JPS6134927B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inner-edge disk milling cutter, and more particularly to an inner-edge disk milling cutter for external milling of shafts, crankshafts, or similar cylindrical workpieces.

DE 2515937 discloses an internal-blade disk milling cutter of this kind. The problem in this case is that internal stresses caused by heat generation during cutting do not have an adverse effect on the tool. Otherwise, the finishing accuracy of machining will deteriorate due to the thermal stress. For this purpose, the individual chip support pieces or segments are connected to the basic body by means of two clamping screws, leaving a circumferential gap in each case. However, in order to replace a chip support piece or segment, the number of fixing screws, which are themselves pre-stressed during assembly, must be loosened by twice as many.

In contrast to these known designs of internal-blade disk milling cutters, the object of the present invention is to increase the positioning accuracy of the chip support pieces, so that most of the chip support pieces do not require fixing means. And in some chip supports that use radial clamping bolts as the fixing means, the clamping bolts do not bend or tension. There is therefore no need to use clamping bolts for most of the chip supports. Furthermore, it is an object to provide an inner edge disk milling cutter that does not require a high degree of machining accuracy for the chip support piece and the inner peripheral support surface of the base body, or that maintains a high degree of accuracy even after the operating time has elapsed. It is. The means adopted for this purpose are structurally simple and user-friendly.

Each of the specific inventions described in the claims is intended to solve this problem, and the embodiments described above embody the contents thereof.

French Patent No. 734552 describes an internal-blade disk milling cutter for milling the outside of cylindrical workpieces such as shafts, crankshafts, etc. This inner blade disc milling cutter is provided with an outer housing formed in half, and a cutting tool is mounted and held in the radial and axial directions over the inner periphery of both half housings. . The side surfaces of adjacent cutting tools are then joined together. In the case of the outer-cut disc milling cutter known from Austrian Patent No. 194,219, the circumferentially facing sides of the chip support pieces, which support most of the cutting chips, are joined to one another.

One of the advantages of the inner-cut disc milling cutter according to the invention is that the chip support pieces supporting the cutting chips can be clamped together in the circumferential direction of the milling cutter by a single member in the form of a clamping wedge. In that case, it is not necessary to radially tighten the individual chip support pieces using radial tightening bolts. All of the chip support pieces arranged in an annular shape are joined together by applying force in the circumferential direction, so that cutting that acts on each chip support piece that is in contact with the workpiece is not possible. The forces are mostly evenly distributed over the radial clamping bolts. Another advantage of the present invention is that each of the chip support pieces has an outer end surface that is in contact with the inner circumferential support surface of the circular annular base body at the position of the joint side surface of the front and rear chip support pieces, or at an outer end surface close to the joint side surface of the front and rear chip support pieces, so as to support the chip. A linear support portion is formed that extends across the width of the piece. That is, the leg portion of the tip support piece is provided with two linear support portions at the front and back in the circumferential direction that ride on the inner circumferential support surface of the circular annular base, thereby making it possible to accurately position the tip support piece against the base. can be positioned. Even if the inner peripheral support surface of the base and the bottom surface of the end of the chip support piece are rough-finished, there is no particular requirement for machining accuracy on the bottom surface of the leg portion of the chip support piece, and the two edges of the bottom surface of the chip support piece are The two linear support portions can be easily brought into contact with the inner peripheral support surface of the base body.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

The base body 1 of the inner-blade disc milling cutter according to the present invention is integrally molded in the shape of a wheel, so that the periphery (not shown) is circular. On the inner peripheral wall surface of the base body 1, there are annular shoulders 3, 3 on both sides, respectively,
An annular protruding top surface 4 sandwiched between the shoulders 3, 3
A convex rib 2 is formed. The base body is integrally molded as a closed circular annular body, on its inner peripheral surface forming shoulders 3, 3 and convex ribs 2 a series of chip support pieces 5 are arranged. The chip support pieces 5 are all of the same shape, except for special chip support pieces 6 and 7, which will be described later, and are provided with a cutting edge tip 8, which is schematically drawn. Cutting blade tips 8 are arranged at the distal end portions 9 of all tip support pieces to form a series of cutting edges;
A chip groove 10 is arranged on the front side of the chip 8 in the rotational direction. The leg portion 11 of each chip support piece is U
formed into a letter-shaped cross section, that is, two protruding legs 13 on both sides,
14, and a cutout groove 12 is formed between the protruding legs 13 and 14. In that case, the top surface 4 of the rib 2 formed on the inner periphery of the base body 1 will abut against the bottom surface 15 of the notched groove 12, or the end surfaces 16 and 17 of the two protruding legs 13 and 14 will come into contact with the surface of the shoulder 3. It is formed into a preferable shape as will be described later so that the two abut against each other. The width of the notch groove 12 corresponds to the width of the convex rib 2 in the axial direction, so the chip support piece is attached to the base 1.
It is supported in a horse-riding manner on the upper side in the direction of the axis C of the milling cutter.

