JP5924944B2 - Sliding guide device - Google Patents

Description

  The present invention relates to a slide guide device, and more particularly to a slide guide device that performs high-accuracy guidance by a half-flying sliding of an air static pressure method.

2. Description of the Related Art Conventionally, a sliding guide device using a precise sliding surface is known as a mechanical movable part guide device or feeding device structure.
Among the slide guide mechanisms, there is a hydraulic hydrostatic semi-levitation type slide guide device that supplies a lubricating oil between a sliding surface and a guide surface to bear a contact pressure (see Patent Documents 1 to 3).

In the device of Patent Document 1, the local hydraulic pressure of the guide surface is dynamically adjusted to eliminate the inclination due to the acceleration of the guided portion.
In the apparatus of Patent Document 2, a valve mechanism is used in combination to control the dynamic pressure on the guide surface.
In the device of Patent Document 3, in order to easily adjust the contact state between the guide surface and the sliding surface, fine irregularities are formed on the guide surface.

Such a sliding guide device is used as a linear motion mechanism along a uniaxial direction and is installed in two orthogonal directions to perform planar movement.
Furthermore, the hydrostatic bearing slide guide device is not limited to a hydraulic type, and an air static pressure type slide guide device using air pressure is also used (see Patent Document 4).

In the apparatus of Patent Document 4, an air static pressure bearing is installed in a two-story structure in order to move a planar moving stage two-dimensionally, and two-dimensional movement is realized by guiding one axis at a time.
In addition, by using an aerostatic bearing, sliding resistance can be reduced as compared with a hydrostatic pressure system, and high positional accuracy and high responsiveness can be obtained.

JP 2005-28543 A JP 2008-215439 A JP-A-6-735 JP 2010-110860 A

  By the way, in an aerostatic bearing, contact pressure is mainly borne by the air pressurized and supplied to the air pocket formed in the sliding surface. However, the sliding surface around the air pocket is opposed to the guide surface with a slight gap. Like the hydraulic hydrostatic bearings of Patent Documents 1 to 3 described above, there is no lubricating oil between the sliding surface and the guide surface. A film is formed, and depending on conditions, the sliding surface and the guide surface may be in direct contact.

The resistance caused by the sliding between the sliding surface and the guide surface around the air pocket affects the performance as an aerostatic bearing. Become.
In particular, when the slide guide device starts moving, that is, when shifting from a stationary state to a moving state, there is no change in the load support by the air in the air pocket, whereas the sliding surface and the guide surface around the air pocket The frictional state during the period will change greatly, resulting in a non-negligible effect.
Further, when the moving speed of the sliding guide device increases, the resistance due to the lubricating oil between the sliding surface and the guide surface around the air pocket increases, which also causes a non-negligible effect.
The Stribeck curve is known as a coefficient of friction between the sliding surface and the guide surface on which such lubricating oil is present.

FIG. 12 shows a Stribeck curve.
In the figure, the vertical axis represents the coefficient of friction and the horizontal axis represents the number of bearing characteristics. The number of bearing characteristics is given by the product of the viscosity of the lubricating oil, the sliding speed, and the load on the sliding surface.
When the sliding guide device is in a stationary state, the sliding surface and the guiding surface around the air pocket are in a state where their minute tips are in solid contact with each other, and between the sliding surface and the guiding surface, Friction resistance is given by the coefficient of static friction between the surfaces.
When the sliding guide device shifts to the moving state, the sliding surface and the guide surface shift from the static friction state to the dynamic friction state, and the portion where the lubricating oil intervenes between the sliding surface and the guide surface expands, and solid contact occurs. In this state, the frictional resistance between the sliding surface and the guide surface is due to the frictional resistance caused by solid contact between each surface, the viscosity of the lubricating oil, and the sliding speed. It is given as the sum of the viscous resistance.

