GB2053041A

GB2053041A - Tool for bevelling edges of openings

Info

Publication number: GB2053041A
Application number: GB8016300A
Authority: GB
Original assignee: Skoda op; Skoda np
Current assignee: Skoda op; Skoda np
Priority date: 1979-05-21
Filing date: 1980-05-16
Publication date: 1981-02-04
Also published as: CS206855B1; GB2053041B; FR2457143B3; DE3015344A1; DE3015344C2; FR2457143A3; CH645827A5

Abstract

A tool for the bevelling of the edges on both sides of an opening in a workpiece on a single setting of the tool and workpiece. The tool comprises a rod (1) having one end adapted to be fixed for rotation by the spindle (3) of the machine tool, and a cutting tip (2) including two oppositely inclined cutting edges and fixed to the rod at the opposite end of the rod. The rod is elastic in a plane containing the cutting edges of the cutting tip. The opposite end has a head having guiding surfaces for guiding the rod in the opening before bevelling the near workpiece bore end, between the bevelling operations at either end when the rod deflects to pass the tip through the bore and after the bevelling of the far workpiece bore end. <IMAGE>

Description

SPECIFICATION Tool for bevelling edges of openings The invention relates to a tool for bevelling edges of openings by means of a machine tool, comprising a rod with a cutting tip arranged on the end of the spindle.

A number of known tools is used for bevelling edges of openings using machine tools, which however are not suitable for working of the part of the opening on the side remote from the spindle of the machine tool. With machine tools with a tool head enabling a lateral deviation of the tool, a similar tool is used for working the remote side of the opening as for making an internal recess. The deburring is however mostly performed manually as a complementary operation, usually on another working site.

Tools are also known designed for deburring or for bevelling edges of an opening on the side remote from the spindle of the machine tool. These tools comprise a holder arranged in the axis of the spindle, with a radially tiltable knife in a recess on the end of the holder. A control means is provided, transmitting an axial movement from a slidable sleeve to the tiltable knife, the position of which it controls. It is generally a rather delicate arrangement, the control means for tilting the radial knife is frequently seized and the life time of the tool is reduced.

It is an object of this invention to provide a tool of this knid, which could be used for bevelling of both sides of an opening by a single operation. The tool for bevelling edges of openings according to this invention is designed for a machine tool, with a rod with a cutting tip fixed on its end, arranged on the spindle of the machine tool. The rod is elastic in a plane, determined by the spindle axis and by the edge of the cutting tip. It is advantageous for bevelling edges of large openings, if the rod is arranged on the spindle eccentrically.

By fixing the cutting tip on a rod which is elastic in a plane determined by the spindle axis and the edge of the cutting tip, a universal tool for a wide range of diameters of openings has been obtained, the working part of which is easily exchangeable and by means of which also the remote side of the opening can be worked.

One embodiment of a tool according to this invention is shown, by way of example, in the accompanying diagrammatic drawing, in which: Figure 1 shows the tool when bevelling edges on the near side of the opening, Figure 2 shows the passage of the working part of the tool through the opening due to an elastic deviation of the rod, and Figure 3 shows the working of the remote side of the opening.

The tool according to the invention for the bevelling of the edges of an opening in a workpiece is intended to be used with a machine tool. In the illustrated embodiment the the tool comprises an elastic rod 1 the rear end of which is adapted to be firmly held, in operation, in a holder, which in turn is held in a spindle 3 of a machine tool for rotation therewith.

The front end of the rod 1 is provided with a head in which is exchangeably mounted a cutting tip 2. The cutting tip 2 is situated in a slit passing transversely through the head and is held in the slit e.g. by a bolt. The head has a a front guiding and bearing surface in front of the cutting tip 2, and a rear guiding and bearing surface behind it. The front end of the head has converging surfaces.

The cutting tip 2 has a pair of working cutting edges oppositely inclined with respect to the guiding and bearing surfaces at a desired angle, i.e. the angle of bevelling, which is usually 45". A blunt portion extends between the two cutting edges, said portion being substantially parallel to the said guiding and bearing surfaces. The working cutting edges extend transversely to the rod 1 which is elastically deformable in a plane containing said cutting edges.

In the illustrated embodiment the cutting tip 2 has two pairs of cutting edges: a pair of working cutting edges (below the head) and a pair of spare cutting edges (above the head).

The two pairs are preferably in all respects identical, so that when the working cutting edges become blunt, the whole rod 2 is turned through 1 80D or the tip 2 is removed and fixed in the head upside down, so that the spare cutting edges become working cut ting edges. The two pairs of cutting edges could, of course, be different and used, re spectively, for different bevelling. With a mi nor modification of the head shown a cutting tip could be used which has more than two pairs of cutting edges.

For operation the tool is fixed in the holder in such a way that its axis is radially displaced from the axis of the spindle, so that when the spindle 3 rotates the rod 1 revolves about the axis of the spindle. (This is not always neces sary.) The rod is so fixed in the holder that the working cutting edges are contained in a plane containing the axis of the spindle 3. The rod 1 is elastically deformable in this plane.

In operation the workpiece is traversed to the tool (this movement may be relative) and the tool is rotated. First the converging sur faces enter the hole and then the front guid ing bearing surface (Fig. 1), and on further traversing the front edge of the opening is bevelled by the front cutting edge of the pair of working cutting edges. The head then enters the opening (due to the elasticity of the rod 2) and is supported and guided therein by the blunt portion between the cutting edges (Fig. 2). On further traversing the rear edge of the opening is bevelled by the rear cutting edge of the pair of working cutting edges (due to the elastic rod 2 trying to reassert its initial position), until the rear guiding and bevelling surface bears on the inside of the opening (Fig. 3). For simplicity the bevelling was not indicated in the drawings.

Claims

1. A tool for the bevelling of the edges on both sides of an opening in a workpiece on a single setting of the tool and workpiece, the tool comprising a rod having one end adapted to be fixed for rotation by the spindle of the machine tool, and a cutting tip including two oppositely inclined cutting edges and fixed to the rod at the opposite end of the rod, the rod being elastic in a plane containing the cutting edges of the cutting tip.

2. A tool according to Claim 1 wherein the cutting edges extend in a plane containing the axis of the rod.

3. A tool according to Claim 1 or 2 wherein said opposite end includes a head having guiding surfaces for guiding the rod in the opening during bevelling thereof.

4. A tool for the bevelling of the edges on both sides of an opening in a workpiece on a single setting of the tool and workpiece, constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.

5. A machine tool having a rotatable spindle and including a tool according to any one of Claims 1 to 4 attached to the spindle for rotation therein, wherein the tool is so situated that the plane in which it is elastic includes the axis of the spindle.

6. A machine tool according to Claim 5 wherein the attachment of the tool is such that the rod is situated eccentrically relative to the spindle.

7. A machine tool according to Claim 5 or 6 constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings.

8. A method of bevelling the edges on both sides of an opening in a workpiece on a single setting of the tool, and a workpiece using a tool according to any one of Claims 1 to 4, or a machine tool according to any one of Claims 5 to 7.

9. An article having an opening the edges of which were bevelled by a tool according to any one of Claims 1 to 4, or were bevelled on a machine tool according to any one of Claims 5 to 7, or were bevelled by a method according to Claim 8.