JPH0574713U - Bowling bar - Google Patents

Abstract

(57) [Summary] [Construction] A plurality of holes 9 are provided in the main body shank portion 2 made of steel material in a direction orthogonal to the longitudinal direction thereof, and a pin 10 made of cemented carbide is embedded in the holes 9. [Effect] Since a plurality of pins 10 made of cemented carbide are embedded in the main body shank portion 2 made of steel, rigidity is significantly improved, and due to the difference in natural frequency between steel and cemented carbide, Vibration of the main body shank portion 2 is not constant and irregular, and chatter vibration is less likely to occur, and chip loss and unstable chip disposal can be prevented. Moreover, the main body shank portion 2 is provided with a plurality of holes 9 orthogonal to the longitudinal direction thereof, and the pins 10 made of cemented carbide are provided in the holes 9.
Since it is manufactured by embedding, it does not require complicated work such as brazing. Therefore, manufacturing becomes very easy.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a boring bar having a throw-away tip attached to its tip.

[0002]

[Prior Art]

 Conventionally, in boring bars, the body shank is generally made of steel. However, this boring bar has a problem that vibration of a certain cycle is likely to occur during cutting, which causes chatter vibration, which easily causes chipping and unstable chip disposal. Therefore, the applicant has improved rigidity by alternately constructing the main body shank portion with a plurality of steel materials and cemented carbide members, and suppresses chatter vibration due to the difference in natural frequency between these. A previous application has been filed for a bowling bar having a configuration (Japanese Utility Model Application No. 1-135558).

[0003]

[Problems to be solved by the device]

 However, the boring bar has a problem that it is complicated and difficult to manufacture because it is necessary to alternately braze a plurality of steel materials and cemented carbide members.

Therefore, an object of the present invention is to provide a boring bar which has high rigidity, can suppress chatter vibration, and is easy to manufacture.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, a boring bar of the present invention has a throw-away tip mounted on the tip thereof, and a plurality of holes are provided in a main body shank portion made of steel material in a direction orthogonal to its longitudinal direction. The pin is made of cemented carbide and is embedded in the hole.

[0006]

[Action]

 According to the boring bar of the present invention, since a plurality of pins made of cemented carbide are embedded in the shank of the body made of steel, the rigidity is significantly improved, and the natural frequency of steel and cemented carbide is reduced. Due to the difference, the vibration of the main shank during cutting is not constant and becomes irregular, and chatter vibration is less likely to occur. Moreover, since a plurality of holes are provided in the shank of the main body at right angles to the longitudinal direction and pins made of cemented carbide are embedded in the holes, no complicated work such as brazing is required. .

[0007]

【Example】

 A boring bar according to a first embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 in the drawing denotes a boring bar of the first embodiment, which is mainly composed of a main body shank portion 2 and a head portion 3 on the tip side thereof, and is made of a steel material. It is manufactured. The main shank portion 2 has a substantially circular cross section, and has two flat surface portions 4 which are parallel to each other on the outer peripheral portion. A tip seat 5 and a tip pocket 6 are formed on the head 3, and a diamond-shaped throwaway tip 7 is placed on the tip seat 5. A clamp screw 8 is inserted through the central portion of the throw-away tip 7, and the clamp screw 8 is screwed into the head 3 to be pressed and fixed to the tip seat 5.

The body shank portion 2 is provided with a plurality of holes 9 which are orthogonal to the longitudinal direction of the body shank portion 2 and pass through the central axis of the body shank portion 2 so as to pass therethrough so as not to interfere with the flat surface portion 4. . These holes 9 are formed such that projections of adjacent members when viewed from the rear end direction of the main shank portion 2 intersect each other at a predetermined angle (see the sectional view of FIG. 3).

Then, in the hole 9, a substantially columnar pin 10 made of cemented carbide is embedded. Here, the pin 10 is formed to have a diameter larger than the diameter of the hole 9 by a predetermined amount and is press-fitted and embedded from the outer peripheral side of the main body shank portion 2. Further, both ends of the pin 10 are flush with the outer peripheral portion of the main body shank portion 2 when embedded in the main body shank portion 2. In the figure, the pin 10 made of cemented carbide is hatched in order to distinguish it from the portion made of steel.