In the same figure, when the movement is started from a static state where the speed is zero (the left end in the figure), the number of bearing characteristics having a low movement speed is in the state of section (A). That is, as shown in the schematic diagram at the top of the figure, when the moving speed is low, the guide surface G and the sliding surface S are in direct contact, and the film pressure h of the lubricating oil L between them is zero. The value is close to. This state is called a “boundary lubrication region” and has the highest friction coefficient.
Along with the movement, when the speed increases and the number of bearing characteristics becomes the section (B), a part of the load is borne by the lubricating oil L between the guide surface G and the sliding surface S. However, part of the direct contact between the guide surface G and the sliding surface S remains, and the film pressure h of the lubricating oil L between them is a value close to the surface roughness R of each surface, that is, the surface roughness R. The oil film of the lubricating oil L is filled between the unevenness. This state is called “mixed lubrication region”, and the friction coefficient is the lowest section.

When the speed further increases and the number of bearing characteristics becomes the section (C), the film pressure h of the lubricating oil L between them becomes sufficiently larger than the surface roughness R of the guide surface G and the sliding surface S, and the guide surface G And the sliding surface S are separated and floated by the oil film, and the load is borne exclusively by the lubricating oil L between the guide surface G and the sliding surface S. This state is called a “fluid lubrication region” and shows a tendency that the coefficient of friction increases as the speed increases. At this time, it is understood that the increase in the friction coefficient accompanying the increase in speed increases as the boundary lubrication region (A) approaches.
Note that the coefficient of friction is static when the speed is zero, that is, when the speed is zero (the left end in the figure). However, even in the current tribology field, the exact behavior from the static friction state has not been confirmed, and boundary lubrication of the Stribeck curve The left end in the region (A) is not fixed.

  As described above, even in a slide guide device using an aerostatic bearing aiming at high precision, sliding resistance due to lubricating oil is unavoidable mechanically, and sliding resistance due to this lubricating oil is suppressed. Technology development was desired.

  An object of the present invention is to provide an aerostatic pressure type sliding guide device capable of suppressing sliding resistance caused by lubricating oil on a sliding surface.

In the present invention, in the bearing characteristic number of the horizontal axis in the above-mentioned Stribeck curve, the viscosity of the lubricating oil and the load applied to the sliding surface are made constant, and the product of the friction coefficient of the vertical axis and the load of the sliding surface is obtained. In terms of sliding resistance, the Stribeck curve can be converted into one that represents the relationship between sliding speed and sliding resistance. Sliding resistance is frictional force, which is the normal force and friction coefficient applied to the contact surface. Based on the knowledge that it is given by the product of
In the present invention, on the basis of the above-described knowledge, the sliding surface is subjected to static air based on the relationship between the friction coefficient, the sliding speed, and the normal force, which are factors that determine the sliding resistance of the sliding surface in the sliding guide device. In the air pocket that forms the pressure pool, the air pressure to be supplied is appropriately controlled for each sliding speed, and the vertical drag applied to the contact surface is controlled to suppress fluctuations in the friction coefficient and sliding resistance. It is intended to obtain motion accuracy.

The slide guide device of the present invention includes a guide having a guide surface, a slider having a slide surface, an air pocket formed on the slide surface and facing the guide surface, and supplying pressurized gas to the air pocket. Gas supply means for controlling, and control means for controlling the gas supply means,
The control means includes an air pressure setting unit that sets an appropriate air pressure based on a sliding resistance between the guide surface and the sliding surface, and the air pressure that is set by the air pressure setting unit. It possesses an air pressure controller for controlling the supply of pressurized gas of the gas supply means, wherein the control means includes an air pressure data table recording the proper air pressure for each moving speed of the slider relative to the guide, An air pressure setting unit that sets an appropriate air pressure from the air pressure data table based on the moving speed of the slider with respect to the guide, and pressurization of the gas supply means according to the air pressure set by the air pressure setting unit characterized by chromatic and air pressure controller for controlling the supply of gas, a.

