JPS5847291B2 - Planted blade type shaving cutter and its manufacturing method - Google Patents

Description

Detailed Description of the Invention In order to finish large-diameter gears, etc. with high precision and high efficiency, it has recently been proposed to perform shaving processing instead of grinding after quench hardening. A manufactured shaving cutter is required.

Of course, manufacturing the entire cutter from cemented carbide increases the material cost, but it also improves the workability and
In particular, the difficulty of forming the tooth profile, attaching the blade along the helix line of the tooth, and attaching the serrations to form the cutting edge is a major obstacle, making it impractical.

Therefore, like other cutting tools using cemented carbide, it is conceivable to make only the blade portion of the tool made of cemented carbide, but this poses the following problems.

(1) Method of holding and fixing the cemented carbide body as the blade part.

(2) Assembly errors due to the use of cemented carbide (i.e. tooth thickness,
Reheating properties of correction by tooth profile grinding (errors such as pitch, tooth profile, tooth trace, pitch circle runout, etc.).

(3) Serration processing method for cemented carbide.

(4) Method of holding and fixing cemented carbide in the torsion groove of teeth.

For example, the shaving cutter disclosed in British Patent No. 576,434 has slits spaced apart in the axial direction on the flank surface of a gear-shaped cutter body having a pedestal around the periphery, and involute tooth profiles made of a hard material are formed in the slits. The blade is inserted and fixed to the main body using an appropriate fixing method such as brazing.

However, a shoulder must be formed at the lower end to prevent lateral displacement of the blade, and furthermore, it is extremely difficult to prefabricate the involute tooth profile itself in a hard material.

Moreover, since a large amount of expensive hard material is required, there is also a problem in terms of cost.

This invention provides a plurality of mounting grooves extending from the tooth tip to the tooth root on the flank surface of the gear-shaped cutter body, forms the cutting edge of the blade with a substitute circular arc that approximates an involute tooth profile, and connects the bottom surface of the blade with the mounting groove. A implanted blade type shaving cutter in which the groove bottom is formed with an arc concentric with the substitute arc, and the cross-sectional shape of the base of the blade is made equal to the cross-sectional shape of the mounting groove, thereby solving the problems of the conventional products described above. The present invention relates to a method of manufacturing this shaving cutter.

Next, an embodiment of the implanted shaving cutter according to the present invention will be described with reference to the drawings. In FIGS. 1 and 2, the cutter body 1 has a gear shape with a large number of tooth-shaped pedestals 2 around the periphery, and the pedestals 2 A plurality of blade mounting grooves 6 are bored in the flank surface 3 of the blade 3 at intervals in the axial direction, reaching from the tooth tip 4 to the tooth root 5, and a blade 7 made of a hard material is inserted into each of these mounting grooves. has been done.

The base portion 8 of the blade 7 has the same cross-sectional shape as the mounting groove 6, and is fixed uniformly within the groove from the tooth tip 4 to the tooth root 5 by an appropriate means such as brazing or bonding.

A cutting edge -9 is formed on the side opposite to the base of the blade 7.

Cutting blade 9 is a cutting blade that acts as a cutting tool, and its width W is the same as that of a normal shaving cutter, but the distance d between the cutting blades 9 and 9 is the same as that of a normal shaving cutter. The spacing between the cutting blades is made larger to improve the strength in terms of holding and fixing the blades, and also to improve the cutting performance of the cutting blades.

Further, the bottom surface 10 of the blade 7 and the groove bottom 11 of the mounting groove 6 are formed of circular arc surfaces having the same radius Ri, as will be described later.

The hard materials used to manufacture the Flede 7 include sintered alloys such as cemented carbide, cermet, and ceramics, or those coated with hard materials, and other materials such as high-speed steel coated with other hard materials. Needless to say.

To explain the manufacturing method of the above-mentioned shaving cutter, in FIG. 2, Ro is an approximate substitute arc radius for the unique involute tooth profile to be formed on the cutting edge of the cutter, and R1 is the height h of the blade I than Ro. The radius of the center of the circle is smaller than the radius of the inner surface of the blade.

In order to uniformly fix the main body 1 and the blade 7 from the tooth tip 4 to the tooth root 5, the inner radius Ri of the blade and the radius of the groove bottom 11 of the mounting groove are made the same.

Therefore, as shown in FIG. 3, the outer radius of the blade 7 is R.
o, the inner surface has an arc shape with a radius of Ri.

To manufacture this, as shown in Figure 5, the outer surface of the blade 7,
An annular body made of a hard material having an outer diameter and a circular diameter equal to the inner radii Ro and Ri is made in advance, and in this state, the outer surface, inner surface, Machining the sides.

This processing can be done by relatively simple machining.

The annular blade material 12 formed in this way is
As shown in the figure, since the blade is cut into predetermined dimensions, precise carbide blades can be manufactured efficiently.

13 indicates a cutting portion. On the other hand, the blade mounting groove 6 of the main body 1
is made by a crank mechanism, a part of which is shown in FIG.

A tool holder 16 movable in the longitudinal direction is provided on the arm 15 which moves around the center 14 of radius Ri as a fulcrum, and a tool holder 17 is attached to the holder 16, and the arc movement of the tip of the tool moves the pedestal 2 of the main body. A groove 6 having an arc-shaped groove bottom 11 is cut on the flank surface 3 of the groove.

