JP4198853B2 - Hybrid actuator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid actuator suitable for vibration isolation of, for example, a high-precision measuring instrument and a semiconductor manufacturing apparatus.
[0002]
[Prior art]
Conventionally, fluid actuators such as air springs, air cylinders, and hydraulic cylinders are well known. These fluid actuators have a supporting load or an operating force determined by the internal pressure and the effective pressure receiving area, while there is a limit to the pressure of the supplied fluid. For this reason, if this fluid actuator can be applied to a high load, the effective pressure receiving area can only be increased.
For example, Japanese Patent Publication No. 7-76576 and Japanese Patent Application Laid-Open No. 3-219141 disclose an apparatus using an air spring to suppress vibration. In order to increase the force by these air springs, it is necessary to increase the number of air springs.
[0003]
Further, in the fine vibration control of precision instruments, active control has been actively used. For this active control, a solid element such as a piezoelectric element or a giant magnetostrictive element, a voice coil motor (VCM), etc. Many researches and developments using linear motors have already been conducted. When these solid elements and linear motors (hereinafter referred to as solid elements or the like) that do not generate a sufficient supporting force against the load are used as vibration control actuators, an elastic material is used in parallel with the solid elements or the like. It is generally done.
[0004]
[Problems to be solved by the invention]
In the field of precision machining, in order to reduce an increase in the cost of maintaining a clean environment, it is required to increase the concentration of equipment without adversely affecting precision machining. On the other hand, there is a demand for increasing the size and speed of equipment, and it is necessary to improve the support capacity and control power per unit area for the equipment. That is, how to generate a large control force in a small space and improve the vibration control capability in a wide frequency range is an important issue.
[0005]
In particular, in the case of an active control device using a solid element or the like that does not generate a sufficient supporting force for a load, there is a problem that a double space is required because the supporting device is attached to the active control device. .
In general, the space occupied by various machines and devices is reduced, and the density of their components tends to increase. For this reason, there is a problem that the effective pressure receiving area cannot be increased by increasing the number of fluid actuators.
In the case of the control actuator, there is a problem that when a large external force is applied, the elastic material is rapidly deteriorated, and the elasticity is easily lost. In addition, the solid element has a problem that the stroke as an actuator is small, and it cannot follow when a large amplitude disturbance acts, and cannot be controlled.
[0006]
The present invention has been made in order to eliminate such a conventional problem, and can be applied to a high load in a small space, can compensate for the above-described drawbacks of the solid state device, and can perform more advanced vibration control. To provide a hybrid actuator.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the first invention is arranged such that a core is disposed inside a cylinder case having an open top and a bottom, and prevents relative movement in the vertical direction between the cylinder case and the core. A small sealing member that does not interfere, and does not hinder the relative movement of the two in the vertical direction between the core and the cylinder case, and has a larger effective pressure receiving area than the small sealing member. A fluid in which a seal member is interposed, a single small space is formed between the small seal member and the large seal member, a pressurized fluid is supplied to the small space, and a fluid in the small space is discharged A fluid actuator connected to the flow path, a vibration actuator formed so as to be extendable in the vertical direction, and an elastic member having elasticity in at least the vertical direction are combined in the vertical direction.
[0008]
Further, the second invention is a small seal member in which a core is disposed inside a cylinder case having an opening at the top and bottom, and does not hinder the relative movement in the vertical direction between the cylinder case and the core. A large seal member is interposed between the core and the cylinder case so as not to disturb the relative movement of the two in the vertical direction and has a larger effective pressure receiving area than the small seal member. The small seal members and the large seal members are alternately arranged, and at least three small spaces adjacent to each other in the vertical direction are formed between the small seal members and the large seal members. A fluid flow path is connected so that pressurized fluid is supplied to the small space and fluid is discharged from the small space, and the even number of small spaces communicate with the atmosphere from below. And Yueta, a vibration actuator which is telescopically formed in the vertical direction, was formed by combining an elastic member having elasticity at least in the vertical direction in the vertical direction.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a hybrid actuator 1A according to a first embodiment of the first invention. This hybrid actuator 1A is generally formed of a fluid actuator 11, a vibration actuator 12, and an elastic member 13 interposed between the two. Has been.