In the present invention, air can be used as the pressurized gas, and other gases such as an inert gas may be used.
In the present invention, by controlling the supply of the pressurized gas to the air pocket with an appropriate air pressure corresponding to the sliding resistance between the guide surface and the sliding surface, for example, guidance caused by lubricating oil The sliding resistance between the surface and the sliding surface can be kept constant regardless of the relative speed between the guide and the slider, and the influence on the highly accurate sliding guide can be avoided.

Furthermore, in the present invention, the air pressure of the air pocket is adjusted by referring to the air pressure data recorded in the air pressure data table, so that the sliding resistance between the guide surface and the sliding surface is reduced between the guide and the slider. It is possible to maintain a constant irrespective of the relative speed of the movement, and to avoid the influence on the highly accurate sliding guide.
In addition, since the data table is created in advance, it is possible to avoid processing system overhead such as calculating the sliding resistance between the guide surface and the sliding surface from the sensor output.

In the present invention, the air pressure recorded on the air pressure data table, while not supplying the pressurized gas in advance in the air pocket, and measuring the sliding speed and sliding resistance to the guide of the slider, found It is desirable that the air pressure in the air pocket for making the sliding resistance constant is calculated for each predetermined value of the sliding speed based on the sliding speed and sliding resistance.
In the present invention, air pressure data obtained by actual measurement can be used to supply the air pocket with air pressure that keeps the sliding resistance constant regardless of the relative speed between the guide and the slider. It is possible to appropriately suppress the frictional resistance according to the speed due to the above.

Although not included in the present invention , the control means includes a measuring unit that measures a state quantity related to sliding resistance between the guide surface and the sliding surface, and a state quantity measured by the measuring unit. An air pressure setting unit that sets an appropriate air pressure based on the air pressure, and an air pressure control unit that controls the supply of pressurized gas of the gas supply means according to the air pressure set by the air pressure setting unit. It is good.

In such a configuration , the air pressure is calculated based on the state quantity indicating the current state of the guide surface and the sliding surface, so that the sliding resistance is constant regardless of the relative speed between the guide and the slider. The pressure can be supplied to the air pocket, thereby appropriately suppressing the frictional resistance according to the speed caused by the lubricating oil.
Further, since an appropriate air pressure is calculated based on the sensor output, it is not necessary to prepare a data table in advance.

Although not included in the present invention , as the state quantity related to the sliding resistance between the guide surface and the sliding surface, the interval between the guide surface and the sliding surface, or the guide surface and The oil pressure of the lubricating oil between the sliding surfaces can be used.
That is, the measurement unit may include a distance sensor that is installed on the sliding surface around the air pocket and measures a distance from the guide surface.
The interval between the guide surface and the sliding surface increases as the oil pressure of the lubricating oil increases, and is a value related to the sliding resistance between the guide surface and the sliding surface.

Or the said measurement part is good also as what has a pressure sensor which is installed in the said sliding surface of the periphery of the said air pocket, and measures the pressure of the lubricating oil between the said guide surfaces.
The hydraulic pressure of the lubricating oil increases as the sliding speed between the guide surface and the sliding surface increases as the relative speed increases, and the sliding resistance between the guide surface and the sliding surface increases. Associated value.

The perspective view which shows the slide guide apparatus of 1st Embodiment of this invention. Sectional drawing which shows the guide and slider of the said 1st Embodiment. The block diagram which shows the control system of the said 1st Embodiment. The block diagram which shows the principal part of the control apparatus of the said 1st Embodiment. The graph which shows the relationship between the sliding resistance and sliding speed in the said 1st Embodiment. The graph which shows the relationship between the sliding resistance and sliding speed in the said 1st Embodiment. The graph which shows the relationship between the sliding resistance and sliding speed in the said 1st Embodiment. The graph which shows the relationship between the sliding speed and air pressure in the said 1st Embodiment. Sectional drawing which shows the guide and slider of 2nd Embodiment which are reference examples . The block diagram which shows the control system of the said 2nd Embodiment. The block diagram which shows the principal part of the control apparatus of the said 2nd Embodiment. The schematic diagram which shows a Stribeck curve.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
1 to 8 show a first embodiment of the present invention.
1 and 2, the sliding guide device 1 includes a slider 30 that can move along a long guide 20.

