JPH07112654B2 - Levitation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a float table or a slide table in which a compressed gas such as compressed air is jetted to a sliding surface of the float table or a slide table which slides along a guide surface of a predetermined bed. The present invention relates to such a levitation device, in particular, an effective blast of pressure gas on a slip surface can be realized, and the levitation device is easy and inexpensive to manufacture.

(Prior Art and Problems Thereof) Conventionally, as a kind of device that slides (moves) with respect to a predetermined bed member in a machine tool such as a float table or a slide table, the guide surface of the bed member has been used. A device main body formed with a slip surface having a corresponding shape is provided with a large number of fumaroles that open to the slip surface and an air supply path for supplying pressurized gas to these fumaroles. There is known a levitation device in which the pressure gas to be ejected is ejected through the ejection hole, and is used for the purpose of reducing frictional resistance during its movement.

By the way, in such a levitation device, generally, a large number of pores are formed in the main body of the apparatus having a predetermined shape by post-processing to form fumaroles, and the fumaroles are further formed. Are formed by forming the air supply holes so that they can communicate with each other.

However, in order to make the surface pressure of the floating surface of the levitation device uniform by the pressure gas, and to increase the rigidity of the air film by the pressure gas to improve the load characteristics of the levitation device, such fumaroles are extremely important. Since it is necessary to provide a small diameter and a uniform distribution form on the slip surface, it is extremely difficult and time-consuming to perform the drilling work, and the larger the device body, the more difficult the work. Therefore, there is a problem that the manufacturing cost is increased.

Therefore, it is conceivable to form the fumaroles of such a levitation device by using a porous member having fine pores inside which the gas can pass. That is, as such a porous member, there is a sintered metal, and a block formed of the sintered metal is used, and by fitting it into a recess provided in the main body of the apparatus, the fumaroles as described above are formed. However, in general, it is difficult to secure sufficient dimensional accuracy with a sintered metal, and it is easy to cause clogging by cutting or polishing, and high cost can be avoided. It was extremely difficult to actually use such a structure because it did not exist.

(Solution) Here, the present invention has been made in view of the circumstances as described above, and an object of the present invention is to make the ejection of pressure air on a slip surface more uniform and stable than a fine hole. Another object of the present invention is to provide a levitation device that can be manufactured, is easy to manufacture, and is inexpensive.

In order to achieve such an object, the feature of the present invention resides in that a device main body formed with a slip surface having a shape corresponding to a predetermined guide surface of a bed has a large number of openings on the slip surface. Fume holes and an air supply path for supplying a pressure gas to the air holes are provided, and the pressure gas supplied through the air supply path is ejected through the air holes to float the apparatus main body, In a levitation device that can be moved along a guide surface, a ceramic structure in which the skeleton itself of a skeletal tissue having a predetermined gap between the skeletons has a hollow structure and continuous pores are formed in the skeleton. By allowing a predetermined matrix material to enter the gap of the skeleton to form an integral composite structure, gas can be permeated through the continuous pores formed in the skeleton. Using a porous member, the bottom surface of the porous member is exposed at the slip surface and the pores at the bottom surface are opened at predetermined positions on the slip surface so that the holes are the fumaroles. , A pressure supplied through the air supply passage by connecting the air supply passage to a hole in the skeleton of the ceramic structure that constitutes the porous member integrally with the device main body. The gas is made to be ejected through the opening of the hole of the ceramic structure.

Further, in the present invention, preferably, the ceramic structure is a ceramic porous body having a skeleton structure of a three-dimensional network structure, and such a ceramic porous body is a tertiary resin in a synthetic resin foam. Obtained by sintering the ceramic material adhered around the skeleton of the original network skeletal structure and by eliminating the synthetic resin portion constituting the skeletal structure of the foam,
While the three-dimensional network structure is retained by the sintering of the adhered ceramic material, the skeleton of the three-dimensional network structure itself is hollow, and continuous pores are formed in the skeleton as a whole. It will be advantageously adopted.

