JPH04152020A - Screw machining tool and screw machining method - Google Patents

Abstract

PURPOSE:To efficiently perform screw machining by allowing a screw machining tool connected to the main spindle of a simultaneous three-axis controllable device to bite into a work, and feeding a cutting edge to form a screw while securing a preset screw pitch. CONSTITUTION:A screw machining tool 1 having one or more stages of cutting edges and having an axial notch section partially to form a cutting edge tip (c) is coupled or fitted by a proper method eccentrically by the eccentricity quantity (e) with respect to the axis of a holding tool 2. It is connected to the shaft end section of the main spindle 4 of a simultaneous three-axis controllable device or a numerically controlled (NC) machine tool by a holding tool 3 coaxially coupled with the holding tool 2. A work 6 having a portion in the shape to be formed with a screw machining face 5 on the inner periphery is fitted on the table of the simultaneous three-axis controllable device or the NC machine tool. The tool 1 is rotated to the screw depth in the screw radius direction along the screw shape to bite into the work 6, the cutting edge is fed at a preset pitch, then a screw is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a thread processing tool and a thread processing method for forming a thread on a workpiece.

(Prior Art) Conventionally, screws have been formed using taps, dies, screw turning, rolling, etc.

For example, when using a tap or die, use a blade diameter that matches the screw diameter, and make sure that the tool rotation axis is the same as the screw center.

For turning and rolling, lathes and rolling equipment were used, respectively.

(Problem II to be solved by the invention) However, in tap processing, it is necessary to select a tap with an appropriate thread diameter from among many types of taps according to the required thread diameter. The work is complicated. Furthermore, the number of times one tap can be used is limited due to wear of the tip of the tap, resulting in poor efficiency.

On the other hand, in thread machining by turning, there is a greater degree of freedom in the machining diameter than in the case of a tap, but there is a problem in that there are restrictions on the shape of the workpiece that is suitable for turning.

SUMMARY OF THE INVENTION Therefore, the present invention provides a thread processing tool and a thread processing method that solves the problems of the conventional device and improves the economical efficiency of the tool and the degree of freedom of processing, regardless of the thread diameter and the shape of the workpiece. The purpose is to

[Structure of the Invention] (Means for Solving the Problems) The present invention includes one or more cutting edges along the axial direction on the outer periphery of the tool in the radial direction, and one or more stages of cutting edges along the axial direction. A device in which a screw machining tool with a notch is mounted eccentrically with respect to the axis of the holding tool, and other holding tools connected coaxially with this holding tool allow for simultaneous three-axis control. This is a thread processing tool that is connected to the shaft end of the main shaft of the machine.This thread processing tool is rotated along the thread shape to the thread depth in the radial direction of the thread, and when cut into the workpiece, the specified The thread is formed by feeding the cutting blade while ensuring the thread pitch.

(Function) As a result, a single thread processing tool can machine threads regardless of the inner or outer diameter of the workpiece, reducing processing time.
Economic efficiency improves.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an example of an internal thread processing method using a thread processing tool according to the present invention.

In the same figure, a screw machining tool 1 is provided with one or more stages of cutting blades and has a notch in the axial direction at the negative part to form a cutting blade tip C. The holding tool 3 is fitted or attached in an appropriate manner in a misaligned manner, and the holding tool 3 is coaxially connected to the holding tool 2.
It is joined to the shaft end of a main shaft 4 of a device capable of simultaneous three-axis control or an NC machine tool (for example, a machining center).

Furthermore, on the table of a device capable of simultaneous three-axis control or an NC machine tool, a workpiece 6 having a portion shaped to allow threading on the inner periphery 5 is mounted by an appropriate method ( (not shown).

Note that the rotating shaft of the holding tool 2 and the holding tool 3 is the main shaft 4.
It is located on the extension of the rotation axis 8 of.

FIG. 2 shows an example of an assembled state of the screw processing tool 1 and the holding tool 2.

Figure (a) shows a side view seen from the tool axis, and figure (b) shows a side view as seen from the tool axis.
) shows a cross-sectional view of the screw processing tool 1 and the holding tool 2 in an assembled state, and FIG. It is a diagram.

In these figures, a screw machining tool 1 has a main body partially fitted into a hole 2a formed in a holding tool 2.

It is fixed by a set screw 7, and at this time, the center CC of the screw processing tool 1 is separated from the tool rotation center RC, which is the same as the center of the holding tool 2, by an eccentric amount e.

With the above configuration, the cutting edge tip C of the screw processing tool 1 eccentrically attached to the holding tools 2 and 3 has a turning radius r centered on the tool rotation center RC, and this turning radius r is equal to the turning radius r of the holding tool 2. The cutting edge C of the screw processing tool 1 is located at a position that protrudes from the holding tool 2.

Here, the relationship between the turning radius r, the eccentricity e, and the thread machining tool radius f is shown below.

r=e+f...(1) Then, adjust the cutting edge tip C of the screw processing tool 1 attached to the main spindle 4 via the holding tool to the thread root diameter d to be machined, and rotate the main spindle 4 to adjust the cutting edge tip. With a device capable of simultaneous three-axis control of the screw processing tool 1, so that the locus of the contact point between C and the thread root diameter d corresponds to the screw pitch p per screw rotation.
Make a spiral movement.

By the way, since the center CC of the screw processing tool 1 is eccentrically e away from the tool rotation center RC, which is the same as the center of the holding tool 2, the depth of cut U of the cutting edge C into the workpiece 6 and the screw root search are The relationship with V is as shown below.