For example, the guide 20 is formed by cutting a groove shape on the upper surface side of a long metal material, and the upper surfaces of a pair of parallel protrusions 29 formed on both sides are formed on a precise flat surface. A guide surface 21 is formed by the flat surface.
Inside the ridge 29 of the guide 20, a pair of inner surfaces opposed to both sides of the groove are formed into flat surfaces that are perpendicular to the guide surface 21 and have a precise surface. 22 is formed.

  For example, the slider 30 is formed in a table shape by flatly forming the upper surface side of a block-shaped metal material and forming two rows of protrusions 39 on the lower surface side. A total of four sliding pads 38 are installed on the outer corners of the ridges 39 at the corners of the bottom surface through ball-type joints 37 (see FIG. 2).

The sliding pad 38 has a lower surface that is a sliding surface 31 that slides facing the guide surface 21 of the guide 20 described above. The sliding surface 31 has an air pocket 32 for forming an air static pressure reservoir. Is formed.
A port 33 communicating with the air pocket 32 is formed on the side surface of the sliding pad 38, and pressurized air is supplied to the port 33 from an external pressurized air tank 34 (see FIG. 1).
As a result, an air static pressure pool is formed by the air pocket 32 on the sliding surface 31 of the sliding pad 38, and the load of the slider 30 is received by the guide surface 21 of the guide 20 via the sliding pad 38. The slider 30 can slide with a very small sliding resistance.

Sub sliding pads 36 are installed on the outer sides of the protrusions 39 of the slider 30.
The sub-sliding pad 36 is set to slide at a predetermined pressure on the sub-guide surface 22 inside the protrusion 29 of the guide 20, and the slider 30 is configured by the sub-sliding pad 36 and the sub-guide surface 22. The movement direction axis is guided in the longitudinal direction of the guide 20.

In order to move the guide 20 and the slider 30 relative to each other, the slide guide device 1 includes a drive mechanism 40.
The drive mechanism 40 includes a drive motor 41 installed at the end of the guide 20 and a feed screw shaft 42 extending in the recessed groove of the guide 20, and a feed screw receiving portion 43 installed on the lower surface of the slider 30. Have.
In such a drive mechanism 40, the feed screw shaft 42 is rotationally driven by the drive motor 41, so that the feed screw receiving portion 43 screwed to the feed screw shaft 42 moves in the longitudinal direction of the guide 20, thereby The slider 30 is driven in the longitudinal direction of the guide 20.

In order to detect the position of the slider 30 with respect to the guide 20, the drive mechanism 40 is installed on the side surface of the scale 49 installed along the feed screw shaft 42 and the feed screw receiving portion 43 and is close to the surface of the scale 49. And a read head 48 arranged. The read head 48 and the scale 49 constitute a linear encoder that detects the position of the slider 30 with respect to the guide 20.
A position signal of the slider 30 detected by the reading head 48 is sent to a control device 50 described later and used for drive control.

In order to perform the drive control of the drive mechanism 40 and the air pressure adjustment of the air pocket 32 described above, the slip guide device 1 includes a control device 50.
As shown in FIG. 1, the control device 50 causes an existing computer system such as a personal computer to read an operation program for executing the drive control of the drive mechanism 40 and the air pressure adjustment of the air pocket 32 described above. A control signal line is connected between the drive mechanism 40 to be controlled and the vicinity of the pressurized air tank 34.

As shown in FIG. 3, the controller 50 includes a drive controller 51 and an air pressure controller 61 based on the above-described operation program.
The drive controller 51 is connected to the read head 48 of the drive mechanism 40 described above via the signal line 52, and can read the current position of the slider 30 relative to the guide 20 from the current position on the scale 49.
The drive controller 51 is connected to the drive motor 41 via the signal line 53 and can drive the slider 30 to move it to a desired position with respect to the guide 20.