The fluid actuator 11 is open at the top and bottom, and has a cylinder case 21 disposed on the support portion X and a core 22 disposed inside the cylinder case 21. The core 22 may be a hollow body.
[0011]
A single annular protrusion 23 projects in the lateral direction on the inner peripheral part of the cylinder case 21, and a single disk 24 projects in the lateral direction on the outer peripheral part of the core 22. A small seal member 25 is interposed between the annular protrusion 23 and the core 22 without interfering with the relative movement of the two in the vertical direction. A large seal member 25 is provided between the disk 24 and the inner peripheral portion of the cylinder case 21. A seal member 26 is interposed.
[0012]
A small space 27 is formed between the small seal member 25 and the large seal member 26 so that the effective pressure receiving area of the large seal member 26 in the small space 27 is larger than the effective pressure receiving area of the small seal member 25. Is formed. The cylinder case 21 is connected to a fluid flow path 29 having a control valve 28 interposed therebetween, whereby pressurized fluid is supplied to the small space 27 and the fluid in the small space 27 is discharged. It has become.
The small seal member 25 and the large seal member 26 are, for example, a diaphragm or an O-ring made of an annular thin plate, and are members that partition the upper and lower space portions without hindering relative movement in the vertical direction of both inner and outer engaging portions. If it is. When this O-ring is used, one of the inner and outer peripheral sides of the O-ring is inserted into a groove formed in a member that engages with the O-ring, and the other side engages with this. It arrange | positions so that it can slide on the surface of a member.
[0013]
The vibration actuator 12 is a voice coil motor (VCM) in addition to a solid element actuator having a built-in solid element such as a piezoelectric element that is distorted by an applied voltage or a magnetostrictive element that is distorted by the action of a magnetic field. Are arranged so that distortion occurs in the vertical direction. Further, the vibration actuator 12 has extremely low rigidity with respect to a shearing force in the lateral direction, and has a characteristic that does not prevent a minute relative movement in the lateral direction between both members engaged with the upper and lower surfaces thereof. .
The elastic member 13 is made of, for example, an elastomer, rubber, or spring, and generates a reaction force proportional to the amount of bending in the vertical direction, and may be formed from one type of material or a combination of a plurality of materials. When a plurality of materials are used, the elastic member 13 may be formed by laminating them.
[0014]
A driven body O is disposed above the core 22 of the fluid actuator 11, and a vibration sensor 31 for detecting the vibration state is attached to the driven body O. A detection signal indicating a vibration state by the vibration sensor 31 is input to the valve controller 32, and a control signal is output from the valve controller 32 to the valve driver 33 that operates the control valve 28.
The control valve 28 is a kind of three-way switching valve having a supply port communicating with a pressurized fluid supply source (not shown), a control port communicating with the small space 27, and an exhaust port communicating with the atmosphere. The flow rate of the pressurized fluid introduced into the small space 27, for example, the supply air flow, and the flow rate of the fluid discharged from the small space 27, for example, the exhaust gas are adjusted.
[0015]
When the control valve 28 is in the first state in which the flow rate of the supply air is maximized, the disc 24 is removed from the annular protrusion 23 by the pressure of the pressurized fluid introduced into the small space 27 from the pressurized fluid source. Operates in the direction of leaving. On the other hand, when the control valve 28 is in the second state that maximizes the flow rate of the exhaust gas, the fluid in the small space 27 flows out. Operates in the opposite direction to the state.
The fluid used for controlling the fluid actuator 11 via the control valve 28 includes oil in addition to gas such as air, nitrogen, carbon dioxide and helium.
[0016]
The cylinder case 21, the annular protrusion 23, and the disk 24 are members having sufficient rigidity so that the disk 24 operates in a direction away from the annular protrusion 23 when a pressurized fluid is introduced into the small space 27. It is made up of.
