JPH10110729A - Position control method for body to be guided by utilizing restriction characteristics of static pressure bearing, and diaphragm valve type automatic restriction regulating device using the control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform fine movement (capable of, for example, 0.5μm being moved) of a body to be guided in a specified direction accurately, rapidly with little vibration by effectively utilizing the characteristics of the diaphragm valve type automatic restriction regulation of a static pressure bearing. SOLUTION: A diaphragm valve type automatic restriction regulating device 5 is formed such that a shield space is partitioned by a diaphragm body 6 and the sides form fluid chambers 7 and 8 and a restriction surface part 9 positioned facing the diaphragm body is arranged in each fluid chamber, and power drive means 20A and 20B are provided to displace at least one restriction surface part or both restriction surface parts in an arbitrary position in a direction crossing the diaphragm body. Fluid having a proper pressure is fed to a space between each throttle surface part and the diaphragm body, and restricted fluid therein is fed to recesses 2a and 3a positioned facing a static pressure bearing. With this state, the power drive means is properly operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the position of a moving body utilizing the throttle characteristic of a hydrostatic bearing, and a diaphragm valve type automatic adjusting throttle device used for this control.

[0002]

2. Description of the Related Art When lubricating oil is supplied to a hydrostatic bearing, the use of a diaphragm valve type automatic adjustment throttle device has already been performed, and an example thereof will be described with reference to FIG.

In FIG. 1, reference numeral 1 denotes a linear guide type hydrostatic bearing, in which a load side pad 2 and a non-load side pad 3 are fixed at a fixed interval, and a load (guided body) is provided therebetween. 4 is arranged so as to be movable only in a direction perpendicular to the paper surface.

[0004] Recesses 2a,
An appropriate number of pads 2 and 3 are provided along the guided body 4 as necessary.

[0005] Reference numeral 5 denotes a diaphragm valve type automatic adjusting diaphragm device, in which a shielding space is partitioned by a diaphragm body 6, each side of which is defined as a fluid chamber 7, 8, and is opposed to the diaphragm body 6 in each of the fluid chambers 7, 8. The configuration is such that a diaphragm surface portion 9 arranged in a manner as described above is provided.

The diaphragm body 6 has a circular pad 6b fixed to the center of the diaphragm 6a, and the diaphragm surface 9 is formed by a projection 9a and a diaphragm surface 9b. A fluid passage 10 connected to the pump P is provided at the center of each throttle surface 9b.
a and 10b are opened, and other fluid passages 11a and 11b connected to the recesses 2a and 3a are opened at locations on the wall surfaces of the fluid chambers 7 and 8 which are separated from the throttle surface portion 9.

In the operating state of the diaphragm valve type automatic adjusting throttle device, lubricating oil of an appropriate pressure is supplied from the pump P through the fluid passages 10a and 10b between the throttle surface 9b and the circular pad 6b. The oil will be able to throttle its flow.

The lubricating oil thus squeezed fills the fluid chambers 7 and 8, and is subsequently supplied to the recesses 2a and 3a of the pads 2 and 3 through the fluid paths 11a and 11b. Each recess 2
The lubricating oil filled in a and 3a flows out through gaps h01 and h03 between the pads 2 and 3 and the guided body 4.

In this state, if the vertical external force acting on the guided body 4 is zero, the gaps hd1 and hd3 between the circular pad 6b and the throttle surface 9b become a specific constant value and are stable, and The gap h0 between each of the pads 2 and 3 and the guided body 4
1, h03 also become a constant value and become stable.

In this state, if, for example, a downward external force acts on the guided body 4, the guided body 4 is lowered.
The gap h01 is reduced, the outflow of lubricating oil therefrom is restricted, and the oil pressure in the recess 2a and that in the fluid chamber 7 rise. On the other hand, since the gap h03 increases, the oil pressure in the recess 3a increases. It in the fluid chamber 8 descends. As a result, the diaphragm 6a is deformed upward, and the circular pad 6b is deformed.
Rises.

As a result, the throttle effect of the lower throttle surface 9b is reduced, and the throttle effect of the upper throttle surface 9b is increased. As a result, the oil pressure in the fluid chamber 7 and that in the recess 2a are increased. The oil pressure in the fluid chamber 8 and that in the recess 3a drop.

