CN203627406U - Zero-friction constant force output air floatation device - Google Patents

Abstract

The utility model provides a zero-friction constant force output air floatation device which comprises a long piston, a cylinder, a gas storage sleeve and an air pressure pressing plate. The long piston is sleeved with the cylinder, the cylinder is sleeved with the gas storage sleeve, and the two ends of the gas storage sleeve and the two ends of the cylinder are sealed through an end cap and a base. The long piston penetrates through the end cap, the air pressure pressing plate is sleeved with the cylinder, a force sensor is arranged below the air pressure pressing plate, and two gas storage cavities are formed between the gas storage sleeve and the cylinder. The long piston is provided with first radial throttling holes and a first pressure relief groove, and the cylinder is provided with second radial throttling holes and a second pressure relief groove. Lubrication is carried out between the cylinder and the long piston through gas, the air pressure is obtained through the air pressure pressing plate and the force sensor, the gas storage cavities are additionally arranged to store the constant pressure gas, and therefore constant force output can be achieved. The zero-friction constant force output air floatation device is simple in structure, accurate in output force value and good in stability.

Description

A frictionless constant force output air flotation device

technical field

The utility model relates to a constant force output device.

Background technique

According to different application environments and application requirements, there are various structures and implementation methods for constant force output. Dynamic constant force output refers to loading a constant force value on a dynamically moving target workpiece.

Hanging the target workpiece through weights is the simplest and most commonly used method of applying constant force. Since the mass of the weight is constant, the force acting on the target workpiece remains unchanged, but when the target workpiece is accelerating or decelerating, the weight The weight will generate an additional force acting on the target workpiece due to the influence of its own inertial force, and the greater the mass of the weight, the greater the effect, so this method is only suitable for low-speed or uniform-speed movement of the target workpiece. Torque motors, hydraulic cylinders, etc. are also often used in the field of constant force output. For example, the patent application number 201120495617.7 "Hydraulic device with constant force output" has announced a hydraulic device that outputs precise force values through a PLC controller, an electromagnetic proportional valve, and a pressure sensor. However, the pressure sensor in this device is installed on the hydraulic device. On the output side, the pressure sensor is in motion and therefore affects the accuracy of the measured value. The air-floating frictionless cylinder is widely used in the realization of ultra-precise constant force output control and micro-pressure action control; there is no friction between the piston and the cylinder through gas lubrication, so the force acting on the piston is related to the cross-sectional area of the piston and The air pressure in the cylinder is related to the size of the air pressure in the cylinder; the patent application No. 201110072339.9 "Frictionless Cylinder with Air Bearing" discloses an air-floating frictionless cylinder. In addition, the response speed of the gas is slow, and the volume change caused by the piston movement in the cylinder will cause the air pressure transient and cause the fluctuation of the output constant force. Therefore, the air-floating frictionless cylinder is generally used to realize the action output, constant pressure The control is more difficult, and it is difficult to ensure the constant value of the output force.

Contents of the invention

In view of the problems in the existing constant force output device that the output force value is difficult to keep constant, the sensor measurement is not accurate enough, and the constant force output accuracy is not high, the utility model provides a device that is not affected by tracheal disturbance, has an accurate output force value, and has good stability. The frictionless constant force output air flotation device.

The technical scheme that the utility model solves its technical problem adopts is:

A non-friction constant force output air flotation device includes a long piston, a cylinder, an air storage sleeve, and an air pressure pressure plate. The long piston is set inside the cylinder and there is a very small gap between the cylinder and the cylinder. The gas storage sleeve is set outside the cylinder. The two ends of the gas storage sleeve and the cylinder are sealed by the end cap and the base. The long piston goes through the end cap.

A first air storage chamber and a second air storage chamber independent of each other are formed between the air storage sleeve and the cylinder.

The air pressure plate is set in the cylinder and has a gap with the cylinder wall. A force sensor is installed under the air pressure plate, and the force sensor is fixed on a base with an air outlet.

The center of the long piston is provided with an air intake through hole and an air discharge through hole, the air intake through hole and the air discharge through hole are separated by a sealing plug, and the air intake through hole is located at one end of the long piston inside the cylinder.

First radial throttle holes are evenly distributed along the circumference of the long piston, the first radial throttle holes communicate with the air intake through hole, and there are at least two sets of first radial throttle holes along the axial direction ; The end of the cylinder near the end cover is evenly distributed along the circumference of the second radial orifice, and the second radial orifice communicates with the second air storage chamber; the air pressure plate is evenly distributed along the circumference of the third A radial throttling hole, the third radial throttling hole communicates with the inner cavity of the cylinder barrel.