The air pressure controller 61 is connected to the reading head 48 via the signal line 52 described above, and can read the current position of the slider 30 relative to the guide 20 from the current position on the scale 49.
The air pressure controller 61 is connected to an air pressure control valve 64 installed in a pipe extending from the pressurized air tank 34 to each sliding pad 38 via the signal line 63, and is connected to each slide from the pressurized air tank 34. The pressurized air supplied to the air pocket 32 of the moving pad 38 can be adjusted, and thereby the air pressure in each air pocket 32 can be adjusted.

As shown in FIG. 4, the air pressure controller 61 includes a speed calculation unit 65, an air pressure data table 66, an air pressure setting unit 67, and an air pressure control unit 68.

The speed calculation unit 65 calculates the moving speed of the slider 30 relative to the guide 20 (the sliding speed between the sliding surface 31 and the guide surface 21) based on the current position of the slider 30 relative to the guide 20 read from the reading head 48 described above. To do.
In the air pressure data table 66, optimum air pressure data is registered in advance as the air pressure in the air pocket 32 for each sliding speed between the sliding surface 31 and the guide surface 21.

The air pressure setting unit 67 reads air pressure data corresponding to the sliding speed from the air pressure data table 66 based on the sliding speed calculated by the speed calculating unit 65 described above, and sets it as the current air pressure. .
The air pressure control unit 68 controls the air pressure control valve 64 described above based on the current air pressure data set by the air pressure setting unit 67 and is sent from the pressurized air tank 34 to each sliding pad 38. The compressed air is adjusted to maintain the current air pressure data in the air pocket 32.

  In such an embodiment, the pressurized air tank 34 described above is the gas supply means of the present invention, and the air pressure control valve 64 and the air pressure controller 61 constitute the control means of the present invention.

In this embodiment, the optimum air pressure data is calculated as the air pressure in the air pocket 32 at this sliding speed for each sliding speed between the sliding surface 31 and the guide surface 21. By registering these as data pairs in the air pressure data table 66 in advance, an expected operation in which the sliding resistance is made constant by the optimum air pressure is performed.
Such data in the air pressure data table 66 is set as follows.

(Create air pressure data)
First, on the premise that the weight of the slider 30 and the viscosity of the lubricating oil are constant, the slider 30 is moved along the guide 20 without supplying compressed air to the air pocket 32 of the sliding pad 38, The relationship between the “sliding resistance” between the sliding surface 31 and the guide surface 21 in this state and the “sliding speed” of the slider 30 with respect to the guide 20 is experimentally obtained.
In this embodiment, since the slider 30 is driven with respect to the guide 20 by a feed screw system, the “sliding resistance” can be converted from the torque of the drive motor 41 transmitted to the feed screw shaft 42. Is determined from the current value supplied to the motor. Further, the “sliding speed” can be obtained by numerically differentiating the position information of the slider 30 detected from the scale 49 and the reading head 48 constituting the linear encoder.
From the above, the characteristics relating “sliding resistance” and “sliding speed” can be obtained.

FIG. 5 is an example of a characteristic curve showing the relationship between “sliding resistance” and “sliding speed” when the slider 30 has a mass M = 100 kg.
The scale on the right side of the vertical axis in FIG. 5 is “friction coefficient”, and is obtained as a value obtained by dividing “sliding resistance” by the weight M (a constant in this case) of the slider 30.
For example, when the friction coefficient μ = 1, the sliding resistance Q = 980 N = (mass M = 100 kg) × (weight acceleration G = 9.8 m / s ² ) × (friction coefficient μ = 1) is meant.

