JPH0641762Y2 - Workpiece holding device for automatic lathe - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for holding a long work piece when processing a long work piece in an automatic lathe machine. More specifically, the present invention relates to a guide bearing whose inner diameter can be adjusted. Of the guide bearing sleeve installed inside is fixed to a stationary body which is a stationary portion of the main body of the automatic lathe, and holds the guide bearing and the end of the work piece at a proper distance from the guide bearing. In a workpiece holding device of an automatic lathe for holding a workpiece by a moving spindle and rotating the workpiece, a suitable position near an end of the guide bearing inside the guide bearing sleeve on the moving spindle side. A hollow main body is attached to the end of the main body by an appropriate means, and a bearing having an inner diameter capable of inserting a workpiece is attached to the end surface of the main body on the moving main shaft side so that the bearing can slide in the entire radial direction by an appropriate size. Along with mounting, a split groove that connects the inner and outer diameters is formed in the proper place on the bearing. By making it possible to adjust the inner diameter of the workpiece, it is possible to securely hold a long workpiece even with a small clearance. Therefore, it is possible to prevent the processing accuracy from deteriorating due to the fluctuation of the workpiece. An object is to provide a work holding device for an automatic lathe machine.

Conventionally, for processing long products, as shown in Fig. 1, there is a guide bearing that has multiple slits and the inside diameter can be adjusted freely.
A guide bearing sleeve 14 provided inside 13 is attached to a fixed body 15 which is a stationary portion of the main body of the automatic lathe, and the guide bearing 13 and the guide bearing 13 are separated from each other by an appropriate distance. There is used a work holding device for an automatic lathe which holds a work by means of a moving main shaft 18 which holds the end of the work and rotates the work.

When processing a long product on such an automatic lathe machine, the material was relatively soft, so there were no processing problems during cutting or due to cutting debris, but these days, such as stainless steel and chrome molybdenum steel, etc. The machining of hard steel is increasing, and when cutting such hard steel, the super-hard alloy portion 11 of the guide bearing 13 as shown in FIG. 1 is burned out.
When processing hard steel as described above under the same conditions as soft steel, in order to prevent burning damage, the super hard alloy portion 11 of the guide bearing 13
And the workpiece 20 must be enlarged to process the
As a result, there is a drawback that the processing accuracy is low.

In addition, from the past, high-precision precision cutting has been the main task of the headstock moving type automatic lathe, and in order to process hard steel with high accuracy, the cutting feed must be reduced by 30 to 50% from soft steel. It was impossible to process, and it was necessary to use cutting oil for stainless steel, which is more than twice as expensive as ordinary cutting oil, as cooling lubricating oil for preventing burnout.

In addition, the rotation guide bearing is also used to prevent the burnout as described above, but the rotation guide bearing has a high wear due to the wear of the steel balls caused by the bearing gap and cutting pressure and the deflection of the rotation guide bearing. Precision processing was impossible.

Further, since the cutting feed is slow, the cutting waste becomes long like wire and becomes entangled with the workpiece or cutting blade during cutting, causing troubles and causing a great obstacle during the machining process.

In addition, the applicant of the present invention, after many years of repeated research,
It has been discovered that the cause of burnout of the superhard alloy portion 11 of the guide bearing 13 is due to the deflection and cutting runout of the work piece 20 that occurs during cutting as shown by the imaginary line in FIG.

The present invention was devised as a result of repeated trial and error in order to eliminate the above-mentioned drawbacks. One embodiment of the present invention will be described in detail below with reference to the drawings, as shown in FIGS. (A) A screw 1A is engraved on the inner peripheral wall of the main body 1 in the shape of a hollow cylinder, and the screw 1A is to be attached near the end of the guide shaft bearing on the moving spindle side. A polygonal tightening cutout 1B is provided on the outer periphery of the front part, and a plurality of female screw parts for tightening bearings 3 and 3 are provided on the rear flat part, that is, the end face on the side of the moving spindle 18 described later.
(B) The bearing 2 has a hollow cylindrical shape, and a plurality of bearing tightening holes 4 are provided by inserting it from one end surface, and a hollow cylindrical superhard alloy 11 is welded to the inner circumference by welding. A portion made of the superhard alloy 11 or the like is formed by polishing and lapping the inner circumference according to the diameter of the workpiece, and a plurality of split grooves 5 are provided in the longitudinal direction of the bearing 2 to form the split grooves 5. Is provided with an inner circumference adjusting female screw portion 6 for making the inner diameter dimension adjustable by varying the dimension of the slit groove so that the inner and outer diameters communicate with each other. Bearing 2 to prevent
On the rear end surface of the main body 1, that is, on the plane portion on the moving spindle side,
It is slidably loosely fitted to form a workpiece holding portion.

(In the adjusting screw female screw portion 6 of the bearing 2, by inserting the adjusting screw 7 the tip of the adjusting screw 7 abuts against the surface portion on the other side of the dividing groove 5 so that the dividing groove dimension can be expanded and the diameter can be increased. , Fine adjustment of the inner circumference and loosening the adjusting screw 7 to close the inner circumference when the superhard alloy 11 is worn for a long time and wears, and repolishing and lapping the 11 part of the superhard alloy for use.) (C) Also, In order to allow the bearing 2 to be slidably fitted therein, the bearing tightening hole 4 is made larger than the outer diameter of the bearing pressing screw 8 or is formed into an elongated hole shape in the sliding direction. The bearing tightening screw portion 3 is provided in the slit 5 of the bearing 2 in a number larger than the number of the bearing tightening holes 4 so that the lubrication tube 10 can be installed at a fixed position. (E) The portion where the bearing 2 is located Insert the bearing holding screw 8 into the bearing tightening hole 4 at right angles to , Around the moving spindle side end portion of the guide bearing which is screwed into the bearing tightening screw portion 3 of the main body 1 and thus installed in the guide bearing sleeve attached to the fixed main body of the headstock moving type automatic lathe. Here, as shown in the figure, it is screwed onto the male screw portion of the guide bearing 13. (f) The lubrication passage 9 is installed near the bearing 2 via the lubrication tube 10 (like the cutting oil nozzle 19), It is connected to a forced cutting oil lubrication system (not shown).