Throttle plugs are installed in the first radial throttling hole, the second radial throttling hole and the third radial throttling hole.

The first pressure relief groove is provided on the long piston, and the first pressure relief groove includes a first groove on the outer cylindrical surface, radial blind holes uniformly distributed along the circumference in the first groove, and radial blind holes. A first axial hole in which the holes communicate; one end of the first axial hole communicates with the gas discharge through hole through a second groove in the gas discharge through hole, and the other end of the first axial hole is sealed by a block; There are at least two groups of first grooves on the outer cylindrical surface and they are located on both sides of the first radial throttling hole; the first pressure relief groove is isolated from the first radial throttling hole.

The cylinder is provided with a second pressure relief groove, the second pressure relief groove includes a third groove on the inner cylindrical surface of the cylinder, a second axial hole communicating with the third groove, the second The other end of the axial hole communicates with the through hole on the end cover; the third groove is located below the second radial orifice, and the second pressure relief groove is isolated from the second radial orifice .

The end of the cylinder near the air pressure plate is evenly distributed along the circumference of the air inlet, and the air storage sleeve is provided with a first air inlet and a second air inlet, and the first air inlet and the first air storage chamber In communication, the second air inlet communicates with the second air storage chamber. The first air inlet and the second air inlet are respectively connected to the proportional valve through air pipes.

The design idea of the present utility model is:

An air storage sleeve is added outside the cylinder, and two air storage chambers are formed between the air storage sleeve and the cylinder. The first air storage chamber communicates with the cylinder intake chamber, which is equivalent to increasing the volume of the cylinder intake chamber. The volume change caused by the movement of the long piston has little effect on the sudden change of air pressure, which improves the accuracy of constant force output; the second air storage chamber supplies air to the second radial orifice on the cylinder to ensure that the cylinder and the long piston A stable air film is formed between them; the two air storage chambers supply air separately through the proportional valve without mutual influence, which improves the accuracy and stability of the constant force output.

A force sensor and an air pressure plate are installed on the base of the cylinder, and the air pressure plate is provided with a third radial orifice, which supplies air through the inner cavity of the long piston. Gas lubrication is formed between the air pressure plate and the cylinder, and there is no friction, because The force acting on the bottom of the piston is equal to the force acting on the air pressure plate, so the force value output by the piston can be measured through the force sensor, and the air pressure in the air storage chamber can be adjusted through the proportional valve to precisely control the output force value and operate convenient.

The long piston is a cylinder, the end located outside the cylinder is the output end, and the end located inside the cylinder has a first radial orifice, and the high-pressure gas in the cylinder passes through the first radial orifice between the piston and An air film is formed between the cylinders; there is a second radial orifice at the upper end of the cylinder, and the high-pressure gas in the second air storage chamber is used to supply air, and an air film is formed in the gap between the cylinder and the long piston. The two air films are long The piston provides support and lubrication, the structure and air supply method are simple, and the bearing capacity is good.

There are pressure relief grooves near the radial orifice. The pressure relief grooves communicate with the external normal pressure. On the one hand, it prevents the high-pressure gas in the cylinder from entering the air-floating gap and affecting the air film, and plays a sealing role. A normal pressure zone is formed inside to promote the formation of gas film.

The utility model has the advantages of simple structure, high precision and good stability.

Description of drawings

Figure 1 is a schematic diagram of a frictionless constant force output air flotation device

Figure 2 is a schematic diagram of the long piston

Figure 3 is a schematic diagram of the cylinder

Detailed ways

1 to 3 , a frictionless constant force output air flotation device includes a long piston 1 , a cylinder 7 , an air storage sleeve 8 , and an air pressure plate 17 . The long piston 1 is set inside the cylinder 7 and there is a very small gap between it and the cylinder 7, the gas storage sleeve 8 is set outside the cylinder, the end cover 3 and the base 14 are set on the gas storage sleeve 8 and the cylinder 7 through the bolt 2 At both ends, the long piston 1 passes through the end cap 3 .

A first air storage chamber 19 and a second air storage chamber 22 are formed between the air storage sleeve 8 and the cylinder 7, which are independent of each other. The air storage sleeve 8 is provided with a first air inlet 12 and a second air inlet 5, the first air inlet 12 communicates with the first air storage chamber 19, and the second air inlet 5 communicates with the second air storage chamber 22 . The first air inlet 12 and the second air inlet 5 are respectively connected to the proportional valve 6 through the air pipe 13 .

The air pressure plate 17 is set in the cylinder barrel 7 and has a gap with the cylinder wall, the force sensor 16 is installed under the air pressure plate 17, the force sensor 16 is fixed on the base 14, and the base 14 has an air outlet 15. The third radial throttle hole 28 is evenly distributed along the circumference on the air pressure plate 17, the third radial throttle hole 28 communicates with the inner cavity of the cylinder barrel through the axial blind hole 29, and a section is installed in the third radial throttle hole 28. flow plug.