The chip support pieces 5 of equal shape together with the special support pieces 6, 7 form an uninterrupted array of chip support pieces with cutting edge chips. The tip support piece 6 shown in FIG. 4 is the same as the embodiment shown in FIG. 1, except for the difference in the mounting direction of the chip groove 10 and the cutting blade tip 8, and has two parallel joining sides 18, 19 and radial tightening. a screw hole 20 for a bolt;
A radially inner end of a tightening bolt, which will be described later, can be screwed into this screw hole 20. In the joint side surface 18 of the special chip support piece 6 adjacent to the chip support piece 7, a cutout recess 21 is formed, which is oriented in the circumferential direction at approximately the center of the height of the support piece, and whose axis of symmetry M are provided with two semi-cylindrical inclined walls 23 which are perpendicular to the front and rear joint side surfaces 18 and 19 and which are inclined in the direction of both upper and lower side surfaces 22 of the chip support piece (only one is shown in FIG. 4); These oblique walls 23 converge inwardly into a dome shape and intersect in a curved green edge at the center of the interior of the chip support piece. This curved green side lies within one virtual plane perpendicular to the axis C. Each of these inclined walls 23, 23 has a corresponding inclined surface portion 24 formed on the clamping wedge half 25 of the clamping wedge 26. These clamping wedge halves 25, 25 of the clamping wedge 26
The outwardly projecting planar flat surface 27 of the chip support 7 is joined to the front side surface 28 of the adjacent chip support 7.
The two clamping wedge halves 25, 25 with threaded holes can be clamped together by two screws 25a with oppositely acting left and right threads, so that the flat surface 27 can be removed from the oblique wall 23 from the cutout groove 21. You can go in and out slightly.

The shape of the chip support piece 7 is a partial annular shape formed between the frontmost and rearmost support pieces of the series of support piece rows when the adjacent front and rear side surfaces of the support piece rows arranged in an annular arrangement are in a state of being joined to each other. In combination with the shape of the chip support piece 6, the gap space is formed to be compensated and filled. In this case, the flat surface 27 of the clamping wedge half 25 of the clamping wedge 26 abuts against the joining side 8 of the chip support piece 7. Wedge 26
wedge 2 to effectively abut the flat surfaces 27 of
6 can rotate within the cutout groove 21 about its axis.

The individual supports 5 of a series of chip support strips are not clamped in their radial direction, or, as the case may be, only every third or fourth support strip 5 is tightened in their radial direction. Tightening bolt 30 (first
It can be tightened and fixed to the base body 1 using the screws shown in FIG. A similarly designed radial tightening bolt 31, which is accommodated in a radial through hole 32 of the base body 1, is inserted into a particular chip support piece 6. The diameter of the through hole 32 or the through hole 32
Since the width in the circumferential direction of is larger than the diameter of the tightening bolt 31, when the support pieces of the series of support pieces arranged in an annular manner are tightened together in the circumferential direction by the tightening wedge 26, the tightening The bolt 31 can be self-adjusted inside the through hole 32. The same can be said of the relationship of the through hole 33 to the tightening bolt 30 that pulls the chip support piece 5 radially outward.

The particular embodiment of the chip support piece 6 shown in FIG. 4 can be slightly modified to form its joint sides. It may be provided that the chip support piece 6 is provided with front and rear flanks 18, 19 which intersect towards the outside of the inner blade disc milling cutter, ie converge with each other in direction A. In this case as well, the tip support piece 6 is inserted after all the tip support pieces 5 and 7 are inserted.
It can be inserted between the tip support piece 7 and the last support piece 5b, after which the circumferential tightening of these tip support pieces 6, 7 and the entire group of tip support pieces of the annular arrangement is performed with respect to each other. The radial clamping bolts 30, 31, which were initially slightly loosened, can then be tightened for final fixation.