In this case, if the shortest distance between the tip of the cutting tool and the center of motion 14 of the arm is set to a radius Ri equal to the inner radius Ri of the blade,
The groove bottom 11 is an arc with a radius Ri, which matches the inner radius of the blade, and can be fixed uniformly from the tip to the root.

Alternatively, when machining a mounting groove with a helical helix angle, unevenness in the depth of the groove can be minimized by adjusting the contact of the tip of the cutting tool to the flank surface 3 of the pedestal using the above-mentioned crank mechanism. The blade fixation assembly error can be kept within a range that can be corrected by tooth profile grinding.

By forming these blade mounting grooves 6 at almost right angles to the helix line of the teeth, that is, the tooth trace 21, as shown in FIG.
It can be easily processed regardless of whether it is a straight cutter or a hazuba cutter.

FIG. 7 shows another embodiment of the implanted blade type shaving cutter according to the present invention, in which the width W of the blade 7 made of carbide material is the cutting edge -9.
The same structure is shown from the top to the bottom surface 10.

The cross-sectional shape of the blade 7 can be appropriately selected as illustrated in FIG.

In this case, it goes without saying that the cross-sectional shape of the mounting groove is made equal to the cross-sectional shape of the base portion 8 of the blade.

After the blade 7 thus formed is fixed in the mounting groove 6, the outer diameter surface, which is an approximate substitute circular arc surface, is repaired and ground to easily manufacture a shaving cutter having a cutting edge with a desired involute tooth profile. be able to.

According to the present invention, as described above, the cutting edge is formed with a substitute circular arc that approximates the involute tooth profile, and only the blade whose bottom surface is formed by an arc concentric with the circular arc is formed of a hard material, and this is attached to the main body. Since it is inserted into the mounting groove and fixed, the cost of the hard material is low.

Moreover, the blade can be processed individually before assembly.
It is now possible to finish the side surface of the cutting edge by grinding, which was previously impossible. This makes it possible to remove the decarburized layer caused by quenching, especially in high-speed steel, and in both cases, the corners at both ends of the cutting edge are even sharper. As a result, sharpness, wear resistance, and machined surface roughness can be significantly improved.

Furthermore, since the spacing between the mounting grooves can be arbitrarily selected, the blade can be held securely in the main body.

Furthermore, since the outer and inner surfaces of the blade and the bottom of the mounting groove are formed with substitute circular arcs that approximate the involute tooth profile, machining that follows the flank surface is possible, and the depth of the mounting groove does not have a large deviation from the flank surface. Therefore, the assembly error when a machined blade is inserted and fixed therein can be practically kept within the range of the correction capability of tooth profile grinding.

In addition, shavings with cutting edges made of conventional carbide materials can be manufactured relatively easily, even if they have a helix angle that is difficult to assemble with other assembly methods. All problems with the cutter can be solved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of an embodiment of the invention, and FIG.
3 is a side view of one embodiment of the blade; FIG. 4 is a sectional view taken along line 3--3 in FIG.
Fig. 5 is a side view of an example of the blade material, Fig. 6 is an explanatory diagram of the method of cutting the plate mounting groove, Fig. 7 is a perspective view of the main part corresponding to Fig. 1 of another embodiment, and Fig. 8 9 is a cross-sectional view showing various shapes of the blade, and FIG. 9 is an explanatory diagram of a method of machining the blade mounting groove. 1... Cutter body, 2... Pedestal, 3.
...Frank surface, 6...Blade mounting groove, 7...Blade, 8...Base of blade, 9...Cutting edge - ,10°10a...
... Bottom of the blade, 11 ... Groove bottom, 12 ...
...Blade material.

Claims (1)

[Scope of Claims] 1. A gear-shaped cutter body having a tooth-shaped pedestal around its periphery is provided with a plurality of mounting portions extending from the tooth tip to the tooth root at intervals in the axial direction on the flank surface thereof, and has a cutting blade ridge. In a implanted shaving cutter in which a blade made of a hard material is inserted and fixed into the mounting portion to form serrations, the mounting portion is used as a mounting groove, and the cutting edge ridge of the blade is formed with a substitute circular arc approximating an involute tooth profile. In addition, the bottom surface of the blade and the groove bottom of the mounting groove are shaped to have an arc concentric with the substitute arc, and the cross-sectional shape of the base of the blade and the cross-sectional shape of the mounting groove are made equal. A blade type shaving cutter. 2. A blade attachment in which a gear-shaped cutter body is formed with a tooth-shaped pedestal around the periphery, and the cross-sectional shape is equal to the cross-sectional shape of the blade base, and the groove bottom is formed with an arcuate surface equal to the inner radius Ri of the blade material. A plurality of grooves are bored in the flank surface of the pedestal at intervals in the axial direction, and then the approximate substitute circular arc radius Ro for the involute tooth profile of the cutting edge is set as the outer diameter, and the approximate substitute circular arc radius Ro is equal to the height of the blade. An annular hard material blade material having an inner diameter with a small radius Ri is cut to form a partially arc-shaped blade, and the blade is inserted and fixed into the blade mounting groove to form serrations, and then the outer diameter surface of the blade is cut. A manufacturing method for a implanted blade type shaving cutter characterized by refinishing and grinding to obtain an involute tooth profile.