Cast metal is generally used as the matrix metal to be introduced into the gap of the skeleton of the ceramic structure, and cast iron or cast steel is appropriately selected as such cast metal.

(Effects of the Invention) Therefore, in the levitation device having the structure according to the present invention, since the pressure gas jet holes are formed by the holes of the ceramic structure forming the porous member, The fumaroles can be set with a fine diameter and at any position on the slip surface with a uniform distribution density.

Further, in the levitation device having the structure according to the present invention,
Machining such as cutting can be adopted by selecting the matrix material that fills the skeleton gap of the ceramic structure, which makes it easy to secure the dimensional accuracy of the slip surface in the levitation device. In addition, the stable performance of the product can be effectively achieved in combination with the good ejection effect of the pressure gas as described above.

Further, in such a levitation device, as compared with the conventional structure in which the ejection holes are formed by post-processing, it is extremely easy to manufacture, so that a product having the above-mentioned excellent performance can be easily manufactured. In addition, it also has an effect that it can be manufactured at low cost.

(Example) Hereinafter, in order to more specifically clarify the present invention, an example of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows an example in which the levitation device having the structure according to the present invention is applied to an air float base in a machine tool.

In this figure, reference numeral 12 is a base or surface plate of the machine tool main body, and is arranged in a state where the air float base 10 which is the main body of the levitation device is placed on a flat upper surface 14 of the machine tool main body. It has become so.

This air float base 10 has a porous member 24 composed of a ceramic structure 16 having continuous pores.
It is a cast product that is integrally provided inside. Further, as shown in the drawing, the outer peripheral surface portion (corresponding to the other 5 surfaces) of the porous member 24 excluding the lower surface (sliding surface) 18 is
By covering with a cover portion 20 having a predetermined thickness formed at the time of casting with a cast metal that does not include a ceramic structure, the pores of the porous member 24 are present only on the sliding surface 18 of the air float base 10. It is open. On the other hand, the cover part 20 of the air float base 10 is provided with an air supply port 22 communicating with the holes of the porous member 24 on the outer peripheral surface of the side part thereof.

Further, in the air float base 10 in the present example, by connecting a predetermined compressed air source to the air supply port 22, the compressed air supplied through the air supply port 22 has its sliding surface 18 Therefore, the air float base 10 can be levitated from the main body base 12 in a state where a predetermined workpiece is placed on the upper surface of the air float base 10. .

Incidentally, the ceramic structure 16 having a three-dimensional network structure used in the air float base 10 according to the present invention,
A ceramic porous body in which the skeleton of the skeletal structure having a predetermined gap between the skeletons has a hollow structure, and continuous pores are formed in the skeleton. For example, as shown in FIG. It has a skeleton structure with a three-dimensional network structure obtained by foaming a resin such as ester polyurethane and then removing the film-like substance (foam film) remaining around the skeleton using compressed air or the like. It is obtained by adhering a ceramic material such as a ceramic slurry to the surface of a skeleton of a synthetic resin foam, further drying and firing the resin foam to burn it off.

And, as the ceramic material forming such a ceramic structure 16, therefore, as the ceramic material attached to the synthetic resin foam, cordierite, alumina, etc. are used depending on the characteristics required for the intended product. , SiC, mullite, zirconia, etc. are appropriately selected and adopted.

Further, in the structure of such a ceramic structure, for example, the thermal decomposition temperature of the urethane resin used as a synthetic resin foam is about 400 ℃, the firing temperature of the ceramic material adhered to the surface of the skeleton, Usually 1300
Since the temperature is not lower than 0 ° C., the urethane resin can be decomposed and disappeared almost completely by adhering the ceramic material on the surface of the skeleton and then firing it for about 24 hours.

