JPH0611705Y2 - Groove cutting blade - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement in the tooth profile of a groove cutting blade such as a broach blade.

In the following description, apply the tooth letter for each tooth,
For a single cutting tool with a large number of teeth, it is shown by using a blade.

(Prior Art) First, a broach blade 1 as an example of a conventional groove cutting blade will be described with reference to FIGS. 2 and 3.

The broaching blade 1 shown in the figure is a broaching blade 1 for machining a square groove having a constant depth on the outer circumference of a cylinder by broaching, for example.
A single groove is cut by a single work of drawing with a strong pressure in the direction of arrow A shown in FIG.

In this case, the large number of cutting teeth 5 are sequentially provided with a high blade height B in the direction opposite to the arrow A, and each of them has a flank C, a side flank D, and a scooping surface E, which are formed on the respective surfaces. The cut surface has a clearance angle so that it will not come into contact even if it bulges after processing, and the scooping surface has sharpened tips to strongly cut the work material.

In this case, when a single groove is machined by a single movement of the broach blade 1 in the direction of arrow A, the outer circumference of a round bar or the like, which is a workpiece (not shown), stops the cutting movement, and the broach blade 1 Is lowered to a low position by a quick return mechanism of a broaching machine (not shown), returned to its original position, the round bar is also rotated at a desired angle and fixed at a new angle position, and the broach blade 1 is also moved to the initial position. Return to the height position and move to the next groove cutting.

Next, the names of the parts of the broaching blade 1 will be described with reference to FIG. 2. The tip of each cutting tooth 5 is a cutting tooth part 7, and the horizontal distance from the cutting tooth part 7 to the end heel 9 of the flank C is the land width F,
The horizontal distance between the continuous cutting teeth 7 is the pitch P, the gap between the cutting teeth 7 and the front heel 9 is the tooth groove 11, and the portion between the tooth grooves 11 and parallel to the bottom surface of the base 3 is the tooth groove bottom 13. A curved portion connecting the scooping surface E and the tooth groove bottom 13 is called a tooth groove bottom roundness 15.

(Problems to be solved by the invention) When a single groove is formed on the outer circumference of the round bar by the broaching blade 1 which is a conventional groove cutting blade as described above, the cutting chips cut by the cutting teeth 7 scoop the surface. E, it moves along the tooth groove bottom roundness 15 and the tooth groove bottom 13 and is generated in the tooth groove 11 in a spiral shape with a large diameter, and there is a problem in dischargeability from the tooth groove 11.

In order to solve the above-mentioned problems, means for reducing the spiral diameter of the cutting chips, a structure for mechanically discharging the cutting chips from the tooth space 11, and the like have been proposed, but lack of certainty of discharging,
There are problems such as complicated configuration.

(Means for Solving Problems) In view of the conventional problems as described above, the present invention provides a large number of cutting teeth at appropriate pitches, and each cutting tooth has a flank and a scooping surface, and A groove cutting blade formed by connecting a tooth groove bottom of a tooth groove formed between each cutting tooth and the scooping surface with a tooth groove bottom roundness, and a vicinity of a connecting portion between the scooping surface and the tooth groove bottom roundness In addition, a stepped portion for bending the cutting chips guided by the scooping surface and advancing toward the tooth groove bottom direction at an acute angle before reaching the tooth groove bottom is formed at an acute angle with respect to the scooping surface. Is.

(Operation) According to the improved groove cutting blade of the present invention, when the chips cut from the work material are guided by the scooping surface and move toward the bottom of the tooth space, they are hit by a step and bent at an acute angle. Since many parts are broken and divided into small pieces, the dischargeability is further improved.

(Embodiment) A broach blade 1 according to an embodiment of the present invention will be described with reference to FIG.

In this embodiment, the stepped portion 17 is provided at a portion where the scooping surface E transitions to the roundness 15 of the tooth groove bottom and has a horizontal distance forward in the land width direction and a height h which is a vertical distance from the cutting tooth portion 7.

More specifically, as apparent from FIG. 1, the step portion 17 is
Is provided in the vicinity of the connecting portion between the scooping surface E and the tooth groove bottom roundness 15, and the step portion 17 is provided with respect to the scooping surface E to bend the chips guided by the scooping surface E into an acute angle. It is provided at an acute angle.

