JPH03104511A - Hob - Google Patents

Abstract

PURPOSE:To prolong the life of a blade and permit the simple exchange of the blade by forming a circular arc recessed surface on a blade base front end wall surface to the axis-perpendicular cutting plane of a main body, and bending a thin plate blade to the above front end wall surface, via a spacer to which a circular arc protruded surface facingly contacting the circular arc recessed surface is provided, to be closely fixed. CONSTITUTION:A blade fitting groove 2 is formed on the outer periphery of a main body 1, and a blade base 3 having a front end wall surface 4 being a circular arc recessed surface is provided. A thin plate blade 5 is arranged along the circular arc recessed surface. The thin plate blade 5 is bendingly held between the circular arc recessed surface and a circular arc protruded surface 7 to be fixed with a spacer 10 having the circular arc protruded surface 7 on one side and a flat surface 9 on the other side. The spacer 10 is fixed with the main body 1 and a clamping bolt 11. When gear grinding is made, a chip can be smoothly moved on the cutting face 12 of the blade 5, the occurrence of crater abrasion or chipping can be prevented, and a life can be prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to an assembly hop for cutting gears using the Sokai method.

(Prior Art) There is an assembly hob in which thick disposable blades coated with a hard thin film such as TiN are attached via spacers to a large number of grooves drilled in the radial direction on the outer periphery of the main body. For example, in the assembly hob disclosed in Japanese Patent Application Laid-Open No. 1-97515,
Each blade is coated with a hard thin film such as TiN.
A longitudinal groove with a V-shaped cross section is provided on each contact surface of the spacer and the blade to form a long groove, and the bolt is inserted into the long groove and the bolt is engaged with the recess provided in the spacer. The blade is fixed to the main body by screwing it into the main body.

(Problems to be Solved by the Invention) However, in such a conventional assembly hob, the incorporated blade has multiple teeth and has a prismatic shape with a large wall thickness, so the rake face of the blade is not flat. The rake angle is usually about 08 to 66. Therefore, the chips hit a flat surface near the cutting edge, and while rubbing against the flat surface, they change direction and are ejected. Crater wear and chipping rapidly occur near the cutting edge due to friction between the blades and the blade, significantly shortening its lifespan.

(Means for Solving the Problems) The present invention forms a circular concave surface on the front end wall surface of the blade base with respect to the cut surface perpendicular to the axis of the main body, and forms a hard coating through a spacer provided with a circular convex surface that opposes the circular concave surface. By curved and closely fixed the thin plate blade coated with the front end surface of the blade base, the blade does not loosen and the occurrence of the above-mentioned crater wear etc. is reduced.

(Function) When the thin plate blade is fixed to the circular concave surface of the front end wall surface of the cutting board via the spacer provided with the circular convex surface, the thin plate blade is pressed and fixed along the circular concave surface. A force acts on the curved thin plate blade that is fixed and pressed against the arcuate concave surface, and the top and bottom of the thin plate blade strongly adheres to the blade base side and the center to the spacer side and is firmly fixed. .

Therefore, it will not come loose even if it receives impact during cutting.

Furthermore, when creating or cutting a gear, the chips flow along the arcuate concave rake face of the thin plate blade, so they easily curl up and move smoothly on the rake face, preventing crater wear and the associated The cutting blade is ejected smoothly without any chiming.

If the blade becomes worn, use a spare
Replace it with a temporary blade and start cutting immediately.

(Example) Next, an example of the present invention will be described with reference to the drawings.
One or more helical grooves (not shown) are formed around the outer periphery of the blade 1), and a blade mounting groove (2) is formed to intersect with the helical groove. provided. The front end wall surface (4) which is the blade mounting side of the blade stand (3)
) forms an arcuate concave surface with respect to the axis-perpendicular cut surface (Cl-A) of the main body (1).

The blade (5) is made of elastic high-speed steel plate and has a thickness (W
) is approximately 1 to 3 mm, and the front end wall surface (
4) Multiple tooth profiles with wider areas and similar shapes (
6) are connected in series, and the surface is TiC, TiN, T
It is coated with a hard coating such as iCN or Alt03. The blade mounting a (2) has a circular convex surface (7) on one side that matches the circular concave surface of the front end wall surface (4), and a flat surface that matches the flat rear end wall surface (8) of the blade mounting groove (2). (9
) on the other side is inserted into the blade mounting groove (2) as shown in Figure 2. The spacer is pulled inward by the tightening bolt αυ toward the center (0) of the main body (1) as shown by the arrow in the figure, and the spacer α is pulled inward by the arcuate convex surface (7) of the spacer and the blade rest ( 3) The thin plate blade (5) inserted between the circular concave surface of the front end wall surface (4) is curved along the circular concave surface of the uneven surface and securely fixed to the main body (1). The thin plate blade (5) fixed to the circular convex surface of the front end wall surface (4) of the blade base (3) via the spacer 00 provided with the circular convex surface (7) is curved and fixed, so that the thin plate blade itself Due to the force of returning to the original position, the upper and lower parts of the thin plate blade are firmly attached to the blade rest (3) side, and the center part is tightly attached to the spacer aω side, so that they will not loosen even if subjected to impact during cutting. There isn't.

Thus, the rake face (self) of the thin plate blade {5} is formed into an arcuate concave surface. Also, thin plate blades (
5) is also prevented from rising from the main body (1).

(Effects) In the present invention, as described above, the thin plate is inserted in a curved manner between the arcuate concave surface of the front end wall surface of the blade base and the arcuate convex surface provided on the spacer that matches the arcuate surface. It adhered tightly to the blade base and spacer and was strongly fixed, and also prevented the thin blade from lifting up. In addition, the rake face (self) of the curved thin plate blade has a concave curve, which reduces crater wear near the cutting edge due to the collision of chips, eliminates the associated chisoping of the cutting edge, and significantly improves the life of the blade.

In addition, since the structure of the hob is simple as mentioned above, even if the thin plate blade wears out, it can be immediately installed with a separately prepared one, which has excellent effects such as being able to continue machining efficiently. play.

[Brief explanation of drawings]

Fig. 1 is a partial front view of an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the attached state of the thin plate blade, Fig. 3 (a) is a front view of the thin plate blade, and the figure (opening) is a side view of the same. , FIG. 4 is a partially cutaway side view of the invention. l...Main body, 2...Blade mounting groove, 3...Blade holder, 4...Front end wall surface of the blade holder (arc concave surface), 5...Thin plate blade, 7...Arc convex surface of spacer , 10... Spacer, 12... Rake face.

Claims (2)

[Claims] (1) A blade in which a twisted groove and a blade mounting groove that intersects with the twisted groove and forms a number of blade holders are formed on the outer periphery of the main body, and a number of cutting blades are connected in a row corresponding to each blade holder. is fixed by a spacer inserted into the blade mounting groove, the spacer is provided with a circular concave surface formed on the front end wall surface of the blade base with respect to a cut surface perpendicular to the axis of the main body, and a circular convex surface opposing the circular concave surface. A hob characterized in that a thin plate blade coated with a hard coating is closely fixed to the front end wall surface of the blade stand, and the rake face is formed into an arcuate concave surface. (2) The hob according to claim 1, wherein the thin plate blade is made of high-speed steel, and the cutting surface and flank surface are coated with a hard coating.