Therefore, in the ceramic structure 16 used in the present invention obtained by such a method, as shown in FIG. 2, the skeleton 34 having a three-dimensional network structure is formed and 34 itself is hollow, and pores 36 that are continuous as a whole are formed in the skeleton 34. Incidentally, the ceramic structure 16 having such a structure generally has a porosity of about 60 to 90%, and varies depending on the number of cells, but the length of one side of the skeleton constituting the cell is 0.1.
It is about 0.4 mm. Further, the continuity of the pores 36 formed in the skeleton 34 of the ceramic structure 16 obtained by such a method is, for example, pouring gypsum into the urethane foam from which the foam film has been removed, drying and sintering. After thermally decomposing the urethane foam by carrying out, the molten metal of aluminum is pressed into the pores generated by the burning of the skeleton and solidified, and the gypsum is removed to obtain an aluminum metal foam. From that point on, it is just a demonstration.

Then, the ceramic structure 16 having such a structure
However, under the condition of being placed in the product cavity of a mold (not shown), a metal melt having a chemical component controlled according to the physical characteristics required for the target product is poured. In the present invention, as such a metal melt, those having a cast iron or cast steel composition are preferably selected, but other metal melts such as aluminum alloy melt and copper alloy melt are also used depending on the purpose. Will be selected accordingly.

Then, after the pouring work of the molten metal is completed, the solidification is performed. In the cast product 26 thus solidified, as shown in FIG.
Skeleton 34 having a three-dimensional mesh structure of the ceramic structure 16
The cast metal 40 enters into the cell constituted by, and the cast metal 40 forms an integral composite structure in which the cast metal 40 forms a matrix for the ceramic structure 16. Since the holes 36 in the skeleton 34 of the cast ceramic structure 16 are closed at the surface of the casting as shown in FIG. Is prevented, so that the holes 36 are maintained in a communicating state.

Further, the cast product 26 thus obtained is subjected to the same open frame, cooling, cleaning by shot blasting and the like as in a normal casting operation, and the steps such as grinder finishing to obtain the target porous member 24. However, particularly in the porous member used in the present invention, by processing such as cutting or polishing, so that it can be used in the target floating device,
The holes 36 of the skeleton 34 of the ceramics structure 16 embedded therein are opened at the exposed surface 38, and thus the fourth
As shown in FIG. 5 and FIG. 5, it is possible to obtain the porous member 24 having the characteristic of being capable of ejecting the pressure gas to be supplied, by providing the inside with fine continuous pores (holes) of a three-dimensional network structure. is there. And the air float base according to this example
In 10, the periphery of the porous member 24 excluding the lower surface 18 is covered by a cover portion 20 formed at the same time of casting from a cast metal or the like that does not include a ceramic structure, so that the target floating device (10 ) Will be constructed.

It should be noted that in FIG. 3, the cast metal 40 is shown in a divided form because the cross-section of the cast product 26 that provides the porous member 24 according to the present invention is shown two-dimensionally. Since the ceramic structure 16 is composed of a skeleton 34 having a three-dimensional mesh structure and has a cell structure in which continuous cells are formed inside, the ceramic structure 16 is formed as a three-dimensional continuous and integral structure. It is to be understood that the

Therefore, in the conventional levitation apparatus, after forming a plate-shaped cast product, a large number of pores opened on the lower surface by post-processing are formed in a form in which they are in communication with each other. By adopting the levitation device integrally provided with a porous member, the pressure gas jet holes are formed by the holes 36 formed in the skeleton 34 of the ceramic structure 16 constituting the porous member 24. Since it is configured, such fumaroles can be easily formed with a fine diameter and a uniform distribution density over the entire sliding surface 18, and the productivity and manufacturing cost thereof are extremely effectively improved. As a result, the performance can be effectively improved.

Further, in such an air float base 10, by selecting a matrix material (cast metal) to be filled in the gap of the skeleton 34 of the ceramic structure 16, the ejection hole (when performing machining such as cutting) ( It is possible to effectively avoid clogging of the holes 36), and therefore, by adopting machining, it is possible to easily achieve the dimensional accuracy of the sliding surface 18 of the air float base 10 to be formed. The performance of the product can be effectively stabilized in combination with the excellent effect of ejecting the pressure gas as described above.