In this way, the guided body 4 is prevented from descending indefinitely, and the gap h01 is maintained at a certain size or more.

When the external force acting on the guided member 4 decreases, an operation symmetric to the above occurs, and the clearance h03 is increased.
Is maintained above a certain value.

Therefore, if the vertical external force acting on the guided member 4 is not excessively large, the guided member 4 will not
The guide body 4 is held in a state of floating at an appropriate height between the pads 2 and 3 by the static pressure of the lubricating oil in the sections a and 3a, and the guided body 4 is smoothly guided in a direction orthogonal to the paper surface.

This diaphragm valve type automatic adjusting / throttling device can be used when no vertical external force acts on the guided member 4.
The guided member 4 is supported at a specific height (origin position) between the pads 2 and 3 by the lubricating oil, and when the same external force acts on the guided member 4, vertical displacement of the guided member 4 is prevented. In other words, it is designed so that the bearing stiffness is not less than a certain level.

[0016]

In the above-mentioned application example of the diaphragm valve type automatic adjustment throttle device, the guided member 4
Even if an external force of any magnitude in the vertical direction acts on the guide member 4, the main purpose is merely to hold the guided body 4 near the origin position.

The present invention seeks to further advance the use example of the above-mentioned diaphragm valve type automatic adjustment / throttling device by one step.
That is, it is an object of the present invention to accurately and quickly displace a guided body to an arbitrary specific position between opposing pads during operation of a hydrostatic bearing.

[0018]

In order to achieve the above object, according to the present invention, a shielding space is partitioned by a diaphragm body, each side of which is defined as a fluid chamber, and a throttle surface facing the diaphragm body is provided in each fluid chamber. A diaphragm valve type automatic adjusting diaphragm device provided with a power drive means for displacing at least one diaphragm surface portion or both diaphragm surface portions to an arbitrary position in a direction orthogonal to the diaphragm body is formed, and each diaphragm surface portion and the diaphragm body are formed. During this time, a fluid of an appropriate pressure is supplied, and the squeezed fluid is supplied to the opposed recess of the hydrostatic bearing, and under this condition, the power driving means is operated appropriately. .

At this time, the motive power driving means is provided with an electrostrictive element or a magnetostrictive element as a driving force generating source.

[0020]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and an embodiment of the present invention will be described below with reference to this figure.

In carrying out the present invention, a diaphragm valve type automatic adjustment throttle device 5 as described below is formed.

That is, power drive means 20A and 20B are provided on each of the fluid chamber walls 7A and 8A. This power drive means 20A,
20B is for displacing each throttle surface portion 9 to an arbitrary position in a direction orthogonal to the diaphragm body 6, and the fluid chamber wall 7
A and 8A are composed of cover bodies 21 and 21 fixed by bolts and drive units 22 and 22 fitted to the cover bodies 21 and 21, respectively.

Each drive section 22 has an expansion / contraction operation section 23 composed of an electrostrictive element or a magnetostrictive element as a driving force generating source and a fluid path section 24, and the throttle surface section 9 is formed at the tip.

Here, the electrostrictive element is an element which can take out a strain proportional to a voltage by applying a voltage, and for example, a piezoelectric material having a piezo effect, such as Ba titanate, is used.

The magnetostrictive element is an element capable of extracting a strain proportional to an input current by applying a magnetic field. For example, a magnetostrictive alloy such as a giant magnetostrictive single crystal alloy TERFENOL-D (US Pat. No. 3,949,351) is used. Used.

Each of the fluid passages 24 has the fluid passage 1
Annular groove 25 connected to 0a or 10b, radial hole 2
6 and a vertical hole 27 are formed.

The other parts are in accordance with the conventional one.

Each of the fluid chambers 7, 8 of the diaphragm valve type automatic adjusting and restricting device 5 having such a structure is connected to the opposed recesses 2a, 3a of the hydrostatic bearing 1 through the fluid passages 11a or 11b.
To be connected.

Thereafter, lubricating oil of an appropriate constant pressure is supplied between each of the throttle surfaces 9 and the diaphragm body 6, and the lubricating oil squeezed here is passed through the respective fluid chambers 7, 8 to form the recesses 2 a,
3a.