The detection signal from the vibration sensor 31 described above is also input to the actuator controller 34, from which a control signal is sent to the actuator driver 35, and the actuator driver 35 operates the vibration actuator 12 to expand and contract in the vertical direction. It is done. In addition to the operation of the fluid actuator 11, an upward or downward force acts on the driven body O by the vertical expansion and contraction of the vibration actuator 12.
[0017]
This hybrid actuator 1A is an improvement of a technique in which a vibration actuator 12 made of a piezoelectric element or the like is used in series with an elastic member 13 having passive characteristics, and generates a displacement proportional to the vibration actuator 12, for example, a drive voltage. By arranging the solid element actuator and the elastic member 13 in series and causing the solid element actuator and the elastic member 13 to interact with each other, the voltage remains constant even if the frequency of the operation voltage applied to the solid element actuator changes. If there is, it can be used as a force generating element that generates a certain force. That is, the solid element actuator is deformed, and a driving force is generated in the elastic member 13 according to the amount of deformation. In principle, a larger force can be generated when the elastic member has a larger spring constant. However, considering that this hybrid actuator 1A is used for a vibration isolation mechanism, it is advantageous to obtain a passive vibration isolation performance at a high frequency. The vibration isolation performance at this time increases as the elastic member 13 is softer. Therefore, the selection of the elastic member is a balance between the generated force and the passive vibration isolation performance. The hybrid actuator 1A is advantageous in providing a soft support mechanism, and can easily cope with fluctuations in the support load by operating the fluid pressure in the fluid actuator 11.
[0018]
The vibration actuator 12 is naturally assumed to be used for position control or vibration control. In this case, it is considered that the control force is also applied in the shear direction of the hybrid actuator 1A. However, as described above, the hybrid actuator 1A can be configured to allow movement in the shear direction as described above. This can avoid force interference in other axial directions.
[0019]
FIG. 2 shows a hybrid actuator 1B according to a second embodiment of the first invention. The parts common to the hybrid actuator described above are denoted by the same reference numerals and description thereof is omitted.
In this hybrid actuator 1B, the elastic member 13 and the vibration actuator 12 are coupled in series to the cylinder case 21 instead of the core 22 of the fluid actuator 11, and the upper end surface of the cylinder case 21 contacts the driven body O instead of the core 22. It is touched. Further, both the vibration actuator 12 and the core 22 are disposed on the support portion X. In this case, the elastic member 13 and the vibration actuator 12 are preferably annular, but are not limited to this shape.
[0020]
FIG. 3 shows a hybrid actuator 1C according to a third embodiment of the first invention. The parts common to the hybrid actuator described above are denoted by the same reference numerals and description thereof is omitted.
In this hybrid actuator 1 </ b> C, the elastic member 13 in the hybrid actuator 1 </ b> A shown in FIG. 1 is also interposed between the vibration actuator 12 and the driven body O. The number of the elastic members 13 is not limited as long as the elastic members 13 are arranged in series with the fluid actuator 11 and the vibration actuator 12.
[0021]
FIG. 4 shows the hybrid actuator 2 according to the second aspect of the invention, and parts common to the hybrid actuator described above are given the same reference numerals and description thereof is omitted.
In this hybrid actuator 2, a plurality of, for example, two annular protrusions 23 projecting in the lateral direction are provided on the inner peripheral part of the cylinder case 21, and two projecting laterally projecting on the outer peripheral part of the core 22, that is, the annular protrusions. The same number of disks 24 as the number of sections 23 are provided. Similarly to the above, a small seal member 25 is interposed between the annular protrusion 23 and the core 22, and a large seal member 26 is interposed between the disk 24 and the cylinder case 21. A fluid flow path 29 is connected to an odd-numbered small space 27, for example, a first-level small space 27, from the bottom, which communicates with each other through a through-hole 41 formed in the core 22. Further, the small spaces 27 located between the odd-numbered small spaces 27 communicate with the atmosphere through through holes 42 formed in the side wall portion of the cylinder case 21.
