JPH0631580A - Cutting tool - Google Patents

Abstract

PURPOSE:To provide an excellent cutting tool which can sufficiently apply a cutting liquid to a cutting point, as a cutting tool using a cutter chip. CONSTITUTION:A discharge nozzle 14 for discharging the high pressure liquid toward the contact point of the cutter flank 13a of a cutter chip 13 and a workpiece X is installed on the step difference surface 12 of the boundary of the large diameter part and the small diameter part of a nearly cylindrical holder 11 which is formed to the large diameter on a root side and the small diameter on a top edge side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool such as an end mill.

[0002]

2. Description of the Related Art Conventionally, in cutting, a liquid such as oil or water is applied to the cutting portion for the purpose of cooling the cutting portion and removing chips. However, the cutting point itself is because the cutting edge of the workpiece and the cutting tool are in pressure contact,
It is not easy to apply enough liquid to the cutting point. If the liquid is not sufficiently applied to the cutting point, the cutting edge will be damaged by the cutting heat, and the chips with the cutting heat will cover the surface of the workpiece and a part of the machine. When heated and expanded and cutting in that state, the processing dimensions are distorted, the work surface is melted by the cutting heat, and the molten metal adheres to the cutting edge of the cutting tool to form a so-called "configured cutting edge" and it is possible to cut. Since problems such as disappearance occur, the solution is strongly desired.

Therefore, recently, in order to be able to spray liquid near the cutting point, for example, in a cutting tool having a cutter tip 2 attached to the tip of the holder 1, as shown in FIG. 3 is formed, and in a tool capable of spraying liquid toward the blade tip of the cutter tip 2 or a drill tool, as shown in FIG. 6, a spiral water injection channel 4 is formed inside the blade, A tool that can spray liquid from the center of the tool tip has been developed and is used in some parts. In addition, corresponding to these tools,
For machine tools such as lathes and machining centers,
A tool having a water injection means communicating with the water injection paths 3 and 4 of the above tool has been developed.

[0004]

However, these tools with a liquid spraying function are designed to carry out liquid spraying from the sliding surface side of the cutting edge solely for the purpose of chip removal. Although it is possible to suppress the heat generation to a certain extent, it is not possible to directly cool the cutting point and its surroundings, so that various problems due to the cutting heat are likely to occur.

The present invention has been made in view of such circumstances, and in a cutting tool using a cutter tip,
It is an object of the present invention to provide an excellent cutting tool that can sufficiently apply liquid to a cutting point.

[0006]

In order to achieve the above object, a cutting tool of the present invention is a cutting tool for cutting by colliding a cutting edge with a workpiece, the root side having a large diameter and the tip side having a large diameter. A substantially cylindrical holder formed to have a small diameter and a cutter tip attached to the tip of the small diameter portion of the holder are provided, and on the step surface at the boundary between the large diameter portion and the small diameter portion of the holder, the cutter tip of the cutter tip during cutting is provided. A discharge port for discharging the high-pressure liquid is provided toward or near the contact point between the cutting edge flank and the workpiece, and a water injection passage communicating with the discharge port is formed in the holder.

[0007]

That is, the present inventor has conducted a series of researches on a structure in which a cutting tool having a cutter tip attached thereto is sufficiently liquid-poured toward the vicinity of the cutting point. As a result, in a generally cylindrical cutting tool such as an end mill,
If the root side of the outer peripheral surface of the holder is made large in diameter and a step is provided and a discharge port capable of discharging high pressure liquid is provided on this step surface, it is conventionally impossible to pour liquid It was found that liquid can be sprayed on and the cutting point can be directly cooled, and the present invention has been reached.

Next, the present invention will be described in detail based on embodiments.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of an embodiment in which the present invention is applied to an end mill, and FIG. 2 is a plan view of the tip end surface thereof as viewed from directly above. In this end mill 10, a substantially cylindrical holder 11 is formed with a large diameter on the base side and a small diameter with the tip side being a paragraph. 12 is the step surface. Then, three notches 11a are formed at equal intervals in the circumferential direction at the tip of the small diameter portion, and a cemented carbide cutter tip 13 is screwed to one side in each notch 11a ( The screws are not shown).

The stepped surface 12 at the boundary between the large diameter portion and the small diameter portion of the holder 11 is provided with three discharge ports 14 at equal intervals in the circumferential direction, and each discharge port 14 is a holder. 11 are respectively communicated with branch water injection passages 15a radially diverging from the water injection passage 15 penetrating in the axial direction to reach the step surface 12 (see FIG. 3, which is a sectional view taken along the line AA 'in FIG. 1). Therefore, the high-pressure liquid is discharged from the three discharge ports 14 toward the tips of the cutting edge flanks 13a of the cutter tip 13 as shown by arrows P, respectively.

