that the existing patented damping adjustment device adjusts separately so that the adjustments are inconsistent.

3. Since the stiffness of the strip damping sheet in the horizontal direction is connected in parallel with the horizontal stiffness of the air spring and connected in series with the horizontal stiffness of the positive and negative pendulum series mechanism, the total horizontal stiffness of the strip damping plate and the air spring is much greater than that of the positive and negative pendulum series connection The horizontal stiffness of the mechanism, therefore, the equivalent horizontal stiffness of the air spring vibration isolator is closer to the horizontal stiffness of the positive and negative pendulum series mechanism, which slightly improves the vibration isolation performance of the vibration isolator in the horizontal direction to a certain extent. In addition, the strip damping plate It guides the inner cylinder of the air spring vibration isolator in the vertical direction.

4. The present invention proposes that a group of throttle holes arranged in a circle be arranged on the inner wall of the outer cylinder, and a cam-driven throttle hole area adjustment device is installed below the throttle holes inside the outer cylinder. The structural characteristics of the air spring vibration isolator of the inverted pendulum series mechanism make the structure of the whole vibration isolator more compact and reasonable.

Description of drawings

Figure 1 is a typical vibration transmissibility curve of the vibration isolation system;

Figure 2 is a schematic diagram of the mechanical model of the air spring isolator based on the gas-solid damping coupling effect of slider adjustment;

Fig. 3 is a schematic cross-sectional view of an air spring vibration isolator based on the gas-solid damping coupling effect adjusted by the slider;

Fig. 4 is a 3D cross-sectional schematic diagram of an air spring isolator based on the gas-solid damping coupling effect adjusted by the slider;

Fig. 5 is a 3D cross-sectional schematic diagram of a cam-driven orifice area adjusting device;

Fig. 6 is a 3D cross-sectional schematic diagram of a strip damper;

Fig. 7 is a 3D cross-sectional schematic diagram of a radial slider driven by a worm gear device.

In the figure: 1. Bearing plate; 2. Annular cover plate; 3. Support rod; 4. Cable-stayed wire rope; 5. Air spring air bag; 6. Inner cylinder; 7. Outer cylinder; 8. Flexible hinge; 9. Piston; 10. Throttle hole; 11. Throttle hole area adjustment device for cam drive; 11a. Retaining ring; 11b. Flange; 11c. Camshaft seat; 11d. Camshaft; 12. Steel spring; 13. Air inlet; 14. Circular bottom plate; 15. Worm gear device; 15a. Worm gear shaft; 15b. Worm gear shaft seat; 15c. Conical boss worm;

Detailed ways

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, as shown in Figure 3, Figure 4, Figure 5, Figure 6 and Figure 7, showing an embodiment of the air spring vibration isolator of the present invention.

