JPH0641766Y2 - Tool for internal surface machining of cylindrical work - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a cutting tool which is attached to a lathe or the like and is used to cut an inner surface of a cylindrical work.

[Conventional technology]

For example, as shown in FIG. 3, a conventional cutting tool (A) of this type has a cutting edge (D) formed by a tip (C) on a side surface of a tip portion of a shank (B). It is common.

[Problems to be solved by the device]

With such a conventional cutting tool (A), as shown in FIG. 3, a cylindrical work (F) having a bag-shaped enlarged hole (E) at the rear end is rotated around the axis (L). While cutting the inner surface (G), the cutting chips (H) enter the enlarged hole (E), and after the processing is completed, the cutting chips (H) that enter the enlarged hole (E) are removed. There is a problem that it is difficult to completely remove it only by the normal cleaning work.

Further, when the enlarged hole (E) is in the shape of a bag as described above, it is difficult to visually confirm whether or not the cutting chips (H) that have entered into the expansion hole can be completely removed. If the work (F) is left in the expansion hole (E), the chips (H) may damage the inner surface of the expansion hole (E) of the work (F) or another member (not shown) when the work (F) is used. There is a risk that it may be caught between and causing malfunction.

In Japanese Utility Model Publication No. 47-36453, an umbrella-shaped deflector is provided at the tip of a cutting tool, and air ejected from a groove provided in front of the deflector is blown to the deflector to make a U-turn. A configuration is disclosed in which the U-turned air blows the chips out of the work. However, with such a configuration, the chips adhere to the inner surface of the back end of the work before cutting with a cutting tool. It is not possible to remove dust and the like from the inside of the work, and there is a risk that cutting chips will fly into the back end side of the work through the gap between the inner surface of the work and the peripheral edge of the deflector. There is a problem.

An object of the present invention is to provide a tool for machining the inner surface of a cylindrical work, which solves the problems of the conventional tool.

[Means for Solving the Problems]

In order to achieve the above object, the invention of claim (1) is a tool for machining an inner surface of a cylindrical work having a cutting edge on a side surface of a tip end portion of a shank, and a rear end portion of the work piece being machined. In addition to providing a substantially circular umbrella-shaped shielding material at the part, at the center of the tip of the shielding material, an air ejection port that ejects air for blowing off chips etc. toward the back end of the work is provided. It has a feature.

The shape of the tip surface of the shielding material is preferably spherical.

Further, it is preferable that the outer diameter of the shielding material is slightly smaller than the inner diameter of the work to be processed (claim 3).

[Action]

The air ejected from the air ejection port provided almost at the center of the tip of the shielding material hits approximately the center of the closed back end of the work, and is radially dispersed from there, and then makes a U-turn along the inner surface of the work. It jets toward the base side of the shank through the gap between the inner surface of the work and the peripheral edge of the shielding material. In the meantime, dust and the like attached to the inner surface of the work before being cut by the cutting tool are discharged from the work.

The air blown toward the base side of the shank through the gap between the inner surface of the work and the peripheral edge of the shield causes the chips generated from the cutting edge to pass through the gap between the shield and the inner surface of the work. The work is prevented from entering the back end side of the work, and the cutting chips accumulated on the base side of the shank from the shielding material are blown out of the work.

〔Example〕

FIG. 1 and FIG. 2 show a state in which the inner surface of a cylindrical work, which is a case for a valve retainer of an automobile engine valve, is being machined by using a cutting tool according to an embodiment of the present invention.

(1) is a bite, and a tip (3) is fitted and fixed to a pin (4) at one side of the tip of the shank (2a) of the holder (2). 3)
A cutting edge (5) is formed in a portion of the holder projecting laterally from the holder (2).

At the tip of the shank (2a) of the holder (2), there is provided a shielding member (6) having a circular front shape, which has a spherical umbrella shape and covers most of the tip (3) and the entire tip of the holder (2). , And the holder (2) are integrally connected.

The radius of the shielding material (6) is the central axis (L1) of the holder (2).
The distance from the tip to the tip of the cutting edge (5) in the tip (3) should be approximately the same or slightly smaller.

(7) is a central axis line (L1) formed in the holder (2)
An air circulation hole parallel to the base end of the shank (2a) connected to a compressed air source (not shown) through an appropriate fluid coupling (not shown). It opens at almost the center of (6) and serves as an air ejection port (7a).

(8) is a cylindrical work, the work (F) shown in FIG.
Similarly, it has a bag-shaped enlarged hole (9) closed at the rear end.

The outer diameter of the shielding material (6) is slightly smaller than the inner diameter of the work (8).

