JPH07299632A - Form milling cutter - Google Patents

Abstract

PURPOSE:To maintain accuracy at manufacturing time by bringing a resharpened surface and a bottom surface of a cutter blade having a resharpened cutting face of an edge part into contact with respective reference surfaces of a cutter head, and making the edge part containing a cutting edge and a second surface appear in the same shape and position before it is resharpened. CONSTITUTION:Cutter blades 4 having respectively an edge part 3 are installed in plural holding grooves 2 formed in an outer peripheral part of a cutter head l, and work is performed. By the way, when the edge part 3 is abraded by work, the cutter blade 4 is removed from the cutter head 1. A cutting surface 3a of the edge part 3 is ground in parallel, and a new cutting edge is ground out, and a resharpened surface 4a on the same plane with this grinding finish cutting face 3a is brought into contact with a contact reference surface 2a on a front side surface of the holding groove 2, and a bottom surface of the cutter blade 4 is brought into contact with a guide reference surface 2b on a bottom surface of the holding groove 2. Thereby, an edge curve position of a cutting edge 3c is made to appear in the same position P before it is resharpened to the cutter head 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a WN gear (Wheat Haber-Novikov gear), a screw compressor rotor and a screw of a screw pump, a milling cutter used for cutting of helical spur gears, etc. Is.

[0002]

[Prior art]

A general-purpose milling cutter of this kind is a kind of milling tool having a blade having a shape corresponding to a cutting cross section of a workpiece.
In particular, it is used for machining machine parts such as screw type compressors, WN gears, screw pumps, etc., which have a complicated axial sectional shape and are twisted in the axial direction.

[0004]

However, in the conventional shape milling machine described above, attention is paid only to the shape accuracy at the time of manufacture, and the shape accuracy after re-sharpening is taken into consideration. Was not done.

The precision of the cutting edge shape after re-sharpening is determined by the relationship between the second face and the rake face. In addition to the fact that the second face as the flank face is a complicated curved surface, the tool by re-sharpening This curved surface cannot be treated theoretically because it has a very complicated property that the cutting edge curve shape must change as the diameter decreases.

[0006] For example, when trying to machine a thread groove with a resharpened reduced-shape milling cutter, the shape accuracy of the workpiece decreases, so the cutting edge curve shape is slightly different from that before resharpening. Must be.

Therefore, in the conventional shape milling cutters, the curved shape of the cutting edge is modified by trial and error each time it is re-ground, which causes a great problem in terms of product accuracy and manufacturing cost. .

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve such an inconvenience, and the gist thereof is to form a plurality of holding grooves on the outer peripheral portion of a cutter head and hold each of them. By assembling a cutter blade having a blade portion in the groove, the side surface on the front side in the rotation direction of the holding groove is formed as a contact reference surface with which the rake surface of the blade portion of the cutter blade and the re-ground surface flush with each other, And the bottom surface of the holding groove is formed as a guide reference surface with which the bottom surface of the cutter blade guides and abuts, and the blade portion of the cutter blade is further shifted in phase with a thin plate blade having the same theoretically desired blade shape. When the blades are worn, the rake face of the blades is re-sharpened when the blades are worn, and the re-sharpened surface and bottom surface of the cutter blade contact the contact reference surface and the guide reference surface. Attached in contact In form-milling the blade unit including a blade and a double-dip surface cut is characterized by being configured so as to emerge in the same shape and the same position as before re-sharpening to.

At this time, by manufacturing the above-mentioned cutter blade by electric discharge machining, it is possible to form a second surface consisting of the second front surface and the second horizontal surface on the blade portion, and the wire can be formed with the cutter blade inclined. A rake angle can be added by manufacturing by electrical discharge machining.

[0010]

When a cutter blade having a blade portion is attached to a plurality of holding grooves formed on the outer peripheral portion of the cutter head and the blade portion reaches the wear limit due to machining of a workpiece, the cutter blade is used. Remove the cutter blade from the head, regrind the rake face of the blade part of the cutter blade parallel to the rake face with a surface grinder, etc., and hold the re-sharpened face flush with the rake face of the cutter blade The cutter blade is attached to the cutter head in contact with the contact reference surface of the front side surface and the bottom surface of the cutter blade with the guide reference surface of the bottom surface of the holding groove.

Here, the blade portion of the cutter blade is formed by stacking a number of thin plate blades having the same theoretical shape as the theoretically desired blade shape in parallel with their phases shifted, And, the blade portion including the second surface appears in the same shape and the same position as before the re-sharpening.

By manufacturing the above-mentioned cutter blade by electric discharge machining, a second surface consisting of the front second surface and the horizontal second surface is formed on the blade portion, and the wire discharge is performed while the cutter blade is inclined. A rake angle will be attached by manufacturing by processing.

[0013]

1 to 15 show an embodiment of the present invention, FIGS. 1 to 10 show a first embodiment, and FIGS. 11 to 15 show a second embodiment.

In the first embodiment of FIGS. 1 to 10, 1
Is a cutter head, and a plurality of concave holding grooves 2 are formed in the outer peripheral portion of the cutter head 1, and a cutter blade 4 having a blade portion 3 in each holding groove 2 is composed of a wedge member 5 and a mounting bolt 6. It is assembled by the fixing mechanism 7.