The center of the long piston 1 has an air intake through hole 24 and an air discharge through hole 26, and the air intake through hole 24 and the air discharge through hole 26 are separated by a sealing plug 9, and the air intake through hole 24 is located in the cylinder 7 of the long piston 1 one end; the long piston 1 is evenly distributed along the circumference of the first radial throttling hole 10, the first radial throttling hole 10 communicates with the air intake through hole 24, the first radial throttling hole 10 has two along the axial direction A throttle plug is installed in the first radial throttle hole 10; a first pressure relief groove is provided on the long piston 1, and the first pressure relief groove includes the first groove 18 on the outer cylindrical surface, the first groove 18, the radial blind holes 23 uniformly distributed along the circumference and the first axial hole 25 communicated with the radial blind holes 23; The air passage holes 26 communicate, and the other end of the first axial hole 25 is sealed by a block 30; the first groove 18 has two groups and is located on both sides of the first radial orifice 10; the first pressure relief groove and the second A radial orifice 10 is isolated from each other.

The end of the cylinder 7 close to the end cover 3 is evenly distributed with second radial throttle holes 4 along the circumference, the second radial throttle holes 4 communicate with the second air storage cavity 22, and the second radial throttle holes 4 There are two groups in the direction, a throttle plug is installed in the second radial throttle hole 4; a second pressure relief groove is provided on the cylinder 7, and the second pressure relief groove includes the third groove 21 on the cylindrical surface of the cylinder , the second axial hole 27 communicating with the third groove 21, the other end of the second axial hole 27 communicates with the through hole on the end cover 3; the third groove 21 is located in the second radial throttle hole 4 Below, the second pressure relief groove and the second radial orifice 4 are isolated from each other; the end of the cylinder 7 close to the air pressure plate 17 is uniformly distributed with air inlets 11 along the circumference.

Claims (1)

1. A frictionless constant force output air flotation device, comprising a long piston, a cylinder, an air storage sleeve, and an air pressure plate; the long piston is set in the cylinder and there is a very small gap between the cylinder, The sleeve is set outside the cylinder, the two ends of the gas storage sleeve and the cylinder are sealed by the end cover and the base, and the long piston passes through the end cover; A first air storage chamber and a second air storage chamber independent of each other are formed between the air storage sleeve and the cylinder; The air pressure plate is set in the cylinder and has a gap with the cylinder wall, a force sensor is installed under the air pressure plate, the force sensor is fixed on a base, and an air outlet is opened on the base; The center of the long piston is provided with an air intake through hole and an air discharge through hole, and the air intake through hole and the air discharge through hole are separated by a sealing plug, and the air intake through hole is located at one end of the long piston inside the cylinder; First radial throttle holes are evenly distributed along the circumference of the long piston, the first radial throttle holes communicate with the air intake through hole, and there are at least two sets of first radial throttle holes along the axial direction ; The end of the cylinder near the end cover is evenly distributed along the circumference of the second radial orifice, and the second radial orifice communicates with the second air storage chamber; the air pressure plate is evenly distributed along the circumference of the third a radial throttling hole, the third radial throttling hole communicates with the inner cavity of the cylinder; A throttling plug is installed in the first radial throttling hole, the second radial throttling hole and the third radial throttling hole; The first pressure relief groove is provided on the long piston, and the first pressure relief groove includes a first groove on the outer cylindrical surface, radial blind holes uniformly distributed along the circumference in the first groove, and radial blind holes. A first axial hole in which the holes communicate; one end of the first axial hole communicates with the gas discharge through hole through a second groove in the gas discharge through hole, and the other end of the first axial hole is sealed by a block; There are at least two groups of first grooves on the outer cylindrical surface and they are located on both sides of the first radial orifice; the first pressure relief groove is isolated from the first radial orifice; The cylinder is provided with a second pressure relief groove, the second pressure relief groove includes a third groove on the inner cylindrical surface of the cylinder, a second axial hole communicating with the third groove, the second The other end of the axial hole communicates with the through hole on the end cover; the third groove is located below the second radial orifice, and the second pressure relief groove is isolated from the second radial orifice ; The end of the cylinder near the air pressure plate is evenly distributed along the circumference of the air inlet, and the air storage sleeve is provided with a first air inlet and a second air inlet, and the first air inlet and the first air storage chamber In communication, the second air inlet communicates with the second air storage chamber; the first air inlet and the second air inlet are respectively connected to the proportional valve through air pipes.

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