CN102297177A - Pneumatic servo actuator - Google Patents

Abstract

The invention relates to a pneumatic servo actuator, in particular to a pneumatic servo actuator with a bellows as an actuator and a frictionless air-floating guide rail, which belongs to the technical field of industrial automation instruments and systems. It includes actuators, air bearing guide rails, displacement sensors, stages and mechanism bodies; the actuators are bellows; the bellows are the actuators of pneumatic servo actuators, and the air bearing guide rails are composed of air bearing guide rail movers and air bearing guide rail stators The displacement sensor is composed of a reading head and a grating ruler; the connection relationship is as follows: one end of the bellows is sealed and connected with the mover of the air-floating guide rail, and the other end is fixed on the mechanism body, which is provided with a bellows air inlet; The object stage is installed on the mover of the air-floating guide rail; the bottom end of the stator of the air-floating guide rail is fixed on the mechanism body; when the air-floating guide rail is working normally, the mover of the air-floating guide rail moves without friction; the grating ruler is fixed on the side of the loading platform ; The reading head is fixed on one side of the mechanism body and is opposite to the grating ruler.

Description

A pneumatic servo actuator

technical field

The invention relates to a pneumatic servo actuator, in particular to a pneumatic servo actuator with a bellows as an actuator and a frictionless air-floating guide rail, which belongs to the technical field of industrial automation instruments and systems.

Background technique

The composition of the pneumatic servo system is no different from that of the general servo system. Its various links are not necessarily all pneumatic, but the actuator must be pneumatic. In the pneumatic servo system, the actuator generally adopts a piston cylinder. When the cylinder works, it mainly relies on the pressure of the inner cavity to push the piston to move. The impact of the pneumatic servo system has resulted in strong nonlinearity and low stiffness. It is difficult to achieve satisfactory control of the pneumatic servo system, and the control accuracy is not high. So far, the application in industry is not mature.

Contents of the invention

The object of the present invention is to propose a pneumatic servo actuator to solve the problem of friction existing in the motion process of the pneumatic servo actuator.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

A pneumatic servo actuator, which includes an actuator, an air bearing guide rail, a displacement sensor, a stage, and a mechanism body; the actuator is a bellows; the bellows is the actuator of the pneumatic servo actuator, and provides the actuator for the pneumatic servo actuator. The air-floating guide rail is composed of the air-floating guide rail mover and the air-floating guide rail stator, which is used to eliminate the friction force during the movement of the pneumatic servo actuator; the displacement sensor is composed of a reading head and a grating ruler, which is the position acquisition device of the pneumatic servo actuator , used to collect and feed back the displacement of the pneumatic servo actuator; the connection relationship is: one end of the bellows is sealed, connected with the mover of the air-floating guide rail, and the other end is fixed on the mechanism body, and the bellows is provided on the mechanism body. The air hole; the stage is installed on the mover of the air-floating guide rail; the bottom end of the stator of the air-floating guide rail is fixed on the mechanism body; when the air-floating guide rail works normally, the mover of the air-floating guide rail moves without friction; the grating scale is fixed on the carrier The side of the object stage; the reading head is fixed on one side of the mechanism body and is opposite to the grating ruler;

Its working process is as follows: open the air source, the gas passes through the filter, one way passes through the first pressure reducing valve to feed a certain pressure gas into the inlet hole of the stator of the air flotation guide rail, and the other way passes through the second pressure reducing valve and through the air inlet hole to feed the corrugated air. A certain pressure of gas is passed through the tube, and the air-floating guide rail works normally. The bellows pushes the mover of the air-floating guide rail to move without friction, and when the stage mounted on the mover of the air-floating guide rail moves together, the reading head can read the The scale change of the grating ruler moving together with the object stage is equal to the moving distance of the stage.

The bellows is preferably made of metal.

The gas pressure that the first pressure reducing valve feeds into the inlet hole of the stator of the air flotation guide rail is 0.3-0.6Mpa; the gas pressure that the second pressure reducing valve feeds into the bellows through the air inlet hole is 0-1.0Mpa.

Beneficial effect

Compared with the prior art, the present invention has the following advantages:

1. By installing the bellows at one end of the stage, the pneumatic servo actuator will not be affected by non-linear factors such as friction during the movement; and the output displacement of the bellows has a linear relationship with the input pressure, which is easy to control.

2. The air-floating guide rail forms a layer of air film between the stator and the mover of the air-floating guide rail through the pressure gas input from the outside, so that the mover of the air-floating guide rail can move smoothly without friction and vibration, so that the pneumatic servo actuator can obtain High motion accuracy and positioning accuracy.

