JPS5839603B2 - drilling tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is an improvement of a tool such as a drill that breaks down one or more cutting edges at the tip of a tool body and performs down cutting in the axial direction. This invention relates to a technology that makes it possible to adjust the outer diameter of a cutting edge by utilizing elastic deformation of the entire tip of a tool body.

Unlike boring tools that widen the hole, tools such as drills must be set to a drill diameter that perfectly corresponds to the diameter of the hole being drilled, so conventional drills that do not have a diameter adjustment function are used. In this case, (1) Even if the diameter of the hole to be machined is slightly different, separate drills must be prepared for each.

(2) It is difficult to obtain the hole diameter as set because it is not possible to compensate for variations in the machined hole diameter caused by changes in drilling conditions or work material.

It had drawbacks such as:

Therefore, it is very preferable from the above point of view that the outer diameter of the cutting edge of this type of drilling tool, such as a drill, can be adjusted.

If this can be done, many types of holes with different diameters can be drilled with a single tool, and even if the material to be drilled (work material) or the drilling conditions change, adjustments can be made. This is because it is possible to always obtain an appropriate hole diameter as set.

However, in spite of this, until now, drilling tools such as this type of drill have not been able to finely adjust the outer diameter of the cutting edge, regardless of whether it is a solid, indexable, or attached-edged tool. I can't find anything that did.

By the way, the present applicant has discovered that even if the inner edge of the cutting edge is moved away from the center of rotation of the tool body relative to the workpiece, that is, even if the cutting edge is removed from the center, the The area is below a certain size (0.2 layers ≦ d ≦ 2.5 M when the distance from the center of rotation to the inner edge of the cutting blade is d/2)
), he discovered that it was possible to drill a hole without leaving a core even without a cutting edge in the center, and proposed a tool for drilling holes without a cutting edge in the center (October 1972). (See patent application ``Hole making is a tool'' filed on May 2nd).

However, this invention is based on that proposal and further improves it.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the solid type drill 1 shown in Figures 1 to 3.
In this application example, lands 2 and margins 3 are formed on the drill body 1a, and in this respect, it is similar to the conventional drill body 1a.

However, in the solid type drill 1 here, a predetermined width t1 extending in the axial direction of the drill and having a long axis perpendicular to the cutting blades 4 and 5 is provided on the tip side of the drill body 1a where the cutting blades 4 and 5 are located. A slit 6 is cut to a predetermined depth.

This slit 6 divides the tip of the drill body 1a into three equal parts 1b, lc, and the three equal parts 1b, 'l.
c can be elastically deformed in a direction intersecting the axis, and therefore its depth should be set with this in mind.

The opening side of this slit 6 forms a groove 6a that also serves as thinning, and the width d of the groove 6a (i.e. the diameter inscribed in the inner edge of each cutting edge 4, 5) is smaller than tl. The slit 6 is set large so that the slit 6 itself can be easily processed.

However, the invention is not limited to this, and for example, each inner edge 4
a and 5a may be performed at the same time as the slit processing.

Of course, in this case, care should be taken to ensure that the width d of the groove 6a is within a range in which the core does not grow in the center even if the outer diameter of the cutting edge is adjusted as described later.

However, the adjustment of the outer diameter of the cutting edge is not only for increasing d, but also for decreasing d as in the later examples (it may be possible to make both of these cases possible in the future). It is not necessarily necessary to set d in the above-mentioned predetermined range in a state where no elastic deformation is performed.

The drill tip 1b is thus divided into three equal parts.

A pressurizing means is added to 1c, whereby the cutting edge 4.5
It is possible to adjust the outer diameter of.

Here, a screw hole γ is provided in one side 1b of the drill tip portions 1b and lc divided into three equal parts, a set screw 8 is screwed into this screw hole, and the tip of the set screw 8 is attached to the opposing drill tip portion. The inner surface 9 of 1c is pressed.

Next, a case will be described in which the outer diameter of the cutting edge of the drill 1 having the above configuration is adjusted.

This drill 1 also has its shank part (not shown) attached to a drilling machine or lathe to make holes, but the actual adjustment of the outer diameter of the cutting edge of the drill is done by rotating the setscrew 8 provided on the drill body 1a. Therefore, the attachment can be carried out freely regardless of the front or rear.