In FIG. 5, when the sliding speed V = about 100 mm / s, the sliding resistance Q = 0.98N, and the friction coefficient μ = 0.001 at this time.
Similarly, when the sliding speed V is about 65 mm / s, the sliding resistance Q is 9.8 N, and the friction coefficient μ at this time is 0.01.
Further, when the sliding speed V = about 40 mm / s, the sliding resistance Q = 98N, and the friction coefficient μ = 0.1 at this time.
In this way, the sliding resistance Q and the friction coefficient μ at each sliding speed V are sequentially calculated.

Next, based on the characteristic values relating to “sliding resistance” and “sliding speed” obtained in advance as shown in FIG. 5 above, the sliding resistance is determined as “a specific reference value” according to the following procedure. The air pressure P supplied to the air pocket 32 of the sliding pad 38 is determined for each sliding speed V so as to be substantially constant.
By changing the air pressure P in the air pocket 32 of the sliding pad 38, fluctuations in the sliding resistance Q can be suppressed. In examining the sliding resistance Q, the mass M of the slider 30 is supported. The load per sliding pad 38 is calculated. Since the number of sliding pads 38 is n = 4, it can be assumed that the pressure receiving area A as the air pocket 32 in the sliding pad 38 is 707 mm ² (calculated assuming that the diameter of the circular air pocket is 30 mm). 6 is converted into the relationship between the sliding resistance q = Q / 4 per sliding pad 38 and the sliding speed V, to obtain the curve of FIG.

In FIG. 6, the vertical drag that is the load per sliding pad 38, that is, the load w ₀ is w ₀ = 245 N, and per sliding pad 38 when the sliding speed V≈100 mm / s. The sliding resistance q is the minimum value q = 0.245N. And the sliding resistance value becomes the minimum standard sliding resistance q _0, the pressure P in the air pocket 32 of the sliding pad 38 in this case as 0 MPa (gauge pressure), successively, sliding in the sliding speed V The air pressure required as the air pressure P in the air pocket 32 is set for each sliding speed V so that the resistance q becomes the reference sliding resistance q ₀ = 0.245N.

(Air pressure data setting)
The specific procedure for setting the air pressure for each sliding speed V to be set to the air pressure P in the air pocket 32 is as follows.
In FIG. 6, for example, when the sliding speed V = 75 mm / s, the sliding resistance q per sliding pad 38 is 0.98 N, and the load per sliding pad 38 is as described above. Since the load (vertical drag) w ₀ = 245 N, the friction coefficient μ is given by the following equation (1).
[Equation 1]
μ = q / w ₀ = 0.98N / 245N = 0.004 (1)
Here, in order to make the sliding resistance q = 0.98N per sliding pad 38 equal to the reference sliding resistance q ₀ = 0.245N, sliding around the air pocket 32 of the sliding pad 38 is performed. The load w _c borne by the surface 31 is a value given by the following equation (2).
[Equation 2]
w _c = q ₀ /μ=0.245N/0.004=61.25N (2)
Further, the load w _a to be borne by the air pressure P in the air pockets 32 is given by the following equation (3).
[Equation 3]
w _a = w ₀ −w _c = 245N−61.25N = 183.75N (3)

Incidentally, the load w _a to be borne by the air in the air pockets 32, because the product of the pressure receiving area A of the air pressure P and the air pocket 32 in the air pockets 32, the air pressure in the air pocket 32 to be set P is given by the following equation (4).
[Equation 4]
^{_{P = w a /A=183.75N/707mm 2 = 0.260MPa}} ... (4)

FIG. 7 shows the air pressure data of the optimum air pressure P in the air pocket 32 in the entire speed region obtained by the above procedure.
In the present embodiment, such air pressure data is registered in the air pressure data table 66 so that the air pressure P corresponding to the measured sliding speed V between the sliding surface 31 and the guide surface 21 can be referred to. Keep it.
Thereby, in the actual driving of the slider 30, the sliding speed V is obtained based on the signal from the linear encoder, and the air pressure control valve 64 is adjusted so that the air pressure P corresponds to the sliding speed V. Compressed air set at a predetermined air pressure P can be supplied into the air pocket 32 of the sliding pad 38, and the sliding resistance between the sliding surface 31 and the guide surface 21 can be made constant.