In order to quickly remove all chip support pieces 5 from the base body 1, it is necessary to remove the clamping force from the support pieces that are clamped together by the clamping wedges 26.
In some cases radial tightening bolts 30, 31
It turns out that all the support pieces need to be loosened from the base body by removing the special chip support piece 6 from its position.

The aforementioned clamping wedge 26 can also be arranged on the support piece 7.

The aforementioned tightening wedge 26 can be provided on one of the chip support pieces 5, but in this case, in addition to the three chip support pieces 5, 6, and 7 of different shapes, another tip support piece of a different shape is provided. must be used.

As can be seen by comparing the chip support pieces 5, 6, and 7 in FIGS. 3 to 5, the milling axis C of the base body 1
The length in the inner circumferential direction of the head of all the supporting pieces facing (Fig. 1) is x, but the length in the outer circumferential direction on the outside of supporting piece 5, supporting piece 6, and supporting piece 7 is y ,
z and u. The support piece 6 has front and rear joining sides 18, 19 that are parallel or converge outwards.
Correspondingly, the angle α between the front and rear surfaces 28 and 29 of the chip support piece 7 is larger than the angle β between the front and rear joint sides 44 and 45 of the support piece 5. As a result, a wheel-like annular arrangement closed by the chip support pieces 5, 6, 7 is formed.

According to another embodiment of the present invention shown in FIG. It is formed into a convex shape. That is, the radius of curvature K of the bottom surfaces 42, 43 is larger than the radius of curvature R of the two shoulder portions 3, 3 on both sides constituting the inner circumferential support surface of the base body 1 (only the chip support piece 5 is shown). Thereby, on both front and rear sides 44, 45 of each tip support piece, supports spaced apart in the direction of the inner circumference of the part of the tip support piece designated by the reference symbol 48 common to the annular shoulder 3 of the basic body 1 are provided. Part 4
A linear support portion is created at 6,47. The support portions of each chip support leg portion are shoulder portions 3, 3, respectively.
The supporting parts 46 and 47 extend across the width of the supporting parts 46 and 47.
At this point, short axially oriented linear support portions are formed, so that the support lines of these support portions extend coaxially and parallel to each other and are tightened in the circumferential direction of the tip support piece using a tightening wedge 26 shown in FIG. Even when a force is applied, the chip support pieces 5, 6 and 7 are precisely aligned and fixed without any particularly precise machining of the bottom surfaces 42, 43 or the support surfaces 49 of the shoulders 3, 3. I can do it. The defined groove bottom surface 52 is slightly separated from the top surface 4 of the rib 2.

The chip support pieces 5, 6 and 7 adjacent to each other are
Furthermore, a small gap 50 can be formed between the front and rear joining sides 44, 45, which narrows in a wedge shape with respect to the axis C (FIG. 1) of the inner disc milling cutter. When such a joining method is used, only the front portions of the upper heads 55 of the support pieces are joined together. Thereby, when the clamping wedge 26 is actuated, not only is the support piece brought into close contact with the base body 1 precisely, but also the support pieces counterbalance each other in the circumferential direction, making it even more precise. This makes it possible to closely bond them. The arc length of the bottom surface 42 in the circumferential direction is shorter than the arc length above the centroid angle γ (FIG. 6).

Furthermore, according to another embodiment shown in FIG.
A bottom surface 5 formed at its radial bottom in 1
2 is used as a support surface that contacts the top surface 4 of the rib 2 of the base body 1. In that case, the chip support pieces 5, 6
The axial stability of and 7 is ensured by two lateral leg parts corresponding to the leg parts 13, 14 shown in FIG.
The end surface of 14 does not contact the top surface 4 of the shoulder portion 3. Also in this embodiment, the chip support pieces 5, 6,
The supporting bottom surface 52 of the bottom portion 48 facing toward the base 1 of 7
As shown in FIG. 7, 53 and 54 on the top surface 4 of the rib 3 constitute a linear axial support portion at or near the front and rear joining sides 44, 45 of the chip support piece.