The lubricating oil is filled in the recesses 2a and 3a and rises to a constant pressure in the recesses 2a and 3a.
It flows out of the gaps h01 and h03 at a relatively small flow rate.
At this time, if the sizes of the gaps hd1 and hd3 are appropriate, the guided body 4 floats to a specific position between the recesses 2a and 3a on each side by the static pressure of the lubricating oil in the recesses 2a and 3a and is stable. I do.

Under such an operating state, the power drive means 20A and 20B are appropriately operated by displacing an operation knob of an operation control device (not shown).

For example, when the gap hd3 is reduced, the lubricating oil from the fluid passage 10a is applied to the diaphragm 6 and the throttle surface 9b.
, The pressure in the recess 3a decreases. Therefore, the guided body 4 moves upward, and the gap h03 becomes smaller, and conversely, the gap h01 becomes larger. As a result, the amount of the lubricating oil that escapes from the gap h01 increases, so that the pressure of the recess 2a decreases. When this pressure is balanced with that of the other recess 3a, the movement of the guided member 4 stops.

Conversely, when the clearance hd3 is increased, the guided body 4 acts symmetrically with the above, and the guided body 4 moves downward by a fixed amount and stops.

Although the above description has been made centering on the gap hd3, the same applies to the case where the gap hd1 is changed to be large or small, and the guided body 4 also stops at a position corresponding to the gap hd3.

In short, by operating the power driving means 20A, 20B to change the gap hd1 or hd3, the guided body 4 is moved to an arbitrary position between the opposed recesses 2a, 3a, and the position is stably changed. Will be retained.

In the above embodiment, the power driving devices 20A and 20B are provided in both the fluid chambers 7 and 8, however, the present invention is not limited to this. For example, the power driving device 20A or 20B may not be provided. The one diaphragm surface 9 may be fixed at a specific position, or the position of one diaphragm surface 9 may be adjustable via a manually operated screw rod.

Next, some application examples of the present invention will be described. (1) Application Example 1 FIG. 2 shows an example in which the present invention is applied to a grinding wheel stand of a grinding machine. In this figure, reference numeral 30 denotes a grindstone table which is movably supported in a front-rear direction f1 and a left-right direction f2 by a linear guide track (not shown). Numeral 31 denotes a grindstone rotating support fixed to the grindstone head 30, which supports a rotating shaft 32 as the guided member 4 of the grindstone head 30, a flange portion 32 a formed halfway along the length of the rotating shaft 32, and the rotating shaft 32. Cylindrical bearing body 3
3. A grindstone 34 fixed to one end of a rotating shaft 32, a rotating shaft 3.
2, a rotary input pulley 35 fixed to the other end, recesses 2a and 3a formed in the grindstone rotary support 31, and a lubricating oil discharge groove 36 and the like.

Numeral 37 denotes a lubricating oil supply section for supplying lubricating oil to the recesses 2a, 3a formed facing the peripheral surface of the rotating shaft 32, and the fluid passages 10a, 10b, 11
a, 11b, a diaphragm valve type automatic adjustment throttle device 5, a pump 38, a motor 39, a pressure adjustment valve 40,
The pressure gauge 41 has a lubricating oil discharge path.

Reference numeral 42 denotes another lubricating oil supply unit which conforms to the lubricating oil supply unit 37, and supplies lubricating oil to the recesses 2a and 3a provided on the left and right of the flange 32a.

In this application example, in the forward and backward f1 cutting and feeding of the peripheral surface of the grindstone 34, the grindstone base 30 is first moved and fixed near the target position, and then the diaphragm valve of the lubricating oil supply unit 37 is moved. The power drive means 20A, 20B of the automatic aperture control device 5 is operated to change the pressure of the lubricating oil in each of the recesses 2a, 3b facing the peripheral surface of the rotary shaft 32, thereby moving the rotary shaft 32 in the front-back direction f1. Make the cut feed.

Further, in the case of the f2 incision feed on the side surface of the grindstone 34, the grindstone table 30 is moved and fixed in the vicinity of the target position as described above, and then the diaphragm valve type automatic adjustment of the lubricating oil supply section 42 is performed. Power drive means 20 of the aperture device 5
A, 20B are operated to change the pressure of the lubricating oil in the recesses 2a, 3a so that the rotary shaft 32 is cut and fed in the left-right direction f2. Note that a knife or the like may be fixed instead of the grinding stone 34.

