JPS6130851B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feeding device for a hydrostatic slide table. In order to drive a table that is slidably placed on the main body, a nut that is screwed onto a feed screw provided on the main body is connected to the table, and as the feed screw rotates, the table slides through the nut. things are being done. In this case, since the straightness of the table is impaired due to misalignment of the screw shaft with respect to the table movement axis, bending of the screw shaft, etc., it is recommended to connect the nut to the table in a floating manner. Various methods have been proposed for this floating support, but none have yet been fully satisfactory.

For example, it is possible to connect the table and the nut with rubber to supply static pressure to the nut and maintain the floating state of the nut, but this poses the problem of disturbances occurring to the table due to the bending force of the hose, etc. There is. Furthermore, although it is possible to connect the oil pressure supply source and the nut directly with piping, there are drawbacks such as a complicated piping system.

The present invention has been made to solve the above-mentioned problems, and it is possible to drive a nut by placing a nut and a table facing each other with a slight gap before and after the nut feeding direction perpendicular to the feeding direction of the table. Floating support is provided, and an oil passage provided in the table and communicating with a static pressure source is opened on each surface facing the nut to form an opposed planar static pressure bearing, and an oil passage branching from the oil passage is formed. A non-contact joint is formed by opening an oil port on each surface facing the nut, forming an oil feeding port on the nut, and opening an oil receiving port at a position corresponding to the oil feeding port on the nut. This invention relates to a hydrostatic slide table feeding device in which an oil passage communicating with each non-contact joint is opened in a nut and a hydrostatic guide surface of a main body.

An embodiment of the present invention will be described below with reference to the drawings. A table 3 is slidably placed on the main body 1 via a static pressure slide surface 2 formed between the main body 1 and the table 3. . A feed screw 4 for feeding the table is built into the main body 1 and is driven by an electric motor 5. A nut 6 screwed onto the feed screw 4 is guided along a static pressure guide surface 7 of the main body 1 and is slidable in the feeding direction of the feed screw 4. The upper part 8 of the nut has a pair of front and rear surfaces 9a and 9b perpendicular to the feeding direction, and is inserted in a floating state into a recess 10 provided on the lower surface of the table 3 with a very small gap. A flexible hose 11 such as a rubber hose is connected to a hose connection port 12 of the table 3 from a static pressure pump unit (not shown).
is connected to. An oil passage 13 communicating with a hose connection port 12 provided in the table 3 passes through an oil passage 14 and is guided to the hydrostatic slide surfaces 2, 2 between the table 3 and the main body. Further, an oil passage 16 that branches from the oil passage 13 back and forth in the table feeding direction at a branch point 15 opens on the surface 25 facing the nut 6 of the recess 10 that accommodates the nut, thereby forming oil feed ports 17a and 17b. . In addition,
Each oil feed port has oil reservoirs 2 of the same size and the same area in symmetrical positions with the upper part of the nut in between.
6, 26 are formed.

On the other hand, the oil feed ports 17a and 17b at the top of the nut 6
The oil feed ports 17a, 1 are provided on the opposing surfaces 9a, 9b.
A pair of oil receiving ports 18a and 18b are formed at positions relative to 7b, and these oil receiving ports 18a and 18b are connected to form a non-contact joint J for oil supply, and a hole is formed through the upper part of the nut 6 in the feeding direction. Oil road 19
is drilled. The oil passage 19 becomes an oil passage 20 at its center, and splits at a branch point 21 to become an oil passage 22 that communicates with the main body and the guide surface 7, and opens into the guide surface to form the hydrostatic slide surfaces 2, 2. do.

Furthermore, an oil passage 13 following the hose connection port 12
The oil passage 23 branches from the branch point 15 forward and backward in the feed direction, and opens into recesses 24a and 24b provided at symmetrical positions sandwiching the above-mentioned non-contact joint J. A bearing B is configured to prevent the nut from being deviated from the center of the screw shaft. In addition,
As shown in the embodiment, the oil passage 19 penetrates to the nut side.
In addition, it is preferable to provide an oil reservoir with the same area in the oil supply port on the table side so that a pressure difference between the front and rear sides does not occur between the oil supply port and the oil receiving port. In addition, in order to minimize oil leakage from the non-contact joints, it is necessary to
It is necessary to make the gap between the opposing surfaces of a and 17b as small as possible, or to increase the area of the opposing surfaces.

