JP2561233Y2 - Shaft drilling tool - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft hole machining tool for line boring, for machining a plurality of holes simultaneously.

[0002]

2. Description of the Related Art Conventionally, in order to simultaneously machine a plurality of holes in line boring or the like, for example, a Japanese Utility Model Publication No.
Shaft hole machining tools such as 33903 or Japanese Utility Model Application Laid-Open No. 63-158709 are known. These shaft hole machining tools are provided with a boring bar that is rotatable around an axis and a plurality of tools attached to the boring server, and the tools are aligned on the same straight line along the axial direction. It is arranged.

[0003]

However, in the case of the above-mentioned tool, since a plurality of cutting tools are provided on the same straight line in parallel with the axial direction of the boring aber, the cutting tools are attached to the cutting tool at the time of cutting. The reaction force of the applied cutting resistance is concentrated in the same direction, and there is a problem that chipping (breakage) easily occurs on the cutting edge. In addition, when the bending moment applied to the boring bar is concentrated in one direction, the aber shaft is easily bent, which is a factor of reducing the processing accuracy.

[0004]

In order to solve such a problem, the present invention provides a boring arbor with at least an axial direction.
Also has three cutting tools, and these cutting tools have an angular phase difference from each other in the rotation direction of the boring arbor.
Was, when the end of the baud ring arbor saw plurality of bight, axes and the spread range of a group of bytes to the central byte group in the lift direction during boring arbor insert for machining holes to the right and left 40 ° For drilling tools
The plurality of byte portions are sequentially arranged on a spiral line .

[0005]

[Action] Since the spread range of at least three bytes unit byte group consisting of the up right and left 40 °, it can be inserted in a state of being offset boring arbor of the processing hole. That is, when the boring arbor is inserted, a sufficient gap between the cutting tool and the inner peripheral surface of the processing hole can be ensured, so that the boring arbor can be easily inserted / pulled out and the processing operation can be performed smoothly. Then, the plurality of bytes are
Since they are arranged in order on the spiral, the direction of the reaction force at the time of cutting is dispersed, the amount of deflection of the boring arbor is reduced, and the processing accuracy is improved. Further, since the amount of bending is reduced, chipping of the cutting edge of the cutting tool is less likely to occur.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a shaft drilling tool according to the present invention. FIG. 1 is a front view showing a machining state of the shaft hole machining tool of the present invention, FIG. 2 is a plan view of the shaft hole machining tool, FIG. 3 is a state diagram when the tool is inserted into a work hole, and FIG. It is a front view. The shaft drilling tool according to the present invention is configured as a line boring tool. As shown in FIGS. 1 and 2, a long boring bar 1 and an axial direction of the boring bar 1 are provided. A plurality of (five in this embodiment) cutting tools are provided at predetermined intervals along the axis, and the cutting tool 2 is provided with a rough cutting tool 3 provided on the front side of the machining feed.
And a set of finishing tools 4 provided on the rear side as one set. One set of the shaft holes is machined with each of the set tools 3 and 4 so that a total of five shaft holes can be machined simultaneously. For this reason, one end of the boring bar 1 is connected to the main shaft 5 of the spindle, and the other end is freely insertable into a guide hole of the support 6. Then, as described later, when the positioning adjustment with the work W is completed, while being driven and rotated around the axis,
The workpiece is fed by a predetermined stroke in the direction of the arrow in FIG. 1 to cut a corresponding processing hole.

By the way, the position of the byte part 2 is shown in FIG.
As shown in FIG. 3, they are not coincident with the axial direction, but are provided with a phase difference in the axial circumferential direction. In the embodiment, the angle difference 2 between the adjacent cutting tools 2 and 2 is, for example, 10 degrees or 20 degrees, which are sequentially shifted by the same angle in the same direction, but this angle is related to the lift amount described below. Or
It is restricted by the relationship with the shaft diameter of the shaft. The lift amount refers to a change in the relative position between the boring bar 1 and the work W when the boring bar is inserted into a shaft hole previously drilled in the work W and when cutting is performed. This means the amount, which corresponds to the interval between A and B shown in FIG. In other words, when the boring abor 51 is inserted into the shaft hole of the work W,
The center of the axis (broken line) is A, and the center of the axis when processing is B.
However, the amount of change d between A and B is the lift amount.
And actually, after inserting the boring aber 51,
The work is started by lowering the work W by the lift amount d.
The lift amount d is set to avoid interference with the cutting tool 52 when the boring aber 51 is inserted and removed. Since the lift amount cannot be set to zero, the lift amount d of the present invention shown in FIG. Also in this case, the angular dispersion range of the cutting tool 2 is limited by the lift amount d.

