Pneumatic control valve for micro-vibration field

Abstract

The pneumatic control valve comprises a valve shell and an ejector rod, a cavity I, a cavity II and a cavity III which are sequentially arranged from top to bottom are formed in the valve shell, a valve sleeve is arranged in the cavity II and used for blocking and sealing a vent hole, and the ejector rod is arranged in the valve shell. The ejector rod is connected into the cavity I in a penetrating mode, the bottom end of the ejector rod penetrates through the ventilation hole to abut against the top of the valve sleeve and blocks a hole, communicated with the cavity III, of the valve sleeve, a ventilation slit is reserved between the ejector rod and the inner wall of the ventilation hole, the ejector rod and the valve sleeve achieve sensitive vertical movement through a spring, and air flow of the ventilation slit can be accelerated in the moving process of the ejector rod. According to the pneumatic control valve disclosed by the utility model, the flow direction is opposite to the conduction direction of the throttling opening A and the throttling opening P and the conduction initial airflow direction of the throttling opening A and the silencer opening, so that the airflow in the pneumatic control valve does not change sharply, the effect of smooth ventilation is achieved, and the advantage of flow control through small hole throttling of the throttling opening A and the throttling opening P is combined; therefore, the pneumatic control valve can timely and synchronously feed back vibration and interference signals from the landslide and the ground.

Description

Technical Field

[0001] This utility model belongs to the field of pneumatic control valves, specifically a pneumatic control valve for use in the field of micro-vibration. Background Technology

[0002] With the development of science and technology, ultra-micro processing, testing, and scientific experiments have placed stringent demands on environmental vibration, especially for large-scale ultra-precision photoelectric measuring instruments, which require increasingly stringent anti-vibration measures. Currently, air spring vibration isolation devices are widely used both domestically and internationally. These devices are equipped with height-controlled pneumatic valves for automatic leveling, effectively isolating the effects of external vibrations. This allows for testing of precision instruments at any time, and the isolation platform has excellent leveling performance, making it the most effective means of preventing micro-vibrations in precision equipment and instruments.

[0003] Traditional height pneumatic control valves are inadequate in this field, mainly due to: 1. low position control reset accuracy; 2. slow system response and low vibration isolation rate.

[0004] Traditional high-speed pneumatic control valves are mostly based on orifice throttling to control flow rate. The flow rate is determined by the area A formed by the orifice diameter, the pressure difference ΔP between port P and port A, the fluid density ρ, and the throttling coefficient C. d The following is the formula for orifice throttling: A pneumatically controlled valve designed solely based on the orifice throttling formula can achieve position detection and control, but its reset accuracy will be greatly reduced due to insufficient sensitivity to speed and acceleration. At the same time, its vibration isolation rate is not high, and it not only fails to provide vibration isolation in certain frequency bands, but also causes signal amplification. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, this utility model provides a pneumatic control valve for the field of micro-vibration.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A pneumatic control valve for micro-vibration applications includes a valve body and a push rod. The valve body contains three chambers arranged sequentially from top to bottom: chamber I, chamber II, and chamber III. The valve body wall has a throttling port A connecting chamber I, a throttling port P connecting chamber II, and a silencer port connecting chamber III. Chambers I and II are connected by a vent hole. A valve sleeve and a spring II are arranged within chamber II. A sealing platform is located at the top of the valve sleeve. The spring II applies force to push the valve sleeve upwards. The valve sleeve is also provided with an axially penetrating inner hole, and the bottom end of the valve sleeve is sealed and inserted into the chamber III. The top end of the push rod is sealed and inserted into the top wall of the chamber I and extends out to the outside of the valve body. The bottom end of the push rod passes through the vent hole and approaches the top of the valve sleeve and seals the top end of the inner hole. A venting slit is left between the push rod and the inner wall of the vent hole. The spring I in the chamber I is sleeved on the push rod, and when the push rod is pressed downward, the spring I acts on the push rod to make the push rod move upward.

[0008] Throttling ports A and P are respectively connected to throttling valves.

[0009] The top opening of chamber I is provided with a sealing ring I, and the top end of the top rod passes through the sealing ring I in a sealed manner.

