JPH10249616A - Boring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the production of burrs or flashes caused by a chamfering process performed later on when cutting the inner diameter of a hole and chamfering the one end opening peripheral part of the hole are carried out by one process. SOLUTION: A chamfering tip 6 is mounted to a place at the tip end side beyond an inner diameter cutting tip 5, and it is so set up that the rotating locus of the tip 6 becomes smaller than the hole diameter before processed. A chamfering part P is formed by revolving a tool holder 3 over a circumference coaxial with the hole H while the tool holder is being rotated by itself. After that, let the axial center of the hole coincide with the axial center of the tool holder 3 so as to allow cutting feed in the axial direction to be given, and inner diameter cutting is thereby carried out by the tip 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boring method, which is one of cutting machining methods, and more particularly to a method of cutting an inner diameter of a hole using a multi-blade type tool holder and chamfering an opening edge of one end of the hole. In a single step.

[0002]

2. Description of the Related Art When a given workpiece is subjected to an inner diameter cutting process of a hole and a chamfering process of an edge of one end opening of the hole,
2. Description of the Related Art In order to reduce the number of processing steps and eliminate waste of tool replacement time, conventionally, both processings are performed in a single step using a multi-blade type tool holder (boring bar or boring tool).

[0003]

In this case, since the machining diameter of the chamfered portion is necessarily larger than the machining diameter of the hole, the tip of the tool holder is usually located closer to the tip side of the chamfering tip (or cutting tool). After the inner diameter cutting tip is attached, the inner diameter cutting tip reaches the inner part of the hole to be machined and after the inner diameter cutting is completed, the chamfering chip contacts the opening edge of the hole after machining and chamfers Is set to do.

[0004] Therefore, since a part of the inner peripheral surface of the hole once finished to a predetermined size is cut off obliquely again by chamfering, especially when the work is made of a material having high ductility, the hole is difficult to cut. In the inner peripheral surface of the inner peripheral surface, bulges occur as burrs or burrs at the position near the ridge line formed by the chamfered part, and as a result the internal diameter accuracy of part of the hole is impaired, so that finishing in a separate process The desired result is not preferred.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and uses a multi-blade type tool holder to perform inner diameter cutting of a hole and chamfering of an opening edge of one end of the hole in one stroke. It is an object of the present invention to provide a processing method in which a bulge is prevented from occurring at a boundary between an inner peripheral surface of a processed hole and a chamfered portion.

[0006]

According to the first aspect of the present invention, as described above, a main spindle of a machine tool having at least three orthogonal degrees of freedom of freedom is provided with an inner diameter cutting tip and a chamfering tip. A boring method in which a tool holder for boring is mounted, and the inner diameter cutting of a hole and the chamfering of one end opening edge of the hole are performed in one step. The chamfering tip is mounted at a position on the tip side of the tool holder with respect to the tip and at a position where the maximum diameter of the locus drawn by the chamfering tip along with the rotation of the tool holder is smaller than the diameter of the hole before processing. The tool holder is revolved on the concentric circle with the hole to be machined while rotating the tool holder, and chamfering is performed with the tip for chamfering.
The tool holder is characterized in that the tool holder is made to coincide with the axis of the hole to be machined, and then the cutting feed in the direction of the axis is given to perform the inner diameter cutting with the inner diameter cutting tip.

As a machine tool having at least three orthogonal degrees of freedom of sliding, a multi-degree-of-freedom machine tool such as a machining center is used.

[0008] The invention described in claim 2 is the first invention.
The invention is characterized in that the inner diameter cutting tip and the chamfering tip according to the invention described in (1) are mounted so as to be out of phase with each other by 180 ° with respect to the center axis of the tool holder.

Therefore, according to the first aspect of the present invention,
By chamfering the opening edge of one end of the hole before the inner diameter cutting, and then performing the inner diameter cutting, even if bulging or burrs occur during the chamfering, The swell will be removed by subsequent inner diameter cutting.

According to the second aspect of the present invention, by disposing the two chips with a phase shift of 180 ° from each other, chips can be removed smoothly as the processing proceeds.

[0011]

According to the first aspect of the present invention, in performing the inner diameter cutting of the hole and the chamfering of the opening edge of one end of the hole in one stroke, the chamfering is performed before the inner diameter cutting. Therefore, if you are chamfering,
Even if swelling such as occurs, it is removed by inner diameter cutting, so that the inner diameter accuracy of the hole after processing does not decrease as before, and finishing processing is unnecessary, improving processing accuracy and processing There is an effect that the number of steps can be reduced.

Further, according to the second aspect of the present invention, both the tips are moved together with respect to the center axis of the tool holder.
Since there is no obstruction on the outer side in the centrifugal direction of each chip because the chips are attached with the phases shifted by 0 °, in addition to the same effect as the invention according to claim 1, the cutting during cutting is also performed. There is an effect that refuse is smoothly removed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 8 are views showing a typical embodiment of the present invention. As shown in FIG. the diameter of the hole H with finish from D ₁ dimension D ₂ dimension by cutting and removing, shows an example of a case of forming a chamfered portion P chamfered edge of the opening of one end of the hole H.

As shown in FIGS. 4 and 5, a tool holder 3 for boring is mounted on a spindle 2 of a machine tool 1 having a degree of freedom of sliding in three orthogonal axes of X, Y, and Z. The point that the cutting and the chamfering of the edge of the one end opening of the hole H are performed in one step is the same as the conventional one.

