JPH05104369A - Rotational guiding surface of moving board of working machine and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a rotational guiding surface of a moving board of a working machine of improved abrasion-proof by forming a member having a welded contact part on which a main body metal that forms the moving board and the rotational guiding surface are welded together in an integrated manner, out of steel. CONSTITUTION:A member 8, which has a rotational guiding surface 7 for guiding on a guiding surface during moving, and which also has a welded contact part 9 on which a main body metal that forms the moving board 1 and the rotational guiding surface 8 in an integrated manner, is provided on the moving board 1 moving on the guiding surface while loaded with a worked material, tool and so on. The material of the main body 2 is made of cast iron, and the member 8 is made of steel. The member 8 is preliminarily imbedded in a casting mold, and the welded contact part 9 is formed by injecting the dissolved main body metal into the casting mold and is thus coagulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling guide surface for a moving base of a machine tool and a method for manufacturing the rolling guide surface. More specifically, the present invention relates to a rolling surface of a moving table of a machine tool such as a pallet, a feed table, a table, and a saddle that moves on a guide surface formed on a bed, a column or the like of the machine tool, and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a table which moves on a fixed guide surface formed on a bed, a column or the like of a machine tool, there are movable tables such as a pallet, a feed table, a table and a saddle. These movable bases have a guide surface (hereinafter referred to as a rolling guide surface) for always sliding or rolling on a fixed guide surface.

In particular, since the pallet is moved while being rolled or slid by the cam followers on the conveying surface other than the machine tool main body, the guide surface is not sufficiently lubricated and often wears. If this wear exceeds a certain limit, an error will occur and the conveyance operation will be hindered. This pallet is often made of cast iron. Detailed observation of the wear of this guide surface revealed that it was caused by both fatigue and slippage.

That is, the rolling guide surface has a pitching (p
itting, or flaking
It is considered that fatigue wear caused by surface fatigue called g) occurs. Regarding the cause of fatigue wear, it is considered that the contact pressure by the member that contacts the rolling guide surface of the pallet, that is, the cam follower exceeds the fatigue limit of repeated compression of the material and fatigue fracture occurs.

The mechanism of fatigue wear is that at the location of the maximum subsurface shear stress imparted by a surface or Hertzian contact, cracking occurs when the shear stress exceeds the fatigue limit of the cyclic pressure of the material. It is a popular theory. When the material is cast iron, the holes after the graphite has fallen from the surface become stress concentration nuclei (especially because the FC agent has flaky graphite, the internal notch effect is large, and stress concentration is likely to occur), resulting in fatigue. Therefore, it is considered that cracks are generated even with low stress and the peeling proceeds to a deep position along the graphite.

Further, it is presumed that sliding wear occurs due to a defective rotation of the cam follower. This is because slippage is added due to defective rotation of the cam follower, so that the convex portion of the rolling surface is mechanically broken and wear progresses. Furthermore, it is considered that the lapping action of cutting chips and abrasion powder is added to this. Further, there is a problem that the rolling guide surface has a low hardness, that is, it is easily worn due to cast iron. Therefore, a method of quenching the rolling guide surface is also adopted.

[0007]

However, cast iron, which is a brittle material for forming pallets, particularly gray cast iron, is disadvantageous to fatigue wear. Further, there are many factors that affect the wear amount such as the shape of graphite and the pearlite ratio, which is disadvantageous. The present invention has been invented in the above technical background, and achieves the following objects.

An object of the present invention is to provide a rolling guide surface of a movable table of a machine tool and a method of manufacturing the rolling guide surface, in which a steel material having fatigue resistance higher than that of cast iron is used for the rolling guide surface to improve wear resistance. To do.

Another object of the present invention is to provide a rolling guide surface for a movable base of a machine tool having improved rigidity and a method for manufacturing the rolling guide surface.

[0010]

Means and Actions for Solving the Problems To solve the problems, the following means are adopted.

[0011] A movable table for mounting a workpiece, a tool, etc., on the guide surface, and a rolling guide surface provided on the movable table for guiding on the guide surface during movement, and It is a rolling guide surface of a moving base of a machine tool, which is composed of a main body metal which constitutes the moving base and a member having a welded joint portion in which the rolling guide surface is integrally welded.

Further, it is preferable that the material of the main body is cast iron and the member is made of steel.

In this manufacturing method, the member is embedded in a mold in advance, and the body metal melted in the mold is poured and solidified to form the welded joint.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a front view of a pallet for a machining center. FIG. 2 is a plan view of FIG. The pallet 1 is used for processing a workpiece and conveying it. The pallet body 2 is a member having a substantially quadrangular thickness and is made of gray cast iron (FC25). Pallet top 3
Is a plane for placing and fixing the workpiece.