The side surface of the holding groove 2 on the front side in the rotational direction is formed as a contact reference surface 2a with which the rake surface 3a of the blade portion 3 of the cutter blade 4 and the re-sharpened surface 4a contact.
Moreover, the bottom surface of the holding groove 2 is replaced with the bottom surface 4 of the cutter blade 4.
It is formed on the guide reference surface 2b with which b comes into contact with the guide.

Further, the blade portion 3 of the cutter blade 4 is formed by stacking a number of thin plate blades having the same theoretical shape as the theoretically desired blade shape in parallel with each other by shifting the phase. When worn, the rake face 3a of the blade portion 3 is re-ground, and the re-ground surface 4a and the bottom surface 4b of the cutter blade 4 abut on the contact reference surface 2a and the guide reference surface 2b. The blade portion 3 including the number surface 3c is formed so as to appear in the same shape and the same position as before the re-sharpening. Here, the cutting edge 3b is a line of intersection between the rake surface 3a and the second side surface 3c, and is composed of the front cutting edge N and the left and right lateral cutting edges M, and the second side surface 3c is also the front second side surface K and the left and right lateral sides. Face number L
Consists of.

Further, in this case, as shown in FIGS. 9 and 10, the cutter blade 4 is subjected to electric discharge machining with a wire cut electric discharge machine by inclining the wire electrode W in accordance with the clearance angle T, and the cutting edge 3b and the second blade having the above shape. The surface 3c is manufactured so that the cutter blade 4 having the blade portion 3 having the above-described shape shown in FIGS. 6 to 8 is formed.

Since the first embodiment has the above-mentioned construction, the cutter blade 4 having the blade portion 3 is assembled to the plurality of holding grooves 2 formed in the outer peripheral portion of the cutter head 1, and is attached to, for example, the arbor of the horizontal milling machine. It will be rotated and used for processing.

When the blade portion 3 reaches the wear limit due to long-time machining of the workpiece, the cutter blade 4 is removed from the cutter head 1 and the rake face 3a of the blade portion 3 of the cutter blade 1 is flat-ground grinder. Rake face 3 by etc.
A new cutting edge 3a is ground in parallel with a, and a sharpened surface 4a flush with the rake surface 3a of the cutter blade 4 that has been sharpened again is used as a reference surface for contact 2a on the front side in the rotational direction of the holding groove 2. And the bottom surface 4b of the cutter blade 4 is brought into contact with the guide reference surface 2b of the bottom surface of the holding groove 2, and in this state each cutter blade 4 is attached to the cutter head 1.
Will be installed in.

By this re-sharpening, the re-sharpening surface 4a parallel to the rake face 3a is ground, so that the curved shape of the cutting edge 3a does not change, and when each re-sharpening cutter blade 4 is attached to the cutter head 1, the cutter Blade 4
Since the bottom surface 4b is attached by sliding on the guide reference surface of the cutter head, the position of the blade curve of the cutting edge 3a of the cutter blade 4 is, after all, the same position as before the re-sharpening with respect to the cutter head 1. It will appear in P. Therefore, the precision at the time of production can be maintained as it is even after re-sharpening.

That is, paying attention to the fact that the curved shape of the cutting edge does not need to be changed by restoring the cutting edge of which the diameter has been reduced to the original position by re-sharpening, the shape milling cutter is used as the cutter blade 4 having the cutting edge 3b. It is said that the cutter head 1 supporting this is divided into two parts and an assembly method is adopted, and in the process of assembling them, the cutting edge 3b having a reduced diameter is automatically restored to the original position by re-sharpening. I can say.

Therefore, the large-sized milling machine is worn out by milling a large amount of workpieces and must be re-sharpened. However, in the case of the conventional flat-shaped milling machine, accuracy is deteriorated due to a decrease in tool diameter due to re-sharpening. Due to the deterioration of accuracy due to the uncertainity of the number surface, it was necessary to modify the cutting edge curve shape each time it was re-ground, and it was not possible to expect stable machining accuracy and high accuracy. Theoretically, the accuracy of the curved shape of the cutting edge 3a does not deteriorate due to re-sharpening, and the tool diameter does not decrease. Therefore, it is possible to always maintain the same accuracy as the tool manufacturing accuracy. Higher precision is possible, which can contribute to improved productivity and higher product quality.

Further, in this case, the cutting blade 3b and the second surface 3c having the above-mentioned shapes can be easily and accurately manufactured by processing the cutter blade 4 with a wire cut electric discharge machine, and the front second surface K Also, the blade portion 3 having the second side surface 3c composed of the second side surface L can be easily formed.