The air spring vibration isolator is equipped with an inner cylinder 6 inside the outer cylinder 7, and the air spring airbag 5 is set outside the upper end of the inner cylinder 6. The outer cylinder 7 is sealed and connected with the lower end of the air spring airbag 5 through its upper end boss, and the inner cylinder 6 passes The annular cover plate 2 affixed to its upper end is sealingly connected with the upper end of the air spring air bag 5 , the air inlet 13 is arranged on the outer wall of the outer cylinder 7 , a group of throttle holes 10 arranged in a circle are arranged on the inner wall of the outer cylinder 7 , and at the lower end of the outer cylinder 7 The circular bottom plate 14 is sealed and fitted, and the support rod 3 passes through the annular cover plate 2 and is fitted in the cavity of the inner cylinder 6 . The lower end is fixed, the cable-stayed steel wire rope 4 constitutes a single pendulum mechanism, the load-bearing plate 1 is fixed on the upper end of the support rod 3, the steel spring 12 is installed at the bottom of the inner cylinder 6, the piston 9 is in contact with the steel spring 12, and the lower end of the flexible hinge 8 is assembled. On the upper end face of the piston 9, the upper end of the flexible hinge 8 is fitted on the lower end of the support rod 3, and the flexible hinge 8, the piston 9 and the steel spring 12 form an inverted swing mechanism; the strip-shaped damping sheets 17 arranged in a circle are fitted into the inner cylinder 6 At the bottom, the radially evenly distributed slider group 16 is fitted on the upper end surface of the inner bottom of the outer cylinder 7, and the worm gear device 15 composed of a worm gear shaft 15a, a worm shaft seat 15b, and a conical boss worm 15c is fitted on the outer cylinder 7 On the lower end surface of the inner bottom, and on the same side as the air inlet 13, the outer part of the slider group 16 is in contact with the strip damping sheet 17, the inner part of the slider group 16 is in contact with the tapered boss worm 15c, and the worm shaft 15a It is rotatably fitted on the worm wheel shaft seat 15b, and the conical boss worm 15c is fitted up and down at the bottom center of the inner side of the outer cylinder 7, and its lower end is in contact with the worm wheel shaft 15a; the orifice area adjustment device 11 driven by the cam Fitted below the throttle hole 10 on the inner wall of the outer cylinder 7, and on the same side as the air intake hole 13, the throttle hole area adjustment device 11 of the cam drive consists of a retaining ring 11a, a flange 11b, a camshaft seat 11c, a camshaft 11d, the retaining ring 11a is mounted on the inner wall of the outer cylinder 7 in a liftable manner, the flange 11b is fixed on the inner wall of the outer cylinder 7, the camshaft seat 11c is installed on the flange 11b, and the camshaft 11d is rotatably fitted on the camshaft seat On 11c, the cam of the camshaft 11d contacts and fits with the retaining ring 11a.

The number of strip-shaped damping sheets 17 is 2 to 100, and they are evenly distributed around the circumference.

The radially evenly distributed slider group 16 is composed of 2 to 100 sliders, and is uniformly distributed around the circumference.

The number of the cable-stayed steel wire ropes 4 is 3 to 50, and they are evenly distributed.

The angle between the cable-stayed steel wire rope 4 and the plumb line ranges from 0° to 30°.

The cable-stayed steel wire rope 4 is a round strand, special-shaped strand or multi-strand non-twisting organic core steel wire rope, fiber core steel wire rope, asbestos core steel wire rope, steel wire core steel wire rope.

The number of the orifices 10 is 2 to 100, and they are evenly distributed around the circumference.

The steel spring 12 can be a helical spring, a conical spring, a disc spring or a rubber spring.

Analysis of vibration from the environment can be divided into vertical vibration and horizontal vibration according to the vibration direction. The horizontal vibration successively passes through the outer cylinder 7, the air spring airbag 5, the slider group 16, the strip damper 17, the inner cylinder 6, and the positive and negative pendulum series mechanism (cable-stayed wire rope 4, flexible hinge 8, piston 9 and steel spring 12) And the support rod 3 acts on the load-bearing plate 1. Except for the positive and negative pendulum series mechanism, the other links are approximately rigid bodies, so the horizontal vibration cannot cause the movement of the inner cylinder 6 relative to the outer cylinder 7. The orifice 10 and the strip damping Sheet 17 has no damping effect on horizontal vibration; vertical vibration successively passes through outer cylinder 7, air spring airbag 5, inner cylinder 6, cable-stayed steel wire rope 4 and support rod 3, acting on load-bearing plate 1, except for air spring airbag 5, other links Approximate to a rigid body, the inverted pendulum composed of the flexible hinge 8, the piston 9 and the steel spring 12 only serves as an auxiliary support in the vertical direction, so the vertical vibration can cause the reciprocating motion of the inner cylinder 6 relative to the outer cylinder 7, and the inner and outer chambers The air enters and exits through the orifice 10 to provide air throttling damping for the vertical vibration. The strip damping plate 17 reciprocates with the inner cylinder 6 relative to the slider group 16, and rubs against the surface of the slider group 16, which is vertical Vibration provides Coulomb damping.

