JPS61168436A - Slidable contact member of machine tool - Google Patents

Abstract

PURPOSE:To reduce contact area of slidable contact face and to supply lubricant equally and remove surplus lubricant by inscribing fine concave grooves on a slidable contact face of a sliding member. CONSTITUTION:The bed 4 and the carriage 5 of a lathe are formed by fine ceramics and plural fine concave grooves 6 are inscribed in parallel on slidable faces 4a, 4b and 4c of the bed 4 among slidable contact faces of members, at an inclination of 5 deg., for example, to the sliding direction of the carriage 5. Then, even if slidable contact faces 4a, 4b, 4c, 5a, 5b, 5c are finished to mirror face, sticking resistance value is reduced and smooth sliding becomes possible. The fine concave grooves 6 are provided on the entire areas of slidable contact faces 4a, 4b and 4c, and lubricant can be supplied equally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sliding contact member for a machine tool, and particularly to a ceramic sliding member for a sliding portion of an ultra-precision machine tool.

[Conventional technology]

In ultra-precision machine tools such as ultra-precision lathes, sliding guide parts such as beds have a small expansion coefficient, small thermal change, and are hard with a small coefficient of friction and wear resistance, which are necessary conditions for ultra-precision machine tools. There is a growing trend to use fine ceramics as a material that satisfies the requirements of not changing over time and adhering to a flat surface.

[Problem that the invention seeks to solve]

As mentioned above, when the sliding contact members of the sliding parts of the bed, carriage, etc. of an ultra-precision lathe are made of fine ceramic, for example, the sliding surfaces can be finished to an extremely precise mirror surface. However, when this sliding member slides with its mirror-finished sliding surfaces facing each other, if a lubricating oil film or vapor film is formed on the sliding surfaces, a phenomenon of sticking of both sliding surfaces occurs. . As a result, when moving under so-called NC control, for example, the carriage sticks to the bed and does not move, the driving force is strong, it suddenly slides, goes too far, goes backwards, and then moves forward again, accurately and quickly. There is a problem that accurate positioning and minute movement adjustment are difficult.

[Means for solving problems]

The present invention solves the above-mentioned problems and makes it possible to obtain accurate and smooth moving sliding contact using a ceramic material that eliminates the need to float the upper sliding contact member using hydraulic or air pressure as in the case of metal sliding contact members. The purpose is to provide a sliding contact member, and as a specific means, in the movable part of a machine tool, the sliding contact member that forms a pair as a fixed member and a sliding member is formed of fine ceramic, and each of them is This sliding member for a machine tool is characterized in that at least one of the sliding surfaces is provided with an appropriate number of narrow grooves parallel to or inclined to the sliding direction.

[For production]

- According to the present invention having the above configuration, for example, the lathe bed (fixed member) and carriage (sliding member) are formed of fine ceramic, and at least one of the sliding surfaces of both members is formed of fine ceramic. By carving a plurality of thin concave grooves in parallel on the sliding surface of a bed (for example, a bed) at an inclination of, for example, 5 degrees with respect to the sliding direction of the carriage, the sliding surface can be finished with a mirror finish. Even if the adhesive is attached, the sticking resistance value can be reduced and smooth sliding can be achieved. Furthermore, the narrow grooves extend over the entire surface of the sliding surface, allowing lubricating oil to be supplied evenly.

In addition, if a narrow groove is carved in the same direction as the sliding direction, the sliding resistance will be reduced, but there is a risk of wear loss and partial loss of lubricating oil due to long-term use. By tilting as in the present invention, these are eliminated.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on the drawings in an embodiment implemented in an ultra-precision lathe. FIG. 1 is a front view of an ultra-precision lathe embodying the present invention.

The movable parts of the lathe 1 include a spindle 2, a headstock 3, and a bed 4.
and a carriage 5, among which a headstock 3 and a bed 4.
is a fixed member, and the main shaft 2 and the carriage 5 are sliding members, and when the sliding parts of these fixed members and sliding members are brought into opposing sliding contact, ζ forms a pair of sliding contacts. The member is made of fine ceramic. Figure 2 shows a bed 4 which is a sliding contact member.
3 is a perspective view of the sliding surface of the bed 4, and FIG. 4 is a plan view of the sliding surface of the carriage 5.

In FIG. 2, the bed 4 has a flat sliding surface 4a on the right side of the drawing, and sloped sliding surfaces 4b and 4C on the left side.
A carriage 5 is arranged so that it can come into sliding contact with each of the sliding surfaces 4a, 4b, and 4c.
In the figure, there are a flat sliding contact surface 5a and slope sliding contact surfaces 5b and 5c on the bottom surface.
is formed.

As shown in FIGS. 3 and 4, each sliding surface 4a, 4b, 4c of the bed 4 has a plurality of narrow grooves 6, 6, . It is carved at an inclination angle of about 12 degrees with respect to the sliding direction (arrow A). Furthermore, communicating narrow grooves 7, 7, etc. are cut in a cross-shape with respect to these parallel narrow grooves 6, at opposite inclination angles.

Also, each sliding surface 5a, 5b, 5c of the carriage 5 is provided with a plurality of thin grooves 6, 6' lined at an angle of about 12 degrees with respect to the sliding direction (arrow B). , a narrow groove 6' on the flat sliding surface 5a
is formed in a zigzag shape.