For example, in order to increase the outer diameter of the cutting edge 4.degree. 5 of the drill 1, the set screw 8 may be rotated in the direction of arrow A.

Then, the tip of the set screw 8 strongly presses the inner surface 9 of the drill tip 1c, causing the drill tip 1c to move in the direction A, while at the same time, the opposing drill tip 1b moves in the direction of arrow B due to the reaction force. are elastically deformed toward each other.

In this case, since the slit 6 passes through the axis, the shapes of the drill tips 1b and lc are symmetrical, and when they are elastically deformed as described above, the amount of deformation is equal.

Furthermore, if the outer diameter of the cutting edges 4, 5 of the drill 1 has been adjusted too much, the readjustment can be easily carried out by rotating the screw 8 in the opposite direction, that is, by rotating it in the direction of arrow B. .

Next, the clamp type drill 1 shown in FIGS.
An example of application to 0 will be explained.

In this clamp type drill 10 as well, the drill tip 1a is divided into parts by the same slit 6 as described above, and the tips 13 and 14 having the cutting edges 4 and 5 are attached to the divided drill tips 1b and lc with screws 11°. It is fixed by 12.

Further, a hole 16 having a sink hole 15 is formed in one drill tip 1b, and a screw hole 17 is correspondingly provided in the other drill tip 1c.

A hexagonal socket bolt 18 is passed through the hole 16 on the drill tip 1b side and screwed into the screw hole 17 on the drill tip 1c side.

This hexagon socket head bolt 18 corresponds to the set screw 81, and when adjusting the outer diameter of the cutting edge in this clamp type drill 10, this hexagon socket head bolt 18 is used.
This is done by tightening.

By this tightening, the drill tip portions 1b and 1c are elastically deformed in a direction in which the outer diameter of the cutting edge becomes smaller.

In each of the above embodiments, the slit 6 is formed linearly in the axial direction of the drill, but the slit 6 is not limited to this. For example, if the drill body is twisted, the slit 6 may be formed as a twisted slit aligned with the twisting. Good too.

Further, in each of the above embodiments, the long axis of the slit 6 is provided perpendicularly to the cutting blade, but is not limited to this. For example, the slit 6 is provided perpendicularly to the bolt for adjusting the outer diameter of the cutting blade. It's okay.

Further, in each of the above embodiments, a screw mechanism is used as a pressurizing means for deforming the tip of the drill, but the mechanism is not limited to this, and it is also possible to use a wedge, a lever, a cam, etc., or a combination of these mechanisms. It may be something.

As explained above, according to the tool, the hole drilling according to the present invention involves dividing the tip end side of the tool body with the cutting edge by a slit along the axis, and elastically deforming the divided part by pressurizing means such as a screw. Because of the structure, it is possible to adjust the outer diameter of the cutting edge, which not only reduces the number of tools required for hole drilling and facilitates tool management, but also has excellent effects such as the ability to drill holes with high precision through adjustment. has.

[Brief explanation of the drawing]

Fig. 1 is a bottom view showing an embodiment of the drilling tool according to the present invention, Fig. 2 is a front view thereof, Fig. 3 is a sectional view taken along the line ■-■ in Fig. A bottom view showing another embodiment according to the invention, FIG. 5 is a front view thereof, and FIG. 6 is a Vl of FIG.
It is a sectional view along the -VI line. 1a...Drill body, lb, lc...
Drill tip, 4, 5... Cutting blade, 4a, 5a.
...Inner edge, 6...Slit, 8...
... Set screw, 18 ... Hexagon socket head bolt.

Claims (1)

[Claims] 1 Having one or more cutting edges at the tip of the tool body,
For drilling holes such as drills that perform down cutting in the axial direction, the tip of the tool body with the cutting edge is divided into two by a slit along the axis, and the tip of the bisected tool body is attached with a screw or the like. The outer diameter of the cutting blade can be adjusted by elastically deforming it by a pressure means, and this adjustment is performed when the distance d/2 between the inner edge of each cutting blade and the center of rotation of the tool body relative to the workpiece is A tool is characterized in that drilling is performed within the range of 0.1 M≦d/2≦1.25 layers.