According to the boring bar 1 having the above-described configuration, the plurality of pins 10 made of cemented carbide are embedded in the main body shank portion 2 made of steel in a direction orthogonal to the longitudinal direction of the main body shank portion 2. , The rigidity is improved and the deflection can be greatly reduced. However, the adjacent pins 10 are arranged so that the projections viewed from the rear end direction of the main body shank portion 2 intersect at a predetermined angle. Since it is installed, the rigidity is further improved. In addition, due to the difference in natural frequency between the steel material and cemented carbide, the vibration of the main body shank 2 during cutting becomes irregular and irregular, and chatter vibration is less likely to occur. Unstable chip disposal can be prevented.

Further, since the pin 10 is provided up to the outer peripheral portion of the main shank portion 2, the torsional rigidity is improved and the torsion due to the cutting load can be greatly reduced.

Further, since a plurality of holes 9 are provided in the main body shank portion 2 at right angles to the longitudinal direction thereof, and a pin 10 made of a cemented carbide is embedded in the holes 9, the brazing is performed. It does not require complicated work such as Therefore, manufacturing becomes very easy.

Next, a boring bar according to a second embodiment of the present invention will be described below with reference to FIGS. 4 to 6. The boring bar of the second embodiment is different from the boring bar of the first embodiment in that the shapes of the holes and the pins are changed. Therefore, the difference will be mainly described below. The same parts as those in the embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the boring bar 1 of the second embodiment, one opening 9a of the hole 9 has a larger diameter than the other opening 9b by a predetermined amount, and the entire hole 9 is tapered. These holes 9 are provided so that adjacent ones are inversely tapered, and one end 10a of the pin 10 made of cemented carbide is the other side in conformity with the shape of the holes 9. Has a larger diameter than the end portion 10b.

According to the boring bar 1 of the second embodiment having such a configuration, the same effect as that of the first embodiment can be obtained, and of course, the pin 9 is formed in the opening 9a on the large diameter side of the hole 9. Since 10 1 is inserted and press-fitted from the end portion 10b side on the small diameter side, there is an effect that it is easy to insert and further easy to manufacture.

[0017]

[Effect of the device]

 As described in detail above, according to the boring bar of the present invention, since a plurality of pins made of cemented carbide are embedded in the main body shank portion made of steel, the rigidity is significantly improved, and it is also possible to improve the rigidity of steel. Due to the difference in natural frequency from the hard alloy, the vibration of the main body shank during cutting becomes irregular and irregular, making chatter vibration less likely to occur, and preventing chip loss and unstable chip disposal caused by chatter vibration. can do. However, since the shank of the main body is provided with a plurality of holes orthogonal to the longitudinal direction and pins made of cemented carbide are embedded in the holes, complicated work such as brazing is required. do not do. Therefore, manufacturing becomes very easy.

[Brief description of drawings]

FIG. 1 is a front view showing a boring bar according to a first embodiment of the present invention.

FIG. 2 is a bottom view of FIG. 1 showing a boring bar according to a first embodiment of the present invention.

3 is a cross-sectional view of the boring bar according to the first embodiment of the present invention, (a) taken along the line AA in FIG. 2, and (b) taken along the line B- in FIG. It is along the B line.

FIG. 4 is a front view showing a boring bar according to a second embodiment of the present invention.

5 is a bottom view of FIG. 4 showing a boring bar according to a second embodiment of the present invention.

6 is a cross-sectional view of a boring bar according to a second embodiment of the present invention, in which (a) is taken along line CC in FIG. 5 and (b) is D- in FIG. It is along the D line.

[Explanation of symbols]

 1 Boring bar 2 Body shank 9 Hole 10 pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Shimizu 1511 Furumagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Mitsubishi Materials Corporation Tsukuba Works

Claims (1)

[Scope of utility model registration request] 1. A boring bar having a throw-away tip attached to the tip thereof, wherein a plurality of holes are provided in a shank portion of a main body made of steel material at right angles to the longitudinal direction thereof, and a pin made of cemented carbide is provided in the hole portions. A bowling bar characterized by being embedded.