[Brief explanation of the drawing]

FIG. 1 is a partial top view of a milling cutter, FIG. 2 is a front view of one of the tip support pieces of the inner blade disc milling cutter of the present invention, and FIG. 3 is a top view of a part of the milling cutter. An explanatory view showing one of the chip support pieces, FIG. 4 is an explanatory view of a chip support piece having parallel front and rear joint sides, and FIG. Explanatory diagram,
FIGS. 6 and 7 are explanatory diagrams showing a linear support mode of one chip support leg portion supported on the inner circumferential surface of the base. 1... Base body, 2... Central convex rib, 3, 3...
Both sides shoulders, 4... Top surface, 5, 6, 7... Chip support piece, 8... Cutting chip, 10... Chip groove, 12
...Notch groove, 13, 14... Leg portion of chip support piece, 16, 17... End surface of leg portion, 18, 19...
...Anteroposterior joint side surface, 20...Connection screw hole, 21...
Wedge notch recess, 23... Slanted wall, 26... Tightening wedge, 28, 29... Front/rear joint side surfaces, 30, 31
... Radial tightening bolt, 32, 33 ... Through hole, 42, 43 ... Leg end surface, 44, 45 ...
Anterior and posterior joint sides.

Claims (1)

[Scope of Claims] 1. An inner-blade disc milling cutter for milling a cylindrical workpiece, the milling cutter having a convex shape extending over 360° on the inner circumferential surface of an annular disc-shaped base body 1 formed in one piece. A large number of chip support pieces 5, 6, each having a ring-shaped rib 2 and both shoulders 3, 3 thereof, and having cutting chips 8 protruding radially inward on the rib 2;
7 are joined to each other in the circumferential direction and arranged in an annular shape, and the cross-sectional shapes of the respective chip support pieces 5, 6, and 7 in the annular arrangement in a plane including the milling axis C are all formed to be substantially the same. Leg portions 11 of these chip support pieces
is formed into a U-shaped cross section by a notched groove 12 corresponding to the axial width of the annular rib 2 and both side protrusions 13, 14 corresponding to the both side shoulders 3, 3, and the rib 2 and the shoulders 33, The cross-sectional shape of most of the chip holding pieces in a plane perpendicular to the milling cutter axis C is arranged so as to fit on the top of the cutter 33 in a horse-riding manner and press and support it in the radial direction. Part joint side 28, 29; 44, 45)
The chip support pieces are formed into a fan-shaped outer shape having a circular shape, and are configured to prevent the support pieces from falling off when a series of chip support pieces arranged in an annular manner are subjected to a pressing force in the circumferential direction. At least one specific chip support piece 6 has its front and rear joint sides 18,1
9 are inserted in such a manner that they are parallel to each other or converge and narrow toward the outside, and the connecting side surface 28 on one side of one chip holding piece 7 adjacent to the chip supporting piece 6 is arranged in a series. The partial annular space created between the frontmost and rearmost joint sides of the chip support piece 5 is tilted so as to be compensated for by the combination of the chip support pieces 6 and 7 having the specific shape, and further converged in the parallel or outward direction. Before this, a series of annularly arranged groups of 5 chip support pieces are tightened to press in the circumferential direction on either one of the chip support piece 6 having the rear joint side surfaces 18 and 19 and the chip support piece 7 adjacent thereto. In addition to the wedge 26 being installed, fixing means 30 and 31 are provided for fixing not all of the chip support pieces 5, 6 and 7 but a plurality of them to the base body 1. Features an inner blade disc milling cutter. 2. The clamping wedge 26 has front and rear joining surfaces 18, 19 that are parallel or inclined outwardly toward each other.
2. The inner blade disk milling cutter according to claim 1, wherein the inner edge disk milling cutter is disposed at or approximately at the center position in the radial height of the tip support piece 6. 3. The clamping wedge 26 has front and rear joining surfaces 18, 19 that are parallel or inclined outwardly toward each other.
The chip support piece 6 is provided so as to protrude outward in the circumferential direction from either one of the joining side surfaces between the chip support piece 6 having the shape and the adjoining chip support piece 7 having a specific shape. An inner blade disk milling cutter according to claim 1 or 2. 4. A semi-circular notch 21 is formed on the joint side surface of the tip support piece 6 or 7 on which the tightening wedge 26 is to be installed, and the notch 21 is included in a plane substantially perpendicular to the axis C of the milling cutter. The recesses 2 are formed so as to intersect from both the front and back surfaces toward the curved green side.