[Second Embodiment]
FIGS. 9 to 11 show a second embodiment as a reference example not included in the present invention.
The slip guide device 1 according to the present embodiment includes a guide 20, a slider 30, and a drive mechanism 40 similar to those in the first embodiment. For this reason, the same code | symbol is attached | subjected about a common structure and the overlapping description is abbreviate | omitted, and the part different from 1st Embodiment is demonstrated below.

In FIG. 9, an interval sensor 35 that measures the interval between the opposed sliding surface 31 and the guide surface 21 is installed in a part of the sliding surface 31 of the sliding pad 38 around the air pocket 32. Has been.
As the distance sensor 35, an ultrasonic type, an optical type, or any other type can be used.

  In FIG. 10, the air pressure controller 61 is connected to the distance sensor 35 of each sliding pad 38 via a signal line 62, and measures the distance between the sliding surface 31 and the guide surface 21 in each sliding pad 38. Can do.

As shown in FIG. 11, the air pressure controller 61 includes a sensor interface 69, an air pressure setting unit 67, and an air pressure control unit 68.
The sensor interface 69 is connected to the distance sensor 35 of each sliding pad 38 described above, and acquires the distance data between the sliding surface 31 and the guide surface 21 in each distance sensor 35.

The air pressure setting unit 67 sets air pressure data to be a target air pressure of the pressurized air sent to the sliding pad 38 based on the current interval data acquired by the sensor interface 69 described above.
The air pressure control unit 68 controls the air pressure control valve 64 described above based on the current air pressure data calculated by the air pressure setting unit 67, and is sent from the pressurized air tank 34 to each sliding pad 38. The compressed air is adjusted to maintain the current air pressure data in the air pocket 32.

  Here, as a method of setting the air pressure data that becomes the target air pressure based on the interval data, for example, a test using an actual machine of the slip guide device 1 is performed, and the slide guide device 1 is connected to the sliding surface 31 and the guide surface 21. In this state, the range of the interval data by the interval sensor 35 (the range in which the appropriate state can be obtained) is recorded so that the interval data falls within the range. A method of feedback control of air pressure data can be adopted. In addition, a method of calculating the air pressure data from the interval data obtained by the interval sensor 35 by setting the relationship between the interval data and the appropriate range of air pressure data as an approximate function through the same actual machine test is adopted. May be.

In this embodiment, the above-described pressurized air tank 34 is the gas supply means of the present invention, and the above-described distance sensor 35 or sensor interface 69 is the measuring unit of the present invention, and the air pressure control valve 64 and The distance sensor 35 and the air pressure controller 61 constitute the control means of the present invention.
In the present embodiment, the interval data measured by the interval sensor 35 is a state quantity related to the sliding resistance between the guide surface 21 and the sliding surface 31.

  According to the present embodiment, the air pressure can be adjusted based on the distance between the sliding surface 31 and the guide surface 21 so that the sliding resistance between them is constant. The frictional resistance according to the speed to perform can be suppressed appropriately.

[Third Embodiment]
The present embodiment is a reference example not included in the present invention, and has the same configuration as the second embodiment. Since the configuration is almost the same, the drawings are omitted.
The difference of this embodiment from the second embodiment is that the pressure of the lubricating oil filled in these intervals is measured instead of the interval sensor 35 that measures the interval between the sliding surface 31 and the guide surface 21. The pressure sensor is installed.
Further, the air pressure controller 61 of the present embodiment is a target air based on pressure data between the sliding surface 31 and the guide surface 21 instead of data on the distance between the sliding surface 31 and the guide surface 21. It is comprised so that pressure data may be calculated.