[0010] The top of the push rod is equipped with a wear-resistant ball.

[0011] A sealing ring II is provided on the connection port between chamber II and chamber III, and the bottom end of the valve sleeve is sealed and inserted into chamber III through the sealing ring II.

[0012] The bottom of chamber III is provided with an installation port, and a sealing bottom cover is fixedly installed on the installation port.

[0013] The top of the valve housing is open and is closed by a gap gland, which forms the chamber I after the gap gland is closed.

[0014] Both spring I and spring II are pagoda springs.

[0015] The surface of the top port of the inner hole of the valve sleeve at the bottom of the push rod is spherical.

[0016] The beneficial effects of this utility model are as follows: This utility model arranges chambers I and II, connected by a vent hole, between throttling orifice A and throttling orifice P. A valve sleeve is installed in chamber II to seal the vent hole. A push rod passes through chamber I, with its bottom end passing through the vent hole and pressing against the top of the valve sleeve, sealing the hole connecting the valve sleeve to chamber III. A vent slit is left between the push rod and the inner wall of the vent hole. Both the push rod and the valve sleeve achieve sensitive up-and-down movement via springs. During the movement of the push rod, the airflow through the vent slit is accelerated, allowing air to pass through the throttling orifice. A. The opening of the throttle port P and the opening of the throttle port A and the silencer port initially counteract each other, preventing the airflow in the pneumatic control valve from changing drastically, thus achieving a smooth ventilation effect. This allows the pneumatic control valve to introduce sensitive control of gas acceleration, thereby ensuring stable operation. Combining the advantages of flow control through the small orifice throttling of throttle ports A and P, the pneumatic control valve can promptly and synchronously feedback vibration and interference signals from the ground veins and the ground, improving the vibration isolation rate of the air spring vibration isolation device and further enhancing its performance. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is the control principle diagram of this utility model;

[0019] Figure 2 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0020] Reference Figure 1 , Figure 2 A pneumatic control valve for micro-vibration applications includes a valve housing 1 and a push rod 2. The valve housing 1 contains chambers I, II, and III arranged sequentially from top to bottom. The valve housing 1 has a throttle port A3 connecting chamber I, a throttle port P4 connecting chamber II, and a silencer port 5 connecting chamber III on its wall. Throttling port A3 is equipped with a throttle valve 11 and is connected to the cylinder of an air spring vibration isolation device. Throttling port P4 is equipped with a throttle valve 11 and is connected to an external air source. The silencer port 5 is connected to the atmosphere via a silencer.

[0021] The chambers I and II are connected by a vent hole 6. A valve sleeve 7 and a spring II 9 are arranged in the chamber II. The top of the valve sleeve 7 is also provided with a sealing platform. The spring II 9 applies force to make the top of the valve sleeve 7 press against the vent hole 6 and seal it. The valve sleeve 7 is also provided with an axially penetrating inner hole 8. The bottom end of the valve sleeve 7 is sealed and penetrates into the chamber III. The top end of the push rod 2 is sealed and penetrates the top wall of the chamber I and extends to the outside of the valve body 1. The bottom end of the push rod 2 passes through the vent hole 6 and approaches the top of the valve sleeve 7 and seals the top end of the inner hole 8. A venting slit is left between the push rod 2 and the inner wall of the vent hole 6. The spring I 10 in the chamber I is sleeved on the push rod 2. When the push rod 2 is pressed and moves downward, the spring I 10 acts on the push rod 2 to make the push rod 2 move upward.

[0022] When in a calm environment, the push rod 2 is not triggered. At this time, the push rod 2 tightly seals the inner hole 8 of the valve sleeve 7, preventing chamber I from connecting to chamber III through the inner hole 8 of the valve sleeve 7, thus preventing the throttling port A3 from connecting to the silencer port 5. At this time, the valve sleeve 7 is not pressed down by the push rod 2 to tightly seal the vent 6. At this time, chamber I and chamber II are isolated from each other, preventing the throttling port P4 from connecting to the throttling port A3. Moreover, chamber II is also completely sealed, preventing the gas entering through the throttling port P4 from flowing out.