[0022]
In addition, the 2nd invention does not limit the number of the small spaces 27, You may provide more small spaces 27 than the small spaces 27 of the hybrid actuator 2 shown in FIG. In this case, the odd-numbered small spaces 27 are communicated with each other from the bottom, the fluid channel 29 is connected to any position of these small spaces 27, and the even-numbered small spaces 27 are communicated with the atmosphere from the bottom. That's fine.
And by increasing the number of the small spaces 27 in this way, the fluid actuator 11 can withstand a high load.
[0023]
FIG. 5 shows the hybrid actuator 3A according to the first embodiment of the third invention. The parts common to the hybrid actuator described above are denoted by the same reference numerals and description thereof is omitted.
In this hybrid actuator 3 </ b> A, a plurality of, for example, two annular protrusions 23 projecting in the lateral direction are provided on the inner peripheral part of the cylinder case 21, and a single disk 24 projecting in the lateral direction is provided on the outer peripheral part of the core 22. Is provided. Similarly to the above, a small seal member 25 is interposed between the annular protrusion 23 and the core 22, and a large seal member 26 is interposed between the disk 24 and the cylinder case 21. Each small space 27 formed on both sides of the small seal member 25 communicates with each of the fluid flow paths 29A and 29B provided separately. A control valve 28 is provided in each of the fluid flow paths 29 </ b> A and 29 </ b> B and can be operated separately by a valve driver 33 controlled by a valve controller 32. Similarly to the above, the effective pressure receiving area of the large seal member 26 in the small space 27 formed between the small seal member 25 and the large seal member 26 is formed to be larger than the effective pressure receiving area of the small seal member 25. Has been.
In the figure, two * marks indicate communication with each other.
[0024]
FIG. 6 shows a hybrid actuator 3B according to a second embodiment of the third invention. The parts common to the hybrid actuator described above are denoted by the same reference numerals and description thereof is omitted.
In this hybrid actuator 3B, a plurality of, for example, two annular protrusions 23 projecting in the lateral direction are provided on the inner peripheral portion of the cylinder case 21, and a plurality of, for example, two discs projecting in the lateral direction on the outer peripheral portion of the core 22 are provided. 24 is provided. Similarly to the above, a small seal member 25 is interposed between the annular protrusion 23 and the core 22, and a large seal member 26 is interposed between the annular disk 24 and the cylinder case 21. A small space 27 is formed between the small seal member 25 and the large seal member 26. Further, the odd-numbered small spaces 27 from the bottom communicate with each other through a through hole 41 </ b> A formed in the core 22, and the even-numbered small spaces 27 from the bottom communicate with each other through a through-hole 41 </ b> B formed in the cylinder case 12. . Further, a first fluid channel 29A communicating with the odd-numbered small spaces 27 is connected, and a second fluid channel 29B communicating with the even-numbered small spaces 27 is connected.
[0025]
The hybrid actuators 3A and 3B shown in FIGS. 5 and 6 will be described in more detail. The pressure of the fluid supplied from the fluid channel 29A and the fluid channel 29B includes a static pressure component and a dynamic pressure component. ing. When the dynamic pressure components of the fluid channel 29A and the fluid channel 29B are in opposite phases, the force based on the fluid pressure in the fluid channel 29A and the force based on the fluid pressure in the fluid channel 29B are added and added. The applied force acts on the core 22. On the other hand, when the dynamic pressure components of the fluid channel 29A and the fluid channel 29B are in phase, a force based on the fluid pressure in the fluid channel 29A and a force based on the fluid pressure in the fluid channel 29B are generated. The forces that cancel each other and remain as the difference between the two act on the core 22. Therefore, in the fluid actuator 11 using the fluid channel 29A and the fluid channel 29B, the core 22 can be maintained at a position where the forces based on the pressures of the fluid channel 29A and the fluid channel 29B are balanced. Thus, the forces based on the static pressure components of the fluid flow path 29A and the fluid flow path 29B can be canceled each other, and only the dynamic pressure components can act on the driven body O.