The second embodiment of FIGS. 11 to 15 shows another structure, and the same mode parts as those of the first embodiment will be described with the same reference numerals. In this case, when the cutter blade 4 is manufactured, Wire electrode W according to clearance angle T as in 9
11 and tilt the material of the cutter blade 4 from the imaginary line to the solid line as shown in FIG. 11 by an angle θ, and perform electric discharge machining with the wire electrode W. As a result, as shown in FIG. Since the half of the front second surface K is formed and the material of the cutter blade 4 is inclined by the angle θ, the second surface 3 effective for the other side of the second surface K and half of the front second surface K is used.
Since c is not formed, the escape portion Q is notched, and the wire electrode W is tilted, and the material of the cutter blade 4 is tilted by an angle θ on the side opposite to FIG.
The electric discharge machining is carried out by means of this, thereby forming half of the one horizontal second surface K and the front two second surface K as shown in FIG. 13, and the other horizontal second surface K for tilting the material of the cutter blade 4 by the angle θ. Further, since the effective second surface 3c is not formed in half of the front second surface K, the relief portion Q is notched and the cutter blades 4 shown in FIGS. 12 and 13 are formed by half each of the necessary total number, and As shown in FIG. 14, the guide reference surface 2a of the holding groove 2 formed in the cutter head 1 is formed by inclining by an angle θ, and the adjacent guide reference surface 2a is formed by inclining by an angle θ in the opposite direction. As described above, the cutter blades 4 shown in FIGS. 12 and 13 are alternately mounted.

Also in this second embodiment, the same effects as those of the first embodiment can be obtained, and the rake face 2a can be obtained.
It is possible to add a rake angle corresponding to the angle θ to
The cutting performance can be improved by that much, and a high quality formed milling cutter can be manufactured.

The present invention is not limited to the above-described embodiment, but the shape of the cutter head 1, the shape and number of the cutter blades 4, the shape of the blades 3, the structure of the fixing mechanism 7, etc. may be changed appropriately. It is designed.

[0027]

As described above, according to the present invention, theoretically, the accuracy of the curved shape of the cutting edge is not deteriorated by the re-sharpening, and the tool diameter is not reduced. Therefore, the processing accuracy can be stabilized and the accuracy can be improved, which can contribute to the improvement of productivity and the improvement of product quality.

At this time, by tilting the cutter blade and machining it with a wire-cut electric discharge machine, the cutting edge and the second surface having the above-mentioned shape can be easily and accurately manufactured, and a good general-purpose milling cutter can be manufactured. can do.

Further, when the cutter blade is tilted, it is possible to form a rake angle by manufacturing it by wire electric discharge machining, so that the cutting performance can be improved by that much, and a high-quality shaped milling cutter can be manufactured.

The above-mentioned intended purpose can be sufficiently achieved.

[Brief description of drawings]

FIG. 1 is an overall front view of a first embodiment of the present invention.

FIG. 2 is a side view of the first embodiment of the present invention.

FIG. 3 is a side development explanatory diagram of the first embodiment of the present invention.

FIG. 4 is a partial side sectional view of the first embodiment of the present invention.

FIG. 5 is a partial side enlarged view of the first embodiment of the present invention.

FIG. 6 is a perspective view of a cutter blade according to the first embodiment of the present invention.

FIG. 7 is a plan view of a cutter blade according to the first embodiment of the present invention.

FIG. 8 is a side view of the cutter blade according to the first embodiment of this invention.

FIG. 9 is a side view of a processing state of the cutter blade according to the first embodiment of this invention.

FIG. 10 is a perspective view of a processing state of the cutter blade according to the first embodiment of this invention.

FIG. 11 is a perspective view of a cutter blade of a second embodiment of the present invention in a processed state.

FIG. 12 is a plan view of a cutter blade according to a second embodiment of the present invention.

FIG. 13 is a plan view of a cutter blade according to a second embodiment of the present invention.

FIG. 14 is a partially enlarged side view of the second embodiment of the present invention.

FIG. 15 is a side development explanatory diagram of a second embodiment of the present invention.

[Explanation of symbols]

 1 Cutter head 2 Holding groove 2a Abutment reference surface 2b Guide reference surface 3 Blade part 3a Rake surface 3b Cutting edge 3c No. 2 surface 4 Cutter blade 4a Sharpened surface 4b Bottom surface

Claims (3)

[Claims] 1. A plurality of holding grooves are formed in an outer peripheral portion of a cutter head, and a cutter blade having a blade portion is attached to each of the holding grooves, and a side surface of the holding groove on the front side in the rotation direction is the cutter blade. Is formed on the abutting reference surface where the raked surface of the blade portion and the re-ground surface flush with each other abut, and the bottom surface of the holding groove is formed on the guide reference surface on which the bottom surface of the cutter blade guides and abuts. The blade part of the blade is formed into a shape in which thin plate blades of the same shape as the theoretically desired blade shape are stacked in parallel by shifting the phase,
At the time of wear of the blade portion, including the cutting edge and the second surface when the razor surface of the blade portion is re-ground and the re-ground surface and bottom surface of the cutter blade are in contact with the contact reference surface and the guide reference surface. A general-purpose milling cutter characterized in that the blade has the same shape and the same position as before the sharpening. 2. The form milling machine according to claim 1, wherein the cutter blade is manufactured by wire electric discharge machining. 3. The forming milling cutter according to claim 2, wherein the cutter blade is manufactured by wire electric discharge machining with the cutter blade being inclined.