U≦V (2) Screw processing tool 1 used in the screw processing method according to the present invention
The structure of the cutting edge tip C is shown in Fig. 3.

The screw processing tool 1 rotates around a tool rotation center RC. As a result, the tip C of the cutting blade having the cutting depth U of the thread moves with a length equal to the sum of the thread radius g and the cutting depth U, and the locus of this movement forms the thread.

Moreover, the thread processing tool 1 can shift the cutting edge portion in the angular direction about the center CC.

As a result, the initial cutting edge tip C has a re-sharpening allowance H that is sufficient to perform a sufficient cutting blade function after re-sharpening, and can be transferred to the next cutting edge tip C'.

At this time, the grinding allowance H is determined from the center CC of the thread processing tool 1 by an angle RA that sufficiently satisfies the above-mentioned cutting blade function. After re-sharpening the cutting edge, the tip of the cutting edge moves to C' and Cn by appropriately performing the operations described above, but the contact position with the workpiece 6 is as shown in FIG. It is adjusted and fixed at the same position as the original cutting edge tip C.

In addition, the center CC of the screw processing tool 1 is mounted with an eccentric amount θ apart from the tool rotation center RC, which is the same as the center of the holding tool 2, so that the part opposite to the cutting blade rotation direction n is
This essentially forms a relief R between the two sides.

As a result, the outer diameter surface of the cutting edge of the screw processing tool 1 takes over the flank surface, and the second cutting work (finishing work), which was previously performed using special equipment such as a tap, becomes unnecessary.

In this way, the screw machining tool according to this embodiment can be manufactured using a device capable of simultaneous three-axis control or an NC machine tool, and can be used with the same tool regardless of the inner or outer diameter.

It is possible to process multiple types of screws.

In addition, by shifting the mounting angle each time the cutting blade is re-sharpened, a larger amount of grinding allowance is secured compared to conventional equipment. R
By substantially forming the hole, there is no need for a second cut, which was performed using a special device such as a tap in the conventional device, thereby improving tool life and economic efficiency.

FIG. 4 shows another embodiment of the screw machining tool according to the present invention.

FIG. 4(,) shows a cutter having one or more stages of cutting blades, in which cutting blade tips C having a notch in the axial direction are similarly formed at positions 180 degrees apart from each other.

As a result, even if the polishing allowance on one side is eliminated, 18
The cutting edges formed at 0 degrees opposite positions can improve tool life and economy.

Fig. 4(b) shows the tips of the cutting blades Ca and C, which are equipped with one or more stages of cutting blades and have a notch portion with a partially changed depth in the axial direction.
Two or more b are formed and similarly formed at positions 180 degrees apart.

As a result, two or more types of cutting depth can be selected.6 Figure 4 (c) shows that by setting the cutting blade to one stage, the amount of movement of the device that can simultaneously control three axes can be adjusted. Thread pitch can be changed.

Moreover, FIG. 5 shows an example in which a throw-away type carbide cutting blade is attached to the tip of the cutting blade.

A throw-away type carbide cutting blade 11 is attached to a screw machining tool 1 having one or more stages of cutting blades, a part of which has a notch in the axial direction to form a cutting blade tip C, using a cutting blade fixing screw 12. By attaching it, it becomes possible to form screws on workpieces with different hardnesses.

It goes without saying that the method for mounting the indexable carbide cutting blade using the cutting blade fixing screw 12 can be applied to each of the embodiments shown in FIG.

In this way, the number of cutting edges on the outer circumference of the tool in the radial direction can be selected according to the material of the workpiece, and if the number of cutting edges in the tool axis direction is also formed appropriately depending on the length of the threaded part of the workpiece, it is possible to The machining time can be reduced by the length of the cutting edge of the machining tool.

[Effects of the Invention] As explained above, according to the present invention, thread processing can be performed efficiently regardless of the workpiece, thread diameter, and shape.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the configuration of a screw machining device according to an embodiment of the present invention, FIG. 2 (a) is a side view from the perspective of the tool axis, and FIG. 2(C) is a sectional view showing the assembled state of the holding tool 2, FIG. An explanatory diagram illustrating the structure of the blade tip C, FIG. 4 is a configuration diagram showing another embodiment of the screw processing tool according to the present invention, and FIG. 5 is an example in which a throw-away type carbide cutting blade is attached to the cutting blade tip. FIG. ■...Screw processing tool, 2, 3...Holding tool, 40.
...Main axis.

Claims (2)

[Claims] (1) A thread machining tool that forms a thread in a workpiece, which has one or more cutting edges along the axial direction on the outer periphery of the tool in the radial direction, and has one or more cuts along the axial direction on the cutting edge. A screw machining tool with a notch is installed eccentrically with respect to the axis of the holding tool, and another holding tool connected coaxially with this holding tool allows simultaneous three-axis control of the main axis of the device. A screw processing tool characterized by being joined at the end. (2) A screw machining tool is equipped with one or more cutting edges along the axial direction on the outer periphery of the tool in the radial direction, and one or more notches along the axial direction are provided in the cutting edge. This holding tool is mounted eccentrically with respect to the shaft, and other holding tools connected coaxially with this holding tool allow the screw machining tool connected to the shaft end of the main spindle of a device capable of simultaneous three-axis control to be machined. A thread processing method characterized by forming a thread by feeding a cutting blade while ensuring a predetermined thread pitch while cutting into an object.