Next, the operation and effect of the shaft hole machining tool according to the present invention will be described with reference to FIGS. Here, FIG. 5 is an explanatory diagram for explaining the cutting resistance at the time of cutting, and FIG. 6 is a comparison table of the processing accuracy when the phase angle is changed. Wow
When the workpiece W is positioned at a fixed position, the boring bar 1 is inserted into a shaft hole formed in the workpiece W in advance. At this time, the boring bar 1 is set so that the cutting tool 2 faces upward (the state shown in FIG. 3), while the work W is positioned at a position higher by a predetermined lift amount d. ing. The work W is, for example, a combination of an aluminum alloy W1 and a cast iron W2 as shown in FIG. 3, and as will be described later, the working tool of the present invention is used for joining work materials combining such different materials. Demonstrates effectiveness in turning parts.

When the boring bar 1 is inserted and the state shown in FIG. 1 is reached, the work W is lowered by the lift d.
Clamped. That is, each rough cutting tool 3 faces each shaft hole. Then, the boring bar 1 starts rotating and is machined and fed in the direction of the arrow in FIG. Here, the force acting during cutting will be described with reference to FIG. 5. The cutting resistance R applied to each cutting tool can be divided into a main component Rc in the cutting direction and a back component Rt in a direction perpendicular thereto. Force Rc
Acts on the boring bar 1 as a torsional force, and the back force R
The t acts on the boring bar 1 as a bending moment. If the directions of the cutting tools are all the same as in the prior art, the directions of the back force Rt are all the same, so that the bending moment direction is concentrated and the aber shaft is easily bent. On the other hand, by providing the cutting tool with a phase difference as in the present invention, the direction of the back force Rt is dispersed, so that the aber shaft is hardly bent. The main component Rc
In the case of (1), the direction changes, but as a result, there is no difference in the torsional moment received by the aber shaft.

[0010] The effect of the bending of the boring bar 1 is particularly remarkable when cutting a joint of different materials as described above, that is, in such a work material, cutting is performed at the joint surface. Since the resistance changes, the chipping of the cutting edge is apt to occur when the resistance changes as in the conventional case where the deflection is large, but the chipping is unlikely to occur when the deflection is small. Further, the processing accuracy is improved by reducing the amount of bending. That is, FIG. 6 is a comparison table of actual measurement values of machining accuracy when the phase angle of the cutting tool 2 is changed.
When the roundness of each of 15 samples is measured when the phase is changed to 10 degrees and 20 degrees, when the phase is 0 degree,
9.82 μm, 4.51 μm at 10 ° phase, phase 2
At 0 degree, it was 3.90 μm. It is apparent from this data that the processing accuracy is improved as the phase angle is increased.

Thus, when the boring amber 1 is processed and fed by a predetermined stroke, five shaft holes are simultaneously formed in the respective cutting portions 2 until finishing. When the machining is completed, the cutting tool 2 is turned upward and stopped.
Is lifted by the lift amount d, and the boring amber 1 is pulled out.

[0012]

[Effect of the invention] As described above, the shaft hole machining tool of the invention is
Since the spread range of the bit group consisting of at least three bit portions is up to 40 ° on each of the right and left sides, it is possible to insert the boring arbor in a state where it is offset to the processing hole. That is, when the boring arbor is inserted, a sufficient gap between the cutting tool and the inner peripheral surface of the processing hole can be ensured, so that the boring arbor can be easily inserted / pulled out and the processing operation can be performed smoothly. Then, insert the multiple bytes on the spiral
, The direction of the reaction force during cutting is dispersed,
The amount of bending of the boring arbor is reduced, and the processing accuracy is improved. Further, since the amount of bending is reduced, chipping of the cutting edge of the cutting tool is less likely to occur. In particular, it is effective to prevent chipping when turning a joint of a work material in which different materials are combined as in the embodiment.

[Brief description of the drawings]

FIG. 1 is a diagram showing a machining state of a shaft hole machining tool of the present invention.

FIG. 2 is a plan view of a shaft drilling tool.

FIG. 3 is a view showing a state when a shaft hole machining tool is inserted into a work hole;

FIG. 4 is a front view of a conventional example.

FIG. 5 is an explanatory diagram for explaining cutting resistance.

FIG. 6 is a comparison table of machining accuracy when the phase angle is changed.

[Explanation of symbols]

(1) Boring aber (2) Tool part (3) Tool bit for rough cutting (4) Tool bit for finish cutting (W) Work

Claims (1)

(57) [Scope of request for utility model registration] 1. A boring arbor having a small amount along an axial direction.
In each case, three cutting tools are attached, and these cutting tools have an angular phase difference from each other in the rotation direction of the boring arbor.
Was, when the end of the baud ring arbor saw plurality of bight, axes and the spread range of a group of bytes to the central byte group in the lift direction during boring arbor insert for machining holes to the right and left 40 ° For drilling tools
The plurality of cutting tools are arranged in order on a helical line .