[0023] When the ground pulsates or is disturbed, the vibration isolator vibrates synchronously with the ground, causing the top rod 2 to be triggered and pressed down. At the same time, the valve sleeve 7 is also pressed down and leaves the bottom of the vent hole 6, opening the vent hole 6 and connecting chamber II with chamber I. That is, the throttle port P4 is connected to the throttle port A3. The external air source flows through the vent slit between the vent hole 6 and the top rod 2 and through the throttle port A3 to inflate the vibration isolation device. The gas enters the damping chamber of the vibration isolation device and then the load chamber, forming a phase difference. Due to the compressibility of air, the amplitude transmitted from the ground reaches the load plate of the vibration isolation device, and its amplitude is greatly reduced, thus forming vibration isolation. When the environment returns to calm, the valve sleeve 7 resets and resumes its blockage of the vent 6. When the push rod 2 is triggered and pressed down, it is rebounded by the action of the spring I 10, causing the bottom end of the push rod 2 to leave the top port of the inner hole 8 of the valve sleeve 7, so that chamber I and chamber III are connected. That is, the throttle port A3 is connected to the silencer port 5. The gas entering through the throttle port A3 flows through the vent slit between the vent 6 and the push rod 2 and is exhausted to the outside of the vibration isolator through the silencer port 5. The gas in the load chamber of the vibration isolator is discharged through the damping chamber, which directly causes the load plate of the vibration isolator to move slightly downward. The gas from the load chamber, through the damping chamber of the vibration isolator, and then through the throttle port A3 to the silencer port 5 forms a phase difference. Due to the compressibility of air, the amplitude of the load plate of the vibration isolator is much lower than the vibration amplitude of the ground, thus forming vibration isolation.

[0024] The above-described inflation and deflation process solves the problem of unbalanced oscillations caused by uneven inflation and deflation rhythms, which leads to amplified interference signals at specific frequencies. Furthermore, during both inflation and deflation, the airflow passes through the vent slit between vent 6 and the push rod 2. In addition to the flow control achieved through the small orifice throttling at throttling ports A3 and P4, slit throttling is added. The flexible movement of the push rod 2 accelerates the airflow through the vent slit, counteracting the initial airflow direction of the opening between throttling ports A3 and P4, and between throttling port A3 and silencer port 5. This prevents abrupt changes in airflow within the pneumatic control valve, achieving stable ventilation. This allows the pneumatic control valve to incorporate sensitive control of gas acceleration, resulting in stable operation and timely, synchronous feedback of vibrations and interference signals from the ground and ley lines.

[0025] The fundamental principle of slit throttling is the calculation of flow rate in a concentric annular slit. When the cylinder moves relative to the inner hole 8, the formula is: Q = πdh³Δp / 12μL ± πdhu0 / 2; when there is no relative movement between the cylinder and the inner hole 8, the formula is: Q = πdh³Δp / 12μL. From the above formulas, it can be seen that the flow rate of the concentric annular slit needs to consider two parts: the size of the slit and the relative speed of the cylinder's movement relative to the inner hole 8. When this principle is introduced into this invention, when the throttling port P4 is connected to the throttling port A3, or when the throttling port A3 is connected to the silencer port 5, under the influence of disturbance, u0 (the speed of the push rod) and the pressure difference ΔP are key factors determining the ventilation performance of the vibration isolation device. When the pneumatic air valve is triggered, the push rod 2 moves to counteract the initial airflow direction of the airflow through the ventilation slit with the conduction of the throttle ports A3 and P4, as well as the conduction of the throttle port A3 and the silencer port 5. This solves the problem of rapid changes in inflation and deflation, making the pace uniform and balanced, eliminating the specific frequency generated by unbalanced oscillations, and greatly helping to improve vibration isolation performance.