A clamping wedge 26 consisting of two half-parts 25, 25 is inserted into the recess from both sides and the screw 25 is inserted into the recess from both sides.
4. The inner blade disc milling cutter according to claim 1, wherein the inner blade disk milling cutter is provided so as to generate a circumferential tightening force when tightened by the inner edge disk milling cutter. 5 Solidifying means for tightening some of the chip support pieces 5, 6, and 7 in the radial direction of the inner circumference of the base body 1 is provided in the bolt through holes 32 and 33 drilled in the radial direction of the base body 1. The bolt through holes 32, 33 are constructed of a substantially radially extending tightening bolt 30, 31 and a connecting means between the tightening bolt and the chip support piece, and the circumferential cross section of the bolt through hole 32, 33 is similar to that of the tightening bolt 30, 31. It is characterized in that it is formed to have an oval shape with a width greater than the diameter or a circular cross-section of a large diameter to enable self-alignment with a group of chip support pieces in an annular arrangement. An inner blade disk milling cutter according to any one of claims 1 to 4. 6 This is an inner blade disk milling cutter for milling an inner cylindrical workpiece, and the milling cutter has an annular rib 2 having a convex shape extending over 360° on the inner peripheral surface of an annular disk-shaped base 1 formed in one piece. A large number of chip support pieces 5, 6, 7 each having both shoulder portions 3, 3 formed thereon and having cutting chips 8 protruding radially inward on the rib 2.
are joined to each other in the circumferential direction and arranged in an annular shape, and the cross-sectional shapes of the annularly arranged chip support pieces 5, 6, and 7 in a plane including the milling axis C are all formed to be approximately the same. The leg portion 11 of the support piece is formed into a U-shaped cross section by a cutout groove 12 corresponding to the axial width of the convex annular rib 2 and protrusions 13 and 14 on both sides corresponding to the shoulder portions 3 and 3 on both sides. 2 and shoulder portions 3, 3 in a horse-riding manner to press and support them in the radial direction, and the cross-sectional shape of most of the chip support pieces in a plane perpendicular to the axis C is directed outward. Before opening in a divergent manner, the tip is formed into a fan-shaped outer shape with rear joint sides 28, 29; It is configured to prevent falling off, and furthermore, the front and rear joining sides 18 and 19 of at least one specific chip support piece 6 in the annular arrangement are formed to be parallel to each other or to converge and narrow outward. The joint side surface 28 on one side of the chip support piece 7 adjacent thereto is inclined at an appropriate inclination angle, and these particular chip support pieces 6 and 7 are combined to form the series of annular arrays. A group of 5 chip support pieces arranged in an annular manner are inserted into the front and rear sides of the chip support pieces 5 and pressed in the circumferential direction against either one of the specified chip support pieces 6 and 7 which are joined adjacent to each other. For this reason, a tightening wedge 26 is provided, and this is attached to the base 1 for the several chip support pieces 5, 6, 7.
In a milling cutter provided with fixing means for tightening in the radial direction on the sides, the outer bottom surfaces 16, 1 of both leg portions formed on the leg portions 11 of the tip support pieces 5, 6, 7
7 or the support parts 45, 47 or 53, 54 which are clamped and supported in the radial direction against the annular shoulders 3, 3 or the convex ribs 2 of the base body 1, which the bottom surface 15 of the cutout groove 12 faces, are the chip supports. A line forming a line in the direction of the axis C between the front and rear contact surfaces of the pieces 5, 6, 7 and the shoulders 3, 3 of the base 1 or the top surface 4 of the rib 2, and the front side of the support piece. A disc milling cutter characterized in that an inner blade is formed on the rear side. 7 a chip support piece 5 facing the shoulders 3 or the convex annular rib 2 formed on the inner circumferential surface of the base 1;
The outer bottom surfaces 16 and 17 of both leg portions 13 and 14 formed on the leg portions 6 and 7 or the bottom surface 15 of the notch groove 12 thereof
Claim 6, characterized in that the radius of curvature K is larger than the radius of curvature R of the ring-shaped shoulders 3, 3 of the base 1 or the top surface 4 of the rib 2.
Internal blade disc milling cutter as described in section.