The end mill 10 is mounted on a known machining center (having a function of pouring water into the water pouring passage 15 of the holder 11), and a high pressure liquid is discharged from the discharge port 15 of the end mill 10 by an arrow P in FIG. When the cutting process is performed by discharging as shown in the drawing, the liquid can be directly sprayed from the side of the cutting edge flank 13a in the vicinity of the cutting point where the cutter tip 13 is pressed against the workpiece X. Is almost not conducted into the workpiece X and the inside of the cutter tip 13 of the end mill 10, and neither the workpiece X nor the cutting edge of the cutter tip 13 is thermally damaged. This allows
The high-speed cutting of the hard work X, which has conventionally caused many troubles, can be favorably performed over a long period of time.

In the end mill 10, it is possible to directly spray liquid to the cutting edge flank 13a, which has been conventionally difficult to spray, to a position very close to the cutting point.
As shown in FIG. 4, the cutting edge flank 1 of the cutter tip 13
Even if 3a is initially a smooth surface, this surface is worn as the cutting progresses and many streaks are formed in the vertical direction, and it is considered that the liquid enters into the vicinity of the cutting point by utilizing these streaks. Then, once the liquid enters this streak, not only the effect of directly cooling the cutting point but also the effect that the smoothness of the cutting edge flank 13a is improved and the wear on this surface is significantly suppressed Play.

By the way, when an end mill having the same structure as that described above was used to carry out groove machining under the following conditions, it was impossible to machine under the following conditions in the past, but to obtain a good finished product. I was able to.

Workpiece: Material SKD61 Hardness HRC45 ° Shape Flat plate end mill: Tip material Cemented carbide Cutting conditions: Cutting speed 100 m / min Number of blades 3 pieces Depth of cut 5 mm Feed rate 150 mm / min

In the above embodiment, the cutter tip 1
Discharge port 1 capable of discharging high-pressure liquid to the cutting edge flank 13a of 3
Although only 4 is formed, if a discharge port capable of discharging high-pressure liquid toward the cutting edge slip surface of the cutter tip 13 is also provided on the step surface 12 or another portion,
It is possible to more effectively cool the cutting point and remove chips.

Further, although the end mill 10 is used as the cutting tool in the above embodiment, the present invention is not limited to this, and has various substantially cylindrical holders for performing planing, drilling, grooving and the like. It can be applied to cutting tools. The present invention can be applied not only to those mounted on a machining center but also to those that can be mounted and used on various cutting devices such as milling machines and NC lathes.

Further, in the above embodiment, the discharge port 14
The high-pressure liquid discharged from may be water or oil, or may contain various chemicals. The discharge pressure is set appropriately according to the cutting conditions, but it is generally preferable to set it to ⁵ to 200 kg / cm ² .

The position of the discharge port 14 for spraying liquid toward the cutting edge flank 13a and the arrangement of the water injection passages 15 and 15a formed inside are not limited to those in the above embodiment, but the cutter tip 13 is attached. It can be appropriately changed according to the mode, cutting conditions, and the like. Further, the stepped surface 12 itself for providing the ejection port 14 may be an inclined surface instead of a flat surface, or only the portion forming the ejection port 14 may be partially raised to be angled.

[0019]

As described above, the cutting tool of the present invention is
A stepped surface is formed in the middle of the body of the substantially cylindrical holder, and an ejection port capable of ejecting the high-pressure liquid toward the cutting edge flank of the cutter tip is provided on the stepped surface. Therefore, according to the present invention, since it is possible to directly pour liquid in the vicinity of the cutting point from the flank of the cutting edge, which has hitherto been considered impossible to pour liquid, it is possible to exhibit a very excellent cooling effect. It is possible to maintain good cutting performance for a long period of time. Moreover, since the liquid enters the cutting edge flank, the cutting edge flank, which was often damaged by friction with the workpiece, is smoothed, so that the damage on this surface can be suppressed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a cutting tool of the present invention.

FIG. 2 is a plan view looking down on the front end surface of the embodiment.

FIG. 3 is a sectional view taken along the line AA ′ in FIG.

FIG. 4 is an explanatory diagram of a usage mode of a cutting edge flank of a cutter tip.

FIG. 5 is an explanatory diagram of an example of a conventional cutting tool.

FIG. 6 is an explanatory view of another example of a conventional cutting tool.

[Explanation of symbols]

 10 End Mill 11 Holder 11a Notch 12 Stepped Surface 13 Cutter Tip 13b Cutting Edge Relief Surface 14 Discharge Port 15,15a Water Injection Channel X Workpiece

Claims (1)

[Claims] 1. A cutting tool for performing cutting by colliding a cutting edge with a workpiece, comprising a substantially cylindrical holder having a large diameter at a base side and a small diameter at a tip side, and a tip of a small diameter portion of the holder. Equipped with a cutter tip that can be attached, discharges high-pressure liquid toward the contact surface of the cutting edge of the cutter tip and the workpiece contact point or its vicinity at the step surface of the boundary between the large diameter part and the small diameter part of the holder. The cutting tool is characterized in that a discharge port is provided and a water injection channel communicating with the discharge port is formed in the holder.