The required installation area for the fluid actuator 11 is the same as the installation area required for the single fluid actuator described above corresponding to one small space 27.
[0026]
As in the hybrid actuator 1A shown in FIG. 1, in any of the above-described embodiments, the effective pressure receiving area of the large seal member 26 in the small space 27 is formed to be larger than the effective pressure receiving area of the small seal member 25. ing.
By the way, in each embodiment shown in FIGS. 1-6, the fluid actuator 11 which has the structure where the small space 27 of the 1st step | line was formed between the upper large seal member 26 and the lower small seal member 25 from the bottom. Although shown, the fluid actuator 11 may have a structure in which the large seal member 26 forming the first-stage small space 27 from the bottom is positioned below and the small seal member 25 is positioned above. That is, the vertical relationship between the annular protrusion 23 and the disk 24 may be the reverse of the illustrated embodiment.
[0027]
In the second and third inventions, the means for communicating each of the odd-numbered small spaces 27 or the even-numbered small spaces 27 from the bottom is a through-hole or groove formed in the core 22, a cylinder case Any of the through holes or grooves formed in 21 may be used, or each of the small spaces 27 may be communicated by piping, or each of the small spaces 27 may be communicated by appropriately combining them.
Further, in the fluid actuator 11 in the third invention, the number of the small spaces 27 is not limited, and the number of the small spaces 27 communicating directly or indirectly with the first fluid flow path 29A and the second fluid flow are not limited. The number of small spaces 27 communicating directly or indirectly with the path 29B is not necessarily the same as in the illustrated embodiment.
[0028]
In addition, as will be enumerated below, the configurations shown in FIGS. 2 and 3 relating to the first invention, that is, the configurations different from those in FIG. 1 are also applied to the second and third inventions.
(1) Any one of the cylinder case 21 and the core 22 may be brought into contact with the driven body O.
(2) It is sufficient that at least one of the cylinder case 21 and the core 22 is held by the support portion X.
(3) The fluid actuator 11, the vibration 12, and the elastic member 13 are only required to be coupled in the vertical direction, and the coupling order thereof is not limited at all.
(4) The elastic member 13 does not need to be one, and a plurality of elastic members 13 may be provided.
(5) The vibration actuator 12 and the elastic member 13 may be coupled to the core 22 in the vertical direction, and the vibration actuator 12 and the elastic member 13 may be coupled to the cylinder case 21 in the vertical direction.
(6) In each of the embodiments described above, signals are input from the vibration sensor 31 to the valve controller 32 and the actuator controller 34. However, a control system for operating the control valve 28 and a control system for operating the vibration actuator 12 are used. May be separated. For example, a signal is input only from the vibration sensor 31 to the actuator controller 34, a sensor for detecting the vibration state of the driven body O is provided separately from the vibration sensor 31, and a detection signal thereby is input to the valve controller 32. It may be.
[0029]
In addition, in the present specification, the vertical direction is determined in order to clarify the configuration of each hybrid actuator, and is independent of the arrangement direction of each hybrid actuator. That is, the illustrated hybrid actuators may be arranged in the lateral direction or may be arranged upside down. Accordingly, the illustrated support portion X may be positioned below each hybrid actuator, may be positioned on the side, or may be positioned on the upper side, and the above-described hybrid actuator can be used with an inclination.
When the hybrid actuator 1C shown in FIG. 3 is used upside down from the illustrated state, that is, the support portion X is located above, and the fluid actuator 11 and the vibration actuator 12 are suspended from the support portion X. In the case of using the disc 24 and the ring projection 23, the large seal member 26 is positioned upward and the small seal member 25 is positioned downward in order to apply an upward force to the core 22. Must be formed.