Workpiece tightening screw holes 4 are formed in the pallet upper surface 3 at equal intervals. The workpiece fastening screw hole 4 is for screwing a bolt for workpiece clamping. Edge locators 5 and 5 for positioning a workpiece or a mounting jig are integrally provided on two outer peripheral sides of the pallet upper surface 3. A T-shaped groove 6 is formed on the lower surface of the pallet 1. One surface defining the groove 6 is used as the rolling guide surface 7. A rotating cam follower (not shown) comes into contact with the rolling guide surface 7 and rolls (in the direction perpendicular to the paper surface of FIG. 1) to convey the pallet 1.

A member forming the rolling guide surface 7 is a plate member 8 having a rectangular parallelepiped cross section, and in this embodiment, S45C is joined and welded. In this welding, the plate material 8 is embedded in the mold along the pallet body 2 in advance, and the molten casting metal, FC25 in this embodiment, is poured into the mold.

By the heat of fusion of the molten cast metal, only the portion close to the surface of the steel plate member 8, that is, the surface in contact with the molten cast iron is melted, and the components of the cast iron metal and the steel are melted together. When this is cooled, the cast iron metal and the steel are firmly welded to each other to form the welded joint 9. Note that this method of fusion welding integrally is disclosed in, for example, Japanese Patent Laid-Open No. 1-91951 and is a known technique.

After the plate material 8 is welded and joined, it is hardened by a well-known method and then polished and processed to a required accuracy. A pallet tightening surface 10 is formed in the T groove 6 in parallel with the rolling guide surface 7. This is the tightening surface with which the clamped member comes into contact when the pallet 1 is clamped on the table of the machining center.

A pallet mounting reference surface 11 is formed on the lower surface of the pallet 1. This is a reference surface in the thickness direction when the pallet 1 is clamped on the table of the machining center. The pallet mounting reference surface 11 is provided with a pallet positioning reference hole 12. This is for determining the position of the pallet 1 in the plane direction.

[Other Embodiments] In the above embodiment, the rolling guide surface of the pallet 1 is applied, but the present invention is not limited to this. It may be applied to another moving table as long as it has a rolling guide surface such as a feed table, a table and a saddle of a machine tool. Further, in the above-mentioned embodiment, the casting metal and the steel material are integrally formed by casting, but the welding means is not limited to this.

The welding means may be joined by a welding method. Various methods for joining dissimilar metals by welding are known. For example, welding may be performed by gas welding, arc welding or the like, diffusion method, explosion welding, pressure welding such as friction welding, or brazing such as hard brazing. Further, the cast iron-based material includes types such as steel cast iron, pearlite cast iron, and meehanite cast iron, which are generally used as frame materials for machine tools.

Further, it is apparent from the above-mentioned object of the present invention that the steel material includes all those which can achieve the above object such as standardized structural carbon steel and special alloys.

Further, the fusion-bonded portion of the steel material is T-shaped as in the embodiment.
The surface is not limited to the inside of the groove, and may be another surface such as an outer surface or a side surface.

[0024]

As described above in detail, according to the present invention, since the steel material constituting the rolling guide surface of the moving base of the machine tool is integrally welded to the cast metal of the main body, the durability of the rolling guide surface is improved. It also improved the rigidity of the moving base.

[Brief description of drawings]

FIG. 1 is a front view of a pallet.

FIG. 2 is a plan view of FIG.

[Explanation of symbols]

1 ... pallet, 2 ... pallet body, 3 ... pallet top surface,
4 ... Screw holes for workpiece tightening, 5 ... Edge locator, 7 ... Rolling guide surface, 8 ... Plate material, 9 ... Welded joint

Claims (3)

[Claims] 1. A moving table having a work, a tool, etc. mounted thereon and moving on the guide surface; and a rolling guide surface provided on the moving table for guiding the moving surface on the guide surface. A rolling guide surface for a movable table of a machine tool, comprising a main body metal forming the movable table and a member having a welded joint in which the rolling guide surface is integrally welded. 2. The rolling guide surface of a moving base of a machine tool according to claim 1, wherein the material of the main body is cast iron and the member is steel. 3. The machine tool according to claim 1, wherein the member is embedded in a mold in advance, and the main body metal melted in the mold is poured and solidified to form the welded joint. Manufacturing method of rolling guide surface of moving table.