Although the air float table as one example of the levitation device having the structure according to the present invention has been described above in detail, this is a literal example, and the present invention is construed as being limited to such a specific example. However, in the present embodiment, for example, the formed porous member (24)
The air float base (10) according to the present invention is configured by covering the above with a cover (20). In the present invention, the ceramic structure used in the present invention is arranged in the product cavity. It is also possible to inject a matrix material appropriately selected therein to form a structure in which the ceramic structure is integrally embedded, and to form a desired floating device. The shape, the shape of the sliding surface, the disposition position of the porous member, and the like are appropriately changed according to the levitation device to be applied.

Further, as the matrix material forming the porous member, a plastic material, a glass material, a ceramic material or the like can be used in addition to the cast metal as illustrated.

Further, as the ceramic structure constituting the porous member, in addition to the resin foam having a three-dimensional network structure as illustrated, a comb-shaped body formed of a material such as a resin that can be burnt out during sintering, or Any of those obtained by adhering a predetermined ceramic material around the skeleton of a sword-shaped product, etc., and firing and sintering it can be used.

In addition, although not enumerated one by one, the present invention can be carried out in a mode in which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art, and such an embodiment is the gist of the present invention. Needless to say, all of them are included in the scope of the present invention without departing from the above.

[Brief description of drawings]

FIG. 1 is a sectional explanatory view showing an example of an air float base having a structure according to the present invention, and FIG. 2 is an enlarged sectional explanatory view showing a main part of a ceramic structure suitably used in such an air float base. FIG. 3 is an enlarged cross-sectional explanatory view of a main part showing a cast product obtained by using such a ceramic structure, and FIG.
FIG. 5 is an enlarged cross-sectional explanatory view of a main part of a porous member obtained by subjecting the cast product shown in the drawing to a predetermined process, and FIG. 5 is an overall perspective view of the porous member. 10: Air float base 16: Ceramic structure 18: Slip surface, 20: Cover part 22: Air supply port, 24: Porous member 34: Skeleton, 36: Hole 40: Cast metal

Claims (5)

[Claims] 1. A device main body formed with a slip surface having a shape corresponding to a predetermined guide surface of a bed, and a large number of fumaroles opening in the slip surface, and pressurized gas is supplied to these fumaroles. In a levitation device, which is provided with an air supply passage, and in which the main body of the device can be levitated and moved along the guide surface by ejecting a pressure gas supplied through the air supply passage through the fumarole. The skeleton of the skeletal tissue having a predetermined gap between the skeletons has a hollow structure, and a predetermined matrix material is inserted into the skeleton of the skeleton in the ceramic structure having continuous pores formed therein. By using an integral composite structure, a porous member capable of transmitting gas through continuous pores formed in the skeleton is used.
The porous member is integrated with the apparatus main body in a state where the bottom surface is exposed at the slip surface and the holes located at the bottom surface are opened at predetermined positions on the slip surface so that the holes are the fumaroles. The holes in the skeleton of the ceramic structure that constitutes the porous member,
A levitation device, wherein the air supply passage is connected to allow the pressure gas supplied through the air supply passage to be ejected through the opening of the hole of the ceramic structure. 2. The levitating apparatus according to claim 1, wherein the ceramic structure is a porous ceramic body having a skeleton structure of a three-dimensional network structure. 3. The synthetic resin that constitutes the skeletal structure of the foam while the ceramic porous body sinters the ceramic material adhered around the skeleton of the skeletal structure of the three-dimensional network structure in the synthetic resin foam. While the three-dimensional network structure is retained by the sintering of the adhered ceramic material obtained by eliminating the part, the skeleton itself of the three-dimensional network structure is hollow, and continuous pores are formed as a whole. The levitation device according to claim 2, which is formed in the skeleton. 4. The levitation apparatus according to claim 1, wherein the matrix metal is a cast metal. 5. The levitating apparatus according to claim 4, wherein the cast metal is cast iron or cast steel.