(2) Application Example 2 FIG. 3 shows an example in which the present invention is applied to a feed screw mechanism of a table. In this figure, reference numeral 50 denotes a table movably guided in a left-right direction f2 by a linear guide track (not shown). 51 is a feed screw in the left-right direction f2,
The nut body 52 is screwed. The nut body 52 and the table 50 are connected by a hydrostatic joint 1A, which is a type of hydrostatic bearing. In the static pressure joint 1A, specifically, a projection h is provided on the nut body 52, and the projection h is sandwiched between the left pad member 53 and the right pad member 54 fixed to the table 50.
The recesses 3a and 3a are provided on the inner surfaces of the recesses 3 and 54, respectively.

In this application example, when positioning the table 50 at a specific position, the lubricating oil supply unit 37 is used.
In a state in which the lubricating oil is supplied to the respective recesses 2a and 3a, the moving force of the nut body 52 is transmitted to the table 50 via the hydrostatic bearing 1A by rotating the feed screw 51 and moved to the vicinity of the target position. Let it. Subsequently, the power driving means 20A, 20B of the diaphragm valve type automatic adjusting and squeezing device 5 is operated to change the pressure of the lubricating oil in the recesses 2a, 3a so that the table 50 is slightly fed by a required dimension in the left-right direction f2. To

[0044]

According to the present invention constructed as described above, the guided member of the hydrostatic bearing can be minutely moved accurately and quickly (for example, 0.1 mm) by utilizing the characteristics of the diaphragm valve type automatic adjustment diaphragm. A movement of about 5 μm is also possible). In addition, if the amount of throttle on the throttle surface on each side of the diaphragm body can be changed arbitrarily, the rigidity of the bearing can be kept large and the efficiency of power consumption for lubricating oil supply can be increased at any position of the guided body. Is to be achieved.

Further, if the present invention is applied to a machine tool or the like, extremely precise processing can be performed more than the above-mentioned effects.

According to the second and third aspects, since the electrostrictive element or the magnetostrictive element has a characteristic that theoretically almost unlimited resolution can be obtained in a minute section of about several tens of μm, The guided member of the hydrostatic bearing can be minutely moved accurately and quickly by a simple operation, and the position can be stably held.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 shows an example in which the present invention is applied to a grindstone stand of a grinding machine, where A is a sectional view in plan view and B is a sectional view in side view.

FIG. 3 is a diagram illustrating an example in which the present invention is applied to a feed screw mechanism of a table.

FIG. 4 is a diagram showing an example of use of a conventional diaphragm valve type automatic adjustment throttle device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Static pressure bearing 2a, 2b Recess 5 Diaphragm valve type automatic adjustment expansion device 6 Diaphragm body 7, 8 Fluid chamber 9 Throttle surface part 20A, 20B Power drive means

Claims (3)

[Claims] 1. A closed space is partitioned by a diaphragm body, each side of which is defined as a fluid chamber, and a throttle surface portion facing the diaphragm body is provided in each fluid chamber, and at least one of the throttle surface portions or both of the throttle surface portions is a diaphragm body. A diaphragm valve type automatic adjustment diaphragm device provided with a power drive means for displacing to an arbitrary position in a direction perpendicular to the direction of the diaphragm is formed, and a fluid of an appropriate pressure is supplied between each diaphragm surface portion and the diaphragm body, where the diaphragm is throttled. Supplying the fluid to the opposite recess of the hydrostatic bearing,
In this state, a method of controlling the position of the guided body using the throttle characteristic of the hydrostatic bearing, wherein the power drive means is operated appropriately. 2. A guided object utilizing a throttle characteristic of a hydrostatic bearing according to claim 1, wherein the power driving means has an electrostrictive element or a magnetostrictive element as a driving force generating source. Position control method. 3. A closed space is partitioned by a diaphragm body, each side of which is defined as a fluid chamber, and a throttle surface facing the diaphragm body is provided in each fluid chamber, and at least one of the throttle surfaces or both of the throttle surfaces is a diaphragm body. Power drive means for displacing to an arbitrary position in a direction orthogonal to the direction, the power drive means has a configuration provided with an electrostrictive element or a magnetostrictive element as a driving force generating source, characterized in that the hydrostatic bearing Diaphragm valve type automatic adjustment diaphragm device used for position control of a guided body utilizing the diaphragm characteristic.