[0026] To facilitate the installation of internal components such as the push rod 2 and valve sleeve 7, the valve body 1 achieves sealed isolation between chambers I, II, and III by installing sealing rings. Specifically, chamber I has a sealing ring I12 at its top opening, through which the top end of the push rod 2 passes. The top of the valve body 1 is open and closed by a gap cover 16, which forms chamber I. The gap cover 16 is fastened to the lower part of the valve body 1 with screws, and the opening is... After the pressure cap 16 is removed, the sealing ring I12 can be disassembled and installed, thereby enabling the installation and maintenance of the push rod 2 and the spring I10. A sealing ring II14 is provided on the communication port between chamber II and chamber III. The bottom end of the valve sleeve 7 is sealed and inserted into chamber III through the sealing ring II14. An installation port is provided at the bottom of chamber III. A sealing bottom cover 15 is fixedly installed on the installation port. After opening the sealing bottom cover 15, the sealing ring II14 can be disassembled and installed, thereby enabling the installation and maintenance of the valve sleeve 7 and the spring II9.

[0027] In this embodiment, spring I10 and spring II9 are both pagoda springs. Pagoda springs have the characteristics of small size, large load and small working space, which are very suitable for application in the pneumatic control valve.

[0028] Preferably, the surface of the bottom end of the push rod 2 that blocks the top port of the inner hole 8 of the valve sleeve 7 is spherical, which can easily and effectively seal the top port of the inner hole 8 of the valve sleeve 7.

[0029] Preferably, the top of the push rod 2 is provided with a wear-resistant ball 13 to improve the durability of the pneumatic control valve.

Claims

1. A pneumatic control valve for use in the field of micro-vibration, comprising a valve body (1) and a push rod (2), characterized in that: The valve housing (1) has chambers I, II and III arranged sequentially from top to bottom, and the valve housing (1) has a throttle port A (3) connecting chamber I, a throttle port P (4) connecting chamber II and a silencer port (5) connecting chamber III respectively on its wall. The chamber I and chamber II are connected by a vent hole (6). A valve sleeve (7) and a spring II (9) are arranged in the chamber II. The top of the valve sleeve (7) is also provided with a sealing platform. The spring II (9) applies force to make the top of the valve sleeve (7) press against the vent hole (6) tightly. The valve sleeve (7) is also provided with an axially penetrating inner hole (8). The bottom end of the valve sleeve (7) is sealed and penetrates into the chamber III. The top end of the push rod (2) is sealed and connected to the top wall of the chamber I and extends to the outside of the valve body (1); the bottom end of the push rod (2) passes through the vent hole (6) and approaches the top of the valve sleeve (7) and seals the top port of the inner hole (8). A venting slit is left between the push rod (2) and the inner wall of the vent hole (6). The spring I (10) in the chamber I is sleeved on the push rod (2) and the spring I (10) acts on the push rod (2) when the push rod (2) is pressed and moves downward, causing the push rod (2) to move upward.

2. The pneumatic control valve according to claim 1, characterized in that: The throttling port A (3) and throttling port P (4) are respectively connected to throttling valves (11).

3. The pneumatic control valve according to claim 1, characterized in that: The top opening of the chamber I is provided with a sealing ring I (12), and the top end of the top rod (2) passes through the sealing ring I (12) in a sealed manner.

4. The pneumatic control valve according to claim 1 or 3, characterized in that: The top of the top rod (2) is provided with a wear-resistant ball (13).

5. The pneumatic control valve according to claim 1 or 3, characterized in that: A sealing ring II (14) is provided on the connection between chamber II and chamber III, and the bottom end of the valve sleeve (7) is sealed and inserted into chamber III through the sealing ring II (14).

6. The pneumatic control valve according to claim 5, characterized in that: The bottom of the chamber III is provided with an installation port, and a sealing bottom cover (15) is fixedly installed on the installation port.

7. The pneumatic control valve according to claim 1 or 3, characterized in that: The top of the valve housing (1) is open and is covered by a gap cover (16), which forms the chamber I after the gap cover (16) is closed.

8. The pneumatic control valve according to claim 1, characterized in that: Both spring I (10) and spring II (9) are pagoda springs.

9. The pneumatic control valve according to claim 1, characterized in that: The surface of the top port of the inner hole (8) of the valve sleeve (7) at the bottom end of the top rod (2) is spherical.

Images