Now, when pressure oil for static pressure is supplied to the table 3 via the rubber hose 11, the pressure oil is transferred to the oil path 13 and the branch point 1.
5. The oil is discharged through the oil passage 14 to the sliding surface 2 of the main body and table, forming a static pressure sliding surface and supporting the table with static pressure. Furthermore, a part of the pressure oil is transferred to branch point 15.
From there, the oil is guided through an oil path 16 to oil feed ports 17a and 17b which open into a recess 10 into which the nut upper part 8 is inserted. A part of the pressure oil discharged from the oil supply port is transferred to the oil receiving port 18 of the nut that forms a non-contact joint J with the oil supply port.
Enter a, 18b, oil passage 19 oil passage 20, oil passage 22
The nut is discharged onto the guide surface 7 through the axial direction, forming a static pressure surface, and supports the nut under static pressure so that the nut's own weight is not directly applied to the feed screw 4.

On the other hand, in the recesses 24a and 24b formed on both sides of the oil feed ports 17a and 17b of the table, oil passages
Pressure oil is sent to the recess from 3 and 23, and an opposed planar static pressure bearing B is formed in the feed direction in a slight gap with the nut, and the table and the nut are connected without contact.

When the nut 6 is moved by driving the feed screw 4, the table moves following the nut because the nut and table are connected by the opposed plane guide bearing B. Furthermore, this connection transmits force only in the feeding direction, and can float freely without any binding force in a plane perpendicular to the feeding direction, so the slide table can be moved straight by air motion in a direction perpendicular to the feeding direction. It can eliminate all negative effects on sexuality.

Furthermore, since oil is supplied from the table to the nut by the non-contact joint J, the floating of the slide table is not hindered, and the straightness of the table can be maintained. Furthermore, since the nut is supported by the static pressure guide surface 7 of the main body, the weight of the nut is not applied to the male thread, and the movement of the nut with respect to the rotation of the male thread becomes light and accurate. Furthermore, the floating-supported nut does not cause any disturbance to the table, the piping is simplified, and the adverse effect of the rigidity of the piping system on the table straightness precision can be completely eliminated.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a main part of an embodiment of the present invention, Fig.
The figure is a sectional view taken along line AA in FIG. 1...Body, 2...Static pressure slide surface, 3...Table, 4...Feed screw, 6...Nut, 7...
Static pressure guide surface, 11... Flexible hose, 13... Oil path, 14... Oil path, 15... Branch point, 16... Oil path, 17a, 17b... Oil feed port, 18a, 18b
...Oil receiving port, 19...Oil channel, 20...Oil channel, 21
... Branch point, 22 ... Oil path, B ... Opposed planar hydrostatic bearing, J ... Non-contact joint.

Claims (1)

[Scope of Claims] 1. A hydrostatic slide in which a nut screwed onto a table drive feed screw is coupled to a table slidably placed on a main body, and the nut is supported on the main body by a static pressure guide surface. The table is placed in a feeding device, and the nut is floatingly supported by placing the nut and table facing each other with a slight gap before and after the nut feeding direction perpendicular to the feeding direction of the table, and communicates with a hydraulic pressure source for static pressure provided on the table. An oil passage is opened on each surface facing the nut to form an opposed planar static pressure bearing, and an oil passage branching from the oil passage is opened on each surface facing the nut to form an oil feed port. , a non-contact joint is formed by opening an oil receiving port at a position corresponding to the oil feed port of the nut, and an oil passage communicating with each non-contact joint is opened in the static pressure guide surface of the nut and the main body. Features a static pressure slide table feeding device. 2. The feeding device for a static pressure slide table according to claim 1, wherein a pair of said opposed planar static pressure bearings are provided at symmetrical positions with the non-contact joint in between on each opposing surface. 3. The feeding device for a static pressure slide table according to claim 1, wherein the cross sections of each of the oil feed ports have the same shape and the same area. 4. The feeding device for a static pressure slide table according to claim 1 or 3, wherein each oil feed port has an oil reservoir having the same area.