In order to cut the inner surface (10) of the work (8) using the cutting tool (1), the work (8) is fixed to a work head (not shown) on a lathe or the like, and the work is rotated about the center of rotation of the work head. While rotating around the axis line (L2), which is the center of the workpiece (8), and ejecting air (11) for blowing off chips and the like from the air ejection port (7a), the cutting blade (5) is moved to the inner surface (10) of the work (8). ), The bite (1) is gradually moved parallel to the axis (L2) of the work (8) as shown by the arrow in FIG.

Then, the cutting powder (12) that is cut by the cutting blade (5) and comes out from the portion of the cutting blade (5) usually while spirally winding.
Is blocked by the shielding material (6) from heading toward the shank (2a) of the holder (2). That is, the cutting chips (10) come into contact with the spherical inner surface of the shielding material (6) and are deflected toward the base side of the holder (2).

Further, the air (11) ejected from the air ejection port (7a) once fills the bag-shaped enlarged hole (9) at the far end of the work (8), and then, as shown by the arrow in FIG. Inner surface of work (8) (1
0) and the shielding material (6) through the gap, shank (2a)
Is ejected toward the base side of the shank (2a), and the cutting force (12) is blown away toward the base side of the shank (2a).

Therefore, the cutting process of the inner surface (10) of the work (8) is completed without the chips (12) passing over the shielding material (6) and entering the bag-shaped enlarged hole (7) in the work (8). It is possible, and after processing, the enlarged hole (9) of the work (8)
And the cutting chips (12) do not remain on the inner surface (10), and the work (8) can be kept beautiful and the cutting chips (1)
Cleaning work to remove 2) is not required.

In addition to the above-described embodiments, various changes and modifications can be made, for example, by screwing the shielding material to the bite or by detachably providing it.

Further, the present invention can be applied not only to the throw-away type bite consisting of the holder and the tip as in the above-mentioned embodiment, but also to a completed bite or a bite with a blade.

[Effect of device]

According to the present invention, the following effects can be achieved.

(A) The air ejected from the air ejection port provided approximately in the center of the tip of the shielding material hits the central portion of the closed end of the work and is dispersed radially from there, and then U along the inner surface of the work. Before turning by the cutting tool with this cutting tool, it adheres to the inner surface of the work before it is turned and then jets toward the base side of the shank through the gap between the inner surface of the work and the peripheral edge of the shielding material. Dust etc. can be discharged from inside the work to clean the inner surface of the work.

(B) Due to the air jetted toward the base side of the shank through the gap between the inner surface of the work and the peripheral edge of the shielding material, the chips generated from the cutting edge portion cause the gap between the shielding material and the inner surface of the work. The inner surface of the work can be prevented from being damaged by the cutting chips.

(C) Blow off the chips accumulated on the base side of the shank from the shielding material to the outside of the work by the air jetted toward the base side of the shank through the gap between the inner surface of the work and the peripheral edge of the shielding material. You can

(D) If the shape of the tip surface of the shielding material is spherical, the air that has entered the back end side of the work can be smoothly guided to the gap between the inner surface of the work and the peripheral edge of the shielding material, and It is possible to prevent turbulence from being generated in the air in the inner end portion, and improve the efficiency of removing dust and the like by the air (claim 2).

(E) When the outer diameter of the shielding material is made slightly smaller than the inner diameter of the work to be machined, the gap between the inner surface of the work and the peripheral edge of the shielding material is reduced, and the jetting force of air passing therethrough is increased, The effects of (a) to (c) above can be further improved (claim 3).

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a state in which an inner surface of a cylindrical work is processed by using the first embodiment of the present invention, and FIG. 2 is a vertical sectional view taken along line XX in FIG. FIG. 3 is a vertical cross-sectional side view showing a state in which the inner surface of a cylindrical work is processed using a conventional cutting tool. (1) Tool, (2) Holder (2a) Shank, (3) Tip (4) Pin, (5) Cutting blade (6) Shielding material, (7) Air circulation hole (7a) Air jet, (8) Work (9) Enlarged hole, (19) Inner surface (11) Air, (12) Chip (L1) Center axis of holder, (L2) axis

Claims (3)

[Scope of utility model registration request] 1. A cutting tool for machining an inner surface of a cylindrical work having a cutting edge on a side surface of a shank and having a closed rear end, wherein a substantially circular umbrella-shaped shielding material is provided at the front end of the shank. In addition to the above, a cutting tool for the inner surface of a cylindrical work is provided in the center of the tip of the shielding material with an air ejection port for ejecting air for blowing off chips and the like toward the back end of the work. . 2. The cutting tool for machining the inner surface of a cylindrical work according to claim 1, wherein the shape of the end surface of the shielding material is spherical. 3. The cutting tool for machining the inner surface of a cylindrical work according to claim 1, wherein the outer diameter of the shielding material is slightly smaller than the inner diameter of the work to be machined.