[0030]
【The invention's effect】
As is clear from the above description, according to the first invention, the core is disposed inside the cylinder case with the upper and lower portions opened, and the relative relationship between the cylinder case and the core in the vertical direction therebetween. A small seal member that does not hinder movement is interposed, and an effective pressure receiving area that is larger than the small seal member and that does not hinder relative movement in the vertical direction between the core and the cylinder case. A large seal member is interposed, a single small space is formed between the small seal member and the large seal member, a pressurized fluid is supplied to the small space, and the fluid in the small space is A fluid actuator to which a fluid flow path to be discharged is connected, a vibration actuator formed to be extendable in the vertical direction, and an elastic member having elasticity in at least the vertical direction are coupled in the vertical direction. It is formed.
[0031]
According to the second aspect of the invention, the core is disposed inside the cylinder case with the upper and lower portions opened, and the small relative length between the cylinder case and the core does not hinder the relative movement of the two in the vertical direction. A large seal member is interposed between the core and the cylinder case, and has a larger effective pressure-receiving area than the small seal member. The small seal member and the large seal member are alternately arranged, and at least three small spaces adjacent to each other in the vertical direction are formed between the small seal member and the large seal member. A fluid flow path is formed so that pressurized fluid is supplied to the small space in the stage and the fluid flow path for discharging the fluid in the small space is connected, and the small space in the even numbered stage communicates with the atmosphere from below. An actuator, a vibration actuator which is telescopically formed in the vertical direction, are formed by combining an elastic member having elasticity at least in the vertical direction in the vertical direction.
[0032]
For this reason, it becomes possible to apply to a high load in a small space, and a large stroke can be obtained as a whole, and even if a large amplitude disturbance acts, the drive body can be driven following this, over a long period of time. It has the effect of maintaining stable performance, compensating for the drawbacks of vibration actuators such as solid elements, and enabling advanced vibration control.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a hybrid actuator according to a first embodiment of the first invention.
FIG. 2 is a diagram showing an overall configuration of a hybrid actuator according to a second embodiment of the first invention.
FIG. 3 is a diagram showing an overall configuration of a hybrid actuator according to a third embodiment of the first invention.
FIG. 4 is a diagram showing an overall configuration of a hybrid actuator according to a second invention.
FIG. 5 is a diagram showing an overall configuration of a hybrid actuator according to a first embodiment of the third invention.
FIG. 6 is a diagram showing an overall configuration of a hybrid actuator according to a second embodiment of the third invention.
[Explanation of symbols]
1A to 1C, 2, 3A, 3B Hybrid actuator 11 Fluid actuator 12 Vibration actuator 13 Elastic member 21 Cylinder case 22 Core 23 Annular protrusion 24 Disc 25 Small seal member 26 Large seal member 27 Small space 28 Control valves 29, 29A, 29B Fluid flow path 31 Vibration sensor 32 Valve controller 33 Valve driver 34 Actuator controller 35 Actuator driver 41, 42, 42A, 42B Through hole O Driven object X Support part

Claims (2)

A core is disposed inside a cylinder case having an opening at the top and bottom, and a small seal member is interposed between the cylinder case and the core so as not to prevent the relative movement of the two in the vertical direction. A large seal member is interposed between the small seal member and the cylinder case so as not to interfere with the relative movement of the two in the vertical direction and has an effective pressure receiving area larger than that of the small seal member. A fluid actuator in which a single small space is formed between the large seal member, a fluid flow path for supplying pressurized fluid to the small space and discharging the fluid in the small space;
A vibration actuator formed to be extendable in the vertical direction;
A hybrid actuator comprising: an elastic member having elasticity in at least the vertical direction; A core is disposed inside a cylinder case having an opening at the top and bottom, and a small seal member is interposed between the cylinder case and the core so as not to prevent the relative movement of the two in the vertical direction. And a large seal member having an effective pressure receiving area larger than that of the small seal member is interposed between the small seal member and the cylinder case. Seal members are alternately arranged, and at least three small spaces adjacent to each other in the vertical direction are formed between the small seal members and the large seal members. A fluid actuator that is connected to a fluid flow path that discharges the fluid in the small space, and that the even-numbered small space communicates with the atmosphere from below,
A vibration actuator formed to be extendable in the vertical direction;
A hybrid actuator comprising: an elastic member having elasticity in at least the vertical direction;

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