Since the present invention has the structure as described above, when using it, (a) the fixed main body 15 which is a non-movable part of the automatic lathe machine is used.
Fit the guide bearing sleeve 14 in it and tighten it in place with the guide bearing sleeve pressing screw 16. (b) Insert the guide bearing 13 into the guide bearing sleeve 14 and screw in the adjusting tightening ring nut 12. Then, the superhard alloy portion 11 of the guide bearing 13 is adjusted to the diameter of the workpiece 20. (Up to this point, it is the same as the conventional mounting method.) (C) Next, the main body 1 is screwed into the threaded portion of the guide bearing 13 and tightened together with the adjusting tightening ring nut 12, and (D) the inner circumference of the bearing 2 is adjusted. The adjusting screw 7 is screwed into the screw portion 6 to match the diameter of the workpiece 20, the bearing holding screw 8 is inserted into the bearing tightening hole 4, and the bearing tightening screw portion 3 of the main body 1 is inserted.
It is screwed in and temporarily fixed.

(E) Insert the workpiece 20 from the rear of the moving spindle 18 to the bearing 2, which is a holding device, the main body 1, and the guide bearing 13,
Is tightened with a collet chuck in the moving spindle 18, (f) the bearing 2 matching the diameter of the workpiece 20 is tightened with the bearing pressing screw 8, and (g) the cutting tool 17 is attached, and the moving spindle 18 is fixed. At the same time as rotating the cutting oil,
From the guide bearing 13 and the rear lubrication passage 9 to inject it into the holding device and pull a handle (not shown) for automatic cutting feed.
It is for cutting a work piece.

When the machining is performed as described above, the bearing 2 of the holding device holds the workpiece even if the cutting feed rate of the long workpiece is increased, so that the deflection of the workpiece 20 as in the conventional example shown in FIG. ,
Super hard alloy of the guide bearing 13 even if the cutting run-out is eliminated and the load that the cutting feed rate becomes 6 times or more of the conventional value by the forced lubrication from the lubrication passage 9 will damage the cutting edge. The part 11 does not burn out, and therefore the cutting feed amount can be increased, which shortens the processing time,
By eliminating the cutting runout, the life of the cutting tool is more than double that of conventional products.

Also, conventionally, the gap between the super hard alloy part 11 of the guide bearing 13 and the workpiece is adjusted from 3/100 mm to 1/100 mm in diameter, but when this device is installed it becomes 3/1000 mm Even if it is adjusted in micron units, it will not burn out, so processing precision is also excellent, expensive cutting oil is not required, and wear of the super hard alloy part 11 of the guide bearing 13 and the collet chuck in the moving main spindle 18 By installing the holding device, the number of cutting chips is drastically reduced compared to the conventional one, and the cutting scraps become small spiral scraps or ring-shaped cut scraps and the troubles caused by cutting are completely eliminated.

In this way, various effects are achieved by not only holding the work piece in the vicinity of the cutting blade as in the conventional case but also holding the work piece in the vicinity of the end portion on the moving spindle side of the guide bearing.

As a result of various experiments as described above, an unexpected phenomenon was discovered, and as a result of further research, a device with great practical effects capable of attaining the desired purpose was completed.

In this device, the expensive guide bearing 13 used conventionally can be used as it is without changing its shape.

[Brief description of drawings]

The drawing shows an embodiment of the present invention, and FIG.
Sectional view showing a fixed guide bearing part of a conventional automatic lathe machine. Fig. 2 is a sectional view showing a state where the holding device of the present invention is attached to the fixed guide bearing part of the automatic lathe machine. Fig. 3 is a fixed guide bearing part. FIG. 3 is an exploded perspective view of each part of the holding device of the present invention mounted on the section. In the drawing, 1 is a main body, 2 is a bearing 3, 3 is a bearing tightening screw part, 4 is a bearing tightening hole, 5 is a bearing split groove, 6 is a bearing inner peripheral adjusting screw part, 7 is a bearing adjusting screw, 8 is a bearing holding screw, and 9 is a water injection passage. .

Claims (1)

[Scope of utility model registration request] 1. A guide bearing sleeve in which a guide bearing having an adjustable inner diameter is installed is attached to a fixed body which is a stationary portion of an automatic lathe machine body, and the guide bearing and the guide bearing are provided. In a workpiece holding device of an automatic lathe for holding a workpiece and rotating the workpiece by a moving spindle that holds an end portion of the workpiece at an appropriate distance, the guide bearing sleeve is internally provided. A hollow main body (1) is attached to an appropriate position near the end of the main shaft (1) on the side of the moving main shaft by means of an appropriate means. A bearing (2) having an inner diameter that allows the workpiece to be inserted by expanding the diameter with substantially the same size is attached so that the bearing can be slid over the entire area in the radial direction by an appropriate dimension, and at the proper place of the bearing (2). Has a split groove that communicates the inner and outer diameters so that the inner diameter can be adjusted. And a workpiece holding device for an automatic lathe.