The bed 4 and the carriage 5 as sliding contact members are molded with fine ceramic mink, dried, reshaped and fired, and the sliding contact surfaces 4a, 4b, 4c, 5a, 5b, 5c are mirror-finished. conduct. After that, the fine grooves 6, 6 are formed by diamond grinding.
', 7... are engraved.

The sliding contact members 4, 5 having the above configuration are connected to each sliding contact surface 4a, 4b, 4c.
, 5a, 5b, and 5c are disposed in a predetermined opposing manner and used as the bed 4 and carriage 5 of the ultra-precision lathe 1, the sliding surface is a contact between ceramic and ceramic rigid bodies, There is no change in the contact between the sliding surfaces due to changes in external pressure, and the low resistance value of the mirror finish allows for accurate and smooth movement. ...
The presence of this reduces the area of the sliding surface and allows excess lubricating oil to be removed from the sliding surface. In addition, the oil film on the sliding surface can be evened out and the sliding resistance can be reduced. In particular, since the narrow grooves 6, 6', and 7 are inclined with respect to the sliding direction, even sliding contact can be maintained over the entire surface, and lubricating oil is evenly supplied to the sliding surface, resulting in no oil-drained parts. do not have.

The size of the narrow grooves 6, 6', and 7 depends on the load, shape, etc.
Therefore, make changes as appropriate. The total area of the narrow grooves on the sliding surface may be 50% or less of the area of the sliding surface. 50%
This is because when exceeding , it is sufficient to reduce the area of the sliding surface itself. Regarding the depth of the fine grooves, if the parallel width of the fine grooves, the number of parallel grooves, etc. are large, a shallow groove or a narrow groove in the micron range is sufficient.

Further, the oil reservoir may be formed by making the desired region deeper or wider.

If the narrow grooves are made parallel to the sliding direction, the resistance value will decrease, but oil will flow only in the sliding direction and will not penetrate in the lateral direction, creating areas where oil runs out and creating wear grooves, so this is preferable. do not have.

FIG. 5 shows a cross section of the second embodiment. This example is lathe 1
This was carried out on the sliding contact area between the headstock 3 and the spindle 2. The bearing portion 3a of the headstock 3 as a sliding member and the main shaft 2 are made of fine ceramic.

The sliding surfaces 2a and 2b of the main shaft 2 are spirally carved with narrow grooves 8°8. That is, the narrow grooves 8 are formed in an inclined manner with respect to the rotational and sliding direction of the main shaft 2. The main shaft 2 is molded in a ceramic mold, reshaped after firing, and has a sliding contact surface 2a.
After mirror finishing, fine grooves 8, 8 are carved by diamond grinding.

The width, depth, parallel spacing, etc. of the narrow grooves 8 are changed as appropriate depending on the size of the main shaft, the size of the sliding surface, etc.

FIG. 6 shows a cross section of the bearing portion 3a. A narrow groove 9 is spirally carved on the inner circumferential surface of the bearing portion 3a, that is, the sliding contact surface 3b, so as to be inclined with respect to the sliding rotation direction of the main shaft 2.

When the sliding member 3a + 2, which is a pair of the bearing part 3a as a fixed member and the main shaft 2 as a sliding member having the above configuration, is incorporated into the lathe 1 in a normal manner and used, the sliding surface 2a,
The sliding resistance of 3b is reduced, lubricating oil is evenly supplied to the sliding surface, and accurate and smooth sliding can be achieved.

The present invention is not limited to the above configuration.

In FIG. 1, the carriage 5 is used as a fixed member, and the tool post 9 is used as a sliding member, and narrow grooves can be similarly carved on each sliding surface thereof. Furthermore, the narrow grooves may not be straight lines but may be curved lines.

〔effect〕

As described above, the present invention has narrow grooves carved on the sliding surface of the sliding member, so that (i) the contact area of the sliding surface can be reduced, and lubricating oil can be evenly supplied; The surplus can be eliminated.

Since the sliding contact surface has a narrow groove formed at an angle with respect to the sliding direction, the sliding contact surface in the sliding direction is not continuous but is divided into several positions, which reduces the sticking force and makes it difficult to stick. This has the effect of eliminating malfunctions caused by sticking phenomena.

[Brief explanation of the drawing]

The drawings relate to the present invention; FIG. 1 is a front view of an ultra-precision lathe, FIG. 2 is a cross-sectional view of essential parts of the bed and carriage as sliding members, FIG. 3 is a perspective view of the sliding surface of the bed, and FIG. 4 is a plan view of the slide contact surface of the carriage, FIG. 5 is a front view of the main part of the headstock as a sliding member and the main shaft, and FIG. 6 is a top view of the bearing portion in FIG. 5. 1...Ultra precision lathe 2...Main shafts 2a and 2b as sliding members (fixed members)
... Sliding surface 3 ... Headstock 3a as a sliding member (sliding member)...
・Bearing part 3b...Sliding surface 4...Sliding member (
Beds 4a, 4b, 4cm as fixed members) sliding surfaces 5... carriages 5a, 5 as sliding members (sliding members)
b, 5cm sliding contact surface 6.6', 7.8.9... Thin groove A, B... Sliding direction

Claims (1)

[Claims] In the movable part of a machine tool, the sliding contact member that forms a pair between the fixed member and the sliding member is made of fine ceramic, and at least one of the sliding contact surfaces is made of a material that is parallel or inclined to the sliding direction. A sliding contact member for a machine tool characterized by having an appropriate number of narrow grooves carved therein.