Description of drawings

Fig. 1 is the overall structural diagram of the pneumatic servo actuator of the present invention;

Fig. 2 is a sectional structure diagram of the pneumatic servo actuator of the present invention;

Fig. 3 is a structural diagram of the air-floating guide rail of the present invention;

Fig. 4 is a pneumatic circuit diagram of the pneumatic servo actuator of the present invention;

Fig. 5 is a connection diagram of a DC voltage and a grating ruler in the pneumatic servo actuator of the present invention;

In the figure, 1-metal bellows, 2-intake hole, 3-air-floating guide rail mover, 4-air-floating guide rail stator, 5-air-floating guide rail stator air inlet, 6-grating ruler, 7-reading head, 8-mechanism body, 9-stage, 10-filter, 11-air source, 12-first pressure reducing valve, 13-second pressure reducing valve, 14-DC power supply.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

A pneumatic servo actuator in this embodiment has a structural composition as shown in Figure 1, including a metal bellows 1, an air-floating guide rail mover 3, an air-floating guide rail stator 4, a grating ruler 6, a reading head 7, and a mechanism body 8. Stage 9. Wherein, an air inlet 2 is provided at the center of one end of the metal bellows 1 . The mover 3 of the air-floating guide rail and the stator 4 of the air-floating guide rail form the air-floating guide rail, and one side of the stator of the air-floating guide rail is provided with an air inlet 5 .

The connection relationship of the above components is as follows:

One end of the metal bellows 1 is sealed and connected with the mover 3 of the air-floating guide rail, and one end provided with the air inlet 2 is fixed on the mechanism body 8 . The stage 9 is installed on the mover 3 of the air bearing guide rail. The stator 4 of the air bearing guide rail is fixedly connected to the mechanism body 8 . The mover 3 of the air-floating guide rail passes through the stator 4 of the air-floating guide rail;

The reading head 7 and the grating ruler 6 form a displacement sensor, and the grating ruler 6 is fixed on the side of the stage 9 . The reading head 7 is fixed on one side of the mechanism body 8, and is opposite to the grating ruler 6, and the DC power supply 14 provides the working voltage 14 to the reading head 7;

When the pneumatic servo actuator is working, the air supply pressure generated by the air source 11 passes through the gas filter 10, and one path supplies air to the metal bellows through the second pressure reducing valve 13 through the air inlet 2 of the bellows 1; the other path passes through the first The pressure reducing valve 12 supplies air to the air-floating guide rail through the air inlet 6 of the stator 4 of the air-floating guide rail.

Preferably, the working pressure of the metal bellows 1 is an adjustable pressure of 0.5Mpa, the working pressure of the air-floating guide rail is 0.4MPa, and the working voltage of the displacement sensor is 5V.

Turn on the gas source 11, the gas passes through the filter 10, and provides a pressure of 0.4 MPa to the air-floating guide rail through the first pressure reducing valve 12, the air-floating guide rail works normally, and the mover 3 of the air-floating guide rail can move without friction.

At the same time, the air source 11 provides an adjustable pressure of 0.5 MPa to the air inlet 2 of the metal bellows 1 through the second pressure reducing valve 13, and the DC power supply 14 provides a working voltage of 5V for the reading head 7 of the displacement sensor. The inner cavity of the metal bellows 1 will elongate when subjected to air pressure, and drive the air-floating guide rail mover 3 and the stage 5 installed on the air-floating guide rail mover 3 to move together, and the reading head 7 reads out together with the stage 9 The variation of the grating ruler 6 scale of the moving displacement sensor, that is, the moving distance of the stage 9 is 1.797 mm.

By adjusting the second decompression valve 13 and changing the pressure input to the metal bellows 1 within the range of 0-0.8Mpa, the corresponding displacement measured by the displacement sensor can be obtained.

Through the above process, the metal bellows 1 converts the input pressure into displacement output, and the input pressure and output displacement have a linear relationship, as shown in FIG. 5 . It can be seen that in this process, the disturbance of nonlinear factors is completely avoided.

Claims (2)

1. A pneumatic servo actuator, characterized in that: it comprises an actuator, an air bearing guide rail, a displacement sensor, a stage (9) and a mechanism body (8); the actuator is a bellows; the bellows is a pneumatic servo actuator The executive element provides the execution force for the pneumatic servo actuator; the air-floating guide rail is composed of the air-floating guide rail mover (3) and the air-floating guide rail stator (4), which is used to eliminate the friction force during the movement of the pneumatic servo actuator; the displacement sensor Composed of a reading head (7) and a grating ruler (6), it is a position acquisition device for the pneumatic servo actuator, which is used to collect and feed back the displacement of the pneumatic servo actuator; The connection relationship is: one end of the bellows is sealed and connected to the mover (3) of the air-floating guide rail, the other end is fixed on the mechanism body (8), and the bellows air inlet (2) is provided on the mechanism body (8) ; The stage (9) is installed on the air-floating guide rail mover (3); the bottom end of the air-floating guide rail stator (4) is fixed on the mechanism body; when the air-floating guide rail works normally, the air-floating guide rail mover (3) ) moves without friction; the grating ruler (6) is fixed on the side of the stage (9); the reading head (7) is fixed on one side of the mechanism body and is opposite to the grating ruler (6); Its working process is: open the gas source (11), the gas passes through the filter (10), and one path passes through the first pressure reducing valve (12) to feed gas into the air flotation guide rail stator inlet hole (5), at the same time, the other path passes through The second pressure reducing valve (13) feeds gas into the bellows through the air inlet (2), and the air flotation guide rail works normally, and the bellows pushes the mover (3) of the air flotation guide rail to move without friction, driving When the stage (9) on the sub (3) moves together, the reading head (7) can read the scale variation of the grating ruler (6) moving together with the stage (9), which is equal to the The moving distance of platform (9). 2. A pneumatic servo actuator according to claim 1, wherein the bellows is made of metal.

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