  Here, as a means for measuring the pressure of the lubricating oil between the sliding surface 31 and the guide surface 21, a pressure sensor is provided on the sliding surface 31 on the moving side. As the pressure sensor, a pressure sensor installed facing the space between the sliding surface 31 and the guide surface 21 can be used. However, in order to obtain reliable pressure detection stably, It is desirable to form a thin concave lubricating oil pocket on the surface 31 and to install a pressure sensor facing the pocket to detect the oil pressure in the pocket. Note that a plurality of minute hydraulic sensors may be arranged on the sliding surface 31 in a planar shape toward the guide surface 21 and used as a pressure sensor array.

  In this embodiment, the pressure data between the sliding surface 31 and the guide surface 21 is used as a state quantity related to the sliding resistance between the guide surface 21 and the sliding surface 31, and this pressure data is used. Therefore, the air pressure can be adjusted so that the sliding resistance between the sliding surface 31 and the guide surface 21 is constant. Thereby, the sliding resistance according to speed can be suppressed appropriately, and also by this embodiment, the effect similar to 2nd Embodiment mentioned above is acquired.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to each said embodiment, The deformation | transformation etc. in the range which can achieve the objective of this invention are included in this invention.
For example, the fluid supplied to the air pocket is not limited to normal air but may be an inert gas or a specific vapor.
The drive mechanism 40 is not limited to a feed screw shaft system, and may be linear motor drive, roller drive, precision gear drive, or the like.
As the linear encoder constituted by the scale 49 and the reading head 48, an optical type, a capacitance type, a magnetic type, and other types can be arbitrarily adopted.
The auxiliary guide surface 22 and the auxiliary sliding pad 36 may be other feed direction guide means, and can be omitted as appropriate.
In each of the above-described embodiments, the uniaxial slip guide device 1 has been described. However, a slide guide device for a two-dimensional movement table may be configured in combination with the cross direction.

DESCRIPTION OF SYMBOLS 1 ... Guide apparatus 20 ... Guide 21 ... Guide surface 22 ... Sub guide surface 29 ... Projection 30 ... Slider 31 ... Sliding surface 32 ... Air pocket 33 ... Port 34 ... Pressurized air tank 35 ... Space sensor 36 ... Sub sliding Pad 38 ... Sliding pad 39 ... Projection 40 ... Drive mechanism 41 ... Drive motor 42 ... Feed screw shaft 43 ... Feed screw receiving portion 48 ... Read head 49 ... Scale 50 ... Control device 51 ... Drive controller 52, 53 ... Signal Wire 61 ... Air pressure controller 62, 63 ... Signal line 64 ... Air pressure control valve 65 ... Speed calculation unit 66 ... Air pressure data table 67 ... Air pressure setting unit 68 ... Air pressure control unit 69 ... Sensor interface

Claims (2)

A guide having a guide surface, a slider having a slide surface, an air pocket formed on the slide surface and facing the guide surface, a gas supply means for supplying pressurized gas to the air pocket, and the gas Control means for controlling the supply means,
The control means includes an air pressure setting unit that sets an appropriate air pressure based on a sliding resistance between the guide surface and the sliding surface, and the air pressure that is set by the air pressure setting unit. It possesses an air pressure controller for controlling the supply of pressurized gas of the gas supply means, wherein the control means includes an air pressure data table recording the proper air pressure for each moving speed of the slider relative to the guide, An air pressure setting unit that sets an appropriate air pressure from the air pressure data table based on the moving speed of the slider with respect to the guide, and pressurization of the gas supply means according to the air pressure set by the air pressure setting unit sliding guide device, characterized in that the perforated and air pressure controller for controlling the supply of gas, a. In the slip guide apparatus described in Claim 1 ,
The air pressure recorded on the air pressure data table, while not supplying the pressurized gas in advance in the air pocket, and measuring the sliding speed and sliding resistance to the guide of the slider, actually measured the sliding 2. A sliding guide device according to claim 1, wherein the air pressure in the air pocket for making the sliding resistance constant is calculated for each predetermined value of the sliding speed based on the moving speed and the sliding resistance.

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