Claims (8)

1. An air spring vibration isolator based on the air-solid damping coupling effect adjusted by the slider, the inner cylinder (6) is equipped inside the outer cylinder (7), and the air spring airbag (5) is set on the upper end of the inner cylinder (6) Externally, the outer cylinder (7) is sealingly connected with the lower end of the air spring airbag (5) through its upper end boss, and the inner cylinder (6) is sealingly connected with the upper end of the air spring airbag (5) through the annular cover plate (2) fixed at its upper end , the air intake hole (13) is arranged on the outer wall of the outer cylinder (7), a group of throttle holes (10) arranged in a circle is arranged on the inner wall of the outer cylinder (7), and a circular bottom plate ( 14), the support rod (3) passes through the annular cover plate (2) and fits in the cavity of the inner cylinder (6), the upper end of the cable-stayed steel wire rope (4) is fixedly connected with the annular cover plate (2), and the cable-stayed steel wire rope (4) ) is fixedly connected to the lower end of the support rod (3), the cable-stayed wire rope (4) constitutes a single pendulum mechanism, the bearing plate (1) is fixed on the upper end of the support rod (3), and the steel spring (12) is installed in the inner cylinder (6 ) bottom, the piston (9) is in contact with the steel spring (12), the lower end of the flexible hinge (8) is fitted on the upper end of the piston (9), and the upper end of the flexible hinge (8) is fitted on the lower end of the support rod (3) , a flexible hinge (8), a piston (9) and a steel spring (12) constitute an inverted pendulum mechanism, and the air spring isolator is characterized in that: strip-shaped damping sheets (17) arranged in a circle are fitted in the inner cylinder ( 6) Bottom, radially and uniformly distributed slider group (16) is fitted on the upper end surface of the inner bottom of the outer cylinder (7), consisting of worm gear shaft (15a), worm gear shaft seat (15b), conical boss worm (15c ) composed of a worm and gear device (15) is fitted on the inner bottom lower end surface of the outer cylinder (7), and is located on the same side as the air inlet (13). Contact fit, the inner part of the slider group (16) is in contact with the conical boss worm (15c), the worm wheel shaft (15a) is rotatably fitted on the worm wheel shaft seat (15b), and the conical boss worm (15c) Fitted in the center of the inner bottom of the outer cylinder (7) in a liftable manner, and its lower end is in contact with the worm gear shaft (15a); the throttle hole area adjustment device (11) driven by the cam is fitted on the throttling hole on the inner wall of the outer cylinder (7) Below the hole (10), and on the same side as the air intake hole (13), the throttle hole area adjustment device (11) of the cam drive consists of a retaining ring (11a), a flange (11b), a camshaft seat (11c), camshaft (11d), retaining ring (11a) is set on the inner wall of outer cylinder (7) in a liftable manner, flange (11b) is fixed on the inner wall of outer cylinder (7), and camshaft seat (11c) is installed on flange ( 11b), the camshaft (11d) is rotatably fitted on the camshaft seat (11c), and the cam of the camshaft (11d) is in contact with the retaining ring (11a). 2. The air spring vibration isolator based on the air-solid damping coupling effect adjusted by the slider according to claim 1, characterized in that: the number of strip damping pieces (17) is 2 to 100 , and distributed uniformly around the circumference. 3. The air spring vibration isolator based on slider-adjustable gas-solid damping coupling according to claim 1, characterized in that: the radially evenly distributed slider groups (16) range from 2 to 100 It consists of sliders and is evenly distributed around the circumference. 4. The air spring vibration isolator based on the air-solid damping coupling effect adjusted by the slider according to claim 1, characterized in that: the number of the cable-stayed steel wire ropes (4) is 3 to 50, And evenly distributed. 5. The air spring vibration isolator based on the air-solid damping coupling effect adjusted by the slider according to claim 1, characterized in that: the range of the angle between the cable-stayed wire rope (4) and the plumb line is 0 ° to 30° 6. The air spring vibration isolator based on the air-solid damping coupling effect adjusted by the slider according to claim 1, characterized in that: the cable-stayed wire rope (4) is a round strand, a special-shaped strand or a multi-strand Twisted organic core wire rope, fiber core wire rope, asbestos core wire rope, steel wire core wire rope. 7. The air spring vibration isolator according to claim 1, characterized in that: the number of said throttle holes (10) is 2 to 100, and they are evenly distributed around the circumference. 8. The air spring vibration isolator according to claim 1, characterized in that: the steel spring (12) can be a coil spring, a conical spring, a butterfly spring or a rubber spring.

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