At this time, the inner diameter cutting tip 5 and the chamfering tip 6 are mounted on the holder body 4 of the boring tool holder 3 at the same phase position. As shown in FIG. 3, the throw-away type chamfering tip 6 is also arranged so as to be located on the tip side of the tool holder 3 with respect to the indexable inside diameter cutting tip 5 provided on the outer periphery of the tool holder 3.
The chamfering tip 6 is set so as to be located closer to the axis of the tool holder 3 than the inner diameter cutting tip 5.

That is, when the tool holder 3 is driven to rotate together with the main shaft 2 (rotational motion), the maximum diameter of the rotation locus drawn by the chamfering chip 6 is the diameter D ₁ of the hole H before machining.
The position of the chamfering chip 6 is set in advance so as to be smaller.

The tool holder 3 is detachably held by a tapered shank portion 7 integral with the holder body 4 and taperedly connected to a tapered hole 8 on the main shaft 2 side. A drawbar 10 is engaged with a pull stud 9 at the rear end of the pulley 7.

At the time of cutting, the tool holder 3 is driven to rotate together with the main shaft 2 as shown in FIG. 2, while the axis of the tool holder 3 is moved from the state shown in FIG. As shown in FIG.
Only by gradually offsetting, the cutting feed in the radial direction is given, and at the same time, the tool holder 3 revolves on the concentric circle with the hole H to be machined.

The offset amount a can be given by using the degree of freedom of the machine tool 1 in the Y or Z direction shown in FIG. 4, and the revolving motion of the tool holder 3 is also the same in the Y and Z directions. Can be given by a composite feed with a degree of freedom.

As described above, the edge of one end opening of the hole H before the inner diameter cutting is chamfered by the chamfering chip 6 to form the chamfered portion P.

When the chamfering is completed, the axis of the tool holder 3 is made to coincide with the axis of the hole H to be machined as shown in FIG. performed inside diameter cutting by the inner diameter cutting tip 5, finish the diameter of the hole H as shown in FIGS. 2 and 3 in a predetermined D ₂ dimension.

At this time, the cutting and feeding of the tool holder 3 is given by using the degree of freedom of the machine tool 1 in the X direction. Since it is near the axis of the holder 3, the chamfering chip 6 does not interfere with the inner peripheral surface of the hole H.

As described above, according to the present embodiment, a bulge F occurs at a position immediately adjacent to a ridge line formed by the inner peripheral surface of the hole H and the chamfered portion P before the inner diameter cutting, as shown in FIG. Even if the inside diameter is cut, the bulge F is cut and removed at the same time, so that the bulge F or the inner diameter accuracy of the hole H is not reduced.

Here, in the above-described embodiment, an example in which the holder main body 4 of the tool holder 3 and the tapered shank portion 7 are of an integral structure is shown, but the holder main body 4 and the tapered shank portion 7 can be divided into two parts. If it is not necessary to frequently replace the tool holder 3 with the spindle 2, the tool holder 3 may be used.
May be fastened with bolts.

Further, in the above embodiment, FIGS.
9 shows an example in which both chips 5 and 6 are arranged in the same phase position. For example, as shown in FIGS. In the case of mounting the chip, it is necessary to arrange both chips 5 and 6 out of phase by 180 ° as a condition for establishing the layout as shown in FIG.

In this case, since the phases of the two chips 5 and 6 are shifted from each other by 180 °, there is no obstacle on the outer side in the centrifugal direction of the chips 5 and 6 for removing chips, and the cutting is performed. There is an advantage that swarf removal during processing is performed smoothly.

[Brief description of the drawings]

FIG. 1 is a diagram showing a typical embodiment of the present invention;
(A) is an explanatory diagram at the time of chamfering, (B) is an explanatory diagram at the time of inner diameter cutting.

FIG. 2 is an explanatory diagram showing a relationship between a work and a tool holder before machining is started.

FIG. 3 is an explanatory diagram at the time of completion of inner diameter cutting.

FIG. 4 is a perspective view of a main part showing an example of a machine tool having three degrees of freedom of sliding in orthogonal directions.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is an enlarged view of a main part of FIG. 5;

FIG. 7 is a left side view of FIG. 6;

FIG. 8 is an enlarged view of a portion A in FIG. 2 and is an explanatory diagram when a bulge such as “burr” or “burr” occurs.

FIG. 9 is an enlarged view of a main part of a tool holder according to another embodiment of the present invention.

FIG. 10 is a left side view of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Machine tool 2 ... Spindle 3 ... Tool holder 4 ... Holder main body 5 ... Tip for inside diameter cutting 6 ... Tip for chamfering H ... Hole P ... Chamfering part W ... Work

Claims (2)

[Claims] 1. A boring tool holder provided with an inner diameter cutting tip and a chamfering tip is mounted on a main spindle of a machine tool having at least three orthogonal degrees of freedom of sliding, and the inner diameter of a hole is cut and the hole is drilled. A chamfering process of the edge of one end opening of the tool holder in a single step, the tip of the tool holder being closer to the tip of the inner diameter cutting tip attached to the tool holder and the rotation of the tool holder. At the same time, the chamfering tip is mounted at a position where the maximum diameter of the locus drawn by the chamfering tip is smaller than the diameter of the hole before machining, and revolves on the concentric circle with the hole to be machined while rotating the tool holder The tool holder is moved to perform chamfering with the chamfering tip.After that, the tool holder is aligned with the axis of the hole to be machined, and then the cutting feed in that axis direction is performed. A boring method characterized in that an inner diameter is cut by a given inner diameter cutting tip. 2. An inner diameter cutting tip and a chamfering tip,
2. The boring method according to claim 1, wherein the mounting is performed with a phase shifted by 180 degrees from the center axis of the tool holder.