In this case, the horizontal projection distance of the stepped portion 17 may be parallel to the moving direction of the broaching blade 1 indicated by the arrow A (or may be inclined so as to be nearly parallel to the flank C, and the flank E). The step portion 17 may be connected to the tooth groove bottom roundness 15 by a curve having a sufficiently small radius of curvature.

When the work material is cut by the broaching blade 1 having the above-mentioned configuration, the cutting chips cut by the cutting tooth portions 7 of the respective cutting teeth 5 are guided by the scooping surface E and move toward the tooth groove bottom 13.
Then, since the chips are bent at an acute angle in the step portion 17, the chips are divided one after another, and the chips are prevented from becoming a long and continuous form. Further, even if the chips are temporarily continuous, the chips 17 are bent at an acute angle by the step portion 17, so that the chips are wound in a spiral shape with a small diameter, and sometimes the chips are bent at an acute angle. As a result of being cut, the spiral portion does not grow large.

In other words, the presence of the step portion 17 cuts the chips cut in the tooth cutting portion 7 into small pieces, and even if the cutting dust is formed into a spiral shape, it does not have a small diameter and becomes large.
Emissions from the product are improved.

[Effects of the Invention] As will be understood from the above description of the embodiment, in short, the present invention provides a large number of cutting teeth 5 at appropriate pitches, and each of the cutting teeth 5 has a flank C and a scooping surface E. Further, a groove cutting blade is formed by connecting the tooth groove bottom 13 of the tooth groove 11 formed between the cutting teeth 5 and the scooping surface E by the tooth groove bottom roundness 15 to form the scooping surface E. Rounded bottom 1
In the vicinity of the connection portion with 5, the step portion 17 for bending the cutting chips guided by the scooping surface E toward the tooth groove bottom 13 at an acute angle before reaching the tooth groove bottom 13 is provided with the scooping surface. It is formed at an acute angle with respect to E.

As is apparent from the above configuration, in the present invention, the scooping surface E is guided near the connection portion between the scooping surface E of the cutting tooth 5 and the tooth groove bottom roundness 15 connected to the tooth groove bottom 13 of the tooth groove 11. The chips advancing in the direction of the tooth groove bottom 13 are
The stepped portion 17 for bending at an acute angle before reaching
Since it is formed at an acute angle with respect to the cutting material, the chips generated during the processing of the work material are guided by the scooping surface E, and the tooth groove bottom 1 of the tooth groove 11 is guided.
When advancing in the direction of 3, the step portion 17 bends at an acute angle.

Therefore, the chips which are originally easy to break are the chips which are successively divided into small pieces in the step portion 17 without being continuous. Further, when the step 17 is bent at an acute angle, even if it becomes a continuous swarf, it becomes a small spiral shape, and since it is sometimes cut by the acute bend at the step 17, It does not form a long continuous large spiral.

Therefore, the discharging property of the chips generated during the cutting process from the tooth space 11 is improved.

[Brief description of drawings]

1 is a side view of an embodiment of the present invention, FIG. 2 is a side view of a conventional groove cutting blade, and FIG. 3 is a sectional view taken along the line III-III of FIG. (Explanation of the symbols indicating the main parts of the drawing) 1 ... Brooch blade, C ... Flank surface E ... Scooping surface, 7 ... Cutting tooth portion F ... Land width, 15 ... Tooth groove bottom roundness 17 ... Step

Claims (1)

[Scope of utility model registration request] 1. A plurality of cutting teeth (5) are provided at an appropriate pitch,
Each of the cutting teeth (5) has a flank (C) and a scooping surface (E), and further has a tooth groove bottom (13) of the tooth groove (11) formed between the cutting teeth (5). The scooping surface (E)
Is a groove cutting blade formed by connecting and with a groove bottom roundness (15), and is guided to the scooping surface (E) in the vicinity of a connecting portion between the scooping surface (E) and the tooth groove bottom roundness (15). A stepped portion (17) for bending the chips advancing toward the tooth groove bottom (13) into an acute angle before reaching the tooth groove bottom (13) is formed at an acute angle with respect to the scooping surface (E). A groove cutting blade characterized by being formed.